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Sample records for central incisors based

  1. Estimating the color of maxillary central incisors based on age and gender

    PubMed Central

    Gozalo-Diaz, David; Johnston, William M.; Wee, Alvin G.

    2008-01-01

    Statement of problem There is no scientific information regarding the selection of the color of teeth for edentulous patients. Purpose The purpose of this study was to evaluate linear regression models that may be used to predict color parameters for central incisors of edentulous patients based on some characteristics of dentate subjects. Material and methods A spectroradiometer and an external light source were set in a noncontacting 45/0 degree (45-degree illumination and 0-degree observer) optical configuration to measure the color of subjects’ vital craniofacial structures (maxillary central incisor, attached gingiva, and facial skin). The subjects (n=120) were stratified into 5 age groups with 4 racial groups and balanced for gender. Linear first-order regression was used to determine the significant factors (α=.05) in the prediction model for each color direction of the color of the maxillary central incisor. Age, gender, and color of the other craniofacial structures were studied as potential predictors. Final predictions in each color direction were based only on the statistically significant factors, and then the color differences between observed and predicted CIELAB values for the central incisors were calculated and summarized. Results The statistically significant predictors of age and gender accounted for 36% of the total variability in L*. The statistically significant predictor of age accounted for 16% of the total variability in a*. The statistically significant predictors of age and gender accounted for 21% of the variability in b*. The mean ΔE (SD) between predicted and observed CIELAB values for the central incisor was 5.8 (3.2). Conclusions Age and gender were found to be statistically significant determinants in predicting the natural color of central incisors. Although the precision of these predictions was less than the median color difference found for all pairs of teeth studied, and may be considered an acceptable precision, further

  2. Velocardiofacial syndrome with single central incisor.

    PubMed

    Oberoi, Snehlata; Vargervik, Karin

    2005-01-15

    Three siblings and their mother are reported who all had cytogenetically proven velocardiofacial syndrome (VCFS). One boy had normal dental and craniofacial findings, except for an increased cranial base angle. His sister had only one central incisor in the maxilla. One central incisor had also been missing in the primary dentition. She had no labial frenulum present. Cephalometry showed a small maxillary unit length indicating mild maxillary hypoplasia, an increased anterior face height, steep mandibular plane angle, retruded chin, and a large cranial base angle. Dental measurements showed retroclined lower incisors and increased interincisal angle. A second sister had a cleft of the secondary palate. All permanent teeth were present with the exception of a missing central incisor in the lower jaw: the single lower central incisor was situated in the midline. Her cephalometry showed similar findings as in her sister. All three siblings required palate surgery for speech. Mother was not available for detailed dental and other oral investigations. A single maxillary central incisor has previously been reported in VCFS, but to our knowledge a single central incisor in the mandible has not been reported previously in this entity.

  3. Age estimation using maxillary central incisors: A radiographic study

    PubMed Central

    Agarwal, Nitin; Ahuja, Parul; Sinha, Abhishek; Singh, Anil

    2012-01-01

    Background: In the field of forensic dentistry, secondary changes in teeth with advancing age have been used as reliable predictors of age in various studies. Aim: The purpose of the present study was to present a method for assessing the chronological age based on the relationship between age and morphological parameters of maxillary central incisors. Materials and Methods: Fifty subjects between 20-70 years of age were included in the study. Intraoral periapical radiographs were taken in relation to maxillary central incisors using paralleling technique. The following measurements were recorded: lengths of tooth, pulp, root and width of root and pulp at three different points. Regression formulas were used to calculate the dental age. Results: The mean estimated age showed no statistically significant difference from the actual mean age (P > 0.05). Also, maximum difference was seen for root length variable (-1.035 ± 1.86 years). PMID:23741151

  4. Review of Dilaceration of Maxillary Central Incisor: A Mutidisciplinary Challenge.

    PubMed

    Walia, Pawanjit Singh; Rohilla, Ajit Kumar; Choudhary, Shweta; Kaur, Ravneet

    2016-01-01

    Traumatic injuries to primary dentition may interfere with the development of permanent dentition. Among the many malformations, dilaceration is particularly important to the clinician. Management of dilacerated maxillary central incisor requires a multidisciplinary approach. The main purpose of this review is to present the etiological factors, the mechanism, clinical features, radiographic features and treatment of dilaceration of the maxillary central incisors. How to cite this article: Walia PS, Rohilla AK, Choudhary S, Kaur R. Review of Dilaceration of Maxillary Central Incisor: A Multidisciplinary Challenge. Int J Clin Pediatr Dent 2016;9(1):90-98.

  5. Review of Dilaceration of Maxillary Central Incisor: A Mutidisciplinary Challenge

    PubMed Central

    Rohilla, Ajit Kumar; Choudhary, Shweta; Kaur, Ravneet

    2016-01-01

    ABSTRACT Traumatic injuries to primary dentition may interfere with the development of permanent dentition. Among the many malformations, dilaceration is particularly important to the clinician. Management of dilacerated maxillary central incisor requires a multidisciplinary approach. The main purpose of this review is to present the etiological factors, the mechanism, clinical features, radiographic features and treatment of dilaceration of the maxillary central incisors. How to cite this article: Walia PS, Rohilla AK, Choudhary S, Kaur R. Review of Dilaceration of Maxillary Central Incisor: A Multidisciplinary Challenge. Int J Clin Pediatr Dent 2016;9(1):90-98. PMID:27274164

  6. Dental transposition of canine and lateral incisor and impacted central incisor treatment: A case report

    PubMed Central

    Gebert, Tarcisio Jacinto; Palma, Vinícius Canavarros; Borges, Alvaro Henrique; Volpato, Luiz Evaristo Ricci

    2014-01-01

    Introduction Dental transposition and impaction are disorders related to ectopic eruption or failure in tooth eruption, which can affect child physical, mental and social development and may be difficult to be clinically solved. Methods We describe a case of transposition between the upper left canine and lateral incisor associated with impaction of the central incisor on the same side, in a 12-year-old patient. Conservative treatment involving surgical-orthodontic correction of transposed teeth and traction of the central incisor was conducted. Conclusion The option of correcting transposition and orthodontic traction by means of the segmented arch technique with devices such as cantilever and TMA rectangular wire loops, although a complex alternative, was proved to be esthetically and functionally effective. PMID:24713567

  7. Prosthetic considerations in the restoration of orthodontically treated maxillary lateral incisors to replace missing central incisors: a clinical report.

    PubMed

    Chaushu, S; Becker, A; Zalkind, M

    2001-04-01

    The treatment of young patients with missing maxillary incisors poses a challenge to prosthodontists and orthodontists. The 2 principal treatment options are (1) the reopening or maintenance of space for future autotransplantation and/or prosthodontic restoration of the missing teeth, or (2) total orthodontic space closure, followed by prosthodontic modification of the lateral incisors to simulate the central incisors. This article discusses only the second option and describes 2 alternative methods for the modification of crown anatomy. These procedures facilitate the orthodontic closure of missing central incisor spaces to ensure satisfactory, esthetic results. PMID:11319528

  8. Esthetic periodontal surgery for impacted dilacerated maxillary central incisors.

    PubMed

    Wei, Yu-Ju; Lin, Yi-Chun; Kaung, Shou-Shin; Yang, Shue-Fen; Lee, Shyh-Yuan; Lai, Yu-Lin

    2012-10-01

    Clinicians do not frequently see impacted dilacerated maxillary incisors in their patients. When they do, there are several diagnostic and management challenges for correcting root dilacerations. An unfavorable esthetic outcome might occur as a result of soft-tissue complications during surgical eruption procedures. We present 2 patients with an impacted and dilacerated maxillary central incisor. Computed tomography scans with 3-dimensional reformation were used to accurately assess the positions of the dilacerated teeth, the degree of dilaceration, and the stage of root formation. The therapy primarily involved 2-stage crown exposure surgery combined with orthodontic traction. An apicoectomy was performed on 1 dilacerated tooth; the other exhibited pulp vitality. This article highlights the periodontal surgical strategies for the esthetic management of inverted crowns. Through periodontal plastic surgery and interdisciplinary cooperation, the impacted dilacerated central incisors were properly aligned, and successful esthetic results were achieved. PMID:22999678

  9. Fragment Reattachment after Atypical Crown Fracture in Maxillary Central Incisor

    PubMed Central

    Vaz, Vanessa Torraca Peraro; Presoto, Cristina Dupim; Jordão, Keren Cristina Fagundes; Paleari, André Gustavo; Dantas, Andrea Abi-Rached; Segalla, José Claudio Martins; de Oliveira Junior, Osmir Batista

    2014-01-01

    Background. Fracture by trauma is one of the most common types of dental injury in the permanent dentition among children and teenagers. Aim. The aim of this study was to report the treatment performed to an atypical dental trauma case in a maxillary central incisor of a young patient by means of reattachment of the tooth fragment. Case Description. A 12-year-old male patient suffered a vertical crown fracture to the maxillary right central incisor. After clinical and radiographic examinations, a conservative restorative treatment which consisted in the reattachment of the tooth fragment with flow resin was performed in order to preserve the dental element and to obtain maximum aesthetics. Conclusion. The reattachment of fractured fragment is a fast and easy technique that can be used successfully as an option to restore dental element which suffered trauma. Clinical Significance. This technique restores the aesthetics and function of the dental element with minimal discomfort to the patient. PMID:25610663

  10. Compound odontoma associated with an impacted permanent central incisor.

    PubMed

    Shelton, J T; Owens, B M; Schuman, N J

    1997-10-01

    In this case report, an eleven-year-old female presented to a rural dental clinic for routine dental examination. Upon evaluation of the dentition, the attending dentist discovered an over-retained primary tooth. Radiographically, a compound odontoma was present, gingival to an unerupted permanent maxillary left central incisor (number nine) and apical to the erupted primary central incisor (F). The odontoma and its overlying primary tooth were removed by an oral surgeon. The extraction site has healed uneventfully and an Orthodontic treatment plan was formulated. The etiology of odontomas is unknown but thought to be caused by trauma, infection, inheritance and/or genetic mutation. These lesions are usually found in the second decade of life and are more common in male patients. Treatment consists of complete enucleation and curettage of the odontoma site.

  11. Atypical presentation of bilateral supplemental maxillary central incisors with unusual talon cusp.

    PubMed

    Nuvvula, Sivakumar; Pavuluri, Chaitanya; Mohapatra, Abinash; Nirmala, S V S G

    2011-01-01

    Delayed eruption of maxillary permanent central incisors in a child poses a distressing esthetic quandary to parents, by virtue of its location in the dental architecture. Well-aligned anterior teeth add confidence to smile and have enhanced self-esteem, which is critical even in early life. Impaction of the maxillary central incisors compared to third molars or the canines is less reported; bilateral supplemental maxillary central incisors related to impacted permanent maxillary central incisors are rare and one of the supplemental central incisors showing unusual talon is still infrequent. A case of impacted maxillary permanent central incisors related to supplemental maxillary central incisors, with one of them showing an unusual talon cusp, is presented. PMID:21911955

  12. Esthetic improvement in the patient with one missing maxillary central incisor restored with porcelain laminate veneers.

    PubMed

    Park, Dong-Jin; Yang, Jae-Ho; Lee, Jai-Bong; Kim, Sung-Hun; Han, Jung-Suk

    2010-09-01

    This article describes esthetic improvement in a patient with a missing maxillary left central incisor. Space analysis of the anterior dentition showed that minor tooth rearrangement was needed. Optimal space distribution for restorations was attained by orthodontic treatment. Through transforming tooth shape with porcelain laminate veneers, the maxillary left lateral incisor was transformed into central incisor and the maxillary left canine into a lateral incisor. The maxillary right central incisor was also restored for esthetic improvement. In a case of changing a tooth shape with porcelain laminate veneers, pre-treatment evaluation, space analysis and diagnostic wax-up are important factors.

  13. Surgical Management of Mandibular Central Incisors with Dumbbell Shaped Periapical Lesion: A Case Report

    PubMed Central

    Venigalla, Bhuvan Shome; Patil, Jayaprakash D.; Jayaprakash, Thumu; Chaitanya, C. H. Krishna; Kalluru, Rama S.

    2014-01-01

    Dental traumatic injuries may affect the teeth and alveolar bone directly or indirectly. Pulpal necrosis and chronic and apical periodontitis with cystic changes are the most common sequelae of the dental traumatic injuries, if the teeth are not treated immediately. This case report focuses on the conventional and surgical management of mandibular central incisors. A twenty-four-year-old male patient presented with pain in the mandibular central incisors. Radiographic examination revealed mandibular central incisors with dumbbell shaped periapical lesion. After root canal treatment, parendodontic surgery was performed for mandibular central incisors. After one-year recall examination, the teeth were asymptomatic and periapical lesion had healed. PMID:25105031

  14. Traumatic loss of a maxillary central incisor treated with nonextraction orthodontics.

    PubMed

    Huang, Shiyou; Kang, Ting; Duan, Yinzhong

    2013-02-01

    This case report describes the orthodontic treatment of a girl who lost her maxillary left central incisor from trauma. The patient had a concave profile, a Class I molar relationship on the right side and a Class II molar relationship on the left side, with a slight maxillary retrusion, an anterior edge-to-edge bite, and a posterior crossbite. Therefore, the treatment consisted of rapid palatal expansion to widen the maxilla in a transverse direction along with reverse headgear to improve the incisor relationship. The crown of the left canine was modified to resemble the left lateral incisor, and a porcelain veneer was placed to make the left lateral incisor resemble the left central incisor. This case report illustrates how orthodontics alone can be used to treat a missing central incisor, without a bridge or an implant. PMID:23374932

  15. Treatment of cariously involved fused maxillary primary lateral and central incisors.

    PubMed

    ElBadrawy, H E; Diab, M

    2001-01-01

    A 3-and-a-half-year-old male child presented with fused cariously involved right maxillary primary central and lateral incisors as well as a previously traumatized non-vital left primary central incisor with a draining fistula. The child also had other restorative needs and the decision taken was to address all needs under a G.A. With respect to the fused incisors, these were split and root canals treatment was performed for all three incisors which were then restored with stainless steel crowns with esthetic facings. PMID:11572502

  16. Variation in Size and Form between Left and Right Maxillary Central Incisor Teeth

    PubMed Central

    Vadavadagi, Suneel V; Hombesh, M N; Choudhury, Gopal Krishna; Deshpande, Sumith; Anusha, C V; Murthy, D Kiran

    2015-01-01

    Background: To compare the variation in size of left and right maxillary central incisors for male patients (using digital calipers of 0.01 mm accuracy). To compare the variation in size of left and right maxillary central incisors for female patients (using digital calipers of 0.01 mm accuracy). To find out the difference between the maxillary central incisors of men and women. Its clinical applicability if difference exists. Materials and Methods: A total of 70 dental students of PMNM Dental College and Hospital were selected. Of 70 dental students, 40 male and 30 female were selected. Impressions were made for all subjects, using irreversible hydrocolloid (Algitex, manufacturer DPI, Batch-T-8804) using perforated stock metal trays. The mesiodistal crown width and cervical width were measured for each incisor and recorded separately for left and right teeth. The length was measured for each incisor and recorded separately for left and right maxillary central incisor using digitec height caliper. Results: The mean value of maximum crown length of maxillary left central incisor of male was greater in length compared with maxillary right central incisor. Mean value of maximum crown length for male patient right and left side was greater compared with maximum crown length of female patient. Conclusion: When compared the dimensions of teeth between two sex, male group shows larger values to female group. PMID:25859104

  17. Esthetic considerations for reshaping of autotransplanted premolars replacing maxillary central incisors: a case report.

    PubMed

    Lima, Juliana Paiva Marques; Neto, José Jeová Siebra Moreira; Beltrão, Haroldo César Pinheiro; Borges, Fátima Maria Cavalcante; Nogueira, Renato Luis Maia; de Araújo Lima, Augusto Darwin Moeira

    2009-12-01

    Autotransplantation is a safe and currently common procedure in cases of agenesis and tooth loss. Autotransplantation of premolars to replace missing maxillary central incisors has been shown to be an excellent treatment choice, especially in young patients in the 9-12-year-old age range. The choice for adequate restorative materials and techniques is also essential, direct composite resin being indicated in most cases. This paper reports the case of two premolars autotransplanted to replace both maxillary central incisors and addresses the esthetic issues involved in the reshaping of these teeth to incisor morphology. PMID:19788424

  18. Avulsed Immature Permanent Central Incisors Obturated With Mineral Trioxide Aggregate: A Case Report

    PubMed Central

    Al-Kahtani, Ahmed

    2013-01-01

    The endodontic management of immature permanent incisors in young children can be challenging. This case reported an avulsed immature maxillary central incisors that underwent complete endodontic obturation using mineral trioxide aggregate. A 10-year-old male who suffered a fall injury avulsed both his central incisors. The revascularization process was not possible due to patient compliance and geographic reasons. Mineral trioxide aggregate was utilized as a novel endodontic treatment. After one year post-injury, the teeth remained symptom-free, the clinical and radiographic follow-up showed evidence of healthy periodontium. How to cite this article: Al-Kahtani A. Avulsed Immature Permanent Central Incisors Obturated With Mineral Trioxide Aggregate: A Case Report. J Int Oral Health 2013; 5(3):88-96. PMID:24155609

  19. Fracture resistance of upper central incisors restored with different posts and cores

    PubMed Central

    Rezaei Dastjerdi, Maryam; Amirian Chaijan, Kamran

    2015-01-01

    Objectives To determine and compare the fracture resistance of endodontically treated maxillary central incisors restored with different posts and cores. Materials and Methods Forty-eight upper central incisors were randomly divided into four groups: cast post and core (group 1), fiber-reinforced composite (FRC) post and composite core (group 2), composite post and core (group 3), and controls (group 4). Mesio-distal and bucco-lingual dimensions at 7 and 14 mm from the apex were compared to ensure standardization among the groups. Twelve teeth were prepared for crown restoration (group 4). Teeth in other groups were endodontically treated, decoronated at 14 mm from the apex, and prepared for posts and cores. Resin-based materials were used for cementation in groups 1 and 2. In group 3, composite was used directly to fill the post space and for core build-up. All samples were restored by standard metal crowns using glass ionomer cement, mounted at 135° vertical angle, subjected to thermomechanical aging, and then fractured using a universal testing machine. Kruskal-Wallis and Mann-Whitney U tests were used to analyze the data. Results Fracture resistance of the groups was as follows: Control (group 4) > cast post and core (group 1) > fiber post and composite core (group 2) > composite post and core (group 3). All samples in groups 2 and 3 fractured in restorable patterns, whereas most (58%) in group 1 were non-restorable. Conclusions Within the limitations of this study, FRC posts showed acceptable fracture resistance with favorable fracture patterns for reconstruction of upper central incisors. PMID:26295027

  20. Clinical and radiographic evaluation of maxillary central incisors exposure in patients undergoing maxillary advancement

    PubMed Central

    Trento, Guilherme dos Santos; Bernabé, Felipe Bueno Rosettti; da Costa, Delson João; Rebellato, Nelson Luis Barbosa; Klüppel, Leandro Eduardo; Scariot, Rafaela

    2015-01-01

    Abstract Introduction: Patients with dentofacial deformities may undergo orthodontic or orthodontic-surgical treatment. Both modalities can affect esthetics. Objective: This study aims to evaluate clinical and radiographic changes in exposure of maxillary central incisors occurring after orthognathic surgery for maxillary advancement. Methods: A total of 17 patients who underwent orthognathic surgery for maxillary advancement between September, 2010 and July, 2011 were selected. Exposure of maxillary central incisors was evaluated clinically and by lateral cephalograms. Measurements were taken one week before and three months after surgery. Data were paired in terms of sex, age, nasolabial angle, height and thickness of the upper lip, the amount of maxillary advancement, clinical exposure and inclination of maxillary central incisor by statistical tests (CI 95%). Results: After maxillary advancement, incisor clinical exposure had increased even with relaxed lips and under forced smile. Moreover, there was a mean increase of 23.33% revealed by lateral cephalograms. There was an inverse correlation between upper lip thickness and incisors postsurgical exposure revealed by radiographic images (p = 0.002). Conclusions: Significant changes in the exposure of maxillary central incisors occur after maxillary advancement, under the influence of some factors, especially lip thickness. PMID:26691970

  1. Innovative biomechanics for orthodontic correction of torsiversion of maxillary central incisor caused by twin mesiodens

    PubMed Central

    Monga, Nitika; Kharbanda, Om Prakash; Duggal, Ritu

    2014-01-01

    Mesiodens is the most common type of supernumerary teeth found in the premaxilla between the two central incisors. Early and proper diagnosis and appropriate treatment plan is critical in eluding the extent of treatment needed. This case report presents the successful orthodontic and esthetic management of an unusual case of Indian origin with twin mesiodens in the maxillary arch causing torsiversion and attrition of mandibular incisors due to occlusal trauma. PMID:24963264

  2. Bilateral presence of two root canals in maxillary central incisors: A rare case study.

    PubMed

    Kavitha, M; Gokul, Kannan; Ramaprabha, B; Lakshmi, Amudha

    2014-04-01

    Success in root canal treatment is achieved after thorough cleaning and shaping followed by complete obturation of the canal system. Therefore, endodontic therapy requires specific and complete knowledge of the internal and external dental anatomy, and its variations in presentation. The internal anatomy of the maxillary central incisor is well-known and usually presents one root canal system. This case report describes an endodontic treatment of traumatized both maxillary central incisors with two canal systems. Knowledge of dental anatomy is fundamental for proper endodontic practice. When root canal treatment is performed, the clinician should be aware that both external and internal anatomy may be abnormal.

  3. Management of an intruded primary central incisor with a natural crown under general anesthesia

    PubMed Central

    Altunsoy, Mustafa; Bilgin, Mehmet Selim

    2014-01-01

    Tooth intrusion is the most common trauma during early infancy. Primary maxillary central incisors are the most affected teeth. There are a few treatment approaches which depend upon the severity of the trauma, and the treatment must be managed professionally. In this case report, a 3-year-old girl with a history of trauma 40 days before referring to our pediatric clinic is presented. Deciduous maxillary right central incisor was intruded through labial and alveolar socket and completely covered with soft tissue. The intruded deciduous incisor tooth was surgically extracted and impression was taken under general anesthesia. The removable partial prosthesis was completed by using the patient's own extracted tooth. Using natural crown on removable prosthesis gives psychological satisfaction to the patient and his/her family, and can be better tolerated since its shape, size, and color are exactly in harmony. PMID:24966781

  4. A new computational method for automatic dental measurement: The case of maxillary central incisor.

    PubMed

    Di Angelo, L; Di Stefano, P; Bernardi, S; Continenza, M A

    2016-03-01

    This paper proposes a new automatic approach to determine the accurate measure of human teeth. The aim of the proposed computer based method is to reduce inaccuracy of measurement with respect to traditional approaches. Starting from a 3D model of the teeth which is obtained from 3D scanning, the method algorithmically evaluates the most important dimensional features detectable in central incisors. For this purpose, specific rules are put forward and implemented in original software with a view to identifying repere points, from which to detect dimensional features both unambiguously and accurately. The automatic method which is proposed here is verified by means of the analysis of real teeth and is then compared with the current state-of-the-art methods for teeth measurement. PMID:26851728

  5. Correlation between maxillary central incisor crown morphology and mandibular dental arch form in normal occlusion subjects.

    PubMed

    Paranhos, Luiz Renato; Lima, Carolina Souto; da Silva, Ricardo Henrique Alves; Daruge Júnior, Eduardo; Torres, Fernando Cesar

    2012-01-01

    The aim of this study was to evaluate the correlation between the morphology of the mandibular dental arch and the maxillary central incisor crown. Cast models from 51 Caucasian individuals, older than 15 years, with optimal occlusion, no previous orthodontic treatment, featuring 4 of the 6 keys to normal occlusion by Andrews (the first being mandatory) were observed. The models were digitalized using a 3D scanner, and images of the maxillary central incisor and mandibular dental arch were obtained. These were printed and placed in an album below pre-set models of arches and dental crowns, and distributed to 12 dental surgeons, who were asked to choose which shape was most in accordance with the models and crown presented. The Kappa test was performed to evaluate the concordance among evaluators while the chi-square test was used to verify the association between the dental arch and central incisor morphology, at a 5% significance level. The Kappa test showed moderate agreement among evaluators for both variables of this study, and the chi-square test showed no significant association between tooth shape and mandibular dental arch morphology. It may be concluded that the use of arch morphology as a diagnostic method to determine the shape of the maxillary central incisor is not appropriate. Further research is necessary to assess tooth shape using a stricter scientific basis.

  6. Canine transposition following trauma and loss of a central incisor: treatment options.

    PubMed

    Lewis, B; Durning, P; McLaughlin, W; Nicholson, P T

    2005-03-01

    The aim of this article is to make clinicians aware of the possibility of canine transposition following loss of the upper central incisor. Using two case reports it considers the opportunities for rehabilitation of the occlusion, and discusses surgical, orthodontic and restorative considerations. PMID:15784937

  7. Management of a congenitally missing maxillary central incisor. A case study.

    PubMed

    Tichler, Howard M; Abraham, Jenny E

    2007-03-01

    When a maxillary lateral incisor is missing, often the treatment options can be clearly defined, that is, substitute an adjacent tooth for the missing one; open the space for an implant, a bonded bridge or fixed bridge. When a maxillary central incisor is missing and the space for the tooth is absent, the treatment choices become complicated, especially in a growing child. There must be multi-disciplinary coordination among the restorative dentist, the oral surgeon or periodontist, and the orthodontist to obtain the optimum result. At the initiation of treatment, this information must be relayed and the treatment plan agreed upon by the patient or the parents of the patient.

  8. Crowns to create esthetics for mal-aligned central incisors: a case report.

    PubMed

    Savadi, Ravindra C; Savadi, Anupama R; Kumar, Preeti Satheesh

    2011-06-01

    This case report describes the smile design of crowded upper central anteriors in a female patient aged 25 years. The patient wanted the correction to be completed in a short period of time. A smile design schedule was drawn up involving root canal treatment of the central incisors and placing posts in both the teeth. All ceramic crowns were then fabricated to establish a very satisfactory and pleasing esthetics.

  9. Dental Items of Interest: The Case of Delphic Sibyl by Michelangelo: Solitary Median Maxillary Central Incisor or Mesiodens.

    PubMed

    Perciaccante, Antonio; Coralli, Alessia

    2015-01-01

    A case of an anomaly in the maxillary dental arch on "Delphic Sibyl," a fresco by Michelangelo is reported. An accurate analysis of this fresco shows a single incisor tooth is present precisely in the midline. We hypothesize that it may be a case of solitary median maxillary central incisor (SMMCI) and discuss the differential diagnosis with another similar anomaly--the mesiodens.

  10. Simultaneous Replacement of Maxillary Central Incisors with CEREC Biogeneric Reference Technique: A Case Report

    PubMed Central

    Akgungor, Gokhan; Sen, Deniz; Bal, Eray; Özcan, Mutlu

    2013-01-01

    Biogeneric Reference Technique (BRT) of the CEREC 3D v.3.8 software is an effective technique for single anterior ceramic crowns because it provides computer-controlled match of the tooth form to the contralateral tooth. BRT also enables the fabrication of two or more anterior all-ceramic crowns simultaneously. This clinical report demonstrates the clinical application of BRT for designing and milling two central incisors in one appointment using a single optical impression. After completing the virtual design of the first central incisor, it was copied and a mirror image was created. The second central incisor was designed using this replicated image and therefore a computer-controlled symmetry was obtained. The crowns were milled from monolithic feldspathic ceramic blocks and adhesively luted with dual-cured resin cement following dentin conditioning. At the two-year follow-up appointment, the restorations were intact, no adverse effects were noted, and the resultant appearance was highly satisfactory for the patient. A step-by-step protocol is described from design to cementation of these restorations. PMID:23875091

  11. Rare Root Morphology of a Maxillary Central Incisor Associated With Gingival Hyperplasia

    PubMed Central

    Monea, Monica; Moldovan, Cosmin

    2016-01-01

    Abstract Dilaceration is a developmental disturbance characterized by the angulation of the crown or root of a permanent tooth, which is often related to trauma of primary dentition. We report a case of a dilacerated root in a maxillary central incisor associated with gingival hyperplasia in a patient under fixed orthodontic treatment, a combination of pathological conditions that had never been mentioned before in the scientific literature. A 10-year-old female patient presented to the Department of Odontology and Oral Pathology with tenderness to palpation and bleeding from the oral aspect of the central incisor, alerted by the proliferation of the gingiva. During clinical examination, the palpation performed with a dental probe revealed a carious lesion with dental pulp exposure on the distal aspect of right central incisor and the presence of a sessile mass of inflamed gingival tissue that proliferated inside the defect. On the preoperative radiograph a dilacerated root canal was noted, without periapical bone resorption. The main diagnosis was irreversible pulpitis and gingival hyperplasia and the treatment option was surgical removal of the inflamed tissue with histopathological examination and root canal treatment. Successful endodontic treatment with a good prognosis was recorded. The measurement of the root curvature proved to be extremely helpful in choosing the right endodontic technique and made the treatment easier than expected. An important observation was that, despite the rare clinical and radiographic aspect of this dilacerated tooth, the endodontic treatment proved to be relatively easy to perform and, therefore, the prognosis was considered favorable. PMID:27149498

  12. Rare Root Morphology of a Maxillary Central Incisor Associated With Gingival Hyperplasia: An Endodontic Case Report.

    PubMed

    Monea, Monica; Moldovan, Cosmin

    2016-05-01

    Dilaceration is a developmental disturbance characterized by the angulation of the crown or root of a permanent tooth, which is often related to trauma of primary dentition. We report a case of a dilacerated root in a maxillary central incisor associated with gingival hyperplasia in a patient under fixed orthodontic treatment, a combination of pathological conditions that had never been mentioned before in the scientific literature.A 10-year-old female patient presented to the Department of Odontology and Oral Pathology with tenderness to palpation and bleeding from the oral aspect of the central incisor, alerted by the proliferation of the gingiva. During clinical examination, the palpation performed with a dental probe revealed a carious lesion with dental pulp exposure on the distal aspect of right central incisor and the presence of a sessile mass of inflamed gingival tissue that proliferated inside the defect. On the preoperative radiograph a dilacerated root canal was noted, without periapical bone resorption.The main diagnosis was irreversible pulpitis and gingival hyperplasia and the treatment option was surgical removal of the inflamed tissue with histopathological examination and root canal treatment. Successful endodontic treatment with a good prognosis was recorded.The measurement of the root curvature proved to be extremely helpful in choosing the right endodontic technique and made the treatment easier than expected. An important observation was that, despite the rare clinical and radiographic aspect of this dilacerated tooth, the endodontic treatment proved to be relatively easy to perform and, therefore, the prognosis was considered favorable.

  13. Agenesis of Permanent Mandibular Central Incisors: A Concordant Condition in Siblings

    PubMed Central

    Namineni, Srinivas; Tupalli, Abhinaya Reddy; Challa, Santhosh Kumar

    2016-01-01

    ABSTRACT Concordance is an identical expression of phenotype in two related individuals. Concordance expression of hypodontia is an uncommon condition where associated individuals are affected with exactly similar kind and number of missing teeth. There is very limited documentation of this condition either in twins or in siblings, and literature shows paucity of data with regard to this anomaly. To the best of our knowledge, there is only one such case reported in the literature, which has actually showed similar missing lower central incisors in siblings. This report presents a case of two girl siblings aged 11 and 13 years with congenital bilateral missing of permanent mandibular central incisors, which is an absolute concordant condition. Apart from discussing etiology, clinical implications and management, this article highlights the significance of concordant and discordant condition of hypodontia and expression of this condition in twins and siblings. How to cite this article: Kagitha PK, Namineni S, Tupalli AR, Challa SK. Agenesis of Permanent Mandibular Central Incisors: A Concordant Condition in Siblings. Int J Clin Pediatr Dent 2016;9(1):74-77. PMID:27274160

  14. Congenital nasal pyriform aperture stenosis in association with solitary median maxillary central incisor: unique radiologic features.

    PubMed

    Yang, Sara; Orta, Pedro; Renk, Elizabeth M; Inman, Jared C

    2016-09-01

    Solitary median maxillary central incisor (SMMCI) coexists in 34%-65% of patients initially diagnosed with congenital nasal pyriform aperture stenosis. SMMCI, a genetic syndrome, warrants consideration for further screening because of its high prevalence of other diagnostic possibilities-specifically central defects, like nasal obstruction and hypothalamo-pituitary axis abnormalities. We report on a presentation of SMMCI with congenital nasal pyriform aperture stenosis which highlights the unique radiologic features and notes the relationship between these two central associated findings in the literature. PMID:27594945

  15. Management of a Horizontally Impacted and Dilacerated Central Incisor in the Early Mixed Dentition.

    PubMed

    Dave, Heemanshu R; Samrit, Vilas D; Duggal, Ritu; Kharbanda, Om Prakash

    2015-01-01

    An impacted maxillary incisor in the early mixed dentition can pose a clinical challenge for orthodontists and pediatric dentists. Clinical observations supported with a 3-D imaging technique can help not only in assessing the precise location of the impacted tooth and its relation with neighboring teeth but also in correctly executing a treatment plan. The purpose of this paper is to describe the management of a severely rotated and horizontally impacted central incisor using intrabony rotation and simultaneous orthodontically-guided eruption. Timely intervention avoided disturbance in arch integrity and meticulous management helped to produce an excellent outcome in terms of function, esthetics, and stability of occlusion during two years of follow-up.

  16. Morphometric analysis of pulp size in maxillary permanent central incisors correlated with age: An indirect digital study

    PubMed Central

    Ravindra, S. V.; Mamatha, G. P.; Sunita, J. D.; Balappanavar, Aswini Y.; Sardana, Varun

    2015-01-01

    Context: Teeth are hardest part of the body and are least affected by the taphonomic process. They are considered as one of the reliable methods of identification of a person in forensic sciences. Aim: The aim of the following study is to establish morphometeric measurements by AutoCad 2009 (Autodesk, Inc) of permanent maxillary central incisors in different age groups of Udaipur population. Setting and Design: Hospital-based descriptive cross-sectional study carried out in Udaipur. Materials and Methods: A study was carried out on 308 subjects of both genders with the age range of 9-68 years. Standardized intra-oral radiographs were made by paralleling technique and processed. The radiographs were scanned and the obtained images were standardized to the actual size of radiographic film. This was followed by measuring them using software AutoCad 2009. Statistical Analysis Used: F-test, post-hoc test, Pearson's correlation test. Results: For left maxillary central incisor, the total pulp area was found to be of 38.41 ± 12.88 mm and 14.32 ± 7.04 mm respectively. For right maxillary central incisor, the total pulp size was 38.39 ± 14.95 mm and 12.35 ± 5 mm respectively. Males (32.50, 32.87 mm2) had more pulp area when compared with females (28.82, 30.05 mm2). Conclusion: There was a decrease in total pulp area with increasing age which may be attributed to secondary dentin formation. PMID:26816461

  17. The non-vital discolored central incisor dilemma.

    PubMed

    Schlichting, Luís Henrique; Stanley, Kyle; Magne, Michel; Magne, Pascal

    2015-01-01

    The restoration of anterior teeth is frequently a demanding mission. Patients generally have high expectations for the anterior region, which makes the emotional side of treatment especially important. When this involves discolored endodontically treated teeth, consensus can hardly ever be found as to the chosen approach. Bleaching with direct composites is undoubtedly the most conservative choice for these cases. However, this may require more maintenance (touch-up bleaching and repairs) in the long term, which is an important issue for adult patients. On the other hand, bonded porcelain veneers represent a more 'high-end' option, as they recover the original biomechanics of the intact tooth, allow an optimal masking of the substrate, remain stable, and have a reasonable biological cost when compared to full-coverage crowns. This strategy is explained in this article and documented with a clinical case. We describe treatment planning based on the biomimetic concept, taking into consideration what is possible with current materials and techniques when combined with the patient's particular needs, including the introduction of an innovative step during dentin sealing--the microsuction. The laboratory work was totally accomplished by 'teledentistry', with no direct contact between the dental technologist and the patient. PMID:26794051

  18. Dental Items of Interest: The Case of Delphic Sibyl by Michelangelo: Solitary Median Maxillary Central Incisor or Mesiodens.

    PubMed

    Perciaccante, Antonio; Coralli, Alessia

    2015-01-01

    A case of an anomaly in the maxillary dental arch on "Delphic Sibyl," a fresco by Michelangelo is reported. An accurate analysis of this fresco shows a single incisor tooth is present precisely in the midline. We hypothesize that it may be a case of solitary median maxillary central incisor (SMMCI) and discuss the differential diagnosis with another similar anomaly--the mesiodens. PMID:26930847

  19. Rare Root Morphology of a Maxillary Central Incisor Associated With Gingival Hyperplasia: An Endodontic Case Report.

    PubMed

    Monea, Monica; Moldovan, Cosmin

    2016-05-01

    Dilaceration is a developmental disturbance characterized by the angulation of the crown or root of a permanent tooth, which is often related to trauma of primary dentition. We report a case of a dilacerated root in a maxillary central incisor associated with gingival hyperplasia in a patient under fixed orthodontic treatment, a combination of pathological conditions that had never been mentioned before in the scientific literature.A 10-year-old female patient presented to the Department of Odontology and Oral Pathology with tenderness to palpation and bleeding from the oral aspect of the central incisor, alerted by the proliferation of the gingiva. During clinical examination, the palpation performed with a dental probe revealed a carious lesion with dental pulp exposure on the distal aspect of right central incisor and the presence of a sessile mass of inflamed gingival tissue that proliferated inside the defect. On the preoperative radiograph a dilacerated root canal was noted, without periapical bone resorption.The main diagnosis was irreversible pulpitis and gingival hyperplasia and the treatment option was surgical removal of the inflamed tissue with histopathological examination and root canal treatment. Successful endodontic treatment with a good prognosis was recorded.The measurement of the root curvature proved to be extremely helpful in choosing the right endodontic technique and made the treatment easier than expected. An important observation was that, despite the rare clinical and radiographic aspect of this dilacerated tooth, the endodontic treatment proved to be relatively easy to perform and, therefore, the prognosis was considered favorable. PMID:27149498

  20. Maturogenesis of Two Maxillary Central Incisors: A Case Report with 10 Years of Follow Up

    PubMed Central

    Ghorbanzadeh, Abdollah

    2015-01-01

    This case report describes the treatment of two immature maxillary central incisors in a 7-year-old female patient. She suffered complicated crown fracture because of trauma, and the root formation was incomplete. White mineral trioxide aggregate (MTA) was selected as the pulp-capping material after cervical pulpotomy to preserve the pulp tissue vitality and achieve maturogenesis. Follow-up evaluations showed successful treatment in terms of preservation of pulp vitality and demonstrated marked continuous physiological root development. During 10 years of follow-up, both teeth were clinically asymptomatic, and radiographic evaluations showed apparent root regeneration with apical root-end closure without pulp or periapical pathosis. PMID:26622286

  1. Re-attachment of Subgingivally Oblique Fractured Central Incisor Using a Fiber Post

    PubMed Central

    Adanir, Necdet; Ok, Evren; Erdek, Yesim

    2008-01-01

    This case report presents a 32 year old male with an oblique fractured maxillary right central incisor. The procedure used to repair the fracture included flap surgery with an intrasulcular incision and endodontic treatment. The root canal was filled with a root canal sealer and gutta-percha. After root canal obturation, fragments were luted with composite resin using a glass fibers post. After 12 months, clinical and radiographic examinations showed a stable reattachment of the fragments, good aesthetics and periodontal health. (Eur J Dent 2008;2:138–141) PMID:19212525

  2. Implant Prosthetic Rehabilitation with Bone Regenerative Techniques after Fracture of the Upper Central Incisors

    PubMed Central

    Amato, Massimo; Bruno, Vincenzo; Pantaleo, Giuseppe; Cerutti, Antonio; Spagnuolo, Gianrico; Sammartino, Gilberto

    2013-01-01

    A case of implant-bone prosthetic rehabilitation, after the fracture of the maxillary central incisors, which had been treated with grafting of a bone substitute, is reported. This case was followed by the normal procedures of implantology within the traditional timeframe for bone regeneration. However, a barrier membrane was not used which shows that even along with the use of graft material a sufficient amount of bone could be achieved for a subsequent rehabilitation. Therefore, after a five-year follow-up period, osseointegration was maintained with no marginal bone loss. PMID:23762642

  3. Multidisciplinary treatment approach to restore deep horizontally fractured maxillary central incisor.

    PubMed

    Patil, Pravinkumar G; Nimbalkar-Patil, Smita P; Karandikar, Aamod B

    2014-01-01

    This case report demonstrates sequential periodontic, orthodontic and prosthodontic treatment modalities to save and restore deep horizontally fractured maxillary central incisor. The location of fracture was deep in the mucosa which reveals less than 2 mm of tooth structure to receive the crown. The procedures like surgical crown lengthening, endodontic post placement, orthodontic forced eruption, core build-up and metal-ceramic crown restoration were sequentially performed to conserve the fractured tooth. Forced eruption is preferred to surgical removal of supporting alveolar bone, since forced eruption preserves the biologic width, maintains esthetics, and at the same time exposes sound tooth structure for the placement of restorative margins.

  4. Finite elements study of the Flexi Post and Flexi Flange post systems in a maxillary central incisor.

    PubMed

    Lewgoy, Hugo Roberto; Youssef, Michel Nicolau; Matson, Maurício Rufaiel; Bocangel, Jorge Antônio Javier Saldivar; Netto, Camillo Anauate; Amore, Ricardo

    2003-01-01

    The use of post and core systems has become an excellent alternative for restoring endodontically treated teeth. The aim of this study was to evaluate the von Mises, maximal compressive and tensile stresses distribution using the Finite Element Method (FEM) on human teeth restored with different post and core systems. The analysis was made on endodontically treated maxillary central incisors. The post systems used in this investigation were the stainless steel or titanium Flexi Post/Flexi Flange. Composite resin was used as core material and resin cement was the cement material of choice to seat a full porcelain crown. The bi-dimensional mathematical model was created from pictures taken from an intact human maxillary central incisor and prefabricated posts. This image was transferred to a personal computer in the MSC/Nastran 4.5 software. A static and linear analysis treatment was performed when a 45 load of 100 N was applied on the lingual surface of the tooth. Based on the results obtained, it can be concluded that the post design and its material can alter the stress pattern distribution. PMID:14569354

  5. Temporary management of permanent central incisors loss caused by trauma in primary dentition with natural crowns: a case report.

    PubMed

    Tüzüner, Tamer; Kuşgöz, Adem; Nur, Bilge Gülsüm

    2009-10-01

    Primary teeth injuries may cause developmental disturbances in the permanent dentition and loss of permanent incisors could be treated with different options. In this case report, an 11-year-old boy, with a history of trauma at the age of 4 years, is presented. Premature loss of permanent upper right central and upper left central teeth because of the mobility and arrest in root development were treated using patient's own natural crowns on a removable appliance. This treatment option could be considered as an esthetic and functional temporary management of permanent central incisors loss until the definitive treatment will be completed in the future.

  6. A morphometric analysis of maxillary central incisor on the basis of facial appearance in Korea

    PubMed Central

    Ku, Ji-Eun; Yang, Hong-So

    2012-01-01

    PURPOSE We aimed to identify a more esthetic width-to-length ratio by analyzing maxillary central incisor of Korean adult population. Information regarding tooth ratio in the Korean population may be useful to clinicians when restoring anterior teeth. MATERIALS AND METHODS A total of 40 men and 40 women were included in this study. The NON-MEDIA group included 40 non-celebrities, who were healthy and 25 to 39 years old, with normal dentofacial appearance. The MEDIA group consisted of 40 celebrities selected only on the basis of their soft-tissue facial appearance. The facial photographs of 40 celebrities were collected from the Internet websites. The width and length of the maxillary central incisor were measured using Adobe Photoshop® 7.0, a software for analysis, measurement and edition of photographs. Data were analyzed statistically using the Independent t-test at 5% statistical significance level. RESULTS The mean ratio for the MEDIA group was 0.77, whereas that of the NON-MEDIA group was 0.88. The difference between the two groups was statistically significant. No significant gender differences were found in the width-to-length ratio in MEDIA group. In NON-MEDIA group, however, there were significant differences between female and male. CONCLUSION After analyzing maxillary anterior teeth of Korean adults, our results were in accordance with the general Western standards of esthetics. A dentist restoring the natural look and beauty of teeth will have to consider those standards. PMID:22439095

  7. Management of a Two-rooted Maxillary Central Incisor Using Cone-beam Computed Tomography: Importance of Three-dimensional Imaging

    PubMed Central

    Kumar Gupta, Saurabh; Saxena, Payal; Khetarpal, Shaleen; Solanki, Mishthu

    2015-01-01

    We report a rare case of a two-rooted maxillary central incisor, stressing the importance of three-dimensional imaging in treatment planning and conservative approach of management. Endodontic treatment of this central incisor was carried out with a successful outcome. PMID:26697155

  8. Corono-radicular biological restoration of maxillary central incisors by direct method

    PubMed Central

    Aggarwal, Sonia; Sahoo, Sujit Ranjan; Pandharkar, Kartik

    2014-01-01

    This case report refers to the esthetic and functional restorations of extensively damaged maxillary central incisors with dental caries in a 32-year-old woman, with the use of posts and crowns made from natural extracted teeth. Proper restoration of such teeth with the use of natural teeth fragments are known as “biological restoration.” Biological restorations can be done by using the fragments of the patients own tooth and if that is not available, tooth fragment can be obtained from an extracted tooth. These biological posts and crowns present a low cost option and an alternative technique for the morphofunctional recovery of extensively damaged teeth. There are limitations with the use of natural extracted teeth (homogenous bonding) for restoration such as the difficulty of finding teeth with a similar color and shape as that of the destroyed element, or patient may refuse to accept a tooth fragment from another patient, which prevents execution of the restoration. PMID:25540666

  9. Surgical Retreatment of an Invaginated Maxillary Central Incisor Following Overfilled Endodontic Treatment: A Case Report

    PubMed Central

    Ozbas, Hakan; Subay, Rustem Kemal; Ordulu, Melike

    2010-01-01

    This case report presents the periapical surgical retreatment of an Oehlers Class III invaginated maxillary central incisor with extruded root canal filling into the periapical lesion. After local anesthesia, a full-thickness mucoperiosteal flap was reflected, and the granulomatous tissue and extruded gutta-percha points were curetted carefully. A deep and wide root-end cavity was prepared and filled with mineral trioxide aggregate (MTA). At 6 months and 2 years after the treatment, the tooth exhibited no clinical symptoms, and the radiograph performed during the 2-year follow-up showed a complete periapical healing around the root end. The present report indicates that MTA retrofilling can be used successfully in the surgical retreatment of dens invaginatus type III cases in which the invagination exits apically. PMID:20613922

  10. Replacement of mandibular central incisors with implant-supported crowns: a case report.

    PubMed

    Bäumer, Daniel; Zuhr, Otto; Hürzeler, Markus

    2016-01-01

    Anterior teeth are often affected by accidental dental trauma and may eventually be lost. When the neighboring teeth are unharmed, implant-supported crowns are often the preferred treatment choice. When not only the teeth but also the supporting hard and soft tissue has been lost, surgical reconstruction may be needed. However, in combined horizontal and vertical class III defects, the available augmentation techniques are often not predictable. In this case report, two neighboring mandibular central incisors were replaced by two implants after soft and hard tissue augmentation with the cortical bone plate method. The interdental soft tissue was reconstructed with remarkable success, making this an example of what can be achieved in cases such as this. PMID:27092347

  11. Torquing an upper central incisor with aligners--acting forces and biomechanical principles.

    PubMed

    Hahn, Wolfram; Zapf, Antonia; Dathe, Henning; Fialka-Fricke, Julia; Fricke-Zech, Susanne; Gruber, Rudolf; Kubein-Meesenburg, Dietmar; Sadat-Khonsari, Reza

    2010-12-01

    The forces delivered by aligners during torquing have still not been investigated. The purpose of this study was to measure the forces delivered to an upper central incisor during torquing with three different materials of the same thickness, and to describe the biomechanical principles of torquing with aligners. Five identical appliances were manufactured from each of three materials, all with a thickness of 1.0 mm (Ideal Clear®, Erkodur®, and Biolon®). An upper central incisor, as part of the measuring device, was torqued in defined steps in the vestibular and palatal directions with the respective appliance in place. For statistical analysis, the resulting forces, Fx (forces acting in the palatal and facial directions) and Fz (intrusive force as a side-effect) at a displacement of ±0.15 and ±0.8 mm from the tooth at the gingival margin were calculated. The mean Fx forces for ±0.15 mm displacement ranged from -1.89 N [standard deviation (SD) 0.48] to 0.11 N (SD 0.1). The mean Fz forces were between -0.97 N (SD 0.57) and -0.07 N (SD 0.22). The highest intrusive forces were measured during palatal displacement of the measuring tooth. An influence of direction of displacement on the levels of force was observed, especially for Fz at the greater displacement of ±0.8 mm. In relation to the intended amount of root movement during torquing, aligners tend to 'lift up' and therefore no effective force couple can be established for further root control. The force delivery properties are also influenced by the material used and the shape of the tooth.

  12. [Differences between laypersons and orthodontists in recognizing the light reflection zone on the maxillary central incisors crowns].

    PubMed

    Shmuli, T; Wasserstein, A; Turgeman, R; Brezniak, N

    2014-07-01

    The light reflection zone (LRZ) is a new parameter that may serve as a tool for the diagnosis of smile esthetics. It is a bright white dot or area that appears on the surface of the maxillary central incisors and/or the gingiva of the front teeth, visible in intra-oral and smile extra-oral photographs. Recently it was found that the general population defines a nicer smile when the LRZ is located in the gingival area of the upper central incisors' surface rather than the incisal third. The aim of this study was to find out in two populations that are not aware of this new parameter, laypersons and orthodontists, whether there is a difference in the identification of the LRZ and the importance of the LRZ in determining the quality of the smile. Twelve pairs of facial photographs, including 10 of ordinary smiling persons and 2 of smiling models, were presented to 108 laypersons and 30 orthodontists. The only difference between each pair was the location of the LRZ that was moved, compared to the original photograph, gingivally or incisally respectively, using Photoshop (Adobe). Each participant was asked to mark whether he/she noticed a difference between the 2 pictures, and if so, to score the nicer smile. Data analysis was carried out using Chi square test and Fisher's exact test (SPSS v17). The results showed that both populations had difficulty in recognizing the differences between the pictures that were based solely on the LRZ parameter. However, when differences were recognized, most of the participants in both populations pointed on the smile where the LRZ was located gingivally as the nicer one. The orthodontic population recognized the difference between the two pictures, in which only the LRZ was changed, to a lesser extent compared to the laypersons populations. This result was with statistical significance (p = 0.007).

  13. Initial forces generated by three types of thermoplastic appliances on an upper central incisor during tipping.

    PubMed

    Hahn, Wolfram; Fialka-Fricke, Julia; Dathe, Henning; Fricke-Zech, Susanne; Zapf, Antonia; Gruber, Rudolf; Kubein-Meesenburg, Dietmar; Sadat-Khonsari, Reza

    2009-12-01

    The force properties of thermoformed appliances have not been systematically investigated. Therefore, the aim of the present study was to quantify the forces delivered by thermoplastic appliances manufactured from three different materials, with the same thickness, on a central upper incisor, during tipping. Five identical appliances were manufactured from three different materials all with a thickness of 1.0 mm (Ideal Clear, Erkodur, and Biolon). For measuring the forces, an isolated measuring tooth, as part of a standardized resin model incorporated in a newly developed measuring device, was tipped in nine 2.7 arc minute (0.04629 degree) steps, from 0 to 0.416 degrees in the vestibular and palatal directions around a rotational axis through the virtual apex, after positioning an appliance on the model. For statistical analysis, the force components Fx/tipping and Fz/intrusion at a displacement of +/-0.151 mm from the incisor edge were determined. Means and standard deviations (SDs) were calculated. The Kruskal-Wallis test for overall effects and the Wilcoxon two-sample test for individual group pairings were used (P < 0.05 significance level). The mean Fx forces ranged from -2.82 N (SD 0.62) to 5.42 N (SD 0.56). The mean Fz forces were between -0.14 N (SD 0.52) and -2.3 N (SD 0.43). The highest intrusive forces were measured during vestibular displacement of the measuring tooth. The forces delivered by the Biolon appliance were found to be much greater (P < 0.01) than those of the other materials. The forces delivered by the materials investigated were mostly higher than those stated in the literature.

  14. Stress distributions in maxillary central incisors restored with various types of post materials and designs.

    PubMed

    Madfa, A A; Kadir, M R Abdul; Kashani, J; Saidin, S; Sulaiman, E; Marhazlinda, J; Rahbari, R; Abdullah, B J J; Abdullah, H; Abu Kasim, N H

    2014-07-01

    Different dental post designs and materials affect the stability of restoration of a tooth. This study aimed to analyse and compare the stability of two shapes of dental posts (parallel-sided and tapered) made of five different materials (titanium, zirconia, carbon fibre and glass fibre) by investigating their stress transfer through the finite element (FE) method. Ten three-dimensional (3D) FE models of a maxillary central incisor restored with two different designs and five different materials were constructed. An oblique loading of 100 N was applied to each 3D model. Analyses along the centre of the post, the crown-cement/core and the post-cement/dentine interfaces were computed, and the means were calculated. One-way ANOVAs followed by post hoc tests were used to evaluate the effectiveness of the post materials and designs (p=0.05). For post designs, the tapered posts introduced significantly higher stress compared with the parallel-sided post (p<0.05), especially along the centre of the post. Of the materials, the highest level of stress was found for stainless steel, followed by zirconia, titanium, glass fibre and carbon fibre posts (p<0.05). The carbon and glass fibre posts reduced the stress distribution at the middle and apical part of the posts compared with the stainless steel, zirconia and titanium posts. The opposite results were observed at the crown-cement/core interface.

  15. Stress distributions in maxillary central incisors restored with various types of post materials and designs.

    PubMed

    Madfa, A A; Kadir, M R Abdul; Kashani, J; Saidin, S; Sulaiman, E; Marhazlinda, J; Rahbari, R; Abdullah, B J J; Abdullah, H; Abu Kasim, N H

    2014-07-01

    Different dental post designs and materials affect the stability of restoration of a tooth. This study aimed to analyse and compare the stability of two shapes of dental posts (parallel-sided and tapered) made of five different materials (titanium, zirconia, carbon fibre and glass fibre) by investigating their stress transfer through the finite element (FE) method. Ten three-dimensional (3D) FE models of a maxillary central incisor restored with two different designs and five different materials were constructed. An oblique loading of 100 N was applied to each 3D model. Analyses along the centre of the post, the crown-cement/core and the post-cement/dentine interfaces were computed, and the means were calculated. One-way ANOVAs followed by post hoc tests were used to evaluate the effectiveness of the post materials and designs (p=0.05). For post designs, the tapered posts introduced significantly higher stress compared with the parallel-sided post (p<0.05), especially along the centre of the post. Of the materials, the highest level of stress was found for stainless steel, followed by zirconia, titanium, glass fibre and carbon fibre posts (p<0.05). The carbon and glass fibre posts reduced the stress distribution at the middle and apical part of the posts compared with the stainless steel, zirconia and titanium posts. The opposite results were observed at the crown-cement/core interface. PMID:24834856

  16. Strain Distribution in Root Surface Dentin of Maxillary Central Incisors during Lateral Compaction

    PubMed Central

    Pilo, Raphael; Metzger, Zvi; Brosh, Tamar

    2016-01-01

    Aim To precisely quantify the circumferential strains created along the radicular dentin of maxillary incisors during a simulated clinical procedure of lateral compaction. Methods Six miniature strain gauges were bonded on the roots of fourteen recently extracted maxillary central incisors that were subjected to root canal instrumentation. The strain gauges were bonded at three levels (apical, middle, and coronal) and four aspects (buccal, lingual, mesial, and distal) of the roots. Each tooth was embedded in a PVC cylinder containing polyvinyl-siloxane impression material. Root filling was then performed by simulating the clinical procedure of lateral compaction using nickel-titanium finger spreaders. The force applied to the spreader and the strains developing in the surface root dentin were continuously recorded at a frequency of 10 Hz. Results The highest strains that developed during lateral compaction were in the mesial and distal aspects at the apical level of the root. The magnitudes of the maximal mesial/distal strains at the apical as well as the mid-root levels were approximately 2.5–3 times higher than those at the buccal/lingual aspects (p = 0.041). The strains decreased significantly (p<0.04) from the apical through the mid-root levels to the coronal level, yielding gradients of 2.5- and 6-fold, respectively. The mesial and distal strains were consistently tensile and did not differ significantly; however, the buccal strains were generally 35–65% higher than the lingual strains (p = 0.078). Lateral compaction resulted in the gradual build-up of residual strains, resulting in generation of a 'stair-step' curve. These strains declined gradually and almost completely disappeared after 1000 sec. Conclusions With proper mounting of several miniature strain gauges at various levels and aspects of the root, significant circumferential strains can be monitored under clinically relevant compaction forces. The residual strains at the end of lateral

  17. Management of synodontia between dilacerated permanent maxillary central incisor and supernumerary tooth with aid of cone-beam computed tomography

    PubMed Central

    Das, Suroopa; Warhadpande, Manjusha M.; Redij, Saurabh Anil; Sabir, Husain; Shirude, Tushar

    2015-01-01

    A malformed tooth characterized by one or more developmental disturbances is often difficult to treat. When such teeth are present in anterior region, they pose a technical challenge for the clinician to restore esthetics as well as function. This case describes endodontic, surgical, and restorative management of fused and dilacerated maxillary central incisor. Cone-beam computed tomography (CBCT) was used in the present case to aid in understanding of complicated tooth morphology and managing the case successfully. PMID:25829699

  18. The effect of maxillary first premolar extraction and incisor retraction on mandibular position: testing the central dogma of "functional orthodontics".

    PubMed

    Luecke, P E; Johnston, L E

    1992-01-01

    It has been argued by a vocal coterie of disaffected dentists that premolar extraction, incisor retraction, and "backward-pulling" mechanics conspire to "distalize" the condyles and, pari passu, to produce craniomandibular dysfunction. Given the gravity of this conjecture, it seemed appropriate to test the predictions it generates in a sample of patients of the type most often said to be at risk: 42 "edgewise" patients with Class II, Division 1 malocclusions, treated in conjunction with the extraction of two maxillary first premolars. Regional and anterior cranial-base cephalometric superimpositions were used to quantify the individual components of the molar and overjet corrections, to measure both at the chin and condyles the mandibular displacement seen during treatment, and to examine the extent to which this displacement is related to the correction of maxillary incisor protrusion. Although the present patients underwent marked upper incisor retraction (on average, about 5 mm), lip retraction was much less pronounced, and 70% of the sample showed a net forward displacement of mandibular basal bone. Significantly, changes in condylar position were not correlated with incisor retraction, as the "functional orthodontists" would have it, but rather with the changes in the buccal occlusion and the growth of the maxilla. Thus, 30% of the patients who showed evidence of distal displacement were generally nongrowing patients who underwent more than average anchorage loss in the mandible and less than average loss in the maxilla.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Resin-based composite coronal augmentation of diminutive lateral incisors: an update.

    PubMed

    Croll, Theodore P; Bond, James

    2006-10-01

    The 2 cases presented here document methods of enlarging diminutive lateral incisors using bonded resin-based composite materials. Former methods are reviewed, and descriptions of a matrix strip stabilization technique and the use of a self-etching adhesive agent are included. PMID:17120388

  20. Treatment of a maxillary central incisor with class III invasive cervical resorption and compromised ferrule: a clinical report.

    PubMed

    Harris, Bryan T; Caicedo, Ricardo; Lin, Wei-Shao; Morton, Dean

    2014-05-01

    This clinical report presents the treatment of a maxillary central incisor with class III invasive cervical resorption and a compromised ferrule. Nonsurgical endodontic therapy combined with periodontal surgery was provided for debridement. Direct light-polymerizing resin-modified glass ionomer cement and a zirconia crown were used to repair the defect. Symptomatic endodontic complication was diagnosed with localized cone beam computed tomography at 6-month follow-up, and periapical microsurgery was rendered. The patient was followed-up for 30 months after treatment and had no further complications. PMID:24423455

  1. Fracture resistance of endodontically treated maxillary central incisors with varying ferrule heights and configurations: In vitro study

    PubMed Central

    Singh, Smita; Thareja, Prerna

    2014-01-01

    Objective: The objective of this study is to determine the best ferrule configuration of endodontically treated teeth. Materials and Methods: A total of 40 freshly extracted maxillary central incisors were collected. Teeth were allocated into following four groups of each having 10 teeth. Group 1 teeth restored with crowns (CRN), Group 2 endodontically treated teeth restored with crowns (RCT and CRN), Group 3 endodontically treated teeth restored with cast dowel cores and crowns incorporating uniform 2 mm ferrule (2 FRL), Group 4 endodontically treated teeth restored with cast dowel cores and crowns incorporating uniform 1 mm ferrule (1 FRL). Crown preparation was performed with varying ferrule heights, crowns were cemented with resin modified glass ionomer cement and were kept in 100% humidity for 3 days, all specimens were loaded to failure in a universal testing machine at 0.5 mm/min. Results were obtained in the form of kilo Newton and Newton. Result: The statistical analysis applied was an analysis of variance to detect the presence of group differences. Pair wise comparisons between the groups were analyzed with the Tukey Kramer significant difference test for multiple comparisons. Conclusion: Ferrule had a significant role in the fracture resistance of custom cast post core restored teeth. Endodontically treated maxillary central incisors with a uniform 2 mm ferrule were more fracture resistant than those with a uniform 1 mm ferrule. PMID:24778504

  2. Changes in force associated with the amount of aligner activation and lingual bodily movement of the maxillary central incisor

    PubMed Central

    Li, Xiaowei; Ren, Chaochao; Wang, Zheyao; Zhao, Pai; Wang, Hongmei

    2016-01-01

    Objective The purposes of this study were to measure the orthodontic forces generated by thermoplastic aligners and investigate the possible influences of different activations for lingual bodily movements on orthodontic forces, and their attenuation. Methods Thermoplastic material of 1.0-mm in thickness was used to manufacture aligners for 0.2, 0.3, 0.4, 0.5, and 0.6 mm activations for lingual bodily movements of the maxillary central incisor. The orthodontic force in the lingual direction delivered by the thermoplastic aligners was measured using a micro-stress sensor system for the invisible orthodontic technique, and was monitored for 2 weeks. Results Orthodontic force increased with the amount of activation of the aligner in the initial measurements. The attenuation speed in the 0.6 mm group was faster than that of the other groups (p < 0.05). All aligners demonstrated rapid relaxation in the first 8 hours, which then decreased slowly and plateaued on day 4 or 5. Conclusions The amount of activation had a substantial influence on the orthodontic force imparted by the aligners. The results suggest that the activation of lingual bodily movement of the maxillary central incisor should not exceed 0.5 mm. The initial 4 or 5 days is important with respect to orthodontic treatment incorporating an aligner. PMID:27019820

  3. A Fused Maxillary Central Incisor and Its Multidisciplinary Treatment: An 18-Year Follow-Up

    PubMed Central

    Brunet-Llobet, Lluís; Lahor-Soler, Eduard; Cahuana, Abel

    2014-01-01

    Fused teeth may cause aesthetic, spacing, periodontal, eruption, and caries problems. The present case report describes a 7-year-old boy patient with a chief complaint of unerupted maxillary incisor. Radiographic examination indicated a fused tooth which had two fused roots but two independent root canals. A complex management of a fused tooth is really difficult to standardize. In this case an orthodontic, endodontic, and surgical treatment (intentional replantation) allowed the tooth to be retained until 18 years following intervention. Maintenance of the root and alveolar bone in young adults at least until full skeletal maturation should be the main treatment objective. PMID:24738034

  4. Compound odontoma associated with an unerupted and dilacerated maxillary primary central incisor in a young patient.

    PubMed

    Yeung, K H; Cheung, R C T; Tsang, M M H

    2003-05-01

    The occurrence of odontoma in the primary dentition is uncommon. There are very few reports of non-eruption of a dilacerated primary tooth in the literature. A rare case of compound odontoma in association with an unerupted dilacerated maxillary primary incisor in a young patient is reported. There was also a developing supernumerary tooth in the vicinity of the odontoma. The clinical features and management of these conditions are discussed. The relevant literature is reviewed. A possible causal relationship between odontoma and dilaceration is highlighted.

  5. Compound odontoma associated with impacted maxillary central incisor dictates a need to be vigilant to canine eruption pattern: A 2-year follow-up.

    PubMed

    Singla, Shilpy; Gupta, Sachin

    2016-01-01

    Canine deviation from its path of eruption is usually followed by either delayed or impaction of canine. One of the important and not so noticed reasons for canine displacement is formerly impacted central incisor. The difference in age of eruption of these two teeth is 4 years; however, the absence of maxillary incisor should be perceived with utmost conviction about impending canine displacement leading to its impaction as well. This case presents similar picture where composite, compound odontoma with respect to maxillary central incisor led to its impaction resulted in deviated path of eruption for erupting canine. This canine displacement to worsen prognosis ended up getting impacted if not dealt with cautiously in the later stages of occlusal development. PMID:27307685

  6. Compound odontoma associated with impacted maxillary central incisor dictates a need to be vigilant to canine eruption pattern: A 2-year follow-up.

    PubMed

    Singla, Shilpy; Gupta, Sachin

    2016-01-01

    Canine deviation from its path of eruption is usually followed by either delayed or impaction of canine. One of the important and not so noticed reasons for canine displacement is formerly impacted central incisor. The difference in age of eruption of these two teeth is 4 years; however, the absence of maxillary incisor should be perceived with utmost conviction about impending canine displacement leading to its impaction as well. This case presents similar picture where composite, compound odontoma with respect to maxillary central incisor led to its impaction resulted in deviated path of eruption for erupting canine. This canine displacement to worsen prognosis ended up getting impacted if not dealt with cautiously in the later stages of occlusal development.

  7. Compound odontoma associated with impacted maxillary central incisor dictates a need to be vigilant to canine eruption pattern: A 2-year follow-up

    PubMed Central

    Singla, Shilpy; Gupta, Sachin

    2016-01-01

    Canine deviation from its path of eruption is usually followed by either delayed or impaction of canine. One of the important and not so noticed reasons for canine displacement is formerly impacted central incisor. The difference in age of eruption of these two teeth is 4 years; however, the absence of maxillary incisor should be perceived with utmost conviction about impending canine displacement leading to its impaction as well. This case presents similar picture where composite, compound odontoma with respect to maxillary central incisor led to its impaction resulted in deviated path of eruption for erupting canine. This canine displacement to worsen prognosis ended up getting impacted if not dealt with cautiously in the later stages of occlusal development. PMID:27307685

  8. The Shape of the Maxillary Central Incisors and Its Correlation with Maxillary Anterior Papillary Display: A Clinical Study.

    PubMed

    Nichani, Ashish S; Ahmed, Arshia Zainab; Ranganath, V

    2016-01-01

    The aim of this study was to define shapes of maxillary central incisors and determine their relationship with the visual display of interdental papillae during smiling. A sample of 100 patients aged 20 to 25 years were recruited. Photographs were taken and gingival angle, crown width (CW), crown length (CL), contact surface (CS), CW/CL ratio, CS/CL ratio, gingival smile line (GSL), and interdental smile line (ISL) were measured. The data showed an increase in GA leading to an increase in CW and CS/CL ratio. Women showed a higher percentage of papillary display compared with men. This study reinforces the proposed hypothesis that the shape of the teeth and papilla affect the periodontium. PMID:27333012

  9. Analysis of dentinal stress distribution of maxillary central incisors subjected to various post-and-core applications.

    PubMed

    Toksavul, Suna; Zor, Mehmet; Toman, Muhitten; Güngör, Mehmet Ali; Nergiz, Ibrahim; Artunç, Celal

    2006-01-01

    This study evaluated the stress distribution on an endodontically treated maxillary central incisor restored with different post-and-core systems by using a three-dimensional finite element analysis model. Seven three-dimensional finite element models were created. Each model contained cortical bone, cancelous bone, periodontal ligament, 3 mm apical root canal filling, post-and-core and all-ceramic crowns. Two different pre-fabricated zirconia ceramic post systems, a glass fiber-reinforced post system and a titanium post system were modeled. As a control, an all-ceramic crown on an endodontically treated maxillary central incisor without a post-and-core was modeled. Each model received a 45 degrees oblique occlusal load at a constant intensity of 100 N. In each model, the ratio of Von Mises stress distribution was compared. The greatest stresses were observed in the coronal third of the roots on facial surfaces. The ratio of Von Mises stress distribution in dentin for the zirconia ceramic post (CosmoPost) and ceramic core (Cosmo Ingot), zirconia ceramic post (CosmoPost) and composite core (Tetric Ceram), glass fiber-reinforced post (FRC Postec) and composite core (Tetric Ceram), titanium post (Er post) and composite core (Tetric Ceram), zirconia ceramic post (Cerapost) and ceramic core (Cosmo Ingot), zirconia ceramic post (Cerapost) and composite core (Tetric Ceram) and the control group were 0.886, 0.889, 0.988, 0.924, 0.889, 0.893 and 1, respectively. The stress concentrations in dentin created by two different zirconia ceramic post systems were nearly the same. The zirconia ceramic post systems created slightly less stress concentration in dentin than the glass fiber-reinforced and titanium posts.

  10. Comparison of Stress Distribution in a Maxillary Central Incisor Restored with Two Prefabricated Post Systems with and without Ferrule Using Finite Element Method

    PubMed Central

    Kumar, Arun; Sabarinathan; Raja, Ramesh

    2016-01-01

    Introduction When restoring an endodontically treated tooth with deficient coronal tooth structure, posts can be used to strengthen the tooth. Recently prefabricated posts are widely used as they exclude the need for complex laboratory procedures making the procedure time saving. But the post-placement can produce stresses that cause root fracture. Different techniques can be used to study the stress distribution due to different posts, but most of them are two-dimensional and difficult to reproduce. Aim The aim of the study was to compare the stress distribution in a maxillary central incisor with Titanium and Glass fiber posts with and without ferrule using the three dimensional finite element analysis. Materials and Methods In this study 3D finite element analysis was used. Four models P1(Endodontically treated maxillary central incisor with a ferrule of coronal dentin and restored with parallel sided prefabricated titanium post and composite resin core), P2 (Endodontically treated maxillary central incisor restored with parallel sided prefabricated Titanium post and composite resin core without a ferrule of coronal dentin), P3 (Endodontically treated maxillary central incisor with a ferrule of coronal dentin and restored with parallel sided prefabricated glass fiber reinforced composite post and composite core), P4 (Endodontically treated maxillary central incisor restored with parallel sided prefabricated glass fiber reinforced composite post and composite core without a ferrule of coronal dentin), were modeled using PRO E software. Then stress analysis was done using ANSYS WORKBENCH 10.0software. A load of 100 N was applied to the models at 2mm from the incisal edge on the palatal surface with an angle of 45o to the long axis of the tooth. Results The results suggested that maximum stresses were seen around posts in order of Titanium post without ferrule followed by Titanium post with ferrule next Glass fiber post without ferrule followed by Glass fiber post

  11. Influence of post and resin cement on stress distribution of maxillary central incisors restored with direct resin composite.

    PubMed

    Spazzin, A O; Galafassi, D; de Meira-Júnior, A D; Braz, R; Garbin, C A

    2009-01-01

    The current study evaluated the influence of two endodontic post systems and the elastic modulus and film thickness of resin cement on stress distribution in a maxillary central incisor (MCI) restored with direct resin composite using finite element analysis (FEA). A three-dimensional model of an MCI with a coronary fracture and supporting structures was performed. A static chewing pressure of 2.16 N/mm2 was applied to two areas on the palatal surface of the composite restoration. Zirconia ceramic (ZC) and glass fiber (GF) posts were considered. The stress distribution was analyzed in the post, dentin and cement layer when ZC and GF posts were fixed to the root canals using resin cements of different elastic moduli (7.0 and 18.6 GPa) and different layer thicknesses (70 and 200 microm). The different post materials presented a significant influence on stress distribution with lesser stress concentration when using the GF post. The higher elastic modulus cement created higher stress levels within itself. The cement thicknesses did not present significant changes. PMID:19363979

  12. 3D FEA of cemented glass fiber and cast posts with various dental cements in a maxillary central incisor.

    PubMed

    Madfa, Ahmed A; Al-Hamzi, Mohsen A; Al-Sanabani, Fadhel A; Al-Qudaimi, Nasr H; Yue, Xiao-Guang

    2015-01-01

    This study aimed to analyse and compare the stability of two dental posts cemented with four different luting agents by examining their shear stress transfer through the FEM. Eight three-dimensional finite element models of a maxillary central incisor restored with glass fiber and Ni-Cr alloy cast dental posts. Each dental post was luted with zinc phosphate, Panavia resin, super bond C&B resin and glass ionomer materials. Finite element models were constructed and oblique loading of 100 N was applied. The distribution of shear stress was investigated at posts and cement/dentine interfaces using ABAQUS/CAE software. The peak shear stress for glass fiber post models minimized approximately three to four times of those for Ni-Cr alloy cast post models. There was negligible difference in peak of shear stress when various cements were compared, irrespective of post materials. The shear stress had same trend for all cement materials. This study found that the glass fiber dental post reduced the shear stress concentration at interfacial of post and cement/dentine compared to Ni-Cr alloy cast dental post.

  13. 3D FEA of cemented glass fiber and cast posts with various dental cements in a maxillary central incisor.

    PubMed

    Madfa, Ahmed A; Al-Hamzi, Mohsen A; Al-Sanabani, Fadhel A; Al-Qudaimi, Nasr H; Yue, Xiao-Guang

    2015-01-01

    This study aimed to analyse and compare the stability of two dental posts cemented with four different luting agents by examining their shear stress transfer through the FEM. Eight three-dimensional finite element models of a maxillary central incisor restored with glass fiber and Ni-Cr alloy cast dental posts. Each dental post was luted with zinc phosphate, Panavia resin, super bond C&B resin and glass ionomer materials. Finite element models were constructed and oblique loading of 100 N was applied. The distribution of shear stress was investigated at posts and cement/dentine interfaces using ABAQUS/CAE software. The peak shear stress for glass fiber post models minimized approximately three to four times of those for Ni-Cr alloy cast post models. There was negligible difference in peak of shear stress when various cements were compared, irrespective of post materials. The shear stress had same trend for all cement materials. This study found that the glass fiber dental post reduced the shear stress concentration at interfacial of post and cement/dentine compared to Ni-Cr alloy cast dental post. PMID:26543733

  14. An In Vitro Study on the Effects of Post-Core Design and Ferrule on the Fracture Resistance of Endodontically Treated Maxillary Central Incisors

    PubMed Central

    Sreedevi, S; Sanjeev, R; Raghavan, Rekha; Abraham, Anna; Rajamani, T; Govind, Girish Kumar

    2015-01-01

    Background: Endodontically treated teeth have significantly different physical and mechanical properties compared to vital teeth and are more prone to fracture. The study aims to compare the fracture resistance of endodontically treated teeth with and without post reinforcement, custom cast post-core and prefabricated post with glass ionomer core and to evaluate the ferrule effect on endodontically treated teeth restored with custom cast post-core. Materials and Methods: A total of 40 human maxillary central incisors with similar dimensions devoid of any root caries, restorations, previous endodontic treatment or cracks were selected from a collection of stored extracted teeth. An initial silicone index of each tooth was made. They were treated endodontically and divided into four groups of ten specimens each. Their apical seal was maintained with 4 mm of gutta-percha. Root canal preparation was done and then post core fabrication was done. The prepared specimens were subjected to load testing using a computer coordinated UTM. The fracture load results were then statistically analyzed. One-way ANOVA was followed by paired t-test. Results: 1. Reinforcement of endodontically treated maxillary central incisors with post and core, improved their fracture resistance to be at par with that of endodontically treated maxillary central incisor, with natural crown. 2. The fracture resistance of endodontically treated maxillary central incisors is significantly increased when restored with custom cast post-core and 2 mm ferrule. Conclusion: With 2 mm ferrule, teeth restored with custom cast post-core had a significantly higher fracture resistance than teeth restored with custom cast post-core or prefabricated post and glass ionomer core without ferrule. PMID:26464537

  15. Amalgamation of allogenic bone graft, platelet-rich fibrin gel, and PRF membrane in auto-transplantation of an impacted central incisor.

    PubMed

    Chaudhary, Zainab; Kumar, Yuvika Raj; Mohanty, Sujata; Khetrapal, Ambica

    2015-01-01

    "Social six" teeth refers to the maxillary incisors and canines that play a vital role in the appearance of an individual and absence of any one of them has a significant psycho-social impact. Hence, early treatment and rehabilitation of the same are extremely important. A multitude of treatment options ranging from orthodontic extrusion, extraction followed by implant placement, fixed partial denture, and auto-transplantation have been advocated. This case report discusses the unique amalgamation of platelet-rich fibrin (PRF), demineralized freeze-dried bone graft with use of PRF membrane during auto-transplantation of an impacted central incisor. The authors have focused on maximum usage of autogenous materials in the most economic and least invasive manner. Furthermore, this amalgamation has been used to provide rehabilitation in the least span of time.

  16. Amalgamation of allogenic bone graft, platelet-rich fibrin gel, and PRF membrane in auto-transplantation of an impacted central incisor

    PubMed Central

    Chaudhary, Zainab; Kumar, Yuvika Raj; Mohanty, Sujata; Khetrapal, Ambica

    2015-01-01

    “Social six” teeth refers to the maxillary incisors and canines that play a vital role in the appearance of an individual and absence of any one of them has a significant psycho-social impact. Hence, early treatment and rehabilitation of the same are extremely important. A multitude of treatment options ranging from orthodontic extrusion, extraction followed by implant placement, fixed partial denture, and auto-transplantation have been advocated. This case report discusses the unique amalgamation of platelet-rich fibrin (PRF), demineralized freeze-dried bone graft with use of PRF membrane during auto-transplantation of an impacted central incisor. The authors have focused on maximum usage of autogenous materials in the most economic and least invasive manner. Furthermore, this amalgamation has been used to provide rehabilitation in the least span of time. PMID:26097366

  17. Age estimation by pulp/tooth ratio in lateral and central incisors by peri-apical X-ray.

    PubMed

    Cameriere, R; Cunha, E; Wasterlain, S N; De Luca, S; Sassaroli, E; Pagliara, F; Nuzzolese, E; Cingolani, M; Ferrante, L

    2013-07-01

    Since 2004, several papers on the analysis of the apposition of secondary dentine have been published. The aim of this paper was to study a sample of peri-apical X-ray images of upper and lower incisors, both lateral and medial, to examine the application of pulp/tooth area ratio as an indicator of age. A sample of 116 individuals, 62 men and 54 women, aged between 18 and 74 years, was studied. Data were fitted with age as a linear function of the pulp/tooth ratio of incisors. The total variance explained by the regression equation ranged from 51.3% of age, when lower lateral incisors were used as explanatory variable, to 81.6% when upper lateral incisors were used. The accuracy of the corresponding regression model yielded ME = 8.44 and 5.34 years, respectively. These results show that, although incisors are less reliable than canines or lower premolars, they can be used to estimate age-at-death when the latter are absent.

  18. Neonatal line width in deciduous incisors from Neolithic, mediaeval and modern skeletal samples from north-central Poland.

    PubMed

    Kurek, Marta; Żądzińska, Elżbieta; Sitek, Aneta; Borowska-Strugińska, Beata; Rosset, Iwona; Lorkiewicz, Wiesław

    2016-01-01

    The neonatal line is usually the first accentuated incremental line visible on the enamel. The prenatal environment significantly contributes to the width of the neonatal line, influencing the pace of reaching post-delivery homeostasis by the newborn's organism. Studies of the enamel of the earliest developing deciduous teeth can provide an insight into the prenatal development and the perinatal conditions of children of past human populations, thus being an additional source contributing to consideration of the influence of prenatal and perinatal factors modifying growth processes. The aim of this study was to examine whether the neonatal line, reflecting the conditions of the prenatal and perinatal environment, differed between the Neolithic, the mediaeval and the modern populations from the Kujawy region in north-central Poland. The material consisted of longitudinally ground sections of 57 human deciduous incisors obtained from children aged 1.0-7.5 years representing three archaeological series from Brześć Kujawski site. All teeth were sectioned in the labio-linqual plane using a diamond blade (Buechler IsoMet 1000). Final specimens were observed with the microscope Delta Optical Evolution 300 at 10× and 40× magnifications. For each tooth, linear measurements of the neonatal line width were performed on its labial surface at the three levels from the cemento-enamel junction. No significant difference was found in the mean neonatal line width depending on the tooth type and archaeological site, although the thickest neonatal line characterised children from the Neolithic series. In all analysed series, the neonatal line width was diversified depending on the child's age at death. The value of Spearman's rank correlation coefficient calculated for the correlation between the child's age at death and the neonatal line width was statistically significant. A clear increase in the width of the neonatal line was thus observed along with a decrease in the child

  19. A comparative study to evaluate the vertical position of maxillary central incisor and canine in relation to incisive papilla line

    PubMed Central

    Shah, Mayank; Verma, Ashok Kumar; Chaturvedi, Saurabh

    2014-01-01

    Objectives: The aim of the study was to determine the vertical distance of maxillary central incisor (CI) and maxillary canine (CA) from the incisive papilla (IP) line and their variation with age and sex. Materials and Methods: A total of 120 dentulous subjects following the inclusion and exclusion criteria were randomly selected from the local population. On the basis of gender and age, subjects were divided into four groups: Ma, Mb, Fa and Fb . Maxillary impressions of selected subjects were made and corresponding casts were retrieved. The cast was positioned on the surveyor and the center of IP was transferred to the labial side of maxillary right CI and CA regions with the help of analyzing rod of the surveyor and a line was drawn in this region which was referred to as “IP line”. The measurements were made from the IP line to the mesio-incisal line angle of right maxillary CI-IP and cusp tip of right maxillary CA with the help of digital vernier caliper (CA to IP). Result: The mean vertical distance of maxillary CI-IP ranged from 6.31 ± 0.74 mm to 7.04 ± 0.87 mm and the mean vertical distance of maxillary CA-IP ranged from 5.83 ± 0.80 mm to 6.30 ± 0.82 mm. Conclusion: The CA position in relation to the IP line is more stable to its position than the CI position irrespective of age and sex. PMID:25125915

  20. Effect of labiolingual inclination of a maxillary central incisor and surrounding alveolar bone loss on periodontal stress: A finite element analysis

    PubMed Central

    Choi, Sung-Hwan; Kim, Young-Hoon; Lee, Kee-Joon

    2016-01-01

    Objective The aim of this study was to investigate whether labial tooth inclination and alveolar bone loss affect the moment per unit of force (Mt/F) in controlled tipping and consequent stresses on the periodontal ligament (PDL). Methods Three-dimensional models (n = 20) of maxillary central incisors were created with different labial inclinations (5°, 10°, 15°, and 20°) and different amounts of alveolar bone loss (0, 2, 4, and 6 mm). The Mt/F necessary for controlled tipping (Mt/Fcont) and the principal stresses on the PDL were calculated for each model separately in a finite element analysis. Results As labial inclination increased, Mt/Fcont and the length of the moment arm decreased. In contrast, increased alveolar bone loss caused increases in Mt/Fcont and the length of the moment arm. When Mt/F was near Mt/Fcont, increases in Mt/F caused compressive stresses to move from a predominantly labial apical region to a palatal apical position, and tensile stresses in the labial area moved from a cervical position to a mid-root position. Although controlled tipping was applied to the incisors, increases in alveolar bone loss and labial tooth inclination caused increases in maximum compressive and tensile stresses at the root apices. Conclusions Increases in alveolar bone loss and labial tooth inclination caused increases in stresses that might cause root resorption at the root apex, despite the application of controlled tipping to the incisors. PMID:27226961

  1. Management of bilateral invasive cervical resorption lesions in maxillary incisors using a novel calcium silicate-based cement: A case report.

    PubMed

    Karypidou, Athanasia; Chatzinikolaou, Ino-Dimitra; Kouros, Pantelis; Koulaouzidou, Elisabeth; Economides, Nikolaos

    2016-01-01

    Invasive cervical resorption is a pathologic process leading to progressive and usually destructive loss of tooth structure. The pathogenic mechanism is not completely understood and the diagnosis may be challenging. The aim of this article is to present an unusual case of bilateral presence of invasive cervical resorption lesions in maxillary central incisors and to discuss the treatment procedures using a novel repair material. The management of the present case was carried out in three phases. The first stage of the treatment aimed at curetting the active tissue from the resorption cavity and restoring the defect with the novel calcium silicate-based cement (Biodentine, Septodont). In the maxillary left central incisor it was not possible to remove the resorptive tissue without exposing the pulp, and therefore root canal treatment was performed. At the second phase, a full-thickness flap was raised in order to expose and repair the defect that was extending subgingivally. At the third phase teeth were restored with composite resin. The patient was kept under review and after a follow-up period of 2 years neither signs of periradicular lesion nor recurrence of resorption were observed. The teeth were asymptomatic, and restorations appeared to be in excellent condition. In conclusion, Biodentine seems to be a promising material for the treatment of invasive cervical resorption lesions. PMID:27341468

  2. The effect of central incisor's root proximity to the cortical plate and apical root resorption in extraction and non-extraction treatment

    PubMed Central

    Agarwal, Akhil; Sharma, Vijay P; Singh, Gulshan K; Tikku, Tripti; Agarwal, Nidhi; Mengi, Arvind

    2014-01-01

    Aims: The present study was conducted to investigate the relevance of cortical plate proximity of maxillary central incisor root, maxillary alveolar bone width, and the apical root resorption in extraction and non-extraction orthodontically treated cases. Further, the correlation between the apical root resorption and the various parameters was investigated. Materials and Methods: A total of 80 lateral head cephalographs, 40 pre-treatment and 40 post-treatment, of orthodontic subjects with a mean age of 15 years treated with fixed standard edgewise appliance were obtained. All subjects were divided into two groups as extraction and non-extraction cases. Twelve linear and three angular parameters were measured and evaluated. The paired “t”-test, Pearson's correlation coefficient, and the stepwise regression analysis were done to test the relationship between the apical root resorption and the various parameters. Results and Conclusions: The study revealed slightly greater amount of apical root resorption in extraction subjects as compared to non-extraction subjects. However, no statistically significant difference was found between the two treatment modalities. In extraction subjects, the apical root resorption was directly proportional to the pre-treatment length of maxillary central incisor and inversely proportional to the root width in apical one-third region, though there was a weak correlation. In non-extraction subjects, the pre-treatment anteroposterior position of the root apex of maxillary central incisor in the alveolar bone, in combination with its root width in the apical one-third region formed the predictive factors for the variance in the amount of the apical root resorption, though there was a weak correlation. Furthermore, the changes in the alveolar widths at the root apex and mid-root region were considered as predictive factors for the amount of apical root resorption during extraction and non-extraction treatment, respectively. PMID

  3. Adhesive placement of a zirconia fixed partial denture to replace a maxillary central incisor: a clinical report.

    PubMed

    Kalogirou, Marietta; Trushkowsky, Richard; Andrade, Jorje; David, Steven

    2011-01-01

    The replacement of a single maxillary incisor is an esthetic challenge. Many options provide various degrees of longevity and ease of fabrication. The introduction of zirconia-supported fixed partial dentures (FPDs) has seen increased use in the last several years. However, abutment preparation guidelines and laboratory fabrication have to adhere to the guidelines established by the manufacturers and clinical researchers. Zirconia FPDs can provide long-term strength and esthetics if they are designed and fabricated appropriately. PMID:21462621

  4. Esthetic restoration of primary incisors.

    PubMed

    Carranza, F; García-Godoy, F

    1999-04-01

    A simple and esthetic technique for restoring cariously involved primary maxillary incisors is described. The technique includes mini-pins, a preformed celluloid crown and resin-based composite. PMID:10477982

  5. Evaluation of the Load-bearing Capacity of Fractured Incisal Edge of Maxillary Permanent Central Incisors restored with a Glass Fiber-reinforced Nanocomposite: An in vitro Study

    PubMed Central

    Srilatha, KT; Nandlal, B; Dhull, Kanika Singh

    2015-01-01

    ABSTRACT Objectives: The aim of this study was to evaluate and compare the load-bearing capacity of fractured incisal edge of maxillary permanent central incisors restored with a nanocomposite and a glass fiber-reinforced nanocomposite. Materials and methods: Thirty-six extracted sound maxillary central incisors randomly divided in three groups were used for the present study. Group I (control) contained untreated teeth. Samples in experimental groups II and III were prepared by cutting the incisal (one-third) part of the crown horizontally and subjected to enamel preparations and restored with a nanocomposite and a glass fiber-reinforced nanocomposite respectively. All restored teeth were stored in distilled water at room temperature for 24 hours. Fracture resistance was evaluated as peak load at failure (Newton) for samples tested in a cantilever-bending test using Hounsfield universal testing machine. Failure modes were microscopically examined. Results: Highest mean peak failure load (Newton) among experimental groups was observed in glass fiber-reinforced nano composite group (863.50 ± 76.12 N) followed by nanocomposite group (633.67 ± 40.14 N). One-way analysis of variance (ANOVA) revealed that the restoration technique significantly affected the load-bearing capacity (p < 0.001). Scheffe’s post-hoc comparison test (subset for α = 0.05) revealed that there was significant difference in the mean peak failure load values of nanocomposite and glass fiber-reinforced nanocomposite groups when considered together (p < 0.001). Experimental groups showed similar types of failure modes with majority occurring ascohesive and mixed type. Fifty-eight percent of the teeth in glass fiber-reinforced nanocomposite group fractured below the cementoenamel junction. Conclusion: By using fiber-reinforced composite substructure under conventional composites in the repair of fractured incisors, the load-bearing capacity of the restored incisal edge could be substantially

  6. Evaluation of the mineralization degree of the vestibular surface of the upper central incisors with a 655-nm diode laser in mouth breathers: preliminary results

    NASA Astrophysics Data System (ADS)

    Pinheiro Ladalardo, Thereza C. C. G.; Cappellette, Mario, Jr.; Zanin, Fatima A. A.; Brugnera, Aldo, Jr.; Anthero de Azevedo, Ramiro; Pignatari, Shirley; Weckx, Luc L. M.

    2003-06-01

    Mouth breathing unbalances the physiological mechanisms of the dental surface hydration by compromising lip closure, and, very often, causing the vestibular positioning of upper incisors. That variance leads to the interruption of the dental demineralization and remineralization feedback, prevailing a demineralized condition of the dental surface which increases caries risk. The laser fluorescence examination allows an early demineralization diagnosis, thus it makes possible through preventive measures to minimize the risk factor - dental mineral structure loss - in the bacterial infection of the demineralized area, and hence, preventing invasive therapeutical procedures. A DIAGNOdent apparatus was used to evaluate the mineralization degree of the upper central incisors in 40 patients - twenty of them with a mouth breathing diagnosis; the remaining twenty were nasal breathers (control group). Age ranging from 6 to 12 years, both male and female. To measure the vestibular surface of the incisors, it was divided into 3 segments: cervical, medial and incisal. The average of the results pertaining to the mouth breathing patients was as follows: tooth 11 cervical third - 5.45, medial third - 7.15, incisal third - 7.95, and tooth 21 - cervical third - 5.95, medial third - 7.25, incisal third - 8.15. The control patients, nasal breathers, presented the following results: tooth 11 cervical third - 1.75, medial third - 2.30, incisal third - 1.85, and tooth 21 - cervical third - 1.80, medial third - 2.20, incisal third - 2.15. The mouth breathing patients showed demineralization in the teeth examined at the initial stage, subclinical, comparing with the control patients, nasal breathers, who did not present any mineral deficit in these teeth.

  7. Ex vivo fracture resistance of endodontically treated maxillary central incisors restored with fiber-reinforced composite posts and experimental dentin posts

    PubMed Central

    Kathuria, Ambica; Kavitha, M; Khetarpal, Suchit

    2011-01-01

    Aim: To compare the fracture resistance of teeth restored with fiber-reinforced composite (FRC) posts and experimental dentin posts milled from human root dentin. Materials and Methods: Thirty maxillary central incisors were divided into three groups of ten each. Twenty teeth were restored with FRC posts and solid dentin posts and numbered as Groups 2 and 3 respectively while Group 1 acted as the control, without any post. The teeth were loaded at 135° angle to their long axes after core build-up and the failure loads were recorded. Results: One-way Analysis of Variance (ANOVA) and Bonferroni multiple comparisons revealed a significant difference among test groups with the control group showing the highest fracture resistance, followed by the dentin post group and lastly the FRC post group. Conclusions: Teeth restored with dentin posts exhibited better fracture resistance than those restored with FRC posts. PMID:22144812

  8. Reconstruction and Intentional Replantation of a Maxillary Central Incisor with a Complete Vertical Root Fracture: A Rare Case Report with Three Years Follow up.

    PubMed

    Dua, Deepti; Dua, Ankur

    2015-09-01

    Vertical root fractures in teeth present with challenges not only with diagnosis but also with management. The prognosis in such teeth is generally questionable with extraction of the tooth being the most common treatment option. However, conservative treatment options such as reconstruction of the fractured fragments with adhesive resin followed by intentional replantation have been recently suggested. There are only a few case reports that describe management of complete vertical root fracture by reconstruction of fragments. The present case report describes successful management of an unusual complete vertical root fracture of a maxillary right central incisor in a 23-year-old male by reconstructing the fragments with a dual cure resin followed by intentional replantation. At the three year follow up, the tooth was asymptomatic, radiographically sound with probing depth and mobility within normal physiological limits.

  9. Reconstruction and Intentional Replantation of a Maxillary Central Incisor with a Complete Vertical Root Fracture: A Rare Case Report with Three Years Follow up

    PubMed Central

    Dua, Deepti

    2015-01-01

    Vertical root fractures in teeth present with challenges not only with diagnosis but also with management. The prognosis in such teeth is generally questionable with extraction of the tooth being the most common treatment option. However, conservative treatment options such as reconstruction of the fractured fragments with adhesive resin followed by intentional replantation have been recently suggested. There are only a few case reports that describe management of complete vertical root fracture by reconstruction of fragments. The present case report describes successful management of an unusual complete vertical root fracture of a maxillary right central incisor in a 23-year-old male by reconstructing the fragments with a dual cure resin followed by intentional replantation. At the three year follow up, the tooth was asymptomatic, radiographically sound with probing depth and mobility within normal physiological limits. PMID:26501026

  10. Endodontic and Esthetic Management of a Dilacerated Maxillary Central Incisor Having Two Root Canals Using Cone Beam Computed Tomography as a Diagnostic Aid

    PubMed Central

    Sharma, Sarang; Grover, Shibani; Sharma, Vivek; Srivastava, Dhirendra; Mittal, Meenu

    2014-01-01

    Traumatic injuries to the primary dentition are quite common. When primary teeth are subjected to trauma, force transmission and/or invasion of the underlying tooth germs lying in close proximity can result in a variety of disturbances in the permanent successors. Few of these disturbances include hypoplasia, dilaceration, or alteration in the eruption sequence and pattern. Dilaceration is defined as an angulation or sharp bend or curve in the linear relationship of the crown of a tooth to its root. A rare case of maxillary left central incisor having crown dilaceration and Vertucci's type II canal configuration with symptomatic periapical periodontitis is reported. Cone beam computed tomography was used for better understanding of the anomaly and complicated root canal morphology. The tooth was successfully managed by nonsurgical root canal therapy and restoration with resin composite to restore esthetics. PMID:24955260

  11. Relationship of central incisor implant placement to the ridge configuration anterior to the nasopalatine canal in dentate and partially edentulous individuals: a comparative study

    PubMed Central

    2015-01-01

    Background. The aims of this study were to investigate the ridge contour anterior to the nasopalatine canal, and the difference between the incidences of the nasopalatine canal perforation in dentate and partially edentulous patients by cone-beam computed tomography. Methods. Cone-beam computed tomography scan images from 72 patients were selected from database and divided into dentate and partially edentulous groups. The configuration of the ridge anterior to the canal including palatal concavity depth, palatal concavity height, palatal concavity angle, bone height coronal to the incisive foramen, and bone width anterior to the canal was measured. A virtual implant placement procedure was used, and the incidences of perforation were evaluated after implant placement in the cingulum position with the long axis along with the designed crown. Results. Comparing with variable values from dentate patients, the palatal concavity depth and angle were greater by 0.9 mm and 4°, and bone height was shorter by 1.1 mm in partially edentulous patients, respectively. Bone width in edentulous patients was narrower than in dentate patients by 1.2 mm at incisive foramen level and 0.9 mm at 8 mm subcrestal level, respectively. After 72 virtual cylindrical implants (4.1 × 12 mm) were placed, a total of 12 sites (16.7%) showed a perforation and three-fourths occurred in partially edentulous patients. After replacing with 72 tapered implants (4.3 × 13 mm), only 6 implants (8.3%) broke into the canal in the partially edentulous patient group. Conclusions. The nasopalatine canal may get close to the implant site and the bone width anterior to the canal decreases after the central incisor extraction. The incidence of nasopalatine canal perforation may occur more commonly during delayed implant placement in central incisor missing patients. PMID:26557434

  12. [Incisors with a mind of their own].

    PubMed

    van Heumen, C M; Termeer, D; Oosterkamp, B C M; Meijer, G J

    2014-01-01

    A 43-year-old man, known to have hypodontia, was bothered by his over-erupted central incisors. After the placement of implants and the accompanying crown- and bridgework, the central incisors appear to be increasingly over-erupted. The history shows that this phenomenon has already been seen in the past. Three mechanisms can be responsible for the over-eruption, specifically: continuous facial growth, over-eruption of both central incisors in the maxilla as a consequence of agenesis of opposing dentition and relapse of the orthodontic treatment as a result of the fact that orthodontic retention is not readily possible. After the central incisors were first cut in such a way that an acceptable incisal line has again been formed, the single-unit fixed dental prostheses on the front elements were replaced with porcelain ones. PMID:25174187

  13. Macrodontic maxillary incisor in alagille syndrome

    PubMed Central

    Cozzani, Mauro; Fontana, Mattia

    2012-01-01

    This case report describes the surgical-orthodontic guided-eruption of a deeply impacted macrodontic maxillary central incisor in a 10-year-old patient with Alagille syndrome (ALGS). In the first stage, orthodontic treatment with fixed appliance on deciduous teeth allowed to create enough space for the eruption of the maxillary right central incisor. The second stage included closed surgical exposure and vertical traction. After impacted tooth erupted in the proper position, accessory periodontal treatment and dental reshaping procedures may be indicated to camouflage macrodontic incisor with the adjacent teeth. This is the first report that presents a patient with ALGS undergoing orthodontic and surgical treatment. PMID:23814595

  14. Management of Traumatized Permanent Incisors. Revascularization and Delayed Replantation.

    PubMed

    Gharechahi, Maryam; Shojaeian, Shiva

    2016-01-01

    This article reports a clinical case of a 9-year-old boy with a traumatic injury to the maxillary central incisors 24 hours after a fall in his schoolyard. The upper left central incisor was avulsed and was kept in saliva for four hours from the moment of trauma until its replantation. The right one was necrotized after one month. We describe successful revascularization treatment of right necrotic immature upper incisor and delayed replantation of left one. After 18 months, radiolucent lesions in the periapical areas of both maxillary central incisors had healed, and root apex development was noted with thickening of the walls in tooth #8. PMID:26939157

  15. 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.

  16. Surgical endodontic management of infected lateral canals of maxillary incisors

    PubMed Central

    2015-01-01

    This case report presents surgical endodontic management outcomes of maxillary incisors that were infected via the lateral canals. Two cases are presented in which endodontically-treated maxillary central incisors had sustained lateral canal infections. A surgical endodontic treatment was performed on both teeth. Flap elevation revealed vertical bone destruction along the root surface and infected lateral canals, and microscopy revealed that the lateral canals were the origin of the lesions. After the infected lateral canals were surgically managed, both teeth were asymptomatic and labial fistulas were resolved. There were no clinical or radiographic signs of surgical endodontic management failure at follow-up visits. This case report highlights the clinical significance and surgical endodontic management of infected lateral canal of maxillary incisor. It is important to be aware of root canal anatomy variability in maxillary incisors. Maxillary central incisors infected via the lateral canal can be successfully managed by surgical endodontic treatment. PMID:25671217

  17. Surgical endodontic management of infected lateral canals of maxillary incisors.

    PubMed

    Jang, Ji-Hyun; Lee, Jung-Min; Yi, Jin-Kyu; Choi, Sung-Baik; Park, Sang-Hyuk

    2015-02-01

    This case report presents surgical endodontic management outcomes of maxillary incisors that were infected via the lateral canals. Two cases are presented in which endodontically-treated maxillary central incisors had sustained lateral canal infections. A surgical endodontic treatment was performed on both teeth. Flap elevation revealed vertical bone destruction along the root surface and infected lateral canals, and microscopy revealed that the lateral canals were the origin of the lesions. After the infected lateral canals were surgically managed, both teeth were asymptomatic and labial fistulas were resolved. There were no clinical or radiographic signs of surgical endodontic management failure at follow-up visits. This case report highlights the clinical significance and surgical endodontic management of infected lateral canal of maxillary incisor. It is important to be aware of root canal anatomy variability in maxillary incisors. Maxillary central incisors infected via the lateral canal can be successfully managed by surgical endodontic treatment.

  18. Association between Molar Incisor Hypomineralization in Schoolchildren and Both Prenatal and Postnatal Factors: A Population-Based Study

    PubMed Central

    Corrêa-Faria, Patrícia; Ferreira, Raquel Conceição; Bendo, Cristiane Baccin; Zarzar, Patrícia Maria; Vale, Miriam Pimenta

    2016-01-01

    Background Although studies throughout the world have investigated potential factors involved in the occurrence of molar incisor hypomineralization (MIH), the findings are varied and inconclusive. Objective The aim of the present study was to evaluate the prevalence of MIH and identify associated prenatal, perinatal and postnatal factors among Brazilian schoolchildren aged 8 and 9 years. Methods A cross-sectional study was conducted with a randomly selected population-based sample of 1181 schoolchildren. Information on demographic and socioeconomic characteristics as well as prenatal, perinatal and postnatal aspects was obtained through questionnaires. The clinical examination included the investigation of MIH based on the criteria of the European Academy of Paediatric Dentistry. Dental caries in the permanent dentition and developmental defects of enamel (DDE) on the primary second molars were also recorded. Data analysis involved descriptive statistics, bivariate tests and Poisson regression with robust variance. Results The prevalence of MIH was 20.4%. MIH was more frequent among children with dental caries in the permanent dentition (PR: 2.67; 95% CI: 1.98–3.61), those with DDE on the primary second molars (PR: 2.54; 95% CI: 1.87–3.45) and those who experienced asthma/bronchitis in the first four years of life (PR: 1.93; 95% CI: 1.45–2.56). Conclusions The prevalence of MIH was high and was associated with dental caries, the presence of DDE on primary second molars and the experience of asthma/bronchitis in early life. These findings could be useful in the identification of children in need of shorter recall intervals to prevent the consequences of MIH, such as enamel breakdown dental caries. PMID:27280451

  19. Molar incisor hypomineralization.

    PubMed

    Takahashi, Karine; Correia, Adriana de Sales Cunha; Cunha, Robson Frederico

    2009-01-01

    Enamel defects are common alterations that can occur in both the primary or permanent dentition. A range of etiological factors related to this pathology can be found in the literature. Molar Incisor Hypomineralization (MIH) is a kind of enamel defect alteration that requires complex treatment solutions, and for this reason, it is of great clinical interest for dental practice. This article describes the management of a clinical case of MIH in a 7-year-old child. The different treatment options depending on the extension of the defect, the degree of tooth eruption and the hygiene and diet habits of the patient are also discussed.

  20. Post-traumatic impaction of maxillary incisors: diagnosis and treatment

    PubMed Central

    Paoloni, Valeria; Pavoni, Chiara; Mucedero, Manuela; Bollero, Patrizio; Laganà, Giuseppina; Cozza, Paola

    2013-01-01

    Summary Aim To provide clinicians with useful information for immediate diagnosis and management of impacted maxillary incisors due to trauma. Methods We present a case of post-traumatic impaction of a central right maxillary incisor in a young patient. The treatment plan consisted in the interceptive management (surgical and orthodontic), the valuation of the necessary space to move the impacted tooth in the normal position and the biomechanical approach for anchorage, avoiding prosthetic/implants replacement. Results The therapy of an impacted maxillary incisor due to trauma requires a multidisciplinary approach: orthodontic, surgical, endodontic and periodontal considerations are essential for successful treatment. Conclusions Surgical exposure and orthodontic traction is the treatment most often used in case of posttraumatic impacted incisor: this technique in fact can lead to suitable results at the periodontal, occlusal and esthetics levels at an early stage and more definitively than with other treatment options. PMID:23991268

  1. Intrusion of incisors in adult patients with marginal bone loss.

    PubMed

    Melsen, B; Agerbaek, N; Markenstam, G

    1989-09-01

    Elongated and spaced incisors are common problems in patients suffering from severe periodontal disease. Thirty patients characterized by marginal bone loss and deep overbite were treated by intrusion of incisors. Three different methods for intrusion were applied: (1) J hooks and extraoral high-pull headgear, (2) utility arches, (3) intrusion bent into a loop in a 0.17 x 0.25-inch wire, and (4) base arch as described by Burstone. The intrusion was evaluated from the displacement of the apex, incision, and the center of resistance of the most prominent or elongated central incisor. Change in the marginal bone level and the amount of root resorption were evaluated on standardized intraoral radiographs. The pockets were assessed by standardized probing and the clinical crown length was measured on study casts. The results showed that the true intrusion of the center of resistance varied from 0 to 3.5 mm and was most pronounced when intrusion was performed with a base arch. The clinical crown length was generally reduced by 0.5 to 1.0 mm. The marginal bone level approached the cementoenamel junction in all but six cases. All cases demonstrated root resorption varying from 1 to 3 mm. The total amount of alveolar support--that is, the calculated area of the alveolar wall--was unaltered or increased in 19 of the 30 cases. The dependency of the results on the oral hygiene, the force distribution, and the perioral function was evaluated in relation to the individual cases. It was obvious that intrusion was best performed when (1) forces were low (5 to 15 gm per tooth) with the line of action of the force passing through or close to the center of resistance, (2) the gingiva status was healthy, and (3) no interference with perioral function was present.

  2. Effect of coffe and a cola-based soft drink on the color stability of bleached bovine incisors considering the time elapsed after bleaching

    PubMed Central

    PIROLO, Rodrigo; MONDELLI, Rafael Francisco Lia; CORRER, Gisele Maria; GONZAGA, Carla Castiglia; FURUSE, Adilson Yoshio

    2014-01-01

    There is no consensus about the waiting time necessary for the patient to start consuming beverages containing colorants again after bleaching. Objective: To evaluate the influence of beverages with coloring agents on bleached bovine incisors considering the time elapsed after bleaching. Materials and methods: Sixty bovine incisors were bleached with 35% hydrogen peroxide for in-office use (Whiteness HP Max) and divided into 10 groups. The color was evaluated with a spectrophotometer (Spectro Shade MICRO) before and after bleaching, employing the CIE-Lab system. After bleaching, the teeth were exposed for 5 min to coffee or cola-based soft drink (CBSD) at different periods after bleaching: 10 min, 1 h, 24 h, 48 h, and 72 h. Color (∆E) and lightness (∆L) variations were obtained from the CIE-Lab coordinates. Data were subjected to two-way ANOVA and Tukey HSD tests (p<0.05). Results: Significant differences were observed between groups for both the ∆L and ∆E values (p<0.001). All specimens presented a decrease in brightness (negative ∆L). The highest ∆E values were observed for teeth stained with a CBSD at 10 min and 1 h (4.12 and 4.16, respectively). Teeth pigmented with coffee presented ∆E values below 3.3 units for all evaluation times. Conclusion: The exposure to coffee after bleaching causes less color changes than the exposure to a CBSD regardless of the time after bleaching. PMID:25075672

  3. Molar Incisor Hypomineralization.

    PubMed

    Rao, Murali H; Aluru, Srikanth C; Jayam, Cheranjeevi; Bandlapalli, Anila; Patel, Nikunj

    2016-01-01

    Molar incisor hypomineralization (MIH) is a developmental defect affecting teeth. High prevalence rates of MIH and its clinical implications are significant for both the patients and clinicians. A wide variation in defect prevalence (2.4-40.2%) is reported. It seems to differ with regions and various birth cohorts. Some of the recent prevalence studies are tabulated. Patient implications include hypersensitive teeth, rapid progression of caries, mastication impairment due to rapid attrition, and esthetic repercussions. Implications for clinicians include complexity in treatment planning and treatment implementation, poor prognosis of the restorations, difficulty in achieving pain control during treatment, and behavior management problems. Intention of this paper is to review the etio-pathogenesis, prevalence, clinical features, diagnostic features, and eventually present a sequential treatment approach, i.e., in accordance with current clinical practice guidelines. PMID:27595731

  4. Social judgments made by children (10–15 year old) in relation to visible incisors trauma: School-based cross-sectional study in Khartoum state, Sudan

    PubMed Central

    Awooda, Elhadi Mohieldin; Ali, Yasmeen Abdul-Hai

    2015-01-01

    Background: Dento-alveolar trauma is a very common occurrence in childhood; however, there is a paucity of data about children's judgments in relation to dental status. There is a significant correlation between the children's incisor teeth status and the social judgments made by their peers. Aim: The purpose of this study was to determine whether the social attributes of a school child would be influenced by his or her incisor teeth status. Also, it is aimed to determine the judgment between male and female children and different age groups within the same class. Setting and Design: A descriptive cross-sectional study conducted among 178 male and female children from year 5 (age 10–11 years) of primary school and year 2 of secondary school (age 14–15 years) within Khartoum state. Materials and Methods: Students were invited to look at colored photographs of four different children's faces and to make a social judgment about these children's photographs. Using a previously validated child-centered questionnaire, participants rated subjects using a four-point Likert scale for three negative and six positive attributes. Statistical Analysis: Total attribute scores were tested for significant differences, according to whether the subject had visible incisor trauma or not, using t-test and analysis of variance (ANOVA) test with the level of significance set at P ≤ 0.05. Results: Children with visible incisor trauma were given more negative attributes than children without incisor trauma (P = 0.05). Results were similar in both genders and both school years. Younger students within the same class gave more negative attributes toward children with visible incisor trauma than their older peers, with P = 0.04 and P = 0.9 for children aged 10 years and 11 years, respectively. Conclusion: The data confirmed results of previous studies that children with visible incisor trauma are seen more negatively than those without visible incisor trauma. PMID:26539397

  5. Orthodontic intrusion of maxillary incisors: a 3D finite element method study

    PubMed Central

    Saga, Armando Yukio; Maruo, Hiroshi; Argenta, Marco André; Maruo, Ivan Toshio; Tanaka, Orlando Motohiro

    2016-01-01

    Objective: In orthodontic treatment, intrusion movement of maxillary incisors is often necessary. Therefore, the objective of this investigation is to evaluate the initial distribution patterns and magnitude of compressive stress in the periodontal ligament (PDL) in a simulation of orthodontic intrusion of maxillary incisors, considering the points of force application. Methods: Anatomic 3D models reconstructed from cone-beam computed tomography scans were used to simulate maxillary incisors intrusion loading. The points of force application selected were: centered between central incisors brackets (LOAD 1); bilaterally between the brackets of central and lateral incisors (LOAD 2); bilaterally distal to the brackets of lateral incisors (LOAD 3); bilaterally 7 mm distal to the center of brackets of lateral incisors (LOAD 4). Results and Conclusions: Stress concentrated at the PDL apex region, irrespective of the point of orthodontic force application. The four load models showed distinct contour plots and compressive stress values over the midsagittal reference line. The contour plots of central and lateral incisors were not similar in the same load model. LOAD 3 resulted in more balanced compressive stress distribution. PMID:27007765

  6. Dual embryonic origin of maxillary lateral incisors: clinical implications in patients with cleft lip and palate

    PubMed Central

    Garib, Daniela Gamba; Rosar, Julia Petruccelli; Sathler, Renata; Ozawa, Terumi Okada

    2015-01-01

    Introduction: Cleft lip and palate are craniofacial anomalies highly prevalent in the overall population. In oral clefts involving the alveolar ridge, variations of number, shape, size and position are observed in maxillary lateral incisors. The objective of this manuscript is to elucidate the embryonic origin of maxillary lateral incisors in order to understand the etiology of these variations. Contextualization: The hypothesis that orofacial clefts would split maxillary lateral incisor buds has been previously reported. However, recent studies showed that maxillary lateral incisors have dual embryonic origin, being partially formed by both the medial nasal process and the maxillary process. In other words, the mesial half of the lateral incisor seems to come from the medial nasal process while the distal half of the lateral incisor originates from the maxillary process. In cleft patients, these processes do not fuse, which results in different numerical and positional patterns for lateral incisors relating to the alveolar cleft. In addition to these considerations, this study proposes a nomenclature for maxillary lateral incisors in patients with cleft lip and palate, based on embryology and lateral incisors position in relation to the alveolar cleft. Conclusion: Embryological knowledge on the dual origin of maxillary lateral incisors and the use of a proper nomenclature for their numerical and positional variations renders appropriate communication among professionals and treatment planning easier, in addition to standardizing research analysis. PMID:26560830

  7. Incisor-molar relationships in chimpanzees and other hominoids: implications for diet and phylogeny.

    PubMed

    Pickford, Martin

    2005-01-01

    In chimpanzees, the cutting edge of the incisor battery is longer in relation to the length of the molar row than in any other hominoid, extant or fossil, the only other lineage approaching it being the orangutan. Apart from their increased mesio-distal dimensions, the upper and lower incisors of chimpanzees differ in additional ways from those of almost all other hominoids. The I2/ is enlarged, so that the difference in size between it and the central upper incisor is less than it is in the heteromorphic upper incisors of other hominoids. The lower incisors are expanded mesio-distally, so much so that isolated I/2 crowns can resemble upper central incisors. In chimpanzees the lingual surface of the lower incisors is generally more procumbent than it is in other hominoids, which have more vertically oriented incisor crowns and there is a greater difference in enamel thickness between labial and lingual sides. The re-orientation of the lower incisor crown is reflected in the root, which in lateral view is anteriorly concave in chimpanzees whereas it is more orthogonal or convex in other hominoids. The molars of chimpanzees, especially the lowers, have extensive and relatively deep occlusal basins, and the main cusps are peripheralised and labio-lingually compressed, making them more trenchant than those of other hominoids. This paper examines the incisor-lower molar proportions in extinct and living hominoids and develops a new hypothesis about the evolution of the dentition of chimpanzees and links it to their diet. It also examines the incisor-molar proportions of hominids and African apes in order to throw light on the phylogenetic relationships between them. It is shown that chimpanzees are highly derived in this respect and that several recent ideas concerning the chimp-like appearance of the last common ancestor of hominids and African apes are likely to be incorrect. PMID:15503253

  8. Familial aggregation of maxillary lateral incisor agenesis (MLIA)

    PubMed Central

    Pandey, Pallavi; Ansari, Afroz Alam; Choudhary, Kartik; Saxena, Aditya

    2013-01-01

    Agenesis of maxillary lateral incisors and mandibular second premolars is the most frequent form of hypodontia. Its prevalence varies across population from 0.8% to 4.5%. Genetic aberrations and environmental factors may cause agenesis of one or more teeth. The management of child having such a problem is very important since diastema in teeth especially in upper anteriors not only affects child's physical appearance but also its psychological development as the child wants to look like other children. In this article is presented a case of non-syndromic agenesis of maxillary lateral incisors (MLIA) and mandibular central incisors in a 10-year-old boy (patient) in permanent dentition with its management along with the radiographic investigations and photographic presentations of the other members of his family affected with this condition. PMID:23536620

  9. Evaluating Stress Distribution Pattern in Periodontal Ligament of Maxillary Incisors during Intrusion Assessed by the Finite Element Method

    PubMed Central

    Salehi, Parisa; Gerami, Alayar; Najafi, Amirhosein; Torkan, Sepideh

    2015-01-01

    Statement of the Problem The use of miniscrews has expedited the true maxillary incisor intrusion and has minimized untoward side effects such as labial tipping. Purpose The aim of this study was to assess the stress distribution in the periodontal ligament of maxillary incisors when addressed to different models of intrusion mechanics using miniscrews by employing finite element methods. The degree of relative and absolute intrusion of maxillary incisors in different conditions was also evaluated. Materials and Method Finite element model of maxillary central incisor to first premolar was generated by assembling images obtained from a three-dimensional model of maxillary dentition. Four different conditions of intrusion mechanics were simulated with different placement sites of miniscrews as well as different points of force application. In each model, 25-g force was applied to maxillary incisors via miniscrews. Results In all four models, increased stress values were identified in the apical region of lateral incisor. Proclination of maxillary incisors was also reported in all the four models. The minimum absolute intrusion was observed when the miniscrew was placed between the lateral incisor and canine and the force was applied at right angles to the archwire, which is very common in clinical practice. Conclusion From the results yield by this study, it seems that the apical region of lateral incisor is the most susceptible region to root resorption during anterior intrusion. When the minimum flaring of maxillary incisors is required in clinical situations, it is suggested to place the miniscrew halfway between the roots of lateral incisor and canine with the force applied to the archwire between central and lateral incisor. In order to achieve maximum absolute intrusion, it is advised to place miniscrew between the roots of central and lateral incisors with the force applied at a right angle to the archwire between these two teeth. PMID:26636119

  10. Mandibular incisor extraction treatment in Angle's Class I malocclusion with peg-shaped maxillary lateral incisors

    PubMed Central

    Shah, Ankit H; Shah, Darshit H

    2016-01-01

    Accurate diagnosis and treatment planning are essential for obtaining ideal treatment result in cases involving mandibular incisor extraction. This case report describes a 15-year-old female with balanced soft-tissue profile, peg-shaped maxillary lateral incisors, and moderate mandibular anterior crowding treated with a mandibular incisor extraction. Ideal overbite and overjet were achieved. “Black triangle” formation was avoided due to the bodily movement of mandibular incisors and the use of uprighting springs for ideal axial inclination of mandibular incisors. A mandibular incisor extraction can be an effective treatment option in carefully selected clinical situations. PMID:27556022

  11. Impacted permanent incisors associated with compound odontoma.

    PubMed

    Machado, Cintia de Vasconcellos; Knop, Luégya Amorin Henriques; da Rocha, Maria Celina Barreiros Siquara; Telles, Paloma Dias da Silva

    2015-01-12

    Odontomas are the most common odontogenic tumours of the maxillary bones, characterised by a slow growth and benign behaviour. They are usually small, asymptomatic and diagnosed after routine radiographic examination. The aim of this study was to report a case of a compound odontoma in the anterior maxilla of a 7-year-old girl, which was causing the impaction of the maxillary right central and lateral incisors, as well as the prolonged retention of the corresponding primary teeth. We also aimed to review the literature about these tumours, since they are not part of the dentist's day-to-day clinical practice. The clinical and radiographic features, the diagnosis and treatment of the case were discussed in this work.

  12. [Incisor repositioning: a new approach in orthodontics].

    PubMed

    Dallel, Ines; Khemiri, Mourad; Fathallah, Safa; Ben Rejeb, Salwa; Tobji, Samir; Ben Amor, Adel

    2015-12-01

    Lower incisors axis has a "key" position in different cephalometric analysis. However, several critics are directed towards the cephalometric profile and cephalometric landmarks (point, line and angle). The published norms and the cephalometric standards recommended for the optimal positioning of incisors could only be used as general clinical guidelines. Incisor repositioning to achieve optimal facial aesthetics requires taking into consideration the hard and soft tissues of the face, the profile, the muscular dynamics as well as the facial growth. In this work, we propose a new approach of incisor repositioning taking into account the variability of periodontal, functional and aesthetic factors.

  13. Root resorption of upper permanent incisor caused by impacted canine. An analysis of 23 cases.

    PubMed

    Sasakura, H; Yoshida, T; Murayama, S; Hanada, K; Nakajima, T

    1984-08-01

    Unusual root resorption of 12 central and 11 lateral upper permanent incisors in 11 patients is described. The degree of resorption ranged from loss of the apical 1/4 to almost complete loss of root structure. Excepting 1 case, permanent canines were partially or completely impacted and their crowns were in close apposition to the resorbed surfaces of the incisors. The roots of the canines were either in the process of formation or completely formed. The findings suggest that the pressure from the canine which persists in moving downward despite the lack of space to permit normal eruption could cause root resorption of adjacent incisors even in the absence of systemic factors. Of 14 extracted incisors, 10 were replaced orthodontically by the impacted canines, whereas the spaces of the extracted incisors were restored by prosthetic means in the 4 other cases. 6 incisors were preserved without any treatment and 2 with the aid of a sapphire dento-osseous anchor pin. Since the resorbed incisors were mostly free of pain, early detection by radiographic examination is essential to establish a proper diagnosis.

  14. A comparative study of incisor procumbency and mandibular morphology in vampire bats.

    PubMed

    Davis, Jillian S; Nicolay, Christopher W; Williams, Susan H

    2010-07-01

    The three species of vampire bats (Phyllostomidae: Desmodontinae), Desmodus rotundus, Diaemus youngi, and Diphylla ecaudata, are the only mammals that obtain all nutrition from vertebrate blood (sanguinivory). Because of the unique challenges of this dietary niche, vampire bats possess a suite of behavioral, physiological, and morphological specializations. Morphological specializations include a dentition characterized by small, bladelike, non-occlusive cheek teeth, large canines, and extremely large, procumbent, sickle-shaped upper central incisors. The tips of these incisors rest in cuplike pits in the mandible behind the lower incisors (mandibular pits). Here, we use microCT scanning and high-resolution radiography to describe the morphology of the mandible and anterior dentition in vampire bats, focusing on the relationship between symphyseal fusion, mandibular pit size, incisor size, and procumbency. In Desmodus and Diaemus, highly procumbent upper incisors are associated with relatively small mandibular pits, an unfused mandibular symphysis with substantial bony interdigitations linking the dentaries, and a diastema between the lower central incisors that helps to facilitate the lapping of blood from a wound. In Diphylla, less procumbent upper incisors are associated with relatively large mandibular pits, a completely fused mandibular symphysis, and a continuous lower toothrow lacking a central diastema. We hypothesize that symphyseal morphology and the presence or absence of the diastema are associated with the angle of upper incisor procumbency and mandibular pit development, and that spatial constraints influence the morphology of the symphysis. Finally, this morphological variation suggests that Diphylla utilizes a different feeding strategy as compared to Desmodus and Diaemus, possibly resulting from the functional demands of specialization on avian, rather than mammalian, blood.

  15. A comparative study of incisor procumbency and mandibular morphology in vampire bats.

    PubMed

    Davis, Jillian S; Nicolay, Christopher W; Williams, Susan H

    2010-07-01

    The three species of vampire bats (Phyllostomidae: Desmodontinae), Desmodus rotundus, Diaemus youngi, and Diphylla ecaudata, are the only mammals that obtain all nutrition from vertebrate blood (sanguinivory). Because of the unique challenges of this dietary niche, vampire bats possess a suite of behavioral, physiological, and morphological specializations. Morphological specializations include a dentition characterized by small, bladelike, non-occlusive cheek teeth, large canines, and extremely large, procumbent, sickle-shaped upper central incisors. The tips of these incisors rest in cuplike pits in the mandible behind the lower incisors (mandibular pits). Here, we use microCT scanning and high-resolution radiography to describe the morphology of the mandible and anterior dentition in vampire bats, focusing on the relationship between symphyseal fusion, mandibular pit size, incisor size, and procumbency. In Desmodus and Diaemus, highly procumbent upper incisors are associated with relatively small mandibular pits, an unfused mandibular symphysis with substantial bony interdigitations linking the dentaries, and a diastema between the lower central incisors that helps to facilitate the lapping of blood from a wound. In Diphylla, less procumbent upper incisors are associated with relatively large mandibular pits, a completely fused mandibular symphysis, and a continuous lower toothrow lacking a central diastema. We hypothesize that symphyseal morphology and the presence or absence of the diastema are associated with the angle of upper incisor procumbency and mandibular pit development, and that spatial constraints influence the morphology of the symphysis. Finally, this morphological variation suggests that Diphylla utilizes a different feeding strategy as compared to Desmodus and Diaemus, possibly resulting from the functional demands of specialization on avian, rather than mammalian, blood. PMID:20544874

  16. Comparison of the Physiological Properties of Human Periodontal-Masseteric Reflex Evoked by Incisor and Canine Stimulation

    PubMed Central

    Ohmori, Hiroko; Kirimoto, Hiroaki; Ono, Takashi

    2012-01-01

    Introduction: The present study was designed to clarify whether the bilateral cooperation in the human periodontal-masseteric reflex (PMR) differs between central incisors and canines. Methods: Surface array electrodes were placed on the bilateral masseter muscles to simultaneously record the firing activities of single motor units from both sides in seven healthy adults. During light clenching, mechanical stimulation was applied to the right maxillary central incisor and canine to evoke the PMR. Unitary activity was plotted with respect to the background activity and firing frequency. The slope of the regression line (sRL) and the correlation coefficient (CC) between the central incisor and canine and the lateral differences between these values were compared. Results: There were significant differences in the sRL and CC, as well as lateral differences, between the central incisor- and canine-driven PMR. Discussion: These results suggest that the PMR differs depending on both the tooth position and laterality. PMID:22754541

  17. Lower incisor position in different malocclusions and facial patterns

    PubMed Central

    Hernández-Sayago, Estrella; Barrera-Mora, Jose M.; Ruiz-Navarro, Maria B.; Llamas-Carreras, Jose M.; Solano-Reina, Enrique

    2013-01-01

    Introduction: The position of lower incisor has been of considerable concern when planning an orthodontic treatment, having been recognized as one of diagnostic keys, Very important in the development of malocclusion and facial pattern. Objectives: In this study we claim to determine the importance of the position and inclination of lower incisor in the different malocclusions and facial patterns, and to base which of the cephalometric measurement parameters are the mostreliable. Material and Methods: Ninety lateral radiographies were taken, and they were classified by skeletal malocclusion and facial pattern.These teleradiographies have been performed cephalometric analysis, which includelower incisor position belong the following analysis: Ricketts, Riolo, Tweed, McHorris, Jarabak-MSE and Holdaway. Study Design: Cross-sectional study where we perform statistical analysis Anova test, Pearson correlations and Bonferroni analysis. Results: The analyzed measurements present a statistically significant differentiation in lower incisor inclination respect to the anterior cranial base, McHorris angle, angulation of lower incisor respect to occlusal plane and mandibular plane. Conclusions: There are statistically significant differentiation in lower incisor position and inclination respect the malocclusion and individual facial pattern. Key words:Lower incisor, cephalometric analysis, facial patterns, facial biotype, skeletal malocclusions. PMID:23229262

  18. Incisor wear and age in Yellowstone bison

    USGS Publications Warehouse

    Christianson, D.A.; Gogan, P.J.P.; Podruzny, K.M.; Olexa, E.M.

    2005-01-01

    Biologists commonly use tooth eruption and wear patterns or cementum annuli techniques to estimate age of ungulates. However, in some situations the accuracy or sampling procedures of either approach are undesirable. We investigated the progression of several quantitative measures of wear with age, using permanent first incisors from Yellowstone bison (Bison bison), and tested for differences between sexes and herds. We further investigated the relationship of wear and age to explore an age-estimation method. Labial-lingual width (LLW) correlated best with assigned age (r2=0.66, males; r2=0.76 females). Labial-lingual width differed between sexes, with females showing ∼0.2 mm more wear than males. Additionally, differences in rate of wear existed between bison of the northern and central Yellowstone herds (1.2 and 0.9 mm/year, respectively). We developed a regression formula to test the power of LLW as an estimator of Yellowstone bison age. Our method provided estimated ages within 1 year of the assigned age 73% and 82% of the time for female and male bison, respectively.

  19. Management of horizontally impacted dilacerated lateral incisor

    PubMed Central

    Katta, Anil Kumar; Peddu, Revathi; Vannala, Venkataramana; Dasari, Vaishnavi

    2015-01-01

    Impaction of maxillary lateral incisor with odontome and retained deciduous tooth is not often seen in regular dental practice. Impaction of anterior teeth cause generalized spacing which affects the esthetics of the face. Here we report a case of an 18-year-old patient with horizontally impacted dilacerated lateral incisor, which was bought into occlusion with the help of orthodontic tooth movement within a span of 18 months. PMID:26538954

  20. Dynamics-based centrality for directed networks.

    PubMed

    Masuda, Naoki; Kori, Hiroshi

    2010-11-01

    Determining the relative importance of nodes in directed networks is important in, for example, ranking websites, publications, and sports teams, and for understanding signal flows in systems biology. A prevailing centrality measure in this respect is the PageRank. In this work, we focus on another class of centrality derived from the Laplacian of the network. We extend the Laplacian-based centrality, which has mainly been applied to strongly connected networks, to the case of general directed networks such that we can quantitatively compare arbitrary nodes. Toward this end, we adopt the idea used in the PageRank to introduce global connectivity between all the pairs of nodes with a certain strength. Numerical simulations are carried out on some networks. We also offer interpretations of the Laplacian-based centrality for general directed networks in terms of various dynamical and structural properties of networks. Importantly, the Laplacian-based centrality defined as the stationary density of the continuous-time random walk with random jumps is shown to be equivalent to the absorption probability of the random walk with sinks at each node but without random jumps. Similarly, the proposed centrality represents the importance of nodes in dynamics on the original network supplied with sinks but not with random jumps.

  1. Dynamics-based centrality for directed networks

    NASA Astrophysics Data System (ADS)

    Masuda, Naoki; Kori, Hiroshi

    2010-11-01

    Determining the relative importance of nodes in directed networks is important in, for example, ranking websites, publications, and sports teams, and for understanding signal flows in systems biology. A prevailing centrality measure in this respect is the PageRank. In this work, we focus on another class of centrality derived from the Laplacian of the network. We extend the Laplacian-based centrality, which has mainly been applied to strongly connected networks, to the case of general directed networks such that we can quantitatively compare arbitrary nodes. Toward this end, we adopt the idea used in the PageRank to introduce global connectivity between all the pairs of nodes with a certain strength. Numerical simulations are carried out on some networks. We also offer interpretations of the Laplacian-based centrality for general directed networks in terms of various dynamical and structural properties of networks. Importantly, the Laplacian-based centrality defined as the stationary density of the continuous-time random walk with random jumps is shown to be equivalent to the absorption probability of the random walk with sinks at each node but without random jumps. Similarly, the proposed centrality represents the importance of nodes in dynamics on the original network supplied with sinks but not with random jumps.

  2. Removable orthodontic appliance with nickel-titanium spring to reposition the upper incisors in an autistic patient.

    PubMed

    Saito, Kan; Jang, Insan; Kubota, Kazumi; Hoshino, Tomonori; Hotokezaka, Hitoshi; Yoshida, Noriaki; Fujiwara, Taku

    2013-01-01

    A newly designed removable appliance with a shape-memory wire was used for the orthodontic treatment of the anterior teeth in an 11-year-old child who had autism and intellectual disability. The device was designed to reduce the lateral incisor crossbite and the central incisors' labial rotation. The child was treated for 1 year with this removable appliance. Tooth movement was analyzed using cephalograms and surface data were derived from study models. This device proved to be very durable. The lateral incisor crossbite was corrected, and the inclination of the upper central incisors and the interincisal angle were improved. This appliance exerts light and continuous orthodontic force, without requiring any adjustments of the spring wire. The appliance also facilitated orthodontic treatment in a child with intellectual disability in whom treatment with a standard orthodontic device would be unsuitable.

  3. Clinical management of a fused mandibular lateral incisor with supernumerary tooth: A case report

    PubMed Central

    Aydemir, Seda; Ozel, Emre; Arukaslan, Goze; Tekce, Neslihan

    2016-01-01

    The purpose of this report is to present a rare case of a fused mandibular lateral incisor with supernumerary tooth with a follow-up for 18-months. A 35-year-old female patient was referred to our clinic with an extraoral sinus tract in the chin. The intraoral diagnosis revealed the fusion of her mandibular lateral incisors. Vitality pulp tests were negative for mandibular right central and lateral incisors. Radiographic examinations showed a fused tooth with two separate pulp chambers, two distinct roots, and two separate root canals. There were also periapical lesion of fused teeth and mandibular right central incisor, so endodontic treatment was carried out the related teeth. Radiographic examination revealed a complete healing of the lesion postoperatively at the end of 18-months. This paper reports the successful endodontic and restorative treatment of unilateral fused incisors. Because of the abnormal morphology of the crown and the complexity of the root canal system in fused teeth, treatment protocols require special attention. PMID:26962321

  4. Clinical management of a fused mandibular lateral incisor with supernumerary tooth: A case report.

    PubMed

    Aydemir, Seda; Ozel, Emre; Arukaslan, Goze; Tekce, Neslihan

    2016-01-01

    The purpose of this report is to present a rare case of a fused mandibular lateral incisor with supernumerary tooth with a follow-up for 18-months. A 35-year-old female patient was referred to our clinic with an extraoral sinus tract in the chin. The intraoral diagnosis revealed the fusion of her mandibular lateral incisors. Vitality pulp tests were negative for mandibular right central and lateral incisors. Radiographic examinations showed a fused tooth with two separate pulp chambers, two distinct roots, and two separate root canals. There were also periapical lesion of fused teeth and mandibular right central incisor, so endodontic treatment was carried out the related teeth. Radiographic examination revealed a complete healing of the lesion postoperatively at the end of 18-months. This paper reports the successful endodontic and restorative treatment of unilateral fused incisors. Because of the abnormal morphology of the crown and the complexity of the root canal system in fused teeth, treatment protocols require special attention. PMID:26962321

  5. Age estimation from pulp/tooth area ratio in maxillary incisors among Egyptians using dental radiographic images.

    PubMed

    Zaher, Jaklin Fekri; Fawzy, Irene Atef; Habib, Sahar Refaat; Ali, Magdy Mohamed

    2011-02-01

    Age estimation from dental radiographs is a non-destructive, simple method to obtain information. The aim of this study was to determine the reliability of age estimation from Egyptians' incisors radiographs. 144 periapical radiographs of maxillary (central & lateral) incisors (both sexes) aged 12-60 were used. Digital camera was used to image the radiographs. Images were computed and pulp/tooth area ratios were determined by AutoCAD Program. Data were subjected to correlation and regression analysis which showed statistically significant correlation (r = 0.23 &P = 0.006 for maxillary central incisors and r = -0.2 &P = 0.05 for maxillary lateral incisors) between age and pulp tooth area ratio. Linear regression equations were determined separately for both central and lateral incisors along with the corresponding Standard Error of Estimate, which ranged from 1.2 to 5.08 years. Consequently, it was concluded that pulp/tooth area ratios of incisors are reliable for estimation of age among Egyptians in forensic work. PMID:21315299

  6. Is bodily advancement of the lower incisors possible?

    PubMed

    Strahm, Catherine; De Sousa, Ana Paula; Grobéty, Dominique; Mavropoulos, Anestis; Kiliaridis, Stavros

    2009-08-01

    Some Class II malocclusions are due, at least in part, to a retruded lower dental arch relative to the mandibular body. The purpose of this study was to determine if a direct anterior force on the lower incisors could lead to bodily movement of these teeth. Twenty-seven patients (9 males, 18 females; mean age: 9.8 years) were treated with a reverse headgear (RHG) in the lower dental arch combined with labial root torque of the lower incisors. An activator was added to disclude the arches. This group was compared with 26 patients (10 males, 16 females; mean age: 9.7 years) treated with an activator combined with conventional posterior extraoral traction on the upper molars. All patients had a second stage of treatment with fixed appliances and Class II elastic wear. At the end of treatment, all patients had a Class I relationship and a normal overjet. Lateral cephalograms were taken before (T1), after the first stage (T2), and at the end of active (T3) treatment. Independent sample t-tests were used to assess the differences between the two groups of patients. In the RHG group, despite the applied root torque, the lower incisors showed anterior crown tipping. Labial root displacement was not observed. At T2, this labial tipping partially relapsed. Furthermore, the use of RHG appeared to decrease bone apposition in the anterior part of the symphysis, leading to a reduction in width. Bodily advancement of the lower incisors was not achieved with the application of labial root torque and anteriorly directed force on the mandibular arch. The width limit of the lower anterior apical base should be respected during orthodontic treatment planning.

  7. Class I malocclusion treatment: influence of a missing mandibular incisor on anterior guidance.

    PubMed

    Barros, Sérgio Estelita C; Janson, Guilherme; Torres, Fernando César; de Freitas, Marcos Roberto; de Almeida, Renato Rodrigues

    2010-07-01

    This case report describes the orthodontic treatment of a patient with a deep-overbite Angle Class I malocclusion, agenesis of a mandibular central incisor, and 2 supernumerary teeth, which caused impaction of the mandibular first premolars. The 15-year-old patient also had a convex profile, maxillary dentoalveolar protrusion, and deficiency of space for the correct alignment of teeth. Therefore, treatment consisted of fixed appliance therapy, cervical headgear, extraction of the supernumeraries and the mandibular and maxillary first premolars, and mesiodistal reduction of the maxillary incisors to solve the arch perimeter discrepancy as much as possible with interproximal stripping. This method of treatment significantly improved the patient's facial and dental esthetics and provided a good functional occlusion, despite the absence of a mandibular incisor, which generally impairs achieving adequate incisal guidance.

  8. Immediate post-traumatic upper incisor reconstruction using composite resin materials.

    PubMed

    Panduric, Vlatko; Gabric, Dragana; Negovetic-Mandic, Visnja

    2008-02-01

    Single visit reconstruction of the fractured crown can be completed with composite resins if there is no bleeding due to the soft tissue injury. Clinical inspection revealed a complex crown fracture of the central incisor as well as a simple horizontal fracture of the lateral incisor crown of the enamel-dentin type. Vertical fracture separated the palatal enamel wall from the rest of the lateral incisor crown. After the completion of the endodontic sanitation, root canals were prepared for prefabricated composite posts and crown reconstructions were performed with the Finger Tip Technique by using composite resin materials. The advantage of this kind of reconstruction is preservation of the hard dental crown tissue removed in case of prosthetic therapy, especially in younger patients. Reconstruction can be finished in one visit, without the need for a dental technician and laboratory.

  9. Dental management of a talon cusp on a primary incisor.

    PubMed

    Yoon, Richard K; Chussid, Steven

    2007-01-01

    There are many treatment options for the pediatric patient with a talon cusp (TC). The purpose of this paper was to report the case of a TC involving a primary maxillary right central incisor in a 14-month-old male causing displacement of the affected tooth. The etiology of a TC is thought to be a disturbance during the morphodifferentiation stage of tooth development. Clinical problems include: (1) occlusal interferences; (2) esthetic disturbances; (3) accidental cusp fracture; (4) tongue irritation; (5) nursing difficulty; (6) caries; and (7) displacement of the affected tooth. The TC affecting the central incisor was reduced over a period of 4 visits, followed by immediate placement of a 5% sodium fluoride varnish at the conclusion of each reduction visit. Restoration of esthetics and function was evident within 1 month following complete cusp reduction. There were no clinical signs of any problems related to the reduction, and the prognosis was considered to be guarded. The pediatric patient was placed on a 6-month oral hygiene maintenance follow-up.

  10. [Upper lateral incisor with 2 canals].

    PubMed

    Fabra Campos, H

    1991-01-01

    Clinical case summary of the patient with an upper lateral incisor with two root canals. The suspicion that there might be an anatomic anomaly in the root that includes a complex root canal system was made when an advanced radicular groove was detected in the lingual surface or an excessively enlarged cingulum.

  11. [Upper lateral incisor with 2 canals].

    PubMed

    Fabra Campos, H

    1991-01-01

    Clinical case summary of the patient with an upper lateral incisor with two root canals. The suspicion that there might be an anatomic anomaly in the root that includes a complex root canal system was made when an advanced radicular groove was detected in the lingual surface or an excessively enlarged cingulum. PMID:1659854

  12. The distribution of magnesium in developing rat incisor dentin

    SciTech Connect

    Steinfort, J.; Driessens, F.C.; Heijligers, H.J.; Beertsen, W. )

    1991-03-01

    Previous studies have shown that rat incisor dentin contains a considerable amount of magnesium that is distributed heterogeneously. The cementum-related dentin, especially its incisal portion, is richest in magnesium. It was the purpose of the present study to investigate the changes that occur in the magnesium content during dentin maturation. Cross-sections were prepared from rat incisors at the apical, middle, and incisal levels. By means of an electron microprobe, tracings were made of the Ca-, Mg-, and P- signal frequencies. Comparison of corresponding dentin layers within and between the cross-sections showed that the Mg/P molar ratio was always higher in the cementum-related dentin (CRD) than in the enamel-related dentin (ERD) and increased from the apex toward the incisal edge. Especially in the incisal cross-section, an increase in Mg/P was found from the older (peripheral) toward the younger (central) dentin layers. As the Mg/P ratio varied from 0.07 to 0.33, the Ca/P ratio was found to fluctuate from 1.48 to 1.15. The two ratios appeared to be highly correlated (r = -0.97; p less than 0.001), suggesting that Mg replaces Ca and is bound to phosphate.

  13. Imaging of the central skull base.

    PubMed

    Borges, Alexandra

    2009-08-01

    The central skull base (CSB) constitutes a frontier between the extracranial head and neck and the middle cranial fossa. The anatomy of this region is complex, containing most of the bony foramina and canals of the skull base traversed by several neurovascular structures that can act as routes of spread for pathologic processes. Lesions affecting the CSB can be intrinsic to its bony-cartilaginous components; can arise from above, within the intracranial compartment; or can arise from below, within the extracranial head and neck. Crosssectional imaging is indispensable in the diagnosis, treatment planning, and follow-up of patients with CSB lesions. This review focuses on a systematic approach to this region based on an anatomic division that takes into account the major tissue constituents of the CSB.

  14. Imaging of the central skull base.

    PubMed

    Borges, Alexandra

    2009-11-01

    The central skull base (CSB) constitutes a frontier between the extracranial head and neck and the middle cranial fossa. The anatomy of this region is complex, containing most of the bony foramina and canals of the skull base traversed by several neurovascular structures that can act as routes of spread for pathologic processes. Lesions affecting the CSB can be intrinsic to its bony-cartilaginous components; can arise from above, within the intracranial compartment; or can arise from below, within the extracranial head and neck. Crosssectional imaging is indispensable in the diagnosis, treatment planning, and follow-up of patients with CSB lesions. This review focuses on a systematic approach to this region based on an anatomic division that takes into account the major tissue constituents of the CSB.

  15. Forces that fracture teeth during extraction with mandibular premolar and maxillary incisor forceps.

    PubMed

    Ahel, V; Ćabov, T; Špalj, S; Perić, B; Jelušić, D; Dmitrašinović, M

    2015-12-01

    Our aim was to measure the forces that fracture teeth during extraction based on the effectiveness of the extraction forceps, and to compare them with data collected about forces applied to extracted teeth that did not fracture. We studied 208 patients whose teeth fractured during both the standard and our new method of extraction: maxillary incisors (n=79) extracted with forceps 1 (maxillary incisor forceps), and both maxillary (n=95) and mandibular incisors (n=34) extracted with forceps 13 (mandibular premolar forceps). Forces needed to fracture were assessed with a specially-designed instrument for measuring pressure and rotation. Mean (SD) pressure at the fracture site was significantly higher in maxillary incisors extracted with forceps 1 (1.26 (0.26) bar) then in both maxillary and mandibular incisors extracted with forceps 13 (0.96 (0.19) and 0.98 (0.16), p<0.001). Pressure at dislocation and both left and right rotation showed similar patterns. Pressure correlated to root surfaces of teeth ranging from r=0.35-0.54 but the correlation coefficients did not differ significantly between the teeth-forceps groups. Pressure was higher in fractured than in extracted teeth, and this varied from 3%-48%. In conclusion, forces that break teeth during extractions are sometimes only slightly higher than the extraction forces, so caution is needed during extraction.

  16. Reattachment of fractured teeth fragments in mandibular incisors: a case report

    PubMed Central

    Yousef, Mohammed K

    2015-01-01

    The majority of dental trauma involves anterior teeth, especially the maxillary central incisors. A mandibular incisor fracture with or without pulp tissue involvement is considerably less common. Different approaches for treating these fractured teeth have been reported in the literature. The type of treatment rendered depends mainly on the extent of fracture, pulp involvement, radicular fracture, biologic width infringement or violation, and presence of the fractured piece. This case report illustrates reattachment of fractured fragments on two mandibular incisors without pulp exposure using a new proposed reattachment method using a combination of two different types of composite materials together with an orthodontic lingual retention wire. An 8-year-old female patient presented with fractured mandibular left incisors (Ellis class II fracture). Broken pieces were saved and brought in a closed container in water. Periapical radiographs revealed no evidence of pulpal involvement in either tooth and no periapical radiolucency was noticed. Fractured fragments and the broken teeth were prepared with circumferential bevels. Reattachment of the fractured fragments were done using two types of composite resin materials and a lingual orthodontic retention wire was also used. The patient was recalled after 8 months to follow up both teeth. Clinical examination revealed excellent composite restorations covering the fracture lines. PMID:25897267

  17. Reattachment of fractured teeth fragments in mandibular incisors: a case report.

    PubMed

    Yousef, Mohammed K

    2015-01-01

    The majority of dental trauma involves anterior teeth, especially the maxillary central incisors. A mandibular incisor fracture with or without pulp tissue involvement is considerably less common. Different approaches for treating these fractured teeth have been reported in the literature. The type of treatment rendered depends mainly on the extent of fracture, pulp involvement, radicular fracture, biologic width infringement or violation, and presence of the fractured piece. This case report illustrates reattachment of fractured fragments on two mandibular incisors without pulp exposure using a new proposed reattachment method using a combination of two different types of composite materials together with an orthodontic lingual retention wire. An 8-year-old female patient presented with fractured mandibular left incisors (Ellis class II fracture). Broken pieces were saved and brought in a closed container in water. Periapical radiographs revealed no evidence of pulpal involvement in either tooth and no periapical radiolucency was noticed. Fractured fragments and the broken teeth were prepared with circumferential bevels. Reattachment of the fractured fragments were done using two types of composite resin materials and a lingual orthodontic retention wire was also used. The patient was recalled after 8 months to follow up both teeth. Clinical examination revealed excellent composite restorations covering the fracture lines.

  18. Current controversies in late incisor crowding.

    PubMed

    Samspon, W J

    1995-01-01

    Although the terminology is mildly controversial, late incisor crowding (tertiary crowding, late secondary crowding, post-adolescent crowding) is widely regarded as a normal maturation event which is likely to affect most individuals to some extent. Disagreement arises when attempts are made to quantify the change and to predict the timing of the crowding. Most young adults experience some degree of loss of incisor alignment, usually near the anticipated emergence time for the third molars, and almost characteristically it is the lower anterior teeth which best demonstrate the phenomenon. Unfortunately, the physiological crowding changes are frequently confused with orthodontic treatment relapse. Greater controversy surrounds the aetiology of the undesirable crowding changes and despite many attempts we are still not in the enlightened position of explaining, predicting or preventing the problem (except by permanent retention). It is illogical to assume a single cause as the beguilingly simple observation of crowding belies the complexity of possible interacting factors. Perhaps it is a capricious combination of: tooth size and arch form; facial growth pattern (differential soft tissue and skeletal maturation); continuing late growth rotations; cumulative effects of resting, functional and parafunctional soft tissue pressures; lack of compensating attrition; and an ill-defined, mesially acting force emanating from the back of the dental arch. Many theories have attempted to resolve the mystery of the mesially acting force, including: pressure from erupting third molars; an inherent mesial migration; continuing mesial and occlusal dental drifting; maturation and contraction of periodontal soft tissues (particularly the transseptal fibres); the anterior component of occlusal forces; and the lower anterior arch contracting influence of the incisor overbite.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Compound odontoma associated with impacted maxillary incisors.

    PubMed

    Sreedharan, S; Krishnan, I S

    2012-01-01

    Odontomas are considered to be the most common odontogenic tumors of the oral cavity. Some authors consider it as malformations rather than true neoplasms. The exact etiology of odontomes is still not known. Most odontomes are asymptomatic and are discovered during routine radiographic investigations. Odontomes generally cause disturbances in the eruption of the teeth, most commonly delayed eruption or deflection. The present report describes the surgical management of a case of compound odontoma in a 10-year-old boy who presented with a complaint of swelling in the maxillary right anterior region and retained deciduous incisors. The related literature is also being reviewed in this article.

  20. Esthetic restoration of discolored primary incisors.

    PubMed

    Margolis, Fred S

    2005-01-01

    Restoring primary teeth can be a strenuous task for many dentists who would like to have an esthetic, easy-to-use and relatively quick restoration for children. But, the restoration of carious, fractured or discolored primary incisors gives the dentist the satisfaction of knowing that he/she has restored the smile and self-confidence of a growing child. This article describes a technique which is relatively easy and produces a beautiful outcome in a relatively short time. The author has used the technique in hundreds of children for over twenty-five years. Modifications in the technique have been made as newer materials and techniques have evolved. PMID:15739584

  1. How much incisor decompensation is achieved prior to orthognathic surgery?

    PubMed Central

    McNeil, Calum; Laverick, Sean

    2014-01-01

    Objectives: To quantify incisor decompensation in preparation for orthognathic surgery. Study design: Pre-treatment and pre-surgery lateral cephalograms for 86 patients who had combined orthodontic and orthognathic treatment were digitised using OPAL 2.1 [http://www.opalimage.co.uk]. To assess intra-observer reproducibility, 25 images were re-digitised one month later. Random and systematic error were assessed using the Dahlberg formula and a two-sample t-test, respectively. Differences in the proportions of cases where the maxillary (1100 +/- 60) or mandibular (900 +/- 60) incisors were fully decomensated were assessed using a Chi-square test (p<0.05). Mann-Whitney U tests were used to identify if there were any differences in the amount of net decompensation for maxillary and mandibular incisors between the Class II combined and Class III groups (p<0.05). Results: Random and systematic error were less than 0.5 degrees and p<0.05, respectively. A greater proportion of cases had decompensated mandibular incisors (80%) than maxillary incisors (62%) and this difference was statistically significant (p=0.029). The amount of maxillary incisor decompensation in the Class II and Class III groups did not statistically differ (p=0.45) whereas the mandibular incisors in the Class III group underwent statistically significantly greater decompensation (p=0.02). Conclusions: Mandibular incisors were decompensated for a greater proportion of cases than maxillary incisors in preparation for orthognathic surgery. There was no difference in the amount of maxillary incisor decompensation between Class II and Class III cases. There was a greater net decompensation for mandibular incisors in Class III cases when compared to Class II cases. Key words:Decompensation, orthognathic, pre-surgical orthodontics, surgical-orthodontic. PMID:25136421

  2. Using Composite Resin Inclined Plane for the Repositioning of a Laterally Luxated Primary Incisor: A Case Report

    PubMed Central

    Arikan, Volkan; Sari, Saziye

    2011-01-01

    This case report describes the repositioning of a laterally luxated primary central incisor with occlusal interference, using a composite inclined plane. The patient was a 4-year-old girl who applied to our clinic three days after the injury. Because of the time delay between injury and presentation, it was not possible to reposition the tooth with pressure. Following a root-canal treatment, an inclined plane was prepared on the lower primary incisors, using composite resin. The tooth was repositioned in two weeks, and the inclined plane was then removed. After 1 year of follow-up, the treatment was found to be successful, both clinically and radiographically. The use of a composite inclined plane, accompanied by careful follow-up, is an effective alternative to extraction for laterally luxated primary incisors with occlusal interference. PMID:21228962

  3. Using composite resin inclined plane for the repositioning of a laterally luxated primary incisor: a case report.

    PubMed

    Arikan, Volkan; Sari, Saziye

    2011-01-01

    This case report describes the repositioning of a laterally luxated primary central incisor with occlusal interference, using a composite inclined plane. The patient was a 4-year-old girl who applied to our clinic three days after the injury. Because of the time delay between injury and presentation, it was not possible to reposition the tooth with pressure. Following a root-canal treatment, an inclined plane was prepared on the lower primary incisors, using composite resin. The tooth was repositioned in two weeks, and the inclined plane was then removed. After 1 year of follow-up, the treatment was found to be successful, both clinically and radiographically. The use of a composite inclined plane, accompanied by careful follow-up, is an effective alternative to extraction for laterally luxated primary incisors with occlusal interference.

  4. Restoration of decayed primary incisors using strip crowns.

    PubMed

    Pollard, M A; Curzon, J A; Fenlon, W L

    1991-05-01

    Caries of the primary incisors is a common problem that can be arrested if recognized early enough. However, the arrested decay is unsightly. Celluloid 'strip' crown forms, used with composite resin, now allow the restoration of even the most badly decayed primary incisors. The authors describe this quick and efficient technique. PMID:1884866

  5. [Behavior of the periodontium during leveling of the mandibular incisors: what precautions are needed?].

    PubMed

    Castelli, Alicia; Le Gall, Michel; Monnet-Corti, Virginie

    2016-03-01

    Since the position of the mandibular incisors is one of the keys to successful treatment, most orthodontic treatments focus on control but take no special precautions regarding the periodontal environment. Can we trust the lateral headfilm alone when evaluating such slender quantities of bone surrounding the mandibular incisors? What is the true bone situation prior to treatment and above all, following alignment, leveling and uprighting of the incisors? We performed a prospective 3-year study on 50 patients to assess the periodontal behavior of the mandibular incisors following a leveling phase by means of a clinical approach using periodontal and radiologic probing based on measurements of bone thickness obtained by cone beam. The bone loss observed was not inconsiderable given the thinness of the initial bone. In the face of this clinical situation, we need to adapt our treatment by performing a pre-orthodontic periodontal check-up and by supplementing the diagnosis with 3D examinations for at-risk patients and by checking the incisal axes during the leveling phase. The advent of cone beam has provided us with a valuable tool making it possible to individualize orthodontic treatment and view the posttreatment bone environment and root positions. PMID:27083231

  6. In vivo administration of dental epithelial stem cells at the apical end of the mouse incisor

    PubMed Central

    Orsini, Giovanna; Jimenez-Rojo, Lucia; Natsiou, Despoina; Putignano, Angelo; Mitsiadis, Thimios A.

    2015-01-01

    Cell-based tissue regeneration is an attractive approach that complements traditional surgical techniques for replacement of injured and lost tissues. The continuously growing rodent incisor provides an excellent model system for investigating cellular and molecular mechanisms that underlie tooth renewal and regeneration. An active population of dental epithelial progenitor/stem cells located at the posterior part of the incisor, commonly called cervical loop area, ensures the continuous supply of cells that are responsible for the secretion of enamel matrix. To explore the potential of these epithelial cells in therapeutic approaches dealing with enamel defects, we have developed a new method for their in vivo administration in the posterior part of the incisor. Here, we provide the step-by-step protocol for the isolation of dental epithelial stem cells and their delivery at targeted areas of the jaw. This simple and yet powerful protocol, consisting in drilling a hole in the mandibular bone, in close proximity to the cervical loop area of the incisor, followed up by injection of stem cells, is feasible, reliable, and effective. This in vivo approach opens new horizons and possibilities for cellular therapies involving pathological and injured dental tissues. PMID:25914649

  7. Interim Restorative Approach for the Management of Congenitally Missing Permanent Mandibular Incisors: Presentation of Three Cases

    PubMed Central

    Prakash, Prashanth; Hallur, Jayadev M.; Gowda, Rachana Narse

    2011-01-01

    Congenital missing of mandibular permanent incisors with retained primary incisors may jeopardize the esthetic appearance and psychological development of children, especially during the years of transition into adolescence. The retained primary teeth are necessary for the maintenance and normal development of alveolar bone, which in turn is essential for future definitive rehabilitation. In such situations, an interim restoration may be provided before any definitive treatment is given to comfort the young patient during this transition period. Interim restorations may include resin-modified additions to the existing teeth as well as more sophisticated restorations such as resin-retained bridge and removable partial dentures. However, this restoration differs for different clinical situations based on various factors such as age and patient compliance, and also consideration has to be given for the growth changes of the child. The aim of this present paper is to discuss the esthetic management of three cases with bilateral agenesis of permanent mandibular incisors and retained primary incisors with composite interim restoration. PMID:22567446

  8. Facial talon cusp on mandibular incisor: a rare case report with review of literature.

    PubMed

    Sachdeva, Suresh K; Verma, Pradhuman; Dutta, Sanjay; Verma, Kanika Gupta

    2014-01-01

    Talon cusp is a relatively rare developmental dental anomaly thought to arise as a result of evagination on the surface of a tooth crown before calcification has occurred. It is characterized by cusp-like projections from the cingulum area, or cemento-enamel junction of maxillary or mandibular anterior teeth, in both the primary and permanent dentition, usually observed on the lingual surface of the affected tooth. The cusp may or may not contain an extension of the pulp. The etiology remains unknown. The incidence is 0.04-8%. Any tooth may have a talon cusp but most of the cases involve maxillary lateral incisors. The anomaly has been reported to be rare especially when it occurs on mandibular teeth. This article reports a case of talon cusp on permanent mandibular central incisor that too on facial aspect which makes it a rare entity. PMID:25099002

  9. Cone beam-computed topographic evaluation of a central incisor with an open apex and a failed root canal treatment using one-step apexification with Biodentine™: A case report.

    PubMed

    Sinha, Nidhi; Singh, Bijay; Patil, Santosh

    2014-05-01

    A symptomatic endodontically treated immature tooth with periapical pathology presents multiple challenges to the clinician. Owing to incomplete root formation, gutta percha removal has to be done carefully without further damaging the periapical tissue or pushing the obturating material beyond the apex. Nonsurgical approach toward treating such a tooth would necessitate the creation of an apical barrier followed by conventional root canal treatment. Current literature suggests one-step apexification with mineral trioxide aggregate (MTA), with an apical matrix as the treatment of choice. A new calcium silicate-based cement also called as dentine substitute by the manufacturers with good handling properties has been introduced recently by the trade name Biodentine™ (Septodont, St. Maurdes Fossés, France). This case report presents management of a secondary endodontic case with an open apex treated with the concept of 'lesion sterilization and tissue repair (LSTR)' using triantibiotic paste and Biodentine™ for apical barrier formation. A 12-month follow up with cone beam-computed topography (CBCT) exhibited progressive involution of periapical radiolucency with indications of good healing of the periapical tissues and absence of clinical symptoms.

  10. Dens invaginatus in a geminated maxillary lateral incisor.

    PubMed

    Pallivathukal, Renjith George; Misra, Alok; Nagraj, Sumanth Kumbargere; Donald, Preethy Mary

    2015-01-01

    Dens invaginatus (DI) and gemination are two developmental abnormalities that are well reported in the dental literature, but their coexistence in a single tooth is rare. Such situations worsen the risk factors associated with these anomalies, and the treatment plan should be customised as they possess altered morphology and anatomy. A 19-year-old girl came for evaluation of a cracked tooth in the front region of the upper jaw. The tooth showed clinical features of gemination and radiographic features of DI, and was diagnosed as DI in geminated maxillary lateral incisor. The differential diagnoses based on clinical appearance without radiographic investigation may warrant the treatment approach if these two abnormalities coexist in a single tooth. The report also highlights the importance of three-dimensional imaging in diagnosis and treatment planning of teeth with altered pulp canal anatomy. There are few reported cases in the literature detailing the treatment options for these two anomalies occurring in the same tooth.

  11. Management of chronic luxated central incisor with hopeless prognosis

    PubMed Central

    Patel, Gauresh Kumar; Gujjari, Sheela Kumar; Annapoorna, B. M.; Veerendra Kumar, S. C.

    2013-01-01

    Traumatic injuries are the most studied yet most challenging for a dentist. Extrusive luxation injuries are usually managed by repositioning tooth in the original position and pulp sensibility is evaluated at regular periodic intervals. However, when injuries are chronic, tooth is necrotic with compromised periodontal support, treatment is a challenge. Intentional replantation utilizing growth factors in fibrin rich network of platelet rich fibrin can be a treatment modality in such patients where other restorative modalities to establish function-esthetics rehabilitation is not possible. PMID:24174766

  12. An Identification Key to Rodent Prey in Owl Pellets from the Northwestern and Southeastern United States: Employing Incisor Size to Distinguish among Genera

    ERIC Educational Resources Information Center

    Hager, Stephen B.; Cosentino, Bradley J.

    2006-01-01

    We present an identification key to the common rodent prey found in owl pellets from the Northwestern (NW) and Southeastern (SE) United States that is based on differences in incisor size (arc diameter) among genera.

  13. Unerupted incisors--characteristic features and associated anomalies.

    PubMed

    Bartolo, Adriana; Camilleri, Audrey; Camilleri, Simon

    2010-06-01

    The aims of this study were to investigate the association of unerupted incisors with other dental anomalies and to indicate the aetiological and clinical relevance of such associations. Forty-one patients with unerupted incisors were examined. The group comprised 30 males and 11 females, ranging in age from 7 to 39 years. The patients were assessed for nine dental anomalies: hyperdontia, hypodontia, microdontia, enamel hypoplasia, infraocclusion of the primary molars and ectopia of the canines, premolars, first permanent molars, and second permanent molars. The patients were matched with respect to age and gender to 41 consecutively selected control subjects with similar selection criteria but no history of problems with incisor eruption. The prevalence rates of the dental anomalies in association with failure of eruption of incisors were compared to the reference rates in the control group by means of Pearson chi-square tests. The results of this study revealed that unerupted incisors were more frequent in males than in females. A statistically significant association (P = 0.006) was found between unerupted incisors and other inherited dental anomalies, namely ectopic teeth, hyperdontia, and enamel hypoplasia. Unerupted incisors may be considered part of a spectrum of inheritable dental anomalies. PMID:19745002

  14. The adaptive significance of enamel loss in the mandibular incisors of cercopithecine primates (Mammalia: Cercopithecidae): a finite element modelling study.

    PubMed

    Kupczik, Kornelius; Lev-Tov Chattah, Netta

    2014-01-01

    In several primate groups enamel is reduced or absent from the lingual (tongue) side of the mandibular incisor crowns akin to other placental and marsupial mammalian groups such as rodents, lagomorphs and wombats. Here we investigate the presumed adaptation of crowns with unilateral enamel to the incision of tough foods in cercopithecines, an Old World monkey subfamily, using a simulation approach. We developed and validated a finite element model of the lower central incisor of the rhesus macaque (Macaca mulatta) with labial enamel only to compute three-dimensional displacements and maximum principal stresses on the crown subjected to compressive loads varying in orientation. Moreover, we developed a model of a macaque incisor with enamel present on both labial and lingual aspects, thus resembling the ancestral condition found in the sister taxon, the leaf-eating colobines. The results showed that, concomitant with experimental results, the cercopithecine crown with unilateral enamel bends predominantly towards the inside of the mouth, while displacements decreased when both labial and lingual enamel are present. Importantly, the cercopithecine incisor crown experienced lower maximum principal stress on the lingual side compared to the incisor with enamel on the lingual and labial aspects under non-axial loads directed either towards the inside or outside of the mouth. These findings suggest that cercopithecine mandibular incisors are adapted to a wide range of ingestive behaviours compared to colobines. We conclude that the evolutionary loss of lingual enamel in cercopithecines has conferred a safeguard against crown failure under a loading regime assumed for the ingestion (peeling, scraping) of tough-skinned fruits. PMID:24831704

  15. The Adaptive Significance of Enamel Loss in the Mandibular Incisors of Cercopithecine Primates (Mammalia: Cercopithecidae): A Finite Element Modelling Study

    PubMed Central

    Kupczik, Kornelius; Lev-Tov Chattah, Netta

    2014-01-01

    In several primate groups enamel is reduced or absent from the lingual (tongue) side of the mandibular incisor crowns akin to other placental and marsupial mammalian groups such as rodents, lagomorphs and wombats. Here we investigate the presumed adaptation of crowns with unilateral enamel to the incision of tough foods in cercopithecines, an Old World monkey subfamily, using a simulation approach. We developed and validated a finite element model of the lower central incisor of the rhesus macaque (Macaca mulatta) with labial enamel only to compute three-dimensional displacements and maximum principal stresses on the crown subjected to compressive loads varying in orientation. Moreover, we developed a model of a macaque incisor with enamel present on both labial and lingual aspects, thus resembling the ancestral condition found in the sister taxon, the leaf-eating colobines. The results showed that, concomitant with experimental results, the cercopithecine crown with unilateral enamel bends predominantly towards the inside of the mouth, while displacements decreased when both labial and lingual enamel are present. Importantly, the cercopithecine incisor crown experienced lower maximum principal stress on the lingual side compared to the incisor with enamel on the lingual and labial aspects under non-axial loads directed either towards the inside or outside of the mouth. These findings suggest that cercopithecine mandibular incisors are adapted to a wide range of ingestive behaviours compared to colobines. We conclude that the evolutionary loss of lingual enamel in cercopithecines has conferred a safeguard against crown failure under a loading regime assumed for the ingestion (peeling, scraping) of tough-skinned fruits. PMID:24831704

  16. The adaptive significance of enamel loss in the mandibular incisors of cercopithecine primates (Mammalia: Cercopithecidae): a finite element modelling study.

    PubMed

    Kupczik, Kornelius; Lev-Tov Chattah, Netta

    2014-01-01

    In several primate groups enamel is reduced or absent from the lingual (tongue) side of the mandibular incisor crowns akin to other placental and marsupial mammalian groups such as rodents, lagomorphs and wombats. Here we investigate the presumed adaptation of crowns with unilateral enamel to the incision of tough foods in cercopithecines, an Old World monkey subfamily, using a simulation approach. We developed and validated a finite element model of the lower central incisor of the rhesus macaque (Macaca mulatta) with labial enamel only to compute three-dimensional displacements and maximum principal stresses on the crown subjected to compressive loads varying in orientation. Moreover, we developed a model of a macaque incisor with enamel present on both labial and lingual aspects, thus resembling the ancestral condition found in the sister taxon, the leaf-eating colobines. The results showed that, concomitant with experimental results, the cercopithecine crown with unilateral enamel bends predominantly towards the inside of the mouth, while displacements decreased when both labial and lingual enamel are present. Importantly, the cercopithecine incisor crown experienced lower maximum principal stress on the lingual side compared to the incisor with enamel on the lingual and labial aspects under non-axial loads directed either towards the inside or outside of the mouth. These findings suggest that cercopithecine mandibular incisors are adapted to a wide range of ingestive behaviours compared to colobines. We conclude that the evolutionary loss of lingual enamel in cercopithecines has conferred a safeguard against crown failure under a loading regime assumed for the ingestion (peeling, scraping) of tough-skinned fruits.

  17. Endodontic configuration of the lower incisors in a Romanian population: a radiological study.

    PubMed

    Perlea, Paula; Nistor, Cristina Coralia; Toma, C; Dimitriu, B

    2013-01-01

    The significant rate of failure of endodontic treatment to lower incisors was attributed to poor knowledge of their endodontic morphology. As emphasized by Tinelli ME et al. (2011), the morphology of the endodontic system is strongly related to ethnicity, making possible the existence of important anatomical variations at different population groups. The present study analyzes, using radiological means, the endodontic anatomy of lower incisors extracted from a Romanian population. Five hundred seventy-five lower central and lateral incisors were radiographed and Weine's classification was used to evaluate their endodontic morphology. After processing the data, it was concluded that 81% of the studied teeth have one canal and the remaining 19% have two canals. In terms of endodontic configuration, 81% of 575 studied teeth are Weine Type I, 17% Type II, 1% Type III and 1% Type IV. Results obtained in this study are within existing international endodontic literature. Type II and IV configurations have a high degree of treatment difficulty. This requires thorough clinical and radiological examination of several incidents, possibly cone beam computed tomography (CBCT) and individualized therapeutic means to ensure treatment success. This study is the first of this magnitude in the Romanian specialty literature.

  18. Evaluation of the relationship between upper incisor exposure and cephalometric variables in Korean young adults

    PubMed Central

    Han, Sung-Hoon; Lee, Eon-Hwa; Cho, Jin-Hyoung; Chae, Jong-Moon; Kim, Sang-Cheol; Chang, Na-Young

    2013-01-01

    Objective The purpose of this study was to classify Korean young adults into 3 groups on the basis of upper incisor exposure rates (UIERs) and to compare the skeletal, dental, and soft tissue variables. Methods Samples were obtained from 127 students at the College of Dentistry, Wonkwang University in South Korea. Facial photographs of frontal posed smiles and lateral cephalograms of the subjects were taken. The subjects were divided into 3 groups on the basis of UIERs and 20 measurements were compared among the 3 groups. The correlations between the variables were determined. Results Male and female subjects showed significant differences in the group distribution. Male subjects showed higher frequencies of low smiles, and female subjects showed higher frequencies of high smiles. The vertical height of the anterior alveolar process of the maxilla directly correlated with the UIER. However, the UIER showed no significant correlation with the vertical height of the anterior basal bone or the inclination of the upper incisor axis. In female subjects, the upper central incisor clinical crown length showed an inverse correlation with the UIER. However, this variable showed no significant correlation with the UIER in male subjects. Conclusions The UIER was directly correlated with the levator muscle activity of the upper lip and inversely correlated with the upper lip thickness, yet there was no correlation between the UIER and upper lip length at rest. PMID:24228237

  19. Central Office and Site-Based Management: An Educator's Guide.

    ERIC Educational Resources Information Center

    Sewall, Angela Maynard

    This book describes changes that must be made in central-office administration to facilitate the movement to site-based management. It is intended for educational administrators in central administration or for those who are planning to work as superintendents, business managers, or supervisors of curriculum and instruction. The book covers all…

  20. Upper incisor to Soft Tissue Plane (UI-STP): a new reference for diagnosis and planning in dentofacial deformities.

    PubMed

    Hernandez-Alfaro, Federico

    2010-09-01

    Planning in orthognathic surgery has been and still is an open issue. We have evolved from 2D classical cephalometric hard-tissue planning to 2D soft tissue planning, and finally to 3D and hard and soft tissue evaluation. This, to our knowledge, is the first description of a new Soft Tissue Plane (STP) and its relationship with the anterior position of the upper incisor (UI). Profile photographs of 110 "attractive individuals" with lips at rest or smiling and with upper incisor shown were used. The photographs used were of 65 professional models from two international agencies and 45 individuals considered most attractive in the internet forums, which included catwalk models and actors. In 86 cases (78.18 %), the incisor was located in front of the STP (A). In 15 cases (13.63%), it was on the plane (N); and in the remaining 9 cases (8.18%), it was behind (P). Despite the limitations of this study and based on our series, we can conclude that the upper incisor is located at or in front of the Soft Tissue Plane (STP) in 91.81% of the attractive facial profiles studied. On the other hand, the relative position of the upper incisor to the soft tissue plane (UI-STP) could be a useful diagnostic and planning tool in orthodontic and surgical management of dentofacial deformities.

  1. Upper incisor to Soft Tissue Plane (UI-STP): a new reference for diagnosis and planning in dentofacial deformities.

    PubMed

    Hernandez-Alfaro, Federico

    2010-09-01

    Planning in orthognathic surgery has been and still is an open issue. We have evolved from 2D classical cephalometric hard-tissue planning to 2D soft tissue planning, and finally to 3D and hard and soft tissue evaluation. This, to our knowledge, is the first description of a new Soft Tissue Plane (STP) and its relationship with the anterior position of the upper incisor (UI). Profile photographs of 110 "attractive individuals" with lips at rest or smiling and with upper incisor shown were used. The photographs used were of 65 professional models from two international agencies and 45 individuals considered most attractive in the internet forums, which included catwalk models and actors. In 86 cases (78.18 %), the incisor was located in front of the STP (A). In 15 cases (13.63%), it was on the plane (N); and in the remaining 9 cases (8.18%), it was behind (P). Despite the limitations of this study and based on our series, we can conclude that the upper incisor is located at or in front of the Soft Tissue Plane (STP) in 91.81% of the attractive facial profiles studied. On the other hand, the relative position of the upper incisor to the soft tissue plane (UI-STP) could be a useful diagnostic and planning tool in orthodontic and surgical management of dentofacial deformities. PMID:20383095

  2. View west; interior view of central bay Naval Base ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View west; interior view of central bay - Naval Base Philadelphia-Philadelphia Naval Shipyard, Foundry-Propeller Shop, North of Porter Avenue, west of Third Street West, Philadelphia, Philadelphia County, PA

  3. View east; interior view of central bay Naval Base ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View east; interior view of central bay - Naval Base Philadelphia-Philadelphia Naval Shipyard, Foundry-Propeller Shop, North of Porter Avenue, west of Third Street West, Philadelphia, Philadelphia County, PA

  4. 24. INTERIOR OF CENTRAL ROOM. BASE POWER PANEL VISIBLE ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. INTERIOR OF CENTRAL ROOM. BASE POWER PANEL VISIBLE ON RIGHT WALL OF HALLWAY. - Chollas Heights Naval Radio Transmitting Facility, Transmitter Building, 6410 Zero Road, San Diego, San Diego County, CA

  5. Skeletal Class III malocclusion with unilateral congenitally missing maxillary incisor treated by maxillary protractor and edgewise appliances.

    PubMed

    Tabuchi, Masako; Fukuoka, Hayato; Miyazawa, Ken; Goto, Shigemi

    2010-03-01

    This case report describes the orthodontic treatment of a 10-year-old female patient with a combination of Angle Class III malocclusion, a missing maxillary right lateral incisor, a supernumerary tooth with a short root on the lingual side of the maxillary incisor, a skeletal Class III jaw base relationship caused by a diminutive maxilla, and retroposition of the maxilla. We chose to close the space of the missing tooth, as well as the space created by extraction of the maxillary lateral incisor, by forward movement of the canine and premolars using a maxillary protractor with edgewise appliances. As a result, both the maxillary premolars and the molars were moved mesially, and a Class II molar relationship with tight interdigitation was achieved. Our results suggest that the combination of maxillary protractor and nontorque brackets was effective not only for correcting skeletal Class III malocclusion, but also for forward movement of the maxillary posterior teeth.

  6. [Failure in anterior rehabilitation of agenesic maxillary lateral incisors].

    PubMed

    Le Gall, Michel; Philippart-Rochaix, Martine; Philip-Alliez, Camille

    2016-03-01

    Agenesis of the maxillary lateral incisors poses particular problems for dentists, orthodontists and patients. Treatment of these ageneses is still highly controversial, both functionally and esthetically. The patient's smile and anterior guidance are affected and must be restored. The diagnosis is easy. Few mistakes are possible. However, managing patients with missing maxillary lateral incisors can be a challenge, commonly involving two possible treatment approaches: space opening to replace the missing lateral incisor with a prosthetic unit (denture, bridge or implant) or orthodontic space closure replacing the missing lateral incisor with the maxillary canine camouflaged to mimic the appearance of a lateral incisor. One of these two options will be adopted using multiple means...liable to trigger a multitude of possible errors. Ultimately, optimal results can only be achieved if there is excellent coordination between different practitioners in various specialties. Each clinician will have a specific role to play. Also, the patient and family are at the heart of the decision-making process, by virtue of their consent (treatment duration, financial resources) and their motivation. This multi-factorial, multi-disciplinary decision process means that treatment of the lateral incisor is an ongoing challenge for the clinician striving for the best possible result. Each case is different. No set rules exist. No single factor can be neglected if we are to avoid "failure". PMID:27083223

  7. [Failure in anterior rehabilitation of agenesic maxillary lateral incisors].

    PubMed

    Le Gall, Michel; Philippart-Rochaix, Martine; Philip-Alliez, Camille

    2016-03-01

    Agenesis of the maxillary lateral incisors poses particular problems for dentists, orthodontists and patients. Treatment of these ageneses is still highly controversial, both functionally and esthetically. The patient's smile and anterior guidance are affected and must be restored. The diagnosis is easy. Few mistakes are possible. However, managing patients with missing maxillary lateral incisors can be a challenge, commonly involving two possible treatment approaches: space opening to replace the missing lateral incisor with a prosthetic unit (denture, bridge or implant) or orthodontic space closure replacing the missing lateral incisor with the maxillary canine camouflaged to mimic the appearance of a lateral incisor. One of these two options will be adopted using multiple means...liable to trigger a multitude of possible errors. Ultimately, optimal results can only be achieved if there is excellent coordination between different practitioners in various specialties. Each clinician will have a specific role to play. Also, the patient and family are at the heart of the decision-making process, by virtue of their consent (treatment duration, financial resources) and their motivation. This multi-factorial, multi-disciplinary decision process means that treatment of the lateral incisor is an ongoing challenge for the clinician striving for the best possible result. Each case is different. No set rules exist. No single factor can be neglected if we are to avoid "failure".

  8. Replantation after extended dry storage of avulsed permanent incisors: report of a case.

    PubMed

    Cobankara, Funda Kont; Ungor, Mete

    2007-08-01

    A 15-year-old boy lost his maxillary right and left central incisor teeth in a bicycle accident. He was referred to our clinic 1 week after the injury. The crown-root integrities of both the teeth were not damaged. Although the teeth were stored under dry conditions for 1 week, reimplantation of the teeth was planned to retain the teeth in the mouth for as long a period as possible because of the patient's age. Following the debridement and sterilization of root surfaces in 2.5% NaOCl, root canals were prepared and filled with calcium hydroxide. Then, about 2 mm of the apexes were resected to ensure that the roots easily seated in the alveolar socket and the prepared cavities in root ends were obturated with the amalgam. The teeth were placed into their respective sockets and splinted temporarily. The root canal therapy was completed 5 weeks later. Ankylosis was observed radiographically after 10 months. The patient is now 23 years old and he is still able to use both the central incisors functionally. However, there is a pink appearance on the cervical buccal surface of left central incisor because of progressive replacement resorption. In this case, the new treatment plan is to perform a permanent restoration with dental implants following the extraction of both teeth. Even though the long-term prognosis is uncertain, this treatment technique has provided an advantage for the patient in his adolescent period by maintaining the height of alveolar bone and making the provision of an aesthetically acceptable permanent restoration at a later age possible.

  9. Esthetic and biologic mode of reattaching incisor fracture fragment utilizing glass fiber post

    PubMed Central

    Manju, M.; Shanthraj, Srinivas L.; Savitha, K. C.; Sethi, Ntasha

    2015-01-01

    Trauma to the anterior teeth affects the esthetic and psychological well-being of the patient. Advancement in the adhesive dentistry has facilitated the restoration of the coronal tooth fractures by minimally invasive procedures when the original tooth fragment is available. Reattachment of fractured fragment offers immediate treatment with improved preponderant aesthetics and restoration of function. Here, we describe a case of complicated fracture of the maxillary left immature permanent central incisor, which was treated endodontically followed by esthetic reattachment of the fractured fragment using the glass fiber post. Functional demands and esthetic considerations of the patient were fully met with this biologic mode of fragment reattachment. PMID:26283849

  10. Electron microprobe analyses of Ca, S, Mg and P distribution in incisors of Spacelab-3 rats

    NASA Technical Reports Server (NTRS)

    Rosenberg, G. D.; Simmons, D. J.

    1985-01-01

    The distribution of Ca, S, Mg and P was mapped within the incisors of Spacelab-3 rats using an electron microprobe. The data indicate that Flight rats maintained in orbit for 7 days have significantly higher Ca/Mg ratios in dentin due to both higher Ca and lower Mg content than in dentin of ground-based Controls. There is no statistical difference in distribution of either P or S within Fligth animals and Controls, but there is clear indication that, for P at least, the reason is the greater variability of the Control data. These results are consistent with those obtained on a previous NASA/COSMOS flight of 18.5 days duration, although they are not pronounced. The results further suggest that continuously growing rat incisors provide useful records of the effects of weightlessness on Ca metabolism.

  11. Establishment of crown-root domain borders in mouse incisor.

    PubMed

    Juuri, Emma; Saito, Kan; Lefebvre, Sylvie; Michon, Frederic

    2013-10-01

    Teeth are composed of two domains, the enamel-covered crown and the enamel-free root. The understanding of the initiation and regulation of crown and root domain formation is important for the development of bioengineered teeth. In most teeth the crown develops before the root, and erupts to the oral cavity whereas the root anchors the tooth to the jawbone. However, in the continuously growing mouse incisor the crown and root domains form simultaneously, the crown domain forming the labial and the root domain the lingual part of the tooth. While the crown-root border on the incisor distal side supports the distal enamel extent, reflecting an evolutionary diet adaptation, on the incisor mesial side the root-like surface is necessary for the attachment of the interdental ligament between the two incisors. Therefore, the mouse incisor exhibits a functional distal-mesial asymmetry. Here, we used the mouse incisor as a model to understand the mechanisms involved in the crown-root border formation. We analyzed the cellular origins and gene expression patterns leading to the development of the mesial and distal crown-root borders. We discovered that Barx2, En1, Wnt11, and Runx3 were exclusively expressed on the mesial crown-root border. In addition, the distal border of the crown-root domain might be established by cells from a different origin and by an early Follistatin expression, factor known to be involved in the root domain formation. The use of different mechanisms to establish domain borders gives indications of the incisor functional asymmetry.

  12. a New Centrality Metric Based on Clustering Coefficient

    NASA Astrophysics Data System (ADS)

    Li, Chong; Guo, Shi-Ze; Lu, Zhe-Ming; Qiao, Yu-Long; Song, Guang-Hua

    2013-07-01

    Many centrality metrics have been proposed over the years to compute the centrality of nodes, which has been a key issue in complex network analysis. The most important node can be estimated through a variety of metrics, such as degree, closeness, eigenvector, betweenness, flow betweenness, cumulated nominations and subgraph. Simulated flow is a common method adopted by many centrality metrics, such as flow betweenness centrality, which assumes that the information spreads freely in the entire network. Generally speaking, the farther the information travels, the more times the information passes the geometric center. Thus, it is easy to determine which node is more likely to be the center of the geometry network. However, during information transmission, different nodes do not share the same vitality, and some nodes are more active than others. Therefore, the product of one node's degree and its clustering coefficient can be viewed as a good factor to show how active this node is. In this paper, a new centrality metric called vitality centrality is introduced, which is only based on this product and the simulated flow. Simulation experiments based on six test networks have been carried out to demonstrate the effectiveness of our new metric.

  13. Scaling and adaptations of incisors and cheek teeth in caviomorph rodents (Rodentia, Hystricognathi).

    PubMed

    Becerra, Federico; Vassallo, Aldo I; Echeverría, Alejandra I; Casinos, Adrià

    2012-10-01

    The South American hystricognath rodents are one of the most diverse mammalian clades considering their occupied habitats, locomotor modes and body sizes. This might have been partly evolved by diversification of their masticatory apparatus' structure and its ecological commitment, for example, chisel-tooth digging. In this phylogeny-based comparative study, we test the relationship between ecological behavior and mechanical features of their incisors and molariforms. In 33 species of nine families of caviomorph rodents, we analyze incisor attributes related to structural stress resistance and molar features related with grinding capacity, for example, second moment of inertia and enamel index (EI) (enamel band length/occlusal surface area), respectively. Most of these variables scaled isometrically to body mass, with a strong phylogenetic effect. A principal component analysis discrimination on the EI clustered the species according to their geographic distribution. We presume that selective pressures in Andean-Patagonian regions, on particular feeding habits and chisel-tooth digging behaviors, have modeled the morphological characteristics of the teeth. Subterranean/burrower ctenomyids, coruros, and plains viscachas showed the highest bending/torsion strength and anchorage values for incisors; a simplified enamel pattern in molariforms would be associated with a better grinding of the more abrasive vegetation present in more open and drier biomes.

  14. Scaling and adaptations of incisors and cheek teeth in caviomorph rodents (Rodentia, Hystricognathi).

    PubMed

    Becerra, Federico; Vassallo, Aldo I; Echeverría, Alejandra I; Casinos, Adrià

    2012-10-01

    The South American hystricognath rodents are one of the most diverse mammalian clades considering their occupied habitats, locomotor modes and body sizes. This might have been partly evolved by diversification of their masticatory apparatus' structure and its ecological commitment, for example, chisel-tooth digging. In this phylogeny-based comparative study, we test the relationship between ecological behavior and mechanical features of their incisors and molariforms. In 33 species of nine families of caviomorph rodents, we analyze incisor attributes related to structural stress resistance and molar features related with grinding capacity, for example, second moment of inertia and enamel index (EI) (enamel band length/occlusal surface area), respectively. Most of these variables scaled isometrically to body mass, with a strong phylogenetic effect. A principal component analysis discrimination on the EI clustered the species according to their geographic distribution. We presume that selective pressures in Andean-Patagonian regions, on particular feeding habits and chisel-tooth digging behaviors, have modeled the morphological characteristics of the teeth. Subterranean/burrower ctenomyids, coruros, and plains viscachas showed the highest bending/torsion strength and anchorage values for incisors; a simplified enamel pattern in molariforms would be associated with a better grinding of the more abrasive vegetation present in more open and drier biomes. PMID:22730038

  15. [Disproportionate eruption of maxillary and mandibular incisors in the long-tailed ground squirrel].

    PubMed

    Klevezal', G A; Potapova, E G

    2010-01-01

    Abstract-The surface of the maxillary and mandibular incisors of Spermophilus undulatus long-tailed ground squirrels, including those born in the current year and those that have hibernated (trapped one month or later after hibernation) is studied. The presence of daily growth on the incisors' surface allows the evaluation of their eruption rate; a specific change in the character of the incisors' eruption corresponds to winter hibernation (hibernation zone), which serves as the time mark. Correlation between the eruption rates of the maxillary and mandibular incisors typical for rodents is found in yearlings and some animals after hibernation. The eruption rate of the mandibular incisors is higher than the eruption rate of the maxillary incisors and can be taken as proportional to their length. In individuals that have hibernated and show proportional eruption of the incisors, the proportion of the total length of the incisor formed before and after hibernation is equal for the maxillary and mandibular incisors. In the individuals that have hibernated and show the correlation of the total length of the maxillary and mandibular incisors typical for rodents, the eruption rate of the mandibular incisor is equal to or less than the eruption rate of the maxillary incisor and the proportion of the incisor formed before hibernation is greater in the mandibular incisor than in the maxillary. This disproportionate pattern of incisor eruption is not typical for rodents and is a result of inequal grinding of the maxillary and mandibular incisors, which ultimately results in the normal ratio of the total length of the maxillary and mandibular incisors.

  16. Characteristics of incisor-premolar hypodontia in families.

    PubMed

    Arte, S; Nieminen, P; Apajalahti, S; Haavikko, K; Thesleff, I; Pirinen, S

    2001-05-01

    Nonsyndromic tooth agenesis is a genetically and phenotypically heterogenous condition. It is generally assumed that different phenotypic forms are caused by different mutated genes. We analyzed inheritance and phenotype of hypodontia and dental anomalies in 214 family members in three generations of 11 probands collected for genetic linkage study on incisor-premolar hypodontia (IPH). Our analysis confirms the autosomal-dominant transmission with reduced penetrance of IPH. The prevalence of hypodontia and/or peg-shaped teeth was over 40% in first- and second-degree relatives and 18% in first cousins of the probands. Four of nine noted obligate carriers of hypodontia gene had dental anomalies, including small upper lateral incisors, ectopic canines, taurodontism, and rotated premolars. These anomalies were also observed at higher than normal frequency in relatives affected with hypodontia. We conclude that incisor-premolar hypodontia is a genetic condition with autosomal-dominant transmission and that it is associated with several other dental abnormalities.

  17. Orthodontic treatment of a mandibular incisor extraction case with invisalign.

    PubMed

    Zawawi, Khalid H

    2014-01-01

    Mandibular incisor extraction for orthodontic treatment is considered an unusual treatment option because of the limited number of patients that meet the criteria for such treatment. Accurate diagnosis and treatment planning is essential to achieve the desired results. Adult orthodontic patients are increasingly motivated by esthetic considerations and reject the idea of conventional fixed appliances. In recent years, Invisalign appliances have gained tremendous attention for orthodontic treatment of adult patients to meet their esthetic demands. In this case report, a case of Class I malocclusion was treated with mandibular incisor extraction using the Invisalign appliance system. Successful tooth alignment of both arches was achieved. The use of Invisalign appliance is an effective treatment option in adult patients with Class I malocclusion that requires incisor extraction due to moderate to severe mandibular anterior crowding.

  18. Orthodontic Treatment of a Mandibular Incisor Extraction Case with Invisalign

    PubMed Central

    Zawawi, Khalid H.

    2014-01-01

    Mandibular incisor extraction for orthodontic treatment is considered an unusual treatment option because of the limited number of patients that meet the criteria for such treatment. Accurate diagnosis and treatment planning is essential to achieve the desired results. Adult orthodontic patients are increasingly motivated by esthetic considerations and reject the idea of conventional fixed appliances. In recent years, Invisalign appliances have gained tremendous attention for orthodontic treatment of adult patients to meet their esthetic demands. In this case report, a case of Class I malocclusion was treated with mandibular incisor extraction using the Invisalign appliance system. Successful tooth alignment of both arches was achieved. The use of Invisalign appliance is an effective treatment option in adult patients with Class I malocclusion that requires incisor extraction due to moderate to severe mandibular anterior crowding. PMID:25024852

  19. A study on evaluation of center of resistance of maxillary four incisors during simultaneous intrusion and retraction: A finite element study

    PubMed Central

    Aruna, J.

    2014-01-01

    Aim: The aim of this study is to evaluate the center of resistance of maxillary incisors during simultaneous intrusion and retraction. Subjects and Methods: In this study, the following steps were employed namely, (1) Preprocessing - the creation of geometric model, mesh generation and boundary conditions. (2) Postprocessing - the tooth movement and determination of center of resistance. Results: The center of the mid-sagittal plane approximately 6 mm apical and 4 mm posterior to a line perpendicular to the occlusal plane from the labial alveolar crest of the central incisor resistance for the maxillary four incisors was located within the. Conclusion: Finite element is a sound mechanical method of analysis as it was sufficient enough to provide insight into interactions between orthodontic forces, and dental tissues and reliability of this study. Further by using this study clinically, the center of resistance can be precisely located in single rooted tooth during orthodontic treatment. PMID:25210384

  20. Localized periodontal defect associated with unusual furcation involvement on a mandibular incisor.

    PubMed

    Kwon, TaeHyun; Intini, Giuseppe; Kim, David M; Levin, Liran

    2013-10-01

    A localized periodontal defect associated with an unusual furcation on a mandibular central incisor and its treatment sequences are presented. A 54-year-old woman presented with a persistent localized periodontal defect, which was not responsive to nonsurgical periodontal therapy. An exploratory surgery revealed complete through and through furcation involvement on the right mandibular central incisor, resulting in a three-walled infrabony defect. Following thorough mechanical debridement and root planing, the infrabony aspect of the defect was grafted with freeze-dried bone allograft combined with the recombinant human platelet-derived growth factor-BB. The flaps were positioned to enable patient's home care and professional dental cleaning. Follow-up examination revealed uneventful healing and resolution of the infrabony periodontal defect. Clinicians should be aware of this unusual condition and consider it as a potential etiology when dealing with a persistent localized periodontal defect in the mandibular anterior sextant, which may not respond to the conventional nonsurgical periodontal therapy. Eliminating the active disease as well as enabling careful maintenance and oral hygiene may prevent further deterioration and result in a stable long-term outcome preserving the compromised tooth. PMID:23878844

  1. Management of Ectopically Erupting Maxillary Incisors: A Case Series.

    PubMed

    Suresh, Kotumachagi Sangappa; Uma, H L; Nagarathna, J; Kumar, Pravin

    2015-01-01

    Eruption disturbances related to the position include ectopic eruption and transpositions. The occurrence of ectopic eruption is most commonly associated with maxillary incisors. The normal eruption, position and morphology of these teeth are crucial to craniofacial development, facial esthetics as well as phonetics. It is essential that the clinicians have thorough knowledge of the eruption disturbances in order to make an appropriate, as well as timely intervention, as dictated by the complexity of the problem. How to cite this article: Suresh KS, Uma HL, Nagarathna J, Kumar P. Management of Ectopically Erupting Maxillary Incisors: A Case Series. Int J Clin Pediatr Dent 2015;8(3):227-233. PMID:26604543

  2. A rare occurrence of geminated-taloned maxillary lateral incisor.

    PubMed

    Neeraja, R; Kayal, Vizhi G

    2012-05-01

    The talon cusp is a developmental anomaly characterized by the presence of an accessory cusp like structure projecting from the cingulum area of the anterior teeth. Gemination is an anomaly caused by a single tooth germ that attempted to divide during its development. These developmental anomalies may cause clinical problems including esthetic impairment, pain, caries and tooth crowding. Co-occurrence of two anomalies in a teeth is rare. This paper presents an unusual case of talon cusp on geminated permanent lateral incisor. How to cite this article: Neeraja R, Kayal VG. A Rare Occurrence of Geminated-Taloned Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2012;5(2):136-138.

  3. Management of Ectopically Erupting Maxillary Incisors: A Case Series

    PubMed Central

    Suresh, Kotumachagi Sangappa; Uma, HL; Nagarathna, J

    2015-01-01

    ABSTRACT Eruption disturbances related to the position include ectopic eruption and transpositions. The occurrence of ectopic eruption is most commonly associated with maxillary incisors. The normal eruption, position and morphology of these teeth are crucial to craniofacial development, facial esthetics as well as phonetics. It is essential that the clinicians have thorough knowledge of the eruption disturbances in order to make an appropriate, as well as timely intervention, as dictated by the complexity of the problem. How to cite this article: Suresh KS, Uma HL, Nagarathna J, Kumar P. Management of Ectopically Erupting Maxillary Incisors: A Case Series. Int J Clin Pediatr Dent 2015;8(3):227-233. PMID:26604543

  4. Use of a Resin-Bonded Bridge to Replace a Congenitally Missing Lateral Incisor: Treatment of "Intrusion" of Teeth.

    PubMed

    Rosen, Paul S; Bahat, Oded; Froum, Stuart J; Daftary, Fereidoun; Rosenthal, Howard; Feldman, Sylvan

    2016-07-01

    Craniofacial growth is an important factor to consider when providing dental implant treatment for adolescents to replace missing teeth. Ongoing longitudinal observation has demonstrated that such tooth replacements may appear intruded over time, because there may be ongoing downward and anterior movement of both the alveolus and the teeth at a rate exceeding that of the dental implant, which acts like an ankylosed unit. This case reports on a 23.5-year-old female patient who, at age 16, had orthodontics completed and was left with a space where the maxillary right lateral incisor was congenitally missing with the hope of future restoration with a dental implant. A resin-bonded bridge had been placed to fill the space in the interim. After approximately 7.5 years, the bridge loosened and the patient sought an implant option as its replacement. Clinical images revealed that the bridge, which contained two bonded wings, may have limited physiologic growth, causing both the maxillary right central incisor and canine to appear intruded compared with the left central incisor and canine. This case illustrates, at the very least, that growth and development may not be complete in females aged 16 years and that the way in which a missing tooth is replaced must be carefully considered given the impact that ongoing growth and development may have on restorative care. Moreover, further growth and development may also impact adults.

  5. Use of a Resin-Bonded Bridge to Replace a Congenitally Missing Lateral Incisor: Treatment of "Intrusion" of Teeth.

    PubMed

    Rosen, Paul S; Bahat, Oded; Froum, Stuart J; Daftary, Fereidoun; Rosenthal, Howard; Feldman, Sylvan

    2016-07-01

    Craniofacial growth is an important factor to consider when providing dental implant treatment for adolescents to replace missing teeth. Ongoing longitudinal observation has demonstrated that such tooth replacements may appear intruded over time, because there may be ongoing downward and anterior movement of both the alveolus and the teeth at a rate exceeding that of the dental implant, which acts like an ankylosed unit. This case reports on a 23.5-year-old female patient who, at age 16, had orthodontics completed and was left with a space where the maxillary right lateral incisor was congenitally missing with the hope of future restoration with a dental implant. A resin-bonded bridge had been placed to fill the space in the interim. After approximately 7.5 years, the bridge loosened and the patient sought an implant option as its replacement. Clinical images revealed that the bridge, which contained two bonded wings, may have limited physiologic growth, causing both the maxillary right central incisor and canine to appear intruded compared with the left central incisor and canine. This case illustrates, at the very least, that growth and development may not be complete in females aged 16 years and that the way in which a missing tooth is replaced must be carefully considered given the impact that ongoing growth and development may have on restorative care. Moreover, further growth and development may also impact adults. PMID:27548400

  6. External apical root resorption in maxillary incisors in orthodontic patients: associated factors and radiographic evaluation

    PubMed Central

    Patanaporn, Virush; Janhom, Apirum; Korwanich, Narumanus

    2012-01-01

    Purpose This study was performed to evaluate the incidence and degree of external apical root resorption of maxillary incisors after orthodontic treatment and to evaluate particular associated factors related to external apical root resorption. Materials and Methods The records and maxillary incisor periapical radiographs of 181 patients were investigated. Crown and root lengths were measured and compared on the pre- and post-treatment periapical radiographs. Crown length was measured from the center of the incisal edge to the midpoint of the cemento-enamel junction (CEJ). Root length was measured from the CEJ midpoint to the root apex. A correction factor for the enlargement difference was used to calculate root resorption. Results The periapical radiographs of 564 teeth showed that the average root resorption was 1.39±1.27 (8.24±7.22%) and 1.69±1.14 mm (10.16±6.78%) for the maxillary central and lateral incisors, respectively. The results showed that the dilacerated or pointed roots, maxillary premolar extraction cases, and treatment duration were highly significant factors for root resorption (p<0.001). Allergic condition was a significant factor at p<0.01. Age at the start of treatment, large overjet, and history of facial trauma were also factors significantly associated with root resorption (p<0.05). There was no statistically significant difference in root resorption among the factors of gender, overbite, tongue-thrusting habit, types of malocclusion, and types of bracket. Conclusion These results suggested that orthodontic treatment should be carefully performed in pre-treatment extraction patients who have pointed or dilacerated roots and need long treatment duration. PMID:23071964

  7. Two betweenness centrality measures based on Randomized Shortest Paths

    PubMed Central

    Kivimäki, Ilkka; Lebichot, Bertrand; Saramäki, Jari; Saerens, Marco

    2016-01-01

    This paper introduces two new closely related betweenness centrality measures based on the Randomized Shortest Paths (RSP) framework, which fill a gap between traditional network centrality measures based on shortest paths and more recent methods considering random walks or current flows. The framework defines Boltzmann probability distributions over paths of the network which focus on the shortest paths, but also take into account longer paths depending on an inverse temperature parameter. RSP’s have previously proven to be useful in defining distance measures on networks. In this work we study their utility in quantifying the importance of the nodes of a network. The proposed RSP betweenness centralities combine, in an optimal way, the ideas of using the shortest and purely random paths for analysing the roles of network nodes, avoiding issues involving these two paradigms. We present the derivations of these measures and how they can be computed in an efficient way. In addition, we show with real world examples the potential of the RSP betweenness centralities in identifying interesting nodes of a network that more traditional methods might fail to notice. PMID:26838176

  8. Intentional replantation for a periodontally involved hopeless incisor by using autologous platelet-rich plasma.

    PubMed

    Tözüm, Tolga Fikret; Keçeli, Hüseyin Gencay; Serper, Ahmet; Tuncel, Behram

    2006-06-01

    The aim of the present case is to describe the use of autologous platelet-rich plasma (PRP) in an intentional replantation procedure for a periodontally involved lower right central incisor with 18 months follow-up. Brief information is also given on the preoperative preparation of PRP in the dental office. PRP preparation is a new biotechnology, and the prepared material contains thrombocyte concentrates and high levels of growth factors. This material promotes healing time in a range of various sites. In this case, a tooth with severe periodontal breakdown was treated with PRP with intentional replantation procedure. This tooth was previously treated with root canal treatment and root planing. The tooth was extracted, and was replanted with autologous PRP. Clinical and radiographic follow-up for 18 months demonstrated new bone formation around the apical portion of the root and all clinical parameters indicated a trend of healing. The mobility of this previously grade III mobile incisor returned to normal limits. We speculate that intentional replantation with PRP application may induce wound healing and may induce bone formation.

  9. Correction of a Severely Rotated Maxillary Incisor by Elastics in Mixed Dentition Complicated by a Mesiodens.

    PubMed

    Sidiq, Mohsin; Yousuf, Asif; Bhat, Manohar; Sharma, Rajesh; Bhargava, Neha; Ganta, Shravani

    2015-01-01

    The aim of this case study was to report a potentially convenient approach instead of a conventional orthodontic procedure for correcting severe rotation of anterior tooth of an 11-year-old Indian boy, with a mixed dentition class I malocclusion. The child reported seeking treatment for severely rotated upper right central incisor with mesiodens and a single tooth crossbite. The supernumerary tooth was first extracted and bondable buttons were placed on the rotated tooth, an appliance composed of a removable plate with Adam's clasp with distal extension and a loop for engagement of elastics was delivered. Circumferential supracrestal fibrotomy was performed on the corrected derotated tooth. Then, Hawley's appliance with a z-spring and posterior bite plane was fabricated and placed for correction of crossbite. Thus, this removable appliance can be a simplified and a cost-effective treatment alternative for derotation of anterior tooth, especially during the mixed dentition period. How to cite this article: Sidiq M, Yousuf A, Bhat M, Sharma R, Bhargava N, Ganta S. Correction of a Severely Rotated Maxillary Incisor by Elastics in Mixed Dentition Complicated by a Mesiodens. Int J Clin Pediatr Dent 2015;8(3):234-238.

  10. The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha.

    PubMed

    Mothé, Dimila; Ferretti, Marco P; Avilla, Leonardo S

    2016-01-01

    The incisors of proboscideans (tusks and tushes) are one of the most important feature in conservation, ecology and evolutionary history of these mammals. Although the absence of upper incisors is rare in proboscideans (occurring only in deinotheres), the independent losses of lower incisors are recognized for most of its lineages (dibelodont condition). The presence of lower incisors in the Pan-American gomphothere Cuvieronius hyodon was reported a few times in literature, but it was neglected in systematic studies. We analyzed several specimens of Cuvieronius hyodon from the Americas and recognized that immature individuals had lower incisors during very early post-natal developmental stages. Subsequently, these are lost and lower incisors alveoli close during later developmental stages, before maturity. Moreover, for the first time in a formal cladistic analysis of non-amebelodontine trilophodont gomphotheres, Rhynchotherium and Cuvieronius were recovered as sister-taxa. Among several non-ambiguous synapomorphies, the presence of lower incisors diagnoses this clade. We recognize that the presence of lower incisors in Cuvieronius and Rhynchotherium is an unique case of taxic atavism among the Elephantimorpha, since these structures are lost at the origin of the ingroup. The rediscovery of the lower incisors in Cuvieronius hyodon, their ontogenetic interpretation and the inclusion of this feature in a revised phylogenetic analysis of trilophodont gomphotheres brought a better understanding for the evolutionary history of these proboscideans.

  11. The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha

    PubMed Central

    2016-01-01

    The incisors of proboscideans (tusks and tushes) are one of the most important feature in conservation, ecology and evolutionary history of these mammals. Although the absence of upper incisors is rare in proboscideans (occurring only in deinotheres), the independent losses of lower incisors are recognized for most of its lineages (dibelodont condition). The presence of lower incisors in the Pan-American gomphothere Cuvieronius hyodon was reported a few times in literature, but it was neglected in systematic studies. We analyzed several specimens of Cuvieronius hyodon from the Americas and recognized that immature individuals had lower incisors during very early post-natal developmental stages. Subsequently, these are lost and lower incisors alveoli close during later developmental stages, before maturity. Moreover, for the first time in a formal cladistic analysis of non-amebelodontine trilophodont gomphotheres, Rhynchotherium and Cuvieronius were recovered as sister-taxa. Among several non-ambiguous synapomorphies, the presence of lower incisors diagnoses this clade. We recognize that the presence of lower incisors in Cuvieronius and Rhynchotherium is an unique case of taxic atavism among the Elephantimorpha, since these structures are lost at the origin of the ingroup. The rediscovery of the lower incisors in Cuvieronius hyodon, their ontogenetic interpretation and the inclusion of this feature in a revised phylogenetic analysis of trilophodont gomphotheres brought a better understanding for the evolutionary history of these proboscideans. PMID:26756209

  12. Relationship between cell proliferation and eruption rate in the rat incisor.

    PubMed

    Gomes, J R; Omar, N F; Do Carmo, E R; Neves, J S; Soares, M A M; Narvaes, E A; Novaes, P D

    2013-07-01

    The aim of this study was to further define the relationship between cell proliferation and the rate of tooth eruption in the rat incisor. Vinblastine is a drug that blocks cellular mitosis and was used to inhibit cell proliferation in the odontogenic region of rat incisors that were submitted to a shortening treatment or to higher masticatory forces. Male Wistar rats were divided into five groups: normofunctional (control group for incisor eruption), hypofunctional (incisor submitted to eruption acceleration), hyperfunctional (incisors under higher masticatory forces), hypofunctional with vinblastine and hyperfunctional with vinblastine. In incisors submitted to shortening procedures, a significant decrease in the eruption rate and cell proliferation was observed two days after vinblastine injection, suggesting that incisor eruption is dependent on cell proliferation.

  13. Adenomatoid odontogenic tumor associated with an unerupted mandibular lateral incisor: a case report

    PubMed Central

    2015-01-01

    Adenomatoid odontogenic tumor (AOT) is a rare, benign odontogenic tumor that predominantly appears in the second decade of life in female patients. Most AOTs occur in the anterior part of the maxilla and are usually associated with impacted anterior teeth. There are three types of AOT, follicular, extrafollicular, and peripheral, which are classified based on the location of the lesion and its association with the impacted tooth. We report a rare case of AOT associated with an impacted right mandibular lateral incisor in an 11-year-old female patient. PMID:26734563

  14. Sex determination using the mesio-distal dimension of permanent maxillary incisors and canines in a modern Chilean population.

    PubMed

    Peckmann, Tanya R; Logar, Ciara; Garrido-Varas, Claudia E; Meek, Susan; Pinto, Ximena Toledo

    2016-03-01

    The pelvis and skull have been shown to be the most accurate skeletal elements for the determination of sex. Incomplete or fragmentary bones are frequently found at forensic sites however teeth are often recovered in forensic cases due to their postmortem longevity. The goal of the present research was to investigate sexual dimorphism between the mesio-distal dimension of the permanent maxillary incisors and canines for the determination of sex in a contemporary Chilean population. Three hundred and three dental models (126 males and 177 females) from individuals ranging in age from 13 years to 37 years old were used from the School of Dentistry, University of Chile. The statistical analyses showed that only the central incisors and canines were sexually dimorphic. Discriminant function score equations were generated for use in sex determination. The average accuracy of sex classification ranged from 59.7% to 65.0% for the univariate analysis and 60.1% to 66.7% for the multivariate analysis. Comparisons to other populations were made. Overall, the accuracies ranged from 54.4% to 63.3% with males most often identified correctly and females most often misidentified. The determination of sex from the mesio-distal width of incisors and canines in Chilean populations does not adhere to the Mohan and Daubert criteria and therefore would not be presented as evidence in court.

  15. A Study of Central Auction Based Wholesale Electricity Markets

    NASA Astrophysics Data System (ADS)

    Ceppi, Sofia; Gatti, Nicola

    The deregulation of electricity markets produced significant economic benefits, reducing prices to customers and opening several opportunities for new actors, e.g., new generators and distributors. A prominent scientific and technological challenge is the automation of such markets. In particular, we focus our attention on wholesale electricity markets based on a central auction. In these markets, generators sell electricity by means of a central auction to a public authority. Instead, the distribution of electricity to customers takes part in retail markets. The main works presented in the literature model wholesale markets as oligopolies, neglecting thus the specific auction mechanism. In this paper, we enrich these models by introducing an auction mechanism shaped on that used in the Italian wholesale electricity market, we solve the winner determination problem, and we preliminarily study the problem of searching for equilibria.

  16. Finite element analysis of equine incisor teeth. Part 2: investigation of stresses and strain energy densities in the periodontal ligament and surrounding bone during tooth movement.

    PubMed

    Schrock, P; Lüpke, M; Seifert, H; Staszyk, C

    2013-12-01

    This study investigated the hypothetical contribution of biomechanical loading to the onset of equine odontoclastic tooth resorption and hypercementosis (EOTRH) and to elucidate the physiological age-related positional changes of the equine incisors. Based on high resolution micro-computed tomography (μCT) datasets, 3-dimensional models of entire incisor arcades and the canine teeth were constructed representing a young and an old incisor dentition. Special attention was paid to constructing an anatomically correct model of the periodontal ligament (PDL). Using previously determined Young's moduli for the equine incisor PDL, finite element (FE) analysis was performed. Resulting strains, stresses and strain energy densities (SEDs), as well as the resulting regions of tension and compression within the PDL and the surrounding bone were investigated during occlusion. The results showed a distinct distribution pattern of high stresses and corresponding SEDs in the PDL and bone. Due to the tooth movement, peaks of SEDs were obtained in the PDL as well as in the bone on the labial and palatal/lingual sides of the alveolar crest. At the root, highest SEDs were detected in the PDL on the palatal/lingual side slightly occlusal of the root tip. This distribution pattern of high SEDs within the PDL coincides with the position of initial resorptive lesions in EOTRH affected teeth. The position of high SEDs in the bone can explain the typical age-related alteration of shape and angulation of equine incisors.

  17. Structural and Morphometric Comparison of Lower Incisors in PACAP-Deficient and Wild-Type Mice.

    PubMed

    Sandor, B; Fintor, K; Reglodi, D; Fulop, D B; Helyes, Z; Szanto, I; Nagy, P; Hashimoto, H; Tamas, A

    2016-06-01

    Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide with widespread distribution. PACAP plays an important role in the development of the nervous system, it has a trophic and protective effect, and it is also implicated in the regulation of various physiological functions. Teeth are originated from the mesenchyme of the neural crest and the ectoderm of the first branchial arch, suggesting similarities with the development of the nervous system. Earlier PACAP-immunoreactive fibers have been found in the odontoblastic and subodontoblastic layers of the dental pulp. Our previous examinations have shown that PACAP deficiency causes alterations in the morphology and structure of the developing molars of 7-day-old mice. In our present study, morphometric and structural comparison was performed on the incisors of 1-year-old wild-type and PACAP-deficient mice. Hard tissue density measurements and morphometric comparison were carried out on the mandibles and the lower incisors with micro-CT. For structural examination, Raman microscopy was applied on frontal thin sections of the mandible. With micro-CT morphometrical measurements, the size of the incisors and the relative volume of the pulp to dentin were significantly smaller in the PACAP-deficient group compared to the wild-type animals. The density of calcium hydroxyapatite in the dentin was reduced in the PACAP-deficient mice. No structural differences could be observed in the enamel with Raman microscopy. Significant differences were found in the dentin of PACAP-deficient mice with Raman microscopy, where increased carbonate/phosphate ratio indicates higher intracrystalline disordering. The evaluation of amide III bands in the dentin revealed higher structural diversity in wild-type mice. Based upon our present and previous results, it is obvious that PACAP plays an important role in tooth development with the regulation of morphogenesis, dentin, and enamel mineralization. Further studies are

  18. A Rare Occurrence of Geminated-Taloned Maxillary Lateral Incisor

    PubMed Central

    Kayal, Vizhi G

    2012-01-01

    ABSTRACT The talon cusp is a developmental anomaly characterized by the presence of an accessory cusp like structure projecting from the cingulum area of the anterior teeth. Gemination is an anomaly caused by a single tooth germ that attempted to divide during its development. These developmental anomalies may cause clinical problems including esthetic impairment, pain, caries and tooth crowding. Co-occurrence of two anomalies in a teeth is rare. This paper presents an unusual case of talon cusp on geminated permanent lateral incisor. How to cite this article: Neeraja R, Kayal VG. A Rare Occurrence of Geminated-Taloned Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2012;5(2):136-138. PMID:25206153

  19. A rare occurrence of geminated-taloned maxillary lateral incisor.

    PubMed

    Neeraja, R; Kayal, Vizhi G

    2012-05-01

    The talon cusp is a developmental anomaly characterized by the presence of an accessory cusp like structure projecting from the cingulum area of the anterior teeth. Gemination is an anomaly caused by a single tooth germ that attempted to divide during its development. These developmental anomalies may cause clinical problems including esthetic impairment, pain, caries and tooth crowding. Co-occurrence of two anomalies in a teeth is rare. This paper presents an unusual case of talon cusp on geminated permanent lateral incisor. How to cite this article: Neeraja R, Kayal VG. A Rare Occurrence of Geminated-Taloned Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2012;5(2):136-138. PMID:25206153

  20. Primary incisor restoration using resin-veneered stainless steel crowns.

    PubMed

    Croll, T P

    1998-01-01

    The restoration of primary incisors with extensive caries lesions is a clinical challenge of severe dimensions. Not only are these teeth difficult to restore, but the patient's behavior can affect the treatment negatively. Requirements for an acceptable restoration include natural color; durability; adhesive cementation that is biocompatible with the pulp; easily and rapidly placed; requires only one treatment visit. Compared to other options, stainless steel crowns are the easiest to place. The most attractive restoration for these cases today is the adhesively bonded resin-composite crown, made by using acetate crown-form matrices, but this is being surpassed by the stainless steel crown forms (3M Unitek) that can be preveneered. This article describes a step-by-step method of placing preveneered stainless steel crowns for primary incisors. PMID:9617447

  1. Management of a complicated crown-root fracture in a young permanent incisor using intentional replantation.

    PubMed

    Wang, Zhengyan; Heffernan, Michelle; Vann, William F

    2008-02-01

    The purpose of this case presentation is to review the rationale for and illustrate the clinical procedures involved in intentional replantation of a maxillary central incisor following a complicated crown-root fracture. The treatment of complicated crown-root fractures in children often is compromised by a fracture below the gingival margin and/or bone. This makes isolation difficult and comprises the hermetic seal that is critical for a successful endodontic treatment. Orthodontic or surgical extrusion with gingivectomy has been suggested; however, these approaches can be expensive, time-consuming, esthetically compromising, and unsatisfactory when the fracture line is deep below the gingiva. Our presentation will discuss the treatment options for such cases and introduce the concept of intentional replantation as an option to manage complicated crown-root fractures in young permanent anterior teeth.

  2. Gene expression and dental enamel structure in developing mouse incisor.

    PubMed

    Sehic, Amer; Risnes, Steinar; Khan, Qalb-E-Saleem; Khuu, Cuong; Osmundsen, Harald

    2010-04-01

    At the mouse incisor tip the initially differentiated ameloblasts produce a thin, prism-free enamel, while further apically, in the immediate adjacent segment, the enamel thickness increases and the four-layered enamel of mouse incisor is formed. Comparative gene-expression profiling was carried out on RNA isolated from these two segments of incisor tooth germs at embryonic day (E)17.5 and at postnatal days (P)0, 1, 2, and 10 using microarrays to measure messenger RNA (mRNA) and microRNA (miRNA) species present in the segments. Validation of expression data was achieved using real-time reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. Bioinformatic data suggested enhanced cellular apoptosis in the incisal tip segment, which, together with diminished expression of the Amelx and Enam genes, may contribute to the production of the thin enamel seen in this tooth segment. For genes exhibiting higher levels of expression in the adjacent segment where complex enamel is being formed, bioinformatic analysis suggested significant associations with cellular functions involving the actin cytoskeleton, cellular development, morphology, and movement. This is suggested to reflect that ameloblasts with Tomes' process are being organized in transverse rows, facilitating the transverse movement that results in prism decussation in the inner enamel of the adjacent segment. Bioinformatic analysis of miRNA expression data lends support to these suggestions.

  3. In vitro effects of retinoic acid on mouse incisor development.

    PubMed

    Bloch-Zupan, A; Mark, M P; Weber, B; Ruch, J V

    1994-10-01

    The developing dentition is known to express the complete set of retinoic acid (RA) nuclear receptors and cytoplasmic RA-binding proteins (CRABPI and II), and RA is required for in vitro mouse molar morphogenesis, so the role of RA during in vitro mouse incisor development was investigated. Histological procedures, immunocytochemical detection of proliferating cells, immunofluorescence detection of laminin, and in situ hybridization with RNA probes for CRABPI and II were done on the tooth-germ cultures either in the presence or in the absence of RA. RA appeared to control initial morphogenesis, particularly the asymmetrical growth of the cervical loop, and to regulate required differential mitotic activity. RA seemed also to be involved in asymmetrical laminin deposition. The distribution of the CRABP gene transcripts was similar during in vivo and in vitro incisor development. However, CRABPI gene transcript distribution in the labial part of the epithelial loop was detected in vitro only in the presence of RA. A direct role of the CRABPs during tooth development is, however, unlikely because Ch55, a synthetic RA analogue that does not bind to CRABP, had the same effects as RA on in vitro incisor development. PMID:7741659

  4. Periodontal response to two intracanal medicaments in replanted monkey incisors.

    PubMed

    Thong, Y L; Messer, H H; Siar, C H; Saw, L H

    2001-12-01

    Intracanal medicaments are recommended for use in replanted teeth to inhibit inflammatory root resorption. This study compared the effect of calcium hydroxide (Pulpdent) and a corticosteroid-antibiotic paste (Ledermix) on periodontal healing and root resorption following replantation. Incisors of eight Macaca fascicularis monkeys were extracted, stored dry for 15 min and replanted. After 11 days, root canals in two adjacent maxillary incisors were treated with one medicament and contralateral incisors with the other medicament, or left as untreated controls. Animals were sacrificed 8 weeks later and the teeth prepared for histomorphometric evaluation of periodontal ligament inflammation and root resorption. Periodontal ligament inflammation and inflammatory root resorption were markedly inhibited by both calcium hydroxide and corticosteroid-antibiotic relative to untreated controls. Replacement resorption was lowest in the corticosteroid-antibiotic group, and significantly (P<0.05) more normal periodontal ligament was present in this group (79.6%) than in calcium hydroxide and control groups (64.6% and 62.7%, respectively). Treatment with the corticosteroid-antibiotic inhibited inflammatory resorption and was slightly more effective than calcium hydroxide in producing a periodontal healing response. PMID:11766092

  5. Splitting placodes: effects of bone morphogenetic protein and Activin on the patterning and identity of mouse incisors.

    PubMed

    Munne, Pauliina M; Felszeghy, Szabolcs; Jussila, Maria; Suomalainen, Marika; Thesleff, Irma; Jernvall, Jukka

    2010-01-01

    The single large rodent incisor in each jaw quadrant is evolutionarily derived from a mammalian ancestor with many small incisors. The embryonic placode giving rise to the mouse incisor is considerably larger than the molar placode, and the question remains whether this large incisor placode is a developmental requisite to make a thick incisor. Here we used in vitro culture system to experiment with the molecular mechanism regulating tooth placode development and how mice have thick incisors. We found that large placodes are prone to disintegration and formation of two to three small incisor placodes. The balance between one large or multiple small placodes was altered through the regulation of bone morphogenetic protein (BMP) and Activin signaling. Exogenous Noggin, which inhibits BMP signaling, or exogenous Activin cause the development of two to three incisors. These incisors were more slender than normal incisors. Additionally, two inhibitor molecules, Sostdc1 and Follistatin, which regulate the effects of BMPs and Activin and have opposite expression patterns, are likely to be involved in the incisor placode regulation in vivo. Furthermore, inhibition of BMPs by recombinant Noggin has been previously suggested to cause a change in the tooth identity from the incisor to the molar. This evidence has been used to support a homeobox code in determining tooth identity. Our work provides an alternative interpretation, where the inhibition of BMP signaling can lead to splitting of the large incisor placode and the formation of partly separate incisors, thereby acquiring molar-like morphology without a change in tooth identity.

  6. Reversed palatal perforation by upper incisors in ageing blind mole-rats (Spalax ehrenbergi)

    PubMed Central

    ZURI, I.; TERKEL, J.

    2001-01-01

    Blind mole-rats (Spalax ehrenbergi) are fossorial solitary rodents that present striking morphological, physiological and behavioural adaptations to the subterranean environment in which they live. Previous studies have shown that mole-rats are specialised in tooth-digging. The rapid eruption-rate of their incisors has evolved to compensate for their excessive wear by excavation. Males use their incisors more than females for digging and fighting, and their rate of incisor eruption is significantly more rapid than in females. Since mole-rats use their incisors for digging throughout the year, we suggest that continuous mechanical pressure on their oral tissues concentrated at the apical sites of the upper incisors leads to cell and tissue fatigue. We provide evidence for 5 stages of palatal perforation by the upper incisors at their apical sites, with maximum perforation characterising aged males. Interspecies comparisons with 7 other fossorial and semi-fossorial rodent species, and with beavers, which expose their incisors to enormous mechanical pressure, revealed that this palatal perforation is unique to the male mole-rat. We suggest that while the fast eruption rate of incisors in the mole-rat compensates for the rapid wear resulting from digging, evolutionary adaptation to continuous tooth-digging is still ongoing, since the physical pressure of digging at the apical sites of the upper incisors leads to tissue destruction, breakage of the palatal bone and possibly to death, as a result of maxillary inflammation. PMID:11760890

  7. Non-linear viscoelastic finite element analysis of the effect of the length of glass fiber posts on the biomechanical behaviour of directly restored incisors and surrounding alveolar bone.

    PubMed

    Ferrari, Marco; Sorrentino, Roberto; Zarone, Fernando; Apicella, Davide; Aversa, Raffaella; Apicella, Antonio

    2008-07-01

    The study aimed at estimating the effect of insertion length of posts with composite restorations on stress and strain distributions in central incisors and surrounding bone. The typical, average geometries were generated in a FEA environment. Dentin was considered as an elastic orthotropic material, and periodontal ligament was coupled with nonlinear viscoelastic mechanical properties. The model was then validated with experimental data on displacement of incisors from published literature. Three post lengths were investigated in this study: root insertion of 5, 7, and 9 mm. For control, a sound incisor model was generated. Then, a tearing load of 50 N was applied to both sound tooth and simulation models. Post restorations did not seem to affect the strain distribution in bone when compared to the control. All simulated post restorations affected incisor biomechanics and reduced the root's deforming capability, while the composite crowns underwent a higher degree of deformation than the sound crown. No differences could be noticed in incisor stress and strain. As for the influence of post length, it was not shown to affect the biomechanics of restored teeth. PMID:18833761

  8. Hypomineralized Second Primary Molars as Predictor of Molar Incisor Hypomineralization.

    PubMed

    Negre-Barber, A; Montiel-Company, J M; Boronat-Catalá, M; Catalá-Pizarro, M; Almerich-Silla, J M

    2016-01-01

    Molar incisor hypomineralization (MIH) is a developmental defect of dental enamel that shares features with hypomineralized second primary molars (HSPM). Prior to permanent tooth eruption, second primary molars could have predictive value for permanent molar and incisor hypomineralization. To assess this possible relationship, a cross-sectional study was conducted in a sample of 414 children aged 8 and 9 years from the INMA cohort in Valencia (Spain). A calibrated examiner (linear-weighted Kappa 0.83) performed the intraoral examinations at the University of Valencia between November 2013 and 2014, applying the diagnostic criteria for MIH and HSPM adopted by the European Academy of Paediatric Dentistry. 100 children (24.2%) presented MIH and 60 (14.5%) presented HSPM. Co-occurrence of the two defects was observed in 11.1% of the children examined. The positive predictive value was 76.7% (63.9-86.6) and the negative predictive value 84.7% (80.6-88.3). The positive likelihood ratio (S/1-E) was 10.3 (5.9-17.9) and the negative likelihood ratio (1-S/E) 0.57 (0.47-0.68). The odds ratio was 18.2 (9.39-35.48). It was concluded that while the presence of HSPM can be considered a predictor of MIH, indicating the need for monitoring and control, the absence of this defect in primary dentition does not rule out the appearance of MIH. PMID:27558479

  9. Hypomineralized Second Primary Molars as Predictor of Molar Incisor Hypomineralization.

    PubMed

    Negre-Barber, A; Montiel-Company, J M; Boronat-Catalá, M; Catalá-Pizarro, M; Almerich-Silla, J M

    2016-08-25

    Molar incisor hypomineralization (MIH) is a developmental defect of dental enamel that shares features with hypomineralized second primary molars (HSPM). Prior to permanent tooth eruption, second primary molars could have predictive value for permanent molar and incisor hypomineralization. To assess this possible relationship, a cross-sectional study was conducted in a sample of 414 children aged 8 and 9 years from the INMA cohort in Valencia (Spain). A calibrated examiner (linear-weighted Kappa 0.83) performed the intraoral examinations at the University of Valencia between November 2013 and 2014, applying the diagnostic criteria for MIH and HSPM adopted by the European Academy of Paediatric Dentistry. 100 children (24.2%) presented MIH and 60 (14.5%) presented HSPM. Co-occurrence of the two defects was observed in 11.1% of the children examined. The positive predictive value was 76.7% (63.9-86.6) and the negative predictive value 84.7% (80.6-88.3). The positive likelihood ratio (S/1-E) was 10.3 (5.9-17.9) and the negative likelihood ratio (1-S/E) 0.57 (0.47-0.68). The odds ratio was 18.2 (9.39-35.48). It was concluded that while the presence of HSPM can be considered a predictor of MIH, indicating the need for monitoring and control, the absence of this defect in primary dentition does not rule out the appearance of MIH.

  10. Identification of genetic risk factors for maxillary lateral incisor agenesis.

    PubMed

    Alves-Ferreira, M; Pinho, T; Sousa, A; Sequeiros, J; Lemos, C; Alonso, I

    2014-05-01

    Tooth agenesis affects 20% of the world population, and maxillary lateral incisors agenesis (MLIA) is one of the most frequent subtypes, characterized by the absence of formation of deciduous or permanent lateral incisors. Odontogenesis is a complex mechanism regulated by sequential and reciprocal epithelial-mesenchymal interactions, controlled by activators and inhibitors involved in several pathways. Disturbances in these signaling cascades can lead to abnormalities in odontogenesis, resulting in alterations in the formation of the normal teeth number. Our aim was to study a large number of genes encoding either transcription factors or key components in signaling pathways shown to be involved in tooth odontogenesis. We selected 8 genes-MSX1, PAX9, AXIN2, EDA, SPRY2, TGFA, SPRY4, and WNT10A-and performed one of the largest case-control studies taking into account the number of genes and variants assessed, aiming at the identification of MLIA susceptibility factors. We show the involvement of PAX9, EDA, SPRY2, SPRY4, and WNT10A as risk factors for MLIA. Additionally, we uncovered 3 strong synergistic interactions between MLIA liability and MSX1-TGFA, AXIN2-TGFA, and SPRY2-SPRY4 gene pairs. We report the first evidence of the involvement of sprouty genes in MLIA susceptibility. This large study results in a better understanding of the genetic components and mechanisms underlying this trait.

  11. Preformed resin-veneered stainless steel crowns for restoration of primary incisors.

    PubMed

    Croll, T P; Helpin, M L

    1996-05-01

    Stainless steel crown forms with bonded resin veneers for primary incisors are commercially available to dentists. This type of preveneered crown was developed to serve as a convenient, durable, reliable, and esthetic solution to the difficult challenge of restoring severely carious primary incisors. This article describes preveneered crowns, reviews their advantages and disadvantages, and details a technique for placement of such restorations.

  12. Variations in the shape of permanent maxillary lateral incisors in Sundanese.

    PubMed

    Schlegel, D; Satravaha, S

    1984-01-01

    During a survey in Java we found unusual shaped upper lateral incisors. A total of 110 school children shows 3 cases with pegging, approximately 20% with canine-like shape. In all cases the lateral incisor was present. Compared with other publication the incidence of pegging is low, the canine-like variation never described as far as we know.

  13. Orthodontic Management of Congenitally Missing Maxillary Lateral Incisors: A Case Report

    PubMed Central

    Rongo, Roberto; Cupo, Antonello; Valletta, Rosa

    2014-01-01

    This case report describes the orthodontic treatment of a woman, aged 15 years, with permanent dentition, brachyfacial typology, with congenitally missing maxillary lateral incisors. Multibracket straightwire fixed appliance was used to open the space for dental implant placement, and treat the impaired occlusion. The missing lateral incisors were substituted with oral implants. PMID:24711929

  14. Preformed resin-veneered stainless steel crowns for restoration of primary incisors.

    PubMed

    Croll, T P; Helpin, M L

    1996-05-01

    Stainless steel crown forms with bonded resin veneers for primary incisors are commercially available to dentists. This type of preveneered crown was developed to serve as a convenient, durable, reliable, and esthetic solution to the difficult challenge of restoring severely carious primary incisors. This article describes preveneered crowns, reviews their advantages and disadvantages, and details a technique for placement of such restorations. PMID:8941812

  15. Lower incisor extraction treatment with the Invisalign® technique: three case reports.

    PubMed

    Giancotti, Aldo; Garino, Francesco; Mampieri, Gianluca

    2015-03-01

    The extraction of a lower incisor can lead to satisfactory orthodontic results for patients with moderate to severe lower incisor crowding. Invisalign(®) is a treatment modality for such treatments, moving teeth with precision and reducing inconvenience for the patient. Three case reports are presented in this article supporting the above statements.

  16. The Single-tooth Implant Treatment of Congenitally Missing Maxillary Lateral Incisors Using Angled Abutments: A Clinical Report

    PubMed Central

    Tuna, Suleyman Hakan; Keyf, Filiz; Pekkan, Gurel

    2009-01-01

    The maxillary lateral incisor is the second most common congenitally absent tooth. There are several treatment options for replacing the missing maxillary lateral incisor, including canine substitution, tooth-supported restoration, or single-tooth implant. Dental implants are an appropriate treatment option for replacing missing maxillary lateral incisor teeth in adolescents when their dental and skeletal development is complete. This case report presents the treatment of a patient with congenitally missing maxillary lateral incisors using dental implants with angled abutments. PMID:21528038

  17. Correction of palatally displaced maxillary lateral incisors without brackets

    PubMed Central

    Choi, Kyung-Hee; Lee, Yoonjung; Kim, Minji

    2013-01-01

    This article describes the orthodontic treatment of a 25-year-old Korean female patient with anterior crowding, including palatally displaced lateral incisors. Her facial profile was satisfactory, but 3.5 mm of maxillary anterior crowding was observed. To correct this crowding, we decided to minimize the use of the conventional fixed orthodontic appliances and employed a less bulky and more aesthetic appliance for applying light continuous force. We determined the final positions of the maxillary teeth via a working model for diagnostic set up and achieved space gaining and alignment with simple Ni-Ti spring and stainless steel round tubes. Tooth alignment was achieved efficiently and aesthetically without the conventional brackets. PMID:24015390

  18. Hypomineralized Second Primary Molars as Predictor of Molar Incisor Hypomineralization

    PubMed Central

    Negre-Barber, A.; Montiel-Company, J. M.; Boronat-Catalá, M.; Catalá-Pizarro, M.; Almerich-Silla, J. M.

    2016-01-01

    Molar incisor hypomineralization (MIH) is a developmental defect of dental enamel that shares features with hypomineralized second primary molars (HSPM). Prior to permanent tooth eruption, second primary molars could have predictive value for permanent molar and incisor hypomineralization. To assess this possible relationship, a cross-sectional study was conducted in a sample of 414 children aged 8 and 9 years from the INMA cohort in Valencia (Spain). A calibrated examiner (linear-weighted Kappa 0.83) performed the intraoral examinations at the University of Valencia between November 2013 and 2014, applying the diagnostic criteria for MIH and HSPM adopted by the European Academy of Paediatric Dentistry. 100 children (24.2%) presented MIH and 60 (14.5%) presented HSPM. Co-occurrence of the two defects was observed in 11.1% of the children examined. The positive predictive value was 76.7% (63.9–86.6) and the negative predictive value 84.7% (80.6–88.3). The positive likelihood ratio (S/1-E) was 10.3 (5.9–17.9) and the negative likelihood ratio (1-S/E) 0.57 (0.47–0.68). The odds ratio was 18.2 (9.39–35.48). It was concluded that while the presence of HSPM can be considered a predictor of MIH, indicating the need for monitoring and control, the absence of this defect in primary dentition does not rule out the appearance of MIH. PMID:27558479

  19. [Molar incisor hypomineralization (MIH)--a literature review].

    PubMed

    Gotler, M; Ratson, T

    2010-04-01

    MIH was defined by Weerheijm (2001) as "hypomineralisation of systemic origin of 1-4 permanent first molars, frequently associated with affected incisors". The prevalence of MIH varies between 2.8% and 25%, dependent upon the study. At their sixth congress in 2003, The European Association of pediatric dentistry defined criteria for diagnosis of the phenomena. It included the presence of demarcated opacity, posteruptive enamel breakdown, atypical restoration, extracted molar due to MIH and unerupted teeth. According to the teeth involved and to the time of the crown formation, researches focused on environmental and systemic conditions as possible reasons for MIH.The etiologies were divided into five groups: Exposure to environmental contaminants, pre/peri and neonatal problems, exposure to fluoride, common childhood illnesses and medically compromised children. The clinical implications include highly sensitive teeth, difficulty to achieve adequate anesthesia, behavioral problems and anxiety, rapid progression of caries and the esthetic implications. A six step approach to management was described suggested: risk identification, early diagnosis, remineralization and desensitization, prevention of caries and posteruption breakdown, restorations and extractions and finally maintenance. Restoring an affected molar can vary from adhesive intra coronal restorations (resin composite is the material of choice) to extra coronal restorations (e.g. preformed metal crown). Esthetic solutions to affected incisors may include microabrasion (that shows little improvement) and resin composite or porcelain veneer. The key for a successful treatment is early diagnosis, intense follow up and usage of remineralizating agents as soon as the teeth erupt. There is still need for further research to clarify the etiological factors and improve the durability of restoration in affected teeth.

  20. Developmental disturbances associated with agenesis of the permanent maxillary lateral incisor.

    PubMed

    Pinho, T; Maciel, P; Pollmann, C

    2009-12-19

    The aim of this study was to characterise the intra and extra-oral phenotype associated with agenesis of the permanent maxillary lateral incisor. We compared three groups: (1) subjects with agenesis of one or both permanent maxillary lateral incisors (n=80); (2) first and second degree relatives of group 1 with no agenesis of the permanent maxillary lateral incisor and (3) subjects with no agenesis of the maxillary lateral incisor or family history of it (n=49). For each of the 201 subjects detailed clinical information was reviewed and panoramic radiographs were analysed. Considering only the sample with unilateral agenesis, microdontia of the contralateral permanent maxillary lateral incisor was significantly more frequent in group 1 (82.4%) than in group 2 (25%) and the control group (2%). This supports the theory that microdontia is a variable expression of the same developmental disturbance that causes tooth agenesis. The absence of third molars occurred more often in group 1 (36.2%) than in groups 2 and 3 (18.6% and 18.9% respectively), confirming that agenesis of third molars was markedly associated with the agenesis of the permanent maxillary lateral incisor. Agenesis of teeth other than third molars was not significantly different among subjects with agenesis of the permanent maxillary lateral incisor and their relatives. The frequencies of supernumerary teeth, permanent maxillary canine impaction, general health condition and minor anomalies were not significantly different between the three groups. PMID:19876043

  1. [Incisors crossbite correction with spring inclined plane appliance: principles and procedures].

    PubMed

    Suphanthavanich, K; Raungpaka, S

    1990-01-01

    The spring inclined plane is one of the removable appliances that can be used to correct incisors crossbite which is designed for the early treatment period. In order to prevent skeletal malocclusion and reestablish proper muscle balance. The appliance is very simple which composes of clasps on the first molar both sides and spring 0.9 millimetre diameter. This spring was bended as an inclined plane above the lower incisors. The force from this spring will push upper incisors anteriorly. The spring inclined plane is very effective in mixed dentition. Nevertheless this spring is appropriate to use in the patient who can not wear the removeable orthodontic appliance in the upper jaw.

  2. Notching and anterior beveling on fossil horse incisors: Indicators of domestication?

    NASA Astrophysics Data System (ADS)

    Rogers, Richard A.; Rogers, Laurine A.

    1988-01-01

    One of the lines of evidence cited for possible late Pleistocene human control of horses has been the presence of notching and anterior beveling on horse incisor teeth recovered from upper and middle Paleolithic sites in Europe. Similar forms of wear have been found on the incisor teeth of wild horses from early and middle Pleistocene deposits in North America. Notching appears partly due to malocclusion and chipping. The causes of beveling are less certain but may involve the eating of bark. Therefore, the presence of notching and anterior beveling on horse incisor teeth may not be a reliable indicator of human control.

  3. Space-Based Detection of Sinkhole Activity in Central Florida

    NASA Astrophysics Data System (ADS)

    Oliver-Cabrera, T.; Kruse, S.; Wdowinski, S.

    2015-12-01

    Central Florida's thick carbonate deposits and hydrological conditions have made the area prone to sinkhole development. Sinkhole collapse is a major geologic hazard in central Florida threatening human life and causing substantial damage to property. According to the Florida Senate report in 2010, between 2006-2010 total insurance claims due to sinkhole activity were around $200 million per year. Detecting sinkhole deformation before a collapse is a very difficult task, due to small or sometimes unnoticeable surface changes. Most techniques used to monitor sinkholes provide very localized information and cannot be implemented to study broad areas. This is the case of central Florida, where the active zone spans over hundreds of square-kilometers. In this study we use Interferometric Synthetic Aperture Radar (InSAR) observations acquired over several locations in central Florida to detect possible pre-collapse deformation. The study areas were selected because they have shown suspicious sinkhole behavior. One of the sites collapsed on March 2013 destroying a property and killing a man. To generate the InSAR results we use six datasets acquired by the TerraSAR-X and Cosmo-SkyMed satellites with various acquisition modes reflecting pixel resolutions between 25cm and 2m. Preliminary InSAR results show good coherence over constructed areas and low coherence in vegetated zones, justifying our analysis that focuses on the man-made structures. After full datasets will be acquired, a Persistent Scatterer Interferometry (PSI) time series analysis will be performed for detecting localized deformation at spatial scale of 1-5 meters. The project results will be verified using Ground Penetrating Radar.

  4. Weighting links based on edge centrality for community detection

    NASA Astrophysics Data System (ADS)

    Sun, Peng Gang

    2014-01-01

    Link weights have the equally important position as links in complex networks, and they are closely associated with each other for the emergence of communities. How to assign link weights to make a clear distinction between internal links of communities and external links connecting communities is of vital importance for community detection. Edge centralities provide a powerful approach for distinguishing internal links from external ones. Here, we first use edge centralities such as betweenness, information centrality and edge clustering coefficient to weight links of networks respectively to transform unweighted networks into weighted ones, and then a weighted function that both considers links and link weights is adopted on the weighted networks for community detection. We evaluate the performance of our approach on random networks as well as real-world networks. Better results are achieved on weighted networks with stronger weights of internal links of communities, and the results on unweighted networks outperform that of weighted networks with weaker weights of internal links of communities. The availability of our findings is also well-supported by the study of Granovetter that the weak links maintain the global integrity of the network while the strong links maintain the communities. Especially in the Karate club network, all the nodes are correctly classified when we weight links by edge betweenness. The results also give us a more comprehensive understanding on the correlation between links and link weights for community detection.

  5. Extraction of an incisor embedded within the nasal cavity in two guinea pigs

    PubMed Central

    KIDO, Nobuhide; ONO, Kaori; OMIYA, Tomoko; OGUCHI, Yukio; SETOGAWA, Moemi; MACHIDA, Yuuki

    2015-01-01

    Oral examination of two guinea pigs revealed that the unilateral incisor was absent. On radiographic examination, the incisor was identified within the nasal cavity in both patients. Under anesthesia in both patients, the skin was incised from the nostril to 1.5 cm proximal, and the premaxilla and part of the maxilla were exposed. The bone was removed using a surgical drill, and the incisor was exposed in the nasal cavity. The root was grasped with forceps and carefully extracted as it was degraded and very fragile. Diagnosis was easy using oral and radiographic examination. In guinea pig patients where an incisor is absent on oral examination, this condition should be considered. PMID:26118492

  6. Excess NF-κB induces ectopic odontogenesis in embryonic incisor epithelium.

    PubMed

    Blackburn, J; Kawasaki, K; Porntaveetus, T; Kawasaki, M; Otsuka-Tanaka, Y; Miake, Y; Ota, M S; Watanabe, M; Hishinuma, M; Nomoto, T; Oommen, S; Ghafoor, S; Harada, F; Nozawa-Inoue, K; Maeda, T; Peterková, R; Lesot, H; Inoue, J; Akiyama, T; Schmidt-Ullrich, R; Liu, B; Hu, Y; Page, A; Ramírez, Á; Sharpe, P T; Ohazama, A

    2015-01-01

    Nuclear factor kappa B (NF-κB) signaling plays critical roles in many physiological and pathological processes, including regulating organogenesis. Down-regulation of NF-κB signaling during development results in hypohidrotic ectodermal dysplasia. The roles of NF-κB signaling in tooth development, however, are not fully understood. We examined mice overexpressing IKKβ, an essential component of the NF-κB pathway, under keratin 5 promoter (K5-Ikkβ). K5-Ikkβ mice showed supernumerary incisors whose formation was accompanied by up-regulation of canonical Wnt signaling. Apoptosis that is normally observed in wild-type incisor epithelium was reduced in K5-Ikkβ mice. The supernumerary incisors in K5-Ikkβ mice were found to phenocopy extra incisors in mice with mutations of Wnt inhibitor, Wise. Excess NF-κB activity thus induces an ectopic odontogenesis program that is usually suppressed under physiological conditions.

  7. Skull base tumours Part II. Central skull base tumours and intrinsic tumours of the bony skull base.

    PubMed

    Borges, Alexandra

    2008-06-01

    With the advances of cross-sectional imaging radiologists gained an increasing responsibility in the management of patients with skull base pathology. As this anatomic area is hidden to clinical exam, surgeons and radiation oncologists have to rely on imaging studies to plan the most adequate treatment. To fulfil these endeavour radiologists need to be knowledgeable about skull base anatomy, about the main treatment options available, their indications and contra-indications and needs to be aware of the wide gamut of pathologies seen in this anatomic region. This article will provide a radiologists' friendly approach to the central skull base and will review the most common central skull base tumours and tumours intrinsic to the bony skull base.

  8. Class II, Division 1 Angle malocclusion with severe proclination of maxillary incisors.

    PubMed

    Montanha, Kátia

    2016-01-01

    Protrusion of maxillary incisors is a common complaint among patients seeking orthodontic treatment. This report addresses the correction of Class II Angle malocclusion with excessively bucally proclined maxillary incisors, in an adolescent female patient, through the use of extraoral and fixed appliances. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) as part of the requirements for obtaining the title of certified by the BBO. PMID:27007768

  9. [Treatment of complete traumatic avulsion of an incisor tooth in adults].

    PubMed

    Benmansour, A

    2013-05-01

    It is possible to replant an incisor tooth completely avulsed after trauma in adults. These cases are relatively frequent among athletes. It is essential to conserve the tooth in saline solution. The time before replantation must be as short as possible. The simple technique described here, which requires a minimum of material and no dental chair, makes it possible to replant an avulsed incisor with a good success rate. PMID:23803559

  10. Aesthetic Rehabilitation of a Complicated Crown-Root Fracture of the Maxillary Incisor: Combination of Orthodontic and Implant Treatment

    PubMed Central

    de Avila, Érica Dorigatti; de Molon, Rafael Scaf; Cardoso, Mauricio de Almeida; Capelozza Filho, Leopoldino; Campos Velo, Marilia Mattar de Amoêdo; Mollo, Francisco de Assis; Borelli Barros, Luiz Antonio

    2014-01-01

    The aim of this paper is to present a complex rehabilitation, of fractured tooth, with implants in anterior region considering the orthodontics extrusion to clinical success. At 7 years old, the patient fractured the maxillary left central incisor and the dentist did a crown with the fragment. Twenty years later, the patient was referred to a dental clinic for orthodontic treatment, with the chief complaint related to an accentuated deep bite, and a professional started an orthodontic treatment. After sixteen months of orthodontic treatment, tooth 21 fractured. The treatment plan included an orthodontic extrusion of tooth 21 and implant placement. This case has been followed up and the clinical and radiographic examinations show excellence esthetic results and satisfaction of patient. The forced extrusion can be a viable treatment option in the management of crown root fracture of an anterior tooth to gain bone in a vertical direction. This case emphasizes that to achieve the esthetic result a multidisciplinary approach is necessary. PMID:24872900

  11. Surgical Treatment of an Immature Short-Rooted Traumatized Incisor with an Extensive Apical Lesion Using CEM Cement

    PubMed Central

    Asgary, Saeed; Fazlyab, Mahta

    2015-01-01

    Severe traumatic injuries to immature teeth often cause damage to periodontal ligament as well as dental pulp; pulp necrosis, root resorption and subsequent apical lesion are common consequences. This article reports the surgical management of an infected immature maxillary central incisor associated with a gigantic periradicular lesion and severe root resorption. The tooth had a history of trauma and the patient suffered from purulent sinus tract and tooth mobility. After unsuccessful multi-session disinfection with calcium hydroxide, root end surgery was planned. During flap surgery and lesion enucleation, the root end was cleaned and filled with calcium-enriched mixture (CEM) cement. After one year, the radiographic examination revealed that the lesion was almost completely replaced with newly formed bone. In addition, clinical examination showed favorable outcomes; the tooth was symptom-free and in function. Due to chemical, physical and biological properties of CEM cement, this biomaterial might be considered as the root-end filling material of choice. PMID:25834603

  12. Mineralized deposits in pulps of incompletely developed permanent monkey incisors after pulpotomy with tungsten carbide fissure burs.

    PubMed

    Heide, S; Koppang, H S

    1994-06-01

    The exposed pulp of incompletely developed permanent incisors of nine monkeys were treated with partial pulpotomy with tungsten carbide fissure burs on an air turbine equipment. The pulps were capped with calcium hydroxide (Dycal) followed by insertion of conventional amalgam. The results were studied by conventional light microscopy after 1 and 6 months. Rod-like mineralized pulpal deposits were seen in five of the nine animals, in 9 out of 67 teeth, evenly distributed at the two observation times. Also the lengths of the deposits appeared similar, while the thickness had increased markedly after 6 months. After 1 month the presence of a central vessel lumen was observed in the deposits. The results seemed to indicate that the mechanism of formation was an initial pathologic mineralization of the vessel wall, and a growth of the deposits by the elaboration of fibrous, atubular dentin on to the outside of this wall.

  13. Management of Delayed Eruption of Permanent Maxillary Incisor associated with the Presence of Supernumerary Teeth: A Case Report

    PubMed Central

    Nagpal, Rajni; Singh, Mousumi; Chaudhary, Seema

    2011-01-01

    A supernumerary tooth is one that is additional to the normal series and can be found in almost any region of the dental arch. Clinically, supernumerary teeth are able to cause different local disorders. It is important for the dentist to be aware of the clinical complications of supernumerary teeth, the most common being the delayed eruption of permanent teeth. Early diagnosis and management of supernumerary teeth is important to prevent the need for more complex surgical and orthodontic treatment. This case report highlights the problem of delayed eruption of permanent maxillary left central incisor in a 9-year-old boy due to two supernumerary teeth, one tuberculate type and other impacted inverted mesiodens.

  14. Analysis of fused maxillary incisor dentition in p53-deficient exencephalic mice

    PubMed Central

    KAUFMAN, M. H.; KAUFMAN, D. B.; BRUNE, R. M.; STARK, M.; ARMSTRONG, J. F.; CLARKE, A. R.

    1997-01-01

    Out of a total of 21 exencephalic p53-deficient embryonic and newborn mice, 6 (28.6%) possessed fused maxillary incisor teeth. On histological analysis of the 5 examples seen on day 19.5 of gestation and newborn mice, 3 varieties were observed: an example of ‘simple’ fusion, 3 examples of simple fusion each of which contained a ‘dens in dente’ (‘tooth within a tooth’), and a single example in which the fused teeth were associated with a median supernumerary incisor tooth which, while deeply indenting the labial surface of the fused teeth, was in all locations a completely separate unit. 3-D reconstructions of the fused teeth demonstrated that they were all of the fusio subtotalis variety. No gross abnormalities were observed in the other dentition in these mice. It is noted that in mice fused maxillary incisor teeth are relatively commonly associated with both hypervitaminosis A-induced and trypan blue-induced exencephaly. It is believed that the presence of dens in dente within fused maxillary incisor teeth has only once been reported in mice, and the association between fused maxillary incisor teeth and a median supernumerary incisor tooth has not previously been reported in this species. PMID:9279659

  15. Extraction of the lateral incisors to treat maxillary protrusion: quantitative evaluation of the stomatognathic functions.

    PubMed

    Ishihara, Yoshihito; Kuroda, Shingo; Sumiyoshi, Kumi; Takano-Yamamoto, Teruko; Yamashiro, Takashi

    2013-03-01

    To treat morphological abnormalities, impaction, and severe malposition of the teeth, the lateral incisors are sometimes extracted, followed by orthodontic space closure. This procedure often requires special consideration, not only with regard to esthetics but also for functional issues. However, thus far, few reports that have performed a functional evaluation in such cases. The purpose of this article is to report the successful treatment of an adult patient with a Class II division 1 malocclusion who was treated with extraction of the upper lateral incisors. The female patient, aged 23 years and 6 months, had a chief complaint of maxillary incisal protrusion and crooked teeth. In this patient, the upper lateral incisors were extracted to fulfill the patient's strong request, followed by orthodontic treatment using edgewise appliances. A high-pull J-hook headgear on the lower dental arch was used to prevent further labial inclination of the lower incisors. The total active treatment period was 37 months. The resulting occlusion and a satisfactory facial profile were maintained during a 4-year retention period. Additionally, this treatment did not affect the stomatognathic functions as assessed by the following criteria: range of the incisal path or condylar motion during maximal open-close movement, protrusive excursion, lateral excursion, and the chewing test. In conclusion, extraction of the upper lateral incisors can be an effective treatment choice when the upper lateral incisors are dwarfed, are nonvital, or demonstrate severe malposition.

  16. An agent-based model of centralized institutions, social network technology, and revolution.

    PubMed

    Makowsky, Michael D; Rubin, Jared

    2013-01-01

    This paper sheds light on the general mechanisms underlying large-scale social and institutional change. We employ an agent-based model to test the impact of authority centralization and social network technology on preference falsification and institutional change. We find that preference falsification is increasing with centralization and decreasing with social network range. This leads to greater cascades of preference revelation and thus more institutional change in highly centralized societies and this effect is exacerbated at greater social network ranges. An empirical analysis confirms the connections that we find between institutional centralization, social radius, preference falsification, and institutional change.

  17. An Agent-Based Model of Centralized Institutions, Social Network Technology, and Revolution

    PubMed Central

    Makowsky, Michael D.; Rubin, Jared

    2013-01-01

    This paper sheds light on the general mechanisms underlying large-scale social and institutional change. We employ an agent-based model to test the impact of authority centralization and social network technology on preference falsification and institutional change. We find that preference falsification is increasing with centralization and decreasing with social network range. This leads to greater cascades of preference revelation and thus more institutional change in highly centralized societies and this effect is exacerbated at greater social network ranges. An empirical analysis confirms the connections that we find between institutional centralization, social radius, preference falsification, and institutional change. PMID:24278280

  18. New prediction equations for the estimation of maxillary mandibular canine and premolar widths from mandibular incisors and mandibular first permanent molar widths: A digital model study

    PubMed Central

    Shahid, Fazal; Khamis, Mohd Fadhli

    2016-01-01

    Objective The primary aim of the study was to generate new prediction equations for the estimation of maxillary and mandibular canine and premolar widths based on mandibular incisors and first permanent molar widths. Methods A total of 2,340 calculations (768 based on the sum of mandibular incisor and first permanent molar widths, and 1,572 based on the maxillary and mandibular canine and premolar widths) were performed, and a digital stereomicroscope was used to derive the the digital models and measurements. Mesiodistal widths of maxillary and mandibular teeth were measured via scanned digital models. Results There was a strong positive correlation between the estimation of maxillary (r = 0.85994, r2 = 0.7395) and mandibular (r = 0.8708, r2 = 0.7582) canine and premolar widths. The intraclass correlation coefficients were statistically significant, and the coefficients were in the strong correlation range, with an average of 0.9. Linear regression analysis was used to establish prediction equations. Prediction equations were developed to estimate maxillary arches based on Y = 15.746 + 0.602 × sum of mandibular incisors and mandibular first permanent molar widths (sum of mandibular incisors [SMI] + molars), Y = 18.224 + 0.540 × (SMI + molars), and Y = 16.186 + 0.586 × (SMI + molars) for both genders, and to estimate mandibular arches the parameters used were Y = 16.391 + 0.564 × (SMI + molars), Y = 14.444 + 0.609 × (SMI + molars), and Y = 19.915 + 0.481 × (SMI + molars). Conclusions These formulas will be helpful for orthodontic diagnosis and clinical treatment planning during the mixed dentition stage. PMID:27226963

  19. Two cases with supernumerary teeth in lower incisor region.

    PubMed

    Yokose, Taishi; Sakamoto, Teruo; Sueishi, Kenji; Yatabe, Kenichi; Tsujino, Keiichirou; Kubo, Shuhei; Yakushiji, Masashi; Yamaguchi, Hideharu

    2006-02-01

    Abnormalities in number of teeth are occasionally noted in clinical cases. Many theories have been proposed as regards the causes of the occurrence of supernumerary teeth, including atavism theory, mechanical tooth germ separation theory, tissue induction theory, and dental laminar morphological disturbance theory. However, none of these theories alone offers a sufficient explanation for this phenomenon. The incidence of supernumerary permanent teeth is approximately 1-3%. These are the maxillary anterior teeth, the maxillary molars, and the maxillo-mandibular premolars in terms of descending order of site of occurrence. On the other hand, incidence in the mandibular anterior tooth area, of which there have been few detailed reports, is about 0.01%, a markedly low value. In this paper, we report two rare cases of supernumerary teeth in the mandibular incisor area. We discuss their etiology and orthodontic treatment, and detail a differential diagnosis between the normal and supernumerary teeth. We found that it was difficult to establish a clear etiology and differentiation between the normal and supernumerary teeth. PMID:16924155

  20. A development-based compartmentalization of the Drosophila central brain

    PubMed Central

    Pereanu, Wayne; Kumar, Abilasha; Jennett, Arnim; Reichert, Heinrich; Hartenstein, Volker

    2010-01-01

    The neuropile of the Drosophila brain is subdivided into anatomically discrete compartments. Compartments are rich in terminal neurite branching and synapses; they are the neuropile domains in which signal processing takes place. Compartment boundaries are defined by more or less dense layers of glial cells, as well as long neurite fascicles. These fascicles are formed during the larval period when the approximately 100 neuronal lineages that constitute the Drosophila central brain differentiate. Each lineage forms an axon tract with a characteristic trajectory in the neuropile; groups of spatially related tracts congregate into the brain fascicles that can be followed from the larva throughout metamorphosis into the adult stage. In this paper we provide a map of the adult brain compartments and the relevant fascicles defining compartmental boundaries. We have identified the neuronal lineages contributing to each fascicle, which allowed us to directly compare compartments of the larval and adult brain. Most adult compartments can be recognized already in the early larval brain where they form a “protomap” of the later adult compartments. Our analysis highlights the morphogenetic changes shaping the Drosophila brain; the data will be important for studies that link early acting genetic mechanisms to the adult neuronal structures and circuits controlled by these mechanisms. PMID:20533357

  1. Chytridiomycosis risk among Central European amphibians based on surveillance data.

    PubMed

    Balá, Vojtech; Vojar, Jirří; Civi, Petr; Andera, Martin; Rozínek, Roman

    2014-11-13

    The Czech Republic hosts a surprisingly rich biodiversity of amphibians representing the majority of amphibian species present in all of Central and Eastern Europe. Surveillance data of Batrachochytrium dendrobatidis (Bd) collected during 2008 to 2012 were analysed for basic patterns of prevalence and infection intensity among species, age groups and localities. In addition, an investigation was made into possible data bias due to varying PCR inhibition. Infection prevalence in the genus Pelophylax was significantly higher than in other sampled taxa, while Bombina and Bufo were infected with intermediate prevalence. Individual mortalities putatively caused by chytridiomycosis were detected in Bombina and Bufo, but not in Pelophylax. Differences among localities were seen to modulate the pathogen's infection rate and influence overall individual infection intensities. PCR inhibition occurred significantly more often in samples from the genus Pelophylax than in other tested taxa (Bufo bufo, B. viridis, Bombina bombina, Pelobates fuscus and Rana dalmatina). Although we found no completely inhibited samples within the genus Bombina, the infection loads were lower in the sample set processed without bovine serum albumin, suggesting some level of PCR inhibition. The combination of high Bd prevalence with no apparent deleterious effect and the high dispersal abilities of water frogs predispose them to act as vectors for chytridiomycosis. It is possible that the role of Pelophylax frogs in the spread of Bd is overlooked due to a large proportion of unrecognized false negatives, but this issue needs further confirmation.

  2. A compilation of partial sequences of randomly selected cDNA clones from the rat incisor.

    PubMed

    Matsuki, Y; Nakashima, M; Amizuka, N; Warshawsky, H; Goltzman, D; Yamada, K M; Yamada, Y

    1995-01-01

    The formation of tooth organs is regulated by a series of developmental programs. We have initiated a genome project with the ultimate goal of identifying novel genes important for tooth development. As an initial approach, we constructed a unidirectional cDNA library from the non-calcified portion of incisors of 3- to 4-week-old rats, sequenced cDNA clones, and classified their sequences by homology search through the GenBank data base and the PIR protein data base. Here, we report partial DNA sequences obtained by automated DNA sequencing on 400 cDNA clones randomly selected from the library. Of the sequences determined, 51% represented sequences of new genes that were not related to any previously reported gene. Twenty-six percent of the clones strongly matched genes and proteins in the data bases, including amelogenin, alpha 1(I) and alpha 2(I) collagen chains, osteonectin, and decorin. Nine percent of clones revealed partial sequence homology to known genes such as transcription factors and cell surface receptors. A significant number of the previously identified genes were expressed redundantly and were found to encode extracellular matrix proteins. Identification and cataloging of cDNA clones in these tissues are the first step toward identification of markers expressed in a tissue- or stage-specific manner, as well as the genetic linkage study of tooth anomalies. Further characterization of the clones described in this paper should lead to the discovery of novel genes important for tooth development. PMID:7876422

  3. Biofilm-based central line-associated bloodstream infections.

    PubMed

    Yousif, Ammar; Jamal, Mohamed A; Raad, Issam

    2015-01-01

    Different types of central venous catheters (CVCs) have been used in clinical practice to improve the quality of life of chronically and critically ill patients. Unfortunately, indwelling devices are usually associated with microbial biofilms and eventually lead to catheter-related bloodstream infections (CLABSIs).An estimated 250,000-400,000 CLABSIs occur every year in the United States, at a rate of 1.5 per 1,000 CVC days and a mortality rate of 12-25 %. The annual cost of caring for patients with CLABSIs ranges from 296 million to 2.3 billion dollars.Biofilm formation occurs on biotic and abiotic surfaces in the clinical setting. Extensive studies have been conducted to understand biofilm formation, including different biofilm developmental stages, biofilm matrix compositions, quorum-sensing regulated biofilm formation, biofilm dispersal (and its clinical implications), and multi-species biofilms that are relevant to polymicrobial infections.When microbes form a matured biofilm within human hosts through medical devices such as CVCs, the infection becomes resistant to antibiotic treatment and can develop into a chronic condition. For that reason, many techniques have been used to prevent the formation of biofilm by targeting different stages of biofilm maturation. Other methods have been used to diagnose and treat established cases of CLABSI.Catheter removal is the conventional management of catheter associated bacteremia; however, the procedure itself carries a relatively high risk of mechanical complications. Salvaging the catheter can help to minimize these complications.In this article, we provide an overview of microbial biofilm formation; describe the involvement of various genetic determinants, adhesion proteins, organelles, mechanism(s) of biofilm formation, polymicrobial infections, and biofilm-associated infections on indwelling intravascular catheters; and describe the diagnosis, management, and prevention of catheter-related bloodstream infections.

  4. School-Based Management in Hong Kong: Centralizing or Decentralizing

    ERIC Educational Resources Information Center

    Pang, I-Wah

    2008-01-01

    This paper examined the debate on a reform of school-based management in Hong Kong, which was to set up the Incorporated Management Committee (IMC) to manage the subsidized school. The nature of the debate during legislation and the characteristics of the reform were examined. The advantages, disadvantages and the implications of the reform were…

  5. A diagnostic dilemma of central skull base osteomyelitis mimicking neoplasia in a diabetic patient

    PubMed Central

    Ganhewa, Aparna Dasunmalee; Kuthubutheen, Jafri

    2013-01-01

    We present a case which illustrates the diagnostic difficulty in distinguishing between osteomyelitis of the central skull base and base of skull tumours. A woman in her early forties presented with seizures and multiple cranial nerve palsies. She also had a background of chronic otalgia and poorly controlled diabetes mellitus. The clinical diagnosis of skull base osteomyelitis (SBO) was made, but both MRI and bone scans were unable to distinguish this from a skull base malignancy on imaging criteria. Eventually biopsies were required to exclude the diagnosis of malignancy and the patient was treated for central SBO. PMID:23355560

  6. Lateral incisor agenesis, canine impaction and characteristics of supernumerary teeth in a South European male population

    PubMed Central

    Delli, Konstantina; Livas, Christos; Bornstein, Michael M.

    2013-01-01

    Objective: To assess the prevalence of lateral incisor agenesis impacted canines and supernumerary teeth in a young adult male population. Materials and Methods: The panoramic radiographs of 1745 military students (mean age: 18.6 ± 0.52 years) who attended the Center of Aviation Medicine of the Armed Forces of Greece during the period 1997-2011 were initially analyzed for lateral incisor agenesis by two observers. After exclusion of the known orthodontic cases, a subgroup of 1636 examinees (mean age: 18.6 ± 0.44 years) was evaluated for canine impaction and supernumerary teeth. Results: Twenty-eight missing lateral incisors were observed in 22 military students, indicating an incidence of 1.3% in the investigated population. No lateral incisor agenesis was detected in the mandibular arch. A prevalence rate of 0.8% was determined for canine impaction in the sample of young adults. The majority of impacted teeth (86.7%) were diagnosed in the maxillary arch. Thirty-five supernumerary teeth were observed in 24 examinees (prevalence rate: 1.5%). The ratio of supernumerary teeth located in the maxilla versus the mandible was 2.2:1. The most common type of supernumerary tooth was the upper distomolar. Conclusion: The prevalence of lateral incisor agenesis, canine impaction, and supernumerary teeth ranged from 0.8 to 1.5% in the sample of male Greek military students. PMID:24926206

  7. Comparison of rates of enamel synthesis in impeded and unimpeded rat incisors.

    PubMed

    Skobe, Z; Heeley, J D; Dobeck, J M; Prostak, K S; Maravelis, L; Stern, D N

    1993-01-01

    Periodic intubations of rats with solutions of fluoride (F) lead to the appearance of bands of disrupted pigmentation in continuously erupting incisors. Distances between fluorotic bands reflect time intervals between intubations. In this experiment, the periodicity of fluorotic banding was used for estimation of the rate of enamel synthesis in impeded and unimpeded rat incisors. Rats kept on a low-F diet and distilled water were intubated two or four times per week with 2 mg NaF/150 g body weight. In a group of rats, one of the mandibular incisors was cut at the gingival margin after two weeks, and intubations were continued for an additional two weeks. In another group of F-intubated rats, incisors were cut or notched at the gingival margin twice, six days apart. Control rats either received the same periodic F intubations or were maintained on the low-F diet without intubation. Measurements of spacing between fluorotic bands were identical in impeded and unimpeded teeth, even though the latter erupted at a faster rate. In an unimpeded mandibular incisors, there was a significant elongation of the secretory zone and a shortening of the pigmentation zone, resulting in reduced pigmentation intensity of the erupted portions of the teeth. The results show that the rate of enamel synthesis is independent of the eruption rate.

  8. Gastrin-releasing peptide expression and its effect on the calcification of developing mouse incisor.

    PubMed

    Lee, Dong-Joon; Jin, Chengri; Kim, Eun-Jung; Lee, Jong-Min; Jung, Han-Sung

    2015-09-01

    Gastrin-releasing peptide (GRP) is considered to be one of the cancer growth factors. This peptide's receptor (GRPR) is known as a G protein-coupled receptor, regulating intracellular calcium storage and releasing signals. This study is the first to investigate the function of GRP during mouse incisor development. We hypothesized that GRP is one of the factors that affects the regulation of calcification during tooth development. To verify the expression pattern of GRP, in situ hybridization was processed during incisor development. GRP was expressed at the late bell stage and hard tissue formation stage in the epithelial tissue. To identify the genuine function of GRP during incisor development, a gain-of-function analysis was performed. After GRP overexpression in culture, the phenotype of ameloblasts, odontoblasts and predentin was altered compared to control group. Moreover, enamel and dentin thickness was increased after renal capsule transplantation of GRP-overexpressed incisors. With these results, we suggest that GRP plays a significant role in the formation of enamel and dentin by regulating ameloblasts and predentin formation, respectively. Thus, GRP signaling is strongly related to calcium acquisition and secretion during mouse incisor development.

  9. The Effect of Changes in Lower Incisor Inclination on Gingival Recession

    PubMed Central

    Kamak, Gulen; Kamak, Hasan; Keklik, Hakan; Gurel, Hakan Gurcan

    2015-01-01

    Aim. Orthodontic treatment may promote development of recessions. The mechanism by which orthodontic treatment influences occurrence of recessions remains unclear. The aim of this study was to test the hypothesis that a change of mandibular incisor inclination promotes development of labial gingival recessions. Materials and Methods. The study sample comprised dental casts and lateral cephalograms obtained from 109 subjects before orthodontic treatment (Tb) and after orthodontic treatment (Ta). Depending on the change of lower incisor inclination during treatment, the subjects were divided into three groups: Retroclination (R), Stable Position (S), and Proclination (P). The presence of gingival recessions of mandibular incisors and clinical crown heights were assessed on plaster models. Results and Conclusions. From Tb to Ta, Inc_Incl showed a statistically significant change in the R, P, and S groups (p < 0.05). Increase of clinical crown heights of the lower incisors (42, 4, and 31) was not statistically significant in any group. The only statistically significant intergroup difference was the greater increase of the clinical crown height of tooth number 32 in the P group in comparison with the R group (p = 0.049). The change of lower incisor inclination during treatment did not lead to development of labial gingival recessions in the study sample. PMID:25961071

  10. Survival rate and fracture strength of maxillary incisors, restored with different kinds of full veneers.

    PubMed

    Stappert, C F J; Stathopoulou, N; Gerds, T; Strub, J R

    2005-04-01

    This in vitro study evaluated the survival rate and fracture strength of different kinds of ceramic full veneers, fabricated with a new experimental press ceramic (EPC VP2117/TC2, Ivoclar-Vivadent AG, Schaan, Liechtenstein). Eighty, caries-free human maxillary central incisors were used as abutments and were randomly divided into one control group and four test-groups of 16 samples each. In group A, unprepared teeth served as control. In the test groups, four different types of full veneer preparations were performed. In test groups B/C, the preparation was maintained in enamel and the contact point was on the tooth/on the veneer, respectively. In test groups D/E, the preparation was extended into dentin and the contact point was on the tooth/on the veneer, respectively. All veneers were adhesively luted using Variolink II (Ivoclar-Vivadent AG). Then, the samples were exposed to the artificial mouth for 1.2 million chewing cycles (49 N). After exposure in the artificial mouth, a survival rate of the abutment teeth of 81-100% was reported among the different groups, but was not significantly different between the groups. However, no failures of the ceramic materials could be recognized. The median fracture strength of group A was 713.3 N, of group B 647.1 N, of group C 594.8 N, of group D 483.8 N and of group E 502.6 N. Among the different groups no significant difference was found. All mean values obtained were within the limits of clinical acceptance, indicating further clinical investigations on full veneers made out of the EPC.

  11. Sequelae of trauma to primary maxillary incisors. I. Complications in the primary dentition.

    PubMed

    Borum, M K; Andreasen, J O

    1998-02-01

    Two hundred and eighty-seven children with a total of 545 traumatized primary upper incisors were followed using standardized procedures until the age of 10. Extraction was the only treatment offered when intervention was necessary. The immediate as well as the long-term consequences of trauma were studied on the basis of this material. Consequences in the primary dentition comprised: color changes (53%), pulp necrosis (25%), pulp canal obliteration (36%), gingival retraction (6%), permanent displacement after luxation (5-22%), pathological root resorption (1-10%) as well as disturbances in physiological root resorption (4%) and, lastly, premature tooth loss (46%). In a multivariate analysis of the development of pulp necross in primary teeth after trauma, the following decisive factors were found: age of the patient at the time of injury, degree of displacement of the tooth as well as the degree of loosening and presence of crown fracture. The factors found to influence development of pulp canal obliteration were: displacement of the tooth at time of injury as well as detectable physiologic root resorption at time of trauma. The presence of crown fracture seemed to decrease the risk of obliteration. The need for scientifically based treatment strategies for managing and reducting complications after trauma in the primary dentition is stressed.

  12. Orthodontic treatment of a mandibular incisor fenestration resulting from a broken retainer.

    PubMed

    Farret, Marcel M; Farret, Milton M B; da Luz Vieira, Gustavo; Assaf, Jamal Hassan; de Lima, Eduardo Martinelli S

    2015-08-01

    This article describes the orthodontic relapse with mandibular incisor fenestration in a 36-year-old man who had undergone orthodontic treatment 21 years previously. The patient reported that his mandibular 3 × 3 bonded retainer had been partially debonded and broken 4 years earlier. The mandibular left lateral incisor remained bonded to the retainer and received the entire load of the incisors; consequently, there was extreme labial movement of the root, resulting in dental avulsion. As part of the treatment, the root was repositioned lingually using a titanium-molybdenum segmented archwire for 8 months, followed by endodontic treatment, an apicoectomy, and 4 months of alignment and leveling of both arches. The treatment outcomes were excellent, and the tooth remained stable, with good integrity of the mesial, distal, and lingual alveolar bones and periodontal ligament. The 1-year follow-up showed good stability of the results. PMID:26232842

  13. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor

    PubMed Central

    Ravi, GR

    2016-01-01

    ABSTRACT Dilaceration of the permanent tooth usually is a consequence of traumatic injuries to the primary teeth. Although it may appear anywhere in the long axis of the tooth, i.e., crown, cementoenamel junction, or root, most often the root is involved. However, crown dilaceration is a rare condition representing 3% of the total injuries. Maxillary incisors are more susceptible to such injury and affected tooth may either erupt buccally or lingually or remain impacted. Hitherto, the treatment options also differ as per the clinical scenario. This article proposes a novel technique of restoring esthetic function of the affected permanent maxillary lateral incisor with crown-root dilaceration while preserving the vitality of tooth. How to cite this article: Achary RC, Ravi GR. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2016;9(2):152-155. PMID:27365939

  14. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor.

    PubMed

    Achary, Ravindranath C; Ravi, G R

    2016-01-01

    Dilaceration of the permanent tooth usually is a consequence of traumatic injuries to the primary teeth. Although it may appear anywhere in the long axis of the tooth, i.e., crown, cementoenamel junction, or root, most often the root is involved. However, crown dilaceration is a rare condition representing 3% of the total injuries. Maxillary incisors are more susceptible to such injury and affected tooth may either erupt buccally or lingually or remain impacted. Hitherto, the treatment options also differ as per the clinical scenario. This article proposes a novel technique of restoring esthetic function of the affected permanent maxillary lateral incisor with crown-root dilaceration while preserving the vitality of tooth. How to cite this article: Achary RC, Ravi GR. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2016;9(2):152-155.

  15. Premature loss of the maxillary primary incisors: effect on speech production.

    PubMed

    Gable, T O; Kummer, A W; Lee, L; Creaghead, N A; Moore, L J

    1995-01-01

    The residual effect of premature loss due to extraction of the four maxillary primary incisors on speech production was studied. The articulation of twenty-six subjects who had their teeth extracted before the age of five years was evaluated at eight, nine, or ten years old and compared with the articulation of an age-matched comparison group with normal exfoliation of their incisors. T-tests for related measures revealed no statistically significant differences between the group with premature loss and the comparison group. These results suggest that loss of maxillary incisors in children younger than five years is not likely to result in defective articulation while the teeth are missing or when the permanent dentition is acquired.

  16. Caribbean and Central American Women's Feminist Inquiry through Theater-Based Action Research

    ERIC Educational Resources Information Center

    Sánchez Ares, Rocío

    2015-01-01

    Feminist action research interrogates gendered dynamics in the development of a collective consciousness. A group of immigrant Latina women (Latinas) from the Caribbean and Central America employed community-based theater as an instrument to mobilize diverse audiences against discriminatory practices and policies. Based on their theater work, I…

  17. Spectrophotometric color evaluation of permanent incisors, canines and molars. A cross-sectional clinical study

    PubMed Central

    POP-CIUTRILA, IOANA-SOFIA; COLOSI, HORATIU ALEXANDRU; DUDEA, DIANA; BADEA, MANDRA EUGENIA

    2015-01-01

    Background and aims An accurate color reproduction represents the final validation level of an esthetic anterior or posterior restoration. The aim of this study was to evaluate the color of permanent maxillary incisors, canines and molars, using a clinical spectrophotometer. Methods The Vita Easyshade Advance 4.0® intraoral spectrophotometer was used by one clinician to determine the color of 369 permanent maxillary incisors, canines and molars. The best matches to Vitapan Classical® and 3D-Master® shade guides were recorded. A one-way analysis of variance and Kruskal-Wallis test were used to compare L*, a*, b*, c* and h* color coordinates among the 3 types of teeth. Differences between the mean values of all color coordinates were evaluated by use of Bonferroni corrections. Color difference (ΔE*) between incisors, canines and molars was calculated from ΔL*, Δa* and Δb* data and the results were compared to ΔE*=3.3 acceptability threshold. Results Except for Δa* and Δh* between canines and molars, statistically significant differences among the mean differences of all color coordinates were found when the 3 types of teeth were compared by pairs. The most frequently measured shades were A1 (48.4%), respectively 1M1 (31.5%) for incisors, B3 (36.6%), respectively 2M3 (39.8%) for canines and B3 (44.7%), respectively 2M3 (52%) for molars. Incisors had the highest lightness values, followed by canines and molars. Molars were the most chromatic with the highest a* and b* values. Conclusions Despite the limitations of this study, color differences among incisors, canines and molars were found to be statistically significant, above the clinical acceptability threshold established. In conclusion, successful esthetic restorations of permanent teeth of the same patient need an individual color assessment and reproduction of every type of tooth. PMID:26733753

  18. Endodontic management of an unusual foreign body in a maxillary central incisor

    PubMed Central

    Chand, Keerthi; Joesph, Sam; Varughese, Jolly Mary; Nair, Mali G; Prasanth, Santhosh

    2013-01-01

    The discovery of foreign bodies in the teeth is often diagnosed accidentally. It is commonly seen in children. These foreign objects may act as a potential source of infection and may later lead to a painful condition. Detailed case history, clinical and radiographic examinations are necessary to come to a conclusion about the nature, size, and location of the foreign body, and the difficulty involved in its retrieval. This paper discusses the types of foreign objects found in and around the teeth and reports an unusual case of a stapler pin in the root canal of a tooth, its retrieval, and associated management of the involved teeth. PMID:24082582

  19. Repair of central incisors on a child with diastema using a novel matrix.

    PubMed

    Small, Bruce W

    2007-01-01

    Using the wax-up and putty matrix simplifies the clinical operations and speeds up the process as well. In addition, the matrix can be saved and used again when repairs become necessary. PMID:17899712

  20. Glass-fiber reinforced composite in management of avulsed central incisor: a case report.

    PubMed

    Aydin, M Yalçin; Kargül, Betül

    2004-01-01

    Reimplantation failure of avulsed anterior tooth in an adolescent patient requires removal of the failed tooth and consideration of restorative options. These options may include a removable partial denture, conventional 3-unit fixed partial denture, implant, or a resin-bonded appliance with a metal substructure (Maryland bridge). The glass-fiber reinforced composite material (everSTICK, StickTech Ltd, Turku, Finland) offers a restorative solution that is conservative and esthetic when compared to other restorations. Advantages include reduction of cost compared to conventional bridges, saving of time, elimination of second visit, ease of application, absence of metal allergy, ease of cleaning, and naturalness of feel. Its limitations include occlusal factors, and the presence of unsuitable abutment teeth. Another traditional contraindication is the presence of diastemas, which may limit the potential esthetic gains. This case of an 11-year-old girl, addresses the indications, preparation guidelines, and restorative procedures for an everSTICK bridge. PMID:15272660

  1. Maxillary lateral incisors with two canals and two separate curved roots

    PubMed Central

    Mohan, Ajit George; Rajesh, Ebenezar A. V.; George, Liza; Sujathan; Josy, Susan Ann

    2012-01-01

    Variation in the roots and root canal anatomy seems to be the norm rather than an exception. For a successful endodontic treatment, a clinician should have a thorough knowledge of the internal and external dental anatomy and its variations. Maxillary lateral incisors usually exhibit single canal with a single root. In this case, clinical examination and radiographs clearly demonstrates the presence of two root canals with two separate curved roots. This case report emphasizes the need for attention during endodontic management of maxillary lateral incisors. PMID:23633825

  2. Agenesis of Maxillary Lateral Incisors: Treatment Involves Much More Than Just Canine Guidance

    PubMed Central

    Silveira, Giordani Santos; Mucha, José Nelson

    2016-01-01

    Objective: In this study, we aimed highlight some clinical features present in patients whose maxillary lateral incisors are missing, and proposed more logical, rational and predictable solutions to inform decision making in rehabilitation procedures. Methods: Literature review and discussion. Conclusion: Choosing the best possible treatment for congenital absence of maxillary lateral incisors depends on the multidisciplinary diagnosis of facial, occlusal, functional and periodontal features. It also depends on the individual long-term stability, and it does not only rely on canine-guided disocclusion. PMID:27006720

  3. Simulating certain aspects of hypogravity: Effects on the mandibular incisors of suspended rats (PULEH model)

    NASA Technical Reports Server (NTRS)

    Simmons, D. J.; Winter, F.; Morey-Holton, E. R.

    1984-01-01

    The effect of a hypogravity simulating model on the rate of mandibular incisor formation, dentinogenesis and, amelogenesis in laboratory rats was studied. The model is the partial unloading by elevating the hindquarters. In this system, rat hindquarters are elevated 30 to 40 deg from the cage floors to completely unload the hindlimbs, but the animals are free to move about using their forelimbs. This model replicates the fluid sift changes which occur during the weightlessness of spaceflight and produces an osteopenia in the weight bearing skeletons. The histogenesis and/or mineralization rates of the mandibular incisor during the first 19d of PULEH in young growing rats are recorded.

  4. The distribution of proliferating cells during odontogenesis in the incisor teeth of Plecoglossus altivelis.

    PubMed

    Kubo, Kin-ya; Yamada, Kumiko; Komada, Noritomo

    2007-08-01

    To examine the distribution of enameloid and proliferating cells during odontogenesis in the incisor teeth of Plecoglossus altivelis, we investigated the distribution of enameloid using alizarin red S and the distribution of bromodeoxyuridine (BrdU)-immunoreactive cells during odontogenesis of the teeth of the fish. Enameloid was present over the entire surface layer of the incisor teeth. BrdU-immunoreactive cells were observed in the inner and outer enamel epithelium, the odontoblasts, and dental papilla cells around the regions currently being formed. These findings suggest that ameloblasts and odontoblasts actively divide around the region currently being formed, suggesting that enameloid and dentin are made in cooperation by ameloblasts and odontoblasts.

  5. Spatial drought reconstructions for central High Asia based on tree rings

    NASA Astrophysics Data System (ADS)

    Fang, Keyan; Davi, Nicole; Gou, Xiaohua; Chen, Fahu; Cook, Edward; Li, Jinbao; D'Arrigo, Rosanne

    2010-11-01

    Spatial reconstructions of drought for central High Asia based on a tree-ring network are presented. Drought patterns for central High Asia are classified into western and eastern modes of variability. Tree-ring based reconstructions of the Palmer drought severity index (PDSI) are presented for both the western central High Asia drought mode (1587-2005), and for the eastern central High Asia mode (1660-2005). Both reconstructions, generated using a principal component regression method, show an increased variability in recent decades. The wettest epoch for both reconstructions occurred from the 1940s to the 1950s. The most extreme reconstructed drought for western central High Asia was from the 1640s to the 1650s, coinciding with the collapse of the Chinese Ming Dynasty. The eastern central High Asia reconstruction has shown a distinct tendency towards drier conditions since the 1980s. Our spatial reconstructions agree well with previous reconstructions that fall within each mode, while there is no significant correlation between the two spatial reconstructions.

  6. Autotransplantation of a Supernumerary Tooth to Replace a Misaligned Incisor with Abnormal Dimensions and Morphology: 2-Year Follow-Up

    PubMed Central

    Tirali, R. Ebru; Sar, Cagla; Ates, Ufuk; Kizilkaya, Metin; Cehreli, S. Burcak

    2013-01-01

    Autotransplantation is a viable treatment option to restore esthetics and function impaired by abnormally shaped teeth when a suitable donors tooth is available. This paper describes the autotransplantation and 2-year follow-up of a supernumerary maxillary incisor as a replacement to a misaligned maxillary incisor with abnormal crown morphology and size. The supernumerary incisor was immediately autotransplanted into the extraction site of the large incisor and was stabilized with a bonded semirigid splint for 2 weeks. Fixed orthodontic therapy was initiated 3 months after autotransplantation. Ideal alignment of the incisors was accomplished after 6 months along with radiographic evidence of apical closure and osseous/periodontal regeneration. In autogenous tooth transplantation, a successful clinical outcome can be achieved if the cases are selected and treated properly. PMID:23476813

  7. Management of a Previously Treated, Calcified, and Dilacerated Maxillary Lateral Incisor: A Combined Nonsurgical/Surgical Approach Assisted by Cone-beam Computed Tomography.

    PubMed

    Dudeja, Pooja Gupta; Dudeja, Krishan Kumar; Garg, Arvind; Srivastava, Dhirendra; Grover, Shibani

    2016-06-01

    Teeth with calcified canals, dilacerated roots, and associated large periradicular lesions involving both cortical plates pose a challenge to dentists. In addition to the nonsurgical endodontic treatment, such teeth may require surgical intervention with concomitant use of bone grafting materials and barrier techniques. These techniques, when combined with the use of a host modulating agent such as platelet-rich fibrin (PRF), may improve the chances of success. A 26-year-old woman was referred for dental treatment with a recurrence of an intraoral sinus tract 2 months after periradicular surgery in the upper anterior region. Clinical and radiographic examinations revealed a calcified and perforated maxillary left lateral incisor with a severely dilacerated root as well as an associated large radiolucent lesion surrounding the roots of the maxillary left central and lateral incisors. A cone-beam computed tomographic scan of the anterior maxilla showed erosion of the labial and palatal cortical plates in the same region. A calcified canal in the lateral incisor was negotiated up to the straight line portion of the canal. Periradicular surgery with root-end resection was performed, and root-end filling was performed with mineral trioxide aggregate. The perforation present on the middle third of the labial surface of the root was repaired with mineral trioxide aggregate, and the canal was cleaned, shaped, and obturated. A PRF scaffold was prepared and used with a collagen membrane and a freeze-dried bone allograft. Follow-up visits after 3 months, 6 months, and 1 year revealed satisfactory clinical and radiographic healing. The combined use of nonsurgical and surgical modes of treatment cannot be overemphasized in this case. The use of PRF along with a bone graft and a barrier membrane may have enhanced the speed of healing and the resolution of periradicular radiolucency by enhancing bone regeneration. PMID:27140443

  8. Molar Incisor Hypomineralization: An Epidemiological Study with Prevalence and Etiological Factors in Indian Pediatric Population

    PubMed Central

    Pandey, Ramesh K

    2016-01-01

    ABSTRACT Aims: To determine the prevalence of molar incisor hypomineralization (MIH) in Indian children and to analyze the possible etiological factors. Materials and methods: First permanent molars and all permanent incisors were examined in 1,369 children aged 8 to 12 years. Examinations were performed by two calibrated observers. The subjects were evaluated using judgment criteria proposed by Weerheijm et al in 2003. The parents accompanying children were given a questionnaire regarding pre- and postnatal history of the children. Results: A total of 191 children were diagnosed with MIH with a prevalence of 13.9%. Chi-square/Fisher exact test was used to compare the dichotomous variables. The relative risk with its 95% confidence interval was calculated to find the risk of clinical infections, such as chicken pox, jaundice, renal disorders, cardiac disorders, and affected molars with sex and type of delivery. Pre- and postnatal history of infection in a child was significantly correlated with the prevalence of MIH. Conclusion: The prevalence of MIH was 13.9% in the age group of 8 to 12 years. Prenatal and postnatal infections play an important role in hypomineralization of molars and incisors. How to cite this article: Mishra A, Pandey RK. Molar Incisor Hypomineralization: An Epidemiological Study with Prevalence and Etiological Factors in Indian Pediatric Population. Int J Clin Pediatr Dent 2016;9(2):167-171. PMID:27365942

  9. An Evolutionarily Conserved Enhancer Regulates Bmp4 Expression in Developing Incisor and Limb Bud

    PubMed Central

    O’Connell, Daniel J.; Aboukhalil, Anton; Li, Xiao; Choe, Sung E.; Ho, Joshua W. K.; Turbe-Doan, Annick; Robertson, Erin A.; Olsen, Bjorn R.; Bulyk, Martha L.; Amendt, Brad A.; Maas, Richard L.

    2012-01-01

    To elucidate the transcriptional regulation of Bmp4 expression during organogenesis, we used phylogenetic footprinting and transgenic reporter analyses to identify Bmp4 cis-regulatory modules (CRMs). These analyses identified a regulatory region located ∼46 kb upstream of the mouse Bmp4 transcription start site that had previously been shown to direct expression in lateral plate mesoderm. We refined this regulatory region to a 396-bp minimal enhancer, and show that it recapitulates features of endogenous Bmp4 expression in developing mandibular arch ectoderm and incisor epithelium during the initiation-stage of tooth development. In addition, this enhancer directs expression in the apical ectodermal ridge (AER) of the developing limb and in anterior and posterior limb mesenchyme. Transcript profiling of E11.5 mouse incisor dental lamina, together with protein binding microarray (PBM) analyses, allowed identification of a conserved DNA binding motif in the Bmp4 enhancer for Pitx homeoproteins, which are also expressed in the developing mandibular and incisor epithelium. In vitro electrophoretic mobility shift assays (EMSA) and in vivo transgenic reporter mutational analyses revealed that this site supports Pitx binding and that the site is necessary to recapitulate aspects of endogenous Bmp4 expression in developing craniofacial and limb tissues. Finally, Pitx2 chromatin immunoprecipitation (ChIP) demonstrated direct binding of Pitx2 to this Bmp4 enhancer site in a dental epithelial cell line. These results establish a direct molecular regulatory link between Pitx family members and Bmp4 gene expression in developing incisor epithelium. PMID:22701669

  10. Growth and the modeling/remodeling of the alveolar bone of the rat incisor.

    PubMed

    Merzel, José; Salmon, Cristiane R

    2008-07-01

    The modeling and remodeling of the rat incisor alveolar bone was followed as the animals grew. The weight of the hemimandible, the length of the socket, and the width of the lower incisor were measured. Osteoclasts and resorption areas were identified by tartrate-resistant acid phosphatase staining. Fluorochrome markers were used to detect and measure osteogenic activities. In the socket related to the periodontal ligament, osteoclasts appeared in scattered sites as well as isolated sites of osteogenic activity, apparently without any variation related to the age of the animals. At the socket facing the dental follicle of young rats, the inner surface was lined with osteoclasts. The number of osteoclasts decreased steadily as the rats grew. In 1-year-old rats, in addition to a few scattered osteoclasts, the internal aspect of the labial wall showed some sites lined with osteoblasts and cement lines indicative of prior bone formation. In young rats, there was a continuous osteogenic activity at the external surface of this wall. The thickness of the labial wall of the socket remained apparently constant; therefore, bone resorption must have occurred at the internal side of the wall. Such osteogenic activity was not observed in old rats. The main forces acting on rat incisors, biting and eruption, are continuous through the life of the animals. Thus, these results indicate that the modeling of the alveolar bone related to the dental follicle, in young rats, can only be associated with another force, specifically, the growth of the incisor. PMID:18461598

  11. Cultivating Urban Naturalists: Teaching Experiential, Place-Based Learning through Nature Journaling in Central Park

    ERIC Educational Resources Information Center

    Warkentin, Traci

    2011-01-01

    Preservice educators engaged in experiential, place-based learning through a semester-long assignment in which they observed a specific place in Central Park in Manhattan, New York, and kept a nature journal. The assignment was organized around two pivotal elements: direct, sensory experience and time in place. Both elements added vital dimensions…

  12. How to decide intervention thresholds based on FRAX in central south Chinese postmenopausal women.

    PubMed

    Zhang, Zhimin; Ou, Yangna; Sheng, Zhifeng; Liao, Eryuan

    2014-03-01

    The FRAX tool has been used to determine possible thresholds for therapeutic intervention; however, there are no FRAX-based intervention thresholds available for China, we proposed that the 10-year probability of major osteoporotic fracture and hip fracture of about 4.0 and 1.3%, respectively, may be acceptable intervention thresholds for central south Chinese postmenopausal women.

  13. Is electrical stimulation of the rat incisor an appropriate experimental nociceptive stimulus?

    PubMed

    Rajaona, J; Dallel, R; Woda, A

    1986-08-01

    The purpose of this study was to determine whether or not tooth pulp stimulation in the rat can selectively activate the pulp nerve fibers without excitation of the periodontium and to decide if the nerve fibers situated in the pulp of the rat's incisor are involved in the nociceptive reactions caused by an intrapulpal stimulation. The experiments were carried out on 20 awake and freely moving Sprague-Dawley rats. Bipolar stimulating electrodes were inserted into the pulp of the left lower incisor and in the right incisor after removal of the pulp. Special cares were taken to avoid, on the right side, direct stimulation of the stump of the apical nerve. The jaw opening reflexes were recorded from the digastric muscles ipsilaterally to the stimulated teeth and the thresholds were compared. Using the same animals, four typical and reproducible nociceptive behavioral reactions caused by a long tooth pulp stimulation were also observed (shock of 0.5 ms at 50 Hz during 1 s). The stimulus intensity was progressively increased, and the threshold of each reaction was recorded. For each of the 20 rats tested, the jaw opening reflex and the nociceptive reactions did not disappear after removal of the pulp, but the threshold of the responses to the stimulation of the nonvital tooth were significantly above the threshold of the responses to the stimulation of the vital incisor. The conclusion was tooth pulp stimulation activates the periodontal nerve fibers in the rat, and stimulation of the incisor pulp is significant in pain study in the rat because the thresholds of the jaw opening reflex and the nociceptive reactions were increased after the tooth pulp tissue was removed. PMID:3732470

  14. Chemical and structural composition of Atlantic Canadian moose (Alces alces) incisors with patterns of high breakage.

    PubMed

    MacKenzie, Cynthia S Kendall; Clough, Michael J; Broders, Hugh G; Tubrett, Mike

    2011-11-15

    Analysis of mammalian teeth can provide information regarding local environmental conditions. For example, a high incidence of breakage and wear within a population may indicate poor food quality. Individuals consuming a diet causing high mechanical stress on their teeth, and/or lacking the appropriate minerals for proper development, could experience degradation of tooth condition. Previously, we documented a high rate of incisor tooth breakage, with age, in two genetically distinct moose populations in Atlantic Canada. In this study, multi-element (11B, 63Cu, 64Zn, 75As, 85Rb, 88Sr, 111Cd, 118Sn, 137Ba, 208Pb, 232Th, and 238U) analyses using laser ablation ICP-MS were performed on moose incisors from multiple North American regions. The purpose was to determine whether the elemental composition of moose incisors varies among regions, and whether that variation is related to tooth degradation among Atlantic Canadian populations. A principal components analysis revealed that nearly 50% of the elemental variation in the inner enamel matrix of moose teeth was explained by three groupings of elements. The element groupings revealed differences among geographic regions, but did not explain the variation between incisors that were broken and those that were not. Regression models indicate that the elemental group which includes Cu, Pb, and Zn is related to decreases in incisal integrity. It is likely that other environmental factors contribute to the occurrence of increased incisor breakage in affected populations. The relationship between food resource quantity and quality, as a function of moose density, is hypothesized to explain loss of tooth integrity.

  15. Organic and inorganic content of fluorotic rat incisors measured by FTIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Porto, Isabel Maria; Saiani, Regina Aparecida; Chan, K. L. Andrew; Kazarian, Sergei G.; Gerlach, Raquel Fernanda; Bachmann, Luciano

    2010-09-01

    Details on how fluoride interferes in enamel mineralization are still controversial. Therefore, this study aimed at analyzing the organic contents of fluorosis-affected teeth using Fourier Transformation Infrared spectroscopy. To this end, 10 male Wistar rats were divided into two groups: one received 45 ppm fluoride in distilled water for 60 days; the other received distilled water only. Then, the lower incisors were removed and prepared for analysis by two FTIR techniques namely, transmission and micro-ATR. For the first technique, the enamel was powdered, whereas in the second case one fluorotic incisor was cut longitudinally for micro-ATR. Using transmission and powdered samples, FTIR showed a higher C-H content in the fluorotic enamel compared with control enamel ( p < 0.05, n = 4 in the flurotic, and n = 5 in the control group). Results from the micro-ATR-FTIR spectroscopic analysis on one longitudinally cut incisor carried out at six points reveal a higher C-H bond content at the surface of the enamel, with values decreasing toward the dentine-enamel junction, and reaching the lowest values at the subsuperficial enamel. These results agree with the morphological data, which indicate that in the rat incisor the fluorotic lesion is superficial, rather than subsuperficial, as in the case of human enamel. The results also suggest that the increased C-H bond content may extend toward the more basal enamel (intraosseous), indicating that fluorotic enamel may intrinsically contain more protein. Finally, particularly when coupled to ATR, FTIR is a suitable tool to study the rat incisor enamel, which is a largely used model of normal and abnormal amelogenesis. Further studies along this line may definitely answer some questions regarding protein content in fluorotic enamel as well as their origin.

  16. Organic and inorganic content of fluorotic rat incisors measured by FTIR spectroscopy.

    PubMed

    Porto, Isabel Maria; Saiani, Regina Aparecida; Chan, K L Andrew; Kazarian, Sergei G; Gerlach, Raquel Fernanda; Bachmann, Luciano

    2010-09-15

    Details on how fluoride interferes in enamel mineralization are still controversial. Therefore, this study aimed at analyzing the organic contents of fluorosis-affected teeth using Fourier Transformation Infrared spectroscopy. To this end, 10 male Wistar rats were divided into two groups: one received 45 ppm fluoride in distilled water for 60 days; the other received distilled water only. Then, the lower incisors were removed and prepared for analysis by two FTIR techniques namely, transmission and micro-ATR. For the first technique, the enamel was powdered, whereas in the second case one fluorotic incisor was cut longitudinally for micro-ATR. Using transmission and powdered samples, FTIR showed a higher C-H content in the fluorotic enamel compared with control enamel (p<0.05, n=4 in the flurotic, and n=5 in the control group). Results from the micro-ATR-FTIR spectroscopic analysis on one longitudinally cut incisor carried out at six points reveal a higher C-H bond content at the surface of the enamel, with values decreasing toward the dentine-enamel junction, and reaching the lowest values at the subsuperficial enamel. These results agree with the morphological data, which indicate that in the rat incisor the fluorotic lesion is superficial, rather than subsuperficial, as in the case of human enamel. The results also suggest that the increased C-H bond content may extend toward the more basal enamel (intraosseous), indicating that fluorotic enamel may intrinsically contain more protein. Finally, particularly when coupled to ATR, FTIR is a suitable tool to study the rat incisor enamel, which is a largely used model of normal and abnormal amelogenesis. Further studies along this line may definitely answer some questions regarding protein content in fluorotic enamel as well as their origin.

  17. Amputation of an Extra-root with an Endodontic Lesion in an Invaginated Vital Maxillary Lateral Incisor: A Rare Case with Seven-year Follow-up.

    PubMed

    Çalışkan, Mehmet Kemal; Asgary, Saeed; Tekin, Uğur; Güneri, Pelin

    2016-01-01

    The developmental abnormality of tooth resulting from the infolding of enamel/dentin into the root is called dens invaginatus. Management of such cases is usually challenging due to the morphological complexity of root canal system. This report presents a rare treatment protocol of a clinical case of Oehler's type III dens invaginatus combined with an endodontic lesion in a vital maxillary lateral incisor. Access to the endodontic lesion located between the central and lateral incisors was achieved by reflection of a full mucoperiosteal flap. Granulomatous tissue as well as aberrant root was removed and the surface of the root and adjacent coronal region were reshaped. Three years later, the patient was orthodontically treated. Seven years after completion of surgical/orthodontic management, the tooth remained asymptomatic and functional with normal periodontium/vital pulp. Radiographically, the healing of the lesion was observed. Actually, vitality of the invaginated tooth and communication between the invagination and the root canal were the most important factors in determining such minimally invasive treatment protocol. Depending on the anatomy of the root canal system, surgical amputation of an invaginated root can be performed to achieve a successful outcome in Oehler's type III dens invaginatus cases, even though it is associated with apical periodontitis. PMID:27141224

  18. Amputation of an Extra-root with an Endodontic Lesion in an Invaginated Vital Maxillary Lateral Incisor: A Rare Case with Seven-year Follow-up

    PubMed Central

    Çalışkan, Mehmet Kemal; Asgary, Saeed; Tekin, Uğur; Güneri, Pelin

    2016-01-01

    The developmental abnormality of tooth resulting from the infolding of enamel/dentin into the root is called dens invaginatus. Management of such cases is usually challenging due to the morphological complexity of root canal system. This report presents a rare treatment protocol of a clinical case of Oehler’s type III dens invaginatus combined with an endodontic lesion in a vital maxillary lateral incisor. Access to the endodontic lesion located between the central and lateral incisors was achieved by reflection of a full mucoperiosteal flap. Granulomatous tissue as well as aberrant root was removed and the surface of the root and adjacent coronal region were reshaped. Three years later, the patient was orthodontically treated. Seven years after completion of surgical/orthodontic management, the tooth remained asymptomatic and functional with normal periodontium/vital pulp. Radiographically, the healing of the lesion was observed. Actually, vitality of the invaginated tooth and communication between the invagination and the root canal were the most important factors in determining such minimally invasive treatment protocol. Depending on the anatomy of the root canal system, surgical amputation of an invaginated root can be performed to achieve a successful outcome in Oehler’s type III dens invaginatus cases, even though it is associated with apical periodontitis. PMID:27141224

  19. One Odontogenic Cell-Population Contributes to the Development of the Mouse Incisors and of the Oral Vestibule.

    PubMed

    Hovorakova, Maria; Lochovska, Katerina; Zahradnicek, Oldrich; Domonkosova Tibenska, Kristina; Dornhoferova, Michaela; Horakova-Smrckova, Lucie; Bodorikova, Silvia

    2016-01-01

    The area of the oral vestibule is often a place where pathologies appear (e.g., peripheral odontomas). The origin of these pathologies is not fully understood. In the present study, we traced a cell population expressing Sonic hedgehog (Shh) from the beginning of tooth development using Cre-LoxP system in the lower jaw of wild-type (WT) mice. We focused on Shh expression in the area of the early appearing rudimentary incisor germs located anteriorly to the prospective incisors. The localization of the labelled cells in the incisor germs and also in the inner epithelial layer of the vestibular anlage showed that the first very early developmental events in the lower incisor area are common to the vestibulum oris and the prospective incisor primordia in mice. Scanning electron microscopic analysis of human historical tooth-like structures found in the vestibular area of jaws confirmed their relation to teeth and thus the capability of the vestibular tissue to form teeth. The location of labelled cells descendant of the early appearing Shh expression domain related to the rudimentary incisor anlage not only in the rudimentary and functional incisor germs but also in the externally located anlage of the oral vestibule documented the odontogenic potential of the vestibular epithelium. This potential can be awakened under pathological conditions and become a source of pathologies in the vestibular area. PMID:27611193

  20. One Odontogenic Cell-Population Contributes to the Development of the Mouse Incisors and of the Oral Vestibule

    PubMed Central

    Hovorakova, Maria; Lochovska, Katerina; Zahradnicek, Oldrich; Domonkosova Tibenska, Kristina; Dornhoferova, Michaela; Horakova-Smrckova, Lucie; Bodorikova, Silvia

    2016-01-01

    The area of the oral vestibule is often a place where pathologies appear (e.g., peripheral odontomas). The origin of these pathologies is not fully understood. In the present study, we traced a cell population expressing Sonic hedgehog (Shh) from the beginning of tooth development using Cre-LoxP system in the lower jaw of wild-type (WT) mice. We focused on Shh expression in the area of the early appearing rudimentary incisor germs located anteriorly to the prospective incisors. The localization of the labelled cells in the incisor germs and also in the inner epithelial layer of the vestibular anlage showed that the first very early developmental events in the lower incisor area are common to the vestibulum oris and the prospective incisor primordia in mice. Scanning electron microscopic analysis of human historical tooth-like structures found in the vestibular area of jaws confirmed their relation to teeth and thus the capability of the vestibular tissue to form teeth. The location of labelled cells descendant of the early appearing Shh expression domain related to the rudimentary incisor anlage not only in the rudimentary and functional incisor germs but also in the externally located anlage of the oral vestibule documented the odontogenic potential of the vestibular epithelium. This potential can be awakened under pathological conditions and become a source of pathologies in the vestibular area. PMID:27611193

  1. The Pocket Medical Record—Do We Need a Centralized Medical Data Base?

    PubMed Central

    Ash, S. R.; Mertz, S. L.; Robinson, F. C.; Ulrich, D. K.

    1982-01-01

    As an alternative to a centralized, digital medical data base, a physically separate, microprocessor-generated, portable medical record has been developed. The medical information of this data base is processed and emphasized by physicians or nurses during their direct entry with the CNS* program. Implementation of the CNS program in several medical institutions has shown that the portable medical data base is “useful in transfer of medical information between such institutions, and the data base is adaptable to a variety of practice settings.

  2. Eigencentrality based on dissimilarity measures reveals central nodes in complex networks

    PubMed Central

    Alvarez-Socorro, A. J.; Herrera-Almarza, G. C.; González-Díaz, L. A.

    2015-01-01

    One of the most important problems in complex network’s theory is the location of the entities that are essential or have a main role within the network. For this purpose, the use of dissimilarity measures (specific to theory of classification and data mining) to enrich the centrality measures in complex networks is proposed. The centrality method used is the eigencentrality which is based on the heuristic that the centrality of a node depends on how central are the nodes in the immediate neighbourhood (like rich get richer phenomenon). This can be described by an eigenvalues problem, however the information of the neighbourhood and the connections between neighbours is not taken in account, neglecting their relevance when is one evaluates the centrality/importance/influence of a node. The contribution calculated by the dissimilarity measure is parameter independent, making the proposed method is also parameter independent. Finally, we perform a comparative study of our method versus other methods reported in the literature, obtaining more accurate and less expensive computational results in most cases. PMID:26603652

  3. Bacterial penetration of the root canal of intact incisor teeth after a simulated traumatic injury.

    PubMed

    Love, R M

    1996-12-01

    One of the aims in treating traumatised teeth is to maintain the vitality of the pulp or allow conditions favourable for pulp revascularisation. However, infection of the pulp and root canal system may prevent this. A number of pathways have been proposed that allow bacteria to invade the root canal system, however most of these pathways cannot account for pulp infection in teeth that did not sustain injury to the periodontal attachment. Enamel/dentine cracks have been proposed as a portal for bacterial invasion of seemingly intact teeth and the aim of this study was to determine if bacteria could invade the root canal system after a simulated traumatic episode. Twenty intact and sound upper central incisors were chosen and prepared. One tooth was selected as a sterility control and the external crown surface of the remaining 19 teeth was subjected to infection with Streptococcus gordonii in a bacterial microleakage model. Over 7 days samples of growth media from the root canal system were taken and tested for bacteria. Sixteen of the teeth did not demonstrate bacterial invasion over the time frame. These teeth were then prepared for testing in a pendulum impact device and were subjected to a blow which did not fracture the crowns or dislodge the tooth from its simulated alveolus. The teeth were then prepared and tested in the bacterial microleakage model. After impact seven of the teeth demonstrated bacterial invasion of the root canal system (P = 0.002). These teeth were then reprepared for testing in the bacterial microleakage model. The crowns of five teeth, selected at random, were coated with two layers of light cured unfilled resin, the remaining two were used as positive controls. All the teeth coated with resin did not demonstrate bacterial invasion (P = 0.00), while the positive controls demonstrated invasion. The results suggested that enamel/dentine infractions were pathways for bacterial invasion of the root canal system of traumatised teeth. The

  4. The variation in the size and shape of the human speech pattern with incisor-tooth relation.

    PubMed

    Howell, P G

    1987-01-01

    A mandibular kinesiograph was used to monitor the movement of the lower incisors of young dentate adults reading a standard text. An interface to a microcomputer which recorded and analysed these movements. As the tracings accumulated on the computer monitor, a characteristic pattern was produced. The dimensions of this speech pattern, or envelope of movement, were measured and correlated with the subject's sex and incisor classification. Four distinct patterns were found and these correlated well with incisor classification. Small differences were noted in the dimensions of the speech envelope between men and women, but these were not significant. PMID:3479100

  5. Evaluation of the Effect of Different Ferrule Designs on Fracture Resistance of Maxillary Incisors Restored with Bonded Posts and Cores

    PubMed Central

    Mahdavi Izadi, Z.; Jalalian, E.; Eyvaz Ziaee, A.; Zamani, L.; Javanshir, B.

    2010-01-01

    Introduction: In cases of severe hard tissue loss, 2 mm circumferential ferrule is difficult to achieve. So in these cases we should use different ferrule designs. This in vitro study investigated the effect of different ferrule designs on the fracture resistance of teeth restored with bonded post and cores. Materials and Methods: Forty freshly-extracted central incisors were endodontically treated. The teeth were randomly divided into four groups; group 1 were teeth with 2 mm circumferential ferrule above the CEJ, group 2 were teeth with 2 mm ferrule only on the palatal side of the teeth, group 3 consisted of teeth with 2 mm ferrule only on the facial side and group 4 were teeth with 2 mm ferrule on the palatal and facial side of teeth with interproximal concavities. All teeth were restored with fiber posts and composite cores. The specimen was mounted on a universal testing machine and compressive load was applied to the long axis of the specimen until failure occurred. Results: The fracture resistance was 533.79 ± 232.28 in group 1, 634.75± 133.35 in group 2, 828.90 ±118.27 in group 3 and 678.78± 160.20 in group 4. The post hoc analysis showed statistically significant difference between groups 1 and 3. Conclusions: The results of this in vitro study showed that facial ferrule increases the fracture resistance of endodontically treated teeth restored with bonded post and cores. PMID:21998789

  6. Development of a Physiologically-Based Pharmacokinetic Model of the Rat Central Nervous System

    PubMed Central

    Badhan, Raj K. Singh; Chenel, Marylore; Penny, Jeffrey I.

    2014-01-01

    Central nervous system (CNS) drug disposition is dictated by a drug’s physicochemical properties and its ability to permeate physiological barriers. The blood–brain barrier (BBB), blood-cerebrospinal fluid barrier and centrally located drug transporter proteins influence drug disposition within the central nervous system. Attainment of adequate brain-to-plasma and cerebrospinal fluid-to-plasma partitioning is important in determining the efficacy of centrally acting therapeutics. We have developed a physiologically-based pharmacokinetic model of the rat CNS which incorporates brain interstitial fluid (ISF), choroidal epithelial and total cerebrospinal fluid (CSF) compartments and accurately predicts CNS pharmacokinetics. The model yielded reasonable predictions of unbound brain-to-plasma partition ratio (Kpuu,brain) and CSF:plasma ratio (CSF:Plasmau) using a series of in vitro permeability and unbound fraction parameters. When using in vitro permeability data obtained from L-mdr1a cells to estimate rat in vivo permeability, the model successfully predicted, to within 4-fold, Kpuu,brain and CSF:Plasmau for 81.5% of compounds simulated. The model presented allows for simultaneous simulation and analysis of both brain biophase and CSF to accurately predict CNS pharmacokinetics from preclinical drug parameters routinely available during discovery and development pathways. PMID:24647103

  7. Unilateral Fusion of Maxillary Lateral Incisor: Diagnosis Using Cone Beam Computed Tomography

    PubMed Central

    Castro, Iury Oliveira; Estrela, Carlos; Souza, Vinícius Rezende; Lopes, Lawrence Gonzaga; de Souza, João Batista

    2014-01-01

    Objective. The objective of this paper is to report a dental fusion case focusing on clinical and radiographic features for the diagnosis. Method. To report a case of right maxillary lateral incisor fusion and a supernumerary tooth, the anatomy of the root canal and dental united portion were assessed by cone beam computed tomography (CBCT). Results. The clinical examination showed dental juxtaposition with the absence of interdental papilla and esthetic impairment in the right maxillary lateral incisor region. The periapical radiography did not provide enough information for the differential diagnosis due to the inherent limitations of this technique. CBCT confirmed the presence of tooth fusion. Conclusion. CBCT examination supports the diagnosis and provides both the identification of changes in tooth development and the visualization of their extent and limits. PMID:25587463

  8. Ageing horses by an examination of their incisor teeth: an (im)possible task?

    PubMed

    Muylle, S; Simoens, P; Lauwers, H

    1996-03-30

    It is generally considered that the age of a horse can be determined by examining its incisor teeth. However, the criteria used to determine age from dental configurations differ widely. The existence of this variety of rules and guidelines was the challenge for the present examination. Detailed descriptions of the incisor teeth of 212 horses of registered age were recorded and the results were compared with the age criteria of various authors. The time at which teeth were shed and the appearance of dental stars seemed to be more reliable features than the disappearance of the cups. The disappearance of the marks occurred four years later than usually stated. Other criteria, such as the presence of the seven-year notch and Galvayne's groove, were too variable and inconsistent to be reliable for the determination of age. PMID:8730689

  9. C-fos expression in rat brain nuclei following incisor tooth movement.

    PubMed

    Magdalena, C M; Navarro, V P; Park, D M; Stuani, M B S; Rocha, M J A

    2004-01-01

    In the rat experimental model, molar tooth movement induced by Waldo's method is known to cause a temporally and spatially defined pattern of brain neuronal activation. Since orthodontic correction usually involves the entire dental arch, we used a spring-activated appliance to extend the investigation to incisors, and we included brain regions related to antinociception. Adjustment of the non-activated appliance on incisors resulted in c-fos expression in the dorsal raphe, peri-aqueductal gray matter, and the locus coeruleus, in addition to trigeminal sensory subnuclei and the parabrachial nucleus, where neuronal activation has already been detected in previous studies on molar tooth movement. Appliance activation with a 70-g force resulted in a further increase in Fos-immunoreactive neurons in the trigeminal sensory subnucleus caudalis and in the dorsal raphe. This result suggests that there is a recruitment of neurons related to nociception and to antinociception when tooth movement is increased.

  10. A Simplified Method for the Restoration of Severely Decayed Primary Incisors

    PubMed Central

    Talebi, Maryam; Parisay, Iman; Khorakian, Fatemeh; Nik, Elham

    2015-01-01

    Objectives: Caries and dental trauma are common reasons for primary anterior teeth restorations in children. This non-control clinical trial was designed to evaluate crown restorations reinforced with a sectioned file post for the restoration of severely damaged primary maxillary incisors. Materials and Methods: Thirty-eight primary maxillary incisors of 12 children (3–5 years old) with early childhood caries (ECC) received composite restorations with a custom made post. The restorations were evaluated using the modified United State Public Health Service (USPHS) criteria. The results were statistically analyzed by descriptive –analytical tests. Results: In this trial, the quality of marginal adaptation decreased after three and 12 months intervals. Recurrent carious lesions were observed during intervals. In terms of restoration retention, only one patient lost both the post and the restoration at the 12-month follow up. Conclusion: The sectioned file post technique showed good retention and aesthetics for restoring severely damaged primary maxillary anterior teeth. PMID:26622269

  11. Interdisciplinary Management of Maxillary Canine Buccal Ectopia Associated with Peg Shaped Lateral Incisor

    PubMed Central

    Sawhny, Asheesh

    2016-01-01

    Aligning a displaced maxillary canine into the dental arch is one of the most complicated problems in orthodontics. In cases of extremely high displacement, the tooth is frequently removed surgically. Because of the upper canines' significance to dental esthetics and functional occlusion, such a decision is a very serious one. The purpose of this report is to illustrate an interdisciplinary approach involving both orthodontic management and conservative tooth restoration. The case was treated through an orthodontic nonextraction fixed appliance mechanotherapy for successful alignment of buccally ectopic upper left canine followed by a conservative direct composite tooth buildup of peg lateral incisor associated with the upper left ectopic canine in a 16-year-old adolescent North Indian female. Posttreatment records demonstrated good alignment of the displaced tooth and restoration of normal anatomy of the peg shaped lateral incisor. PMID:27725890

  12. Ageing horses by an examination of their incisor teeth: an (im)possible task?

    PubMed

    Muylle, S; Simoens, P; Lauwers, H

    1996-03-30

    It is generally considered that the age of a horse can be determined by examining its incisor teeth. However, the criteria used to determine age from dental configurations differ widely. The existence of this variety of rules and guidelines was the challenge for the present examination. Detailed descriptions of the incisor teeth of 212 horses of registered age were recorded and the results were compared with the age criteria of various authors. The time at which teeth were shed and the appearance of dental stars seemed to be more reliable features than the disappearance of the cups. The disappearance of the marks occurred four years later than usually stated. Other criteria, such as the presence of the seven-year notch and Galvayne's groove, were too variable and inconsistent to be reliable for the determination of age.

  13. All the Mandibular Incisors with Double Canals in a Single Patient: A Rare Case

    PubMed Central

    Daokar, Sadashiv G; Kalekar (Yadao), Anita S; Ghunawat, Dhananjay B; Kakde, Deepak D

    2015-01-01

    Single rooted tooth are considered to be the easiest for root canal treatment. The literature has documented cases with single rooted tooth showing more than single canal. Understanding of root canal morphology thus is an important aspect to be considered for successful endodontic treatment. The case presented here shows a rare entity of having double canals in all the mandibular incisors in a single patient. PMID:25859107

  14. Integrated flight/propulsion control system design based on a centralized approach

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Mattern, Duane L.; Bullard, Randy E.

    1989-01-01

    An integrated flight/propulsion control system design is presented for the piloted longitudinal landing task with a modern, statically unstable, fighter aircraft. A centralized compensator based on the Linear Quadratic Gaussian/Loop Transfer Recovery methodology is first obtained to satisfy the feedback loop performance and robustness specificiations. This high-order centralized compensator is then partitioned into airframe and engine sub-controllers based on modal controllability/observability for the compensator modes. The order of the sub-controllers is then reduced using internally-balanced realization techniques and the sub-controllers are simplified by neglecting the insignificant feedbacks. These sub-controllers have the advantage that they can be implemented as separate controllers on the airframe and the engine while still retaining the important performance and stability characteristics of the full-order centralized compensator. Command prefilters are then designed for the closed-loop system with the simplified sub-controllers to obtain the desired system response to airframe and engine command inputs, and the overall system performance evaluation results are presented.

  15. Periostin is an extracellular matrix protein required for eruption of incisors in mice

    SciTech Connect

    Kii, Isao; Amizuka, Norio; Minqi, Li; Kitajima, Satoshi; Saga, Yumiko; Kudo, Akira . E-mail: akudo@bio.titech.ac.jp

    2006-04-14

    A characteristic tooth of rodents, the incisor continuously grows throughout life by the constant formation of dentin and enamel. Continuous eruption of the incisor is accompanied with formation of shear zone, in which the periodontal ligament is remodeled. Although the shear zone plays a role in the remodeling, its molecular biological aspect is barely understood. Here, we show that periostin is essential for formation of the shear zone. Periostin {sup -/-} mice showed an eruption disturbance of incisors. Histological observation revealed that deletion of periostin led to disappearance of the shear zone. Electron microscopy revealed that the disappearance of the shear zone resulted from a failure in digestion of collagen fibers in the periostin {sup -/-} mice. Furthermore, immunohistochemical analysis using anti-periostin antibodies demonstrated the restricted localization of periostin protein in the shear zone. Periostin is an extracellular matrix protein, and immunoelectron microscopy showed a close association of periostin with collagen fibrils in vivo. These results suggest that periostin functions in the remodeling of collagen matrix in the shear zone.

  16. Upper lip changes correlated to maxillary incisor retraction--a metallic implant study.

    PubMed

    Ramos, Adilson Luiz; Sakima, Maurício Tatsuei; Pinto, Ary dos Santos; Bowman, S Jay

    2005-07-01

    The soft tissue changes after the extraction of maxillary first premolars and subsequent anterior tooth retraction were evaluated for 16 Class II, division 1 patients. Pre- and posttreatment lateral head cephalograms were evaluated using superimpositions on Björk-type metallic implants in the maxilla. The patient sample was divided into group I patients, those who did exhibit lip seal at rest in the pretreatment cephalogram and group II patients, those who did not exhibit lip seal at rest in the pretreatment cephalogram. Upper incisor retraction was followed by a similar ratio of upper lip retraction in both the lip seal and nonsealed groups (1:0.75 and 1:0.70 mean ratios, respectively). However, those without lip seal did demonstrate more retraction at stomion (USt). The final upper lip position (Ls) was reasonably correlated with retraction of the cervical maxillary incisor point (cU1) with determination coefficients of 63.6% in the lip sealed and 68.5% in the lip incompetent groups. Although labial and nasolabial angles tended to open after incisor retraction, there was little predictability for this response.

  17. Interproximal wear versus incisors extraction to solve anterior lower crowding: A systematic review

    PubMed Central

    de Almeida, Natália Valli; Silveira, Giordani Santos; Pereira, Daniele Masterson Tavares; Mattos, Claudia Trindade; Mucha, José Nelson

    2015-01-01

    OBJECTIVE: To determine by means of a systematic review the best treatment, whether interproximal wear or incisor extraction, to correct anterior lower crowding in Class I patients in permanent dentition. METHODS: A literature review was conducted using MEDLINE, Scopus and Web of Science to retrieve studies published between January 1950 and October 2013. In selecting the sample, the following inclusion criteria were applied: studies involving interproximal wear and/or extraction of mandibular incisors, as well as Class I cases with anterior lower crowding in permanent dentition. RESULTS: Out of a total of 943 articles found after excluding duplicates, 925 were excluded after abstract analysis. After full articles were read, 13 were excluded by the eligibility criteria and one due to methodological quality; therefore, only fours articles remained: two retrospective and two randomized prospective studies. Data were collected, analyzed and organized in tables. CONCLUSION: Both interproximal wear and mandibular incisor extraction are effective in treating Class I malocclusion in permanent dentition with moderate anterior lower crowding and pleasant facial profile. There is scant evidence to determine the best treatment option for each case. Clinical decision should be made on an individual basis by taking into account dental characteristics, crowding, dental and oral health, patient's expectations and the use of set-up models. PMID:25741827

  18. Soft Tissue Stability around Single Implants Inserted to Replace Maxillary Lateral Incisors: A 3D Evaluation

    PubMed Central

    Mangano, F. G.; Picciocchi, G.; Park, K. B.

    2016-01-01

    Purpose. To evaluate the soft tissue stability around single implants inserted to replace maxillary lateral incisors, using an innovative 3D method. Methods. We have used reverse-engineering software for the superimposition of 3D surface models of the dentogingival structures, obtained from intraoral scans of the same patients taken at the delivery of the final crown (S1) and 2 years later (S2). The assessment of soft tissues changes was performed via calculation of the Euclidean surface distances between the 3D models, after the superimposition of S2 on S1; colour maps were used for quantification of changes. Results. Twenty patients (8 males, 12 females) were selected, 10 with a failing/nonrestorable lateral incisor (test group: immediate placement in postextraction socket) and 10 with a missing lateral incisor (control group: conventional placement in healed ridge). Each patient received one immediately loaded implant (Anyridge®, Megagen, Gyeongbuk, South Korea). The superimposition of the 3D surface models taken at different times (S2 over S1) revealed a mean (±SD) reduction of 0.057 mm (±0.025) and 0.037 mm (±0.020) for test and control patients, respectively. This difference was not statistically significant (p = 0.069). Conclusions. The superimposition of the 3D surface models revealed an excellent peri-implant soft tissue stability in both groups of patients, with minimal changes registered along time. PMID:27298621

  19. Effectiveness of three methods for evaluating root canal anatomy of mandibular incisors.

    PubMed

    Prado, Marina C; Gusman, Heloisa; Belladonna, Felipe G; Prado, Maíra; Ormiga, Fabíola

    2016-01-01

    This study compared the effectiveness of clinical observation, clinical microscopic observation, and tooth-clearing technique in determining the number of canals in mandibular incisors. Root canal ramifications were also analyzed. Using clinical and microscopic analyses, we determined the number of canal entrances in 277 mandibular incisors. In addition, tooth-clearing technique was used to determine the number of canals and frequency of ramifications in the samples. The kappa coefficient was used to compare the different methods with regard to frequency of canals. Most teeth had one canal entrance. The proportion of teeth with two canals was 23.5% by tooth-clearing analysis, 5.8% by clinical microscopy, and 1.1% by clinical analysis. A large number of samples had some type of ramification (40.1%), and most ramifications were present in teeth with two canals. The most frequent ramification was lateral canals (8.3%). Clinical microscopy improved identification of a second canal in mandibular incisors. However, it did not identify second canals in all teeth with two canals. (J Oral Sci 58, 347-351, 2016). PMID:27665973

  20. The Multidisciplinary Management of Fused Maxillary Lateral Incisor with a Supernumerary Tooth in Cleft Lip Adolescence

    PubMed Central

    Yagci, Ahmet; Cantekin, Kenan; Buyuk, Suleyman Kutalmis; Pala, Kansad

    2014-01-01

    Fusion, an uncommon anomaly of the hard dental tissues, is potentially the cause of clinical problems related to esthetics, tooth spacing, and other periodontal complications. This paper describes a multidisciplinary approach involving surgical, endodontic, restorative, and orthodontic attention for the successful, functional, and esthetic rehabilitation of a maxillary left lateral incisor fused with a supernumerary tooth in unilateral cleft lip adolescence in contralateral side. After clinical and radiographic examinations, a fusion between the left maxillary lateral incisor and a supernumerary tooth was diagnosed in the patient, and a small connection was detected between the pulp systems of the two root canals. The case reported in this paper presents the successful resolution of a fused maxillary lateral incisor with a supernumerary tooth, using endodontic, surgical, restorative, and orthodontic management. The decision made in extracting or retaining the fused tooth depends on the arch discrepancy and esthetic needs. Future studies, with long-term followup, will be helpful in evaluating the long-term efficacy of the different treatment options. PMID:24516763

  1. On the cutting edge of organ renewal: identification, regulation and evolution of incisor stem cells

    PubMed Central

    Hu, Jimmy Kuang-Hsien; Mushegyan, Vagan; Klein, Ophir D.

    2014-01-01

    The rodent incisor is one of a number of organs that grow continuously throughout the life of an animal. Continuous growth of the incisor arose as an evolutionary adaptation to compensate for abrasion at the distal end of the tooth. The sustained turnover of cells that deposit the mineralized dental tissues is made possible by epithelial and mesenchymal stem cells residing at the proximal end of the incisor. A complex network of signaling pathways and transcription factors regulates the formation, maintenance, and differentiation of these stem cells during development and throughout adulthood. Research over the past 15 years has led to significant progress in our understanding of this network, which includes FGF, BMP, Notch, and Hh signaling, as well as cell adhesion molecules and microRNAs. This review surveys key historical experiments that laid the foundation of the field and discusses more recent findings that definitively identified the stem cell population, elucidated the regulatory network, and demonstrated possible genetic mechanisms for the evolution of continuously growing teeth. PMID:24307456

  2. Soft Tissue Stability around Single Implants Inserted to Replace Maxillary Lateral Incisors: A 3D Evaluation.

    PubMed

    Mangano, F G; Luongo, F; Picciocchi, G; Mortellaro, C; Park, K B; Mangano, C

    2016-01-01

    Purpose. To evaluate the soft tissue stability around single implants inserted to replace maxillary lateral incisors, using an innovative 3D method. Methods. We have used reverse-engineering software for the superimposition of 3D surface models of the dentogingival structures, obtained from intraoral scans of the same patients taken at the delivery of the final crown (S1) and 2 years later (S2). The assessment of soft tissues changes was performed via calculation of the Euclidean surface distances between the 3D models, after the superimposition of S2 on S1; colour maps were used for quantification of changes. Results. Twenty patients (8 males, 12 females) were selected, 10 with a failing/nonrestorable lateral incisor (test group: immediate placement in postextraction socket) and 10 with a missing lateral incisor (control group: conventional placement in healed ridge). Each patient received one immediately loaded implant (Anyridge®, Megagen, Gyeongbuk, South Korea). The superimposition of the 3D surface models taken at different times (S2 over S1) revealed a mean (±SD) reduction of 0.057 mm (±0.025) and 0.037 mm (±0.020) for test and control patients, respectively. This difference was not statistically significant (p = 0.069). Conclusions. The superimposition of the 3D surface models revealed an excellent peri-implant soft tissue stability in both groups of patients, with minimal changes registered along time. PMID:27298621

  3. Effect of single-dose amoxicillin on rat incisor odontogenesis: a morphological study.

    PubMed

    Kumazawa, Kaido; Sawada, Takashi; Yanagisawa, Takaaki; Shintani, Seikou

    2012-06-01

    The effect of exposure to amoxicillin on tooth development remains to be elucidated. The purpose of this study was to investigate the effect of amoxicillin on rat incisor odontogenesis. Male Wistar rats weighing approximately 100 g were given a single intraperitoneal injection of 3.0 g/kg body weight amoxicillin. One week after injection, the rats were fixed, and the lower incisors were demineralized and prepared into paraffin sections for light microscopy (LM) and immunohistochemistry. Undemineralized samples were embedded in resin and ground for processing for contact microradiography (CMR) and scanning electron microscopy (SEM). Serum calcium, phosphate, and magnesium concentrations were measured. At 1 week after amoxicillin administration, LM, CMR, and SEM revealed a clear increase in the area of interglobular dentin, representing disruption of mineralization by odontoblasts. Immunohistochemistry demonstrated moderate levels of the small integrin-binding ligand N-linked glycoprotein family dentin matrix protein 1 in large areas of interglobular dentin. On the other hand, no morphological alteration or hypomineralization was observed in the enamel. Serum calcium values showed no significant differences between the control and experimental rats during the experimental period although both serum phosphate and magnesium levels increased at day 1 after amoxicillin injection. The results suggest that a single dose of amoxicillin specifically affects normal tooth dentin mineralization, but not enamel mineralization in rat incisor odontogenesis. The present results further our understanding of the clinical association between dentin abnormality and amoxicillin exposure during tooth development.

  4. A Digital Stereomicroscopic Study of the Radicular Wall Thickness of Two-Canal Mandibular Incisors

    PubMed Central

    Khedmat, Sedigheh; Mohamadian, Sohayla; Kharrazifard, Mohamad Javad

    2015-01-01

    Objectives: This study aimed to assess the radicular wall thickness in mandibular incisors with two canals and find the maximum and minimum thickness to prevent root canal treatment (RCT) procedural errors. Materials and Methods: A total of 160 extracted mandibular incisors were selected and radiographed; out of which, 55 had two canals. Three parallel transverse sections were made in each tooth at 1mm below the cementoenamel junction (CEJ), mid-root and 1 millimeter to the apex. Specimens were evaluated under a stereomicroscope and the thickness of radicular walls in each section was determined for the buccal, lingual and proximal surfaces. Data were statistically analyzed using Pearson’s correlation coefficient test. Results: The thickness of radicular wall decreased from the cervical towards the apex. In all three sections (cervical, mid-root and apical), the thickness of lingual wall was significantly greater than the buccal wall. Also, the thickness of buccal and lingual walls was significantly higher than that of the proximal walls. Conclusion: The lingual radicular wall had the highest thickness in two-canal mandibular incisors. Therefore, in these teeth, the lingual canal is a better choice for post placement. PMID:26877738

  5. Central-force decomposition of spline-based modified embedded atom method potential

    NASA Astrophysics Data System (ADS)

    Winczewski, S.; Dziedzic, J.; Rybicki, J.

    2016-10-01

    Central-force decompositions are fundamental to the calculation of stress fields in atomic systems by means of Hardy stress. We derive expressions for a central-force decomposition of the spline-based modified embedded atom method (s-MEAM) potential. The expressions are subsequently simplified to a form that can be readily used in molecular-dynamics simulations, enabling the calculation of the spatial distribution of stress in systems treated with this novel class of empirical potentials. We briefly discuss the properties of the obtained decomposition and highlight further computational techniques that can be expected to benefit from the results of this work. To demonstrate the practicability of the derived expressions, we apply them to calculate stress fields due to an edge dislocation in bcc Mo, comparing their predictions to those of linear elasticity theory.

  6. Evidence-based measures to prevent central line-associated bloodstream infections: a systematic review 1

    PubMed Central

    Perin, Daniele Cristina; Erdmann, Alacoque Lorenzini; Higashi, Giovana Dorneles Callegaro; Sasso, Grace Teresinha Marcon Dal

    2016-01-01

    ABSTRACT Objective: to identify evidence-based care to prevent CLABSI among adult patients hospitalized in ICUs. Method: systematic review conducted in the following databases: PubMed, Scopus, Cinahl, Web of Science, Lilacs, Bdenf and Cochrane Studies addressing care and maintenance of central venous catheters, published from January 2011 to July 2014 were searched. The 34 studies identified were organized in an instrument and assessed by using the classification provided by the Joanna Briggs Institute. Results: the studies presented care bundles including elements such as hand hygiene and maximal barrier precautions; multidimensional programs and strategies such as impregnated catheters and bandages and the involvement of facilities in and commitment of staff to preventing infections. Conclusions: care bundles coupled with education and the commitment of both staff and institutions is a strategy that can contribute to decreased rates of central line-associated bloodstream infections among adult patients hospitalized in intensive care units. PMID:27598378

  7. Assessing the ecological base and peak flow of the alpine streams in Central Taiwan

    NASA Astrophysics Data System (ADS)

    Wei, C.; Yang, P. S.; Tian, P. L.

    2009-04-01

    The ecological base and peak flow are crucial for the assessment and design for habitat rehabilitation and recovery. The amount of discharge affects the aquatic creatures and may severely damage the existence and balance of the community under extreme conditions. Aquatic insects are selected as the target species in this study to evaluate the influence of the discharge and to estimate the ecological base and peak flow. The distribution of the number of species and abundance (density) versus discharge is assessed to define the critical discharge. Two streams located at the alpine area in central Taiwan are selected as the study area to evaluate the base and peak flow. From the preliminary data (Aug 2008 to Dec 2008) collected from one stream Creek C originating from Sitou Area in Central Taiwan shows that the abundance of several species varies with the discharge. The dominate family and genus of aquatic insects is Baetidae (Order Ephemeroptera) and Baetis spp. that accounts for 32.47% and 31.11%, respectively. The Hilsenhoff family biotic index (FBI) shows that the water quality is classified to "Good" and "Very Good" level while the river pollution index (RPI) indicates that the stream is non-polluted. The discharge of base flow interpreted from the 95% curve of duration for the daily discharge is 0.0234 cms. Consistent observations are yet to be collected to yield more accurate result and ecological peak flow in rainy and typhoon seasons.

  8. High-order central Hermite WENO schemes: Dimension-by-dimension moment-based reconstructions

    NASA Astrophysics Data System (ADS)

    Tao, Zhanjing; Li, Fengyan; Qiu, Jianxian

    2016-08-01

    In this paper, a class of high-order central finite volume schemes is proposed for solving one- and two-dimensional hyperbolic conservation laws. Formulated on staggered meshes, the methods involve Hermite WENO (HWENO) spatial reconstructions, and Lax-Wendroff type discretizations or the natural continuous extension of Runge-Kutta methods in time. Differently from the central Hermite WENO methods we developed previously in Tao et al. (2015) [34], the spatial reconstructions, a core ingredient of the methods, are based on the zeroth-order and the first-order moments of the solution, and are implemented through a dimension-by-dimension strategy when the spatial dimension is higher than one. This leads to much simpler implementation of the methods in higher dimension and better cost efficiency. Meanwhile, the proposed methods have the attractive features of the general central Hermite WENO methods such as being compact in reconstruction and requiring neither flux splitting nor numerical fluxes, while being accurate and essentially non-oscillatory. A collection of one- and two-dimensional numerical examples is presented to demonstrate high resolution and robustness of the methods in capturing smooth and non-smooth solutions.

  9. Nasomaxillary osteotomy in lesions of the central compartment of the middle cranial base.

    PubMed

    Karci, B; Oner, K; Günhan, O; Ovül, I; Bilgen, C

    2001-09-01

    The pituitary fossa, sphenoid rostrum, sphenoid sinus, nasopharynx, pterygopalatine fossa and clivus are the components of the central compartment of the middle cranial base. It is a surgical challenge to gain access to this region. This fact has led to the development of a number of surgical procedures reported in the literature. However, none of these techniques can provide a wide and direct exposure to the middle cranial fossa without morbidity on its own. In this report, nasomaxillary osteotomy is described as a satisfactory alternative to reach the middle cranial fossa. With the nasomaxillary osteotomy technique, a wide access can be obtained to the central compartment of the skull base, caudally till the inferior clivus and upper cervical vertebrae (C1, C2). Since bilateral, internal carotid arteries are in sight laterally, the technique provides a secure resection of tumors with marked lateral extensions. Repositioning the translocated bone segment, surrounding the apertura piriformis, results in satisfactory cosmesis postoperatively. The technique is discussed on the basis of eight cases with the histopathological diagnosis of squamous cell carcinoma (1 case), olfactory neuroblastoma (2 cases), chordoma (2 cases) and juvenile nasopharyngeal angiofibroma (3 cases). No vascular complication has been encountered. One chordoma patient died of the disease in the follow-up period. All other cases, including one squamous cell carcinoma patient, are alive and disease-free without cosmetic deformity. In conclusion, nasomaxillary osteotomy provides a wide and direct exposure to the central compartment of the skull base in a relatively short period of time, securing the vascular and neural structures. Besides, it offers the advantage that it can be combined with other techniques in extensive tumors, while cosmesis and nasal functions are preserved.

  10. Modeling infection transmission in primate networks to predict centrality-based risk.

    PubMed

    Romano, Valéria; Duboscq, Julie; Sarabian, Cécile; Thomas, Elodie; Sueur, Cédric; MacIntosh, Andrew J J

    2016-07-01

    Social structure can theoretically regulate disease risk by mediating exposure to pathogens via social proximity and contact. Investigating the role of central individuals within a network may help predict infectious agent transmission as well as implement disease control strategies, but little is known about such dynamics in real primate networks. We combined social network analysis and a modeling approach to better understand transmission of a theoretical infectious agent in wild Japanese macaques, highly social animals which form extended but highly differentiated social networks. We collected focal data from adult females living on the islands of Koshima and Yakushima, Japan. Individual identities as well as grooming networks were included in a Markov graph-based simulation. In this model, the probability that an individual will transmit an infectious agent depends on the strength of its relationships with other group members. Similarly, its probability of being infected depends on its relationships with already infected group members. We correlated: (i) the percentage of subjects infected during a latency-constrained epidemic; (ii) the mean latency to complete transmission; (iii) the probability that an individual is infected first among all group members; and (iv) each individual's mean rank in the chain of transmission with different individual network centralities (eigenvector, strength, betweenness). Our results support the hypothesis that more central individuals transmit infections in a shorter amount of time and to more subjects but also become infected more quickly than less central individuals. However, we also observed that the spread of infectious agents on the Yakushima network did not always differ from expectations of spread on random networks. Generalizations about the importance of observed social networks in pathogen flow should thus be made with caution, since individual characteristics in some real world networks appear less relevant than

  11. Structural analysis of the central Columbia Plateau utilizing radar, digital topography, and magnetic data bases

    SciTech Connect

    Thiessen, R.L.; Eliason, J.R.; Johnson, L.K.; Brougher, C.W. . Dept. of Geology); Foley, M.G.; Beaver, D.E. )

    1991-08-01

    Interest in the Hanford site (Washington) as a nuclear production, power, and waste disposal site has led to generation of a vast quantity of geophysical and remote sensing data sets of the central Columbia Plateau. To data, these various studies, including at least 13 independent magnetic linear and image lineament studies, have not been adequately correlated. Therefore, these studies provide a unique opportunity to compare and contrast the viability of the different geophysical and remote sensing techniques. The geology of the central Columbia Plateau is characterized by subdued topography and limited outcrop, with most of the exposure concentrated in localized folded/faulted mountains (the Yakima folds) and along river canyons. In order to efficiently compare lineament data bases, we have written an automated computer routine that correlated lineaments that are within a user specified distance of each other. The angle between their trends has to be less than an input maximum separation angle. If more than two lineament maps exist for the area, the analyst may also specify the minimum number of times each structure must be seen. The lineament correlation routine was applied to data bases of all aeromagnetic linears as well as lineaments seen on radar and a digital elevation model DEM image. Geologic structures align with a set of three-dimensional planar structures identified with our Geologic Spatial Analysis (GSA) system. The GSA analysis is based upon computer automated detection of valley bottoms as defined by a DEM.

  12. Centralized PI control for high dimensional multivariable systems based on equivalent transfer function.

    PubMed

    Luan, Xiaoli; Chen, Qiang; Liu, Fei

    2014-09-01

    This article presents a new scheme to design full matrix controller for high dimensional multivariable processes based on equivalent transfer function (ETF). Differing from existing ETF method, the proposed ETF is derived directly by exploiting the relationship between the equivalent closed-loop transfer function and the inverse of open-loop transfer function. Based on the obtained ETF, the full matrix controller is designed utilizing the existing PI tuning rules. The new proposed ETF model can more accurately represent the original processes. Furthermore, the full matrix centralized controller design method proposed in this paper is applicable to high dimensional multivariable systems with satisfactory performance. Comparison with other multivariable controllers shows that the designed ETF based controller is superior with respect to design-complexity and obtained performance.

  13. Central FPGA-based destination and load control in the LHCb MHz event readout

    NASA Astrophysics Data System (ADS)

    Jacobsson, R.

    2012-10-01

    The readout strategy of the LHCb experiment is based on complete event readout at 1 MHz. A set of 320 sub-detector readout boards transmit event fragments at total rate of 24.6 MHz at a bandwidth usage of up to 70 GB/s over a commercial switching network based on Gigabit Ethernet to a distributed event building and high-level trigger processing farm with 1470 individual multi-core computer nodes. In the original specifications, the readout was based on a pure push protocol. This paper describes the proposal, implementation, and experience of a non-conventional mixture of a push and a pull protocol, akin to credit-based flow control. An FPGA-based central master module, partly operating at the LHC bunch clock frequency of 40.08 MHz and partly at a double clock speed, is in charge of the entire trigger and readout control from the front-end electronics up to the high-level trigger farm. One FPGA is dedicated to controlling the event fragment packing in the readout boards, the assignment of the farm node destination for each event, and controls the farm load based on an asynchronous pull mechanism from each farm node. This dynamic readout scheme relies on generic event requests and the concept of node credit allowing load control and trigger rate regulation as a function of the global farm load. It also allows the vital task of fast central monitoring and automatic recovery in-flight of failing nodes while maintaining dead-time and event loss at a minimum. This paper demonstrates the strength and suitability of implementing this real-time task for a very large distributed system in an FPGA where no random delays are introduced, and where extreme reliability and accurate event accounting are fundamental requirements. It was in use during the entire commissioning phase of LHCb and has been in faultless operation during the first two years of physics luminosity data taking.

  14. Accentuated lines in the enamel of primary incisors from skeletal remains: A contribution to the explanation of early childhood mortality in a medieval population from Poland.

    PubMed

    Żądzińska, Elżbieta; Lorkiewicz, Wiesław; Kurek, Marta; Borowska-Strugińska, Beata

    2015-07-01

    Physiological disruptions resulting from an impoverished environment during the first years of life are of key importance for the health and biological status of individuals and populations. Studies of growth processes in archaeological populations point to the fact that the main causes of childhood mortality in the past are to be sought among extrinsic factors. Based on this assumption, one would expect random mortality of children, with the deceased individuals representing the entire subadult population. The purpose of this study is to explore whether differences in early childhood survival are reflected in differences in deciduous tooth enamel, which can provide an insight into the development of an individual during prenatal and perinatal ontogeny. Deciduous incisors were taken from 83 individuals aged 2.0-6.5 years from a medieval inhumation cemetery dated AD 1300-1600. Prenatal and postnatal enamel formation time, neonatal line width, and the number of accentuated lines were measured using an optical microscope. The significantly wider neonatal line and the higher frequency of accentuated lines in the enamel of the incisors of children who died at the age of 2-3 years suggest the occurrence of stronger or more frequent stress events in this group. These results indicate that in skeletal populations mortality was not exclusively determined by random external factors. Individuals predisposed by an unfavorable course of prenatal and perinatal growth were more likely to die in early childhood. PMID:25711723

  15. The Central Simulation Committee (CSC): a model for centralization and standardization of simulation-based medical education in the U.S. Army healthcare system.

    PubMed

    Deering, Shad; Sawyer, Taylor; Mikita, Jeffrey; Maurer, Douglas; Roth, Bernard J

    2012-07-01

    In this report, we describe the organizational framework, operations and current status of the Central Simulation Committee (CSC). The CSC was established in 2007 with the goals of standardizing simulation-based training in Army graduate medical education programs, assisting in redeployment training of physicians returning from war, and improving patient safety within the Army Medical Department. Presently, the CSC oversees 10 Simulation Centers, controls over 21,000 sq ft of simulation center space, and provides specialty-specific training in 14 medical specialties. In the past 2 years, CSC Simulation Centers have trained over 50,000 Army medical students, residents, physician assistants, nurses, Soldiers and DoD civilian medical personnel. We hope this report provides simulation educators within the military, and our civilian simulation colleagues, with insight into the workings of our organization and provides an example of centralized support and oversight of simulation-based medical education. PMID:22808890

  16. The Central Simulation Committee (CSC): a model for centralization and standardization of simulation-based medical education in the U.S. Army healthcare system.

    PubMed

    Deering, Shad; Sawyer, Taylor; Mikita, Jeffrey; Maurer, Douglas; Roth, Bernard J

    2012-07-01

    In this report, we describe the organizational framework, operations and current status of the Central Simulation Committee (CSC). The CSC was established in 2007 with the goals of standardizing simulation-based training in Army graduate medical education programs, assisting in redeployment training of physicians returning from war, and improving patient safety within the Army Medical Department. Presently, the CSC oversees 10 Simulation Centers, controls over 21,000 sq ft of simulation center space, and provides specialty-specific training in 14 medical specialties. In the past 2 years, CSC Simulation Centers have trained over 50,000 Army medical students, residents, physician assistants, nurses, Soldiers and DoD civilian medical personnel. We hope this report provides simulation educators within the military, and our civilian simulation colleagues, with insight into the workings of our organization and provides an example of centralized support and oversight of simulation-based medical education.

  17. Central obesity in Yemeni children: A population based cross-sectional study

    PubMed Central

    Bamoshmoosh, Mohamed; Massetti, Luciano; Aklan, Hameed; Al-Karewany, Mahdi; Goshae, Husni Al; Modesti, Pietro Amedeo

    2013-01-01

    AIM: To establish percentile curves and to explore prevalence and correlates of central obesity among Yemeni children in a population based cross-sectional study. METHODS: A representative sample of 3114 Yemeni children (1564 boys, 1550 girls) aged 6-19 years participating in the HYpertension and Diabetes in Yemen study was studied. Data collection was conducted at home by survey teams composed of two investigators of both genders. Study questionnaire included questions about demographics, lifestyle, and medical history. Anthropometric measurements included body weight, height, waist circumference (WC) and hip circumferences. Waist to hip ratio (WHR) and waist-to-height ratio (WHtR) were then calculated. Age and gender specific smoothed percentiles of WC, WHR, and WHtR were obtained using lambda-mu-sigma parameters (LMS method). The independent predictors of central obesity defined as (1) WC percentile ≥ 90th; (2) WHtR ≥ 0.5; or (3) WC percentile ≥ 90th and WHtR ≥ 0.5, were identified at multivariate logistic regression analysis adjusted for age, gender, urban/rural location, years of school education, sedentary/active life-style. RESULTS: Percentile curves for WC, WHR and WHtR are presented. Average WC increased with age for both genders. Boys had a higher WC than girls until early adolescence and thereafter girls had higher values than boys. WHR decreased both in boys and girls until early adolescence. Thereafter while in boys it plateaued in girls it continued to decrease. Mean WHtR decreased until early adolescence with no gender related differences and thereafter increased more in girls than in boys towards adult age. Prevalence of central obesity largely varied according to the definition used which was 10.9% for WC ≥ 90th percentile, 18.3% for WHtR ≥ 0.5, and 8.6% when fulfilling both criteria. At adjusted logistic regression WC ≥ 90th percentiles and WHtR ≥ 0.5 were less prevalent in rural than in urban areas (OR = 0.52, 95%CI: 0.41-0.67 and

  18. New approaches to solve old water problems: community based organizations in Central Asia

    NASA Astrophysics Data System (ADS)

    Nurymgereyev, Kanysh

    2010-05-01

    The dry summer of 2009 has once again shown unsteadiness of economy of the Central-Asian countries, first of all, in agricultural sector and serious dependence of the region on water resources. For example, decreasing of water level in Toktogul reservoir forces the Government of the Kyrgyz Republic, the country where the largest rivers of the Central Asia originate, to the systematic switching-off of the electricity in three regions. Already in the spring of 2009, the experts predicted decreasing of gross production of agriculture in region, especially for the main cultures of cotton and rice. Coupled by natural cataclysms, the problems with water resources management have seriously aggravated conditions that are directly reflected on the livelihood of the rural population of Central Asia. This demands a search for new approaches and methods of solution of the main problems of water resources management. Despite the fact that the main issues of water distribution are solved at a level of the governments of the countries of Central Asia, a serious role in this process is associated directly to local water users. In recent years in some countries of the region, a process of creation of new community based Institutes of water resources management like Water Users Associations of (WUA) has started. The main idea for creation of these organizations is the necessity to involve the local water users like farmers to the process of water resources management and distribution. However, activity of the WUAs in the region has shown certain weaknesses both regarding the legal status of these organizations and institutional development. The main weakness of many WUAs is a lack of opportunities and mechanisms of involving of associations in decision-making processes. Members of WUAs have an opportunity to participate in distribution of water only within the borders of the associations while the main requirement of efficient water resources management is the principle of the

  19. A Comparison of a Centralized Versus De-Centralized Recruitment Schema in Two Community-Based Participatory Research Studies for Cancer Prevention

    PubMed Central

    Adams, Swann Arp; Heiney, Sue P.; Brandt, Heather M.; Wirth, Michael D.; Khan, Samira; Johnson, Hiluv; Davis, Lisa; Wineglass, Cassandra M.; Warren-Jones, Tatiana Y.; Felder, Tisha M.; Drayton, Ruby F.; Davis, Briana; Farr, Deeonna E.; Hébert, James R.

    2014-01-01

    Use of community-based participatory research (CBPR) approaches is increasing with the goal of making more meaningful and impactful advances in eliminating cancer-related health disparities. While many reports have espoused its advantages, few investigations have focused on comparing CBPR-oriented recruitment and retention. Consequently, the purpose of this analysis was to report and compare two different CBPR approaches in two cancer prevention studies. We utilized frequencies and chi-squared tests to compare and contrast subject recruitment and retention for two studies that incorporated a randomized, controlled intervention design of a dietary and physical activity intervention among African Americans. One study utilized a de-centralized approach to recruitment in which primary responsibility for recruitment was assigned to the general AA community of various church partners whereas the other incorporated a centralized approach to recruitment in which a single lay community individual was hired as research personnel to lead recruitment and intervention delivery. Both studies performed equally well for both recruitment and retention (75 and 88% recruitment rates and 71 and 66% retention rates) far exceeding those rates traditionally cited for cancer clinical trials (~5%). The de-centralized approach to retention appeared to result in statistically greater retention for the control participants compared to the centralized approach (77 vs 51%, P<0.01). Consequently, both CBPR approaches appeared to greatly enhance recruitment and retention rates of AA populations. We further note lessons learned and challenges to consider for future research opportunities. PMID:25086566

  20. Mobile devices for community-based REDD+ monitoring: a case study for Central Vietnam.

    PubMed

    Pratihast, Arun Kumar; Herold, Martin; Avitabile, Valerio; de Bruin, Sytze; Bartholomeus, Harm; Souza, Carlos M; Ribbe, Lars

    2012-12-20

    Monitoring tropical deforestation and forest degradation is one of the central elements for the Reduced Emissions from Deforestation and Forest Degradation in developing countries (REDD+) scheme. Current arrangements for monitoring are based on remote sensing and field measurements. Since monitoring is the periodic process of assessing forest stands properties with respect to reference data, adopting the current REDD+ requirements for implementing monitoring at national levels is a challenging task. Recently, the advancement in Information and Communications Technologies (ICT) and mobile devices has enabled local communities to monitor their forest in a basic resource setting such as no or slow internet connection link, limited power supply, etc. Despite the potential, the use of mobile device system for community based monitoring (CBM) is still exceptional and faces implementation challenges. This paper presents an integrated data collection system based on mobile devices that streamlines the community-based forest monitoring data collection, transmission and visualization process. This paper also assesses the accuracy and reliability of CBM data and proposes a way to fit them into national REDD+ Monitoring, Reporting and Verification (MRV) scheme. The system performance is evaluated at Tra Bui commune, Quang Nam province, Central Vietnam, where forest carbon and change activities were tracked. The results show that the local community is able to provide data with accuracy comparable to expert measurements (index of agreement greater than 0.88), but against lower costs. Furthermore, the results confirm that communities are more effective to monitor small scale forest degradation due to subsistence fuel wood collection and selective logging, than high resolution remote sensing SPOT imagery.

  1. Mobile Devices for Community-Based REDD+ Monitoring: A Case Study for Central Vietnam

    PubMed Central

    Pratihast, Arun Kumar; Herold, Martin; Avitabile, Valerio; de Bruin, Sytze; Bartholomeus, Harm; Souza, Carlos M.; Ribbe, Lars

    2013-01-01

    Monitoring tropical deforestation and forest degradation is one of the central elements for the Reduced Emissions from Deforestation and Forest Degradation in developing countries (REDD+) scheme. Current arrangements for monitoring are based on remote sensing and field measurements. Since monitoring is the periodic process of assessing forest stands properties with respect to reference data, adopting the current REDD+ requirements for implementing monitoring at national levels is a challenging task. Recently, the advancement in Information and Communications Technologies (ICT) and mobile devices has enabled local communities to monitor their forest in a basic resource setting such as no or slow internet connection link, limited power supply, etc. Despite the potential, the use of mobile device system for community based monitoring (CBM) is still exceptional and faces implementation challenges. This paper presents an integrated data collection system based on mobile devices that streamlines the community-based forest monitoring data collection, transmission and visualization process. This paper also assesses the accuracy and reliability of CBM data and proposes a way to fit them into national REDD+ Monitoring, Reporting and Verification (MRV) scheme. The system performance is evaluated at Tra Bui commune, Quang Nam province, Central Vietnam, where forest carbon and change activities were tracked. The results show that the local community is able to provide data with accuracy comparable to expert measurements (index of agreement greater than 0.88), but against lower costs. Furthermore, the results confirm that communities are more effective to monitor small scale forest degradation due to subsistence fuel wood collection and selective logging, than high resolution remote sensing SPOT imagery. PMID:23344371

  2. A multidisciplinary treatment of congenitally missing maxillary lateral incisors: a 14-year follow-up case report

    PubMed Central

    de ALMEIDA, Renato Rodrigues; MORANDINI, Ana Carolina Faria; de ALMEIDA-PEDRIN, Renata Rodrigues; de ALMEIDA, Marcio Rodrigues; CASTRO, Renata Cristina Faria Ribeiro; INSABRALDE, Natalia Martins

    2014-01-01

    Absence of the maxillary lateral incisor creates an aesthetic problem which can be managed in various ways. The condition requires careful treatment planning and consideration of the options and outcomes following either space closure or prosthetic replacement. Recent developments in restorative dentistry have warranted a re-evaluation of the approach to this clinical situation. Factors relating both to the patient and the teeth, including the presentation of malocclusion and the effect on the occlusion must be considered. The objective of this study was to describe the etiology, prevalence and alternative treatment modalities for dental agenesis and to present a clinical case of agenesis of the maxillary lateral incisors treated by the closure of excessive spaces and canine re-anatomization. A clinical case is presented to illustrate the interdisciplinary approach between orthodontics and restorative dentistry for improved esthetic results. In this report, the treatment of a girl with a Class II malocclusion of molars and canines with missing maxillary lateral incisors and convex facial profile is shown. Treatment was successfully achieved and included the space closure of the areas corresponding to the missing upper lateral incisors, through movement of the canines and the posterior teeth to mesial by fixed appliances as well as the canines transformation in the maxillary lateral incisors. This is a 14-year follow-up case report involving orthodontics and restorative dentistry in which pretreatment, post-treatment, and long-term follow-up records for the patient are presented. PMID:25466480

  3. CENTERA: A Centralized Trust-Based Efficient Routing Protocol with Authentication for Wireless Sensor Networks †

    PubMed Central

    Tajeddine, Ayman; Kayssi, Ayman; Chehab, Ali; Elhajj, Imad; Itani, Wassim

    2015-01-01

    In this paper, we present CENTERA, a CENtralized Trust-based Efficient Routing protocol with an appropriate authentication scheme for wireless sensor networks (WSN). CENTERA utilizes the more powerful base station (BS) to gather minimal neighbor trust information from nodes and calculate the best routes after isolating different types of “bad” nodes. By periodically accumulating these simple local observations and approximating the nodes' battery lives, the BS draws a global view of the network, calculates three quality metrics—maliciousness, cooperation, and compatibility—and evaluates the Data Trust and Forwarding Trust values of each node. Based on these metrics, the BS isolates “bad”, “misbehaving” or malicious nodes for a certain period, and put some nodes on probation. CENTERA increases the node's bad/probation level with repeated “bad” behavior, and decreases it otherwise. Then it uses a very efficient method to distribute the routing information to “good” nodes. Based on its target environment, and if required, CENTERA uses an authentication scheme suitable for severely constrained nodes, ranging from the symmetric RC5 for safe environments under close administration, to pairing-based cryptography (PBC) for hostile environments with a strong attacker model. We simulate CENTERA using TOSSIM and verify its correctness and show some energy calculations. PMID:25648712

  4. CENTERA: a centralized trust-based efficient routing protocol with authentication for wireless sensor networks.

    PubMed

    Tajeddine, Ayman; Kayssi, Ayman; Chehab, Ali; Elhajj, Imad; Itani, Wassim

    2015-01-01

    In this paper, we present CENTERA, a CENtralized Trust-based Efficient Routing protocol with an appropriate authentication scheme for wireless sensor networks (WSN). CENTERA utilizes the more powerful base station (BS) to gather minimal neighbor trust information from nodes and calculate the best routes after isolating different types of "bad" nodes. By periodically accumulating these simple local observations and approximating the nodes' battery lives, the BS draws a global view of the network, calculates three quality metrics-maliciousness, cooperation, and compatibility-and evaluates the Data Trust and Forwarding Trust values of each node. Based on these metrics, the BS isolates "bad", "misbehaving" or malicious nodes for a certain period, and put some nodes on probation. CENTERA increases the node's bad/probation level with repeated "bad" behavior, and decreases it otherwise. Then it uses a very efficient method to distribute the routing information to "good" nodes. Based on its target environment, and if required, CENTERA uses an authentication scheme suitable for severely constrained nodes, ranging from the symmetric RC5 for safe environments under close administration, to pairing-based cryptography (PBC) for hostile environments with a strong attacker model. We simulate CENTERA using TOSSIM and verify its correctness and show some energy calculations. PMID:25648712

  5. Non-Surgical Root Canal Treatment of Dens Invaginatus 3 in a Maxillary Lateral Incisor

    PubMed Central

    Moradi, Saeed; Donyavi, Zakyeh; Esmaealzade, Mohammad

    2008-01-01

    The aim of this case report was to describe the clinical management of an unusual dens invaginatus type 3. A case of dens invaginatus in a maxillary lateral incisor with a periapical lesion is reported. The patient presented with pain and localized swelling. Despite the complex anatomy and diagnosis of dens invaginatus, non-surgical root canal treatment was performed successfully. Key Learning Points: - Dens invaginatus may be presented in different forms, and the etiology of this phenomenon is not fully understood. - Due to abnormal anatomical configuration, dens invaginatus presents technical difficulties in its clinical management. - Non-surgical root canal treatment can be performed successfully. PMID:24171017

  6. Mandibular lateral incisor with Vertucci Type IV root canal morphological system: A rare case report

    PubMed Central

    Aggarwal, Kanika

    2016-01-01

    Abnormalities in the root canal anatomy are commonly occurring phenomenon. A thorough knowledge of root canal anatomy and its variation is necessary for successful completion of endodontic treatment. Mandibular anteriors are known for having extra canals. The role of genetics and racial variations may result in difference of incidence of root number and canal number. This paper attempts at explaining a rare case of successful endodontic management of two-rooted lateral incisor with awareness of data pertaining to number of canals, knowledge of canal morphology, correct radiographic interpretation, and tactile examination of canal wall which are important in detecting the presence of multiple canals. PMID:27003981

  7. Orthodontic-associated localized gingival recession of lower incisors: who should treat it?

    PubMed

    Chaushu, Stella; Stabholz, Ayala

    2013-07-01

    Gingival recession of lower incisors in the young population has become more prevalent in association with the increased uptake of orthodontic treatment. The two main predisposing factors are thin gingival biotype and bone dehiscence caused by labially displaced roots. Management is sometimes challenging, and the achievement of a successful result requires close cooperation between the orthodontist and periodontist. This article proposes a decision tree, which includes both orthodontic and periodontal considerations, to help the clinician in making the correct diagnosis and choosing the most suitable treatment in post-orthodontic gingival recessions. PMID:24568245

  8. Eruptive malpositioning of the mandibular permanent lateral incisors: three case reports.

    PubMed

    Bradley, E J; Bell, R A

    1990-01-01

    Ectopic eruption of the mandibular permanent lateral incisors involving the loss of the adjacent primary canines is not uncommon, yet the extreme distalization and transposition of such teeth (partial or true) has been reported infrequently. Three cases that illustrate various anomalous eruption-exfoliation patterns are presented. Theories that attempt to explain the etiology of anomalous eruption positions are discussed. However, the multifactorial process of growth and development makes it difficult to identify specific primary etiological factors. Treatment options also are discussed and illustrated, with emphasis on early orthodontic intervention for optimal results.

  9. Branch-Based Centralized Data Collection for Smart Grids Using Wireless Sensor Networks

    PubMed Central

    Kim, Kwangsoo; Jin, Seong-il

    2015-01-01

    A smart grid is one of the most important applications in smart cities. In a smart grid, a smart meter acts as a sensor node in a sensor network, and a central device collects power usage from every smart meter. This paper focuses on a centralized data collection problem of how to collect every power usage from every meter without collisions in an environment in which the time synchronization among smart meters is not guaranteed. To solve the problem, we divide a tree that a sensor network constructs into several branches. A conflict-free query schedule is generated based on the branches. Each power usage is collected according to the schedule. The proposed method has important features: shortening query processing time and avoiding collisions between a query and query responses. We evaluate this method using the ns-2 simulator. The experimental results show that this method can achieve both collision avoidance and fast query processing at the same time. The success rate of data collection at a sink node executing this method is 100%. Its running time is about 35 percent faster than that of the round-robin method, and its memory size is reduced to about 10% of that of the depth-first search method. PMID:26007734

  10. Separating temporal and topological effects in walk-based network centrality

    NASA Astrophysics Data System (ADS)

    Colman, Ewan R.; Charlton, Nathaniel

    2016-07-01

    The recently introduced concept of dynamic communicability is a valuable tool for ranking the importance of nodes in a temporal network. Two metrics, broadcast score and receive score, were introduced to measure the centrality of a node with respect to a model of contagion based on time-respecting walks. This article examines the temporal and structural factors influencing these metrics by considering a versatile stochastic temporal network model. We analytically derive formulas to accurately predict the expectation of the broadcast and receive scores when one or more columns in a temporal edge-list are shuffled. These methods are then applied to two publicly available data sets and we quantify how much the centrality of each individual depends on structural or temporal influences. From our analysis, we highlight two practical contributions: a way to control for temporal variation when computing dynamic communicability and the conclusion that the broadcast and receive scores can, under a range of circumstances, be replaced by the row and column sums of the matrix exponential of a weighted adjacency matrix given by the data.

  11. Branch-based centralized data collection for smart grids using wireless sensor networks.

    PubMed

    Kim, Kwangsoo; Jin, Seong-il

    2015-05-21

    A smart grid is one of the most important applications in smart cities. In a smart grid, a smart meter acts as a sensor node in a sensor network, and a central device collects power usage from every smart meter. This paper focuses on a centralized data collection problem of how to collect every power usage from every meter without collisions in an environment in which the time synchronization among smart meters is not guaranteed. To solve the problem, we divide a tree that a sensor network constructs into several branches. A conflict-free query schedule is generated based on the branches. Each power usage is collected according to the schedule. The proposed method has important features: shortening query processing time and avoiding collisions between a query and query responses. We evaluate this method using the ns-2 simulator. The experimental results show that this method can achieve both collision avoidance and fast query processing at the same time. The success rate of data collection at a sink node executing this method is 100%. Its running time is about 35 percent faster than that of the round-robin method, and its memory size is reduced to about 10% of that of the depth-first search method.

  12. Separating temporal and topological effects in walk-based network centrality.

    PubMed

    Colman, Ewan R; Charlton, Nathaniel

    2016-07-01

    The recently introduced concept of dynamic communicability is a valuable tool for ranking the importance of nodes in a temporal network. Two metrics, broadcast score and receive score, were introduced to measure the centrality of a node with respect to a model of contagion based on time-respecting walks. This article examines the temporal and structural factors influencing these metrics by considering a versatile stochastic temporal network model. We analytically derive formulas to accurately predict the expectation of the broadcast and receive scores when one or more columns in a temporal edge-list are shuffled. These methods are then applied to two publicly available data sets and we quantify how much the centrality of each individual depends on structural or temporal influences. From our analysis, we highlight two practical contributions: a way to control for temporal variation when computing dynamic communicability and the conclusion that the broadcast and receive scores can, under a range of circumstances, be replaced by the row and column sums of the matrix exponential of a weighted adjacency matrix given by the data. PMID:27575154

  13. Physics-based real time ground motion parameter maps: the Central Mexico example

    NASA Astrophysics Data System (ADS)

    Ramirez Guzman, L.; Contreras Ruiz Esparza, M. G.; Quiroz Ramirez, A.; Carrillo Lucia, M. A.; Perez Yanez, C.

    2013-12-01

    We present the use of near real time ground motion simulations in the generation of ground motion parameter maps for Central Mexico. Simple algorithm approaches to predict ground motion parameters of civil protection and risk engineering interest are based on the use of observed instrumental values, reported macroseismic intensities and their correlations, and ground motion prediction equations (GMPEs). A remarkable example of the use of this approach is the worldwide Shakemap generation program of the United States Geological Survey (USGS). Nevertheless, simple approaches rely strongly on the availability of instrumental and macroseismic intensity reports, as well as the accuracy of the GMPEs and the site effect amplification calculation. In regions where information is scarce, the GMPEs, a reference value in a mean sense, provide most of the ground motion information together with site effects amplification using a simple parametric approaches (e.g. the use of Vs30), and have proven to be elusive. Here we propose an approach that includes physics-based ground motion predictions (PBGMP) corrected by instrumental information using a Bayesian Kriging approach (Kitanidis, 1983) and apply it to the central region of Mexico. The method assumes: 1) the availability of a large database of low and high frequency Green's functions developed for the region of interest, using fully three-dimensional and representative one-dimension models, 2) enough real time data to obtain the centroid moment tensor and a slip rate function, and 3) a computational infrastructure that can be used to compute the source parameters and generate broadband synthetics in near real time, which will be combined with recorded instrumental data. By using a recently developed velocity model of Central Mexico and an efficient finite element octree-based implementation we generate a database of source-receiver Green's functions, valid to 0.5 Hz, that covers 160 km x 300 km x 700 km of Mexico, including a

  14. Efficient crop type mapping based on remote sensing in the Central Valley, California

    NASA Astrophysics Data System (ADS)

    Zhong, Liheng

    Most agricultural systems in California's Central Valley are purposely flexible and intentionally designed to meet the demands of dynamic markets. Agricultural land use is also impacted by climate change and urban development. As a result, crops change annually and semiannually, which makes estimating agricultural water use difficult, especially given the existing method by which agricultural land use is identified and mapped. A minor portion of agricultural land is surveyed annually for land-use type, and every 5 to 8 years the entire valley is completely evaluated. So far no effort has been made to effectively and efficiently identify specific crop types on an annual basis in this area. The potential of satellite imagery to map agricultural land cover and estimate water usage in the Central Valley is explored. Efforts are made to minimize the cost and reduce the time of production during the mapping process. The land use change analysis shows that a remote sensing based mapping method is the only means to map the frequent change of major crop types. The traditional maximum likelihood classification approach is first utilized to map crop types to test the classification capacity of existing algorithms. High accuracy is achieved with sufficient ground truth data for training, and crop maps of moderate quality can be timely produced to facilitate a near-real-time water use estimate. However, the large set of ground truth data required by this method results in high costs in data collection. It is difficult to reduce the cost because a trained classification algorithm is not transferable between different years or different regions. A phenology based classification (PBC) approach is developed which extracts phenological metrics from annual vegetation index profiles and identifies crop types based on these metrics using decision trees. According to the comparison with traditional maximum likelihood classification, this phenology-based approach shows great advantages

  15. Spatial and seasonal variability of base flow in the Verde Valley, central Arizona, 2007 and 2011

    USGS Publications Warehouse

    Garner, Bradley D.; Bills, Donald J.

    2012-01-01

    Synoptic base-flow surveys were conducted on streams in the Verde Valley, central Arizona, in June 2007 and February 2011 by the U.S. Geological Survey (USGS), in cooperation with the Verde River Basin Partnership, the Town of Clarkdale, and Yavapai County. These surveys, also known as seepage runs, measured streamflow under base-flow conditions at many locations over a short period of time. Surveys were conducted on a segment of the Verde River that flows through the Verde Valley, between USGS streamflow-gaging stations 09504000 and 09506000, a distance of 51 river miles. Data from the surveys were used to investigate the dominant controls on Verde River base flow, spatial variability in gaining and losing reaches, and the effects that human alterations have on base flow in the surface-water system. The most prominent human alterations in the Verde Valley are dozens of surface-water diversions from streams, including gravity-fed ditch diversions along the Verde River.Base flow that entered the Verde River from the tributary streams of Oak Creek, Beaver Creek, and West Clear Creek was found to be a major source of base flow in the Verde River. Groundwater discharge directly into the Verde River near these three confluences also was an important contributor of base flow to the Verde River, particularly near the confluence with Beaver Creek. An examination of individual reaches of the Verde River in the Verde Valley found three reaches (largely unaffected by ditch diversions) exhibiting a similar pattern: a small net groundwater discharge in February 2011 (12 cubic feet per second or less) and a small net streamflow loss in June 2007 (11 cubic feet per second or less). Two reaches heavily affected by ditch diversions were difficult to interpret because of the large number of confounding human factors. Possible lower and upper bounds of net groundwater flux were calculated for all reaches, including those heavily affected by ditches.

  16. Situational Lightning Climatologies for Central Florida: Phase IV: Central Florida Flow Regime Based Climatologies of Lightning Probabilities

    NASA Technical Reports Server (NTRS)

    Bauman, William H., III

    2009-01-01

    The threat of lightning is a daily concern during the warm season in Florida. Research has revealed distinct spatial and temporal distributions of lightning occurrence that are strongly influenced by large-scale atmospheric flow regimes. Previously, the Applied Meteorology Unit (AMU) calculated the gridded lightning climatologies based on seven flow regimes over Florida for 1-, 3- and 6-hr intervals in 5-, 10-, 20-, and 30-NM diameter range rings around the Shuttle Landing Facility (SLF) and eight other airfields in the National Weather Service in Melbourne (NWS MLB) county warning area (CWA). In this update to the work, the AMU recalculated the lightning climatologies for using individual lightning strike data to improve the accuracy of the climatologies. The AMU included all data regardless of flow regime as one of the stratifications, added monthly stratifications, added three years of data to the period of record and used modified flow regimes based work from the AMU's Objective Lightning Probability Forecast Tool, Phase II. The AMU made changes so the 5- and 10-NM radius range rings are consistent with the aviation forecast requirements at NWS MLB, while the 20- and 30-NM radius range rings at the SLF assist the Spaceflight Meteorology Group in making forecasts for weather Flight Rule violations during Shuttle landings. The AMU also updated the graphical user interface with the new data.

  17. Estimation of Vulnerability of Coastal Regions Using the Central Pressure of Typhoon Based on Global Climate Change

    NASA Astrophysics Data System (ADS)

    Hashimura, R.

    2014-12-01

    Typhoons strike the Kyushu Island in the west of Japan a few times a year. Damage of the maritime structures by storm surges and wind waves induced by typhoon frequently occurs in the western prefectures, for example, Kumamoto Prefecture. The coastline in this prefecture is complex. It faces open and closed seas. The coastline is divided into 4 coastal regions in this paper. Each coast has different topographical characteristics. Using data on the damage of maritime structures caused by typhoons during past 25 years from 1980 to 2004 and the path and central pressure of typhoons during past 110 years from 1902 to 2011, damage of 4 regions along the coast line of Kumamoto Prefecture in Japan for 13 groups of typhoon with different paths is estimated. All typhoons had passed through an area delineated by a latitude of 30° N and 35° N and at a longitude of 127° E and 132° E. The improved Central Pressure (iCP) Method can be used to estimate the damage of maritime structures that will occur along the coast before typhoon strikes. The improved Central Pressure Method is developed based on the 25 years from 1980 to 2004. The estimation of the damage is done using the central pressure of typhoon at a latitude of 30° N. To develop the central pressure method considering the influence of global warming, the data of the central pressure of typhoons based on the 100 years more term is needed. The trend of the depression of central pressure due to the global warming is discussed using the central pressure based on the 110 years term typhoon data. Furthermore, the risk of each coastal regions in a future is estimated using the increasing or decreasing value of central pressure which is determined on this period data.

  18. [The Development of Information Centralization and Management Integration System for Monitors Based on Wireless Sensor Network].

    PubMed

    Xu, Xiu; Zhang, Honglei; Li, Yiming; Li, Bin

    2015-07-01

    Developed the information centralization and management integration system for monitors of different brands and models with wireless sensor network technologies such as wireless location and wireless communication, based on the existing wireless network. With adaptive implementation and low cost, the system which possesses the advantages of real-time, efficiency and elaboration is able to collect status and data of the monitors, locate the monitors, and provide services with web server, video server and locating server via local network. Using an intranet computer, the clinical and device management staffs can access the status and parameters of monitors. Applications of this system provide convenience and save human resource for clinical departments, as well as promote the efficiency, accuracy and elaboration for the device management. The successful achievement of this system provides solution for integrated and elaborated management of the mobile devices including ventilator and infusion pump. PMID:26665944

  19. [Study on the control of dynamic artificial limb ankle based on central pattern generator].

    PubMed

    Guo, Xin; Xu, Caiyu; Li, Mingyue; Su, Longtao

    2014-12-01

    In order to obtain the normal gait for the prosthesis-carrier with the change of external environment and gait, we designed a model of dynamic ankle prosthesis and control system and introduced the strategy of central pattern generator (CPG) about the moving trail of dynamic ankle prosthesis. The dynamic parts, which are incorporated in the model of dynamic ankle prosthesis, provide power in order to have anthropic function and character. The tool of Matlab/simulink was used to simulate the strategy. The simulation results showed that the strategy of CPG learn- ing control in this study was effective and could track the reference trail rapidly and fit the moving trail of a person's normal limb. It can make the prosthetic timely regulation and action, enhance the prosthetic intelligence. It has im- portant practical value for intelligent prosthesis development based on this analysis of technology.

  20. Village-based primary health care in the Central Highlands of Vietnam.

    PubMed

    Barrett, B; Ladinsky, J; Volk, N

    2001-02-01

    This paper describes the first year of an ongoing village health care and economic development project in the Krong Buk district of Dak Lak province in Vietnam's Central Highlands. The project serves 21 villages with a total population of just over 15,000. Most belong to ethnic minority groups. Physicians from the province capital of Boun Me Thuot were trained by a multi-disciplinary team of American health care workers to be trainers and supervisors of 21 village health care workers (VHWs). Two months later, a VHW from each village was trained in primary and preventive health care by the physician-supervisors. Since this initial training, each VHW has been provided with materials, medicines and monthly supervision by the physician-supervisors. The health care component has been complemented by an economic development project based on a system of small loans. Data from the first year of monthly reports and from a baseline survey are presented in this paper.

  1. Measuring Long-Term Impact Based on Network Centrality: Unraveling Cinematic Citations

    PubMed Central

    Spitz, Andreas; Horvát, Emőke-Ágnes

    2014-01-01

    Traditional measures of success for film, such as box-office revenue and critical acclaim, lack the ability to quantify long-lasting impact and depend on factors that are largely external to the craft itself. With the growing number of films that are being created and large-scale data becoming available through crowd-sourced online platforms, an endogenous measure of success that is not reliant on manual appraisal is of increasing importance. In this article we propose such a ranking method based on a combination of centrality indices. We apply the method to a network that contains several types of citations between more than 40,000 international feature films. From this network we derive a list of milestone films, which can be considered to constitute the foundations of cinema. In a comparison to various existing lists of ‘greatest’ films, such as personal favourite lists, voting lists, lists of individual experts, and lists deduced from expert polls, the selection of milestone films is more diverse in terms of genres, actors, and main creators. Our results shed light on the potential of a systematic quantitative investigation based on cinematic influences in identifying the most inspiring creations in world cinema. In a broader perspective, we introduce a novel research question to large-scale citation analysis, one of the most intriguing topics that have been at the forefront of scientific enquiries for the past fifty years and have led to the development of various network analytic methods. In doing so, we transfer widely studied approaches from citation analysis to the the newly emerging field of quantification efforts in the arts. The specific contribution of this paper consists in modelling the multidimensional cinematic references as a growing multiplex network and in developing a methodology for the identification of central films in this network. PMID:25295877

  2. Measuring long-term impact based on network centrality: unraveling cinematic citations.

    PubMed

    Spitz, Andreas; Horvát, Emőke-Ágnes

    2014-01-01

    Traditional measures of success for film, such as box-office revenue and critical acclaim, lack the ability to quantify long-lasting impact and depend on factors that are largely external to the craft itself. With the growing number of films that are being created and large-scale data becoming available through crowd-sourced online platforms, an endogenous measure of success that is not reliant on manual appraisal is of increasing importance. In this article we propose such a ranking method based on a combination of centrality indices. We apply the method to a network that contains several types of citations between more than 40,000 international feature films. From this network we derive a list of milestone films, which can be considered to constitute the foundations of cinema. In a comparison to various existing lists of 'greatest' films, such as personal favourite lists, voting lists, lists of individual experts, and lists deduced from expert polls, the selection of milestone films is more diverse in terms of genres, actors, and main creators. Our results shed light on the potential of a systematic quantitative investigation based on cinematic influences in identifying the most inspiring creations in world cinema. In a broader perspective, we introduce a novel research question to large-scale citation analysis, one of the most intriguing topics that have been at the forefront of scientific enquiries for the past fifty years and have led to the development of various network analytic methods. In doing so, we transfer widely studied approaches from citation analysis to the the newly emerging field of quantification efforts in the arts. The specific contribution of this paper consists in modelling the multidimensional cinematic references as a growing multiplex network and in developing a methodology for the identification of central films in this network.

  3. Results-Based Financing in Mozambique’s Central Medical Store: A Review After 1 Year

    PubMed Central

    Spisak, Cary; Morgan, Lindsay; Eichler, Rena; Rosen, James; Serumaga, Brian; Wang, Angela

    2016-01-01

    ABSTRACT Background: Public health commodity supply chains are typically weak in low-income countries, partly because they have many disparate yet interdependent functions and components. Approaches to strengthening supply chains in such settings have often fallen short—they address technical weaknesses, but not the incentives that motivate staff to perform better. Methods: We reviewed the first year of a results-based financing (RBF) program in Mozambique, which began in January 2013. The program aimed to improve the performance of the central medical store—Central de Medicamentos e Artigos Medicos (CMAM)—by realigning incentives. We completed in-depth interviews and focus group discussions with 33 key informants, including representatives from CMAM and donor agencies, and collected quantitative data on performance measures and use of funds. Implementation: The RBF agreement linked CMAM performance payments to quarterly results on 5 performance indicators related to supply planning, distribution planning, and warehouse management. RBF is predicated on the theory that a combination of carrot and stick—i.e., shared financial incentives, plus increased accountability for results—will spur changes in behavior. Important design elements: (1) indicators were measured against quarterly targets, and payments were made only for indicators that met those targets; (2) targets were set based on documented performance, at levels that could be reasonably attained, yet pushed for improvement; (3) payment was shared with and dependent on all staff, encouraging teamwork and collaboration; (4) results were validated by verifiable data sources; and (5) CMAM had discretion over how to use the funds. Findings: We found that CMAM’s performance continually improved over baseline and that CMAM achieved many of its performance targets, for example, timely submission of quarterly supply and distribution planning reports. Warehouse indicators, such as inventory management and

  4. Tooth-type specific expression of dHAND/Hand2: possible involvement in murine lower incisor morphogenesis.

    PubMed

    Abe, Makoto; Tamamura, Yoshihiro; Yamagishi, Hiroyuki; Maeda, Takashi; Kato, Joji; Tabata, Makoto J; Srivastava, Deepak; Wakisaka, Satoshi; Kurisu, Kojiro

    2002-11-01

    dHAND/Hand2 is a basic helix-loop-helix transcription factor required for the development of the heart, pharyngeal arches, and vasculature and is expressed during embryogenesis. However, there are no reports on the involvement of the dHAND gene in tooth development. In the present study, the expression of dHAND was examined in developing tooth germs of mice. The dHAND gene was expressed in the mesenchyme of the presumptive incisor region of the lower jaw at an early stage and in the mesenchyme of the lower incisor tooth germ at a later stage. However, the dHAND gene was not expressed in the upper incisor region or the upper and lower molar regions during jaw development. Treatment of tooth germ explants of lower incisors with antisense oligodeoxinucleotide (ODN) against dHAND prevented the differentiation of tooth germ cells, including ameloblasts and odontoblasts, the formation of dentin and enamel, and the proliferation of tooth germ cells and increased the apoptosis of tooth germ cells, suggesting that dHAND is essential for these cells during development. On the other hand, the treatment of tooth germ explants of upper incisor and upper or lower molars did not induce severe effects on their development. Treatment of the explants with basic fibroblast growth factor in association with antisense ODN partially rescued them from the effects of antisense ODN. The present results suggest that the dHAND gene plays important roles in type-specific development of lower incisors, and that basic fibroblast growth factor is involved downstream of the dHAND pathway in tooth germ cells. PMID:12397375

  5. Adaptive diversity of incisor enamel microstructure in South American burrowing rodents (family Ctenomyidae, Caviomorpha).

    PubMed

    Vieytes, Emma C; Morgan, Cecilia C; Verzi, Diego H

    2007-09-01

    The aim of this study was to analyse the morphofunctional and adaptive significance of variation in the upper incisor enamel microstructure of South American burrowing ctenomyids and other octodontoid taxa. We studied the specialized subterranean tooth-digger daggerEucelophorus chapalmalensis (Pliocene - Middle Pleistocene), and compared it with other fossil and living ctenomyids with disparate digging adaptations, two fossorial octodontids and one arboreal echimyid. Morphofunctionally significant enamel traits were quite similar among the species studied despite their marked differences in habits, digging behaviour and substrates occupied, suggesting a possible phylogenetic constraint for the Octodontoidea. In this context of relative similarity, the inclination of Hunter-Schreger bands, relative thickness of external index (EI) and prismless enamel zone were highest in daggerEucelophorus, in agreement with its outstanding craniomandibular tooth-digging specialization. Higher inclination of Hunter-Schreger bands reinforces enamel to withstand high tension forces, while high external index provides greater resistance to wear. Results suggest increased frequency of incisor use for digging in daggerEucelophorus, which could be related to a more extreme tooth-digging strategy and/or occupancy of hard soils. Higher external index values as recurring patterns in distant clades of tooth-digging rodents support an adaptive significance of this enamel trait.

  6. Re-eruption of an intruded immature permanent incisor with necrotic pulp: a case report.

    PubMed

    Altun, Ceyhan; Güven, Günseli; Cehreli, Zafer C; Gurbuz, Taskin; Aydin, Cumhur

    2008-01-01

    Intrusive luxation is a serious dental injury that causes damage to the pulp and supporting structures of a tooth because of its dislocation into the alveolar process. This paper presents the case of the re-eruption of a severely intruded immature permanent incisor with a crown-root fracture. A 9-year-old boy was referred to the clinic 1 day after a fall. Clinical and radiographic examinations revealed intrusive luxation of the immature left permanent incisor and a crown-root fracture without pulp exposure. Palatal gingivectomy was done 2 weeks later to facilitate re-eruption. Root canal therapy with intracanal calcium hydroxide paste was initiated during the first month owing to severe spontaneous pain. Six months later, the tooth re-erupted to a normal position, after which root canal obturation and a final esthetic restoration were done. The present case demonstrates the possibility of obtaining re-eruption of intruded immature permanent teeth with interim medication (calcium hydroxide) in the root canal.

  7. Prevalence of lesions in incisors of mule deer from Colorado Springs, Colorado

    SciTech Connect

    Borrero, L.M.; Scanlon, P.F.

    1995-12-31

    Lesions in teeth may be influenced by exposure to fluorides, malnutrition and trauma. Incisors of 228 mule deer (Odocoileus hemionus) taken from the USAF Academy, Colorado Springs, CO during the 1993 hunting season were examined for lesions. A classification scheme (scale = 0--5) for lesions was derived from the method of Shupe et al. 1963. Lesions were present in at least one incisor of 84.6% of deer. Of the deer with lesions, 86% had at least one tooth with very slight effect (one to few white spots), 9.8% had a slight effect (generalized mottling), 2.6% had a moderate effect (generalized mottling and wear), 10.04% had a marked effect (mottling and hypoplasia of the enamel) , and 0.5 % ad severe effects (hypoplasia of the enamel and abnormal wear). Lesions that affect the enamel are produced during the period of formation of the tooth. The severity of lesions depends on the cause and the length of exposure to the causative agent. Generally mottling and hypoplasia of the enamel are associated with fluorosis. The relationship of lesions to bone and tooth fluoride concentrations was examined.

  8. Investigation of the maxillary lateral incisor agenesis and associated dental anomalies in an orthodontic patient population

    PubMed Central

    Kamak, Hasan; Yildirim, Hanifi; Ceylan, Ismail

    2012-01-01

    Objectives: The aim of this study was to investigate the prevalence of maxillary lateral incisor (MLI) agenesis and associated dental anomalies as well as skeletal patterns in an orthodontic population, and then to compare it with the prevalence of these anomalies in the general population. Study Design: The material of the present study included the records of the 3872 orthodontic patients. The followings were recorded for each subject with the agenesis of MLI: Age, sex, unilateral or bilateral absence, anterior-posterior skeletal relationship of the maxilla and mandible, and presence of associated dental anomalies. The occurrence of these anomalies was compared with data previously reported for the general populations. Results: Of the 3872 patients examined, 94 were found to have agenesis of the MLI, representing a prevalence of 2.4 per cent, with females being more frequently observed. The most commonly found associated anomalies were ectopic eruption of maxillary canines and reduced or peg- shaped contralateral incisor with the frequencies of 21.3 per cent and 20.2 per cent respectively. Conclusions: Patients with agenesis of MLI showed a significantly higher prevalence of skeletal Class III malocclusion compared with the general population. The prevalence of ectopic eruption, transposition, and transmigration of the maxillary canine and reduced or peg- shaped MLIs were significantly increased. Key words:Hypodontia, missing laterals, associated dental anomalies. PMID:22549676

  9. Impact of gamma radiation on the eruption rate of rat incisors

    NASA Astrophysics Data System (ADS)

    El-Faramawy, Nabil; El-Haddad, Khaled; Ali, Mohamed; Talaat, Mona

    2015-09-01

    The present work aims to test the effect of gamma radiation on the rate of eruption of rat incisors. One hundred and five adult male albino rats were used and irradiated at different gamma doses. The effects of irradiation were investigated by numerical measurements of eruption rate, histological investigation using light microscope and spectral analysis using Fourier Transform Infra-Red (FTIR). No detectable changes were observed in the groups with smaller radiation doses. There was a significant decrease in the eruption rate starting from the 4 Gy radiation dose. The observation of histological sections revealed disturbance in cellular elements responsible for eruption as well as periodontal disturbance in the samples irradiated with 4 and 6 Gy. FTIR Spectroscopy of control group and the group irradiated by 0.5 Gy showed similar absorption bands with minor differences. However, samples irradiated by 1 Gy showed significant changes in both molecular structure and conformation related to carbonates and hydroxyl groups. From the previous results, it could be concluded that gamma irradiation negatively affects the eruption rate of the rat incisors especially with higher doses.

  10. Adaptive diversity of incisor enamel microstructure in South American burrowing rodents (family Ctenomyidae, Caviomorpha)

    PubMed Central

    Vieytes, Emma C; Morgan, Cecilia C; Verzi, Diego H

    2007-01-01

    The aim of this study was to analyse the morphofunctional and adaptive significance of variation in the upper incisor enamel microstructure of South American burrowing ctenomyids and other octodontoid taxa. We studied the specialized subterranean tooth-digger †Eucelophorus chapalmalensis (Pliocene – Middle Pleistocene), and compared it with other fossil and living ctenomyids with disparate digging adaptations, two fossorial octodontids and one arboreal echimyid. Morphofunctionally significant enamel traits were quite similar among the species studied despite their marked differences in habits, digging behaviour and substrates occupied, suggesting a possible phylogenetic constraint for the Octodontoidea. In this context of relative similarity, the inclination of Hunter–Schreger bands, relative thickness of external index (EI) and prismless enamel zone were highest in †Eucelophorus, in agreement with its outstanding craniomandibular tooth-digging specialization. Higher inclination of Hunter–Schreger bands reinforces enamel to withstand high tension forces, while high external index provides greater resistance to wear. Results suggest increased frequency of incisor use for digging in †Eucelophorus, which could be related to a more extreme tooth-digging strategy and/or occupancy of hard soils. Higher external index values as recurring patterns in distant clades of tooth-digging rodents support an adaptive significance of this enamel trait. PMID:17584181

  11. Theoretical Study of the Effect of Enamel Parameters on Laser-Induced Surface Acoustic Waves in Human Incisor

    NASA Astrophysics Data System (ADS)

    Yuan, Ling; Sun, Kaihua; Shen, Zhonghua; Ni, Xiaowu; Lu, Jian

    2015-06-01

    The laser ultrasound technique has great potential for clinical diagnosis of teeth because of its many advantages. To study laser surface acoustic wave (LSAW) propagation in human teeth, two theoretical methods, the finite element method (FEM) and Laguerre polynomial extension method (LPEM), are presented. The full field temperature values and SAW displacements in an incisor can be obtained by the FEM. The SAW phase velocity in a healthy incisor and dental caries is obtained by the LPEM. The methods and results of this work can provide a theoretical basis for nondestructive evaluation of human teeth with LSAWs.

  12. Retreatment of a Maxillary Lateral Incisor With Two Separate Root Canals Confirmed With Cone Beam Computed Tomography

    PubMed Central

    Aydemir, Seda; Helvacioglu-Yigit, Dilek; Sinanoglu, Alper; Ozel, Emre

    2015-01-01

    The purpose of this report is to present a rare case of a maxillary lateral incisor exhibiting two separate root canals confirmed by cone-beam computed tomography (CBCT). A 65-year-old female patient with an esthetic complaint regarding her maxillary left lateral incisor was referred to our clinic. During a radiographical examination, an endodontically treated root canal and an extra root canal with an apical lesion were observed. The retreatment was performed. CBCT findings confirmed the root canal mophology of the maxillary left lateral with two distinct canals. We conclude that the CBCT imaging is an adjunctive tool for better assessment of complex root canal systems. PMID:26015823

  13. Studying Geology of Central Texas through Web-Based Virtual Field Trips

    NASA Astrophysics Data System (ADS)

    Chan, C.; Khan, S. D.; Wellner, J. S.

    2007-12-01

    Each year over 2500 students, mainly non-science majors, take introductory geology classes at the University of Houston. Optional field trips to Central Texas for these classes provide a unique learning opportunity for students to experience geologic concepts in a real world context. The field trips visit Enchanted Rock, Inks Lake, Bee Cave Road, Lion Mountain, and Slaughter Gap. Unfortunately, only around 10% of our students participate in these field trips. We are developing a web-based virtual field trip for Central Texas to provide an additional effective learning experience for students in these classes. The module for Enchanted Rock is complete and consists of linked geological maps, satellite imagery, digital elevation models, 3-D photography, digital video, and 3-D virtual reality visualizations. The ten virtual stops focus on different geologic process and are accompanied by questions and answers. To test the efficacy of the virtual field trip, we developed a quiz to measure student learning and a survey to evaluate the website. The quiz consists of 10 questions paralleling each stop and information on student attendance on the Central Texas field trip and/or the virtual field trip. From the survey, the average time spent on the website was 26 minutes, and overall the ratings of the virtual field trip were positive. Most noticeably students responded that the information on the website was relevant to their class and that the pictures, figures, and animations were essential to the website. Although high correlation coefficients between responses were expected for some questions (i.e., 0.89 for "The content or text of the website was clear" and "The information on the website was easy to read"), some correlations were less expected: 0.77 for "The number of test questions was appropriate" and "The information on the website was easy to read," and 0.70 for "The test questions reinforced the material presented on the website" and "The information on the

  14. Orthodontic Treatment of Maxillary Incisors with Severe Root Resorption Caused by Bilateral Canine Impaction in a Class II Division 1 Patient.

    PubMed

    Chang, Na-Young; Park, Jae Hyun; Lee, Mi-Young; Cho, Jin-Woo; Cho, Jin-Hyoung; An, Ki-Yong; Chae, Jong-Moon

    2016-01-01

    This case report shows the successful alignment of bilateral impacted maxillary canines. A 12-year-old male with the chief complaint of the protrusion of his maxillary anterior teeth happened to have bilateral maxillary canine impaction on the labial side of his maxillary incisors. Four maxillary incisors showed severe root resorption because of the impacted canines. The patient was diagnosed as skeletal Class II malocclusion with proclined maxillary incisors. The impacted canine was carefully retracted using sectional buccal arch wires to avoid further root resorption of the maxillary incisors. To distalize the maxillary dentition, two palatal miniscrews were used. After 25 months of treatment, the maxillary canines were well aligned without any additional root resorption of the maxillary incisors.

  15. Tree ring density-based summer temperature reconstruction for the central Hengduan Mountains in southern China

    NASA Astrophysics Data System (ADS)

    Fan, Ze-Xin; Bräuning, Achim; Yang, Bao; Cao, Kun-Fang

    2009-01-01

    Variations in ring width and wood density of Picea brachytyla were used to develop high-resolution climate proxy data to extend the existing climate record in the central Hengduan Mountains, north-western Yunnan Province, China. Growth-climate response analyses showed that the total ring width (TRW) and maximum latewood density (MXD) in the sub-alpine zone are mainly influenced by summer temperature variability. Based on a MXD regional chronology derived from two high elevation sites, we developed a warm season (April-September) temperature reconstruction for the period A.D. 1750-2006. The climate/tree-growth model accounts for 41% of the instrumental temperature variance during the period 1958-2004. Warm summers occurred during 1750s, 1820-50s, 1880-1890s, 1930-1950s and 1990-present; while the periods of 1790-1810s, 1860-1870s, 1900-1920s, and 1960-1985 were relatively cold. Spatial climate correlation analyses with gridded land surface data revealed that our warm season temperature reconstruction contains a strong regional temperature signal for the Hengduan Mountain ranges. Our reconstruction successfully captured recent abrupt climatic changes and agreed in general with other tree ring-based temperature reconstructions from nearby regions on a decadal timescale. In addition, reconstructed summer temperature variations were consistent with recorded glacier fluctuations in the surrounding high mountains.

  16. Familial malignant mesothelioma: a population-based study in central Italy (1980-2012).

    PubMed

    Ascoli, Valeria; Romeo, Elisa; Carnovale Scalzo, Caterina; Cozzi, Ilaria; Ancona, Laura; Cavariani, Fulvio; Balestri, Anna; Gasperini, Letizia; Forastiere, Francesco

    2014-06-01

    Malignant mesothelioma is a sporadic cancer linked to asbestos exposure. Its occurrence among blood relatives (familial mesothelioma) may point to genetic susceptibility or shared exposures. The burden of the familial disease is unknown. The aims of the study were to assess at population level the proportion of familial mesotheliomas among all mesotheliomas and to investigate the family history of cancer among relatives of mesothelioma cases. We actively searched familial clusters based on a mesothelioma registry from central Italy (5.5 million people, 10% of the Italian population) of the National Mesothelioma Register network (ReNaM) as well as a pathology-based archive. Among 997 incident mesotheliomas recorded in a 32-year-period (1980-2012), we detected 13 clusters and 34 familial cases, accounting for 3.4% of all mesotheliomas. The most common clusters where those with affected siblings and unaffected parents. Asbestos exposure was occupational (n=7 clusters), household (n=2), environmental (n=1), or not attributable for insufficient information (n=3). There were 25 additional cancers in nine families. Some were cancer sites for which there is sufficient evidence (lung and larynx) or limited evidence (stomach and colon) of causal association with asbestos. The results suggest potential genetic recessive effects in mesothelioma that interact with asbestos exposure, but it is not possible to estimate the specific proportion attributable to each of these components.

  17. Precipitation, streamflow, and base flow in west-central Texas, December 1974 through March 1977

    USGS Publications Warehouse

    Kuniansky, Eve L.

    1989-01-01

    Precipitation, streamflow, and base-flow data were analyzed for December 1974 through March 1977 as a part of the Edwards-Trinity Regional Aquifer-System Analysis in west-central Texas. The period of record analyzed corresponds to the calibrating period of a digital groundwater-flow model of the aquifer system currently (1988) being developed. Precipitation at individual stations ranged from 6 to 45 in/yr. Precipitation normally (1951-80) ranged from 10 to 32 in/year from east to west in the study area. Precipitation was near normal over most of the area and above normal in the southeastern part of the study area. Streamflow ranged from less than 1 in/year in the western part of the study area to 13 in/yr in the southeastern part. Streamflow was 8 in/yr above normal in the southeast. Base flow ranged from less than 0.1 in/yr in the western part of the study area to 6 in/yr in the southeastern part. (USGS)

  18. Central Retinal Vein Occlusion: A Review of Current Evidence-based Treatment Options

    PubMed Central

    Patel, Amy; Nguyen, Christine; Lu, Stephanie

    2016-01-01

    A central retinal vein occlusion (CRVO) can induce an ischemic and hypoxic state with resulting sequelae of macular edema and neovascularization. Many treatment options have been studied. Our review aims to investigate the safety and efficacy of the multiple treatment options of CRVO. A PubMed and Cochrane literature search was performed. Well-controlled randomized clinical trials that demonstrated strong level 1 evidence-based on the rating scale developed by the British Centre for Evidence-Based Medicine were included. Seven clinical trials met inclusion criteria to be included in this review. These included studies that investigated the safety and efficacy of retinal photocoagulation (1 study), intravitreal steroid treatment (2 studies), and antivascular endothelial growth factor treatment (4 studies) for the treatment of CRVO. In addition, studies evaluating surgical treatment options for CRVO were also included. Many treatment modalities have been demonstrated to be safe and efficacious in the treatment of CRVO. These treatment options offer therapeutic benefits for patients and clinically superior visual acuity and perhaps the quality of life after suffering from a CRVO. PMID:26957838

  19. Fully automated 3D prostate central gland segmentation in MR images: a LOGISMOS based approach

    NASA Astrophysics Data System (ADS)

    Yin, Yin; Fotin, Sergei V.; Periaswamy, Senthil; Kunz, Justin; Haldankar, Hrishikesh; Muradyan, Naira; Turkbey, Baris; Choyke, Peter

    2012-02-01

    One widely accepted classification of a prostate is by a central gland (CG) and a peripheral zone (PZ). In some clinical applications, separating CG and PZ from the whole prostate is useful. For instance, in prostate cancer detection, radiologist wants to know in which zone the cancer occurs. Another application is for multiparametric MR tissue characterization. In prostate T2 MR images, due to the high intensity variation between CG and PZ, automated differentiation of CG and PZ is difficult. Previously, we developed an automated prostate boundary segmentation system, which tested on large datasets and showed good performance. Using the results of the pre-segmented prostate boundary, in this paper, we proposed an automated CG segmentation algorithm based on Layered Optimal Graph Image Segmentation of Multiple Objects and Surfaces (LOGISMOS). The designed LOGISMOS model contained both shape and topology information during deformation. We generated graph cost by training classifiers and used coarse-to-fine search. The LOGISMOS framework guarantees optimal solution regarding to cost and shape constraint. A five-fold cross-validation approach was applied to training dataset containing 261 images to optimize the system performance and compare with a voxel classification based reference approach. After the best parameter settings were found, the system was tested on a dataset containing another 261 images. The mean DSC of 0.81 for the test set indicates that our approach is promising for automated CG segmentation. Running time for the system is about 15 seconds.

  20. Assessing the ecological base flow in an experimental watershed of Central Taiwan

    NASA Astrophysics Data System (ADS)

    Wei, Chiang; Yang, Ping-Shih; Tian, Pei-Ling

    2010-05-01

    The ecological base flow is crucial for the assessment and design for habitat rehabilitation and recovery. The amount of discharge affects the aquatic creatures and may damage the existence and balance of the community under extreme low conditions. Aquatic insect is selected as the target species in this study to evaluate the influence of the discharge and to estimate the ecological base flow. The distribution of the number of species and abundance (density) versus discharge is assessed to define the critical discharge. A stream located at the alpine area in central Taiwan is selected as the study area to evaluate the base flow. From the preliminary data (Aug 2008 to May 2009) collected from Creek C of Sitou watershed (area: 1.3 km^2) shows that the abundance of several species varies with the discharge. The dominate family and genus of aquatic insects is Baetidae (Order Ephemeroptera) and Baetis spp. that accounts for 26.3 and 17.2 %, respectively. The Hilsenhoff family biotic index (FBI) shows that the water quality is classified to "Excellent" and "Good" level while the EPT Index (Index of three orders: Ephemeroptera, Plecoptera, and Trichoptera) indicates that the stream is non-polluted. The discharge of base flow interpreted from the 90%, 95% and 96% curve of duration for the daily discharge is 0.1582, 0.0476 and 0.0378 cms; the threshold value evaluated by curve of abundance vs. discharge is 0.0154 cms. Consistent observations are yet to be collected to yield more accurate results.

  1. Improving Residents' Knowledge of Arterial and Central Line Placement With a Web-Based Curriculum

    PubMed Central

    Grover, Shilpa; Currier, Paul F.; Elinoff, Jason M.; Katz, Joel T.; McMahon, Graham T.

    2010-01-01

    Background Procedural skill is predicated on knowledge. We used a previously validated test to evaluate the impact of a web-based education program on medical residents' knowledge of 2 advanced medical procedures. Methods We enrolled 210 internal medicine residents at 3 residency programs in a randomized, controlled, educational trial. Study participants completed a 20-item, validated online test of their knowledge of central venous and arterial line (CVL and AL, respectively) placement at baseline and after performing their next 2 procedures (test 1 and test 2). Between test 1 and test 2, participants were randomized to online educational material for CVL insertion, AL insertion, both, or neither. The primary outcome of the study was the difference in test scores between test 1 and test 2 by randomization group. Results Though residents in the baseline cohort were confident about their knowledge of procedural technique, their mean test scores were low (62% and 58% in the CVL and AL tests, respectively). Baseline test score correlated with the number of prior procedures performed. Sixty-five residents completed all 3 CVL tests, and 85 residents completed all 3 AL tests. Access to the web-based procedure education was associated with a significant improvement in scores for both the CVL test (effect size, d  =  0.25, P  =  .01) and AL test (d  =  0.52, P < .001). Conclusions Web-based procedure training improves knowledge of procedures to a significantly greater extent than performing the procedure alone. Web-based curricula can effectively supplement other methods of skill development. PMID:22132276

  2. Evidence-based consensus on the insertion of central venous access devices: definition of minimal requirements for training.

    PubMed

    Moureau, N; Lamperti, M; Kelly, L J; Dawson, R; Elbarbary, M; van Boxtel, A J H; Pittiruti, M

    2013-03-01

    There is a lack of standard minimal requirements for the training of insertion techniques and maintenance of central venous access devices (CVADs). An international evidence-based consensus task force was established through the World Congress of Vascular Access (WoCoVA) to provide definitions and recommendations for training and insertion of CVADs. Medical literature published from February 1971 to April 2012 regarding 'central vascular access', 'training', 'competency', 'simulation', and 'ultrasound' was reviewed on Pubmed, BioMed Central, ScienceDirect, and Scopus databases. The GRADE and the GRADE-RAND methods were utilized to develop recommendations. Out of 156 papers initially identified, 83 papers described training for central vascular access placement. Sixteen recommendations are proposed by this task force, each with an evidence level, degree of consensus, and recommendation grade. These recommendations suggest central venous access education include didactic or web-based teaching with insertion procedure, infection prevention, complications, care, and maintenance of devices, along with laboratory models and tools for simulation practice incorporating ultrasound. Clinical competence should be determined by observation during clinical practice using a global rating scale rather than by the number of procedures performed. Ensuring safe insertion and management of central venous devices requires standardized education, simulation practice, and supervised insertions. PMID:23361124

  3. Characteristics and Composition of Atmospheric Aerosols in Phimai, Central Thailand During BASE-ASIA

    NASA Technical Reports Server (NTRS)

    Li, Can; Tsay, Si-Chee; Hsu, N. Christina; Kim, Jin Young; Howell, Steven G.; Huebert, Barry J.; Ji, Qiang; Jeong, Myeong-Jae; Wang, Sheng-Hsiang; Hansell, Richard A.; Bell, Shaun W.

    2012-01-01

    Popular summary: Atmospheric aerosols play an important role in the Earth's climate system, and can also have adverse effects on air quality and human health. The environmental impacts of aerosols, on the other hand, are highly regional, since their temporal/spatial distribution is inhomogeneous and highly depends on the regional emission sources. To better understand the effects of aerosols, intensive field experiments are necessary to characterize the chemical and physical properties on a region-by-region basis. From late February to early May in 2006, NASA/GSFC's SMARTLabs facility was deployed at a rural site in central Thailand, Southeast Asia, to conduct a field experiment dubbed BASE-ASIA (Biomass-burning Aerosols in South East-Asia: Smoke Impact Assessment). The group was joined by scientists from the University of Hawaii and other regional institutes. Comprehensive measurements were made during the experiment, including aerosol chemical composition, optical and microphysical properties, as well as surface energetics and local . meteorology. This study analyzes part of the data from the BASE-ASIA experiment. It was found that, even for the relatively remote rural site, the aerosol loading was still substantial. Besides agricultural burning in the area, industrial pollution near the Bangkok metropolitan area, about 200 km southeast of the site, and even long-range transport from China, also contribute to the area's aerosol loading. The results indicate that aerosol pollution has developed into a regional problem for northern Indochina, and may become more severe as the region's population and economy continue to grow. Abstract: Comprehensive measurements of atmospheric aerosols were made in Phimai, central Thailand (15.l83 N, 102.565 E, elevation: 206 m) during the BASE-ASIA field experiment from late February to early May in 2006. The observed aerosol loading was sizable for this rural site (mean aerosol scattering: 108 +/- 64 Mm(exp -1); absorption: 15

  4. Status and future transition of rapid urbanizing landscape in central Western Ghats - CA based approach

    NASA Astrophysics Data System (ADS)

    Bharath, S..; Rajan, K. S.; Ramachandra, T. V.

    2014-11-01

    The land use changes in forested landscape are highly complex and dynamic, affected by the natural, socio-economic, cultural, political and other factors. The remote sensing (RS) and geographical information system (GIS) techniques coupled with multi-criteria evaluation functions such as Markov-cellular automata (CA-Markov) model helps in analysing intensity, extent and future forecasting of human activities affecting the terrestrial biosphere. Karwar taluk of Central Western Ghats in Karnataka state, India has seen rapid transitions in its forest cover due to various anthropogenic activities, primarily driven by major industrial activities. A study based on Landsat and IRS derived data along with CA-Markov method has helped in characterizing the patterns and trends of land use changes over a period of 2004-2013, expected transitions was predicted for a set of scenarios through 2013-2022. The analysis reveals the loss of pristine forest cover from 75.51% to 67.36% (1973 to 2013) and increase in agriculture land as well as built-up area of 8.65% (2013), causing impact on local flora and fauna. The other factors driving these changes are the aggregated level of demand for land, local and regional effects of land use activities such as deforestation, improper practices in expansion of agriculture and infrastructure development, deteriorating natural resources availability. The spatio temporal models helped in visualizing on-going changes apart from prediction of likely changes. The CA-Markov based analysis provides us insights into the localized changes impacting these regions and can be useful in developing appropriate mitigation management approaches based on the modelled future impacts. This necessitates immediate measures for minimizing the future impacts.

  5. Structural analysis of the central Columbia Plateau utilizing radar, digital topography, and magnetic data bases

    SciTech Connect

    Thiessen, R.L.; Eliason, J.R.; Johnson, L.K.; Brougher, C.W.; Foley, M.G.; Beaver, D.E.

    1988-01-01

    The geology of the central Columbia Plateau is characterized by subdued topography and limited outcrop, with most of the exposure concentrated in localized folded/faulted mountains (the Yakima folds) and along river canyons. In order to efficiently compare lineament data bases, we have written an automated computer routine that correlates lineaments that are within a user specified distance of each other. The angle between their trends has to be less than an input maximum separation angle. If more than two lineament maps exist for the area, the analyst may also specify the minimum number of times each structure must be seen. The lineament correlation routine was applied to data bases of all aeromagnetic linears as well as lineaments seen on radar and a digital elevation model image. Due to their topographic expression and associated deformation, the Yakima folds are detected by nearly all of the studies. Other features that do not correspond to known structures are detected in a number of the above data types and so are likely to have a strong structural control. Previously mapped small faults that obliquely cross the Yakima folds were identified a multiple number of times. These structures align with a set of three-dimensional planar structures identified with our unique Geologic Spatial Analysis (GSA) system. The GSA analysis is based upon computer automated detection of valley bottoms as defined by a DEM. Valley vectors which are coplanar may be controlled by a planar geologic structure whose three-dimensional orientation can be calculated by GSA routines. 58 refs., 7 figs.

  6. A new species of Docosia Winnertz from Central Europe, with DNA barcoding based on four gene markers (Diptera, Mycetophilidae)

    PubMed Central

    Ševčík, Jan; Kaspřák, David; Rulik, Björn

    2016-01-01

    Abstract A new species of Docosia Winnertz, Docosia dentata sp. n., is described and illustrated, based on a single male specimen collected in Muránska planina National Park in Central Slovakia. DNA sequences (COI, COII, CytB, and ITS2) are included and compared for 13 species of Docosia. There was found only little congruence between the molecular results and previous scarce data about interspecific relationships based on morphology. The COI and CytB gene markers showed the highest interspecific gene distances while ITS2 showed the lowest ones. An updated key to the 23 Central European species of Docosia is also presented. PMID:26843833

  7. Five root canals in peg lateral incisor with dens invaginatus: A case report with new nomenclature for the five canals

    PubMed Central

    Jaikailash, Shanmugam; Kavitha, Mahendran; Ranjani, Muthukrishnan Sudharshana; Saravanan, Balasubramaniam

    2014-01-01

    This case report describes endodontic treatment completed in a peg-shaped maxillary lateral incisor, with single root and five root canals of which, one is due to dens invaginatus. Cone beam computed tomogram scanning confirmed the unique morphology of the tooth. New nomenclature for the five canals is proposed. PMID:25125854

  8. The effects of day length, hibernation, and ambient temperature on incisor dentin in the Turkish hamster (Mesocricetus brandti).

    PubMed

    Batavia, Mariska; Nguyen, George; Zucker, Irving

    2013-05-01

    Dentin is deposited on a circadian basis, and daily layers manifest as bands on the medial surfaces of rodent incisors. Hibernation alters dentin deposition, and a distinct hibernation mark has been described on incisor surfaces of several rodent species; the factors that influence the morphology of this mark are poorly understood. We tested the effects of day length, torpor expression, and ambient temperature on incisor surface morphology in Turkish hamsters housed in one of four conditions: long days (LDs) at 22 °C, short days (SDs) at 22 °C, SDs at 5 °C, and SDs at 13 °C. Body temperature was monitored continuously with implanted radio transmitters, and teeth examined postmortem. Teeth of SD hamsters had narrower, less distinct circadian increments than those of LD hamsters, but the width of ultradian increments was similar in both photoperiods. Hibernation at both 5 and 13 °C was associated in most specimens with very narrow, sharply defined dentin increments and increased tooth heterogeneity. Hamsters in SDs at 5 °C that did not hibernate lacked characteristic hibernation increments. At 5 °C, but not 13 °C, the number and cumulative width of hibernation increments were related to number and cumulative duration of periodic arousals. Our results suggest that incremental deposition of dentin in rodent incisors may be a useful trait for characterizing hibernation behavior in both evolutionary and historical contexts.

  9. Novel treatment of equine odontoclastic tooth resorption and hypercementosis of incisor teeth in a 22-year-old Arabian mare.

    PubMed

    Grier-Lowe, Candace K; Anthony, James

    2015-08-01

    Equine odontoclastic tooth resorption and hypercementosis is a rarely reported condition in the incisor and canine teeth of older horses. Histologically, there is internal and external resorption of the tooth with formation of excessive cementum. Once lesions become infected or supragingival this condition is very painful. The clinical manifestation, diagnosis and treatment of hypercementosis in an Arabian mare are described.

  10. Hyperlipidemia induced by high-fat diet enhances dentin formation and delays dentin mineralization in mouse incisor.

    PubMed

    Ye, Xin; Zhang, Jin; Yang, Pishan

    2016-10-01

    Dyslipidemia has become a serious health problem in children and adolescents worldwide for its high prevalence. Since hard tissues of permanent teeth form mainly during this period and lipids are actively involved in tooth development, the effects of hyperlipidemia on dental tissue formation and mineralization need to be illustrated. In this study, hyperlipidemia model was established in mice fed with high-fat diet (HFD). Micro-CT and histomorphological analyses were performed on the mandibular bones to assess the morphological changes of the mandibular incisor and first molar. After 4 weeks of HFD feeding, mice had significantly elevated serum lipid levels compared with mice fed with control diet. After 8 weeks, the mandibular incisor presented significantly increased dentin thickness and decreased diameter of pulp cavity in HFD-fed mice compared with control diet-fed mice, while its gross morphology and enamel thickness were not altered. In the mandibular first molar, dentin thickness of root did not show difference between the two groups. Histological section showed that mandibular incisor of HFD-fed mice manifested a wider predentin region and a lower mineral apposition rate compared with that of the control mice. In conclusion, hyperlipidemia induced by HFD feeding enhances dentin formation and delays dentin mineralization in the developing mouse incisor. PMID:27558143

  11. Novel treatment of equine odontoclastic tooth resorption and hypercementosis of incisor teeth in a 22-year-old Arabian mare

    PubMed Central

    Grier-Lowe, Candace K.; Anthony, James

    2015-01-01

    Equine odontoclastic tooth resorption and hypercementosis is a rarely reported condition in the incisor and canine teeth of older horses. Histologically, there is internal and external resorption of the tooth with formation of excessive cementum. Once lesions become infected or supragingival this condition is very painful. The clinical manifestation, diagnosis and treatment of hypercementosis in an Arabian mare are described. PMID:26246633

  12. Novel treatment of equine odontoclastic tooth resorption and hypercementosis of incisor teeth in a 22-year-old Arabian mare.

    PubMed

    Grier-Lowe, Candace K; Anthony, James

    2015-08-01

    Equine odontoclastic tooth resorption and hypercementosis is a rarely reported condition in the incisor and canine teeth of older horses. Histologically, there is internal and external resorption of the tooth with formation of excessive cementum. Once lesions become infected or supragingival this condition is very painful. The clinical manifestation, diagnosis and treatment of hypercementosis in an Arabian mare are described. PMID:26246633

  13. Hyperlipidemia induced by high-fat diet enhances dentin formation and delays dentin mineralization in mouse incisor.

    PubMed

    Ye, Xin; Zhang, Jin; Yang, Pishan

    2016-10-01

    Dyslipidemia has become a serious health problem in children and adolescents worldwide for its high prevalence. Since hard tissues of permanent teeth form mainly during this period and lipids are actively involved in tooth development, the effects of hyperlipidemia on dental tissue formation and mineralization need to be illustrated. In this study, hyperlipidemia model was established in mice fed with high-fat diet (HFD). Micro-CT and histomorphological analyses were performed on the mandibular bones to assess the morphological changes of the mandibular incisor and first molar. After 4 weeks of HFD feeding, mice had significantly elevated serum lipid levels compared with mice fed with control diet. After 8 weeks, the mandibular incisor presented significantly increased dentin thickness and decreased diameter of pulp cavity in HFD-fed mice compared with control diet-fed mice, while its gross morphology and enamel thickness were not altered. In the mandibular first molar, dentin thickness of root did not show difference between the two groups. Histological section showed that mandibular incisor of HFD-fed mice manifested a wider predentin region and a lower mineral apposition rate compared with that of the control mice. In conclusion, hyperlipidemia induced by HFD feeding enhances dentin formation and delays dentin mineralization in the developing mouse incisor.

  14. Using Community-Based Participatory Research to Reduce Health Disparities in East and Central Harlem

    PubMed Central

    Horowitz, Carol R.; Arniella, Agueda; James, Sherline; Bickell, Nina A.

    2015-01-01

    Objective It is important to teach community members about the causes, magnitude and effects of health disparities that affect them, and to partner with them to develop, test and disseminate programs that they can sustain to improve health. East and Central Harlem are two underserved, predominantly minority, inner-city communities whose residents have disproportionately high morbidity and mortality from chronic conditions. We developed an approach to educate and work together with Harlem residents to study health disparities, and to use peer-led classes to improve chronic disease management and outcomes. Methods Researchers and community leaders formed a community-based research core (“Core”) with funds from a large health disparities grant. We then assembled a community advisory board and partnered with them to start a community newsletter to explain the causes of local health disparities and suggest ways to eliminate them. Together, we also began to create a self-sustaining cadre of community-based peer educators to teach culturally acceptable chronic disease self-management skills. Results The recruited board consists of 33 leaders of community-based health and social service organizations, religious institutions, and tenant organizations, as well as local activists. We produced and distributed our first educational newsletter to more than 4,000 community leaders, members and community-based organizations. We also adapted an existing chronic disease self-management program for the Harlem population and developed strategies to recruit peer educators and sustain their efforts in the future. To help them attain expertise in teaching chronic disease self-management, the board selected four individuals to become master peer-education trainers. The board then helped recruit more than 60 community members and leaders for our first two peer-education courses. Conclusions Researchers, clinicians and community leaders worked together to disseminate knowledge about

  15. 2. Wind speed change in central Europe: the projections based on regional climate models

    NASA Astrophysics Data System (ADS)

    Siedlecki, M.

    2010-09-01

    This work presents dynamically downscaled near-surface wind speed fields and examines the impact of climate changes on wind speed across central Europe. The analysis is based on regional model simulation (5 RCM simulations taken from the project PRUDENCE and CLM regional climate model from M&D group) forced by IPCC emission scenario SRES - A2. Each model provided data from two 30-year simulations: a control run under present day climate conditions for the period 1961-90 and a simulation under conditions projected for the period 2021-2050. The research domain covered region from 42°N to 62°N and from 6°E to 36°E. The model ensemble shows a possible increase in future mean wind speed during winter season, especially over zonal belt from North German to North Poland where the future mean wind speed is 0.4 m/s higher than in the control period. The projected climate change in summer over most research domain shows a decrease of mean wind speed (about 0.2 m/s). The Jutland Peninsula and North German is the region with the highest simulated wind speed. The simulated changes are more pronounced in 95th percentile than in the mean. In winter, the values of the 95th percentile will increase over the North German, Jutland Peninsula and North Poland but the highest change is projected over east coast of Baltic Sea (1m/s).

  16. The contribution of a central pattern generator in a reflex-based neuromuscular model

    PubMed Central

    Dzeladini, Florin; van den Kieboom, Jesse; Ijspeert, Auke

    2014-01-01

    Although the concept of central pattern generators (CPGs) controlling locomotion in vertebrates is widely accepted, the presence of specialized CPGs in human locomotion is still a matter of debate. An interesting numerical model developed in the 90s’ demonstrated the important role CPGs could play in human locomotion, both in terms of stability against perturbations, and in terms of speed control. Recently, a reflex-based neuro-musculo-skeletal model has been proposed, showing a level of stability to perturbations similar to the previous model, without any CPG components. Although exhibiting striking similarities with human gaits, the lack of CPG makes the control of speed/step length in the model difficult. In this paper, we hypothesize that a CPG component will offer a meaningful way of controlling the locomotion speed. After introducing the CPG component in the reflex model, and taking advantage of the resulting properties, a simple model for gait modulation is presented. The results highlight the advantages of a CPG as feedforward component in terms of gait modulation. PMID:25018712

  17. Base of Principal Aquifer for the Elkhorn-Loup Model Area, North-Central Nebraska

    USGS Publications Warehouse

    McGuire, V.L.; Peterson, Sean M.

    2008-01-01

    In Nebraska, the water managers in the Natural Resources Districts and the Nebraska Department of Natural Resources are concerned with the effect of ground-water withdrawal on the availability of surface water and the long-term effects of ground-water withdrawal on ground- and surface-water resources. In north-central Nebraska, in the Elkhorn and Loup River Basins, ground water is used for irrigation, domestic supply, and public supply; surface water is used in this area for irrigation, recreation, and hydropower production. In recognition of these sometimes competing ground- and surface-water uses in the Elkhorn and Loup River Basins, the U.S. Geological Survey, the Lewis and Clark Natural Resources District, the Lower Elkhorn Natural Resources District, the Lower Loup Natural Resources District, the Lower Niobrara Natural Resources District, the Lower Platte North Natural Resources District, the Middle Niobrara Natural Resources District, the Upper Elkhorn Natural Resources District, and the Upper Loup Natural Resources District agreed to cooperatively study water resources in the Elkhorn and Loup River Basins. The goals of the overall study were to construct and calibrate a regional ground-water flow model of the area and to use that flow model as a tool to assess current and future effects of ground-water irrigation on stream base flow and to help develop long-term water-resource management strategies for this area, hereafter referred to as the Elkhorn-Loup model area. The Elkhorn-Loup model area covers approximately 30,800 square miles, and extends from the Niobrara River in the north to the Platte River in the south. The western boundary of the Elkhorn-Loup model area coincides with the western boundary of the Middle Niobrara, Twin Platte, and Upper Loup Natural Resources Districts; the eastern boundary coincides with the approximate location of the western extent of glacial till in eastern Nebraska. The principal aquifer in most of the Elkhorn-Loup model

  18. Characteristics and composition of atmospheric aerosols in Phimai, central Thailand during BASE-ASIA

    NASA Astrophysics Data System (ADS)

    Li, Can; Tsay, Si-Chee; Hsu, N. Christina; Kim, Jin Young; Howell, Steven G.; Huebert, Barry J.; Ji, Qiang; Jeong, Myeong-Jae; Wang, Sheng-Hsiang; Hansell, Richard A.; Bell, Shaun W.

    2013-10-01

    Comprehensive measurements of atmospheric aerosols were made in Phimai, central Thailand (15.183°N, 102.565°E, elevation: 206 m) during the BASE-ASIA field experiment from late February to early May in 2006. The observed aerosol loading was sizable for this rural site (mean aerosol scattering: 108 ± 64 Mm-1; absorption: 15 ± 8 Mm-1; PM10 concentration: 33 ± 17 μg m-3), and dominated by submicron particles. Major aerosol compounds included carbonaceous (OC: 9.5 ± 3.6 μg m-3; EC: 2.0 ± 2.3 μg m-3) and secondary species (SO42-: 6.4 ± 3.7 μg m-3, NH4+: 2.2 ± 1.3 μg m-3). While the site was seldom under the direct influence of large forest fires to its north, agricultural fires were ubiquitous during the experiment, as suggested by the substantial concentration of K+ (0.56 ± 0.33 μg m-3). Besides biomass burning, aerosols in Phimai during the experiment were also strongly influenced by industrial and vehicular emissions from the Bangkok metropolitan region and long-range transport from southern China. High humidity played an important role in determining the aerosol composition and properties in the region. Sulfate was primarily formed via aqueous phase reactions, and hygroscopic growth could enhance the aerosol light scattering by up to 60%, at the typical morning RH level of 85%. The aerosol single scattering albedo demonstrated distinct diurnal variation, ranging from 0.86 ± 0.04 in the evening to 0.92 ± 0.02 in the morning. This experiment marks the first time such comprehensive characterization of aerosols was made for rural central Thailand. Our results indicate that aerosol pollution has developed into a regional problem for northern Indochina, and may become more severe as the region's population and economy continue to grow.

  19. A tunable protein-based scaffold for the study of central nervous system regeneration

    NASA Astrophysics Data System (ADS)

    Straley, Karin

    Central nervous system (CNS) injuries pose a significant and potentially debilitating health problem in society today and, to date, no successful clinical repair strategies have been advanced. The development of effective treatments is severely hindered by the quick formation of a complex, inhibitory scar at the site of CNS injury. This scar both physically blocks and chemically suppresses nerve regeneration. It has been hypothesized that combinatorial approaches involving biomaterial scaffolds, cell transplantation, and pro-survival factors, which provide a more permissive growth environment, have the highest chance of stimulating regeneration. The work completed in this thesis focuses on the design and characterization of a biomimetic hydrogel scaffold constructed from chemically crosslinked recombinant proteins. This protein-based scaffold has been designed to offer a flexible platform for the systematic optimization of key scaffold design parameters, such as mechanical strength, degradation, cellular interaction, molecule delivery, and topography. Specifically, a collection of proteins containing sequences previously shown to enhance cell adhesion, to promote neurite extension, and to exhibit varying susceptibility to cleavage by neurite-secreted proteases were synthesized to serve as the polymer backbone for the scaffold. Experiments were conducted to analyze the capacity of scaffolds, constructed from single proteins or mixtures of proteins, to independently control cell behavior, scaffold degradation properties, and scaffold mechanical properties based upon differences in the primary protein sequence and crosslinking conditions. In addition, composite scaffolds constructed by layered spatial deposition of chemically crosslinked, protease-degradable proteins were applied to the formation of dynamic internal, three-dimensional scaffold patterns that can be directly coupled to molecule delivery. Overall, this work demonstrates the tunable and bio

  20. Nonsurgical endodontic treatment of a maxillary lateral incisor with dens invaginatus type II: A case report

    PubMed Central

    Shadmehr, Elham; Kiaani, Sima; Mahdavian, Parinaz

    2015-01-01

    Dens invaginatus is a rare developmental anomaly of teeth with complex root canal system morphology. The present case describes a peg shape maxillary lateral incisor with dens invaginatus (Oehlers type II), necrotic pulp, and an associated large periradicular lesion. Nonsurgical endodontic treatment was performed with the aim of removing the blind sac with diamond bur under the use of operating surgical microscope. The root canal system was obturated with thermoplastic technique. Final restoration was done using composite. The 20-months clinical and radiological follow up revealed an asymptomatic tooth with healing of the periapical pathology; however, for complete healed periradicular lesion more follow up is needed. This case illustrated that a dens invaginatus malformed teeth with a large periradicular lesion can be managed successfully with nonsurgical root canal therapy (NSRCT). PMID:25878686

  1. Palatogingival Groove: Recognizing and Managing the Hidden Tract in a Maxillary Incisor: A Case Report

    PubMed Central

    Sharma, Sarang; Deepak, Passi; Vivek, Sharma; Ranjan Dutta, Shubha

    2015-01-01

    Palatogingival grooves are developmental malformations quite notorious for precipitating endodontic - periodontal lesions. Owing to their inconspicuous occurrence, funnel-shaped morphology and variable extent on tooth root, they promote adherence of plaque and bacteria to levels significant for the development of pathology. Several treatment approaches have been recognized in literature for the management of this anomaly. Here in this report, a 25-year-old patient reported with the complaint of pain and swelling in maxillary right lateral incisor. Clinical examination confirmed an endodontic - periodontal lesion in relation to palatogingival groove. Endodontic treatment was instituted, followed by odontoplasty of the groove and restoration with newer calcium silicate cement, Biodentine. Combined endodontic - periodontal approach was successful in resolving the pathology with complete healing seen both clinically and radiographically. Timely diagnosis, prevention and management are highly recommended to prevent tooth loss due to complications arising secondary to their presence. PMID:26124612

  2. Bilateral supplemental permanent maxillary lateral incisors in a non-syndromic patient

    PubMed Central

    Bhullar, Mandeep Kaur; Uppal, Amandeep Singh; Kochhar, Gulsheen Kaur; Singh, Ranjit

    2014-01-01

    A supernumerary tooth is an additional entity to the normal series and can be seen in all quadrants of the jaw. Occurrence may be single or multiple, unilateral or bilateral, erupted or impacted in one or in both jaws. Multiple supernumeraries are rare in individuals with no other associated disease or syndromes. The conditions commonly associated with an increased prevalence of supernumerary teeth include cleft lip and palate, cleidocranial dysplasia and Gardner syndrome. The supplemental supernumerary refers to a duplication of teeth in normal series and is found at the end of a tooth series. A supplemental tooth may closely resemble the teeth of the group to which it belongs or it may bear little resemblance in size or shape to the teeth with which it is associated. This report presents a case with bilateral supplemental upper permanent lateral incisors without any symptoms of associated disorders. PMID:25168674

  3. A Case of Successful Retreatment of a Maxillary Lateral Incisor with a Supernumerary Root

    PubMed Central

    Aminsobhani, Mohsen

    2015-01-01

    Knowledge about the morphology of the root canal system is a pre-requisite for achieving a successful outcome in root canal treatment. In this report, a patient with a maxillary lateral incisor which had previously undergone orthograde endodontic retreatment for two times is discussed. The tooth had been misdiagnosed with a palatal groove or a root fracture, its prognosis had been determined to be poor and extraction was advised by a practitioner. During our evaluation, an unrecognized supernumerary root and root canal were detected and the tooth was maintained successfully with orthograde endodontic retreatment. The use of cone beam computed tomography (CBCT) and magnification were of significance in the treatment process of this case. PMID:27252762

  4. Zirconia crowns for rehabilitation of decayed primary incisors: an esthetic alternative.

    PubMed

    Ashima, G; Sarabjot, K Bhatia; Gauba, K; Mittal, H C

    2014-01-01

    Esthetic management of extensively decayed primary maxillary anterior teeth requiring full coronal coverage restoration is usually challenging to the pediatric dentists especially in very young children. Many esthetic options have been tried over the years each having its own advantages, disadvantages and associated technical, functional or esthetic limitations. Zirconia crowns have provided a treatment alternative to address the esthetic concerns and ease of placement of extra-coronal restorations on primary anterior teeth. The present article presents a case where grossly decayed maxillary primary incisors were restored esthetically and functionally with ready made zirconia crowns (ZIRKIZ, HASS Corp; Korea). After endodontic treatment the decayed teeth were restored with zirconia crowns. Over a 30 months period, the crowns have demonstrated good retention and esthetic results. Dealing with esthetic needs in children with extensive loss of tooth structure, using Zirconia crowns would be practical and successful. The treatment described is simple and effective and represents a promising alternative for rehabilitation of decayed primary teeth.

  5. Palatogingival Groove: Recognizing and Managing the Hidden Tract in a Maxillary Incisor: A Case Report.

    PubMed

    Sharma, Sarang; Deepak, Passi; Vivek, Sharma; Ranjan Dutta, Shubha

    2015-06-01

    Palatogingival grooves are developmental malformations quite notorious for precipitating endodontic - periodontal lesions. Owing to their inconspicuous occurrence, funnel-shaped morphology and variable extent on tooth root, they promote adherence of plaque and bacteria to levels significant for the development of pathology. Several treatment approaches have been recognized in literature for the management of this anomaly. Here in this report, a 25-year-old patient reported with the complaint of pain and swelling in maxillary right lateral incisor. Clinical examination confirmed an endodontic - periodontal lesion in relation to palatogingival groove. Endodontic treatment was instituted, followed by odontoplasty of the groove and restoration with newer calcium silicate cement, Biodentine. Combined endodontic - periodontal approach was successful in resolving the pathology with complete healing seen both clinically and radiographically. Timely diagnosis, prevention and management are highly recommended to prevent tooth loss due to complications arising secondary to their presence.

  6. Agenesis of maxillary lateral incisor in an Angle Class II, Division 1 malocclusion patient

    PubMed Central

    Thiesen, Guilherme

    2015-01-01

    The present case report describes the orthodontic treatment of a patient with agenesis of maxillary left lateral incisor and Angle Class II, Division 1 malocclusion. The patient also presented with maxillary midline deviation and inclination of the occlusal plane in the anterior region. Treatment objectives were: correction of sagittal relationship between the maxilla and the mandible; correction of midline deviation, so as to cause maxillary and mandibular midlines to coincide; correction of overbite and leveling of the occlusal plane, so as to create ideal conditions for esthetic rehabilitation of anterior teeth. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) as a requirement for the title of certified by the BBO. PMID:26560829

  7. Implant-Prosthetic Rehabilitation in Bilateral Agenesis of Maxillary Lateral Incisors with a Mini Split Crest.

    PubMed

    Figliuzzi, M M; Giudice, A; Pileggi, S; Pacifico, D; Marrelli, M; Tatullo, M; Fortunato, L

    2016-01-01

    The reported clinical case describes the surgical procedure of ridge augmentation by using a "split crest" technique with a partial thickness flap and a subsequent implant-prosthetic rehabilitation aimed at treating a bilateral agenesis of the upper lateral incisors. In such cases with vestibule-palatal and mesial-distal scarce bone thicknesses associated with the need of a proper functional and aesthetic rehabilitation, the split crest technique is particularly suitable. In the case we reported, because of the poor bone thicknesses, we performed a minimally invasive split crest which allowed a correct insertion of the fixtures. This technique allowed us to achieve an optimal functional and aesthetic rehabilitation; moreover, we obtained a good emergency profile, ensuring the vitality of the close teeth and ensuring a good primary stability and the following osseointegration of dental implants. PMID:27190658

  8. [Prevention of the eruption of an upper later incisor by a compound odontoma. Case report].

    PubMed

    Vlcek, Daniel; Reichart, Peter A; Bosshardt, Dieter D; Sleiter, Roberto; Bornstein, Michael M

    2012-01-01

    Odontomas are the most common odontogenic tumours. They are considered as hamartomas - a local tissue malformation without autonomous growth potential - and are non-neoplastic. Clinically and histopathologically, compound and complex odontomas can be differentiated. Compound odontomas consist of a varying number of tooth-like structures and histology show dental tissues in an orderly pattern. Most often compound odontomas are diagnosed in young patients in the anterior maxilla. Patients are rarely complaining of symptoms and they are usually diagnosed during routine radiographic examinations or due to late eruption of permanent or persistence of deciduous teeth. The following case report presents a disturbed eruption of a lateral right incisor of the maxilla in a 8-year old female patient. Clinical, radiological and histopathological characteristics of this lesion will be discussed as well as therapy and follow-up.

  9. Implant-Prosthetic Rehabilitation in Bilateral Agenesis of Maxillary Lateral Incisors with a Mini Split Crest

    PubMed Central

    Figliuzzi, M. M.; Giudice, A.; Pileggi, S.; Pacifico, D.; Marrelli, M.; Tatullo, M.; Fortunato, L.

    2016-01-01

    The reported clinical case describes the surgical procedure of ridge augmentation by using a “split crest” technique with a partial thickness flap and a subsequent implant-prosthetic rehabilitation aimed at treating a bilateral agenesis of the upper lateral incisors. In such cases with vestibule-palatal and mesial-distal scarce bone thicknesses associated with the need of a proper functional and aesthetic rehabilitation, the split crest technique is particularly suitable. In the case we reported, because of the poor bone thicknesses, we performed a minimally invasive split crest which allowed a correct insertion of the fixtures. This technique allowed us to achieve an optimal functional and aesthetic rehabilitation; moreover, we obtained a good emergency profile, ensuring the vitality of the close teeth and ensuring a good primary stability and the following osseointegration of dental implants. PMID:27190658

  10. Direct pulp capping in an immature incisor using a new bioactive material

    PubMed Central

    Bhat, Sham S.; Hegde, Sundeep K.; Adhikari, Fardin; Bhat, Vidya S.

    2014-01-01

    Preservation of the pulp in a traumatized immature fractured incisor tooth is of prime importance in order to achieve apexogenesis, a natural apical closure. The main factor influencing this is pulpal protection by a bioactive material proving optimum marginal seal in preventing any microleakage. This case report presents an 8-year-old female diagnosed with Ellis Class 3 fracture of immature tooth 11 involving the mesial pulp horn. Under rubber dam isolation, a partial pulpotomy was performed and the pulp was sealed using a new bioactive material BIODENTINE to stimulate apexogenesis, dentine replacement and pulp protection. The fractured segment was reattached for optimum esthetics, which was a concern for the patient. The patient was followed-up for 1, 3, 6 and 12 months, which revealed continued apical closure and maintenance of pulp vitality. The patient remained asymptomatic. This case report provides evidence for the potential use of Biodentine as an effective pulp capping material in the future. PMID:25191081

  11. Palatogingival Groove: Recognizing and Managing the Hidden Tract in a Maxillary Incisor: A Case Report.

    PubMed

    Sharma, Sarang; Deepak, Passi; Vivek, Sharma; Ranjan Dutta, Shubha

    2015-06-01

    Palatogingival grooves are developmental malformations quite notorious for precipitating endodontic - periodontal lesions. Owing to their inconspicuous occurrence, funnel-shaped morphology and variable extent on tooth root, they promote adherence of plaque and bacteria to levels significant for the development of pathology. Several treatment approaches have been recognized in literature for the management of this anomaly. Here in this report, a 25-year-old patient reported with the complaint of pain and swelling in maxillary right lateral incisor. Clinical examination confirmed an endodontic - periodontal lesion in relation to palatogingival groove. Endodontic treatment was instituted, followed by odontoplasty of the groove and restoration with newer calcium silicate cement, Biodentine. Combined endodontic - periodontal approach was successful in resolving the pathology with complete healing seen both clinically and radiographically. Timely diagnosis, prevention and management are highly recommended to prevent tooth loss due to complications arising secondary to their presence. PMID:26124612

  12. The effects of spaceflight on the mineralization of rat incisor dentin

    NASA Technical Reports Server (NTRS)

    Simmons, D. J.; Rosenberg, G. D.

    1984-01-01

    Specific effects of space flight on dentin formation on the lower incisors of male rats were determined. Data were Fourier analyzed to determine the spectra of chemical growth rhythms. It was found that Calcium and P were more concentrated in the newly forming dentin of the Flight rats than in comparable regions of control tissues. There was no significant difference in the mean S-concentration between the two groups, but the pattern of S-distribution in the recently formed dentin from the Flight rats was different from that in the control group. Sulfur fluctuations in flight animals periodically peak above the irregular background fluctuations, but there are no comparable sulfur peaks across the dentin in the control. It is indicated that spaceflight has measurable effects on dentinogenesis, and may also bear on the problem of the regulatory role of proteoglycans in mineralization and the maturation of mineral and matrix moieties in skeletal tissue.

  13. Very Large Inflammatory Odontogenic Cyst with Origin on a Single Long Time Traumatized Lower Incisor

    PubMed Central

    Freitas, Filipe; Andre, Saudade; Moreira, Andre; Carames, Joao

    2015-01-01

    One of the consequences of traumatic injuries is the chance of aseptic pulp necrosis to occur which in time may became infected and give origin to periapical pathosis. Although the apical granulomas and cysts are a common condition, there appearance as an extremely large radiolucent image is a rare finding. Differential diagnosis with other radiographic-like pathologies, such as keratocystic odontogenic tumour or unicystic ameloblastoma, is mandatory. The purpose of this paper is to report a very large radicular cyst caused by a single mandibular incisor traumatized long back, in a 60-year-old male. Medical and clinical histories were obtained, radiographic and cone beam CT examinations performed and an initial incisional biopsy was done. The final decision was to perform a surgical enucleation of a lesion, 51.4 mm in length. The enucleated tissue biopsy analysis was able to render the diagnosis as an inflammatory odontogenic cyst. A 2 year follow-up showed complete bone recovery. PMID:26393219

  14. A river based stable isotope record of orographic precipitation: Taurus Mountains, south central Turkey

    NASA Astrophysics Data System (ADS)

    Schemmel, Fabian; Mulch, Andreas; Mikes, Tamás.; Schildgen, Taylor

    2010-05-01

    lapse rate of dD is about -20 per mil/km. Select samples have higher d18O and dD values than expected for their respective elevations due to strong evaporative effects at the sampling sites. In areas of very steep topography (waterfalls, valley gorges) the d18O and dD values of water samples are biased towards values lower than expected for their respective elevations. However, such irregularities can be accounted for by plotting the measured isotopic compositions against the hypsometric mean elevations instead of the actual sampling elevations. Comparison with data gathered by the GNIP network at four neighboring stations (Adana, Antalya, Güzeloluk, and Kocebeyli) shows that the longer-term (1 to 18 years) isotopic composition of precipitation agrees very well with the data collected in this study. Collectively, the data presented here may serve as a modern template against which late Neogene proxy-based records of paleoprecipitation along the southern margin of the central Anatolian plateau may be calibrated.

  15. Basement structure based on gravity anomaly in the northern Noto peninsula, Central Japan

    NASA Astrophysics Data System (ADS)

    Mizubayashi, T.; Sawada, A.; Hamada, M.; Hiramatsu, Y.; Honda, R.

    2012-12-01

    Upper crustal block structures are usually defined by using surface information, such as geological and morphological data. The northern Noto Peninsula, central Japan, is divided into four geological block structures from tectonic geomorphologic perspectives (Ota and Hirakawa, 1979). This division is based on the surface crustal movement. To image the geological blocks three-dimensionally, it is necessary to construct a subsurface structure model. Gravity survey can clarify the detailed subsurface structure with dense gravity measurement. From the detailed Bouguer anomalies in the northwestern Noto Peninsula, Honda et al. (2008) suggested that the rupture size of the 2007 Noto Hanto earthquake was constrained by the geological block structures. Hiramatsu et al. (2008) also suggested the active faults on the seafloor, such as the source fault of the 2007 Noto Hanto earthquake plays a major role for the formation of the geological block structures. In this study, we analyze subsurface density structure based on the Bouguer anomaly and estimate the distribution of basement depth in the northern Noto Peninsula. We focus the relationship among the basement depth, the block structures and the active faults on the seafloor and discuss the block movement in the northern Noto Peninsula. We compiled the data measured and published previously (Gravity Database of Southwest Japan, 2001; Geological survey of Japan, 2004; Geographical survey institute of Japan, 2006; The Gravity Research Group in Southwest Japan, 2001; Komazawa and Okuma, 2010; Hokuriku electric power Co. Ltd., undisclosed) and calculated Bouguer anomaly in the northern Noto Peninsula. Based on this Bouguer anomaly, we analyzed subsurface density structures along 13 northeastern-southwestern profiles and 35 northwestern-southeastern profiles with the interval of 2 km using the two dimensional Talwani's method (Talwani et al., 1959). In the analysis, we assumed a density structure with four layers: basement

  16. Identification of genes in ulcerative colitis associated colorectal cancer based on centrality analysis of co-expression network.

    PubMed

    Zhu, J; Li, C; Ji, W

    2015-01-01

    PreviousColorectal cancer (CRC) is a well-recognized complication of Ulcerative colitis (UC) and patients with UC have a higher incidence of CRC than the general population. Early detection and mechanism of colitis-associated colorectal cancer (CAC) is still challenging. The aim of present study is to identify genes associated with CAC by centrality analysis of co-expression networks. Co-expression networks of CRC and UC were constructed by empirical Bayes approach based on top 200 gene signatures which identified by the model of genome-wide relative significance and genome-wide global significance across multiple datasets. Centrality of degree, stress centrality, betweenness centrality and closeness centrality of co-expression networks were selected to explore hub genes presented in CRC and UC. Validation of mRNA expression in CRC patients was conducted by real-time quantitative Polymerase Chain Reaction (qPCR). Pathway analysis was conducted based on Kyoto Encyclopedia of Genes and Genomes database. We found 21 common genes, such as SLC4A4 and AQP8, both existed in CRC and UC top 200 genes. By accessing centralities analyses of co-expression networks, HPGD and AQP8 were common hub genes in CRC and UC, and various centralities analyses of the same gene were not consistent. Patients with alteration of AQP8 have significantly reduced the survival rate according to real-time qPCR results. Our study displayed genes associated with CAC (AQP8 and HPGD), and they might be reliable biomarkers for early detection and therapies of CAC. PMID:26278145

  17. Assessment of association between molar incisor hypomineralization and hypomineralized second primary molar

    PubMed Central

    Mittal, Rakesh; Chandak, Shweta; Chandwani, Manisha; Singh, Prabhat; Pimpale, Jitesh

    2016-01-01

    Background: The term molar incisor hypomineralization (MIH) has been described as a clinical entity of systemic origin affecting the enamel of one or all first permanent molars and also the incisors; less frequently the second primary molars have also been reported to develop hypomineralization of the enamel, along with MIH. Aim: To scrutinize the association between hypomineralized second primary molars (HSPMs) and MIH and their prevalence in schoolgoing pupils in Nagpur, Maharashtra, India and the associated severity of dental caries. Design: A sample of 1,109 pupils belonging to 3–12-year-old age group was included. The entire sample was then divided into Group I (3–5 years) and Group II (6–12 years). The scoring criteria proposed by the European Academy of Pediatric Dentistry for hypomineralization was used to score HSPM and MIH. The International Caries Detection and Assessment System II (ICDAS II) was used for appraising caries status in the hypomineralized molars. The examination was conducted by a single calibrated dentist in schools in daylight. The results, thus obtained, were statistically analyzed using Chi-square test and odds ratio. Result: Of the children examined, 10 in Group I (4.88%) had HSPM and 63 in Group II (7.11%) had MIH in at least one molar. In Group II, out of 63 subjects diagnosed with MIH, 30 subjects (48%) also had HSPM. Carious lesions with high severity were appreciated in hypomineralized molars. Conclusion: The prevalence of HSPM was 4.88% and of MIH was 7.11%. Approximately half of the affected first permanent molars were associated with HSPM. The likelihood of development of caries increased with the severity of hypomineralization defect. PMID:27011930

  18. New Reforms in the Management of the University: Transition from Centralized to Decentralized (University-Based Management) in Iran

    ERIC Educational Resources Information Center

    Mehralizadeh, Y.

    2005-01-01

    This article focuses on new reforms in Iran's higher education management system--Transition from centralized to decentralized (University-Based management--UBM). This is an important subject since Iran's Ministry of Science, Research, and Technology (MSRT) has begun to introduce new reforms for the improvement and the enhancement of Iranian…

  19. The Most Proficient Enzyme as the Central Theme in an Integrated, Research-based Biochemistry Laboratory Course

    ERIC Educational Resources Information Center

    Smiley, Jeffrey A.

    2002-01-01

    The enzyme orotidine-5'-monophosphate decarboxylase is an attractive choice for the central theme of an integrated, research-based biochemistry laboratory course. A series of laboratory exercises common to most instructional laboratories, including enzyme assays, protein purification, enzymatic characterization, elementary kinetics, and…

  20. An EO-Based Approach to Modelling Ecosystem Health in Response to Wildfire in Central Greece

    NASA Astrophysics Data System (ADS)

    Evans, Aaron; Petropoulos, George P.

    2014-05-01

    Assessment of ecosystem health is becoming more relevant in a world where ecosystems are being used unsustainably and have been showing increased signs of stress and dysfunction. Therefore, this research has set out to establish an Earth Observation (EO) based methodology in conjunction with Geographical Information Systems (GIS) to establish and monitor the indicators of ecosystem health in a region affected by wildfire in Central Greece. A further goal has been to assess the responses of ecosystem health to wildfire and urban expansion in the studied region. The methodology integrated GIS software and EO data to assess ecosystem characteristics including: vigour, organisation and resilience. The characteristics were quantified using remote sensing techniques focusing on Normalised Difference Vegetation Index (NDVI) images derived from Landsat imagery from 1999-2011. Topographic features including slope and aspect were extracted from a digital elevation model (DEM). These elements were then assigned weightings based upon research and combined in a model to produce a map of ecosystem health. The map of ecosystem health was validated against a compound topographic index that was produced for the study region, completed by overlaying the layers in Google Earth. This software allowed for a direct comparison of each layer. The results of the model have demonstrated correlations with past wildfires and the associated recovery. The findings are in agreement with the hypothesis that ecosystem health maps can illustrate the effect wildfires have on ecosystem health, thus providing useful information to land managers and policy makers who manage wildfire. The results further demonstrate that the resolution of Landsat imagery is excellent for obtaining a general overview of ecosystem health mapping. The methods described in this study could provide more detailed information if applied to high resolution imagery such as Worldview or IKONOS data. Results could be further

  1. A BiomeBGC-based Evaluation of Dryness Stress of Central European Forests

    NASA Astrophysics Data System (ADS)

    Buddenbaum, H.; Hientgen, J.; Dotzler, S.; Werner, W.; Hill, J.

    2015-04-01

    Dryness stress is expected to become a more common problem in central European forests due to the predicted regional climate change. Forest management has to adapt to climate change in time and think ahead several decades in decisions on which tree species to plant at which locations. The summer of 2003 was the most severe dryness event in recent time, but more periods like this are expected. Since forests on different sites react quite differently to drought conditions, we used the process-based growth model BiomeBGC and climate time series from sites all over Germany to simulate the reaction of deciduous and coniferous tree stands in different characteristics of drought stress. Times with exceptionally high values of water vapour pressure deficit coincided with negative modelled values of net primary production (NPP). In addition, in these warmest periods the usually positive relationship between temperature and NPP was inversed, i.e., under stress conditions, more sunlight does not lead to more photosynthesis but to stomatal closure and reduced productivity. Thus we took negative NPP as an indicator for drought stress. In most regions, 2003 was the year with the most intense stress, but the results were quite variable regionally. We used the Modis MOD17 gross and net primary production product time series and MOD12 land cover classification to validate the spatial patterns observed in the model runs and found good agreement between modelled and observed behaviour. Thus, BiomeBGC simulations with realistic site parameterization and climate data in combination with species- and variety-specific ecophysiological constants can be used to assist in decisions on which trees to plant on a given site.

  2. Remote Sensing Based Biophysical Characterization of Tropical Deciduous Forest in Central India

    NASA Astrophysics Data System (ADS)

    Singh, R. P.; Goroshi, S.; Sharma, N. K.; Bairagi, G. D.; Sharma, R.; Jalil, P.; Jain, A.; Sonakia, A.; Parihar, J. S.

    2011-09-01

    The paper reports the measurements of biophysical parameters using field and satellite data over a tropical deciduous forest Kanha National Park (KNP), central India. Field measurement (GBH, LAI, litter, soil moisture) was carried out over ten quadrates of 0.1ha in KNP for characterization of biophysical parameters with specified measurement protocol and sampling. Satellite based remote sensing analysis (LAI, Phenology, and NPP) was carried out using multi date observations of IRS-LISS-III, IMS-1MX, SPOT-VEGETATION and EOS-MODIS instruments. Rank correlation analysis using field data collected in the selected quadrates at KNP showed Sal (Shorea robusta) is dominant forest species followed by Lendia, Jamun (Syzygium cumini), Saja, Harra and Dhawda etc. Field measurement of Sal showed GBH range from 20 cm to 170 cm. Different forest classes such as Sal; Sal mixed with Jamun, Bamboo (Dendrocalamus strictus) etc, including grasslands/scrubland were classified with overall accuracy of 85.56 percent using March, May and October multi spectral data. Sal has distinct growth characteristics (low vegetation growth/ leaf fall in March instead of May) as compared to other vegetation species. As per the Leaf Area Index (LAI) measurement using hemispherical photographs, Sal showed the highest LAI (6.95 m2/m2) during September and lowest LAI (2.63 m2/m2) during March. Overall good agreement (r= 0.79) was found between the LAI generated from LISS-III and MODIS data product. It was observed from SPOT-VEGETATION analysis that NPP varied from 8.4 tC/ha/year (dry deciduous forest) to 14.25 tC/ha/year (Moist deciduous forest) in KNP.

  3. Disease burden of enterovirus 71 in rural central China: A community-based survey

    PubMed Central

    Gan, Zheng-kai; Jin, Hui; Li, Jing-xin; Yao, Xue-jun; Zhou, Yang; Zhang, Xue-feng; Zhu, Feng-cai

    2015-01-01

    In recent years, the epidemics of hand, foot, and mouth disease (HFMD) centered in the Asian-Pacific region have been characterized by high morbidity and mortality. Enterovirus 71 (EV71) infections were responsible for the majority of the infections leading to severe cases of HFMD and death. This is a community-based survey aimed to estimate the disease burden of EV71 in rural central China, especially for HFMD. From 2011 to 2013, demographic and socio-economic data were gathered from 343 ill children and their parents using a structured questionnaire. We quantified the health burden of disease resulting from EV71 infection in disability-adjusted life years (DALYs). Among 343 cases, 303 had confirmed HFMD, 6 presented with herpangina, 25 presented with respiratory symptoms, and 9 presented with non-specific symptoms. The number of severe cases was 47 (including 1 death) and all of these presented with HFMD. The total cost per patient for severe HFMD, mild HFMD, herpangina, respiratory disease, and non-specific disease was $2149.47, $513.22, $53.28, $31.95, and $39.25, respectively. The overall cost of EV71-related diseases as a proportion of local farmers' per capita net income ranged from 0.18% for those with non-specific disease to 187.12% for those with severe HFMD. The loss of DALYs for the 5 forms of disease were 3.47, 1.76, 1.07, 1.44, 1.22 person-years per 1000 persons, respectively. This study provides data on cost of treatment and health burden for diseases caused by EV71, which can be used in the evaluation of EV71 vaccine cost-effectiveness. PMID:26158689

  4. Retrieval of Iatrogenically Pushed Pulp Stone From Middle Third of Root Canal in Permanent Maxillary Central Incisor: A Case Report

    PubMed Central

    Juneja, Suruchi; Randhawa, Sohajpreet; Dhebar, Tejal Malay; Raheja, Anupama

    2015-01-01

    The pulp stones are the discrete nodular calcified masses commonly existing in coronal and occasionally in radicular pulp, placed freely, attached or embedded into the dentine. The present case report revealed the iatrogenic pushing of pulp stone and blockage of root canal that caused endodontic failure. The case enlightens the proper use of ultrasonic instruments with irrigating solutions to manage the calcifications in root canal for successful endodontic therapy. PMID:26266224

  5. Autotransplantation combined with orthodontic treatment: a case involving the maxillary central incisors with root resorption after traumatic injury

    PubMed Central

    Ferreira, Hugo M.; Botelho, Filomena; Carrilho, Eunice

    2015-01-01

    Traumatic dental injury can result in avulsion of anterior teeth. In young patients, it is a challenge to the dental professional because after replantation, late complications such as ankylosis require tooth extraction. Although prosthetic and orthodontic treatment, and implant placement have been described as the options for intervention, autogenous tooth transplantation could be an effective procedure in growing patients if there is a suitable donor tooth available. This case presents the treatment of a patient who suffered a traumatic injury at 9 years old with avulsion of tooth 21, which had been replanted, and intrusion of tooth 11. Both teeth ankylosed; thus they were removed and autotransplantation of premolars was carried out. After transplantation, the tooth underwent root canal treatment because of pulpal necrosis. Orthodontic treatment began 3 months after transplantation and during 7 years' follow-up the aesthetics and function were maintained without signs of resorption. PMID:26295028

  6. A Rare Case of Bilateral Agenesis of Central Lower Incisors Associated With Upper Impacted Canine- A Case Report

    PubMed Central

    PORUMB, Anca; IGNAT ROMANUL, Ioana; DALAI, Camelia; CIAVOI, Gabiela; TIG, Ioan Andrei

    2016-01-01

    This case of a female patient, 14 yr old with association of the two anomalies, which we came across with in 2014, is rarely met in the specialty practice. The impacted canines are part of the group of dental anomalies of position, while the agenesis is part of the group of dental number anomalies. The orthodontic treatment in the two arches has to be differentiated, the therapeutic objectives being, also different in the two arches. PMID:27141502

  7. Double talon cusps on supernumerary tooth fused to maxillary central incisor: Review of literature and report of case

    PubMed Central

    2014-01-01

    Human tooth development is a continuous process begin at the sixth weeks in utero and extends to about sixth months after birth for the primary dentition and from sixteenth week in utero to late adolescence for permanent dentition. There is no other organ of the human body which takes so long to attain its ultimate morphology as dentition. Several physiologic growth processes participate in the progressive development of the teeth including: initiation, proliferation, histodifferentiation, morphodifferentiation, apposition, calcification, and eruption. Aberrations in different stages of tooth development can result in unique manifestations both in primary and permanent dentitions. The fact that premaxilla is the predilection site for the occurrence of supernumerary teeth, talon cusp, dens invaginatus, and geminated teeth may suggest that the embryological development of premaxilla differ from other sites of the jaws. The dental abnormalities presented in this review are of great concern to dentist and parents because they create clinical, pathological and esthetic problems. Dental practitioner should be aware of the clinical sign, associated problems and treatment options for a given case. Key words:Double talon cusps, fusion, supernumerary, case report. PMID:25593664

  8. Mediating pathways from central obesity to childhood asthma: a population-based longitudinal study.

    PubMed

    Chih, An-Hsuan; Chen, Yang-Ching; Tu, Yu-Kang; Huang, Kuo-Chin; Chiu, Tai-Yuan; Lee, Yungling Leo

    2016-09-01

    The mediating pathways linking obesity and asthma are largely unknown. We aimed to investigate the mediating pathways and to search for the most prominent pathological mechanism between central obesity and childhood asthma.In the Taiwan Children Health Study, we collected data on an open cohort of children aged 9-13 years. Children's respiratory outcomes, atopic conditions, obesity measures and pulmonary function were surveyed annually between 2010 and 2012. Exhaled nitric oxide fraction concentrations were recorded in 2012. Generalised estimating equations and general linear models were used to examine the associations between central obesity, possible mediators and asthma. Structural equation models were applied to investigate the pathways that mediate the link between central obesity and asthma.Central obesity (waist-to-hip ratio) most accurately predicted childhood asthma. In the active asthma model, the percentage of mediation was 28.6% for pulmonary function, 18.1% for atopy and 5.7% for airway inflammation. The percentage of mediation for pulmonary function was 40.2% in the lifetime wheeze model. Pulmonary function was responsible for the greatest percentage of mediation among the three mediators in both models.Decline in pulmonary function is the most important pathway in central obesity related asthma. Pulmonary function screening should be applied to obese children for asthma risk prediction.

  9. A device for continuous monitoring of true central fixation based on foveal birefringence.

    PubMed

    Gramatikov, Boris; Irsch, Kristina; Müllenbroich, Marie; Frindt, Nicole; Qu, Yinhong; Gutmark, Ron; Wu, Yi-Kai; Guyton, David

    2013-09-01

    A device for continuous monitoring of central fixation utilizes birefringence, the property of the Henle fibers surrounding the human fovea, to change the polarization state of light. A circular scan of retinal birefringence, where the scanning circle encompasses the fovea, allows identification of true central fixation-an assessment much needed in various applications in ophthalmology, psychology, and psychiatry. The device allows continuous monitoring for central fixation over an extended period of time in the presence of fixation targets and distracting stimuli, which may be helpful in detecting attention deficit hyperactivity disorder, autism spectrum disorders, and other disorders characterized by changes in the subject's ability to maintain fixation. A proof-of-concept has been obtained in a small study of ADHD patients and normal control subjects.

  10. Direct evidence of central European forest refugia during the last glacial period based on mollusc fossils

    NASA Astrophysics Data System (ADS)

    Juřičková, Lucie; Horáčková, Jitka; Ložek, Vojen

    2014-07-01

    Although there is evidence from molecular studies for the existence of central European last glacial refugia for temperate species, there is still a great lack of direct fossil records to confirm this theory. Here we bring such evidence in the form of fossil shells from twenty strictly forest land snail species, which were recorded in radiocarbon-dated late glacial or older mollusc assemblages of nine non-interrupted mollusc successions situated in the Western Carpathians, and one in the Bohemian Massif. We proposed that molluscs survived the last glacial period in central Europe in isolated small patches of broadleaf forest, which we unequivocally demonstrate for two sites of last glacial maximum age.

  11. Comparing the Gibraltar and Calabrian subduction zones (central western Mediterranean) based on seismic tomography

    NASA Astrophysics Data System (ADS)

    Argnani, Andrea; Battista Cimini, Giovanni; Frugoni, Francesco; Monna, Stephen; Montuori, Caterina

    2016-04-01

    The Central Western Mediterranean (CWM) was shaped by a complex tectonic and geodynamic evolution. Deep seismicity and tomographic studies point to the existence, under the Alboran and Tyrrhenian Seas, of lithospheric slabs extending down to the bottom of the mantle transition zone, at 660 km depth. Two narrow arcs correspond to the two slabs, the Gibraltar and Calabrian Arcs (e.g., Monna et al., 2013; Montuori et al., 2007). Similarities in the tectonic and mantle structure of the two areas have been explained by a common subduction and roll-back mechanism for the opening of the CWM, in which the two arcs are symmetrical end products. In spite of this unifying model, a wide amount of literature from different disciplines shows that many aspects of the two areas are still controversial. We present a new 3-D tomographic model at mantle scale for the Calabrian Arc and compare it with a recently published 3-D tomographic model for the Gibraltar Arc by Monna et al (2013). The two models are based on non-linear inversion of teleseismic phase arrivals, and have scale and parametrization that allow for a direct comparison. Unlike previous studies the tomographic models here presented include Ocean Bottom Seismometer broadband data, which improved the resolution of the mantle structures in the marine areas surrounding the arcs. We focus on key features of the two models that constrain reconstructions of the geodynamic evolution of the CWM (e.g., Monna et al., 2015). At Tortonian time the opening of the Tyrrhenian basin was in its initial stage, and the Calabrian arc formed subsequently; on the contrary, the Gibraltar arc was almost completely defined. We hypothesize that the complexity of the continental margin approaching the subduction zone played a key role during the final stages of the arc formation. References Monna, S., G. B. Cimini, C. Montuori, L. Matias, W. H. Geissler, and P. Favali (2013), New insights from seismic tomography on the complex geodynamic evolution

  12. Paleoceanography of the Eocene Central Arctic Basin Based on Geochemical Measurements of Biogenic Matter

    NASA Astrophysics Data System (ADS)

    Takahashi, K.-; Ogawa, Y.-; Onodera, J.-

    2006-12-01

    The IODP Leg 302 Arctic Coring Expedition retrieved approximately 120 m long continuous Eocene section from the Lomonosov Ridge in the central Arctic for the first time. The Eocene section is lithologically classified into Unit 2 with the assigned age of ~49-44Ma below and Unit 1/6 with 44Ma above the unit boundary. Unit 2 consists of very dark gray mud bearing siliceous ooze and Unit 1/6 consists of very dark gray silty clay to clayey silt. Biogenic opal (293 samples), organic carbon, nitrogen, and sulfur (150 samples) were measured. The sample resolutions are approximately 16 kyrs for Unit 2 and 8 kyrs interval for Unit 1/6, respectively. In Unit 2 biogenic opal ranged from 40 to 70% whereas in Unit 1/6, it decreased down to 10-20%, except for a peak of 37% at approximately 203 mbsf. Organic carbon consistently showed high values such as 1.4-5.7% both in Units 2 and 1/6. C/N ratios ranged from 15 to 20. Sulfur values ranged 2.6-7.7% in Unit 2 and it significantly increased to 4.0-19.4% in Unit 1/6. Based on the presence of abundant framboidal pyrites and the observed extremely low C/S ratios of <1.2 clearly indicate that the basin was under euxinic marine condition with sluggish bottom water circulation. Siliceous plankton mainly contributed to the biological productivity from 250 to 220 mbsf in Unit 2 and from 216 to 207 mbsf in Unit 1/6, judging from positive correlations of %biogenic opal vs %organic carbon. In other parts of the section such a positive correlation was not seen, implying something else other than siliceous plankton mainly contributed the total productivity. From Unit 2 to Unit 1/6, three rather drastic environmental changes are suggested: decrease of siliceous plankton productivity, increase of sulfate availability, and intensification of the euxinic conditions. In Unit 1/6 where sulfur values significantly increased, an increase of marine water inflow from the North Atlantic suggested by a study on silicofragellates assemblages. The marine

  13. Estimation of Evapotranspiration of Almond orchards using Remote Sensing based SEBAL model in Central Valley, California

    NASA Astrophysics Data System (ADS)

    Roy, S.; Ustin, S.; Kefauver, S. C.

    2009-12-01

    Evapotranspiration is one of the main components of the hydrologic cycle and its impact to hydrology, agriculture,forestry and environmental studies is very crucial. SEBAL (Surface Energy Balance Algorithm for Land) is an image-processing model comprised of twenty-five computational sub-models that computes actual evapotranspiration (ETa) and other energy exchanges as a component of energy balance which is used to derive the surface radiation balance equation for the net surface radiation flux (Rn) on a pixel-by-pixel basis. For this study, SEBAL method is applied to Level 1B dataset of visible, near-infrared and thermal infrared radiation channels of MASTER instrument on-board NASA-DC 8 flight. This paper uses the SEBAL method to (1) investigate the spatial distribution property of land surface temperature (Ls), NDVI, and ETa over the San Joaquin valley. (2) Estimate actual evapotranspiration of almond class on pixel-by-pixel basis in the Central valley, California. (3) Comparison of actual Evapotranspiration obtained from SEBAL model with reference evapotranspiration (Eto) using Penman Monteiths method based on the procedures and available data from California Irrigation Management Information System (CIMIS) stations. The results of the regression between extracted land surface temperature, NDVI and, evapotranspiration show negative (-) correlation. On the other hand Ls possessed a slightly stronger negative correlation with the ETa than with NDVI for Almond class. The correlation coefficient of actual ETa estimates from remote sensing with Reference ETo from Penmann Monteith are 0.8571. ETa estimated for almond crop from SEBAL were found to be almost same with the CIMIS_Penman Monteith method with bias of 0.77 mm and mean percentage difference is 0.10%. These results indicate that combination of MASTER data with surface meteorological data could provide an efficient tool for the estimation of regional actual ET used for water resources and irrigation scheduling

  14. Geodiversity of the Umbria region (central Italy): a GIS-based quantitative index

    NASA Astrophysics Data System (ADS)

    Melelli, Laura; Pica, Alessia; Del Monte, Maurizio

    2014-05-01

    The measure of natural range related to geological bedrock, landforms and geomorphological processes is the necessary starting point to geodiversity evaluation. Geodiversity plays a strategic role in landscape management. Whereas geotourism and geosites are identified as a driving power for the scientific and economic promotion of an area, the geodiversity knowledge is required for a complete and accurate research. For example, high values of this abiotic parameter identify and support the foundation of geoparks. According to this perspective, the geodiversity is the unifying factor for these areas of interest. While a subjective and qualitative approach may be adequate for geosites definition, identification and cultural promotion, the geodiversity concept needs a different evaluation method. A quantitative procedure allows achieving an objective and repeatable process exportable in different geographic units. Geographical Information Systems and spatial analysis techniques are the base to quantitative evaluation involving topographic, geological and geomorphological data. Therefore, the assessment of a numerical index derived from the overlay of spatial parameters can be conveniently computed in GIS environment. In this study, a geodiversity index is proposed where geological, geomorphological and landcover factors deriving mainly from maps and field survey; topographic ones are employed from DEM and remote sensed data. Each abiotic parameter is modelled in a grid format; focal functions do provide neighbourhood analysis and computing variety statistics. A particular extent is dedicated to topographic information and terrain roughness, that are strictly related to efficiency of geomorphological processes and generally corresponding to the abiotic components variability. The study area is located in central Italy and is characterized by a well known natural heritage. Thirty-seven geosites are detected in the Umbria region, where seven regional and one natural

  15. Sexual Precocity--Genetic Bases of Central Precocious Puberty and Autonomous Gonadal Activation.

    PubMed

    Macedo, Delanie Bulcão; Silveira, Letícia Ferreira Gontijo; Bessa, Danielle Souza; Brito, Vinicius Nahime; Latronico, Ana Claudia

    2016-01-01

    Precocious puberty has been classically defined as the onset of sexual secondary characteristics in girls younger than 8 years and in boys younger than 9 years. The discovery of potential factors which trigger human puberty is one of the central mysteries of reproductive biology. Several approaches, including mutational analysis of candidate genes, large-scale genome-wide association studies, and (more recently) whole-exome sequencing, have been performed in attempt to identify novel genetic factors that modulate the human hypothalamic-pituitary-gonadal axis, resulting in premature sexual development. In the last two decades, it has been well established that autonomous gonadal activation can be caused by somatic (GNAS) or germline (LHCGR)-activating mutations of genes that encode essential elements for signal transduction of G protein-coupled receptors, resulting in peripheral precocious puberty in McCune-Albright syndrome and testotoxicosis, respectively. More recently, dominant activating and inactivating mutations of excitatory (KISS1/KISS1R) and inhibitory (MKRN3) modulators of gonadotropin-releasing hormone secretion, respectively, were associated with central precocious puberty phenotype. Indeed, loss-of-function mutations of MKRN3, a maternal imprinted gene located at chromosome 15q, currently represent a frequent cause of central precocious puberty diagnosed in families from distinct geographic origins. Here, we review the known genetic defects in central and peripheral precocious puberty.

  16. Sensor-based mapping of soil quality on degraded claypan landscapes of the central United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Claypan soils (Epiaqualfs) in the central USA have experienced severe erosion as a result of tillage practices of the late 1800s and 1900s. Because of the site-specific nature of erosion processes within claypan fields, research is needed to achieve cost-effective sensing and mapping of soil and lan...

  17. Isotopic constraints on the genesis of base-metal ores in southern and central Sardinia

    USGS Publications Warehouse

    Ludwig, K. R.; Vollmer, R.; Turi, B.; Simmons, K.R.; Perna, G.

    1989-01-01

    The Pb-Zn-Ag deposits of southwestern and central Sardinia occur within a restricted region, but comprise a variety of mineralization ages and styles. New Pb-isotope data, together with published data provide a reasonably coherent picture of possible sources for the various types of deposits. -from Authors

  18. Comparative failure load values of acrylic resin denture teeth bonded to three different heat cure denture base resins: An in vitro study

    PubMed Central

    Phukela, Sumit Singh; Dua, Amit; Dua, Mahima; Sehgal, Varun; Setya, Gaurav; Dhall, Rupinder Singh

    2016-01-01

    Aim and Objectives: Acrylic teeth are used for fabrication of dentures. Debonding of tooth – denture base bond is routine problem in dental practice. The aim of this study was to comparatively evaluate failure load of acrylic resin denture teeth bonded to three different heat resin. Materials and Methods: Four groups were created out of test samples central incisors (11). Group I: Control, whereas Group II, Group III and Group IV were experimental groups modified with diatoric hole, cingulum ledge lock and Teeth modified with both diatoric hole and cingulum ledge lock, respectively. These test specimens with 3 teeth (2 central [11, 21] and 1, lateral [12] incisors) positioned imitating arrangement of teeth in the conventional denture, prepared by three different heat cure materials (DPI, Trevalon, Acralyn-H). A shear load was applied at cingulum of central incisor (11) at 130° to its long axis using universal tester at a cross head speed of 5 mm/min until failure occurred. Failure load test was conducted and statistical analysis was performed using SPSS 16 software package (IBM Company, New York, U.S). Results: Highest failure load was seen in Group IV specimens, prepared by Trevalon but did not significantly differ from that of DPI. Conclusion: The failure load of bonding denture teeth to three different heat cure materials was notably affected by modifications of ridge lap before processing. The specimens with a combination of diatoric hole and cingulum ledge lock, prepared by Trevalon showed highest failure load but did not significantly vary from that of DPI. The control group prepared by Acralyn-H showed lowest failure load but did not significantly differ from that of DPI. PMID:27195221

  19. Secretion of Shh by a neurovascular bundle niche supports mesenchymal stem cell homeostasis in the adult mouse incisor

    PubMed Central

    Zhao, Hu; Feng, Jifan; Seidel, Kerstin; Shi, Songtao; Klein, Ophir; Sharpe, Paul; Chai, Yang

    2014-01-01

    Mesenchymal stem cells (MSCs) are typically defined by their in vitro characteristics, and as a consequence the in vivo identity of MSCs and their niches are poorly understood. To address this issue, we used lineage tracing in a mouse incisor model and identified the neurovascular bundle (NVB) as an MSC niche. We found that NVB sensory nerves secrete Shh protein, which activates Gli1 expression in periarterial cells that contribute to all mesenchymal derivatives. These periarterial cells do not express classical MSC markers used to define MSCs in vitro. In contrast, NG2+ pericytes represent an MSC subpopulation derived from Gli1+ cells; they express classical MSC markers and contribute little to homeostasis but are actively involved in injury repair. Likewise, incisor Gli1+ cells but not NG2+ cells exhibit typical MSC characteristics in vitro. Collectively, we demonstrate that MSCs originate from periarterial cells and are regulated by Shh secretion from a NVB. PMID:24506883

  20. CeFunMO: A centrality based method for discovering functional motifs with application in biological networks.

    PubMed

    Kouhsar, Morteza; Razaghi-Moghadam, Zahra; Mousavian, Zaynab; Masoudi-Nejad, Ali

    2016-09-01

    Detecting functional motifs in biological networks is one of the challenging problems in systems biology. Given a multiset of colors as query and a list-colored graph (an undirected graph with a set of colors assigned to each of its vertices), the problem is reduced to finding connected subgraphs, which best cover the multiset of query. To solve this NP-complete problem, we propose a new color-based centrality measure for list-colored graphs. Based on this newly-defined measure of centrality, a novel polynomial time algorithm is developed to discover functional motifs in list-colored graphs, using a greedy strategy. This algorithm, called CeFunMO, has superior running time and acceptable accuracy in comparison with other well-known algorithms, such as RANGI and GraMoFoNe. PMID:27454243

  1. Conservative Treatment of an Invaginated Maxillary Lateral Incisor with a C-shaped Canal Using Cone-Beam Computed Tomography

    PubMed Central

    Forghani, Maryam; Moghim Farooji, Elaheh; Abuchenari, Javad; Bidar, Maryam; Eslami, Neda

    2015-01-01

    This report describes the non-surgical treatment of an invaginated maxillary lateral incisor with two fused roots. The mesial root had a C-shaped canal, while the distal one had a type III dens invagination. Cone-beam computed tomography (CBCT) was used to help with the diagnosis and treatment decision making. Clinical and radiographic follow-up revealed satisfactory periapical repair and absence of symptoms after 15 months. PMID:26576164

  2. Replacement of missing lateral incisors with lithium disilicate glass-ceramic veneer-fixed dental prostheses: a clinical report

    PubMed Central

    Bissasu, Sami M; Al-houri, Nabil A

    2014-01-01

    Key Clinical Message This report describes the use of lithium disilicate glass-ceramic veneer-fixed dental prostheses in replacing congenitally missing maxillary lateral incisors. This kind of prosthesis has an advantage over a lingual-retainer resin-bonded fixed dental prosthesis in its capability of changing the color and shape of the abutment teeth. The prostheses provided an acceptable esthetics and comfort for the patient. PMID:25356269

  3. Treatment outcome and efficacy of an aligner technique – regarding incisor torque, premolar derotation and molar distalization

    PubMed Central

    2014-01-01

    Background The aim of this study was to investigate the efficacy of orthodontic treatment using the Invisalign® system. Particularly, we analyzed the influence of auxiliaries (Attachment/Power Ridge) as well as the staging (movement per aligner) on treatment efficacy. Methods We reviewed the tooth movements of 30 consecutive patients who required orthodontic treatment with Invisalign®. In all patients, one of the following tooth movements was performed: (1) Incisor Torque >10°, (2) Premolar derotation >10° (3) Molar distalization >1.5 mm. The groups (1)-(3) were subdivided: in the first subgroup (a) the movements were supported with the use of an attachment, while in the subgroup (b) no auxiliaries were used (except incisor torque, in which Power Ridges were used). All tooth movements were performed in a split-mouth design. To analyze the clinical efficacy, pre-treatment and final plaster cast models were laser-scanned and the achieved tooth movement was determined by way of a surface/surface matching algorithm. The results were compared with the amount of tooth movement predicted by ClinCheck®. Results The overall mean efficacy was 59% (SD = 0.2). The mean accuracy for upper incisor torque was 42% (SD = 0.2). Premolar derotation showed the lowest accuracy with approximately 40% (SD = 0.3). Distalization of an upper molar was the most effective movement, with efficacy approximately 87% (SD = 0.2). Conclusion Incisor torque, premolar derotation and molar distalization can be performed using Invisalign® aligners. The staging (movement/aligner) and the total amount of planned movement have an significant impact on treatment efficacy. PMID:24923279

  4. Mineral Deposit Data for Epigenetic Base- and Precious-metal and Uranium-thorium Deposits in South-central and Southwestern Montana and Southern and Central Idaho

    USGS Publications Warehouse

    Klein, T.L.

    2004-01-01

    Metal deposits spatially associated with the Cretaceous Boulder and Idaho batholiths of southwestern Montana and southern and central Idaho have been exploited since the early 1860s. Au was first discovered in placer deposits; exploitation of vein deposits in bedrock soon followed. In 1865, high-grade Ag vein deposits were discovered and remained economically important until the 1890s. Early high-grade deposits of Au, Ag and Pb were found in the weathered portions of the veins systems. As mining progressed to deeper levels, Ag and Pb grades diminished. Exploration for and development of these vein deposits in this area have continued until the present. A majority of these base- and precious-metal vein deposits are classified as polymetallic veins (PMV) and polymetallic carbonate-replacement (PMR) deposits in this compilation. Porphyry Cu and Mo, epithermal (Au, Ag, Hg and Sb), base- and precious-metal and W skarn, W vein, and U and Th vein deposits are also common in this area. The world-class Butte Cu porphyry and the Butte high-sulfidation Cu vein deposits are in this study area. PMV and PMR deposits are the most numerous in the region and constitute about 85% of the deposit records compiled. Several types of syngenetic/diagenetic sulfide mineral deposits in rocks of the Belt Supergroup or their equivalents are common in the region and they have been the source of a substantial metal production over the last century. These syngenetic deposits and their metamorphosed/structurally remobilized equivalents were not included in this database; therefore, deposits in the Idaho portion of the Coeur d'Alene district and the Idaho Cobalt belt, for example, have not been included because many of them are believed to be of this type.

  5. The Relationship between Palatal Displacement of Upper Canines and Incisors Widths in a Syrian Sample of Patients with Uncrowded Arches.

    PubMed

    Mahaini, Luai

    2015-11-01

    The aim of this study investigates mesiodistal crown size of the maxillary and mandibular incisors of patients with palatally impacted canines (PDC). Pretreatment dental casts of orthodontic patients with PDC of one or both maxillary canines (N: 33) were collected. This PDC sample was matched according to age and sex with pretreatment dental casts from unaffected orthodontic patients. For the PDC and matched control samples, maximum mesiodistal crown diameters were recorded for the four incisors on the right side only. The results showed that, on average, the mesiodistal crown diameters for the maxillary and mandibular incisors measured smaller in the PDC sample than in the control sample. These findings of statistically significant tooth-size reductions associated with PDC occurrence indicate a generalized pattern of reduced tooth size as a characteristic associated with the PDC anomaly. Further, the presence of generalized tooth-size reduction in cases with palatally displaced canines help explain why most orthodontic treatment plans for PDC patients are of the nonextraction type.

  6. Finite element analysis of maxillary incisor displacement during en-masse retraction according to orthodontic mini-implant position

    PubMed Central

    Song, Jae-Won; Lim, Joong-Ki; Lee, Kee-Joon; Sung, Sang-Jin; Chun, Youn-Sic

    2016-01-01

    Objective Orthodontic mini-implants (OMI) generate various horizontal and vertical force vectors and moments according to their insertion positions. This study aimed to help select ideal biomechanics during maxillary incisor retraction by varying the length in the anterior retraction hook (ARH) and OMI position. Methods Two extraction models were constructed to analyze the three-dimentional finite element: a first premolar extraction model (Model 1, M1) and a residual 1-mm space post-extraction model (Model 2, M2). The OMI position was set at a height of 8 mm from the arch wire between the second maxillary premolar and the first molar (low OMI traction) or at a 12-mm height in the mesial second maxillary premolar (high OMI traction). Retraction force vectors of 200 g from the ARH (-1, +1, +3, and +6 mm) at low or high OMI traction were resolved into X-, Y-, and Z-axis components. Results In M1 (low and high OMI traction) and M2 (low OMI traction), the maxillary incisor tip was extruded, but the apex was intruded, and the occlusal plane was rotated clockwise. Significant intrusion and counter-clockwise rotation in the occlusal plane were observed under high OMI traction and -1 mm ARH in M2. Conclusions This study observed orthodontic tooth movement according to the OMI position and ARH height, and M2 under high OMI traction with short ARH showed retraction with maxillary incisor intrusion. PMID:27478801

  7. α11β1 Integrin-Dependent Regulation of Periodontal Ligament Function in the Erupting Mouse Incisor

    PubMed Central

    Popova, Svetlana N.; Barczyk, Malgorzata; Tiger, Carl-Fredrik; Beertsen, Wouter; Zigrino, Paola; Aszodi, Attila; Miosge, Nicolai; Forsberg, Erik; Gullberg, Donald

    2007-01-01

    The fibroblast integrin α11β1 is a key receptor for fibrillar collagens. To study the potential function of α11 in vivo, we generated a null allele of the α11 gene. Integrin α11−/− mice are viable and fertile but display dwarfism with increased mortality, most probably due to severely defective incisors. Mutant incisors are characterized by disorganized periodontal ligaments, whereas molar ligaments appear normal. The primary defect in the incisor ligament leads to halted tooth eruption. α11β1-defective embryonic fibroblasts displayed severe defects in vitro, characterized by (i) greatly reduced cell adhesion and spreading on collagen I, (ii) reduced ability to retract collagen lattices, and (iii) reduced cell proliferation. Analysis of matrix metalloproteinase in vitro and in vivo revealed disturbed MMP13 and MMP14 synthesis in α11−/− cells. We show that α11β1 is the major receptor for collagen I on mouse embryonic fibroblasts and suggest that α11β1 integrin is specifically required on periodontal ligament fibroblasts for cell migration and collagen reorganization to help generate the forces needed for axial tooth movement. Our data show a unique role for α11β1 integrin during tooth eruption. PMID:17420280

  8. Prediction of extreme floods in the eastern Central Andes based on a complex networks approach

    NASA Astrophysics Data System (ADS)

    Boers, N.; Bookhagen, B.; Barbosa, H. M. J.; Marwan, N.; Kurths, J.; Marengo, J. A.

    2014-10-01

    Changing climatic conditions have led to a significant increase in the magnitude and frequency of extreme rainfall events in the Central Andes of South America. These events are spatially extensive and often result in substantial natural hazards for population, economy and ecology. Here we develop a general framework to predict extreme events by introducing the concept of network divergence on directed networks derived from a non-linear synchronization measure. We apply our method to real-time satellite-derived rainfall data and predict more than 60% (90% during El Niño conditions) of rainfall events above the 99th percentile in the Central Andes. In addition to the societal benefits of predicting natural hazards, our study reveals a linkage between polar and tropical regimes as the responsible mechanism: the interplay of northward migrating frontal systems and a low-level wind channel from the western Amazon to the subtropics.

  9. Global economic restructuring and international migration: some observations based on the Mexican and Central American experience.

    PubMed

    Hamilton, N; Chinchilla, N S

    1996-01-01

    "The purpose of this article is to explore the relationship between processes of global economic restructuring and international migration through an examination of Mexican and Central American immigration to the U.S. and the experiences of Central American and Mexican immigrants in the U.S. This relationship is analysed as one of mutual causation: on the one hand, global restructuring affects conditions in both sending and receiving countries (it is not only a factor in emigration but also in the economic and political receptivity to immigrants at their point of destination); on the other, international migration in turn has an important impact on countries of origin, receiving countries, and the relationship between them." (SUMMARY IN FRE AND SPA) PMID:12347343

  10. New Structural Interpretation of the Central Confusion Range, Western Utah, Based On Balanced Cross Sections

    NASA Astrophysics Data System (ADS)

    Yezerski, D.; Greene, D. C.

    2009-12-01

    The Confusion Range is a topographically low mountain range in the Basin and Range of west-central Utah, located east of and in the hanging wall of the Snake Range core complex. Previous workers have used a gravity sliding model to interpret the Confusion Range as a large structural trough or synclinorium (e.g. Hose, 1977). Based on existing mapping (Hose, 1965; Hintze, 1974) and new field data, we use balanced and restored cross sections to reinterpret the structure of the Confusion Range as an east-vergent fold-and-thrust belt formed during the Sevier Orogeny. The Confusion Range consists of Cambro-Ordovician through Triassic strata, with predominantly thick-bedded, competent carbonate rocks in the lower Paleozoic (lPz) section and incompetent shales and thin-bedded carbonates in the upper Paleozoic (uPz) section. The contrasting mechanical behavior of these stratigraphic sections results in faulted folds within uPz carbonates above detachments in shale-rich units, deforming in response to ramp-flat thrust faulting of the underlying lPz units. East of the axis of the Conger Mountain (Mtn) syncline, we attribute the increase in structural elevation of lPz rocks to a subsurface thrust sheet consisting of lPz strata that advanced eastward via a high-angle ramp from a lower detachment in the Kanosh Shale to an upper detachment in the Pilot Shale. The doubling of lPz strata that resulted continues through the eastern Confusion Range where a series of small-displacement thrust faults comprising the Kings Canyon thrust system gently tilt strata to the west. In the Conger Range, west of the Conger Mtn syncline, our analysis focuses on reinterpreting the geometrically unlikely folding depicted in previous cross sections as more admissible, fault-cored, asymmetric, detached folding. In our interpretation, resistance created by a steeply-dipping thrust ramp in the lPz section west of Conger Mtn resulted in folding of uPz strata into an east-vergent anticline. Continued east

  11. Genes expressed in dental enamel development are associated with molar-incisor hypomineralization.

    PubMed

    Jeremias, Fabiano; Koruyucu, Mine; Küchler, Erika C; Bayram, Merve; Tuna, Elif B; Deeley, Kathleen; Pierri, Ricardo A; Souza, Juliana F; Fragelli, Camila M B; Paschoal, Marco A B; Gencay, Koray; Seymen, Figen; Caminaga, Raquel M S; dos Santos-Pinto, Lourdes; Vieira, Alexandre R

    2013-10-01

    Genetic disturbances during dental development influence variation of number and shape of the dentition. In this study, we tested if genetic variation in enamel formation genes is associated with molar-incisor hypomineralization (MIH), also taking into consideration caries experience. DNA samples from 163 cases with MIH and 82 unaffected controls from Turkey, and 71 cases with MIH and 89 unaffected controls from Brazil were studied. Eleven markers in five genes [ameloblastin (AMBN), amelogenin (AMELX), enamelin (ENAM), tuftelin (TUFT1), and tuftelin-interacting protein 11 (TFIP11)] were genotyped by the TaqMan method. Chi-square was used to compare allele and genotype frequencies between cases with MIH and controls. In the Brazilian data, distinct caries experience within the MIH group was also tested for association with genetic variation in enamel formation genes. The ENAM rs3796704 marker was associated with MIH in both populations (Brazil: p=0.03; OR=0.28; 95% C.I.=0.06-1.0; Turkey: p=1.22e-012; OR=17.36; 95% C.I.=5.98-56.78). Associations between TFIP11 (p=0.02), ENAM (p=0.00001), and AMELX (p=0.01) could be seen with caries independent of having MIH or genomic DNA copies of Streptococcus mutans detected by real time PCR in the Brazilian sample. Several genes involved in enamel formation appear to contribute to MIH.

  12. Er:YAG Laser and Fractured Incisor Restorations: An In Vitro Study

    PubMed Central

    Fornaini, C.; Petruzzella, S.; Podda, R.; Merigo, E.; Nammour, S.; Vescovi, P.

    2012-01-01

    Introduction. The aim of this study was to analyse the effects of an Er:YAG laser on enamel and dentine in cases of dental restorations involving fractured teeth, utilizing the dental fragment. Materials and Methods. Seventy-two freshly extracted bovine incisors were fractured at the coronal level by using a hammer applied with a standardized method, and the fragment was reattached by using three different methods: Er:YAG laser, orthophosphoric acid, and laser plus acid. The different groups were evaluated by a test realized with the dynamometer to know the force required to successfully detach the reattached fragment and by a microinfiltration test by using a 0.5% methylene blue solution followed by the optic microscope observation. Results. The compression test showed only a slight difference between the three groups, without any statistical significance. The infiltration test used to evaluate the marginal seal between the fracture fragment and the tooth demonstrated that etching with Er:YAG laser alone or in combination with orthophosphoric acid gives better results than orthophosphoric acid alone, with a highly significant statistical result. Discussion. Reattaching a tooth fragment represents a clinically proven methodology, in terms of achieving resistance to detachment, and the aim of this work was to demonstrate the advantages of Er:YAG laser on this procedure. Conclusion. This “in vitro” study confirms that Er:YAG laser can be employed in dental traumatology to restore frontal teeth after coronal fracture. PMID:23091491

  13. Computer-assisted intraosseous anaesthesia for molar and incisor hypomineralisation teeth. A preliminary study.

    PubMed

    Cabasse, C; Marie-Cousin, A; Huet, A; Sixou, J L

    2015-03-01

    Anesthetizing MIH (Molar and Incisor Hypomineralisation) teeth is one of the major challenges in paediatric dentistry. Computer-assisted IO injection (CAIO) of 4% articaine with 1:200,000 epinephrine (Alphacaine, Septodont) has been shown to be an efficient way to anesthetize teeth in children. The aim of this study was to assess the efficacy of this method with MIH teeth. This preliminary study was performed using the Quick Sleeper system (Dental Hi Tec, Cholet, France) that allows computer-controlled rotation of the needle to penetrate the bone and computer-controlled injection of the anaesthetic solution. Patients (39) of the department of Paediatric Dentistry were included allowing 46 sessions (including 32 mandibular first permanent molars) to be assessed. CAIO showed efficacy in 93.5% (43/46) of cases. Failures (3) were due to impossibility to reach the spongy bone (1) and to achieve anaesthesia (2). This prospective study confirms that CAIO anaesthesia is a promising method to anesthetize teeth with MIH that could therefore be routinely used by trained practitioners.

  14. The application of fiber core posts in restoring badly destroyed primary incisors.

    PubMed

    Sharaf, Aly A

    2002-01-01

    Early childhood caries (ECC) represents a challenge to pediatric dentists especially, when teeth are badly destroyed. ECC involves the upper anterior teeth early in life and by the time the dentist sees the child, most of the coronal structure is lost. Dentally, this is a very devastating situation for both the dentist and parents, as in many cases, extraction of these teeth is the only option. With the introduction of new adhesive systems and restorative materials, a new approach for treating these teeth is explained and documented by clinical cases, where fiber core posts are introduced into the root canals of primary incisors for a distance of 2 to 3 mm. It is retained in place by flowable composite, then the coronal part is reconstructed by a strip crown to restore the crown form. After a follow up period of one year, only 2 teeth out of 30 had to be extracted. The failure was attributed to failure in pulpal therapy rather than failure in the restorations, which were totally intact. A laboratory testing of the fracture load resistance of the restored teeth proved that this technique significantly improved the fracture load resistance of composite celluloid crowns, making it a valuable procedure to consider when the coronal tooth structure is not enough to support and retain a composite celluloid strip crown. PMID:11990042

  15. Relapse of incisor crowding: A visit to the prince of salina

    PubMed Central

    Gandía, Jose L.

    2013-01-01

    The management of the retention period after comprehensive orthodontic treatment is of great importance, as a primary goal of clinician. Considerable controversy still surrounds the problem of stability after the retention period. Many studies analyze factors associated to the presence of crowding or incisor irregularity and find predictive features on its relapse. Most studies have reported little o no correlation between the treatment changes in the biological parameters - clinical, biometric (irregularity index, intermolar width, intercanine width, arch length, overjet, overbite), or cephalometric variables- that ocurred and the posttretament and postretention changes that may predict their future development. This article provides a bibliographical overview on the relapse of dental alignment in treated cases. In a brief historical introduction, the first studies on the long-term stability of orthodontic results are analysed. The article then goes on to assess studies that focus attention on anteroinferior alignment before finally studying relapse of upper crowding. It concludes by making some final comments in the light of the bibliography provided and the differents schools regarding retention needs and methods. Key words:Retention, stability, irregularity, dental alignment. PMID:23229267

  16. Modified subfossil aye-aye incisors from southwestern Madagascar: species allocation and paleoecological significance.

    PubMed

    MacPhee, R D; Raholimavo, E M

    1988-01-01

    Two of the three drilled aye-aye incisors collected in 1901 by Grandidier at the subfossil site of Lamboharana were recently rediscovered in uncatalogued collections of the Institut de Paléontologie in Paris. These teeth are not much wider or thicker than those of the extant aye-aye (Daubentonia madagascariensis), but their arc of curvature is noticeably greater. These facts indicate that the teeth probably belong to D. robusta, a large extinct aye-aye whose dentition is otherwise unknown. No other remains referable to Daubentonia have been reported from Lamboharana, although D. robusta is known from other localities in the southwest. The presence of Daubentonia in southern Madagascar does not demonstrate that this region was markedly more humid or densely forested in the recent past. It remains to be established whether the extinction of D. robusta throughout its range in southern Madagascar, and local disappearance of D. madagascariensis everywhere but in the eastern forest biotope, is due to late Holocene climatic change, to anthropogenic effects, or both factors combined. PMID:3254846

  17. Genes Expressed in Dental Enamel Development Are Associated with Molar-Incisor Hypomineralization

    PubMed Central

    Jeremias, Fabiano; Koruyucu, Mine; Küchler, Erika C.; Bayram, Merve; Tuna, Elif B.; Deeley, Kathleen; Pierri, Ricardo A.; Souza, Juliana F.; Fragelli, Camila M.B.; Paschoal, Marco A.B.; Gencay, Koray; Seymen, Figen; Caminaga, Raquel M.S.; dos Santos-Pinto, Lourdes; Vieira, Alexandre R.

    2013-01-01

    Genetic disturbances during dental development influence variation of number and shape of the dentition. In this study, we tested if genetic variation in enamel formation genes is associated with molar-incisor hypomineralization (MIH), also taking into consideration caries experience. DNA samples from 163 cases with MIH and 82 unaffected controls from Turkey, and 71 cases with MIH and 89 unaffected controls from Brazil were studied. Eleven markers in five genes [ameloblastin (AMBN), amelogenin (AMELX), enamelin (ENAM), tuftelin (TUFT1), and tuftelin-interacting protein 11 (TFIP11)] were genotyped by the TaqMan method. Chi-square was used to compare allele and genotype frequencies between cases with MIH and controls. In the Brazilian data, distinct caries experience within the MIH group was also tested for association with genetic variation in enamel formation genes. The ENAM rs3796704 marker was associated with MIH in both populations (Brazil: p=0.03; OR=0.28; 95% C.I.=0.06–1.0; Turkey: p=1.22e–012; OR=17.36; 95% C.I.=5.98–56.78). Associations between TFIP11 (p=0.02), ENAM (p=0.00001), and AMELX (p=0.01) could be seen with caries independent of having MIH or genomic DNA copies of Streptococcus mutans detected by real time PCR in the Brazilian sample. Several genes involved in enamel formation appear to contribute to MIH. PMID:23790503

  18. A retrospective evaluation of 204 diagonal incisor malocclusion corrections in the horse.

    PubMed

    DeLorey, Mary S

    2007-09-01

    The goal of this retrospective study was to record the direction of the diagonal incisor malocclusion (DIM) and excursion to molar contact (EMC) distances both before and after corrective procedures to determine if any general trends were apparent which may aid in predicting the outcome of DIM corrections. Pre-correction and post-correction data were compared to confirm a benefit to the patient from the corrective procedure. The results of this preliminary study reveal a few general trends to serve as basic guidelines for the practitioner Lateral EMC distances to the left and right in cases of DIM are commonly asymmetric. When prudently performed, corrective measures usually result in increased symmetry of EMCs. In cases of DIM, the side with the shorter EMC is more likely to remain the same rather than change after DIM correction. Decreases of EMC in one or both directions are much more common than increases in EMC after correction. In 100-300 quadrant DIMs, the EMC to the right will most likely decrease and in 200-400 quadrant DIMs, the EMC to the left will most likely decrease. Despite these helpful findings, the data obtained from this study strongly suggest the existence of multiple etiologies and progressive compensatory mechanisms complicating precise prediction of correction outcome.

  19. The design of future central receiver power plants based on lessons learned from the Solar One Pilot Plant

    NASA Astrophysics Data System (ADS)

    Kolb, G. J.

    The 10-MW(sub e) Solar One Pilot Plant was the world's largest solar central receiver power plant. During its power production years it delivered over 37,000 MWhrs (net) to the utility grid. In this type of electric power generating plant, large sun-tracking mirrors called heliostats reflect and concentrate sunlight onto a receiver mounted on top of a tower. The receiver transforms the solar energy into thermal energy that heats water, turning it into superheated steam that drives a turbine to generate electricity. The Solar One Pilot Plant successfully demonstrated the feasibility of generating electricity with a solar central receiver power plant. During the initial 2 years the plant was tested and 4 years the plant was operated as a power plant, a great deal of data was collected relating to the efficiency and reliability of the plant's various systems. This paper summarizes these statistics and compares them to goals developed by the U.S. Department of Energy. Based on this comparison, improvements in the design and operation of future central receiver plants are recommended. Research at Sandia National Laboratories and the U.S. utility industry suggests that the next generation of central receiver power plants will use a molten salt heat transfer fluid rather than water/steam. Sandia has recently completed the development of the hardware needed in a molten salt power plant. Use of this new technology is expected to solve many of the performance problems encountered at Solar One. Projections for the energy costs from these future central receiver plants are also presented. For reference, these projections are compared to the current energy costs from the SEGS parabolic trough plants now operating in Southern California.

  20. Headset Bluetooth and cell phone based continuous central body temperature measurement system.

    PubMed

    Sanches, J Miguel; Pereira, Bruno; Paiva, Teresa

    2010-01-01

    The accurate measure of the central temperature is a very important physiologic indicator in several clinical applications, namely, in the characterization and diagnosis of sleep disorders. In this paper a simple system is described to continuously measure the body temperature at the ear. An electronic temperature sensor is coupled to the microphone of a common commercial auricular Bluetooth device that sends the temperature measurements to a mobile phone to which is paired. The measurements are stored at the mobile phone and periodically sent to a medical facility by email or SMS (short messaging service).

  1. Conservation action based on threatened species capture taxonomic and phylogenetic richness in breeding and wintering populations of Central Asian birds.

    PubMed

    Schweizer, Manuel; Ayé, Raffael; Kashkarov, Roman; Roth, Tobias

    2014-01-01

    Although phylogenetic diversity has been suggested to be relevant from a conservation point of view, its role is still limited in applied nature conservation. Recently, the practice of investing conservation resources based on threatened species was identified as a reason for the slow integration of phylogenetic diversity in nature conservation planning. One of the main arguments is based on the observation that threatened species are not evenly distributed over the phylogenetic tree. However this argument seems to dismiss the fact that conservation action is a spatially explicit process, and even if threatened species are not evenly distributed over the phylogenetic tree, the occurrence of threatened species could still indicate areas with above average phylogenetic diversity and consequently could protect phylogenetic diversity. Here we aim to study the selection of important bird areas in Central Asia, which were nominated largely based on the presence of threatened bird species. We show that although threatened species occurring in Central Asia do not capture phylogenetically more distinct species than expected by chance, the current spatially explicit conservation approach of selecting important bird areas covers above average taxonomic and phylogenetic diversity of breeding and wintering birds. We conclude that the spatially explicit processes of conservation actions need to be considered in the current discussion of whether new prioritization methods are needed to complement conservation action based on threatened species.

  2. Conservation Action Based on Threatened Species Capture Taxonomic and Phylogenetic Richness in Breeding and Wintering Populations of Central Asian Birds

    PubMed Central

    Schweizer, Manuel; Ayé, Raffael; Kashkarov, Roman; Roth, Tobias

    2014-01-01

    Although phylogenetic diversity has been suggested to be relevant from a conservation point of view, its role is still limited in applied nature conservation. Recently, the practice of investing conservation resources based on threatened species was identified as a reason for the slow integration of phylogenetic diversity in nature conservation planning. One of the main arguments is based on the observation that threatened species are not evenly distributed over the phylogenetic tree. However this argument seems to dismiss the fact that conservation action is a spatially explicit process, and even if threatened species are not evenly distributed over the phylogenetic tree, the occurrence of threatened species could still indicate areas with above average phylogenetic diversity and consequently could protect phylogenetic diversity. Here we aim to study the selection of important bird areas in Central Asia, which were nominated largely based on the presence of threatened bird species. We show that although threatened species occurring in Central Asia do not capture phylogenetically more distinct species than expected by chance, the current spatially explicit conservation approach of selecting important bird areas covers above average taxonomic and phylogenetic diversity of breeding and wintering birds. We conclude that the spatially explicit processes of conservation actions need to be considered in the current discussion of whether new prioritization methods are needed to complement conservation action based on threatened species. PMID:25337861

  3. Conservation action based on threatened species capture taxonomic and phylogenetic richness in breeding and wintering populations of Central Asian birds.

    PubMed

    Schweizer, Manuel; Ayé, Raffael; Kashkarov, Roman; Roth, Tobias

    2014-01-01

    Although phylogenetic diversity has been suggested to be relevant from a conservation point of view, its role is still limited in applied nature conservation. Recently, the practice of investing conservation resources based on threatened species was identified as a reason for the slow integration of phylogenetic diversity in nature conservation planning. One of the main arguments is based on the observation that threatened species are not evenly distributed over the phylogenetic tree. However this argument seems to dismiss the fact that conservation action is a spatially explicit process, and even if threatened species are not evenly distributed over the phylogenetic tree, the occurrence of threatened species could still indicate areas with above average phylogenetic diversity and consequently could protect phylogenetic diversity. Here we aim to study the selection of important bird areas in Central Asia, which were nominated largely based on the presence of threatened bird species. We show that although threatened species occurring in Central Asia do not capture phylogenetically more distinct species than expected by chance, the current spatially explicit conservation approach of selecting important bird areas covers above average taxonomic and phylogenetic diversity of breeding and wintering birds. We conclude that the spatially explicit processes of conservation actions need to be considered in the current discussion of whether new prioritization methods are needed to complement conservation action based on threatened species. PMID:25337861

  4. The use of web-based learning for simulation-based education and training of central venous catheterization in novice learners.

    PubMed

    Cheung, Jeffrey J H; Koh, Jansen; Mackinnon, Kim; Brett, Clare; Bägli, Darius; Kapralos, Bill; Dubrowski, Adam

    2013-01-01

    Both simulation-based education and training (SBET) and Web-based Learning (WBL) are increasingly used in medical education. We developed a Web-based learning course on "Observational Practice and Educational Networking" (OPEN), to augment SBET for central venous catheterization (CVC), a complex clinical skill, for novice learners. This pilot study aimed to firstly, understand the perspectives of novice learners on using WBL in preparation for SBET for a psychomotor skill and secondly, to observe how learners use the OPEN courseware to learn more about how to perform this skill. PMID:23400133

  5. Peripherally inserted central catheter: compliance with evidence-based indications for insertion in an inpatient setting.

    PubMed

    Wojnar, Danuta G; Beaman, Margaret L

    2013-01-01

    A randomized, retrospective chart review was conducted at a medium-sized community hospital to verify appropriateness of peripherally inserted central catheter (PICC) use in 49 inpatient patients. Study results support the Infusion Nurses Society recommendation to use PICCs to facilitate either short- or long-term intravenous therapy of vesicants, irritants, and any medications with a pH less than 5 or greater than 9 and osmolarity greater than 600 mOsm/L. All PICC insertion criteria recommended by the Centers for Disease Control and Prevention were met except one--the intended duration of intravenous therapy of more than 6 days. Identical PICC selection criteria are needed to standardize clinical practice. PMID:23823005

  6. Peripherally inserted central catheter: compliance with evidence-based indications for insertion in an inpatient setting.

    PubMed

    Wojnar, Danuta G; Beaman, Margaret L

    2013-01-01

    A randomized, retrospective chart review was conducted at a medium-sized community hospital to verify appropriateness of peripherally inserted central catheter (PICC) use in 49 inpatient patients. Study results support the Infusion Nurses Society recommendation to use PICCs to facilitate either short- or long-term intravenous therapy of vesicants, irritants, and any medications with a pH less than 5 or greater than 9 and osmolarity greater than 600 mOsm/L. All PICC insertion criteria recommended by the Centers for Disease Control and Prevention were met except one--the intended duration of intravenous therapy of more than 6 days. Identical PICC selection criteria are needed to standardize clinical practice.

  7. Prenatal factors associated with the neonatal line thickness in human deciduous incisors.

    PubMed

    Kurek, M; Żądzińska, E; Sitek, A; Borowska-Strugińska, B; Rosset, I; Lorkiewicz, W

    2015-06-01

    The neonatal line (NNL) is used to distinguish developmental events observed in enamel which occurred before and after birth. However, there are few studies reporting relationship between the characteristics of the NNL and factors affecting prenatal conditions. The aim of the study was to determine prenatal factors that may influence the NNL thickness in human deciduous teeth. The material consisted of longitudinal ground sections of 60 modern human deciduous incisors obtained from full-term healthy children with reported birth histories and prenatal factors. All teeth were sectioned in the labio-lingual plane using diamond blade (Buechler IsoMet 1000). Final specimens were observed using scanning electron microscopy at magnifications 320×. For each tooth, linear measurements of the NNL thickness were taken on its labial surface at the three levels from the cemento-enamel junction. The difference in the neonatal line thickness between tooth types and between males and females was statistically significant. A multiple regression analyses confirmed influence of two variables on the NNL thickness standardised on tooth type and the children's sex (z-score values). These variables are the taking of an antispasmodic medicine by the mother during pregnancy and the season of the child's birth. These two variables together explain nearly 17% of the variability of the NNL. Children of mothers taking a spasmolytic medicine during pregnancy were characterised by a thinner NNL compared with children whose mothers did not take such medication. Children born in summer and spring had a thinner NNL than children born in winter. These results indicate that the prenatal environment significantly contributes to the thickness of the NNL influencing the pace of reaching the post-delivery homeostasis by the newborn's organism. PMID:25618810

  8. Relationship between dental anomalies and orthodontic root resorption of upper incisors.

    PubMed

    Van Parys, Katrien; Aartman, Irene H A; Kuitert, Reinder; Zentner, Andrej

    2012-10-01

    The aim of this study was to examine the potential relationship between the occurrence of orthodontic root resorption and presence of dental anomalies such as tooth agenesis and pipette-shaped roots. Dental anomalies and root resorption were assessed on dental panoramic tomographs (DPT) of 88 subjects, 27 males and 61 females, mean age 28.4 (SD = 11.3 years), selected from orthodontic patients on the basis of the following exclusion criteria: previous fixed appliance treatment, bad quality of the DPTs and no visibility of the periodontal ligament of every tooth, and younger than 15 years of age at the onset of treatment with fixed edgewise appliance lasting at least 18 months. A pipette-shaped root was identified as defined by a drawing. Tooth agenesis was assessed on DPTs and from subjects' dental history. Root resorption was calculated as the difference between the root length before and after treatment, with and without a correction factor (crown length post-treatment/crown length pre-treatment). If one of the four upper incisors showed root resorption of ≥2.3 mm with both formulas, the patient was scored as having root resorption. Chi-square tests indicated that there was no relationship between orthodontic root resorption and agenesis (P = 0.885) nor between orthodontic root resorption and pipette-shaped roots (P = 0.800). There was no relationship between having one of the anomalies and root resorption either (P = 0.750). In the present study, it was not possible to confirm on DPTs a relationship between orthodontic root resorption and dental anomalies, such as agenesis and pipette-shaped roots.

  9. Intracanal bisphosphonate does not inhibit replacement resorption associated with delayed replantation of monkey incisors.

    PubMed

    Thong, Yo Len; Messer, Harold H; Zain, Rosnah Binti; Saw, Lip Hean; Yoong, Lai Thong

    2009-08-01

    Progressive replacement resorption following delayed replantation of avulsed teeth has proved to be an intractable clinical problem. A wide variety of therapeutic approaches have failed to result in the predictable arrest of resorption, with a good long-term prognosis for tooth survival. Bisphosphonates are used in the medical management of a range of bone disorders and topically applied bisphosphonate has been reported to inhibit root resorption in dogs. This study evaluated the effectiveness of a bisphosphonate (etidronate disodium) as an intracanal medicament in the root canals of avulsed monkey teeth, placed before replantation after 1 h of extraoral dry storage. Incisors of six Macaca fascicularis monkeys were extracted and stored dry for 1 h. Teeth were then replanted after canal contamination with dental plaque (negative control) or after root canal debridement and placement of etidronate sealed in the canal space. A positive control of calcium hydroxide placed 8-9 days after replantation was also included. All monkeys were sacrificed 8 weeks later and block sections were prepared for histomorphometric assessment of root resorption and periodontal ligament status. Untreated teeth showed the greatest extent of root resorption (46% of the root surface), which was predominantly inflammatory in nature. Calcium hydroxide treated teeth showed the lowest overall level of resorption (<30% of the root surface), while the bisphosphonate-treated group was intermediate (39%). Ankylosis, defined as the extent of the root surface demonstrating direct bony union to both intact and resorbed root surface, was the lowest in the untreated control group (15% of the root surface), intermediate in the calcium hydroxide group (27%) and the highest in the bisphosphonate group (41%). Bony attachment to the tooth root was divided approximately equally between attachment to intact cementum and to previously resorbed dentin. Overall, bisphosphonate resulted in a worse outcome than

  10. Sustainability and cost of a community-based strategy against Aedes aegypti in northern and central Vietnam.

    PubMed

    Kay, Brian H; Tuyet Hanh, Tran T; Le, Nguyen Hoang; Quy, Tran Minh; Nam, Vu Sinh; Hang, Phan V D; Yen, Nguyen Thi; Hill, Peter S; Vos, Theo; Ryan, Peter A

    2010-05-01

    We previously reported a new community-based mosquito control that resulted in the elimination of Aedes aegypti in 40 of 46 communes in northern and central Vietnam. During 2007 and 2008, we revisited Nam Dinh and Khanh Hoa provinces in northern and central Vietnam, respectively, to evaluate whether or not these programs were still being maintained 7 years and 4.5 years after formal project activities had ceased, respectively. Using a previously published sustainability framework, we compared 13 criteria from Tho Nghiep commune in Nam Dinh where the local community had adopted our community-based project model using Mesocyclops from 2001. These data were compared against a formal project commune, Xuan Phong, where our successful intervention activities had ceased in 2000 and four communes operating under the National Dengue Control Program with data available. In Khanh Hoa province, we compared 2008 data at Ninh Xuan commune with data at project completion in 2003 and benchmarked these, where possible, against an untreated control commune, Ninh Binh, where few control activities had been undertaken. The three communes where the above community-based strategy had been adopted were rated as well-sustained with annual recurrent total costs (direct and indirect) of $0.28-0.89 international dollars per person.

  11. A new map of the vegetation of central European Russia based on high-resolution satellite data.

    PubMed

    Ershov, D V; Gavrilyuk, E A; Karpukhina, D A; Kovganko, K A

    2015-01-01

    The scientific basis of and approaches to regional thematic mapping of vegetation based on high-resolution satellite data have been elaborated. A vegetation map of central European Russia has been compiled. The map includes 12 thematic classes, six of which pertain to forest ecosystems. The map has been compared to the data of the GFC project (University of Maryland, United States) and the official data of the Rosstat Federal Service of State Statistics (Russia). The new vegetation map is currently used in the information system of the remote monitoring of forest fires in Russia. PMID:26530069

  12. A new map of the vegetation of central European Russia based on high-resolution satellite data.

    PubMed

    Ershov, D V; Gavrilyuk, E A; Karpukhina, D A; Kovganko, K A

    2015-01-01

    The scientific basis of and approaches to regional thematic mapping of vegetation based on high-resolution satellite data have been elaborated. A vegetation map of central European Russia has been compiled. The map includes 12 thematic classes, six of which pertain to forest ecosystems. The map has been compared to the data of the GFC project (University of Maryland, United States) and the official data of the Rosstat Federal Service of State Statistics (Russia). The new vegetation map is currently used in the information system of the remote monitoring of forest fires in Russia.

  13. Aerosol optical depth over central north Asia based on MODIS-Aqua data

    NASA Astrophysics Data System (ADS)

    Avgousta Foutsi, Athina; Korras Carraca, Marios Bruno; Matsoukas, Christos; Biskos, George

    2016-04-01

    Atmospheric aerosols, both natural and anthropogenic, can affect the regional and global climate through their direct, indirect, and semi-direct effects on the radiative energy budget of the Earth-atmosphere system. To quantify these effects it is important to determine the aerosol load, and an effective way to do that is by measuring the aerosol optical depth (AOD). The central Asia region (mainly the Caspian and Aral sea basins), the arid and semi-arid regions of Western China as well as Siberia are of great interest due to the significant natural sources of mineral aerosols originating from local deserts and biomass burning from wildfires in boreal forests. What is of particular interest in the region is the phenomenal shrinking and desertification of the Aral Sea that drives an intense salt and dust transport from the exposed sea-bed to the surrounding regions with important implications in regional air quality. Anthropogenic particles are also observed due to fossil-fuel combustion occurring mainly at oil refineries in the Caspian Sea basin. Here we investigate the spatial and temporal variability of the AOD at 550 nm over central Asia, Siberia and western China, in the region located between 35° N - 65° N and 45° E - 110° E. For our analysis we use Level-3 daily MODIS - Aqua Dark Target - Deep Blue combined product, from the latest collection (006), available in a 1°×1° resolution (ca. 100 km × 100 km) over the period 2002-2014. Our results indicate a significant spatial variability of the aerosol load over the study region. The highest AODs are observed over the Aral Sea year-round, with extreme values reaching 2.1 during July. In the rest of our study region a clear seasonal cycle with highest AOD values (up to 1.2 over the Taklamakan Desert) during spring and summer is observed. The arid parts of central north Asia are characterized by larger aerosol loads during spring, lower but still high AOD in summer and much lower values in autumn and spring

  14. [Appositional rate of incisor dentin and hematic calcium level in rats. Application of time marking method using lead acetate].

    PubMed

    Matsumoto, S

    1990-12-01

    Matsumoto et al. have reported that the remineralization of rat incisor dentin following administration of various drugs depends upon the hematic calcium (hCa) level in parathyroidectomized (PTX) rats. It is known that injected lead according to a time marking method deposits at the mineralizing front in hard tissues. In the present study, we observed the alteration of the mineralizing front of the incisor dentin and examined the dependency of the dentin remineralization on the hCa level in PTX rats given 1,25 (OH)2D3. Male Wistar rats (7-8 weeks old) were used. They were fed a synthetic diet containing 0.3% Ca or 0.02% Ca (Ca-deficient) from 3 days before PTX. In order to mark the time in the incisor dentin, lead acetate was injected at 3 day intervals. Exp. I: A group of rats fed a diet containing 0.3% Ca was given a single injection (400 ng/kg) of 1,25 (OH)2D3 on the 9th day after PTX. Exp. II: four groups of rats were given daily injections of various doses (vehicle, 25, 50 and 100 ng/kg) of 1,25 (OH)2D3 from the 11th day after PTX for 13 days. The distance between the two lead-lines observed in the histological sections of the incisor was measured as an indicator of the appositional rate of dentin. In rats given a diet containing Ca below 0.3%, the hCa level was about 5 mg/dl after PTX. Mineralization of the incisor dentin was suppressed markedly, and a hematoxylin unstained zone was observed in the histological sections, indicating that the mineralizing front had been stagnant. In Exp I, a high dosage of 1,25 (OH)2D3 raised the hCa level to over 8 mg/dl within 12 hours; formation of a new mineralizing front and remineralization of the dentin were observed. In Exp. II, daily injections of 1.25 (OH)2D3 raised the hCa levels gradually and dose dependently. The hCa levels in groups of rats given 50 and 100 ng/kg of 1,25 (OH)2D3 were over 8 and 10 mg/dl respectively after the 6th day from the beginning of the drug administrations. The distance between the two lead

  15. The generation of antiphase oscillations and synchrony by a rebound-based vertebrate central pattern generator.

    PubMed

    Li, Wen-Chang; Merrison-Hort, Robert; Zhang, Hong-Yan; Borisyuk, Roman

    2014-04-23

    Many neural circuits are capable of generating multiple stereotyped outputs after different sensory inputs or neuromodulation. We have previously identified the central pattern generator (CPG) for Xenopus tadpole swimming that involves antiphase oscillations of activity between the left and right sides. Here we analyze the cellular basis for spontaneous left-right motor synchrony characterized by simultaneous bursting on both sides at twice the swimming frequency. Spontaneous synchrony bouts are rare in most tadpoles, and they instantly emerge from and switch back to swimming, most frequently within the first second after skin stimulation. Analyses show that only neurons that are active during swimming fire action potentials in synchrony, suggesting both output patterns derive from the same neural circuit. The firing of excitatory descending interneurons (dINs) leads that of other types of neurons in synchrony as it does in swimming. During synchrony, the time window between phasic excitation and inhibition is 7.9 ± 1 ms, shorter than that in swimming (41 ± 2.3 ms). The occasional, extra midcycle firing of dINs during swimming may initiate synchrony, and mismatches of timing in the left and right activity can switch synchrony back to swimming. Computer modeling supports these findings by showing that the same neural network, in which reciprocal inhibition mediates rebound firing, can generate both swimming and synchrony without circuit reconfiguration. Modeling also shows that lengthening the time window between phasic excitation and inhibition by increasing dIN synaptic/conduction delay can improve the stability of synchrony.

  16. Centralized Monitoring of the Microsoft Windows-based computers of the LHC Experiment Control Systems

    NASA Astrophysics Data System (ADS)

    Varela Rodriguez, F.

    2011-12-01

    The control system of each of the four major Experiments at the CERN Large Hadron Collider (LHC) is distributed over up to 160 computers running either Linux or Microsoft Windows. A quick response to abnormal situations of the computer infrastructure is crucial to maximize the physics usage. For this reason, a tool was developed to supervise, identify errors and troubleshoot such a large system. Although the monitoring of the performance of the Linux computers and their processes was available since the first versions of the tool, it is only recently that the software package has been extended to provide similar functionality for the nodes running Microsoft Windows as this platform is the most commonly used in the LHC detector control systems. In this paper, the architecture and the functionality of the Windows Management Instrumentation (WMI) client developed to provide centralized monitoring of the nodes running different flavour of the Microsoft platform, as well as the interface to the SCADA software of the control systems are presented. The tool is currently being commissioned by the Experiments and it has already proven to be very efficient optimize the running systems and to detect misbehaving processes or nodes.

  17. Kinematics of the New Madrid seismic zone, central United States, based on stepover models

    USGS Publications Warehouse

    Pratt, Thomas L.

    2012-01-01

    Seismicity in the New Madrid seismic zone (NMSZ) of the central United States is generally attributed to a stepover structure in which the Reelfoot thrust fault transfers slip between parallel strike-slip faults. However, some arms of the seismic zone do not fit this simple model. Comparison of the NMSZ with an analog sandbox model of a restraining stepover structure explains all of the arms of seismicity as only part of the extensive pattern of faults that characterizes stepover structures. Computer models show that the stepover structure may form because differences in the trends of lower crustal shearing and inherited upper crustal faults make a step between en echelon fault segments the easiest path for slip in the upper crust. The models predict that the modern seismicity occurs only on a subset of the faults in the New Madrid stepover structure, that only the southern part of the stepover structure ruptured in the A.D. 1811–1812 earthquakes, and that the stepover formed because the trends of older faults are not the same as the current direction of shearing.

  18. Growth and wear of incisor and cheek teeth in domestic rabbits (Oryctolagus cuniculus) fed diets of different abrasiveness.

    PubMed

    Müller, Jacqueline; Clauss, Marcus; Codron, Daryl; Schulz, Ellen; Hummel, Jürgen; Fortelius, Mikael; Kircher, Patrick; Hatt, Jean-Michel

    2014-06-01

    Although patterns of tooth wear are crucial in palaeo-reconstructions, and dental wear abnormalities are important in veterinary medicine, experimental investigations on the relationship between diet abrasiveness and tooth wear are rare. Here, we investigated the effect of four different pelleted diets of increasing abrasiveness (due to both internal [phytoliths] and external abrasives [sand]) or whole grass hay fed for 2 weeks each in random order to 16 rabbits (Oryctolagus cuniculus) on incisor and premolar growth and wear, and incisor and cheek tooth length. Wear and tooth length differed between diets, with significant effects of both internal and external abrasives. While diet abrasiveness was linked to tooth length for all tooth positions, whole forage had an additional effect on upper incisor length only. Tooth growth was strongly related to tooth wear and differed correspondingly between diets and tooth positions. At 1.4-3.2 mm/week, the growth of cheek teeth measured in this study was higher than previously reported for rabbits. Dental abnormalities were most distinct on the diet with sand. This study demonstrates that concepts of constant tooth growth in rabbits requiring consistent wear are inappropriate, and that diet form (whole vs. pelleted) does not necessarily affect cheek teeth. Irrespective of the strong effect of external abrasives, internal abrasives have the potential to induce wear and hence exert selective pressure in evolution. Detailed differences in wear effects between tooth positions allow inferences about the mastication process. Elucidating feedback mechanisms that link growth to tooth-specific wear represents a promising area of future research.

  19. Effects of chronic fluoride exposure on morphometric parameters defining the stages of amelogenesis and ameloblast modulation in rat incisors.

    PubMed

    Smith, C E; Nanci, A; Denbesten, P K

    1993-10-01

    The response of ameloblasts to long-term (6 weeks) exposure to 100 ppm fluoride was examined in continuously erupting mandibular incisors of female Sprague-Dawley rats as compared to control rats receiving a similar diet (Teklad L-356) but no sodium fluoride in their drinking water. After treatment, animals from both groups were perfused intravascularly with glutaraldehyde, and the incisors were removed and processed for light microscope morphometric analyses directly from 1 microns thick Epon sections. Other animals were injected intravenously with calcein (green fluorescence) followed 4 hours later by xylenol orange (red fluorescence) in order to reveal smooth-ended ameloblast modulation bands and thereby allow quantification of parameters related to the creation and movement of modulation waves within the maturation zone of these teeth. The results indicated that rat incisors expressed four major changes in normal amelogenesis which could be attributed to the chronic fluoride treatment. First, ameloblasts produced a thinner than normal enamel layer by the time they completed the secretory stage and entered the maturation stage of amelogenesis. Second, enamel organ cells within the maturation zone, especially those from the papillary layer, were shorter in height than normal. Third, ameloblasts related to maturing enamel in areas where it was partially soluble and/or fully soluble in EDTA modulated at a rate that was much slower than normal. In some locations ameloblasts remained ruffle-ended for as much as 30% longer than normal per cycle. This upset the usual pattern such that fewer total modulation cycles were completed per unit time by these ameloblasts. Fourth, enamel proteins were lost from the maturing enamel layer at a rate that was about 40% slower than normal. The data suggested that ameloblasts detected the delay in the extracellular breakdown and/or loss of enamel proteins and they responded by remaining ruffle-ended for longer intervals than usual

  20. The beaver Anchitheriomys from the Miocene of Central Europe

    SciTech Connect

    Stefen, C.; Mors, T.

    2008-09-15

    New finds of teeth and mandibles of Anchitheriomys from the Hambach opencast lignite mine in Northwest Germany and the first detailed descriptions of other mandibles from South Germany and Switzerland allow a review of the Central European specimens of this rare beaver genus. The metric variation of cheek teeth and especially the great differences in dimensions of incisors can be much better assessed. The observed range in size can be attributed to ontogenetic changes, and all material is assigned to Anchitheriomys suevicus. Stratigraphically, this species is restricted to the early middle Miocene, European Mammalian Neogene biozones MN 5-6.

  1. Indoor Mobile Robot Navigation by Central Following Based on Monocular Vision

    NASA Astrophysics Data System (ADS)

    Saitoh, Takeshi; Tada, Naoya; Konishi, Ryosuke

    This paper develops the indoor mobile robot navigation by center following based on monocular vision. In our method, based on the frontal image, two boundary lines between the wall and baseboard are detected. Then, the appearance based obstacle detection is applied. When the obstacle exists, the avoidance or stop movement is worked according to the size and position of the obstacle, and when the obstacle does not exist, the robot moves at the center of the corridor. We developed the wheelchair based mobile robot. We estimated the accuracy of the boundary line detection, and obtained fast processing speed and high detection accuracy. We demonstrate the effectiveness of our mobile robot by the stopping experiments with various obstacles and moving experiments.

  2. Bilateral dens evaginatus (talon cusp) in permanent maxillary lateral incisors: a rare developmental dental anomaly with great clinical significance

    PubMed Central

    Manuja, Naveen; Chaudhary, Seema; Nagpal, Rajni; Rallan, Mandeep

    2013-01-01

    Talon cusp is an accessory cusp-like structure which projects from the cingulum area or cementoenamel junction. It is important for dentists to be aware of the potential complications that may occur with talon cusp. Early diagnosis and treatment is important, especially to prevent pulpal complications in permanent teeth which may be in developing stage in paediatric patients. The purpose of this paper is to report a case of bilateral talon cusp in permanent maxillary lateral incisors. Associated dental anomalies and clinical problems are discussed along with successful management of the case with conservative therapy. PMID:23813995

  3. Partial replacement of the dentin-pulp complex by periodontal supporting tissues in a traumatically intruded primary maxillary incisor.

    PubMed

    Nelson-Filho, Paulo; Borsatto, Maria Cristina; de Oliveira, Paulo Tambasco; da Silva, Raquel Assed Bezerra

    2008-10-01

    This paper describes a case of a 9-year-old patient who presented a completely intruded primary maxillary incisor because of a traumatic injury sustained at the age of 3 years. After tooth extraction, histological analysis revealed that the dentin-pulp complex was partially replaced by cementum, periodontal ligament and alveolar bone. No signs of ankylosis were noticed. It is suggested that the lack of spontaneous re-eruption of the traumatized primary tooth after 6 years could be due to the development of functional periodontal supporting tissues in the pulp chamber secondary to the traumatism.

  4. Spontaneous eruption of an occult incisor fragment from the lip after eight months: report of a case.

    PubMed

    Rao, Dinesh; Hegde, Sapna

    2006-01-01

    Large majorities of dental traumas are associated with soft-tissue injury and tooth fragments. They are often found embedded in the oral soft tissues, most commonly the lip. Early detection and complete removal of such fragments is critical in order to prevent infection and scarring. Adequate communication between medical and dental professionals involved is of considerable value in the management of such cases. This report presents a case of spontaneous extrusion of an occult incisor fragment from the lower lip, eight months after trauma. PMID:16683665

  5. Management of an Endodontic-Periodontal Lesion in a Maxillary Lateral Incisor with Palatal Radicular Groove: A Case Report

    PubMed Central

    Sooratgar, Aidin; Tabrizizade, Mehdi; Nourelahi, Maryam; Asadi, Yasin; Sooratgar, Hosein

    2016-01-01

    The radicular groove is a developmental anomaly that predisposes the tooth to periodontal break-down. Sometimes the situation becomes more complicated by pulp necrosis and development of a combined endodontic-periodontal lesion which is a diagnostic and treatment challenge for the clinician. This report presents the successful management of an endodontic-periodontal lesion in a maxillary lateral incisor that has a developmental palatal radicular groove using a combination of nonsurgical endodontic therapy and periodontal regenerative techniques. Conclusion: The combination of nonsurgical endodontic and periodontal regenerative treatment is a predictable method in treating combined endodontic-periodontal lesions caused by palato-gingival groove. PMID:27141225

  6. Orthodontic management of bilateral maxillary canine-first premolar transposition and bilateral agenesis of maxillary lateral incisors: a case report

    PubMed Central

    Palma, Elena Di; Giuseppe, Biagio Di; Tepedino, Michele; Chimenti, Claudio

    2015-01-01

    INTRODUCTION: Maxillary canine-first premolar transposition (Mx.C.P1) is an uncommon dental positional anomaly that may create many orthodontic problems from both esthetic and functional points of view. OBJECTIVE: In this report we show the orthodontic management of a case of Mx.C.P1 associated with bilateral maxillary lateral incisor agenesis and unilateral mandibular second premolar agenesis METHODS: The patient was treated with a multibracket appliance and the extraction of the lower premolar. RESULTS: treatment was completed without the need for any prosthetic replacement. PMID:25992994

  7. The central role of chloride in the metabolic acid-base changes in canine parvoviral enteritis.

    PubMed

    Burchell, Richard K; Schoeman, Johan P; Leisewitz, Andrew L

    2014-04-01

    The acid-base disturbances in canine parvoviral (CPV) enteritis are not well described. In addition, the mechanisms causing these perturbations have not been fully elucidated. The purpose of the present study was to assess acid-base changes in puppies suffering from CPV enteritis, using a modified strong ion model (SIM). The hypothesis of the study was that severe acid-base disturbances would be present and that the SIM would provide insights into pathological mechanisms, which have not been fully appreciated by the Henderson-Hasselbalch model. The study analysed retrospective data, obtained from 42 puppies with confirmed CPV enteritis and 10 healthy control dogs. The CPV-enteritis group had been allocated a clinical score, to allow classification of the data according to clinical severity. The effects of changes in free water, chloride, l-lactate, albumin and phosphate were calculated, using a modification of the base excess algorithm. When the data were summated for each patient, and correlated to each individual component, the most important contributor to the metabolic acid-base changes, according to the SIM, was chloride (P<0.001). Severely-affected animals tended to demonstrate hypochloraemic alkalosis, whereas mildly-affected puppies had a hyperchloraemic acidosis (P=0.007). In conclusion, the acid-base disturbances in CPV enteritis are multifactorial and complex, with the SIM providing information in terms of the origin of these changes.

  8. Paleoecology and Paleoclimate of Tanjung Formation Deposition, Based on Palynological Data From Siung Malopot, Central Borneo

    NASA Astrophysics Data System (ADS)

    Kristyarin, D. A.; Rahardjo, A. T.; Bambang, P.

    2016-01-01

    The northern part of Barito basin is exposed around Siung Malopot area (Central Kalimantan), showing the late cretaceous basement of andesite lavas and granite intrusion. The basement is unconformably overlied by the rocks of Tanjung formation at middle to late Eocene age. Compressive phase during Miocene and Plio-Pleistocene folded and uplifted all existing rocks, made the rocks become relatively north-south structurally oriented. The exposed Tanjung formation consists of sandstone, mudstone, siltstone with intercalation of coals and thin layers of limestone. These lithologies may represent the upper parts of Tanjung formation. Palynology quantitative study is an approach to identify the palaeoclimate and palaeoecology of a certain sedimentation system. Analyses from 18 samples taken from lithologies of Tanjung formation show the presence of palinomorph fossils associated in Proxapertites operculatus zonation indicating the P18-P20 age intervals, or late eocene age. The ratio of spore and non-spore percentage, as well as the comparison between arboreal pollen (AP) and non-arboreal pollen (NAP) show the significant change of environment from time to time during the deposition of the Tanjung formation, also indicating the climate humidity that became more stabile to the younger ages. From 52 observed taxa in the samples, the ratio of marine versus non-marine taxon indicates the influence of sea-water influx in the sedimentation system, explaining the possible presence of thin limestone intercalations at the upper parts of Tanjung formation. Palynology quantitative study on Tanjung Formation indicates the sedimentation of this formation was in backmangrove environment that tends to become more influenced by marine conditions.

  9. Magmatic occurrences in the Central Arava (southern Israel) based on Geology and Magnetometry

    NASA Astrophysics Data System (ADS)

    Hanan, Ginat; Michael, Rybakov; Boris, Shirman; Michael, Lazar

    2014-05-01

    The Eshet Ridge is located in the Central Arava near Wadi Paran. Geological data were collected using ground magnetic surveys and petrophysical measurements (magnetic susceptibility and density). The goal was to reveal the structure and nature of a concealed magmatic body under the ridge. Integrated gravity and magnetic interpretation together with seismic reflection data (including 2¾ modeling) indicated the presence of a deep-seated basic magmatic intrusion. Occurrence of Fe-mineralized rocks along the ridge supports subsurface data. The magmatic body was intruded in the hard Turonian rocks of the Eshet Ridge. Basic magmatic exposures dating from the Early Miocene were evident along Wadi Ashosh (in the eastern Negev) and its margins 18 km. to the north of the ridge. A new outcrop of basic magmatic intrusion was found southwest of the Tzukim settlement. Magnetic measurements indicated a similarity between their magnetic pattern and the Ashosh basic magmatics, which were dated to 20.4 ± 0.7 Ma. Volcanoclastic tuff pebbles (magnetic susceptibility of around 2-7 * 10-3 SI) surrounded by conglomerate were discovered at two sites in Wadi Demma and Wadi Menuha (streams that drain near the Eshet Ridge and 2 km south of it, respectively). The conglomerates contained mostly limestone, chalk and chert fragments; not more than 5% of which were volcanic pebbles. Two pebbles were dated to 24.4 ± 0.7and 21.5 ± 0.5 Ma. The magmatic outcrops in Wadi Ashosh, the magmatic dyke near Tzukim and the volcanic purple and black pebbles near Wadi Menuha were all dated to the very Late Oligocene-Early Miocene. The magmatic body identified in this study under the Eshet Ridge was termed the Eshet Intrusion and is connected to, and even the source of, all these phenomena.

  10. Endodontic Management of a Mandibular Incisor Exhibiting Concurrence of Fusion, Talon Cusp and Dens Invaginatus using CBCT as a Diagnostic Aid

    PubMed Central

    Kumar, Varun

    2016-01-01

    Teeth with aberrant anatomy present a challenge to the endodontist. Advanced tools like cone beam computed tomography aid in exploring the details of endodontic architecture in such cases. The aim of this case report is to highlight the advantage of CBCT in endodontic management of teeth with multiple dental anomalies. A mandibular lateral incisor associated with an extraoral sinus tract revealed unusual clinical anatomy. A provisional diagnosis of type III dens in dente was made based on radiographic findings. Considering the complex anatomy, CBCT was advised to get a confirmatory diagnosis. The anatomic details revealed by CBCT differed significantly from the provisional diagnosis. A final diagnosis of concurrence of fusion with a supernumerary tooth, talon cusp and type II dens invaginatus was established and endodontic treatment of the concerned tooth was carried out. Non-surgical endodontic treatment resulted in successful resolution of the sinus tract and healing of the periapical lesion. CBCT, thus proves to be an excellent diagnostic tool for management of teeth with unusual anatomy, paving way for a conservative treatment free of endodontic mishaps. PMID:27042591

  11. Endodontic Management of a Mandibular Incisor Exhibiting Concurrence of Fusion, Talon Cusp and Dens Invaginatus using CBCT as a Diagnostic Aid.

    PubMed

    Juneja, Ruchi; Kumar, Varun

    2016-02-01

    Teeth with aberrant anatomy present a challenge to the endodontist. Advanced tools like cone beam computed tomography aid in exploring the details of endodontic architecture in such cases. The aim of this case report is to highlight the advantage of CBCT in endodontic management of teeth with multiple dental anomalies. A mandibular lateral incisor associated with an extraoral sinus tract revealed unusual clinical anatomy. A provisional diagnosis of type III dens in dente was made based on radiographic findings. Considering the complex anatomy, CBCT was advised to get a confirmatory diagnosis. The anatomic details revealed by CBCT differed significantly from the provisional diagnosis. A final diagnosis of concurrence of fusion with a supernumerary tooth, talon cusp and type II dens invaginatus was established and endodontic treatment of the concerned tooth was carried out. Non-surgical endodontic treatment resulted in successful resolution of the sinus tract and healing of the periapical lesion. CBCT, thus proves to be an excellent diagnostic tool for management of teeth with unusual anatomy, paving way for a conservative treatment free of endodontic mishaps.

  12. Knowledge-Based, Central Nervous System (CNS) Lead Selection and Lead Optimization for CNS Drug Discovery.

    PubMed

    Ghose, Arup K; Herbertz, Torsten; Hudkins, Robert L; Dorsey, Bruce D; Mallamo, John P

    2012-01-18

    The central nervous system (CNS) is the major area that is affected by aging. Alzheimer's disease (AD), Parkinson's disease (PD), brain cancer, and stroke are the CNS diseases that will cost trillions of dollars for their treatment. Achievement of appropriate blood-brain barrier (BBB) penetration is often considered a significant hurdle in the CNS drug discovery process. On the other hand, BBB penetration may be a liability for many of the non-CNS drug targets, and a clear understanding of the physicochemical and structural differences between CNS and non-CNS drugs may assist both research areas. Because of the numerous and challenging issues in CNS drug discovery and the low success rates, pharmaceutical companies are beginning to deprioritize their drug discovery efforts in the CNS arena. Prompted by these challenges and to aid in the design of high-quality, efficacious CNS compounds, we analyzed the physicochemical property and the chemical structural profiles of 317 CNS and 626 non-CNS oral drugs. The conclusions derived provide an ideal property profile for lead selection and the property modification strategy during the lead optimization process. A list of substructural units that may be useful for CNS drug design was also provided here. A classification tree was also developed to differentiate between CNS drugs and non-CNS oral drugs. The combined analysis provided the following guidelines for designing high-quality CNS drugs: (i) topological molecular polar surface area of <76 Å(2) (25-60 Å(2)), (ii) at least one (one or two, including one aliphatic amine) nitrogen, (iii) fewer than seven (two to four) linear chains outside of rings, (iv) fewer than three (zero or one) polar hydrogen atoms, (v) volume of 740-970 Å(3), (vi) solvent accessible surface area of 460-580 Å(2), and (vii) positive QikProp parameter CNS. The ranges within parentheses may be used during lead optimization. One violation to this proposed profile may be acceptable. The

  13. Knowledge-Based, Central Nervous System (CNS) Lead Selection and Lead Optimization for CNS Drug Discovery.

    PubMed

    Ghose, Arup K; Herbertz, Torsten; Hudkins, Robert L; Dorsey, Bruce D; Mallamo, John P

    2012-01-18

    The central nervous system (CNS) is the major area that is affected by aging. Alzheimer's disease (AD), Parkinson's disease (PD), brain cancer, and stroke are the CNS diseases that will cost trillions of dollars for their treatment. Achievement of appropriate blood-brain barrier (BBB) penetration is often considered a significant hurdle in the CNS drug discovery process. On the other hand, BBB penetration may be a liability for many of the non-CNS drug targets, and a clear understanding of the physicochemical and structural differences between CNS and non-CNS drugs may assist both research areas. Because of the numerous and challenging issues in CNS drug discovery and the low success rates, pharmaceutical companies are beginning to deprioritize their drug discovery efforts in the CNS arena. Prompted by these challenges and to aid in the design of high-quality, efficacious CNS compounds, we analyzed the physicochemical property and the chemical structural profiles of 317 CNS and 626 non-CNS oral drugs. The conclusions derived provide an ideal property profile for lead selection and the property modification strategy during the lead optimization process. A list of substructural units that may be useful for CNS drug design was also provided here. A classification tree was also developed to differentiate between CNS drugs and non-CNS oral drugs. The combined analysis provided the following guidelines for designing high-quality CNS drugs: (i) topological molecular polar surface area of <76 Å(2) (25-60 Å(2)), (ii) at least one (one or two, including one aliphatic amine) nitrogen, (iii) fewer than seven (two to four) linear chains outside of rings, (iv) fewer than three (zero or one) polar hydrogen atoms, (v) volume of 740-970 Å(3), (vi) solvent accessible surface area of 460-580 Å(2), and (vii) positive QikProp parameter CNS. The ranges within parentheses may be used during lead optimization. One violation to this proposed profile may be acceptable. The

  14. Knowledge-Based, Central Nervous System (CNS) Lead Selection and Lead Optimization for CNS Drug Discovery

    PubMed Central

    2011-01-01

    The central nervous system (CNS) is the major area that is affected by aging. Alzheimer’s disease (AD), Parkinson’s disease (PD), brain cancer, and stroke are the CNS diseases that will cost trillions of dollars for their treatment. Achievement of appropriate blood–brain barrier (BBB) penetration is often considered a significant hurdle in the CNS drug discovery process. On the other hand, BBB penetration may be a liability for many of the non-CNS drug targets, and a clear understanding of the physicochemical and structural differences between CNS and non-CNS drugs may assist both research areas. Because of the numerous and challenging issues in CNS drug discovery and the low success rates, pharmaceutical companies are beginning to deprioritize their drug discovery efforts in the CNS arena. Prompted by these challenges and to aid in the design of high-quality, efficacious CNS compounds, we analyzed the physicochemical property and the chemical structural profiles of 317 CNS and 626 non-CNS oral drugs. The conclusions derived provide an ideal property profile for lead selection and the property modification strategy during the lead optimization process. A list of substructural units that may be useful for CNS drug design was also provided here. A classification tree was also developed to differentiate between CNS drugs and non-CNS oral drugs. The combined analysis provided the following guidelines for designing high-quality CNS drugs: (i) topological molecular polar surface area of <76 Å2 (25–60 Å2), (ii) at least one (one or two, including one aliphatic amine) nitrogen, (iii) fewer than seven (two to four) linear chains outside of rings, (iv) fewer than three (zero or one) polar hydrogen atoms, (v) volume of 740–970 Å3, (vi) solvent accessible surface area of 460–580 Å2, and (vii) positive QikProp parameter CNS. The ranges within parentheses may be used during lead optimization. One violation to this proposed profile may be acceptable. The

  15. Provenance of the Subinal Formation, Central Guatemala, Based on Point-Counting of Pebbles in Conglomerates

    NASA Astrophysics Data System (ADS)

    Gutierrez, A.; Martens, U.

    2007-05-01

    The continental Subinal Formation of Central Guatemala is composed of red conglomerates and sandstones that outcrop in the Motagua valley between the San Agustín and Cabañas fault, and in the southeastern corner of Guatemala. Stratigraphic position implies a post-Cretaceous depositional age, which has not been accurately established. Point counts of pebbles in conglomerates were performed in localities distributed along the Motagua valley from Granados to Los Amates, and in the Jocotán-Esquipulas area near the border with Honduras. Pebble types contained in conglomerates in the Motagua area are very diverse, and include sandstones, limestones, chert, milky quartz, phyllite, marble, chlorite schist, quartz-muscovite schist, amphibolite, eclogite, gneiss, granite, gabbro/diorite, volcanic rocks, and abundant serpentinite. Schist and gneiss resembles rocks of the Chuacús complex. Serpentinite, gabbro, amphibolite, and eclogite clasts are similar to oceanic lithosphere from the Motagua suture. Abundant white mica in interbedded sandstones is ubiquitous, suggesting derivation from the mica-rich Chuacús complex. Unfoliated granites and volcanic clasts were probably derived from the northern edge of the Chortis block or an unknown terrane, as no unmetamorphosed igneous rocks are known from the southern edge of the Maya block. The relative abundance of some clast groups correlates with the rock units exposed immediately adjacent to the north across the San Agustín fault. Serpentinite in conglomerate is most abundant near Juan de Paz; eclogite, amphibolite and gneiss are most abundant in the Granados area; and white mica is most abundant where Chuacús complex schists are most pelitic. This suggests that the Cabañas fault accommodated most of the strike-slip movement of the Motagua fault system. In contrast, conglomerates in southeastern Guatemala are more homogeneous, containing chiefly clasts of volcanic origin, with minor limestone, graphitic phyllite, chert, and

  16. Spatial point analysis based on dengue surveys at household level in central Brazil

    PubMed Central

    Siqueira-Junior, João B; Maciel, Ivan J; Barcellos, Christovam; Souza, Wayner V; Carvalho, Marilia S; Nascimento, Nazareth E; Oliveira, Renato M; Morais-Neto, Otaliba; Martelli, Celina MT

    2008-01-01

    Background Dengue virus (DENV) affects nonimunne human populations in tropical and subtropical regions. In the Americas, dengue has drastically increased in the last two decades and Brazil is considered one of the most affected countries. The high frequency of asymptomatic infection makes difficult to estimate prevalence of infection using registered cases and to locate high risk intra-urban area at population level. The goal of this spatial point analysis was to identify potential high-risk intra-urban areas of dengue, using data collected at household level from surveys. Methods Two household surveys took place in the city of Goiania (~1.1 million population), Central Brazil in the year 2001 and 2002. First survey screened 1,586 asymptomatic individuals older than 5 years of age. Second survey 2,906 asymptomatic volunteers, same age-groups, were selected by multistage sampling (census tracts; blocks; households) using available digital maps. Sera from participants were tested by dengue virus-specific IgM/IgG by EIA. A Generalized Additive Model (GAM) was used to detect the spatial varying risk over the region. Initially without any fixed covariates, to depict the overall risk map, followed by a model including the main covariates and the year, where the resulting maps show the risk associated with living place, controlled for the individual risk factors. This method has the advantage to generate smoothed risk factors maps, adjusted by socio-demographic covariates. Results The prevalence of antibody against dengue infection was 37.3% (95%CI [35.5–39.1]) in the year 2002; 7.8% increase in one-year interval. The spatial variation in risk of dengue infection significantly changed when comparing 2001 with 2002, (ORadjusted = 1.35; p < 0.001), while controlling for potential confounders using GAM model. Also increasing age and low education levels were associated with dengue infection. Conclusion This study showed spatial heterogeneity in the risk areas of dengue

  17. Limited irrigation of corn-based no-till crop rotations in west central Great Plains.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identifying the most profitable crop rotation for an area is a continuous research challenge. The objective of this study was to evaluate 2, 3, and 4 yr. limited irrigation corn (Zea mays L.) based crop rotations for grain yield, available soil water, crop water productivity, and profitability in co...

  18. Limited irrigation of corn-based no-till crop rotations in West Central Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to numerous alternatives in crop sequence and changes in crop yield and price, finding the most profitable crop rotation for an area is a continuous research challenge. The objective of this study was to evaluate 1-, 2-, 3-, and 4-yr limited irrigation corn (Zea mays L.)-based crop rotations for...

  19. A Field-Based Aquatic Life Benchmark for Conductivity in Central Appalachian Streams (Final Report)

    EPA Science Inventory

    Cover of the Field-<span class=Based Aquatic Life Benchmark for Conductivity ...

  20. Central Issues in the Use of Computer-Based Materials for High Volume Entrepreneurship Education

    ERIC Educational Resources Information Center

    Cooper, Billy

    2007-01-01

    This article discusses issues relating to the use of computer-based learning (CBL) materials for entrepreneurship education at university level. It considers CBL as a means of addressing the increased volume and range of provision required in the current context. The issues raised in this article have importance for all forms of computer-based…

  1. Beyond the Central Dogma: Model-Based Learning of How Genes Determine Phenotypes

    ERIC Educational Resources Information Center

    Reinagel, Adam; Speth, Elena Bray

    2016-01-01

    In an introductory biology course, we implemented a learner-centered, model-based pedagogy that frequently engaged students in building conceptual models to explain how genes determine phenotypes. Model-building tasks were incorporated within case studies and aimed at eliciting students' understanding of 1) the origin of variation in a population…

  2. The influence of central neuropathic pain in paraplegic patients on performance of a motor imagery based Brain Computer Interface☆

    PubMed Central

    Vuckovic, A.; Hasan, M.A.; Osuagwu, B.; Fraser, M.; Allan, D.B.; Conway, B.A.; Nasseroleslami, B.

    2015-01-01

    Objective The aim of this study was to test how the presence of central neuropathic pain (CNP) influences the performance of a motor imagery based Brain Computer Interface (BCI). Methods In this electroencephalography (EEG) based study, we tested BCI classification accuracy and analysed event related desynchronisation (ERD) in 3 groups of volunteers during imagined movements of their arms and legs. The groups comprised of nine able-bodied people, ten paraplegic patients with CNP (lower abdomen and legs) and nine paraplegic patients without CNP. We tested two types of classifiers: a 3 channel bipolar montage and classifiers based on common spatial patterns (CSPs), with varying number of channels and CSPs. Results Paraplegic patients with CNP achieved higher classification accuracy and had stronger ERD than paraplegic patients with no pain for all classifier configurations. Highest 2-class classification accuracy was achieved for CSP classifier covering wider cortical area: 82 ± 7% for patients with CNP, 82 ± 4% for able-bodied and 78 ± 5% for patients with no pain. Conclusion Presence of CNP improves BCI classification accuracy due to stronger and more distinct ERD. Significance Results of the study show that CNP is an important confounding factor influencing the performance of motor imagery based BCI based on ERD. PMID:25698307

  3. Aetiologies of Central Nervous System Infection in Viet Nam: A Prospective Provincial Hospital-Based Descriptive Surveillance Study

    PubMed Central

    Ho Dang Trung, Nghia; Le Thi Phuong, Tu; Wolbers, Marcel; Nguyen Van Minh, Hoang; Nguyen Thanh, Vinh; Van, Minh Pham; Thieu, Nga Tran Vu; Le Van, Tan; Song, Diep To; Le Thi, Phuong; Thi Phuong, Thao Nguyen; Van, Cong Bui; Tang, Vu; Ngoc Anh, Tuan Hoang; Nguyen, Dong; Trung, Tien Phan; Thi Nam, Lien Nguyen; Kiem, Hao Tran; Thi Thanh, Tam Nguyen; Campbell, James; Caws, Maxine; Day, Jeremy; de Jong, Menno D.; Van Vinh, Chau Nguyen; Van Doorn, H. Rogier; Tinh, Hien Tran; Farrar, Jeremy; Schultsz, Constance

    2012-01-01

    Background Infectious diseases of the central nervous system (CNS) remain common and life-threatening, especially in developing countries. Knowledge of the aetiological agents responsible for these infections is essential to guide empiric therapy and develop a rational public health policy. To date most data has come from patients admitted to tertiary referral hospitals in Asia and there is limited aetiological data at the provincial hospital level where most patients are seen. Methods We conducted a prospective Provincial Hospital-based descriptive surveillance study in adults and children at thirteen hospitals in central and southern Viet Nam between August 2007– April 2010. The pathogens of CNS infection were confirmed in CSF and blood samples by using classical microbiology, molecular diagnostics and serology. Results We recruited 1241 patients with clinically suspected infection of the CNS. An aetiological agent was identified in 640/1241 (52%) of the patients. The most common pathogens were Streptococcus suis serotype 2 in patients older than 14 years of age (147/617, 24%) and Japanese encephalitis virus in patients less than 14 years old (142/624, 23%). Mycobacterium tuberculosis was confirmed in 34/617 (6%) adult patients and 11/624 (2%) paediatric patients. The acute case fatality rate (CFR) during hospital admission was 73/617 (12%) in adults and to 42/624 (7%) in children. Conclusions Zoonotic bacterial and viral pathogens are the most common causes of CNS infection in adults and children in Viet Nam. PMID:22662232

  4. Configuring calendar variation based on time series regression method for forecasting of monthly currency inflow and outflow in Central Java

    NASA Astrophysics Data System (ADS)

    Setiawan, Suhartono, Ahmad, Imam Safawi; Rahmawati, Noorgam Ika

    2015-12-01

    Bank Indonesia (BI) as the central bank of Republic Indonesiahas a single overarching objective to establish and maintain rupiah stability. This objective could be achieved by monitoring traffic of inflow and outflow money currency. Inflow and outflow are related to stock and distribution of money currency around Indonesia territory. It will effect of economic activities. Economic activities of Indonesia,as one of Moslem country, absolutely related to Islamic Calendar (lunar calendar), that different with Gregorian calendar. This research aims to forecast the inflow and outflow money currency of Representative Office (RO) of BI Semarang Central Java region. The results of the analysis shows that the characteristics of inflow and outflow money currency influenced by the effects of the calendar variations, that is the day of Eid al-Fitr (moslem holyday) as well as seasonal patterns. In addition, the period of a certain week during Eid al-Fitr also affect the increase of inflow and outflow money currency. The best model based on the value of the smallestRoot Mean Square Error (RMSE) for inflow data is ARIMA model. While the best model for predicting the outflow data in RO of BI Semarang is ARIMAX model or Time Series Regression, because both of them have the same model. The results forecast in a period of 2015 shows an increase of inflow money currency happened in August, while the increase in outflow money currency happened in July.

  5. Phylogeny and biogeography of Poecilia (Cyprinodontiformes: Poeciliinae) across Central and South America based on mitochondrial and nuclear DNA markers.

    PubMed

    Ho, Adeljean L F C; Pruett, Christin L; Lin, Junda

    2016-08-01

    Poeciliids are a diverse group of small Neotropical fishes, and despite considerable research attention as models in ecology and evolutionary biology, our understanding of their biogeographic and phylogenetic relationships is still limited. We investigated the phylogenetic relationships of South and Central American Poecilia, by examining 2395 base pairs of mitochondrial DNA (ATPase 8/6, COI) and nuclear DNA (S7) for 18 species across six subgenera. Fifty-eight novel sequences were acquired from newly collected specimens and 20 sequences were obtained from previously published material. Analyses of concatenated and partitioned mitochondrial DNA and nuclear DNA sets resulted in a well-supported phylogeny that resolved several monophyletic groups corresponding to previously hypothesized subgenera and species complexes. A divergence-dating analysis supported the hypothesis of the genus Poecilia dispersing into Central America in the early Pliocene (ancestors of Psychropoecilia+Allopoecilia+Mollienesia: 7.3-2.0Mya) from predominantly South America. Subsequently, one lineage (subgenus Allopoecilia: 5.1-1.3Mya) expanded deeper into South America from Lower-Central America, and one lineage expanded from Nuclear-Central America into South America (subgenus Mollienesia: 0.71-0.14Mya). The subgenus Mollienesia diverged into three monophyletic groups that can be identified by nuptial male dorsal fin morphology and inner jaw dentition. A subclade of the unicuspid short-fins (subgenus Mollienesia) was the lineage that expanded into South America during the middle Pleistocene. Species in this subclade are now distributed across northern South America, where they are partially sympatric with Allopoecilia. However the P. (A.) caucana complex was not monophyletic, with P. (A.) wandae clustering in the Mollienesia subclade that expanded into South America. It is apparent that characters (body size, scale count, pigmentation, and gonopodium morphology) used to define the P. (A

  6. Effect of Ligation Method on Maxillary Arch Force/Moment Systems for a Simulated Lingual Incisor Malalignment

    PubMed Central

    Seru, Surbhi; Romanyk, Dan L; Toogood, Roger W; Carey, Jason P; Major, Paul W

    2014-01-01

    Introduction: The objectives of this study were to determine whether there is a difference in the magnitude of forces and moments produced by elastic ligation when compared to passive ligation, and whether these forces and moments propagate differently along the arch for the two ligation types. A lingual incisor malalignment was used in this study. Methods: The Orthodontic Simulator (OSIM) was used to quantify the three-dimensional forces and moments applied on the teeth given a lingually displaced incisor. A repeated measures MANOVA was performed to statistically analyze the data. Results: The interaction factor illustrated convincing evidence that there is a difference in maximum force and moment values for all outcome variables between ligation types considering all tooth positions along the arch. The mean differences for FX and FY between ligation types were found to be clinically significant, with values for elastic ligation consistently higher than passive ligation. Conclusion: It was found that the maximum forces and moments produced by elastic ligation are greater than those produced by passive ligation and that the magnitude of this difference for the mesiodistal and buccolingual forces is clinically relevant. Additionally, it was determined that elastic ligation causes forces and moments to propagate further along the arch than passive ligation for all outcome variables. PMID:25400715

  7. An Immature Type II Dens Invaginatus in a Mandibular Lateral Incisor with Talon's Cusp: A Clinical Dilemma to Confront

    PubMed Central

    Singal, Deepa; Giri, K. Y.; Keerthi, S. Sruthi

    2014-01-01

    Dens invaginatus (DI) is a malformation of teeth probably resulting from an infolding of the dental papilla during tooth development. DI is classified as type I, II, and III by Oehlers depending on the severity of malformation. The maxillary lateral incisor is the most commonly affected tooth. Structural defects do exist in the depth of the invagination pits, and as a consequence, the early development of caries and the subsequent necrosis of the dental pulp, as well as abscess and cyst formation are clinical implications associated with DI. Occasionally, we can see more than one developmental anomaly occurring in a single tooth. In such cases it becomes important to identify the anomalies and initiate a proper treatment plan for good prognosis. In this paper, an unusual case of DI which clinically presented as a huge talons cusp affecting a mandibular lateral incisor tooth is described. This case report illustrates grinding of the talons cusp followed by nonsurgical endodontic management of dens invaginatus type II with an immature apex and periapical lesions, in which Mineral Trioxide Aggregate (MTA) shows a complete periapical healing with bone formation at the site of the lesions. PMID:24660071

  8. Histological and immunohistochemical analyses of the chronology of healing process after immediate tooth replantation in incisor rat teeth.

    PubMed

    Panzarini, Sônia Regina; Okamoto, Roberta; Poi, Wilson Roberto; Sonoda, Celso Koogi; Pedrini, Denise; da Silva, Paula Ervolino; Saito, Celia Tomiko Matida Hamata; Marão, Heloísa Fonseca; Sedlacek, Paulo

    2013-02-01

    Dental tissues have special characteristics, and its regenerative capacity is noteworthy. However, understanding the circumstances that lead to regeneration is challenging. In this study, the chronology of the healing process after immediate replantation of rat incisor teeth was examined by histological and immunohistochemical analyses within a 60-day period. Thirty-six male Wistar rats had their maxillary right incisors extracted and replanted after 15 min in saline storage. The rats were sacrificed immediately 3, 7, 15, 28, and 60 days after replantation. The histological analysis showed rupture of the periodontal ligament and formation of a blood clot, which started being replaced by a connective tissue after 3 days. At 7 days, the gingival mucosa epithelium was reinserted and areas of root resorption could be seen. At 15 days, the periodontal ligament was repaired. At 3 days, the pulp presented an absence of the odontoblast layer, which started being replaced by a connective tissue. This tissue suffered gradual calcification, filling the root canal at 28 and 60 days. The root ends were closed. The immunohistochemical analysis revealed greater expression of OP, OPG, and RANK proteins in the initial periods (0 and 3 days), while TRAP expression predominated at 28 and 60 days (P < 0.05). In conclusion, in delayed tooth replantation, there is great new bone formation activity in the earlier periods of the repair process, while a predominance of bone resorption and remodeling is observed in the more advanced periods.

  9. Temperature changes on the root surfaces of mandibular incisors after an 810-nm high-intensity intracanal diode laser irradiation

    NASA Astrophysics Data System (ADS)

    da Fonseca Alvarez, Andrea; Moura-Netto, Cacio; Daliberto Frugoli, Alexandre; Fernando, Casemiro; Correa Aranha, Ana Cecilia; Davidowicz, Harry

    2012-01-01

    Temperature changes caused by laser irradiation can promote damage to the surrounding dental tissues. In this study, we evaluated the temperature changes of recently extracted human mandibular incisors during intracanal irradiation with an 810-nm diode laser at different settings. Fifty mandibular incisors were enlarged up to an apical size of ISO No. 40 file. After the final rinse with 17% ethylenediaminetetraacetic acid, 0.2% lauryl sodium sulfate biologic detergent, and sterile water, samples were irradiated with circular movements from apex to crown through five different settings of output power (1.5, 2.0, 2.5, 3.0, and 3.5 W) in continuous mode. The temperature changes were measured on both sides of the apical and middle root thirds using two thermopar devices. A temperature increase of 7 °C was considered acceptable as a safe threshold when applying the diode laser. Results: The results showed that only 3.5-W output power increased the outer surface temperature above the critical value. Conclusion: The recommended output power can be stipulated as equal to or less than 3 W to avoid overheating during diode laser irradiation on thin dentin walls.

  10. [Effects of strontium on incisor and femurs in rats under drinking condition at constant concentrations of fluoride].

    PubMed

    Hirata, Y

    1990-09-01

    Thirty 28-day-old male Wistar rats were randomly divided into 5 experimental groups of 6 animals, and fed low-fluoride diet (0.07 ppm F) and drinking water containing fluoride at constant concentration (20 ppm F) ad libitum for 49 days in combination with strontium chloride added to provide 0, 5, 10, 20, 40 ppm Sr. Enamel mottling was observed through over-all experimental period, and at an end of the experiment, all animals were sacrificed. There was no significant difference in weight gain among groups. Enamel mottling of mandibular incisors in Sr groups appeared at 7th day (cumulated fluoride ingested: under 3.0mg), while mottling in control group (0 ppm Sr and 20 ppm F) appeared at 14th day (cumulated fluoride ingested: ca. 6.6 mg). However, severity of mottling was higher in low-strontium group (5 and 10 ppm Sr) than in high-strontium groups (20 and 40 ppm Sr). Data of contents of Sr, F, Ca and P in incisors and femurs obtained through chemical analysis suggested that an exchange of Sr and Ca would take place in apatite and that the exchange reaction of F- and OH- could be urged by Sr. Further, data of serum F level demonstrated that the fluoride retention in serum could be urged by lower level of strontium rather than higher one.

  11. Fracture resistance of cementum-extended composite fillings in severely damaged deciduous incisors: An in vitro study

    PubMed Central

    Seraj, Bahman; Ehsani, Sara; Taravati, Shirin; Ghadimi, Sara; Fatemi, Mostafa; Safa, Sahar

    2014-01-01

    Objective: The aim of this study was to comparatively assess the fracture resistance of the cementum-extended and conventional composite fillings with or without intracanal composite posts in severely damaged deciduous incisors. Materials and Methods: This in vitro study was performed on 60 extracted deciduous maxillary incisors that were randomly divided into four groups: Group 1: Composite filling (CF); Group 2: Composite filling with composite posts (CF + CP); Group 3: Composite filling extended 0.5 mm to cementum (ceCF); Group 4: Composite filling extended 0.5 mm to cementum with composite posts (ceCF + CP). The fracture resistance was assessed by exerting a progressively increasing load with a cross-head speed of 0.5 mm/min in a Universal Testing Machine. Statistical Analysis: Data were analyzed by SPSS-18 using one-way analysis of variance at α < 0.05. Results: The mean fracture resistance (MFR) values of the experimental groups were 410.57 ± 139.44 N, 564.44 ± 92.63 N, 507.5 ± 76.37 N and 601.08 ± 96.04 N. A significant difference was found between the MFR of Groups 1 and 2, Groups 1 and 4 and Groups 3 and 4 (P < 0.05). Conclusion: A superior outcome was achieved by intracanal composite posts in both conventional and cementum-extended composite fillings. PMID:25512722

  12. Micro-CT evaluation of the radioprotective effect of resveratrol on the mandibular incisors of irradiated rats.

    PubMed

    Barbosa, Gabriella Lopes de Rezende; Pimenta, Luiz André; Almeida, Solange Maria de

    2016-01-01

    The purpose of this study was to perform a microcomputed tomographic evaluation of the radioprotective effect of resveratrol on the volume of mandibular incisors of irradiated rats. A second aim was to make a quantitative assessment of the effect of x-ray exposure on these dental tissues. Twenty adult male rats were divided into four groups: control, irradiated control, resveratrol, and irradiated resveratrol. The resveratrol groups received 100 mg/kg of resveratrol, whereas the irradiated groups were exposed to 15 Gy of irradiation. The animals were sacrificed 30 days after the irradiation procedure, and their mandibles were removed and scanned in a microcomputed tomography unit. The images were loaded into Mimics software to allow segmentation of the mandibular incisor and assessment of its volume. The results were compared by One-way ANOVA and Tukey's post hoc test, considering a 5% significance level. The irradiated groups showed significantly diminished volumes of the evaluated teeth, as compared with the control group (p < 0.05). The resveratrol group presented higher values than those of the irradiated groups, and volumes similar to those of the control group. High radiation doses significantly affected tooth formation, resulting in alterations in the dental structure, and thus lower volumes. Moreover, resveratrol showed no effective radioprotective impact on dental tissues. Future studies are needed to evaluate different concentrations of this substance, in an endeavor to verify its potential as a radioprotector for these dental tissues. PMID:26981750

  13. Endodontic and periodontal management of a severely affected maxillary lateral incisor having combined mucosal fenestration and palatogingival groove

    PubMed Central

    Sharma, Sarang; Srivastava, Dhirendra; Sood, Vishal; Yadav, Priya

    2015-01-01

    Mucosal fenestrations, wherein the tooth root apices are clinically discernible in the oral cavity subsequent to loss of overlying alveolar bone and mucosa, are rare pathologic entities. Palato gingival grooves- anatomic aberrations are also infrequent occurrences that notoriously predispose to periodontal pathologies of varying extent. Both conditions independently are known to popularly affect maxillary lateral incisors. Coexistent fenestration defect and palato gingival groove in the same tooth is extremely rare and undoubtedly is a perfect combination to precipitate severe endodontic-periodontal consequences. In this report, a 34-year-old patient presented to the dental department with complaint of esthetics in relation to exposed root of right maxillary lateral incisor. On closer inspection, a palato gingival groove in addition to fenestration defect was evident on the root surface along with a periodontal pocket of >5 mm. An interdisciplinary treatment was instituted which included endodontic treatment followed by root end resection, osseous bone graft placement and guided tissue regeneration procedures for repair of mucosal fenestration defect. Debridement of the palatal pocket, with saucerization of the groove and restoration with glass ionomer cement were simultaneously employed to correct the palatal defect. PMID:26229283

  14. CT and MR imaging of the central skull base. Part 2. Pathologic spectrum.

    PubMed

    Laine, F J; Nadel, L; Braun, I F

    1990-09-01

    The radiologist must have a thorough knowledge of the normal anatomy and the pathologic spectrum of the skull base to determine the extent of abnormality and to help plan the surgical approach. The authors describe and present examples of congenital, benign, and malignant lesions that affect this region, including cephalocele, fracture, fistula, juvenile angiofibroma, meningioma, chordoma, pituitary adenoma, chondrosarcoma, nasopharyngeal carcinoma, and rhabdomyosarcoma. Metastatic, infectious, and other miscellaneous processes are also discussed. Imaging strategies with computed tomography and magnetic resonance imaging to aid in the diagnosis are suggested.

  15. Improving depth imaging of legacy seismic data using curvelet-based gather conditioning: A case study from Central Poland

    NASA Astrophysics Data System (ADS)

    Górszczyk, A.; Cyz, M.; Malinowski, M.

    2015-06-01

    In presented work we test the ray-based pre-stack depth migration (PreSDM) and tomographic velocity model building (VMB) workflow applied to vintage seismic data, acquired in the 70s and 80s, in the area affected by intense salt tectonics in Central Poland. We demonstrate that the key for successful VMB is the consistency of the input residual moveouts (RMO) picks, which we obtain by developing proper gather conditioning workflow. It is based on the 2D discrete curvelet transform (DCT). DCT-based conditioning algorithm is run in a two-step mode on the common offset sections and on the depth-slices, improving the performance of the autopicker and thus providing a more reliable input to a grid tomography. Additionally, in the case of the legacy data, such conditioning acts as a trace regularization. Taking into account limitations associated with low fold and low signal-to-noise ratio, obtained results are satisfactory, providing depth sections and velocity models for verifying structural interpretation of the study area. In the case when the grid-based tomography is applied to vintage data, we strongly recommend to devote some time for proper data conditioning aimed at signal coherency improvement before running the RMO autopicker.

  16. A conodont-based standard reference section in central Nevada for the lower Middle Ordovician Whiterockian Series

    USGS Publications Warehouse

    Sweet, W.C.; Ethington, Raymond L.; Harris, A.G.

    2005-01-01

    Ranges of conodonts in stratigraphic sections at five localities in the Monitor and Antelope ranges of central Nevada are used graphically to assemble a standard reference section for the lower Middle Ordovician Whiterockian Series. The base of the series is officially 0.3 m above the base of the Antelope Valley Limestone in the stratotype in Whiterock Canyon (Monitor Range). The top is the level at which Baltoniodus gerdae makes a brief appearance in an exposure of the Copenhagen Formation on the flanks of Hill 8308 in the western Antelope Range. Graphic compilation of the sections considered in this report also indicates that a level correlative with the base of the Whiterockian Series in the stratotype section is 66 m above the base of the Antelope Valley Limestone in its de facto type section on Martin Ridge in the eastern part of the Monitor Range. Ranges, diversity, and the composition of the conodont faunas differ markedly in lithofacies adjacent to the basal boundary of the series; hence we are unable to identify a single conodont species, in a credible developmental sequence, to serve as biological marker of that boundary.

  17. Prevalence of tics in schoolchildren in central Spain: a population-based study.

    PubMed

    Cubo, Esther; Gabriel y Galán, José María Trejo; Villaverde, Vanesa Ausín; Velasco, Sara Sáez; Benito, Vanesa Delgado; Macarrón, Jesús Vicente; Guevara, José Cordero; Louis, Elan D; Benito-León, Julián

    2011-08-01

    Tic disorders constitute a neurodevelopmental disorder of childhood. This study sought to determine the prevalence of tic disorders in a school-based sample. A randomized sample of 1158 schoolchildren, based on clusters (classrooms) in the province of Burgos (Spain), was identified on a stratified sampling frame combining types of educational center and setting (mainstream schools and special education), using a two-phase approach (screening and diagnosis ascertainment by a neurologist). Tics with/without impairment criterion were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders criteria. In mainstream schools, tics were observed in 125/741 students (16.86%; 95% confidence interval, 14.10-19.63), and were more frequent in boys (87/448, 19.42%; 95% confidence interval, 15.64-23.19) compared with girls (38/293, 12.96%; 95% confidence interval, 8.95-16.98; P = 0.03). In special education centers, tics disorders were observed in 11/54 of children (20.37%; 95% confidence interval, 8.70-32.03). Overall, tics with impairment criteria were less frequent than tics without impairment criteria (4.65% vs 11.85%, P < 0.0001). The most frequent diagnoses involved chronic motor tics (6.07%) and Tourette syndrome (5.26%). Tic disorders are common in childhood, and the use or nonuse of impairment criteria exerts a significant impact on tic prevalence estimates.

  18. Object based change detection of Central Asian Tugai vegetation with very high spatial resolution satellite imagery

    NASA Astrophysics Data System (ADS)

    Gärtner, Philipp; Förster, Michael; Kurban, Alishir; Kleinschmit, Birgit

    2014-09-01

    Ecological restoration of degraded riparian Tugai forests in north-western China is a key driver to combat desertification in this region. Recent restoration efforts attempt to recover the forest along with its most dominant tree species, Populus euphratica. The present research observed the response of natural vegetation using an object based change detection method on QuickBird (2005) and WorldView2 (2011) data. We applied the region growing approach to derived Normalized Difference Vegetation Index (NDVI) values in order to identify single P. euphratica trees, delineate tree crown areas and quantify crown diameter changes. Results were compared to 59 reference trees. The findings confirmed a positive tree crown growth and suggest a crown diameter increase of 1.14 m, on average. On a single tree basis, tree crown diameters of larger crowns were generally underestimated. Small crowns were slightly underestimated in QuickBird and overestimated in Worldview2 images. The results of the automated tree crown delineation show a moderate relation to field reference data with R20052: 0.36 and R20112: 0.48. The object based image analysis (OBIA) method proved to be applicable in sparse riparian Tugai forests and showed great suitability to evaluate ecological restoration efforts in an endangered ecosystem.

  19. Simulation of a rubber plantation productivity in central Cambodia using the individual-based dynamic vegetation model SEIB-DGVM

    NASA Astrophysics Data System (ADS)

    Kumagai, T.; SATO, H.; Shinjiro, Ph. D., F.

    2013-12-01

    To provide a useful tool for building strategy of forest plantation management, we developed the Spatially Explicit Individual-Based (SEIB) Dynamic Global Vegetation Model (DGVM) applicable to simulate productivity of tree plantations (SEIB-PP). Rubber (Hevea brasiliensis Müll. Arg.) plantations, which are rapidly expanding into both climatically optimal and sub-optimal environments throughout mainland Southeast Asia, potentially change the partitioning of water, energy, and carbon at multiple scales, compared with traditional land covers that are being replaced. Describing both primary and latex productivities in rubber plantations via SEIB-PP is, therefore, important to understanding the climatic impacts on productive processes. Model results are compared with measurements collected at a field site in central Cambodia, and here, we show some examples of projections: the rubber plantation production under future climate change conditions.

  20. A new species of Centropages (Copepoda: Calanoida: Centropagidae) from the central Red Sea based on morphological and molecular evidence.

    PubMed

    El-Sherbiny, Mohsen M; Al-Aidaroos, Ali M

    2015-01-01

    Centropages mohamedi sp. nov. (Copepoda: Calanoida) is described from specimens collected in zooplankton samples off Obhur Creek on the Saudi Arabian coast of the central Red Sea. The new species is most closely related to C. orsinii Giesbrecht, 1889, a species described from the Red Sea and widely distributed in the neritic waters of the Indo-West Pacific region. The new species is mainly distinguished by the female genital double somite, male antennules, male leg 4, and leg 5 of both sexes. DNA sequences of the mitochondrial cytochrome C oxidase subunit one (mtCOI) of the two species differ by 20.8%, supporting their morphology-based identification as distinct species.  PMID:25661620