Radiographic evaluation of third molar development in 6- to 24-year-olds

PubMed Central

Jung, Yun-Hoa

2014-01-01

Purpose This study investigated the developmental stages of third molars in relation to chronological age and compared third molar development according to location and gender. Materials and Methods A retrospective analysis of panoramic radiographs of 2490 patients aged between 6 and 24 years was conducted, and the developmental stages of the third molars were evaluated using the modified Demirjian's classification. The mean age, standard deviation, minimal and maximal age, and percentile distributions were recorded for each stage of development. A Mann-Whitney U test was performed to test the developmental differences in the third molars between the maxillary and mandibular arches and between genders. A linear regression analysis was used for assessing the correlation between the third molar development and chronological age. Results The developmental stages of the third molars were more advanced in the maxillary arch than the mandibular arch. Males reached the developmental stages earlier than females. The average age of the initial mineralization of the third molars was 8.57 years, and the average age at apex closure was 21.96 years. The mean age of crown completion was 14.52 and 15.04 years for the maxillary and the mandibular third molars, respectively. Conclusion The developmental stages of the third molars clearly showed a strong correlation with age. The third molars developed earlier in the upper arch than the lower arch; further, they developed earlier in males than in females. PMID:25279338

Third molar development in a contemporary Danish 13-25year old population.

PubMed

Arge, Sara; Boldsen, Jesper Lier; Wenzel, Ann; Holmstrup, Palle; Jensen, Niels Dyrgaard; Lynnerup, Niels

2018-05-16

We present a reference database for third molar development based on a contemporary Danish population. A total of 1302 digital panoramic images were evaluated. The images were taken at a known chronological age, ranging from 13 to 25years. Third molar development was scored according to the Köhler modification of the 10-stage method of Gleiser and Hunt. We found that third molar development was generally advanced in the maxilla compared to the mandible and in males compared to females; in addition, the mandibular third molar mesial roots were generally more advanced in development than were the distal roots. There was no difference in third molar development between the left and right side of the jaws. Establishing global and robust databases on dental development is crucial for further development of forensic methods to evaluate age. Copyright © 2018. Published by Elsevier B.V.

Morphometric analysis of developing crowns of maxillary primary second molars and permanent first molars in humans.

PubMed

Peretz, B; Nevis, N; Smith, P

1998-07-01

The purpose of this study was firstly to characterize the changes occurring in size and form of the mineralizing maxillary second primary molar and first permanent molar crowns, and secondly to determine if similar changes in size and form characterize enamel apposition in the crowns of these teeth. Twenty-five primary second molars and 20 maxillary permanent first molars at various stages of development, found in archaeological excavations in Israel, were examined for a number of measured variables using image analyser software. Teeth were divided into two groups according to their stage of development: stage I included all teeth at an early stage of development in which mesiobuccal-cusp height was less than 5 mm for the primary molar and 5.9 mm for the permanent molar; stage 2 included all teeth in later stages of development where mesiobuccal-cusp height was greater than these values. In the primary molar, a significant increase was found between the two stages in almost all variables. Significant correlations were also found between all intercusp distances and the external variables. Strong correlations between height of the mesiobuccal cusp and all external and internal variables were noted in stage 1, but fewer in stage 2. In the permanent tooth, no increase was observed in intercusp distances and very few correlations were found between and among the variables. The results suggest that a change in the shape of the maxillary primary second molar occurs during formation, with the lingual cusp tips moving lingually and distally, and the distobuccal cusp tips moving distally. No change occurs in the shape of the maxillary permanent first molar during crown formation. Growth of the maxillary primary second and permanent first molar crowns occurs in 'bursts' of development.

Vertical bone growth following autotransplantation of the developing maxillary third molar to replace a retained mandibular permanent molar: a case report.

PubMed

Plakwicz, Paweł; Czochrowska, Ewa Monika; Milczarek, Anna; Zadurska, Malgorzata

2014-01-01

A retained permanent mandibular first molar caused arrested development and a defect of the alveolar bone in a 16-year-old girl. Extraction of the ankylosed tooth was immediately followed by autotransplantation of the developing maxillary third molar. At the 3-year follow-up examination the interproximal bone level at the autotransplanted molar was equal to that of the neighboring teeth. Cone beam computed tomography showed bone at the labial aspect of the transplant. The eruption of the autotransplanted tooth stimulated vertical alveolar bone development and repaired the bone defect. Additionally, there was closure of the posterior open bite that was initially present at the ankylosed molar site.

Radiographic assessment of third molars development and it's relation to dental and chronological age in an Iranian population.

PubMed

Monirifard, Mohamad; Yaraghi, Navid; Vali, Ava; Vali, Asana; Vali, Amrita

2015-01-01

The aim of the present study was to estimate chronological age based on third molar development and to determine the association between dental age and third molar calcification stages. In this cross-sectional study, 505 digital panoramic radiographs of 223 males (44.2%) and 282 females (55.8%) between the age of 6 and 17 were selected from patients who were treated in Departments of Pediatrics and Orthodontics of Isfahan University of Medical Sciences between the years of 2009 and 2013. Correlation between chronological age and third molar development was analyzed with SPSS 21 using Spearman's Rank correlation coefficient, Chi-square test and multiple regression statistical tests (P < 0.05). All third molars demonstrated a highly significant correlation with dental age (P < 0.001). The teeth showing the highest relationship with dental age were mandibular left third molar in males and mandibular right third molar in females (r s = 0.072). When multiple regression was used to predict dental age based on molar calcification stage, the only significant correlation was between maxillary left third molar in males (P < 0.05). There was no statistically significant correlation for any of third molars in females. Relationship between chronological age and molars development stage was significant in all age subgroups and in both gender (P < 0.001). Strong correlation was observed between left third molars and dental age in males. Results showed that third molar calcification stage can be used as an age predictor and in general mandibular teeth seems to be more reliable for this purpose in both genders and in all ages.

Radiological age estimation: based on third molar mineralization and eruption in Turkish children and young adults.

PubMed

Karadayi, Beytullah; Kaya, Ahsen; Kolusayın, Melek Ozlem; Karadayi, Sükriye; Afsin, Hüseyin; Ozaslan, Abdi

2012-11-01

Radiographic evaluation of mineralization and eruption stages of third molars using dental panoramic radiographies can be an efficient tool for chronological age estimation in both forensic sciences and legal medicine. The third molar tooth is utilized for dental age estimation about the age span of 15-23 years because it represents the only tooth still in development. The aim of this study is to obtain and analyze data regarding third molar development and eruption in Turkish population for dental age estimation. A total of 744 dental panoramic radiographies of 394 female and 350 male subjects aged between 8 and 22 years were examined. Third molar development was determined according to the Nolla classification system, and eruption was assessed relative to the alveolar bone level. Mandibular and maxillary third molars were generally found at similar stages of development on both sides. Nolla stage 6 (completed crown calcification) was reached at around the age of 15 in both maxillary and mandibular third molars in both sexes. Alveolar emergence was at around the age of 16 in males and around age of 17 in females. Although third molars' eruption shows greater variability than development of third molars, data which were obtained from this study about eruption of these teeth can be supportive to development data for age estimation.

Evaluation of third molar development and its relation to chronological age: a panoramic radiographic study.

PubMed

Zandi, Mohammad; Shokri, Abbas; Malekzadeh, Hamid; Amini, Payam; Shafiey, Parastu

2015-06-01

Third molar development, in comparison to other teeth in the dentition, has the greatest variation in morphology, anatomical position, and time of development and eruption, and its reliability for chronological age estimation is controversial. The aim of the present study was to evaluate third molar development and its relation to chronological age using panoramic radiography. A total of 2536 digital panoramic radiographs of individuals aged between 5 and 26 years were selected. The developmental status of the third molars was assessed using eight-stage developmental scoring proposed by Demirjian et al., with one modification: a stage 0 was added. The collected data were entered into a checklist and subjected to statistical analyses. The mean ages of the first appearance of third molar bud, complete crown formation, and root apex closure were around 9, 14, and 22 years, respectively. In both jaws, third molar development occurred symmetrically, and sexual dimorphism was observed at some developmental stages. Finally, two formulas were presented to estimate age of the juveniles and adolescents based on their gender and developmental stages of the third molars, and validated on a second sample consisting of 523 individuals aged between 8 and 22. Assessment of third molar development was found to be a reliable method for age estimation of individuals between 11 and 22 years. Because of possible ethnic and geographic differences in third molar development, population specific researches were recommended.

Amino derivatives of glycyrrhetinic acid as potential inhibitors of cholinesterases.

PubMed

Schwarz, Stefan; Lucas, Susana Dias; Sommerwerk, Sven; Csuk, René

2014-07-01

The development of remedies against the Alzheimer's disease (AD) is one of the biggest challenges in medicinal chemistry nowadays. Although not completely understood, there are several strategies fighting this disease or at least bringing some relief. During the progress of AD, the level of acetylcholine (ACh) decreases; hence, a therapy using inhibitors should be of some benefit to the patients. Drugs presently used for the treatment of AD inhibit the two ACh controlling enzymes, acetylcholinesterase as well as butyrylcholinesterase; hence, the design of selective inhibitors is called for. Glycyrrhetinic acid seems to be an interesting starting point for the development of selective inhibitors. Although its glycon, glycyrrhetinic acid is known for being an AChE activator, several derivatives, altered in position C-3 and C-30, exhibited remarkable inhibition constants in micro-molar range. Furthermore, five representative compounds were subjected to three more enzyme assays (on carbonic anhydrase II, papain and the lipase from Candida antarctica) to gain information about the selectivity of the compounds in comparison to other enzymes. In addition, photometric sulforhodamine B assays using murine embryonic fibroblasts (NiH 3T3) were performed to study the cytotoxicity of these compounds. Two derivatives, bearing either a 1,3-diaminopropyl or a 1H-benzotriazolyl residue, showed a BChE selective inhibition in the single-digit micro-molar range without being cytotoxic up to 30μM. In silico molecular docking studies on the active sites of AChE and BChE were performed to gain a molecular insight into the mode of action of these compounds and to explain the pronounced selectivity for BChE. Copyright © 2014 Elsevier Ltd. All rights reserved.

Third molar development: measurements versus scores as age predictor.

PubMed

Thevissen, P W; Fieuws, S; Willems, G

2011-10-01

Human third molar development is widely used to predict chronological age of sub adult individuals with unknown or doubted age. For these predictions, classically, the radiologically observed third molar growth and maturation is registered using a staging and related scoring technique. Measures of lengths and widths of the developing wisdom tooth and its adjacent second molar can be considered as an alternative registration. The aim of this study was to verify relations between mandibular third molar developmental stages or measurements of mandibular second molar and third molars and age. Age related performance of stages and measurements were compared to assess if measurements added information to age predictions from third molar formation stage. The sample was 340 orthopantomograms (170 females, 170 males) of individuals homogenously distributed in age between 7 and 24 years. Mandibular lower right, third and second molars, were staged following Gleiser and Hunt, length and width measurements were registered, and various ratios of these measurements were calculated. Univariable regression models with age as response and third molar stage, measurements and ratios of second and third molars as predictors, were considered. Multivariable regression models assessed if measurements or ratios added information to age prediction from third molar stage. Coefficients of determination (R(2)) and root mean squared errors (RMSE) obtained from all regression models were compared. The univariable regression model using stages as predictor yielded most accurate age predictions (males: R(2) 0.85, RMSE between 0.85 and 1.22 year; females: R(2) 0.77, RMSE between 1.19 and 2.11 year) compared to all models including measurements and ratios. The multivariable regression models indicated that measurements and ratios added no clinical relevant information to the age prediction from third molar stage. Ratios and measurements of second and third molars are less accurate age predictors than stages of developing third molars. Copyright © 2011 Elsevier Ltd. All rights reserved.

Radiographic assessment of third molars development and it's relation to dental and chronological age in an Iranian population

PubMed Central

Monirifard, Mohamad; Yaraghi, Navid; Vali, Ava; Vali, Asana; Vali, Amrita

2015-01-01

Background: The aim of the present study was to estimate chronological age based on third molar development and to determine the association between dental age and third molar calcification stages. Materials and Methods: In this cross-sectional study, 505 digital panoramic radiographs of 223 males (44.2%) and 282 females (55.8%) between the age of 6 and 17 were selected from patients who were treated in Departments of Pediatrics and Orthodontics of Isfahan University of Medical Sciences between the years of 2009 and 2013. Correlation between chronological age and third molar development was analyzed with SPSS 21 using Spearman's Rank correlation coefficient, Chi-square test and multiple regression statistical tests (P < 0.05). Results: All third molars demonstrated a highly significant correlation with dental age (P < 0.001). The teeth showing the highest relationship with dental age were mandibular left third molar in males and mandibular right third molar in females (rs = 0.072). When multiple regression was used to predict dental age based on molar calcification stage, the only significant correlation was between maxillary left third molar in males (P < 0.05). There was no statistically significant correlation for any of third molars in females. Relationship between chronological age and molars development stage was significant in all age subgroups and in both gender (P < 0.001). Conclusion: Strong correlation was observed between left third molars and dental age in males. Results showed that third molar calcification stage can be used as an age predictor and in general mandibular teeth seems to be more reliable for this purpose in both genders and in all ages. PMID:25709677

Radiographic correlation of dental and skeletal age: Third molar, an age indicator.

PubMed

Suma, Gn; Rao, Balaji B; Annigeri, Rajeshwari G; Rao, Dayashankara Jk; Goel, Sumit

2011-01-01

Age estimation plays a great role in forensic investigations, orthodontic and surgical treatment planning, and tooth transplantation. Teeth offer an excellent material for age determination by stages of development below the age of 25 years and by secondary changes after the age of 25 years. Third molar is often not included for this purpose due to its notorious developmental patterns. The aim of this study was to evaluate the development of third molar anlage in relation to skeletal maturities and the chronological age. One hundred and fifty-six young individuals, 78 males and 78 females, were selected. The stages of development of all the third molars in every individual were determined from panoramic radiographs. The skeletal development was assessed using hand wrist radiographs. Data were analyzed statistically for mean value, standard deviation and the relationship between the recorded characteristics. A STRONG CORRELATION WAS FOUND BETWEEN THIRD MOLAR DEVELOPMENT AND SKELETAL MATURITY (IN MALES: r=0.88, P<0.001; in females: r=0.77 for maxillary third molar and 0.89 for mandibular third molar, P<0.001). Hence, it is concluded that a strong correlation exists between chronological age, developmental stages of third molars and maturation of epiphyses of hand. Any of the three parameters could be used for the assessment of other maturities.

Human dental age estimation combining third molar(s) development and tooth morphological age predictors.

PubMed

Thevissen, P W; Galiti, D; Willems, G

2012-11-01

In the subadult age group, third molar development, as well as age-related morphological tooth information can be observed on panoramic radiographs. The aim of present study was to combine, in subadults, panoramic radiographic data based on developmental stages of third molar(s) and morphological measurements from permanent teeth, in order to evaluate its added age-predicting performances. In the age range between 15 and 23 years, 25 gender-specific radiographs were collected within each age category of 1 year. Third molar development was classified and registered according the 10-point staging and scoring technique proposed by Gleiser and Hunt (1955), modified by Köhler (1994). The Kvaal (1995) measuring technique was applied on the indicated teeth from the individuals' left side. Linear regression models with age as response and third molar-scored stages as explanatory variables were developed, and morphological measurements from permanent teeth were added. From the models, determination coefficients (R (2)) and root-mean-square errors (RMSE) were calculated. Maximal-added age information was reported as a 6 % R² increase and a 0.10-year decrease of RMSE. Forensic dental age estimations on panoramic radiographic data in the subadult group (15-23 year) should only be based on third molar development.

Risk of osteoradionecrosis after extraction of impacted third molars in irradiated head and neck cancer patients.

PubMed

Oh, Hee-Kyun; Chambers, Mark S; Garden, Adam S; Wong, Pei-Fong; Martin, Jack W

2004-02-01

This study was performed to compare the risk of osteoradionecrosis (ORN) in head and neck cancer patients in whom 1 or more impacted third molars were extracted before radiotherapy with patients whose impacted third molars were left intact. Eighty-one patients were selected from the medical records from 1989 to 1998. Patients had at least 1 impacted third molar and received radiotherapy for a head and neck cancer. These patients were divided into 2 groups on the basis of preirradiation extraction: group 1, patients who had impacted third molars extracted before radiotherapy (n = 55), and group 2, patients whose impacted third molars were left intact before radiotherapy (n = 38). In 12 patients of combined groups 1 and 2, at least 1 but not all of the impacted third molars were extracted before radiotherapy. Before radiotherapy, a total of 99 impacted third molars were extracted from the 55 patients in group 1 and a total of 55 impacted third molars were left intact in the 38 patients in group 2. After radiotherapy, a total of 7 impacted third molars were removed from 5 patients as treatment for infection (5 lower molars) or discomfort (2 upper molars). A total of 4 patients (2 from group 1 and 2 from group 2) developed ORN in the mandible. Of these 4 cases of ORN, 1 from group 1 appeared to be related to a dry socket that developed after preirradiation extraction of a lower impacted third molar, 1 from group 2 seemed to be related to infection of a lower impacted third molar after radiotherapy, and the remaining 2 cases appeared to be unrelated to an impacted third molar. Because few patients in this study developed ORN, the study failed to demonstrate whether preirradiation extraction versus retention of impacted third molars affects the risk for ORN.

Three-dimensional analysis of third molar development to estimate age of majority.

PubMed

Márquez-Ruiz, Ana Belén; Treviño-Tijerina, María Concepción; González-Herrera, Lucas; Sánchez, Belén; González-Ramírez, Amanda Rocío; Valenzuela, Aurora

2017-09-01

Third molars are one of the few biological markers available for age estimation in undocumented juveniles close the legal age of majority, assuming an age of 18years as the most frequent legal demarcation between child and adult status. To obtain more accurate visualization and evaluation of third molar mineralization patterns from computed tomography images, a new software application, DentaVol©, was developed. Third molar mineralization according to qualitative (Demirjian's maturational stage) and quantitative parameters (third molar volume) of dental development was assessed in multi-slice helical computed tomography images of both maxillary arches displayed by DentaVol© from 135 individuals (62 females and 73 males) aged between 14 and 23years. Intra- and inter-observer agreement values were remarkably high for both evaluation procedures and for all third molars. A linear correlation between third molar mineralization and chronological age was found, with third molar maturity occurring earlier in males than in females. Assessment of dental development with both procedures, by using DentaVol© software, can be considered a good indicator of age of majority (18years or older) in all third molars. Our results indicated that virtual computed tomography imaging can be considered a valid alternative to orthopantomography for evaluations of third molar mineralization, and therefore a complementary tool for determining the age of majority. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

Age estimation using development of third molars in South Indian population: A radiological study.

PubMed

Priyadharshini, K Indra; Idiculla, Jose Joy; Sivapathasundaram, B; Mohanbabu, V; Augustine, Dominic; Patil, Shankargouda

2015-05-01

To assess the estimation of chronological age based on the stages of third molar development following the eight stages (A-H) method of Demirjian et al. in Chennai population of South India. A sample consisting of 848 individuals (471 males and 377 females) aged between 14 and 30 years was randomly selected for the clinical evaluation and 323 orthopantomograms with clinically missing third molars were taken for radiological evaluation using Demirjian's method from a Chennai population of known chronological age and sex. Statistical analysis was performed using Pearson's Chi-square test and mean values were compared between the study groups using t-test or analysis of variance (ANOVA) followed by Tukey's highly significant difference (HSD). In the present study, P < 0.05 was considered as the level of significance. The results showed that the mean age of having clinically completely erupted maxillary third molars was 22.41 years in male subjects and 23.81 years in female subjects and that of mandibular third molars was 21.49 years in male subjects and 23.34 years in female subjects. Mandibular third molars were clinically missing more often in females than in males. Eruption of mandibular third molars was generally ahead of the emergence of maxillary third molars into the oral cavity. Third molar development between male and female subjects showed statistically significant differences at calcification stage F and stage G in maxillary third molars and stage F in mandibular third molars (P < 0.05). There are differences indicating that maxillary and mandibular third molar eruption reached Demirjian's formation stages earlier in males than in females. It is suggested that in future studies, to increase the accuracy of age determination, indications of sexual maturity and ossification should also be evaluated in addition to third molar mineralization.

Comparative temporospatial expression profiling of murine amelotin protein during amelogenesis.

PubMed

Somogyi-Ganss, Eszter; Nakayama, Yohei; Iwasaki, Kengo; Nakano, Yukiko; Stolf, Daiana; McKee, Marc D; Ganss, Bernhard

2012-01-01

Tooth enamel is formed in a typical biomineralization process under the guidance of specific organic components. Amelotin (AMTN) is a recently identified, secreted protein that is transcribed predominantly during the maturation stage of enamel formation, but its protein expression profile throughout amelogenesis has not been described in detail. The main objective of this study was to define the spatiotemporal expression profile of AMTN during tooth development in comparison with other known enamel proteins. A peptide antibody against AMTN was raised in rabbits, affinity purified and used for immunohistochemical analyses on sagittal and transverse paraffin sections of decalcified mouse hemimandibles. The localization of AMTN was compared to that of known enamel proteins amelogenin, ameloblastin, enamelin, odontogenic ameloblast-associated/amyloid in Pindborg tumors and kallikrein 4. Three-dimensional images of AMTN localization in molars at selected ages were reconstructed from serial stained sections, and transmission electron microscopy was used for ultrastructural localization of AMTN. AMTN was detected in ameloblasts of molars in a transient fashion, declining at the time of tooth eruption. Prominent expression in maturation stage ameloblasts of the continuously erupting incisor persisted into adulthood. In contrast, amelogenin, ameloblastin and enamelin were predominantly found during the early secretory stage, while odontogenic ameloblast-associated/amyloid in Pindborg tumors and kallikrein 4 expression in maturation stage ameloblasts paralleled that of AMTN. Secreted AMTN was detected at the interface between ameloblasts and the mineralized enamel. Recombinant AMTN protein did not mediate cell attachment in vitro. These results suggest a primary role for AMTN in the late stages of enamel mineralization. Copyright © 2011 S. Karger AG, Basel.

Antioxidant and immunoregulatory activity of alkali-extractable polysaccharides from mung bean.

PubMed

Yao, Yang; Zhu, Yingying; Ren, Guixing

2016-03-01

Alkali-extractable polysaccharides from the seeds of mung beans and two polysaccharide sub-fractions (MAP-1 and MAP-2) were isolated and purified by anion-exchange and gel filtration chromatography. The average molecular weights (Mws) of MAP-1 and MAP-2 were 94.2 kDa and 60.4 kDa, respectively. Monosaccharide component analysis indicated that MAP-1 was composed of Rha, Ara, Glu, Gal, and GalA in a molar ratio of 1.1:0.4:0.7:0.5:0.3. MAP-2 consisted of Xyl, Rha, Gal, Glu and GalA with a relative molar ratio of 0.4:1.4:1.6:0.5:0.2. Antioxidant assays indicated that both MAP-1 and MAP-2 exhibit significant antioxidant activity in a dose-dependent manner. An in vitro study further showed that MAP-1 and MAP-2 were both able to stimulate the production of secretory molecules (NO, TNF-α and IL-6) by RAW 264.7 murine macrophages in a concentration-dependent manner. These findings suggest that the polysaccharides isolated in our study have immunoregulatory effects on macrophages and can be used as a beneficial health food. Copyright © 2015. Published by Elsevier B.V.

Forensic age estimation based on development of third molars: a staging technique for magnetic resonance imaging.

PubMed

De Tobel, J; Phlypo, I; Fieuws, S; Politis, C; Verstraete, K L; Thevissen, P W

2017-12-01

The development of third molars can be evaluated with medical imaging to estimate age in subadults. The appearance of third molars on magnetic resonance imaging (MRI) differs greatly from that on radiographs. Therefore a specific staging technique is necessary to classify third molar development on MRI and to apply it for age estimation. To develop a specific staging technique to register third molar development on MRI and to evaluate its performance for age estimation in subadults. Using 3T MRI in three planes, all third molars were evaluated in 309 healthy Caucasian participants from 14 to 26 years old. According to the appearance of the developing third molars on MRI, descriptive criteria and schematic representations were established to define a specific staging technique. Two observers, with different levels of experience, staged all third molars independently with the developed technique. Intra- and inter-observer agreement were calculated. The data were imported in a Bayesian model for age estimation as described by Fieuws et al. (2016). This approach adequately handles correlation between age indicators and missing age indicators. It was used to calculate a point estimate and a prediction interval of the estimated age. Observed age minus predicted age was calculated, reflecting the error of the estimate. One-hundred and sixty-six third molars were agenetic. Five percent (51/1096) of upper third molars and 7% (70/1044) of lower third molars were not assessable. Kappa for inter-observer agreement ranged from 0.76 to 0.80. For intra-observer agreement kappa ranged from 0.80 to 0.89. However, two stage differences between observers or between staging sessions occurred in up to 2.2% (20/899) of assessments, probably due to a learning effect. Using the Bayesian model for age estimation, a mean absolute error of 2.0 years in females and 1.7 years in males was obtained. Root mean squared error equalled 2.38 years and 2.06 years respectively. The performance to discern minors from adults was better for males than for females, with specificities of 96% and 73% respectively. Age estimations based on the proposed staging method for third molars on MRI showed comparable reproducibility and performance as the established methods based on radiographs.

Assessment of ability of murine and human anti-lipid A monoclonal antibodies to bind and neutralize lipopolysaccharide

PubMed Central

1993-01-01

The use of monoclonal antibodies (mAbs) directed to lipid A for the therapy of gram-negative sepsis is controversial. In an attempt to understand their biologic basis of action, we used a fluid-phase radioimmunoassay to measure binding between bacterial lipopolysaccharide (LPS) and two IgM mAbs directed to lipid A that are being evaluated for the treatment of gram-negative bacterial sepsis. Both antibodies bound 3H-LPS prepared from multiple strains of gram- negative bacteria when large excesses of antibody were used, although binding was modest and only slightly greater than control preparations. We also studied the ability of each anti-lipid A antibody to neutralize some of the biological effects of LPS in vitro. Despite large molar excesses, neither antibody neutralized LPS as assessed by the limulus lysate test, by a mitogenic assay for murine splenocytes, or by the production of cytokines interleukin (IL)-1, IL-6, or tumor necrosis factor from human monocytes in culture medium or in whole blood. Our experiments do not support the hypothesis that either of these anti- lipid A mAbs function by neutralizing the toxic effects of LPS. PMID:8418211

Development of caries in permanent first molars adjacent to primary second molars with interproximal caries: four-year prospective radiographic study.

PubMed

Vanderas, Apostole P; Kavvadia, Katerina; Papagiannoulis, Lisa

2004-01-01

This study investigated the effect of the primary second molars' distal surface caries on the incidence of the permanent first molars' mesial surface caries in 613 paired tooth surfaces of children ages 6 to 8 years at baseline examination. Proximal caries and its progression were diagnosed by bite-wing radiographs taken at a 1-year interval over a period of 4 years. The permanent first molars' mesial surfaces and primary second molars' distal surfaces were examined. Recorded were: (1) sound surfaces; (2) carious lesions on the enamel's external and internal half and on the dentin's external, middle, and internal third; (3) filled, extracted, and exfoliated teeth. The logistic model for panel data was employed to estimate the effect of proximal caries of the primary second molars' distal surfaces on the incidence of the permanent first molars' mesial surface caries. The 95% confidence interval probability was used. Sensitivity and specificity as well as the positive and negative predictive rates were computed. The results showed that the presence of proximal caries on each primary second molars' distal surfaces significantly affected the development of proximal caries on the corresponding permanent first molar's mesial surfaces. Age was estimated to exert a positive and highly significant impact, while gender had no effect. The odds ratio values ranged from 4.86 to 63.43. The values of sensitivity and specificity ranged from 45% to 97% and 80% to 89%, respectively, while the positive and negative rates ranged from 40% to 56% and 90% to 99%, respectively. Proximal caries present on the primary second molars' distal surfaces increases the risk of developing caries on the permanent first molars' mesial surfaces. This risk, however, is different among the paired surfaces studied.

New models for age estimation and assessment of their accuracy using developing mandibular third molar teeth in a Thai population.

PubMed

Duangto, P; Iamaroon, A; Prasitwattanaseree, S; Mahakkanukrauh, P; Janhom, A

2017-03-01

Age estimation using developing third molar teeth is considered an important and accurate technique for both clinical and forensic practices. The aims of this study were to establish population-specific reference data, to develop age prediction models using mandibular third molar development, to test the accuracy of the resulting models, and to find the probability of persons being at the age thresholds of legal relevance in a Thai population. A total of 1867 digital panoramic radiographs of Thai individuals aged between 8 and 23 years was selected to assess dental age. The mandibular third molar development was divided into nine stages. The stages were evaluated and each stage was transformed into a development score. Quadratic regression was employed to develop age prediction models. Our results show that males reached mandibular third molar root formation stages earlier than females. The models revealed a high correlation coefficient for both left and right mandibular third molar teeth in both sexes (R = 0.945 and 0.944 in males, R = 0.922 and 0.923 in females, respectively). Furthermore, the accuracy of the resulting models was tested in randomly selected 374 cases and showed low error values between the predicted dental age and the chronological age for both left and right mandibular third molar teeth in both sexes (-0.13 and -0.17 years in males, 0.01 and 0.03 years in females, respectively). In Thai samples, when the mandibular third molar teeth reached stage H, the probability of the person being over 18 years was 100 % in both sexes.

A radiographic study of permanent molar development in wild Virunga mountain gorillas of known chronological age from Rwanda.

PubMed

Kralick, Alexandra E; Loring Burgess, M; Glowacka, Halszka; Arbenz-Smith, Keely; McGrath, Kate; Ruff, Christopher B; Chan, King Chong; Cranfield, Michael R; Stoinski, Tara S; Bromage, Timothy G; Mudakikwa, Antoine; McFarlin, Shannon C

2017-05-01

While dental development is important to life history investigations, data from wild known-aged great apes are scarce. We report on the first radiographic examination of dental development in wild Virunga mountain gorillas, using known-age skeletal samples recovered in Rwanda. In 43 individuals (0.0-14.94 years), we collected radiographs of mandibular molars, and where possible, cone beam CT scans. Molar crown and root calcification status was assessed using two established staging systems, and age prediction equations generated using polynomial regression. Results were compared to available data from known-age captive and wild chimpanzees. Mountain gorillas generally fell within reported captive chimpanzee distributions or exceeded them, exhibiting older ages at equivalent radiographic stages of development. Differences reflect delayed initiation and/or an extended duration of second molar crown development, and extended first and second molar root development, in mountain gorillas compared to captive chimpanzees. However, differences in the duration of molar root development were less evident compared to wild chimpanzees. Despite sample limitations, our findings extend the known range of variation in radiographic estimates of molar formation timing in great apes, and provide a new age prediction technique based on wild specimens. However, mountain gorillas do not appear accelerated in radiographic assessment of molar formation compared to chimpanzees, as they are for other life history traits. Future studies should aim to resolve the influence of species differences, wild versus captive environments, and/or sampling phenomena on patterns observed here, and more generally, how they relate to variation in tooth size, eruption timing, and developmental life history. © 2017 Wiley Periodicals, Inc.

Age estimation using development of third molars in South Indian population: A radiological study

PubMed Central

Priyadharshini, K. Indra; Idiculla, Jose Joy; Sivapathasundaram, B.; Mohanbabu, V.; Augustine, Dominic; Patil, Shankargouda

2015-01-01

Aim: To assess the estimation of chronological age based on the stages of third molar development following the eight stages (A–H) method of Demirjian et al. in Chennai population of South India. Materials and Methods: A sample consisting of 848 individuals (471 males and 377 females) aged between 14 and 30 years was randomly selected for the clinical evaluation and 323 orthopantomograms with clinically missing third molars were taken for radiological evaluation using Demirjian's method from a Chennai population of known chronological age and sex. Statistical analysis was performed using Pearson's Chi-square test and mean values were compared between the study groups using t-test or analysis of variance (ANOVA) followed by Tukey's highly significant difference (HSD). In the present study, P < 0.05 was considered as the level of significance. Results: The results showed that the mean age of having clinically completely erupted maxillary third molars was 22.41 years in male subjects and 23.81 years in female subjects and that of mandibular third molars was 21.49 years in male subjects and 23.34 years in female subjects. Mandibular third molars were clinically missing more often in females than in males. Eruption of mandibular third molars was generally ahead of the emergence of maxillary third molars into the oral cavity. Third molar development between male and female subjects showed statistically significant differences at calcification stage F and stage G in maxillary third molars and stage F in mandibular third molars (P < 0.05). Conclusion: There are differences indicating that maxillary and mandibular third molar eruption reached Demirjian's formation stages earlier in males than in females. It is suggested that in future studies, to increase the accuracy of age determination, indications of sexual maturity and ossification should also be evaluated in addition to third molar mineralization. PMID:25984465

Third molar development: evaluation of nine tooth development registration techniques for age estimations.

PubMed

Thevissen, Patrick W; Fieuws, Steffen; Willems, Guy

2013-03-01

Multiple third molar development registration techniques exist. Therefore the aim of this study was to detect which third molar development registration technique was most promising to use as a tool for subadult age estimation. On a collection of 1199 panoramic radiographs the development of all present third molars was registered following nine different registration techniques [Gleiser, Hunt (GH); Haavikko (HV); Demirjian (DM); Raungpaka (RA); Gustafson, Koch (GK); Harris, Nortje (HN); Kullman (KU); Moorrees (MO); Cameriere (CA)]. Regression models with age as response and the third molar registration as predictor were developed for each registration technique separately. The MO technique disclosed highest R(2) (F 51%, M 45%) and lowest root mean squared error (F 3.42 years; M 3.67 years) values, but differences with other techniques were small in magnitude. The amount of stages utilized in the explored staging techniques slightly influenced the age predictions. © 2013 American Academy of Forensic Sciences.

Evolution of the hypercarnivorous dentition in mammals (Metatheria, Eutheria) and its bearing on the development of tribosphenic molars.

PubMed

Solé, Floréal; Ladevèze, Sandrine

2017-03-01

One major innovation of mammals is the tribosphenic molar, characterized by the evolution of a neomorphic upper cusp (=protocone) and a lower basin (=talonid) that occlude and provide shearing and crushing functions. This type of molar is an evolutionarily flexible structure that enabled mammals to achieve complex dental adaptations. Among carnivorous mammals, hypercarnivory is a common trend that evolved several times among therians (marsupials, placentals, and stem relatives). Hypercarnivory involves an important simplification of the carnassial molar pattern from the ancestral tribosphenic molar pattern, with the modification of the triangular tooth crown, and the loss of several cusps and cuspids typical of the tribosphenic molar. These losses confer to the molars of the hypercarnivorous mammals a plesiomorphic/paedomorphic morphology that resembles more the earliest mammaliaforms than the earliest therians. Here, we demonstrate that the modification of the molar morphology is fully explained by a patterning cascade mode of cusp development. Contrary to what was previously proposed, our study concludes that the metaconid (mesiolingual cusp of lower molars, associated with a puncturing function) does not influence cusp development of the talonid (distal crushing heel of lower molars). Moreover, it provides a new example of how heterochronic changes were crucial to the evolution of mammal dentition. To overcome the difficulty of applying behavioral or ecological definitions of diets to fossil animals, we characterize hypercarnivorous dentitions on the basis of the molar morphology and more particularly on the loss or retention of crushing structures, each dentition resulting from adaptations to a distinct ecomorphotype. Despite repeated and convergent evolution of hypercarnivorous forms, hypercarnivory appears as a highly constrained specialization (i.e., "dead end") that is unlikely to evolve back to omnivorous dentition, especially when the crushing structures are lost. © 2017 Wiley Periodicals, Inc.

Mandibular molar uprighting using mini-implants: different approaches for different clinical cases--two case reports.

PubMed

Derton, Nicola; Perini, Alessandro; Mutinelli, Sabrina; Gracco, Antonio

2012-01-01

To detail two different clinical protocols and case studies using mini-implant anchorage developed to respond to certain clinical conditions. Two clinical protocols are described to upright mesially tilted mandibular molars. In the first protocol, a single mini-implant is inserted distally to the molar to be uprighted, and an elastic traction chain is applied to the tooth. In the second clinical approach, two mini-implants are inserted mesially. A screw-suspended TMA sectional archwire is applied (Derton-Perini technique). Two cases, descriptive of the two different treatment protocols, are described. In the first case, the mandibular right second premolar was missing and the adjacent first molar needed to be uprighted. A single screw was inserted distally to the first molar, and an elastic chain was applied. In the second case, the mandibular left second molar was missing and the third molar needed to be uprighted. Two mini-implants were inserted mesially and a fully screw-supported sectional archwire was used to upright and bodily mesialize the third molar. Both uprighting approaches uprighted the molar axis without loss of anchorage. The two approaches to mandibular molar uprighting, developed as rational responses to different clinical cases, were both found to be effective.

Demirjian's method in the estimation of age: A study on human third molars.

PubMed

Lewis, Amitha J; Boaz, Karen; Nagesh, K R; Srikant, N; Gupta, Neha; Nandita, K P; Manaktala, Nidhi

2015-01-01

The primary aim of the following study is to estimate the chronological age based on the stages of third molar development following the eight stages (A to H) method of Demirjian et al. (along with two modifications-Orhan) and secondary aim is to compare third molar development with sex and age. The sample consisted of 115 orthopantomograms from South Indian subjects with known chronological age and gender. Multiple regression analysis was performed with chronological age as the dependable variable and third molar root development as independent variable. All the statistical analysis was performed using the SPSS 11.0 package (IBM ® Corporation). Statistically no significant differences were found in third molar development between males and females. Depending on the available number of wisdom teeth in an individual, R (2) varied for males from 0.21 to 0.48 and for females from 0.16 to 0.38. New equations were derived for estimating the chronological age. The chronological age of a South Indian individual between 14 and 22 years may be estimated based on the regression formulae. However, additional studies with a larger study population must be conducted to meet the need for population-based information on third molar development.

Autotransplantation of a maxillary third molar to replace a maxillary premolar with vertical root fracture.

PubMed

Tsurumachi, T; Kakehashi, Y

2007-12-01

To report the successful autotransplantation of a fully developed third molar that required nonsurgical and surgical interventions for tooth adaptation. This case report describes the autotransplantation of a third molar with complete root development after the loss of a fractured premolar in a 47-year-old male. To allow better adaptation of the donor tooth, the buccal roots of the third molar were removed using a diamond bur and the canal entrances were filled. Recall examination 6 years after completion of root-canal treatment showed normal periodontal healing with absence of infection, ankylosis or progressive resorption. The transplantation of a third molar is seen as a promising method to replace a lost permanent tooth, and to restore aesthetics and function. *Autotransplantation is a viable option for the treatment of a missing tooth or for replacement of traumatized tooth when there is a donor tooth available. *Fully developed third molars are potentially reliable candidates in the absence of other suitable donor teeth.

Epithelial topography for repetitive tooth formation

PubMed Central

Gaete, Marcia; Fons, Juan Manuel; Popa, Elena Mădălina; Chatzeli, Lemonia; Tucker, Abigail S.

2015-01-01

ABSTRACT During the formation of repetitive ectodermally derived organs such as mammary glands, lateral line and teeth, the tissue primordium iteratively initiates new structures. In the case of successional molar development, new teeth appear sequentially in the posterior region of the jaw from Sox2+ cells in association with the posterior aspect of a pre-existing tooth. The sequence of molar development is well known, however, the epithelial topography involved in the formation of a new tooth is unclear. Here, we have examined the morphology of the molar dental epithelium and its development at different stages in the mouse in vivo and in molar explants. Using regional lineage tracing we show that within the posterior tail of the first molar the primordium for the second and third molar are organized in a row, with the tail remaining in connection with the surface, where a furrow is observed. The morphology and Sox2 expression of the tail retains characteristics reminiscent of the earlier stages of tooth development, such that position along the A-P axes of the tail correlates with different temporal stages. Sox9, a stem/progenitor cell marker in other organs, is expressed mainly in the suprabasal epithelium complementary with Sox2 expression. This Sox2 and Sox9 expressing molar tail contains actively proliferating cells with mitosis following an apico-basal direction. Snail2, a transcription factor implicated in cell migration, is expressed at high levels in the tip of the molar tail while E-cadherin and laminin are decreased. In conclusion, our studies propose a model in which the epithelium of the molar tail can grow by posterior movement of epithelial cells followed by infolding and stratification involving a population of Sox2+/Sox9+ cells. PMID:26538639

Monitoring for periodontal inflammatory disease in the third molar region.

PubMed

Golden, Brent A; Baldwin, Carrie; Sherwood, Colin; Abdelbaky, Omar; Phillips, Ceib; Offenbacher, Steven; White, Raymond P

2015-04-01

To assess changes at 2-year intervals in the periodontal status of the third molar region in participants enrolled with asymptomatic third molars and no clinical evidence of third molar region periodontal pathology. The included participants who presented with a healthy periodontal status (all probing depths [PDs], <4 mm) in the third molar region, defined as distal of second molars and around adjacent third molars, were from a larger longitudinal study of participants with asymptomatic third molars. Full-mouth periodontal PD data from 6 sites per tooth were obtained clinically at enrollment and at subsequent 2-year intervals. Data were aggregated to the patient level. Outcome variables were the presence or absence of periodontal pathology, defined as at least 1 PD of at least 4 mm in the third molar region. One hundred twenty-nine participants had a third molar region PD shallower than 4 mm at enrollment. Most participants were Caucasian (85%), women (60%), younger than 25 years (62%), educated beyond high school (84%), and with good oral health habits. At 6 years, excluding the 61 participants lost to follow-up, 47% participants had had third molars removed, 21% had developed at least 1 PD of at least 4 mm in the third molar region since enrollment, and 32% retained the periodontal status at enrollment (all PDs in third molar region, <4 mm). Demographic characteristics were not statistically different for participants followed for 6 years compared with those lost to follow-up. Although not all participants could be followed for 6 years after enrollment or chose to retain third molars, one third of participants maintained the third molar region periodontal status assessed at baseline for 6 years after enrollment; no clinical evidence of pathology developed over time. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Growth and metabolism of murine and bovine embryos in bovine uterine flushing-supplemented culture media.

PubMed Central

Rondeau, M; Guay, P; Goff, A K; Cooke, G M

1996-01-01

The aim of this study was to compare the development and metabolic activity of cultured murine and bovine embryos in 2 standard media (HAM F-10 and RPMI) in the presence or absence of bovine uterine flushings. Murine morulae (n = 653) and day 7 bovine embryos (n = 273) were cultured for 18 h or 36 h in either HAM F-10 or RPMI in the presence or absence of bovine uterine flushings. After culture, the development, quality, and metabolic activity (glucose utilization or methionine uptake and incorporation) of embryos was assessed. It was found that HAM F-10 (without uterine flushings) was a more suitable medium than RPMI for optimal development and metabolism of murine and bovine embryos. Poor quality and development, as well as decreased metabolism, were evident after culture of murine embryos in RPMI; in contrast, this medium had no adverse effects on bovine embryos in culture. Supplementation of HAM F-10 with bovine uterine flushings improved the growth of murine embryos and the protein synthesis (as measured by an increased methionine incorporation) for both murine and bovine embryos. However, supplementation with bovine uterine flushings could not overcome deficiencies of an inappropriate medium (RPMI) for murine embryos. Supplementation of a well-defined culture medium with uterine flushings increased metabolism of embryos in culture, and thus might help to increase pregnancy rates after transfer of such embryos to recipient cows. PMID:8825988

[Influence of the mandibular second premolar extraction on the angulation of the mandibular third molar].

PubMed

Feng, Guang-yao; Zou, Bing-shuang; Gao, Xue-mei; Zeng, Xiang-long; Wang, Xiu-jing; Yan, Yan

2013-02-18

To compare the angular changes in the developing mandibular third molars in the mandibular second premolar extraction and non-extraction cases and to determine whether the mandibular second premolar extraction causes favorable rotational changes in the angulations of the developing mandibular third molars and benefits its later eruption. Pretreatment and posttreatment panoramic radiographs were taken from 45 subjects who had been treated by the extraction of the mandibular second premolars and 48 subjects who had been treated without extraction. The horizontal reference plane was used to measure and compare the changes in the angulations of the developing mandibular third molars. The mean uprighting of the mandibular third molars seen in the extraction group was (5.9±2.5) degrees on the right side and (8.0±3.4) degrees on the left side following treatment. For the nonextraction group the mean uprighting was (1.8±2.4) degrees on the right side and (1.5±2.1) degrees on the left side. There was a statistically significant difference between the groups (P<0.05). Mandibular second premolar extraction might be a helpful procedure on the angulations of the developing mandibular third molars.

Demirjian's method in the estimation of age: A study on human third molars

PubMed Central

Lewis, Amitha J.; Boaz, Karen; Nagesh, K. R; Srikant, N; Gupta, Neha; Nandita, K. P; Manaktala, Nidhi

2015-01-01

Aim: The primary aim of the following study is to estimate the chronological age based on the stages of third molar development following the eight stages (A to H) method of Demirjian et al. (along with two modifications-Orhan) and secondary aim is to compare third molar development with sex and age. Materials and Methods: The sample consisted of 115 orthopantomograms from South Indian subjects with known chronological age and gender. Multiple regression analysis was performed with chronological age as the dependable variable and third molar root development as independent variable. All the statistical analysis was performed using the SPSS 11.0 package (IBM ® Corporation). Results: Statistically no significant differences were found in third molar development between males and females. Depending on the available number of wisdom teeth in an individual, R2 varied for males from 0.21 to 0.48 and for females from 0.16 to 0.38. New equations were derived for estimating the chronological age. Conclusion: The chronological age of a South Indian individual between 14 and 22 years may be estimated based on the regression formulae. However, additional studies with a larger study population must be conducted to meet the need for population-based information on third molar development. PMID:26005306

Correlation between the frequency of eruption disorders for first permanent molars and the occurrence of malocclusions in early mixed dentition.

PubMed

Salbach, Anja; Schremmer, Britt; Grabowski, Rosemarie; Stahl de Castrillon, Franka

2012-08-01

We analyzed the incidence of eruption disorders in 6-year molars during the first phase of mixed dentition, and then determined the risks for later dental arch development according to specific combinations of orthodontic malocclusions. We, thus, aimed to derive potential conclusions for preventative orthodontics. In this cross-sectional study, 8,041 kindergarten and school children with early mixed dentition were randomly selected and clinically examined. Examinations were performed in two consecutive years during the standard dental screening that school children undergo. The average age was 6.9 years. We defined an eruption of the 6-year molars as being disturbed when (1) the distal cusps had erupted further than the mesial cusps, (2) the mesial inclination of the occlusal surface revealed disturbed eruption, and (3) the 6-year molar had erupted below the second primary molar. Disturbed eruption of the first permanent molars was observed in 102 of these children. The upper 6-year molars were affected more often (88.5%) than the lower molars. Bilateral disturbed eruption of the upper molars was the most frequent combination of symptoms found. Although disturbed eruption was diagnosed most often in 6- and 7-year-old children, the 8-year-old children presented 20% of the eruption disorders. Moreover, 72.6% of the children with disturbed eruption presented at least one additional orthodontic malocclusion. Crowding (p ≤ 0.001), lateral malocclusions (p ≤ 0.001), and mandibular prognathism (p = 0.009) were present significantly more often in children with disturbed eruption of 6-year molars. Delayed eruption and false direction of eruption of the upper 6-year molars may-already at an early stage-raise the likelihood of problems during later dental arch development, such as crowding in the sagittal and transverse directions or Class III developments.

Masticatory muscle architecture in a water-rat from Australasia (Murinae, Hydromys) and its implication for the evolution of carnivory in rodents.

PubMed

Fabre, P-H; Herrel, A; Fitriana, Y; Meslin, L; Hautier, L

2017-09-01

Murines are well known for their generalist diet, but several of them display specializations towards a carnivorous diet such as the amphibious Indo-Pacific water-rats. Despite the fact that carnivory evolved repeatedly in this group, few studies have investigated associated changes in jaw muscle anatomy and biomechanics. Here, we describe the jaw muscles and cranial anatomy of a carnivorous water-rat, Hydromys chrysogaster. The architecture of the jaw musculature of six specimens captured both on Obi and Papua were studied and described using dissections. We identified the origin and insertions of the jaw muscles, and quantified muscle mass, fiber length, physiological cross-sectional area, and muscle vectors for each muscle. Using a biomechanical model, we estimated maximum incisor and molar bite force at different gape angles. Finally, we conducted a 2D geometric morphometric analyses to compare jaw shape, mechanical potential, and diversity in lever-arm ratios for a set of 238 specimens, representative of Australo-Papuan carnivorous and omnivorous murids. Our study reveals major changes in the muscle proportions among Hydromys and its omnivorous close relative, Melomys. Hydromys was found to have large superficial masseter and temporalis muscles as well as a reduced deep masseter and zygomatico-mandibularis, highlighting major functional divergence among omnivorous and carnivorous murines. Changes in these muscles are also accompanied by changes in jaw shape and the lines of action of the muscles. A more vertically oriented masseter, reduced masseteric muscles, as well as an elongated jaw with proodont lower incisors are key features indicative of a reduced propalinality in carnivorous Hydromys. Differences in the fiber length of the masseteric muscles were also detected between Hydromys and Melomys, which highlight potential adaptations to a wide gape in Hydromys, allowing it to prey on larger animals. Using a biomechanical model, we inferred a greater bite force in Hydromys than in Melomys, implying a functional shift between omnivory and carnivory. However, Melomys has an unexpected greater bite force at large gape compared with Hydromys. Compared with omnivorous Melomys, Hydromys have a very distinctive low mandible with a well-developed coronoid process, and a reduced angular process that projects posteriorly to the ascending rami. This jaw shape, along with our mechanical potential and jaw lever ratio estimates, suggests that Hydromys has a faster jaw closing at the incisor, with a higher bite force at the level of the molars. The narrowing of the Hydromys jaw explains this higher lever advantage at the molars, which constitutes a good compromise between a wide gape, a reduced anterior masseteric mass, and long fiber lengths. Lever arms of the superficial and deep masseter are less favourable to force output of the mandible in Hydromys but more favourable to speed. Compared with the small input lever arm defined between the condyle and the angular process, the relatively longer mandible of Hydromys increases the speed at the expense of the output force. This unique combination of morphological features of the masticatory apparatus possibly has permitted Hydromys to become a highly successful amphibious predator in the Indo-Pacific region. © 2017 Anatomical Society.

An aegialodontid upper molar and the evolution of mammal dentition.

PubMed

Lopatin, Alexey V; Averianov, Alexander O

2006-08-25

The most obvious key synapomorphy of the therian mammals is the tribosphenic pattern of their molars. Tribosphenic teeth are capable of both shearing and grinding, which substantially increase effectiveness of food processing and, in turn, permit evolution of a wide range of dietary specializations. Functional tribospheny developed repeatedly during mammalian evolution but was successful only in the Boreosphenida. The earliest stage in the development of boreosphenidan tribospheny has remained poorly understood, being documented only by lower molars of aegialodontids. Here, we report a known upper molar of an aegialodontid mammal, Kielantherium, from the Early Cretaceous of Mongolia.

An automated system using spatial oversampling for optical mapping in murine atria. Development and validation with monophasic and transmembrane action potentials.

PubMed

Yu, Ting Yue; Syeda, Fahima; Holmes, Andrew P; Osborne, Benjamin; Dehghani, Hamid; Brain, Keith L; Kirchhof, Paulus; Fabritz, Larissa

2014-08-01

We developed and validated a new optical mapping system for quantification of electrical activation and repolarisation in murine atria. The system makes use of a novel 2nd generation complementary metal-oxide-semiconductor (CMOS) camera with deliberate oversampling to allow both assessment of electrical activation with high spatial and temporal resolution (128 × 2048 pixels) and reliable assessment of atrial murine repolarisation using post-processing of signals. Optical recordings were taken from isolated, superfused and electrically stimulated murine left atria. The system reliably describes activation sequences, identifies areas of functional block, and allows quantification of conduction velocities and vectors. Furthermore, the system records murine atrial action potentials with comparable duration to both monophasic and transmembrane action potentials in murine atria. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

[Study of the relationship between congenital missing of the third molar and the development of the mandibular angle].

PubMed

Chen, Yan-Na; Zheng, Bo-Wen; Liu, Yi

2017-02-01

Based on the research of the congenital missing of the third molar and the missing number, the relationship beteen congenital missing of the third molar and the development of the mandibular angle was evaluated. Patients were divided into experimental group and control group, the experimental group included 227 patients, each had at least one of the third molars congenital lost; 227 patients who had four third molar were selected as control group. Winceph software was used to measure the lateral cephalograms. SPSS17.0 software package was used to perform statistical analysis. Gonial angle, upper Gonial angle and lower Gonial angle between the experimental group and the control group showed significant difference and the values in the experimental group were significantly smaller than in the control group, but there was no gender difference between the two groups.There was no difference between Gonial angle, upper Gonial angle,lower Gonial angle and the missing number of the third molar. There is a close relationship between congenital missing third molar and Gonial angle, upper Gonial angle, lower Gonial angle, but there is no significant association with gender and the patients with congenital missing third molar have shorter craniofacial structure. Congenital missing number of the third molar has no significant association with Gonial angle, upper Gonial angle and lower Gonial angle.

Effects of first premolar extraction on maxillary and mandibular third molar angulation after orthodontic therapy

PubMed Central

Gohilot, Avinash; Pradhan, Tejashri; Keluskar, Kanhoba Mahabaleshwar

2012-01-01

Background/Aims To compare the change in the angulation of developing mandibular third molar in both first premolar extraction and non-extraction cases and to determine whether premolar extraction results in a more mesial movement of the mandibular buccal segment and causes favorable rotational changes in the mandibular third molar tilt, which can enhance later eruption of the third molars. Materials and methods Pretreatment (T1) and post treatment (T2) panoramic radiographs were taken of 25 subjects (age 14–19 years) who had been treated by the extraction of all the first premolars and 25 subjects who had been treated with non-extraction. The horizontal reference plane was used to measure and compare the changes in the angles of the developing mandibular third molars. Results The mean uprighting of the maxillary third molars seen in the extraction group was 4 ± 9° on the left side and −17 ± 13° on the right side following treatment (T2 _ T1). For the non-extraction group the mean difference was −16 ± 12° on the left side and 2 ± 13° on the right side. There was a statistically significant difference between the groups (P _ 0.021 on the right side and P _ 0.041 on the left side). Mandibular 3rd molars in extraction group showed no statistical significant change in the angulation. Conclusion Premolar extractions had a positive influence on the developing maxillary third molar angulations both on right and left. Mandibular 3rd molar have shown change in the angulation but not statistically significant. Non-extraction therapy did not have any adverse effect. PMID:25737843

Effects of first premolar extraction on maxillary and mandibular third molar angulation after orthodontic therapy.

PubMed

Gohilot, Avinash; Pradhan, Tejashri; Keluskar, Kanhoba Mahabaleshwar

2012-01-01

To compare the change in the angulation of developing mandibular third molar in both first premolar extraction and non-extraction cases and to determine whether premolar extraction results in a more mesial movement of the mandibular buccal segment and causes favorable rotational changes in the mandibular third molar tilt, which can enhance later eruption of the third molars. Pretreatment (T1) and post treatment (T2) panoramic radiographs were taken of 25 subjects (age 14-19 years) who had been treated by the extraction of all the first premolars and 25 subjects who had been treated with non-extraction. The horizontal reference plane was used to measure and compare the changes in the angles of the developing mandibular third molars. The mean uprighting of the maxillary third molars seen in the extraction group was 4 ± 9° on the left side and -17 ± 13° on the right side following treatment (T2 _ T1). For the non-extraction group the mean difference was -16 ± 12° on the left side and 2 ± 13° on the right side. There was a statistically significant difference between the groups (P _ 0.021 on the right side and P _ 0.041 on the left side). Mandibular 3rd molars in extraction group showed no statistical significant change in the angulation. Premolar extractions had a positive influence on the developing maxillary third molar angulations both on right and left. Mandibular 3rd molar have shown change in the angulation but not statistically significant. Non-extraction therapy did not have any adverse effect.

Western Saudi adolescent age estimation utilising third molar development.

PubMed

Alshihri, Amin M; Kruger, Estie; Tennant, Marc

2014-07-01

The aim of this study was to establish reference data on third molar morphology/development for age estimation in Western Saudi adolescents, between ages 14 and 23 years of old. The orthopantomograms of 130 individuals (males and females), were examined, and the stage of third molar development were evaluated. Mean ages, standard deviations, and percentile distributions are presented for each stage of development. The mean estimated age for all participants (n = 130) was 219.7 months, and this differed significantly (P < 0.05) from the mean chronological age (226.5 months). Deviations of predicted age from real age showed 28.5% of all participants had their age estimated within 1 year (±12 months) of their chronological age. Most (43%) had their age underestimated by more than 12 months and the remaining 28.5% had their age overestimated by more than 12 months of their chronological age. Differences in left-right symmetry information of third molars were detected and were higher in the maxilla (92%) than in the mandible (82%). For all molars reaching stage "H" most individuals (males and females) were over the age 18 years of old. Males reach the developmental stages earlier than females. Third molar tooth development can be reliably used to generate mean age and the estimated age range for an individual of unknown chronological age. Further studies with large populations are needed for better statistical results.

The third molar as an age marker in adolescents: new approach to age evaluation.

PubMed

Rozkovcova, Eva; Dostalova, Tatjana; Markova, Marie; Broukal, Zdenek

2012-09-01

Adolescence is a relatively short period between childhood and adulthood. It is very difficult to determine adulthood based on biological indicators. The third molar may be considered a potential age marker for the period between the ages of 16-21. Our study evaluated a set of 1700 panoramic radiographs of individuals aged between 5 and 21 years. Results confirmed the statistically significant difference in the course of third molars development. The mean deviation for individuals with one third molar agenesis is -0.98 years, for individuals with two third molars agenesis -1.89 years, and with three molars agenesis -3.28 years. Thus, the extent of the deviation is directly proportional to the number of unformed third molars. The calculation of age according to the mean of stages of all third molars could lead to the underestimation of age. No intergender differences were found. Age determination using third molars could be used for forensic purposes. © 2012 American Academy of Forensic Sciences.

Loss of Permanent First Molars in the Mixed Dentition: Circumstances Resulting in Extraction and Requiring Orthodontic Management.

PubMed

Mathu-Muju, Kavita R; Kennedy, David B

2016-10-15

Extraction of significantly compromised permanent first molars may be indicated during the mixed dentition stage of occlusal development. The purpose of this article was to review circumstances that can result in the loss of a permanent first molar-including dental caries, molar incisor hypomineralization, eruption disturbances of permanent teeth, and failure of restorative treatment to affirm that a complete dental arch is not necessary for the existence of a functional dental arch. The extraction of permanent first molar(s) with subsequent orthodontic treatment in a young patient can be considered a cost-effective alternative to placing complex restorations that require replacement over the lifespan. Approaches to establish a functional dental arch in the event of the loss of a permanent first molar(s) are outlined. Additionally, orthodontic diagnostic and treatment principles are reviewed. Case histories are provided to illustrate the clinical management of permanent first molar extractions to achieve a functional dental arch.

Spontaneous emergence of overgrown molar teeth in a colony of Prairie voles (Microtus ochrogaster)

PubMed Central

Jheon, Andrew H; Prochazkova, Michaela; Sherman, Michael; Manoli, Devanand S; Shah, Nirao M; Carbone, Lawrence; Klein, Ophir

2015-01-01

Continuously growing incisors are common to all rodents, which include the Microtus genus of voles. However, unlike many rodents, voles also possess continuously growing molars. Here, we report spontaneous molar defects in a population of Prairie voles (Microtus ochrogaster). We identified bilateral protuberances on the ventral surface of the mandible in several voles in our colony. In some cases, the protuberances broke through the cortical bone. The mandibular molars became exposed and infected, and the maxillary molars entered the cranial vault. Visualisation upon soft tissue removal and microcomputed tomography (microCT) analyses confirmed that the protuberances were caused by the overgrowth of the apical ends of the molar teeth. We speculate that the unrestricted growth of the molars was due to the misregulation of the molar dental stem cell niche. Further study of this molar phenotype may yield additional insight into stem cell regulation and the evolution and development of continuously growing teeth. PMID:25634121

Autotransplantation of third molars as treatment in advanced periodontal disease.

PubMed

Kristerson, L; Johansson, L A; Kisch, J; Stadler, L E

1991-08-01

The aim of this study was to investigate the prognosis of replacing molars with advanced periodontitis by autotransplanted fully developed third molars. The patient sample consisted of 18 subjects, 24-58 years of age. The patients selected had at least 1 molar with advanced periodontal tissue destruction. After extraction of the diseased molar, autotransplantation of a third molar was immediately performed. After a splinting and healing period of 2-3 weeks, endodontic treatment was carried out. The follow-up included recordings of the clinical parameters, probing periodontal pocket depth, probing attachment level, percussion sound, and mobility. Radiographs were taken immediately after the surgical procedure, after 6 months, 1 year, and thereafter annually. The results of this study indicate that autotransplantation may be an alternative treatment procedure for molars with advanced periodontal disease.

The indications for third-molar extractions.

PubMed

Steed, Martin B

2014-06-01

Defining the indications for third-molar extraction continues to be a topic of controversy. The dentist's management of third molars commonly hinges on identifying the presence of symptoms or disease that clearly is attributable to the third molar. Use of a guide that serves as a systematic and unambiguous way to classify third molars has been advocated. Patients' symptoms are designated as present and attributable to the third molar (Sx+) or as absent (Sx-). In addition, clinical or radiographic evidence of disease is evaluated and designated as present (D+) or absent (D-). Evidence-based clinical data developed from prospective investigations have shown that an asymptomatic third molar does not necessarily reflect the absence of disease. Current data are not sufficient to refute or support prophylactic extraction versus active surveillance for the routine management of third molars that are asymptomatic and free of disease (group D). Although decisions regarding third-molar management usually are straightforward, the evidence supporting extraction versus retention of asymptomatic disease-free (group D) third molars is lacking. Active surveillance, a prescribed program of follow-up and reassessment at regular intervals are recommended for retained third molars rather than waiting for the onset of symptoms.

Correlations between Cervical Vertebral Maturation (CVM) and Dental Development in Thai Cleft Patients.

PubMed

Chongcharueyskul, Pathomporn; Wangsrimonkol, Tasanee; Pisek, Poonsak; Pisek, Araya; Manosudprasit, Montian

2015-08-01

To examine correlations between cervical vertebral maturation stages (CVMs) and dental development stages, and cervical vertebral maturation (CVM) stage 6 and completion of root formation of mandibular third molar in Thai cleft patients. Lateral cephalograms of 366 cleft subjects aged 7-9 years were assessed for CVMs using Baccetti method. Calcication stages of all left mandibular teeth within each CVMs were assessed from panoramic films using Demirjian method. Spearman rank correlation coefficients comparing CVMs and teeth were 0.51-0.79 (p<0.001). Second molar had the highest and central incisor had the lowest correlations. In CVMs 6, 2.9% of third molars had completed root formation. However, only CVMs 6 could be predicted from third molar stage G that had a high likelihood ratio (30.94). Dental development was highly correlated with CVM in clefts. Third molar stage G could predict completed growth of mandible in individual patients, but it should be combined with other maturation indicators.

Western Saudi adolescent age estimation utilising third molar development

PubMed Central

Alshihri, Amin M.; Kruger, Estie; Tennant, Marc

2014-01-01

Objective: The aim of this study was to establish reference data on third molar morphology/development for age estimation in Western Saudi adolescents, between ages 14 and 23 years of old. Materials and Methods: The orthopantomograms of 130 individuals (males and females), were examined, and the stage of third molar development were evaluated. Results: Mean ages, standard deviations, and percentile distributions are presented for each stage of development. The mean estimated age for all participants (n = 130) was 219.7 months, and this differed significantly (P < 0.05) from the mean chronological age (226.5 months). Deviations of predicted age from real age showed 28.5% of all participants had their age estimated within 1 year (±12 months) of their chronological age. Most (43%) had their age underestimated by more than 12 months and the remaining 28.5% had their age overestimated by more than 12 months of their chronological age. Differences in left-right symmetry information of third molars were detected and were higher in the maxilla (92%) than in the mandible (82%). For all molars reaching stage “H” most individuals (males and females) were over the age 18 years of old. Males reach the developmental stages earlier than females. Conclusion: Third molar tooth development can be reliably used to generate mean age and the estimated age range for an individual of unknown chronological age. Further studies with large populations are needed for better statistical results. PMID:25202206

Clinical significance of computed tomography assessment for third molar surgery

PubMed Central

Nakamori, Kenji; Tomihara, Kei; Noguchi, Makoto

2014-01-01

Surgical extraction of the third molar is the most commonly performed surgical procedure in the clinical practice of oral surgery. Third molar surgery is warranted when there is inadequate space for eruption, malpositioning, or risk for cyst or odontogenic tumor formation. Preoperative assessment should include a detailed morphologic analysis of the third molar and its relationship to adjacent structures and surrounding tissues. Due to developments in medical engineering technology, computed tomography (CT) now plays a critical role in providing the clear images required for adequate assessment prior to third molar surgery. Removal of the maxillary third molar is associated with a risk for maxillary sinus perforation, whereas removal of the mandibular third molar can put patients at risk for a neurosensory deficit from damage to the lingual nerve or inferior alveolar nerve. Multiple factors, including demographic, anatomic, and treatment-related factors, influence the incidence of nerve injury during or following removal of the third molar. CT assessment of the third molar prior to surgery can identify some of these risk factors, such as the absence of cortication between the mandibular third molar and the inferior alveolar canal, prior to surgery to reduce the risk for nerve damage. This topic highlight presents an overview of the clinical significance of CT assessment in third molar surgery. PMID:25071882

Uprighting of severely impacted mandibular second molars: a case report.

PubMed

Fujita, Tadashi; Shirakura, Maya; Hayashi, Hidetaka; Tsuka, Yuji; Fujii, Eri; Tanne, Kazuo

2012-11-01

The incidence of mandibular first and second molar impaction is increasing but still recorded as rare. Treatment methods involving uprighting, extraction, or autologous tooth transplantation have been described. The present study describes the uprighting of 3 impacted mandibular second molars presenting with eruptive disorders. The application of limited and appropriate orthodontic therapy completed treatment in 11 months, 5 months, and 2 years and 3 months, respectively. Although no absolute anchorage in the form of miniscrews was required, no significant anchorage demands were considered necessary. Although the third molar tooth germs were identified and preserved in each case, no adverse influence on the uprighting of the second molars was encountered. The favourable molar repositioning results were likely due to the youth of the 3 patients as the third molars were in early development and bone remodelling was marked. Furthermore, no problems related to anchorage or alveolar bone loss were identified after treatment. The results indicated the benefits of limited orthodontic treatment and early intervention for the uprighting of impacted mandibular second molars.

Autogenous transplantation of mandibular third molar to replace tooth with vertical root fracture

PubMed Central

Asgary, Saeed

2009-01-01

Autogenous tooth transplantation (ATT) can be considered when there is a hopeless molar tooth and suitable donor present. This report presents an unconventional case of successful ATT of a third molar replacing the adjacent fractured second molar in a 33 year old woman. This wisdom tooth had completely developed roots. Root-end filling with Calcium Enriched Mixture (CEM) cement was performed in the third molar. The second molar was extracted non-traumatically without any bone removal; the wisdom tooth was immediately transplanted into the recipient socket. No endodontic treatment was carried out either during or after the ATT. At six-month and 2-year clinical examination the patient was asymptomatic; the transplanted tooth was still functional, with no evidence of marginal periodontal pathosis. At the same follow ups, radiographic evaluation illustrated bone regeneration, normal PDL, and absence of external root resorption. Transplantation of mature third molar seems to be a promising method for replacing a lost permanent molar tooth and restoring aesthetics and function. PMID:24003333

Effect of a chlorhexidine/thymol and a fluoride varnish on caries development in erupting permanent molars: a comparative study.

PubMed

Flamee, S; Gizani, S; Caroni, C; Papagiannoulis, L; Twetman, S

2015-12-01

To compare the caries preventive effect of a chlorhexidine/thymol-containing antibacterial varnish with a fluoride varnish when topically applied during the eruption of permanent molars. The study group consisted of 189 patients, 5-14 years of age, with one 1st or 2nd permanent molar in the process of eruption. After stratification for type of molar and stage of eruption, the patients were randomised to either quarterly topical applications with an antibacterial varnish (Cervitec(®) Plus; CV group) or biannual applications with a fluoride varnish plus biannual treatments with placebo varnish (Fluor Protector; FV group). The duration of the study was 2 years. The primary endpoint was caries incidence (initial and cavitated) in the erupting molars and the secondary outcome was salivary mutans streptococci (MS) counts. The groups were balanced with respect to socio-economy, oral hygiene, dietary habits and caries experience at baseline. The dropout rate was 11.6 %. The caries incidence was low (< 10 %) in both groups and there was no significant difference between the CV and FV groups with respect to occlusal caries development in the erupting molars (relative risk 1.08, 95 % CI 0.94-1.25). Significantly lower levels of salivary MS were disclosed in the CV group at the end of the study (p < 0.05). No difference in occlusal caries development in young permanent molars was displayed after topical applications of either a chlorhexidine/thymol varnish or a fluoride varnish during tooth eruption.

Dental age estimation in Japanese individuals combining permanent teeth and third molars.

PubMed

Ramanan, Namratha; Thevissen, Patrick; Fleuws, Steffen; Willems, G

2012-12-01

The study aim was, firstly, to verify the Willems et al. model on a Japanese reference sample. Secondly to develop a Japanese reference model based on the Willems et al. method and to verify it. Thirdly to analyze the age prediction performance adding tooth development information of third molars to permanent teeth. Retrospectively 1877 panoramic radiographs were selected in the age range between 1 and 23 years (1248 children, 629 sub-adults). Dental development was registered applying Demirjian 's stages of the mandibular left permanent teeth in children and Köhler stages on the third molars. The children's data were, firstly, used to validate the Willems et al. model (developed a Belgian reference sample), secondly, split ino a training and a test sample. On the training sample a Japanese reference model was developed based on the Willems method. The developed model and the Willems et al; model were verified on the test sample. Regression analysis was used to detect the age prediction performance adding third molar scores to permanent tooth scores. The validated Willems et al. model provided a mean absolute error of 0.85 and 0.75 years in females and males, respectively. The mean absolute error in the verified Willems et al. and the developed Japanese reference model was 0.85, 0.77 and 0.79, 0.75 years in females and males, respectively. On average a negligible change in root mean square error values was detected adding third molar scores to permanent teeth scores. The Belgian sample could be used as a reference model to estimate the age of the Japanese individuals. Combining information from the third molars and permanent teeth was not providing clinically significant improvement of age predictions based on permanent teeth information alone.

Human dental pulp pluripotent-like stem cells promote wound healing and muscle regeneration.

PubMed

Martínez-Sarrà, Ester; Montori, Sheyla; Gil-Recio, Carlos; Núñez-Toldrà, Raquel; Costamagna, Domiziana; Rotini, Alessio; Atari, Maher; Luttun, Aernout; Sampaolesi, Maurilio

2017-07-27

Dental pulp represents an easily accessible autologous source of adult stem cells. A subset of these cells, named dental pulp pluripotent-like stem cells (DPPSC), shows high plasticity and can undergo multiple population doublings, making DPPSC an appealing tool for tissue repair or maintenance. DPPSC were harvested from the dental pulp of third molars extracted from young patients. Growth factors released by DPPSC were analysed using antibody arrays. Cells were cultured in specific differentiation media and their endothelial, smooth and skeletal muscle differentiation potential was evaluated. The therapeutic potential of DPPSC was tested in a wound healing mouse model and in two genetic mouse models of muscular dystrophy (Scid/mdx and Sgcb-null Rag2-null γc-null). DPPSC secreted several growth factors involved in angiogenesis and extracellular matrix deposition and improved vascularisation in all three murine models. Moreover, DPPSC stimulated re-epithelialisation and ameliorated collagen deposition and organisation in healing wounds. In dystrophic mice, DPPSC engrafted in the skeletal muscle of both dystrophic murine models and showed integration in muscular fibres and vessels. In addition, DPPSC treatment resulted in reduced fibrosis and collagen content, larger cross-sectional area of type II fast-glycolytic fibres and infiltration of higher numbers of proangiogenic CD206 + macrophages. Overall, DPPSC represent a potential source of stem cells to enhance the wound healing process and slow down dystrophic muscle degeneration.

Analysis of cardiomyocyte movement in the developing murine heart

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hashimoto, Hisayuki; Yuasa, Shinsuke, E-mail: yuasa@a8.keio.jp; Tabata, Hidenori

The precise assemblage of several types of cardiac precursors controls heart organogenesis. The cardiac precursors show dynamic movement during early development and then form the complicated heart structure. However, cardiomyocyte movements inside the newly organized mammalian heart remain unclear. We previously established the method of ex vivo time-lapse imaging of the murine heart to study cardiomyocyte behavior by using the Fucci (fluorescent ubiquitination-based cell cycle indicator) system, which can effectively label individual G1, S/G2/M, and G1/S-transition phase nuclei in living cardiomyocytes as red, green, and yellow, respectively. Global analysis of gene expression in Fucci green positive ventricular cardiomyocytes confirmed that cellmore » cycle regulatory genes expressed in G1/S, S, G2/M, and M phase transitions were upregulated. Interestingly, pathway analysis revealed that many genes related to the cell cycle were significantly upregulated in the Fucci green positive ventricular cardiomyocytes, while only a small number of genes related to cell motility were upregulated. Time-lapse imaging showed that murine proliferating cardiomyocytes did not exhibit dynamic movement inside the heart, but stayed on site after entering the cell cycle. - Highlights: • We directly visualized cardiomyocyte movement inside the developing murine heart. • Cell cycle related genes were upregulated in the proliferating cardiomyocytes. • Time-lapse imaging revealed that proliferating murine cardiomyocytes stayed in place. • Murine ventricular cardiomyocytes proliferate on site during development.« less

Sharp mandibular bone irregularities after lower third molar extraction: Incidence, clinical features and risk factors

PubMed Central

Alves-Pereira, Daniela; Valmaseda-Castellón, Eduard; Laskin, Daniel M.; Berini-Aytés, Leonardo; Gay-Escoda, Cosme

2013-01-01

Objectives: The purpose of this study was to determine the incidence and clinical symptoms associated with sharp mandibular bone irregularities (SMBI) after lower third molar extraction and to identify possible risk factors for this complication. Study Design: A mixed study design was used. A retrospective cohort study of 1432 lower third molar extractions was done to determine the incidence of SMBI and a retrospective case-control study was done to determine potential demographic and etiologic factors by comparing those patients with postoperative SMBI with controls. Results: Twelve SMBI were found (0.84%). Age was the most important risk factor for this complication. The operated side and the presence of an associated radiolucent image were also significantly related to the development of mandibular bone irregularities. The depth of impaction of the tooth might also be an important factor since erupted or nearly erupted third molars were more frequent in the SMBI group. Conclusions: SMBI are a rare postoperative complication after lower third molar removal. Older patients having left side lower third molars removed are more likely to develop this problem. The treatment should be the removal of the irregularity when the patient is symptomatic. Key words:Third molar, postoperative complication, bone irregularities, age. PMID:23524429

MRI-based morphological modeling, synthesis and characterization of cardiac tissue-mimicking materials.

PubMed

Kossivas, Fotis; Angeli, S; Kafouris, D; Patrickios, C S; Tzagarakis, V; Constantinides, C

2012-06-01

This study uses standard synthetic methodologies to produce tissue-mimicking materials that match the morphology and emulate the in vivo murine and human cardiac mechanical and imaging characteristics, with dynamic mechanical analysis, atomic force microscopy (AFM), scanning electron microscopy (SEM) and magnetic resonance imaging. In accordance with such aims, poly(glycerol sebacate) (PGS) elastomeric materials were synthesized (at two different glycerol (G)-sebacic (S) acid molar ratios; the first was synthesized using a G:S molar ratio of 2:2, while the second from a 2:5 G:S molar ratio, resulting in PGS2:2 and PGS2:5 elastomers, respectively). Unlike the synthesized PGS2:2 elastomers, the PGS2:5 materials were characterized by an overall mechanical instability in their loading behavior under the three successive loading conditions tested. An oscillatory response in the mechanical properties of the synthesized elastomers was observed throughout the loading cycles, with measured increased storage modulus values at the first loading cycle, stabilizing to lower values at subsequent cycles. These elastomers were characterized at 4 °C and were found to have storage modulus values of 850 and 1430 kPa at the third loading cycle, respectively, in agreement with previously reported values of the rat and human myocardium. SEM of surface topology indicated minor degradation of synthesized materials at 10 and 20 d post-immersion in the PBS buffer solution, with a noted cluster formation on the PGS2:5 elastomers. AFM nanoindentation experiments were also conducted for the measurement of the Young modulus of the sample surface (no bulk contribution). Correspondingly, the PGS2:2 elastomer indicated significantly decreased surface Young's modulus values 20 d post-PBS immersion, compared to dry conditions (Young's modulus = 1160 ± 290 kPa (dry) and 200 ± 120 kPa (20 d)). In addition to the two-dimensional (2D) elastomers, an integrative platform for accurate construction of three-dimensional tissue-mimicking models of cardiac anatomy from 2D MR images using rapid prototyping manufacturing processes was developed. For synthesized elastomers, doping strategies with two different concentrations of the MRI contrast agent Dotarem allowed independent and concurrent control of the imaging characteristics (contrast and relaxivity) during the synthetic process for increased contrast agent absorption, with tremendous potential for non-destructive in vivo use and applications to cardiovascular and cerebrovascular diseases.

Effects of conventional anchorage on premolar root development during treatment with a pendulum appliance.

PubMed

Kinzinger, Gero; Pantel, Cora; Ludwig, Björn; Gülden, Norbert; Glasl, Bettina; Lisson, Jörg

2010-07-01

By metrically analyzing orthopantomograms, we aimed in this study to retrospectively investigate whether maxillary premolars used as anchoring teeth during molar distalization with pendulum appliances would reveal inhibited root development. The upper molars were distalized with a modified pendulum appliance (Pendulum K) in 36 adolescents (14 males, 22 females, mean age 12.3 years). Mean treatment period was 19.5 weeks. Orthopantomograms of each patient were taken at the start (time point T1) and after completion of molar distalization (time point T2). The enlargement of the posterior region was ascertained individually quadrant by quadrant for each radiograph, followed by measurement of the vestibular tooth lengths of the premolars whose root development was for the most part not yet complete. To assess further root development in the premolar region, the differences were calculated between tooth lengths at the start and end of treatment. During treatment with the pendulum appliance a general increase in tooth lengths in the anchorage region was observed (1.37 +/- 1.70 mm, p<0.0001). Differentiated by dental age, we noted increases in tooth lengths of patients with second molars in the budding stage (patient group PG 1: 0.93 +/- 1.37 mm, p<0.0001) as well as of patients with fully-erupted second molars (patient group PG 2: 1.81 +/- 1.88 mm, p<0.0001). Both groups demonstrated greater increases in the second premolars than the first premolars; the increases group-wise were larger in PG 2 than PG 1. However, both the group comparison (PG 1 versus PG 2) and the side comparison (right versus left) (differentiated into first and second molars) showed no statistically relevant differences. Visual assessment of the radiographs revealed no evidence of treatment-related root deviations. A highly complex system of forces acts on the anchoring teeth during molar distalization with the conventionally-anchored Pendulum K. However, the Pendulum K appliance's specific biomechanics make it possible to transfer the reactive forces and moments to the anchorage unit so that they remain within the physiological range, allowing uninhibited premolar root development. This also applies after completed eruption of the second molars, when the treatment period and hence duration of exposure to the active and reactive forces and moments arising during molar distalization are comparatively increased.

An in vitro morphological investigation of the endodontic spaces of third molars.

PubMed

Cosić, Jozo; Galić, Nada; Vodanović, Marin; Njemirovskij, Vera; Segović, Sanja; Pavelić, Bozidar; Anić, Ivica

2013-06-01

Aim of this paper was to investigate the particular anatomic features of the endodontic space of third molars in the general population of Croatia. A total of 106 fully developed third molars (56 maxillar and 50 mandibular) has been analyzed. The respective number of roots and of root canals, the structure of the roots, and the curvature and absolute length of the root-canals were analyzed. In most cases, upper third molars had three roots (83.9%), while most of the lower molars were single rooted (56.0%). Upper third molars had mostly three root canals (75.1%), lower third molars two (90.0%). In both jaws, most third molars had curved canals (60.7% in the upper and 84.0% in the lower jaw). 12.5% of upper third molars had lateral and accessory canals, whereas only 4.0% of the lower third molars were found to have them. The Student t-test showed statistically significant differences (p < 0.05) in the length of the root-canals, mesiobuccal and distobuccal canals being significantly shorter than palatinal canals. The same test showed that in the lower third molars the mesial root canals were significantly longer that the distal ones, although slightly. The results obtained are in compliance with similar results by other authors; however, they tend to show some specific population-related features.

Mechanical constraint from growing jaw facilitates mammalian dental diversity

PubMed Central

Renvoisé, Elodie; Kavanagh, Kathryn D.; Lazzari, Vincent; Häkkinen, Teemu J.; Rice, Ritva; Pantalacci, Sophie; Salazar-Ciudad, Isaac; Jernvall, Jukka

2017-01-01

Much of the basic information about individual organ development comes from studies using model species. Whereas conservation of gene regulatory networks across higher taxa supports generalizations made from a limited number of species, generality of mechanistic inferences remains to be tested in tissue culture systems. Here, using mammalian tooth explants cultured in isolation, we investigate self-regulation of patterning by comparing developing molars of the mouse, the model species of mammalian research, and the bank vole. A distinct patterning difference between the vole and the mouse molars is the alternate cusp offset present in the vole. Analyses of both species using 3D reconstructions of developing molars and jaws, computational modeling of cusp patterning, and tooth explants cultured with small braces show that correct cusp offset requires constraints on the lateral expansion of the developing tooth. Vole molars cultured without the braces lose their cusp offset, and mouse molars cultured with the braces develop a cusp offset. Our results suggest that cusp offset, which changes frequently in mammalian evolution, is more dependent on the 3D support of the developing jaw than other aspects of tooth shape. This jaw–tooth integration of a specific aspect of the tooth phenotype indicates that organs may outsource specific aspects of their morphology to be regulated by adjacent body parts or organs. Comparative studies of morphologically different species are needed to infer the principles of organogenesis. PMID:28808032

[Orthodontic Management of the Impacted Mandibular Second Molar Tooth].

PubMed

Mah, Michael; Takada, Kenji

2016-09-01

When the mandibular permanent second molar becomes impacted, it is identified as a malocclusion that needs treatment as it often leads to unwanted complications such as caries and periodontitis of the adjacent permanent first molar. Other less common complications include root resorption of the adjacent first molar root or continued root development to be in close proximity to the inferior dental alveolar nerve. This paper seeks to differentiate various levels of severity of impaction and review treatment options that are considered clinically available for the proper management of the impacted mandibular permanent second molar. Treatment options that will be discussed in this article include timing of second molar removal for replacement by the third molar, relief of impaction via second premolar removal, surgical repositioning and the combination of third molar removal, surgical exposure and orthodontic uprighting of the impacted tooth. Depending on the severity of the impaction, most impactions can be easily and predictably corrected with nickel titanium archwires or auxillary open coil springs or uprighting springs. Uncommonly, the mandibular permanent second molar can become severely impacted and in close proximity to the inferior dentoalveolar nerve. In these instances, the use of temporary anchorage devices such as microimplants has shown to be successful in uprighting the severely impacted mandibular permanent second molars. © EDP Sciences, SFODF, 2016.

Maxillary second molar extractions in orthodontic treatment.

PubMed

Lee, Wilson; Wong, Ricky Wing-Kit; Ikegami, Tomio; Hägg, Urban

2008-01-01

This article is a review of the rationales, indications, methods, and effects of orthodontic treatment with maxillary second molar extractions. In addition to the patient's malocclusion, specific considerations about the status and position of the maxillary second and third molars should be taken into account. In recent years, the development of temporary anchorage devices, in addition to extraoral traction and intraoral distalization appliances, has become another armamentarium in the distalization of the maxillary posterior teeth, which may affect the selection of teeth to be extracted from second to third molars. In conclusion, extraction of maxillary second molars is a viable option in selected cases at present, but it is important to understand the indications and limitations of this treatment choice.

A prospective study on transplantation of third molars with complete root formation.

PubMed

Mejàre, Bertil; Wannfors, Karin; Jansson, Leif

2004-02-01

The study objective was to evaluate the prognosis for autotransplantation of third molar teeth with fully developed roots followed by endodontic treatment on the basis of a time-table analysis. A total of 50 third molars with completely developed roots were autotransplanted to replace a lost first or second molar in the same number of admitted patients. Root canal treatment was started 3 to 4 weeks later. Clinical and radiographic checkup of the transplanted and root-filled third molars was done annually according to a predesigned record form. Descriptive statistics including a life table and statistical analysis were performed. The cumulative survival rate during 4 years' follow-up was 81.4%. In all, 7 transplants were lost during the follow-up time, 4 of them due to marginal periodontal pathosis and the other 3 due to root resorption. None of the root resorptions was observed before the second postoperative year. The radiographic periapical status was considered normal in 96% of the transplants at the latest follow-up visit. Autotransplantation of mature third molar teeth is a reasonable treatment alternative to conventional prosthetic rehabilitation or implant treatment in cases of partial edentualism from both a therapeutic and an economic point of view.

[Establish Assessment Model of 18 Years of Age in Chinese Han Population by Mandibular Third Molar].

PubMed

Fan, Fei; Dai, Xin-hua; Wang, Liang; Li, Yuan; Zhang, Kui; Deng, Zhen-hua

2016-02-01

To explore the value of estimating chronologic age based on the grades of mandibular third molar development. To evaluate whether mandibular third molar could be used as an indicator for estimating the age under or over 18 years. The mineralization status of mandibular third molar of 1 845 individuals aged 10 - 30 was graded and marked based on Demirjian's classification of grades reformed by Orhan. Gender difference was examined by t-test. A cubic regression model was established to analyze the correlation between third molar and chronologic age. Each grade of age cumulative distribution diagram and ROC curve was respectively performed to evaluate the relationship between third molar and the age of 18. Using Bayes discriminant analysis, an equation was established for estimating the age of 18. The inner-rater reliability was 0.903. Statistical analysis showed a moderate correlation between age and grade. Significant differences of both genders were found only in grade D and H (P < 0.05). Males at the grades from 1 to D and females at the grades from 1 to C were under 18 years old, and both males and females at grade H were over 18 years old. The area under the ROC curve was 0.797 (P < 0.05). Third molar development shows a high correlation with age, and combined with other indicators, it can be used to estimate the age of 18.

Forensic age estimation based on magnetic resonance imaging of third molars: converting 2D staging into 3D staging.

PubMed

De Tobel, Jannick; Hillewig, Elke; Verstraete, Koenraad

2017-03-01

Established methods to stage development of third molars for forensic age estimation are based on the evaluation of radiographs, which show a 2D projection. It has not been investigated whether these methods require any adjustments in order to apply them to stage third molars on magnetic resonance imaging (MRI), which shows 3D information. To prospectively study root stage assessment of third molars in age estimation using 3 Tesla MRI and to compare this with panoramic radiographs, in order to provide considerations for converting 2D staging into 3D staging and to determine the decisive root. All third molars were evaluated in 52 healthy participants aged 14-26 years using MRI in three planes. Three staging methods were investigated by two observers. In sixteen of the participants, MRI findings were compared with findings on panoramic radiographs. Decisive roots were palatal in upper third molars and distal in lower third molars. Fifty-seven per cent of upper third molars were not assessable on the radiograph, while 96.9% were on MRI. Upper third molars were more difficult to evaluate on radiographs than on MRI (p < .001). Lower third molars were equally assessable on both imaging techniques (93.8% MRI, 98.4% radiograph), with no difference in level of difficulty (p = .375). Inter- and intra-observer agreement for evaluation was higher in MRI than in radiographs. In both imaging techniques lower third molars showed greater inter- and intra-observer agreement compared to upper third molars. MR images in the sagittal plane proved to be essential for staging. In age estimation, 3T MRI of third molars could be valuable. Some considerations are, however, necessary to transfer known staging methods to this 3D technique.

Dental age assessment of adolescents and emerging adults in United Kingdom Caucasians using censored data for stage H of third molar roots.

PubMed

Boonpitaksathit, Teelana; Hunt, Nigel; Roberts, Graham J; Petrie, Aviva; Lucas, Victoria S

2011-10-01

The root of the third permanent molar is the only dental structure that continues development after completion of growth of the second permanent molar. It is claimed that the lack of a clearly defined end point for completion of growth of the third permanent molar means that this tooth cannot be used for dental age assessment. The aim of this study was to estimate the mean age of attainment of the four stages (E, F, G, and H) of root development of the third molar. The way in which the end point of completion of stage H can be identified is described. A total of 1223 dental panoramic tomographs (DPTs) available in the archives of the Eastman Dental Hospital, London, were used for this study. The ages of the subjects ranged from 12.6 to 24.9 years with 63 per cent of the sample being female. Demirjan's tooth development stages (TDSs), for the first and second molars, were applied to the third molars by a single examiner. For each of stages E, F, and G and for stage H censored data, the mean ages of the males and females were compared, separately within each tooth morphology type using the two sample t-test (P < 0.01). The same test was used to compare the mean ages of the upper and lower third molars on each side, separately for each gender. The mean age of attainment and the 99 per cent confidence interval (CI) for each TDS were calculated for each third molar. The final stage H data were appropriately censored to exclude data above the age of completion of root growth. The results showed that, for each gender, the age in years at which individuals attained each of the four TDSs was approximately normally distributed. The mean age for appropriately censored data was always lower than the corresponding mean age of the inappropriately censored data for stage H (male UR8 19.57, UL8 19.53, LL8 19.91, and LR8 20.02 and female UR8 20.08, UL8 20.13, LL8 20.78, and LR8 20.70). This inappropriately censored data overestimated the mean age for stage H. The appropriately censored data for the TDSs of the third molar may be used to estimate the age of adolescents and emerging adults assuming average growth and development and recent attainment of stage H.

Radiologic assessment of third molar tooth and spheno-occipital synchondrosis for age estimation: a multiple regression analysis study.

PubMed

Demirturk Kocasarac, Husniye; Sinanoglu, Alper; Noujeim, Marcel; Helvacioglu Yigit, Dilek; Baydemir, Canan

2016-05-01

For forensic age estimation, radiographic assessment of third molar mineralization is important between 14 and 21 years which coincides with the legal age in most countries. The spheno-occipital synchondrosis (SOS) is an important growth site during development, and its use for age estimation is beneficial when combined with other markers. In this study, we aimed to develop a regression model to estimate and narrow the age range based on the radiologic assessment of third molar and SOS in a Turkish subpopulation. Panoramic radiographs and cone beam CT scans of 349 subjects (182 males, 167 females) with age between 8 and 25 were evaluated. Four-stage system was used to evaluate the fusion degree of SOS, and Demirjian's eight stages of development for calcification for third molars. The Pearson correlation indicated a strong positive relationship between age and third molar calcification for both sexes (r = 0.850 for females, r = 0.839 for males, P < 0.001) and also between age and SOS fusion for females (r = 0.814), but a moderate relationship was found for males (r = 0.599), P < 0.001). Based on the results obtained, an age determination formula using these scores was established.

Evo-devo models of tooth development and the origin of hominoid molar diversity

PubMed Central

Bailey, Shara E.; Schwartz, Gary T.; Skinner, Matthew M.

2018-01-01

The detailed anatomical features that characterize fossil hominin molars figure prominently in the reconstruction of their taxonomy, phylogeny, and paleobiology. Despite the prominence of molar form in human origins research, the underlying developmental mechanisms generating the diversity of tooth crown features remain poorly understood. A model of tooth morphogenesis—the patterning cascade model (PCM)—provides a developmental framework to explore how and why the varying molar morphologies arose throughout human evolution. We generated virtual maps of the inner enamel epithelium—an indelibly preserved record of enamel knot arrangement—in 17 living and fossil hominoid species to investigate whether the PCM explains the expression of all major accessory cusps. We found that most of the variation and evolutionary changes in hominoid molar morphology followed the general developmental rule shared by all mammals, outlined by the PCM. Our results have implications for the accurate interpretation of molar crown configuration in hominoid systematics. PMID:29651459

Correlation between chronological age and third molar developmental stages in an Iranian population (Demirjian method)

PubMed Central

Khosronejad, Aria; Navabi, Manijeh; Sakhdari, Shirin; Rakhshan, Vahid

2017-01-01

Background: Third molar development is the only available tool for estimating the age of individuals after puberty. Since this tooth has very high interethnic variability, formulas calculated to estimate the age from its development stages cannot be generalized to other populations and should be adjusted for each region. Therefore, this study was conducted to evaluate this method in a sample of Tehran individuals for the first time, and also to compare the development of third molars across sexes and arches, and to estimate cutoff developmental stages for legal minor/major identification. Materials and Methods: A total of 150 dental patients aged between 15 and 25 years old were prospectively enrolled, and their Demirjian stages were recorded. The associations between chronological age and Demirjian stages were evaluated. Dental formation was compared between sexes and jaws. Cutoff stages were determined to identify legal minor/major cases (above or below 18 years old). Age estimation formula was found for this population. Results: Of the 150 included patients, 56 were males. The difference between the ages of males and females at each given developmental stage was nonsignificant (P > 0.05), except for the H stage. Age difference between same stage teeth of the maxilla and mandible was nonsignificant. Each of the G and H stages was significantly above 18 years old (P < 0.001). Furthermore, E and F stages were below 18 years old (P < 0.001). All the correlations between Demirjian stages and age were above 90% (all P < 0.001). Third molar development was positively affected by the chronological age (P = 0.000) and being maxillary (P = 0.000) but not sex (P = 0.113). Regression formula for age estimation was: age = 6.52+ (0.64 × sex) + (0.32 × arch) + (1.86 × Demirjian stage). Conclusion: Development of third molar might complete after the age 22. Iranian individuals with third molars at the G and H stages are likely above 18 while those at E and F are likely below 18. Pace of molar development differs for jaws, but intergender differences are open to further investigations. PMID:28584539

Correlation between chronological age and third molar developmental stages in an Iranian population (Demirjian method).

PubMed

Khosronejad, Aria; Navabi, Manijeh; Sakhdari, Shirin; Rakhshan, Vahid

2017-01-01

Third molar development is the only available tool for estimating the age of individuals after puberty. Since this tooth has very high interethnic variability, formulas calculated to estimate the age from its development stages cannot be generalized to other populations and should be adjusted for each region. Therefore, this study was conducted to evaluate this method in a sample of Tehran individuals for the first time, and also to compare the development of third molars across sexes and arches, and to estimate cutoff developmental stages for legal minor/major identification. A total of 150 dental patients aged between 15 and 25 years old were prospectively enrolled, and their Demirjian stages were recorded. The associations between chronological age and Demirjian stages were evaluated. Dental formation was compared between sexes and jaws. Cutoff stages were determined to identify legal minor/major cases (above or below 18 years old). Age estimation formula was found for this population. Of the 150 included patients, 56 were males. The difference between the ages of males and females at each given developmental stage was nonsignificant ( P > 0.05), except for the H stage. Age difference between same stage teeth of the maxilla and mandible was nonsignificant. Each of the G and H stages was significantly above 18 years old ( P < 0.001). Furthermore, E and F stages were below 18 years old ( P < 0.001). All the correlations between Demirjian stages and age were above 90% (all P < 0.001). Third molar development was positively affected by the chronological age ( P = 0.000) and being maxillary ( P = 0.000) but not sex ( P = 0.113). Regression formula for age estimation was: age = 6.52+ (0.64 × sex) + (0.32 × arch) + (1.86 × Demirjian stage). Development of third molar might complete after the age 22. Iranian individuals with third molars at the G and H stages are likely above 18 while those at E and F are likely below 18. Pace of molar development differs for jaws, but intergender differences are open to further investigations.

Associations between Carabelli trait and cusp areas in human permanent maxillary first molars.

PubMed

Kondo, Shintaro; Townsend, Grant C

2006-02-01

Few dental anthropological studies have investigated the associations between tooth crown size and crown traits in humans using quantitative methods. We tested several hypotheses about overall crown size, individual cusp areas, and expression of Carabelli cusps in human permanent first molars by obtaining data from standardized occlusal photographs of 308 Australians of European descent (171 males and 137 females). Specifically, we aimed to calculate the areas of the four main molar cusps, and also Carabelli cusp, and to compare the relative variability of cusp areas in relation to timing of development. We also aimed to compare cusp areas between males and females and to describe how Carabelli cusp interacted with other molar cusps. Measurements included maximum crown diameters (mesiodistal and buccolingual crown diameters), the areas of the four main cusps, and the area of Carabelli cusp. The pattern of relative variability in absolute areas of molar cusps corresponded with their order of formation, the first-forming paracone displaying the least variation, and the last-forming Carabelli cusp showing the greatest. Overall crown size and areas of individual cusps all showed sexual dimorphism, with values in males exceeding those in females. Sexual dimorphism was smallest for paracone area and greatest for Carabelli cusp area. Overall crown size and cusp areas were larger in individuals displaying a Carabelli cusp, especially the hypocone area. Although the combined area of the protocone and a Carabelli cusp was greater in cuspal forms than noncuspal forms, protocone area alone was significantly smaller in the former. Our findings lead us to propose that, in individuals with the genotype for Carabelli trait expression, larger molar crowns are more likely to display Carabelli cusps, whereas molars with smaller crowns are more likely to display reduced forms of expression of the trait. We suggest that the pattern of folding of the internal enamel epithelium in developing molar crowns, particularly in the protocone region, can be modified by a developing Carabelli cusp.

Lineage-Specific Responses of Tooth Shape in Murine Rodents (Murinae, Rodentia) to Late Miocene Dietary Change in the Siwaliks of Pakistan

PubMed Central

Kimura, Yuri; Jacobs, Louis L.; Flynn, Lawrence J.

2013-01-01

Past ecological responses of mammals to climate change are recognized in the fossil record by adaptive significance of morphological variations. To understand the role of dietary behavior on functional adaptations of dental morphology in rodent evolution, we examine evolutionary change of tooth shape in late Miocene Siwalik murine rodents, which experienced a dietary shift toward C4 diets during late Miocene ecological change indicated by carbon isotopic evidence. Geometric morphometric analysis in the outline of upper first molars captures dichotomous lineages of Siwalik murines, in agreement with phylogenetic hypotheses of previous studies (two distinct clades: the Karnimata and Progonomys clades), and indicates lineage-specific functional responses to mechanical properties of their diets. Tooth shapes of the two clades are similar at their sympatric origin but deviate from each other with decreasing overlap through time. Shape change in the Karnimata clade is associated with greater efficiency of propalinal chewing for tough diets than in the Progonomys clade. Larger body mass in Karnimata may be related to exploitation of lower-quality food items, such as grasses, than in smaller-bodied Progonomys. The functional and ecophysiological aspects of Karnimata exploiting C4 grasses are concordant with their isotopic dietary preference relative to Progonomys. Lineage-specific selection was differentially greater in Karnimata, and a faster rate of shape change toward derived Karnimata facilitated inclusion of C4 grasses in the diet. Sympatric speciation in these clades is most plausibly explained by interspecific competition on resource utilization between the two, based on comparisons of our results with the carbon isotope data. Interspecific competition with Karnimata may have suppressed morphological innovation of the Progonomys clade. Pairwise analyses of morphological and carbon isotope data can uncover ecological causes of sympatric speciation and define functional adaptations of teeth to resources. PMID:24155885

Lineage-specific responses of tooth shape in murine rodents (murinae, rodentia) to late Miocene dietary change in the Siwaliks of Pakistan.

PubMed

Kimura, Yuri; Jacobs, Louis L; Flynn, Lawrence J

2013-01-01

Past ecological responses of mammals to climate change are recognized in the fossil record by adaptive significance of morphological variations. To understand the role of dietary behavior on functional adaptations of dental morphology in rodent evolution, we examine evolutionary change of tooth shape in late Miocene Siwalik murine rodents, which experienced a dietary shift toward C4 diets during late Miocene ecological change indicated by carbon isotopic evidence. Geometric morphometric analysis in the outline of upper first molars captures dichotomous lineages of Siwalik murines, in agreement with phylogenetic hypotheses of previous studies (two distinct clades: the Karnimata and Progonomys clades), and indicates lineage-specific functional responses to mechanical properties of their diets. Tooth shapes of the two clades are similar at their sympatric origin but deviate from each other with decreasing overlap through time. Shape change in the Karnimata clade is associated with greater efficiency of propalinal chewing for tough diets than in the Progonomys clade. Larger body mass in Karnimata may be related to exploitation of lower-quality food items, such as grasses, than in smaller-bodied Progonomys. The functional and ecophysiological aspects of Karnimata exploiting C4 grasses are concordant with their isotopic dietary preference relative to Progonomys. Lineage-specific selection was differentially greater in Karnimata, and a faster rate of shape change toward derived Karnimata facilitated inclusion of C4 grasses in the diet. Sympatric speciation in these clades is most plausibly explained by interspecific competition on resource utilization between the two, based on comparisons of our results with the carbon isotope data. Interspecific competition with Karnimata may have suppressed morphological innovation of the Progonomys clade. Pairwise analyses of morphological and carbon isotope data can uncover ecological causes of sympatric speciation and define functional adaptations of teeth to resources.

Ectopic Molar Pregnancy: Diagnostic Efficacy of Magnetic Resonance Imaging and Review of the Literature.

PubMed

Yamada, Yasushi; Ohira, Satoshi; Yamazaki, Teruyuki; Shiozawa, Tanri

2016-01-01

Ectopic molar pregnancy is extremely rare, and preoperative diagnosis is difficult. Our literature search found only one report of molar pregnancy diagnosed preoperatively. Moreover, there is no English literature depicting magnetic resonance image (MRI) findings of ectopic molar pregnancy. We report a case of ectopic molar pregnancy preoperatively diagnosed using MRI. A literature review of 31 cases of ectopic molar pregnancy demonstrated that lesions have been found in the fallopian tube (19 cases, 61%), ovary (5 cases, 16%), cornu (3 cases, 10%), peritoneum (2 cases, 6%), uterine cervix (1 case, 3%), and cesarean scar (1 case, 3%). Abdominal pain and abnormal vaginal bleeding were reported in 70% and 61% of the patients, respectively. Twenty-one cases (67%) presented with rupture and hemoperitoneum. All patients underwent surgical resection or dilatation and curettage. Methotrexate therapy was performed in one case because residual trophoblastic tissue was suspected. A second operation was performed in one case of ovarian molar pregnancy because serum hCG levels increased again after primary focal ovarian resection. No patients developed metastatic disease or relapsed. These findings suggest the prognosis of ectopic molar pregnancy to be favorable.

Wisdom Teeth Management

MedlinePlus

Wisdom Teeth Management Wisdom teeth, or third molars, are the last teeth to develop and appear in your mouth. They come ... of third molars, disease status, and to suggest management options ranging from removal to a monitored retention ...

Improved Murine Blastocyst Quality and Development in a Single Culture Medium Compared to Sequential Culture Media

PubMed Central

Hennings, Justin M.; Zimmer, Randall L.; Nabli, Henda; Davis, J. Wade; Sutovsky, Peter; Sutovsky, Miriam; Sharpe-Timms, Kathy L.

2015-01-01

Objective: Validate single versus sequential culture media for murine embryo development. Design: Prospective laboratory experiment. Setting: Assisted Reproduction Laboratory. Animals: Murine embryos. Interventions: Thawed murine zygotes cultured for 3 or 5 days (d3 or d5) in single or sequential embryo culture media developed for human in vitro fertilization. Main Outcome Measures: On d3, zygotes developing to the 8 cell (8C) stage or greater were quantified using 4’,6-diamidino-2-phenylindole (DAPI), and quality was assessed by morphological analysis. On d5, the number of embryos reaching the blastocyst stage was counted. DAPI was used to quantify total nuclei and inner cell mass nuclei. Localization of ubiquitin C-terminal hydrolase L1 (UCHL1) and ubiquitin C-terminal hydrolase L3 (UCHL3) was reference points for evaluating cell quality. Results: Comparing outcomes in single versus to sequential media, the odds of embryos developing to the 8C stage on d3 were 2.34 time greater (P = .06). On d5, more embryos reached the blastocyst stage (P = <.0001), hatched, and had significantly more trophoblast cells (P = .005) contributing to the increased total cell number. Also at d5, localization of distinct cytoplasmic UCHL1 and nuclear UCHL3 was found in high-quality hatching blastocysts. Localization of UCHL1 and UCHL3 was diffuse and inappropriately dispersed throughout the cytoplasm in low-quality nonhatching blastocysts. Conclusions: Single medium yields greater cell numbers, an increased growth rate, and more hatching of murine embryos. Cytoplasmic UCHL1 and nuclear UHCL3 localization patterns were indicative of embryo quality. Our conclusions are limited to murine embryos but one might speculate that single medium may also be more beneficial for human embryo culture. Human embryo studies are needed. PMID:26668049

Improved Murine Blastocyst Quality and Development in a Single Culture Medium Compared to Sequential Culture Media.

PubMed

Hennings, Justin M; Zimmer, Randall L; Nabli, Henda; Davis, J Wade; Sutovsky, Peter; Sutovsky, Miriam; Sharpe-Timms, Kathy L

2016-03-01

Validate single versus sequential culture media for murine embryo development. Prospective laboratory experiment. Assisted Reproduction Laboratory. Murine embryos. Thawed murine zygotes cultured for 3 or 5 days (d3 or d5) in single or sequential embryo culture media developed for human in vitro fertilization. On d3, zygotes developing to the 8 cell (8C) stage or greater were quantified using 4',6-diamidino-2-phenylindole (DAPI), and quality was assessed by morphological analysis. On d5, the number of embryos reaching the blastocyst stage was counted. DAPI was used to quantify total nuclei and inner cell mass nuclei. Localization of ubiquitin C-terminal hydrolase L1 (UCHL1) and ubiquitin C-terminal hydrolase L3 (UCHL3) was reference points for evaluating cell quality. Comparing outcomes in single versus to sequential media, the odds of embryos developing to the 8C stage on d3 were 2.34 time greater (P = .06). On d5, more embryos reached the blastocyst stage (P = <.0001), hatched, and had significantly more trophoblast cells (P = .005) contributing to the increased total cell number. Also at d5, localization of distinct cytoplasmic UCHL1 and nuclear UCHL3 was found in high-quality hatching blastocysts. Localization of UCHL1 and UCHL3 was diffuse and inappropriately dispersed throughout the cytoplasm in low-quality nonhatching blastocysts. Single medium yields greater cell numbers, an increased growth rate, and more hatching of murine embryos. Cytoplasmic UCHL1 and nuclear UHCL3 localization patterns were indicative of embryo quality. Our conclusions are limited to murine embryos but one might speculate that single medium may also be more beneficial for human embryo culture. Human embryo studies are needed. © The Author(s) 2015.

Summaries of Research, Fiscal Year 1990

DTIC Science & Technology

1991-04-01

identification of third molars at risk to develop pcricoronitis. Data on 324 patients were collected relating to complications associated to the...extraction of third molars . A report was submitted to the Chief, Navy Dental Corps on 31 March 1990 following preliminary data analysis. An abstract has been...Cohen, M. E., Arthur, J. S. and Rodden, J. W. Patients’ Retrospective Preference for Extraction of Asymptomatic Third Molars . Community Dentistry and

Dental Stigmata of Congenital Syphilis: A Historic Review With Present Day Relevance.

PubMed

Nissanka-Jayasuriya, Eranga H; Odell, Edward W; Phillips, Carina

2016-09-01

Syphilis was the first sexually transmitted disease to be diagnosed in childhood. Most developed countries controlled syphilis effectively after the 1950s and congenital syphilis became rare. Since the late 1990s there has been a resurgence of syphilis in developed and developing countries and the WHO estimates that at least half a million infants die of congenital syphilis every year. The earliest reference to the dental manifestations of congenital syphilis was by Sir Jonathan Hutchinson, Assistant Surgeon at The London Hospital in 1861. Three main dental defects are described in congenital syphilis; Hutchinson's incisors, Moon's molars or bud molars, and Fournier's molars or mulberry molars. Although many physicians, dentists, and pathologists in developed countries will be aware of the dental features of syphilis, most will never have seen a case or made the diagnosis. The purpose of this article is to review some of the history of congenital syphilis, remind healthcare professionals of the features, and bring to their attention that the changes are still prevalent and that milder cases can be mistaken for other causes of hypoplasia.

Distalization of Maxillary First Permanent Molar by Pendulum Appliance in Mixed Dentition Period.

PubMed

Paranna, Sujatha; Shetty, Prakashchandra; Anandakrishna, Latha; Rawat, Anuradha

2017-01-01

Mesial drifting of molar teeth in maxillary arch is corrected by movement of the molars distally. In addition to traditional distal movement techniques, such as extraoral force application and removable appliances, various intra-arch devices have been introduced since 1980s. These intra-arch appliances have nearly eliminated the need for patient cooperation. The purpose of this paper is to report a case of 10-year-old male patient with loss of space in maxillary molar teeth treated by intra-arch appliance-pendulum appliance by distalization of maxillary first permanent molar teeth. Distaliza-tion of the permanent molar teeth helped in proper eruption of second premolar teeth without any extensive treatment procedures. In the present case report, the treatment of developing malocclusion was corrected by utilizing the concept of interceptive orthodontics. Hence, correction of space loss in mixed dentition period using pendulum appliance can eliminate the fixed orthodontic therapy. Paranna S, Shetty P, Anandakrishna L, Rawat A. Distalization of Maxillary First Permanent Molar by Pendulum Appliance in Mixed Dentition Period. Int J Clin Pediatr Dent 2017;10(3):299-301.

Effect of ultrasonic treatment on immunological activities of polysaccharides from adlay.

PubMed

Yao, Yang; Zhu, Yingying; Gao, Yue; Ren, Guixing

2015-09-01

Alkali-extractable polysaccharides from the seed of adlay and their two polysaccharide sub-fractions (AAP-1 and AAP-2) were isolated and purified by anion-exchange and gel filtration chromatography. Ultrasonic treatment was put in place to obtain AAP-1' and AAP-2'. Average molecular weights (Mws) of AAP-1, AAP-1', AAP-2, and AAP-2' were 94.2 kDa, 63.1 kDa, 82.3 kDa, and 60.4 kDa, respectively. Monosaccharides composition analysis indicated that AAP-1 and AAP-1' were composed of Rha, Ara, Glc, and Gal in a molar ratio of 1.1:0.4:0.7:0.5 and 1.4:1.6:0.4:0.7. AAP-2 and AAP-2' were composed of Xyl, Rha, Gal and Glc in a molar percent of 0.4:1.4:1.6:0.5 and 0.3:1.6:1.1:0.7. In vitro study showed that AAP-1, AAP-1', AAP-2, and AAP-2' were all able to encourage the production of secretory molecules (NO, TNF-α and IL-6) of RAW264.7 murine macrophages in concentrations determines manner. AAP-2' seemed to be the most potent and induced significantly higher the NO production. These findings suggest that the ultrasonic polysaccharides isolated in our study have immune potentiation effects on macrophages and should serve as a beneficial health food. Copyright © 2015 Elsevier B.V. All rights reserved.

Tooth Morphogenesis and FGF4 Expression During Development of Molar Tooth in Three Muroid Rodents: Calomyscus elburzensis (Calomyscidae), Mesocricetus auratus (Cricetidae) and Mus musculus (Muridae).

PubMed

Hamidi, Kordiyeh; Darvish, Jamshid; Matin, Maryam M; Javanmard, Athar Sadat; Kilpatrick, C William

2017-12-01

To date, no studies have examined the tooth formation during developmental stages of brush-tailed mice (Calomyscidae) and true hamsters (Cricetidae). Herein, we compared the timing of tooth morphogenesis and FGF4 expression pattern during development of the first lower molar in Goodwin's brush-tailed mouse, Calomyscus elburzensis with two other muroid rodents; the house mouse, Mus musculus (Muridae), model organism for tooth morphogenesis, and the golden hamster, Mesocricetus auratus which shares great similarities in cusp pattern with brush-tailed mice. All three species were bred in captivity and developing embryos were isolated at different embryonic days (E). Histological evaluation of lower molars was performed and spatiotemporal pattern of FGF4 expression was determined by immunohistochemistry. Results indicated that morphogenesis of the tooth cusps starts at the beginning of the cap stage of the first lower molar (E14 in house mouse, about E11.5 in golden hamster and E22 in Goodwin's brush-tailed mouse). During the cap to bell stage (E15 in house mouse, E12 in golden hamster and at about E24 in Goodwin's brush-tailed mouse), a decrease in the expression of FGF4 was observed in the mesenchyme, except for the cusp tips. According to our observations, the developmental process of the first lower molar formation in Goodwin's brush-tailed mouse began much later as compared with the other two species. Despite the differences in the temporal pattern of molar development between these three members of the same superfamily (Muroidea), the correlation in the expression of FGF4 with specific stages of tooth morphogenesis supported its regulatory function. Anat Rec, 300:2138-2149, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Digital radiographic evaluation of mandibular third molar for age estimation in young adults and adolescents of South Indian population using modified Demirjian's method

PubMed Central

Mohammed, Rezwana Begum; Koganti, Ravichandra; Kalyan, Siva V.; Tircouveluri, Saritha; Singh, Johar Rajvinder; Srinivasulu, Enganti

2014-01-01

In recent years, it has become increasingly important to determine the age of living people for a variety of reasons, including identifying criminal and legal responsibility and for many other social events such as birth certificate, marriage, beginning a job, joining the army and retirement Objectives: The aim of this study was to assess the developmental stages of mandibular third molar for estimation of dental age (DA) in different age groups and to evaluate the possible correlation between DA and chronological age (CA) in South Indian population. Materials and Methods: Digital orthopantomography of 330 subjects (165 males, 165 females) who fit the study and the criteria were obtained. Assessment of mandibular third molar development was performed using Demirjian et al., modified method and DA was assessed using tooth specific stages. Results and Discussion: The present study showed a significant correlation between DA and CA in both males and females. Third molar development commenced around 9 years and root completion takes place around 18.9 years in males and in females 9 years and 18.6 years respectively. Demirjian modified method underestimated the mean age of males by 0.8 years and females by 0.5 years and also showed that females mature earlier than males in selected population. Conclusion: Digital radiographic assessment of mandibular third molar development can be used to generate mean DA using Demirjian modified method and also the estimated age range for an individual of unknown CA. Since the Demirjian method is based on French-Canadian population, to enhance the accuracy of forensic age estimates based on third molar development, the use of population-specific standards is recommended. PMID:25177143

Digital radiographic evaluation of mandibular third molar for age estimation in young adults and adolescents of South Indian population using modified Demirjian's method.

PubMed

Mohammed, Rezwana Begum; Koganti, Ravichandra; Kalyan, Siva V; Tircouveluri, Saritha; Singh, Johar Rajvinder; Srinivasulu, Enganti

2014-09-01

In recent years, it has become increasingly important to determine the age of living people for a variety of reasons, including identifying criminal and legal responsibility and for many other social events such as birth certificate, marriage, beginning a job, joining the army and retirement. The aim of this study was to assess the developmental stages of mandibular third molar for estimation of dental age (DA) in different age groups and to evaluate the possible correlation between DA and chronological age (CA) in South Indian population. Digital orthopantomography of 330 subjects (165 males, 165 females) who fit the study and the criteria were obtained. Assessment of mandibular third molar development was performed using Demirjian et al., modified method and DA was assessed using tooth specific stages. The present study showed a significant correlation between DA and CA in both males and females. Third molar development commenced around 9 years and root completion takes place around 18.9 years in males and in females 9 years and 18.6 years respectively. Demirjian modified method underestimated the mean age of males by 0.8 years and females by 0.5 years and also showed that females mature earlier than males in selected population. Digital radiographic assessment of mandibular third molar development can be used to generate mean DA using Demirjian modified method and also the estimated age range for an individual of unknown CA. Since the Demirjian method is based on French-Canadian population, to enhance the accuracy of forensic age estimates based on third molar development, the use of population-specific standards is recommended.

Preparation, characterization and in vitro evaluation of a new nucleotide analogue prodrug cyclodextrin inclusion complexes.

PubMed

Diab, Roudayna; Jordheim, Lars P; Degobert, Ghania; Peyrottes, Suzanne; Périgaud, Christian; Dumontet, Charles; Fessi, Hatem

2009-01-01

Bis(tbutyl-S-acyl-2-thioethyl)-cytidine monophosophate is a new cytotoxic mononucleotide prodrug which have been developed to reverse the cellular resistance to nucleoside analogues. Unfortunately, its in vivo utilisation was hampered by its poor water solubility, raising the need of a molecular vector capable to mask its physicochemical characteristics although without affecting its cytotoxic activity. Hydroxypropyl-beta-cyclodextrin was used to prepare the prodrug inclusion complexes, allowing it to be solubilized in water and hence to be used for in vitro and in vivo experiments. A molar ratio of the cyclodextrin: prodrug of 3 was sufficient to obtain complete solubilization of the prodrug. The inclusion complex was characterized by differential scanning calorimetry, which revealed the disappearance of the melting peak of the prodrug suggesting the formation of inclusion complex. Proton Nuclear Magnetic Resonance spectroscopy provided a definitive proof of the inclusion complex formation, which was evidenced by the large chemical shift displacements observed for protons located in the interior of the hydrophobic cyclodextrin cavity. The complex retained its cytotoxic activity as shown by in vitro cell survival assays on murine leukemia cells. These results provided a basis for potential therapeutic applications of co-formulation of this new nucleotide analogue with hydroxypropyl-beta-CD in cancer therapy.

CD8+ T Cells Contribute to the Development of Coronary Arteritis in the Lactobacillus casei Cell Wall Extract-Induced Murine Model of Kawasaki Disease.

PubMed

Noval Rivas, Magali; Lee, Youngho; Wakita, Daiko; Chiba, Norika; Dagvadorj, Jargalsaikhan; Shimada, Kenichi; Chen, Shuang; Fishbein, Michael C; Lehman, Thomas J A; Crother, Timothy R; Arditi, Moshe

2017-02-01

Kawasaki disease (KD) is the leading cause of acquired heart disease among children in developed countries. Coronary lesions in KD in humans are characterized by an increased presence of infiltrating CD3+ T cells; however, the specific contributions of the different T cell subpopulations in coronary arteritis development remain unknown. Therefore, we sought to investigate the function of CD4+ and CD8+ T cells, Treg cells, and natural killer (NK) T cells in the pathogenesis of KD. We addressed the function of T cell subsets in KD development by using a well-established murine model of Lactobacillus casei cell wall extract (LCWE)-induced KD vasculitis. We determined which T cell subsets were required for development of KD vasculitis by using several knockout murine strains and depleting monoclonal antibodies. LCWE-injected mice developed coronary lesions characterized by the presence of inflammatory cell infiltrates. Frequently, this chronic inflammation resulted in complete occlusion of the coronary arteries due to luminal myofibroblast proliferation (LMP) as well as the development of coronary arteritis and aortitis. We found that CD8+ T cells, but not CD4+ T cells, NK T cells, or Treg cells, were required for development of KD vasculitis. The LCWE-induced murine model of KD vasculitis mimics many histologic features of the disease in humans, such as the presence of CD8+ T cells and LMP in coronary artery lesions as well as epicardial coronary arteritis. Moreover, CD8+ T cells functionally contribute to the development of KD vasculitis in this murine model. Therapeutic strategies targeting infiltrating CD8+ T cells might be useful in the management of KD in humans. © 2016, American College of Rheumatology.

[The design of removable appliances for tooth movement and tooth migration].

PubMed

Voss, H

1989-06-01

Removable/functional appliance therapy can still be further expanded and developed. Retentive elements in the anterior region increase anchorage. Thereby, active forces can be utilised without anchorage loss. Functional appliances are indicated following extraction, to maximise on tooth migration. In first molar extraction cases, treatment with activators is relatively straightforward. When considering premolar extraction cases with possible need for extraction later of the third molars as well, then one should consider extraction of the first permanent molars. With correct use of the appliance, it is possible to optimally align the second molar teeth as well as favourably influencing the soft tissue profile.

Continuous production of lipase-catalyzed biodiesel in a packed-bed reactor: optimization and enzyme reuse study.

PubMed

Chen, Hsiao-Ching; Ju, Hen-Yi; Wu, Tsung-Ta; Liu, Yung-Chuan; Lee, Chih-Chen; Chang, Cheng; Chung, Yi-Lin; Shieh, Chwen-Jen

2011-01-01

An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in a tert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature have significant effects on the percentage of molar conversion. On the basis of ridge max analysis, the optimum conditions were as follows: flow rate 0.1 mL/min, temperature 52.1°C, and substrate molar ratio 1 : 4. The predicted and experimental values of molar conversion were 83.31 ± 2.07% and 82.81 ± .98%, respectively. Furthermore, the continuous process over 30 days showed no appreciable decrease in the molar conversion. The paper demonstrates the applicability of using immobilized lipase and a packed-bed reactor for continuous biodiesel synthesis.

Temperature gradient interaction chromatography of polymers: A molecular statistical model.

PubMed

Radke, Wolfgang; Lee, Sekyung; Chang, Taihyun

2010-11-01

A new model describing the retention in temperature gradient interaction chromatography of polymers is developed. The model predicts that polymers might elute in temperature gradient interaction chromatography in either an increasing or decreasing order or even nearly independent of molar mass, depending on the rate of the temperature increase relative to the flow rate. This is in contrast to solvent gradient elution, where polymers elute either in order of increasing molar mass or molar mass independent. The predictions of the newly developed model were verified with the literature data as well as new experimental data. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Four osteotomy methods with piezosurgery to remove complicated mandibular third molars: a retrospective study.

PubMed

Ge, Jing; Yang, Chi; Zheng, Jia-Wei; He, Dong-Mei; Zheng, Ling-Yan; Hu, Ying-Kai

2014-11-01

Piezosurgery has been used widely in oral and maxillofacial surgery, but there has been no report systematically describing an osteotomy method with piezosurgery for complicated mandibular third molar removal. The aim of this study was to introduce 4 osteotomy methods using piezosurgery and evaluate their effects. A retrospective study was conducted of patients with a complicated impacted mandibular third molar requiring extraction. The predictor variable was the extraction technique. Four osteotomy methods using piezosurgery were tested according to different impaction types: method 1 involved complete bone removal; method 2 involved segmental bone removal; method 3 involved bone removal combined with tooth splitting; and method 4 involved block bone removal. Outcome variables were success rate, operative time, major complications (including nerve injury, mandible fracture, severe hematoma, or severe edema), and serious pyogenic infection. Data were analyzed using descriptive statistics. The study was composed of 55 patients with 74 complicated impacted mandibular third molars. All impacted mandibular third molars were removed successfully. The average surgical time was 15 minutes (range, 8 to 26 minutes). Thirty-eight molars (51.4%) were extracted by method 1, 18 molars (24.3%) by method 2, 12 molars (16.2%) by method 3, and 6 molars (8.1%) by method 4. Two cases (2.7%) developed postoperative infections and recovered within 1 week using drainage and antibiotic administration. The 4 osteotomy methods with piezosurgery provide effective ways of removing complicated impacted mandibular third molars. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Influence of orthodontic treatment with first premolar extraction on the angulation of the mandibular third molar.

PubMed

Al Kuwari, Huda M; Talakey, Arwa A; Al-Sahli, Reem M; Albadr, Anisa H

2013-06-01

To evaluate the influence of orthodontic treatment that involved first premolars extraction on the angulation of the developing mandibular third molars, and whether this will result in an improvement in it's path of eruption during tooth development. A cross-sectional radiographic study was conducted using 80 panoramic radiographs of 40 orthodontic patients previously treated at the College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia. The sample consisted of 2 groups, extraction and non-extraction orthodontic therapy group with equal number of patients in each group. The orthodontic treatment of the extraction group involved the extraction of first premolars, whilst non-extraction group had received orthodontic therapy without teeth extraction. The angulation of the right and left third mandibular molars was measured in each patient separately, and the data was analyzed using the non-parametric Mann-Whitney Test. The present data has shown significant improvement in the third molars angulation in the extraction orthodontic therapy group compared to non-extraction group, Although this finding was significant in both genders, females tend to show better response in the improvement of third molar angulation to extraction therapy than males (p=0.001, p=0.006). Orthodontic treatment with first premolars extraction has improved the third molars angulation during their course of eruptions and consequently supports the decision of the orthodontic extraction therapy approach in borderline cases.

The Effect of Sodium Hydroxide Molarity on Strength Development of Non-Cement Class C Fly Ash Geopolymer Mortar

NASA Astrophysics Data System (ADS)

Wardhono, A.

2018-01-01

The use of fly ash as cement replacement material can overcome the environmental issues, especially the global warming problem caused by the greenhouse effect. This is attributed to the CO2 gas produced during the cement manufacturing process, which 1 ton of cement is equivalent to 1 ton CO2. However, the major problem of fly ash is the requirement of activators to activate the polymer reactions. The most common activator used in non-cement or geopolymer material is the combination of sodium hydroxide (NaOH) and sodium silicate. This study aims to identify the effect of NaOH molarity as activator on strength development of non-cement class C fly ash geopolymer mortar. The molarity variations of NaOH were 6 Molar (M), 8M, 10M, 12M, 14M and 15M. The compressive strength test was performed at the age of 3, 7 and 28 days in accordance with ASTM standard, and the specimens were cured at room temperature. The results show that the highest compressive strength was achieved by geopolymer mortar with a molarity of 12M. It exhibits a higher strength to that normal mortar at 28 days. However, the use of NaOH molarity more than 12M tends to decrease the strength of non-cement geopolymer mortar specimens.

Distalization of Maxillary First Permanent Molar by Pendulum Appliance in Mixed Dentition Period

PubMed Central

Shetty, Prakashchandra; Anandakrishna, Latha; Rawat, Anuradha

2017-01-01

Introduction Mesial drifting of molar teeth in maxillary arch is corrected by movement of the molars distally. In addition to traditional distal movement techniques, such as extraoral force application and removable appliances, various intra-arch devices have been introduced since 1980s. These intra-arch appliances have nearly eliminated the need for patient cooperation. Case report The purpose of this paper is to report a case of 10-year-old male patient with loss of space in maxillary molar teeth treated by intra-arch appliance-pendulum appliance by distalization of maxillary first permanent molar teeth. Distaliza-tion of the permanent molar teeth helped in proper eruption of second premolar teeth without any extensive treatment procedures. Conclusion In the present case report, the treatment of developing malocclusion was corrected by utilizing the concept of interceptive orthodontics. Hence, correction of space loss in mixed dentition period using pendulum appliance can eliminate the fixed orthodontic therapy. How to cite this article Paranna S, Shetty P, Anandakrishna L, Rawat A. Distalization of Maxillary First Permanent Molar by Pendulum Appliance in Mixed Dentition Period. Int J Clin Pediatr Dent 2017;10(3):299-301. PMID:29104393

A Structural Molar Volume Model for Oxide Melts Part I: Li2O-Na2O-K2O-MgO-CaO-MnO-PbO-Al2O3-SiO2 Melts—Binary Systems

NASA Astrophysics Data System (ADS)

Thibodeau, Eric; Gheribi, Aimen E.; Jung, In-Ho

2016-04-01

A structural molar volume model was developed to accurately reproduce the molar volume of molten oxides. As the non-linearity of molar volume is related to the change in structure of molten oxides, the silicate tetrahedral Q-species, calculated from the modified quasichemical model with an optimized thermodynamic database, were used as basic structural units in the present model. Experimental molar volume data for unary and binary melts in the Li2O-Na2O-K2O-MgO-CaO-MnO-PbO-Al2O3-SiO2 system were critically evaluated. The molar volumes of unary oxide components and binary Q-species, which are model parameters of the present structural model, were determined to accurately reproduce the experimental data across the entire binary composition in a wide range of temperatures. The non-linear behavior of molar volume and thermal expansivity of binary melt depending on SiO2 content are well reproduced by the present model.

A radiographic survey of agenesis of the third molar: A panoramic study.

PubMed

Singh, Nisha; Chaudhari, Shrinivas; Chaudhari, Rohan; Nagare, Sagar; Kulkarni, Abhay; Parkarwar, Pratik

2017-01-01

It is a well-known fact that nature tries to eliminate what is not in use. Because of this, the number of certain teeth which are no longer necessary for function are either getting increasingly impacted or are not developing at all. This is especially the case where third molars are concerned. Furthermore, the presence or absence of the third molar is significant to all branches of dentistry and in particular, forensic dentistry. The objectives of this study is to assess (1) The prevalence of third molar agenesis in population of age group 18-25 years. (2) The genderwise difference of third molar agenesis. (3) The difference between maxilla and mandible. Dental patients, who are advised or referred for orthopantomograph, visited to the Department of Oral Medicine and Radiology were included in the study. The study population comprised 300 patients. The data obtained was tabulated and subjected to statistical analysis. SPSS version 17 software was used for the analysis of the data. The Chi-square test was used for the same. The incidence of agenesis of the third molar is significantly higher for tooth number 18 ( P < 0.001). Overall, it is significantly higher among females compared to the males ( P < 0.001) in our study population. (1) The present study reports 46.7% agenesis of the third molar. (2) The frequency of third molar agenesis was found significantly greater in the females. (3) Third molar agenesis showed a greater predilection in maxilla compared to mandible.

Novel human mutation and CRISPR/Cas genome-edited mice reveal the importance of C-terminal domain of MSX1 in tooth and palate development

PubMed Central

Mitsui, Silvia Naomi; Yasue, Akihiro; Masuda, Kiyoshi; Naruto, Takuya; Minegishi, Yoshiyuki; Oyadomari, Seiichi; Noji, Sumihare; Imoto, Issei; Tanaka, Eiji

2016-01-01

Several mutations, located mainly in the MSX1 homeodomain, have been identified in non-syndromic tooth agenesis predominantly affecting premolars and third molars. We identified a novel frameshift mutation of the highly conserved C-terminal domain of MSX1, known as Msx homology domain 6 (MH6), in a Japanese family with non-syndromic tooth agenesis. To investigate the importance of MH6 in tooth development, Msx1 was targeted in mice with CRISPR/Cas system. Although heterozygous MH6 disruption did not alter craniofacial development, homozygous mice exhibited agenesis of lower incisors with or without cleft palate at E16.5. In addition, agenesis of the upper third molars and the lower second and third molars were observed in 4-week-old mutant mice. Although the upper second molars were present, they were abnormally small. These results suggest that the C-terminal domain of MSX1 is important for tooth and palate development, and demonstrate that that CRISPR/Cas system can be used as a tool to assess causality of human disorders in vivo and to study the importance of conserved domains in genes. PMID:27917906

Novel human mutation and CRISPR/Cas genome-edited mice reveal the importance of C-terminal domain of MSX1 in tooth and palate development.

PubMed

Mitsui, Silvia Naomi; Yasue, Akihiro; Masuda, Kiyoshi; Naruto, Takuya; Minegishi, Yoshiyuki; Oyadomari, Seiichi; Noji, Sumihare; Imoto, Issei; Tanaka, Eiji

2016-12-05

Several mutations, located mainly in the MSX1 homeodomain, have been identified in non-syndromic tooth agenesis predominantly affecting premolars and third molars. We identified a novel frameshift mutation of the highly conserved C-terminal domain of MSX1, known as Msx homology domain 6 (MH6), in a Japanese family with non-syndromic tooth agenesis. To investigate the importance of MH6 in tooth development, Msx1 was targeted in mice with CRISPR/Cas system. Although heterozygous MH6 disruption did not alter craniofacial development, homozygous mice exhibited agenesis of lower incisors with or without cleft palate at E16.5. In addition, agenesis of the upper third molars and the lower second and third molars were observed in 4-week-old mutant mice. Although the upper second molars were present, they were abnormally small. These results suggest that the C-terminal domain of MSX1 is important for tooth and palate development, and demonstrate that that CRISPR/Cas system can be used as a tool to assess causality of human disorders in vivo and to study the importance of conserved domains in genes.

Magnetic resonance imaging of third molars: developing a protocol suitable for forensic age estimation.

PubMed

De Tobel, Jannick; Hillewig, Elke; Bogaert, Stephanie; Deblaere, Karel; Verstraete, Koenraad

2017-03-01

Established dental age estimation methods in sub-adults study the development of third molar root apices on radiographs. In living individuals, however, avoiding ionising radiation is expedient. Studying dental development with magnetic resonance imaging complies with this requirement, adding the advantage of imaging in three dimensions. To elaborate the development of an MRI protocol to visualise all third molars for forensic age estimation, with particular attention to the development of the root apex. Ex vivo scans of porcine jaws and in vivo scans of 10 volunteers aged 17-25 years were performed to select adequate sequences. Studied parameters were T1 vs T2 weighting, ultrashort echo time (UTE), fat suppression, in plane resolution, slice thickness, 3D imaging, signal-to-noise ratio, and acquisition time. A bilateral four-channel flexible surface coil was used. Two observers evaluated the suitability of the images. T2-weighted images were preferred to T1-weighted images. To clearly distinguish root apices in (almost) fully developed third molars an in plane resolution of 0.33 × 0.33 mm 2 was deemed necessary. Taking acquisition time limits into account, only a T2 FSE sequence with slice thickness of 2 mm generated images with sufficient resolution and contrast. UTE, thinner slice T2 FSE and T2 3D FSE sequences could not generate the desired resolution within 6.5 minutes. Three Tesla MRI of the third molars is a feasible technique for forensic age estimation, in which a T2 FSE sequence can provide the desired in plane resolution within a clinically acceptable acquisition time.

Current Translational Research and Murine Models For Duchenne Muscular Dystrophy

PubMed Central

Rodrigues, Merryl; Echigoya, Yusuke; Fukada, So-ichiro; Yokota, Toshifumi

2016-01-01

Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder characterized by progressive muscle degeneration. Mutations in the DMD gene result in the absence of dystrophin, a protein required for muscle strength and stability. Currently, there is no cure for DMD. Since murine models are relatively easy to genetically manipulate, cost effective, and easily reproducible due to their short generation time, they have helped to elucidate the pathobiology of dystrophin deficiency and to assess therapies for treating DMD. Recently, several murine models have been developed by our group and others to be more representative of the human DMD mutation types and phenotypes. For instance, mdx mice on a DBA/2 genetic background, developed by Fukada et al., have lower regenerative capacity and exhibit very severe phenotype. Cmah-deficient mdx mice display an accelerated disease onset and severe cardiac phenotype due to differences in glycosylation between humans and mice. Other novel murine models include mdx52, which harbors a deletion mutation in exon 52, a hot spot region in humans, and dystrophin/utrophin double-deficient (dko), which displays a severe dystrophic phenotype due the absence of utrophin, a dystrophin homolog. This paper reviews the pathological manifestations and recent therapeutic developments in murine models of DMD such as standard mdx (C57BL/10), mdx on C57BL/6 background (C57BL/6-mdx), mdx52, dystrophin/utrophin double-deficient (dko), mdxβgeo, Dmd-null, humanized DMD (hDMD), mdx on DBA/2 background (DBA/2-mdx), Cmah-mdx, and mdx/mTRKO murine models. PMID:27854202

Localization of type IV collagen a 1 to a 6 chains in basement membrane during mouse molar germ development.

PubMed

Nagai, N; Nakano, K; Sado, Y; Naito, I; Gunduz, M; Tsujigiwa, H; Nagatsuka, H; Ninomiya, Y; Siar, C H

2001-10-01

The dental basement membrane (BM) putatively mediates epithelial-mesenchymal interactions during tooth morphogenesis and cytodifferentiation. Type IV collagen alpha chains, a major network-forming protein of the dental BM, was studied and results disclosed distinct expression patterns at different stages of mouse molar germ development. At the dental placode and bud stage, the BM of the oral epithelium expressed alpha 1, alpha 2, alpha 5 and alpha 6 chains while the gubernaculum dentis, in addition to the above four chains, also expressed a 4 chain. An asymmetrical expression for alpha 4, alpha 5 and alpha 6 chains was observed at the bud stage. At the early bell stage, the BM associated with the inner enamel epithelium (IEE) of molar germ expressed alpha 1, alpha 2 and alpha 4 chains while the BM of the outer enamel epithelium (OEE) expressed only alpha 1 and a 2 chains. With the onset of dentinogenesis, the collagen a chain profile of the IEE BM gradually disappeared. Howeverfrom the early to late bell stage, the gubernaculum dentis consistently expressed alpha 1, alpha 2, alpha 5 and a 6 chains resembling fetal oral mucosa. These findings suggest that stage- and position-specific distribution of type IV collagen alpha subunits occur during molar germ development and that these changes are essential for molar morphogenesis and cytodifferentiation.

Occurrence of cervical invasive root resorption in first and second molar teeth of orthodontic patients eight years after bracket removal.

PubMed

Thönen, Andrea; Peltomäki, Timo; Patcas, Raphael; Zehnder, Matthias

2013-01-01

The occurrence and potential orthodontic causes of cervical invasive root resorption (CIRR) are unknown. We aimed to identify the occurrence of CIRR in molar teeth of orthodontic patients treated with fixed appliances. All patients invited for final orthodontic recall between November 2009 and March 2011 were included. From 175 patients, 108 (46 men/62 women; mean age, 25 ± 5 years; mean time after bracket removal, 8 ± 2 years) were available. The first and second molar teeth (N = 858) of these patients were investigated for clinical and radiographic signs of CIRR. Patients identified with such signs were asked to have limited-volume cone-beam computed tomography scans performed. No clinical signs of CIRR were detected. CIRR could not be ruled out on bite-wing radiographs in 18 patients. CIRR was thus identified in 1 patient in whom a second maxillary molar was affected. All first molars had been extracted in this patient, and the second molars had been moved mesially over a long distance. The 3 other second molars showed surface resorption. CIRR in molar teeth of orthodontic patients have a low mid-term occurrence (0.9%; 95% confidence interval, 0.2%-5.2%). Long movement distances and/or long treatment duration may be related to the development of these lesions. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Does grafting of third molar extraction sockets enhance periodontal measures in 30- to 35-year-old patients?

PubMed

Hassan, Khalid S; Marei, Hesham F; Alagl, Adel S

2012-04-01

This study was designed to evaluate the use of xenograft plus a membrane as grafting material for periodontal osseous defects distal to the mandibular second molar compared with nongrafted extraction sites after removal of impacted mandibular third molars. We performed a single-blind, randomized, controlled clinical trial, and the sample comprised of subjects at high risk for the development of periodontal osseous defects distal to the second molar after third molar extraction (aged 30-35 years), pre-existing osseous defects distal to the second molar, and horizontal third molar impaction. The predictor variable was the treatment status of the second molar osseous defects. The third molar extraction sites were grafted with an anorganic xenograft plus a membrane. The other sites received a full-thickness flap and extraction of the third molar without placement of the grafting materials. The outcome variables were the change in gingival index, pocket probing depth, and clinical attachment level on the distobuccal aspect of the second molar preoperatively and at 3, 6, 9, and 12 months after surgery. Data were statistically analyzed by multivariate analysis of variance, and the statistical significance was set at P < .05. The study was composed of 28 sites that were selected by use of a split-mouth design for each patient, and this was randomly determined through a biased coin randomization. Twelve months after third molar removal, there was a statistically significant gain in the clinical attachment level and a reduction in the probing pocket depth in the grafted sites compared with the nongrafted sites (P < .001). Moreover, there was a significant difference in the alveolar bone height during the monitoring periods for the grafted sites compared with the nongrafted sites (P < .001). Grafting of osseous defects distal to mandibular second molars with an anorganic xenograft plus a membrane predictably resulted in a significant reduction in the probing pocket depth, clinical attachment level gain, and bone fill, which suggests that grafting the extraction sites with an anorganic xenograft plus a membrane could prevent periodontal disease in the future. Published by Elsevier Inc.

Incisor and molar overjet, arch contraction, and molar relationship in the mixed dentition in repaired complete unilateral cleft lip and palate: A qualitative and quantitative appraisal.

PubMed

Disthaporn, Suteeta; Suri, Sunjay; Ross, Bruce; Tompson, Bryan; Baena, Diogenes; Fisher, David; Lou, Wendy

2017-07-01

To compare the mixed dentition incisor and molar overjet, severity of contraction of the dental arch, and the sagittal molar relationship on the cleft side vs the noncleft side in children with repaired complete unilateral cleft of the lip and palate (UCLP). Orthodontic records taken prior to orthodontic preparation for alveolar bone grafting were screened to select study casts from patients with nonsyndromic repaired complete UCLP who did not have mandibular skeletal or dental asymmetry. The study sample comprised dental casts from 74 children aged 8.9 ± 1 years. Standardized digital photographs were acquired at 1:1 magnification. A coordinate system was developed using digital image-processing software (Photoshop CS4 and Adobe Illustrator). Incisor and molar overjet, Angle's classification, and arch contraction were recorded. Descriptive statistics, paired t-tests, and kappa statistics were used to compare the cleft and noncleft sides. A negative overjet of -1 to -5 mm was often present at the incisors, with greater frequency and magnitude on the cleft side. Class II molar relation was more frequent on the cleft side (61.1%) than on the noncleft side (47.2%). Significantly greater contraction of the cleft side deciduous canine and deciduous first molar was noted, while the difference was very minor at the first permanent molar. Cleft side maxillary arch contraction was most severe in the deciduous canine and first deciduous molar region and progressively less severe in the posterior region of the arch. A greater frequency and severity of negative overjet and Class II molar relationship was seen on the cleft side.

Third molar development by measurements of open apices in an Italian sample of living subjects.

PubMed

De Luca, Stefano; Pacifici, Andrea; Pacifici, Luciano; Polimeni, Antonella; Fischetto, Sara Giulia; Velandia Palacio, Luz Andrea; Vanin, Stefano; Cameriere, Roberto

2016-02-01

The aim of this study is to analyse the age-predicting performance of third molar index (I3M) in dental age estimation. A multiple regression analysis was developed with chronological age as the independent variable. In order to investigate the relationship between the I3M and chronological age, the standard deviation and relative error were examined. Digitalized orthopantomographs (OPTs) of 975 Italian healthy subjects (531 female and 444 male), aged between 9 and 22 years, were studied. Third molar development was determined according to Cameriere et al. (2008). Analysis of covariance (ANCOVA) was applied to study the interaction between I3M and the gender. The difference between age and third molar index (I3M) was tested with Pearson's correlation coefficient. The I3M, the age and the gender of the subjects were used as predictive variable for age estimation. The small F-value for the gender (F = 0.042, p = 0.837) reveals that this factor does not affect the growth of the third molar. Adjusted R(2) (AdjR(2)) was used as parameter to define the best fitting function. All the regression models (linear, exponential, and polynomial) showed a similar AdjR(2). The polynomial (2nd order) fitting explains about the 78% of the total variance and do not add any relevant clinical information to the age estimation process from the third molar. The standard deviation and relative error increase with the age. The I3M has its minimum in the younger group of studied individuals and its maximum in the oldest ones, indicating that its precision and reliability decrease with the age. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Dental development in living and fossil orangutans.

PubMed

Smith, Tanya M

2016-05-01

Numerous studies have investigated molar development in extant and fossil hominoids, yet relatively little is known about orangutans, the only great ape with an extensive fossil record. This study characterizes aspects of dental development, including cuspal enamel daily secretion rate, long-period line periodicities, cusp-specific molar crown formation times and extension rates, and initiation and completion ages in living and fossil orangutan postcanine teeth. Daily secretion rate and periodicities in living orangutans are similar to previous reports, while crown formation times often exceed published values, although direct comparisons are limited. One wild Bornean individual died at 4.5 years of age with fully erupted first molars (M1s), while a captive individual and a wild Sumatran individual likely erupted their M1s around five or six years of age. These data underscore the need for additional samples of orangutans of known sex, species, and developmental environment to explore potential sources of variation in molar emergence and their relationship to life history variables. Fossil orangutans possess larger crowns than living orangutans, show similarities in periodicities, and have faster daily secretion rate, longer crown formation times, and slower extension rates. Molar crown formation times exceed reported values for other fossil apes, including Gigantopithecus blacki. When compared to African apes, both living and fossil orangutans show greater cuspal enamel thickness values and periodicities, resulting in longer crown formation times and slower extension rates. Several of these variables are similar to modern humans, representing examples of convergent evolution. Molar crown formation does not appear to be equivalent among extant great apes or consistent within living and fossil members of Pongo or Homo. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

Human and Murine Innate Immune Cell Populations Display Common and Distinct Response Patterns during Their In Vitro Interaction with the Pathogenic Mold Aspergillus fumigatus.

PubMed

Hellmann, Anna-Maria; Lother, Jasmin; Wurster, Sebastian; Lutz, Manfred B; Schmitt, Anna Lena; Morton, Charles Oliver; Eyrich, Matthias; Czakai, Kristin; Einsele, Hermann; Loeffler, Juergen

2017-01-01

Aspergillus fumigatus is the main cause of invasive fungal infections occurring almost exclusively in immunocompromised patients. An improved understanding of the initial innate immune response is key to the development of better diagnostic tools and new treatment options. Mice are commonly used to study immune defense mechanisms during the infection of the mammalian host with A. fumigatus . However, little is known about functional differences between the human and murine immune response against this fungal pathogen. Thus, we performed a comparative functional analysis of human and murine dendritic cells (DCs), macrophages, and polymorphonuclear cells (PMNs) using standardized and reproducible working conditions, laboratory protocols, and readout assays. A. fumigatus did not provoke identical responses in murine and human immune cells but rather initiated relatively specific responses. While human DCs showed a significantly stronger upregulation of their maturation markers and major histocompatibility complex molecules and phagocytosed A. fumigatus more efficiently compared to their murine counterparts, murine PMNs and macrophages exhibited a significantly stronger release of reactive oxygen species after exposure to A. fumigatus . For all studied cell types, human and murine samples differed in their cytokine response to conidia or germ tubes of A. fumigatus . Furthermore, Dectin-1 showed inverse expression patterns on human and murine DCs after fungal stimulation. These specific differences should be carefully considered and highlight potential limitations in the transferability of murine host-pathogen interaction studies.

Human and Murine Innate Immune Cell Populations Display Common and Distinct Response Patterns during Their In Vitro Interaction with the Pathogenic Mold Aspergillus fumigatus

PubMed Central

Hellmann, Anna-Maria; Lother, Jasmin; Wurster, Sebastian; Lutz, Manfred B.; Schmitt, Anna Lena; Morton, Charles Oliver; Eyrich, Matthias; Czakai, Kristin; Einsele, Hermann; Loeffler, Juergen

2017-01-01

Aspergillus fumigatus is the main cause of invasive fungal infections occurring almost exclusively in immunocompromised patients. An improved understanding of the initial innate immune response is key to the development of better diagnostic tools and new treatment options. Mice are commonly used to study immune defense mechanisms during the infection of the mammalian host with A. fumigatus. However, little is known about functional differences between the human and murine immune response against this fungal pathogen. Thus, we performed a comparative functional analysis of human and murine dendritic cells (DCs), macrophages, and polymorphonuclear cells (PMNs) using standardized and reproducible working conditions, laboratory protocols, and readout assays. A. fumigatus did not provoke identical responses in murine and human immune cells but rather initiated relatively specific responses. While human DCs showed a significantly stronger upregulation of their maturation markers and major histocompatibility complex molecules and phagocytosed A. fumigatus more efficiently compared to their murine counterparts, murine PMNs and macrophages exhibited a significantly stronger release of reactive oxygen species after exposure to A. fumigatus. For all studied cell types, human and murine samples differed in their cytokine response to conidia or germ tubes of A. fumigatus. Furthermore, Dectin-1 showed inverse expression patterns on human and murine DCs after fungal stimulation. These specific differences should be carefully considered and highlight potential limitations in the transferability of murine host–pathogen interaction studies. PMID:29270175

Dental treatment needs of permanent first molars in mashhad schoolchildren.

PubMed

Ebrahimi, Masoumeh; Ajami, Behjat-Al-Molook; Sarraf Shirazi, Ali Reza; Afzal Aghaee, Monavar; Rashidi, Somayeh

2010-01-01

In spite of their enormous importance, permanent first molars might be affected by caries in children in developing countries. The aim of this study was to evaluate the treatment needs of first permanent molars in a group of schoolchildren in Mashhad. This cross-sectional descriptive study was carried out on 700, 7-9 year-old students in primary schools in Mashhad. The schools were randomly selected from each district. Treatment needs and DMFT of first perma-nent molars were calculated. Data was analyzed using ANOVA, Chi-Square and t-test. A total of 95.3% of the children required dental treatment. Fissure sealant application and filling were the treat-ments most required in all age groups. The mean DMFT of first permanent molars was 1.31±1.4. It was significantly higher in girls than boys (P=0.040). Great treatment needs and caries prevalence in permanent first molars in Mashhad schoolchildren show that dental caries is still a serious problem in the children of our society; therefore, education of parents and teachers is necessary for promoting children's oral health.

Comparison of optical projection tomography and optical coherence tomography for assessment of murine embryonic development

NASA Astrophysics Data System (ADS)

Singh, Manmohan; Nair, Achuth; Vadakkan, Tegy; Piazza, Victor; Udan, Ryan; Frazier, Michael V.; Janecek, Trevor; Dickinson, Mary E.; Larin, Kirill V.

2015-03-01

The murine model is a common model for studying developmental diseases. In this study, we compare the performance of the relatively new method of Optical Projection Tomography (OPT) to the well-established technique of Optical Coherence Tomography (OCT) to assess murine embryonic development at three stages, 9.5, 11.5, and 13.5 days post conception. While both methods can provide spatial resolution at the micrometer scale, OPT can provide superior imaging depth compared to OCT. However, OPT requires samples to be fixed, placed in an immobilization media such as agar, and cleared before imaging. Because OCT does not require fixing, it can be used to image embryos in vivo and in utero. In this study, we compare the efficacy of OPT and OCT for imaging murine embryonic development. The data demonstrate the superior capability of OPT for imaging fine structures with high resolution in optically-cleared embryos while only OCT can provide structural and functional imaging of live embryos ex vivo and in utero with micrometer scale resolution.

Glass ionomer ART sealant and fluoride-releasing resin sealant in fissure caries prevention – results from a randomized clinical trial

PubMed Central

2014-01-01

Background The relative performance of ART sealant and fluoride-releasing resin sealant in preventing fissure caries in permanent molars was compared in a randomized clinical trial conducted in southern China (ClinicalTrials.gov NCT01829334). Methods After obtaining ethical approval, healthy schoolchildren who had permanent first molars with occlusal fissures which were sound but deep or presented with only incipient caries were recruited for the study. Included molars were randomly allocated into one of four parallel study groups in units of left/right teeth per mouth. Two of the four groups adopted the methods of ART or fluoride-releasing resin sealant placement while the other two groups adopted the topical fluoride application methods. Fissure status of the molars in each group was evaluated every 6 months. Development of dentine caries and sealant retention over 24 months in the molars in the two sealant-using groups was compared in this report. Outcome on cost-effectiveness of all four groups over 36 months will be reported elsewhere. Results At baseline, a total of 280 children (383 molars) with mean age 7.8 years were involved for the two sealant groups. After 24 months, 261 children (357 molars) were followed. Proportions of molars with dentine caries were 7.3% and 3.9% in the ART sealant and fluoride-releasing resin sealant groups, respectively (chi-square test, p = 0.171). Life-table survival analysis showed that sealant retention (full and partial) rate over 24 months for the resin sealant (73%) was significantly higher than that (50%) for the ART sealant (p < 0.001). Molar survival (no development of dentine caries) rates in the ART sealant (93%) and fluoride-releasing resin sealant (96%) groups were not significantly different (p = 0.169). Multilevel logistic regression (GEE modeling) accounting for the effects of data clustering and confounding factors confirmed this finding. Conclusions Though the retention of fluoride-releasing resin sealant was better than that of the ART sealant, their effectiveness in preventing fissure caries in permanent molars did not differ significantly over 24 months. ART sealants could be a good alternative when and where resources for resin sealant placement are not readily available. PMID:24886444

A radiographic survey of agenesis of the third molar: A panoramic study

PubMed Central

Singh, Nisha; Chaudhari, Shrinivas; Chaudhari, Rohan; Nagare, Sagar; Kulkarni, Abhay; Parkarwar, Pratik

2017-01-01

Purpose: It is a well-known fact that nature tries to eliminate what is not in use. Because of this, the number of certain teeth which are no longer necessary for function are either getting increasingly impacted or are not developing at all. This is especially the case where third molars are concerned. Furthermore, the presence or absence of the third molar is significant to all branches of dentistry and in particular, forensic dentistry. Objectives: The objectives of this study is to assess (1) The prevalence of third molar agenesis in population of age group 18–25 years. (2) The genderwise difference of third molar agenesis. (3) The difference between maxilla and mandible. Materials and Methods: Dental patients, who are advised or referred for orthopantomograph, visited to the Department of Oral Medicine and Radiology were included in the study. The study population comprised 300 patients. Statistical Analysis: The data obtained was tabulated and subjected to statistical analysis. SPSS version 17 software was used for the analysis of the data. The Chi-square test was used for the same. Results: The incidence of agenesis of the third molar is significantly higher for tooth number 18 (P < 0.001). Overall, it is significantly higher among females compared to the males (P < 0.001) in our study population. Conclusion: (1) The present study reports 46.7% agenesis of the third molar. (2) The frequency of third molar agenesis was found significantly greater in the females. (3) Third molar agenesis showed a greater predilection in maxilla compared to mandible. PMID:29657489

Dental computed tomographic imaging as age estimation: morphological analysis of the third molar of a group of Turkish population.

PubMed

Cantekin, Kenan; Sekerci, Ahmet Ercan; Buyuk, Suleyman Kutalmis

2013-12-01

Computed tomography (CT) is capable of providing accurate and measurable 3-dimensional images of the third molar. The aims of this study were to analyze the development of the mandibular third molar and its relation to chronological age and to create new reference data for a group of Turkish participants aged 9 to 25 years on the basis of cone-beam CT images. All data were obtained from the patients' records including medical, social, and dental anamnesis and cone-beam CT images of 752 patients. Linear regression analysis was performed to obtain regression formulas for dental age calculation with chronological age and to determine the coefficient of determination (r) for each sex. Statistical analysis showed a strong correlation between age and third-molar development for the males (r2 = 0.80) and the females (r2 = 0.78). Computed tomographic images are clinically useful for accurate and reliable estimation of dental ages of children and youth.

Prostaglandin E/sub 2/ localization and receptor identification within the developing murine secondary palate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, J.

1986-01-01

Transient elevations in murine secondary palatal adenosine 3',5'-monophosphate (cAMP) levels occur during palate ontogeny. Since palatal processes exposed to dibutyryl cAMP differentiate precociously, increases in palatal cAMP levels are of interest. Prostaglandin E/sub 2/ (PGE/sub 2/), which is synthesized by murine embryonic palate mesenchyme cells (MEPM), regulates cAMP levels in adult tissues via specific membrane bound receptors coupled to adenylate cyclase. Therefore, a PGE/sub 2/ receptor-adenylate cyclase systems was proposed in the developing murine secondary palate. Utilizing a radioligand binding assay, it was determined that murine palatal tissue on day 13 of gestation contained PGE/sub 2/ receptors that were saturable,more » of high affinity and low capacity. Specific (/sup 3/H)-PGE/sub 2/ binding was reversible by 30 min. The order of prostanoid binding affinity at specific PGE/sub 2/ binding sites was E/sub 2/ > F/sub 2//sub ..cap alpha../ > A/sub 2/ > E/sub 1/ = D/sub 2/ indicating specificity of the receptor for PGE/sub 2/. The ability of MEPM cells to respond to PGE/sub 2/ with dose-dependent accumulations of intracellular cAMP demonstrated the functional nature of these binding sites. Analysis of palatal PGE/sub 2/ receptor characteristics on days 12 and 14 of palate development indicated temporal alterations in receptor affinity and density during palate ontogeny.« less

Taurodontism, variations in tooth number, and misshapened crowns in Wnt10a null mice and human kindreds

PubMed Central

Yang, Jie; Wang, Shih-Kai; Choi, Murim; Reid, Bryan M; Hu, Yuanyuan; Lee, Yuan-Ling; Herzog, Curtis R; Kim-Berman, Hera; Lee, Moses; Benke, Paul J; Kent Lloyd, K C; Simmer, James P; Hu, Jan C-C

2015-01-01

WNT10A is a signaling molecule involved in tooth development, and WNT10A defects are associated with tooth agenesis. We characterized Wnt10a null mice generated by the knockout mouse project (KOMP) and six families with WNT10A mutations, including a novel p.Arg104Cys defect, in the absence of EDA,EDAR, or EDARADD variations. Wnt10a null mice exhibited supernumerary mandibular fourth molars, and smaller molars with abnormal cusp patterning and root taurodontism. Wnt10a−/− incisors showed distinctive apical–lingual wedge-shaped defects. These findings spurred us to closely examine the dental phenotypes of our WNT10A families. WNT10A heterozygotes exhibited molar root taurodontism and mild tooth agenesis (with incomplete penetrance) in their permanent dentitions. Individuals with two defective WNT10A alleles showed severe tooth agenesis and had fewer cusps on their molars. The misshapened molar crowns and roots were consistent with the Wnt10a null phenotype and were not previously associated with WNT10A defects. The missing teeth contrasted with the presence of supplemental teeth in the Wnt10a null mice and demonstrated mammalian species differences in the roles of Wnt signaling in early tooth development. We conclude that molar crown and root dysmorphologies are caused by WNT10A defects and that the severity of the tooth agenesis correlates with the number of defective WNT10A alleles. PMID:25629078

Prevalence of Extra Roots in Permanent Mandibular First Molars in Iranian Population: A CBCT Analysis.

PubMed

Rahimi, Saeed; Mokhtari, Hadi; Ranjkesh, Bahram; Johari, Masoomeh; Frough Reyhani, Mohammad; Shahi, Shahriar; Seif Reyhani, Sina

2017-01-01

Having knowledge about the anatomy of root canal system is essential for success of endodontic treatment. The present study used cone-beam computed tomography (CBCT), to evaluate the prevalence of third root in mandibular first molars in a selected Iranian population. A total of 386 CBCT images from subjects referred to oral and maxillofacial radiology department of dental faculty of Tabriz University of Medical Sciences from 2011 to 2013 were selected and evaluated for this study and the cases with well-developed permanent mandibular first molars were included. The 3D images were reconstructed in axial cross sections and evaluated by two endodontists for the presence of the third extra lingual (radix entomolaris) or buccal (radix paramolaris) root. The chi-squared test was used to evaluate the relationship between gender and bilateral incidence of extra roots in mandibular first molars. The distribution of three-rooted mandibular first molars with an additional root was 3%, (3.53% in female and 2.50% in male patients). There was no significant relationship between gender and bilateral occurrence of three-rooted mandibular first molars. The occurrence of three-rooted mandibular first molars in Iranian population is not uncommon which should be taken into consideration by the dental practitioners during root canal treatment of these teeth.

Effect of orthodontic treatment involving first premolar extractions on mandibular third molar angulation and retromolar space.

PubMed

Mendoza-García, Luz-Victoria; Vaillard-Jiménez, Esther; García-Rocha, Araceli; Bellot-Arcís, Carlos; Paredes-Gallardo, Vanessa

2017-03-01

Third molars present more problems than other teeth because they are the last teeth to erupt, and so it is important to assess their development when designing an orthodontic treatment plan. The aim of this study was to compare the angulation of the mandibular third molar and retromolar space before and after orthodontic treatment in cases involving first premolar extraction. 76 patients, 59 women (77.63%) and 17 men (22.36%), were recruited from the Orthodontics Clinic at Benemérita Universidad Autónoma de Puebla (Mexico). Panoramic radiographs were analyzed before and after orthodontic treatment that included first premolar extractions, measuring retromolar space (RS) and the angles formed by the intersection of the axes of the third and second molar (α) and the intersection of the axis of the mandibular plane and third molar (β). The data obtained underwent statistical analysis. The angle α and β showed statistically significant differences on the left side in women. In men, only the right side α angle showed significant differences. Retromolar space increased significantly on both sides for both sexes. Third molar angulation presents different behaviors between men and women, with greater verticalization in women. Key words: Third molar, retromolar space, orthodontics.

Effect of orthodontic treatment involving first premolar extractions on mandibular third molar angulation and retromolar space

PubMed Central

Vaillard-Jiménez, Esther; García-Rocha, Araceli; Bellot-Arcís, Carlos; Paredes-Gallardo, Vanessa

2017-01-01

Background Third molars present more problems than other teeth because they are the last teeth to erupt, and so it is important to assess their development when designing an orthodontic treatment plan. The aim of this study was to compare the angulation of the mandibular third molar and retromolar space before and after orthodontic treatment in cases involving first premolar extraction. Material and Methods 76 patients, 59 women (77.63%) and 17 men (22.36%), were recruited from the Orthodontics Clinic at Benemérita Universidad Autónoma de Puebla (Mexico). Panoramic radiographs were analyzed before and after orthodontic treatment that included first premolar extractions, measuring retromolar space (RS) and the angles formed by the intersection of the axes of the third and second molar (α) and the intersection of the axis of the mandibular plane and third molar (β). Results The data obtained underwent statistical analysis. The angle α and β showed statistically significant differences on the left side in women. In men, only the right side α angle showed significant differences. Retromolar space increased significantly on both sides for both sexes. Conclusions Third molar angulation presents different behaviors between men and women, with greater verticalization in women. Key words:Third molar, retromolar space, orthodontics. PMID:28298970

Does Administration of Oral Versus Intravenous Antibiotics for Third Molar Removal Have an Effect on the Incidence of Alveolar Osteitis or Postoperative Surgical Site Infections?

PubMed

Reiland, Matthew D; Ettinger, Kyle S; Lohse, Christine M; Viozzi, Christopher F

2017-09-01

To compare the incidence of postoperative alveolar osteitis (AO) and surgical site infections (SSIs) in 2 separate cohorts of patients undergoing elective third molar removal: those who received postoperative oral (PO) antibiotics and those who received perioperative intravenous (IV) antibiotics. A retrospective cohort study of all patients 14 to 30 years old undergoing elective outpatient third molar removal under a single surgeon's service over a 12-year period was completed. Patients undergoing third molar removal during the first 72 months received postoperative PO antibiotics alone. Patients undergoing third molar removal during the second 72 months received perioperative IV antibiotics alone. The primary predictor variable for the study was the antibiotic regimen used at the time of third molar removal. The primary outcome variable was the postoperative development of AO or SSI. Covariates included age and gender. Univariable and multivariable regression models assessed for associations between the antibiotic regimen used and the presence of AO and SSI. The study sample consisted of 1,895 patients (1,020 patients receiving postoperative PO antibiotics and 875 patients receiving perioperative IV antibiotics). Of patients receiving postoperative PO antibiotics, 6.4% developed AO an average of 5.7 days after the procedure and 2.6% developed an SSI an average of 23.2 days after the procedure. Of patients receiving perioperative IV antibiotics, 5.5% developed AO an average of 6.2 days after the procedure and 3.3% developed an SSI an average of 18.2 days after the procedure. No statistically significant associations between the antibiotic regimen used and the presence of AO or SSI were identified in univariable (P = 0.42 for AO, P = 0.32 for SSI) or multivariable (P = 0.65 for AO, P = 0.26 for SSI) analyses. In the postoperative PO antibiotic cohort, older age (P < .001) and female gender (P < .001) were significantly associated with the development of AO, and female gender (P = .015) was significantly associated with the presence of an SSI. In the perioperative IV antibiotic cohort, female gender was significantly associated with the development of AO (P = .011), and younger age was significantly associated with the presence of an SSI (P = .011). The use of a postoperative PO versus a perioperative IV antibiotic regimen does not significantly alter the incidence of AO or SSI after elective third molar removal. If the surgeon chooses to use antibiotics in the setting of third molar surgery, then perioperative IV antibiotics are preferable over postoperative PO antibiotics because they obviate any issues with patient compliance and might be less costly. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Human-murine transthyretin heterotetramers are kinetically stable and non-amyloidogenic. A lesson in the generation of transgenic models of diseases involving oligomeric proteins.

PubMed

Reixach, Natàlia; Foss, Ted R; Santelli, Eugenio; Pascual, Jaime; Kelly, Jeffery W; Buxbaum, Joel N

2008-01-25

The transthyretin amyloidoses appear to be caused by rate-limiting tetramer dissociation and partial monomer unfolding of the human serum protein transthyretin, resulting in aggregation and extracellular deposition of amorphous aggregates and amyloid fibrils. Mice transgenic for few copies of amyloid-prone human transthyretin variants, including the aggressive L55P mutant, failed to develop deposits. Silencing the murine transthyretin gene in the presence of the L55P human gene resulted in enhanced tissue deposition. To test the hypothesis that the murine protein interacted with human transthyretin, preventing the dissociation and partial unfolding required for amyloidogenesis, we produced recombinant murine transthyretin and human/murine transthyretin heterotetramers and compared their structures and biophysical properties to recombinant human transthyretin. We found no significant differences between the crystal structures of murine and human homotetramers. Murine transthyretin is not amyloidogenic because the native homotetramer is kinetically stable under physiologic conditions and cannot dissociate into partially unfolded monomers, the misfolding and aggregation precursor. Heterotetramers composed of murine and human subunits are also kinetically stable. These observations explain the lack of transthyretin deposition in transgenics carrying a low copy number of human transthyretin genes. The incorporation of mouse subunits into tetramers otherwise composed of human amyloid-prone transthyretin subunits imposes kinetic stability, preventing dissociation and subsequent amyloidogenesis.

Development of a broadly reactive nested reverse transcription-PCR assay to detect murine noroviruses, and investigation of the prevalence of murine noroviruses in laboratory mice in Japan.

PubMed

Kitajima, Masaaki; Oka, Tomoichiro; Tohya, Yukinobu; Katayama, Hiroyuki; Takeda, Naokazu; Katayama, Kazuhiko

2009-09-01

A broadly reactive nested RT-PCR assay to detect MNV was developed and subsequently used to investigate the prevalence of MNV in laboratory mice in Japan. MNV were detected in 8 (22%) of 37 murine stool specimens by second-round PCR, although no positive band was obtained from any specimen by first-round PCR. Genetic analysis of the second round PCR products showed that MNV sequences detected in this study were closely matched (97.2 approximately 99.1%) to that of MNV-3 (DQ223042). This is the first report demonstrating the prevalence of MNV in Japan.

Third molar cut-off value in assessing the legal age of 18 in Saudi population.

PubMed

AlQahtani, Sakher; Kawthar, Alemad; AlAraik, Ayman; AlShalan, Ahmad

2017-03-01

Teeth plays a major role in forensic sciences especially in age assessment of an individual, which can be used to aid in criminal or civil matters. The importance of teeth comes from their ability to survive inhumation well and because they are hardly affected by exogenous and endogenous factors. Third molars are the only teeth still developing after the age of 14 years and during the legal age of adulthood, which is 18 years. The consequences of criminal violation can strongly affect the individual's life, it is important to set different parameters to decide whether an individual is a minor or an adult in the absence of documents. Depending on the different legal requirement, such parameters can set above 90% probability for criminal matters and from 51% to civil matters. The aim of this research was to find the cut-off value of third molar development for the legal age of 18 amongst Saudi individuals using the third molar maturity index method by Cameriere et al. (2008) [17]. This was a cross sectional study on 300 archived orthopantomogram (OPG) of healthy Saudi patients between the ages 14 and 22 years attending the Dental Hospital at King Saud University, Riyadh, Saudi Arabia. All OPGs were taken by PLANMECA - ProMax machine and evaluated by the Romaxis software. The inclusion criteria were good quality OPGs taken during the course of treatment. All patients were healthy with no systemic diseases or disorders with the presence of third molars and clear root apex. The lower left mandibular third molar (LL3rdM) was assessed using third molar maturity index (I3m) to determine if the individual is younger or older than 18 years old. The cut-off value of I3m for the Saudi population was (I3m<0.08). The sensitivity of this method was 51.7% and the specificity was 98.5%. Early mineralization was found in males except when I3m was ranging from (0.0 to 0.4) and (0.9 to 1.7). Cameriere et al. (2014, 2008) [16,17] test was reproducible with good measure of reliability. This method is suitable for assessing the attainment of legal age of adulthood in Saudi population and the cut-off value of I3m is similar to other populations. Although dental age assessment by means of third molar development is useful, it still has its limitation because of its variation in position, morphology and development. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Efficiency of a pendulum appliance for molar distalization related to second and third molar eruption stage.

PubMed

Kinzinger, Gero S M; Fritz, Ulrike B; Sander, Franz-Günter; Diedrich, Peter R

2004-01-01

A modified pendulum appliance, including a distal screw and special preactivated pendulum springs (built-in straightening activation and toe-in bending), was used for bilateral maxillary molar distalization in 36 adolescent patients in various stages of the molar dentition. The patients were divided into 3 groups (PG 1-3) according to the stage of eruption of their second and third molars. In PG 1 (18 patients), eruption of the second molars had either not yet taken place or was not complete. In PG 2 (15 patients), the second molars had already developed as far as the occlusal plane, with the third molars at the budding stage. In PG 3 (3 patients), germectomy of the wisdom teeth had been carried out, and the first and second molars on both sides had completely erupted. Analysis of cephalograms to identify any changes in the sagittal plane showed that, in the direction of distalization, a tooth bud acts on the mesial neighboring tooth like a fulcrum, and that tipping of the first molars in patients in whom the second molar was still at the budding stage was thus greater. In patients whose second molars had erupted completely, the degree of tipping was greater again when a third molar bud was located in the direction of movement. After previously completed germectomy of the wisdom teeth, almost exclusively bodily distalization of both molars is possible, even without bands being applied to the second molars. However, if the first and second molars are distalized simultaneously with a pendulum appliance, the duration of therapy will be longer, greater forces will have to be applied, and more anchorage will be lost. Statistical analysis of the results of dental-angular measurements showed significant differences in the degree of molar tipping and reciprocal incisor protrusion. The degree of distal tipping of first molars was less in patients with erupted second molars (PG 2 and PG 3) than in those whose second molars were not yet erupted (PG 1). For instance, the measured angles were 0.9 degrees +/- 3.43 degrees (to the palatal plane) and 0.8 degrees +/- 3.4 degrees (to the anterior cranium floor) in PG 2, and -0.33 degrees +/- 0.58 degrees and 0.67 degrees +/- 2.08 degrees, respectively, in PG 3, contrasting with respective values of 5.89 degrees +/- 3.74 degrees and 5.36 degrees +/- 3.49 degrees in PG 1. Tipping of erupted second molars was much more marked in PG 2 (7.92 degrees +/- 5.83 degrees to the palatal plane and 7.55 degrees +/- 5.28 degrees to the anterior cranium floor), but much less pronounced in PG 3 (2 degrees +/- 1.73 degrees to the palatal plane and 2 degrees +/- 2 degrees to the anterior cranium floor) than the corresponding movement of the second budding-stage molars in PG 1 (4.06 degrees +/- 2.15 degrees and 3.97 degrees +/- 2.27 degrees, respectively). The degree of incisor protrusion occurring reciprocally with molar distalization was much less in these patients (measured angles of 3.28 degrees +/- 1.97 degrees and 2.89 degrees +/- 2.17 degrees to the palatal plane and anterior cranium floor, respectively) than in the patients presenting different stages of the dentition (angles of 5.5 degrees +/- 3.33 degrees and 6.03 degrees +/- 4.29 degrees, respectively, in PG 2, and angles of 5.5 degrees +/- 3.28 degrees and 6.67 degrees +/- 3.09 degrees, respectively, in PG 3). Moreover, measurement of dental casts in the horizontal plane showed not only the targeted mesiobuccal rotation of both maxillary molars, but also a vestibular drift of the unbanded second molars.

Isentropic expansion and related thermodynamic properties of non-ionic amphiphile-water mixtures.

PubMed

Reis, João Carlos R; Douhéret, Gérard; Davis, Michael I; Fjellanger, Inger Johanne; Høiland, Harald

2008-01-28

A concise thermodynamic formalism is developed for the molar isentropic thermal expansion, ES,m = ( partial differential Vm/ partial differential T)(Sm,x), and the ideal and excess quantities for the molar, apparent molar and partial molar isentropic expansions of binary liquid mixtures. Ultrasound speeds were determined by means of the pulse-echo-overlap method in aqueous mixtures of 2-methylpropan-2-ol at 298.15 K over the entire composition range. These data complement selected extensive literature data on density, isobaric heat capacity and ultrasound speed for 9 amphiphile (methanol, ethanol, propan-1-ol, propan-2-ol, 2-methylpropan-2-ol, ethane-1,2-diol, 2-methoxyethanol, 2-ethoxyethanol or 2-butoxyethanol)-water binary systems, which form the basis of tables listing molar and excess molar isobaric expansions and heat capacities, and molar and excess molar isentropic compressions and expansions at 298.15 K and at 65 fixed mole fractions spanning the entire composition range and fine-grained in the water-rich region. The dependence on composition of these 9 systems is graphically depicted for the excess molar isobaric and isentropic expansions and for the excess partial molar isobaric and isentropic expansions of the amphiphile. The analysis shows that isentropic thermal expansion properties give a much stronger response to amphiphile-water molecular interactions than do their isobaric counterparts. Depending on the pair property-system, the maximum excess molar isentropic value is generally twenty- to a hundred-fold greater than the corresponding maximum isobaric value, and occurs at a lower mole fraction of the amphiphile. Values at infinite dilution of the 9 amphiphiles in water are given for the excess partial molar isobaric heat capacity, isentropic compression, isobaric expansion and isentropic expansion. These values are interpreted in terms of the changes occurring when amphiphile molecules cluster into an oligomeric form. Present results are discussed from theoretical and experimental thermodynamic viewpoints. It is concluded that isentropic thermal expansion properties constitute a new distinct resource for revealing particular features and trends in complex mixing processes, and that analyses using these new properties compare favourably with conventional approaches.

Pendulum and modified pendulum appliances for maxillary molar distalization in Class II malocclusion - a systematic review.

PubMed

Al-Thomali, Yousef; Basha, Sakeenabi; Mohamed, Roshan Noor

2017-08-01

The main purpose of the present systematic review was to evaluate the quantitative effects of the pendulum appliance and modified pendulum appliances for maxillary molar distalization in Class II malocclusion. Our systematic search included MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus and key journals and review articles; the date of the last search was 30 January 2017. We graded the methodological quality of the studies by means of the Quality Assessment Tool for Quantitative Studies, developed for the Effective Public Health Practice Project (EPHPP). In total, 203 studies were identified for screening, and 25 studies were eligible. The quality assessment rated four (16%) of the study as being of strong quality and 21 (84%) of these studies as being of moderate quality. The pendulum appliances showed mean molar distalization of 2-6.4 mm, distal tipping of molars from 6.67° to 14.50° and anchorage loss with mean premolar and incisor mesial movement of 1.63-3.6 mm and 0.9-6.5 mm, respectively. The bone anchored pendulum appliances (BAPAs) showed mean molar distalization of 4.8-6.4 mm, distal tipping of molars from 9° to 11.3° and mean premolar distalization of 2.7-5.4 mm. Pendulum and modified pendulum appliances are effective in molar distalization. Pendulum appliance with K-loop modification, implant supported pendulum appliance and BAPA significantly reduced anchorage loss of the anterior teeth and distal tipping of the molar teeth.

A geometric morphometric analysis of hominin upper second and third molars, with particular emphasis on European Pleistocene populations.

PubMed

Gómez-Robles, Aida; Bermúdez de Castro, José María; Martinón-Torres, María; Prado-Simón, Leyre; Arsuaga, Juan Luis

2012-09-01

The study of dental morphology by means of geometric morphometric methods allows for a detailed and quantitative comparison of hominin species that is useful for taxonomic assignment and phylogenetic reconstruction. Upper second and third molars have been studied in a comprehensive sample of Plio- and Pleistocene hominins from African, Asian and European sites in order to complete our analysis of the upper postcanine dentition. Intraspecific variation in these two molars is high, but some interspecific trends can be identified. Both molars exhibit a strong reduction of the distal cusps in recent hominin species, namely European Homo heidelbergensis, Homo neanderthalensis and Homo sapiens, but this reduction shows specific patterns and proportions in the three groups. Second molars tend to show four well developed cusps in earlier hominin species and their morphology is only marginally affected by allometric effects. Third molars can be incipiently reduced in earlier species and they evince a significant allometric component, identified both inter- and intraspecifically. European Middle Pleistocene fossils from Sima de los Huesos (SH) show a very strong reduction of these two molars, even more marked than the reduction observed in Neanderthals and in modern human populations. The highly derived shape of SH molars points to an early acquisition of typical Neanderthal dental traits by pre-Neanderthal populations and to a deviation of this population from mean morphologies of other European Middle Pleistocene groups. Copyright © 2012 Elsevier Ltd. All rights reserved.

Association between eruption state of the third molar and the occurrence of mandibular angle fractures.

PubMed

Rahimi-Nedjat, Roman K; Sagheb, Keyvan; Jacobs, Collin; Walter, Christian

2016-10-01

Fractures of the mandible, especially the mandibular angle, are one of the most frequent types of injuries of the facial skeleton. In many cases, a retained third molar can be found in the line of the fracture. However, it remains unclear whether a relationship between third molars and mandibular angle fractures exists. Patients with isolated or combined fractures of the lower jaw between January 2001 and December 2007 were analyzed retrospectively. Electronic health records were investigated regarding the types of mandibular fractures, and panoramic radiographs were reviewed concerning the existence of third molars. In addition, a systematic review was performed to compare the findings of this study with existing data. Six hundred and thirty-two patients were treated for mandibular fractures within the time frame. Two hundred and sixty-seven had a mandibular angle fracture. In 461 patients, panoramic radiographs were available, of which 45.6% did not have a third molar. About 3.8% were edentulous. There is a significant relationship between the existence of unerupted third molars and the occurrence of mandibular angle fractures (P < 0.001). No correlation exists for erupted third molars. Fractures of the mandibular angle are more likely to appear in patients with retained third molars which might be due to the reduced bone mass. Once the wisdom teeth have erupted, the bone structure is more solid and more resistant to external forces and the development of fractures. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of carbohydrate and peptide biotinylation on the immunological activity of IgG1 murine monoclonal antibodies.

PubMed

Miralles, F; Takeda, Y; Escribano, M J

1991-07-05

When the classical amino acid esterification procedure was used for the biotinylation of the IgG1 monoclonal antibody J28 it resulted in a loss of immunological activity. This antibody recognizes the fetoacinar pancreatic (FAP) antigen and the decrease in reactivity was directly proportional to the molar biotin/antibody ratio indicating substitutions at or near the antibody combining site. This effect was specific to J28 since the IgG1 Mab F22 which recognises the same antigen was not damaged by this procedure. Active Mab J28 conjugates were obtained using biotinylation via oligosaccharide moieties. The biotinylation efficiency using this method was dependent on the previous degree of antibody periodate oxidation and the maximal substitution was 3 mol biotin per mol of antibody. Using these conditions the sensitivity of the biotinylated J28 for the FAP antigen was similar to that obtained when using non-substituted antibody in the two antibodies technique.

Structural and Immunological Activity Characterization of a Polysaccharide Isolated from Meretrix meretrix Linnaeus

PubMed Central

Li, Li; Li, Heng; Qian, Jianying; He, Yongfeng; Zheng, Jialin; Lu, Zhenming; Xu, Zhenghong; Shi, Jinsong

2015-01-01

Polysaccharides from marine clams perform various biological activities, whereas information on structure is scarce. Here, a water-soluble polysaccharide MMPX-B2 was isolated from Meretrix meretrix Linnaeus. The proposed structure was deduced through characterization and its immunological activity was investigated. MMPX-B2 consisted of d-glucose and d-galctose residues at a molar ratio of 3.51:1.00. The average molecular weight of MMPX-B2 was 510 kDa. This polysaccharide possessed a main chain of (1→4)-linked-α-d-glucopyranosyl residues, partially substituted at the C-6 position by a few terminal β-d-galactose residues or branched chains consisting of (1→3)-linked β-d-galactose residues. Preliminary immunological tests in vitro showed that MMPX-B2 could stimulate the murine macrophages to release various cytokines, and the structure-activity relationship was then established. The present study demonstrated the potential immunological activity of MMPX-B2, and provided references for studying the active ingredients in M. meretrix. PMID:26729136

Characterization of an acidic polysaccharide isolated from the leaves of Corchorus olitorius (Moroheiya).

PubMed

Ohtani, K; Okai, K; Yamashita, U; Yuasa, I; Misaki, A

1995-03-01

An acidic polysaccharide was isolated from the water-soluble mucilage extracted from dried leaves of Corchorus olitorius, known as Moroheiya in Japan (3.0 g per 100 g). This polysaccharide showed a single peak in a Sepharose CL-6B column, and the specific rotation in H2O at 25 degrees C was +250 degrees. The polysaccharide was rich in uronic acid (65%), and consisted of rhamnose, glucose, galacturonic acid, and glucuronic acid in a molar ratio of 1.0:0.2:0.2:0.9:1.7, in addition to 3.7% of the acetyl group. A methylation analysis, Smith degradation study and fragmentation analysis suggested that this polysaccharide mainly consisted of O-4 substituted galacturonic acid and glucuronic acid, and O-2 substituted rhamnose residues, and that most of the (1-->4)-linked uronic acid residues were substituted at the O-3 position with glucuronic acid residues. This polysaccharide showed proliferative activity toward the murine splenocyte.

Highly efficient gene transfer using a retroviral vector into murine T cells for preclinical chimeric antigen receptor-expressing T cell therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kusabuka, Hotaka; Fujiwara, Kento; Tokunaga, Yusuke

Adoptive immunotherapy using chimeric antigen receptor-expressing T (CAR-T) cells has attracted attention as an efficacious strategy for cancer treatment. To prove the efficacy and safety of CAR-T cell therapy, the elucidation of immunological mechanisms underlying it in mice is required. Although a retroviral vector (Rv) is mainly used for the introduction of CAR to murine T cells, gene transduction efficiency is generally less than 50%. The low transduction efficiency causes poor precision in the functional analysis of CAR-T cells. We attempted to improve the Rv gene transduction protocol to more efficiently generate functional CAR-T cells by optimizing the period ofmore » pre-cultivation and antibody stimulation. In the improved protocol, gene transduction efficiency to murine T cells was more than 90%. In addition, almost all of the prepared murine T cells expressed CAR after puromycin selection. These CAR-T cells had antigen-specific cytotoxic activity and secreted multiple cytokines by antigen stimulation. We believe that our optimized gene transduction protocol for murine T cells contributes to the advancement of T cell biology and development of immunotherapy using genetically engineered T cells. - Highlights: • We established highly efficient gene transduction protocols for murine T cells. • CD8{sup +} CAR-T cells had antigen-specific cytotoxic activity. • CD4{sup +} CAR-T cells secreted multiple cytokines by antigen stimulation. • This finding can contribute to the development of T-cell biology and immunotherapy.« less

Comparative gene expression supports the origin of the incisor and molar process from a single endite in the mandible of the red flour beetle Tribolium castaneum

PubMed Central

2013-01-01

Background The biting edge of the primitive arthropod mandible consists of a biting incisor process and a crushing molar process. These structures are thought to be derived from a structure known as an endite but the precise details of this are not understood. Various hypotheses concerning the number of endites present in the arthropod mandible have been proposed. In the developing embryo, the mandible has an inner and outer lobe that are likely to develop into the incisor and molar processes of the larval mandible; these two lobes are commonly held to be derived from separate endites and to be serially homologous to the galea and lacinia endites of the maxillary appendage respectively (Machida). Results We undertook a study of the development of the embryonic mandible of the beetle Tribolium castaneum using the expression of developmental genes as markers of the developing endites in the mandible and maxilla. The Tribolium ortholog of paired (Tc-prd) has expression domains in the developing maxillary and labial endites as well as the inner and outer lobes of the mandible. Following the expression of Tc-prd in the developing mandible through to late stage embryos shows that the molar and incisor process develop from the inner and outer lobes respectively. In addition to Tc-prd, we compared the expression of genes in the endites of the maxilla to the mandible to draw conclusions about the number of endites in the mandible. Homologs of dachshund are typically expressed in the endites of mandibulate gnathal appendages. Comparison of the expression of Tc-prd, Tribolium dachshund (Tc-dac) and Tribolium wingless (Tc-wg) between the endites of the maxilla and the mandible suggest that, while there are two endites in the maxilla only a single endite is present in the mandible. Conclusions Comparative gene expression suggests that the Tribolium mandible has a single endite from which both mandible lobes are derived. Our results do not support Machida’s hypothesis homologising the incisor and molar processes of the mandible to the galea and lacinia endites of the maxilla. We propose, instead, that both incisor and molar processes are derived from a single endite serially homologous to the lacinia of the maxilla. PMID:23280103

Clinical measurement of force systems upon activation of transpalatal arch in the treatment of unilateral crossbite.

PubMed

Yoshida, N; Koga, Y; Jost-Brinkmann, P G; Kobayashi, K

2003-01-01

in this study, forces and moments acting on the molars were theoretically determined by means of small-deflection analysis when an asymmetric third-order activation of the TPA was carried out. the transpalatal arch (TPA) is used to correct unilateral crossbites through the application of buccal root torque to the anchorage molar and lingual root torque to the contralateral molar in crossbite, combined with expansion. Unfortunately, the complex force systems created at the molars upon activation of the TPA cannot be easily estimated. our computations revealed that the vertical forces developed on the molars when both ends of the TPA are inserted into the lingual sheaths (two-couple system) is four-times greater than those when only one end is tied to the lingual sheath as a single-point contact (one-couple system). we propose a method of clinical estimation of the force system in a two-couple system by directly measuring the vertical force produced by the one-couple system.

Third molar observations in a sample of British male young offenders.

PubMed

Andrews, Sally E

2015-07-01

Development, morphology and eruption of third molars are highly variable, and it is generally accepted that the emergence time is between the ages of 17 and 21 years. This study reports on variation in timing encountered in a sample of 155 young males (15-18 years) of British nationality who were detained at Her Majesty's Prison and Young Offenders Institution (HMP&YOI) Ashfield as young offenders. All 155 participants were self-reported in terms of their chronological age and their ethnic origin. Of the 17 year-olds, 68% of Black males displayed one or more erupted third molars compared to 39% of the White males. For those who were of mixed ancestry, 50% showed evidence of eruption of at least one third molar in this age group. This difference between Black and White ethnicity was further supported when missing first or second molars were taken into consideration. Whilst it has been suggested in the literature that ethnicity plays no major part in eruption timings for the third molars, this clinical observation poses some interesting questions about the accuracy of dental age assessment. Copyright © 2015 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Influence of ZnO seed layer precursor molar ratio on the density of interface defects in low temperature aqueous chemically synthesized ZnO nanorods/GaN light-emitting diodes

NASA Astrophysics Data System (ADS)

Alnoor, Hatim; Pozina, Galia; Khranovskyy, Volodymyr; Liu, Xianjie; Iandolo, Donata; Willander, Magnus; Nur, Omer

2016-04-01

Low temperature aqueous chemical synthesis (LT-ACS) of zinc oxide (ZnO) nanorods (NRs) has been attracting considerable research interest due to its great potential in the development of light-emitting diodes (LEDs). The influence of the molar ratio of the zinc acetate (ZnAc): KOH as a ZnO seed layer precursor on the density of interface defects and hence the presence of non-radiative recombination centers in LT-ACS of ZnO NRs/GaN LEDs has been systematically investigated. The material quality of the as-prepared seed layer as quantitatively deduced by the X-ray photoelectron spectroscopy is found to be influenced by the molar ratio. It is revealed by spatially resolved cathodoluminescence that the seed layer molar ratio plays a significant role in the formation and the density of defects at the n-ZnO NRs/p-GaN heterostructure interface. Consequently, LED devices processed using ZnO NRs synthesized with molar ratio of 1:5 M exhibit stronger yellow emission (˜575 nm) compared to those based on 1:1 and 1:3 M ratios as measured by the electroluminescence. Furthermore, seed layer molar ratio shows a quantitative dependence of the non-radiative defect densities as deduced from light-output current characteristics analysis. These results have implications on the development of high-efficiency ZnO-based LEDs and may also be helpful in understanding the effects of the ZnO seed layer on defect-related non-radiative recombination.

Tributyltin impairs dentin mineralization and enamel formation in cultured mouse embryonic molar teeth.

PubMed

Salmela, Eija; Sahlberg, Carin; Alaluusua, Satu; Lukinmaa, Pirjo-Liisa

2008-11-01

Tributyltin (TBT), earlier used as an antifouling agent in marine paints, causes damage to the aquatic ecosystem, for example, impaired shell calcification in oysters. TBT affects hard tissue mineralization even in mammals: delayed bone mineralization has been observed in rodents exposed to TBT in utero. To see if TBT interferes with tooth development, especially dental hard tissue formation, we exposed mouse E18 mandibular first and second molars to 0.1, 0.5, 1.0, and 2.0 microM TBT chloride in organ culture for 7-12 days. The amount of enamel was assessed and the sizes of the first molars were measured from photographs taken after the culture. TBT concentration dependently impaired enamel formation (p < 0.001) and reduced tooth size (p < 0.001). Histological analysis showed slight arrest of dentin mineralization and enamel formation in first molars exposed to 0.1 microM TBT. At the concentration of 1.0 microM the effect was overt. The differentiation of ameloblasts in the mesial cusps was retarded but TBT had no effect on odontoblast morphology. The dental epithelium showed enhanced apoptosis. The failure of ameloblasts to form enamel was likely to be secondary to the effect of TBT on dentin mineralization. In the second molars, where predentin deposition had not started, ameloblasts and odontoblasts were nonpolarized and proliferative. The results showed that TBT concentration dependently impairs dental hard tissue formation and reduces tooth size in cultured mouse embryonic molars. The effects depend on the stage of tooth development at the start of exposure and may involve epithelial-mesenchymal interactions.

Novel Application of Micro-Computerized Tomography for Morphologic Characterization of the Murine Penis.

PubMed

O'Neill, Marisol; Huang, Gene O; Lamb, Dolores J

2017-12-01

The murine penis model has enriched our understanding of anomalous penile development. The morphologic characterization of the murine penis using conventional serial sectioning methods is labor intensive and prone to errors. To develop a novel application of micro-computerized tomography (micro-CT) with iodine staining for rapid, non-destructive morphologic study of murine penis structure. Penises were dissected from 10 adult wild-type mice and imaged using micro-CT with iodine staining. Images were acquired at 5-μm spatial resolution on a Bruker SkyScan 1272 micro-CT system. After images were acquired, the specimens were washed of any remaining iodine and embedded in paraffin for conventional histologic examination. Histologic and micro-CT measurements for all specimens were made by 2 independent observers. Measurements of penile structures were made on virtual micro-CT sections and histologic slides. The Lin concordance correlation coefficient demonstrated almost perfect strength of agreement for interobserver variability for histologic section (0.9995, 95% CI = 0.9990-0.9997) and micro-CT section (0.9982, 95% CI = 0.9963-0.9991) measurements. Bland-Altman analysis for agreement between the 2 modalities of measurement demonstrated mean differences of -0.029, 0.022, and -0.068 mm for male urogenital mating protuberance, baculum, and penile glans length, respectively. There did not appear to be a bias for overestimation or underestimation of measured lengths and limits of agreement were narrow. The enhanced ability offered by micro-CT to phenotype the murine penis has the potential to improve translational studies examining the molecular pathways contributing to anomalous penile development. The present study describes the first reported use of micro-CT with iodine staining for imaging the murine penis. Producing repeated histologic sections of identical orientation was limited by inherent imperfections in mounting and tissue sectioning, but this was compensated for by using micro-CT reconstructions to identify matching virtual sections. This study demonstrates the successful use of micro-CT with iodine staining, which has the potential for submicron spatial resolution, as a non-destructive method of characterizing murine penile morphology. O'Neill M, Huang GO, Lamb DJ. Novel Application of Micro-Computerized Tomography for Morphologic Characterization of the Murine Penis. J Sex Med 2017;14:1533-1539. Copyright © 2017. Published by Elsevier Inc.

Prevalence of Extra Roots in Permanent Mandibular First Molars in Iranian Population: A CBCT Analysis

PubMed Central

Rahimi, Saeed; Mokhtari, Hadi; Ranjkesh, Bahram; Johari, Masoomeh; Frough Reyhani, Mohammad; Shahi, Shahriar; Seif Reyhani, Sina

2017-01-01

Introduction: Having knowledge about the anatomy of root canal system is essential for success of endodontic treatment. The present study used cone-beam computed tomography (CBCT), to evaluate the prevalence of third root in mandibular first molars in a selected Iranian population. Methods and Materials: A total of 386 CBCT images from subjects referred to oral and maxillofacial radiology department of dental faculty of Tabriz University of Medical Sciences from 2011 to 2013 were selected and evaluated for this study and the cases with well-developed permanent mandibular first molars were included. The 3D images were reconstructed in axial cross sections and evaluated by two endodontists for the presence of the third extra lingual (radix entomolaris) or buccal (radix paramolaris) root. The chi-squared test was used to evaluate the relationship between gender and bilateral incidence of extra roots in mandibular first molars. Results: The distribution of three-rooted mandibular first molars with an additional root was 3%, (3.53% in female and 2.50% in male patients). There was no significant relationship between gender and bilateral occurrence of three-rooted mandibular first molars. Conclusion: The occurrence of three-rooted mandibular first molars in Iranian population is not uncommon which should be taken into consideration by the dental practitioners during root canal treatment of these teeth. PMID:28179928

Regenerative endodontic treatment (revascularization) of immature necrotic molars medicated with calcium hydroxide: a case series.

PubMed

Cehreli, Zafer C; Isbitiren, Beste; Sara, Sezgi; Erbas, Gizem

2011-09-01

Revascularization is an emerging regenerative treatment protocol with little published data available in immature molar teeth. The present case series demonstrates the outcome of revascularization treatment with intracanal medicament of calcium hydroxide in immature necrotic molars. Immature necrotic permanent first molars (n = 6) of patients 8-11 years old were treated by a revascularization protocol that used 2.5% NaOCl irrigation, medication with calcium hydroxide placed in the coronal third of the root canals, induction of apical bleeding, and coronal sealing with white mineral trioxide aggregate. Among the treated teeth, 4 molars had undergone prior root canal instrumentation by the referring dentists. National Institutes of Health Image-J program with TurboReg plug-in was used for standardization of the radiographs and to determine the increase in root length and root width. After a follow-up period of 10 months, all teeth demonstrated radiographic evidence of complete periapical healing, progressive thickening of dentinal walls, and continued apical development in the absence of clinical symptoms. Two uninstrumented molars showed a positive response to cold testing at 9 months. On the basis of a follow-up period of 10 months, the present cases demonstrate a favorable outcome of the revascularization procedure in immature necrotic molars by using calcium hydroxide medication in the coronal third of the root canals. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Carabelli's trait revisited: an examination of mesiolingual features at the enamel-dentine junction and enamel surface of Pan and Homo sapiens upper molars.

PubMed

Ortiz, Alejandra; Skinner, Matthew M; Bailey, Shara E; Hublin, Jean-Jacques

2012-10-01

Carabelli's trait is a morphological feature that frequently occurs on the mesiolingual aspect of Homo sapiens upper molars. Similar structures also referred to as Carabelli's trait have been reported in apes and fossil hominins. However, the morphological development and homology of these mesiolingual structures among hominoids are poorly understood. In this study, we employ micro-computed tomography to image the enamel-dentine junction (EDJ) and outer enamel surface (OES) of Pan (n = 48) and H. sapiens (n = 52) upper molars. We investigate the developmental origin of mesiolingual features in these taxa and establish the relative contribution of the EDJ and enamel cap to feature expression. Results demonstrate that mesiolingual features of H. sapiens molars develop at the EDJ and are similarly expressed at the OES. Morphological variation at both surfaces in this taxon can satisfactorily be assessed using standards for Carabelli's trait developed by the Arizona State University Dental Anthropology System (ASUDAS). Relative to H. sapiens, Pan has an even greater degree of correspondence in feature expression between the EDJ and OES. Morphological manifestations in Pan molars are not necessarily limited to the protocone and are best characterized by a lingual cingulum that cannot be captured by the ASUDAS. Cusp-like structures, similar to those seen in marked Carabelli's trait expressions in H. sapiens, were not found in Pan. This study provides a foundation for further analyses on the evolutionary history of mesiolingual dental traits within the hominoid lineage. It also highlights the wealth of morphological data that can be obtained at the EDJ for understanding tooth development and for characterizing tooth crown variation in worn fossil teeth. Copyright © 2012 Elsevier Ltd. All rights reserved.

New Poly(3-hydroxybutyrate) Microparticles with Paclitaxel Sustained Release for Intraperitoneal Administration.

PubMed

Bonartsev, Anton P; Zernov, Anton L; Yakovlev, Sergey G; Zharkova, Irina I; Myshkina, Vera L; Mahina, Tatiana K; Bonartseva, Garina A; Andronova, Natalia V; Smirnova, Galina B; Borisova, Juliya A; Kalishjan, Mikhail S; Shaitan, Konstantin V; Treshalina, Helena M

2017-01-01

Poly(hydroxyalkanoates) (PHA) have recently attracted increasing attention due to their biodegradability and high biocompatibility, which makes them suitable for the development of new prolong drug formulations. This study was conducted to develop new prolong paclitaxel (PTX) formulation based on poly(3- hydroxybutyrate) (PHB) microparticles. PHB microparticles loaded with antitumor cytostatic drug PTX were obtained by spray-drying method using Nano Spray Dryer B-90. The PTX release kinetics in vitro from PHB microparticles and their cytotoxity on murine hepatoma cell line MH-22a were studied. Microparticles antitumor activity in vivo was studied using intraperitoneally (i.p.) transplanted tumor models: murine Lewis lung carcinoma and xenografts of human breast cancer RMG1. Uniform PTX release from PHB-microparticles during 2 months was observed. PTX-loaded PHB microparticles have demonstrated a significant antitumor activity versus pure drug both in vitro in murine hepatoma cells and in vivo when administered i.p. to mice with murine Lewis lung carcinoma and xenografts of human breast cancer RMG1. The developed technique of PTX sustained delivery from PHB-microparticles has therapeutic potential as prolong anticancer drug formulation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Morphologic analysis of third-molar maturity by digital orthopantomographic assessment.

PubMed

Introna, Francesco; Santoro, Valeria; De Donno, Antonio; Belviso, Maura

2008-03-01

Accurate timing of the eruption of first and permanent teeth is an important parameter in forensic odontology to establish the age of dead or live individuals. Determination of adulthood may determine, for example, whether an individual convicted of a crime is sentenced as an adult and incarcerated in a state penal institution or as a juvenile and sent to a juvenile camp. At present, there is a large immigrant population in Italy, and young foreign criminals sometimes have false passports bearing a later birth date, with the aim of evading punishment. In such circumstances, age determination is becoming a significant forensic issue.Late in adolescence, after formation of the premolars and canines, only the third molars continue to develop. According to several studies, although the third molars are the most variable teeth in the dentition, they remain the most reliable biologic indicator available for estimation of age during the middle teens and early twenties.In this study, the authors test the possibilities offered by orthopantomography executed by means of digital technology, with the aim of exploiting the advantages of the computerized digital technique compared with the conventional technique, to determine adult age on the basis of root development of the third molar.Digital radiography is simple to use, quick, and effective, allowing superimposition and enlargement; the images can be electronically stored and transported. In comparison with traditional orthopantomography, the digital technique features greater diagnostic accuracy of some anatomic structures: upper and lower front teeth, root apexes, floor of the nasal fossa and maxillary sinus, nasal septum, mandibular condylus. Moreover, digital orthopantomography suffers less from artifacts.The digital orthopantomographies of 83 Caucasian subjects (43 females and 40 males) aged between 16 and 22 years were analyzed in standard conditions, assessing the degree of maturation of the upper and lower third molars. A standardized computer procedure was used to acquire the x-ray images, recording 3 per plate: the overall orthopantomography and 2 enlargements of optical type of the left and right sides, to reveal the third molars while maintaining unaltered the image resolution.For the analysis, the authors adopted Demirjian's staging system that classifies development of the third molar in 8 stages (A, B, C, D, E, F, G, H) on the basis of morphologic criteria. This has been statistically proved to feature notable precision and high predictive ability.To assess any sex-related variations in mineralization speed, the series was subdivided by gender. The study demonstrated that such differences are more evident under the age of 18 years.Overall, the observation of 245 third molars showed faster development of the upper than the lower third molars, a prevalence of stages D to G in the age range between 16 and 18 years, and a clear predominance of stage H in individuals over 18 years of age. Finally, an intermediate stage between G and H was demonstrated in subjects aged between 17 and 21 years.

Simple and efficient liposomal encapsulation of topotecan by ammonium sulfate gradient: stability, pharmacokinetic and therapeutic evaluation.

PubMed

Liu, Jun-Jen; Hong, Ruey-Long; Cheng, Wen-Fang; Hong, Keelung; Chang, Fu-Hsiung; Tseng, Yun-Long

2002-08-01

Topotecan (TPT), a topoisomerase I inhibitor, is presently undergoing clinical evaluation worldwide. Previous studies have shown that entrapping TPT within multi-lamellar vesicle liposome can stabilize the lactone moiety, which is structurally important for biological activity. However, low drug:lipid ratios due to the amphipathic character and small entrapment volume in the unilamellar vesicle limits the development of pharmaceutically acceptable liposomal formulation. With an aim to improve on this drawback, we herein describe a method that utilizes the ammonium sulfate gradient to entrap TPT into liposomes. By this method, the encapsulation efficiency was over 90% and a drug:lipid molar ratio as high as 1:5.4 was reached. In comparison with free drug, liposome-encapsulated TPT is more stable in physiological conditions and shows higher in vitro cytotoxicity. Because of increased blood circulation time, the initial plasma concentration and area under the plasma concentration of liposomal drugs were 14 and 40 times, respectively, of those of free drug. Furthermore, liposome encapsulation enhanced the antitumor activity of TPT in syngeneic murine C-26 and human HTB-9 xenograft models in vivo. At a dose of 5 mg/kg, the tumor growth delay of liposomal formulation was significantly than that of free TPT. Based on these results, we believe that this liposomal TPT formulation is worthy of further clinical study. Copyright 2002 Lippincott Williams & Wilkins.

Development of an ex vivo BrdU labeling procedure for the murine LLNA

EPA Science Inventory

The murine local lymph node assay (LLNA) is widely used to identify chemicals that may cause allergic contact dermatitis. Exposure to a dermal sensitizer results in proliferation of local lymph node T cells, which has traditionally been measured by in vivo incorporation of [3H]m...

Genetic integration of molar cusp size variation in baboons

PubMed Central

Koh, Christina; Bates, Elizabeth; Broughton, Elizabeth; Do, Nicholas T.; Fletcher, Zachary; Mahaney, Michael C.; Hlusko, Leslea J.

2010-01-01

Many studies of primate diversity and evolution rely on dental morphology for insight into diet, behavior, and phylogenetic relationships. Consequently, variation in molar cusp size has increasingly become a phenotype of interest. In 2007 we published a quantitative genetic analysis of mandibular molar cusp size variation in baboons. Those results provided more questions than answers, as the pattern of genetic integration did not fit predictions from odontogenesis. To follow up, we expanded our study to include data from the maxillary molar cusps. Here we report on these later analyses, as well as inter-arch comparisons with the mandibular data. We analyzed variation in two-dimensional maxillary molar cusp size using data collected from a captive pedigreed breeding colony of baboons, Papio hamadryas, housed at the Southwest National Primate Research Center. These analyses show that variation in maxillary molar cusp size is heritable and sexually dimorphic. We also estimated additive genetic correlations between cusps on the same crown, homologous cusps along the tooth row, and maxillary and mandibular cusps. The pattern for maxillary molars yields genetic correlations of one between the paracone-metacone and protocone-hypocone. Bivariate analyses of cuspal homologues on adjacent teeth yield correlations that are high or not significantly different from one. Between dental arcades, the non-occluding cusps consistently yield high genetic correlations, especially the metaconid-paracone and metaconid-metacone. This pattern of genetic correlation does not immediately accord with the pattern of development and/or calcification, however these results do follow predictions that can be made from the evolutionary history of the tribosphenic molar. PMID:20034010

Genetic integration of molar cusp size variation in baboons.

PubMed

Koh, Christina; Bates, Elizabeth; Broughton, Elizabeth; Do, Nicholas T; Fletcher, Zachary; Mahaney, Michael C; Hlusko, Leslea J

2010-06-01

Many studies of primate diversity and evolution rely on dental morphology for insight into diet, behavior, and phylogenetic relationships. Consequently, variation in molar cusp size has increasingly become a phenotype of interest. In 2007 we published a quantitative genetic analysis of mandibular molar cusp size variation in baboons. Those results provided more questions than answers, as the pattern of genetic integration did not fit predictions from odontogenesis. To follow up, we expanded our study to include data from the maxillary molar cusps. Here we report on these later analyses, as well as inter-arch comparisons with the mandibular data. We analyzed variation in two-dimensional maxillary molar cusp size using data collected from a captive pedigreed breeding colony of baboons, Papio hamadryas, housed at the Southwest National Primate Research Center. These analyses show that variation in maxillary molar cusp size is heritable and sexually dimorphic. We also estimated additive genetic correlations between cusps on the same crown, homologous cusps along the tooth row, and maxillary and mandibular cusps. The pattern for maxillary molars yields genetic correlations of one between the paracone-metacone and protocone-hypocone. Bivariate analyses of cuspal homologues on adjacent teeth yield correlations that are high or not significantly different from one. Between dental arcades, the nonoccluding cusps consistently yield high genetic correlations, especially the metaconid-paracone and metaconid-metacone. This pattern of genetic correlation does not immediately accord with the pattern of development and/or calcification, however these results do follow predictions that can be made from the evolutionary history of the tribosphenic molar. Copyright 2009 Wiley-Liss, Inc.

Possible effects of insulin-like growth factor-I, IGF-binding protein-3 and IGF-1/IGFBP-3 molar ratio on mammographic density: a cross-sectional study.

PubMed

Meggiorini, M L; Cipolla, V; Borgoni, G; Nofroni, I; Pala, A; de Felice, C

2012-01-01

The purpose of this study was to examine the possible effects of IGF-1, IGFBP-3 and IGF-1/IGFBP-3 molar ratio on mammographic density and assess whether this relationship was similar in subgroups of pre- and postmenopausal women. A group of 341 Italian women of childbearing age or naturally postmenopausal who had performed mammographic examination at the section of radiology of our department a maximum three months prior to recruitment were enrolled. A blood sample was drawn for determination of IGF-1, IGFBP-3 levels and IGF-1/IGFBP-3 molar ratio was calculated. On the basis of recent mammograms the women were divided into two groups: dense breast (DB) and non-dense breast (NDB). To assess the association between mammographic density and IGF-1, IGFBP-3 and Molar ratio Student's t-test was employed before and after stratified by menopausal status. The analysis of the relationship between mammographic density and plasma levels of IGF-1, IGFBP-3 and IGF-1/IGFBP-3 molar ratio showed that IGF-1 levels and molar ratio varied in the two groups resulting in higher mean values in the DB group whereas IGFBP-3 showed similar values in both groups (DB and NDB). After stratification of the study population by menopausal status, no association was found. Our study provides strong evidence of a crude association between breast density, and plasma levels of IGF-1 and molar ratio. IGF-1 and molar ratio might increase mammographic density and thus the risk of developing breast cancer.

Are Hypomineralized Primary Molars and Canines Associated with Molar-Incisor Hypomineralization?

PubMed

da Silva Figueiredo Sé, Maria Jose; Ribeiro, Ana Paula Dias; Dos Santos-Pinto, Lourdes Aparecida Martins; de Cassia Loiola Cordeiro, Rita; Cabral, Renata Nunes; Leal, Soraya Coelho

2017-11-01

The purpose of this study was to evaluate the prevalence of and relationship between hypomineralized second primary molars (HSPM) and hypomineralized primary canines (HPC) with molar-incisor hypomineralization (MIH) in 1,963 schoolchildren. The European Academy of Paediatric Dentistry (EAPD) criterion was used for scoring HSPM/HPC and MIH. Only children with four permanent first molars and eight incisors were considered in calculating MIH prevalence (n equals 858); for HSPM/HPC prevalence, only children with four primary second molars (n equals 1,590) and four primary canines (n equals 1,442) were considered. To evaluate the relationship between MIH/HSPM, only children meeting both criteria cited were considered (n equals 534), as was true of MIH/HPC (n equals 408) and HSPM/HPC (n equals 360; chi-square test and logistic regression). The prevalence of MIH was 14.69 percent (126 of 858 children). For HSPM and HPC, the prevalence was 6.48 percent (103 of 1,592) and 2.22 percent (32 of 1,442), respectively. A significant relationship was observed between MIH and both HSPM/HPC (P<0.001). The odds ratio for MIH based on HSPM was 6.31 (95 percent confidence interval [CI] equals 2.59 to 15.13) and for HPC was 6.02 (95 percent CI equals 1.08 to 33.05). The results led to the conclusion that both hypomineralized second primary molars and hypomineralized primary canines are associated with molar-incisor hypomineralization, because children with HSPM/HPC are six times more likely to develop MIH.

An automated technique to stage lower third molar development on panoramic radiographs for age estimation: a pilot study.

PubMed

De Tobel, J; Radesh, P; Vandermeulen, D; Thevissen, P W

2017-12-01

Automated methods to evaluate growth of hand and wrist bones on radiographs and magnetic resonance imaging have been developed. They can be applied to estimate age in children and subadults. Automated methods require the software to (1) recognise the region of interest in the image(s), (2) evaluate the degree of development and (3) correlate this to the age of the subject based on a reference population. For age estimation based on third molars an automated method for step (1) has been presented for 3D magnetic resonance imaging and is currently being optimised (Unterpirker et al. 2015). To develop an automated method for step (2) based on lower third molars on panoramic radiographs. A modified Demirjian staging technique including ten developmental stages was developed. Twenty panoramic radiographs per stage per gender were retrospectively selected for FDI element 38. Two observers decided in consensus about the stages. When necessary, a third observer acted as a referee to establish the reference stage for the considered third molar. This set of radiographs was used as training data for machine learning algorithms for automated staging. First, image contrast settings were optimised to evaluate the third molar of interest and a rectangular bounding box was placed around it in a standardised way using Adobe Photoshop CC 2017 software. This bounding box indicated the region of interest for the next step. Second, several machine learning algorithms available in MATLAB R2017a software were applied for automated stage recognition. Third, the classification performance was evaluated in a 5-fold cross-validation scenario, using different validation metrics (accuracy, Rank-N recognition rate, mean absolute difference, linear kappa coefficient). Transfer Learning as a type of Deep Learning Convolutional Neural Network approach outperformed all other tested approaches. Mean accuracy equalled 0.51, mean absolute difference was 0.6 stages and mean linearly weighted kappa was 0.82. The overall performance of the presented automated pilot technique to stage lower third molar development on panoramic radiographs was similar to staging by human observers. It will be further optimised in future research, since it represents a necessary step to achieve a fully automated dental age estimation method, which to date is not available.

A novel murine model for evaluating bovine papillomavirus prophylactics/therapeutics for equine sarcoid-like tumours

PubMed Central

Bogaert, Lies; Woodham, Andrew W.; Da Silva, Diane M.; Martens, Ann; Meyer, Evelyne

2015-01-01

Equine sarcoids are highly recurrent bovine papillomavirus (BPV)-induced fibroblastic neoplasms that are the most common skin tumours in horses. In order to facilitate the study of potential equine sarcoid prophylactics or therapeutics, which can be a slow and costly process in equines, a murine model for BPV-1 protein-expressing equine sarcoid-like tumours was developed in mice through stable transfection of BPV-1 E5 and E6 in a murine fibroblast tumour cell line (K-BALB). Like equine sarcoids, these murine tumour cells (BPV-KB) were of fibroblast origin, were tumorigenic and expressed BPV-1 proteins. As an initial investigation of the preclinical potential of this tumour model for equine sarcoids prophylactics, mice were immunized with BPV-1 E5E6 Venezuelan equine encephalitis virus replicon particles, prior to BPV-KB challenge, which resulted in an increased tumour-free period compared with controls, indicating that the BPV-KB murine model may be a valuable preclinical alternative to equine clinical trials. PMID:26044793

A novel murine model for evaluating bovine papillomavirus prophylactics/therapeutics for equine sarcoid-like tumours.

PubMed

Bogaert, Lies; Woodham, Andrew W; Da Silva, Diane M; Martens, Ann; Meyer, Evelyne; Kast, W Martin

2015-09-01

Equine sarcoids are highly recurrent bovine papillomavirus (BPV)-induced fibroblastic neoplasms that are the most common skin tumours in horses. In order to facilitate the study of potential equine sarcoid prophylactics or therapeutics, which can be a slow and costly process in equines, a murine model for BPV-1 protein-expressing equine sarcoid-like tumours was developed in mice through stable transfection of BPV-1 E5 and E6 in a murine fibroblast tumour cell line (K-BALB). Like equine sarcoids, these murine tumour cells (BPV-KB) were of fibroblast origin, were tumorigenic and expressed BPV-1 proteins. As an initial investigation of the preclinical potential of this tumour model for equine sarcoids prophylactics, mice were immunized with BPV-1 E5E6 Venezuelan equine encephalitis virus replicon particles, prior to BPV-KB challenge, which resulted in an increased tumour-free period compared with controls, indicating that the BPV-KB murine model may be a valuable preclinical alternative to equine clinical trials.

A longitudinal study of occlusal caries in Newark New Jersey school children: relationship between initial dental finding and the development of new lesions

PubMed Central

Markowitz, Kenneth; Fairlie, Karen; Ferrandiz, Javier; Nasri-Heir, Cibele

2012-01-01

Objective Dental caries is a significant public health problem especially amongst children from low-income backgrounds. This longitudinal study examined the development of new occlusal caries in 227 Newark, NJ children ages 10–18. The role of previous caries experience and the presence of occlusal white and dark lesions in predicting the development of new lesions were examined. Design At each visit, the patient’s teeth were given a visual-tactile examination and the subject’s decayed; missing and filled (DMFS) score was determined. Next, molars lacking probeable caries or restorations were examined using transillumination for occlusal white and dark spots. This examination was repeated periodically. A Cox proportional hazard was used to analyze data concerning the development of new occusal caries in molars. Results The longitudinal data indicates that patients who were caries free at visit-1 developed significantly fewer occlusal caries during the longitudinal study. The hazard ratio for subjects who had first-visit caries was 2.27 compared to caries free subjects. Intact molars with occlusal white or dark lesions had caries hazard ratios of 0.78 and 1.49 respectively, compared to molars lacking initial color changes. Conclusion Having a prior caries history places the subject at increased risk of developing future caries. Teeth with dark lesions but not white lesions are at significantly increased risk for developing decay. White lesions may represent remineralizing or slowly progressing lesions. The results of this study can help identify patients and tooth surfaces at risk for future occlusal decay. PMID:22841633

Dental age assessment of young Iranian adults using third molars: A multivariate regression study.

PubMed

Bagherpour, Ali; Anbiaee, Najmeh; Partovi, Parnia; Golestani, Shayan; Afzalinasab, Shakiba

2012-10-01

In recent years, a noticeable increase in forensic age estimations of living individuals has been observed. Radiologic assessment of the mineralisation stage of third molars is of particular importance, with regard to the relevant age group. To attain a referral database and regression equations for dental age estimation of unaccompanied minors in an Iranian population was the goal of this study. Moreover, determination was made concerning the probability of an individual being over the age of 18 in case of full third molar(s) development. Using the scoring system of Gleiser and Hunt, modified by Köhler, an investigation of a cross-sectional sample of 1274 orthopantomograms of 885 females and 389 males aged between 15 and 22 years was carried out. Using kappa statistics, intra-observer reliability was tested. With Spearman correlation coefficient, correlation between the scores of all four wisdom teeth, was evaluated. We also carried out the Wilcoxon signed-rank test on asymmetry and calculated the regression formulae. A strong intra-observer agreement was displayed by the kappa value. No significant difference (p-value for upper and lower jaws were 0.07 and 0.59, respectively) was discovered by Wilcoxon signed-rank test for left and right asymmetry. The developmental stage of upper right and upper left third molars yielded the greatest correlation coefficient. The probability of an individual being over the age of 18 is 95.6% for males and 100.0% for females in case four fully developed third molars are present. Taking into consideration gender, location and number of wisdom teeth, regression formulae were arrived at. Use of population-specific standards is recommended as a means of improving the accuracy of forensic age estimates based on third molars mineralisation. To obtain more exact regression formulae, wider age range studies are recommended. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Rate and pattern of interproximal dental attrition.

PubMed

Sarig, Rachel; Hershkovitz, Israel; Shpack, Nir; May, Hila; Vardimon, Alexander D

2015-08-01

Although occlusal and interproximal attrition occur because of diverse etiology and present dissimilar features, both progress with age. The objectives of this study were to reveal the rate and pattern of development of interproximal attrition facets (PAF) with age and to compare those with occlusal attrition (OA) changes. Five-hundred and ninety-four teeth were collected from 198 skulls (of adults, 20-71 yr of age). Three mandibular teeth [first premolar (P1), second premolar (P2), and first molar (M1)] were examined for PAF size and OA rate. Interproximal attrition and OA followed similar patterns of development until subjects reached 40-45 yr of age, after which they took different paths: PAF did not increase in size and were not as large as in younger groups, regardless of facet location, whereas OA continued to progress. The PAF changes with age differed between premolars and molars, unlike OA, which presented a similar rate for all teeth studied. Although OA scores presented significantly moderate correlations with age, PAF area size demonstrated low correlations with age. Low, but significant, correlations were found between the rate of OA and that of PAF. However, PAF and OA exhibited different patterns of development with age. Premolars and molars presented dissimilar development of PAF, which is probably caused by a unique attrition pattern in the molar teeth, different morphology, and force vectors. © 2015 Eur J Oral Sci.

Pendulum Therapy of Molar Distalization in Mixed Dentition.

PubMed

Patil, Raju Umaji; Prakash, Amit; Agarwal, Anshu

2016-01-01

Early and timely pedo-orthodontic treatment is aimed at eliminating the disturbances of skeletal or dentoalveolar development, to harmonize the stomatognathic system before the full eruption of all permanent teeth. The advantages of pendulum appliance are its minimal dependence on patient's compliance (child cooperation), ease of fabrication, onetime activation and adjustment of the springs if necessary to correct minor transverse and vertical molar positions. This article reports a successful treatment method of class II malocclusion with pendulum appliance in mixed dentition phase. Distalization of maxillary molar was done, followed by guidance of canine impaction orthodontically and other dental correction using 0.022 MBT appliances. Posttreatment results were stable and remarkable. How to cite this article: Patil RU, Prakash A, Agarwal A. Pendulum Therapy of Molar Distalization in Mixed Dentition. Int J Clin Pediatr Dent 2016;9(1):67-73.

Pendulum Therapy of Molar Distalization in Mixed Dentition

PubMed Central

Prakash, Amit; Agarwal, Anshu

2016-01-01

ABSTRACT Early and timely pedo-orthodontic treatment is aimed at eliminating the disturbances of skeletal or dentoalveolar development, to harmonize the stomatognathic system before the full eruption of all permanent teeth. The advantages of pendulum appliance are its minimal dependence on patient’s compliance (child cooperation), ease of fabrication, onetime activation and adjustment of the springs if necessary to correct minor transverse and vertical molar positions. This article reports a successful treatment method of class II malocclusion with pendulum appliance in mixed dentition phase. Distalization of maxillary molar was done, followed by guidance of canine impaction orthodontically and other dental correction using 0.022 MBT appliances. Posttreatment results were stable and remarkable. How to cite this article: Patil RU, Prakash A, Agarwal A. Pendulum Therapy of Molar Distalization in Mixed Dentition. Int J Clin Pediatr Dent 2016;9(1):67-73. PMID:27274159

Radiographic evaluation of third-molar development in relation to the chronological age of Turkish children in the southwest Eastern Anatolia region.

PubMed

Karataş, Orhan H; Öztürk, Fırat; Dedeoğlu, Numan; Çolak, Cemil; Altun, Oğuzhan

2013-10-10

To study the chronological age of third-molar mineralisation of Turkish children from the southwest Eastern Anatolia region, the Demirjian staging method was used to determine the stage of the mineralisation of four third molars (18, 28, 38 and 48) and to compare third-molar development by sex and age with the results of previous studies. The study comprised 832 Turkish children from the southwest Eastern Anatolia region aged 6-16 years based on radiological evidence from digital orthopantomograms. The mean age of the 832 patients was 11.03±1.98 years, with 424 males (mean age, 10.97±1.97) and 408 females (mean age, 11.09±2.00). The orthopantomograms were scored by two observers. The Wilcoxon matched-pairs signed-rank test used to assess intra- and inter-observer assessment revealed strong agreement between both observers' measurements. Statistical analysis of the association between sex and age was performed with the Mann-Whitney U-test and the Wilcoxon test. Regression analysis was performed to obtain regression formulae for calculating the dental and the chronological age. The statistical analysis showed a strong correlation between age and third-molar development in males (R(2)=0.61) and females (R(2)=0.63). New equations (age=7.49+0.69, development stage (DS) 38+0.70, DS18) were derived for estimation of the chronological age. The results showed that there was no significant difference in mineralisation between 18 and 28 and 38 and 48 in males or females. For both sexes, the dental age was lower than the chronological age. Males reached the developmental stages earlier than females. In the whole population, the boys' and the girls' dental ages were 0.84 years and 0.16 years earlier, respectively, than their chronological ages. The use of third-molar teeth as a developmental marker is suitable, particularly when comparing the obtained standard deviation with other skeletal-age calculation techniques. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Autotransplantation of immature third molars using a computer-aided rapid prototyping model: a report of 4 cases.

PubMed

Jang, Ji-Hyun; Lee, Seung-Jong; Kim, Euiseong

2013-11-01

Autotransplantation of immature teeth can be an option for premature tooth loss in young patients as an alternative to immediately replacing teeth with fixed or implant-supported prostheses. The present case series reports 4 successful autotransplantation cases using computer-aided rapid prototyping (CARP) models with immature third molars. The compromised upper and lower molars (n = 4) of patients aged 15-21 years old were transplanted with third molars using CARP models. Postoperatively, the pulp vitality and the development of the roots were examined clinically and radiographically. The patient follow-up period was 2-7.5 years after surgery. The long-term follow-up showed that all of the transplants were asymptomatic and functional. Radiographic examination indicated that the apices developed continuously and the root length and thickness increased. The final follow-up examination revealed that all of the transplants kept the vitality, and the apices were fully developed with normal periodontal ligaments and trabecular bony patterns. Based on long-term follow-up observations, our 4 cases of autotransplantation of immature teeth using CARP models resulted in favorable prognoses. The CARP model assisted in minimizing the extraoral time and the possible Hertwig epithelial root sheath injury of the transplanted tooth. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Quantitative analysis of the orthodontic and orthopedic effects of maxillary traction.

PubMed

Baumrind, S; Korn, E L; Isaacson, R J; West, E E; Molthen, R

1983-11-01

This article analyzes differences in displacement of ANS and of the upper first molar when different vectors of force are delivered to the maxilla in non-full-banded Phase I mixed-dentition treatment of Class II malocclusion. The sample is identical to that for which we have previously reported differences in change in several key measures of mandibular and facial shape. It includes a cervical-traction group, a high-pull-to-upper-molar group, a modified-activator group, and an untreated Class II control group. Using newly developed computer-conducted procedures, which are described, we have been able to partition the orthodontic and orthopedic components of upper molar displacement and also to isolate treatment effects from those attributable to spontaneous growth and development. In the region of ANS, small but statistically significant and clinically meaningful differences were noted between treatments. When the intercurrent effects of growth and development had been factored out (Table III), orthopedic distal displacement of ANS was significantly greater in the high-pull and cervical groups than in the activator group. Orthopedic downward displacement of ANS was seen to be significantly greater in the cervical group than in the high-pull and activator groups. In the region of the first molar cusp, mean distal displacement of the tooth as an orthopedic effect was found to be almost identical in the cervical and high-pull groups (although variability was greater in the cervical group), but the mean orthodontic effect was significantly greater in the high-pull group than in the cervical group. In the cervical group, where relatively light forces were used for relatively long treatment periods on average, more of the total distal displacement of the upper molar was of an orthopedic character than of an orthodontic character. Conversely, in the high-pull group, in which relatively heavier forces tended to be used for briefer treatment periods, most of the distal displacement at the upper molar was of an orthodontic character. These observations are contrary to expectations from conventional orthodontic theory. In the activator-treated group, roughly equal components of the treatment-associated distal displacement of the upper molar were of the orthodontic and orthopedic types. As concerns changes in the vertical direction in the region of the molar cusp, significant intrusion of both the orthopedic and orthodontic types was seen in the high-pull sample as compared to each of the other groups examined.(ABSTRACT TRUNCATED AT 400 WORDS)

A finite element analysis of the optimal bending angles in a running loop for mesial translation of a mandibular molar using indirect skeletal anchorage.

PubMed

Kim, M-J; Park, J H; Kojima, Y; Tai, K; Chae, J-M

2018-02-01

To estimate the optimal bending angles in the running loop for mesial translation of a mandibular second molar using indirect skeletal anchorage and to clarify the mechanics of tipping and rotating the molar. A three-dimensional finite element model was developed for predicting tooth movement, and a mechanical model based on the beam theory was constructed for clarifying the force systems. When using a running loop without bends, the molar tipped mesially 14.4° and lingually 0.6°, rotated counterclockwise 4.1°, and the incisors retracted 0.02 mm and intruded 0.05 mm. These angles were about the same as those estimated by the beam theory. When the amount of tip back and toe-in angles was 11.0°, mesial translation of the molar was achieved, and incisors retracted 0.10 mm and intruded 0.30 mm. Mesial translation of a mandibular second molar without any significant movement of anterior teeth was achieved during protraction by controlling the tip back and toe-in angles and enhancing anterior anchorage with the combined use of a running loop and indirect skeletal anchorage. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

In-situ growth of ZIF-8 on layered double hydroxide: Effect of Zn/Al molar ratios on their structural, morphological and adsorption properties.

PubMed

Yang, Yingli; Yan, Xinlong; Hu, Xiaoyan; Feng, Rui; Zhou, Min

2017-11-01

In-situ growth of Zeolite imidazolate frameworks (ZIFs) on layered double hydroxides (LDHs) to form porous composites is a promising and challenging strategy to develop materials for separation application. Herein, the Zn-Al LDH with different Zn/Al molar ratios was prepared and used as matrix for the growth of ZIF-8 on its surface. The resulting composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N 2 physisorption, thermogravimetric (TG), scanning electron microscope (SEM) and elemental analysis followed by testing for As V removal from aqueous solution. Results showed that ZIF-8 could form on the surface of LDH with different Zn/Al molar ratios. At low Zn/Al molar ratios, the morphology and surface area of the ZIF/LDH composites and the content of ZIF-8 in the composites were little affected by the Zn/Al molar ratio. With increasing Zn/Al molar ratio, ZIF-8/LDH exhibited a lower surface area, which resulted from reduced content of ZIF-8 caused by impurities generated in the LDH matrix. All ZIF-8/LDH samples showed high As V adsorption capacity, which was significantly higher than that of pure LDH or ZIF-8. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of ZnO seed layer precursor molar ratio on the density of interface defects in low temperature aqueous chemically synthesized ZnO nanorods/GaN light-emitting diodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alnoor, Hatim, E-mail: hatim.alnoor@liu.se; Iandolo, Donata; Willander, Magnus

Low temperature aqueous chemical synthesis (LT-ACS) of zinc oxide (ZnO) nanorods (NRs) has been attracting considerable research interest due to its great potential in the development of light-emitting diodes (LEDs). The influence of the molar ratio of the zinc acetate (ZnAc): KOH as a ZnO seed layer precursor on the density of interface defects and hence the presence of non-radiative recombination centers in LT-ACS of ZnO NRs/GaN LEDs has been systematically investigated. The material quality of the as-prepared seed layer as quantitatively deduced by the X-ray photoelectron spectroscopy is found to be influenced by the molar ratio. It is revealedmore » by spatially resolved cathodoluminescence that the seed layer molar ratio plays a significant role in the formation and the density of defects at the n-ZnO NRs/p-GaN heterostructure interface. Consequently, LED devices processed using ZnO NRs synthesized with molar ratio of 1:5 M exhibit stronger yellow emission (∼575 nm) compared to those based on 1:1 and 1:3 M ratios as measured by the electroluminescence. Furthermore, seed layer molar ratio shows a quantitative dependence of the non-radiative defect densities as deduced from light-output current characteristics analysis. These results have implications on the development of high-efficiency ZnO-based LEDs and may also be helpful in understanding the effects of the ZnO seed layer on defect-related non-radiative recombination.« less

Three-dimensional quantification of orthodontic root resorption with time-lapsed imaging of micro-computed tomography in a rodent model.

PubMed

Yang, Chongshi; Zhang, Yuanyuan; Zhang, Yan; Fan, Yubo; Deng, Feng

2015-01-01

Despite various X-ray approaches have been widely used to monitor root resorption after orthodontic treatment, a non-invasive and accurate method is highly desirable for long-term follow up. The aim of this study was to build a non-invasive method to quantify longitudinal orthodontic root resorption with time-lapsed images of micro-computed tomography (micro-CT) in a rodent model. Twenty male Sprague Dawley (SD) rats (aged 6-8 weeks, weighing 180-220 g) were used in this study. A 25 g orthodontic force generated by nickel-titanium coil spring was applied to the right maxillary first molar for each rat, while contralateral first molar was severed as a control. Micro-CT scan was performed at day 0 (before orthodontic load) and days 3, 7, 14, and 28 after orthodontic load. Resorption of mesial root of maxillary first molars at bilateral sides was calculated from micro-CT images with registration algorithm via reconstruction, superimposition and partition operations. Obvious resorption of mesial root of maxillary first molar can be detected at day 14 and day 28 at orthodontic side. Most of the resorption occurred in the apical region at distal side and cervical region at mesiolingual side. Desirable development of molar root of rats was identified from day 0 to day 28 at control side. The development of root concentrated on apical region. This non-invasive 3D quantification method with registration algorithm can be used in longitudinal study of root resorption. Obvious root resorption in rat molar can be observed three-dimensionally at day 14 and day 28 after orthodontic load. This indicates that registration algorithm combined with time-lapsed images provides clinic potential application in detection and quantification of root contour.

Dental age estimation from the developmental stage of the third molars in western Chinese population.

PubMed

Li, Guo; Ren, Jiayin; Zhao, Shuping; Liu, Yuanyuan; Li, Na; Wu, Wanhong; Yuan, Shanshan; Wang, Hu

2012-06-10

The purpose of this study is to provide reference data about estimating dental age from third molars of the western Chinese population for comparing with other populations and being applied to the age estimation of western Chinese juveniles and adolescents. A total of 2078 digital panoramic radiographs of 989 male and 1089 female Chinese subjects aged between 5 and 23 years were examined. The mineralization status of the third molars was assessed using the formation stages described by Demirjian et al. with two modifications. The results showed that the development of third molars in the western Chinese population was likely to begin at age 5 in both males and females. The third molars 28 and 48 showed significantly higher frequency in females than in males. The third molars 18 in the stage 1, 38 in the stages 1, A and G, and 48 in the stage H showed significantly older average age in females than in males. The Demirjian's stages C and D could be used as a reference stage to determine dichotomously whether a western Chinese is more likely to be under or above age 14 or 16, respectively. This study provided reference data for the age estimation of western Chinese juveniles and adolescents by the mineralization stages of the third molar. Apart from forensic age determination in living subjects, the presented reference data can also be used for age estimations of unidentified corpses and skeletons. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

The presence of accessory cusps in chimpanzee lower molars is consistent with a patterning cascade model of development

PubMed Central

Skinner, Matthew M; Gunz, Philipp

2010-01-01

Tooth crown morphology is of primary importance in fossil primate systematics and understanding the developmental basis of its variation facilitates phenotypic analyses of fossil teeth. Lower molars of species in the chimp/human clade (including fossil hominins) possess between four and seven cusps and this variability has been implicated in alpha taxonomy and phylogenetic systematics. What is known about the developmental basis of variation in cusp number – based primarily on experimental studies of rodent molars – suggests that cusps form under a morphodynamic, patterning cascade model involving the iterative formation of enamel knots. In this study we test whether variation in cusp 6 (C6) presence in common chimpanzee and bonobo lower molars (n = 55) is consistent with predictions derived from the patterning cascade model. Using microcomputed tomography we imaged the enamel-dentine junction of lower molars and used geometric morphometrics to examine shape variation in the molar crown correlated with variation in C6 presence (in particular the size and spacing of the dentine horns). Results indicate that C6 presence is consistent with predictions of a patterning cascade model, with larger molars exhibiting a higher frequency of C6 and with the location and size of later-forming cusps correlated with C6 variation. These results demonstrate that a patterning cascade model is appropriate for interpreting cusp variation in Pan and have implications for cusp nomenclature and the use of accessory cusp morphology in primate systematics. PMID:20629983

Influence of maxillary posterior discrepancy on upper molar vertical position and facial vertical dimensions in subjects with or without skeletal open bite

PubMed Central

Aliaga-Del Castillo, Aron; Pérez-Vargas, Luis Fernando; Flores-Mir, Carlos

2016-01-01

Summary Objectives: To determine the influence of maxillary posterior discrepancy on upper molar vertical position and dentofacial vertical dimensions in individuals with or without skeletal open bite (SOB). Materials and methods: Pre-treatment lateral cephalograms of 139 young adults were examined. The sample was divided into eight groups categorized according to their sagittal and vertical skeletal facial growth pattern and maxillary posterior discrepancy (present or absent). Upper molar vertical position, overbite, lower anterior facial height and facial height ratio were measured. Independent t-test was performed to determine differences between the groups considering maxillary posterior discrepancy. Principal component analysis and MANCOVA test were also used. Results: No statistically significant differences were found comparing the molar vertical position according to maxillary posterior discrepancy for the SOB Class I group or the group with adequate overbite. Significant differences were found in SOB Class II and Class III groups. In addition, an increased molar vertical position was found in the group without posterior discrepancy. Limitations: Some variables closely related with the individual’s intrinsic craniofacial development that could influence the evaluated vertical measurements were not considered. Conclusions and implications: Overall maxillary posterior discrepancy does not appear to have a clear impact on upper molar vertical position or facial vertical dimensions. Only the SOB Class III group without posterior discrepancy had a significant increased upper molar vertical position. PMID:26385786

Influence of maxillary posterior discrepancy on upper molar vertical position and facial vertical dimensions in subjects with or without skeletal open bite.

PubMed

Arriola-Guillén, Luis Ernesto; Aliaga-Del Castillo, Aron; Pérez-Vargas, Luis Fernando; Flores-Mir, Carlos

2016-06-01

To determine the influence of maxillary posterior discrepancy on upper molar vertical position and dentofacial vertical dimensions in individuals with or without skeletal open bite (SOB). Pre-treatment lateral cephalograms of 139 young adults were examined. The sample was divided into eight groups categorized according to their sagittal and vertical skeletal facial growth pattern and maxillary posterior discrepancy (present or absent). Upper molar vertical position, overbite, lower anterior facial height and facial height ratio were measured. Independent t-test was performed to determine differences between the groups considering maxillary posterior discrepancy. Principal component analysis and MANCOVA test were also used. No statistically significant differences were found comparing the molar vertical position according to maxillary posterior discrepancy for the SOB Class I group or the group with adequate overbite. Significant differences were found in SOB Class II and Class III groups. In addition, an increased molar vertical position was found in the group without posterior discrepancy. Some variables closely related with the individual's intrinsic craniofacial development that could influence the evaluated vertical measurements were not considered. Overall maxillary posterior discrepancy does not appear to have a clear impact on upper molar vertical position or facial vertical dimensions. Only the SOB Class III group without posterior discrepancy had a significant increased upper molar vertical position. © The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Ebselen, a Small-Molecule Capsid Inhibitor of HIV-1 Replication.

PubMed

Thenin-Houssier, Suzie; de Vera, Ian Mitchelle S; Pedro-Rosa, Laura; Brady, Angela; Richard, Audrey; Konnick, Briana; Opp, Silvana; Buffone, Cindy; Fuhrmann, Jakob; Kota, Smitha; Billack, Blase; Pietka-Ottlik, Magdalena; Tellinghuisen, Timothy; Choe, Hyeryun; Spicer, Timothy; Scampavia, Louis; Diaz-Griffero, Felipe; Kojetin, Douglas J; Valente, Susana T

2016-04-01

The human immunodeficiency virus type 1 (HIV-1) capsid plays crucial roles in HIV-1 replication and thus represents an excellent drug target. We developed a high-throughput screening method based on a time-resolved fluorescence resonance energy transfer (HTS-TR-FRET) assay, using the C-terminal domain (CTD) of HIV-1 capsid to identify inhibitors of capsid dimerization. This assay was used to screen a library of pharmacologically active compounds, composed of 1,280in vivo-active drugs, and identified ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one], an organoselenium compound, as an inhibitor of HIV-1 capsid CTD dimerization. Nuclear magnetic resonance (NMR) spectroscopic analysis confirmed the direct interaction of ebselen with the HIV-1 capsid CTD and dimer dissociation when ebselen is in 2-fold molar excess. Electrospray ionization mass spectrometry revealed that ebselen covalently binds the HIV-1 capsid CTD, likely via a selenylsulfide linkage with Cys198 and Cys218. This compound presents anti-HIV activity in single and multiple rounds of infection in permissive cell lines as well as in primary peripheral blood mononuclear cells. Ebselen inhibits early viral postentry events of the HIV-1 life cycle by impairing the incoming capsid uncoating process. This compound also blocks infection of other retroviruses, such as Moloney murine leukemia virus and simian immunodeficiency virus, but displays no inhibitory activity against hepatitis C and influenza viruses. This study reports the use of TR-FRET screening to successfully identify a novel capsid inhibitor, ebselen, validating HIV-1 capsid as a promising target for drug development. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Prevalence of missing and impacted third molars in adults aged 25 years and above

PubMed Central

Jung, Yun-Hoa

2013-01-01

Purpose The purpose of this study was to determine the prevalence of missing and impacted third molars in people aged 25 years and above. Materials and Methods The study sample of 3,799 patients was chosen randomly from patients who visited Pusan National University Dental Hospital and had panoramic radiographs taken. The data collected included presence and impaction state, angulation, and depth of impaction of third molars, and radiographically detected lesions of third molars and adjacent second molars. Results A greater percentage of men than women retained at least one third molar. The incidence of third molars decreased with increasing age. The incidence of partially impacted third molars greatly declined after the age of 30. Vertically impacted maxillary third molars and horizontally impacted mandibular third molars were most frequent in all age groups. Among the maxillary third molars, those impacted below the cervical line of the second molar were most frequent in all age groups, and among the mandibular third molars, deeply impacted third molars were most frequent in those aged over 40. Dental caries was the most common radiographic lesion of the third molars. Mesioangularly impacted third molars showed radiographic lesions in 13 (9.5%) adjacent maxillary second molars and 117 (27.4%) mandibular second molars. Conclusion The number of remaining third molars decreased and the percentage of Class C depth increased with age. Caries was the most frequent lesion in third molars. Partially impacted mesioangular third molars showed a high incidence of caries or periodontal bone loss of the adjacent second molar. Regular oral examination will be essential to keep asymptomatic third molars in good health. PMID:24380060

Patterning by heritage in mouse molar row development.

PubMed

Prochazka, Jan; Pantalacci, Sophie; Churava, Svatava; Rothova, Michaela; Lambert, Anne; Lesot, Hervé; Klein, Ophir; Peterka, Miroslav; Laudet, Vincent; Peterkova, Renata

2010-08-31

It is known from paleontology studies that two premolars have been lost during mouse evolution. During mouse mandible development, two bud-like structures transiently form that may represent rudimentary precursors of the lost premolars. However, the interpretation of these structures and their significance for mouse molar development are highly controversial because of a lack of molecular data. Here, we searched for typical tooth signaling centers in these two bud-like structures, and followed their fate using molecular markers, 3D reconstructions, and lineage tracing in vitro. Transient signaling centers were indeed found to be located at the tips of both the anterior and posterior rudimentary buds. These centers expressed a similar set of molecular markers as the "primary enamel knot" (pEK), the signaling center of the first molar (M1). These two transient signaling centers were sequentially patterned before and anterior to the M1 pEK. We also determined the dynamics of the M1 pEK, which, slightly later during development, spread up to the field formerly occupied by the posterior transient signaling center. It can be concluded that two rudimentary tooth buds initiate the sequential development of the mouse molars and these have previously been mistaken for early stages of M1 development. Although neither rudiment progresses to form an adult tooth, the posterior one merges with the adjacent M1, which may explain the anterior enlargement of the M1 during mouse family evolution. This study highlights how rudiments of lost structures can stay integrated and participate in morphogenesis of functional organs and help in understanding their evolution, as Darwin suspected long ago.

Unilateral distalization of a maxillary molar with sliding mechanics: a case report.

PubMed

Keles, Ahmet

2002-06-01

A unilateral Class II relationship could arise due to early loss of an upper second deciduous molar on one side during the mixed dentition period. This would allow the mesial drift of the molars, which may block the eruption of the second premolar. A 15-year 8-month-old male patient presented with a Class II molar relationship on the right, and Class I canine and molar relationship on the left side. His E was extracted when he was 5 years old. The 54 were impacted and the 3 was ectopically positioned due to the space loss from the mesial migration of the 76. In addition 21 1 were in cross-bite. Skeletally he had Class III tendency with low MMPA. He presented with a straight profile and retruded upper lip. For maxillary molar distalization, a newly developed 'Keles Slider' was used. The appliance was composed of one premolar and two molar bands, and the anchorage unit was composed of a wide Nance button. 46 were connected to the Nance button and, therefore, included into the anchorage unit. The point of distal force application was close to the centre of resistance of the 6 and parallel to the occlusal plane. Ni-Ti coil springs were used and 200 g of distal force was applied. Seven months later the space required for eruption of the permanent premolars and canine was regained, and the anterior cross-bite corrected. The appliance was removed and final alignment of the teeth was achieved with fixed appliances. At the end of the second phase treatment Class I molar and canine relationship was achieved on the both sides, the anterior cross-bite was corrected, inter-incisal angle was improved, and ideal overbite and overjet relationship was achieved. The active treatment time was 27 months.

Interceptive management of eruption disturbances: case report.

PubMed

Cozza, Paola; Marino, Alessandra; Lagana, Giuseppina

2004-01-01

The aim of the present report is to describe a case of a patient with eruption disturbances of an ankylosed lower primary second molar, delayed development of a maxillary permanent canine associated with an odontoma and a class III dental malocclusion. In such a case the objectives of treatment are: to prevent impaction of the lower second premolar and tipping of the lower first molar; to establish correct anterior overbite and overjet and to control the development of the permanent upper canine.

Prevalence and distribution of dental anomalies: a comparison between maxillary and mandibular tooth agenesis.

PubMed

Al-Abdallah, Mariam; AlHadidi, Abeer; Hammad, Mohammad; Al-Ahmad, Hazem; Saleh, Raja'

2015-11-01

The aim of this study was to compare the pattern and prevalence of associated dental anomalies between maxillary and mandibular tooth agenesis (hypodontia). A sample of 3315 dental patients, aged 8.6 to 25.4 years, was surveyed for tooth agenesis (excluding third molars): 106 subjects were diagnosed with maxillary hypodontia (group 1) and 70 with mandibular hypodontia (group 2). Both groups were examined for the following dental anomalies: retained deciduous molars, infraocclusion of deciduous molars, impaction, microdontia of maxillary lateral incisors, supernumerary teeth, transposition, transmigration, and ectopic eruption of the permanent molars. For statistical testing, the chi-square test (P <0.05) was used to compare the occurrences of these anomalies among the groups. We found that 77.5% of the patients in the mandibular hypodontia group had at least 1 dental anomaly compared with 49.5% in the maxillary hypodontia group (P <0.0001). The only dental anomaly with a significantly increased prevalence in the maxillary hypodontia group compared with the mandibular hypodontia group was microdontia of the maxillary lateral incisors (groups 1, 46.7%; group 2, 12.9%; P <0.0001). On the other hand, the prevalences of retained deciduous molars (group 1, 9.4%; group 2, 60.0%), infraoccluded deciduous molars (group 1, 0.9%; group 2, 7.1%), and impacted teeth (group 1, 22.6%; group 2, 38.6%) were significantly higher in the mandibular hypodontia group. The prevalences of supernumerary teeth, transposition, transmigration, and ectopic eruption of permanent molars were low and not significantly different between the groups. Tooth agenesis isolated to the maxilla is frequently associated with microdontia of the maxillary lateral incisors, whereas tooth agenesis isolated to the mandible is frequently associated with retained deciduous molars, infraoccluded deciduous molars, and impacted teeth. The results of this study may provide additional evidence supporting the field-specific genetic control theory for dental development in both jaws. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Managing molar-incisor hypomineralization: A systematic review.

PubMed

Elhennawy, Karim; Schwendicke, Falk

2016-12-01

We systematically reviewed treatment modalities for MIH-affected molars and incisors. Trials on humans with ≥1 MIH molar/incisor reporting on various treatments were included. Two authors independently searched and extracted records. Sample-size-weighted annual failure rates were estimated where appropriate. The risk of bias was assessed using the Newcastle-Ottawa scale. Electronic databases (PubMed, Embase, Cochrane CENTRAL, Google Scholar) were screened, and hand searches and cross-referencing performed. Fourteen (mainly observational) studies were included. Ten trials (381 participants) investigated MIH-molars, four (139) MIH-incisors. For molars, remineralization, restorative or extraction therapies had been assessed. For restorative approaches, mean (SD) annual failure rates were highest for fissure sealants (12[6]%) and glass-ionomer restorations (12[2]%), and lowest for indirect restorations (1[3]%), preformed metal crowns (1.3 [2.1]%) and composite restorations (4[3]%). Ony study assessed extraction of molars in young patients (median age 8.2 years), the majority of them without malocclusions, but third molars in development. Spontaneous alignment of second molars was more frequent in the maxilla (55%) than the mandible (47%). For incisors, desensitizing agents successfully managed hypersensitivity. Micro-abrasion and composite veneers improved aesthetics. Few, mainly moderate to high-risk-studies investigated treatment of MIH. Remineralization or sealants seem suitable for MIH-molars with limited severity and/or hypersensitivity. For severe cases, restorations with composites or indirect restorations or preformed metal crowns seem suitable. Prior to tooth extraction as last resort factors like the presence of a general malocclusion, patients' age and the status of neighboring teeth should be considered. No recommendations can be given for MIH-incisors. Dentists need to consider the specific condition of each tooth and the needs and expectations of patients when deciding how to manage MIH. Strong recommendations are not possible based on the current evidence. Copyright © 2016 Elsevier Ltd. All rights reserved.

Human age estimation combining third molar and skeletal development.

PubMed

Thevissen, P W; Kaur, J; Willems, G

2012-03-01

The wide prediction intervals obtained with age estimation methods based on third molar development could be reduced by combining these dental observations with age-related skeletal information. Therefore, on cephalometric radiographs, the most accurate age-estimating skeletal variable and related registration method were searched and added to a regression model, with age as response and third molar stages as explanatory variable. In a pilot set up on a dataset of 496 (283 M; 213 F) cephalometric radiographs, the techniques of Baccetti et al. (2005) (BA), Seedat et al. (2005) (SE), Caldas et al. (2007) and Rai et al. (2008) (RA) were verified. In the main study, data from 460 (208 F, 224 M) individuals in an age range between 3 and 26 years, for which at the same day an orthopantogram and a cephalogram were taken, were collected. On the orthopantomograms, the left third molar development was registered using the scoring system described by Gleiser and Hunt (1955) and modified by Köhler (1994) (GH). On the cephalograms, cervical vertebrae development was registered according to the BA and SE techniques. A regression model, with age as response and the GH scores as explanatory variable, was fitted to the data. Next, information of BA, SE and BA + SE was, respectively, added to this model. From all obtained models, the determination coefficients and the root mean squared errors were calculated. Inclusion of information from cephalograms based on the BA, as well as the SE, technique improved the amount of explained variance in age acquired from panoramic radiographs using the GH technique with 48%. Inclusion of cephalometric BA + SE information marginally improved the previous result (+1%). The RMSE decreased with 1.93, 1.85 and 2.03 years by adding, respectively, BA, SE and BA + SE information to the GH model. The SE technique allows clinically the fastest and easiest registration of the degree of development of the cervical vertebrae. Therefore, the choice of technique to classify cervical vertebrae development in addition to third molar development is preferably the SE technique.

Relationship Between Third Mandibular Molar Angulation and Distal Cervical Caries in the Second Molar.

PubMed

Claudia, Andreescu; Barbu, Horia Mihail; Adi, Lorean; Gultekin, Alper; Reiser, Vadim; Gultekin, Pinar; Mijiritsky, Eitan

2018-03-16

Third lower molar partially erupted is commonly encountered in dental practice. This situation challenges clinicians with the dilemma whether to remove or to monitor it, because this molar can cause pathology of the adjacent second molar. The aim of this retrospective study is to evaluate the relationship between third mandibular molar and distal cervical caries in second molar. This retrospective study analyzed 55 digital orthopantograms of adult patients and a total number of 95 mandibular third molars were assessed for eruption status, angulation, radiographic evidence of caries or restoration in the mandibular third molar, and radiographic evidence of caries or restoration in the distal surface of the mandibular second molar. The distal cervical caries in second molar is associated with fully erupted and partially erupted wisdom molar in horizontal, mesioangular and vertical position and less with presence of caries in third molar. There are caries lesions in distal second molars in mesioangular position when adjacent third molar is caries free.

A Chitin-Like Component on Sclerotic Cells of Fonsecaea pedrosoi Inhibits Dectin-1-Mediated Murine Th17 Development by Masking β-Glucans

PubMed Central

Li, Ruoyu; Chen, Sharon C.-A.; Liu, Weihuang; Liu, Wei; Chen, Liuqing; Chen, Yao; Zhang, Xu; Tong, Zhongsheng; Xia, Yun; Xia, Ping; Wang, Yan; Duan, Yiqun

2014-01-01

Fonsecaea pedrosoi (F. pedrosoi), a major agent of chromoblastomycosis, has been shown to be recognized primarily by C-type lectin receptors (CLRs) in a murine model of chromoblastomycosis. Specifically, the β-glucan receptor, Dectin-1, mediates Th17 development and consequent recruitment of neutrophils, and is evidenced to have the capacity to bind to saprophytic hyphae of F. pedrosoi in vitro. However, when embedded in tissue, most etiological agents of chromoblastomycosis including F. pedrosoi will transform into the sclerotic cells, which are linked to the greatest survival of melanized fungi in tissue. In this study, using immunocompetent and athymic (nu/nu) murine models infected subcutaneously or intraperitoneally with F. pedrosoi, we demonstrated that T lymphocytes play an active role in the resolution of localized footpad infection, and there existed a significantly decreased expression of Th17-defining transcription factor Rorγt and inefficient recruitment of neutrophils in chronically infected spleen where the inoculated mycelium of F. pedrosoi transformed into the sclerotic cells. We also found that Dectin-1-expressing histocytes and neutrophils participated in the enclosure of transformed sclerotic cells in the infectious foci. Furthermore, we induced the formation of sclerotic cells in vitro, and evidenced a significantly decreased binding capacity of human or murine-derived Dectin-1 to the induced sclerotic cells in comparison with the saprophytic mycelial forms. Our analysis of β-glucans-masking components revealed that it is a chitin-like component, but not the mannose moiety on the sclerotic cells, that interferes with the binding of β-glucans by human or murine Dectin-1. Notably, we demonstrated that although Dectin-1 contributed to the development of IL-17A-producing CD3+CD4+ murine splenocytes upon in vitro-stimulation by saprophytic F. pedrosoi, the masking effect of chitin components partly inhibited Dectin-1-mediated Th17 development upon in vitro-stimulation by induced sclerotic cells. Therefore, these findings extend our understanding of the chronicity of chromoblastomycosis. PMID:25490199

Saving the 2(nd) Molar from the 3(rd) Is it Really the Guilt of the Tilt?

PubMed

Yadav, Pankaj; Pruthi, Preeti Jain; Nawal, Ruchika Roongta; Talwar, Sangeeta; Verma, Mahesh

2016-05-01

Clinicians often relate the distal caries in second molars to angulated third molars, which if left undetected can lead to gross decay that may further require removal of the tooth. Due to this fact, many third molars are advised for prophylactic removal to prevent decay in the second molar. But this approach would only be justified when the incidence of decay/loss of second molar due to third molar are reasonably high. We sought to determine incidence of caries experience and also sequel extraction in second molars associated with the third molars. The study was conducted to answer the basic question that whether the incidence of caries and subsequent extraction of second molar due to angulated third molars is high enough to justify the prophylactic removal of third molar or not. This study was conducted on radiographic records of 1187 patients. The effect of tilted third molar on the second molar was measured in relation with three parameters namely level & position of third molar with respect to second molar and the distribution among arches. The results indicated that out of total number of teeth examined only 5.4% of maxillary and 9.6% of mandibular second molars were affected by tilted third molars. Further, only 2.2% of mandibular and 2.9% of maxillary second molars were indicated for extraction. The data was statistically insignificant. It was concluded that distal caries in second molars is not very common. It may be present in some cases of third molar impactions and prophylactic removal of these impacted teeth may not be considered appropriate.

Ecomorphological characterization of murines and non-arvicoline cricetids (Rodentia) from south-western Europe since the latest Middle Miocene to the Mio-Pliocene boundary (MN 7/8–MN13)

PubMed Central

Kimura, Yuri; Blanco, Fernando; Menéndez, Iris; Álvarez-Sierra, María A.; Hernández Fernández, Manuel

2017-01-01

Rodents are the most speciose group of mammals and display a great ecological diversity. Despite the greater amount of ecomorphological information compiled for extant rodent species, studies usually lack of morphological data on dentition, which has led to difficulty in directly utilizing existing ecomorphological data of extant rodents for paleoecological reconstruction because teeth are the most common or often the only micromammal fossils. Here, we infer the environmental ranges of extinct rodent genera by extracting habitat information from extant relatives and linking it to extinct taxa based on the phenogram of the cluster analysis, in which variables are derived from the principal component analysis on outline shape of the upper first molars. This phenotypic “bracketing” approach is particularly useful in the study of the fossil record of small mammals, which is mostly represented by isolated teeth. As a case study, we utilize extinct genera of murines and non-arvicoline cricetids, ranging from the Iberoccitanian latest middle Miocene to the Mio-Pliocene boundary, and compare our results thoroughly with previous paleoecological reconstructions inferred by different methods. The resultant phenogram shows a predominance of ubiquitous genera among the Miocene taxa, and the presence of a few forest specialists in the two rodent groups (Murinae and Cricetidae), along with the absence of open environment specialists in either group of rodents. This appears to be related to the absence of enduring grassland biomes in the Iberian Peninsula during the late Miocene. High consistency between our result and previous studies suggests that this phenotypic “bracketing” approach is a very useful tool. PMID:28966888

Linking molar organizational climate and strategic implementation climate to clinicians' use of evidence-based psychotherapy techniques: cross-sectional and lagged analyses from a 2-year observational study.

PubMed

Williams, Nathaniel J; Ehrhart, Mark G; Aarons, Gregory A; Marcus, Steven C; Beidas, Rinad S

2018-06-25

Behavioral health organizations are characterized by multiple organizational climates, including molar climate, which encompasses clinicians' shared perceptions of how the work environment impacts their personal well-being, and strategic implementation climate, which includes clinicians' shared perceptions of the extent to which evidence-based practice implementation is expected, supported, and rewarded by the organization. Theory suggests these climates have joint, cross-level effects on clinicians' implementation of evidence-based practice and that these effects may be long term (i.e., up to 2 years); however, no empirical studies have tested these relationships. We hypothesize that molar climate moderates implementation climate's concurrent and long-term relationships with clinicians' use of evidence-based practice such that strategic implementation climate will have its most positive effects when it is accompanied by a positive molar climate. Hypotheses were tested using data collected from 235 clinicians in 20 behavioral health organizations. At baseline, clinicians reported on molar climate and implementation climate. At baseline and at a 2-year follow-up, all clinicians who were present in the organizations reported on their use of cognitive-behavioral psychotherapy techniques, an evidence-based practice for youth psychiatric disorders. Two-level mixed-effects regression models tested whether baseline molar climate and implementation climate interacted in predicting clinicians' evidence-based practice use at baseline and at 2-year follow-up. In organizations with more positive molar climates at baseline, higher levels of implementation climate predicted increased evidence-based practice use among clinicians who were present at baseline and among clinicians who were present in the organizations at 2-year follow-up; however, in organizations with less positive molar climates, implementation climate was not related to clinicians' use of evidence-based practice at either time point. Optimizing clinicians' implementation of evidence-based practice in behavioral health requires attention to both molar climate and strategic implementation climate. Strategies that focus exclusively on implementation climate may not be effective levers for behavior change if the organization does not also engender a positive molar climate. These findings have implications for the development of implementation theory and effective implementation strategies.

Maternal Near Miss According to World Health Organization Classification Among Women with a Hydatidiform Mole: Experience at the New England Trophoblastic Disease Center, 1994-2013.

PubMed

Sun, Sue Yazaki; Goldstein, Donald P; Bernstein, Marilyn R; Horowitz, Neil S; Mattar, Rosiane; Maestá, Izildinha; Braga, Antonio; Berkowitz, Ross S

2016-01-01

To investigate the frequency of potentially life-threatening conditions (PLTCs) and maternal near misses (MNMs) at the New England Trophoblastic Disease Center (NETDC) in recent years, when there has been earlier diagnosis of molar pregnancy. This study included patients with molar pregnancy at the NETDC between 1994 and 2013. Clinical and pathologic reports were reviewed. PLTC and MNM criteria and maternal deaths were searched in medical records using the World Health Organization criteria and classification. We identified 375 patients with molar pregnancy and no patient developed a MNM or maternal death. Only 6 (1.6%) had PLTCs (hemorrhage with hemodynamic instability, severe preeclampsia, respiratory distress, blood transfusion, and ICU admission). We observed a low rate of PLTC and no cases of MNMs or maternal deaths related to molar pregnancy, likely due to earlier diagnosis at the NETDC in recent years.

Organic carbonates: experiment and ab initio calculations for prediction of thermochemical properties.

PubMed

Verevkin, Sergey P; Emel'yanenko, Vladimir N; Kozlova, Svetlana A

2008-10-23

This work has been undertaken in order to obtain data on thermodynamic properties of organic carbonates and to revise the group-additivity values necessary for predicting their standard enthalpies of formation and enthalpies of vaporization. The standard molar enthalpies of formation of dibenzyl carbonate, tert-butyl phenyl carbonate, and diphenyl carbonate were measured using combustion calorimetry. Molar enthalpies of vaporization of these compounds were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. Molar enthalpy of sublimation of diphenyl carbonate was measured in the same way. Ab initio calculations of molar enthalpies of formation of organic carbonates have been performed using the G3MP2 method, and results are in excellent agreement with the available experiment. Then the group-contribution method has been developed to predict values of the enthalpies of formation and enthalpies of vaporization of organic carbonates.

Partial Molar Volumes of Aqua Ions from First Principles.

PubMed

Wiktor, Julia; Bruneval, Fabien; Pasquarello, Alfredo

2017-08-08

Partial molar volumes of ions in water solution are calculated through pressures obtained from ab initio molecular dynamics simulations. The correct definition of pressure in charged systems subject to periodic boundary conditions requires access to the variation of the electrostatic potential upon a change of volume. We develop a scheme for calculating such a variation in liquid systems by setting up an interface between regions of different density. This also allows us to determine the absolute deformation potentials for the band edges of liquid water. With the properly defined pressures, we obtain partial molar volumes of a series of aqua ions in very good agreement with experimental values.

Morphologic study of the maxillary molars. Part II: Internal anatomy.

PubMed

Pécora, J D; Woelfel, J B; Sousa Neto, M D; Issa, E P

1992-01-01

The internal anatomy of three hundred and seventy (370) decalcified and cleared human maxillary molars was studied. Seventy-five percent of the first molars, 58% of the second molars and 68% of the third molars studied presented three (3) root canals and 25% of the first molars, 42% of the second molars and 32% of the third molars presented four (4) root canals. The authors observed that the incidence of two root canals in the mesiobuccal root was higher in second maxillary molars than in first maxillary molars.

Saving the 2nd Molar from the 3rd Is it Really the Guilt of the Tilt?

PubMed Central

Yadav, Pankaj; Nawal, Ruchika Roongta; Talwar, Sangeeta; Verma, Mahesh

2016-01-01

Introduction Clinicians often relate the distal caries in second molars to angulated third molars, which if left undetected can lead to gross decay that may further require removal of the tooth. Due to this fact, many third molars are advised for prophylactic removal to prevent decay in the second molar. But this approach would only be justified when the incidence of decay/loss of second molar due to third molar are reasonably high. We sought to determine incidence of caries experience and also sequel extraction in second molars associated with the third molars. Aim The study was conducted to answer the basic question that whether the incidence of caries and subsequent extraction of second molar due to angulated third molars is high enough to justify the prophylactic removal of third molar or not. Materials and Methods This study was conducted on radiographic records of 1187 patients. The effect of tilted third molar on the second molar was measured in relation with three parameters namely level & position of third molar with respect to second molar and the distribution among arches. Results The results indicated that out of total number of teeth examined only 5.4% of maxillary and 9.6% of mandibular second molars were affected by tilted third molars. Further, only 2.2% of mandibular and 2.9% of maxillary second molars were indicated for extraction. The data was statistically insignificant. Conclusion It was concluded that distal caries in second molars is not very common. It may be present in some cases of third molar impactions and prophylactic removal of these impacted teeth may not be considered appropriate. PMID:27437353

Use of a Laboratory Exercise on Molar Absorptivity to Help Students Understand the Authority of the Primary Literature

ERIC Educational Resources Information Center

Soundararajan, Madhavan; Bailey, Cheryl P.; Markwell, John

2008-01-01

To promote understanding of the authority of the primary literature in students taking our biochemistry laboratory courses, a biochemistry laboratory exercise on the determination of an acceptable molar absorptivity value of 2-nitrophenol (2-NP) was developed. This made the laboratory course much more relevant by linking to a thematic thread,…

Pneumomediastinum and subcutaneous emphysema following surgical extraction of mandibular third molars: three case reports.

PubMed

Horowitz, I; Hirshberg, A; Freedman, A

1987-01-01

Three cases of subcutaneous emphysema following surgical extraction of lower third molars are presented. In two of the cases, pneumomediastinum developed. The direct cause of these complications is the combination of the use of an air turbine dental handpiece and the flap design. The propagation of the emphysema and means for its prevention are discussed.

The mutational landscape of MYCN, Lin28b and ALK F1174L driven murine neuroblastoma mimics human disease.

PubMed

De Wilde, Bram; Beckers, Anneleen; Lindner, Sven; Kristina, Althoff; De Preter, Katleen; Depuydt, Pauline; Mestdagh, Pieter; Sante, Tom; Lefever, Steve; Hertwig, Falk; Peng, Zhiyu; Shi, Le-Ming; Lee, Sangkyun; Vandermarliere, Elien; Martens, Lennart; Menten, Björn; Schramm, Alexander; Fischer, Matthias; Schulte, Johannes; Vandesompele, Jo; Speleman, Frank

2018-02-02

Genetically engineered mouse models have proven to be essential tools for unraveling fundamental aspects of cancer biology and for testing novel therapeutic strategies. To optimally serve these goals, it is essential that the mouse model faithfully recapitulates the human disease. Recently, novel mouse models for neuroblastoma have been developed. Here, we report on the further genomic characterization through exome sequencing and DNA copy number analysis of four of the currently available murine neuroblastoma model systems ( ALK, Th- MYCN, Dbh- MYCN and Lin28b ). The murine tumors revealed a low number of genomic alterations - in keeping with human neuroblastoma - and a positive correlation of the number of genetic lesions with the time to onset of tumor formation was observed. Gene copy number alterations are the hallmark of both murine and human disease and frequently affect syntenic genomic regions. Despite low mutational load, the genes mutated in murine disease were found to be enriched for genes mutated in human disease. Taken together, our study further supports the validity of the tested mouse models for mechanistic and preclinical studies of human neuroblastoma.

Replacement of a first molar and 3 second molars by the mesial inclination of 4 impacted third molars in an adult with a Class II Division 1 malocclusion.

PubMed

Tomonari, Hiroshi; Yagi, Takakazu; Kuninori, Takaharu; Ikemori, Takahiro; Miyawaki, Shouichi

2015-06-01

This case report presents the successful replacement of 1 first molar and 3 second molars by the mesial inclination of 4 impacted third molars. A woman, 23 years 6 months old, had a chief complaint of crowding of her anterior teeth and linguoclination of a second molar on the left side. The panoramic radiographic images showed that the maxillary and mandibular third molars on both sides were impacted. Root resorption on the distal surfaces of the maxillary second molars was suspected. The patient was given a diagnosis of Angle Class II Division 1 malocclusion with severe crowding of the anterior teeth and 4 impacted third molars. After we extracted the treated maxillary second premolars and the second molars on both sides, the treated mandibular second premolar and the second molar on the left side, and the root canal-filled mandibular first molar on the right side, the 4 impacted third molars were uprighted and formed part of the posterior functional occlusion. The total active treatment period was 39 months. The maxillary and mandibular third molars on both sides successfully replaced the first and second molars. The replacement of a damaged molar by an impacted third molar is a useful treatment option for using sound teeth. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Effect of platelet-rich fibrin on frequency of alveolar osteitis following mandibular third molar surgery: a double-blinded randomized clinical trial.

PubMed

Eshghpour, Majid; Dastmalchi, Parisa; Nekooei, Amir Hossein; Nejat, AmirHossein

2014-08-01

To evaluate the effectiveness of platelet-rich fibrin (PRF) in preventing the development of alveolar osteitis (AO). In a double-blinded study, patients with bilateral impacted mandibular third molars underwent surgical extractions, with one socket receiving PRF and the other one serving as a control. The surgeon and patient were unaware of the study or control side. The predictor variable was the PRF application and was categorized as PRF and non-PRF. The outcome variable was the development of AO during the first postoperative week. Other study variables included age, gender, smoking status, irrigation volume, extraction difficulty, surgeon experience, and number of anesthetic cartridges. Data were analyzed using χ(2) and t tests, with the significance level set at a P value less than .05. Seventy-eight patients (mean age, 25 yr) underwent 156 impacted third molar surgeries. The overall frequency of AO was 14.74% for all surgeries. The frequency of AO in the PRF group was significantly lower than in the non-PRF group (odds ratio = 0.44; P < .05). Based on the results of the present study, PRF application may decrease the risk of AO development after mandibular third molar surgery. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Dual odontogenic origins develop at the early stage of rat maxillary incisor development.

PubMed

Kriangkrai, Rungarun; Iseki, Sachiko; Eto, Kazuhiro; Chareonvit, Suconta

2006-03-01

Developmental process of rat maxillary incisor has been studied through histological analysis and investigation of tooth-related gene expression patterns at initial tooth development. The tooth-related genes studied here are fibroblast growth factor-8 (Fgf-8), pituitary homeobox gene-2 (Pitx-2), sonic hedgehog (Shh), muscle segment homeobox-1 (Msx-1), paired box-9 (Pax-9) and bone morphogenetic protein-4 (Bmp-4). The genes are expressed in oral epithelium and/or ectomesenchyme at the stage of epithelial thickening to the early bud stage of tooth development. Both the histological observation and tooth-related gene expression patterns during early stage of maxillary incisor development demonstrate that dual odontogenic origins aligned medio-laterally in the medial nasal process develop, subsequently only single functional maxillary incisor dental placode forms. The cascade of tooth-related gene expression patterns in rat maxillary incisor studied here is quite similar to those of the previous studies in mouse mandibular molar, even though the origins of oral epithelium and ectomesenchyme involved in development of maxillary incisor and mandibular molar are different. Thus, we conclude that maxillary incisor and mandibular molar share a similar signaling control of Fgf-8, Pitx-2, Shh, Msx-1, Pax-9 and Bmp-4 genes at the stage of oral epithelial thickening to the early bud stage of tooth development.

A three-dimensional finite element analysis of molar distalization with a palatal plate, pendulum, and headgear according to molar eruption stage.

PubMed

Kang, Ju-Man; Park, Jae Hyun; Bayome, Mohamed; Oh, Moonbee; Park, Chong Ook; Kook, Yoon-Ah; Mo, Sung-Seo

2016-09-01

This study aimed to (1) evaluate the effects of maxillary second and third molar eruption status on the distalization of first molars with a modified palatal anchorage plate (MPAP), and (2) compare the results to the outcomes of the use of a pendulum and that of a headgear using three-dimensional finite element analysis. Three eruption stages were established: an erupting second molar at the cervical one-third of the first molar root (Stage 1), a fully erupted second molar (Stage 2), and an erupting third molar at the cervical one-third of the second molar root (Stage 3). Retraction forces were applied via three anchorage appliance models: an MPAP with bracket and archwire, a bone-anchored pendulum appliance, and cervical-pull headgear. An MPAP showed greater root movement of the first molar than crown movement, and this was more noticeable in Stages 2 and 3. With the other devices, the first molar showed distal tipping. Transversely, the first molar had mesial-out rotation with headgear and mesial-in rotation with the other devices. Vertically, the first molar was intruded with an MPAP, and extruded with the other appliances. The second molar eruption stage had an effect on molar distalization, but the third molar follicle had no effect. The application of an MPAP may be an effective treatment option for maxillary molar distalization.

Retained asymptomatic third molars and risk for second molar pathology.

PubMed

Nunn, M E; Fish, M D; Garcia, R I; Kaye, E K; Figueroa, R; Gohel, A; Ito, M; Lee, H J; Williams, D E; Miyamoto, T

2013-12-01

Prophylactic extraction of unerupted asymptomatic third molars is the most common oral surgery procedure in the United States. However, limited evidence exists to justify its costs and associated morbidity. We analyzed data collected over 25 years from 416 adult men enrolled in the Veterans Affairs Dental Longitudinal Study to evaluate the association of retained asymptomatic third molars with risk of adjacent second molar pathology (caries and/or periodontitis), based on third molar status (i.e., absent, erupted, or unerupted). Unerupted molars were further categorized as either "soft tissue" or "bony" impacted. We found that the lowest prevalence and incidence of second molar pathology occurred when the adjacent third molar was absent. The presence of a third molar that was soft tissue impacted increased the risk of incident second molar pathology 4.88-fold (95% confidence interval: 2.62, 9.08). Having an erupted or "bony" impacted third molar increased the risk of incident second molar pathology by 1.74 (95% confidence interval: 1.34, 2.25) and 2.16 (95% confidence interval: 1.56, 2.99), respectively. The retention of third molars is associated with increased risk of second molar pathology in middle-aged and older adult men.

Retained Asymptomatic Third Molars and Risk for Second Molar Pathology

PubMed Central

Nunn, M.E.; Fish, M.D.; Garcia, R.I.; Kaye, E.K.; Figueroa, R.; Gohel, A.; Ito, M.; Lee, H.J.; Williams, D.E.; Miyamoto, T.

2013-01-01

Prophylactic extraction of unerupted asymptomatic third molars is the most common oral surgery procedure in the United States. However, limited evidence exists to justify its costs and associated morbidity. We analyzed data collected over 25 years from 416 adult men enrolled in the Veterans Affairs Dental Longitudinal Study to evaluate the association of retained asymptomatic third molars with risk of adjacent second molar pathology (caries and/or periodontitis), based on third molar status (i.e., absent, erupted, or unerupted). Unerupted molars were further categorized as either “soft tissue” or “bony” impacted. We found that the lowest prevalence and incidence of second molar pathology occurred when the adjacent third molar was absent. The presence of a third molar that was soft tissue impacted increased the risk of incident second molar pathology 4.88-fold (95% confidence interval: 2.62, 9.08). Having an erupted or “bony” impacted third molar increased the risk of incident second molar pathology by 1.74 (95% confidence interval: 1.34, 2.25) and 2.16 (95% confidence interval: 1.56, 2.99), respectively. The retention of third molars is associated with increased risk of second molar pathology in middle-aged and older adult men. PMID:24132082

Selenium and mercury molar ratios in commercial fish from New Jersey and Illinois: variation within species and relevance to risk communication.

PubMed

Burger, Joanna; Gochfeld, Michael

2013-07-01

There is an emerging consensus that people consuming large amounts of fish with selenium:mercury ratios below 1 are at higher risk from mercury toxicity. As the relative amount of selenium increases compared to mercury, risk may be lowered, but it is unclear how much excess selenium is required. It would be useful if the selenium:mercury ratio was relatively consistent within a species, but this has not been the case in our studies of wild-caught fish. Since most people in developed countries and urban areas obtain their fish and other seafood commercially, we examined selenium:mercury molar ratios in commercial fish purchased in stores and fish markets in central New Jersey and Chicago. There was substantial interspecific and intraspecific variation in molar ratios. Across species the selenium:mercury molar ratio decreased with increasing mean mercury levels, but selenium variation also contributed to the ratio. Few samples had selenium:mercury molar ratios below 1, but there was a wide range in ratios, complicating the interpretation for use in risk management and communication. Before ratios can be used in risk management, more information is needed on mercury:selenium interactions and mutual bioavailability, and on the relationship between molar ratios and health outcomes. Further, people who are selenium deficient may be more at risk from mercury toxicity than others. Copyright © 2013 Elsevier Ltd. All rights reserved.

Selenium and mercury molar ratios in commercial fish from New Jersey and Illinois: Variation within species and relevance to risk communication

PubMed Central

Burger, Joanna; Gochfeld, Michael

2015-01-01

There is an emerging consensus that people consuming large amounts of fish with selenium:mercury ratios below 1 may be at higher risk from mercury toxicity. As the relative amount of selenium increases compared to mercury, risk may be lowered, but it is unclear how much excess selenium is required. It would be useful if the selenium:mercury ratio was relatively consistent within a species, but this has not been the case in our studies of wild-caught fish. Since most people in developed countries and urban areas obtain their fish and other seafood commercially, we examined selenium:mercury molar ratios in commercial fish purchased in stores and fish markets in central New Jersey and Chicago. There was substantial interspecific and intraspecific variation in molar ratios. Across species the selenium:mercury molar ratio decreased with increasing mean mercury levels, but selenium variation also contributed to the ratio. Few samples had selenium:mercury molar ratios below 1, but there was a wide range in ratios, complicating the interpretation for use in risk management and communication. Before ratios can be used in risk management, more information is needed on mercury:selenium interactions and mutual bioavailability, and on the relationship between molar ratios and health outcomes. Further, people who are selenium deficient may be more at risk from mercury toxicity than others. PMID:23541437

[Study on the anti-NTHi infection of Hap recombinant protein in vivo].

PubMed

Li, Wan-yi; Wang, Bao-ning; Zuo, Feng-qiong; Zeng, Wei; Feng, Feng; Kuang, Yu; Jiang, Zhong-hua; Li, Ming-yuan

2010-07-01

To observe the immune effect of Hap recombinant protein on murine model of bronchopneumonia infected with NTHi, and explore the mechanism about the anti-NTHi infection. The C57BL/6 mice intranasally immunized with purified Hap recombinant protein and CT-B were challenged by NTHi encased in agar beads. The immunifaction of anti-infection was observed through encocyte counting of BALF, bacteria detection of lung and the pathologyical change of lung tissue. In the challenge with NTHi experiment, the inflammatory exudation of the infected murine and pathological change of lung tissue was relieved by combined immunization of Hap recombinant protein and CT-B, and quantity of NTHi in lung of the infected murine was reduced obviously. The Hap recombinant protein also had good ability of anti-NTHi infection in the murine model of NTHi bronchopneumonia. This study could offer the oretical and experimental basis for development of new vaccine against NTHi.

Three-dimensional optical coherence tomography of the embryonic murine cardiovascular system

NASA Astrophysics Data System (ADS)

Luo, Wei; Marks, Daniel L.; Ralston, Tyler S.; Boppart, Stephen A.

2006-03-01

Optical coherence tomography (OCT) is an emerging high-resolution real-time biomedical imaging technology that has potential as a novel investigational tool in developmental biology and functional genomics. In this study, murine embryos and embryonic hearts are visualized with an OCT system capable of 2-µm axial and 15-µm lateral resolution and with real-time acquisition rates. We present, to our knowledge, the first sets of high-resolution 2- and 3-D OCT images that reveal the internal structures of the mammalian (murine) embryo (E10.5) and embryonic (E14.5 and E17.5) cardiovascular system. Strong correlations are observed between OCT images and corresponding hematoxylin- and eosin-stained histological sections. Real-time in vivo embryonic (E10.5) heart activity is captured by spectral-domain optical coherence tomography, processed, and displayed at a continuous rate of five frames per second. With the ability to obtain not only high-resolution anatomical data but also functional information during cardiovascular development, the OCT technology has the potential to visualize and quantify changes in murine development and in congenital and induced heart disease, as well as enable a wide range of basic in vitro and in vivo research studies in functional genomics.

Testing the inhibitory cascade model in Mesozoic and Cenozoic mammaliaforms

PubMed Central

2013-01-01

Background Much of the current research in the growing field of evolutionary development concerns relating developmental pathways to large-scale patterns of morphological evolution, with developmental constraints on variation, and hence diversity, a field of particular interest. Tooth morphology offers an excellent model system for such ‘evo-devo’ studies, because teeth are well preserved in the fossil record, and are commonly used in phylogenetic analyses and as ecological proxies. Moreover, tooth development is relatively well studied, and has provided several testable hypotheses of developmental influences on macroevolutionary patterns. The recently-described Inhibitory Cascade (IC) Model provides just such a hypothesis for mammalian lower molar evolution. Derived from experimental data, the IC Model suggests that a balance between mesenchymal activators and molar-derived inhibitors determines the size of the immediately posterior molar, predicting firstly that molars either decrease in size along the tooth row, or increase in size, or are all of equal size, and secondly that the second lower molar should occupy one third of lower molar area. Here, we tested the IC Model in a large selection of taxa from diverse extant and fossil mammalian groups, ranging from the Middle Jurassic (~176 to 161 Ma) to the Recent. Results Results show that most taxa (~65%) fell within the predicted areas of the Inhibitory Cascade Model. However, members of several extinct groups fell into the regions where m2 was largest, or rarely, smallest, including the majority of the polyphyletic “condylarths”. Most Mesozoic mammals fell near the centre of the space with equality of size in all three molars. The distribution of taxa was significantly clustered by diet and by phylogenetic group. Conclusions Overall, the IC Model was supported as a plesiomorphic developmental system for Mammalia, suggesting that mammal tooth size has been subjected to this developmental constraint at least since the divergence of australosphenidans and boreosphenidans approximately 180 Ma. Although exceptions exist, including many ‘condylarths’, these are most likely to be secondarily derived states, rather than alternative ancestral developmental models for Mammalia. PMID:23565593

Impacted lower third molars and distal caries in the mandibular second molar. Is prophylactic removal of lower third molars justified?

PubMed

Marques, José; Montserrat-Bosch, Marta; Figueiredo, Rui; Vilchez-Pérez, Miguel-Angel; Valmaseda-Castellón, Eduard; Gay-Escoda, Cosme

2017-06-01

The objective of this study was to evaluate the association between the presence of mandibular third molars and the occurrence of carious lesions in the distal aspect of the mandibular second molar. A retrospective cohort study comprising 327 lower third molars extracted in the Oral Surgery and Implantology Master's Degree program of the School of Dentistry of the University of Barcelona (Barcelona, Spain) was carried out. A descriptive and bivariate analysis was made. The diagnosis of caries in the second molar and the position of the mandibular third molar were evaluated through panoramic radiographies. The sample included 203 patients, 94 males (46.3%) and 109 females (53.7%), with a mean age of 26,8 years and 327 lower third molars. The prevalence of second molar distal caries was 25.4% (95% CI= 20.6% to 30.2%). This pathology was significantly more frequent when the third molar was in a horizontal position (27.7%), when the contact point was at (45,8%) or below (47.0%) the cementoenamel junction (CEJ), and when the distal CEJ of the mandibular second molar and the mesial CEJ of the third molar was 7 to 12 mm apart. Horizontal lower third molars with contact points at or below the CEJ are more likely to produce distal caries in the mandibular second molars. Due to the high prevalence of this pathology (20.6% to 30.2%), a prophylactic removal of lower third molars with the above-mentioned features might be advisable. Key words: Second molar, caries, third molar, prophylactic removal.

A three-dimensional finite element analysis of molar distalization with a palatal plate, pendulum, and headgear according to molar eruption stage

PubMed Central

Kang, Ju-Man; Park, Jae Hyun; Bayome, Mohamed; Oh, Moonbee; Park, Chong Ook; Mo, Sung-Seo

2016-01-01

Objective This study aimed to (1) evaluate the effects of maxillary second and third molar eruption status on the distalization of first molars with a modified palatal anchorage plate (MPAP), and (2) compare the results to the outcomes of the use of a pendulum and that of a headgear using three-dimensional finite element analysis. Methods Three eruption stages were established: an erupting second molar at the cervical one-third of the first molar root (Stage 1), a fully erupted second molar (Stage 2), and an erupting third molar at the cervical one-third of the second molar root (Stage 3). Retraction forces were applied via three anchorage appliance models: an MPAP with bracket and archwire, a bone-anchored pendulum appliance, and cervical-pull headgear. Results An MPAP showed greater root movement of the first molar than crown movement, and this was more noticeable in Stages 2 and 3. With the other devices, the first molar showed distal tipping. Transversely, the first molar had mesial-out rotation with headgear and mesial-in rotation with the other devices. Vertically, the first molar was intruded with an MPAP, and extruded with the other appliances. Conclusions The second molar eruption stage had an effect on molar distalization, but the third molar follicle had no effect. The application of an MPAP may be an effective treatment option for maxillary molar distalization. PMID:27668192

Efficiency of molar distalization associated with second and third molar eruption stage.

PubMed

Flores-Mir, Carlos; McGrath, Lisa; Heo, Giseon; Major, Paul W

2013-07-01

To evaluate the efficiency of molar distalization associated with the second and third molar eruption stage. A systematic computerized database search was conducted using several databases. Adaptations of the terms molar distalization and distalizing appliances were used. The reference lists of all the selected articles were also searched for any potential articles that might have been missed in the electronic search. The data provided in the selected publications were grouped and analyzed in terms of molar distalization with respect to various eruption stages of maxillary second and third molars. Out of the 13 initially identified articles only four fulfilled the final selection criteria. Three of the four studies showed no statistical significance in linear molar distalization based on the eruptive stage of the second and/or third molars, while one study found that the amount of distal movement of the first molars was significantly greater in the group with unerupted second molars. Only one study found that the amount of molar tipping that occurred as a result of distalization was related to the eruption stage of the maxillary molars. Similarly, three of the four studies found that molar distalization time was not significantly affected by eruption of the second or third molars. The effect of maxillary second and third molar eruption stage on molar distalization-both linear and angular distalization-appears to be minimal. This conclusion is only based on low-level of evidence clinical trials. The large variability in the outcomes should be considered clinically.

Consent for third molar tooth extractions in Australia and New Zealand: a review of current practice.

PubMed

Badenoch-Jones, E K; Lynham, A J; Loessner, D

2016-06-01

Informed consent is the legal requirement to educate a patient about a proposed medical treatment or procedure so that he or she can make informed decisions. The purpose of the study was to examine the current practice for obtaining informed consent for third molar tooth extractions (wisdom teeth) by oral and maxillofacial surgeons in Australia and New Zealand. An online survey was sent to 180 consultant oral and maxillofacial surgeons in Australia and New Zealand. Surgeons were asked to answer (yes/no) whether they routinely warned of a specific risk of third molar tooth extraction in their written consent. Seventy-one replies were received (39%). The only risks that surgeons agreed should be routinely included in written consent were a general warning of infection (not alveolar osteitis), inferior alveolar nerve damage (temporary and permanent) and lingual nerve damage (temporary and permanent). There is significant variability among Australian and New Zealand oral and maxillofacial surgeons regarding risk disclosure for third molar tooth extractions. We aim to improve consistency in consent for third molar extractions by developing an evidence-based consent form. © 2016 Australian Dental Association.

Evaluation of third molar development in the estimation of chronological age.

PubMed

Soares, Caio Belém Rodrigues Barros; Figueiroa, José Natal; Dantas, Renata Moura Xavier; Kurita, Lúcio Mitsuo; Pontual, Andréa dos Anjos; Ramos-Perez, Flávia Maria de Moraes; Perez, Danyel Elias da Cruz; Pontual, Maria Luiza dos Anjos

2015-09-01

The purpose of this study was to evaluate the correlation between chronological age and the degree of third molar mineralization by Demirjian's developmental stages (Demirjian et al., 1973) using panoramic radiography. From a total of 11.396 digital panoramic radiographs of patients from three oral radiology private clinics from the northeast region of Brazil, obtained from January to June 2009, 2097 radiographic images from patients aged between 6 and 22 years were selected. The images were analyzed individually by two obsevers using a 21-inch computer screen and Windows Picture and Fax Viewer. Reliability was achieved by intra- and interobserver evaluation, using the Kappa test. Chronological age, calcification stage, gender and third molar were interrelated using a multiple linear regression model, considering age as a response variable. There was reliability with Demirjian et al.'s developmental stage assesment, displaying a significant relationship between mineralization stages and patients' age (P<0.05). There was no significant difference between the average age and the calcification stage taking gender and localization of the third molar into consideration. It is possible to estimate chronological age based on Demirjian's stage of a third molar, regardless of gender and location. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Association between third molar agenesis and craniofacial structure development.

PubMed

Ramiro-Verdugo, Jara; De Vicente-Corominas, Elena; Montiel-Company, José María; Gandía-Franco, José Luís; Bellot-Arcís, Carlos

2015-11-01

The aim of this investigation was to study the relationship between third molar agenesis-including the number of ageneses-and craniofacial structure growth. We reviewed 305 clinical histories of patients treated at the Orthodontics Unit of the Faculty of Medicine and Dentistry at the University of Valencia in Spain. This included radiographic records of optimal quality. Of these, 40 patients who had agenesis of at least 1 third molar were included in the study group. A control group was formed with another 40 patients with all 4 third molars present. For both groups, a further criterion for inclusion was cone-beam computed tomography records. The cephalometric analysis was performed with NemoCeph 3D software (version 11.3.1.38; Nemotec, Madrid, Spain). The only significant differences between the 2 groups were in the total gonial angle and the upper gonial angle (P ≤0.05), both of which were smaller in the study group. Third molar agenesis is associated with a reduction in Jarabak's gonial angle and upper gonial angle, characteristic of patients with a more horizontal or brachyfacial skeletal pattern. No significant differences were found in other measurements. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Isolation of intact RNA from murine CD4+ T cells after intracellular cytokine staining and fluorescence-activated cell sorting.

PubMed

Kunnath-Velayudhan, Shajo; Porcelli, Steven A

2018-05-01

Intracellular cytokine staining (ICS) is a powerful method for identifying functionally distinct lymphocyte subsets, and for isolating these by fluorescence activated cell sorting (FACS). Although transcriptomic analysis of cells sorted on the basis of ICS has many potential applications, this is rarely performed because of the difficulty in isolating intact RNA from cells processed using standard fixation and permeabilization buffers for ICS. To address this issue, we compared three buffers shown previously to preserve RNA in nonhematopoietic cells subjected to intracellular staining for their effects on RNA isolated from T lymphocytes processed for ICS. Our results showed that buffers containing the recombinant ribonuclease inhibitor RNasin or high molar concentrations of salt yielded intact RNA from fixed and permeabilized T cells. As proof of principle, we successfully used the buffer containing RNasin to isolate intact RNA from CD4 + T cells that were sorted by FACS on the basis of specific cytokine production, thus demonstrating the potential of this approach for coupling ICS with transcriptomic analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

Stromal Cell-Derived Factor-1 Is Associated with Angiogenesis and Inflammatory Cell Infiltration in Aneurysm Walls

PubMed Central

Hoh, Brian L.; Hosaka, Koji; Downes, Daniel P.; Nowicki, Kamil W.; Wilmer, Erin N.; Velat, Gregory J.; Scott, Edward W.

2013-01-01

Object A small percentage of cerebral aneurysms rupture, but when they do, the effects are devastating. Current management of unruptured aneurysms consist of surgery, endovascular treatment, or watchful waiting. If the biology of how aneurysms grow and rupture were better known, a novel drug could be developed to prevent unruptured aneurysms from rupturing. Ruptured cerebral aneurysms are characterized by inflammation-mediated wall remodeling. We studied the role of stromal cell-derived factor-1 (SDF-1) in inflammation-mediated wall remodeling in cerebral aneurysms. Methods Human aneurysms; murine carotid aneurysms; and murine intracranial aneurysms were studied by immunohistochemistry. Flow cytometry analysis was performed on blood from mice developing carotid aneurysms or intracranial aneurysms. The effect of SDF-1 on endothelial cells and macrophages was studied by chemotaxis cell migration assay and capillary tube formation assay. Anti-SDF-1 blocking antibody was given to mice and compared to control (vehicle)-administered mice for its effects on the walls of carotid aneurysms and the development of intracranial aneurysms. Results Human aneurysms, murine carotid aneurysms, and murine intracranial aneurysms, all express SDF-1; and mice with developing carotid aneurysms or intracranial aneurysms have increased progenitor cells expressing CXCR4, the receptor for SDF-1 (P<0.01 and P<0.001, respectively). Human aneurysms and murine carotid aneurysms have endothelial cells, macrophages, and capillaries in the walls of the aneurysms; and the presence of capillaries in the walls of human aneurysms is associated with presence of macrophages (P=0.01). SDF-1 promotes endothelial cell and macrophage migration (P<0.01 for each), and promotes capillary tube formation (P<0.001). When mice are given anti-SDF-1 blocking antibody, there is a significant reduction in endothelial cells (P<0.05), capillaries (P<0.05), and cell proliferation (P<0.05) in the aneurysm wall. Mice given anti-SDF-1 blocking antibody develop significantly fewer intracranial aneurysms (33% versus 89% in mice given control IgG)(P<0.05). Conclusions These data suggest SDF-1 associated with angiogenesis and inflammatory cell migration and proliferation in the walls of aneurysms, and may have a role in the development of intracranial aneurysms. PMID:24160472

Cone-beam Computed Tomographic Study of Root Anatomy and Canal Configuration of Molars in a Spanish Population.

PubMed

Pérez-Heredia, Mercedes; Ferrer-Luque, Carmen María; Bravo, Manuel; Castelo-Baz, Pablo; Ruíz-Piñón, Manuel; Baca, Pilar

2017-09-01

The aim of this study was to identify morphologic peculiarities of roots and analyze the root canal configuration in maxillary and mandibular first and second molars by means using cone-beam computed tomographic (CBCT) imaging in a Spanish population. A total of 284 maxillary molars and 242 mandibular molars from 112 patients were examined in vivo by CBCT imaging; only untreated molars with healthy and fully matured apices were included in this study. Details regarding the number of roots, number of canals, and root canal configuration were recorded. Maxillary first and second molars had 3 roots in 97.2% and 79%, respectively. In mandibular molars, the frequency of 2 roots was 94% in first molars and 83% in second molars. The canal configuration of the palatal root was 100% Vertucci type I (1-1) in first and second molars. The distobuccal root showed a Vertucci type I configuration in 97% of first and 100% of maxillary second molars. The mesiobuccal root for first molars showed a Vertucci type II configuration (2-1) in 56.5% cases and Vertucci type IV (2-2) in 23.2%. For maxillary second molars, the Vertucci type I configuration reached 52.7%. In mandibular molars, the mesial root showed higher variability. Most frequent was the presence of 2 canals, Vertucci type II for first and second molars. In the distal root, the most common configuration was Vertucci type I in both molars. The greater percentage of fused roots was observed in maxillary molars. Vertucci type II configuration was more frequent than type IV in the mesial root of mandibular molars and the mesiobuccal root of maxillary molars. A third canal in the mesial root of first mandibular molars (6.7%) was higher than expected. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The development of a murine model for Forcipomyia taiwana (biting midge) allergy.

PubMed

Lee, Mey-Fann; Yang, Kai-Jei; Wang, Nancy M; Chiu, Yung-Tsung; Chen, Pei-Chih; Chen, Yi-Hsing

2014-01-01

Forcipomyia taiwana (biting midge) allergy is the most prevalent biting insect allergy in Taiwan. An animal model corresponding to the human immuno-pathologic features of midge allergy is needed for investigating the mechanisms and therapies. This study successfully developed a murine model of Forcipomyia taiwana allergy. BALB/c mice were sensitized intra-peritoneally with midge extract on days 0, 7, 14, 21 then intra-dermally on days 28, 31 and 35. Serum midge-specific IgE, IgG1, and IgG2a were measured every 14 days by indirect ELISA. The mice were challenged intradermally with midge extract at day 40 and then sacrificed. Proliferation and cytokine production of splenocytes after stimulation with midge extract were determined by MTT assay and ELISA, respectively. The cytokine mRNA expression in response to midge stimulation was analyzed by RT-PCR. Serum IgE, total IgG, and IgG1 antibody levels against midge extract were significantly higher in the midge-sensitized mice than in the control mice. After the two-step sensitization, all mice in the midge-sensitized group displayed immediate itch and plasma extravasation reactions in response to challenge with midge extract. Skin histology from midge-sensitized mice showed marked eosinophil and lymphocyte infiltrations similar to that observed in humans. Stimulation of murine splenocytes with midge extract elicited significant proliferation, IL-4, IL-10, IL-13 and IFN-γ protein production, and up-regulation of mRNA in a dose-dependent manner in the midge-sensitized group, but not in the control group. A murine model of midge bite allergy has been successfully developed using a two-step sensitization protocol. The sensitized mice have very similar clinical and immunologic reactions to challenge with midge proteins as the reactions of human to midge bites. This murine model may be a useful platform for future research and the development of treatment strategies for insect bite allergy.

Convection enhanced delivery of carmustine to the murine brainstem: a feasibility study.

PubMed

Sewing, A Charlotte P; Caretti, Viola; Lagerweij, Tonny; Schellen, Pepijn; Jansen, Marc H A; van Vuurden, Dannis G; Idema, Sander; Molthoff, Carla F M; Vandertop, W Peter; Kaspers, Gertjan J L; Noske, David P; Hulleman, Esther

2014-12-30

Systemic delivery of therapeutic agents remains ineffective against diffuse intrinsic pontine glioma (DIPG), possibly due to an intact blood-brain-barrier (BBB) and to dose-limiting toxicity of systemic chemotherapeutic agents. Convection-enhanced delivery (CED) into the brainstem may provide an effective local delivery alternative for DIPG patients. The aim of this study is to develop a method to perform CED into the murine brainstem and to test this method using the chemotherapeutic agent carmustine (BiCNU). To this end, a newly designed murine CED catheter was tested in vitro and in vivo. After determination of safety and distribution, mice bearing VUMC-DIPG-3 and E98FM-DIPG brainstem tumors were treated with carmustine dissolved in DW 5% or carmustine dissolved in 10% ethanol. Our results show that CED into the murine brainstem is feasible and well tolerated by mice with and without brainstem tumors. CED of carmustine dissolved in 5% DW increased median survival of mice with VUMC-DIPG-3 and E98FM-DIPG tumors with 35% and 25% respectively. Dissolving carmustine in 10% ethanol further improved survival to 45% in mice with E98FM-DIPG tumors. Since genetically engineered and primary DIPG models are currently only available in mice, murine CED studies have clear advantages over CED studies in other animals. CED in the murine brainstem can be performed safely, is well tolerated and can be used to study efficacy of chemotherapeutic agents orthotopically. These results set the foundation for more CED studies in murine DIPG models. Copyright © 2014 Elsevier B.V. All rights reserved.

Impacted lower third molars and distal caries in the mandibular second molar. Is prophylactic removal of lower third molars justified?

PubMed Central

Marques, José; Montserrat-Bosch, Marta; Vilchez-Pérez, Miguel-Angel; Valmaseda-Castellón, Eduard; Gay-Escoda, Cosme

2017-01-01

Background The objective of this study was to evaluate the association between the presence of mandibular third molars and the occurrence of carious lesions in the distal aspect of the mandibular second molar. Material and Methods A retrospective cohort study comprising 327 lower third molars extracted in the Oral Surgery and Implantology Master’s Degree program of the School of Dentistry of the University of Barcelona (Barcelona, Spain) was carried out. A descriptive and bivariate analysis was made. The diagnosis of caries in the second molar and the position of the mandibular third molar were evaluated through panoramic radiographies. Results The sample included 203 patients, 94 males (46.3%) and 109 females (53.7%), with a mean age of 26,8 years and 327 lower third molars. The prevalence of second molar distal caries was 25.4% (95% CI= 20.6% to 30.2%). This pathology was significantly more frequent when the third molar was in a horizontal position (27.7%), when the contact point was at (45,8%) or below (47.0%) the cementoenamel junction (CEJ), and when the distal CEJ of the mandibular second molar and the mesial CEJ of the third molar was 7 to 12 mm apart. Conclusions Horizontal lower third molars with contact points at or below the CEJ are more likely to produce distal caries in the mandibular second molars. Due to the high prevalence of this pathology (20.6% to 30.2%), a prophylactic removal of lower third molars with the above-mentioned features might be advisable. Key words:Second molar, caries, third molar, prophylactic removal. PMID:28638558

Predictive model of third molar eruption after second molar extraction.

PubMed

De-la-Rosa-Gay, Cristina; Valmaseda-Castellón, Eduard; Gay-Escoda, Cosme

2010-03-01

Extraction of second permanent molars is an option for providing space in orthodontic treatment. Although many articles have described its impact on the outcome, there are few data on the prognosis of the eruption of the adjacent third molars. The aims of this investigation were to provide predictive models of eruption of third molars after second permanent molar extraction and to validate them. A total of 48 patients (ages, 11-23 years) who had 128 second permanent molars (54 maxillary, 74 mandibular) extracted during orthodontic treatment were followed until eruption of the third molars was complete. A lineal regression model predicted the final angle of the third molars with the permanent first molar by using the variables of initial angle, jaw, and the developmental stage of the third molar. A logistic regression model predicted the probability of correct eruption by using the variables of initial angle, jaw, sex, age, and the developmental stage of the third molar. 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Correction of a mutilated dentition with mini-implants as anchorage.

PubMed

Hyun, Jae-Man; Kim, Tae-Woo

2010-11-01

The patient was an adolescent boy, aged 15.6 years, with a mutilated dentition. He had extrusion of the maxillary left first molar because of loss of the mandibular first molar and lingual tilting and rotation of the mandibular second molars. Both left and right second molars were in scissors-bite that was more severe on the left side. By using mini-implants and a TPA with hooks, a 3-mm intrusion was successfully made on the maxillary left first molar. This provided room for mesial movement of the mandibular left second molar. The second molar was protracted into the space of the missing first molar, and the mandibular left third molar was positioned in place of the second molar. The second molars scissors-bite was corrected. Active treatment took 45 months, and the treatment result remained stable 2 years after debonding. Copyright © 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Induction of Protective CTL Responses in Newborn Mice by a Murine Retrovirus

NASA Astrophysics Data System (ADS)

Sarzotti, Marcella; Robbins, Deanna S.; Hoffman, Paul M.

1996-03-01

The susceptibility of neonates to virus-induced disease is thought to reflect, in part, the immaturity of their immune systems. However, inoculation of newborn mice with low doses of Cas-Br-M murine leukemia virus induced a protective cytotoxic T lymphocyte (CTL) response. The inability of neonates to develop a CTL response to high doses of virus was not the result of immunological immaturity but correlated with the induction of a nonprotective type 2 cytokine response. Thus, the initial viral dose is critical in the development of protective immunity in newborns.

Age assessment based on third molar mineralisation : An epidemiological-radiological study on a Central-European population.

PubMed

Hofmann, Elisabeth; Robold, Matthias; Proff, Peter; Kirschneck, Christian

2017-03-01

The method published in 1973 by Demirjian et al. to assess age based on the mineralisation stage of permanent teeth is standard practice in forensic and orthodontic diagnostics. From age 14 onwards, however, this method is only applicable to third molars. No current epidemiological data on third molar mineralisation are available for Caucasian Central-Europeans. Thus, a method for assessing age in this population based on third molar mineralisation is presented, taking into account possible topographic and gender-specific differences. The study included 486 Caucasian Central-European orthodontic patients (9-24 years) with unaffected dental development. In an anonymized, randomized, and blinded manner, one orthopantomogram of each patient at either start, mid or end of treatment was visually analysed regarding the mineralisation stage of the third molars according to the method by Demirjian et al. Corresponding topographic and gender-specific point scores were determined and added to form a dental maturity score. Prediction equations for age assessment were derived by linear regression analysis with chronological age and checked for reliability within the study population. Mineralisation of the lower third molars was slower than mineralisation of the upper third molars, whereas no jaw-side-specific differences were detected. Gender-specific differences were relatively small, but girls reached mineralisation stage C earlier than boys, whereas boys showed an accelerated mineralisation between the ages of 15 and 16. The global equation generated by regression analysis (age = -1.103 + 0.268 × dental maturity score 18 + 28 + 38 + 48) is sufficiently accurate and reliable for clinical use. Age assessment only based on either maxilla or mandible also shows good prognostic reliability.

Aggregation Number in Water/n-Hexanol Molecular Clusters Formed in Cyclohexane at Different Water/n-Hexanol/Cyclohexane Compositions Calculated by Titration 1H NMR.

PubMed

Flores, Mario E; Shibue, Toshimichi; Sugimura, Natsuhiko; Nishide, Hiroyuki; Moreno-Villoslada, Ignacio

2017-11-09

Upon titration of n-hexanol/cyclohexane mixtures of different molar compositions with water, water/n-hexanol clusters are formed in cyclohexane. Here, we develop a new method to estimate the water and n-hexanol aggregation numbers in the clusters that combines integration analysis in one-dimensional 1 H NMR spectra, diffusion coefficients calculated by diffusion-ordered NMR spectroscopy, and further application of the Stokes-Einstein equation to calculate the hydrodynamic volume of the clusters. Aggregation numbers of 5-15 molecules of n-hexanol per cluster in the absence of water were observed in the whole range of n-hexanol/cyclohexane molar fractions studied. After saturation with water, aggregation numbers of 6-13 n-hexanol and 0.5-5 water molecules per cluster were found. O-H and O-O atom distances related to hydrogen bonds between donor/acceptor molecules were theoretically calculated using density functional theory. The results show that at low n-hexanol molar fractions, where a robust hydrogen-bond network is held between n-hexanol molecules, addition of water makes the intermolecular O-O atom distance shorter, reinforcing molecular association in the clusters, whereas at high n-hexanol molar fractions, where dipole-dipole interactions dominate, addition of water makes the intermolecular O-O atom distance longer, weakening the cluster structure. This correlates with experimental NMR results, which show an increase in the size and aggregation number in the clusters upon addition of water at low n-hexanol molar fractions, and a decrease of these magnitudes at high n-hexanol molar fractions. In addition, water produces an increase in the proton exchange rate between donor/acceptor molecules at all n-hexanol molar fractions.

Inactivation of Tgfbr2 in Osterix-Cre expressing Dental Mesenchyme Disrupts Molar Root Formation

PubMed Central

Coricor, George; MacDougall, Mary; Serra, Rosa

2013-01-01

It has been difficult to examine the role of TGF-ß in post-natal tooth development due to perinatal lethality in many of the signaling deficient mouse models. To address the role of Tgfbr2 in postnatal tooth development, we generated a mouse in which Tgfbr2 was deleted in odontoblast-and bone-producing mesenchyme. Osx-Cre;Tgfbr2fl/fl mice were generated (Tgfbr2cko) and postnatal tooth development was compared in Tgfbr2cko and control littermates. X-ray and μCT analysis showed that in Tgfbr2cko mice radicular dentin matrix density was reduced in the molars. Molar shape was abnormal and molar eruption was delayed in the mutant mice. Most significantly, defects in root formation, including failure of the root to elongate, were observed by postnatal day 10. Immunostaining for Keratin-14 (K14) was used to delineate Hertwig's epithelial root sheath (HERS). The results showed a delay in elongation and disorganization of the HERS in Tgfbr2cko mice. In addition, the HERS was maintained and the break up into epithelial rests was attenuated suggesting that Tgfbr2 acts on dental mesenchyme to indirectly regulate the formation and maintenance of the HERS. Altered odontoblast organization and reduced Dspp expression indicated that odontoblast differentiation was disrupted in the mutant mice likely contributing to the defect in root formation. Nevertheless, expression of Nfic, a key mesenchymal regulator of root development, was similar in Tgfbr2cko mice and controls. The number of osteoclasts in the bone surrounding the tooth was reduced and osteoblast differentiation was disrupted likely contributing to both root and eruption defects. We conclude that Tgfbr2 in dental mesenchyme and bone is required for tooth development particularly root formation. PMID:23933490

Local vs general anaesthesia in the development of neurosensory disturbances after mandibular third molars extraction: A retrospective study of 534 cases

PubMed Central

Biasotto, Matteo; Maglione, Michele; Di Lenarda, Roberto

2016-01-01

Background The choice of the anaesthetic modality is one of the primary steps during planning of third molar surgery. The aim of the present study was to compare the risk of developing neurological injures of the inferior alveolar nerve (IAN) and lingual nerve (LN) in patients treated for wisdom teeth removal under general anaesthesia (GA) with a group treated under local anaesthesia (LA). Material and Methods This is an observational retrospective, unicentric study; between September 2013 and September 2014, 534 patients underwent third molar surgery, 194 (36,3%) under GA and 340 (63,7%) under LA by the same oral surgeon. Differences in the incidence of IAN and LN injures between groups have been statistically analyzed with Fisher exact test and estimated odd ratio for development of such complications has been calculated. Results In GA patients the incidence of IAN and LN injures was 4.6% and 2.1%, respectively while in the LA group it was and 0.3% and 0%, respectively. A significant difference in IAN and LN involvement between groups was observed (IAN lesion: Fisher exact test, p<0.001; LN lesions: Fisher exact test, p<0.05). The estimated odd ratio for development of IAN injures after GA was 16.49 (95% CI: 2.07-131.19) and was not calculable for LN injures because no cases were observed in the LA group. Conclusions Since GA is a perioperative variable that seems to significantly increase the risk of developing IAN and LN lesions, when treating patients that request GA, they must be adequately informed that an higher incidence of post-surgical sensory disturbances is expected. Key words:Third molars, general anaesthesia, local anaesthesia, inferior alveolar nerve, lingual nerve. PMID:27694783

A model system for testing gene vectors using murine tumor cells on the chorioallantoic membrane of the chick embryo.

PubMed

Dani, Sergio U; Espindola, Rachel

2002-06-30

We developed a model system for testing gene vectors, based on the growth of murine tumors on the chorioallantoic membrane (CAM) of embryonic chickens. The ability of selected murine cells to grow on the CAM was rated according to the following criteria: i) formation of tumor masses; ii) metastasis formation; iii) reproducibility; iv) yield, indicated as the number of embryos surviving to assessment time with visible tumors on the CAM; v) maintainability of the cell, both in the original host and the embryonic chick, or 'shuttle maintainability'; vi) detection by the naked eye, and vii) cost/benefit relation. The murine melanoma cell lineage, B16F10, which efficiently forms distinct, pigmented tumor masses and metastases on the CAM, performed better in this model than the murine B61 cell line. In vitro transduction of B16F10 cells with a recombinant adenovirus carrying a construct of the E. coli LacZ gene followed by inoculation onto the CAM resulted in beta-galactosidase expression in the tumor mass growing on the CAM. This model is potentially applicable to preclinical evaluation of gene vectors, especially for gene therapy of cancer.

Biological properties in vitro of a combination of recombinant murine interleukin-3 and granulocyte-macrophage colony-stimulating factor.

PubMed

Riklis, I; Kletter, Y; Bleiberg, I; Fabian, I

1989-04-01

The effect of recombinant murine interleukin-3 (rIL-3) and recombinant murine granulocyte-macrophage colony-stimulating factor (rGM-CSF) on in vitro murine myeloid progenitor cell (CFU-C) growth and on the function of murine resident peritoneal macrophages was investigated. Both rIL-3 and rGM-CSF are known to support the growth of CFU-C and, when combined, were found to act synergistically to induce the development of an increased number of CFU-C. The distribution pattern of myeloid colonies in the presence of these two growth factors was in general similar to that in the presence of rGM-CSF alone. Both rGM-CSF and rIL-3 enhanced the phagocytosis of Candida albicans (CA) by mature macrophages producing an increase in the percentage of phagocytosing cells as well as an increase in the number of yeast particles ingested per cell. No additive effect on the phagocytosis was observed when the two growth factors were added concurrently. rGM-CSF, but not rIL-3, enhanced the killing of CA by macrophages. This killing was inhibited by scavengers of oxygen radicals.

Commonly dysregulated genes in murine APL cells

PubMed Central

Yuan, Wenlin; Payton, Jacqueline E.; Holt, Matthew S.; Link, Daniel C.; Watson, Mark A.; DiPersio, John F.; Ley, Timothy J.

2007-01-01

To identify genes that are commonly dysregulated in a murine model of acute promyelocytic leukemia (APL), we first defined gene expression patterns during normal murine myeloid development; serial gene expression profiling studies were performed with primary murine hematopoietic progenitors that were induced to undergo myeloid maturation in vitro with G-CSF. Many genes were reproducibly expressed in restricted developmental “windows,” suggesting a structured hierarchy of expression that is relevant for the induction of developmental fates and/or differentiated cell functions. We compared the normal myeloid developmental transcriptome with that of APL cells derived from mice expressing PML-RARα under control of the murine cathepsin G locus. While many promyelocyte-specific genes were highly expressed in all APL samples, 116 genes were reproducibly dysregulated in many independent APL samples, including Fos, Jun, Egr1, Tnf, and Vcam1. However, this set of commonly dysregulated genes was expressed normally in preleukemic, early myeloid cells from the same mouse model, suggesting that dysregulation occurs as a “downstream” event during disease progression. These studies suggest that the genetic events that lead to APL progression may converge on common pathways that are important for leukemia pathogenesis. PMID:17008535

Characterizing property distributions of polymeric nanogels by size-exclusion chromatography.

PubMed

Mourey, Thomas H; Leon, Jeffrey W; Bennett, James R; Bryan, Trevor G; Slater, Lisa A; Balke, Stephen T

2007-03-30

Nanogels are highly branched, swellable polymer structures with average diameters between 1 and 100nm. Size-exclusion chromatography (SEC) fractionates materials in this size range, and it is commonly used to measure nanogel molar mass distributions. For many nanogel applications, it may be more important to calculate the particle size distribution from the SEC data than it is to calculate the molar mass distribution. Other useful nanogel property distributions include particle shape, area, and volume, as well as polymer volume fraction per particle. All can be obtained from multi-detector SEC data with proper calibration and data analysis methods. This work develops the basic equations for calculating several of these differential and cumulative property distributions and applies them to SEC data from the analysis of polymeric nanogels. The methods are analogous to those used to calculate the more familiar SEC molar mass distributions. Calibration methods and characteristics of the distributions are discussed, and the effects of detector noise and mismatched concentration and molar mass sensitive detector signals are examined.

Incidence, Management, and Outcome of Molar Pregnancies at a Tertiary Care Hospital in Quetta, Pakistan

PubMed Central

Fatima, Mahrukh; Kasi, Pashtoon Murtaza; Baloch, Shahnaz Naseer; Kassi, Masoom; Marri, Shah Muhammad; Kassi, Mahwash

2011-01-01

Molar pregnancies represent a significant burden of disease on the spectrum of gestational trophoblastic diseases. The incidence appears to be higher in women from South Asia. The purpose of our prospective study was to determine the incidence, presentation, and outcomes of all molar pregnancies at our institution. During the study period, there were a total of 16,625 patients admitted to our department; out of whom 85 patients were diagnosed with a molar pregnancy. Vaginal bleeding was the commonest symptom (94.2%); theca lutein cysts were noted in 39% of the cases. Suction, dilatation, and curettage were noted to be the preferred method in almost all cases; hysterectomy was done in 12 (14.1%) patients. Single-agent chemotherapy was employed in high-risk patients and was well tolerated. Mean followup for these patients was 5.7 months (range 1–24 months). None of these patients developed persistent trophoblastic disease, invasive mole, or choriocarcinoma during the follow-up period. PMID:22028979

Determination of partial molar volumes from free energy perturbation theory†

PubMed Central

Vilseck, Jonah Z.; Tirado-Rives, Julian

2016-01-01

Partial molar volume is an important thermodynamic property that gives insights into molecular size and intermolecular interactions in solution. Theoretical frameworks for determining the partial molar volume (V°) of a solvated molecule generally apply Scaled Particle Theory or Kirkwood–Buff theory. With the current abilities to perform long molecular dynamics and Monte Carlo simulations, more direct methods are gaining popularity, such as computing V° directly as the difference in computed volume from two simulations, one with a solute present and another without. Thermodynamically, V° can also be determined as the pressure derivative of the free energy of solvation in the limit of infinite dilution. Both approaches are considered herein with the use of free energy perturbation (FEP) calculations to compute the necessary free energies of solvation at elevated pressures. Absolute and relative partial molar volumes are computed for benzene and benzene derivatives using the OPLS-AA force field. The mean unsigned error for all molecules is 2.8 cm3 mol−1. The present methodology should find use in many contexts such as the development and testing of force fields for use in computer simulations of organic and biomolecular systems, as a complement to related experimental studies, and to develop a deeper understanding of solute–solvent interactions. PMID:25589343

Determination of partial molar volumes from free energy perturbation theory.

PubMed

Vilseck, Jonah Z; Tirado-Rives, Julian; Jorgensen, William L

2015-04-07

Partial molar volume is an important thermodynamic property that gives insights into molecular size and intermolecular interactions in solution. Theoretical frameworks for determining the partial molar volume (V°) of a solvated molecule generally apply Scaled Particle Theory or Kirkwood-Buff theory. With the current abilities to perform long molecular dynamics and Monte Carlo simulations, more direct methods are gaining popularity, such as computing V° directly as the difference in computed volume from two simulations, one with a solute present and another without. Thermodynamically, V° can also be determined as the pressure derivative of the free energy of solvation in the limit of infinite dilution. Both approaches are considered herein with the use of free energy perturbation (FEP) calculations to compute the necessary free energies of solvation at elevated pressures. Absolute and relative partial molar volumes are computed for benzene and benzene derivatives using the OPLS-AA force field. The mean unsigned error for all molecules is 2.8 cm(3) mol(-1). The present methodology should find use in many contexts such as the development and testing of force fields for use in computer simulations of organic and biomolecular systems, as a complement to related experimental studies, and to develop a deeper understanding of solute-solvent interactions.

Murine aggregation chimeras and wholemount imaging in airway stem cell biology.

PubMed

Rosewell, Ian R; Giangreco, Adam

2012-01-01

Local tissue stem cells are known to exist in mammalian lungs but their role in epithelial maintenance remains unclear. We therefore developed murine aggregation chimera and wholemount imaging techniques to assess the contribution of these cells to lung homeostasis and repair. In this chapter we provide further details regarding the generation of murine aggregation chimera mice and their subsequent use in wholemount lung imaging. We also describe methods related to the interpretation of this data that allows for quantitative assessment of airway stem cell activation versus quiescence. Using these techniques, it is possible to compare the growth and differentiation capacity of various lung epithelial cells in normal, repairing, and diseased states.

AXIAL MODIFICATIONS OF PERMANENT LOWER MOLARS AFTER PREMATURE LOSSES OF TEMPORARY MOLARS.

PubMed

Cernei, E R; Mavru, R B; Zetu, Irina Nicoleta

2016-01-01

The aim of our study was to determine the impact of premature loss of temporary lower molars upon the longitudinal axis of the first and second permanent molars. The study groups included 61 patients, 6-9 year olds with premature loss of primary molars and a control group of 24 patients with intact temporary teeth. We evaluated the angle between longitudinal axis of first and second lower permanent molars and occlusal plane. It was observed that premature loss of lower second deciduous molar modifies more the vertical axis of first and second permanent molars than the premature loss of first lower primary molar. Reducing space occurs mainly through mesial inclination of molars that separates the edentulous breach. Temporary loss of both lower first molars on the same quadrant causes an accelerated eruption of both premolars increasing the prevalence of eruption sequence: "4-5-3-7". The preservation of the occlusal morpho-functional complex using space maintainers mainly when the premature loss of the second primary molars occurs is the best interceptive treatment option.

Application of design of experiments for formulation development and mechanistic evaluation of iontophoretic tacrine hydrochloride delivery.

PubMed

Patel, Niketkumar; Jain, Shashank; Madan, Parshotam; Lin, Senshang

2016-11-01

The objective of this investigation is to develop mathematical equation to understand the impact of variables and establish statistical control over transdermal iontophoretic delivery of tacrine hydrochloride. In addition, possibility of using conductivity measurements as a tool of predicting ionic mobility of the participating ions for the application of iontophoretic delivery was explored. Central composite design was applied to study effect of independent variables like current strength, buffer molarity, and drug concentration on iontophoretic tacrine permeation flux. Molar conductivity was determined to evaluate electro-migration of tacrine ions with application of Kohlrausch's law. The developed mathematic equation not only reveals drug concentration as the most significant variable regulating tacrine permeation, followed by current strength and buffer molarity, but also is capable to optimize tacrine permeation with respective combination of independent variables to achieve desired therapeutic plasma concentration of tacrine in treatment of Alzheimer's disease. Moreover, relative higher mobility of sodium and chloride ions was observed as compared to estimated tacrine ion mobility. This investigation utilizes the design of experiment approach and extends the primary understanding of imapct of electronic and formulation variables on the tacrine permeation for the formulation development of iontophoretic tacrine delivery.

Pattern of dental development in Hominid XVIII from the Middle Pleistocene Atapuerca-Sima de los Huesos site (Spain).

PubMed

Bermudez De Castro, J M; Rosas, A

2001-04-01

. We describe the pattern of dental development of Hominid XVIII from the Middle Pleistocene Sima de los Huesos (SH) site of the Sierra de Atapuerca (Burgos, Spain). As expected, this pattern is similar to that of modern humans. A delay of development of the lower and upper canines was observed. In contrast, the relative advanced development of the lower second molars and, especially, the upper and lower third molars is noteworthy. This latter feature seems to be common in Pleistocene hominids, and suggests that the pattern of dental development evolved in the genus Homo during the Pleistocene. In European Middle Pleistocene hominids, this pattern probably was facilitated by the extra space available in the mandible and maxilla for developing teeth. Copyright 2001 Wiley-Liss, Inc.

Early extraction of the mandibular third molar in case of eruption disturbances of the second molar.

PubMed

Kavadia, S; Antoniades, K; Kaklamanos, E; Antoniades, V; Markovitsi, E; Zafiriadis, L

2003-01-01

General consensus has been reached on extracting mandibular third molars when they are involved in pathologic processes. However, early extraction is advisable in cases of eruption disturbances of the mandibular second molar, before or during orthodontic treatment. Thirty-two patients with early extraction of the mandibular third molar before or during orthodontic treatment were examined. In these cases either the presence of the third molar presented an obstacle in the eruption path of the second, or third molar germ removal was considered beneficial to the course of orthodontic treatment. Early extraction of the mandibular third molar facilitates the eruption of the second molar, especially in cases where evidence of crowding and lack of space in the posterior mandibular region exist. Orthodontic treatment may, in some cases, aggravate eruption disturbances of the second molar.

Influence of third molar space on angulation and dental arch crowding.

PubMed

Hasegawa, Yuh; Terada, Kazuto; Kageyama, Ikuo; Tsuchimochi, Takashi; Ishikawa, Fujiro; Nakahara, Sen

2013-01-01

The influence of the third molars on mandibular incisor crowding has been extensively studied but remains controversial. The purpose of this study was to ascertain whether, in Mongolian subjects, the lower third molar can affect anterior crowding and/or the inclination of teeth in the lower lateral segments. Panoramic radiographs, 45° oblique cephalograms, and dental casts were taken from Mongolian subjects (age range 18.3-24.1 years, mean 21.0 years) exhibiting impaction of all four third molars and an Angle Class I molar relationship. The Ganss ratio was calculated using panoramic radiographs, whereas the gonial angle and angulation of lower canines, premolars and molars were measured using 45° oblique cephalograms. Little's index of irregularity was calculated using dental casts. Significant relationships between the angulation of the third and second molars and between the first molars and second premolars were found. Conversely, there was no significant correlation between the angulation of third molars, first premolars and canines. The Ganss ratio calculations showed that the lower first and second molars and the second premolars inclined mesially if there was insufficient space for the lower third molars. However, there was no significant correlation between Little's index of irregularity and third molar angulation. Furthermore, although the third molar influences the lateral segments, no obvious relationship between the third molar and anterior crowding was observed. Therefore, the angulation of the third molar appears not to cause anterior crowding.

Use of cone beam computed tomography to assess significant imaging findings related to mandibular third molar impaction.

PubMed

Matzen, Louise Hauge; Schropp, Lars; Spin-Neto, Rubens; Wenzel, Ann

2017-11-01

The aim of the study was to identify risk factors for pathoses related to mandibular third molars observed in cone beam computed tomography. Cone beam computed tomography volumes of 410 mandibular third molars were assessed by 3 observers, according to the angulation and position of the third molar in relation to the second molar. In addition, pathoses (marginal bone loss, resorption of the second molar, increased follicular space and lingual bone perforation) were assessed. Logistic regression analyses were used to test whether the angulation and position of the third molar were risk factors for pathoses. On average, 41% of second molars had resorption; mesioangulated (odds ratio [OR] 11-107; P < .001) and horizontally positioned (OR 13-120; P < .001) third molars located cervically at the second molar (OR 2-3; P < .027) significantly increased the risk. On average, 49% of second molars had marginal bone loss; mesioangulated (OR 16-85; P < .001) and horizontally positioned (OR 61-573; P < .001) third molars increased the risk. For the third molar, an increased follicular space was seen in 25% of cases; distal (OR 5-9; P < .001) and vertical positions (OR 5; P < .002) increased the risk. Lingual bone perforation was not related to a specific angulation. Specific angulations of the mandibular third molar are risk factors for marginal bone loss and resorption of the second molar. Copyright © 2017 Elsevier Inc. All rights reserved.

Taking advantage of an unerupted third molar: a case report.

PubMed

Pereira, Igor Figueiredo; Santiago, Fernando Zander Mucci; Sette-Dias, Augusto Cesar; Noronha, Vladimir Reimar Augusto de Souza

2017-01-01

Treatments with dental surgery seek to displace tooth to the correct position within the dental arch. To report a clinical case that took advantage of an unerupted third molar. A male patient, 18 years of age, was referred by his dentist to evaluate the third molars. The clinical exam revealed no visible lower third molars. The computed tomography (CT) exam showed the presence of a supernumerary tooth in the region of the mandibular ramus, on the left side, and impaction of the third molar, which was causing root resorption on the second molar, thus making it impossible to remain in the buccal cavity. The preferred option, therefore, was to remove both second molar and the supernumerary tooth, in addition to attaching a device to the third molar during surgery for further traction. After 12 months, the third molar reached the proper position. When a mandibular second permanent molar shows an atypical root resorption, an impacted third molar can effectively substitute the tooth by using an appropriate orthodontic-surgical approach.

Bilateral maxillary fused second and third molars: a rare occurrence

PubMed Central

Liang, Rui-Zhen; Wu, Jin-Tao; Wu, You-Nong; Smales, Roger J; Hu, Ming; Yu, Jin-Hua; Zhang, Guang-Dong

2012-01-01

This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months. PMID:23222992

Bilateral maxillary fused second and third molars: a rare occurrence.

PubMed

Liang, Rui-Zhen; Wu, Jin-Tao; Wu, You-Nong; Smales, Roger J; Hu, Ming; Yu, Jin-Hua; Zhang, Guang-Dong

2012-12-01

This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.

Endodontic management of a mandibular third molar fused with a fourth molar.

PubMed

Turell, I L; Zmener, O

1999-05-01

Developmental anomalies in permanent molars frequently require surgical intervention. A case of a mandibular third molar fused with a fourth molar which was successfully treated with conservative endodontic therapy is reported.

Development of antiproliferative long-circulating liposomes co-encapsulating doxorubicin and curcumin, through the use of a quality-by-design approach.

PubMed

Tefas, Lucia Ruxandra; Sylvester, Bianca; Tomuta, Ioan; Sesarman, Alina; Licarete, Emilia; Banciu, Manuela; Porfire, Alina

2017-01-01

The aim of this work was to use the quality-by-design (QbD) approach in the development of long-circulating liposomes co-loaded with curcumin (CUR) and doxorubicin (DOX) and to evaluate the cytotoxic potential of these liposomes in vitro using C26 murine colon carcinoma cell line. Based on a risk assessment, six parameters, namely the phospholipid, CUR and DOX concentrations, the phospholipid:cholesterol molar ratio, the temperature during the evaporation and hydration steps and the pH of the phosphate buffer, were identified as potential risk factors for the quality of the final product. The influence of these variables on the critical quality attributes of the co-loaded liposomal CUR and DOX was investigated: particle size, zeta potential, drug loading and entrapment efficiency. For this, a 2 6-2 factorial design was employed to establish a proper regression model and to generate the contour plots for the responses. The obtained data served to establish the design space for which different combinations of variables yielded liposomes with characteristics within predefined specifications. The validation of the model was carried out by preparing two liposomal formulations corresponding to the robust set point from within the design space and one outside the design space and calculating the percentage bias between the predicted and actual experimental results. The in vitro antiproliferative test showed that at higher CUR concentrations, the liposomes co-encapsulating CUR and DOX had a greater cytotoxic effect than DOX-loaded liposomes. Overall, this study showed that QbD is a useful instrument for controlling and optimizing the manufacturing process of liposomes co-loaded with CUR and DOX and that this nanoparticulate system possesses a great potential for use in colon cancer therapy.

An Ex-vivo Shear and tensile bond strengths of orthodontic molar tubes bonded using different techniques.

PubMed

Abu-Alhaija, Elham; Jaradat, Mohammad; Alwahadni, Ahed

2017-03-01

Molar bonding procedures need continuous improvement to be widely accepted clinically and eventually replace molar bands. The purpose of this study was to determine the effects of enamel micro-abrasion and silane coating of the base of molar tubes on shear and tensile bond strengths of orthodontic molar tubes. A total of 200 third molars were randomly allocated into five groups of 40 teeth as follows: group 1: molar tubes bonded to etched teeth (37% phosphoric acid gel; control group); group 2: molar tubes bonded to etched teeth (37% phosphoric acid) with the addition of silane to the base of molar tubes; group 3: molar tubes bonded to teeth pre-treated with 18% hydrochloric acid and pumice (micro-abrasion); group 4: molar tubes bonded to teeth pre-treated with microabrasion with the addition of silane to the base of molar tubes; group 5: molar tubes bonded to teeth pre-treated with microabrasion before conventional acid etching combined with the addition of silane to the base of molar tubes. The bond strength testing was performed using a computer control electromechanical universal testing machine. The highest mean shear and tensile bond strengths were recorded in group 5 (13.81±2.54MPa and 13.97±2.29 MPa, respectively). Micro-abrasion alone (group 3) and the combination of enamel micro-abrasion and the addition of silane (group 4) produced bond strength values comparable to the control. Enamel surface pre-treatment (micro abrasion) before conventional acid etching combined with the addition of silane to the base of the molar tube produced the highest bond strengths among all tested groups. Key words: Molar, shear strength, tensile strength, orthodontic appliances.

An Ex-vivo Shear and tensile bond strengths of orthodontic molar tubes bonded using different techniques

PubMed Central

Alwahadni, Ahed

2017-01-01

Background Molar bonding procedures need continuous improvement to be widely accepted clinically and eventually replace molar bands. Material and Methods The purpose of this study was to determine the effects of enamel micro-abrasion and silane coating of the base of molar tubes on shear and tensile bond strengths of orthodontic molar tubes. A total of 200 third molars were randomly allocated into five groups of 40 teeth as follows: group 1: molar tubes bonded to etched teeth (37% phosphoric acid gel; control group); group 2: molar tubes bonded to etched teeth (37% phosphoric acid) with the addition of silane to the base of molar tubes; group 3: molar tubes bonded to teeth pre-treated with 18% hydrochloric acid and pumice (micro-abrasion); group 4: molar tubes bonded to teeth pre-treated with microabrasion with the addition of silane to the base of molar tubes; group 5: molar tubes bonded to teeth pre-treated with microabrasion before conventional acid etching combined with the addition of silane to the base of molar tubes. The bond strength testing was performed using a computer control electromechanical universal testing machine. Results The highest mean shear and tensile bond strengths were recorded in group 5 (13.81±2.54MPa and 13.97±2.29 MPa, respectively). Micro-abrasion alone (group 3) and the combination of enamel micro-abrasion and the addition of silane (group 4) produced bond strength values comparable to the control. Conclusions Enamel surface pre-treatment (micro abrasion) before conventional acid etching combined with the addition of silane to the base of the molar tube produced the highest bond strengths among all tested groups. Key words:Molar, shear strength, tensile strength, orthodontic appliances. PMID:28298990

Relationship between mandibular condyle and angle fractures and the presence of mandibular third molars.

PubMed

Mah, Deuk-Hyun; Kim, Su-Gwan; Moon, Seong-Yong; Oh, Ji-Su; You, Jae-Seek

2015-02-01

We retrospectively evaluated the impact of mandibular third molars on the occurrence of angle and condyle fractures. This was a retrospective investigation using patient records and radiographs. The sample set consisted of 440 patients with mandibular fractures. Eruption space, depth and angulation of the third molar were measured. Of the 144 angle fracture patients, 130 patients had third molars and 14 patients did not. The ratio of angle fractures when a third molar was present (1.26 : 1) was greater than when no third molar was present (0.19 : 1; odds ratio, 6.58; P<0.001). Of the 141 condyle fractures patients, the third molar was present in 84 patients and absent in 57 patients. The ratio of condyle fractures when a third molar was present (0.56 : 1) was lower than when no third molar was present (1.90 : 1; odds ratio, 0.30; P<0.001). The increased ratio of angle fractures with third molars and the ratio of condyle fractures without a third molar were statistically significant. The occurrence of angle and condyle fractures was more affected by the continuity of the cortical bone at the angle than by the depth of a third molar. These results demonstrate that a third molar can be a determining factor in angle and condyle fractures.

The influence of premature loss of temporary upper molars on permanent molars.

PubMed

Cernei, E R; Maxim, Dana Cristiana; Zetu, Irina Nicoleta

2015-01-01

Premature loss of primary molars due to dental caries and their complications has been associated with space loss and eruptive difficulties, especially when the loss occurs early. The aim of our study was to determine the impact of premature loss of temporary upper molars upon the longitudinal axis of the first and second upper permanent molar. The study group included 64 patients 6-9 years old with premature loss of primary molars and a control group of 48 patients with intact temporary teeth. It was evaluated the angle between longitudinal axis of first and second upper permanent molars and occlusal plane. The sofware used is Easy Dent 4 Viewer®.The data were analyzed by using the Statistical Package for the Social Sciences (version 20.0; SPSS, Chicago, III). It was observed that premature loss of upper second deciduous molars modifies greater the vertical axis of the permanent molars than the premature loss of first upper primary molar. First upper primary molar loss cause an acceleration eruption of first premolar, which will produce a distal inclintion of the both permanent molars. The use of space maintainers after premature loss of the second upper temporary molar is a last solution in preventing tridimensional lesions in the dental arch and occlusion.

Effects of first molar extraction on third molar angulation and eruption space.

PubMed

Bayram, Mehmet; Ozer, Mete; Arici, Selim

2009-02-01

The aim was to investigate the effects of orthodontic treatment with 4 first molar extractions on the angulations and eruption spaces of all third molars and to compare these changes with outcomes of nonextraction samples used as a control group. This study was carried out on standardized panoramic radiographs of 41 subjects (8 male, 33 female) with a mean age of 16.6 years (range 13 to 20 years). Twenty-one of the subjects were orthodontically treated with extraction of the 4 first permanent molars, and 20 had nonextraction treatment. The angulational changes and eruption spaces of third molars were evaluated on the panoramic radiographs taken before treatment and at the end of the observation period. Analysis of the linear variables demonstrated a statistically significant difference between the 2 groups for all third molar eruption spaces (P < .001). The mean differences in the third molar eruption spaces between the pretreatment and posttreatment values for the first molar extraction group were higher than those of the nonextraction cases. Orthodontic treatment accomplished with extractions of the permanent first molars increases the eruption spaces of third molars and decreases their impaction. In addition, it has greater favorable effect on the angulation of the upper third molars than of the lower third molars.

Cloning and Characterization of the Genes Encoding the Murine Homologues of the Human Melanoma Antigens MART1 and gp100

PubMed Central

Zhai, Yifan; Yang, James C.; Spiess, Paul; Nishimura, Michael I.; Overwijk, Willem W.; Roberts, Bruce; Restifo, Nicholas P.; Rosenberg, Steven A.

2008-01-01

The recent identification of genes encoding melanoma-associated antigens has opened new possibilities for the development of cancer vaccines designed to cause the rejection of established tumors. To develop a syngeneic animal model for evaluating antigen-specific vaccines in cancer therapy, the murine homologues of the human melanoma antigens MART1 and gp 100, which were specifically recognized by tumor-infiltrating lymphocytes from patients with melanoma, were cloned and sequenced from a murine B16 melanoma cDNA library. The open reading frames of murine MART1 and gp 100 encode proteins of 113- and 626-amino acids with 68.8 and 77% identity to the respective human proteins. Comparison of the DNA sequences of the murine MART1 genes, derived from normal melanocytes, the immortalized nontumorgenic melanocyte line Melan-a and the B16 melanoma, showed all to be identical. Northern and Western blot analyses confirmed that both genes encoded products that were melanocyte lineage proteins. Mice immunized with murine MART1 or gp 100 using recombinant vaccinia virus failed to produce any detectable T-cell responses or protective immunity against B16 melanoma. In contrast, immunization of mice with human gp 100 using recombinant adenoviruses elicited T cells specific for hgp100, but these T cells also cross reacted with B16 tumor in vitro and induced significant but weak protection against B16 challenge. Immunization with human and mouse gp100 together [adenovirus type 2 (Ad2)-hep100 plus recombinant vaccinia virus (rVV)-mgp100], or immunization with human gp100 (Ad2-hgp100) and boosting with heterologous vector (rVV-hgp100 or rVV-mgp100) or homologous vector (Ad2-hgp100), did not significantly enhance the protective response against B16 melanoma. These results may suggest that immunization with heterologous tumor antigen, rather than self, may be more effective as an immunotherapeutic reagent in designing antigen-specific cancer vaccines. PMID:9101410

Elimination of endogenous aberrant kappa chain transcripts from sp2/0-derived hybridoma cells by specific ribozyme cleavage: utility in genetic therapy of HIV-1 infections.

PubMed Central

Duan, L; Pomerantz, R J

1994-01-01

The pooled degenerate-primer polymerase chain reaction (PCR) technology is now widely used in the amplification and cloning of murine hybridoma-specific immunoglobulin gene cDNAs. The design of primers is mainly based on the highly conserved 5' terminus of immunoglobulin gene variable regions and the constant region in the 3' terminus. Of note, most murine hybridoma cell lines are derived from the Sp2/0 cell line, which is demonstrated to express endogenous aberrant kappa chains (abV kappa). This high-level endogenous abV kappa mixes with specific kappa chains in the hybridomas and interferes with the efficiency of the reverse transcriptase (RT)-PCR cloning strategy. In this report, during the cloning of murine anti-human immunodeficiency virus type I (HIV-1) hybridoma immunoglobulin cDNAs, a specific primer-PCR screening system was developed, based on the abV kappa complementarity-defining region (CDR), to eliminate abV kappa-carrying plasmids. Furthermore, an abV kappa sequence-specific derived ribozyme was developed and packaged in a retroviral expression vector system. This abV kappa ribozyme can be transduced into different murine hybridomas, and expressed intracellularly to potently eliminate endogenous abV kappa RNA. Images PMID:7816635

Accidents and complications associated to third molar surgeries performed by dentistry students.

PubMed

Azenha, Marcelo Rodrigues; Kato, Rogerio Bentes; Bueno, Renan Barros Lima; Neto, Patricio Jose Oliveira; Ribeiro, Michel Campos

2014-12-01

The aim of this work is to demonstrate the accidents and complications rates on third molars surgeries performed by senior dentistry students. A retrospective study of 122 patient charts submitted to third molars surgeries was done. Patient age, gender, dental in arch position, and accidents/complications were considered with the charts presenting incomplete dates being excluded from the study. After all, 88 patients (210 surgeries) were included. The majority of the patients were female (70.4 %), with the average age of 24 years. Mandibular molars represented more than half of the surgical procedures (56.2 %), with teeth at vertical position the most found (60.3 %). The cases of accidents and complications totalized 10.4 % of all performed procedures, being hemorrhage (1.9 %), root fractures (1.9 %), and maxillary tuberosity fracture (1.9 %) the most found. Suture dehiscence (1.4 %), dry socket (1.4 %), oroantral communications (0.9 %), paresthesia (0.9 %), and infection (0.4 %) were also observed. Surgeons' inexperience was not considered a determinant factor to modify the rates of accidents and complications at third molars surgeries when compared to previous works developed by experienced surgeons. It is important to highlight the necessity of the students' knowledge of the most adequate treatments of each of the accidents and complications.

Staphylococcus aureus leukocidin ED contributes to systemic infection by targeting neutrophils and promoting bacterial growth in vivo

PubMed Central

Alonzo, Francis; Benson, Meredith A.; Chen, John; Novick, Richard P.; Shopsin, Bo; Torres, Victor J.

2011-01-01

SUMMARY Bloodstream infection with Staphylococcus aureus is common and can be fatal. However, virulence factors that contribute to lethality in S. aureus bloodstream infection are poorly defined. We discovered that LukED, a commonly overlooked leukotoxin, is critical for S. aureus bloodstream infection in mice. We also determined that LukED promotes S. aureus replication in vivo by directly killing phagocytes recruited to sites of hematogenously-seeded tissue. Furthermore, we established that murine neutrophils are the primary target of LukED, as the greater virulence of wild type S. aureus compared to a lukED mutant was abrogated by depleting neutrophils. The in vivo toxicity of LukED toward murine phagocytes is unique among S. aureus leukotoxins, implying its crucial role in pathogenesis. Moreover, the tropism of LukED for murine phagocytes highlights the utility of murine models to study LukED pathobiology, including development and testing of strategies to inhibit toxin activity and control bacterial infection. PMID:22142035

Pattern of mandibular third molar impaction and its association to caries in mandibular second molar: A clinical variant.

PubMed

Prajapati, V K; Mitra, Ruchi; Vinayak, K M

2017-01-01

Caries in second molar is common and prophylactic removal of the impacted teeth may be considered appropriate. Caries detection and restoration can be difficult and a restored second molar can undergo recurrent caries if the third molar is not removed prophylactically. In this study, the clinical findings related to impaction and its association with angular position and depth of impacted third molar were evaluated. A retrospective descriptive study was carried out among the patients visiting the outpatient, department of Dentistry, RIMS, Ranchi. The clinical examination, periapical radiographs and Pre-op OPG were taken. Teeth positions were analyzed by Pell and Gregory and Winter classification. The angulation and depth of mandibular third molar impaction and caries in the second molar with the eruption status of the mandibular third molar was determined. A total of 200 patients were included in the study between age group 17-45 years. Majority of the Patients reported to the hospital with complaints of decayed tooth (66%) and pain (59%). The most common third molar impaction was mesioangular followed by distoangular. A statistically highly significant difference ( P = 0.001) was obtained with the presence of caries in second molar adjacent to mesioangular third molar in class I and level B. According to this study, pattern of mandibular third molar impaction is in association to caries in mandibular second molar. More future studies are needed. In addition, the results of the present study can be used to screen and inform the patients about the possibility of caries in relation to third molar mandibular impaction.

Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular first and second molars in Turkish individuals

PubMed Central

Sekerci, Ahmet E.; Dinçer, Asiye N.; Cayabatmaz, Muhammed; Zorba, Yahya O.

2013-01-01

Objective: The aim of this study was to investigate the root and canal morphology of mandibular first and second molars in a Turkish population by using cone beam computed tomography (CBCT). Study design: CBCT images of mandibular first (n = 823) and second molar (n = 925) teeth from 605 Turkish patients were analyzed. The root canal configurations were classified according to the method of Vertucci. Results: The majority of mandibular molars (95.8% of first molars, 85.4% of second molars) had two separate roots; however, three roots were identified in 2.06% of first molars and 3.45% of second molars. C-shaped canals occurred 0.85% of first molars and 4.1% of second molars. Three canals were found in 79.9% of first molars and 72.8% of second molars. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal. The most common root morphology of first and second molars is the two rooted morphology with three canals. Both the mesial and distal roots showed wide variations in canal anatomy with type IV and type I canal configuration predominating in the mesial and distal roots, respectively. Conclusion: Vertucci type I and IV canal configurations were the most prevalent in the distal and mesial roots, respectively, of both the mandibular first and second permanent molar teeth. Key words:Cone-beam CT, Turkish, mandibular molars, root and canal morphology. PMID:23524421

Construction of a cDNA library for miniature pig mandibular deciduous molars

PubMed Central

2014-01-01

Background The miniature pig provides an excellent experimental model for tooth morphogenesis because its diphyodont and heterodont dentition resembles that of humans. However, little information is available on the process of tooth development or the exact molecular mechanisms controlling tooth development in miniature pigs or humans. Thus, the analysis of gene expression related to each stage of tooth development is very important. Results In our study, after serial sections were made, the development of the crown of the miniature pigs’ mandibular deciduous molar could be divided into five main phases: dental lamina stage (E33-E35), bud stage (E35-E40), cap stage (E40-E50), early bell stage (E50-E60), and late bell stage (E60-E65). Total RNA was isolated from the tooth germ of miniature pig embryos at E35, E45, E50, and E60, and a cDNA library was constructed. Then, we identified cDNA sequences on a large scale screen for cDNA profiles in the developing mandibular deciduous molars (E35, E45, E50, and E60) of miniature pigs using Illumina Solexa deep sequencing. Microarray assay was used to detect the expression of genes. Lastly, through Unigene sequence analysis and cDNA expression pattern analysis at E45 and E60, we found that 12 up-regulated and 15 down-regulated genes during the four periods are highly conserved genes homologous with known Homo sapiens genes. Furthermore, there were 6 down-regulated and 2 up-regulated genes in the miniature pig that were highly homologous to Homo sapiens genes compared with those in the mouse. Conclusion Our results not only identify the specific transcriptome and cDNA profile in developing mandibular deciduous molars of the miniature pig, but also provide useful information for investigating the molecular mechanism of tooth development in the miniature pig. PMID:24750690

Glass ionomer-silver cermet Class II tunnel-restorations for primary molars.

PubMed

Croll, T P

1988-01-01

Tunnel preparations preserve the anatomical marginal ridge and minimize the loss of healthy tooth structure adjacent to the carious lesion. When the practitioner has developed proficiency in restoring class II carious lesions with tunnel restorations, less treatment time is required than with traditional class II preparations. The technique for restoring a primary first molar with a class II carious lesion, using a tunnel preparation and Ketac-Silver restorative material is described.

The variability of lower third molar development in Northeast Malaysian population with application to age estimation.

PubMed

Johan, N A; Khamis, M F; Abdul Jamal, N Sk; Ahmad, B; Mahanani, E S

2012-07-01

This study aimed to assess the variability of the lower third molar (tooth 38 and 48) development in Northeast Malaysian population with respect to the side of dentition, to generate age prediction models and to compare the outcome with other studies. A total of 1080 orthopantomograms of Northeast Malaysian population aged between 14 and 25 years (540 males and 540 females) from the Hospital Universiti Sains Malaysia's archive which met the inclusion and exclusion criteria were selected and the maturity stages of tooth 38 and 48 were scored using Demirjian's stages (A-H). The findings showed a wide variation of the development of lower third molars in the Northeast Malaysian population. The roots developed earlier in males than in females. The development of the dentition on opposite sides of the mandible was synchronously in females and males. A multiple regression analysis shows that 71.1% of variance in age was explained by sex and developmental stage of tooth 48. An age prediction model was generated from the regression analysis: [Age = 7.117 + 1.907*(stage of tooth 48) - 0.432*(sex)] with mean prediction errors between -0.17 to 3.14 years. The obtained data in the current study are useful for references and determining age of unidentified human remains for identification investigation.

A new sum parameter to estimate the bioconcentration and baseline-toxicity of hydrophobic compounds in river water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loon, W.M.G.M. van; Hermens, J.L.M.

1994-12-31

A large part of all aquatic pollutants can be classified as narcosis-type (baseline toxicity) chemicals. Many chemicals contribute to a joint baseline aquatic toxicity even at trace concentrations. A novel surrogate parameter, which simulated bioconcentration of hydrophobic substances from water and estimates internal molar concentrations, has been explored by Verhaar et al.. These estimated biological concentrations can be used to predict narcosis-type toxic effects, using the Lethal Body Burden (LBB) concept. The authors applied this toxicological-analytical concept to river water, and some recent technological developments and field results are pointed out. The simulation of bioconcentration is performed by extracting watermore » samples with empore{trademark} disks. The authors developed two extraction procedures; i.e., laboratory extraction and field extraction. Molar concentrations measurements are performed using vapor pressure osmometry, GC-FID and GC-MS. Results on the molar concentrations of hydrophobic compounds which can be bioaccumulated from several Dutch river systems will be presented.« less

Distal cervical caries in the mandibular second molar: an indication for the prophylactic removal of third molar teeth? Update.

PubMed

McArdle, Louis W; McDonald, Fraser; Jones, Judith

2014-02-01

In 2005 we reported the clinical findings of 100 patients who had mandibular third molars removed because of distal cervical caries in the mandibular second molar. The aim of this follow-up study was to find out whether the findings in a new group of patients corroborate those of our previous study. We report on the clinical features of 239 patients (mean (SD) age 32.1 (7.85) years, range 20-65) who had 288 mandibular third molars removed because of distal cervical caries in the second molar. Patients had better dental health than average, and 67% had a DMF (decayed, missing, or filled) score of 5 or less. In 89% of third molars the mesial angulation was between 40° and 80°. Distal cervical caries in second molars is a late complication of third molar retention. The prophylactic removal of a partially erupted mesioangular third molar will prevent distal cervical caries forming in the second molar tooth. Copyright © 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Positional changes of the third molar in orthodontically treated patients.

PubMed

Mihai, A M; Lulache, I R; Grigore, R; Sanabil, A S; Boiangiu, S; Ionescu, E

2013-06-15

Over the years, the effects of the third molars eruption on the dental arches have been studied extensively. Still, literature provides less data regarding the effects of the orthodontic treatment on the third molars position. The aim of our study was to assess the positional changes of the third molars relative to the occlusal plane and to the second molar long axis, changes occurred during orthodontic treatment performed with or without premolar extractions. This study included 20 orthodontic treated patients: 10 of them with premolar extractions and 10 without premolar extractions. The pretreatment and post treatment panoramic radiographs were analyzed, and the angles between the third molar long axis and the occlusal plane and between the long axis of the third molar and the long axis of the second molar were measured. Changes in third molar position, from pretreatment to post treatment, for the two groups of patients were evaluated by using the Student's t-test. The results of the statistical analysis revealed an improvement in third molars position, the best results were seen in the lower third molars, in the group of patients treated with premolar extractions.

40 CFR Table 1 to Subpart Ja of... - Molar Exhaust Volumes and Molar Heat Content of Fuel Gas Constituents

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Molar Exhaust Volumes and Molar Heat... Exhaust Volumes and Molar Heat Content of Fuel Gas Constituents Constituent MEVa dscf/mol MHCb Btu/mol... standard conditions of 68 °F and 1 atmosphere. b MHC = molar heat content (higher heating value basis), Btu...

40 CFR Table 1 to Subpart Ja of... - Molar Exhaust Volumes and Molar Heat Content of Fuel Gas Constituents

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Molar Exhaust Volumes and Molar Heat... Exhaust Volumes and Molar Heat Content of Fuel Gas Constituents Constituent MEVa dscf/mol MHCb Btu/mol... standard conditions of 68 °F and 1 atmosphere. b MHC = molar heat content (higher heating value basis), Btu...

Relationship between mandibular condyle and angle fractures and the presence of mandibular third molars

PubMed Central

Mah, Deuk-Hyun; Moon, Seong-Yong; Oh, Ji-Su; You, Jae-Seek

2015-01-01

Objectives We retrospectively evaluated the impact of mandibular third molars on the occurrence of angle and condyle fractures. Materials and Methods This was a retrospective investigation using patient records and radiographs. The sample set consisted of 440 patients with mandibular fractures. Eruption space, depth and angulation of the third molar were measured. Results Of the 144 angle fracture patients, 130 patients had third molars and 14 patients did not. The ratio of angle fractures when a third molar was present (1.26 : 1) was greater than when no third molar was present (0.19 : 1; odds ratio, 6.58; P<0.001). Of the 141 condyle fractures patients, the third molar was present in 84 patients and absent in 57 patients. The ratio of condyle fractures when a third molar was present (0.56 : 1) was lower than when no third molar was present (1.90 : 1; odds ratio, 0.30; P<0.001). Conclusion The increased ratio of angle fractures with third molars and the ratio of condyle fractures without a third molar were statistically significant. The occurrence of angle and condyle fractures was more affected by the continuity of the cortical bone at the angle than by the depth of a third molar. These results demonstrate that a third molar can be a determining factor in angle and condyle fractures. PMID:25741462

Age estimation in the living: Transition analysis on developing third molars.

PubMed

Tangmose, Sara; Thevissen, Patrick; Lynnerup, Niels; Willems, Guy; Boldsen, Jesper

2015-12-01

A radiographic assessment of third molar development is essential for differentiating between juveniles and adolescents in forensic age estimations. As the developmental stages of third molars are highly correlated, age estimates based on a combination of a full set of third molar scores are statistically complicated. Transition analysis (TA) is a statistical method developed for estimating age at death in skeletons, which combines several correlated developmental traits into one age estimate including a 95% prediction interval. The aim of this study was to evaluate the performance of TA in the living on a full set of third molar scores. A cross sectional sample of 854 panoramic radiographs, homogenously distributed by sex and age (15.0-24.0 years), were randomly split in two; a reference sample for obtaining age estimates including a 95% prediction interval according to TA; and a validation sample to test the age estimates against actual age. The mean inaccuracy of the age estimates was 1.82 years (±1.35) in males and 1.81 years (±1.44) in females. The mean bias was 0.55 years (±2.20) in males and 0.31 years (±2.30) in females. Of the actual ages, 93.7% of the males and 95.9% of the females (validation sample) fell within the 95% prediction interval. Moreover, at a sensitivity and specificity of 0.824 and 0.937 in males and 0.814 and 0.827 in females, TA performs well in differentiating between being a minor as opposed to an adult. Although accuracy does not outperform other methods, TA provides unbiased age estimates which minimize the risk of wrongly estimating minors as adults. Furthermore, when corrected ad hoc, TA produces appropriate prediction intervals. As TA allows expansion with additional traits, i.e. stages of development of the left hand-wrist and the clavicle, it has a great potential for future more accurate and reproducible age estimates, including an estimated probability of having attained the legal age limit of 18 years. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Root and Root Canal Morphology of Human Third Molar Teeth.

PubMed

Mohammadi, Zahed; Jafarzadeh, Hamid; Shalavi, Sousan; Bandi, Shilpa; Patil, Shankargouda

2015-04-01

Successful root canal treatment depends on having comprehensive information regarding the root(s)/canal(s) anatomy. Dentists may have some complication in treatment of third molars because the difficulty in their access, their aberrant occlusal anatomy and different patterns of eruption. The aim of this review was to review and address the number of roots and root canals in third molars, prevalence of confluent canals in third molars, C-shaped canals, dilaceration and fusion in third molars, autotransplantation of third molars and endodontic treatment strategies for third molars.

Prevalence of Distal Caries in Mandibular Second Molar Due to Impacted Third Molar

PubMed Central

Alshahrani, Fatima Saeed; Alabsi, Wejdan Saad; Alqahtani, Zainab Ali; Hameed, Mohammad Shahul; Mustafa, Abdel Bagi; Alam, Tanveer

2017-01-01

Introduction A tooth is said to be impacted if it does not reach the occlusal plane even after two-thirds root formation. The aetiology of impacted teeth is varied and multi-factorial. Significant problems associated with impacted teeth include trismus, infection, cervical caries of second molars. Aim This study was aimed to assess the prevalence of distal caries in second molar teeth due to impacted third molars and to compare with similar studies conducted elsewhere. Materials and Methods Study included assessment of patients reporting between 2009 to 2014 for dental care at College of Dentistry, King Khalid University, Abha, Kingdom of Saudi Arabia. This is a retrospective cross-sectional study which included a total of 6000 Orthopantomograms (OPGs). The data collected was decoded and entered into excel spread sheet. Descriptive analysis of the data was done and results were displayed as frequency table and graphs. Results A total of 979 patients had impacted third molars (16.31%). A total of 39% patient’s with impacted third molars had distal cervical caries in second molar. Mesioangular impaction was the most prominent type. This was closely followed by horizontal impaction causing distal caries in second molars. Age group between 21-28 years and male gender had the higher prevalence of distal caries in second molar teeth due to impacted third molars. Conclusion A total of 39% of the patients with impacted mandibular third molars had distal cervical caries in second molars. Mesioangular type, male gender, age group 21-28 years were the prominent factors associated with distal caries in second molar teeth due to impacted third molars. PMID:28511504

Pattern of mandibular third molar impaction and its association to caries in mandibular second molar: A clinical variant

PubMed Central

Prajapati, V. K.; Mitra, Ruchi; Vinayak, K. M.

2017-01-01

Background: Caries in second molar is common and prophylactic removal of the impacted teeth may be considered appropriate. Caries detection and restoration can be difficult and a restored second molar can undergo recurrent caries if the third molar is not removed prophylactically. In this study, the clinical findings related to impaction and its association with angular position and depth of impacted third molar were evaluated. Materials and Methods: A retrospective descriptive study was carried out among the patients visiting the outpatient, department of Dentistry, RIMS, Ranchi. The clinical examination, periapical radiographs and Pre-op OPG were taken. Teeth positions were analyzed by Pell and Gregory and Winter classification. The angulation and depth of mandibular third molar impaction and caries in the second molar with the eruption status of the mandibular third molar was determined. Results: A total of 200 patients were included in the study between age group 17-45 years. Majority of the Patients reported to the hospital with complaints of decayed tooth (66%) and pain (59%). The most common third molar impaction was mesioangular followed by distoangular. A statistically highly significant difference (P = 0.001) was obtained with the presence of caries in second molar adjacent to mesioangular third molar in class I and level B. Conclusion: According to this study, pattern of mandibular third molar impaction is in association to caries in mandibular second molar. More future studies are needed. In addition, the results of the present study can be used to screen and inform the patients about the possibility of caries in relation to third molar mandibular impaction. PMID:28584538

Accuracy of an equation for estimating age from mandibular third molar development in a Thai population

PubMed Central

Verochana, Karune; Prapayasatok, Sangsom; Mahasantipiya, Phattaranant May; Korwanich, Narumanas

2016-01-01

Purpose This study assessed the accuracy of age estimates produced by a regression equation derived from lower third molar development in a Thai population. Materials and Methods The first part of this study relied on measurements taken from panoramic radiographs of 614 Thai patients aged from 9 to 20. The stage of lower left and right third molar development was observed in each radiograph and a modified Gat score was assigned. Linear regression on this data produced the following equation: Y=9.309+1.673 mG+0.303S (Y=age; mG=modified Gat score; S=sex). In the second part of this study, the predictive accuracy of this equation was evaluated using data from a second set of panoramic radiographs (539 Thai subjects, 9 to 24 years old). Each subject's age was estimated using the above equation and compared against age calculated from a provided date of birth. Estimated and known age data were analyzed using the Pearson correlation coefficient and descriptive statistics. Results Ages estimated from lower left and lower right third molar development stage were significantly correlated with the known ages (r=0.818, 0.808, respectively, P≤0.01). 50% of age estimates in the second part of the study fell within a range of error of ±1 year, while 75% fell within a range of error of ±2 years. The study found that the equation tends to estimate age accurately when individuals are 9 to 20 years of age. Conclusion The equation can be used for age estimation for Thai populations when the individuals are 9 to 20 years of age. PMID:27051633

Accuracy of an equation for estimating age from mandibular third molar development in a Thai population.

PubMed

Verochana, Karune; Prapayasatok, Sangsom; Janhom, Apirum; Mahasantipiya, Phattaranant May; Korwanich, Narumanas

2016-03-01

This study assessed the accuracy of age estimates produced by a regression equation derived from lower third molar development in a Thai population. The first part of this study relied on measurements taken from panoramic radiographs of 614 Thai patients aged from 9 to 20. The stage of lower left and right third molar development was observed in each radiograph and a modified Gat score was assigned. Linear regression on this data produced the following equation: Y=9.309+1.673 mG+0.303S (Y=age; mG=modified Gat score; S=sex). In the second part of this study, the predictive accuracy of this equation was evaluated using data from a second set of panoramic radiographs (539 Thai subjects, 9 to 24 years old). Each subject's age was estimated using the above equation and compared against age calculated from a provided date of birth. Estimated and known age data were analyzed using the Pearson correlation coefficient and descriptive statistics. Ages estimated from lower left and lower right third molar development stage were significantly correlated with the known ages (r=0.818, 0.808, respectively, P≤0.01). 50% of age estimates in the second part of the study fell within a range of error of ±1 year, while 75% fell within a range of error of ±2 years. The study found that the equation tends to estimate age accurately when individuals are 9 to 20 years of age. The equation can be used for age estimation for Thai populations when the individuals are 9 to 20 years of age.

Regenerative Endodontic Treatment of an Immature Necrotic Molar with Arrested Root Development by Using Recombinant Human Platelet-derived Growth Factor: A Case Report.

PubMed

Zhujiang, Annie; Kim, Sahng G

2016-01-01

Regenerative endodontic treatment has provided a treatment option that aims to allow root maturation. The present report describes the regenerative endodontic treatment of a necrotic, immature molar by using recombinant human platelet-derived growth factor (rhPDGF-BB) and shows the continued root maturation in the tooth with arrested root development. A regenerative endodontic procedure that used a growth factor was performed for a necrotic molar with arrested root formation in a 20-year-old patient. Thorough disinfection by using mechanical instrumentation and copious irrigation of antimicrobial agents as well as intracanal medication with calcium hydroxide was performed throughout the first 2 appointments. At the third appointment, the root canals were irrigated with an antimicrobial solution and 17% EDTA, and bleeding was evoked by passing sterile paper points beyond the apex in each canal. Small pieces of a collagen membrane saturated with rhPDGF-BB solution from GEM 21S were packed into each canal. Mineral trioxide aggregate was placed, and Cavit and composite resin were used to restore the tooth. Complete root maturation and resolution of a periapical radiolucency were observed at the 15-month follow-up. The present report presents a regenerative endodontic procedure that uses rhPDGF-BB for a necrotic molar with arrested root development. The finding of continued root development in the present case suggests that regenerative endodontic treatment may be able to resume the root maturation process in teeth with arrested root formation. Further clinical studies are required to investigate the efficacy of rhPDGF-BB in regenerative endodontic treatment. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

ApcMin, A Mutation in the Murine Apc Gene, Predisposes to Mammary Carcinomas and Focal Alveolar Hyperplasias

NASA Astrophysics Data System (ADS)

Moser, Amy Rapaich; Mattes, Ellen M.; Dove, William F.; Lindstrom, Mary J.; Haag, Jill D.; Gould, Michael N.

1993-10-01

ApcMin (Min, multiple intestinal neoplasia) is a point mutation in the murine homolog of the APC gene. Min/+ mice develop multiple intestinal adenomas, as do humans carrying germ-line mutations in APC. Female mice carrying Min are also prone to develop mammary tumors. Min/+ mammary glands are more sensitive to chemical carcinogenesis than are +/+ mammary glands. Transplantation of mammary cells from Min/+ or +/+ donors into +/+ hosts demonstrates that the propensity to develop mammary tumors is intrinsic to the Min/+ mammary cells. Long-term grafts of Min/+ mammary glands also gave rise to focal alveolar hyperplasias, indicating that the presence of the Min mutation also has a role in the development of these lesions.

[Effects of the first premolar extraction on the third molar angulation].

PubMed

He, Yu-hong; Duan, Yin-zhong; Pan, Ji-jun; Xi, Lan-lan

2008-08-01

To analyze the effects about inclinations of the second and the third molars in patients treated with or without premolar extractions. Fifty-six adolescents were chosen and divided into the first premolar extraction and non-extraction groups, 30 and 26 patients respectively. The pre-treatment and post-treatment panoramic radiographs were made. Angles between long axis of the third molar and the occlusal plane (the second molar alike), and long axis of the second and the third molar were measured and evaluated. The maxillary and mandibular third molar angulations were all improved after treatment in two groups. Compared with non-extraction group, the average changes of angle between long axis of the third molar and the occlusal plane increased significantly in maxilla and mandible (P < 0.05). Average changes of angles between long axis of the second and the third molar decreased and had statistically significant difference (P < 0.05). The change of angle between long axis of mandibular second molar and the occlusal plane had statistically significant difference (P < 0.05), but there was no statistically significant difference in maxillary second molar (P > 0.05). The first premolar extraction in orthodontic treatment could improve the third molar angulations and it would promote the eruption of the third molar.

Impacted Mandibular Third Molars: A Retrospective Study of 1198 Cases to Assess Indications for Surgical Removal, and Correlation with Age, Sex and Type of Impaction-A Single Institutional Experience.

PubMed

Patel, Shital; Mansuri, Saloni; Shaikh, Faizan; Shah, Taksh

2017-03-01

To study the incidence of mandibular third molar impaction in relation to type and side of impaction, age and sex of patients and indications for its surgical removal through data collected from a single institute over a period of 3 and half years. The records of 1198 patients who underwent the surgical removal of impacted mandibular third molars were reviewed retrospectively. Records were divided into groups according to sex, age, type and side of impaction. Radiographs were studied to determine angular position of impacted mandible third molar. We found that there was a high incidence of mesioangular lower third molar impaction (33.97 %), highest number of patients were found in 15-30 years of age group (48.33 %), a left side (56.93 %) was more commonly involved, female predominance (63.44 %) was observed and recurrent pericoronitis (33.81 %) was the most common indication. Awareness of the indications for surgical removal of impacted mandibular third molar to the patients will help to avoid future risk of complications and morbidity associated with the same. This will not only help in saving time and money but also prevents the psychological trauma associated with delayed treatment. Removal of only symptomatic IMTM seems to be the logical choice in view of financial constraint in developing countries like India but at the same time early removal offers freedom from future complications in selected cases. So surgeons should apply a meticulous approach in selecting the patients for SRIMTM.

The Voronoi volume and molecular representation of molar volume: equilibrium simple fluids.

PubMed

Hunjan, Jagtar Singh; Eu, Byung Chan

2010-04-07

The Voronoi volume of simple fluids was previously made use of in connection with volume transport phenomena in nonequilibrium simple fluids. To investigate volume transport phenomena, it is important to develop a method to compute the Voronoi volume of fluids in nonequilibrium. In this work, as a first step to this goal, we investigate the equilibrium limit of the nonequilibrium Voronoi volume together with its attendant related molar (molal) and specific volumes. It is proved that the equilibrium Voronoi volume is equivalent to the molar (molal) volume. The latter, in turn, is proved equivalent to the specific volume. This chain of equivalences provides an alternative procedure of computing the equilibrium Voronoi volume from the molar volume/specific volume. We also show approximate methods of computing the Voronoi and molar volumes from the information on the pair correlation function. These methods may be employed for their quick estimation, but also provide some aspects of the fluid structure and its relation to the Voronoi volume. The Voronoi volume obtained from computer simulations is fitted to a function of temperature and pressure in the region above the triple point but below the critical point. Since the fitting function is given in terms of reduced variables for the Lennard-Jones (LJ) model and the kindred volumes (i.e., specific and molar volumes) are in essence equivalent to the equation of state, the formula obtained is a reduced equation state for simple fluids obeying the LJ model potential in the range of temperature and pressure examined and hence can be used for other simple fluids.

New methodology to reconstruct in 2-D the cuspal enamel of modern human lower molars.

PubMed

Modesto-Mata, Mario; García-Campos, Cecilia; Martín-Francés, Laura; Martínez de Pinillos, Marina; García-González, Rebeca; Quintino, Yuliet; Canals, Antoni; Lozano, Marina; Dean, M Christopher; Martinón-Torres, María; Bermúdez de Castro, José María

2017-08-01

In the last years different methodologies have been developed to reconstruct worn teeth. In this article, we propose a new 2-D methodology to reconstruct the worn enamel of lower molars. Our main goals are to reconstruct molars with a high level of accuracy when measuring relevant histological variables and to validate the methodology calculating the errors associated with the measurements. This methodology is based on polynomial regression equations, and has been validated using two different dental variables: cuspal enamel thickness and crown height of the protoconid. In order to perform the validation process, simulated worn modern human molars were employed. The associated errors of the measurements were also estimated applying methodologies previously proposed by other authors. The mean percentage error estimated in reconstructed molars for these two variables in comparison with their own real values is -2.17% for the cuspal enamel thickness of the protoconid and -3.18% for the crown height of the protoconid. This error significantly improves the results of other methodologies, both in the interobserver error and in the accuracy of the measurements. The new methodology based on polynomial regressions can be confidently applied to the reconstruction of cuspal enamel of lower molars, as it improves the accuracy of the measurements and reduces the interobserver error. The present study shows that it is important to validate all methodologies in order to know the associated errors. This new methodology can be easily exportable to other modern human populations, the human fossil record and forensic sciences. © 2017 Wiley Periodicals, Inc.

Increased occurrence of dental anomalies associated with infraocclusion of deciduous molars.

PubMed

Shalish, Miriam; Peck, Sheldon; Wasserstein, Atalia; Peck, Leena

2010-05-01

To test the null hypothesis that there is no relationship between infraocclusion and the occurrence of other dental anomalies in subjects selected for clear-cut infraocclusion of one or more deciduous molars. The experimental sample consisted of 99 orthodontic patients (43 from Boston, Mass, United States; 56 from Jerusalem, Israel) with at least one deciduous molar in infraocclusion greater than 1 mm vertical discrepancy, measured from the mesial marginal ridge of the first permanent molar. Panoramic radiographs and dental casts were used to determine the presence of other dental anomalies, including agenesis of permanent teeth, microdontia of maxillary lateral incisors, palatally displaced canines (PDC), and distal angulation of the mandibular second premolars (MnP2-DA). Comparative prevalence reference values were utilized and statistical testing was performed using the chi-square test (P < .05) and odds ratio. The studied dental anomalies showed two to seven times greater prevalence in the infraocclusion samples, compared with reported prevalence in reference samples. In most cases, the infraoccluded deciduous molar exfoliated eventually and the underlying premolar erupted spontaneously. In some severe phenotypes (10%), the infraoccluded deciduous molar was extracted and space was regained to allow uncomplicated eruption of the associated premolar. Statistically significant associations were observed between the presence of infraocclusion and the occurrence of tooth agenesis, microdontia of maxillary lateral incisors, PDC, and MnP2-DA. These associations support a hypothesis favoring shared causal genetic factors. Clinically, infraocclusion may be considered an early marker for the development of later appearing dental anomalies, such as tooth agenesis and PDC.

Are hypomineralised lesions on second primary molars (HSPM) a predictive sign of molar incisor hypomineralisation (MIH)? A systematic review and a meta-analysis.

PubMed

Garot, Elsa; Denis, Alice; Delbos, Yves; Manton, David; Silva, Mihiri; Rouas, Patrick

2018-05-01

Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) involve qualitative structural developmental anomalies of tooth enamel affecting the first permanent molars (and often incisors) and the second primary molars, respectively. A putative relationship between HSPM and MIH has been reported in the scientific literature. The aim was to determine whether children with HSPM are more likely to develop MIH. A systematic search using PubMed/Medline, Embase and Cochrane Library electronic databases for publications from 2001 to August 2017 investigating the link between MIH and HSPM was undertaken. Four reviewers selected the studies independently, extracted the data according to PRISMA statement, and assessed the bias risk with the Newcastle-Ottawa Scale (NOS) criteria. From 645 potentially eligible studies, 14 were selected for full text analysis and 5 were included in the meta-analysis. Cross-sectional and cohort studies were reported and 4662 participants were included. The meta-analyses were performed with a random model calculated an OR total of 4.66 (95% CI 2.11-10.26; P < 0.001). The weighted mean of the co-occurrence of HSPM and MIH prevalence was 19.94%. The high heterogeneity (I 2  = 88%) can be explained by the great variation present in number of participants and variable caries risk. Despite the limitations of the study, the presence of HSPM is predictive for MIH, with greater MIH prevalence in the presence of mild HSPM. Early detection and preventive intervention could reduce MIH complications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Growth differentiation factor‑5 induces tenomodulin expression via phosphorylation of p38 and promotes viability of murine mesenchymal stem cells from compact bone.

PubMed

Qu, Yanlong; Zhou, Li; Lv, Bing; Wang, Chunlei; Li, Pengwei

2018-03-01

Growth differentiation factor (GDF)‑5 serves a role in tissue development and tenomodulin serves an important role in the development of tendons. The effects of GDF‑5 on mesenchymal stem cells (MSCs), particularly with regards to tendon bioengineering, are poorly understood. The present study aimed to investigate the effects of GDF‑5 on cell viability and tenomodulin expression in MSCs from murine compact bone. MSCs were isolated from murine compact bones and confirmed by flow cytometric analysis. In addition, the adipogenic, osteoblastic and chondrocyte differentiation capabilities of the MSCs were determined. MSCs were treated with GDF‑5 and the effects of GDF‑5 on MSC viability were determined. The mRNA and protein expression levels of tenomodulin were detected by reverse transcription‑quantitative polymerase chain reaction and western blotting, respectively. MSCs from murine compact bone were successfully isolated. GDF‑5 had optimal effects on cell viability at 100 ng/ml (+36.9% of control group without GDF‑5 treatment, P<0.01) and its effects peaked after 6 days of treatment (+56.6% of control group, P<0.001). Compared with the control group, treatment with 100 ng/ml GDF‑5 for 4 days enhanced the mRNA expression levels of tenomodulin (3.56±0.94 vs. 1.02±0.25; P<0.05). In addition, p38 was activated by GDF‑5, as determined by enhanced expression levels of phosphorylated p38 (p‑p38). The GDF‑5‑induced protein expression levels of p‑p38 and tenomodulin were markedly inhibited following treatment with SB203580, an inhibitor of p38 mitogen‑activated protein kinase. These results suggested that GDF‑5 treatment may increase tenomodulin protein expression via phosphorylation of p38 in MSCs from murine compact bone. These findings may aid the future development of tendon bioengineering.

Adoptive transfer of syngeneic T cells transduced with a chimeric antigen receptor that recognizes murine CD19 can eradicate lymphoma and normal B cells.

PubMed

Kochenderfer, James N; Yu, Zhiya; Frasheri, Dorina; Restifo, Nicholas P; Rosenberg, Steven A

2010-11-11

Adoptive T-cell therapy with anti-CD19 chimeric antigen receptor (CAR)-expressing T cells is a new approach for treating advanced B-cell malignancies. To evaluate anti-CD19-CAR-transduced T cells in a murine model of adoptive T-cell therapy, we developed a CAR that specifically recognized murine CD19. We used T cells that were retrovirally transduced with this CAR to treat mice bearing a syngeneic lymphoma that naturally expressed the self-antigen murine CD19. One infusion of anti-CD19-CAR-transduced T cells completely eliminated normal B cells from mice for at least 143 days. Anti-CD19-CAR-transduced T cells eradicated intraperitoneally injected lymphoma cells and large subcutaneous lymphoma masses. The antilymphoma efficacy of anti-CD19-CAR-transduced T cells was critically dependent on irradiation of mice before anti-CD19-CAR-transduced T-cell infusion. Anti-CD19-CAR-transduced T cells had superior antilymphoma efficacy compared with the anti-CD19 monoclonal antibody from which the anti-CD19 CAR was derived. Our results demonstrated impressive antilymphoma activity and profound destruction of normal B cells caused by anti-CD19-CAR-transduced T cells in a clinically relevant murine model.

IL-9-Producing Mast Cell Precursors and Food Allergy

DTIC Science & Technology

2017-10-01

established genetically modified murine strains, a new reconstitution model of experimental food allergy, and the system to acquire duodenal biopsy...development in vivo using murine model of food allergy. Other Subtasks which are designed to study the molecular mechanisms underlying the FcεR signaling...for effective MMC9 expansion using FcεR deficient mice (Fig. 6). The cellular and molecular mechanisms underlining the FcεR signaling pathway will

Relationships for mercury and selenium in muscle and ova of gravid freshwater fish.

PubMed

Donald, David B

2016-10-01

At high concentrations, mercury (Hg) is toxic to vertebrates, causing neurological, behavioral, and teratological dysfunction. Selenium (Se) not only is an essential element but also has a high affinity for Hg, binding to organic methyl mercury at a molar ratio of Se/Hg of 1:1. Ratios of <1 increase risk of Hg toxicity. For gravid fish, low concentrations of Se in ova could increase potential for Hg toxicity, compromising embryonic development and fitness of fry. Mercury and selenium concentrations and ratios were investigated in the muscle and ovaries of six species from five families of fish to assess potential for risk to ecological fitness. Molar ratios of Se/Hg in muscle were typically >18 for lower trophic level species but ≤2 for piscivores. For all species combined, the concentrations of Hg in ova were significantly related to concentrations of Hg in muscle. Concentrations of Se in ova versus muscle showed a similar significant relationship that was independent of muscle Hg concentration. Mean ova molar Se/Hg ratios were high, ranging from 69 to 955 for the 6 species. However, a declining relationship between the ova Se/Hg molar ratio and the muscle concentration of Hg for all species combined suggests that development of ova and fry might be compromised for those piscivores with the highest muscle Hg concentrations because of Hg-related Se deficiency.

Nothing new under the heavens: MIH in the past?

PubMed

Ogden, A R; Pinhasi, R; White, W J

2008-12-01

This was to study an archaeological population of subadult teeth in 17th and 18th century skeletal material from a London (England) cemetery for enamel defects including molar-incisor-hypomineralisation (MIH). Dentitions of 45 sub-adults were examined using standard macroscopic methods and systematically recorded. A total of 557 teeth were examined with a *5 lens and photographed. Ages of the individuals were estimated from their dental crown and root development stages and not from charts that combine tooth eruption with development stages. The dental age of the individual and the approximate age of onset of enamel defects was then calculated on the basis of the chronological sequence of incremental deposition and calcification of the enamel matrix. Affected enamel was graded macroscopically as: - Mild: <30% of the tooth's enamel surface area visibly disrupted (this encompasses the entire range reported in most other studies), Moderate: 31-49% of the tooth's enamel surface area visibly disrupted and Severe: >50% of the tooth's enamel surface area visibly disrupted. Of the total number of individuals 41 (93.2%) showed signs of enamel developmental dysplasia or MIH, 28 of them showing moderate or severe lesions of molars, primary or permanent (63.6% of the sample). Incisors and canines, though surviving much less often, showed episodes of linear hypoplasia. The extensive lesions seen on many of the molars displayed cuspal enamel hypoplasia (CEH). Many of these teeth also exhibited Molar Incisal Hypomineralisation (MIH).

Maxillary second molar impaction in the adjacent ectopic third molar: Report of five rare cases

PubMed Central

Souki, Bernardo Q.; Cheib, Paula L.; de Brito, Gabriela M.; Pinto, Larissa S. M. C.

2015-01-01

Maxillary second molar impaction in the adjacent ectopic third molar is a rare condition that practitioners might face in the field of pediatric dentistry and orthodontics. The early diagnosis and extraction of the adjacent ectopic third molar have been advocated, and prior research has reported a high rate of spontaneous eruption following third molar removal. However, some challenges in the daily practice are that the early diagnosis of this type of tooth impaction is difficult with conventional radiographic examination, and sometimes the early surgical removal of the maxillary third molar must be postponed because of the risks of damaging the second molar. The objective of this study is to report a case series of five young patients with maxillary second molar impaction and to discuss the difficulty of early diagnosis with the conventional radiographic examination, and unpredictability of self-correction. PMID:26321848

Maxillary molar intrusion with micro-implant anchorage (MIA).

PubMed

Park, Hyo-Sang; Jang, Bong-Kyu; Kyung, Hee-Moon

2005-11-01

Intrusion of the maxillary molars is difficult to accomplish using traditional methods of anchorage. To describe methods of maxillary molar intrusion with the aid of micro-implants. Micro-implants provide stable intra-oral anchorage and enable the maxillary molars to be intruded without the usual side effects. Three adult patients are presented showing how micro-implants can be used to intrude the maxillary molars. In the first patient micro-implants were placed in the alveolar process between the second premolar and first molar, in the second patient micro-implants were placed in the palatal alveolar process between the first and second molars, and in the third patient a micro-implant was placed in the palate paramedially. A transpalatal bar was used to prevent bucco- or linguoversion of the molars during intrusion. The maxillary molars can be intruded with intra-oral anchorage derived from microscrew implants.

Positional changes of the third molar in orthodontically treated patients

PubMed Central

Mihai, AM; Lulache, IR; Grigore, R; Sanabil, AS; Boiangiu, S; Ionescu, E

2013-01-01

Objective and Rationale. Over the years, the effects of the third molars eruption on the dental arches have been studied extensively. Still, literature provides less data regarding the effects of the orthodontic treatment on the third molars position. The aim of our study was to assess the positional changes of the third molars relative to the occlusal plane and to the second molar long axis, changes occurred during orthodontic treatment performed with or without premolar extractions. Method. This study included 20 orthodontic treated patients: 10 of them with premolar extractions and 10 without premolar extractions. The pretreatment and post treatment panoramic radiographs were analyzed, and the angles between the third molar long axis and the occlusal plane and between the long axis of the third molar and the long axis of the second molar were measured. Results. Changes in third molar position, from pretreatment to post treatment, for the two groups of patients were evaluated by using the Student’s t-test. The results of the statistical analysis revealed an improvement in third molars position, the best results were seen in the lower third molars, in the group of patients treated with premolar extractions. PMID:23904878

Effects of Lower Third Molar Angulation and Position on Lower Arch Crowding.

PubMed

Selmani, Mimoza E; Gjorgova, Julijana; Selmani, Manushaqe E; Shkreta, Mirsad; Duci, Shkelzen B

2016-01-01

The role of the third molars in lower arch crowding has been debated for more than a century. The aim of this study was to determine the relationship between lower arch crowding and the presence of angulation and position of lower third molar. The measurements of the dental arch were made in 120 subjects aged 16 to 21 years, with average age to 18 years. The subjects were divided into two groups: Class I normal occlusion comprised 35 male and 25 female with mean age 18.87years, whereas Class I crowding comprised 27 males and 33 females with mean age 18.5 years. The dental pantomogram (DPT) were used to calculate the ratio of retromolar space (Ganss ratio), angulation of third molar to second molar and third molar to the base of the mandible. The results showed that measurements of Ganss ratio, third molar angulation to the base of the mandible, and third molar to second molar inclination, was statistically significant between crowded and normal groups. It can be concluded that there was a strong relationship between angulation and position of third molars and lower arch crowding. Key words: Third molars, angulation, lower arch, crowding

Patient with oligodontia treated with a miniscrew for unilateral mesial movement of the maxillary molars and alignment of an impacted third molar.

PubMed

Maeda, Aya; Sakoguchi, Yoko; Miyawaki, Shouichi

2013-09-01

This report describes the treatment of a 20-year-old woman with a dental midline deviation and 7 congenitally missing premolars. She had retained a maxillary right deciduous canine and 4 deciduous second molars, and she had an impacted maxillary right third molar. The maxillary right deciduous second molar was extracted, and the space was nearly closed by mesial movement of the maxillary right molars using an edgewise appliance and a miniscrew for absolute anchorage. The miniscrew was removed, and the extraction space of the maxillary right deciduous canine was closed, correcting the dental midline deviation. After the mesial movement of the maxillary right molars, the impacted right third molar was aligned. To prevent root resorption, the retained left deciduous second molars were not aligned by the edgewise appliance. The occlusal contact area and the maximum occlusal force increased over the 2 years of retention. The miniscrew was useful for absolute anchorage for unilateral mesial movement of the maxillary molars and for the creation of eruption space and alignment of the impacted third molar in a patient with oligodontia. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Effect of premolar extraction on mandibular third molar impaction in young adults.

PubMed

Türköz, Cağrı; Ulusoy, Cağrı

2013-07-01

To test the null hypothesis that orthodontic therapy with or without premolar extraction does not result in any difference in third molar impaction. Two groups were formed: 22 patients in one group with first premolar extractions and 22 patients in the other group without extractions. All patients were nongrowing subjects who had normal gonial angles and were skeletal Class I at the beginning of treatment. The available space for third molars, inclination of second and third molars, and angle between the second and third molars were evaluated. Also, the correlation of measured parameters and type of orthodontic therapy with the eruption of third molars was evaluated. Of the third molars, 81.8% were impacted in the nonextraction group and 63.6% were impacted in the extraction group. Impaction of mandibular third molars was significantly correlated to the pretreatment and posttreatment inclination of third molars and the angle between the second and third molars. In the extraction therapy group, the retromolar distance increased significantly with a mean of 1.30 ± 1.25 mm. When the inclination of the third molar is inconvenient, the tooth may remain impacted even if there is enough retromolar space.

Consequences of early extraction of compromised first permanent molar: a systematic review.

PubMed

Saber, Afnan M; Altoukhi, Doua H; Horaib, Mariam F; El-Housseiny, Azza A; Alamoudi, Najlaa M; Sabbagh, Heba J

2018-04-05

The aim of this study was to systematically review the literature to determine the sequelae of early extraction of compromised first permanent molars (FPMs) with regard to the skeletal and dental development of 5- to 15-year-old children. Meta-analysis was conducted when applicable. Our research protocol included a search strategy, inclusion/exclusion criteria, and a data extraction plan. The search engines used were PubMed, Scopus, and Science Direct. Study selection was performed independently by three reviewers. Articles published from 1960 to 2017 were reviewed based on inclusion and exclusion criteria. Meta-analysis was performed to compare space closure between upper and lower arches. Eleven studies fulfilled the inclusion criteria. The consequences were decrease in post extraction space, accelerated development and eruption of second permanents molars (SPMs) and third molars, a decrease in caries and/or fillings on the proximal surfaces of adjacent teeth, lingual tipping and retrusion of incisors, and counter clockwise rotation of the occlusal plane. There were several consequences of early extraction of FPMs, which were related to skeletal and dental development. Our systematic review suggests that comprehensive evaluation of the compromised FPMs should be performed before planning an extraction. The ideal time for FPM extraction is when the SPM is at the early bifurcation stage in order to achieve complete closure of the extraction space by the SPM. Benefits should be weighed over the risks to decrease the risk of unfavorable outcomes as much as possible. However, due to the limited evidence on the outcomes and variables that influence them, high-quality prospective studies are needed.

Comparative evaluation of surgical outcome after removal of impacted mandibular third molars using a Piezotome or a conventional handpiece: a prospective study.

PubMed

Goyal, Manoj; Marya, Karan; Jhamb, Aakarsh; Chawla, Sonia; Sonoo, Priyanshu Ranjan; Singh, Veenita; Aggarwal, Anuj

2012-09-01

Our aim was to compare the use of a conventional rotary handpiece and a Piezosurgical unit for extraction of lower third molars. We studied 40 patients, who were allocated alternately to have the third molar removed with either the handpiece or the Piezosurgical unit. Pain, trismus, and oedema were evaluated at baseline and then postoperatively, together with paraesthesiae, on postoperative days 1, 3, 5, 7, and 15. Damage to surrounding tissue was checked on the same day whereas dry socket was evaluated from postoperative day 3 onwards. More patients complained of pain in the conventional group, they also required more analgesics, and they developed trismus more often than in the Piezosurgery group. There was also significantly more postoperative swelling in the conventional group. Patients were also evaluated using the subjective Postoperative Symptom Severity (PoSSe) scale. Our results suggest that apart from some inherent limitations with the Piezotome, it is a valuable alternative for extraction of third molars. Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Autotransplantation of Immature Third Molars and Orthodontic Treatment After En Bloc Resection of Conventional Ameloblastoma.

PubMed

Osterne, Rafael Lima Verde; Moreira Neto, José Jeová Siebra; de Araújo Lima, Augusto Darwin Moreira; Nogueira, Renato Luiz Maia

2015-09-01

Ameloblastoma treatment can lead to significant bone defects; consequently, oral rehabilitation can be challenging. We present the case of a 14-year-old girl diagnosed with a conventional ameloblastoma in the mandible who was treated using en bloc resection and rehabilitated with autotransplantation of the immature third molars and orthodontic treatment. The lesion was in the region of the lower left canine and premolars, and en bloc resection resulted in a significant alveolar bone defect. Autotransplantation of the lower third molars to the site of the lower left premolars was performed. After 2 years, the upper left third molar was transplanted to the site of the lower left canine. During the orthodontic treatment period, considerable alveolar bone formation was observed in the region of the transplanted teeth, and roots developed. To the best of our knowledge, this is the first reported case of alveolar bone formation induction caused by tooth transplantation after ameloblastoma treatment. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

An anisotropic, hyperelastic model for skin: experimental measurements, finite element modelling and identification of parameters for human and murine skin.

PubMed

Groves, Rachel B; Coulman, Sion A; Birchall, James C; Evans, Sam L

2013-02-01

The mechanical characteristics of skin are extremely complex and have not been satisfactorily simulated by conventional engineering models. The ability to predict human skin behaviour and to evaluate changes in the mechanical properties of the tissue would inform engineering design and would prove valuable in a diversity of disciplines, for example the pharmaceutical and cosmetic industries, which currently rely upon experiments performed in animal models. The aim of this study was to develop a predictive anisotropic, hyperelastic constitutive model of human skin and to validate this model using laboratory data. As a corollary, the mechanical characteristics of human and murine skin have been compared. A novel experimental design, using tensile tests on circular skin specimens, and an optimisation procedure were adopted for laboratory experiments to identify the material parameters of the tissue. Uniaxial tensile tests were performed along three load axes on excised murine and human skin samples, using a single set of material parameters for each skin sample. A finite element model was developed using the transversely isotropic, hyperelastic constitutive model of Weiss et al. (1996) and was embedded within a Veronda-Westmann isotropic material matrix, using three fibre families to create anisotropic behaviour. The model was able to represent the nonlinear, anisotropic behaviour of the skin well. Additionally, examination of the optimal material coefficients and the experimental data permitted quantification of the mechanical differences between human and murine skin. Differences between the skin types, most notably the extension of the skin at low load, have highlighted some of the limitations of murine skin as a biomechanical model of the human tissue. The development of accurate, predictive computational models of human tissue, such as skin, to reduce, refine or replace animal models and to inform developments in the medical, engineering and cosmetic fields, is a significant challenge but is highly desirable. Concurrent advances in computer technology and our understanding of human physiology must be utilised to produce more accurate and accessible predictive models, such as the finite element model described in this study. Copyright © 2012 Elsevier Ltd. All rights reserved.

External root resorption of the second molar associated with third molar impaction: comparison of panoramic radiography and cone beam computed tomography.

PubMed

Oenning, Anne Caroline Costa; Neves, Frederico Sampaio; Alencar, Phillipe Nogueira Barbosa; Prado, Rodrigo Freire; Groppo, Francisco Carlos; Haiter-Neto, Francisco

2014-08-01

The aim of the present study was to compare panoramic radiography and cone beam computed tomography (CBCT) for the assessment of external root resorption (ERR) of second molars associated with impacted third molars. In addition, the prevalence of ERR in second molars and the inclinations of the third molars more associated with ERR were investigated in both imaging methods. The sample consisted of 66 individuals with maxillary and mandibular impacted third molars (n = 188) seen on panoramic radiographs and CBCT images. The presence of ERR on the adjacent second molar was investigated, and the position of the third molar was determined using Winter's classification (vertical, horizontal, mesioangular, distoangular, and transverse). Statistical analysis was performed using the χ(2) test, Fisher exact test, and 2-proportion Z test (the significance level was set at 5%). A significantly greater number of cases of ERR (P < .0001) was diagnosed from CBCT images (n = 43, 22.88%) than panoramic radiographs (n = 10, 5.31%). The agreement between the panoramic radiographs and CBCT scans for diagnosing ERR was 4.3%. Mandibular third molars in mesioangular and horizontal inclinations were more likely to cause resorption of the adjacent teeth. CBCT should be indicated for the diagnosis of ERR in second molars when direct contact between the mandibular second and third molars has been observed on panoramic radiographs, especially in mesioangular or horizontal impactions. Furthermore, considering the propensity of these teeth to cause ERR in second molars, third molar prophylactic extraction could be suggested. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Banding versus bonding of first permanent molars: a multi-centre randomized controlled trial.

PubMed

Nazir, Mariyah; Walsh, Tanya; Mandall, Nicky A; Matthew, Susie; Fox, Dee

2011-06-01

To assess the effectiveness of banding versus bonding of first permanent molars during fixed appliance treatment; in terms of attachment failure, patient discomfort and post-treatment enamel demineralization. Multi-centre randomized clinical trial. One District General Hospital Orthodontic Department and two Specialist Orthodontic Practices. Orthodontic patients aged between 10 and 18 years old, randomly allocated to either receive molar bands (n=40) or molar bonds (n=40). Bands were cemented with a conventional glass ionomer cement and tubes were bonded with light-cured composite to all four first permanent molar teeth for each subject. Attachments were reviewed at each recall appointment to assess loosening or loss. The clinical end point of the trial was the day of appliance debond. Enamel demineralization at debond was assessed using the modified International Caries Assessment and Detection System (ICDAS). The first time failure rate for molar bonds was 18·4% and 2·6% for molar bands (P=0·0002). Survival analysis demonstrated molar bonds were more likely to fail compared with molar bands. First permanent molars with bonded tubes experienced more demineralization than those with cemented bands (P=0·027). There was no statistically significant difference in discomfort experienced by patients after banding or bonding first permanent molars (P>0·05). This study shows that as part of fixed appliance therapy, American Orthodontics photoetched first permanent molar bands cemented with 3M ESPE Ketac-Cem perform better than American Orthodontics low profile photo-etched and mesh-based first permanent molar tubes bonded with 3M Unitek Transbond XT in terms of failure behaviour and molar enamel demineralization.

Compensation trends of the angulation of first molars: retrospective study of 1403 malocclusion cases.

PubMed

Su, Hong; Han, Bing; Li, Sa; Na, Bin; Ma, Wen; Xu, Tian-Min

2014-09-01

We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First, angulation of the upper first molar varied significantly with age and tipped most distally in cases aged <12 years and least distally in cases aged >16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability.

Endodontic treatment of an unusual connation of permanent mandibular molars: a case report.

PubMed

Liu, Shengbo; Fan, Bing; Peng, Bin; Fan, Mingwen; Bian, Zhuan

2006-10-01

A 27-year-old patient with an anomalous mandibular molar was referred for endodontic therapy. Clinical and radiographic examination revealed the connation of a second mandibular molar with a third molar. Challenging endodontic therapy was performed in the unusual connated molars. A 2-year recall showed good treatment result.

Postoperative socket irrigation with drinking tap water reduces the risk of inflammatory complications following surgical removal of third molars: a multicenter randomized trial.

PubMed

Ghaeminia, H; Hoppenreijs, Th J M; Xi, T; Fennis, J P; Maal, T J; Bergé, S J; Meijer, G J

2017-01-01

The primary aim of the present study was to evaluate the effectiveness of postoperative irrigation of the socket with drinking tap water on inflammatory complications following lower third molar removal. A multicenter randomized controlled trial was carried out from June 2013 to June 2014. In one arm of the study, patients were instructed to irrigate the tooth socket and surgical site with a Monoject® Curved 412 Tip Syringe (Tyco/healthcare-Kendall, Mansfield, MA, USA) with tap water. In a second arm of the study, the standard postoperative instructions did not include irrigation instructions. The incidences of alveolar osteitis and wound infection were recorded for each group and analyzed by the Fisher's exact test. A total of 280 patients with 333 mandibular third molars were analyzed. According to the intention-to-treat (ITT) analysis, inflammatory complications occurred in 18 cases in the Monoject® group (11.4 %) compared to 34 cases (19.1 %) in the control group (p = 0.04). These complications were associated with significant worse outcomes regarding quality of life, pain, and trismus and caused significantly more missed days of work or study. Female gender, age >26, bone removal, deep impacted third molars, less experienced surgeons, and a high amount of debris at the surgical site were also identified as risk factors for developing inflammatory complications following lower third molar removal. Irrigation of the surgical site with drinking tap water using a curved syringe following removal of third molars is effective in reducing the risk of inflammatory complications. Water is a very accessible, cost-effective irrigant without side effects and the results from this study have proven that it can be used to reduce the risk of inflammatory complications and associated morbidity following lower third molar removal.

Size exclusion chromatography-gradients, an alternative approach to polymer gradient chromatography: 2. Separation of poly(meth)acrylates using a size exclusion chromatography-solvent/non-solvent gradient.

PubMed

Schollenberger, Martin; Radke, Wolfgang

2011-10-28

A gradient ranging from methanol to tetrahydrofuran (THF) was applied to a series of poly(methyl methacrylate) (PMMA) standards, using the recently developed concept of SEC-gradients. Contrasting to conventional gradients the samples eluted before the solvent, i.e. within the elution range typical for separations by SEC, however, the high molar mass PMMAs were retarded as compared to experiments on the same column using pure THF as the eluent. The molar mass dependence on retention volume showed a complex behaviour with a nearly molar mass independent elution for high molar masses. This molar mass dependence was explained in terms of solubility and size exclusion effects. The solubility based SEC-gradient was proven to be useful to separate PMMA and poly(n-butyl crylate) (PnBuA) from a poly(t-butyl crylate) (PtBuA) sample. These samples could be separated neither by SEC in THF, due to their very similar hydrodynamic volumes, nor by an SEC-gradient at adsorbing conditions, due to a too low selectivity. The example shows that SEC-gradients can be applied not only in adsorption/desorption mode, but also in precipitation/dissolution mode without risking blocking capillaries or breakthrough peaks. Thus, the new approach is a valuable alternative to conventional gradient chromatography. Copyright © 2011 Elsevier B.V. All rights reserved.

Age estimation using the radiographic visibility of the periodontal ligament in lower third molars in a Portuguese population.

PubMed

Sequeira, Catarina-Dourado; Teixeira, Alexandra; Caldas, Inês-Morais; Afonso, Américo; Pérez-Mongiovi, Daniel

2014-12-01

The mineralization of third molars has been used repeatedly as a method of forensic age estimation. However, this procedure is of little use beyond age 18, especially to determinate if an individual is older than 21 years of age; thus, the development of new approaches is essential. The visibility of the periodontal ligament has been suggested for this purpose. The aim of this work was to determine the usefulness of this methodology in a Portuguese population. Periodontal ligament visibility was assessed in the lower third molars, using a sample of 487 orthopantomograms, 228 of which belonging to females and 259 to males, from a Portuguese population aged 17 to 31 years. A classification of four stages based on the visual phenomenon of disappearance of the periodontal ligament of fully mineralized third molars was used. For each stage, median, variance, minimal and maximal age were assessed. The relationship between age and stage of periodontal ligament had a statistical significance for both sexes. In this population, stage 3 can be used to state that a male person is over 21 years-old; for females, another marker should be used. This technique can be useful for determining age over 21, particularly in males. Differences between studies are evident, suggesting that specific population standards should be used when applying this technique. Key words:Forensic sciences, forensic odontology, age estimation, third molar, periodontal ligament.

Evaluation of skeletal maturation using mandibular third molar development in Indian adolescents.

PubMed

Mehta, Nishit; Patel, Dolly; Mehta, Falguni; Gupta, Bhaskar; Zaveri, Grishma; Shah, Unnati

2016-01-01

This study was done with the following objectives: to estimate dental maturity using the Demirjian Index (DI) for the mandibular third molar; to investigate the relationship between dental maturity and skeletal maturity among growing patients; to evaluate the use of the mandibular third molar as an adjunctive tool for adolescent growth assessment in combination with the cervical vertebrae; to evaluate the clinical value of the third molar as a growth evaluation index. Samples were derived from panoramic radiographs and lateral cephalograms of 615 subjects (300 males and 315 females) of ages ranging 9-18 years, and estimates of dental maturity (DI) and skeletal maturity [cervical vertebrae maturation indicators (CVMI)] were made. A highly significant association (r = 0.81 for males and r = 0.72 for females) was found between DI and CVMI. DI Stage B corresponded to Stage 2 of CVMI (prepeak of pubertal growth spurt) in both sexes. In males, DI stages C and D represent the peak of the pubertal growth spurt. In females, stages B and C show that the peak of the pubertal growth spurt has not been passed. DI stage E in females and DI Stage F in males correlate that the peak of the pubertal growth spurt has been passed. A highly significant association exists between DI and CVMI. Mandibular third molar DI stages are reliable adjunctive indicators of skeletal maturity.

Volume of reaction by the Archibald ultracentrifuge method (lobster hemocyanin).

PubMed

Saxena, V P; Kegeles, G; Kikas, R

1976-07-01

Samples of lobster hemocyanin (Homarus americanus) under conditions of reversible reaction between whole (25 S) and half (17 S) molecules have been subjected to accurately known nitrogen pressures in analytical ultracentrifuge cells. A modified pressurization chamber of the type developed by Schumaker and colleagues has been constructed for this purpose. The molecular weight was then determined at the top (liquid-gas) meniscus, by means of the Archibald method. The logarithmic dependence upon pressure of the derived equilibrium constant then gave directly the volume of reaction. Experiments were performed in veronal-citrate buffers at pH 8, where the molar volume of formation of whole (dodecameric) molecules from half molecules appears to be negative, and at pH 8.46 in veronal-citrate buffer in the presence of 0.003 molar free calcium ion, where the molar volume of formation was estimated to be + 390 cm3/mole. In glycine-sodium hydroxide buffer at pH 9.6 containing 0.0047 molar free calcium, the molar volume of formation of whole molecules was estimated to be +120 +/- 70 cm3, corresponding to an estimated difference in partial specific volume between whole molecules and half molecules of only 1.3 (10)-4cm3/gram. The correctness of the sign of this value in glycine buffer has been verified by pressure-jump light-scattering experiments.

External root resorption of the second molar associated with mesially and horizontally impacted mandibular third molar: evidence from cone beam computed tomography.

PubMed

Wang, Dongmiao; He, Xiaotong; Wang, Yanling; Li, Zhongwu; Zhu, Yumin; Sun, Chao; Ye, Jinhai; Jiang, Hongbing; Cheng, Jie

2017-05-01

The aim of the present study was to assess the incidence and risk factors of ERR in second molars with mesially and horizontally impacted mandibular third molars using cone beam computed tomography (CBCT) images from patients in a Chinese tertiary referral hospital. A total number of 216 patients with 362 mesially and horizontally impacted mandibular third molars who were treated at our institution from 2014 to 2015 was retrospectively included. The ERR in second molars was identified on CBCT multiplanar images. The associations between incidence of ERR and multiple clinical parameters were statistically analyzed by Chi-square test. Moreover, the risk factors for ERR in second molars were further assessed by multivariate regression analysis. The overall incidence of ERR in second molars was 20.17 % (73/362) as detected on CBCT images. The presence of ERR significantly associated with patients age and impaction depth of mandibular third molars. However, no significant relationship was found between ERR severity and impaction depth or ERR location. Multivariate regression analyses further revealed age over 35 years and impaction depth as important risk factors affecting the ERR incidence caused by mesial and horizontal impaction of mandibular third molar. ERR in second molar resulted from mesially and horizontally impacted mandibular third molar is not very rare and can be reliably identified via CBCT scan. Given the possibility of ERR associated with third molar impaction, the prophylactic removal of these impacted teeth could be considered especially for those patients with over 35 years and mesially and horizontally impacted teeth.

Size of the lower third molar space in relation to age in Serbian population.

PubMed

Zelić, Ksenija; Nedeljković, Nenad

2013-10-01

It is considered that the shortage of space is the major cause of the third molar impaction. The aim of this study was to establish the frequency of insufficient lower third molar eruption space in Serbian population, to question the differences in this frequency in the subjects of different age, to determine the influence of the lower third molar space (retromolar space) size on third molar eruption, and to investigate a possible correlation between the size of gonial angle and the space/third molar width ratio. Digital orthopantomograms were taken from 93 patients divided into two groups: early adult (16-18 years of age) and adult (18-26) patients. Retromolar space, mesiodistal third molar crown width, gonial angle and eruption levels were measured. The space/third molar width in early adult subjects was smaller (p < 0.0001) and insufficient space was significantly more frequent (p = 0.0003) than in adult patients. Considerably more third molars erupted in case of enough space in both age groups (p < 0.0001). There was no difference between the means of gonial angle size in relations to the available space. The retromolar space/third molar width ratio is more favorable in adult subjects. Gonial angle is not in correlation with the retromolar space/third molar width ratio.

Comparative evaluation of molar distalization therapy with erupted second molar: Segmented versus Quad Pendulum appliance.

PubMed

Caprioglio, Alberto; Cozzani, Mauro; Fontana, Mattia

2014-01-01

There are controversial opinions about the effect of erupted second molars on distalization of the first molars. Most of the distalizing devices are anchored on the first molars, without including second molars; so, differences between sequentially distalize maxillary molars (second molar followed by the first molar) or distalize second and first molars together are not clear. The aim of the study was to compare sequential versus simultaneous molar distalization therapy with erupted second molar using two different modified Pendulum appliances followed by fixed appliances. The treatment sample consisted of 35 class II malocclusion subjects, divided in two groups: group 1 consisted of 24 patients (13 males and 11 females) with a mean pre-treatment age of 12.9 years, treated with the Segmented Pendulum (SP) and fixed appliances; group 2 consisted of 11 patients (6 males and 5 females) with a mean pre-treatment age of 13.2 years, treated with the Quad Pendulum (QP) and fixed appliances. Lateral cephalograms were obtained before treatment (T1), at the end of distalization (T2), and at the end of orthodontic fixed appliance therapy (T3). A Student t test was used to identify significant between-group differences between T1 to T2, T2 to T3, and T1 to T3. QP and SP were equally effective in distalizing maxillary molars (3.5 and 4 mm, respectively) between T1 and T2; however, the maxillary first molar showed less distal tipping (4.6° vs. 9.6°) and more extrusion (1.1 vs. 0.2 mm) in the QP group than in the SP group, as well as the vertical facial dimension, which increased more in the QP group (1.2°) than in the SP group (0.7°). At T3, the QP group maintained greater increase in lower anterior facial height and molar extrusion and decrease in overbite than the SP group. Quad Pendulum seems to have greater increase in vertical dimension and molar extrusion than the Segmented Pendulum.

The flap recovery on the impacted lower third molar surgery comparing 3 different flap designs: a clinical study.

PubMed

Ottria, L; Luciani, F; Piva, P; Alagna, A M; Arcuri, C; Bartuli, F N

2017-01-01

The purpose of the study was to analyze the healing of the deep and superficial lower first and second molars periodontium, after the surgical extraction of the contiguous impacted third molar, comparing 3 mucoperiosteal flap designs. 150 patients which had to undergo a impacted lower third molar surgery were enrolled in this study. They were checked from day 0 to day 90, in order to focus on the recovery quality of the soft tissues around the lower second molar, comparing 3 different flap designs. No intraoperatory incident happened. The complete recovery of the periodontium around the second molar has been shown in each patient after 90 days from surgery and each adverse reaction happened within the sixth week after surgery. Only 2 slight gengival recessions 0,5 mm have been find out. The impacted third molar surgery is an operation that, if rightly programmed and performed, is relatively safe. Besides, the correct handling and management of periodontium around the second molar and the choice of the flap type to be used support a correct recovery on the second molar periodontium, avoiding any long-term damage. This study wanted to analyze the healing of the deep and superficial lower second molar periodontium, after the impacted lower third molar surgery. In order to improve the surgical technique used for lower third molar germectomies, we wanted to compare 3 different kind of flap designs.

Fabrication and Evaluation of a Noncompliant Molar Distalizing Appliance: Bonded Molar Distalizer

PubMed Central

Sodagar, A.; Ahmad Akhoundi, M. S.; Rafighii, A.; Arab, S.

2011-01-01

Objective Attempts to treat class II malocclusions without extraction in non-compliant patients have led to utilization of intraoral molar distalizing appliances. The purpose of this study was to investigate dental and skeletal effects of Bonded Molar Distalizer (BMD) which is a simple molar distalizing appliance. Materials and Methods Sixteen patients (12 girls, four boys) with bilateral half-cusp class II molar relationship, erupted permanent second molars and normal or vertical growth pattern were selected for bilateral distalization of maxillary molars via BMD. The screws were activated every other day, alternately. Lateral cephalograms and study models were obtained before treatment and after 11 weeks activation of the appliance. Results Significant amounts of molar distalization, molar distal tipping and anchorage loss were observed. The mean maxillary first molar distal movement was 1.22±0.936 mm with a distal tipping of 2.97±3.74 degrees in 11 weeks. The rate of distal movement was 0.48 mm per month. Reciprocal mesial movement of the first premolars was 2.26±1.12 mm with a mesial tipping of 4.25±3.12 degrees. Maxillary incisors moved 3.55±1.46 mm and tipped 9.87±5.03 degrees mesially. Lower anterior face height (LAFH) decreased 1.28±1.36 mm. Conclusion BMD is appropriate for distalizing maxillary molars, especially in patients with critical LAFH, although significant amounts of anchorage loss occur using this appliance. PMID:22457837

Compensation trends of the angulation of first molars: retrospective study of 1 403 malocclusion cases

PubMed Central

Su, Hong; Han, Bing; Li, Sa; Na, Bin; Ma, Wen; Xu, Tian-Min

2014-01-01

We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1 403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First, angulation of the upper first molar varied significantly with age and tipped most distally in cases aged <12 years and least distally in cases aged >16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability. PMID:24699185

The flap recovery on the impacted lower third molar surgery comparing 3 different flap designs: a clinical study

PubMed Central

OTTRIA, L.; LUCIANI, F.; PIVA, P.; ALAGNA, A.M.; ARCURI, C.; BARTULI, F.N.

2017-01-01

SUMMARY Aim The purpose of the study was to analyze the healing of the deep and superficial lower first and second molars periodontium, after the surgical extraction of the contiguous impacted third molar, comparing 3 mucoperiosteal flap designs. Materials and methods 150 patients which had to undergo a impacted lower third molar surgery were enrolled in this study. They were checked from day 0 to day 90, in order to focus on the recovery quality of the soft tissues around the lower second molar, comparing 3 different flap designs. Results No intraoperatory incident happened. The complete recovery of the periodontium around the second molar has been shown in each patient after 90 days from surgery and each adverse reaction happened within the sixth week after surgery. Only 2 slight gengival recessions 0,5 mm have been find out. Conclusions The impacted third molar surgery is an operation that, if rightly programmed and performed, is relatively safe. Besides, the correct handling and management of periodontium around the second molar and the choice of the flap type to be used support a correct recovery on the second molar periodontium, avoiding any long-term damage. Clinical significance This study wanted to analyze the healing of the deep and superficial lower second molar periodontium, after the impacted lower third molar surgery. In order to improve the surgical technique used for lower third molar germectomies, we wanted to compare 3 different kind of flap designs. PMID:29285329

Analysis of C-shaped root canal configuration in maxillary molars in a Korean population using cone-beam computed tomography

PubMed Central

Jo, Hyoung-Hoon; Min, Jeong-Bum

2016-01-01

Objectives The purpose of this study was to investigate the incidence of root fusion and C-shaped root canals in maxillary molars, and to classify the types of C-shaped canal by analyzing cone-beam computed tomography (CBCT) in a Korean population. Materials and Methods Digitized CBCT images from 911 subjects were obtained in Chosun University Dental Hospital between February 2010 and July 2012 for orthodontic treatment. Among them, a total of selected 3,553 data of maxillary molars were analyzed retrospectively. Tomography sections in the axial, coronal, and sagittal planes were displayed by PiViewstar and Rapidia MPR software (Infinitt Co.). The incidence and types of root fusion and C-shaped root canals were evaluated and the incidence between the first and the second molar was compared using Chi-square test. Results Root fusion was present in 3.2% of the first molars and 19.5% of the second molars, and fusion of mesiobuccal and palatal root was dominant. C-shaped root canals were present in 0.8% of the first molars and 2.7% of the second molars. The frequency of root fusion and C-shaped canal was significantly higher in the second molar than the first molar (p < 0.001). Conclusions In a Korean population, maxillary molars showed total 11.3% of root fusion and 1.8% of C-shaped root canals. Furthermore, root fusion and C-shaped root canals were seen more frequently in the maxillary second molars. PMID:26877991

Permanent first molar extraction in adolescents and young adults and its effect on the development of third molar.

PubMed

Halicioglu, Koray; Toptas, Orcun; Akkas, Ismail; Celikoglu, Mevlut

2014-01-01

The aim of the present study was to determine the prevalence of permanent first molar (P1M) extraction among Turkish adolescents and young adult subpopulation, and to investigate the effects of P1M extraction on development of the third molars (3Ms) in the same quadrant. A retrospective study including 2,925 panoramic radiographs (PRs) taken from patients (aged 13-20 years) who were examined to identify cases of had at least one maxillary or mandibular P1Ms extracted was performed. Additionally, 294 PRs with the maxillary or mandibular unilateral loss of a P1M were used to assess the developmental grades of the 3Ms. Statistical analyses were performed by means of parametric tests after performing a Shapiro-Wilks normality test to the data. A total of 945 patients (32.3 %) presented with at least one P1M extraction with no gender difference (P = 0.297). There were more cases of mandibular P1Ms extracted (784 patients, 1,066 teeth) than maxillary P1Ms extracted (441 patients, 549 teeth) (P < 0.001). The development of the 3Ms on the extraction side, in the both maxilla and mandible, was significantly accelerated when compared with the contralateral teeth (P = 0.000, P = 0.000, respectively). No statistically significant differences were found in the differences in the developmental of the 3Ms between the maxilla and mandible (P = 0.718). High prevalence of P1Ms extraction among Turkish adolescents and young adults shows a need for targeted dental actions, including prevention and treatment. The development of the 3Ms on the extraction side, in the both maxilla and mandible, was significantly accelerated. To date, no information about prevalence of P1Ms extraction among Turkish adolescents and young adults is documented. In addition, the present study has a larger population and complementary information about 3Ms development than previous studies.

Advances in the development of enterohemorrhagic Escherichia coli vaccines using murine models of infection

PubMed Central

Garcia-Angulo, Victor A.; Kalita, Anjana; Torres, Alfredo G.

2013-01-01

Enterohemorrhagic Escherichia coli (EHEC) strains are food borne pathogens with importance in public health. EHEC colonizes the large intestine and causes diarrhea, hemorrhagic colitis and in some cases, life-threatening hemolytic-uremic syndrome (HUS) due to the production of Shiga toxins (Stx). The lack of effective clinical treatment, sequelae after infection and mortality rate in humans supports the urgent need of prophylactic approaches, such as development of vaccines. Shedding from cattle, the main EHEC reservoir and considered the principal food contamination source, has prompted the development of licensed vaccines that reduce EHEC colonization in ruminants. Although murine models do not fully recapitulate human infection, they are commonly used to evaluate EHEC vaccines and the immune/protective responses elicited in the host. Mice susceptibility differs depending of the EHEC inoculums; therefore, displaying different mortality rates and Stx-mediated renal damage. Therefore, several experimental protocols have being pursued in this model to develop EHEC-specific vaccines. Recent candidate vaccines evaluated include those composed of virulence factors alone or as fused-subunits, DNA-based, attenuated bacteria and bacterial ghosts. In this review, we summarize progress in the design and testing of EHEC vaccines and the use of different strategies for the evaluation of novel EHEC vaccines in the murine model. PMID:23707170

Four impacted fourth molars in a young patient: a case report

PubMed Central

CLEMENTINI, M.; OTTRIA, L.; PANDOLFI, C.; AGRESTINI, C.; BARLATTANI, A.

2013-01-01

Summary The occurrence of supernumerary teeth is a relatively uncommon dental anomaly and it’s rare for patients to have impacted fourth molars in all quadrant. Aim of this work is to describe the presence of bilateral fourth molars in the maxilla and the mandible in a young male patient aged 22 years came to our hospital with acute pericoronal infection around unerupted third inferior molars. Routine radiographic examination revealed impacted inferior third molars but also unerupted bilateral upper and inferior fourth molars. The acute infection was treated by local measures and the patient was subsequently admitted for removal of third and fourth impacted upper and lower molars under general anesthesia. PMID:23741604

Characterization of polymeric substance classes in cereal-based beverages using asymmetrical flow field-flow fractionation with a multi-detection system.

PubMed

Krebs, Georg; Becker, Thomas; Gastl, Martina

2017-09-01

Cereal-based beverages contain a complex mixture of various polymeric macromolecules including polysaccharides, peptides, and polyphenols. The molar mass of polymers and their degradation products affect different technological and especially sensory parameters of beverages. Asymmetrical flow field-flow fractionation (AF4) coupled with multi-angle light scattering (MALS) and refractive index detection (dRI) or UV detection (UV) is a technique for structure and molar mass distribution analysis of macromolecules commonly used for pure compound solutions. The objective of this study was to develop a systematic approach for identifying the polymer classes in an AF4//MALS/dRI/UV fractogram of the complex matrix in beer, a yeast-fermented cereal-based beverage. Assignment of fractogram fractions to polymer substance classes was achieved by targeted precipitations, enzymatic hydrolysis, and alignments with purified polymer standards. Corresponding effects on dRI and UV signals were evaluated according to the detector's sensitivities. Using these techniques, the AF4 fractogram of beer was classified into different fractions: (1) the low molar mass fraction was assigned to proteinaceous molecules with different degrees of glycosylation, (2) the middle molar mass fraction was attributed to protein-polyphenol complexes with a coelution of non-starch polysaccharides, and (3) the high molar mass fraction was identified as a mixture of the cell wall polysaccharides (i.e., β-glucan and arabinoxylan) with a low content of polysaccharide-protein association. In addition, dextrins derived from incomplete starch hydrolysis were identified in all fractions and over the complete molar mass range. The ability to assess the components of an AF4 fractogram is beneficial for the targeted design and evaluation of polymers in fermented cereal-based beverages and for controlling and monitoring quality parameters.

A Prospective Study of Clinical Outcomes Related to Third Molar Removal or Retention

PubMed Central

Cunha-Cruz, Joana; Rothen, Marilynn; Spiekerman, Charles; Drangsholt, Mark; Anderson, Loren; Roset, Gayle A.

2014-01-01

Objectives. We investigated outcomes of third molar removal or retention in adolescents and young adults. Methods. We recruited patients aged 16 to 22 years from a dental practice–based research network in the Pacific Northwest from May 2009 through September 2010 who had at least 1 third molar present and had never undergone third molar removal. Data were acquired via questionnaire and clinical examination at baseline, periodic online questionnaires, and clinical examination at 24 months. Results. A total of 801 patients participated. Among patients undergoing third molar removal, rates of paresthesia and jaw joint symptoms lasting more than 1 month were 6.3 and 34.3 per 100 person-years, respectively. Among patients not undergoing removal, corresponding rates were 0.7 and 8.8. Periodontal attachment loss at distal sites of second molars did not significantly differ by third molar removal status. Incident caries at the distal surfaces of second molars occurred in fewer than 1% of all sites. Conclusions. Rates of paresthesia and temporomandibular joint disorder were higher after third molar removal. Periodontal attachment loss and incident caries at the distal sites of second molars were not affected by extraction status. PMID:24524521

Stresses around a miniscrew. 3-D analysis with the finite element method (FEM).

PubMed

Geramy, Allahyar

2009-11-01

Miniscrews used for absolute anchorage may induce stresses in the surrounding tissues that are dependent on their proximity to the miniscrew. To determine the stresses in the buccal walls of the sockets of lower molars adjacent to a miniscrew under load when the position and angulation of the miniscrew are changed. Five 3-D FEM models containing the first and second lower molars, their periodontal ligaments and the surrounding spongy and cortical bone, were modelled in SolidWorks 2006 (SolidWorks, Concord, MA, USA) and transferred to the ANSYS Workbench (ANSYS Inc., Southpointe, Canonsburg, PA, U.S.A.). A tensile force of 2 N, decomposed in 3-D space, was applied to a miniscrew inserted between the lower first and second molars. The von Mises (equivalent) stresses along the buccal walls of the sockets of the first and second molars were derived following changes in miniscrew position and angulation. No direct force was applied to the molars. When the miniscrew was inserted at right angles to the bone and midway between the molars the stress in the crestal area was 0.093 MPa. This stress increased proportionally in the first molar socket as the miniscrew was moved towards the first molar and declined when the miniscrew was tipped towards the second molar. Stresses also decreased in the crestal area of the second molar as the miniscrew was moved towards the first molar, but increased when it was tipped towards the second molar. A 30-55 per cent increase in crestal stress in the first molar socket was detected. Stress occurred in the tissues surrounding a miniscrew subjected to a force vector. Changes in the position or angulation of a miniscrew can affect the stress in the socket walls of adjacent teeth.

Cone beam volume tomography: an imaging option for diagnosis of complex mandibular third molar anatomical relationships.

PubMed

Danforth, Robert A; Peck, Jerry; Hall, Paul

2003-11-01

Complex impacted third molars present potential treatment complications and possible patient morbidity. Objectives of diagnostic imaging are to facilitate diagnosis, decision making, and enhance treatment outcomes. As cases become more complex, advanced multiplane imaging methods allowing for a 3-D view are more likely to meet these objectives than traditional 2-D radiography. Until recently, advanced imaging options were somewhat limited to standard film tomography or medical CT, but development of cone beam volume tomography (CBVT) multiplane 3-D imaging systems specifically for dental use now provides an alternative imaging option. Two cases were utilized to compare the role of CBVT to these other imaging options and to illustrate how multiplane visualization can assist the pretreatment evaluation and decision-making process for complex impacted mandibular third molar cases.

Prevalence of third molars and pathological changes related to them in dental medicine.

PubMed

Mikić, Ivana Medvedec; Zore, Irina Filipović; Crcić, Vlatka Fuchs; Matijević, Jurica; Plancak, Dario; Katunarić, Marina; Buković, Dino

2013-09-01

The purpose of this study was to determine the prevalence of third molars in terms of respondents' age. Furthermore it was desired to determine the extent of the manifestation of pathological changes, such as caries, apical lesions, and alveolar bone resorption. This study was based on 500 OPGs of patients from the Faculty of Dentistry, University of Zagreb. Patients were divided into seven age groups. The total number of molars, the number of cavities on remaining molars, the quality of endodontic treatment and the evaluation of their performance and presence of periapical lesions was analyzed. As apart of the periodontal status, the number of inadequate fillings, the number of damaged furcations and bone resorption was analyzed. The statistical analysis was performed by means of STATISTICA 7 statistical package (StatSoft, Tulsa, USA). The correlation between the total number of molars and the age of patients was analyzed by means of Spearman's correlation to the level of significance of 0.05. The number of first, second and third molars significantly decreased in higher age groups. The prevalence of caries in third molars as compared to first and second molars was generally lower, third molars were endodontic treated at least. Assessment of involved furcations showed that the lowest percentage of 8% was found in third molars. The majority of all remaining molars had bone resorption of 1-3 mm.

Genomic alterations in spontaneous and carcinogen-induced murine melanoma cell lines.

PubMed

Melnikova, Vladislava O; Bolshakov, Svetlana V; Walker, Christopher; Ananthaswamy, Honnavara N

2004-03-25

We have conducted an analysis of genetic alterations in spontaneous murine melanoma cell line B16F0 and its two metastatic clones, B16F1 and B16F10 and the carcinogen-induced murine melanoma cell lines CM519, CM3205, and K1735. We found that unlike human melanomas, the murine melanoma cell lines did not have activating mutations in the Braf oncogene at exon 11 or 15. However, there were distinct patterns of alterations in the ras, Ink4a/Arf, and p53 genes in the two melanoma groups. In the spontaneous B16 melanoma cell lines, expression of p16Ink4a and p19Arf tumor suppressor proteins was lost as a consequence of a large deletion spanning Ink4a/Arf exons 1alpha, 1beta, and 2. In contrast, the carcinogen-induced melanoma cell lines expressed p16Ink4a but had inactivating mutations in either p19Arf (K1735) or p53 (CM519 and CM3205). Inactivation of p19Arf or p53 in carcinogen-induced melanomas was accompanied by constitutive activation of mitogen-activated protein kinases (MAPKs) and/or mutation-associated activation of N-ras. These results indicate that genetic alterations in p16Ink4a/p19Arf, p53 and ras-MAPK pathways can cooperate in the development of murine melanoma.

Retrospective study of root canal configurations of maxillary third molars in Central India population using cone beam computed tomography Part- I.

PubMed

Rawtiya, Manjusha; Somasundaram, Pavithra; Wadhwani, Shefali; Munuga, Swapna; Agarwal, Manish; Sethi, Priyank

2016-01-01

The aim of this study was to investigate the root and canal morphology of maxillary third molars in Central India population using cone-beam computed tomography (CBCT) analysis. CBCT images of 116 maxillary third molars were observed, and data regarding the number of roots, the number of canals, and Vertucci's Classification in each root was statistically evaluated. Majority of Maxillary third molars had three roots (55.2%) and three canals (37.9%). Most MB root (43.8%), DB root (87.5%), and palatal root (100%) of maxillary third molars had Vertucci Type I. Mesiobuccal root of three-rooted maxillary third molars had Vertucci Type I (43.8%) and Type IV (40.6%) configuration. Overall prevalence of C-shaped canals in maxillary third molars was 3.4%. There was a high prevalence of three-rooted maxillary molars with three canals.

Clinical investigation of second mesiobuccal canals in endodontically treated and retreated maxillary molars.

PubMed

Wolcott, James; Ishley, Dave; Kennedy, Wade; Johnson, Scott; Minnich, Scott

2002-06-01

An examination of 1873 conventionally treated and retreated maxillary first and second molars was made in an attempt to determine the percentage of second mesiobuccal (MB2) canals that could be located routinely and evaluate if there were any significant differences between initial treatments and retreatments. The teeth examined were 1193 first molars and 680 second molars treated consecutively over a 2-yr period by five endodontists. Overall the MB2 canal was found in 724 (61%) first molars and 245 (36%) second molars. The incidence of a MB2 canal in first molar retreatments was 67% compared to a 59% incidence in initial treatments. Whereas in second molars, the retreatment incidence was 44% compared with 35% in initial treatments. The significant difference in the incidence of a MB2 canal between initial treatments and retreatments suggests that failure to find and treat existing MB2 canals will decrease the long-term prognosis.

A 5 yr clinical investigation of second mesiobuccal canals in endodontically treated and retreated maxillary molars.

PubMed

Wolcott, James; Ishley, Dave; Kennedy, Wade; Johnson, Scott; Minnich, Scott; Meyers, John

2005-04-01

An examination of 5616 endodontically treated and retreated maxillary first and second molars was made in an attempt to determine the percentage of MB2 canals that could be located routinely, and evaluate if there were any significant differences between initial treatments and retreatments. The teeth examined were 3578 first molars and 2038 second molars treated consecutively over a 5-yr period by six endodontists. Overall the MB2 canal was found in 2133 (60%) first molars, and 712 (35%) second molars. The incidence of a MB2 canal in first molar retreatments was 66% compared to a 58% incidence in initial treatments. Whereas in second molars the retreatment incidence was 40% compared to 34% in initial treatments. The significant difference in the incidence of a MB2 canal between initial treatments and retreatments suggests that failure to find and treat existing MB2 canals will decrease the long-term prognosis.

Rare Occurrence of the Left Maxillary Horizontal Third Molar Impaction, the Right Maxillary Third Molar Vertical Impaction and the Left Mandibular Third Molar Vertical Impaction with Inferior Alveolar Nerve Proximity in a 30 Year Old Female: A Case Report.

PubMed

Shunmugavelu, Karthik

2017-01-01

A combination of horizontal and vertical third molar impaction is a rare occurrence.When the tooth is unable to erupt to its proper position and fail to achieve a normal occlusion, it is known as impacted tooth. In this scientific article, case report of a female patient aged 30 years reported with acombination of horizontally and vertically impacted third molars in the maxilla and mandible has been presented. The treatment included surgical removal of the impacted teeth without any damage to underlying structures. Horizontal impaction of left maxillary third molar, vertical impaction of right maxillary third molar and left mandibular third molar is a rare occurrence. If symptomatic, surgical removal has to be planned as earlier as possible rather than late complications.

Ibuprofen Potentiates the In Vivo Antifungal Activity of Fluconazole against Candida albicans Murine Infection

PubMed Central

Miranda, Isabel M.; Silva-Dias, Ana; Silva, Ana P.; Rodrigues, Acácio G.; Pina-Vaz, Cidália

2015-01-01

Candida albicans is the most prevalent cause of fungemia worldwide. Its ability to develop resistance in patients receiving azole antifungal therapy is well documented. In a murine model of systemic infection, we show that ibuprofen potentiates fluconazole antifungal activity against a fluconazole-resistant strain, drastically reducing the fungal burden and morbidity. The therapeutic combination of fluconazole with ibuprofen may constitute a new approach for the management of antifungal therapeutics to reverse the resistance conferred by efflux pump overexpression. PMID:25845879

MUCI Facilitation of Growth in Chemically Induced Mammary Gland Tumors in Muc-1 Mutant and MUCI Transgenic Mice.

DTIC Science & Technology

1998-08-01

present grant proposed to initiate tumor development using chemical carcinogenesis. Pazos et al. (1991) demonstrated chemical induction of murine...latency of 154 ±19 days. Tumors were mammary adenocarcinomas of the B type of Dunn’s classification ( Pazos , 1991). My hypothesis for these studies was...in rats. Murine response to NMU is only briefly documented in the literature ( Pazos et al., 1991). Following the protocol for NMU induction of mammary

Development and Validation of Radiation-Responsive Protein Bioassays for Biodosimetry Applications

DTIC Science & Technology

2005-01-01

radiation protein biomarker studies using an in vivo murine radiation model. Male BALB/c mice were exposed to 25-cGy 60Co- gamma radiation. Dosimetry ...Csoke, I. Hejja, An on-board TLD system for dose monitor- ing on the International Space Station, Radiation Protection Dosimetry , 84(1-4 Pt1): 321-323...diagnostic information after exposure. Using an ex vivo model system of human peripheral lymphocytes as well as an in vivo murine model, we demonstrated

Histone deacetylase 1 and 2 are essential for murine neural crest proliferation, pharyngeal arch development, and craniofacial morphogenesis.

PubMed

Milstone, Zachary J; Lawson, Grace; Trivedi, Chinmay M

2017-12-01

Craniofacial anomalies involve defective pharyngeal arch development and neural crest function. Copy number variation at 1p35, containing histone deacetylase 1 (Hdac1), or 6q21-22, containing Hdac2, are implicated in patients with craniofacial defects, suggesting an important role in guiding neural crest development. However, the roles of Hdac1 and Hdac2 within neural crest cells remain unknown. The neural crest and its derivatives express both Hdac1 and Hdac2 during early murine development. Ablation of Hdac1 and Hdac2 within murine neural crest progenitor cells cause severe hemorrhage, atrophic pharyngeal arches, defective head morphogenesis, and complete embryonic lethality. Embryos lacking Hdac1 and Hdac2 in the neural crest exhibit decreased proliferation and increased apoptosis in both the neural tube and the first pharyngeal arch. Mechanistically, loss of Hdac1 and Hdac2 upregulates cyclin-dependent kinase inhibitors Cdkn1a, Cdkn1b, Cdkn1c, Cdkn2b, Cdkn2c, and Tp53 within the first pharyngeal arch. Our results show that Hdac1 and Hdac2 function redundantly within the neural crest to regulate proliferation and the development of the pharyngeal arches by means of repression of cyclin-dependent kinase inhibitors. Developmental Dynamics 246:1015-1026, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Life history theory and dental development in four species of catarrhine primates.

PubMed

Dirks, Wendy; Bowman, Jacqui E

2007-09-01

Dental development was reconstructed in several individuals representing four species of catarrhine primates--Symphalangus syndactylus, Hylobates lar, Semnopithecus entellus priam, and Papio hamadryas--using the techniques of dental histology. Bar charts assumed to represent species-typical dental development were constructed from these data and estimated ages at first and third molar emergence were plotted on them along with ages at weaning, menarche, and first reproduction from the literature. The estimated age at first molar emergence appears to occur at weaning in the siamang, lar gibbon, and langur, and just after weaning in the baboon. Age at menarche and first reproduction occur earlier relative to dental development in both cercopithecoids than in the hylobatids, suggesting that early reproduction may be a derived trait in cercopithecoids. The results are examined in the context of life history theory.

Development of Two-Tier Diagnostic Test Pictorial-Based for Identifying High School Students Misconceptions on the Mole Concept

NASA Astrophysics Data System (ADS)

Siswaningsih, W.; Firman, H.; Zackiyah; Khoirunnisa, A.

2017-02-01

The aim of this study was to develop the two-tier pictorial-based diagnostic test for identifying student misconceptions on mole concept. The method of this study is used development and validation. The development of the test Obtained through four phases, development of any items, validation, determination key, and application test. Test was developed in the form of pictorial consisting of two tier, the first tier Consist of four possible answers and the second tier Consist of four possible reasons. Based on the results of content validity of 20 items using the CVR (Content Validity Ratio), a number of 18 items declared valid. Based on the results of the reliability test using SPSS, Obtained 17 items with Cronbach’s Alpha value of 0703, the which means that items have accepted. A total of 10 items was conducted to 35 students of senior high school students who have studied the mole concept on one of the high schools in Cimahi. Based on the results of the application test, student misconceptions were identified in each label concept in mole concept with the percentage of misconceptions on the label concept of mole (60.15%), Avogadro’s number (34.28%), relative atomic mass (62, 84%), relative molecule mass (77.08%), molar mass (68.53%), molar volume of gas (57.11%), molarity (71.32%), chemical equation (82.77%), limiting reactants (91.40%), and molecular formula (77.13%).

Prevalence of plaque and dental decay in the first permanent molar in a school population of south Mexico City.

PubMed

Taboada-Aranza, Olga; Rodríguez-Nieto, Karen

2018-01-01

The first permanent molar is susceptible to acquire tooth decay since its eruption, due to its anatomy and because it has been exposed before other teeth. An observational, prolective, transversal and comparative study in 194 students, with an average age of 9.9 ± 1.8 years. The evaluation of the dentobacterial plate (DBP) was analyzed using the O'Leary index and the tooth decay experience with the DMFS (sum of decayed, missing, extracted and filling dental surfaces) and DMFT (sum of decayed, missing, extracted and filling per tooth) indexes. The prevalence of DBP in the first permanent molar was of 99.4% and tooth decay of 57.2%. The value of DMFT was 1.4 ± 1.4. The tooth decay experience was higher in children from 7.10 years old with a value of 2.2 ± 2.3, who are 7.9 times more likely to develop lesions than younger children (odds ratio: 8.9; 95% confidence interval: 4.1-19.5; p < 0.0001). We found an association between age and the values of the tooth decay experience indexes; even though these were weak in the case of DMF (r = 0.439), the model allowed to explain 19% of the association, and 22% for DMFT (r = 0.464). Tooth decay develops rapidly in the first permanent molars; however, it does not receive the necessary care because it is usually unknown that it is a permanent tooth. Copyright: © 2018 Permanyer.

The distribution and ultrastructure of the forming blood capillaries and the effect of apoptosis on vascularization in mouse embryonic molar mesenchyme.

PubMed

Yuan, Guohua; Zhang, Li; Yang, Guobin; Yang, Jingwen; Wan, Chunyan; Zhang, Lu; Song, Guangtai; Chen, Shuo; Chen, Zhi

2014-04-01

Vascularization is essential for organ and tissue development. Teeth develop through interactions between epithelium and mesenchyme. The developing capillaries in the enamel organ, the dental epithelial structure, occur simultaneously by mechanisms of vasculogenesis and angiogenesis at the onset of dentinogenesis. The vascular neoformation in the dental mesenchyme has been reported to start from the cap stage. However, the mechanisms of vascularization in the dental mesenchyme remain unknown. In the hope of understanding the mechanisms of the formation of dental mesenchymal vasculature, mouse lower molar germs from embryonic day (E) 13.5 to E16.5 were processed for immunostaining of CD31 and CD34, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) and transmission electron microscopy (TEM). In addition, the role of apoptosis for the vascularization in dental mesenchyme was examined by in vitro culture of E14.0 lower molars in the presence of the apoptosis inhibitor (z-VAD-fmk) and a subsequent subrenal culture. Our results showed that CD31- and CD34-positive cells progressively entered the central part of the dental papilla from the peridental mesenchyme. For TEM, angioblasts, young capillaries with thick endothelium and endothelial cells containing vacuoles were observed in peripheral dental mesenchyme, suggesting vasculogenesis was taking place. The presence of lateral sprouting, cytoplasmic filopodia and transluminal bridges in the dental papilla suggested angiogenesis was also occurring. Inhibition of apoptosis delayed the angiogenic vascularization of the dental papilla. Therefore, these data demonstrated that molar mesenchyme is progressively vascularized by mechanisms of both vasculogenesis and angiogenesis and apoptosis partially contributes to the vascularization of the dental papilla.

78 FR 25469 - Notice of Inventory Completion: University of South Alabama Center for Archaeological Studies...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-01

... represent, at minimum, two individuals, consisting of 9 molars, 2 molar fragments, 8 pre-molars, 4 canines..., three individuals, consisting of 16 molars, 10 premolars, 9 incisors, 7 canines, 61 unidentifiable tooth...

Root canal configurations of third molar teeth. A comparison with first and second molars in the Turkish population.

PubMed

Sert, Semih; Sahinkesen, Güneş; Topçu, Fulya T; Eroğlu, Seyda E; Oktay, Elif A

2011-12-01

The purpose of the current study was to determine the similarities of maxillary and mandibular third molars with the other molar teeth. A total of 2016 extracted maxillary and mandibular permanent teeth were evaluated. The teeth were divided into six groups. The teeth were stored in 5% nitric acid solution for 7 days, then placed in increasing concentrations of ethyl alcohol. The teeth were rendered transparent by immersion in xylene solution for 4 days until complete transparency was achieved. Three roots were present in 93.0% of the maxillary molars, and 91.3% of the second molars. Among the maxillary third molars, 35.5% were single-rooted and 24.9% of the mandibular third molars had single roots. Double roots were present in 69.2% of the mandibular third molars, and 5.4% had three roots. Four new root canal configurations were encountered in this study. The root canal configurations of the mandibular and maxillary teeth showed similarities with the results of other studies performed in different populations. © 2010 The Authors. Australian Endodontic Journal © 2010 Australian Society of Endodontology.

[Clinical analysis of caries status of the mandibular second molar].

PubMed

You, Chun-an; Zheng, Ping; Hu, Ning; Su, Qin

2014-04-01

To collect the cases which have caries on the mandibular second molar and analyze the caries status and correlative factors. Patients treated in the Department of Endodontics in West China Hospital of Stomatology were randomly collected. The baseline information, primary sites and severity of dental caries on the mandibular second molar, and eruption pattern of the mandibular third molar were recorded. The data was analyzed with SPSS13.0 software package. Four hundred eighty-one patients including 227 males and 254 females were collected. Caries on the mandibular second molar starting from the occlusal, distal proximal and buccal surfaces accounted for 33.8%, 33.2% and 24.4%, respectively. Caries involving dental pulp (49.7%) were significantly more than deep and shallow to moderate caries (31.7% and 18.6%). Gender was not correlated with the site and severity of caries. However, impacted mandibular third molars and age were significantly related to both caries site and severity. Occlusal and distal proximal surfaces are the most predisposed sites to have caries on mandibular second molar. Impacted mandibular third molar and age are significantly related to caries of mandibular second molar.

Molar axis estimation from computed tomography images.

PubMed

Dongxia Zhang; Yangzhou Gan; Zeyang Xia; Xinwen Zhou; Shoubin Liu; Jing Xiong; Guanglin Li

2016-08-01

Estimation of tooth axis is needed for some clinical dental treatment. Existing methods require to segment the tooth volume from Computed Tomography (CT) images, and then estimate the axis from the tooth volume. However, they may fail during estimating molar axis due to that the tooth segmentation from CT images is challenging and current segmentation methods may get poor segmentation results especially for these molars with angle which will result in the failure of axis estimation. To resolve this problem, this paper proposes a new method for molar axis estimation from CT images. The key innovation point is that: instead of estimating the 3D axis of each molar from the segmented volume, the method estimates the 3D axis from two projection images. The method includes three steps. (1) The 3D images of each molar are projected to two 2D image planes. (2) The molar contour are segmented and the contour's 2D axis are extracted in each 2D projection image. Principal Component Analysis (PCA) and a modified symmetry axis detection algorithm are employed to extract the 2D axis from the segmented molar contour. (3) A 3D molar axis is obtained by combining the two 2D axes. Experimental results verified that the proposed method was effective to estimate the axis of molar from CT images.

QSPR models for various physical properties of carbohydrates based on molecular mechanics and quantum chemical calculations.

PubMed

Dyekjaer, Jane Dannow; Jónsdóttir, Svava Osk

2004-01-22

Quantitative Structure-Property Relationships (QSPR) have been developed for a series of monosaccharides, including the physical properties of partial molar heat capacity, heat of solution, melting point, heat of fusion, glass-transition temperature, and solid state density. The models were based on molecular descriptors obtained from molecular mechanics and quantum chemical calculations, combined with other types of descriptors. Saccharides exhibit a large degree of conformational flexibility, therefore a methodology for selecting the energetically most favorable conformers has been developed, and was used for the development of the QSPR models. In most cases good correlations were obtained for monosaccharides. For five of the properties predictions were made for disaccharides, and the predicted values for the partial molar heat capacities were in excellent agreement with experimental values.

Aortic iron overload with oxidative stress and inflammation in human and murine abdominal aortic aneurysm.

PubMed

Sawada, Hisashi; Hao, Hiroyuki; Naito, Yoshiro; Oboshi, Makiko; Hirotani, Shinichi; Mitsuno, Masataka; Miyamoto, Yuji; Hirota, Seiichi; Masuyama, Tohru

2015-06-01

Although iron is an essential element for maintaining physiological function, excess iron leads to tissue damage caused by oxidative stress and inflammation. Oxidative stress and inflammation play critical roles for the development of abdominal aortic aneurysm (AAA). However, it has not been investigated whether iron plays a role in AAA formation through oxidative stress and inflammation. We, therefore, examined whether iron is involved in the pathophysiology of AAA formation using human AAA walls and murine AAA models. Human aortic walls were collected from 53 patients who underwent cardiovascular surgery (non-AAA=34; AAA=19). Murine AAA was induced by infusion of angiotensin II to apolipoprotein E knockout mice. Iron was accumulated in human and murine AAA walls compared with non-AAA walls. Immunohistochemistry showed that both 8-hydroxy-2'-deoxyguanosine and CD68-positive areas were increased in AAA walls compared with non-AAA walls. The extent of iron accumulated area positively correlated with that of 8-hydroxy-2'-deoxyguanosine expression area and macrophage infiltration area in human and murine AAA walls. We next investigated the effects of dietary iron restriction on AAA formation in mice. Iron restriction reduced the incidence of AAA formation with attenuation of oxidative stress and inflammation. Aortic expression of transferrin receptor 1, intracellular iron transport protein, was increased in human and murine AAA walls, and transferrin receptor 1-positive area was similar to areas where iron accumulated and F4/80 were positive. Iron is involved in the pathophysiology of AAA formation with oxidative stress and inflammation. Dietary iron restriction could be a new therapeutic strategy for AAA progression. © 2015 American Heart Association, Inc.

Amelioration of tissue fibrosis by toll-like receptor 4 knockout in murine models of systemic sclerosis.

PubMed

Takahashi, Takehiro; Asano, Yoshihide; Ichimura, Yohei; Toyama, Tetsuo; Taniguchi, Takashi; Noda, Shinji; Akamata, Kaname; Tada, Yayoi; Sugaya, Makoto; Kadono, Takafumi; Sato, Shinichi

2015-01-01

Bleomycin-induced fibrosis and the tight skin (TSK/+) mouse are well-established experimental murine models of human systemic sclerosis (SSc). Growing evidence has demonstrated the pivotal role of Toll-like receptors (TLRs) in several autoimmune inflammatory diseases, including SSc. This study was undertaken to determine the role of TLR-4 in the fibrotic processes in these murine models. We generated a murine model of bleomycin-induced SSc using TLR-4(-/-) mice and TLR-4(-/-) ;TSK/+ mice. The mechanisms by which TLR-4 contributes to pathologic tissue fibrosis were investigated in these 2 models by histologic examination, hydroxyproline assay, enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and flow cytometry. Dermal and lung fibrosis was attenuated in bleomycin-treated TLR-4(-/-) mice compared with their wild-type counterparts. Inflammatory cell infiltration, expression of various inflammatory cytokines, and pathologic angiogenesis induced by bleomycin treatment were suppressed with TLR-4 deletion. Furthermore, the increased expression of interleukin-6 (IL-6) in fibroblasts, endothelial cells, and immune cells in response to bleomycin in vivo and to lipopolysaccharide in vitro was notably abrogated in the absence of TLR-4. Moreover, TLR-4 deletion was associated with alleviated B cell activation and skew toward a Th2/Th17 response against bleomycin treatment. Importantly, in TSK/+ mice, another SSc murine model, TLR-4 abrogation attenuated hypodermal fibrosis. These results indicate the pivotal contribution of TLR-4 to the pathologic tissue fibrosis of SSc murine models. Our results indicate the critical role of TLR-4 signaling in the development of tissue fibrosis, suggesting that biomolecular TLR-4 targeting might be a potential therapeutic approach to SSc. Copyright © 2015 by the American College of Rheumatology.

Murine CMV-Induced Hearing Loss Is Associated with Inner Ear Inflammation and Loss of Spiral Ganglia Neurons

PubMed Central

Golemac, Mijo; Pugel, Ester Pernjak; Jonjic, Stipan; Britt, William J.

2015-01-01

Congenital human cytomegalovirus (HCMV) occurs in 0.5–1% of live births and approximately 10% of infected infants develop hearing loss. The mechanism(s) of hearing loss remain unknown. We developed a murine model of CMV induced hearing loss in which murine cytomegalovirus (MCMV) infection of newborn mice leads to hematogenous spread of virus to the inner ear, induction of inflammatory responses, and hearing loss. Characteristics of the hearing loss described in infants with congenital HCMV infection were observed including, delayed onset, progressive hearing loss, and unilateral hearing loss in this model and, these characteristics were viral inoculum dependent. Viral antigens were present in the inner ear as were CD3+ mononuclear cells in the spiral ganglion and stria vascularis. Spiral ganglion neuron density was decreased after infection, thus providing a mechanism for hearing loss. The lack of significant inner ear histopathology and persistence of inflammation in cochlea of mice with hearing loss raised the possibility that inflammation was a major component of the mechanism(s) of hearing loss in MCMV infected mice. PMID:25875183

Root growth during molar eruption in extant great apes.

PubMed

Kelley, Jay; Dean, Christopher; Ross, Sasha

2009-01-01

While there is gradually accumulating knowledge about molar crown formation and the timing of molar eruption in extant great apes, very little is known about root formation during the eruption process. We measured mandibular first and second molar root lengths in extant great ape osteological specimens that died while either the first or second molars were in the process of erupting. For most specimens, teeth were removed so that root lengths could be measured directly. When this was not possible, roots were measured radiographically. We were particularly interested in the variation in the lengths of first molar roots near the point of gingival emergence, so specimens were divided into early, middle and late phases of eruption based on the number of cusps that showed protein staining, with one or two cusps stained equated with immediate post-gingival emergence. For first molars at this stage, Gorilla has the longest roots, followed by Pongo and Pan. Variation in first molar mesial root lengths at this stage in Gorilla and Pan, which comprise the largest samples, is relatively low and represents no more than a few months of growth in both taxa. Knowledge of root length at first molar emergence permits an assessment of the contribution of root growth toward differences between great apes and humans in the age at first molar emergence. Root growth makes up a greater percentage of the time between birth and first molar emergence in humans than it does in any of the great apes. Copyright (c) 2009 S. Karger AG, Basel.

Expressly fabricated molar tube bases: enhanced adhesion.

PubMed

Sharma, Tarun; Phull, Tarun Singh; Rana, Tarun; Kumar, Varun

2014-06-01

Clinicians, Orthodontists and their patients' parents often expect the best results in the shortest time span possible. Orthodontic bonding of molar tubes has been an acceptable risk in a modern era of refined biomaterials and instrumentation. Although many orthodontists still prefer banding to bonding, it is the failure rate of the tubes on molars which accounts to an impedance in molar bonding. One of the reasons for molar attachment failures is attributed to improper adaptation of the buccal tube base with or without increased thickness of composite. Merits of banding the second molars especially when these are the terminal teeth for anchorage have been overemphasized in the literature. The present article presents a simple and relatively less time consuming technique of preparing molar tubes to be bonded on tooth surfaces which may be quite difficult to isolate especially for bonding, for example, mandibular second molars. The increased surface area of the composite scaffold helps not only in enhanced bond strength but also serves to reduce the incidence of plaque accumulation given the dexterity of invitro preparation. The removal of the occlusal part of the molar tube scaffold helps in prevention of open / raised bite tendencies. The present innovation, therefore, is not merely serendipity but a structured technique to overcome a common dilemma for the clinical orthodontist. The present dictum of banding being superior to molar tube bonding may prove to be futile with trendsetting molar attachments. It is also an established fact that bonding proves to be a lesser expensive modality when compared to banding procedures.

The Relation Between Dermatoglyphics And Mesiodistal Width Of The Deciduous Second Molar And Permanent First Molar

PubMed Central

Kumar, Vinod; Adusumilli, Hamsini; Reddy, KM Parveen; Kumar, NH Praveen

2017-01-01

Introduction Dermatoglyphics is one of the important diagnostic tools used in the recent days for identification of an individual. Dermatoglyphics is the study of type of patterns present on digits, palms and foot. The mesiodistal diameter of the tooth is an important factor which reveals the tooth-bone discrepancy. Deciduous second molar and permanent first molar exhibit least degree of variation. Both the dermal ridges and the enamel layer of the tooth originate from ectodermal layer and during the same period of intrauterine life. Aim To determine and compare the dermatoglyphics with the mesiodistal width of the deciduous second molar and permanent first molar. Materials and Methods A sample of 120 child ranaged between 6-12 years were included in the study whose digital and palmer traits were recorded using ink method and the mesiodistal widths of the deciduous second molar and permanent first molar were recorded using a vernier caliper. The data was subjected to statistical analysis using unpaired t test. Results The ‘ATD’ angle was found in the range of 40°-50°. The loop patterns were more common followed by whorls and arch patterns. Girls expressed a greater mesiodistal diameter of deciduous second molar than boys. No significant correlation was found in between the dermatoglyphics and tooth size. Conclusion There was no significant correlation between the finger print patterns, ‘ATD’ angle and the mesiodistal diameter of the deciduous second molar and the permanent first molar. PMID:28969275

Comparison of vectorial ion transport in primary murine airway and human sinonasal air-liquid interface cultures, models for studies of cystic fibrosis, and other airway diseases.

PubMed

Zhang, Shaoyan; Fortenberry, James A; Cohen, Noam A; Sorscher, Eric J; Woodworth, Bradford A

2009-01-01

The purpose of this study was to compare vectorial ion transport within murine trachea, murine nasal septa, and human sinonasal cultured epithelium. Our hypothesis is that murine septal epithelium, rather than trachea, will more closely mimic the electrophysiology properties of human sinonasal epithelium. Epithelium from murine trachea, murine septa, and human sinonasal tissue were cultured at an air-liquid interface to confluence and full differentiation. A limited number of homozygous dF508 epithelia were also cultured. Monolayers were mounted in modified Ussing chambers to investigate pharmacologic manipulation of ion transport. The change in forskolin-stimulated current (delta-I(SC), expressed as micro-A/cm(2)) in murine septal (n = 19; 16.84 +/- 2.09) and human sinonasal (n = 18; 12.15 +/- 1.93) cultures was significantly increased over murine tracheal cultures (n = 15; 6.75 +/- 1.35; p = 0.035 and 0.0005, respectively). Forskolin-stimulated I(SC) was inhibited by the specific cystic fibrosis transmembrane regulator (CFTR) inhibitor INH-172 (5 microM). No forskolin-stimulated I(SC) was shown in cultures of dF508 homozygous murine septal epithelium (n = 3). Murine septal I(SC) was largely inhibited by amiloride (12.03 +/- 0.66), whereas human sinonasal cultures had a very limited response (0.70 +/- 0.47; p < 0.0001). The contribution of CFTR to stimulated chloride current as measured by INH-172 was highly significantly different between all groups (murine septa, 19.51 +/- 1.28; human sinonasal, 11.12 +/- 1.58; murine trachea, 4.85 +/- 0.49; p < 0.0001). Human sinonasal and murine septal epithelial cultures represent a useful model for studying CFTR activity and may provide significant advantages over lower airway tissues for investigating upper and lower respiratory pathophysiology.

Lower molar and incisor displacement associated with mandibular remodeling.

PubMed

Baumrind, S; Bravo, L A; Ben-Bassat, Y; Curry, S; Korn, E L

1997-01-01

The purpose of this study was to quantify the amount of alveolar modeling at the apices of the mandibular incisor and first molar specifically associated with appositional and resorptive changes on the lower border of the mandible during growth and treatment. Cephalometric data from superimpositions on anterior cranial base, mandibular implants of the Björk type, and anatomical "best fit" of mandibular border structures were integrated using a recently developed strategy, which is described. Data were available at annual intervals between 8.5 and 15.5 years for a previously described sample of approximately 30 children with implants. The average magnitudes of the changes at the root apices of the mandibular first molar and central incisor associated with modeling/remodeling of the mandibular border and symphysis were unexpectedly small. At the molar apex, mean values approximated zero in both anteroposterior and vertical directions. At the incisor apex, mean values approximated zero in the anteroposterior direction and averaged less than 0.15 mm/year in the vertical direction. Standard deviations were roughly equal for the molar and the incisor in both the anteroposterior and vertical directions. Dental displacement associated with surface modeling plays a smaller role in final tooth position in the mandible than in the maxilla. It may also be reasonably inferred that anatomical best-fit superimpositions made in the absence of implants give a more complete picture of hard tissue turnover in the mandible than they do in the maxilla.

A novel crystallization technique of hydroxyapatite utilizing contact reaction of minute droplet with atmospheric plasmas: Effects of the liquid source composition on the produced crystal properties

NASA Astrophysics Data System (ADS)

Wada, Y.; Kobayashi, T.; Matsumoto, M.; Onoe, K.

2017-10-01

To develop the technique for the control of the crystal composition and properties such as size distribution and morphology utilizing the contact reaction field around the minute droplets in atmospheric pressure plasma, fine spherical particles of hydroxyapatite ((Ca10(PO4)6(OH)2); HAp) were synthesized by a new plasma crystallization method. In this work, to elucidate the effects of the production region and crystal properties of hydroxyapatite for the liquid source composition, Ca2+ concentration and the Ca/P molar ratio in minute droplets were varied. The following results were obtained: (1) fine spherical HAp particles can be produced by the introduction of minute droplets with the initial Ca2+ concentration ((CCa)0) of 0.50 mol/l and the Ca/P molar ratio of 1.67. (2) When the (CCa)0 is set in the range higher than 1.00 mol/l at the constant Ca/P molar ratio of 1.67, fine spherical particles of β-TCP and HAp mixture are crystallized. (3) For the Ca/P molar ratio below 1.67, α-TCP and HAp co-precipitated. (4) The composition of the produced particles depends on both the reactant concentration and Ca/P molar ratio in the HAp source solution. (5) The dependence of the reactant concentration on the average size of the produced HAp particles is large compared with droplet size.

Patterns of third-molar agenesis and associated dental anomalies in an orthodontic population.

PubMed

Celikoglu, Mevlut; Bayram, Mehmet; Nur, Metin

2011-12-01

The aim of this study was to investigate the frequency of dental anomalies in orthodontic patients with different patterns of third-molar agenesis, comparing them with patients without third-molar agenesis. A sample of 374 patients with agenesis of at least 1 third molar was divided into 4 groups according to the third-molar agenesis pattern, and a control group of 98 patients without third-molar agenesis was randomly selected from the patient archives. Panoramic radiographs and cast models were used to determine the associated dental anomalies, such as hypodontia, hyperdontia, impaction, dilaceration, microdontia, ectopic eruption, transposition, and transmigration. The Pearson chi-square and Fisher exact tests were used to determine the differences in the distribution of the associated dental anomalies among the groups. The prevalence of agenesis of other teeth (11.2%, n = 42) was significantly greater in our study sample (groups 1-4) than in the control group (group 5) (4.1%, n = 4; P <0.05). When we compared the groups according to the various third-molar agenesis patterns, we found that agenesis of other teeth was more common in patients with agenesis of 3 and 4 third molars. In addition, the patients with agenesis of 4 third molars exhibited maxillary lateral-incisor microdontia more frequently. Another important finding was a higher prevalence of total dental anomalies in patients with agenesis of 3 and 4 third molars compared with the control group. Permanent tooth agenesis, microdontia of maxillary lateral incisors, and total dental anomalies are more frequently associated with agenesis of 4 third molars than with the presence of third molars. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Long- and short-term effects of headgear traction with and without the maxillary second molars.

PubMed

Shpack, Nir; Brosh, Tamar; Mazor, Yoav; Shapinko, Yoav; Davidovitch, Moshe; Sarig, Rachel; Reimann, Susanne; Bourauel, Christoph; Vardimon, Alexander D

2014-10-01

A quantitative assessment of maxillary first molar distalization with and without the maxillary second molar (M2) was carried out. Fifty-six cervical headgear patients undergoing fixed appliance orthodontic treatment were divided into 2 groups: before (G - M2) and after (G + M2) eruption of the maxillary second molars (ages, 11.87 ± 1.20, and 13.05 ± 1.55 years, respectively). The tightness of the dental contact point (TDCP) and the space between the second premolar and the maxillary first molar were measured at 6 levels of headgear force (0-15 N) at 3 intervals 6 months apart (T0, T1, T2). Relationships were found between space and TDCP, time, and presence or absence of the maxillary second molar at T1 and T2 (P <0.001). The TDCP decreased and space increased with increase in initial headgear force. An increase in initial force beyond 6 to 9 N did not significantly increase the initial maxillary first molar distalization. The G - M2 TDCP and space measurements were similar to those of G + M2 at T2 with the eruption of the maxillary second molar. From T0 to T1, maxillary first molar distalization was greater in G - M2. In comparison with our previous headgear-alone study, initial distalization with a fully bonded appliance was reduced by 4-fold. Headgear therapy is more effective before the eruption of the maxillary second molar. Once it erupts, the distalization pace of the maxillary first molar is reduced, but it can nevertheless be pursued at a slower pace when the maxillary second molar is present. Copyright © 2014 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Effectiveness of a personalized device in the evaluation of mandibular second molar periodontal healing after surgical extraction of adjacent third molar.

PubMed

Pippi, Roberto

2013-01-01

The primary aim of the present study was to validate the effectiveness of a personalized device able to guide periodontal probing in evaluation of second molar periodontal healing after adjacent third molar surgical extraction. Secondarily, the study analyzed if any patient and tooth related factors affected the second molar periodontal healing as well as if they were able to affect the periodontal probing depth performed with or without the personalized device. Thirty-five lower second molars were evaluated after extraction of the adjacent third molar. Pre-operative as well as 3 and 12 month post-operative probing depths of the distal surface of the second molar were evaluated. All measurements were taken by two different methods: standard two-point and four-point probing using a personalized onlay-type guide. Periapical radiographs were also evaluated. The Pearson product moment and the general linear model with backward stepwise procedure were used for inferential statistics. The mean 12-month post-operative probing depth/mean pre-operative probing depth ratio obtained with the guided probing method showed a highly significant effect on the 12-month radiographic post-operative/pre-operative radiographic measure ratio. None of the examined patient- or tooth-related factors showed a significant effect on pre-operative/12-month post-operative radiographic measure ratio. The use of the proposed personalized device seems to provide a more reliable estimate of second molar periodontal healing after adjacent third molar surgical extraction. No patient-or tooth-related factors seem to be able to affect either second molar periodontal healing or probing depth measures obtained with or without the personalized device in individuals younger than 25 years old. It can be therefore recommended that lower third molar surgical extraction be performed in young adults.

Endodontic management of contralateral mandibular first molars with six root canals

PubMed Central

Bhargav, Kambhampati; Sirisha, Kantheti; Jyothi, Mandava; Boddeda, Mohan Rao

2017-01-01

The knowledge of variations in root canal morphology is essential for a successful endodontic outcome. Contralateral mandibular molar with six root canals is a rare entity. Root canal treatment of mandibular molars with aberrant canal configuration can be diagnostically and technically challenging. While dealing with variant mandibular molars, mishaps may happen. This case report describes variations in contralateral mandibular molars and also an endodontic mishap while managing them. PMID:29259369

Prevalence of infraocclusion of primary molars determined using a new 2D image analysis methodology.

PubMed

Odeh, R; Mihailidis, S; Townsend, G; Lähdesmäki, R; Hughes, T; Brook, A

2016-06-01

The reported prevalence of infraocclusion varies widely, reflecting differences in definitions and measurement/scoring approaches. This study aimed to quantify the prevalence and extent of infraocclusion in singletons and twins during the late mixed dentition stage of dental development using a new diagnostic imaging method and objective criteria. The study also aimed to determine any associations between infraocclusion and gender, arch type, arch side and tooth type. Two samples were analysed, 1454 panoramic radiographs of singletons and 270 dental models of twins. Both samples ranged in age from 8 to 11 years. Adobe Photoshop CS5 was used to measure the extent of infraocclusion. Repeatability tests showed systematic and random errors were small. The prevalence in the maxilla was low (<1%), whereas the prevalence in the mandible was 22% in the singleton sample and 32% in the twin sample. The primary mandibular first molar was affected more often than the second molar. There was no significant difference in the expression between genders or sides. A new technique for measuring infraocclusion has been developed with high intra- and interoperator reproducibility. This method should enhance early diagnosis of tooth developmental abnormalities and treatment planning during the late mixed dentition stage of development. © 2016 Australian Dental Association.

Sieve-based device for MALDI sample preparation. III. Its power for quantitative measurements.

PubMed

Molin, Laura; Cristoni, Simone; Seraglia, Roberta; Traldi, Pietro

2011-02-01

The solid sample inhomogeneity is a weak point of traditional MALDI deposition techniques that reflects negatively on quantitative analysis. The recently developed sieve-based device (SBD) sample deposition method, based on the electrospraying of matrix/analyte solutions through a grounded sieve, allows the homogeneous deposition of microcrystals with dimensions smaller than that of the laser spot. In each microcrystal the matrix/analyte molar ratio can be considered constant. Then, by irradiating different portions of the microcrystal distribution an identical response is obtained. This result suggests the employment of SBD in the development of quantitative procedures. For this aim, mixtures of different proteins of known molarity were analyzed, showing a good relationship between molarity and intensity ratios. This behaviour was also observed in the case of proteins with quite different ionic yields. The power of the developed method for quantitative evaluation was also tested by the measurement of the abundance of IGPP[Oxi]GPP[Oxi]GLMGPP (m/z 1219) present in the collagen-α-5(IV) chain precursor, differently expressed in urines from healthy subjects and diabetic-nephropathic patients, confirming its overexpression in the presence of nephropathy. The data obtained indicate that SBD is a particularly effective method for quantitative analysis also in biological fluids of interest. Copyright © 2011 John Wiley & Sons, Ltd.

Phytate intake and molar ratios of phytate to zinc, iron and calcium in the diets of people in China.

PubMed

Ma, G; Li, Y; Jin, Y; Zhai, F; Kok, F J; Yang, X

2007-03-01

To assess the phytate intake and molar ratios of phytate to calcium, iron and zinc in the diets of people in China. 2002 China Nationwide Nutrition and Health Survey is a cross-sectional nationwide representative survey on nutrition and health. The information on dietary intakes was collected using consecutive 3 days 24 h recall by trained interviewers. The data of 68 962 residents aged 2-101 years old from 132 counties were analyzed. The median daily dietary intake of phytate, calcium, iron and zinc were 1186, 338.1, 21.2 and 10.6 mg, respectively. Urban residents consumed less phytate (781 vs 1342 mg/day), more calcium (374.5 vs 324.1 mg/day) and comparable amounts of iron (21.1 vs 21.2 mg/day) and zinc (10.6 vs 10.6 mg/day) than their rural counterparts. A wide variation in phytate intake among residents from six areas was found, ranging from 648 to 1433 mg/day. The median molar ratios of phytate to calcium, iron, zinc and phytate x calcium/zinc were 0.22, 4.88, 11.1 and 89.0, respectively, with a large variation between urban and rural areas. The phytate:zinc molar ratios ranged from 6.2 to 14.2, whereas the phytate x calcium/zinc molar ratios were from 63.7 to 107.2. The proportion of subjects with ratios above the critical values of phytate to iron, phytate to calcium, phytate to zinc and phytate x calcium/zinc were 95.4, 43.7, 23.1 and 8.7%, respectively. All the phytate/mineral ratios of rural residents were higher than that of their urban counterparts. The dietary phytate intake of people in China was higher than those in Western developed countries and lower than those in developing countries. Phytate may impair the bioavailability of iron, calcium and zinc in the diets of people in China.

The murine SNF5/INI1 chromatin remodeling factor is essential for embryonic development and tumor suppression.

PubMed

Klochendler-Yeivin, A; Fiette, L; Barra, J; Muchardt, C; Babinet, C; Yaniv, M

2000-12-01

The assembly of eukaryotic DNA into nucleosomes and derived higher order structures constitutes a barrier for transcription, replication and repair. A number of chromatin remodeling complexes, as well as histone acetylation, were shown to facilitate gene activation. To investigate the function of two closely related mammalian SWI/SNF complexes in vivo, we inactivated the murine SNF5/INI1 gene, a common subunit of these two complexes. Mice lacking SNF5 protein stop developing at the peri-implantation stage, showing that the SWI/SNF complex is essential for early development and viability of early embryonic cells. Furthermore, heterozygous mice develop nervous system and soft tissue sarcomas. In these tumors the wild-type allele was lost, providing further evidence that SNF5 functions as a tumor suppressor gene in certain cell types.

The murine SNF5/INI1 chromatin remodeling factor is essential for embryonic development and tumor suppression

PubMed Central

Klochendler-Yeivin, Agnes; Fiette, Laurence; Barra, Jaqueline; Muchardt, Christian; Babinet, Charles; Yaniv, Moshe

2000-01-01

The assembly of eukaryotic DNA into nucleosomes and derived higher order structures constitutes a barrier for transcription, replication and repair. A number of chromatin remodeling complexes, as well as histone acetylation, were shown to facilitate gene activation. To investigate the function of two closely related mammalian SWI/SNF complexes in vivo, we inactivated the murine SNF5/INI1 gene, a common subunit of these two complexes. Mice lacking SNF5 protein stop developing at the peri-implantation stage, showing that the SWI/SNF complex is essential for early development and viability of early embryonic cells. Furthermore, heterozygous mice develop nervous system and soft tissue sarcomas. In these tumors the wild-type allele was lost, providing further evidence that SNF5 functions as a tumor suppressor gene in certain cell types. PMID:11263494

Retrospective study of root canal configurations of maxillary third molars in Central India population using cone beam computed tomography Part- I

PubMed Central

Rawtiya, Manjusha; Somasundaram, Pavithra; Wadhwani, Shefali; Munuga, Swapna; Agarwal, Manish; Sethi, Priyank

2016-01-01

Objective: The aim of this study was to investigate the root and canal morphology of maxillary third molars in Central India population using cone-beam computed tomography (CBCT) analysis. Materials and Methods: CBCT images of 116 maxillary third molars were observed, and data regarding the number of roots, the number of canals, and Vertucci's Classification in each root was statistically evaluated. Results: Majority of Maxillary third molars had three roots (55.2%) and three canals (37.9%). Most MB root (43.8%), DB root (87.5%), and palatal root (100%) of maxillary third molars had Vertucci Type I. Mesiobuccal root of three-rooted maxillary third molars had Vertucci Type I (43.8%) and Type IV (40.6%) configuration. Overall prevalence of C-shaped canals in maxillary third molars was 3.4%. Conclusion: There was a high prevalence of three-rooted maxillary molars with three canals. PMID:27011747

Retrospective Study of Root Canal Configurations of Mandibular Third Molars Using CBCT- Part-II.

PubMed

Somasundaram, Pavithra; Rawtiya, Manjusha; Wadhwani, Shefali; Uthappa, Roshan; Shivagange, Vinay; Khan, Sheeba

2017-06-01

Abnormal root canal morphologies of third molars can be diagnostically and technically challenging during root canal treatment. The aim of this retrospective study was to investigate the root and canal morphology of mandibular third molars in Central India population by using Cone Beam Computed Tomography (CBCT) analysis. CBCT images of 171 mandibular third molars were observed and data regarding number of roots, number of canals, Vertucci's classification in each root, prevalence of C shaped canal, gender and topographical relation of morphology in mandibular third molar was statistically evaluated. Majority of mandibular third molars had two roots (84.2%) and three canals (64.3%). Most mesial root had Vertucci Type II (55.6%) and Vertucci Type IV (22.2%), distal root had Type I canals (87.5%). Over all prevalence of C shaped canals in mandibular third molars was 9.4%. There was a high prevalence of two rooted mandibular third molars with three canals.

Molar distalization with 2K appliance: one-year follow-up

PubMed Central

Tripathi, Tulika; Rai, Priyank; Singh, Navneet

2017-01-01

Correction of class II molars in growing patients with acceptable facial profile can be performed by distalization of maxillary first molars. However, in patients where compliance is difficult intraoral means of molar distalization is required. This case report describes the use and effectiveness of a novel 2K appliance in an 11-year-old female having an orthognathic profile, skeletal Class I relation, and Angle's Class II division 1 malocclusion with crowding of 8 mm and 3 mm in the maxillary and mandibular arches, respectively. Nonextraction treatment was planned with bilateral distalization of the maxillary first molars. The amount of distalization achieved by 2K appliance was 3.5 mm with only 1° distal tipping. The 2K appliance required minimal patient cooperation, produced bodily movement of molars with minimal tipping/rotation, and prevented anchorage loss of the anterior teeth. This 2K molar distalization appliance was found to be an effective technique to control molars in all three planes of space. PMID:28717634

Retrospective Study of Root Canal Configurations of Mandibular Third Molars Using CBCT- Part-II

PubMed Central

Somasundaram, Pavithra; Wadhwani, Shefali; Uthappa, Roshan; Shivagange, Vinay; Khan, Sheeba

2017-01-01

Introduction Abnormal root canal morphologies of third molars can be diagnostically and technically challenging during root canal treatment. Aim The aim of this retrospective study was to investigate the root and canal morphology of mandibular third molars in Central India population by using Cone Beam Computed Tomography (CBCT) analysis. Materials and Methods CBCT images of 171 mandibular third molars were observed and data regarding number of roots, number of canals, Vertucci’s classification in each root, prevalence of C shaped canal, gender and topographical relation of morphology in mandibular third molar was statistically evaluated. Results Majority of mandibular third molars had two roots (84.2%) and three canals (64.3%). Most mesial root had Vertucci Type II (55.6%) and Vertucci Type IV (22.2%), distal root had Type I canals (87.5%). Over all prevalence of C shaped canals in mandibular third molars was 9.4%. Conclusion There was a high prevalence of two rooted mandibular third molars with three canals. PMID:28764294

A Novel Objective Method of Estimating the Age of Mandibles from African Elephants (Loxodonta africana Africana)

PubMed Central

Stansfield, Fiona J.

2015-01-01

The importance of assigning an accurate estimate of age and sex to elephant carcasses found in the wild has increased in recent years with the escalation in levels of poaching throughout Africa. Irregularities identified in current ageing techniques prompted the development of a new method to describe molar progression throughout life. Elephant mandibles (n = 323) were studied and a point near the distal dental alveolus was identified as being most useful in ranking each jaw according to molar progression. These ‘Age Reference Lines’ were then associated with an age scale based on previous studies and Zimbabwean mandibles of known age. The new ranking produced a single age scale that proved useful for both male and female mandibles up to the maximum lifespan age of 70–75 years. Methods to aid in molar identification and the sexing of found jaws were also identified. PMID:25970428

Rational Improvement of Molar Absorptivity Guided by Oscillator Strength: A Case Study with Furoindolizine-Based Core Skeleton.

PubMed

Lee, Youngjun; Jo, Ala; Park, Seung Bum

2015-12-21

The rational improvement of photophysical properties can be highly valuable for the discovery of novel organic fluorophores. Using our new design strategy guided by the oscillator strength, we developed a series of full-color-tunable furoindolizine analogs with improved molar absorptivity through the fusion of a furan ring into the indolizine-based Seoul fluorophore. The excellent correlation between the computable values (oscillator strength and theoretical S0 -S1 energy gap) and photophysical properties (molar absorptivity and emission wavelength) confirmed the effectualness of our design strategy. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Deep neck infection after third molar extraction: A case report.

PubMed

da Silva Junior, Alberto Ferreira; de Magalhaes Rocha, Gustavo Silvestre; da Silva Neves de Araujo, Camila Fialho; Franco, Ademir; Silva, Rhonan Ferreira

2017-01-01

Deep neck infections are associated with high morbidity rates in dentistry. Early diagnosis and intervention play an essential part in decreasing morbidity rates. The present study aims to report a case of odontogenic deep neck infection after third molar extraction. A 51-year-old male patient underwent extraction of the mandibular right third molar. Seven days later, the patient developed symptoms and signs of progressive infection. Laboratorial and radiologic examinations in association with clinical investigations confirmed deep neck infection. Extraoral drainage was performed under orotracheal intubation. Postoperative laboratory tests and clinical examinations revealed signs of complete remission within a follow-up period of 10 days. Considering the invasive nature of pathogens related to deep neck infections, it is possible to infer that a combination of accurate diagnosis and early intervention plays an essential role in the field of maxillofacial surgery and pathology.

Use of miniplates as a method for orthodontic anchorage: a case report.

PubMed

Peres, Fernando Gianzanti; Padovan, Luis Eduardo Marques; Kluppel, Leandro Eduardo; Albuquerque, Gustavo Calvalcanti; Souza, Paulo Cesar Ulson de; Claudino, Marcela

2016-01-01

Temporary anchorage devices (TADs) have been developed to be used as direct adjuncts in orthodontic treatment and have facilitated treatment of more complex orthodontic cases, including patients with dental impaction. This clinical case reports the applicability of TADs in the orthodontic treatment of a patient with impacted mandibular second molars. Surgical and orthodontic procedures related to the use of miniplates were also discussed in this study. The use of temporary anchorage devices, such as miniplates, can be suggested as an alternative to treat patients with impacted mandibular second molars.

[Hyperthyroidism in molar pregnancy].

PubMed

Boufettal, H; Mahdoui, S; Noun, M; Hermas, S; Samouh, N

2014-03-01

Hyperthyroidism is a rare complication of molar pregnancy. We report a 39-year-old woman who presented a thyrotoxic syndrome accompanying a molar pregnancy. Serum thyroid hormones were elevated and returned to normal level after uterine evacuation of a molar pregnancy. The authors detail the role of thyroid stimulating property of human gonadotropin chorionic hormone and its structural changes during the gestational trophoblastic diseases. These changes give the latter the thyroid stimulating properties and signs of hyperthyroidism. Molar pregnancy may be a cause of hyperthyroidism. The diagnosis of molar pregnancy should be a mention to thyrotoxicosique syndrome in a woman of childbearing age. Copyright © 2013. Published by Elsevier SAS.

Physicochemical properties of binary solutions of propylene carbonate-acetonitrile in the range of 253.15-313.15 K

NASA Astrophysics Data System (ADS)

Tyunina, E. Yu.; Chekunova, M. D.

2017-05-01

The density, dynamic viscosity, and dielectric constant of propylene carbonate solutions with acetonitrile are measured over the composition of a mixed solvent at temperatures of 253.15, 273.15, 293.15, and 313.15 K. The molar volume, molar viscosity, and molar capacity of a mixture of propylene carbonate-acetonitrile and an excess amount of it are calculated. The effect the temperature and composition of the mixture have on the excess molar properties is discussed. A linear correlation is observed between the values of the molar fluidity, capacity, polarization, and molar volume of the studied system.

The effects of NICE guidelines on the management of third molar teeth.

PubMed

McArdle, L W; Renton, T

2012-09-01

Third molar surgery (TMS) is probably one of the most commonly performed surgical procedures undertaken in the NHS. In 2000, the National Institute of Clinical Excellence (NICE) introduced guidelines relating to TMS. These recommended against the prophylactic removal of third molars and listed specific clinical indications for surgery. The impact of these guidelines has not been fully evaluated and this research hopes to focus the effect of these guidelines over the last ten years. Using data obtained from a variety of NHS databases such as HES (Eng & Wales), the NHSBSA and data from NHS Scotland, we looked at the age range of patients requiring third molar removal and the number of patients having third molars removed in both primary and secondary care environments from 1989 to 2009. In addition we looked at the clinical indications for TMS activity in secondary care. The mean age of patients increased from 25 years in 2000 to 32 years in 2010, with the modal (most common) age increasing from 26 to 29 years. After the introduction of clinical guidelines the number of patients requiring third molar removal in secondary care dropped by over 30%, however, since 2003 the number of patients has risen by 97%. There is also a significant increase in caries as an indication for third molar removal. More patients are requiring third molar removal with an increasing number of patients having caries related to their third molars. Patients are, on average, older confirming that the removal of third molars is shifting from a young adult population group to an older adult population group. NICE guidelines did appear to have contributed to a fall in the volume of third molars removed within the NHS post 2000. However, concluding that this reduction demonstrates the success of NICE's guidance would be a premature assumption. The number of patients now requiring third molar removal is comparable to that of the mid 1990s. NICE has influenced the management of patients with third molars but this has not resulted in any reduction in the number of patients requiring third molar removal. Coding and data collection for third molars is not uniform, leading to potential misrepresentation of data. This perhaps raises the issue that an improved universal coding system is required for the NHS and that the NICE guidelines need review.

Treatment planning considerations for molar uprighting.

PubMed

Kaur, Harsimrat; Pavithra, U S; Shabeer, N N; Reji, Abraham

2014-01-01

Molar uprighting cases require individualized treatment planning depending upon condition of ridge, growth pattern of patient, periodontal condition, lower facial height, position of third molar and anchorage. Uprighting of molar was done in two cases--effectively using simple tip back spring in one case and implant in another.

Sub-10-Minute Characterization of an Ultrahigh Molar Mass Polymer by Multi-detector Hydrodynamic Chromatography

USDA-ARS?s Scientific Manuscript database

Molar mass averages, distributions, and architectural information of polymers are routinely obtained using size-exclusion chromatography (SEC). It has previously been shown that ultrahigh molar mass polymers may experience degradation during SEC analysis, leading to inaccurate molar mass averages a...

40 CFR 1065.665 - THCE and NMHCE determination.

Code of Federal Regulations, 2014 CFR

2014-07-01

... non-oxygenated hydrocarbons, alcohols, and aldehydes. x NOTHC = The sum of the C1-equivalent... this into a C1-equivalent molar concentration. Add these C1-equivalent molar concentrations to the molar concentration of non-oxygenated total hydrocarbon (NOTHC). The result is the molar concentration...

The Effect of Molar Axial Wall Height on CAD/CAM Ceramic Crowns With Moderate Occlusal Convergence

DTIC Science & Technology

2006-05-01

CEREC e.max* CAD crowns on preparations with moderate total occlusal convergence (16 degrees). Methods: 60 recently-extracted maxillary third molars ...The Effect of Molar Axial Wall Height on CAD/CAM Ceramic Crowns With Moderate Occlusal Convergence Wyeth L. Hoopes The Effect of Molar Axial Wall... Molar Axial Wall Height on CAD/CAM Ceramic Crowns With Moderate Occlusal Convergence is appropria tely acknowledged and beyond brief excerpts, is with

Periodontal considerations in the use of bonds or bands on molars in adolescents and adults.

PubMed

Boyd, R L; Baumrind, S

1992-01-01

This longitudinal study compared the periodontal status of bonded and banded molars in 20 adult and 40 adolescent patients before, during and after treatment with fixed orthodontic appliances. Plaque accumulation (measured by the Plaque Index), gingival inflammation (measured by the Gingival Index and the bleeding tendency), and pocket depth were assessed by one examiner at sites along the mesio-buccal line angle of the maxillary right first molar and the mandibular left first molar. Assessments were made immediately prior to the placement of fixed appliances (pretreatment), at 1, 3, 6, 9, 12 and 18 months after appliances were placed; and 3 months after appliances were removed (posttreatment). Loss of attachment between the pretreatment and posttreatment visits also was determined. At pretreatment, no significant differences were found in gingival inflammation between maxillary and mandibular banded and bonded molars. During treatment, both maxillary and mandibular banded molars showed significantly (p less than 0.05) greater gingival inflammation and plaque accumulation than did bonded molars. Three months after appliance removal, the maxillary molars that had been banded continued to show significantly more gingival inflammation and loss of attachment than did the maxillary molars that had been bonded. When all banded and bonded teeth were grouped by patient age, mean values for plaque accumulation and gingival inflammation in the maxillary molar regions were significantly greater for adolescents than for adults.

Second molar impaction associated with lip bumper therapy

PubMed Central

Jacob, Helder Baldi; LeMert, Shawn; Alexander, Richard G.; Buschang, Peter H.

2014-01-01

INTRODUCTION: Although lip bumpers (LBs) provide significant clinical gain of mandibular arch perimeter in mixed-dentition patients, orthodontists are reluctant to use them due to the possibility of permanent second molar eruptive disturbances. OBJECTIVE: The present study was conducted to assess second molar impaction associated with the use of LBs, and to investigate how they can be solved. MATERIAL AND METHODS: Lateral and panoramic radiographs of 67 patients (34 females and 33 males) were assessed prior (T1) and post-LB treatment (T2). LB therapy lasted for approximately 1.8 ± 0.9 years. Concomitant rapid palatal expansion (RPE) was performed in the maxilla at LB treatment onset. Impaction of mandibular second molars was assessed by means of panoramic radiographs in relation to the position of first mandibular molars. Horizontal and vertical movements of first and second molars were assessed cephalometrically on lateral cephalometric radiographs based on mandibular superimpositions. RESULTS: Eight (11.9%) patients had impacted second molars at the end of LB therapy. Two patients required surgical correction, whereas five required spacers and one patient was self-corrected. Mandibular first molar tip and apex migrated forward 1.3 mm and 2.3 mm, respectively. Second molar tip showed no statistically significant horizontal movement. CONCLUSION: Although LB therapy increased the risk of second molar impaction, impactions were, in most instances, easily solved. PMID:25628086

Association between the presence of a partially erupted mandibular third molar and the existence of caries in the distal of the second molars.

PubMed

Falci, S G M; de Castro, C R; Santos, R C; de Souza Lima, L D; Ramos-Jorge, M L; Botelho, A M; Dos Santos, C R R

2012-10-01

The objective of this study was to verify, using periapical radiographs, whether a partially erupted mandibular third molar is a factor in the presence of dental caries on the distal surface of the adjacent second molar. Two-forty six high quality periapical radiographs were selected, each showing a partially erupted mandibular third molar. The variables analyzed were: tooth number; gender; age; radiographic presence of caries on the distal surface of the adjacent molar; Pell and Gregory classification; Winter classification; angulation and distance between the second and mandibular third molar. The examiners were previously calibrated to collect data (kappa statistics from 0.87 to 1.0). The prevalence rate of caries on the distal surface of the second molar was 13.4%. In the logistical multivariate regression analysis, the angulation (OR=8.5; IC95%: 1.7-43.8; p=0.011) and the gender (OR=3.3; IC95%: 1.4-7.7; p=0.005) remained statistically significant after an age adjustment was made. The results indicate that the presence of a partially erupted mandibular third molar with an angulation of 31 degrees or more, is a risk factor for caries on the distal surface of the mandibular second molars. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Mandibular Third Molar Impaction: Review of Literature and a Proposal of a Classification

PubMed Central

Daugela, Povilas

2013-01-01

ABSTRACT Objectives The purpose of present article was to review impacted mandibular third molar aetiology, clinical anatomy, radiologic examination, surgical treatment and possible complications, as well as to create new mandibular third molar impaction and extraction difficulty degree classification based on anatomical and radiologic findings and literature review results. Material and Methods Literature was selected through a search of PubMed, Embase and Cochrane electronic databases. The keywords used for search were mandibular third molar, impacted mandibular third molar, inferior alveolar nerve injury third molar, lingual nerve injury third molar. The search was restricted to English language articles, published from 1976 to April 2013. Additionally, a manual search in the major anatomy and oral surgery journals and books was performed. The publications there selected by including clinical and human anatomy studies. Results In total 75 literature sources were obtained and reviewed. Impacted mandibular third molar aetiology, clinical anatomy, radiographic examination, surgical extraction of and possible complications, classifications and risk factors were discussed. New mandibular third molar impaction and extraction difficulty degree classification based on anatomical and radiologic findings and literature review results was proposed. Conclusions The classification proposed here based on anatomical and radiological impacted mandibular third molar features is promising to be a helpful tool for impacted tooth assessment as well as for planning for surgical operation. Further clinical studies should be conducted for new classification validation and reliability evaluation. PMID:24422029

Molar-incisor-hypomineralisation (MIH). Retrospective clinical study in Greek children. I. Prevalence and defect characteristics.

PubMed

Lygidakis, N A; Dimou, G; Briseniou, E

2008-12-01

This was to evaluate the prevalence and the clinical characteristics of MIH in a group of Greek children. During the years 2003--2005, all MIH cases diagnosed according to the recently set criteria were selected from the new patients clinic of a Community Dental Centre for Children (Athens). Age, gender and teeth involved were recorded. The severity of MIH was determined collectively by dividing the affected teeth in two groups; a) mild defect (demarcated opacities) and b) moderate/severe defect (enamel breakdown and atypical restorations). Evaluation of the distribution of the affected teeth within MIH cases was performed in a separate group of 225 affected children aged 8-12 years with their entire 12 'index' teeth erupted. From the 3,518, 5.5 to 12 year old children that were examined, there were 360 (10.2%) children with MIH, 211 (58.6%) females and 149 (41.4%) males, with 1,926 affected teeth, 1,231 molars and 695 incisors. In the molars group, maxillary molars were more frequently affected (87.8/90.3%) than mandibular (81.7/82.2%). In the central incisor group, maxillary teeth were also more frequently affected (50/55%) than mandibular (24.4/25%), while laterals were the least affected. In all there were 37.9% molars with moderate/severe defects as compared with 4.9% incisors, the remaining 62.1% and 95.1% respectively being mild. The various associations between the affected teeth were evaluated in the sub-group of 225 MIH children with all 'index' teeth erupted (1,286 affected teeth, 776 molars and 510 incisors), with mean number of affected teeth per child being 5.7; separately for molars 3.4 and for incisors 2.2. In these cases 28.4% of the children had only molars affected and 71.6% had both molars and incisors. In descending order the associations of affected teeth more frequently found were: 4 molars/2 incisors (23.5%), 4 molars/4 incisors (16.8%), 4 molars alone (15.1%) and 2 molars alone (9.7%), the remaining being much less. As age increased the clinical severity of the affected teeth became more prevalent (p=0.0001), and when the total number of affected teeth was assessed the likelihood of having severe defect was also increased (p=0.001). The prevalence of the defect in the present study was 10.2% with maxillary teeth being more frequently affected. Severity increased with age. Mild defects were much more frequent, particularly in incisors. The total number of teeth affected and the most frequently found associations were, 4 molars/2 incisors, 4 molars/4 incisors, 4 molars alone and 2 molars alone.

Autotransplantation of mandibular third molar: a case report.

PubMed

Ravi Kumar, Pabbati; Jyothi, Mandava; Sirisha, Kantheti; Racca, Khushboo; Uma, Chalasani

2012-01-01

Autogenous transplantation is a feasible, fast, and economical option for the treatment of nonsalvageable teeth when a suitable donor tooth is available. This paper presents successful autotransplantation of a mature mandibular left third molar (38) without anatomical variances is used to replace a mandibular left second molar (37). The mandibular second molar was nonrestorable due to extensive root caries and resorption of distal root. After extraction of mandibular second and third molars, root canal therapy was done for the third molar extraorally, and the tooth was reimplanted into the extracted socket of second molar site. After one year, clinical and radiographic examination revealed satisfactory outcome with no signs or symptoms suggestive of pathology. In selected cases, autogenous tooth transplantation, even after complete root formation of the donor tooth, may be considered as a practical treatment alternative to conventional prosthetic rehabilitation or implant treatment.

Protraction of mandibular second and third molars into missing first molar spaces for a patient with an anterior open bite and anterior spacing.

PubMed

Baik, Un-Bong; Chun, Youn-Sic; Jung, Min-Ho; Sugawara, Junji

2012-06-01

In a young woman, aged 18 years 8 months, who had an anterior open bite and anterior spacing, the right and left mandibular first molar extraction spaces were closed by protraction of the second and third molars without reciprocal retraction of the incisors and the premolars. The amounts of protraction for the second molars were 12 mm on the right side and 11 mm on the left side. Two miniscrews were inserted into the mesiobuccal side of the edentulous spaces, and 2 more screws were inserted into the anterior sites after removing previous miniscrews. In addition, 4 miniscrews were inserted into the buccal and palatal sides between the first and second maxillary molars to intrude the maxillary posterior teeth, which had extruded into the missing mandibular spaces. Careful biomechanical consideration was used to prevent extrusion of the molars and worsening of the anterior open bite from protraction of the posterior teeth. Ultimately, the anterior open bite was corrected by both intrusion of the maxillary molars and extrusion of the maxillary anterior teeth. Excellent occlusion and correction of the anterior open bite were achieved without tipping, rotation of the posterior teeth, or other problems. The right mandibular third molar, which had been impacted at the beginning of treatment, erupted into the second molar space and functioned properly. At the 1-year follow-up examination, the patient had a slight anterior open bite, but closure of the first molar extraction spaces was well maintained. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

The effect of first and second premolar extractions on third molars: A retrospective longitudinal study.

PubMed

Miclotte, A; Grommen, B; Cadenas de Llano-Pérula, M; Verdonck, A; Jacobs, R; Willems, G

2017-06-01

To analyse the effect of first and second premolar extractions on eruption space for upper and lower third molars and on third molar position and angulation during orthodontic treatment. The sample consisted of 296 patients of which 218 patients were orthodontically treated without extraction and 78 patients with extraction of first or second premolars. The eruption space for third molars was measured on pre- and posttreatment lateral cephalograms, whereas the angulation, vertical position, the relation with the mandibular canal and the mineralization status of third molars were evaluated using pre- and posttreatment panoramic radiographs. All data were statistically analyzed. The increase in eruption space and the change in vertical position of upper and lower third molars significantly differed between patients treated with and without premolar extractions, whereas the change in angulation, relationship with the mandibular canal and mineralization status of the third molars did not significantly differ between patients treated with and without premolar extractions. The retromolar space and the position of third molars significantly change during orthodontic treatment in growing patients. Premolar extractions have a positive influence on the eruption space and vertical position of third molars, whereas they do not influence the angular changes of third molars. Due to the retrospective character of the study, these conclusions should be carefully considered. Further prospective research is necessary for better insights into this complex topic. This study stresses the importance of considering the possible effects of orthodontic treatment on third molars during treatment planning. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Oxygen from Hydrogen Peroxide. A Safe Molar Volume-Molar Mass Experiment.

ERIC Educational Resources Information Center

Bedenbaugh, John H.; And Others

1988-01-01

Describes a molar volume-molar mass experiment for use in general chemistry laboratories. Gives background technical information, procedures for the titration of aqueous hydrogen peroxide with standard potassium permanganate and catalytic decomposition of hydrogen peroxide to produce oxygen, and a discussion of the results obtained in three…

Integrin Based Isolation Enables Purification of Murine Lineage Committed Cardiomyocytes

PubMed Central

Tarnawski, Laura; Xian, Xiaojie; Monnerat, Gustavo; Macaulay, Iain C.; Malan, Daniela; Borgman, Andrew; Wu, Sean M.; Fleischmann, Bernd K.; Jovinge, Stefan

2015-01-01

In contrast to mature cardiomyocytes which have limited regenerative capacity, pluripotent stem cells represent a promising source for the generation of new cardiomyocytes. The tendency of pluripotent stem cells to form teratomas and the heterogeneity from various differentiation stages and cardiomyocyte cell sub-types, however, are major obstacles to overcome before this type of therapy could be applied in a clinical setting. Thus, the identification of extracellular markers for specific cardiomyocyte progenitors and mature subpopulations is of particular importance. The delineation of cardiomyocyte surface marker patterns not only serves as a means to derive homogeneous cell populations by FACS, but is also an essential tool to understand cardiac development. By using single-cell expression profiling in early mouse embryonic hearts, we found that a combination of integrin alpha-1, alpha-5, alpha-6 and N-cadherin enables isolation of lineage committed murine cardiomyocytes. Additionally, we were able to separate trabecular cardiomyocytes from solid ventricular myocardium and atrial murine cells. These cells exhibit expected subtype specific phenotype confirmed by electrophysiological analysis. We show that integrin expression can be used for the isolation of living, functional and lineage-specific murine cardiomyocytes. PMID:26323090

Diagnostic imaging advances in murine models of colitis.

PubMed

Brückner, Markus; Lenz, Philipp; Mücke, Marcus M; Gohar, Faekah; Willeke, Peter; Domagk, Dirk; Bettenworth, Dominik

2016-01-21

Inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis are chronic-remittent inflammatory disorders of the gastrointestinal tract still evoking challenging clinical diagnostic and therapeutic situations. Murine models of experimental colitis are a vital component of research into human IBD concerning questions of its complex pathogenesis or the evaluation of potential new drugs. To monitor the course of colitis, to the present day, classical parameters like histological tissue alterations or analysis of mucosal cytokine/chemokine expression often require euthanasia of animals. Recent advances mean revolutionary non-invasive imaging techniques for in vivo murine colitis diagnostics are increasingly available. These novel and emerging imaging techniques not only allow direct visualization of intestinal inflammation, but also enable molecular imaging and targeting of specific alterations of the inflamed murine mucosa. For the first time, in vivo imaging techniques allow for longitudinal examinations and evaluation of intra-individual therapeutic response. This review discusses the latest developments in the different fields of ultrasound, molecularly targeted contrast agent ultrasound, fluorescence endoscopy, confocal laser endomicroscopy as well as tomographic imaging with magnetic resonance imaging, computed tomography and fluorescence-mediated tomography, discussing their individual limitations and potential future diagnostic applications in the management of human patients with IBD.

Cell Internal Treatable Microplasma Jets in Cancer Therapies

NASA Astrophysics Data System (ADS)

Kim, Jae Young; Wei, Yanzhang; Li, Jinhua; Kim, Sung-O.

2011-10-01

We developed a 15- μm-sized, single-cellular-level, and cell-manipulatable microplasma jet device with a microcapillary glass tip and described its potential in physical cancer therapies. The microcapillary tip is a funnel shaped glass tube and its nozzle has an inner diameter of 15 μm and an outer diameter of 20 μm with 20 capillary angle. The electrical and optical properties of this plasma jet and apoptosis results of cultured murine B16F0 melanoma tumor cells and CL.7 fibroblast cells treated with the plasma jets were described. In spite of the small inner diameter and the low gas flow rate of the microplasma jet device, the generated plasma jets are stable enough to treat tumor cells. The microplasma jet was observed inducing apoptosis in cultured murine melanoma tumor cells in a dose-dependent manner. Furthermore, the percentage of apoptotic cells of murine melanoma tumor cells induced by this plasma device was approximately 2.5 times bigger than that of murine fibroblast cells as indicated by an Annex V-FITC method. This highly precise plasma medicine, which enables new directed cancer therapies, can be combined with current cell manipulation and cell culturing technologies without much difficulty.

Binding Affinity, Specificity and Comparative Biodistribution of the Parental Murine Monoclonal Antibody MX35 (Anti-NaPi2b) and Its Humanized Version Rebmab200

PubMed Central

Lindegren, Sture; Andrade, Luciana N. S.; Bäck, Tom; Machado, Camila Maria L.; Horta, Bruno Brasil; Buchpiguel, Carlos; Moro, Ana Maria; Okamoto, Oswaldo Keith; Jacobsson, Lars; Cederkrantz, Elin; Washiyama, Kohshin; Aneheim, Emma; Palm, Stig; Jensen, Holger; Tuma, Maria Carolina B.; Chammas, Roger; Hultborn, Ragnar; Albertsson, Per

2015-01-01

The aim of this preclinical study was to evaluate the characteristics of the monoclonal antibody Rebmab200, which is a humanized version of the ovarian-specific murine antibody MX35. This investigation contributes to the foundation for future clinical α-radioimmunotherapy of minimal residual ovarian cancer with 211At-Rebmab200. Here, the biodistribution of 211At-Rebmab200 was evaluated, as was the utility of 99mTc-Rebmab200 for bioimaging. Rebmab200 was directly compared with its murine counterpart MX35 in terms of its in-vitro capacity for binding the immobilized NaPi2B epitope and live cells; we also assessed its biodistribution in nude mice carrying subcutaneous OVCAR-3 tumors. Tumor antigen and cell binding were similar between Rebmab200 and murine MX35, as was biodistribution, including normal tissue uptake and in-vivo tumor binding. We also demonstrated that 99mTc-Rebmab200 can be used for single-photon emission computed tomography of subcutaneous ovarian carcinomas in tumor-bearing mice. Taken together, our data support the further development of Rebmab200 for radioimmunotherapy and diagnostics. PMID:25970341

Binding Affinity, Specificity and Comparative Biodistribution of the Parental Murine Monoclonal Antibody MX35 (Anti-NaPi2b) and Its Humanized Version Rebmab200.

PubMed

Lindegren, Sture; Andrade, Luciana N S; Bäck, Tom; Machado, Camila Maria L; Horta, Bruno Brasil; Buchpiguel, Carlos; Moro, Ana Maria; Okamoto, Oswaldo Keith; Jacobsson, Lars; Cederkrantz, Elin; Washiyama, Kohshin; Aneheim, Emma; Palm, Stig; Jensen, Holger; Tuma, Maria Carolina B; Chammas, Roger; Hultborn, Ragnar; Albertsson, Per

2015-01-01

The aim of this preclinical study was to evaluate the characteristics of the monoclonal antibody Rebmab200, which is a humanized version of the ovarian-specific murine antibody MX35. This investigation contributes to the foundation for future clinical α-radioimmunotherapy of minimal residual ovarian cancer with 211At-Rebmab200. Here, the biodistribution of 211At-Rebmab200 was evaluated, as was the utility of 99mTc-Rebmab200 for bioimaging. Rebmab200 was directly compared with its murine counterpart MX35 in terms of its in-vitro capacity for binding the immobilized NaPi2B epitope and live cells; we also assessed its biodistribution in nude mice carrying subcutaneous OVCAR-3 tumors. Tumor antigen and cell binding were similar between Rebmab200 and murine MX35, as was biodistribution, including normal tissue uptake and in-vivo tumor binding. We also demonstrated that 99mTc-Rebmab200 can be used for single-photon emission computed tomography of subcutaneous ovarian carcinomas in tumor-bearing mice. Taken together, our data support the further development of Rebmab200 for radioimmunotherapy and diagnostics.

Expression of genes involved in early cell fate decisions in human embryos and their regulation by growth factors.

PubMed

Kimber, S J; Sneddon, S F; Bloor, D J; El-Bareg, A M; Hawkhead, J A; Metcalfe, A D; Houghton, F D; Leese, H J; Rutherford, A; Lieberman, B A; Brison, D R

2008-05-01

Little is understood about the regulation of gene expression in human preimplantation embryos. We set out to examine the expression in human preimplantation embryos of a number of genes known to be critical for early development of the murine embryo. The expression profile of these genes was analysed throughout preimplantation development and in response to growth factor (GF) stimulation. Developmental expression of a number of genes was similar to that seen in murine embryos (OCT3B/4, CDX2, NANOG). However, GATA6 is expressed throughout preimplantation development in the human. Embryos were cultured in IGF-I, leukaemia inhibitory factor (LIF) or heparin-binding EGF-like growth factor (HBEGF), all of which are known to stimulate the development of human embryos. Our data show that culture in HBEGF and LIF appears to facilitate human embryo expression of a number of genes: ERBB4 (LIF) and LIFR and DSC2 (HBEGF) while in the presence of HBEGF no blastocysts expressed EOMES and when cultured with LIF only two out of nine blastocysts expressed TBN. These data improve our knowledge of the similarities between human and murine embryos and the influence of GFs on human embryo gene expression. Results from this study will improve the understanding of cell fate decisions in early human embryos, which has important implications for both IVF treatment and the derivation of human embryonic stem cells.

Cell source determines the immunological impact of biomimetic nanoparticles.

PubMed

Evangelopoulos, Michael; Parodi, Alessandro; Martinez, Jonathan O; Yazdi, Iman K; Cevenini, Armando; van de Ven, Anne L; Quattrocchi, Nicoletta; Boada, Christian; Taghipour, Nima; Corbo, Claudia; Brown, Brandon S; Scaria, Shilpa; Liu, Xuewu; Ferrari, Mauro; Tasciotti, Ennio

2016-03-01

Recently, engineering the surface of nanotherapeutics with biologics to provide them with superior biocompatibility and targeting towards pathological tissues has gained significant popularity. Although the functionalization of drug delivery vectors with cellular materials has been shown to provide synthetic particles with unique biological properties, these approaches may have undesirable immunological repercussions upon systemic administration. Herein, we comparatively analyzed unmodified multistage nanovectors and particles functionalized with murine and human leukocyte cellular membrane, dubbed Leukolike Vectors (LLV), and the immunological effects that may arise in vitro and in vivo. Previously, LLV demonstrated an avoidance of opsonization and phagocytosis, in addition to superior targeting of inflammation and prolonged circulation. In this work, we performed a comprehensive evaluation of the importance of the source of cellular membrane in increasing their systemic tolerance and minimizing an inflammatory response. Time-lapse microscopy revealed LLV developed using a cellular coating derived from a murine (i.e., syngeneic) source resulted in an active avoidance of uptake by macrophage cells. Additionally, LLV composed of a murine membrane were found to have decreased uptake in the liver with no significant effect on hepatic function. As biomimicry continues to develop, this work demonstrates the necessity to consider the source of biological material in the development of future drug delivery carriers. Copyright © 2015. Published by Elsevier Ltd.

p38 mitogen-activated protein kinase (MAPK) first regulates filamentous actin at the 8-16-cell stage during preimplantation development.

PubMed

Paliga, Andrew J M; Natale, David R; Watson, Andrew J

2005-08-01

The MAPK (mitogen-activated protein kinase) superfamily of proteins consists of four separate signalling cascades: the c-Jun N-terminal kinase or stress-activated protein kinases (JNK/SAPK); the ERKs (extracellular-signal-regulated kinases); the ERK5 or big MAPK1; and the p38 MAPK group of protein kinases, all of which are highly conserved. To date, our studies have focused on defining the role of the p38 MAPK pathway during preimplantation development. p38 MAPK regulates actin filament formation through the downstream kinases MAPKAPK2/3 (MAPK-activated protein kinase 2/3) or MAPKAPK5 [PRAK (p38 regulated/activated kinase)] and subsequently through HSP25/27 (heat-shock protein 25/27). We recently reported that 2-cell-stage murine embryos treated with cytokine-suppressive anti-inflammatory drugs (CSAIDtrade mark; SB203580 and SB220025) display a reversible blockade of development at the 8-16-cell stage, indicating that p38 (MAPK) activity is required to complete murine preimplantation development. In the present study, we have investigated the stage-specific action and role of p38 MAPK in regulating filamentous actin during murine preimplantation development. Treatment of 8-cell-stage embryos with SB203580 and SB220025 (CSAIDtrade mark) resulted in a blockade of preimplantation development, loss of rhodamine phalloidin fluorescence, MK-p (phosphorylated MAPKAPK2/3), HSP-p (phosphorylated HSP25/27) and a redistribution of alpha-catenin immunofluorescence by 12 h of treatment. In contrast, treatment of 2- and 4-cell-stage embryos with CSAIDtrade mark drugs resulted in a loss of MK-p and HSP-p, but did not result in a loss of rhodamine phalloidin fluorescence. All these effects of p38 MAPK inhibition were reversed upon removal of the inhibitor, and development resumed in a delayed but normal manner to the blastocyst stage. Treatment of 8-cell embryos with PD098059 (ERK pathway inhibitor) did not affect development or fluorescence of MK-p, HSP-p or rhodamine phalloidin. Murine preimplantation development becomes dependent on p38 MAPK at the 8-16-cell stage, which corresponds to the stage when p38 MAPK first regulates filamentous actin during early development.

The Adult Livers of Immunodeficient Mice Support Human Hematopoiesis: Evidence for a Hepatic Mast Cell Population that Develops Early in Human Ontogeny

PubMed Central

Muench, Marcus O.; Beyer, Ashley I.; Fomin, Marina E.; Thakker, Rahul; Mulvaney, Usha S.; Nakamura, Masato; Suemizu, Hiroshi; Bárcena, Alicia

2014-01-01

The liver plays a vital role in hematopoiesis during mammalian prenatal development but its hematopoietic output declines during the perinatal period. Nonetheless, hepatic hematopoiesis is believed to persist into adulthood. We sought to model human adult-liver hematopoiesis by transplantation of fetal and neonatal hematopoietic stem cells (HSCs) into adult immunodeficient mice. Livers were found to be engrafted with human cells consisting primarily of monocytes and B-cells with lesser contributions by erythrocytes, T-cells, NK-cells and mast-cells. A resident population of CD117++CD203c+ mast cells was also documented in human midgestation liver, indicating that these cells comprise part of the liver's resident immune cell repertoire throughout human ontogeny. The murine liver was shown to support human multilineage hematopoiesis up to 321 days after transplant. Evidence of murine hepatic hematopoiesis was also found in common mouse strains as old as 2 years. Human HSC engraftment of the murine liver was demonstrated by detection of high proliferative-potential colony-forming cells in clonal cultures, observation of CD38−CD34++ and CD133+CD34++ cells by flow cytometry, and hematopoietic reconstitution of secondary transplant recipients of chimeric liver cells. Additionally, chimeric mice with both hematopoietic and endothelial reconstitution were generated by intrasplenic injection of immunodeficient mice with liver specific expression of the urokinase-type plasminogen activator (uPA) transgene. In conclusion, the murine liver is shown to be a hematopoietic organ throughout adult life that can also support human hematopoiesis in severely immunodeficient strains. Further humanization of the murine liver can be achieved in mice harboring an uPA transgene, which support engraftment of non-hematopoietic cells types. Thus, offering a model system to study the interaction of diverse human liver cell types that regulate hematopoiesis and immune function in the liver. PMID:24819392

Orthodontic uprighting of a horizontally impacted third molar and protraction of mandibular second and third molars into the missing first molar space for a patient with posterior crossbites.

PubMed

Baik, Un-Bong; Kim, Myung-Rae; Yoon, Kyu-Ho; Kook, Yoon-Ah; Park, Jae Hyun

2017-03-01

A 22-year-old woman came with a unilateral missing mandibular first molar and buccal crossbite. The open space was closed by protraction of the mandibular left second molar and uprighting and protraction of the horizontally impacted third molar using temporary skeletal anchorage devices, and her buccal crossbite was corrected with modified palatal and lingual appliances. The total active treatment time was 36 months. Posttreatment records after 9 months showed excellent results with a stable occlusion. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

A role of NF-E2 in chronic inflammation and clonal evolution in essential thrombocythemia, polycythemia vera and myelofibrosis?

PubMed

Hasselbalch, Hans C

2014-02-01

A novel murine model for myeloproliferative neoplasms (MPNs) generated by overexpression of the transcription factor NF-E2 has recently been described. Sustained overexpression of NF-E2 in this model induced myeloid expansion with anemia, leukocytosis and thrombocytosis. Herein, it is debated if NF-E2 overexpression also might have induced a sustained state of in vivo leukocyte and platelet activation with chronic and self-perpetuating production of inflammatory products from activated leukocytes and platelets. If so, this novel murine model also may excellently describe the deleterious impact of sustained chronic NF-E2 overexpression during uncontrolled chronic inflammation upon the hematopoietic system--the development of clonal myeloproliferation. Accordingly, this novel murine model may also have delivered the proof of concept of chronic inflammation as a trigger and driver of clonal evolution in MPNs. Copyright © 2013 Elsevier Ltd. All rights reserved.

A simple way to intrude overerupted upper second molars with miniscrews.

PubMed

Cao, Yang; Liu, Chufeng; Wang, Chunxian; Yang, Xiaoyu; Duan, Peijia; Xu, Chenrong

2013-12-01

Various methods of using skeletal anchorage for the intrusion of overerupted maxillary molars have been reported; however, it is difficult to intrude the overerupted upper second molars because of the low bone density in the region of the tuberosity. This article illustrates a new treatment method using partial fixed edgewise appliances and miniscrews to intrude the overerupted upper second molars. The miniscrews were applied to reinforce the anchorage of the upper first molar. The intrusive force was generated by the Ni-Ti wire. The clinical results showed a significant intrusion effect without root resorption or periodontal problems. This report demonstrates that the combination of partial conventional fixed appliances with miniscrews is a simple and effective treatment option to intrude overerupted upper second molars, especially in situations where miniscrews cannot be inserted directly next to the second molar. © 2013 by the American College of Prosthodontists.

Characterization of cellulose acetates according to DS and molar mass using two-dimensional chromatography.

PubMed

Ghareeb, Hewa Othman; Radke, Wolfgang

2013-11-06

A two-dimensional liquid chromatographic method (2D LC) was developed to analyze the heterogeneities of cellulose acetates (CA) in the DS-range DS=1.5-2.9 with respect to both, molar mass and degree of substitution (DS). The method uses gradient liquid chromatography (HPLC) as the first dimension in order to separate by DS followed by separation of the different fractions by size (SEC) in the second dimension. The 2D experiments revealed different correlations between gradient and SEC elution volume. These correlations might arise from differences in the synthetic conditions. The newly developed 2D LC separation therefore provides new insights into the heterogeneity of CAs. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Model for Evaluating Topical Antimicrobial Efficacy against Methicillin-Resistant Staphylococcus aureus Biofilms in Superficial Murine Wounds

PubMed Central

Renick, Paul J.; Tetens, Shannon P.; Carson, Dennis L.

2012-01-01

A wound biofilm model was created by adapting a superficial infection model. Partial-thickness murine wounds were inoculated with methicillin-resistant Staphylococcus aureus (MRSA). Dense biofilm communities developed at the wound surface after 24 h as demonstrated by microscopy and quantitative microbiology. Common topical antimicrobial agents had reduced efficacy when treatment was initiated 24 h after inoculation compared to 4 h after inoculation. This model provides a rapid in vivo test for new agents to treat wound biofilm infections. PMID:22644024

The Aminopeptidase Inhibitor CHR-2863 Is an Orally Bioavailable Inhibitor of Murine Malaria

PubMed Central

Skinner-Adams, Tina S.; Peatey, Christopher L.; Anderson, Karen; Trenholme, Katharine R.; Krige, David; Brown, Christopher L.; Stack, Colin; Nsangou, Desire M. M.; Mathews, Rency T.; Thivierge, Karine; Dalton, John P.

2012-01-01

Malaria remains a significant risk in many areas of the world, with resistance to the current antimalarial pharmacopeia an ever-increasing problem. The M1 alanine aminopeptidase (PfM1AAP) and M17 leucine aminopeptidase (PfM17LAP) are believed to play a role in the terminal stages of digestion of host hemoglobin and thereby generate a pool of free amino acids that are essential for parasite growth and development. Here, we show that an orally bioavailable aminopeptidase inhibitor, CHR-2863, is efficacious against murine malaria. PMID:22450967

Absorption of nickel, chromium, and iron by the root surface of primary molars covered with stainless steel crowns.

PubMed

Keinan, David; Mass, Eliyahu; Zilberman, Uri

2010-01-01

Objective. The purpose of this study was to analyze the absorption of metal ions released from stainless steel crowns by root surface of primary molars. Study Design. Laboratory research: The study included 34 primary molars, exfoliated or extracted during routine dental treatment. 17 molars were covered with stainless-steel crowns for more than two years and compared to 17 intact primary molars. Chemical content of the mesial or distal root surface, 1 mm apically to the crown or the cemento-enamel junction (CEJ), was analyzed. An energy dispersive X-ray spectrometer (EDS) was used for chemical analysis. Results. Higher amounts of nickel, chromium, and iron (5-6 times) were found in the cementum of molars covered with stainless-steel crowns compared to intact molars. The differences between groups were highly significant (P < .001). Significance. Stainless-steel crowns release nickel, chromium, and iron in oral environment, and the ions are absorbed by the primary molars roots. The additional burden of allergenic metals should be reduced if possible.

Morphometric variation of extant platyrrhine molars: taxonomic implications for fossil platyrrhines

PubMed Central

Nova Delgado, Mónica; Galbany, Jordi

2016-01-01

The phylogenetic position of many fossil platyrrhines with respect to extant ones is not yet clear. Two main hypotheses have been proposed: the layered or successive radiations hypothesis suggests that Patagonian fossils are Middle Miocene stem platyrrhines lacking modern descendants, whereas the long lineage hypothesis argues for an evolutionary continuity of all fossil platyrrhines with the extant ones. Our geometric morphometric analysis of a 15 landmark-based configuration of platyrrhines’ first and second lower molars suggest that morphological stasis may explain the reduced molar shape variation observed. Platyrrhine lower molar shape might be a primitive retention of the ancestral state affected by strong ecological constraints throughout the radiation of the main platyrrhine families. The Patagonian fossil specimens showed two distinct morphological patterns of lower molars, Callicebus—like and Saguinus—like, which might be the precursors of the extant forms, whereas the Middle Miocene specimens, though showing morphological resemblances with the Patagonian fossils, also displayed new, derived molar patterns, Alouatta—like and Pitheciinae—like, thereby suggesting that despite the overall morphological stasis of molars, phenotypic diversification of molar shape was already settled during the Middle Miocene. PMID:27190704

Racemized and Isomerized Proteins in Aging Rat Teeth and Eye Lens

PubMed Central

Warmack, Rebeccah A.; Mansilla, Eduardo; Goya, Rodolfo G.

2016-01-01

Abstract The quantification of aspartic acid racemization in the proteins of nonmetabolically active tissues can be used as a measure of chronological aging in humans and other long-lived organisms. However, very few studies have been conducted in shorter-lived animals such as rodents, which are increasingly used as genetic and metabolic models of aging. An initial study had reported significant changes in the ratio of d- to l-aspartate in rat molars with age. Using a sensitive HPLC method for the determination of d- and l-aspartate from protein hydrolysates, we found no accumulation of d-aspartate in the molars of 17 rats that ranged in age from 2 to 44 months, and the amount of d-aspartate per molar did not correspond with molar eruption date as had been previously reported. However, developing an alternate approach, we found significant accumulation of isomerized aspartyl residues in eye lens proteins that are also formed by spontaneous degradation processes. In this study, we used the human protein l-isoaspartate/d-aspartate O-methyltransferase (PCMT1) as an analytical reagent in a sensitive and convenient procedure that could be used to rapidly examine multiple samples simultaneously. We found levels of isomerized aspartyl residues to be about 35 times higher in the lens extracts of 18-month-old rats versus 2-month-old rats, suggesting that isomerization may be an effective marker for biological aging in this range of ages. Importantly, we found that the accumulation appeared to plateau in rats of 18 months and older, indicating that potentially novel mechanisms for removing altered proteins may develop with age. PMID:26650547

Radiographic assessment of lower third molar eruption in different anteroposterior skeletal patterns and age-related groups.

PubMed

Jakovljevic, Aleksandar; Lazic, Emira; Soldatovic, Ivan; Nedeljkovic, Nenad; Andric, Miroslav

2015-07-01

To analyze radiographic predictors for lower third molar eruption among subjects with different anteroposterior skeletal relations and of different age groups. In total, 300 lower third molars were recorded on diagnostic digital orthopantomograms (DPTs) and lateral cephalograms (LCs). The radiographs were grouped according to sagittal intermaxillary angle (ANB), subject age, and level of lower third molar eruption. The DPT was used to analyze retromolar space, mesiodistal crown width, space/width ratio, third and second molar angulation (α, γ), third molar inclination (β), and gonion angle. The LC was used to determine ANB, angles of maxillar and mandibular prognathism (SNA, SNB), mandibular plane angle (SN/MP), and mandibular lengths. A logistic regression model was created using the statistically significant predictors. The logistic regression analysis revealed a statistically significant impact of β angle and distance between gonion and gnathion (Go-Gn) on the level of lower third molar eruption (P < .001 and P < .015, respectively). The retromolar space was significantly increased in the adult subgroup for all skeletal classes. The lower third molar impaction rate was significantly higher in the adult subgroup with the Class II (62.3%) compared with Class III subjects (31.7%; P < .013). The most favorable values of linear and angular predictors of mandibular third molar eruption were measured in Class III subjects. For valid estimation of mandibular third molar eruption, certain linear and angular measures (β angle, Go-Gn), as well as the size of the retromolar space, need to be considered.

Cone-beam computed tomography as advanced diagnostic aid in endodontic treatment of molars with multiple canals: Two case reports

PubMed Central

Kamble, Amit Pralhad; Pawar, Rohini Rangarao; Mattigatti, Sudha; Mangala, T. M.; Makandar, Saleem

2017-01-01

The purpose of these case reports is to emphasize the importance of knowledge regarding the root canal morphology and current diagnostic aids one should have as both of these important factors going to affect the prognosis of the endodontic treatment. These two case reports describe the maxillary and mandibular first molars with multiple canals. After clinical and radiographic diagnosis, additional help of cone-beam computed tomography (CBCT) of mandibular molar has been taken to evaluate the morphology and canal pattern; while maxillary molar was evaluated using CBCT scan to evaluate the canal configuration and obturation. In CBCT evaluation, the mandibular molar was diagnosed with six separated canals with three mesial and three distal canals and with radix paramolaris and radix entomolaris. The maxillary molar had five canals with three mesiobuccal (MB) canals. Both molars were instrumented with conventional hand and rotary file systems and obturated by conventional lateral compaction method. The axial images from CBCT show Vertucci Type VIII canal pattern in both roots of first mandibular molars and in MB root of maxillary first molar Sert and Bayirli Type XVIII canal configuration and no accessory canal in distobuccal and palatal root. With the recent innovations in diagnostic and operating aids, we can come across many variations in the root canal morphology of both mandibular and maxillary teeth, especially multi-rooted one (i.e., molars), and the knowledge of which leads to successful endodontic treatment with an excellent prognosis. PMID:29259367

Dietary Inference from Upper and Lower Molar Morphology in Platyrrhine Primates

PubMed Central

Allen, Kari L.; Cooke, Siobhán B.; Gonzales, Lauren A.; Kay, Richard F.

2015-01-01

The correlation between diet and dental topography is of importance to paleontologists seeking to diagnose ecological adaptations in extinct taxa. Although the subject is well represented in the literature, few studies directly compare methods or evaluate dietary signals conveyed by both upper and lower molars. Here, we address this gap in our knowledge by comparing the efficacy of three measures of functional morphology for classifying an ecologically diverse sample of thirteen medium- to large-bodied platyrrhines by diet category (e.g., folivore, frugivore, hard object feeder). We used Shearing Quotient (SQ), an index derived from linear measurements of molar cutting edges and two indices of crown surface topography, Occlusal Relief (OR) and Relief Index (RFI). Using SQ, OR, and RFI, individuals were then classified by dietary category using Discriminate Function Analysis. Both upper and lower molar variables produce high classification rates in assigning individuals to diet categories, but lower molars are consistently more successful. SQs yield the highest classification rates. RFI and OR generally perform above chance. Upper molar RFI has a success rate below the level of chance. Adding molar length enhances the discriminatory power for all variables. We conclude that upper molar SQs are useful for dietary reconstruction, especially when combined with body size information. Additionally, we find that among our sample of platyrrhines, SQ remains the strongest predictor of diet, while RFI is less useful at signaling dietary differences in absence of body size information. The study demonstrates new ways for inferring the diets of extinct platyrrhine primates when both upper and lower molars are available, or, for taxa known only from upper molars. The techniques are useful in reconstructing diet in stem representatives of anthropoid clade, who share key aspects of molar morphology with extant platyrrhines. PMID:25738266

Rapid Palatal Expansion in the absence of posterior cross-bite to intercept maxillary incisor crowding in the mixed dentition: a CBCT evaluation of spontaneous changes of untouched permanent molars.

PubMed

Rosa, M; Lucchi, P; Manti, G; Caprioglio, A

2016-12-01

The aim of this study was to investigate the reaction of untouched permanent molars following RPE, anchored on deciduous teeth in the early mixed dentition, aimed to solve maxillary anterior crowding in the absence of posterior cross-bite. A prospective clinical trial comprised 35 consecutive patients (20 males and 15 females) treated by the same orthodontist (MR). All patients showed crowding of the upper permanent incisors in the early mixed dentition in the absence of posterior cross-bite. RPE was anchored on second deciduous molars and on the deciduous canines. CBCT was taken before and after the removal of the RPE appliance. The transverse linear changes in width and the variation in the torque of the permanent molars were measured in the coronal plane. Relief of incisor crowding was found in all patients. The transverse width between permanent molars increased significantly. The apices of the upper permanent molars spontaneously expanded more than the crowns, while the opposite happened on the lower permanent molars. Moreover, the untouched upper permanent molars spontaneously uprighted palatally, while the lower permanent molars spontaneously uprighted buccally. The variation in the torque of the permanent molars mirrored transverse normal growth. In the early mixed dentition and in the absence of posterior cross-bite, it is possible to expand transversally the palate while uprighting the upper permanent molars in the opposite direction. RPE anchored on the deciduous teeth in the early mixed dentition, in the absence of posterior cross-bite, provides an "anticipation of transverse growth" and could be indicated to expand the anterior portion of the maxillary arch perimeter to solve upper incisor crowding.

Root and Canal Morphology of Mandibular Molars in a Selected Iranian Population Using Cone-Beam Computed Tomography

PubMed Central

Madani, Zahra Sadat; Mehraban, Nika; Moudi, Ehsan; Bijani, Ali

2017-01-01

Introduction: The aim of this study was to evaluate the root canal morphology of mandibular first and second molars using cone-beam computed tomography (CBCT) in northern Iranian population and also to indicate the thinnest area around root canals. Methods and Materials: We evaluated CBCT images of 154 first molars and 147 second molars. By evaluating three axial, sagittal and coronal planes of each tooth we determined the number of root canals, prevalence of C-shaped Melton types, and prevalence of Vertucci configuration and inter orifice distance. Also the minimum wall thickness of root canals was determined by measuring buccal, lingual, distal and mesial wall thicknesses of each canal in levels with 2 mm intervals from apex to orifice. Results: Amongst 154 first mandibular molars, 149 (96.7%) had two roots, 3 (1.9%) had three roots and 2 (1.2%) had C-shaped root configuration. Of 147 second mandibular molars, 120 (81.6%) had two roots, 1 (0.6%) had three roots and 26 (17.6%) had C-shaped roots. There was no significant difference in the prevalence of Vertucci’s type between two genders. The most common configuration in mesial roots of first and second molars were type IV (57%-42.9%) and type II (31.5%-28%). Mesial and distal walls had the most frequency as the thinnest wall in all levels of root canals with mostly less than 1 mm thickness. In second molars the DB-DL inter orifice distance and in first molars the MB-ML distance were the minimum. MB-D in first molars had the maximum distance while ML-DL, MB-DB and ML-D had the same and maximum distance in second molars. Conclusion: Vertucci’s type IV and type I were the most prevalent configurations in mesial and distal roots of first and second mandibular molars and the thickness of thinnest area around the canals should be considered during endodontic treatments. PMID:28512476

Radiographic signs of pathology determining removal of an impacted mandibular third molar assessed in a panoramic image or CBCT

PubMed Central

Schropp, Lars; Spin-Neto, Rubens; Wenzel, Ann

2017-01-01

Objectives: To (1) compare pathological findings related to the mandibular third molar in panoramic images (PAN) and CBCT; (2) estimate the frequency of removals if pathological findings were indicative; and (3) assess factors in PAN associated with resorption and marginal bone loss at the second molar as observed in CBCT. Methods: 379 mandibular third molars were examined with PAN and CBCT. Four observers registered resorption and marginal bone loss at the second molar and increased periodontal space at the third molar in both imaging modalities. Agreement between PAN and CBCT, frequency of removals based on pathological findings in either of the two modalities and interobserver reproducibility was calculated. Logistic regression analyses assessed factors in PAN, which could predict marginal bone loss and resorption observed in CBCT. Results: Agreement between PAN and CBCT: resorption 54–74%; marginal bone loss 66–85%; and increased periodontal space 92–97%. Removals based on CBCT and PAN: 58–71% and 36–65%. Interobserver percentage accordance and kappa values ranged from 57 to 98% and 0.10–0.91 for PAN and 61–97% and 0.22–0.78 for CBCT, respectively. Mesioangulated/horizontally positioned third molars were associated with marginal bone loss [odds ratio (OR) = 7.0–31.3; p < 0.001] and resorption (OR = 2.9–35.6; p < 0.001) in CBCT. Overprojection between the third and the second molars in PAN predicted resorption observed in CBCT (OR = 5.6–21.2; p < 0.001). Conclusions: Pathology associated with the third molar is more often observed in CBCT than in PAN. More third molars would be removed if pathological findings are based on CBCT. Mesioangulated/horizontally positioned third molars overprojecting the cervical/root part of the second molar in PAN are strongly associated with pathology observed in CBCT. PMID:27681861

Effectiveness of a personalized device in the evaluation of mandibular second molar periodontal healing after surgical extraction of adjacent third molar

PubMed Central

Pippi, Roberto

2013-01-01

Summary Aim The primary aim of the present study was to validate the effectiveness of a personalized device able to guide periodontal probing in evaluation of second molar periodontal healing after adjacent third molar surgical extraction. Secondarily, the study analyzed if any patient and tooth related factors affected the second molar periodontal healing as well as if they were able to affect the periodontal probing depth performed with or without the personalized device. Materials and methods Thirty-five lower second molars were evaluated after extraction of the adjacent third molar. Pre-operative as well as 3 and 12 month post-operative probing depths of the distal surface of the second molar were evaluated. All measurements were taken by two different methods: standard two-point and four-point probing using a personalized onlay-type guide. Periapical radiographs were also evaluated. The Pearson product moment and the general linear model with backward stepwise procedure were used for inferential statistics. Results The mean 12-month post-operative probing depth/mean pre-operative probing depth ratio obtained with the guided probing method showed a highly significant effect on the 12-month radiographic post-operative/pre-operative radiographic measure ratio. None of the examined patient- or tooth-related factors showed a significant effect on pre-operative/12-month post-operative radiographic measure ratio. Conclusions The use of the proposed personalized device seems to provide a more reliable estimate of second molar periodontal healing after adjacent third molar surgical extraction. No patient-or tooth-related factors seem to be able to affect either second molar periodontal healing or probing depth measures obtained with or without the personalized device in individuals younger than 25 years old. It can be therefore recommended that lower third molar surgical extraction be performed in young adults. PMID:24611086

Effect of removing an impacted mandibular third molar on the periodontal status of the mandibular second molar.

PubMed

Montero, Javier; Mazzaglia, Giuseppe

2011-11-01

The aim of this study was to evaluate the change in the periodontal status of mandibular second molars after surgical extraction of adjacent impacted lower third molars. The study was based on a 1-year follow-up of 48 patients (20 men and 28 women) recruited consecutively after the extraction of an impacted lower third molar. Panoramic radiographs were obtained and clinical examinations were carried out at baseline to determine the periodontal status (probing depth and dental plaque and gingival indices) both for the second molar and for the 4 posterior sextants. After surgical removal of the impacted mandibular third molars, all patients were assessed at 3, 6, 9, and 12 months for changes in periodontal status. The periodontal health of the second molar was found to improve gradually after third molar surgery in all clinical parameters. Probing depth was gradually reduced by about 0.6 mm quarterly, until a final depth of 2.6 ± 0.8 mm was attained. The relative risk of having a plaque index and gingival index coded as 0 (healthy) or 1 (minor problems) was about 10 times higher at the end of the follow-up than at baseline for both indices. The periodontal status of the 4 posterior sextants also improved gradually. Molar depth, according to the Pell and Gregory classes and types, seemed to be the main factor modulating both the baseline probing depth and the change in probing depth during follow-up. Our results suggest that the initial periodontal breakdown established on the distal surfaces of the second molars and in the periodontal health of the 4 posterior sextants can be significantly improved 1 year after surgical removal of the ipsilateral lower third molar. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Radiographic signs of pathology determining removal of an impacted mandibular third molar assessed in a panoramic image or CBCT.

PubMed

Matzen, Louise H; Schropp, Lars; Spin-Neto, Rubens; Wenzel, Ann

2017-01-01

To (1) compare pathological findings related to the mandibular third molar in panoramic images (PAN) and CBCT; (2) estimate the frequency of removals if pathological findings were indicative; and (3) assess factors in PAN associated with resorption and marginal bone loss at the second molar as observed in CBCT. 379 mandibular third molars were examined with PAN and CBCT. Four observers registered resorption and marginal bone loss at the second molar and increased periodontal space at the third molar in both imaging modalities. Agreement between PAN and CBCT, frequency of removals based on pathological findings in either of the two modalities and interobserver reproducibility was calculated. Logistic regression analyses assessed factors in PAN, which could predict marginal bone loss and resorption observed in CBCT. Agreement between PAN and CBCT: resorption 54-74%; marginal bone loss 66-85%; and increased periodontal space 92-97%. Removals based on CBCT and PAN: 58-71% and 36-65%. Interobserver percentage accordance and kappa values ranged from 57 to 98% and 0.10-0.91 for PAN and 61-97% and 0.22-0.78 for CBCT, respectively. Mesioangulated/horizontally positioned third molars were associated with marginal bone loss [odds ratio (OR) = 7.0-31.3; p < 0.001] and resorption (OR = 2.9-35.6; p < 0.001) in CBCT. Overprojection between the third and the second molars in PAN predicted resorption observed in CBCT (OR = 5.6-21.2; p < 0.001). Pathology associated with the third molar is more often observed in CBCT than in PAN. More third molars would be removed if pathological findings are based on CBCT. Mesioangulated/horizontally positioned third molars overprojecting the cervical/root part of the second molar in PAN are strongly associated with pathology observed in CBCT.

The influence of third molars in the line of mandibular angle fractures on wound and bone healing.

PubMed

Ulbrich, N; Ettl, T; Waiss, W; Gosau, M; Moralis, A; Reichert, T E; Mueller, S

2016-07-01

The objective of this study was to evaluate postoperative complications after removal or retention of the third molar in the line of mandibular angle fractures. This retrospective study included the data of 98 patients with a molar in the line of a mandibular angle fracture treated with internal reduction and mini-plate fixation at our department over 9 years. Patients were classified into two groups: tooth removal during osteosynthesis (n = 45) and tooth retention (n = 55). The primary target criterion was the incidence of minor (outpatient treatment, local measures) and major (surgical revision, rehospitalisation) complications. Time between trauma and surgery was 1.4 days (range 0 to 12), and the average follow-up 291 days (range 66 to 863). Regarding the eruption status, 26 of 52 (50.0 %) impacted third molars, 11 of 19 (57.9 %) incompletely erupted and 8 of 27 (29.6 %) completely erupted molars had been removed during open reduction. Overall, 17 (17.3 %) patients had postoperative minor (n = 7) or major (n = 10) complications, in detail 10/45 (22.0 %) patients after tooth removal and 7/55 (13 %) patients after tooth retention (p = 0.286). Complication rates between impacted and incompletely erupted third molars (impacted molars 15.0 %, incompletely erupted molars 10.0 %) did not differ significantly, but completely erupted molars had a complication rate of 26.0 %. Mandibular angle fractures with a completely erupted third molar show the highest complication rate after open reduction and osteosynthesis. Retention of a non-infectious third molar facilitates open reduction and does not increase the complication risk. The study helps with the decision of removing or retention of a third molar during surgical treatment of a mandibular angle fracture.

Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods.

PubMed

Bolla, Eugenio; Muratore, Filippo; Carano, Aldo; Bowman, S Jay

2002-10-01

Maxillary molar distalization is an increasingly popular option for the resolution of Class II malocclusions. This communication describes the effects of one particular molar distalizing appliance, the distal jet, in a sample of 20 consecutively treated and growing subjects (11 females, nine males; mean starting age of 13) and compares these effects with those of similar devices. Pre- and postdistalization cephalometric radiographs and dental models were analyzed to determine the dental and skeletal effects. The distal jet appliances were constructed using a biomechanical couple to direct the distalizing force to the level of the maxillary first molar's center of resistance. The distal jet was the only appliance used during the distalization phase of treatment. Examination of the cephalometric tracings demonstrated that the crowns of the maxillary first molars were distalized an average of 3.2 mm into a Class I molar relationship. In the process, the first molars were tipped distally an average of 3.1 degrees, however, the amount of tipping in each case was influenced by the state of eruption of the second molar. In subjects whose second molars had erupted only to the level of the apical third of the first molar roots, distal tipping was almost twice that seen when the second molar had completed their eruption. Anchorage loss measured at the first premolars averaged 1.3 mm, but the crowns tipped 3.1 degrees distally because of the design of the appliance. The maxillary incisors were proclined an average of 0.6 degrees with minimal effect on the mandibular plane angle and lower facial height. This study suggests that the distal jet appliance effectively moves the maxillary molars distally into a Class I molar relationship with minimal distal tipping, however, some loss of anchorage is to be expected during this process. The distal jet appliance compares favorably with other intraoral distalization devices and with mechanics featuring mandibular protraction for the resolution of patients with Class II, despite the fact that these types of mechanics address different jaws.

Finite element method (FEM) analysis of the force systems produced by asymmetric inner headgear bows.

PubMed

Geramy, Allahyar; Kizilova, Natalya; Terekhov, Leonid

2011-11-01

Extra-oral traction appliances were introduced more than a century ago and continue to be used to produce orthopaedic and/or dental changes in the maxilla. While force systems produced by asymmetric outer bows have been studied extensively, the force systems produced by asymmetric inner bows have been overlooked. To analyse the forces acting on the maxillary first molars: when the size of one bayonet bend is increased; when the point of application of the distalising force on the inner bow is moved to one side; when one molar is displaced palatally. Four FEM models of cervical headgear attached to maxillary first molars were designed in SolidWorks 2010 and transferred to an ANSYS Workbench Ver. 12.1. Model 1, each molar was 23 mm from the midpalatal line and the inner bow was symmetrical; Model 2, the left molar was displaced 4 mm towards the midpalatal line and the inner bow was symmetrical; Model 3, the molars were equidistant (23 mm) from the midpalatal line, but the left molar was engaged by a 2 mm larger bayonet bend; Model 4, the molars were equidistant (23 mm) from the midpalatal line but the join between the inner and outer bows was displaced 2 mm towards the left molar. In all FEM models, a 2N force was applied to the inner bow at the join between inner and outer bows and the energy transmitted to the teeth and the von Mises stresses on the molar PDLs were assessed. There were marked differences in the strain energy on the teeth and the von Mises stresses on their PDLs. A 14 to 20 per cent increase in energy and force was produced on the tooth closer to the symmetric plane of the headgear. In addition, the increase in energy produced a 30 to 62 per cent increase in the von Mises stresses within the PDLs. Small asymmetries in molar position, the size of a bayonet bend and the point of application of a force on an inner bow resulted in asymmetrical forces on the molars. These forces were higher on the molar closer to the symmetric plane of the headgear.

Adhesives for bonded molar tubes during fixed brace treatment.

PubMed

Millett, Declan T; Mandall, Nicky A; Mattick, Rye Cr; Hickman, Joy; Glenny, Anne-Marie

2011-06-15

Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. The success of a fixed appliance depends partly on the metal attachments (brackets and bands) being glued to the teeth so that they do not become detached during treatment. Brackets (metal squares) are usually attached to teeth other than molars, where bands (metal rings that go round each tooth) are more commonly used. Orthodontic tubes (stainless steel tubes that allow wires to pass through them), are typically welded to bands but they may also be glued directly (bonded) to molars. Failure of brackets, bands and bonded molar tubes slows down the progress of treatment with a fixed appliance. It can also be costly in terms of clinical time, materials and time lost from education/work for the patient. To evaluate the effectiveness of the adhesives used to attach bonded molar tubes, and the relative effectiveness of the adhesives used to attach bonded molar tubes versus adhesives used to attach bands, during fixed appliance treatment, in terms of: (1) how often the tubes (or bands) come off during treatment; and (2) whether they protect the bonded (or banded) teeth against decay. The following electronic databases were searched: the Cochrane Oral Health Group Trials Register (to 16 December 2010), the Cochrane Central Register of Controlled Clinical Trials (CENTRAL) (The Cochrane Library 2010, Issue 3), MEDLINE via OVID (1950 to 16 December 2010) and EMBASE via OVID (1980 to 16 December 2010). There were no restrictions regarding language or date of publication. Randomised controlled trials of participants with full arch fixed orthodontic appliance(s) with molar tubes, bonded to first or second permanent molars. Trials which compared any type of adhesive used to bond molar tubes (stainless steel or titanium) with any other adhesive, are included.Trials are also included where:(1) a tube is bonded to a molar tooth on one side of an arch and a band cemented to the same tooth type on the opposite side of the same arch; (2) molar tubes have been allocated to one tooth type in one patient group and molar bands to the same tooth type in another patient group. The selection of papers, decision about eligibility and data extraction were carried out independently and in duplicate without blinding to the authors, adhesives used or results obtained. All disagreements were resolved by discussion. Two trials (n = 190), at low risk of bias, were included in the review and both presented data on first time failure at the tooth level. Pooling of the data showed a statistically significant difference in favour of molar bands, with a hazard ratio of 2.92 (95% confidence intervals (CI) 1.80 to 4.72). No statistically significant heterogeneity was shown between the two studies. Data on first time failure at the patient level were also available and showed statistically different difference in favour of molar bands (risk ratio 2.30; 95% CI 1.56 to 3.41) (risk of event for molar tubes = 57%; risk of event for molar bands 25%).One trial presented data on decalcification again showing a statistically significant difference in favour of molar bands. No other adverse events identified. From the two well-designed and low risk of bias trials included in this review it was shown that the failure of molar tubes bonded with either a chemically-cured or light-cured adhesive was considerably higher than that of molar bands cemented with glass ionomer cement. One trial indicated that there was less decalcification with molar bands cemented with glass ionomer cement than with bonded molar tubes cemented with a light-cured adhesive. However, given there are limited data for this outcome, further evidence is required to draw more robust conclusions.

Correlation Between Dental and Cervical Vertebral Maturation in Iranian Females

PubMed Central

Valizadeh, Solmaz; Eil, Nakissa; Ehsani, Sara; Bakhshandeh, Hooman

2012-01-01

Background Considerable variations in the development stage among patients of the same chronological age have led to introduce the concept of the developmental age based on the maturation of different organs such as cervical vertebrae or teeth. Objectives The purpose of this study was to investigate the correlation between the stages of tooth calcification and the cervical vertebral maturation in Iranian females. Patients and Methods Four hundred females (age range, 8 to 14 years) participated in the study. To determine the dental maturational stage, calcification of the mandibular teeth except for third molars were rated according to the method suggested by Demirjian et al. To evaluate the stage of skeletal maturation, cervical vertebral morphologic changes were assessed on lateral cephalometric radiographs according to the method explained by Baccetti et al. Correlations between bone maturation and teeth calcification were showed by Spearman's correlation and Kendall’s tau-b coefficients. The relevant associations were investigated by ordinal logistic regression models. Results Correlations between the two stages were observed in the first and second premolars, canine and central incisors. All these correlations were significant. The association between cervical vertebral maturation and tooth calcification was greatest in the lateral incisor (odds ratio (OR) = 11, 95% confidence interval (CI): 6.6-18.3). However, considering the 95% CI for OR, no significant difference was detected among the second molar, first molar and lateral incisor. Conclusion The relationship between calcification of teeth and maturation of cervical bones was significant. Bone maturation can be predicted by using teeth calcification stages, especially in the second molar, first molar and lateral incisor. PMID:23599706

Correlation between dental and cervical vertebral maturation in Iranian females.

PubMed

Valizadeh, Solmaz; Eil, Nakissa; Ehsani, Sara; Bakhshandeh, Hooman

2012-12-01

Considerable variations in the development stage among patients of the same chronological age have led to introduce the concept of the developmental age based on the maturation of different organs such as cervical vertebrae or teeth. The purpose of this study was to investigate the correlation between the stages of tooth calcification and the cervical vertebral maturation in Iranian females. Four hundred females (age range, 8 to 14 years) participated in the study. To determine the dental maturational stage, calcification of the mandibular teeth except for third molars were rated according to the method suggested by Demirjian et al. To evaluate the stage of skeletal maturation, cervical vertebral morphologic changes were assessed on lateral cephalometric radiographs according to the method explained by Baccetti et al. Correlations between bone maturation and teeth calcification were showed by Spearman's correlation and Kendall's tau-b coefficients. The relevant associations were investigated by ordinal logistic regression models. Correlations between the two stages were observed in the first and second premolars, canine and central incisors. All these correlations were significant. The association between cervical vertebral maturation and tooth calcification was greatest in the lateral incisor (odds ratio (OR) = 11, 95% confidence interval (CI): 6.6-18.3). However, considering the 95% CI for OR, no significant difference was detected among the second molar, first molar and lateral incisor. The relationship between calcification of teeth and maturation of cervical bones was significant. Bone maturation can be predicted by using teeth calcification stages, especially in the second molar, first molar and lateral incisor.

Piezosurgery for the Lingual Split Technique in Lingual Positioned Impacted Mandibular Third Molar Removal: A Retrospective Study.

PubMed

Ge, Jing; Yang, Chi; Zheng, Jiawei; Qian, Wentao

2016-03-01

The aim of this study was to evaluate the effect and safety of lingual split technique using piezosurgery for the extraction of lingual positioned impacted mandibular 3rd molars with the goal of proposing a more minimally invasive choice for this common surgery.Eighty-nine consecutive patients with 110 lingual positioned impacted mandibular 3rd molars requiring extraction were performed the lingual split technique using piezosurgery. One sagittal osteotomy line and 2 transverse osteotomy line were designed for lingual and occlusal bone removal. The success rate, operative time, postoperative outcome, and major complications (including nerve injury, mandible fracture, severe hematoma or edema, and severe pyogenic infection) were documented and analyzed.All impacted mandibular 3rd molars were successfully removed (110/110). The average time of operation was 14.6 minutes (ranged from 7 to 28 minutes). One hundred and seven extraction sites (97.3%) were primary healing. Pain, mouth opening, swelling, and PoSSe scores on postoperative 7-day were 0.34 ± 0.63, 3.88 ± 0.66(cm), 2.4 ± 0.2(cm), and 23.7 ± 5.9, respectively. There were 6 cases (5.5%) had lingual nerve disturbance and 3 cases (2.7%) developed inferior alveolar nerve impairment, and achieved full recovery within 2 months by neurotrophic drug treatment.Our study suggested piezosurgery for lingual split technique provided an effective way for the extraction of lingual positioned and deeply impacted mandibular 3rd molar.

Piezosurgery for the Lingual Split Technique in Lingual Positioned Impacted Mandibular Third Molar Removal

PubMed Central

Ge, Jing; Yang, Chi; Zheng, Jiawei; Qian, Wentao

2016-01-01

Abstract The aim of this study was to evaluate the effect and safety of lingual split technique using piezosurgery for the extraction of lingual positioned impacted mandibular 3rd molars with the goal of proposing a more minimally invasive choice for this common surgery. Eighty-nine consecutive patients with 110 lingual positioned impacted mandibular 3rd molars requiring extraction were performed the lingual split technique using piezosurgery. One sagittal osteotomy line and 2 transverse osteotomy line were designed for lingual and occlusal bone removal. The success rate, operative time, postoperative outcome, and major complications (including nerve injury, mandible fracture, severe hematoma or edema, and severe pyogenic infection) were documented and analyzed. All impacted mandibular 3rd molars were successfully removed (110/110). The average time of operation was 14.6 minutes (ranged from 7 to 28 minutes). One hundred and seven extraction sites (97.3%) were primary healing. Pain, mouth opening, swelling, and PoSSe scores on postoperative 7-day were 0.34 ± 0.63, 3.88 ± 0.66(cm), 2.4 ± 0.2(cm), and 23.7 ± 5.9, respectively. There were 6 cases (5.5%) had lingual nerve disturbance and 3 cases (2.7%) developed inferior alveolar nerve impairment, and achieved full recovery within 2 months by neurotrophic drug treatment. Our study suggested piezosurgery for lingual split technique provided an effective way for the extraction of lingual positioned and deeply impacted mandibular 3rd molar. PMID:27015214

Triple paternal contribution to a normal/complete molar chimeric singleton placenta.

PubMed

Ariel, I; Goldman-Wohl, D; Yagel, S; Gazit, E; Loewenthal, R

2017-05-01

A comprehensive study of unusual cases of placental pathology may provide insight into mechanisms of normal human fertilization and early embryonic development by examining the exception to the rule. A gravida three para two 39-year-old woman was monitored by ultrasound from 16 weeks of gestation for cystic placenta. A female newborn was born at 36 weeks gestation. Pathologic examination of the partially cystic placenta revealed a singleton placenta comprised of 2/3 normal placenta and 1/3 complete hydatidiform mole, largely degenerated. Immunostaining for p57 was negative in stromal cells of the molar villi. Chromogenic in-situ hybridization revealed diploidy in both normal and molar parts. A total of 16 microsatellites were studied by short tandem repeat analysis, 11 of which were informative. The analysis revealed bipaternal molar tissue of dispermic origin. The paternal monospermic contribution to the normal part was different from that in the molar part, thus resulting in tripaternal contribution to the conceptus. A chimera is a single organism composed of two or more different populations of genetically distinct cells that originated from different zygotes (tetragametic) whereas mosaic is a mixture of two cell lines in one organism originating from one zygote. The possible mechanisms leading to the formation of chimeric/mosaic placenta in our case (one of the components being complete hydatidiform mole), including twinning, fusion at an early embryonic stage and diploidization of triploids, are discussed. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Molar Mass and Second Virial Coefficient of Polyethylene Glycol by Vapor Pressure Osmometry

ERIC Educational Resources Information Center

Schwinefus, Jeffrey J.; Checkal, Caleb; Saksa, Brian; Baka, Nadia; Modi, Kalpit; Rivera, Carlos

2015-01-01

In this laboratory experiment, students determine the number-average molar masses and second virial coefficients of polyethylene glycol (PEG) polymers ranging in molar mass from 200 to 1500 g mol[superscript -1] using vapor pressure osmometry (VPO). Students assess VPO in relation to accurate molar mass calculations of PEG polymers. Additionally,…

Bi-Se doped with Cu, p-type semiconductor

DOEpatents

Bhattacharya, Raghu Nath; Phok, Sovannary; Parilla, Philip Anthony

2013-08-20

A Bi--Se doped with Cu, p-type semiconductor, preferably used as an absorber material in a photovoltaic device. Preferably the semiconductor has at least 20 molar percent Cu. In a preferred embodiment, the semiconductor comprises at least 28 molar percent of Cu. In one embodiment, the semiconductor comprises a molar percentage of Cu and Bi whereby the molar percentage of Cu divided by the molar percentage of Bi is greater than 1.2. In a preferred embodiment, the semiconductor is manufactured as a thin film having a thickness less than 600 nm.

Endodontic treatment of a maxillary second molar with developmental anomaly: a case report.

PubMed

Asgary, Saeed

2007-01-01

Fusion is a rare occurrence in molar teeth. The purpose of this rare case presentation is to describe the nonsurgical endodontic treatment of maxillary molar. A 28-year-old patient was referred for endodontic treatment of her chronic apical abscess of right maxillary second molar. In the clinical examination, a sinus tract adjacent to involved tooth and a small crown of supernumerary tooth fused to the buccal surface of the molar at gingival margin was observed. Endodontic treatment was decided for the involved molar for functional reason. Recall examination, a year after completion of endodontic and restorative treatments, showed the tooth was clinically asymptomatic and there was no radiographic lucency around the apical region.

Characterization of Mixtures. Part 2: QSPR Models for Prediction of Excess Molar Volume and Liquid Density Using Neural Networks.

PubMed

Ajmani, Subhash; Rogers, Stephen C; Barley, Mark H; Burgess, Andrew N; Livingstone, David J

2010-09-17

In our earlier work, we have demonstrated that it is possible to characterize binary mixtures using single component descriptors by applying various mixing rules. We also showed that these methods were successful in building predictive QSPR models to study various mixture properties of interest. Here in, we developed a QSPR model of an excess thermodynamic property of binary mixtures i.e. excess molar volume (V(E) ). In the present study, we use a set of mixture descriptors which we earlier designed to specifically account for intermolecular interactions between the components of a mixture and applied successfully to the prediction of infinite-dilution activity coefficients using neural networks (part 1 of this series). We obtain a significant QSPR model for the prediction of excess molar volume (V(E) ) using consensus neural networks and five mixture descriptors. We find that hydrogen bond and thermodynamic descriptors are the most important in determining excess molar volume (V(E) ), which is in line with the theory of intermolecular forces governing excess mixture properties. The results also suggest that the mixture descriptors utilized herein may be sufficient to model a wide variety of properties of binary and possibly even more complex mixtures. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Accuracy of a cut-off value based on the third molar index: Validation in an Australian population.

PubMed

Franklin, Daniel; Karkhanis, Shalmira; Flavel, Ambika; Collini, Federica; DeLuca, Stefano; Cameriere, Roberto

2016-09-01

According to Recommendation N°196 of the Australian Law Reform Commission (ALRC), the age at which a child reaches adulthood for the purposes of criminal law should be 18 years in all Australian jurisdictions. With specific reference to age at majority, the only tooth with development spanning adolescence (and thus the legally relevant 18 years of age) is the third molar, which limits the number of methods that can be applied from those available in the published literature. The aim of the present study is to test the accuracy of the third molar index (I3M=0.08), based on the correlation between chronological age and normalized measures of the open apices and height of the third mandibular molar, in order to assess the legal adult age of 18 years. Digital orthopantomographs of 143 living Australian subjects (72 boys and 71 girls) are analyzed. The results demonstrate that the sensitivity is 0.90 in boys and 0.90 in girls; associated specificity values are 0.85 and 0.87 respectively. We conclude that the cut-off value of I3M=0.08 is statistically robust and thus valid for forensic application in an Australian population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Ultrafast, efficient separations of large-sized dsDNA in a blended polymer matrix by microfluidic chip electrophoresis: A Design of Experiments approach

PubMed Central

Sun, Mingyun; Lin, Jennifer S.

2012-01-01

Double-stranded (ds) DNA fragments over a wide size range were successfully separated in blended polymer matrices by microfluidic chip electrophoresis. Novel blended polymer matrices composed of two types of polymers with three different molar masses were developed to provide improved separations of large dsDNA without negatively impacting the separation of small dsDNA. Hydroxyethyl celluloses (HECs) with average molar masses of ~27 kDa and ~1 MDa were blended with a second class of polymer, high-molar mass (~7 MDa) linear polyacrylamide (LPA). Fast and highly efficient separations of commercially available DNA ladders were achieved on a borosilicate glass microchip. A distinct separation of a 1 Kb DNA extension ladder (200 bp to 40,000 bp) was completed in 2 minutes. An orthogonal Design of Experiments (DOE) was used to optimize experimental parameters for DNA separations over a wide size range. We find that the two dominant factors are the applied electric field strength and the inclusion of a high concentration of low-molar mass polymer in the matrix solution. These two factors exerted different effects on the separations of small dsDNA fragments below 1 kbp, medium dsDNA fragments between 1 kbp and 10 kbp, and large dsDNA fragments above 10 kbp. PMID:22009451

Novel Immune-Modulating Cellular Vaccine for Prostate Cancer Immunotherapy

DTIC Science & Technology

2015-10-01

the 3-month timeline and details provided in year 1 report. Anti-murine CTLA4 RNA Murine PAP Murine PSMA Murine PAP no signal sequence (mPAP-SS...Murine PSMA no signal sequence (mPSMA-SS) Year 2 (current) report: In addition to what we proposed to do, we wanted to determine if other...PAP, PSCA, PSMA and STEAP in the prostate cell lines TRAMP-C1 and TRAMP-C2. Both are cell lines that have been generated by in vitro propagation of

Radiation Fibrosis of the Vocal Fold: From Man to Mouse

PubMed Central

Johns, Michael M.; Kolachala, Vasantha; Berg, Eric; Muller, Susan; Creighton, Frances X.; Branski, Ryan C.

2013-01-01

Objectives To characterize fundamental late tissue effects in the human vocal fold following radiation therapy. To develop a murine model of radiation fibrosis to ultimately develop both treatment and prevention paradigms. Design Translational study using archived human and fresh murine irradiated vocal fold tissue. Methods 1) Irradiated vocal fold tissue from patients undergoing laryngectomy for loss of function from radiation fibrosis were identified from pathology archives. Histomorphometry, immunohistochemistry, and whole-genome microarray as well as real-time transcriptional analyses was performed. 2) Focused radiation to the head and neck was delivered to mice in a survival fashion. One month following radiation, vocal fold tissue was analyzed with histomorphometry, immunohistochemistry, and real-time PCR transcriptional analysis for selected markers of fibrosis. Results Human irradiated vocal folds demonstrated increased collagen transcription with increased deposition and disorganization of collagen in both the thyroarytenoid muscle and the superficial lamina propria. Fibronectin were increased in the superficial lamina propria. Laminin decreased in the thyroarytenoid muscle. Whole genome microarray analysis demonstrated increased transcription of markers for fibrosis, oxidative stress, inflammation, glycosaminoglycan production and apoptosis. Irradiated murine vocal folds demonstrated increases in collagen and fibronectin transcription and deposition in the lamina propria. Transforming growth factor (TGF)-β increased in the lamina propria. Conclusion Human irradiated vocal folds demonstrate molecular changes leading to fibrosis that underlie loss of vocal fold pliability that occurs in patients following laryngeal irradiation. Irradiated murine tissue demonstrates similar findings, and this mouse model may have utility in creating prevention and treatment strategies for vocal fold radiation fibrosis. PMID:23242839

Image analysis of the eruptive positions of third molars and adjacent second molars as indicators of age evaluation in Thai patients.

PubMed

Mahasantipiya, Phattaranant May; Pramojanee, Sakarat; Thaiupathump, Trasapong

2013-12-01

This study was performed to determine the relationship between the stage of tooth eruption (both vertical and mesio-angular) and chronological age. Indirect digital panoramic radiographs were used to measure the distances from the dentinoenamel junction (DEJ) of the second molars to the occlusal plane of the second molar teeth and of the adjacent third molars in 264 Thai males and 437 Thai females using ImageJ software. The ratio of those distances was calculated by patient age, and the correlation coefficient of the ratio of the third molar length to the second molar length was calculated. The correlation between the height of the vertically erupted upper third molar teeth and age was at the intermediate level. The age range of ≥15 to <16 years was noted to be the range in which the correlation between the chronological age determined from the eruptional height and actual chronological age was statistically significant. The mean age of the female subjects, in which the position of the right upper third molar teeth was at or above the DEJ of the adjacent second molar but below one half of its coronal height was 19.9±2.6 years. That for the left side was 20.2±2.7 years. The mean ages of the male subjects were 20.1±3.3 years and 19.8±2.7 years for the right and left sides, respectively. It might be possible to predict chronological age from the eruption height of the wisdom teeth.

Prevalence, association, and sexual dimorphism of Carabelli's molar and shovel incisor traits amongst Jordanian population.

PubMed

Khraisat, A; Taha, Sahar T; Jung, R E; Hattar, S; Smadi, L; Al-Omari, I K; Jarbawi, M

2007-09-01

The correlation between dental morphological traits can be used as an indicator to show major ethnic differences. Therefore, this study investigated the prevalence of Carabelli's molar and shovel incisor traits and tested their association and sexual dimorphism in Jordanian population. Three hundred subjects of school children at their 10th grade and of 15.5-year as an average age were involved. Alginate impressions for the maxillary arch were taken, poured, and casts were then trimmed. The selected accurate casts were of 132 male- and 155 female-students. The examined morphologic traits were Carabelli's trait on the maxillary first and second molars and shovel-shaped incisors. The relationship between different traits was investigated by Nonparametric Correlation analysis and Independent Sample t test was used to test sexual dimorphism in trait expression. The prevalence of Carabelli's trait in maxillary first molar and shovel trait in maxillary central incisor was relatively high (65.0 % and 53.0 %, respectively). The prevalence of Carabelli's trait on maxillary second molars was 3.8 %. Nonparametric Correlations revealed a strongest positive correlation between Carabelli's trait on maxillary first molar and shovel trait in males (P = 0.005). Significant sexual dimorphism was only found in the prevalence of Carabelli's trait on maxillary first molar (P = 0.013) and shovel trait (P = 0.038). The Jordanian Population had comparatively high prevalence of Carabelli's molar and shovel incisor traits. There was a positive association between Carabelli's trait on maxillary first molar and shovel trait in males. Sexual dimorphism was evident in Carabelli's trait on maxillary first molar and shovel trait.

Optimal dental age estimation practice in United Arab Emirates' children.

PubMed

Altalie, Salem; Thevissen, Patrick; Fieuws, Steffen; Willems, Guy

2014-03-01

The aim of the study was to detect whether the Willems model, developed on a Belgian reference sample, can be used for age estimations in United Arab Emirates (UAE) children. Furthermore, it was verified that if added third molars development information in children provided more accurate age predictions. On 1900 panoramic radiographs, the development of left mandibular permanent teeth (PT) and third molars (TM) was registered according the Demirjian and the Kohler technique, respectively. The PT data were used to verify the Willems model and to develop a UAE model and to verify it. Multiple regression models with PT, TM, and PT + TM scores as independent and age as dependent factor were developed. Comparing the verified Willems- and the UAE model revealed differences in mean error of -0.01 year, mean absolute error of 0.01 year and root mean squared error of 0.90 year. Neglectable overall decrease in RMSE was detected combining PM and TM developmental information. © 2013 American Academy of Forensic Sciences.

Use of miniplates as a method for orthodontic anchorage: a case report

PubMed Central

Peres, Fernando Gianzanti; Padovan, Luis Eduardo Marques; Kluppel, Leandro Eduardo; Albuquerque, Gustavo Calvalcanti; de Souza, Paulo Cesar Ulson; Claudino, Marcela

2016-01-01

ABSTRACT Introduction: Temporary anchorage devices (TADs) have been developed to be used as direct adjuncts in orthodontic treatment and have facilitated treatment of more complex orthodontic cases, including patients with dental impaction. Objectives: This clinical case reports the applicability of TADs in the orthodontic treatment of a patient with impacted mandibular second molars. Surgical and orthodontic procedures related to the use of miniplates were also discussed in this study. Conclusions: The use of temporary anchorage devices, such as miniplates, can be suggested as an alternative to treat patients with impacted mandibular second molars. PMID:27901235

Cloning and characterization of the murine homolog of the sno proto-oncogene reveals a novel splice variant

NASA Technical Reports Server (NTRS)

Pelzer, T.; Lyons, G. E.; Kim, S.; Moreadith, R. W.; Blomqvist, C. G. (Principal Investigator)

1996-01-01

The cellular function(s) of the SNO protein remain undefined. To gain a better understanding of possible developmental roles of this cellular proto-oncogene, we have cloned two murine sno cDNAs and have investigated their expression patterns in embryonic and postnatal tissues. A single major transcript of 7.5 kb is detected in multiple tissues by Northern blot. However, reverse transcriptase polymerase chain reaction (RT-PCR) and RNAse protection assays revealed a novel splice variant in every tissue examined. Two isoforms, termed sno N and sno-dE3 (dE3, deletion within exon 3), were identified. The sno-dE3 isoform employs a novel 5' splice site located within the coding region of the third exon and deletes potential kinase recognition motifs. Transcripts of both sno isoforms accumulate ubiquitously but are most abundant in the developing central nervous system. The in situ hybridization patterns of sno expression during murine development suggest potential roles in tissues with a high degree of cellular proliferation. Expression in terminally differentiated tissues such as muscle and neurons indicates that SNO may have multiple functional activities.

Animal Models of Atherosclerosis

PubMed Central

Getz, Godfrey S.; Reardon, Catherine A.

2012-01-01

Atherosclerosis is a chronic inflammatory disorder that is the underlying cause of most cardiovascular disease. Both cells of the vessel wall and cells of the immune system participate in atherogenesis. This process is heavily influenced by plasma lipoproteins, genetics and the hemodynamics of the blood flow in the artery. A variety of small and large animal models have been used to study the atherogenic process. No model is ideal as each has its own advantages and limitations with respect to manipulation of the atherogenic process and modeling human atherosclerosis or lipoprotein profile. Useful large animal models include pigs, rabbits and non-human primates. Due in large part to the relative ease of genetic manipulation and the relatively short time frame for the development of atherosclerosis, murine models are currently the most extensively used. While not all aspects of murine atherosclerosis are identical to humans, studies using murine models have suggested potential biological processes and interactions that underlie this process. As it becomes clear that different factors may influence different stages of lesion development, the use of mouse models with the ability to turn on or delete proteins or cells in tissue specific and temporal manner will be very valuable. PMID:22383700

Opinions of American and Swedish orthodontists about the role of erupting third molars as a cause of dental crowding.

PubMed

Tüfekçi, E; Svensk, D; Kallunki, J; Huggare, J; Lindauer, S J; Laskin, D M

2009-11-01

To compare the opinions of Swedish orthodontists and American orthodontists regarding the association between third molar eruption and dental crowding. A survey was distributed to Swedish orthodontists (n = 230) asking their views on the force exerted by erupting third molars, its relationship to crowding, and their recommendations for prophylactic removal. Results were compared with those from a similar study conducted in the United States. Chi square analysis was used to determine differences in responses to questions between Swedish and American orthodontists. P < or = .05 was considered significant. Both Swedish and American orthodontists believed that lower third molars were more likely than upper third molars to cause force (65% and 58% for Swedish and American orthodontists, respectively) and crowding (42% and 40%, respectively). No statistically significant differences were seen between the answers of American and Swedish orthodontists regarding the role of upper and lower third molars in causing crowding. Although only 18% of Swedish orthodontists "generally" or "sometimes" recommended prophylactic removal of mandibular third molars, 36% of American orthodontists "generally" or "sometimes" recommended removal (P < .0001). Most orthodontists in the United States and Sweden do believe that erupting lower third molars exert an anterior force; however, they also believe that these teeth "rarely" or "never" cause crowding of the dentition. The reason that more American orthodontists recommend prophylactic removal of mandibular third molars remains unexplained.

Obeservations on association between third molar agenesis and craniofacial morphology.

PubMed

Huang, Yi; Yan, Yinqiu; Cao, Jing; Xie, Bingjie; Xiao, Xueling; Luo, Mengqi; Bai, Ding; Han, Xianglong

2017-11-01

This study was designed to examine the relationship between third molar agenesis and skeletal morphology in the Chinese population. A total of 1043 patients' records were analyzed with panoramic radiographs and cephalograms. Congenitally missing third molars were assessed with respect to gender, jaw, and side, and assessed in various types of facial morphology. Linear, angular, and proportional cephalometric measurements were analyzed and compared among the samples. For the evaluation of results, the following statistics were used: the Pearson χ 2 test, one-way ANOVA, and the Student-Newman-Keuls method. The overall prevalence of third molar agenesis was 28.7%. Missing third molars were more common in the maxilla and on the right side, while the difference was not statistically significant (P > 0.05) between genders. Every hypodontia group had a smaller SN-GoGn angle, Y-axis-FH angle, and a larger S-Go/N-Me ratio. The group with third molar agenesis in both jaws had smaller SNA and Wits values. The frequency of third molar agenesis in subjects with a Class II malocclusion was significantly lower than in other types of malocclusion (P < 0.05), and the incidence of third molar agenesis in hypodivergent growth pattern was higher than in other patterns (P < 0.05). The results demonstrate a possible association between third molar agenesis and both sagittal and vertical craniofacial morphology.

Impact of mandibular third molar extraction in the second molar periodontal status: A prospective study.

PubMed

Stella, Paulo Eduardo Melo; Falci, Saulo Gabriel Moreira; Oliveira de Medeiros, Lorrayne Estéfane; Douglas-de-Oliveira, Dhelfeson Willya; Gonçalves, Patricia Furtado; Flecha, Olga Dumont; Dos Santos, Cássio Roberto Rocha

2017-01-01

The aim of the present study was to assess the periodontal condition and sensitivity of second mandibular molars after the extraction of the adjacent third molar, while also assessing the quality of life of the patients. Twenty-three healthy patients were assessed in terms of probing depth, gingival height, gingival thickness, dental sensitivity, plaque index and bleeding on probing (adjacent second mandibular molar), before the surgical procedure, as well as 60 and 180 days after the surgery. The following data were also recorded and measured: the position and size of the impacted teeth; the size of the alveoli after surgery and the quality of life of the patient. Significant differences were found for probing depth and gingival height before and after 180 days. The plaque index increased significantly after surgery ( P = 0.004), as did bleeding on probing. No significant difference was found for the quality of life. The size of the third molar extracted was correlated with bleeding on probing 180 days after the surgery. An improvement was noted in the periodontal condition of the second mandibular molars after the extraction, based on the assessments of probing depth and gingival height. The position of the third molar affected the periodontal condition of the second mandibular molar. No alterations were recorded for dental sensitivity or the quality of life after the extraction.

Impact of mandibular third molar extraction in the second molar periodontal status: A prospective study

PubMed Central

Stella, Paulo Eduardo Melo; Falci, Saulo Gabriel Moreira; Oliveira de Medeiros, Lorrayne Estéfane; Douglas-de-Oliveira, Dhelfeson Willya; Gonçalves, Patricia Furtado; Flecha, Olga Dumont; Dos Santos, Cássio Roberto Rocha

2017-01-01

Aim: The aim of the present study was to assess the periodontal condition and sensitivity of second mandibular molars after the extraction of the adjacent third molar, while also assessing the quality of life of the patients. Materials and Methods: Twenty-three healthy patients were assessed in terms of probing depth, gingival height, gingival thickness, dental sensitivity, plaque index and bleeding on probing (adjacent second mandibular molar), before the surgical procedure, as well as 60 and 180 days after the surgery. The following data were also recorded and measured: the position and size of the impacted teeth; the size of the alveoli after surgery and the quality of life of the patient. Results: Significant differences were found for probing depth and gingival height before and after 180 days. The plaque index increased significantly after surgery (P = 0.004), as did bleeding on probing. No significant difference was found for the quality of life. The size of the third molar extracted was correlated with bleeding on probing 180 days after the surgery. Conclusion: An improvement was noted in the periodontal condition of the second mandibular molars after the extraction, based on the assessments of probing depth and gingival height. The position of the third molar affected the periodontal condition of the second mandibular molar. No alterations were recorded for dental sensitivity or the quality of life after the extraction. PMID:29456302

Reimbursement rates and policies for primary molar pit-and-fissure sealants across state Medicaid programs.

PubMed

Chi, Donald L; Singh, Jennifer

2013-11-01

Little is known about Medicaid policies regarding reimbursement for placement of sealants on primary molars. The authors identified Medicaid programs that reimbursed dentists for placing primary molar sealants and hypothesized that these programs had higher reimbursement rates than did state programs that did not reimburse for primary molar sealants. The authors obtained Medicaid reimbursement data from online fee schedules and determined whether each state Medicaid program reimbursed for primary molar sealants (no or yes). The outcome measure was the reimbursement rate for permanent tooth sealants (calculated in 2012 U.S. dollars). The authors compared mean reimbursement rates by using the t test (α = .05). Seventeen Medicaid programs reimbursed dentists for placing primary molar sealants (34 percent), and the mean reimbursement rate was $27.57 (range, $16.00 [Maine] to $49.68 [Alaska]). All 50 programs reimbursed dentists for placement of sealants on permanent teeth. The mean reimbursement for permanent tooth sealants was significantly higher in programs that reimbursed for primary molar sealants than in programs that did not ($28.51 and $23.67, respectively; P = .03). Most state Medicaid programs do not reimburse dentists for placing sealants on primary molars, but programs that do so have significantly higher reimbursement rates. Medicaid reimbursement rates are related to dentists' participation in Medicaid and children's dental care use. Reimbursement for placement of sealants on primary molars is a proxy for Medicaid program generosity.

Root canal morphology of primary molars: a micro-computed tomography study.

PubMed

Fumes, A C; Sousa-Neto, M D; Leoni, G B; Versiani, M A; da Silva, L A B; da Silva, R A B; Consolaro, A

2014-10-01

This was to investigate the root canal morphology of primary molar teeth using micro-computed tomography. Primary maxillary (n = 20) and mandibular (n = 20) molars were scanned at a resolution of 16.7 μm and analysed regarding the number, location, volume, area, structured model index (SMI), area, roundness, diameters, and length of canals, as well as the thickness of dentine in the apical third. Data were statistically compared by using paired-sample t test, independent sample t test, and one-way analysis of variance with significance level set as 5%. Overall, no statistical differences were found between the canals with respect to length, SMI, dentine thickness, area, roundness, and diameter (p > 0.05). A double canal system was observed in the mesial and mesio-buccal roots of the mandibular and maxillary molars, respectively. The thickness in the internal aspect of the roots was lower than in the external aspect. Cross-sectional evaluation of the roots in the apical third showed flat-shaped canals in the mandibular molars and ribbon- and oval-shaped canals in the maxillary molars. External and internal anatomy of the primary first molars closely resemble the primary second molars. The reported data may help clinicians to obtain a thorough understanding of the morphological variations of root canals in primary molars to overcome problems related to shaping and cleaning procedures, allowing appropriate management strategies for root canal treatment.

The "hook effect" causing a negative pregnancy test in a patient with an advanced molar pregnancy.

PubMed

Winder, Abigail D; Mora, Adria Suarez; Berry, Emily; Lurain, John R

2017-08-01

•At high hCG levels in molar pregnancies, a "hook effect" can cause an artificially negative value.•Delay in diagnosis of a molar pregnancy due to the "hook effect" can lead to severe complications.•Suspicion of a molar pregnancy should be communicated so a diluted sample is used to quantify hCG.

Systemic Inflammation after Third Molar Removal: A Case-Control Study.

PubMed

Graziani, F; D'Aiuto, F; Gennai, S; Petrini, M; Nisi, M; Cirigliano, N; Landini, L; Bruno, R M; Taddei, S; Ghiadoni, L

2017-12-01

Third molar extraction is one of the most frequent interventions in dentistry. Nevertheless, there is scarce evidence on the host response of individuals with impacted or semi-impacted third molars and the possible effects of surgical removal. A case-control study of 40 patients was designed to evaluate 1) the differences in biomarkers of systemic inflammation, vascular function, and metabolism (high-sensitive C-reactive protein, lipids, fibrinogen, oxidative stress, and endothelial function analysis) and 2) the acute and short-term effects of surgical removal in patients with bilateral impacted or semi-impacted third molars compared to controls with no third molars. Patients undergoing third molar extraction exhibited greater levels of systemic inflammation, oxidative stress, and triglycerides than controls. Raised white blood cell counts as well as peaks of serum levels of C-reactive protein and fibrinogen were noticed in the first postoperative week. Three months after the extraction, all markers returned to baseline values. Malondialdehyde, an indicator of oxidative stress indicator, was significantly reduced after third molar removal. Semi-impacted or impacted third molars are associated with higher systemic inflammation, and their removal may represent a useful human model to study acute inflammation and determine beneficial systemic effects ( ClinicalTrials.gov NCT03048175).

Evaluation of the root and canal morphology of mandibular permanent molars in a south-eastern Turkish population using cone-beam computed tomography

PubMed Central

Nur, Bilge Gulsum; Ok, Evren; Altunsoy, Mustafa; Aglarci, Osman Sami; Colak, Mehmet; Gungor, Enes

2014-01-01

Objective: The aim of this retrospective study was to determine the root and canal morphology of the mandibular first and second permanent molars in a Turkish population using cone-beam computed tomography (CBCT). Materials and Methods: CBCT images of mandibular first (n = 966) and second molar (n = 1165) teeth from 850 Turkish patients were evaluated. The root canal configurations were classified according to the method of Vertucci. The data were analyzed by Pearson's Chi-square test. Results: The majority of mandibular molars were two rooted with three canals; however, three roots were identified in 0.05% of the first molars and 0.01% of the second molars, and 100% of the additional root canals were of type I configuration. Mesial roots had more complex canal systems with more than one canal, whereas most distal roots had a type I configuration. Conclusions: Within the limitations of this study, it can be concluded that CBCT scanning provides supplemental information about the root canal configurations of mandibular molars in a Turkish population. This study may help clinicians in the root canal treatment of mandibular molars. PMID:24966763

Sucralose as co-crystal co-former for hydrochlorothiazide: development of oral disintegrating tablets.

PubMed

Arafa, Mona F; El-Gizawy, Sanaa A; Osman, Mohamed A; El Maghraby, Gamal M

2016-08-01

Development of oral disintegrating tablets requires enhancement of drug dissolution and selection of sweetener. Co-crystallization of drugs with inert co-former is an emerging technique for enhancing dissolution rate. The benefit of this technique will become even greater if one of the sweeteners can act as co-crystal co-former to enhance dissolution and mask the taste. Accordingly, the objective of this work was to investigate the efficacy of sucralose as a potential co-crystal co-former for enhancing the dissolution rate of hydrochlorothiazide. This was extended to prepare oral disintegrating tablets. Co-crystallization was achieved after dissolving hydrochlorothiazide with increasing molar ratios of sucralose in the least amount of acetone. The co-crystallization products were characterized using Fourier transform infrared spectroscopy, differential thermal analysis and powder X-ray diffraction. These measurements indicated that co-crystallization process started at a drug sucralose molar ratio of 1:1 and completed at 1:2. The developed co-crystals exhibited faster drug dissolution compared with the control, with co-crystal containing the drug with sucralose at 1:2 molar ratio being optimum. The later was used to prepare fast disintegrating tablets. These tablets had acceptable physical characteristics and showed fast disintegration with subsequent rapid dissolution. The study introduced sucralose as co-crystal co-former for enhanced dissolution and masking the taste.

Immediate autotransplantation of mandibular third molar in China.

PubMed

Yan, Quanmei; Li, Bo; Long, Xing

2010-10-01

Tooth autotransplantation is a useful surgical method to replace a nonrestorable tooth. We reported our experiences in the replacement of mandibular nonrestorable molars by immediate autotransplantation in a Chinese population. Thirty-five mandibular third molars with open or closed apices from 34 patients were autotransplanted into the same or contralateral fresh recipient sites immediately after the extraction of the nonrestorable mandibular molars. Root canal treatment was routinely performed in the closed-apical molars within 1 month after surgery. Clinical and radiographic examination of the transplanted donor molars was done after surgery. Two teeth were been extracted for progressive root resorption. The remaining 33 autotransplanted teeth were asymptomatic and functioning after a mean follow-up period of 5.2 years. No infection, ankylosis, loss of the transplants, or root resorption was noted in the remaining autotransplanted teeth. Immediate autotransplantation of the mandibular third molar is a reasonable and alternative treatment to replace a nonrestorable tooth in China. Copyright © 2010 Mosby, Inc. All rights reserved.

Prevalence of Third Molar Agenesis: Associated Dental Anomalies in Non-Syndromic 5923 Patients.

PubMed

Sujon, Mamun Khan; Alam, Mohammad Khursheed; Rahman, Shaifulizan Abdul

2016-01-01

The aim of this study was to investigate the prevalence of third molar agenesis and other associated dental anomalies in Bangladeshi population and to investigate the relationship of other dental anomalies with the third molar presence/agenesis. A retrospective study was performed using panoramic radiographs of 5923 patients, who ranged in age from 10 to 50 years. All radiographs were analyzed by Planmeca Romexis® 3.0 software (Planmeca Oy, Helsinki, Finland). Pearson chi-square and one way ANOVA (Post Hoc) test were conducted. The prevalence of third molar agenesis was 38.4%. The frequency of third molar agenesis was significantly higher in females than males (p <0.025). Third molar agenesis was significantly more prevalent in maxilla as compared to mandible (p <0.007). The prevalence of other dental anomalies was 6.5%, among them hypodontia was 3.1%. Prevalence of third molar agenesis varies in different geographic region. Among the other dental anomalies hypodontia was more prevalent.

A Novel Chitin Binding Crayfish Molar Tooth Protein with Elasticity Properties

PubMed Central

Tynyakov, Jenny; Bentov, Shmuel; Abehsera, Shai; Khalaila, Isam; Manor, Rivka; Katzir Abilevich, Lihie; Weil, Simy; Aflalo, Eliahu D.; Sagi, Amir

2015-01-01

The molar tooth of the crayfish Cherax quadricarinatus is part of the mandible, and is covered by a layer of apatite (calcium phosphate). This tooth sheds and is regenerated during each molting cycle together with the rest of the exoskeleton. We discovered that molar calcification occurs at the pre-molt stage, unlike calcification of the rest of the new exoskeleton. We further identified a novel molar protein from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. We termed this protein Cq-M13. The temporal level of transcription of Cq-M13 in an NGS library of molar-forming epithelium at different molt stages coincides with the assembly and mineralization pattern of the molar tooth. The predicted protein was found to be related to the pro-resilin family of cuticular proteins. Functionally, in vivo silencing of the transcript caused molt cycle delay and a recombinant version of the protein was found to bind chitin and exhibited elastic properties. PMID:26010981

Prevalence of Third Molar Agenesis: Associated Dental Anomalies in Non-Syndromic 5923 Patients

PubMed Central

Sujon, Mamun Khan; Alam, Mohammad Khursheed; Rahman, Shaifulizan Abdul

2016-01-01

The aim of this study was to investigate the prevalence of third molar agenesis and other associated dental anomalies in Bangladeshi population and to investigate the relationship of other dental anomalies with the third molar presence/agenesis. A retrospective study was performed using panoramic radiographs of 5923 patients, who ranged in age from 10 to 50 years. All radiographs were analyzed by Planmeca Romexis® 3.0 software (Planmeca Oy, Helsinki, Finland). Pearson chi-square and one way ANOVA (Post Hoc) test were conducted. The prevalence of third molar agenesis was 38.4%. The frequency of third molar agenesis was significantly higher in females than males (p <0.025). Third molar agenesis was significantly more prevalent in maxilla as compared to mandible (p <0.007). The prevalence of other dental anomalies was 6.5%, among them hypodontia was 3.1%. Prevalence of third molar agenesis varies in different geographic region. Among the other dental anomalies hypodontia was more prevalent. PMID:27580050

Maxillary molar distalization with first class appliance

PubMed Central

Ramesh, Namitha; Palukunnu, Biswas; Ravindran, Nidhi; Nair, Preeti P

2014-01-01

Non-extraction treatment has gained popularity for corrections of mild-to-moderate class II malocclusion over the past few decades. The distalization of maxillary molars is of significant value for treatment of cases with minimal arch discrepancy and mild class II molar relation associated with a normal mandibular arch and acceptable profile. This paper describes our experience with a 16-year-old female patient who reported with irregularly placed upper front teeth and unpleasant smile. The patient was diagnosed to have angles class II malocclusion with moderate maxillary anterior crowding, deep bite of 4 mm on a skeletal class II base with an orthognathic maxilla and retrognathic mandible and normal growth pattern. She presented an ideal profile and so molar distalization was planned with the first-class appliance. Molars were distalised by 8 mm on the right and left quadrants and class I molar relation achieved within 4 months. The space gained was utilised effectively to align the arch and establish a class I molar and canine relation. PMID:24577171

Autotransplantation of endodontically treated third molars.

PubMed

Sobhi, Muhammad Bakhsh; Rana, Muzammil Jamil Ahmed; Manzoor, Manzoor Ahmed; Ibrahim, Mohammad; Tasleem-ul-Hudda

2003-07-01

To determine the success rate in autotransplantation of endodontically treated third molars. A descriptive study. This study was carried out at Armed Forces Institute of Dentistry (AFID), Rawalpindi (Pakistan) from January 2002 to December 2002. A total of 50 patients meeting the inclusion criteria were selected who had their first or second molars in unrestorable condition with intact third molars. The donor teeth were extracted after the preparation of recipient site. After endodontically treated in vitro the donor teeth were carried to the recipient site and immobilized. Postoperative variables were recorded and analyzed on SPSS version 10. The overall success rate after six months of the transplantation of third molars was 88% with complete root formation after endodontic treatment. All the patients(12%) who had complaints were more than 35 years of age. Third molars are good substitute for the unrestorable first or second molars and would be as effective as endosseous implants. The procedure is likely to have complications in the advanced age group.

Root canal morphology of South Asian Indian maxillary molar teeth

PubMed Central

Singh, Shishir; Pawar, Mansing

2015-01-01

Objective: The objective was to study the root canal morphology of South Asian Indian Maxillary molars using a tooth clearing technique. Materials and Methods: Hundred teeth each comprising of first, second, and third molars collected from different dental schools and clinics in India were subjected to standard dye penetration, decalcification and clearing procedure before being studied. Results: The first molar mesiobuccal roots exhibited 69% Type I, 24% Type II, 4% Type IV, 2% Type V, and 1% exhibited a Vertuccis Type VIII canal anatomy. In the group with three separate roots the second molar mesiobuccal roots in exhibited 80.6% Type I, 15.3% Type II, 2.7% Type IV, and 1.4% Type V canal anatomy while the third molars mesiobuccal roots exhibited 57.4% Type I, 32% Type II, 2.1% Type III, 8.5% Type IV, 1% had a Type V canal anatomy in the similar group. Conclusion: A varied root canal anatomy was seen in the mesiobuccal root canal of the maxillary molars. PMID:25713497

[Orthodontic partial disimpaction of mandibular third molars prior to surgical extraction].

PubMed

Derton, Nicolà; Perini, Alessandro; Giordanetto, José; Biondi, Giovanni; Siciliani, Giuseppe

2009-06-01

Odontodysplasia of the third molars is a relatively common anomaly. The frequent complications associated with this disorder very often constitute an indication for extraction of the third molar. This surgical treatment can damage the lower alveolar nerve and/or trigger distal bone loss of the second molar, thus jeopardizing the future status of the periodontium. The author presents two case studies treated exclusively with miniscrews with no dental anchorage in order to achieve partial eruption of the third molar moving it away from the lower alveolar nerve and to avoid unwanted impact on other teeth. Following this procedure, the third molar was extracted without complications. In conclusion, this approach can offer an alternative to surgical treatment alone in cases where the proximity of tooth and nerve poses a significant risk.

The postnatal development of the temporal part of the human temporomandibular joint. A quantitative study on skulls.

PubMed

Dibbets, J M; Dijkman, G E

1997-12-01

The morphology of the temporal part of the human temporomandibular joint (TMJ) changes drastically during postnatal development. The glenoid fossa will acquire its characteristic S shape and a tubercle will develop. The combined results of the literature and of this study allow a reconstruction of the actual growth processes. The roof of the glenoid fossa appears to enlarge forward by remodeling while sagittal and vertical growth is mainly achieved by deposition at the top of the tubercle. These latter changes result in a steeper slope of the eminence and take place in 3 phases, parallelling the eruption of the first incisors, the permanent first molars and the permanent second molars. While the zygomatic arch thickens by deposition at all surfaces, it also remodels downward relative to the external meatus. As a result, the neonate anulus occupies a lower position relative to this arch than does the adult meatus.

Production of MPS VII mouse (Gustm(hE540A·mE536A)Sly) doubly tolerant to human and mouse β-glucuronidase

PubMed Central

Tomatsu, Shunji; Orii, Koji O.; Vogler, Carole; Grubb, Jeffrey H.; Snella, Elizabeth M.; Gutierrez, Monica; Dieter, Tatiana; Holden, Christopher C.; Sukegawa, Kazuko; Orii, Tadao; Kondo, Naomi; Sly, William S.

2006-01-01

Mucopolysaccharidosis VII (MPS VII, Sly syndrome) is an autosomal recessive lysosomal storage disease caused by β-glucuronidase (GUS) deficiency. A naturally occurring mouse model of that disease has been very useful for studying experimental approaches to therapy. However, immune responses can complicate evaluation of the long-term benefits of enzyme replacement or gene therapy delivered to adult MPS VII mice. To make this model useful for studying the long-term effectiveness and side effects of experimental therapies delivered to adult mice, we developed a new MPS VII mouse model, which is tolerant to both human and murine GUS. To achieve this, we used homologous recombination to introduce simultaneously a human cDNA transgene expressing inactive human GUS into intron 9 of the murine Gus gene and a targeted active site mutation (E536A) into the adjacent exon 10. When the heterozygote products of germline transmission were bred to homozygosity, the homozygous mice expressed no GUS enzyme activity but expressed inactive human GUS protein highly and were tolerant to immune challenge with human enzyme. Expression of the mutant murine Gus gene was reduced to about 10% of normal levels, but the inactive murine GUS enzyme also conferred tolerance to murine GUS. This MPS VII mouse model should be useful to evaluate therapeutic responses in adult mice receiving repetitive doses of enzyme or mice receiving gene therapy as adults. Heterozygotes expressed only 9.5–26% of wild-type levels of murine GUS instead of the expected 50%, indicating a dominant-negative effect of the mutant enzyme monomers on the activity of GUS tetramers in different tissues. Corrective gene therapy in this model should provide high enough levels of expression of normal GUS monomers to overcome the dominant negative effect of mutant monomers on newly synthesized GUS tetramers in most tissues. PMID:12700165

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Yuanyuan; Smith, Charles E.; Cai, Zhonghou

Amelogenin is required for normal enamel formation and is the most abundant protein in developing enamel. Methods. Amelx +/+, Amelx +/- and Amelx -/- molars and incisors from C57BL/6 mice were characterized using RT-PCR, Western blotting, dissecting and light microscopy, immunohistochemistry (IHC), transmission electron microscopy (TEM), scanning electron microscopy (SEM), backscattered SEM (bSEM), nanohardness testing, and X-ray diffraction. No amelogenin protein was detected by Western blot analyses of enamel extracts from Amelx -/- mice. Amelx -/- incisor enamel averaged 20.3±3.3 μm in thickness, or only 1/6th that of the wild-type (122.3±7.9 μm). Amelx -/- incisor enamel nanohardness was 1.6 Gpa,more » less than half that of wild-type enamel (3.6 Gpa). Amelx +/- incisors and molars showed vertical banding patterns unique to each tooth. IHC detected no amelogenin in Amelx -/- enamel and varied levels of amelogenin in Amelx +/- incisors, which correlated positively with enamel thickness, strongly supporting lyonization as the cause of the variations in enamel thickness. TEM analyses showed characteristic mineral ribbons in Amelx +/+ and Amelx -/- enamel extending from mineralized dentin collagen to the ameloblast. The Amelx-/- enamel ribbons were not well-separated by matrix and appeared to fuse together, forming plates. Furthermore, x-ray diffraction determined that the predominant mineral in Amelx -/- enamel is octacalcium phosphate (not calcium hydroxyapatite). Amelx -/- ameloblasts were similar to wild-type ameloblasts except no Tomes’ processes extended into the thin enamel. Amelx -/- and Amelx +/- molars both showed calcified nodules on their occlusal surfaces. Histology of D5 and D11 developing molars showed nodules forming during the maturation stage. Amelogenin forms a resorbable matrix that separates and supports, but does not shape early secretory stage enamel ribbons. Amelogenin may facilitate the conversion of enamel ribbons into hydroxyapatite by inhibiting the formation of octacalcium phosphate. Finally, amelogenin is necessary for thickening the enamel layer, which helps maintain ribbon organization and development and maintenance of the Tomes process.« less

Third molars and periodontal pathology in American adolescents and young adults: a prevalence study.

PubMed

Blakey, George H; Gelesko, Savannah; Marciani, Robert D; Haug, Richard H; Offenbacher, Steven; Phillips, Ceib; White, Raymond P

2010-02-01

To assess the association between visible third molars and the prevalence of periodontal inflammatory disease of non-third molars. Subjects aged 14 to 45 years with 4 asymptomatic third molars were enrolled in an institutional review board-approved study. Subjects were classified based on whether at least 1 third molar was visible or all third molars were not visible. Full-mouth periodontal probing depth (PD) data, with 6 sites per tooth, were obtained as a measure of a subject's periodontal status. At least 1 non-third molar PD of 4 mm or greater was indicative of periodontal inflammatory disease. Outcomes for the respective groups were compared by use of Cochran-Mantel-Haenszel row mean score statistics. The level of significance for differences was set at .05. The 342 subjects in the visible group were significantly older, with a median age of 26 years (interquartile range, 22.4-32.2 years), as compared with the 69 subjects in the not visible group, with a median age of 21 years (interquartile range, 18.8-24.9 years) (P < .01). The proportion of males and females was not statistically different between groups (P > .05). Most subjects were white. Significantly more subjects with at least a college education were in the visible group than in the not visible group (P < .01). The rate of tobacco use was low and did not differ between groups. Subjects in the visible group were significantly more likely to have at least 1 PD of 4 mm or greater on non-third molars than those in the not visible group: 59% versus 35%. In both groups, first/second molars were more affected than nonmolars when we controlled for differences in age between groups. The visible presence of third molars in adolescents and young adults was significantly associated with periodontal inflammatory disease of non-third molars. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Distal caries of the second molar in the presence of a mandibular third molar - a prevention protocol.

PubMed

Toedtling, V; Coulthard, P; Thackray, G

2016-09-23

Objectives The objectives of the prospective study were to establish the prevalence of distal caries (DC) in the mandibular second molar and to assess the outcomes of these diseased teeth in our population. Further aims were to identify associated risk factors and to design a protocol for prevention.Methods Clinical and radiographic data from 210 consecutive patients were ascertained over a three-month period. The sample population included all patients who had been referred to a hospital oral surgery department for a lower wisdom tooth assessment.Results A total of 224 mandibular third molars were included and assessed. The prevalence of caries affecting the distal aspect of the second molar was 38% (n = 85) in this population. In 18% of patients there was evidence of early enamel caries. Fifty-eight percent of caries was managed with restorative treatment but 11% of patients required second molar extraction and 13% of patients required the removal of the second and third molars. The prevalence of distal caries was significantly higher in patients with partially erupted wisdom teeth positioned below the amelocemental junction (P <0.05) of the adjacent second molar and in patients who presented with mesioangular impactions (P <0.001). However there was no difference in dental health when comparing this group to the remaining study population (P = 0.354). The Pearson chi-square test and Pearson correlation coefficient were used to verify the association between the tested variables.Conclusion This study demonstrates that the eruption status, type of angulation and the nature of tooth contact between both molars are useful disease predictors which can be used to indicate the likelihood of a caries process occurring on the distal aspect of the second mandibular molar. If patients' third molar teeth are not removed then consideration needs to be given to prevention and regular monitoring.

Three-dimensional alginate spheroid culture system of murine osteosarcoma.

PubMed

Akeda, Koji; Nishimura, Akinobu; Satonaka, Haruhiko; Shintani, Ken; Kusuzaki, Katsuyuki; Matsumine, Akihiko; Kasai, Yuichi; Masuda, Koichi; Uchida, Atsumasa

2009-11-01

Osteosarcoma (OS) is the most common primary malignant tumor of the bone and often forms pulmonary metastases, which are the most important prognostic factor. For further elucidation of the mechanism underlying the progression and metastasis of human OS, a culture system mimicking the microenvironment of the tumor in vivo is needed. We report a novel three-dimensional (3D) alginate spheroid culture system of murine osteosarcoma. Two different metastatic clones, the parental Dunn and its derivative line LM8, which has a higher metastatic potential to the lungs, were encapsulated in alginate beads to develop the 3D culture system. The beads containing murine OS cells were also transplanted into mice to determine their metastatic potential in vivo. In this culture system, murine OS cells encapsulated in alginate beads were able to grow in a 3D structure with cells detaching from the alginate environment. The number of detaching cells was higher in the LM8 cell line than the Dunn cell line. In the in vivo alginate bead transplantation model, the rate of pulmonary metastasis was higher with LM8 cells compared with that of Dunn cells. The cell characteristics and kinetics in this culture system closely reflect the original malignant potential of the cells in vivo.

A consensus definition of cataplexy in mouse models of narcolepsy.

PubMed

Scammell, Thomas E; Willie, Jon T; Guilleminault, Christian; Siegel, Jerome M

2009-01-01

People with narcolepsy often have episodes of cataplexy, brief periods of muscle weakness triggered by strong emotions. Many researchers are now studying mouse models of narcolepsy, but definitions of cataplexy-like behavior in mice differ across labs. To establish a common language, the International Working Group on Rodent Models of Narcolepsy reviewed the literature on cataplexy in people with narcolepsy and in dog and mouse models of narcolepsy and then developed a consensus definition of murine cataplexy. The group concluded that murine cataplexy is an abrupt episode of nuchal atonia lasting at least 10 seconds. In addition, theta activity dominates the EEG during the episode, and video recordings document immobility. To distinguish a cataplexy episode from REM sleep after a brief awakening, at least 40 seconds of wakefulness must precede the episode. Bouts of cataplexy fitting this definition are common in mice with disrupted orexin/hypocretin signaling, but these events almost never occur in wild type mice. It remains unclear whether murine cataplexy is triggered by strong emotions or whether mice remain conscious during the episodes as in people with narcolepsy. This working definition provides helpful insights into murine cataplexy and should allow objective and accurate comparisons of cataplexy in future studies using mouse models of narcolepsy.

Twenty-nine-month follow-up of a paediatric zirconia dental crown.

PubMed

Lopez Cazaux, Serena; Hyon, Isabelle; Prud'homme, Tony; Dajean Trutaud, Sylvie

2017-06-14

The aim of this paper is to present the long-term follow-up of one paediatric zirconia crown on a deciduous molar. Preformed crowns are part of the armamentarium in paediatric dentistry. In recent years, aesthetic alternatives to preformed metal crowns have been developed, first preveneered crowns and then zirconia crowns. This paper describes the restoration of a primary molar with a zirconia crown (EZ-Pedo, Loomis, California, USA) in an 8-year-old boy. In this clinical case, the protocol for the implementation and maintenance of zirconia crowns is detailed. The patient was followed up for 29 months until the natural exfoliation of his primary molar. The adaptation of the zirconia crown, the gingival health and the wear on the opposing tooth were considered. In this case, the paediatric zirconia crown allowed sustainable functional restoration while restoring a natural appearance of the tooth. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The history of Latin teeth names.

PubMed

Šimon, František

2015-01-01

This paper aims to give an account of the Latin naming of the different types of teeth by reviewing relevant historical and contemporary literature. The paper presents etymologies of Latin or Greek teeth names, their development, variants and synonyms, and sometimes the names of their authors. The Greek names did not have the status of official terms, but the Latin terms for particular types of teeth gradually established themselves. Names for the incisors, canines and molars are Latin calques for the Greek ones (tomeis, kynodontes, mylai), dens serotinus is an indirect calque of the Greek name (odús) opsigonos, and the term pre-molar is created in the way which is now common in modern anatomical terminology, using the prefix prae- = pre and the adjective molaris. The Latin terms dentes canini and dentes molares occur in the Classical Latin literature, the term (dentes) incisivi is found first time in medieval literature, and the terms dentes premolares and dens serotinus are modern-age ones.

40 CFR 796.1050 - Absorption in aqueous solution: Ultraviolet/visible spectra.

Code of Federal Regulations, 2013 CFR

2013-07-01

... by both molar absorption coefficient (molar extinction coefficient) and band width. However, the..., expressed in cm; and the molar absorption (extinction) coefficient,εi, of each species. The absorbance...

40 CFR 796.1050 - Absorption in aqueous solution: Ultraviolet/visible spectra.

Code of Federal Regulations, 2012 CFR

2012-07-01

... by both molar absorption coefficient (molar extinction coefficient) and band width. However, the..., expressed in cm; and the molar absorption (extinction) coefficient,εi, of each species. The absorbance...

40 CFR 796.1050 - Absorption in aqueous solution: Ultraviolet/visible spectra.

Code of Federal Regulations, 2014 CFR

2014-07-01

... by both molar absorption coefficient (molar extinction coefficient) and band width. However, the..., expressed in cm; and the molar absorption (extinction) coefficient,εi, of each species. The absorbance...

The Ornithine Decarboxylase Gene Is Essential for Cell Survival during Early Murine Development

PubMed Central

Pendeville, Hélène; Carpino, Nick; Marine, Jean-Christophe; Takahashi, Yutaka; Muller, Marc; Martial, Joseph A.; Cleveland, John L.

2001-01-01

Overexpression and inhibitor studies have suggested that the c-Myc target gene for ornithine decarboxylase (ODC), the enzyme which converts ornithine to putrescine, plays an important role in diverse biological processes, including cell growth, differentiation, transformation, and apoptosis. To explore the physiological function of ODC in mammalian development, we generated mice harboring a disrupted ODC gene. ODC-heterozygous mice were viable, normal, and fertile. Although zygotic ODC is expressed throughout the embryo prior to implantation, loss of ODC did not block normal development to the blastocyst stage. Embryonic day E3.5 ODC-deficient embryos were capable of uterine implantation and induced maternal decidualization yet failed to develop substantially thereafter. Surprisingly, analysis of ODC-deficient blastocysts suggests that loss of ODC does not affect cell growth per se but rather is required for survival of the pluripotent cells of the inner cell mass. Therefore, ODC plays an essential role in murine development, and proper homeostasis of polyamine pools appears to be required for cell survival prior to gastrulation. PMID:11533243

Anesthetic Success of an Inferior Alveolar Nerve Block and Supplemental Articaine Buccal Infiltration for Molars and Premolars in Patients with Symptomatic Irreversible Pulpitis.

PubMed

Fowler, Sara; Drum, Melissa; Reader, Al; Beck, Mike

2016-03-01

The purpose of this retrospective study was to determine the anesthetic success of the inferior alveolar nerve (IAN) block, and supplemental articaine buccal infiltration after a failed IAN block, in first and second molars and premolars in patients presenting with symptomatic irreversible pulpitis. As part of 6 studies, 375 emergency patients presenting with symptomatic irreversible pulpitis received 2% lidocaine with 1:100,000 epinephrine via an IAN block. After profound lip numbness, endodontic access and instrumentation were initiated. If the patient felt moderate to severe pain, a supplemental buccal infiltration of a cartridge of 4% articaine with 1:100,000 epinephrine was administered (204 patients), and endodontic treatment continued. Success was defined as the ability to access and instrument the tooth without pain (visual analogue scale rating of 0) or mild pain (visual analogue scale rating less than or equal to 54 mm). IAN block success was 28% for the first molars, 25% for the second molars, and 39% for the premolars. There were no significant differences when comparing molars with premolars. For the supplemental articaine buccal infiltration, success was 42% for the first molars, 48% for the second molars, and 73% for the premolars. There were no significant differences when comparing the molars, but there was a significant difference when comparing the premolars with the molars. For patients presenting with symptomatic irreversible pulpitis, the success rates for the IAN block and supplemental buccal infiltration of articaine of the molars and premolars would not be high enough to ensure profound pulpal anesthesia. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Orthodontic uprighting of severely impacted mandibular second molars.

PubMed

Lau, Catherine K; Whang, Claudia Z Y; Bister, Dirk

2013-01-01

The prevalence of impacted second molars is low, varying from 0% to 2.3%. The etiology of an impaction can involve systemic, local, and periodontal factors, as well as a developmental disruption of the tooth germ. A number of surgical and orthodontic treatment options have been suggested in the literature, including leaving the tooth in situ, removing the impacted second molar, orthodontic uprighting, and autotransplantation. Removal of third molars has been suggested as an adjunct for space creation. This article presents the treatment of a girl with bilateral severely impacted mandibular second molars as well as an ectopic maxillary left canine and severe crowding affecting both the maxillary and mandibular arches. Her treatment was successfully completed with fixed preadjusted edgewise appliances (0.022 × 0.028-in slot size) and MBT prescription (APC precoated Gemini Brackets; 3M Unitek, St. Paul, Minn), along with the removal of 4 first premolars. The maxillary left canine and the mandibular second molars were surgically exposed. The treatment mechanics show that even severely impacted second molars can be uprighted by routine straight-wire techniques, which are easy to apply. The center of rotation of the second molar lies in the bifurcation of the roots of this tooth, and this biomechanical property was used to its full advantage. The techniques applied comprised bracket repositioning, bypass of brackets, conversion of molar tubes to brackets, thermoelastic copper-nickel-titanium archwires, and a push-coil spring. Other orthodontic treatment mechanics, which require complex sectional or segmental techniques, auxiliaries, or artistic wire bending, that have been suggested in the literature were not used here. The third molars were not removed. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Image analysis of the eruptive positions of third molars and adjacent second molars as indicators of age evaluation in Thai patients

PubMed Central

Pramojanee, Sakarat; Thaiupathump, Trasapong

2013-01-01

Purpose This study was performed to determine the relationship between the stage of tooth eruption (both vertical and mesio-angular) and chronological age. Materials and Methods Indirect digital panoramic radiographs were used to measure the distances from the dentinoenamel junction (DEJ) of the second molars to the occlusal plane of the second molar teeth and of the adjacent third molars in 264 Thai males and 437 Thai females using ImageJ software. The ratio of those distances was calculated by patient age, and the correlation coefficient of the ratio of the third molar length to the second molar length was calculated. Results The correlation between the height of the vertically erupted upper third molar teeth and age was at the intermediate level. The age range of ≥15 to <16 years was noted to be the range in which the correlation between the chronological age determined from the eruptional height and actual chronological age was statistically significant. The mean age of the female subjects, in which the position of the right upper third molar teeth was at or above the DEJ of the adjacent second molar but below one half of its coronal height was 19.9±2.6 years. That for the left side was 20.2±2.7 years. The mean ages of the male subjects were 20.1±3.3 years and 19.8±2.7 years for the right and left sides, respectively. Conclusion It might be possible to predict chronological age from the eruption height of the wisdom teeth. PMID:24380069

Ectopic eruption of first permanent molars: presenting features and associations.

PubMed

Mooney, G C; Morgan, A G; Rodd, H D; North, S

2007-09-01

To investigate presenting features of ectopically erupting first permanent molars and associations with other dental anomalies. Prospective convenience study. 28 panoral radiographs were collected, over a 24-month period, of 7-11 year-old children with radiographic evidence of ectopic eruption of first permanent molars who presented to a Dental Teaching Hospital in the North of England. A further 20 radiographs were collected of matched patients with no evidence of ectopic molar eruption. All radiographs were analysed under standard conditions to record the distribution and type of ectopic eruption (if present). In addition, the presence of the following dental anomalies was noted: cleft lip and/or palate; supernumerary teeth; hypodontia, and infraocclusion of primary molars. Chi-squared analysis was performed to determine any significant differences in the frequency of these dental anomalies between ectopic molar and control groups. For patients with ectopic molar eruption, the majority demonstrated ectopic eruption of either one or two first permanent molars (32% and 57% of subjects respectively). There were a similar proportion of 'jumps' and 'holds'. 92% of these were maxillary teeth and there was equal left and right distribution. Interestingly, a positive record of ectopic eruption was only documented in the dental records of 35.7% of these subjects. Children with ectopic eruption were significantly more likely to have at least one additional dental anomaly than was the case for the control group (60.7% versus 25%). Notably, primary molar infraocclusion and cleft lip/palate were significantly more frequent in the ectopic group. This study, the first in a British population, has identified a significant association between ectopic eruption of first permanent molars and other dental anomalies. A multifactorial aetiology is thus supported and clinicians should be alert to the co-existence of ectopic eruption and other dental anomalies.

Morphology of mandibular first molars analyzed by cone-beam computed tomography in a Korean population: variations in the number of roots and canals.

PubMed

Kim, Sin-Young; Kim, Bom Sahn; Woo, Jein; Kim, Yemi

2013-12-01

The aim of this study was to determine the root and canal morphology of the mandibular first molars in a Korean population of Mongolian origin by retrospective analysis of a large number of cone-beam computed tomography (CBCT) images. A total of 976 subjects with bilateral mandibular first molars were examined by using in vivo CBCT methods. The number and configuration of roots, the number of root canals, and the canal configuration based on Vertucci's classification were determined. Overall, 25.82% of examined molars had 3 roots, 73.51% had 2 roots, and 0.67% had 1 root. The incidence of fourth canal was 50.36%. A right-sided predominance was noted for extra distal roots (P < .001), whereas a left-sided predominance was observed for extra distal canals (P < .001). No significant sex-related differences were shown for their prevalence. The bilateral prevalence rate was 69.13% for extra distal roots and 78.08% for extra distolingual (DL) canals. In the mesial roots, type IV canal was the most frequent (76.86% for 2-rooted molars and 72.96% for 3-rooted molars). In the distal roots, type l was the most common (66.62% for 2-rooted molars and 99.40%-100% for 3-rooted molars). The incidence of 2 canals in distobuccal roots, first reported in this study, was 0.15%. Among mandibular first molars, there is a high prevalence of a separate DL root and/or a separate DL canal, and such molars commonly have 4 canals in the Korean population. CBCT is a useful tool for determining root and canal morphology. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The incidence of periodontal defects distal to the maxillary second molar after impacted third molar extraction.

PubMed

Coleman, Michael; McCormick, Adam; Laskin, Daniel M

2011-02-01

This study assessed the incidence of periodontal defects on the distal aspect of maxillary second molars after extraction of impacted maxillary third molars. Subjects enrolled in this institutional review board-approved prospective study consisted of healthy young patients having extraction of at least 1 asymptomatic impacted maxillary third molar adjacent to a second molar. Preoperative periodontal probing data were collected from 4 sites (midbuccal, distobuccal, midpalatal, and distopalatal) on each adjacent second molar, and a similar probing examination was performed at a mean of 6 months postoperatively. All subjects were treated under general anesthesia or conscious sedation by upper-level residents in the outpatient clinic. Twenty subjects with a total of 38 impacted maxillary third molars were treated. There were 9 male subjects (45%) and 11 female subjects (55%), with a mean age of 17 years (range, 14-22 years). The mean follow-up interval was 6 months, with a range of 3 to 15 months. Of the 152 probing sites measured, 92 (61%) decreased, 56 (37%) remained unchanged, and only 4 (2.6%) increased. A decrease in probing depth of 1 mm was found in 35 (23%) of the sites, a decrease of 2 mm was seen in 32 (21%), and 25 (16%) decreased by 3 mm or more. Of the 152 sites probed, 4 (2.6%) increased by 1 or 2 mm. Extraction of the impacted maxillary third molar does not result in significant periodontal defects on the distal aspect of the adjacent second molar, and in many cases it results in an improvement of the probing depths on these teeth. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Autogenous transplantation of maxillary and mandibular molars.

PubMed

Reich, Peter P

2008-11-01

Autogenous tooth transplantation has been used as a predictable surgical approach to correct malocclusion and replace edentulous areas. This article focuses on the surgical approach and technique for molar transplantation. Thirty-two patients aged between 11 and 25 years underwent 44 autogenous molar transplantations. The procedure involved transplantation of impacted or newly erupted third molars into the extraction sockets of nonrestorable molars and surgical removal and replacement of horizontally impacted molars into their proper vertical alignment. Five basic procedural concepts were applied: 1) atraumatic extraction, avoiding disruption of the root sheath and root buds; 2) apical contouring of bone at the transplantation site and maxillary sinus lift via the Summers osteotome technique, when indicated, for maxillary molars; 3) preparation of a 4-wall bony socket; 4) avoidance of premature occlusal interferences; and 5) stabilization of the tooth with placement of a basket suture. All 32 patients successfully underwent the planned procedure. To date, 2 patients have had localized infection that resulted in loss of the transplant. The remaining 42 transplants remain asymptomatic and functioning, with a mean follow-up period of 19 months. No infection, ankylosis, loss of the transplant, or root resorption has been noted. In addition, endodontic therapy has not been necessary on any transplanted teeth. Autogenous tooth transplantation has been discussed and described in the literature previously, with a primary focus on cuspid and bicuspid transplantation. The molar transplant is infrequently discussed in today's literature, possibly because of the preponderance of titanium dental implants. Autogenous molar transplantation is a viable procedure with low morbidity and excellent functional and esthetic outcomes. This report shows the successful transplantation of 42 of 44 molars in 32 patients with a mean follow-up period of 19 months.

Correlation of mandibular impacted tooth and bone morphology determined by cone beam computed topography on a premise of third molar operation.

PubMed

Momin, M A; Matsumoto, K; Ejima, K; Asaumi, R; Kawai, T; Arai, Y; Honda, K; Yosue, T

2013-05-01

To determine the width and morphology of the mandible in the impacted third molar region, and to identify the location of the mandibular canal prior to planning impacted third molar operations. Cone beam computed tomography (CBCT) data of 87 mandibular third molars from 62 Japanese patients were analyzed in this study. The width of the lingual cortical bone and apex-canal distance were measured from cross-sectional images in which the cortical bone was thinnest at the lingual side in the third molar region. Images were used for measuring the space (distance between the inner border of the lingual cortical bone and outer surface of the third molar root), apex-canal distance (distance from the root of the third molar tooth to the superior border of the inferior alveolar canal) and the cortical bone (width between the inner and outer borders of the lingual cortical bone). The means of the space, apex-canal distance and lingual cortical width were 0.31, 1.99, and 0.68 mm, respectively. Impacted third molar teeth (types A-C) were observed at the following frequencies: type A (angular) 37 %; type B (horizontal), 42 %; type C (vertical), 21 %. The morphology of the mandible at the third molar region (types D-F) was observed as: type D (round), 49 %; type E (lingual extended), 18 %; and type F (lingual concave), 32 %. The width and morphology of the mandible with impacted teeth and the location of the mandibular canal at the third molar region could be clearly determined using cross-sectional CBCT images.

An electron spin resonance study for real-time detection of ascorbyl free radicals after addition of dimethyl sulfoxide in murine hippocampus or plasma during kainic acid-induced seizures.

PubMed

Matsumoto, Shigekiyo; Shingu, Chihiro; Koga, Hironori; Hagiwara, Satoshi; Iwasaka, Hideo; Noguchi, Takayuki; Yokoi, Isao

2010-07-01

Electron spin resonance (ESR)-silent ascorbate solutions generate a detectable, likely concentration-dependent signal of ascorbyl free radicals (AFR) immediately upon addition of a molar excess of dimethyl sulfoxide (DMSO). We aimed to perform quantitative ESR analysis of AFR in real time after addition of DMSO (AFR/DMSO) to evaluate ascorbate concentrations in fresh hippocampus or plasma following systemic administration of kainate in mice. Use of a special tissue-type quartz cell allowed immediate detection of AFR/DMSO ESR spectra in fresh tissues from mice. AFR/DMSO content was increased significantly in fresh hippocampus or plasma obtained during kainate-induced seizures of mice, reaching maximum levels at 90 min after intraperitoneal administration of 50 mg/kg kainic acid. This suggests that oxidative injury of the hippocampus resulted from the accumulation of large amounts of ascorbic acid in the brain after kainic acid administration. AFR/DMSO content measured on an ESR spectrometer can be used for real-time evaluation of ascorbate content in fresh tissue. Due to the simplicity, good performance, low cost and real-time monitoring of ascorbate, this method may be applied to clinical research and treatment in the future.

Efficacy of Posaconazole in Murine Experimental Sporotrichosis

PubMed Central

Fernández-Silva, Fabiola; Capilla, Javier; Mayayo, Emilio

2012-01-01

We developed a murine model of systemic sporotrichosis by using three strains of each of the two commonest species causing sporotrichosis, i.e., Sporothrix schenckii sensu stricto and Sporothrix brasiliensis, in order to evaluate the efficacy of posaconazole (PSC). The drug was administered at a dose of 2.5 or 5 mg/kg of body weight twice a day by gavage, and one group was treated with amphotericin B (AMB) as a control treatment. Posaconazole, especially at 5 mg/kg, showed good efficacy against all the strains tested, regardless of their MICs, as measured by prolonged survival, tissue burden reduction, and histopathology. PMID:22330929

Efficacy of posaconazole in murine experimental sporotrichosis.

PubMed

Fernández-Silva, Fabiola; Capilla, Javier; Mayayo, Emilio; Guarro, Josep

2012-05-01

We developed a murine model of systemic sporotrichosis by using three strains of each of the two commonest species causing sporotrichosis, i.e., Sporothrix schenckii sensu stricto and Sporothrix brasiliensis, in order to evaluate the efficacy of posaconazole (PSC). The drug was administered at a dose of 2.5 or 5 mg/kg of body weight twice a day by gavage, and one group was treated with amphotericin B (AMB) as a control treatment. Posaconazole, especially at 5 mg/kg, showed good efficacy against all the strains tested, regardless of their MICs, as measured by prolonged survival, tissue burden reduction, and histopathology.

Catalase-peroxidase activity has no influence on virulence in a murine model of tuberculosis.

PubMed

Cardona, Pere Joan; Gordillo, Sergi; Amat, Isabel; Díaz, Jorge; Lonca, Joan; Vilaplana, Cristina; Pallarés, Angeles; Llatjós, Roger; Ariza, Aurelio; Ausina, Vicenç

2003-01-01

The capacity to generate a chronic and persistent infection in the experimental murine model of tuberculosis induced aerogenically by a low-dose inoculum was determined in eight isoniazid-resistant clinical strains of Mycobacterium tuberculosis showing different catalase-peroxidase (C-P) activities. Determination of bacillary concentration in lung and spleen and the percentage of pulmonary parenchyma occupied by granulomas were monitored. Data showed no relation between the lack of C-P activity and the ability to develop a persistent infection, highlighting the potential of C-P negative strains to spread through the community.

Molar Pregnancy

MedlinePlus

... including a rare form of cancer — and requires early treatment. Symptoms A molar pregnancy may seem like a normal pregnancy at first, but most molar pregnancies cause specific signs and symptoms, including: Dark brown to bright red ...

Effects of zinc oxide-eugenol and calcium hydroxide/ iodoform on delaying root resorption in primary molars without successors.

PubMed

Lin, Bichen; Zhao, Yuming; Yang, Jie; Wang, Wenjun; Ge, Li-hong

2014-01-01

The purpose of this study was to compare the effects of zinc oxide-eugenol (ZOE) and calcium hydroxide/iodoform paste (Vitapex), as root canal filling materials in pulpectomy, on delaying the root resorption of primary molars without permanent successors. Animal models without permanent successors were surgically established in beagle dogs. Root resorption was observed via periapical radiographs. The onset of root resorption of primary mandibular molars without successors occurred later (p<0.05) than physiologic resorption. ZOE pulpectomy clearly delayed the root resorption of primary molars without permanent successors (p<0.05), whereas resorption of primary molars with Vitapex pulpectomy started at almost the same time as physiologic resorption. Compared with Vitapex, ZOE was a more effective root canal filling material in delaying the root resorption of primary molars.

Therapeutic decisions in the presence of decayed permanent first molars in young subjects: a descriptive inquiry.

PubMed

Sayagh, Millewa; Maniere-Ezvan, Armelle; Vernet, Cindy; Muller-Bolla, Michèle

2012-09-01

The aim of this exhaustive descriptive epidemiological study was to determine the clinical approach to be adopted by practitioners specializing exclusively in pediatric odontology and by orthodontists when confronted with decayed molars in children and adolescents. A questionnaire was sent out to all corresponding practitioners (n=2076). Six questions related to treatment decisions taken when faced with decayed permanent first molars (unfavorable short or middle-term prognosis) in patients needing, or not, orthodontic care. The Chi(2) test was used to compare responses. Thirty-eight per cent of pedodontists (n=38) and 12.5% (n=246) of orthodontists answered the questionnaire. Faced with a permanent first molar with an unfavorable middle-term prognosis, 75.7% needed criteria to help them reach their treatment decision. In decreasing order of importance, these criteria were: presence of the third molar, patient motivation, inter-arch relationship, patient's oral hygiene, facial type, anterior jaw-teeth discrepancy and the number of molars to be extracted. Faced with a permanent first molar requiring extraction and when orthodontic treatment was not required, 31.7% of practitioners decided to close the maxillary space immediately as opposed to 13.4% who closed the space at the mandible. In the presence of a single decayed first molar, 68.7% of practitioners did not extract the antagonist or contralateral first molars. These treatment decisions were not always unanimous and call for a combined approach between dental surgeon and orthodontist. Copyright © 2012. Published by Elsevier Masson SAS.

Association between third molar agenesis patterns and agenesis of other teeth in a Japanese orthodontic population.

PubMed

Endo, Saori; Sanpei, Sugako; Ishida, Rieko; Sanpei, Shinya; Abe, Ryota; Endo, Toshiya

2015-01-01

The purpose of this study was to investigate the patterns of third molar agenesis and incidence of agenesis of other permanent teeth in a Japanese orthodontic patient group. A total of 417 Japanese subjects (134 males and 283 females) with agenesis of one or more third molars were divided into four groups according to the agenesis pattern, and 874 other Japanese subjects (302 males and 572 females) without third molar agenesis were assigned to a control group. Panoramic radiographs and medical and dental records were used to examine for tooth agenesis. The Chi-square test and odds ratio were used to make statistical comparisons. The prevalence of third molar agenesis worked out at 32.3% with no statistically significant gender difference. A high prevalence rate of agenesis of third molars, unilateral or bilateral, could be considered characteristic of the Japanese orthodontic population. Significant increases in occurrence of oligodontia, and unilateral or bilateral agenesis of other teeth, including maxillary lateral incisors and maxillary and mandibular second premolars, were observed in all or almost all of the third molar agenesis groups, compared with the controls. A significantly increased prevalence rate of mandibular lateral incisor agenesis was observed in almost all of the third molar agenesis groups. The Japanese patients with third molar agenesis had a significantly increased occurrence of oligodontia, and unilateral or bilateral agenesis of maxillary and mandibular lateral incisors and second premolars, except for bilateral agenesis of mandibular lateral incisors.

Protraction of mandibular second and third molars assisted by partial corticision and miniscrew anchorage.

PubMed

Mimura, Hiroshi

2013-08-01

A woman, aged 47 years 6 months, with an anterior open bite and a left-shifted mandible was treated with a mandibular right first molar extraction and without orthognathic surgery. However, her mandibular second molar did not move mesially during treatment because of the dense lamina dura; therefore, corticision was applied only on the mesial aspect of the mandibular second molar, and a miniscrew was inserted simultaneously. Corticision was introduced as a supplemental dentoalveolar surgery in orthodontic therapy to achieve accelerated tooth movement with minimal surgical intervention. In this technique, a reinforced scalpel was used as a thin chisel to separate the interproximal cortices transmucosally without a flap. This technique was applied not to accelerate tooth movement, but to protract the mandibular molars. One miniscrew was inserted on the mesiobuccal side of the mandibular right molar for protraction and intrusion. In addition, 2 miniscrews were inserted in the buccal sides of the maxillary first and second molars and the palatal side of the maxillary first molar to intrude them for correction of the mandibular shift and the cant of the occlusal plane. Excellent occlusion and correction of the anterior open bite were achieved without surgery. At the 2-year follow-up examination, the patient had a good occlusion and showed good stability with no opening of the extraction space. A partial corticision is an effective option for facilitating movement of mandibular molars. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Coronectomy of Deeply Impacted Lower Third Molar: Incidence of Outcomes and Complications after One Year Follow-Up

PubMed Central

Heijsters, Guido; Salem, Ahmed Sobhy; Van Slycke, Sarah; Schepers, Serge; Politis, Constantinus; Vrielinck, Luc

2015-01-01

ABSTRACT Objectives The purpose of present study was to assess the surgical management of impacted third molar with proximity to the inferior alveolar nerve and complications associated with coronectomy in a series of patients undergoing third molar surgery. Material and Methods The position of the mandibular canal in relation to the mandibular third molar region and mandibular foramen in the front part of the mandible (i.e., third molar in close proximity to the inferior alveolar nerve [IAN] or not) was identified on panoramic radiographs of patients scheduled for third molar extraction. Results Close proximity to the IAN was observed in 64 patients (35 females, 29 males) with an impacted mandibular third molar. Coronectomy was performed in these patients. The most common complication was tooth migration away from the mandibular canal (n = 14), followed by root exposure (n = 5). Re-operation to remove the root was performed in cases with periapical infection and root exposure. Conclusions The results indicate that coronectomy can be considered a reasonable and safe treatment alternative for patients who demonstrate elevated risk for injury to the inferior alveolar nerve with removal of the third molars. Coronectomy did not increase the incidence of damage to the inferior alveolar nerve and would be safer than complete extraction in situations in which the root of the mandibular third molar overlaps or is in close proximity to the mandibular canal. PMID:26229580

Ube3a reinstatement identifies distinct developmental windows in a murine Angelman syndrome model

PubMed Central

Silva-Santos, Sara; van Woerden, Geeske M.; Bruinsma, Caroline F.; Mientjes, Edwin; Jolfaei, Mehrnoush Aghadavoud; Distel, Ben; Kushner, Steven A.; Elgersma, Ype

2015-01-01

Angelman syndrome (AS) is a severe neurodevelopmental disorder that results from loss of function of the maternal ubiquitin protein ligase E3A (UBE3A) allele. Due to neuron-specific imprinting, the paternal UBE3A copy is silenced. Previous studies in murine models have demonstrated that strategies to activate the paternal Ube3a allele are feasible; however, a recent study showed that pharmacological Ube3a gene reactivation in adulthood failed to rescue the majority of neurocognitive phenotypes in a murine AS model. Here, we performed a systematic study to investigate the possibility that neurocognitive rescue can be achieved by reinstating Ube3a during earlier neurodevelopmental windows. We developed an AS model that allows for temporally controlled Cre-dependent induction of the maternal Ube3a allele and determined that there are distinct neurodevelopmental windows during which Ube3a restoration can rescue AS-relevant phenotypes. Motor deficits were rescued by Ube3a reinstatement in adolescent mice, whereas anxiety, repetitive behavior, and epilepsy were only rescued when Ube3a was reinstated during early development. In contrast, hippocampal synaptic plasticity could be restored at any age. Together, these findings suggest that Ube3a reinstatement early in development may be necessary to prevent or rescue most AS-associated phenotypes and should be considered in future clinical trial design. PMID:25866966

Adhesives for bonded molar tubes during fixed brace treatment.

PubMed

Millett, Declan T; Mandall, Nicky A; Mattick, Rye Cr; Hickman, Joy; Glenny, Anne-Marie

2017-02-23

Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. The success of a fixed appliance depends partly on the metal attachments (brackets and bands) being glued to the teeth so that they do not become detached during treatment. Brackets (metal squares) are usually attached to teeth other than molars, where bands (metal rings that go round each tooth) are more commonly used. Orthodontic tubes (stainless steel tubes that allow wires to pass through them), are typically welded to bands but they may also be glued directly (bonded) to molars. Failure of brackets, bands and bonded molar tubes slows down the progress of treatment with a fixed appliance. It can also be costly in terms of clinical time, materials and time lost from education/work for the patient. This is an update of the Cochrane review first published in 2011. A new full search was conducted on 15 February 2017 but no new studies were identified. We have only updated the search methods section in this new version. The conclusions of this Cochrane review remain the same. To evaluate the effectiveness of the adhesives used to attach bonded molar tubes, and the relative effectiveness of the adhesives used to attach bonded molar tubes versus adhesives used to attach bands, during fixed appliance treatment, in terms of: (1) how often the tubes (or bands) come off during treatment; and (2) whether they protect the bonded (or banded) teeth against decay. The following electronic databases were searched: Cochrane Oral Health's Trials Register (to 15 February 2017), the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 1) in the Cochrane Library (searched 15 February 2017), MEDLINE Ovid (1946 to 15 February 2017), and Embase Ovid (1980 to 15 February 2017). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised controlled trials of participants with full arch fixed orthodontic appliance(s) with molar tubes, bonded to first or second permanent molars. Trials which compared any type of adhesive used to bond molar tubes (stainless steel or titanium) with any other adhesive, were included.Trials were also included where:(1) a tube was bonded to a molar tooth on one side of an arch and a band cemented to the same tooth type on the opposite side of the same arch;(2) molar tubes had been allocated to one tooth type in one patient group and molar bands to the same tooth type in another patient group. The selection of papers, decision about eligibility and data extraction were carried out independently and in duplicate without blinding to the authors, adhesives used or results obtained. All disagreements were resolved by discussion. Two trials (n = 190), at low risk of bias, were included in the review and both presented data on first time failure at the tooth level. Pooling of the data showed a statistically significant difference in favour of molar bands, with a hazard ratio of 2.92 (95% confidence intervals (CI) 1.80 to 4.72). No statistically significant heterogeneity was shown between the two studies. Data on first time failure at the patient level were also available and showed statistically different difference in favour of molar bands (risk ratio 2.30; 95% CI 1.56 to 3.41) (risk of event for molar tubes = 57%; risk of event for molar bands 25%).One trial presented data on decalcification again showing a statistically significant difference in favour of molar bands. No other adverse events identified. From the two well-designed and low risk of bias trials included in this review it was shown that the failure of molar tubes bonded with either a chemically-cured or light-cured adhesive was considerably higher than that of molar bands cemented with glass ionomer cement. One trial indicated that there was less decalcification with molar bands cemented with glass ionomer cement than with bonded molar tubes cemented with a light-cured adhesive. However, given there are limited data for this outcome, further evidence is required to draw more robust conclusions.

Application of age estimation methods based on teeth eruption: how easy is Olze method to use?

PubMed

De Angelis, D; Gibelli, D; Merelli, V; Botto, M; Ventura, F; Cattaneo, C

2014-09-01

The development of new methods for age estimation has become with time an urgent issue because of the increasing immigration, in order to estimate accurately the age of those subjects who lack valid identity documents. Methods of age estimation are divided in skeletal and dental ones, and among the latter, Olze's method is one of the most recent, since it was introduced in 2010 with the aim to identify the legal age of 18 and 21 years by evaluating the different stages of development of the periodontal ligament of the third molars with closed root apices. The present study aims at verifying the applicability of the method to the daily forensic practice, with special focus on the interobserver repeatability. Olze's method was applied by three different observers (two physicians and one dentist without a specific training in Olze's method) to 61 orthopantomograms from subjects of mixed ethnicity aged between 16 and 51 years. The analysis took into consideration the lower third molars. The results provided by the different observers were then compared in order to verify the interobserver error. Results showed that interobserver error varies between 43 and 57 % for the right lower third molar (M48) and between 23 and 49 % for the left lower third molar (M38). Chi-square test did not show significant differences according to the side of teeth and type of professional figure. The results prove that Olze's method is not easy to apply when used by not adequately trained personnel, because of an intrinsic interobserver error. Since it is however a crucial method in age determination, it should be used only by experienced observers after an intensive and specific training.

Morphological study on dental caries induced in WBN/KobSlc rats (Rattus norvegicus) fed a standard laboratory diet.

PubMed

Fukuzato, Yoko; Matsuura, Tetsuro; Ozaki, Kiyokazu; Matsuura, Masahiro; Sano, Tomoya; Nakahara, Yutaka; Kodama, Yasushi; Nakagawa, Akihito; Okamura, Sumie; Suido, Hirohisa; Torii, Kayo; Makino, Taketoshi; Narama, Isao

2009-10-01

In our previous studies, WBN/KobSlc was characterized as a rat strain in which only males began to develop pancreatitis, and then presented with diabetic symptoms. In the course of studying their pancreatic inflammation, we detected molar caries in prediabetic males feeding on a standard diet (CRF-1) widely used for experimental animals. The purpose of this study is to confirm whether the WBN/KobSlc strain is caries-susceptible to the diet reported to be non-cariogenic, and to examine the effect of a prediabetic condition on their dental caries. For a morphological study, 25 male WBN/KobSlc rats aged 3.2-7.8 months and 24 females of the same strain aged 3.3-6.6 months were used, along with 10 males and 10 females of 8.2-month-old F344 rats. Marked dental caries were detected in the mandibular molars of male and female WBN/KobSlc rats regardless of pancreatitis, although no similar changes were observed in any teeth of the F344 strain fed the same diet. Soft X-ray examination revealed that the caries began in the crown and progressed horizontally and vertically, and that a severe radiolucent lesion extensively expanded to the entire crown, corresponding to a macroscopically deleted molar. The caries had gradually developed mainly in the second mandibular molar from more than 3.5 months of age, while none were seen in any rats before that time. The WBN/KobSlc rats were caries-susceptible even to the standard laboratory diet, and pancreatitis was not directly associated with the onset of dental caries in this strain.

Receptor for advanced glycation end-products and World Trade Center particulate induced lung function loss: A case-cohort study and murine model of acute particulate exposure

PubMed Central

Haider, Syed H.; Crowley, George; Lee, Audrey; Ebrahim, Minah; Zhang, Liqun; Chen, Lung-Chi; Gordon, Terry; Liu, Mengling; Prezant, David J.; Schmidt, Ann Marie

2017-01-01

World Trade Center-particulate matter(WTC-PM) exposure and metabolic-risk are associated with WTC-Lung Injury(WTC-LI). The receptor for advanced glycation end-products (RAGE) is most highly expressed in the lung, mediates metabolic risk, and single-nucleotide polymorphisms at the AGER-locus predict forced expiratory volume(FEV). Our objectives were to test the hypotheses that RAGE is a biomarker of WTC-LI in the FDNY-cohort and that loss of RAGE in a murine model would protect against acute PM-induced lung disease. We know from previous work that early intense exposure at the time of the WTC collapse was most predictive of WTC-LI therefore we utilized a murine model of intense acute PM-exposure to determine if loss of RAGE is protective and to identify signaling/cytokine intermediates. This study builds on a continuing effort to identify serum biomarkers that predict the development of WTC-LI. A case-cohort design was used to analyze a focused cohort of male never-smokers with normal pre-9/11 lung function. Odds of developing WTC-LI increased by 1.2, 1.8 and 1.0 in firefighters with soluble RAGE (sRAGE)≥97pg/mL, CRP≥2.4mg/L, and MMP-9≤397ng/mL, respectively, assessed in a multivariate logistic regression model (ROCAUC of 0.72). Wild type(WT) and RAGE-deficient(Ager-/-) mice were exposed to PM or PBS-control by oropharyngeal aspiration. Lung function, airway hyperreactivity, bronchoalveolar lavage, histology, transcription factors and plasma/BAL cytokines were quantified. WT-PM mice had decreased FEV and compliance, and increased airway resistance and methacholine reactivity after 24-hours. Decreased IFN-γ and increased LPA were observed in WT-PM mice; similar findings have been reported for firefighters who eventually develop WTC-LI. In the murine model, lack of RAGE was protective from loss of lung function and airway hyperreactivity and was associated with modulation of MAP kinases. We conclude that in a multivariate adjusted model increased sRAGE is associated with WTC-LI. In our murine model, absence of RAGE mitigated acute deleterious effects of PM and may be a biologically plausible mediator of PM-related lung disease. PMID:28926576

Concentration dependent survival and neural differentiation of murine embryonic stem cells cultured on polyethylene glycol dimethacrylate hydrogels possessing a continuous concentration gradient of n-cadherin derived peptide His-Ala-Val-Asp-Lle.

PubMed

Lim, Hyun Ju; Mosley, Matthew C; Kurosu, Yuki; Smith Callahan, Laura A

2017-07-01

N-cadherin cell-cell signaling plays a key role in the structure and function of the nervous system. However, few studies have incorporated bioactive signaling from n-cadherin into tissue engineering matrices. The present study uses a continuous gradient approach in polyethylene glycol dimethacrylate hydrogels to identify concentration dependent effects of n-cadherin peptide, His-Ala-Val-Asp-Lle (HAVDI), on murine embryonic stem cell survival and neural differentiation. The n-cadherin peptide was found to affect the expression of pluripotency marker, alkaline phosphatase, in murine embryonic stem cells cultured on n-cadherin peptide containing hydrogels in a concentration dependent manner. Increasing n-cadherin peptide concentrations in the hydrogels elicited a biphasic response in neurite extension length and mRNA expression of neural differentiation marker, neuron-specific class III β-tubulin, in murine embryonic stem cells cultured on the hydrogels. High concentrations of n-cadherin peptide in the hydrogels were found to increase the expression of apoptotic marker, caspase 3/7, in murine embryonic stem cells compared to that of murine embryonic stem cell cultures on hydrogels containing lower concentrations of n-cadherin peptide. Increasing the n-cadherin peptide concentration in the hydrogels facilitated greater survival of murine embryonic stem cells exposed to increasing oxidative stress caused by hydrogen peroxide exposure. The combinatorial approach presented in this work demonstrates concentration dependent effects of n-cadherin signaling on mouse embryonic stem cell behavior, underscoring the need for the greater use of systematic approaches in tissue engineering matrix design in order to understand and optimize bioactive signaling in the matrix for tissue formation. Single cell encapsulation is common in tissue engineering matrices. This eliminates cellular access to cell-cell signaling. N-cadherin, a cell-cell signaling molecule, plays a vital role in the development of neural tissues, but has not been well studied as a bioactive signaling element in neural tissue engineering matrices. The present study uses a systematic continuous gradient approach to identify concentration dependent effects of n-cadherin derived peptide, HAVDI, on the survival and neural differentiation of murine embryonic stem cells. This work underscores the need for greater use to combinatorial strategies to understand the effect complex bioactive signaling, such as n-cadherin, and the need to optimize the concentration of such bioactive signaling within tissue engineering matrices for maximal cellular response. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Three-dimensional microCT imaging of murine embryonic development from immediate post-implantation to organogenesis: application for phenotyping analysis of early embryonic lethality in mutant animals.

PubMed

Ermakova, Olga; Orsini, Tiziana; Gambadoro, Alessia; Chiani, Francesco; Tocchini-Valentini, Glauco P

2018-04-01

In this work, we applied three-dimensional microCT imaging to study murine embryogenesis in the range from immediate post-implantation period (embryonic day 5.5) to mid-gestation (embryonic day 12.5) with the resolution up to 1.4 µm/voxel. Also, we introduce an imaging procedure for non-invasive volumetric estimation of an entire litter of embryos within the maternal uterine structures. This method allows for an accurate, detailed and systematic morphometric analysis of both embryonic and extra-embryonic components during embryogenesis. Three-dimensional imaging of unperturbed embryos was performed to visualize the egg cylinder, primitive streak, gastrulation and early organogenesis stages of murine development in the C57Bl6/N mouse reference strain. Further, we applied our microCT imaging protocol to determine the earliest point when embryonic development is arrested in a mouse line with knockout for tRNA splicing endonuclease subunit Tsen54 gene. Our analysis determined that the embryonic development in Tsen54 null embryos does not proceed beyond implantation. We demonstrated that application of microCT imaging to entire litter of non-perturbed embryos greatly facilitate studies to unravel gene function during early embryogenesis and to determine the precise point at which embryonic development is arrested in mutant animals. The described method is inexpensive, does not require lengthy embryos dissection and can be applicable for detailed analysis of mutant mice at laboratory scale as well as for high-throughput projects.

Treatment effects of quad-helix on the eruption pattern of maxillary second molars.

PubMed

Kobayashi, Yoshiki; Shundo, Isao; Endo, Toshiya

2012-07-01

To evaluate the effects of quad-helix treatment on the eruption pattern of maxillary second molars in patients with maxillary incisor crowding. The lateral cephalograms of 40 consecutively treated patients in the early mixed-dentition group (treatment group) were examined in comparison with those of the same number of untreated patients with a similar form of malocclusion (control group). The cephalograms of the treated patients were taken at the start (T0) and at the end (T1) of treatment, and those of the untreated patients were also taken at about the same time as T0 and T1. The mean ages at T0 and T1 in the two groups were about the same. Distal tipping and movement and impeded extrusion of the maxillary first molars were notable in the treatment group compared with the control group. The actual treatment changes with the use of the quad-helix found expression in distal tipping and impeded vertical eruption of maxillary second molars. The more the maxillary first molars were tipped distally and the less the maxillary first molars extruded, the more the vertical eruption of the maxillary second molars was impeded. Quad-helix treatment gives rise to spontaneous distal tipping and impeded vertical eruption of the maxillary second molars.

Panoramic radiographic predictors of mandibular third molar eruption.

PubMed

Niedzielska, Iwona Anna; Drugacz, Jan; Kus, Nina; Kreska, Joanna

2006-08-01

Third molar (M3) eruption can be problematic. According to some orthodontic surgeons, the teeth are capable of aggravating the average crowding level in the dental arch. The question is whether it might be possible to give a prognosis for ultimate M3 position in the arch and make an early decision to extract or retain them. The purpose of the study was to determine which measurements made on panoramic tomograms might facilitate prognosis for M3 position in the dental arch over the years. The investigation involved 64 patients who had been enrolled to the study group 10 years earlier, ie, in 1993, when an analysis had been carried out regarding M3 effect on dental arch crowding. At that time panoramic tomograms had been taken, and dental casts made. The procedures were repeated in 2003. The following measurements were taken at baseline (1993) and at the end of the study (2003): (1)/the retromolar space to lower third molar crown width, (2) third molar angulation to the base of the mandible, and (3) third molar to second molar inclination. At some defined values of the Ganss ratio, and M3 inclination to mandibular base and second molar, it is possible to predict potential lower third molar alignment in the dental arch using a panoramic radiograph.

Characteristic findings on panoramic radiography and cone-beam CT to predict paresthesia after extraction of impacted third molar.

PubMed

Harada, Nana; Beloor Vasudeva, Subash; Matsuda, Yukiko; Seki, Kenji; Kapila, Rishabh; Ishikawa, Noboru; Okano, Tomohiro; Sano, Tsukasa

2015-01-01

The purpose of this study was to compare findings on the relationship between impacted molar roots and the mandibular canal in panoramic and three-dimensional cone-beam CT (CBCT) images to identify those that indicated risk of postoperative paresthesia. The relationship between impacted molars and the mandibular canal was first classified using panoramic images. Only patients in whom the molar roots were either in contact with or superimposed on the canal were evaluated using CBCT. Of 466 patients examined using both panoramic and CBCT images, 280 underwent surgical extraction of an impacted molar, and 15 of these (5%) reported postoperative paresthesia. The spatial relationship between the impacted third molar root and the mandibular canal was determined by examining para-sagittal sections (lingual, buccal, inter-radicular, inferior, and combinations) obtained from the canal to the molar root and establishing the proximity of the canal to the molar root (in contact with or without loss of the cortical border and separate). The results revealed that darkening of the roots with interruption of the mandibular canal on panoramic radiographs and the inter-radicular position of the canal in CBCT images were characteristic findings indicative of risk of postoperative paresthesia. These results suggest that careful surgical intervention is required in patients with the above characteristics.

Prevalence of radix entomolaris in mandibular permanent first molars: a study in a South Indian population.

PubMed

Chandra, Saurabh S; Chandra, Supriya; Shankar, Padmanabhan; Indira, Rajamani

2011-09-01

Anatomical racial variations are an acknowledged characteristic in permanent molars. Generally, mandibular first molars have 2 roots; however, the presence of a third root, radix entomolaris (RE), is a major anatomic variant among many population groups. This study evaluated the prevalence of permanent mandibular first molars featuring a distolingual root in a South Indian population. Five hundred patients of South Indian origin possessing bilateral mandibular first molars were selected. The radiographs of these patients were evaluated under optimal conditions. A total of 1000 mandibular first molars were screened and the incidence of 3-rooted mandibular first molars and the correlation between left and right side occurrence and between either gender was recorded. The prevalence of 3-rooted mandibular first molars was 18.6% of the patients examined and 13.3% of the teeth examined. There was no statistically significant difference between genders or side of occurrence (P > .05). The bilateral incidence of a symmetric distribution was 43.01%. RE is considered an Asiatic trait. The occurrence of this macrostructure in the South Indian population was 13.3%, which was lower than that of other patients of Mongoloid origin. The clinician must thoroughly examine the radiograph before initiation of endodontic therapy. Copyright © 2011 Mosby, Inc. All rights reserved.