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.

[Comparison of clinical effects of Co-Cr alloy cast post-core and everStick fiber post in restoration of labially or lingually inclined maxillary central incisor].

PubMed

Qian, Yu-Mei; Zhong, Qun; Chen, Shuang

2017-02-01

To compare the clinical effect of Co-Cr alloy cast post-core and everStick fiber post in restoration of maxillary central incisor with labial or lingual inclination, and provide theoretical basis for clinical application. Ninety-seven labially or lingually inclined maxillary central incisors were treated in our hospital from March 2012 to March 2014. The patients were randomly divided into group A (n=49) and group B (n=48), and received post -core and crown restoration. Patients in group A underwent Co-Cr alloy cast post and core restoration and patients in group B underwent everStick fiber post and core restoration. After two-year of follow-up, root fracture, post break, crown or post dislodgment and gingival marginal discoloration were recorded and analyzed using SPSS 19.0 software package. Chi-square test showed that the success rate of restoration was significantly different between 2 groups (P<0.05). The incidence of root fracture and gingival marginal discoloration of Co-Cr alloy cast post-core was higher than that of everStick fiber post, but there was no significant difference in the incidence of post break, crown or post dislodgment. EverStick fiber post is better than Co-Cr alloy cast post and core to prevent root fracture and gingival marginal discoloration. Its fracture pattern is repairable and favorable for preserving tooth.

Immediate Implant Placement of a Single Central Incisor Using a CAD/CAM Crown-Root Form Technique: Provisional to Final Restoration.

PubMed

Vafiadis, Dean; Goldstein, Gary; Garber, David; Lambrakos, Anthony; Kowalski, Bj

2017-02-01

Preserving soft and hard tissues after extraction and implant placement is crucial for anterior esthetics. This technique will show how the information gathered from a cone-beam computed tomography (CBCT) scan of the maxillary left central incisor and an intra-oral digital impression can be merged to fabricate a CAD/CAM crown-root matrix to be used as an immediate provisional restoration that mimics the natural anatomy. Due to trauma, a left central incisor appeared to be fractured and was scheduled for extraction and implant placement. The crown-root configuration captured by the CBCT scan was merged with the digital files from an intra-oral digital impression. A CAD/CAM crown-root matrix was fabricated. Because the matrix shell was fabricated with the exact anatomy of the natural tooth, it replicated the position and three dimensional anatomy of the soft and hard tissue. It was connected to the implant with a customized provisional abutment. A digital impression of a coded healing abutment was made to fabricate the final implant abutment and final restoration. Throughout the treatment time and 36 months after completion, the thickness of tissue, emergence profile, and adjacent papilla was analyzed by clinical evaluation and photography and seemed to be maintained. The use of a pre-operative intra-oral digital scan of the clinical crown-root architecture and the CBCT scan of the bone/root anatomy, can be used together to fabricate a CAD/CAM crown-root form provisional matrix. This digital design helps in the preservation of the 3D tissue topography, as well as the final restoration. The preservation of soft and hard tissue after extraction and implant placement has always been paramount for ideal anterior implant esthetics. Using the information from digital files from CBCT scans and intra-oral scans may help the clinician identify critical anatomical features that can be replicated in the provisional and final CAD/CAM restoration. (J Esthet Restor Dent 29

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.

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

PubMed

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

2015-08-01

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. 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. 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. 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.

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. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Maxillary canine impactions related to impacted central incisors: two case reports.

PubMed

Bayram, Mehmet; Ozer, Mete; Sener, Ismail

2007-09-01

The purpose of this case report is to describe the combined surgical and orthodontic treatment of two cases with an impacted maxillary central incisor and canine in the same quadrant and to discuss the causal relationship between them. The most common causes of canine impactions are usually the result of one or more factors such as a long path of eruption, tooth size-arch length discrepancies, abnormal position of the tooth bud, prolonged retention or early loss of the deciduous canine, trauma, the presence of an alveolar cleft, ankylosis, cystic or neoplastic formation, dilaceration of the root, supernumerary teeth, and odontomas. Although impaction of the maxillary central incisor is almost as prevalent as impacted canines its etiology is different. The principal factors involved in causing the anomaly are supernumerary teeth, odontomas, and trauma. Case #1: A 10.5-year-old girl in the early mixed dentition stage presented with a chief complaint of the appearance of her anterior teeth. She had a Class I skeletal pattern and a history of trauma to the maxillary central incisors at age five with premature exfoliation. Radiographs revealed an impacted upper right central incisor in the region of the nasal floor, delayed eruption of the maxillary permanent central incisor, and the adjacent lateral incisor was inclined toward the edentulous space. Treatment was done in two stages consisting of surgical exposure and traction of the impacted central incisor and fixed orthodontic treatment. Case #2: An 11.5-year-old girl presented for orthodontic treatment with the chief complaint of an unerupted tooth and the appearance of her upper anterior teeth. She was in the late mixed dentition period with a Class III skeletal pattern along with an anterior cross-bite with some maxillary transverse deficiency. The maxillary right canine and central incisor were absent, but the maxillary right deciduous canine was still present. Treatment included arch expansion followed by

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

Do different vertical positions of maxillary central incisors influence smile esthetics perception?

PubMed Central

Menezes, Erica Bretas Cabral; Bittencourt, Marcos Alan Vieira; Machado, Andre Wilson

2017-01-01

ABSTRACT INTRODUCTION: The purpose of this study was to determine the perception of smile esthetics among orthodontists and layperson, with respect to different maxillary central incisors vertical positions in full-face and close-up smile analyses. METHODS: Frontal photographs of the smiles of two adult women were used. Images were altered to create a symmetrical image with the gingival margin levels of the maxillary canines matching the central incisors and a 1.0-mm central-to-lateral incisal step. Later, the images were altered in order to create six different central incisor vertical positions in 0.5-mm increments. The images were randomly assembled in an album, which was given to 114 judges, 57 orthodontists and 57 laypersons, who were asked to evaluate the attractiveness of the images using the visual analog scale. The data collected were statistically analyzed by means of 1-way analysis of variance with the Tukey post-hoc test and the Student t test. RESULTS: The highest rated smiles showed two notable characteristics: a) the central incisor gingival margins matched or were 0.5 mm below the line of the canine gingival margins and; b) the central-to-lateral incisal step was 1.0 to 1.5 mm. The worst smiles showed two notable characteristics: a) the central incisor gingival margins were 1.0 mm above or 1.5 mm below the canine gingival margins and; b) no step between the centrals and laterals or a 2.5-mm step. CONCLUSION: The vertical position of the maxillary central incisors significantly affected the perception of the smile esthetics, whereas slightly extruded central incisors were more esthetically preferred than intruded. PMID:28658361

Do different vertical positions of maxillary central incisors influence smile esthetics perception?

PubMed

Menezes, Erica Bretas Cabral; Bittencourt, Marcos Alan Vieira; Machado, Andre Wilson

2017-01-01

The purpose of this study was to determine the perception of smile esthetics among orthodontists and layperson, with respect to different maxillary central incisors vertical positions in full-face and close-up smile analyses. Frontal photographs of the smiles of two adult women were used. Images were altered to create a symmetrical image with the gingival margin levels of the maxillary canines matching the central incisors and a 1.0-mm central-to-lateral incisal step. Later, the images were altered in order to create six different central incisor vertical positions in 0.5-mm increments. The images were randomly assembled in an album, which was given to 114 judges, 57 orthodontists and 57 laypersons, who were asked to evaluate the attractiveness of the images using the visual analog scale. The data collected were statistically analyzed by means of 1-way analysis of variance with the Tukey post-hoc test and the Student t test. The highest rated smiles showed two notable characteristics: a) the central incisor gingival margins matched or were 0.5 mm below the line of the canine gingival margins and; b) the central-to-lateral incisal step was 1.0 to 1.5 mm. The worst smiles showed two notable characteristics: a) the central incisor gingival margins were 1.0 mm above or 1.5 mm below the canine gingival margins and; b) no step between the centrals and laterals or a 2.5-mm step. The vertical position of the maxillary central incisors significantly affected the perception of the smile esthetics, whereas slightly extruded central incisors were more esthetically preferred than intruded.

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

PubMed

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

2015-02-01

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. 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. 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. When compared the dimensions of teeth between two sex, male group shows larger values to female group.

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

Managing molar-incisor hypomineralization: A systematic review.

PubMed

Elhennawy, Karim; Schwendicke, Falk

2016-12-01

We systematically reviewed treatment modalities for MIH-affected molars and incisors. Trials on humans with ≥1 MIH molar/incisor reporting on various treatments were included. Two authors independently searched and extracted records. Sample-size-weighted annual failure rates were estimated where appropriate. The risk of bias was assessed using the Newcastle-Ottawa scale. Electronic databases (PubMed, Embase, Cochrane CENTRAL, Google Scholar) were screened, and hand searches and cross-referencing performed. Fourteen (mainly observational) studies were included. Ten trials (381 participants) investigated MIH-molars, four (139) MIH-incisors. For molars, remineralization, restorative or extraction therapies had been assessed. For restorative approaches, mean (SD) annual failure rates were highest for fissure sealants (12[6]%) and glass-ionomer restorations (12[2]%), and lowest for indirect restorations (1[3]%), preformed metal crowns (1.3 [2.1]%) and composite restorations (4[3]%). Ony study assessed extraction of molars in young patients (median age 8.2 years), the majority of them without malocclusions, but third molars in development. Spontaneous alignment of second molars was more frequent in the maxilla (55%) than the mandible (47%). For incisors, desensitizing agents successfully managed hypersensitivity. Micro-abrasion and composite veneers improved aesthetics. Few, mainly moderate to high-risk-studies investigated treatment of MIH. Remineralization or sealants seem suitable for MIH-molars with limited severity and/or hypersensitivity. For severe cases, restorations with composites or indirect restorations or preformed metal crowns seem suitable. Prior to tooth extraction as last resort factors like the presence of a general malocclusion, patients' age and the status of neighboring teeth should be considered. No recommendations can be given for MIH-incisors. Dentists need to consider the specific condition of each tooth and the needs and expectations of

Orthodontically induced eruption of a horizontally impacted maxillary central incisor.

PubMed

Rizzatto, Susana Maria Deon; de Menezes, Luciane Macedo; Allgayer, Susiane; Batista, Eraldo Luiz; Freitas, Maria Perpétua Mota; Loro, Raphael Carlos Drumond

2013-07-01

This case report presents the clinical features and periodontal findings in a patient with a horizontally impacted maxillary central incisor that had been exposed and aligned after a closed-eruption surgical technique. By combining 3 treatment stages-maxillary expansion, crown exposure surgery, and induced eruption-the horizontally impacted incisor was successfully moved into proper position. The patient finished treatment with a normal and stable occlusion between the maxillary and mandibular arches, and an adequate width of attached gingiva, even in the area surrounding the crown. The 5-year follow-up of stability and periodontal health demonstrated esthetic and functional outcomes after orthodontically induced tooth eruption. Clinical evaluation showed that the treated central incisor had periodontal clinical variables related to visible plaque, bleeding on probing, width of attached gingiva, and crown length that resembled the contralateral incisor. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Management of unerupted maxillary deciduous central incisor: a case report.

PubMed

Shakra, Karam Abu

2014-01-01

Failure of eruption of primary teeth can be considered rare, especially in maxillary anterior teeth. The problem can be either mechanical obstruction of eruption or a failure of the eruption mechanism. This case report presents failure of eruption of the maxillary right deciduous central incisor in a 4-year-old girl. The unerupted primary tooth was removed surgically. The histological finding revealed fibroma with reactive giant cells. Periodic follow-up visits were advised to monitor the developing dentition and to ensure enough space for the permanent incisor. How to cite this article: Shakra KA. Management of Unerupted Maxillary Deciduous Central Incisor: A Case Report. Int J Clin Pediatr Dent 2014;7(1):58-60.

Survival of extensively damaged endodontically treated incisors restored with different types of posts-and-core foundation restoration material.

PubMed

Lazari, Priscilla Cardoso; de Carvalho, Marco Aurélio; Del Bel Cury, Altair A; Magne, Pascal

2018-05-01

Which post-and-core combination will best improve the performance of extensively damaged endodontically treated incisors without a ferrule is still unclear. The purpose of this in vitro study was to investigate the restoration of extensively damaged endodontically treated incisors without a ferrule using glass-ceramic crowns bonded to various composite resin foundation restorations and 2 types of posts. Sixty decoronated endodontically treated bovine incisors without a ferrule were divided into 4 groups and restored with various post-and-core foundation restorations. NfPfB=no-ferrule (Nf) with glass-fiber post (Pf) and bulk-fill resin foundation restoration (B); NfPfP=no-ferrule (Nf) with glass-fiber post (Pf) and dual-polymerized composite resin core foundation restoration (P); NfPt=no-ferrule (Nf) with titanium post (Pt) and resin core foundation restoration; and NfPtB=no-ferrule (Nf) with titanium post (Pt) and bulk-fill resin core foundation restoration (B). Two additional groups from previously published data from the same authors (FPf=2mm of ferrule (F) and glass-fiber post (Pf) and composite resin core foundation restoration; and NfPf=no-ferrule (Nf) with glass-fiber post (Pf) and composite resin core foundation restoration), which were tested concomitantly and using the same experimental arrangement, were included for comparison. All teeth were prepared to receive bonded glass-ceramic crowns luted with dual-polymerized resin cement and were subjected to accelerated fatigue testing under submerged conditions at room temperature. Cyclic isometric loading was applied to the incisal edge at an angle of 30 degrees with a frequency of 5 Hz, beginning with a load of 100 N (5000 cycles). A 100-N load increase was applied every 15000 cycles. The specimens were loaded until failure or to a maximum of 1000 N (140000 cycles). The 6 groups (4 groups from the present study and 2 groups from the previously published study) were compared using the Kaplan-Meier survival

Autotransplantation of a Strange Positioned Impacted Central Incisor in a surgically Prepared Socket: A Miracle Esthetic Concept.

PubMed

Jaiswara, Chandresh; Srivastava, Vinay K; Dhiman, Neeraj

2016-01-01

Esthetics is a prime concern for a young lady. Any anomaly in the anterior tooth may create anxiety and depression. This anxiety and depression may hamper her married life and overall personality. This case report reveals an unerupted right central incisor situated in a strange position, creating space in the maxillary anterior region and giving an unesthetic appearance. Autotransplantation is a method of choice for a strangely positioned impacted central incisor in a new appropriate site. This method offers a new treatment option for some clinical situations if orthodontic approach is not possible. It permits tooth movement to a distant or the opposite side of the same dental arch as well as to the opposite jaw. This procedure also offers potential benefits of reestablishment of normal alveolar process development, esthetics, functions, and arch integrity. This procedure has the potential to become a viable alternative treatment plan for young patients of low socioeconomic status, allowing the reestablish-ment and restoration of a missing tooth and their functions. This article discusses methods of auto-reimplantation of a tooth in a fresh surgically prepared socket, its biological principle, and establishment of functions, esthetics, and phonetics. Jaiswara C, Srivastava VK, Dhiman N. Autotransplantation of a Strange Positioned Impacted Central Incisor in a surgically Prepared Socket: A Miracle Esthetic Concept. Int J Clin Pediatr Dent 2016;9(3):269-272.

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

Orthodontic movement of a maxillary incisor through the midpalatal suture: a case report.

PubMed

Garib, Daniela Gamba; Janson, Guilherme; dos Santos, Patrícia Bittencourt Dutra; de Oliveira Baldo, Taiana; de Oliveira, Gabriela Ulian; Ishikiriama, Sérgio Kiyoshi

2012-03-01

Orthodontic space closure is a treatment alternative when a maxillary central incisor is missing. The objective of this report was to present an unusual treatment in which a right maxillary central incisor was moved through the midpalatal suture to replace the absent contralateral tooth. The biologic aspects and clinical appearance of the recontoured lateral and central incisors were analyzed. The position of the examined teeth and the appearance of the surrounding soft tissues were satisfactory; however, the upper midline frenulum deviated to the left. The incisor was successfully moved with no obvious detrimental effects as observed on the final radiographs. In the radiographic and tomographic examinations, the midline suture seemed to have followed the tooth movement. The patient expressed satisfaction with the results. It was concluded that orthodontic movement of the central incisor to replace a missing contralateral tooth is a valid treatment option, and the achievement of an esthetic result requires an interdisciplinary approach, including restorative dentistry and periodontics.

Biologic restoration: a treatment option for reconstruction of anterior teeth.

PubMed

Babaji, Prashant; Khanna, Priyanka; S, Shankar; Chaurasia, Vishwajit Rampratap; Masamatti, Vinaykumar S

2014-11-01

Several procedures are advised to manage fractured anterior tooth structure using acrylic resin, composite restoration, ceramic or metal crown with ceramic facing. Biologic restoration is a procedure to restore fractured tooth structure with natural tooth material. In this in vitro case we have made an attempt for aesthetic rehabilitation of maxillary central incisor with similar biologic crown taken form extracted maxillary central incisor. It was observed that biologic restoration is an aesthetic, economical, fast and functional procedure which can be used as an alternative method to restore fractured primary or permanent anteriors.

Spectral analysis of /s/ sound with changing angulation of the maxillary central incisors.

PubMed

Runte, Christoph; Tawana, Djafar; Dirksen, Dieter; Runte, Bettina; Lamprecht-Dinnesen, Antoinette; Bollmann, Friedhelm; Seifert, Eberhard; Danesh, Gholamreza

2002-01-01

The aim of the study was to measure the influence of the maxillary central incisors free from adaptation phenomena using spectral analysis. The maxillary dentures of 18 subjects were duplicated. The central incisors were fixed in a pivoting appliance so that their position could be changed from labial to palatal direction. A mechanical push/pull cable enabled the incisor section to be handled extraorally. Connected to the control was a sound generator producing a sinus wave whose frequency was related to the central incisor angulation. This acoustic signal was recorded on one channel of a digital tape recorder. After calibration of the unit, the denture duplicate was inserted into the subject's mouth, and the signal of the /s/ sounds subsequently produced by the subject was recorded on the second channel during alteration of the inclination angle simultaneously with the generator signal. Spectral analysis was performed using a Kay Speech-Lab 4300B. Labial displacement in particular produced significant changes in spectral characteristics, with the lower boundary frequency of the /s/ sound being raised and the upper boundary frequency being reduced. Maxillary incisor position influences /s/ sound production. Displacement of the maxillary incisors must be considered a cause of immediate changes in /s/ sound distortion. Therefore, denture teeth should be placed in the original tooth position as accurately as possible. Our results also indicate that neuromuscular reactions are more important for initial speech sound distortions than are aerodynamic changes in the anterior speech sound-producing areas.

Elastic band causing exfoliation of the upper permanent central incisors.

PubMed

Alves, Monica Ghislaine Oliveira; Kitakawa, Dárcio; Becker, Joao Batista Macedo; Brandão, Adriana Aigotti Haberbeck; Cabral, Luiz Antonio Guimarães; Almeida, Janete Dias

2015-01-01

Objective. This study reports a case in which elastic band use culminated in the loss of the incisors. Case Report. An 11-year-old white girl was seen complaining of pain, with purulent discharge and severe tooth mobility. The bone destruction detected radiographically in the region, despite its single location and absence in posterior quadrants of the maxilla and/or mandible, was similar to that observed in Langerhans cell disease. To our surprise, an elastic band involving the midportion of the roots of the two upper central incisors was found during biopsy. The debris was removed and a metal wire was placed in permanent maxillary right and left incisors. The patient was followed up, but no improvement in tooth mobility was observed. Bone loss increased, and internal resorption and root exposure occurred, which culminated in the extraction of permanent maxillary right and left incisors. Conclusion. The present case highlights the fact that professionals sometimes are confronted by anamnestic reports never seen before.

Comprehensive therapy of a fusion between a mandibular lateral incisor and supernumerary tooth: case report.

PubMed

Onçag, Ozant; Candan, Umit; Arikan, Fatih

2005-08-01

The term fusion is used to define a developmental anomaly characterised by the union of two adjacent teeth. In the case reported here, clinical and radiographic examinations suggested a unilateral fusion between the mandibular left permanent incisor and a super-numerary tooth. Radiographs showed that the fused teeth had two distinct pulp chambers and canals. A diagnosis of chronic periapical abscess of the supernumerary tooth was made. Before root canal therapy, a periodontal surgical procedure was performed to section the central incisor and its fused supernumerary. Also, odontoplasty was performed on the roots, to establish an anatomy consistent with a normal central incisor. Later, the chronic apical abscess on the supernumerary tooth was instrumented chemo-mechanically, root canal filling was performed and an anterior composite resin restoration was placed. The patient was evaluated for one year after root canal therapy. The tooth was asymptomatic, not exhibiting any pathological root resorption or alveolar resorption, and the anterior composite restoration was intact. Instead of extracting the supernumerary tooth, the application of endodontic, periodontal, and restorative procedures proved to be an alternative treatment.

[Relationship between crown form of upper central incisors and papilla filling in Chinese Han-nationality youth].

PubMed

Yang, X; Le, D; Zhang, Y L; Liang, L Z; Yang, G; Hu, W J

2016-10-18

To explore a crown form classification method for upper central incisor which is more objective and scientific than traditional classification method based on the standardized photography technique. To analyze the relationship between crown form of upper central incisors and papilla filling in periodontally healthy Chinese Han-nationality youth. In the study, 180 periodontally healthy Chinese youth ( 75 males, and 105 females ) aged 20-30 (24.3±4.5) years were included. With the standardized upper central incisor photography technique, pictures of 360 upper central incisors were obtained. Each tooth was classified as triangular, ovoid or square by 13 experienced specialist majors in prothodontics independently and the final classification result was decided by most evaluators in order to ensure objectivity. The standardized digital photo was also used to evaluate the gingival papilla filling situation. The papilla filling result was recorded as present or absent according to naked eye observation. The papilla filling rates of different crown forms were analyzed. Statistical analyses were performed with SPSS 19.0. The proportions of triangle, ovoid and square forms of upper central incisor in Chinese Han-nationality youth were 31.4% (113/360), 37.2% (134/360) and 31.4% (113/360 ), respectively, and no statistical difference was found between the males and females. Average κ value between each two evaluators was 0.381. Average κ value was raised up to 0.563 when compared with the final classification result. In the study, 24 upper central incisors without contact were excluded, and the papilla filling rates of triangle, ovoid and square crown were 56.4% (62/110), 69.6% (87/125), 76.2% (77/101) separately. The papilla filling rate of square form was higher (P=0.007). The proportion of clinical crown form of upper central incisor in Chinese Han-nationality youth is obtained. Compared with triangle form, square form is found to favor a gingival papilla that fills the

Evaluation of root and alveolar bone development of unilateral osseous impacted immature maxillary central incisors after the closed-eruption technique.

PubMed

Shi, Xiangru; Xie, Xiaoyan; Quan, Junkang; Wang, Xiaozhe; Sun, Xiangyu; Zhang, Chenying; Zheng, Shuguo

2015-10-01

In this study, we evaluated root and alveolar bone development in unilateral osseous impacted immature maxillary central incisors by cone-beam computed tomography before and after closed-eruption treatment, in comparison with naturally erupted contralateral immature maxillary central incisors. The study included 30 patients, 20 boys and 10 girls, with a mean age of 8.44 ± 1.20 years (range, 6.5-11.2 years). After treatment, the root lengths of both the impacted maxillary central incisors (10.66 ± 2.10 mm) and the contralateral maxillary central incisors (11.04 ± 1.76 mm) were significantly greater than their pretreatment values (6.67 ± 1.94 and 9.02 ± 2.13 mm, respectively). The root canal widths of the incisors decreased significantly after treatment. From the posttreatment cone-beam computed tomography images, the ratio of exposed root length to total root length and the thickness of the alveolar bone at 1 mm under the alveolar crest and at the apex were calculated to evaluate alveolar bone development. Impacted immature maxillary central incisors differed significantly from contralateral immature maxillary central incisors in labial exposed root length, labial ratio to total root length, and lingual alveolar crest. Clinical crown height was higher (statistically but not clinically) for the impacted incisors (9.87 mm) than for the contralateral incisors (9.37 mm). Impacted immature incisors grew to the same stage as did erupted contralateral incisors after closed-eruption treatment. Both incisor types had some alveolar bone loss, and thin alveolar bone surrounded the roots. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Torque Control During Intrusion on Upper Central Incisor in Labial and Lingual bracket System - A 3D Finite Element Study.

PubMed

Pol, Tejas R; Vandekar, Meghna; Patil, Anuradha; Desai, Sanjana; Shetty, Vikram; Hazarika, Saptarshi

2018-01-01

The aim of present study was to investigate the difference of torque control during intrusive force on upper central incisors with normal, under and high torque in lingual and labial orthodontic systems through 3D finite element analysis. Six 3D models of an upper right central incisor with different torque were designed in Solid Works 2006. Software ANSYS Version 16.0 was used to evaluate intrusive force on upper central incisor model . An intrusive force of 0.15 N was applied to the bracket slot in different torque models and the displacements along a path of nodes in the upper central incisor was assessed. On application of Intrusive force on under torqued upper central incisor in Labial system produce labial crown movement but in Lingual system caused lingual movement in the apical and incisal parts. The same intrusive force in normal-torqued central incisor led to a palatal movement in apical and labial displacement of incisal edge in Lingual system and a palatal displacement in apical area and a labial movement in the incisal edge in Labial systemin. In overtorqued upper central incisor, the labial crown displacement in Labial system is more than Lingual system. In labial and lingual system on application of the same forces in upper central incisor with different inclinations showed different responses. The magnitudes of torque Loss during intrusive loads in incisors with normal, under and over-torque were higher in Labial system than Lingual orthodontic appliances. Key words: FEM, lingual orthodontics, intrusion, torque control, labial bracket systems.

Comparison of Parental Satisfaction with Three Tooth-Colored Full-Coronal Restorations in Primary Maxillary Incisors.

PubMed

Salami, A; Walia, T; Bashiri, R

2015-01-01

To evaluate and compare the parental satisfaction among resin composite strip crown, preveneered stainless steel crown (PVSSC) and the newly introduced pre-fabricated primary zirconia crown for restoring maxillary primary incisors. A prospective clinical study on 39 children with carious or traumatized primary maxillary incisors. They were randomly and equally distributed in three groups and received one of the full-coronal restorations. Children were recalled to evaluate and compare parental satisfaction about performance of crowns after one year through a questionnaire. Parents were satisfied with all three tooth colored full-coronal restoration techniques. A significant relationship was found between colour of PVSSC (p=0.003) and durability of resin strip crowns (p=0.009) with the overall parental satisfaction levels. Parents who gave poor ratings in these two variables however rated their overall acceptance levels as being satisfied. Parental overall satisfaction was highest for zirconia primary crowns followed by resin composite strip crowns and lowest satisfaction was reported for pre-veneered SSCs. Parents were least satisfied with durability of resin composite strip crowns and colour of pre-veneered stainless steel crowns. However, this did not affect their overall satisfaction with these crowns.

Inner canthal distance and golden proportion as predictors of maxillary central incisor width in south Indian population.

PubMed

George, Shibu; Bhat, Vinaya

2010-01-01

Even though the constant relation of golden proportion and inner canthal distance (ICD) with the width of the maxillary central incisor (CIW) has been found in European population, it may not be applied to Indian population as we differ from Europeans racially and genetically. Hence, this study was carried out with the objectives of determining if these parameters are applicable to our population also. Three hundred south Indian subjects between 18 and 26 years of age, free from facial and dental deformities were examined. Inner canthus of each eye was used as soft tissue landmark. The maxillary central incisors were measured at the contact point area with the help of digital vernier caliper. The CIW was also calculated using golden proportion ratio to obtain the calculated central incisor width. A comparison was made with measured width. Statistical analyses were done to identify any significant difference using "Z" tests. Pearson's Correlation Coefficient test was used to evaluate the measured and the calculated width of the central incisor. ICD and the width of two maxillary incisors were in golden proportion in south Indian population. Also, ICD when multiplied by a decreasing function value of the golden proportion and divided by 2 is a reliable predictor of determining CIW. As in the European population, the ICD and the golden proportion are reliable predictors for determining the width of the maxillary central incisors in the south Indian population also.

[An in vitro study of the fracture strength of tooth preparations for Empress 2 veneers and crowns and mandibular incisors restored with Empress 2 veneers and crowns].

PubMed

Wei, Xue; Li, Yan

2009-12-01

To compare the fracture resistance of mandibular incisors' preparations for veneers and crowns, mandibular incisors restored with Empress 2 veneers and crowns. 50 human mandibular incisors were randomly divided into five groups. Each group consisted of ten teeth and the treatment obtained as follows: A, tooth preparations for veneers; B, tooth preparations for crowns; C, teeth restored with veneers; D, teeth restored with crowns; E, untreated group. The teeth received standardized preparation and the restorations were manufactured with Empress 2 system and cemented with resin luting agent. The fracture resistances of teeth were measured by Instron universal testing machine and statistically analyzed with one-way ANOVA. The fracture resistances of A, B, C, D, E were (576.11 +/- 91.53), (204.13 +/- 85.88), (451.50 +/- 116.81), (386.16 +/- 117.75) and (566.05 +/- 121.37) N, respectively. The statistical analysis demonstrated significant differences between five groups. There were no significant differences between group A and E, group C and D. Tooth preparations for veneers did not significantly reduce the fracture resistance of mandibular incisor. The fracture resistance of teeth restored with Empress 2 veneers and crowns did not significantly differ from each other.

Orthodontic management of a dilacerated central incisor and partially impacted canine with unilateral extraction - A case report.

PubMed

Felicita, A Sumathi

2017-10-01

To align a dilacerated maxillary central incisor and partially impacted canine with unilateral extraction in a young patient with skeletal deep bite. A 14 year old male patient reported to the hospital with skeletal deep bite (basal plane angle-17°), severe horizontal pattern of growth (Go-Gn to Sn -22°), upright maxillary incisors (U1 to NA -26°) and retroclined lower incisors (L1 to NB -11°). The maxillary left central incisor was dilacerated, and the maxillary left canine was partially impacted. Unilateral extraction of the left maxillary premolar and left mandibular central incisor was done. A canine disimpaction spring was used to align the impacted canine. An anterior bite plane was given to open the bite. Superimposition of lateral cephalogram (T1, T2) revealed bite opening, normal overjet and overbite. There was backward rotation of the mandible and increase in lower anterior facial height. There was no evidence of root resorption or loss of vitality in the dilacerated tooth. Clinically the canine was well aligned in the arch. Orthodontic management of a dilacerated incisor can be done without root resorption or loss of vitality. The partially impacted canine was well aligned in the arch. Unilateral extraction can produce good treatment results.

Endodontic treatment of a maxillary central incisor with two roots.

PubMed

Maghsoudlou, Amir; Jafarzadeh, Hamid; Forghani, Maryam

2013-03-01

This clinical report presents a rare case of maxillary central incisor with two separate roots. Unusual morphology of the roots and root canals may exist in any tooth. Recognition of the dental anatomy and its variations is necessary for successful endodontic therapy. It is well known that maxillary incisors are usually single-rooted teeth. The root canals were instrumented with conventional hand files and Gates Glidden and obturated by using the lateral technique. Recall radiograph after 1 year shows the healing process of the preoperative apical periodontitis. Clinicians should be aware of unexpected root canal morphology when performing root canal therapy. The present case demonstrated the importance of accurate preoperative radiograph and adequate access preparation.

Influence of the vertical position of maxillary central incisors on the perception of smile esthetics among orthodontists and laypersons.

PubMed

Machado, Andre Wilson; McComb, Ryan W; Moon, Won; Gandini, Luiz Gonzaga

2013-12-01

The purpose of this study was to determine the perception of smile esthetics among orthodontists and laypeople with respect to different upper central incisor vertical positions in a frontal smile analysis. A frontal close-up smile photo of an adult Caucasian woman was selected. The patient had healthy upper anterior dentition and had no history of orthodontic treatment. Images were altered in order to create six different central incisor vertical positions in 0.5-mm increments. All images were assessed in three different views: full smile, gingival close-up excluding incisal edges, and incisal close-up excluding gingival margins. Images were randomly assembled in an album, which was given to 120 judges: 60 orthodontists and 60 laypersons. Each rater was asked to evaluate the attractiveness of the images using the visual analog scale. The data collected were then statistically analyzed. The highest rated smiles showed two notable characteristics: the central-to-lateral incisal step was 1.5 mm; and the central incisor gingival margins matched the laterals, and both were 0.5 mm below the line of the canine gingival margins. The least attractive smile was the one with no step between the centrals and laterals, and with the central incisor gingival margins 1.0 mm above the canine gingival margins. The results of this study indicate that slightly extruded upper central incisors are more esthetically preferred than intruded. The upper central incisors are the key determinant in evaluating smile esthetics, and thus, the assessment of their ideal vertical positioning is an aspect of paramount importance. © 2013 Wiley Periodicals, Inc.

Esthetic rehabilitation of complicated crown fractures utilizing rapid orthodontic extrusion and two different restoration modalities.

PubMed

Milardovic Ortolan, Sladana; Strujic, Mihovil; Aurer, Andrej; Viskic, Josko; Bergman, Lana; Mehulic, Ketij

2012-01-01

This case report describes the management of a crown-root fractured maxillary right central incisor and a crown fractured maxillary left central incisor using two different techniques. A complex procedure was designed to manage this case including orthodontic extrusion to move the fracture line above the alveolar bone and surgical recontouring of the altered gingival margin. Finally, the right incisor was restored prosthodontically. Prosthetic treatment was based on performing a post and core, and all-ceramic crown on the extruded tooth. The left, less-damaged incisor was restored directly using composite resin. The treatment resulted in good esthetics and secured periodontal health. This case report demonstrates that a multidisciplinary treatment approach is a reliable and predictable option to save a tooth. How to cite this article: Ortolan SM, Strujic M, Aurer A, Viskic J, Bergman L, Mehulic K. Esthetic Rehabilitation of Complicated Crown Fractures Utilizing Rapid Orthodontic Extrusion and Two Different Restoration Modalities. Int J Clin Pediatr Dent 2012;5(1):64-67.

Load-bearing capacity of human incisor restored with various fiber-reinforced composite posts.

PubMed

Le Bell-Rönnlöf, Anna-Maria; Lassila, Lippo V J; Kangasniemi, Ilkka; Vallittu, Pekka K

2011-06-01

The aim of this study was to evaluate the load-bearing capacity and microstrain of incisors restored with posts of various kinds. Both prefabricated titanium posts and different fiber-reinforced composite posts were tested. The crowns of human incisors were cut and post preparation was carried out. The roots were divided into groups: (1) prefabricated serrated titanium posts, (2) prefabricated carbon fiber-reinforced composite posts, (3) individually formed glass fiber-reinforced composite posts with the canal full of fibers, and (4) individually formed "split" glass fiber-reinforced composite posts. The posts were cemented and composite crowns were made. Intact human incisors were used as reference. All roots were embedded in acrylic resin cylinders and stored at room temperature in water. Static load was applied under a loading angle of 45° using a universal testing machine. On half of the specimens microstrain was measured with strain gages and an acoustic emission analysis was carried out. Failure mode assessment was also made. The group with titanium posts showed highest number of unfavorable failures compared to the groups with fiber-reinforced composite posts. With fiber-reinforced composite posts the failures may more often be favorable compared to titanium posts, which clinically means repairable failures. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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.

Autotransplantation and Orthodontic Treatment after Maxillary Central Incisor Region Trauma: A 13-Year Follow-Up Case Report Study.

PubMed

Piroozmand, Farzad; Hessari, Hossein; Shirazi, Mohsen; Khazaei, Pegah

2018-01-01

The anterior maxilla is the most prone region to the trauma during childhood, and tooth loss sometimes happens due to trauma. Replacing the missing teeth has always been one of the dentists' challenges in children and adolescents, since their dentofacial growth is not complete. Autotransplantation of mandibular premolars with two-thirds or three-quarters of root formation provides the best prognosis for the tooth survival. This case report describes the management of a 10-year-old boy suffering a severe dental injury who received the autotransplantation of the premolars from mandible to restore the space caused by trauma in maxillary central incisor region and a 13-year follow-up of the autotransplantation.

A Rare Bilateral Presentation of Multiple Dens Invaginatus, Shovel-Shaped Incisor and Talon Cusp With Mesiodens.

PubMed

Hegde, S; Jain, M; Shubha, A B

2014-01-01

The aim of this paper is to describe a unique and unusual case of concomitant appearance of morphological dental anomalies in the maxillary anterior region, along with its management in a patient with no systemic abnormality. This case report describes the clinical and radiographic features of talon cusp, dens invaginatus, shovel-shaped incisors and a supernumerary tooth occurring in a single patient, which is a rare presentation. All 4 permanent maxillary incisors had dens invaginatus, the permanent maxillary canines showed the presence of talon cusps, the permanent maxillary central incisors were shovel-shaped and an erupted mesiodens was also observed. Treatment included restorative, surgical and orthodontic approaches.

Impaction of Maxillary Central Incisors: Surgical and Orthodontic Treatment--Case Report.

PubMed

Knop, Luegya Amorim Henriques; Shintcovsk, Ricardo Lima; Gandini, Luiz Gonzaga; Parsekian, Lidia; Pinto, Ary Santos

2015-01-01

The aim of this paper is to report two clinical cases, which was performed with surgical exposure and orthodontic traction of a maxillary central incisors. Light forces were used during the orthodontic treatment applied on rigid wires as anchorage. It was noted that teeth presented adequate clinical crown height and gingival contours.

Contour changes in human alveolar bone following tooth extraction of the maxillary central incisor.

PubMed

Li, Bei; Wang, Yao

2014-12-01

The purpose of this study was to apply cone-beam computed tomography (CBCT) to observe contour changes in human alveolar bone after tooth extraction of the maxillary central incisor and to provide original morphological evidence for aesthetic implant treatment in the maxillary anterior area. Forty patients were recruited into the study. Each patient had two CBCT scans (CBCT I and CBCT II), one taken before and one taken three months after tooth extraction of maxillary central incisor (test tooth T). A fixed anatomic reference point was used to orient the starting axial slice of the two scans. On three CBCT I axial slices, which represented the deep, middle, and shallow layers of the socket, labial and palatal alveolar bone widths of T were measured. The number of sagittal slices from the start point to the pulp centre of T was recorded. On three CBCT II axial slices, the pulp centres of extracted T were oriented according to the number of moved sagittal slices recorded in CBCT I. Labial and palatal alveolar bone widths at the oriented sites were measured. On the CBCT I axial slice which represented the middle layer of the socket, sagittal slices were reconstructed. Relevant distances of T on the sagittal slice were measured, as were the alveolar bone width and tooth length of the opposite central incisor. On the CBCT II axial slice, which represented the middle layer of the socket, relevant distances recorded in CBCT I were transferred on the sagittal slice. The height reduction of alveolar bone on labial and palatal sides was measured, as were the alveolar bone width and tooth length of the opposite central incisor at the oriented site. Intraobserver reliability assessed by intraclass correlation coefficients (ICCs) was high. Paired sample t-tests were performed. The alveolar bone width and tooth length of the opposite central incisor showed no statistical differences (P<0.05). The labial alveolar bone widths of T at the deep, middle, and shallow layers all showed

A clinical study to evaluate the correlation between maxillary central incisor tooth form and face form in an Indian population.

PubMed

Koralakunte, Pavankumar R; Budihal, Dhanyakumar H

2012-09-01

A study was performed to examine the correlation between maxillary central incisor tooth form and face form in males and females in an Indian population. The selection of prosthetic teeth for edentulous patients is a primary issue in denture esthetics, especially in the case of maxillary central incisors, which are the most prominent teeth in the arch. Two hundred dental students of Indian origin comprising 79 males and 121 females aged 18-28 years studying at Bapuji Dental College and Hospital were randomly selected as the study subjects. A standardized photographic procedure was used to obtain images of the face and the maxillary central incisors. The outline forms of the face and the maxillary right central incisor tooth were determined using a standardized method. The outline forms obtained were used to classify both face form and tooth form on the basis of visual and William's methods. The means were considered after evaluation by five prosthodontists, and the results were tabulated. Statistical analysis was performed using the chi-squared test for association and Z-test for equality of proportions. A correlation greater than 50% was observed between tooth form and face form by the visual method, compared with one of 31.5% by William's method. There was no highly defined correlation between maxillary central incisor tooth form and face form among the male and female Indian subjects studied.

Prevalence of shovel-shaped incisors in Saudi Arabian dental patients.

PubMed

Saini, T S; Kharat, D U; Mokeem, S

1990-10-01

The prevalence of maxillary incisor shoveling was studied radiographically in 990 Saudi patients. According to the radiomorphologic characteristics, a new classification was developed and shovel teeth were categorized. The findings of this study showed 9% shovel-shaped incisors; among those, 4% were central incisors and 5% were lateral incisors. Frequency of dens invaginatus occurrence with the shovel-shaped incisors was also investigated. Eight percent of shovel-shaped incisors showed presence of dens invaginatus. Prevalence was found to be 4% in central shovel-shaped incisors, whereas that in lateral shovel-shaped incisors was 11%.

Camouflage treatment for class III malocclusion combined with traction of an impacted maxillary central incisor.

PubMed

Closs, Luciane Quadrado; Mundstock, Karina Santos; Ribeiro, Darlene Santos; Reston, Eduardo Galia; Silva, Aurelício Novaes

2010-01-01

This case report describes the treatment of a patient with an unerupted maxillary left central incisor, class III malocclusion with crossbite of the maxillary posterior teeth and lateral open bite. Treatment consisted of rapid maxillary expansion followed by anterior space opening, maxillary protraction and traction of the unerupted teeth with a light force system. Favorable results were obtained in terms of correcting incisor position and class III malocclusion. The results achieved remained stable throughout a 4-year retention period.

Multiple supernumerary teeth associated with an impacted maxillary central incisor: Surgical and orthodontic management

PubMed Central

Yeluri, Ramakrishna; Hegde, Manjunath; Baliga, Sudhindra; Munshi, Autar Krishen

2012-01-01

Various anomalies in the size, shape, number, structure and eruption of the teeth are often observed clinical conditions. Supernumerary teeth can be found in almost any region of the dental arch, and most of the times they are asymptomatic, and are routinely found during radiographic evaluation. The most common cause of impacted maxillary incisors is the presence of the supernumerary teeth. This paper describes a case of multiple supernumerary teeth associated with an impacted permanent maxillary central incisor in an 11-year old child along with its surgical and orthodontic management. PMID:22919229

Incisor crown bending strength correlates with diet and incisor curvature in anthropoid primates.

PubMed

Deane, Andrew S

2015-02-01

Anthropoid incisors are large relative to the postcanine dentition and function in the preprocessing of food items. Previous analyses of anthropoid incisor allometry and shape demonstrate that incisor morphology is correlated with preferred foods and that more frugivorous anthropoids have larger and more curved incisors. Although the relationship between incisal crown curvature and preferred foods has been well documented in extant and fossil anthropoids, the functional significance of curvature variation has yet to be conclusively established. Given that an increase in crown curvature will increase maximum linear crown dimensions, and bending resistance is a function of linear crown dimensions, it is hypothesized that incisor crown curvature functons to increase incisor crown resistance to bending forces. This study uses beam theory to calculate the mesiodistal and labiolingual bending strengths of the maxillary and mandibular incisors of hominoid and platyrrhine taxa with differing diets and variable degrees of incisal curvature. Results indicate that bending strength correlates with incisal curvature and that frugivores have elevated incisor bending resistance relative to folivores. Maxillary central incisor bending strengths further discriminate platyrrhine and hominoid hard- and soft-object frugivores suggesting this crown is subjected to elevated occlusal loading relative to other incisors. These results are consistent with the hypothesis that incisor crown curvature functions to increase incisor crown resistance to bending forces but does not preclude the possibility that incisor bending strength is a composite function of multiple dentognathic variables including, but not limited to, incisor crown curvature. © 2014 Wiley Periodicals, Inc.

Where to position osteotomies in genioglossal advancement surgery based on locations of the mental foramen, canine, lateral incisor, central incisor, and genial tubercle.

PubMed

Park, Joshua S; Lee, Christopher; Rogers, Jason M; Sun, Ho-Hyun; Liu, Yuan F; Elo, Jeffrey A; Inman, Jared C

2017-09-01

The study aimed to provide precise measurements of anterior mandibular structural anatomy and to explore potential osteotomies for genioglossal advancement. Cone beam computed tomography was used to analyze 33 randomly selected patients undergoing surgery for obstructive sleep apnea (OSA) between 2014 and 2016 at an academic surgical hospital. The locations of relevant mandibular structures were measured and statistical modeling was performed. Mean horizontal distances from midline to the mental foramina and the roots of the canine, lateral incisor, and central incisor were 22.11 ± 1.92, 13.56 ± 3.01, 6.19 ± 1.58, and 2.04 ± 0.87 mm, respectively. Mean vertical distances from the inferior border of the mandible were 15.15 ± 1.77, 17.11 ± 3.28, 20.48 ± 3.10, and 21.81 ± 3.49 mm, respectively. The superior border of the genial tubercle was 15.63 ± 2.75 mm, and the inferior border was 6.87 ± 3.29, from the inferior border of the mandible. The angle of decline of the best-fit line through the important structures was about 18° from the occlusion plane at the midline. A straight line estimating the mental foramen, canine, lateral incisor, and central incisor tooth roots crosses at a mean of 22.3-22.6 mm above the inferior border of the mandible at the midline and has an angle of decline of about 18°. Potential osteotomies made parallel to and below this line result in tradeoffs between maximizing capture of the genioglossus muscle attachment and risk of dental/neurovascular injury.

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.

The genetics of shovel shape in maxillary central incisors in man.

PubMed

Blanco, R; Chakraborty, R

1976-03-01

From dental casts of 94 parent-offspring and 127 full-sib pairs, sampled from two Chilean populations, shovelling indices are computed to measure the degree of shovelling of maxillary central incisors quantitatively. Genetic correlations are computed to determine the role of genetic factors in explaining the variation in this trait. Assuming only hereditary factors to be responsible for the transmission of shovel shape, 68% of total variability is ascribed to the additive effect of genes.

Orthodontic treatment of severe anterior open bite and alveolar bone defect complicated by an ankylosed maxillary central incisor: a case report.

PubMed

Lin, Feiou; Sun, Hao; Yao, Linjie; Chen, Qiushuo; Ni, Zhenyu

2014-11-21

Incisor trauma is common in children, and can cause severe complications during adolescent growth and development. This report describes the treatment of a 16-year-old patient with severe anterior open bite due to ankylosis of the maxillary left incisor after dental trauma as an 8-year-old. No examination or active treatment was undertaken until he was 16 years old. Clinical examination revealed that the maxillary left incisor was severely intruded accompanied by a vertical alveolar bone defect. Orthodontic treatment combined with surgical luxation took 3 years and 7 months. During treatment, the intruded incisor was moved to the occlusal level and the alveolar bone defect was restored, achieving normal occlusion. After two years of retention, the maxillary left incisor was retained in a stable normal position with a slightly reduced overbite. This case demonstrates that surgical luxation with orthodontic traction can be an effective approach, especially when the ankylosed tooth has a single root. Long-term monitoring of orthodontic stability and the maintenance of periodontal health are crucial in the post-treatment period.

Relationship between crown-root angulation (collum angle) of maxillary central incisors in Class II, division 2 malocclusion and lower lip line.

PubMed

Srinivasan, Bhadrinath; Kailasam, Vignesh; Chitharanjan, Arun; Ramalingam, Arthi

2013-01-01

The present study aimed to measure the magnitude of the collum angle (crown-root angulation) of maxillary central incisors present in Class II, division 2 malocclusion and to relate the changes in its magnitude with variations in the lower lip line. A set of 120 conventional lateral cephalograms were selected and divided into three groups of 40 each based on the type of malocclusion presented: Class II, division 2 (group 1); Class II, division 1 (group 2); and Class I (group 3). The collum angle of the maxillary central incisor was measured, and the lower lip line was recorded. Analysis of variance (ANOVA) revealed that the mean collum angle was statistically significantly different in the three groups. The mean collum angle was greatest in Class II, division 2 malocclusion (group 1). The mean collum angles were 3.24 ± 4.69 degrees, 0.95 ± 1.06 degrees, and 1.05 ± 1.50 degrees in groups 1, 2, and 3 respectively. In χ ² test comparison of the location of the lower lip line (incisal, middle, or apical third of the central incisor) among the three groups, the lower lip line was found to contact the middle third of the central incisor most frequently in Class II, division 2 malocclusion. ANOVA followed by Tukey honestly significant difference (HSD) test showed that the mean collum angle is significantly increased when the lower lip is in the middle third (P < .05) of the central incisor. Variations in magnitude of the collum angle with the change in the lower lip line suggest a probable etiologic role of the lower lip line in the development of the collum angle.

[Finite element analysis of the maxillary central incisor with traditional and modified crown lengthening surgery and post-core restoration in management of crown-root fracture].

PubMed

Zhen, M; Wei, Y P; Hu, W J; Rong, Q G; Zhang, H

2016-06-01

To construct three-dimensional finite element models with modified crown lengthening surgery and post-core restoration in management of various crown-root fracture types, to investigate the intensity and distribution of stressin models mentioned above, and to compare and analyze the indications of traditional and modified crown lengthening surgeries from the mechanic point of view. Nine three-dimensional finite element models with modified crown lengthening surgery and post-core restoration were established and analyzed by micro-CT scanning technique, dental impression scanner, Mimics 10.0, Geomagic studio 9.0 and ANSYS 14.0 software. The von Mises stress of dentin, periodontal ligament, alveolar bone, post and core, as well as the periodontal ligament area and threshold limit value were calculated and compared with the findings of traditional crown lengthening models which had been published earlierby our research group. The von Mises stress intensity of modified crown lengthening models were: dentin>post>core>alveolar bone>periodontal ligament. The maximum von Mises stress of dentin(44.37-80.58 MPa)distributed in lingual central shoulder. The periodontal ligament area of the modified crown lengthening surgery was reduced by 6% to 28%, under the same crown-root fracture conditions, the periodontal ligament area of modified crown lengthening models was larger than that of the traditional crown lengthening models. In modified crown lengthening surgery models, the von Mises stress of periodontal ligament of B3L1m, B3L2m, B3L3m models exceeded their limit values, however, the von Mises stress of periodontal ligament of the B2L2c, B2L3c, B3L1c, B3L2c, B3L3c models exceeded their limit values in traditional crown lengthening surgery models. The modified crown lengthening surgery conserves more periodontal supporting tissues, which facilitates the long-term survival of teeth. The indication of modified crown lengthening surgery is wider than traditional method. The

Transposition of maxillary canine to central incisor site: aetiology, treatment options and case report.

PubMed

Ali, Zohaib; Jaisinghani, Aneel C; Waring, David; Malik, Ovais

2014-09-01

Dental transposition is relatively infrequent anomaly of the developing dentition. This article focuses on canine transposition and explores the aetiology, diagnosis and treatment of this challenging anomaly. Specifically, the management of a case of canine transposition involving an unerupted maxillary central incisor is described. © 2014 British Orthodontic Society.

Asymmetric extractions in a patient with a hopeless maxillary central incisor, followed by treatment with mini-implant anchorage.

PubMed

Jung, Min-Ho

2018-05-01

Premolar extraction is 1 option for treatment of patients with malocclusion and severe crowding or protrusion. When the patient has missing or hopeless teeth other than premolars, it is possible to consider removal of those teeth to use the space to decrease crowding. A 15-year-old girl sought treatment for severe crowding. She had already lost her maxillary right first premolar as a result of caries 1 year previously and had a hopeless maxillary right central incisor. Her mandibular left first molar still caused discomfort even after endodontic treatment. Extractions of the maxillary right central incisor and mandibular right first premolar and left first molar were chosen to resolve the occlusion problems. Orthodontic mini-implants were placed to translocate the maxillary left central incisor across the midpalatal suture to use the space in the maxillary right quadrant to relieve the crowding. Although a different extraction option was used in each quadrant, the final occlusion was acceptable. After debonding, porcelain crowns were placed on the anterior teeth to improve esthetics. The treatment result remained stable after 2 years of retention. Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Vitality preservation of an anomalous maxillary central incisor after endodontic therapy.

PubMed

Kaufman, A Y; Kaffe, I; Littner, M M

1984-06-01

Endodontic treatment of a case of fused immature central incisor with a supernumerary tooth with dens in dente is described. Although a chronic dentoalveolar abscess was diagnosed, vitality test signs were positive. Treatment consisted of pulpotomy with calcium hydroxide paste; after 2 1/2 months a permanent root canal filling was placed in the amputated part. Follow-up 2 years postoperatively indicated that the tooth has maintained its vitality. The periapical area is completely healed, and apical closure is evident.

The influence of varying maxillary lateral incisor dimensions on perceived smile aesthetics.

PubMed

Bukhary, S M N; Gill, D S; Tredwin, C J; Moles, D R

2007-12-22

The aim of this study was to determine the influence of varying the dimensions of the maxillary lateral incisors on perceived smile aesthetics. Clinical study. Postgraduate dental teaching hospital. A photograph of a female smile displaying only the lips and teeth was digitally altered. First, the width of the maxillary lateral incisors, in proportion to the central incisor, was altered at 5% intervals to produce six images (52%, 57%, 62% [the 'golden proportion'], 67%, 72% and 77%). In a second group, the length of the lateral incisor was altered at 0.5 mm increments to produce five images with the lateral incisor 0.5 mm, 1 mm, 1.5 mm, 2 mm and 2.5 mm shorter than the adjacent central incisor. The photos were ranked from 'most attractive' to 'least attractive' by 41 hypodontia patients, 46 non-hypodontia 'control' patients and 30 dentists. The 67% followed by the 72% lateral-to-central width proportions were the 'most preferred' by all groups. A maxillary lateral incisor that is 1-1.5 mm shorter than the central incisor was the 'most popular' maxillary lateral incisor length. The very short and very long maxillary lateral incisor was consistently perceived as 'least attractive'. There is no evidence to suggest that the golden proportion should be considered the ideal aesthetic standard when creating space for the replacement of missing lateral incisors.

Nonsurgical Management of an Immature Maxillary Central Incisor with Type III Dens Invaginatus Using MTA Plug: A Case Report

PubMed Central

Norouzi, Negar; Kazem, Majid; Gohari, Atefeh

2017-01-01

Dens invaginatus is a developmental anomaly, caused by deepening of the enamel organ into the dental papilla before calcification of the dental tissues. Teeth with dens invagination are susceptible to early caries and pulp necrosis within a few years of eruption or even before root end closure. This article reports two immature maxillary central incisors with type I and III dens invaginatus which had necrotic pulp and a large periradicular lesion, that were treated successfully by nonsurgical root canal treatment. After apical plug placement, the remaining space was backfilled using warm vertical gutta-percha technique and the crowns were restored by composite restoration. At 6 months of follow up the patient was asymptomatic and probing depths were less than 3 mm. In addition, the reduction in the size of apical radiolucencies was observed by radiographic examinations. This case report revealed that even type III des invaginatus with an open apex and large periapical lesion, can be treated non-surgically using MTA as an apical plug. Although this case report presents a favorable result, further studies with long term follow-up periods are encouraged to support the use of nonsurgical endodontic treatment for type III dens invaginatus. PMID:29225653

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

PubMed

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

2015-01-01

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. 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. Hospital-based descriptive cross-sectional study carried out in Udaipur. 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. F-test, post-hoc test, Pearson's correlation test. 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 mm(2)) had more pulp area when compared with females (28.82, 30.05 mm(2)). There was a decrease in total pulp area with increasing age which may be attributed to secondary dentin formation.

Correlation between Visible Length of the Iris and the Length of the Maxillary Central Incisor Using Digital Image Analysis- A Pilot Study.

PubMed

Rohini; Hemalatha; Chander, Gopi Naveen; Anitha, Kuttae Viswanathan

2017-02-01

Complete denture therapy is one such modality where science and art goes hand in hand. Selection of artificial teeth for completely edentulous patients is not easy in the absence of pre extraction records, because till date concrete guidelines do not exist. The purpose of this study was to determine if a correlation existed between the visible length of the iris and the length of the maxillary central incisor to potentially provide a guide for teeth selection. A total of 20 Indian dental students consented to participate in the pilot study. Standardized digital images of the face revealing the eyes and component of teeth on smiling was captured using a digital camera. The digital measurements of the visible iris length (medial aperture height, tangential to iris) and the length of the maxillary central incisor from the zenith to the incisal edge were analysed using Adobe Photoshop creative cloud software. The data was statistically evaluated and results were tabulated. Karl Pearson's Coefficient of Correlation was utilized to detect if any association existed between the two variables. The mean value of length of central incisor was 10.39 mm and the mean value of the visible length of iris was found to be 12.9 mm. A Pearson correlation analysis revealed an r-value <0.3 indicating minimal association between the two variables with a p-value >0.01 (.322). On inference, the correlation between the visible iris length and that of maxillary central incisor were unable to produce a strong positive statistical association. However, an association factor between the two has been obtained. Deduction of 2.5 mm from the dimension of visible iris length will help in attaining the length of artificial maxillary central incisor tooth.

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

Influence of remaining coronal tooth structure on fracture resistance and failure mode of restored endodontically treated maxillary incisors.

PubMed

Santos Pantaleón, Domingo; Morrow, Brian R; Cagna, David R; Pameijer, Cornelis H; Garcia-Godoy, Franklin

2018-03-01

Limited information is available on the effect of an incomplete ferrule because of the varying residual axial wall heights and the volume of residual tooth structure on the fracture resistance of endodontically treated and restored maxillary incisors. The purpose of this in vitro investigation was to examine the effect of varying residual axial wall heights, residual coronal tooth structure, and the absence of 1 proximal axial wall on the fracture resistance and failure mode of endodontically treated teeth restored with metal posts. Sixty intact human maxillary central incisors were divided into 6 groups (n=10): no ferrule (NF), 2-mm complete ferrule (CF2), 2-mm (IF2), 3-mm (IF3), and 4-mm (IF4) incomplete ferrules missing a single interproximal wall, and a control group that had a 6-mm incomplete ferrule (IF6). Cast metal post-and-cores were placed in all experimental specimens except for controls. Control specimens received 1 interproximal cavity preparation extending to the root canal access and a composite resin restoration. Complete metal crowns were then cemented on all specimens. Completed specimens were subjected to thermocycling (6000 cycles, 5°C/55°C) followed by the immediate testing of fracture resistance. Failed specimens were sectioned buccolingually and evaluated to identify the failure mode. The data were analyzed with an analysis of variance (ANOVA) and the Student-Newman-Keuls multiple comparison test (α=.05). An incomplete ferrule (IF2) with 1 interproximal wall missing had significantly reduced fracture resistance (697 N) compared with a complete ferrule (932 N). An increase of 3 to 4 mm of remaining wall height improved fracture resistance, from 844 N (IF3) to 853 N (IF4). Partial decementation was noticed in 8 NF and 5 IF2 specimens. IF3 and IF4 had no decementations. Radicular fractures and cracks (catastrophic failure) were observed in all IF2, IF3, and IF4, 9 CF2, and 6 NF specimens. In 7 specimens without posts (IF6, control

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

The use of a single-step regenerative approach for the treatment of a replanted mandibular central incisor with severe resorption.

PubMed

Chaniotis, A

2016-08-01

To report the clinical and radiographic treatment outcome of an immature replanted mandibular incisor with severe inflammatory external root resorption following a single-step regenerative approach. A 7-year-old female patient was referred 1 week following an extrusion injury to her mandibular central incisor (tooth 31). There was a history of a 6 months previous avulsion injury to the same tooth, which had been replanted after 20 min of extra-oral time. On clinical examination, all teeth were asymptomatic and there was an arch wire splint placed on the mandibular incisors. Radiographic examination revealed severe inflammatory external root resorption of tooth 31. A diagnosis of necrotic pulp and asymptomatic apical periodontitis was made. Under local anaesthesia and rubber dam isolation, an access cavity was prepared. The canal was irrigated using 6% NaOCl solution delivered through the EndoVac negative pressure irrigation system (Endo Vac, Axis/SybronEndo, Coppell, TX, USA). A 17% EDTA solution was used for 5 min followed by a final rinse of sterile water. The periapical tissues were probed using a K-file, and bleeding was induced. A blood clot was allowed to form filling the entire canal. A thick plug of MTA was placed in direct contact with the blood clot. The tooth was restored with composite resin. All procedures were performed in a single visit. The splint was removed 2 weeks later. Recall examination after 24 months revealed healthy soft tissues with normal periodontal probing and mobility. The 24 months radiographic evaluation revealed healing of the severe inflammatory external root resorption and continuous root development/dentine wall thickening of the apical third. No signs of ankylosis or significant discoloration was present. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

[A computer aided design approach of all-ceramics abutment for maxilla central incisor].

PubMed

Sun, Yu-chun; Zhao, Yi-jiao; Wang, Yong; Han, Jing-yun; Lin, Ye; Lü, Pei-jun

2010-10-01

To establish the computer aided design (CAD) software platform of individualized abutment for the maxilla central incisor. Three-dimentional data of the incisor was collected by scanning and geometric transformation. Data mainly included the occlusal part of the healing abutment, the location carinae of the bedpiece, the occlusal 1/3 part of the artificial gingiva's inner surface, and so on. The all-ceramic crown designed in advanced was "virtual cutback" to get the original data of the abutment's supragingival part. The abutment's in-gum part was designed to simulate the individual natural tooth root. The functions such as "data offset", "bi-rail sweep surface" and "loft surface" were used in the process of CAD. The CAD route of the individualized all-ceramic abutment was set up. The functions and application methods were decided and the complete CAD process was realized. The software platform was basically set up according to the requests of the dental clinic.

Immediate provisional restoration of a single-tooth implant in the esthetic zone: a case report.

PubMed

Fu, Po-Sung; Wu, Yi-Min; Tsai, Ching-Fang; Huang, Ta-Ko; Chen, Wen-Cheng; Hung, Chun-Cheng

2011-02-01

Immediate implant restoration of single implants may demonstrate a positive effect on peri-implant soft tissue. Placement of a provisional restoration following implant surgery can create soft tissue contours that resemble normal gingival topography before placement of the definitive prosthesis. This article describes a staged approach of the mandibular permanent right central incisor, which was congenital missing. The proper space for restoration of the missing incisor was created through orthodontic treatment. The scheduled implant site was reconstructed using autogenous bone harvested from the chin region. After a healing period of four months, an implant was installed with the connection of a fixed provisional crown to a prefabricated temporary abutment. The soft tissue around the implant healed according to the contours of the provisional restoration and the emergence profile was used to duplicate the definitive restoration. Peri-implant esthetics was achieved through the staged approach and immediate restoration of the implant. Copyright © 2011. Published by Elsevier B.V.

Crown-root Fracture Restoration on a Patient with Autism Spectrum Disorder.

PubMed

Perez, Edna; Behar-Horenstein, Linda S; Guelmann, Marcio

2016-09-01

Children with intellectual and physical disabilities including autism are susceptible to dental trauma as a sequela from falls due to poor muscular coordination. In addition, their altered muscle tonus often results in an open bite with labial flaring of the maxillary incisors and lip incompetence, predisposing these teeth to fractures. This case report describes an alternative approach of restoring a fractured maxillary permanent central incisor with a composite strip crown during surgical repositioning of the periodontium on an autistic patient. The prognosis of the incisor is guarded due to the probability of re-injury. However, the decision to maintain the tooth clinically was esthetically preferable in comparison to an extraction or decoronation.

Use of a Novel ORMOCER as a Universal Direct Restorative Material.

PubMed

Hakim, Foroud; Vallée, Jessie

2018-01-01

Composite resin is considered the material of choice for direct restoration of teeth when esthetic outcome is a high priority. While material science improvements have mitigated many of the traditional liabilities related to composite resin restorations, shrinkage and related shrinkage stress still play a role in outcomes, placement techniques, and overall success. This case report demonstrates two restorative scenarios using an ORMOCER® composite material. The first features a female patient who, upon completion of preliminary orthodontic treatment, determined in consultation with the orthodontist that her central incisors would present more idealistic display and esthetics if they were lengthened by approximately 1.5 mm. The lengthening of the incisors was to precede the phase II refinement with clear aligners, which would aim to extrude the remaining anterior teeth to develop incisal balance and symmetry. The second case is that of a woman who presented with a newly symptomatic upper right second bicuspid with an existing nearly decade old, large MODL composite resin restoration. This article demonstrates the universal nature of the novel direct restorative material used, making it well-suited for both anterior and posterior applications.

[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.

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.

Evaluation of a technique for color correction in restoring anterior teeth.

PubMed

Rauber, Gabrielle Branco; Bernardon, Jussara Karina; Vieira, Luiz Clovis Cardoso; Baratieri, Luiz Narciso

2017-09-01

This study aimed to evaluate the ability of the proposed technique in producing restorations that exhibit mimesis with tooth structure and to define a restorative clinical protocol. For this study a typodont was used. The right upper central incisor with Class IV lesion was restored with the layering technique (reference tooth, RT). For the left upper central incisor with Class IV lesion, six teeth were restored monochromatically (test teeth, TT), using DA3.5 (n = 3) and DA4 (n = 3) composite resins-resulting in six unsatisfactory color restorations. TT were divided into six groups depending on the color of unsatisfactory restoration and preparation depth. First, a preparation was realized on the labial surface with 0.5 mm, 0.7 mm or 1.0 mm of depth. A second preparation was then performed to reproduce the dentinal mamelons. Next, adhesive procedures were performed and the teeth restored. Opaque halo, opalescent halo and vestibular enamel were then reproduced by the addition of different composite resins. The RT and TT were photographed side by side in typodont to obtain six photographic prints. The photographs of the groups were subjected to visual evaluation by 120 volunteers via a questionnaire. Data were analyzed by the prevalence of answers, and Chi-square test was used to investigate the association between variables at .05 significance. Furthermore, ΔE of groups was evaluated in comparison RT. The results demonstrated that the moderate intensity restorations (DA3.5) with depths of 0.5 mm and 0.7 mm had the highest prevalence of acceptance. For severe intensity restorations (DA4), the preparation depth of 1.0 mm obtained better acceptance. The technique was able to modify the final color of Class IV restorations, producing satisfactory color restorations. This technique can be used for color correction in cases of Class IV restorations, in situations where there is no time for immediate layered restoration, and as a restorative technique. © 2017

[Autotransplantation of a maxillary incisor and orthodontic care: a case study].

PubMed

Charpentier, Valentine; Makaremi, Masrour; Brondeau, François de

2017-12-01

Severely impacted teeth with atypical root anatomy do not respond well to orthodontic traction after surgical exposure. Consequently, they are often removed, but replacing them with dental prostheses can prove difficult in patients who are still growing. Thus, autotransplantation seems to be the only way to preserve a natural tooth and the alveolar bone. An upper central incisor impacted in the region of the nasal cavities with an open apex was diagnosed in an 8.5-year-old female patient. The tooth displayed a curved root pressed against the maxillary cortical bone preventing orthodontic traction treatment. Through this clinical case involving autotransplantation of a maxillary incisor report and a review of the literature, this article explores the indications and exposes the different stages of this orthodontic-surgical protocol. In this case, autotransplantation enabled restoration of maxillary arch continuity. After two years of orthodontic treatment, the bone reconstruction of the extraction site was very satisfactory. The benefits of this technique and the precautions to be taken are discussed as well as the various protocols. The increasing success rate of this surgical procedure makes it possible to consider it as a protocol for the future. © EDP Sciences, SFODF, 2017.

[Three-dimensional finite element analysis of the upper cervical-defected incisor with labial access or lingual access].

PubMed

Su, Fan; Zhao, Ying; Su, Qin

2013-08-01

To evaluate the stress distribution of the cervical-defected incisor with labial or lingual endodontic access with finite element analysis (FEA), and to explore the advantage of resistance in labial endodontic access. 3-D finite element models of upper cervical-defected incisor were established using cone-beam CT (CBCT), Mimics Catia, and Ansys software. The subjects were categorized according to the two endodontic accesses and three restorative ways, which were composite resin, glass fiber-reinforced composite resin and glass fiber-reinforced post-crown. All the models were loaded.The von Mises stress values and distribution were recorded and analyzed with Ansys 10.0 software. In this study, direct composite resin restoration showed no significant difference between the labial and lingual access. In glass fiber-reinforced composite resin, labial access could transfer the stress concentration area. It could reduce the incidence of fracture of the cervical lesion but increase the incidence of root fracture. Post-crown restoration could obviously reduce the incidence of fracture of the cervical lesion. When the cervical-defected incisor is restored with composite resin, labial and lingual accesses can be considered. Labial access with glass fiber-reinforced composite resin or post-crown restoration is a good choice.

The Immediate Aesthetic and Functional Restoration of Maxillary Incisors Compromised by Periodontitis Using Short Implants with Single Crown Restorations: A Minimally Invasive Approach and Five-Year Follow-Up

PubMed Central

Marincola, Mauro; Lombardo, Giorgio; Pighi, Jacopo; Corrocher, Giovanni; Mascellaro, Anna; Lehrberg, Jeffrey; Nocini, Pier Francesco

2015-01-01

The functional and aesthetic restoration of teeth compromised due to aggressive periodontitis presents numerous challenges for the clinician. Horizontal bone loss and soft tissue destruction resulting from periodontitis can impede implant placement and the regeneration of an aesthetically pleasing gingival smile line, often requiring bone augmentation and mucogingival surgery, respectively. Conservative approaches to the treatment of aggressive periodontitis (i.e., treatments that use minimally invasive tools and techniques) have been purported to yield positive outcomes. Here, we report on the treatment and five-year follow-up of patient suffering from aggressive periodontitis using a minimally invasive surgical technique and implant system. By using the methods described herein, we were able to achieve the immediate aesthetic and functional restoration of the maxillary incisors in a case that would otherwise require bone augmentation and extensive mucogingival surgery. This technique represents a conservative and efficacious alternative to the aesthetic and functional replacement of teeth compromised due to aggressive periodontitis. PMID:26649207

Providing a harmonious smile with laminate veneers for a patient with peg-shaped lateral incisors

PubMed Central

Alberton, Simone Beatriz; Alberton, Victória; de Carvalho, Rodrigo Varella

2017-01-01

The most common discrepancy concerning tooth size is the presence of peg-shaped lateral incisors, which can cause teeth with reduced size, anterior diastema, and consequently an unpleasant smile. The development of the adhesive dentistry and ceramic veneers allowed all ceramic-bonded restorations to become an esthetic and functional approach to reestablish the smile harmony. The purpose of this clinical report is to describe a conservative treatment approach to recover an esthetic disharmony caused by bilateral peg-shaped lateral incisors. A 30-year-old female patient was seeking treatment to solve an esthetic disharmony of her smile. Lithium disilicate veneers were planned and build-up with the help of diagnostic models, wax-up, mock-up, and silicone guides, to restore the morphology, size, function, and esthetic of upper lateral incisors and smile. The lithium disilicate veneers were able to provide the harmonization of the patient's smile, recovering the teeth size, shape, and anatomic characteristics. PMID:29279628

Providing a harmonious smile with laminate veneers for a patient with peg-shaped lateral incisors.

PubMed

Alberton, Simone Beatriz; Alberton, Victória; de Carvalho, Rodrigo Varella

2017-01-01

The most common discrepancy concerning tooth size is the presence of peg-shaped lateral incisors, which can cause teeth with reduced size, anterior diastema, and consequently an unpleasant smile. The development of the adhesive dentistry and ceramic veneers allowed all ceramic-bonded restorations to become an esthetic and functional approach to reestablish the smile harmony. The purpose of this clinical report is to describe a conservative treatment approach to recover an esthetic disharmony caused by bilateral peg-shaped lateral incisors. A 30-year-old female patient was seeking treatment to solve an esthetic disharmony of her smile. Lithium disilicate veneers were planned and build-up with the help of diagnostic models, wax-up, mock-up, and silicone guides, to restore the morphology, size, function, and esthetic of upper lateral incisors and smile. The lithium disilicate veneers were able to provide the harmonization of the patient's smile, recovering the teeth size, shape, and anatomic characteristics.

Orthodontic treatment of a patient with unerupted maxillary central and lateral incisors and canine: a case report.

PubMed

Sabuncuoğlu, Fidan Alakuş; Olmez, Hüseyin

2012-05-01

The aim of this case report was to describe the orthodontic and periodontal management of a patient with three impacted anterior teeth. An 18-year-old female with Class I crowding on a Class I skeletal base presented with the chief complaint of an unaesthetic smile. Clinical examination revealed an impacted upper right permanent canine (13), lateral (12) and central incisor (11), a retained deciduous incisor and moderate crowding in the lower arch. The impacted teeth were surgically exposed (closed exposure) and aligned with fixed appliances. The 12 was extracted due to root resorption and 44 extracted to resolve the lower arch crowding. A fraenectomy and gingival recontouring were required. Orthodontic treatment resulted in improved overjet, overbite and an acceptable facial profile. The patient reported improved self esteem. While impacted anterior teeth are a clinical challenge, their surgical exposure, in combination with fixed appliances, is a conservative treatment plan which is not without complications.

[Three-dimensional finite element analysis of maxillary incisor retraction with step-shaped vertical closing loop].

PubMed

Zhang, Sheng; Mai, Li-xiang; Liu, Cong-hua; Wang, Da-wei

2011-07-01

To investigate the displacement and stress distribution of upper incisors in three-dimensional (3D) space controlled by step-shaped vertical closing loop. The maxillary teeth and alveolar bone of a volunteer with normal occlusion were scanned with 3D spiral CT. Modeling and calculation were only carried out on right upper central incisor, lateral incisor and their alveolar bone in order to simplify the procedures. A 3D finite element model of archwire-brackets-upper incisors and periodontal tissues was developed using Ansys finite element package. Finally, a 3D finite element model of archwire-brackets-upper incisors and periodontal tissues was established based on mirror symmetry principle. The displacement of maxillary incisors and stress distribution in periodontal tissues were analyzed. When step-shaped vertical closing loop was simply drew back 1 mm, the maximum displacement of upper central incisor in labial and lingual direction were 5.29 × 10(-2) and 0.71 × 10(-2) mm; 10.47 × 10(-3) and 10.20 × 10(-3) mm in gingival and occlusal direction, 10.26 × 10(-3) and 1.63 × 10(-3) mm in medial and distal direction; the maximum displacement of upper lateral incisor in labial and lingual direction were 3.31 × 10(-2) and 0.41 × 10(-2) mm, 10.52 × 10(-3) and 5.10 × 10(-3) mm in gingival and occlusal direction, 6.29 × 10(-3) and 4.64 × 10(-3) mm in medial and distal direction, the displacement trend of them were moving lingually and gingivally similar to bodily movement. The stress peach of upper central incisor, periodontal ligament and alveolar bone were 31.35, 2.52 and 4.64 MPa, the stress peach of upper lateral incisor, periodontal ligament and alveolar bone were 19.59, 1.28 and 4.12 Mpa, the stress distribution of them were similar and the periodontal ligament buffered the stress imposed on the tooth.

Overjet and overbite analysis during the eruption of the upper permanent incisors.

PubMed

Cuoghi, Osmar A; Sella, Rodrigo C; Mamede, Igo; de Macedo, Fernanda A; Miranda-Zamalloa, Yésselin M; de Mendonça, Marcos R

2009-01-01

ABSTRACT The purpose of this study was to analyze the overjet and overbite behavior during eruption of the upper permanent incisors. Fourth-eight plaster casts of 16 patients from ages 6-13 years were appraised longitudinally. It was found that the overjet remains constant, starting at the eruption of the upper permanent central incisors until eruption of the upper permanent canine teeth, while the overbite increases after eruption of the upper permanent lateral incisors and remains constant with the eruption of the canine teeth.

Molar-incisor-hypomineralisation (MIH). Retrospective clinical study in Greek children. I. Prevalence and defect characteristics.

PubMed

Lygidakis, N A; Dimou, G; Briseniou, E

2008-12-01

This was to evaluate the prevalence and the clinical characteristics of MIH in a group of Greek children. During the years 2003--2005, all MIH cases diagnosed according to the recently set criteria were selected from the new patients clinic of a Community Dental Centre for Children (Athens). Age, gender and teeth involved were recorded. The severity of MIH was determined collectively by dividing the affected teeth in two groups; a) mild defect (demarcated opacities) and b) moderate/severe defect (enamel breakdown and atypical restorations). Evaluation of the distribution of the affected teeth within MIH cases was performed in a separate group of 225 affected children aged 8-12 years with their entire 12 'index' teeth erupted. From the 3,518, 5.5 to 12 year old children that were examined, there were 360 (10.2%) children with MIH, 211 (58.6%) females and 149 (41.4%) males, with 1,926 affected teeth, 1,231 molars and 695 incisors. In the molars group, maxillary molars were more frequently affected (87.8/90.3%) than mandibular (81.7/82.2%). In the central incisor group, maxillary teeth were also more frequently affected (50/55%) than mandibular (24.4/25%), while laterals were the least affected. In all there were 37.9% molars with moderate/severe defects as compared with 4.9% incisors, the remaining 62.1% and 95.1% respectively being mild. The various associations between the affected teeth were evaluated in the sub-group of 225 MIH children with all 'index' teeth erupted (1,286 affected teeth, 776 molars and 510 incisors), with mean number of affected teeth per child being 5.7; separately for molars 3.4 and for incisors 2.2. In these cases 28.4% of the children had only molars affected and 71.6% had both molars and incisors. In descending order the associations of affected teeth more frequently found were: 4 molars/2 incisors (23.5%), 4 molars/4 incisors (16.8%), 4 molars alone (15.1%) and 2 molars alone (9.7%), the remaining being much less. As age increased the

Comparison of interpupillary distance and combined mesiodistal width of maxillary central incisor teeth in two ethnic groups of Northeast India: An in vivo study.

PubMed

Barman, Jogeswar; Serin, Sangma

2018-01-01

Anthropometric measurements of the face can be used as a guide in selecting proper sized anterior teeth. The aim of this study is to evaluate the relationship between the interpupillary distance (IPD) and the combined mesiodistal width of maxillary central incisors (MDW of MCIs) to establish their morphometric criterion and their significance in two ethnic groups of Northeast India. A total of 120 participants consisting of 60 indigenous students each from Assam and Meghalaya in the age group of 18-25 years were selected after taking their written consent. Standardized facial frontal photographs of all the participants were taken using a digital camera in such a manner that maxillary anterior teeth were visible. The photographs were uploaded onto the computer and saved in a file. Anthropometric measurements of IPD and combined MDW of MCIs in centimeters were made using both Adobe Photoshop ® 7.0 software program and manually using a digital vernier caliper on the developed photographs to a same size of 15 cm × 10 cm. Data obtained were tabulated and analyzed using Student "t"-test and Pearson correlation test. The present study reveals a positive correlation with a high degree of statistical significance between IPD and combined mesiodistal width of maxillary central incisors among all the samples irrespective of gender and ethnicity where P < 0.01. IPD can be used as a guide in determining the suitable mesiodistal dimension of the maxillary central incisors.

Masking of Enamel Fluorosis Discolorations and Tooth Misalignment With a Combination of At-Home Whitening, Resin Infiltration, and Direct Composite Restorations.

PubMed

Perdigão, J; Lam, V Q; Burseth, B G; Real, C

This clinical report illustrates a conservative technique to mask enamel discolorations in maxillary anterior teeth caused by hypomineralization associated with enamel fluorosis and subsequent direct resin composite to improve the anterior esthetics. The treatment consisted of at-home whitening with 10% carbamide peroxide gel with potassium nitrate and sodium fluoride in a custom-fitted tray to mask the brown-stained areas, followed by resin infiltration to mask the white spot areas. An existing resin composite restoration in the maxillary right central incisor was subsequently replaced after completion of the whitening and resin infiltration procedures, whereas the two misaligned and rotated maxillary lateral incisors were built up with direct resin composite restorations to provide the illusion of adequate arch alignment, as the patient was unable to use orthodontic therapy.

10-year follow-up of calcifying odontogenic cyst in the periapical region of vital maxillary central incisor.

PubMed

de Carvalhosa, Artur Aburad; de Araújo Estrela, Cyntia Rodrigues; Borges, Alvaro Henrique; Guedes, Orlando Aguirre; Estrela, Carlos

2014-10-01

Radiographic images may lead to misinterpretations of lesions of endodontic and nonendodontic origin. This report describes a case of a 10-year follow-up of a calcifying odontogenic cyst (COC) in the periapical region of a vital maxillary central incisor in a 9-year-old boy. The patient revealed a history of a swelling in the periapical area of tooth #9. The patient denied any dental trauma or history of pain. Clinical examination revealed no mobility, but there was discrete discomfort when horizontal pressure was applied. Pulp vitality was present in all maxillary anterior teeth. Radiographs revealed an oval radiolucent lesion in the periapical region of maxillary central incisor. The therapeutic option was enucleation of the periapical lesion and histologic examination of the specimen. Microscopic findings suggested the diagnosis of a COC. At a follow-up visit 10 years after surgery, panoramic and periapical radiographs showed new bone formation; the patient did not have any pain, and pulp vitality was maintained in all teeth in this area. A COC should be part of the differential diagnosis of other jaw lesions, such as apical periodontitis. The definitive diagnosis of a COC can only be made after microscopic evaluation of the specimen. The follow-up is a helpful reference because it confirms the survival of pulp tissue and no recurrence of the COC. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

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

Implant replacement of the maxillary central incisor utilizing a modified ceramic abutment (Thommen SPI ART) and ceramic restoration.

PubMed

Schneider, Robert

2008-01-01

The prosthetic restoration of a missing anterior tooth with a dental implant is a challenge. Treatment coordination with a multidisciplinary team is critical in the successful outcome of this type of patient treatment. Newer surgical treatment modalities in the management of hard and soft tissues are becoming common, with very good predictability and long-term stability. Additionally, the use of advanced dental technology and materials such as sintered zirconium allows the restorative practitioner the opportunity to fabricate an esthetic, precise-fitting, biocompatible, and strong definitive prosthesis for the patient, with good longevity. The use of an all-ceramic abutment and restoration is described, along with the "soft tissue sculpting" procedure through the use of a custom provisional restoration. The relative ease and convenience of the procedure is also illustrated.

Changes in anteroposterior position and inclination of the maxillary incisors after surgical-orthodontic treatment of skeletal class III malocclusions.

PubMed

Zou, Bingshuang; Zhou, Yang; Lowe, Alan A; Li, Huiqi; Pliska, Benjamin

2015-12-01

The purpose of this study was to evaluate and compare the anteroposterior (AP) position and inclination of the maxillary incisors in subjects with class I normal occlusion and a harmonious profile with patients with skeletal class III malocclusions, and to investigate the changes in maxillary incisor inclination and AP position after surgical-orthodontic treatment in class III patients. Sixty-five subjects (35 female and 30 male; mean age: 21.8 ± 3.89 years) with normal profiles and class I skeletal and dental patterns were selected as a control sample. Sixty-seven patients (38 female and 29 male; mean age: 21.3 ± 3.31 years) with skeletal and dental class III malocclusions who sought surgical-orthodontic treatment were used as the study sample. Subjects were asked to smile and profile photographs were taken with the head in a natural position and the maxillary central incisors and the forehead in full view; cephalograms were taken and superimposed on the profile pictures according to the outline of the forehead and nose. Forehead inclination, maxillary incisor facial inclination and the AP position of the maxillary central incisor relative to the forehead (FAFFA) were measured on the integrated images and statistical analyses were performed. In both groups, there were no significant male/female differences in either the maxillary central incisor inclination or AP position. Female subjects had a significantly steeper forehead inclination compared with males (P < 0.001) in both groups. After combined surgical-orthodontic treatment, the significant labial inclination (P < 0.001) and posterior positioning (P < 0.001) of the maxillary central incisors had been corrected to close to normal range (P > 0.05). In the control group, 84.6% had the facial axial point (FA) of their maxillary central incisors positioned between lines through the forehead facial axis (FFA) point and the glabella. In the study group, however, 79.1% had the maxillary central incisors positioned

Influence of shovel-shaped incisors on the dental arch crowding in Mongolian females.

PubMed

Hasegawa, Yuh; Terada, Kazuto; Kageyama, Ikuo; Tsukada, Shin-ichi; Uzuka, Satoshi; Nakahara, Rizako; Nakahara, Sen

2009-08-01

The aim of this study was to investigate the influences of shovel-shaped incisors on the dental arch crowding in the samples of modern young female adult Mongolians (belonging to the Khalkha-Mogol grouping) ranged between 18.5 and 25.0 years, with a mean age of 20.7 years. Materials in this study comprised of 33 dental casts. Plaster replicas of the A.S.U. system plaques were used to facilitate standardization in scoring and classify shoveling regarding both upper central and lateral incisors. Dimensions of the dental arch namely, overjet, overbite, arch depth, arch width and irregularity index were measured. The correlation between the shovel shape of the central incisor and the lateral incisor was highly significant. Significantly relations were found between the grades of shoveling and the mesiodistal diameters of upper first molars and lower incisors. Positive correlation was admitted between the shoveling and upper arch depth anterior, and upper arch depth. It may be considered that the grades of shoveling are indirectly related with upper and/or lower anterior crowding. Although crowding is looks like an expression of disharmony between teeth and alveolar arch, it may be caused by multiple etiologic factors interacted directly and/or indirectly.

Fracture resistance and primary failure mode of endodontically treated teeth restored with a carbon fiber-reinforced resin post system in vitro.

PubMed

Raygot, C G; Chai, J; Jameson, D L

2001-01-01

This study was undertaken to characterize the fracture resistance and mode of fracture of endodontically treated incisors restored with cast post-and-core, prefabricated stainless steel post, or carbon fiber-reinforced composite post systems. Ten endodontically treated teeth restored with each technique were subjected to a compressive load delivered at a 130-degree angle to the long axis until the first sign of failure was noted. The fracture load and the mode of fracture were recorded. The failure loads registered in the three groups were not significantly different. Between 70%, and 80% of teeth from any of the three groups displayed fractures that were located above the simulated bone level. The use of carbon fiber-reinforced composite posts did not change the fracture resistance or the failure mode of endodontically treated central incisors compared to the use of metallic posts.

Replacement of a hopeless maxillary central incisor: a technique for the fabrication of an immediate implant-supported interim restoration.

PubMed

Graiff, Lorenzo; Vigolo, Paolo

2012-04-01

Placement of a dental implant and an interim restoration in the esthetic zone immediately following tooth extraction is now a common procedure. However, in such clinical situations, the fabrication of an appropriate interim restoration may be challenging. The aim of this article is to present a technique for modifying the extracted tooth so it can be used as an implant-supported interim restoration.

Root morphology and development of labial inversely impacted maxillary central incisors in the mixed dentition: a retrospective cone-beam computed tomography study.

PubMed

Sun, Hao; Wang, Yi; Sun, Chaofan; Ye, Qingsong; Dai, Weiwei; Wang, Xiuying; Xu, Qingchao; Pan, Sisi; Hu, Rongdang

2014-12-01

The aim of this study was to analyze 3-dimensional data of root morphology and development in labial inversely impacted maxillary central incisors. Cone-beam computed tomography images from 41 patients with impacted incisors were divided into early and late dental age groups according to their dental age. Sagittal slices in which the labiolingual width of the tooth was the widest in the axial view were evaluated. The inverse angle, the dilaceration angle, and the length of both impacted and homonym teeth were evaluated with SimPlant Pro software (version 13.0; Materialise Dental NV, Leuven, Belgium). The Student t test indicated that the lengths of the impacted teeth were significantly shorter than those of the homonym teeth (P <0.05), and the root lengths of the early dental age group were significantly shorter than those of the late dental age group. The results from chi-square tests indicated that the incidence of dilacerations was significantly higher in the late dental age group when compared with the early dental age group. Multiple regression analyses indicated that the independent variables for root length of the impacted teeth were dental age (β = 0.958; P <0.001) and length of the nondilacerated part of the root (β = 0.435; P <0.001). Dilaceration was more common in the late dental age group. The roots of labial inversely impacted maxillary central incisors continue developing, but their potential is limited. Copyright © 2014 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

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. ©2012 Special Care Dentistry Association and Wiley Periodicals, Inc.

Altered Esthetics in Primary Central Incisors: The Child's Perception.

PubMed

Soares, Fernanda Cunha; Cardoso, Mariane; Bolan, Michele

2015-01-01

This study's purpose was to determine preschool-age children's social perceptions and self-perceptions regarding altered dental esthetics. A cross-sectional study was carried out involving 431 four- to five-year-olds. The participants were shown four photographs of children with incisors exhibiting discoloration, crown fracture, missing tooth, or normal teeth. The children were asked four questions for analysis of social perceptions and two additional questions for analysis of self-perceptions. Binary logistic regression was used for the statistical analysis. Children had negative social perceptions, as a significant association was found between their negative feelings and the altered dental esthetics in children pictured in the photographs. The affected anterior incisor was indicated as the main reason for this feeling (odds ratio equals 4.68, 95 percent confidence interval [CI] equals 2.39 to 9.15). When analyzing self-perceptions, a significant association was found between negative feelings and the child's own altered dental esthetics. Children with altered esthetics felt 1.92-fold sadder than those without altered esthetics (95 percent CI equals 1.22 to 3.02). Again, the affected teeth were indicated as the main reason for this feeling (prevalence ratio equals 1.22) in comparison to reasons cited. Four- to five-year-olds have negative social perceptions and self-perceptions regarding altered dental esthetics.

Morphological features of the maxillary incisors roots and relationship with neighbouring anatomical structures: possible implications in endodontic surgery.

PubMed

Taschieri, S; Weinstein, T; Rosano, G; Del Fabbro, M

2012-05-01

The purpose of this study was to investigate the relationship between the root apex of the upper incisors and neighbouring anatomical structures as well as the morphology of the root-end foramen after apicoectomy. Fifty-seven patients requiring endodontic surgical treatment for a maxillary anterior root were enrolled. A preoperative diagnostic computed tomography (CT) scan was analysed to determine: the distance between the anterior wall of the nasopalatine duct and the central (CI-ND) incisor root 4mm from the apex; and the distance between the floor of the nasal cavity and the tip of either the central (CI-NF) or the lateral (LI-NF) incisor root. After apicoectomy, root-end foramen endoscopic pictures were taken in order to characterize their morphology. Fifty-nine central and 26 lateral incisors were evaluated. The average CI-ND was 4.71 ± 1.26 (SD) mm. The average CI-NF was 10.62 ± 2.25 mm. The average LI-NF was 13.05 ± 2.43 mm. The foramen shape after apicoectomy was ovoid to circular in about 90% of cases in both central and lateral incisors. A sound knowledge of the anatomical relationships at the surgical site is essential for the clinician to perform a safe endodontic surgical procedure. Copyright © 2011 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Clinical attachment level gain and three-year maintenance of a maxillary incisor with 100% bone loss: A case report.

PubMed

Tirone, Federico; Salzano, Stefano

2016-01-01

This case report discusses a patient suffering from chronic periodontal disease and diagnosed with a hopeless central incisor. The intention was to show the possibility of gaining new clinical attachment via regenerative surgery in a tooth with 100% bone loss around the root. Treatment of hopeless and questionable teeth in periodontal patients has become an ideological matter. On the one hand, dental implants have proved to be a reliable solution to replace lost teeth; on the other hand, newly emerging evidence suggests that successful periodontal treatment of teeth diagnosed as hopeless is possible. Here we describe surgical, orthodontic, and restorative treatments that led to clinical attachment gain and achieved clinical success over a three-year follow-up period.

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.

Biometric analysis of the clinical crown and the width/length ratio in the maxillary anterior region.

PubMed

Orozco-Varo, Ana; Arroyo-Cruz, Gema; Martínez-de-Fuentes, Rafael; Jiménez-Castellanos, Emilio

2015-06-01

Restorative dentistry often involves correcting tooth size discrepancies. Therefore, dental biometrics should play an important role in the planning of an esthetic restoration. The purpose of this study was to analyze the clinical crown width, length, and width/length ratio of maxillary central incisors, lateral incisors, and canines in an adult population. The study also aimed to determine whether a correlation exists between natural tooth dimensions and the optimal tooth dimension guidelines suggested for planning esthetic restorations. Stone casts were poured from irreversible hydrocolloid impressions of 412 healthy adult participants. These casts were used to measure the maximum mesiodistal width and maximum crown-root length of the maxillary central incisors, lateral incisors, and canines with a digital precision caliper (0.01 mm). The width/length ratio was calculated for each tooth, and 40 casts were selected to test the reliability of the measuring method. The mean age of the participants in the sample was 33.94 years; 60.7% were women and 39.3% were men. The mean width value was 8.71 mm for central incisors, 6.75 mm for lateral incisors, and 7.81 mm for canines. The mean length was 10.23 mm for central incisors, 8.59 mm for lateral incisors, and 9.93 mm for canines. The average width/length ratio was 85% for central incisors and 79% for lateral incisors and canines. The data obtained from the population studied are similar to those from previous research studies with similar methodology. However, great discrepancies in the absolute values were found when compared with other studies of ideal tooth dimension guidelines on the personal preferences and the esthetic perception of dentists. The perception of what is considered natural seems to differ from what is considered esthetically perfect. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Restored agricultural wetlands in Central Iowa: habitat quality and amphibian response

USGS Publications Warehouse

Reeves, Rebecca A.; Pierce, Clay; Smalling, Kelly L.; Klaver, Robert W.; Vandever, Mark W.; Battaglin, William A.; Muths, Erin L.

2016-01-01

Amphibians are declining throughout the United States and worldwide due, partly, to habitat loss. Conservation practices on the landscape restore wetlands to denitrify tile drainage effluent and restore ecosystem services. Understanding how water quality, hydroperiod, predation, and disease affect amphibians in restored wetlands is central to maintaining healthy amphibian populations in the region. We examined the quality of amphibian habitat in restored wetlands relative to reference wetlands by comparing species richness, developmental stress, and adult leopard frog (Lithobates pipiens) survival probabilities to a suite of environmental metrics. Although measured habitat variables differed between restored and reference wetlands, differences appeared to have sub-lethal rather than lethal effects on resident amphibian populations. There were few differences in amphibian species richness and no difference in estimated survival probabilities between wetland types. Restored wetlands had more nitrate and alkaline pH, longer hydroperiods, and were deeper, whereas reference wetlands had more amphibian chytrid fungus zoospores in water samples and resident amphibians exhibited increased developmental stress. Restored and reference wetlands are both important components of the landscape in central Iowa and maintaining a complex of fish-free wetlands with a variety of hydroperiods will likely contribute to the persistence of amphibians in this landscape.

Partially arrested root formation in a permanent maxillary central incisor subsequent to trauma to the primary dentition.

PubMed

Nagatani, S; Mathieu, G P

1994-02-01

When the primary dentition sustains a traumatic insult, the development of the succedaneous teeth can be disturbed leading to a number of malformations. In this case report, the patient presented with a history of prior trauma to his primary maxillary incisors which resulted in partially arrested root formation for a permanent incisor. The considerations in formulating a treatment plan which included orthodontics are discussed.

Prognosis of a mandibular incisor with apical and periodontal lesion: an 18-month follow-up.

PubMed

Yilmaz, Burak; Er, Serkan; Sonbay, Burcin Hilal

2009-01-01

Oral habits that are performed daily, can be a factor in the progression of periodontal and/or endodontic diseases. The purpose of this clinical report was to describe the treatment of a wide periodontal lesion and 18-month follow-up of a 13-year-old male patient's permanent mandibular central incisor that was traumatized due to chronic pencil biting. The lesion was curreted surgically while the compromised mandibular central incisor was endodontically and periodontally treated. The interdisciplinary approach showed a successful clinical outcome, as the survival of the infected tooth and the recovery of the soft tissues and the alveolar bone could have been achieved.

Biomechanical Effect of Ferrule on Incisors Restored with a Fiberglass Post and Lithium-Disilicate Ceramic Crown after Thermal Cycling and Fatigue Loading.

PubMed

Valdivia, Andréa Dolores Correia Miranda; Rodrigues, Monise de Paula; Bicalho, Aline Aredes; Van Meerbeek, Bart; Sloten, Jos Vander; Pessoa, Roberto Sales E; Soares, Carlos José

2018-04-19

To evaluate the biomechanics of endodontically treated incisors restored with a fiberglass post and a CAD/CAM lithium-disilicate ceramic crown with/without a ferrule after thermal and mechanical aging. Twenty bovine incisors were divided into two groups (n = 10): 1. Fe, with a ferrule of 2 mm, and 2. NFe, without a ferrule. After endodontic treatment, the teeth were restored using a fiberglass post (Exacto 3, Angelus) and composite core (Tetric Ceram, Ivoclar Vivadent). They then received a CAD/CAM lithium-disilicate ceramic crown (IPS e.max CAD) luted using a self-adhesive composite (RelyX Unicem 2, 3M Oral Care). All specimens were subjected to 20,000 thermocycles and 2,400,000 simulated chewing cycles. Ceramic crown and root dentin strains (μS) were measured using strain gauges (n = 10) during 100-N loading before and after the thermal and mechanical aging, and upon fracture loading. The specimens were subsequently loaded to fracture (N). The stress distribution was analyzed using 3D individualized finite-element models created by micro-CT of experimental samples (n = 3). Strain data were analyzed using two-way ANOVA and Tukey's HSD test. Fracture resistance was analyzed using Student's t-test and fracture mode was analyzed using the chi-squared test (α = 0.05). After aging, NFe exhibited significantly higher root dentin deformation (buccal: 1248.0 ± 282.8; lingual: 516.2 ± 195.0; p < 0.001) than Fe (buccal, 554.0 ± 233.8; lingual: 311.8 ± 159.0; p < 0.001). The deformation measured on ceramic crowns was not influenced by ferrule presence or aging process. Significantly higher fracture resistance (N) was observed for the Fe (1099.6 ± 214.8) than the NFe group (675.3 ± 113.8) (p < 0.001). The NFe group revealed a lower fracture resistance:root strain ratio than did the Fe group. The stress levels on root dentin and fiberglass were lower for the Fe group. The NFe group showed increased root dentin strain after the aging process. The Fe group revealed

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.

Diagnosis and management of maxillary incisors affected by incisal wear: an interdisciplinary case report.

PubMed

Bernardo, Jussara Karina; Maia, Elaine A Vilela; Cardoso, Antônio Carlos; de Araújo Júnior, Edson Medeiros; Monteiro Júnior, Sylvio

2002-01-01

In the attempt to restore anterior teeth affected by erosion and bruxism, many clinicians have been frustrated with the constant restorative failures. Frequently, these failures are attributed to the restorative materials employed, especially in cases in which composite resins are used. However, some flaws of the restorations are related to the oversight of occlusal principles. The purpose of this article is to discuss the etiology, signs, and symptoms of incisal wear, with special attention to that caused by bruxism and chemical erosion. Relatively simple management techniques (e.g., occlusal adjustment, adhesive restorations) are proposed, and the diagnosis and management of a representative clinical case is presented. In some cases of bruxism and/or dental erosion, it is possible to acquire space to recuperate the esthetics and function of maxillary incisors affected by incisal wear through a conservative treatment associated with the control of the etiologic factors.

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.

Developmental Disturbances of a Maxillary Central Incisor due to Trauma to Its Predecessor: A Case Report

PubMed Central

Karataş, Merve Safa; Sönmez, Işıl Şaroğlu

2013-01-01

Objective To report the effects of a primary tooth trauma on the underlying permanent tooth germ. Clinical Presentation and Intervention A 12-year-old girl was referred to our clinic with a complaint of poor aesthetic appearance. The crown of the permanent maxillary left central tooth exhibited an increased clinical crown height with an ‘enamel hyperplasia’ in the cervical third and had hypoplastic enamel with yellowish-brown discoloration extending from the middle third to the incisal edge. Radiographic examination revealed that the permanent maxillary left central tooth had abnormal root morphology with root dilaceration. The patient revealed a history of trauma at the age of 4 years. An aesthetic restoration with light-curing resin composite was performed on the vestibular surface of the maxillary left permanent central tooth. Conclusion Sequelae of a primary tooth trauma on the permanent tooth were restored. We recommend that parents should be aware of the consequences of untreated trauma to a primary tooth. Educational and preventive programmes on dental trauma are required to educate parents about emergency knowledge and sequelae of dental trauma. PMID:23689528

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

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.

Three-dimensional anatomy of equine incisors: tooth length, enamel cover and age related changes

PubMed Central

2013-01-01

Background Equine incisors are subjected to continuous occlusal wear causing multiple, age related changes of the extragingival crown. It is assumed that the occlusal wear is compensated by continued tooth elongation at the apical ends of the teeth. In this study, μCT-datasets offered the opportunity to analyze the three-dimensional appearance of the extra- and intraalveolar parts of the enamel containing dental crown as well as of the enamel-free dental root. Multiple morphometric measurements elucidated age related, morphological changes within the intraalveolar part of the incisors. Results Equine incisors possess a unique enamel cover displaying large indentations on the mesial and distal sides. After eruption tooth elongation at the apical end outbalances occlusal wear for two to four years resulting in increasing incisor length in this period of time. Remarkably, this maximum length is maintained for about ten years, up to a tooth age of 13 to 15 years post eruption. Variances in the total length of individual teeth are related to different Triadan positions (central-, middle- and corner incisors) as well as to the upper and lower arcades. Conclusion Equine incisors are able to fully compensate occlusal wear for a limited period of time. However, after this ability ceases, it is expected that a diminished intraalveolar tooth length will cause massive changes in periodontal biomechanics. The time point of these morphodynamic and biomechanical changes (13 to 15 years post eruption) occurs in coincidence with the onset of a recently described destructive disease of equine incisor (equine odontoclastic tooth resorption and hypercementosis) in aged horses. However, further biomechanical, cell biological and microbiological investigations are needed to elucidate a correlation between age related changes of incisor morphology and this disease. PMID:24321365

Three-dimensional anatomy of equine incisors: tooth length, enamel cover and age related changes.

PubMed

Schrock, Patricia; Lüpke, Matthias; Seifert, Hermann; Staszyk, Carsten

2013-12-09

Equine incisors are subjected to continuous occlusal wear causing multiple, age related changes of the extragingival crown. It is assumed that the occlusal wear is compensated by continued tooth elongation at the apical ends of the teeth. In this study, μCT-datasets offered the opportunity to analyze the three-dimensional appearance of the extra- and intraalveolar parts of the enamel containing dental crown as well as of the enamel-free dental root. Multiple morphometric measurements elucidated age related, morphological changes within the intraalveolar part of the incisors. Equine incisors possess a unique enamel cover displaying large indentations on the mesial and distal sides. After eruption tooth elongation at the apical end outbalances occlusal wear for two to four years resulting in increasing incisor length in this period of time. Remarkably, this maximum length is maintained for about ten years, up to a tooth age of 13 to 15 years post eruption. Variances in the total length of individual teeth are related to different Triadan positions (central-, middle- and corner incisors) as well as to the upper and lower arcades. Equine incisors are able to fully compensate occlusal wear for a limited period of time. However, after this ability ceases, it is expected that a diminished intraalveolar tooth length will cause massive changes in periodontal biomechanics. The time point of these morphodynamic and biomechanical changes (13 to 15 years post eruption) occurs in coincidence with the onset of a recently described destructive disease of equine incisor (equine odontoclastic tooth resorption and hypercementosis) in aged horses. However, further biomechanical, cell biological and microbiological investigations are needed to elucidate a correlation between age related changes of incisor morphology and this disease.

Apical root resorption in maxillary incisors when employing micro-implant and J-hook headgear anchorage: a 4-month radiographic study.

PubMed

Wang, Qingzhu; Chen, Wenjing; Smales, Roger J; Peng, Hui; Hu, Xiaokun; Yin, Lu

2012-10-01

This study evaluated, over a 4-month study period, the amount of apical root resorption occurring in maxillary central incisors following their retraction when employing either micro-implant or J-hook headgear anchorage. The prospective randomised clinical trial was conducted in Orthodontic Clinic, College of Stomatology, China from 2008-2009. Subjects are patients requiring fixed appliances on waiting list (n=20). In female Han Chinese patients aged from 16-26 years, standardized periapical radiographs from 10 randomly assigned patients with maxillary protrusions comprising the micro-implant group, and from 10 similar patients comprising the J-hook headgear group, were assessed for maxillary central incisor apical root resorption. Measurements before and after orthodontic therapy were also obtained from lateral cephalometric radiographs to calculate incisor horizontal retraction and vertical intrusion distances. Estimated retraction force vectors were calculated in horizontal and vertical directions for both treatment groups. Data analysis employed t-tests and the Pearson correlation test, with α=0.05 for statistical significance. The results showed that when compared with the J-hook group, significantly more apical root resorption shortening of the maxillary central incisors was observed in the micro-implant group (1.27 mm difference, 95% CI=0.70-1.84, P<0.001), which was associated with a significantly larger retraction distance (P=0.004) and a smaller vertical force component (P<0.0001). We are led to conclude that continuous activation of the nickel-titanium coil springs used in the micro-implant group resulted in significantly more apical root resorption shortening and maxillary central incisor retraction than when intermittent J-hook retraction was employed. The employment of continuous duration orthodontic forces presents a risk for increased apical root resorption that requires careful radiographic monitoring.

Influence of Preadjusted Bracket Shape and Positioning Reference on Angulation of Upper Central Incisor.

PubMed

Topolski, Francielle; de O Accorsi, Mauricio A; Trevisi, Hugo J; Cuoghi, Osmar A; Moresca, Ricardo

2016-10-01

To verify the influence of different bracket shapes and placement references according to Andrews and MBT systems on the expression of angulation in upper central incisors (UCI). Bracket positioning and mesiodistal dental movement simulations were performed and the angulations produced in the dental crown were evaluated, based on computed tomography scan images of 30 UCI and AutoCAD software analysis. Rectangular (Andrews) and rhomboid (MBT) brackets were placed according to the references recommended by Andrews and MBT systems - long axis of the clinical crown (LACC) and incisal edge (IE) respectively. Data showed that the use of LACC as reference for bracket positioning produced 5° and 4° UCI angulations in Andrews and MBT brackets respectively. The use of IE produced a 1.2° mean angulation in UCI for both brackets. When the LACC was used as reference for bracket positioning, the UCI crown angulation corresponded to the angulation built into the brackets, regardless of shape, while the use of IE resulted in natural crown angulation, regardless of bracket shape. This research contributes to guide the orthodontist in relation to the different treatment techniques based on the use of preadjusted brackets.

Molar incisor hypomineralization (MIH): conservative treatment management to restore affected teeth.

PubMed

Fragelli, Camila Maria Bullio; Souza, Juliana Feltrin de; Jeremias, Fabiano; Cordeiro, Rita de Cássia Loiola; Santos-Pinto, Lourdes

2015-01-01

The purpose of this study was to evaluate the 12-month clinical performance of glass ionomer restorations in teeth with MIH. First permanent molars affected by MIH (48) were restored with glass ionomer cement (GIC) and evaluated at baseline, at 6 and at 12 months, by assessing tooth enamel breakdown, GIC breakdown and caries lesion associations. The data were analyzed using the chi-square test and actuarial survival analysis. The likelihood of a restored tooth remaining unchanged at the end of 12 months was 78%. No statistically significant difference was observed in the association between increased MIH severity and caries at baseline (p > 0.05) for a 6-month period, or between increased MIH severity and previous unsatisfactory treatment at baseline (p > 0.05) for both a 6- and 12-month period. A statistically significant difference was observed in the association between increased MIH severity and extension of the restoration, involving 2 or more surfaces (p < 0.05) at both periods, and between increased MIH severity and caries at baseline (p < 0.05) at a 12-month period. Because the likelihood of maintaining the tooth structures with GIC restorations is high, invasive treatment should be postponed until the child is sufficiently mature to cooperate with the treatment, mainly of teeth affected on just one face.

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

Apical stress distribution on maxillary central incisor during various orthodontic tooth movements by varying cemental and two different periodontal ligament thicknesses: a FEM study.

PubMed

Vikram, N Raj; Senthil Kumar, K S; Nagachandran, K S; Hashir, Y Mohamed

2012-01-01

During fixed orthodontic therapy, when the stress levels in the periodontal ligament (PDL) exceedsan optimum level, it could lead to root resorption. To determine an apical stress incident on the maxillary central incisor during tooth movement with varying cemental and periodontal ligament thickness by Finite Element Method (FEM) modeling. A three dimensional finite element model of a maxillary central incisor along with enamel, dentin, cementum, PDL and alveolar bone was recreated using EZIDCOM and AUTOCAD software. ALTAIR Hyper mesh 7.0 version was used to create the Finite Element meshwork of the tooth. This virtual model was transferred to Finite Element Analysis software, ANSYS where different tooth movements were performed. Cemental thickness at the root apex was varied from 200 μm to 1000 μm in increments of 200 μm. PDL thickness was varied as 0.24 mm and 0.15 mm. Intrusive, Extrusive, Rotation and Tipping forces were delivered to determine an apical stress for each set of parameters. Results indicated that an apical stress induced in the cementum and PDL, increased with an increase in cementum and PDL thickness respectively. Apical stress induced in the cementum remained the same or decreased with an increase in the PDL thickness. Apical stress induced in the PDL decreased with an increase in the cementum thickness. The study concluded that the clinical delivery of an orthodontic forces will cause stress in the cementum and PDL. Hence, it is necessary to limit the orthodontic force to prevent root resorption.

How much incisor decompensation is achieved prior to orthognathic surgery?

PubMed

McNeil, Calum; McIntyre, Grant T; Laverick, Sean

2014-07-01

To quantify incisor decompensation in preparation for orthognathic surgery. 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). 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). 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.

Application of the 2-piece orthodontic C-implant for provisional restoration with laser welded customized coping: a case report.

PubMed

Paek, Janghyun; Ahn, Hyo-Won; Jeong, Do-Min; Shim, Jeong-Seok; Kim, Seong-Hun; Chung, Kyu-Rhim

2015-03-25

This article presents the application of laser welding technique to fabricate an orthodontic mini-implant provisional restoration in missing area after limited orthodontic treatment. A 15-year-old boy case is presented. Two-piece orthodontic C-implant was placed after regaining space for missing right mandibular central incisor. Due to angular deviation of implant, customized abutment was required. Ready-made head part was milled and lingual part of customized abutment was made with non-precious metal. Two parts then were laser welded (Master 1000, Elettrolaser Italy, Verona, Italy) and indirect lab composite (3 M ESPE Sinfony, St. Paul, MN, USA) was built up. The patient had successful result, confirmed by clinical and radiographic examinations. Before the patient is ready to get a permanent restoration later on, this provisional restoration will be used. This case shows that a two-piece orthodontic C-implant system can be used to maintain small edentulous space after orthodontic treatment.

Scan-layered reconstructions: A pilot study of a nondestructive dental histoanatomical analysis method and digital workflow to create restorations driven by natural dentin and enamel morphology.

PubMed

Malta Barbosa, João; Tovar, Nick; A Tuesta, Pablo; Hirata, Ronaldo; Guimarães, Nuno; Romanini, José C; Moghadam, Marjan; Coelho, Paulo G; Jahangiri, Leila

2017-07-08

This work aims to present a pilot study of a non-destructive dental histo-anatomical analysis technique as well as to push the boundaries of the presently available restorative workflows for the fabrication of highly customized ceramic restorations. An extracted human maxillary central incisor was subject to a micro computed tomography scan and the acquired data was transferred into a workstation, reconstructed, segmented, evaluated and later imported into a Computer-Aided Design/Computer-Aided Manufacturing software for the fabrication of a ceramic resin-bonded prosthesis. The obtained prosthesis presented an encouraging optical behavior and was used clinically as final restoration. The digitally layered restorative replication of natural tooth morphology presents today as a clear possibility. New clinical and laboratory-fabricated, biologically inspired digital restorative protocols are to be expected in the near future. The digitally layered restorative replication of natural tooth morphology presents today as a clear possibility. This pilot study may represent a stimulus for future research and applications of digital imaging as well as digital restorative workflows in service of esthetic dentistry. © 2017 Wiley Periodicals, Inc.

Flare up rate related to root canal treatment of asymptomatic pulpally necrotic central incisor teeth in patients attending a military hospital.

PubMed

Al-Negrish, Abdul Rohman Salem; Habahbeh, Riyad

2006-10-01

This prospective study was conducted to determine the flare up rate related to root canal treatment of asymptomatic non vital maxillary central incisor teeth performed in one and two appointments and the relationship, if any between pain and number of treatment visits. The frequency of postobturation pain and swelling was recorded and evaluated over an observation period of 1 week in a 120 consecutive patients undergoing root canal treatment. The patients were assigned randomly into one of two groups of 60 patients each. The canals of all teeth were prepared and filled using the step-back preparation and lateral condensation filling techniques. The data were analyzed statistically using Mann-Whitney test. Eight of the 120 patients were excluded from the analysis as they failed to attend for postoperative reviews. Out of the 112 patients involved in the study 90 patients had no pain, 9 patients had slight pain, 8 patients had moderate pain, and 5 patients had severe pain after 2 days. After 7 days 104 patients had no pain, 4 patients had slight pain, 3 patients had moderate pain and 1 patient had severe pain. No statistically significant difference in the incidence and degree of postoperative pain was found between one and two visit Endodontic procedures. The rate of post obturation flare up in asymptomatic Endodontically treated non vital maxillary centarl incisors was 11.6 and 3.6% after 2 and 7 days, respectively.

Incisor malalignment and the risk of periodontal disease progression.

PubMed

Alsulaiman, Ahmed A; Kaye, Elizabeth; Jones, Judith; Cabral, Howard; Leone, Cataldo; Will, Leslie; Garcia, Raul

2018-04-01

The objective of this study was to investigate the association between incisor crowding, irregularity, and periodontal disease progression in the anterior teeth. Data collected over 35 years from men enrolled in the Veterans Affairs Dental Longitudinal Study included information concerning pocket depth and alveolar bone loss. Plaster casts of the maxillary (n = 400) and mandibular (n = 408) arches were available for baseline measurements. Periodontal disease in the anterior teeth was defined as per arch sum of pathologic pocket depth and sum of teeth with any alveolar bone loss in the anterior sextants. Incisor malalignment status was defined by the anterior tooth size-arch length discrepancy index and Little's Irregularity Index. Adjusted mixed effects linear models computed the beta (β) estimates and 95% confidence intervals (95% CI) of the amounts of change in periodontal disease outcomes by the level of malalignment. In the anterior maxillary arch, crowding and spacing were significantly associated with an increased per-arch sum of pathologic pocket depth (β, 0.70 mm; 95% CI, 0.20-1.21, and β, 0.49 mm; 95% CI, 0.06-0.91, respectively). In the anterior mandibular arch, incisor crowding and irregularity were significantly associated with an increased per-arch sum of pathologic pocket depth (mild crowding: β, 0.47 mm; 95% CI, 0.01-0.93; severe irregularity: β, 0.94 mm; 95% CI, 0.50-1.38), and the sum number of teeth with alveolar bone loss (mild and moderate-to-severe crowding: β, 0.45 teeth; 95% CI, 0.08-0.82; and β, 0.45 teeth; 95% CI, 0.13-0.83, respectively; moderate irregularity: β, 0.34 teeth; 95% CI, 0.06-0.62). Certain incisor malalignment traits (ie, maxillary incisor crowding, maxillary incisor spacing, mandibular incisor mild crowding, mandibular incisor moderate-to-severe crowding, mandibular incisor moderate irregularity, and mandibular incisor severe irregularity) are associated with significant periodontal disease progression

First records of talon cusps on baboon maxillary incisors argue for standardizing terminology and prompt a hypothesis of their formation.

PubMed

Heaton, Jason L; Pickering, Travis Rayne

2013-12-01

Dental characters can provide vital clues for understanding intra- and intertaxonomic morphological variation and its underlying genetic and environmental components. However, the unambiguous identification of particular traits and their comparative study is often confounded by lack of consistent terminology in the relevant literature. This difficulty is exacerbated when the etiologies are not completely understood, as is the case with talon cusps. To date, research on talon cusps has focused on modern humans. In many instances, descriptions of talon cusps appear in clinical case studies focusing on their treatment and removal. What is lacking in those discussions, though, is a comparative framework, in which the occurrence of talon cusps in nonhuman primates, and possibly other mammals, is established and understood. Here, we report on a taloned upper central incisor of a wild baboon (Papio hamadryas ursinus) from South Africa. The anomalous incisor of this individual includes an exaggerated accessory cusp diagnosed as a Type II talon. Microcomputed tomographic and radiographic analyses show that the taloned cusp possesses enamel, dentin, and pulp. In addition, we identified an unclassifiable talon cusp on a central maxillary incisor of a baboon skull housed in the Smithsonian Institution's Natural History Museum collection. Our observations of talon cusps on baboon incisors demonstrate that, with regard to this phenomenon, systematic study of nonhuman primates is much needed, along with a consistent use of terminology in the anatomical and anthropological literature. Finally, we present a hypothesis of the formation of talon cusps on mammalian incisors. Copyright © 2013 Wiley Periodicals, Inc.

Aesthetic evaluation of profile incisor inclination.

PubMed

Ghaleb, Nathalie; Bouserhal, Joseph; Bassil-Nassif, Nayla

2011-06-01

The objectives of this study were to evaluate (1) the impact of maxillary incisor inclination on the aesthetics of the profile view of a smile, (2) to determine the most aesthetic inclination in the profile view of a smile and correlate it with facial features, and (3) to determine if dentists, orthodontists, and laypeople appreciate differently incisor inclination in smile aesthetics. A smiling profile photograph of a female subject (22 years of age) who fulfilled the criteria of soft tissue normative values and a balanced smile was obtained. The photograph was manipulated to simulate six lingual and labial inclinations at 5 degree increments to a maximum of 15 degrees. The seven photographs were randomly distributed in a binder to three groups of raters (30 dentists, 30 orthodontists, and 30 laypeople) who scored the attractiveness of the photographic variations using a visual analogue scale. Comparison of the mean scores was carried out by repeated analysis of variance, univariate tests, and multiple Bonferroni comparisons. The results showed a statistically significant interaction between the rater's profession and the aesthetic preference of incisor inclination (P = 0.013). The profile smile corresponding to an increase of 5 degrees in a labial direction had the highest score among all professions and among male and female raters. Orthodontists preferred labial crown torque; dentists and laypeople did not appreciate excessive incisor inclination in either the lingual or the labial directions. The most preferred smile matched with a maxillary incisor inclined 93 degrees to the horizontal line and +7 degrees to the lower facial third.

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.

How serious is Molar Incisor Hypomineralisation (MIH) among 8- and 9-year-old children in Bosnia-Herzegovina? A clinical study.

PubMed

Mulic, A; Cehajic, E; Tveit, A B; Stenhagen, K R

2017-06-01

To determine the prevalence of MIH in 8- and 9 year-old children in the city of Kljuc, Bosnia-Herzegovina, and to describe the distribution and severity of the affected teeth. Study design: All 8- and 9-year-olds (n=104) living in Kljuc (born 2004/2005) were invited to participate, and 103 were examined by a calibrated clinician. Written, informed consent was obtained from all participants' relatives, as well as a questionnaire designed to assess potential risk indicators. Index teeth were all permanent first molars and incisors (12 teeth). Opacities (>1mm), post eruptive breakdown (PEB), atypical restorations and previous extractions caused by MIH were registered. The prevalence of MIH was 11.7% (n=12), significantly higher for girls than for boys (14.6% vs. 9.7%; p<0.05). The maxillary first molars and incisors were 1.8 (p<0.02) and 2.3 (p<0.05) times more frequently affected than the mandibular ones, respectively. Seven (30%) of the affected molars had opacities, 8 (35%) had PEB and 8 (35%) atypical restorations. No molars had been extracted due to MIH. The use of penicillin due to adenoid infections in the first 5 years was associated with a higher prevalence of MIH (41.7% vs. 19.6%). The prevalence of MIH (11.7%) supports the data previously published from Bosnia-Herzegovina. Girls had higher prevalence of MIH than boys; first molars and incisors in the maxilla were almost twice as often affected as in the mandible. Use of penicillin in the first 5 years was associated with a higher prevalence.

16-Year follow-up of an avulsed maxillary central incisor after replantation following 10-h storage: An unusual case.

PubMed

Kırzıoğlu, Zuhal; Erken Güngör, Özge; Erdoğan, Yıldırım

2017-07-01

Tooth avulsion is a type of dental injury defined as the complete displacement of a tooth out of the alveolar socket, and the lack of prompt treatment measures can result in the loss of function, poor quality of life, and psychological and social problems. However, several factors may not permit the immediate replantation of an avulsed tooth; therefore, delayed replantation has emerged as an alternative to meet the esthetic, functional, and psychological demands of patients. Here it was described that the successful replantation of an avulsed maxillary central incisor in a 9-year-old boy who presented at the clinic with the tooth stored in unfavorable conditions as dry and then in olive oil-milk mixture almost 10 h after the event. The tooth has remained in its socket healthy for 16 years after treatment. The patient was satisfied with both esthetics and function. © 2017 Special Care Dentistry Association and Wiley Periodicals, Inc.

Implant-supported restoration of congenitally missing teeth using cancellous bone block-allografts.

PubMed

Nissan, Joseph; Mardinger, Ofer; Strauss, Morris; Peleg, Michael; Sacco, Roberto; Chaushu, Gavriel

2011-03-01

Patients with congenitally missing teeth may present with undeveloped alveolar bone morphology, making implant reconstruction a challenge. The aim of the present study was to evaluate the outcome of dental implants after ridge augmentation with cancellous freeze-dried block bone allografts in patients with congenitally missing teeth. Twelve patients with a mean age of 21 ± 4 years, were included. Congenitally missing teeth included maxillary lateral incisors, a maxillary canine, and mandibular central and lateral incisors. A bony deficiency of ≥3 mm horizontally and ≤3 mm vertically according to computerized tomography served as inclusion criteria. Twenty-one implants were inserted after a healing period of 6 months. Five out of 21 implants were immediately restored. Bone measurements were taken before bone augmentation, during implant placement, and at second-stage surgery. Nineteen cancellous allogeneic bone-blocks were used. The mean follow-up time was 30 ± 16 months. Bone block and implant survival rates were 100% and 95.2%, respectively. Mean bone gain was statistically significant (P < .001): 5 ± 0.5 mm horizontally and 2 ± 0.5 mm vertically. All of the patients received a fixed implant-supported prosthesis. Soft tissue complications occurred in 4 patients (30%). Complications after cementation of the crowns were seen in 1 implant (4.8%). All implants remained clinically osseointegrated at the end of the follow-up examination. There was no crestal bone loss around the implants beyond the first implant thread. Cancellous bone block-allografts can be used successfully for implant-supported restorations in patients with congenitally missing teeth. Copyright © 2011 Mosby, Inc. All rights reserved.

COMPUTED TOMOGRAPHIC FEATURES OF INCISOR PSEUDO-ODONTOMAS IN PRAIRIE DOGS (CYNOMYS LUDOVICIANUS).

PubMed

Pelizzone, Igor; Di Ianni, Francesco; Volta, Antonella; Gnudi, Giacomo; Manfredi, Sabrina; Bertocchi, Mara; Parmigiani, Enrico

2017-05-01

Maxillary incisor pseudo-odontomas are common in pet prairie dogs and can cause progressive respiratory obstruction, while mandibular pseudo-odontomas are rarely clinically significant. The aim of this retrospective cross-sectional study was to describe CT features of maxillary and mandibular incisor pseudo-odontomas vs. normal incisors in a group of pet prairie dogs. All pet prairie dogs with head CT scans acquired during the period of 2013-2015 were included. A veterinary radiologist who was aware of final diagnosis reviewed CT scans and recorded qualitative features of affected and normal incisors. Mean density values for the pulp cavity and palatal and buccal dentin were also recorded. A total of 16 prairie dogs were sampled (12 normal maxillary incisors, 20 confirmed maxillary incisor pseudo-odontomas, 20 normal mandibular incisors, 12 presumed mandibular incisor pseudo-odontomas). Maxillary incisors with confirmed pseudo-odontomas had a significantly hyperattenuating pulp and dentin in the reserve crown and apical zone, when compared to normal maxillary incisors. Pseudo-odontomas appeared as enlargements of the apical zone with a globular/multilobular hyperattenuating mass formation haphazardly arranged, encroaching on midline and growing caudally and ventrally. Presumed mandibular incisor pseudo-odontomas had similar CT characteristics. In 60% of prairie dogs with maxillary incisor pseudo-odontomas, the hard palate was deformed and the mass bulged into the oral cavity causing loss of the palatine bone. The common nasal meatus was partially or totally obliterated in 81.8% of prairie dogs with maxillary pseudo-odontomas. Findings supported the use of CT for characterizing extent of involvement and surgical planning in prairie dogs with pseudo-odontomas. © 2017 American College of Veterinary Radiology.

Assessing the benefits and costs of dryland forest restoration in central Chile.

PubMed

Schiappacasse, Ignacio; Nahuelhual, Laura; Vásquez, Felipe; Echeverría, Cristian

2012-04-30

Investment in natural capital restoration is increasing as a response to the widespread ecological degradation of dryland forests. However, finding efficient mechanisms to promote restoration among private landowners is a significant challenge for policy makers with limited financial resources. Furthermore, few attempts have been made to evaluate the costs and benefits of restoration interventions even though this information is relevant to orient decision making. Hence, our goal was to estimate the benefits and costs of dryland forest restoration by means of reforestation with native trees in a study area in central Chile. To determine benefits we applied a Contingent Valuation questionnaire that allowed for the calculation of willingness to pay measures. Restoration costs were calculated based on market prices following existing technical recommendations developed for the study area. The results showed that the restoration project had a negative NPV irrespective of the discount rate applied in the analysis. Thus, the NPV varied between -US$71,000 and -US$258,000. The NPV attained positive results only for negative discount rates (US$15,039 for -2%) and only when the national subsidy available for forest restoration was taken into account. This shows that landowners in Colliguay do not have incentives for carrying out restoration interventions due to a classic market failure: that in which ecosystems are mismanaged because many of their benefits are externalities from the perspective of landowners. Overall, these results stress the need for developing new compensation mechanisms and enhancing those in existence, with the aim of making restoration competitive with other land uses. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

In vitro study comparing fracture strength recovery of teeth restored with three esthetic bonding materials using different techniques.

PubMed

Rajput, Akhil; Ataide, Ida; Lambor, Rajan; Monteiro, Jeanne; Tar, Malika; Wadhawan, Neeraj

2010-01-01

Reattachment of the fractured fragment of a traumatized tooth (whenever available and usable) has become the treatment of choice in cases of uncomplicated crown fractures. Despite the presence of various bonding materials and techniques, laboratory data evaluating the biomechanical aspects of such procedures is largely lacking in the literature. The objective of this in vitro study was to evaluate the fracture strength recovery of incisors, following fragment restoration with three different techniques. A total of 90 extracted human maxillary central incisors were subjected to crown fractured under standard conditions. This was carried out by applying a compressive force from the buccal aspect of the clinical crown using a universal strength testing machine. The fractured teeth were equality distributed in three groups, defined on the basis of the technique used for reattachment: i) overcontour, ii) internal dentinal groove and iii) direct buildup. Each group was further subdivided into three subgroups on the basis of the intermediate restorative material used for reattachment, namely: i) hybrid composite (Filtek Z100 Universal Restorative, ii) nanocomposite (Filtek Z350) and iii) Ormocer (Voco Admira). Following reattachment, the crowns were re-fractured under standard conditions. The force required for fracture was recorded and was expressed as a percentage of the fracture strength of the intact tooth. The data was expressed as a percentage of the fracture strength of the intact tooth. The data was analyzed using two-way ANOVA and Bonferroni tests for pair-wise comparison. The results showed no statistically significant differences in fractures strength between the three groups (P > 0.05). However, comparison of the subgroups revealed statistically significant higher strength recovery percentages for the hybrid and the nanocomposite compared with the Ormocer material (P < 0.05). It was concluded that material properties have a significant influence on the success

Lingual eruption of mandibular permanent incisors: a space correlated phenomenon?

PubMed

Aminabadi, Naser Asl; Farahani, Ramin Mostofi Zadeh; Sohrabi, Aydin; Pouralibaba, Firuz

2009-01-01

The aim of the present study was to investigate the prevalence and distribution according to various arch length conditions of lingually erupted mandibular permanent incisors and the effect of space condition on this phenomenon with long-term follow-up of these teeth. A total of 105 children aged 5-7.5 years with one or more permanent mandibular incisors erupting lingual to the corresponding primary incisors were included in the study. A space analysis was performed. The subjects were divided into six groups according to various space conditions. The subjects were followed for 2 years. In this study the prevalence of lingual eruption was 18.4%. Eighty-three point seven percent of the subjects had either equivalent space, mild space excess, or a space deficiency (not more than 3 mm). No relationship was found between groups and clinical outcomes (P>.05). Follow up of the main three groups (according to the space analysis results) revealed in the adequate space group 75% of the children lost their primary incisors without any intervention. Similar outcomes occurred in 85.7% and 57.14% of cases in the mild space excess and space deficiency groups, respectively. Considering the three main groups combined, equivalent space, mild space excess, and mild space deficiency, 70.45% of children lost their primary incisors without any intervention and 14.8% needed primary incisor extraction (17.4%, 14.3%, and 10.7% in each group, respectively). There was no predisposition toward a space deficiency or excess found in these subjects so the wait-and-see policy versus early extraction can be considered for lingually erupting permanent mandibular incisors. Lingual eruption of mandibular incisors is a common clinical problem in the early mixed dentition period that is a source of discomfort for parents of patients with this condition. The present study provides a unique insight into the prevalence of the problem as well as the clinical decisions such as favoring retention of primary

Nasopalatine duct cyst mimicking an endodontic periapical lesion: a case report.

PubMed

Bains, Rhythm; Verma, Promila; Chandra, Anil; Tikku, A P; Singh, Nimisha

2016-01-01

Lesions of nonendodontic origin, such as nasopalatine or globulomaxillary cysts, may mimic periapical radiolucencies associated with pulpal pathosis, and incorrect diagnosis may lead to unnecessary endodontic treatment. Horizontal root fractures most commonly affect the maxillary central and lateral incisors. Prognosis depends largely on the level of fracture; fractures in the apical third have the best prognosis, and those in the cervical third have the worst. This case report discusses surgical and restorative management of a patient who had a nasopalatine cyst that had been misdiagnosed and treated as an endodontic lesion of the maxillary right central incisor as well as a midroot horizontal fracture of the adjacent lateral incisor.

Enamel-free teeth: Tbx1 deletion affects amelogenesis in rodent incisors.

PubMed

Catón, Javier; Luder, Hans-Ulrich; Zoupa, Maria; Bradman, Matthew; Bluteau, Gilles; Tucker, Abigail S; Klein, Ophir; Mitsiadis, Thimios A

2009-04-15

TBX1 is a principal candidate gene for DiGeorge syndrome, a developmental anomaly that affects the heart, thymus, parathyroid, face, and teeth. A mouse model carrying a deletion in a functional region of the Tbx1 gene has been extensively used to study anomalies related to this syndrome. We have used the Tbx1 null mouse to understand the tooth phenotype reported in patients afflicted by DiGeorge syndrome. Because of the early lethality of the Tbx1-/- mice, we used long-term culture techniques that allow the unharmed growth of incisors until their full maturity. All cultured incisors of Tbx1-/- mice were hypoplastic and lacked enamel, while thorough histological examinations demonstrated the complete absence of ameloblasts. The absence of enamel is preceded by a decrease in proliferation of the ameloblast precursor cells and a reduction in amelogenin gene expression. The cervical loop area of the incisor, which contains the niche for the epithelial stem cells, was either severely reduced or completely missing in mutant incisors. In contrast, ectopic expression of Tbx1 was observed in incisors from mice with upregulated Fibroblast Growth Factor signalling and was closely linked to ectopic enamel formation and deposition in these incisors. These results demonstrate that Tbx1 is essential for the maintenance of ameloblast progenitor cells in rodent incisors and that its deletion results in the absence of enamel formation.

Incisor microwear and diet in three species of Colobus.

PubMed

Kelley, J

1990-01-01

Examination of incisor microwear in three species of Colobus revealed that the predominantly folivorous C. badius more closely resembles C. satanas, a seed predator/folivore, than C. guereza, another predominantly folivorous species. This demonstrates that species of the same broad dietary category can have very different patterns of incisor microwear, indicative of differences in food procurement behavior and/or the physical properties of dietary items for some portion of the diet. Conversely, species of different categories can have microwear patterns that, superficially at least, are quite similar. The dissimilarity in incisor microwear between C. badius and C. guereza is mirrored to a certain extent in molar microwear, although the differences are not nearly so great on the molars. The differences between C. badius and C. guereza may involve different food items in the major, folivorous portions of their diets, or they may relate to differences in the very minor fruit and bark components. The similar microwear patterns of C. badius and C. satanas demonstrate that incisor microwear by itself is unreliable for assigning fossil species to broad dietary categories. Incisor microwear can be used to infer finer dietary distinctions in fossil species for which dietary category has been determined by other means.

Surgical management of impacted incisors in associate with supernumerary teeth: a combine case report of spontaneous eruption and orthodontic extrusion.

PubMed

Das, D; Misra, J

2012-01-01

Maxillary permanent incisors impaction is not a frequent case in dental practice, but its treatment is challenging because of its importance to facial esthetics. Supernumerary teeth are the main cause of impaction of upper incisors. Supernumerary teeth when present can cause both esthetic and pathologic problems. Early detection of such teeth is most important if complications are to be avoided. In this reported case, the orthopantamogram of a 9-year-old boy revealed two impacted supernumerary teeth in the maxillary anterior region, which was interfering with the eruption of the permanent central incisors. The impacted supernumerary teeth were surgically removed, 11 was repositioned in the arch as it was situated very high in the arch, close to the nasal floor. Twenty-one erupted spontaneously but orthodontic force was applied over 11 to bring it into the occlusion and alignment was achieved with 0.014 mm NiTi wire.

Fracture resistance of glazed, full-contour ZLS incisor crowns.

PubMed

Schwindling, Franz Sebastian; Rues, Stefan; Schmitter, Marc

2017-07-01

To compare the failure behaviour of zirconia-reinforced lithium silicate (Celtra Duo, DeguDent) with that of lithium disilicate (IPS e.max CAD, Ivoclar Vivadent) and feldspar (Mark II, VITA) ceramics. Three groups of sixteen glazed maxillary incisor crowns were produced. The inner surfaces of the crowns were etched, then luted to metal dies with self-adhesive cement. Single load-to-failure tests were performed before and after thermo-mechanical ageing. To simulate clinical conditions, the specimens were thermocycled (10,000 cycles between 6.5°C and 60°C) and underwent chewing simulation (1,200,000 cycles, F max =86N). Statistical analyses were performed by use of non-parametric Kruskal-Wallis and Mann-Whitney U-tests. Before ageing, all the monolithic incisor crowns fractured at test forces >285N. Mean fracture loads were highest for zirconia-reinforced lithium silicate (725N, SD 162N), slightly lower for lithium disilicate (701N, SD 276N), and lowest for feldspar (554N, SD 190N). The differences between the results were not statistically significant. After ageing, fracture resistance decreased for all materials except zirconia-reinforced lithium silicate. Mean fracture loads were highest for zirconia-reinforced lithium silicate (766N, SD 98N) and significantly lower for both lithium disilicate (485N, SD 64N) and feldspar (372N, SD 116N). Monolithic restorations fabricated from zirconia-reinforced lithium silicate retain high fracture resistance after extensive thermo-mechanical ageing. This preclinical study suggests that cohesive failures of monolithic anterior crowns produced of these ceramics will not be a major problem in dental practice. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Angle Class I malocclusion treated with lower incisor extraction.

PubMed

Barbosa, Vanessa Leal Tavares

2013-01-01

In planning orthodontic cases that include extractions as an alternative to solve the problem of negative space discrepancy, the critical decision is to determine which teeth will be extracted. Several aspects must be considered, such as periodontal health, orthodontic mechanics, functional and esthetic alterations, and treatment stability. Despite controversies, extraction of teeth to solve dental crowding is a therapy that has been used for decades. Premolar extractions are the most common, but there are situations in which atypical extractions facilitate mechanics, preserve periodontal health and favor maintenance of the facial profile, which tends to unfavorably change due to facial changes with age. The extraction of a lower incisor, in selected cases, is an effective approach, and literature describes greater post-treatment stability when compared with premolar extractions. This article reports the clinical case of a patient with Angle Class I malocclusion and upper and lower anterior crowding, a balanced face and harmonious facial profile. The presence of gingival and bone recession limited large orthodontic movements. The molars and premolars were well occluded, and the discrepancy was mainly concentrated in the anterior region of the lower dental arch. The extraction of a lower incisor in the most ectopic position and with compromised periodontium, associated with interproximal stripping in the upper and lower arches, was the alternative of choice for this treatment, which restored function, providing improved periodontal health, maintained facial esthetics and allowed finishing with a stable and balanced occlusion. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO), as part of the requirements for obtaining the BBO Diplomate title.

Spectrophotometric Evaluation of the Pulpal Peroxide Levels in Intact and Restored Teeth - An Invitro Study.

PubMed

Patri, Gaurav; Acharya, Gourismita; Agrawal, Pratik; Panda, Vijeta

2016-08-01

Hydrogen peroxide (30%) is a commonly used "in office" bleaching agent. Deleterious effects of hydrogen peroxide on the pulp have been observed. The present study was conducted with the aim to evaluate the penetration of 30% hydrogen peroxide into the pulp chamber through intact teeth and through the surface of teeth, restored with either hybrid composite or Resin Modified Glass Ionomer Cement (RMGIC). Sixty extracted human maxillary central incisors were selected and divided into six groups. Two groups were restored with hybrid composite resin and two with RMGIC, while two groups were left intact. The teeth with acetate buffer solution in their pulp cavity were then immersed in either 30% hydrogen peroxide or distilled water depending upon the group, for 60 minutes at 37°C. Then horseradish peroxidase and leucocrystal violet were added to the acetate buffer solution present in the pulp chamber after it was transferred to a test tube and the optical density of the resultant blue solution obtained was measured spectrophotometrically. The data obtained were analyzed using one way ANOVA and Student's t-test. The data obtained established that hydrogen peroxide penetrated into the pulp from the bleaching agent used. Hydrogen peroxide (30%) showed the highest pulpal peroxide level in teeth restored with RMGIC followed by teeth restored with hybrid composite resin and the least amount of penetration was observed in intact teeth. The amount of peroxide penetration into the tooth is more through restored tooth than intact tooth and is also dependant on the type of restorative materials used.

Prevalence, association, and sexual dimorphism of Carabelli's molar and shovel incisor traits amongst Jordanian population.

PubMed

Khraisat, A; Taha, Sahar T; Jung, R E; Hattar, S; Smadi, L; Al-Omari, I K; Jarbawi, M

2007-09-01

The correlation between dental morphological traits can be used as an indicator to show major ethnic differences. Therefore, this study investigated the prevalence of Carabelli's molar and shovel incisor traits and tested their association and sexual dimorphism in Jordanian population. Three hundred subjects of school children at their 10th grade and of 15.5-year as an average age were involved. Alginate impressions for the maxillary arch were taken, poured, and casts were then trimmed. The selected accurate casts were of 132 male- and 155 female-students. The examined morphologic traits were Carabelli's trait on the maxillary first and second molars and shovel-shaped incisors. The relationship between different traits was investigated by Nonparametric Correlation analysis and Independent Sample t test was used to test sexual dimorphism in trait expression. The prevalence of Carabelli's trait in maxillary first molar and shovel trait in maxillary central incisor was relatively high (65.0 % and 53.0 %, respectively). The prevalence of Carabelli's trait on maxillary second molars was 3.8 %. Nonparametric Correlations revealed a strongest positive correlation between Carabelli's trait on maxillary first molar and shovel trait in males (P = 0.005). Significant sexual dimorphism was only found in the prevalence of Carabelli's trait on maxillary first molar (P = 0.013) and shovel trait (P = 0.038). The Jordanian Population had comparatively high prevalence of Carabelli's molar and shovel incisor traits. There was a positive association between Carabelli's trait on maxillary first molar and shovel trait in males. Sexual dimorphism was evident in Carabelli's trait on maxillary first molar and shovel trait.

Analysis of the golden proportion and width/height ratios of maxillary anterior dentition in patients with lateral incisor agenesis.

PubMed

Pini, Núbia Pavesi; de-Marchi, Luciana Manzotti; Gribel, Bruno Frazão; Ubaldini, Adriana Lemos Mori; Pascotto, Renata Corrêa

2012-12-01

  The purpose of this study was to assess the presence of the golden proportion (GP) in the facial view tooth-to-tooth width proportion of the six maxillary anterior teeth and to evaluate the width/height (W/H) ratios of the incisors of patients with maxillary lateral incisor (LI) agenesis treated either with implants or orthodontically (by moving canines into the position of the laterals, recontouring them, and placing composite restorations over the repositioned teeth).   Forty-eight patients with LI agenesis were divided into four experimental groups: unilateral recontouring group (N = 10), bilateral recontouring group (BRG, N = 18), unilateral implant group (UIG, N = 10), bilateral implant group (N = 10), and a control group (CG, N = 25) of patients without agenesis. GP ratios were determined on patients' dental casts placed over Levin's grids, whereas W/H ratios were measured directly on the casts and a millimeter ruler to determine these distances. Statistical analysis was performed with Shapiro-Wilk, Kruskal-Wallis, Mann-Whitney, Friedman, and Wilcoxon tests (p < 0.05).   The incidence of GP in the tooth-to-tooth width proportions was significantly different between groups and more commonly found between centrals and laterals than between laterals and canines. The GP was more likely to be observed in the BRG, UIG, and CG. The results demonstrated that the GP was not found to be present in the majority of the cases treated with maxillary agenesis, regardless of the method of treatment. The mean W/H ratios of the laterals ranged between 0.75 and 0.90.   Although the GP may be a useful diagnostic guide, it was not observed in the majority of esthetic outcomes of patients treated with maxillary LI agenesis in this study. The assessment of the golden proportion and width/height ratio of upper anterior teeth in patients with upper lateral incisor agenesis treated with either implants or tooth re-contouring may assist dentists and

Gender differences in the form of maxillary central incisors analyzed using AutoCAD software.

PubMed

Brunetto, Juliana; Becker, Mirian Marly; Volpato, Claudia A Maziero

2011-08-01

Female teeth are considered more rounded and male teeth more quadrangular. Although lacking in scientific support, this theory helps in selecting the mold of artificial teeth for dentures. Parameters that are more reliable are sought to determine gender differences in tooth form. The purpose of this study was to assess possible differences between genders in terms of tooth form: oval, triangular, or quadrangular. The sample comprised 433 subjects with a mean age of 15 years selected from a population of Brazilian high school students. The maxillary right central incisor (MCI) of each subject was photographed. The images were adjusted to standardize the long axis of the tooth in the vertical position. The AutoCAD computer program was used to analyze graphically the geometric form of the tooth. According to analysis results, form was classified as oval, triangular, or quadrangular. Intraexaminer consistency was analyzed by using linear correlation coefficient and Bland Altman analysis. The relationship between gender and tooth form was analyzed by chi-square and linear regression (α=.05). In women, the form was 57.73% (n=127) oval, 23.54% (n=52) triangular, and 18.64% (n=41) quadrangular; while in men, the form was 54.93% (n=117) oval, 36.15% (n=77) triangular, and 8.92% (n=19) quadrangular (P<.001). The oval form was the most prevalent in both genders. However, the triangular form was more common in men than in women, and the quadrangular form more frequent in women than in men. Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Enamel-free teeth: Tbx1 deletion affects amelogenesis in rodent incisors

PubMed Central

Catón, Javier; Luder, Hans-Ulrich; Zoupa, Maria; Bradman, Matthew; Bluteau, Gilles; Tucker, Abigail S.; Klein, Ophir; Mitsiadis, Thimios A.

2010-01-01

TBX1 is a principal candidate gene for DiGeorge syndrome, a developmental anomaly that affects the heart, thymus, parathyroid, face, and teeth. A mouse model carrying a deletion in a functional region of the Tbx1 gene has been extensively used to study anomalies related to this syndrome. We have used the Tbx1 null mouse to understand the tooth phenotype reported in patients afflicted by DiGeorge syndrome. Because of the early lethality of the Tbx1−/− mice, we used long-term culture techniques that allow the unharmed growth of incisors until their full maturity. All cultured incisors of Tbx1−/− mice were hypoplastic and lacked enamel, while thorough histological examinations demonstrated the complete absence of ameloblasts. The absence of enamel is preceded by a decrease in proliferation of the ameloblast precursor cells and a reduction in amelogenin gene expression. The cervical loop area of the incisor, which contains the niche for the epithelial stem cells, was either severely reduced or completely missing in mutant incisors. In contrast, ectopic expression of Tbx1 was observed in incisors from mice with upregulated Fibroblast Growth Factor signalling and was closely linked to ectopic enamel formation and deposition in these incisors. These results demonstrate that Tbx1 is essential for the maintenance of ameloblast progenitor cells in rodent incisors and that its deletion results in the absence of enamel formation. PMID:19233155

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

Central venous recanalization in patients with short gut syndrome: restoration of candidacy for intestinal and multivisceral transplantation.

PubMed

Lang, Elvira V; Reyes, Jorge; Faintuch, Salomao; Smith, Amy; Abu-Elmagd, Kareem

2005-09-01

To assess feasibility and success of venous recanalization in patients with short gut syndrome who have lost their traditional central venous access and required intestinal or multivisceral transplantation. Twelve patients between the ages of 7 and 55 years with short gut syndrome and long-standing total parenteral nutrition (TPN) dependency and/or hypercoagulability were treated. All had extensive chronic central venous occlusions and survival was dependent on restoration of access and planned transplantation. Central venous recanalizations were obtained via sharp needle recanalization techniques, venous reconstructions with stents, and/or extraanatomic access to the central venous system for placement of central venous tunneled catheters. Central venous access was restored in all patients without operative-related mortality. Three major hemodynamic perioperative technical complications were recorded and successfully treated. There were three self-limited early infectious complications. With a mean follow-up of 22 months, eight of the 12 patients were alive with successful small bowel or multivisceral transplantation; six of those became independent of TPN. The remaining four patients died of complications related to TPN (n = 3) or transplantation (n = 1). With a mean follow-up of 20 months, all but two of the recanalized venous accesses were maintained, for a success rate of 83%. Recanalizations of extensive chronic vein occlusions are feasible but associated with high risk. The technique is life-saving for TPN-dependent patients and can restore candidacy for intestinal and multivisceral transplantation. This approach is likely to be increasingly requested because of the current clinical availability of the transplant procedure.

Determinants of permanent first incisor eruption in grazing Australian Angora goats.

PubMed

McGregor, B A; Butler, K L

2011-12-01

To investigate the effects of live weight, sex and other factors on deciduous (first incisor) loss and permanent first incisor development in Angora goats. Goats were part of a pen study on the effects of energy intake in Angora does during pregnancy and lactation on kid growth and development. The design was three levels of nutrition in mid-pregnancy × two levels of postnatal nutrition in 17 randomised blocks. Conception times were calculated by using artificial insemination, with ultrasound examination 43 days after insemination. Does were fed different amounts of a formulated diet in their pens. After weaning, goats were grazed in sex groups. Deciduous first incisor loss and permanent first incisor development were recorded at 11 time points from 14 to 20 months of age. For each sex, the time for visible eruption and full development of permanent first incisor declined linearly with increased live weight by 5.9 and 5.4 days/kg live weight, respectively. The time to reach similar development stages for first permanent incisors eruption was 3 months longer for the lightest animals compared with the heaviest animals. Date of birth, birth weight, doe age, growth rates, mid-pregnancy and postnatal nutrition, parity, day of weaning and weaning weight had no detectable effect. The results explain much of the substantial range in reported first permanent incisor eruption dates for small ruminants and have application in ageing of goats, marketing of kids for meat, in the selection of animals for breeding flocks and in educational material. © 2011 The Authors. Australian Veterinary Journal © 2011 Australian Veterinary Association.

Comparison of the intrusion effects on the maxillary incisors between implant anchorage and J-hook headgear.

PubMed

Deguchi, Toru; Murakami, Takashi; Kuroda, Shingo; Yabuuchi, Toshinori; Kamioka, Hiroshi; Takano-Yamamoto, Teruko

2008-05-01

Recently, miniscrews have been used to provide anchorage during orthodontic treatment, especially for incisor intrusion. Miniscrews during incisor intrusion are commonly used in implant orthodontics. Traditionally, effective incisor intrusion has been accomplished with J-hook headgear. In this study, we compared the effect of incisor intrusion, force vector, and amount of root resorption between implant orthodontics and J-hook headgear. Lateral cephalometric radiographs from 8 patients in the implant group and 10 patients in the J-hook headgear group were analyzed for incisor retraction. The estimated force vector was analyzed in the horizontal and vertical directions in both groups. Root resorption was also measured on periapical radiographs. In the implant group, significant reductions in overjet, overbite, maxillary incisor to palatal plane, and maxillary incisor to upper lip were observed after intrusion of the incisors. In the J-hook headgear group, significant reductions in overjet, overbite, maxillary incisor to upper lip, and maxillary incisor to SN plane were observed after intrusion of the incisors. There were significantly greater reductions in overbite, maxillary incisor to palatal plane, and maxillary incisor to upper lip in the implant group than in the J-hook headgear group. Estimated force analysis resulted in significantly more force in the vertical direction and less in the horizontal direction in the implant group. Furthermore, significantly less root resorption was observed in the implant group compared with the J-hook headgear group. The maxillary incisors were effectively intruded by using miniscrews as orthodontic anchorage without patient cooperation. The amount of root resorption was not affected by activating the ligature wire from the miniscrew during incisor intrusion.

Lower incisor intrusion with intraoral transosseous stainless steel wire anchorage in rabbits.

PubMed

Wu, Jian-chao; Huang, Ji-na; Lin, Xin-ping

2010-06-01

The purpose of this research was to investigate the potential use of intraoral transosseous stainless steel wires as anchorage for intrusion of the lower incisors using a rabbit model. Placement of intraoral transosseous stainless steel wires around incisors is similar to that of intraoral transosseous wiring of edentulous mandibular fractures. Ten male New Zealand rabbits, 9 +/- 1.5 months of age, average weight 1.8 +/- 0.3 kg, were used in this study. One lower incisor was intruded with a 50 g bilateral force using a coil spring for 10 weeks, while the other incisor served as the control. Clinical measurements of the distances between the occlusal edges of the incisors (EE) were performed weekly with a calliper. In addition to standard descriptive statistical calculations, a paired Student's t-test was used for comparison of the two groups. All surgical sites healed uneventfully after insertion of the wires. Significant differences were found in the change of EE between the experimental and control sides from 4 weeks onwards. Intrusion of the incisor, 4 +/- 0.58 mm, was seen on the test side, while EE on the control side remained unchanged. Within the limits of this animal study, it is concluded that the intraoral transosseous stainless steel wire anchorage system is a cost-effective method for intrusion of lower incisors when the use of other anchorage system is not possible.

An Analysis of Maxillary Anterior Teeth Dimensions for the Existence of Golden Proportion: Clinical Study.

PubMed

Sandeep, Nalla; Satwalekar, Parth; Srinivas, Siva; Reddy, Chandra Sekhar; Reddy, G Ramaswamy; Reddy, B Anantha

2015-09-01

Appearance of the face is a great concern to everyone, as it is a significant part of self-image. The study analyzed the clinical crown dimensions of the maxillary anterior teeth with respect to their apparent mesiodistal widths, width-to-height ratio to determine whether golden proportion existed among the South Indian population. A total of 240 dentulous subjects were chosen for the study (120 males and 120 females) age ranging between 18 and 28 years. Full face and anterior teeth images of the subjects were made on specially designed device resembling a face-bow, mounted onto the wall under a standard light source. The width and height of the maxillary central incisors were measured on the stone casts using a digital caliper. The mean perceived maxillary lateral incisor to central incisor width ratio was 0.67 in males and 0.703 in females. The mean perceived maxillary canine to lateral incisor width ratio was 0.744 in males and 0.714 in females. The mean width-to-height ratio of the maxillary central incisor was 79.49% in males and 79.197% in females. The golden proportion was not found between perceived mesiodistal widths of maxillary central and lateral incisors and nor between perceived mesiodistal widths of maxillary lateral incisors and canines. In the majority of subjects, the width-to-height ratio of maxillary central incisor was within 75-80%. There are no statistically significant differences in maxillary anterior teeth proportions between males and females. The results may serve as guidelines for treatment planning in restorative dentistry and periodontal surgery.

Magnesium-Assisted Continuous Growth of Strongly Iron-Enriched Incisors.

PubMed

Srot, Vesna; Bussmann, Birgit; Salzberger, Ute; Deuschle, Julia; Watanabe, Masashi; Pokorny, Boštjan; Jelenko Turinek, Ida; Mark, Alison F; van Aken, Peter A

2017-01-24

Teeth are an excellent example where optimally designed nanoarchitectures with precisely constructed components consist of simple compounds. Typically, these simple constituent phases with insignificant properties show mechanical property amplifications when formed into composite architectures. Material properties of functional composites are generally regulated on the nanoscale, which makes their characterization particularly demanding. Using advanced analytical and imaging transmission electron microscopy techniques, we identified innovative microstructural adjustments combined with astonishing compositional adaptations in incisors of coypu. Unique constituents, recognized as an additional amorphous Fe-rich surface layer followed by a transition zone covering pigmented enamel, provide the required structural stability to withstand repeated mechanical load. The chemically diverse Fe-rich surface layer, including ferrihydrite and iron-calcium phosphates, gives the typical orange-brown coloration to the incisors. Within the spaces between elongated hydroxyapatite crystals in the pigmented enamel, only ferrihydrite was found, implying that enamel pigmentation is a very strictly controlled process. Most significantly, an unprecedentedly high amount of Mg was measured in the amorphous flake-like material within the dentinal tubules of the incisors, suggesting the presence of a (Mg,Ca) phosphate phase. This unusually high influx of Mg into the dentin of incisors, but not molars, suggests a substantial functionality of Mg in the initial formation stages and constant growth of incisors. The present results emphasize the strong mutual correlation among the microstructure, chemical composition, and mechanical properties of mineralized dental tissues.

BCL11B Regulates Epithelial Proliferation and Asymmetric Development of the Mouse Mandibular Incisor

PubMed Central

Kyrylkova, Kateryna; Kyryachenko, Sergiy; Biehs, Brian; Klein, Ophir; Kioussi, Chrissa; Leid, Mark

2012-01-01

Mouse incisors grow continuously throughout life with enamel deposition uniquely on the outer, or labial, side of the tooth. Asymmetric enamel deposition is due to the presence of enamel-secreting ameloblasts exclusively within the labial epithelium of the incisor. We have previously shown that mice lacking the transcription factor BCL11B/CTIP2 (BCL11B hereafter) exhibit severely disrupted ameloblast formation in the developing incisor. We now report that BCL11B is a key factor controlling epithelial proliferation and overall developmental asymmetry of the mouse incisor: BCL11B is necessary for proliferation of the labial epithelium and development of the epithelial stem cell niche, which gives rise to ameloblasts; conversely, BCL11B suppresses epithelial proliferation, and development of stem cells and ameloblasts on the inner, or lingual, side of the incisor. This bidirectional action of BCL11B in the incisor epithelia appears responsible for the asymmetry of ameloblast localization in developing incisor. Underlying these spatio-specific functions of BCL11B in incisor development is the regulation of a large gene network comprised of genes encoding several members of the FGF and TGFβ superfamilies, Sprouty proteins, and Sonic hedgehog. Our data integrate BCL11B into these pathways during incisor development and reveal the molecular mechanisms that underlie phenotypes of both Bcl11b−/− and Sprouty mutant mice. PMID:22629441

The Role of Epithelial Stat3 in Amelogenesis during Mouse Incisor Renewal.

PubMed

Zhang, Bin; Meng, Bo; Viloria, Edward; Naveau, Adrien; Ganss, Bernhard; Jheon, Andrew H

2018-03-16

The aim of this study was to evaluate the role of epithelial signal transducer and activator of transcription 3 (STAT3) in mouse incisor amelogenesis. Since Stat3 is expressed in the epithelial component of developing and adult mouse teeth, we generated and analyzed Krt14Cre/+;Stat3fl/fl mutant mice in which Stat3 was inactivated in epithelia including ameloblast progenitors and ameloblasts, the cells responsible for enamel formation. Histological analysis showed little enamel matrix in mutant incisors compared to controls. Delayed incisor enamel mineralization was demonstrated using micro-computed X-ray tomography analysis and was supported by an increase in the pre-expression distance of enamel-enriched proteins such as amelogenin, ameloblastin, and kallikrein-4. Lastly, scanning electron microscopy analysis showed little enamel mineralization in mutant incisors underneath the mesial root of the 1st molar; however, the micro-architecture of enamel mineralization was similar in the erupted portion of control and mutant incisors. Taken together, our findings demonstrate for the first time that the absence of epithelial Stat3 in mice leads to delayed incisor amelogenesis. © 2018 S. Karger AG, Basel.

Crown-root morphology of lower incisors in patients with class III malocclusion.

PubMed

Wang, Bo; Shen, Guofang; Fang, Bing; Zhang, Li

2012-07-01

The purpose of this study was to investigate the crown-root morphology of lower incisors in patients with class III malocclusion using cone-beam computed tomography. Cone-beam computed tomography images were analyzed from 53 adult class I patients (group 1), 37 preadolescent class III patients (group 2), and 66 adult class III patients (group 3) comprising 3 divisions (divisions 1, 2, and 3 corresponded to mild, moderate, and severe class III malocclusions). The size and crown-root angulations of lower incisors in different groups and divisions were statistically appraised with group 1 used as the control group. No significant differences were found for the size of lower incisors among different groups and divisions (P > 0.05). Compared with group 1, the crown-root angulations of lower incisors in groups 2 and 3 were significantly larger (P < 0.01), and among 3 divisions, the lower incisors of division 3 rather than divisions 2 and 3 exhibited larger crown-root angulations (P < 0.01). Attention should be paid to the enlarged crown-root angulations of lower incisors in class III patients during orthodontic and orthognathic treatment, especially in severe ones.

Experimental strength of restorations with fibre posts at different stages, with and without using a simulated ligament.

PubMed

Pérez-González, A; González-Lluch, C; Sancho-Bru, J L; Rodríguez-Cervantes, P J; Barjau-Escribano, A; Forner-Navarro, L

2012-03-01

The aim of this study was to analyse the strength and failure mode of teeth restored with fibre posts under retention and flexural-compressive loads at different stages of the restoration and to analyse whether including a simulated ligament in the experimental setup has any effect on the strength or the failure mode. Thirty human maxillary central incisors were distributed in three different groups to be restored with simulation of different restoration stages (1: only post, 2: post and core, 3: post-core and crown), using Rebilda fibre posts. The specimens were inserted in resin blocks and loaded by means of a universal testing machine until failure under tension (stage 1) and 50º flexion (stages 2-3). Half the specimens in each group were restored using a simulated ligament between root dentine and resin block and the other half did not use this element. Failure in stage 1 always occurred at the post-dentine interface, with a mean failure load of 191·2 N. Failure in stage 2 was located mainly in the core or coronal dentine (mean failure load of 505·9 N). Failure in stage 3 was observed in the coronal dentine (mean failure load 397·4 N). Failure loads registered were greater than expected masticatory loads. Fracture modes were mostly reparable, thus indicating that this post is clinically valid at the different stages of restoration studied. The inclusion of the simulated ligament in the experimental system did not show a statistically significant effect on the failure load or the failure mode. © 2011 Blackwell Publishing Ltd.

Forest products cluster development in central Arizona—implications for landscape-scale forest restoration

Treesearch

David Nicholls

2014-01-01

Since 2004, close to 50,000 ac of hazardous fuels have been mechanically treated in east-central Arizona as part of the USDA Forest Service's first 10-year stewardship project on national forest lands. The need for coordinated wood products and biomass utilization in Arizona is likely to increase as broad-scale restoration treatments across Arizona's national...

Assessment of restorative treatment of patients with amelogenesis imperfecta.

PubMed

Chen, Chiung-Fen; Hu, Jan Ching Chun; Estrella, Maria Regina Padilla; Peters, Mathilde C; Bresciani, Eduardo

2013-01-01

The purpose of this study was to assess restorative treatment outcomes in the mixed dentition of amelogenesis imperfecta (AI) patients and determine the postrehabilitation oral health status and satisfaction of the patients. Clinical and radiographic examinations were performed on eight AI patients, who had 74 restorations placed in permanent incisors and molars, to allow evaluation of the integrity of the restorations and periodontal status post-treatment. Subjects completed a survey regarding esthetics, function, and sensitivity. Among the 74 restorations evaluated, seven were lost; of the remaining restorations, 31 were posterior, and 36 were anterior. Ten were rated clinically unacceptable. Teeth with stainless steel crowns had a moderate gingival index (mean=2.3) and plaque index (mean=2.0) scores. Widening of the periodontal ligament and pulp canal obliteration were common radiographic findings. Subject's recall of satisfaction regarding esthetics (P=.002) and sensitivity (brushing-P=.03; eating-P=.01) showed a statically significant difference before and after treatment. During mixed dentition, teeth with amelogenesis imperfecta may be restored with conventional treatment modalities. Direct restorations should be considered "interim" with multiple repairs anticipated. Post-treatment, gingival inflammation and plaque accumulation were observed. Subjects were satisfied with their appearance and reported a decrease of hypersensitivity.

Decision-making for children with traumatized permanent incisors: a holistic approach.

PubMed

Rodd, Helen D; Murray, Alison M; Yesudian, Grainne; Lewis, Benjamin R K

2008-09-01

Traumatic injury to permanent central incisors is a common occurrence in childhood and adolescence. It is of paramount importance that expedient and appropriate care is provided to ensure an optimum short- and long-term outcome for injured teeth and, importantly, the patients themselves. Treatment planning should thus adopt a holistic approach, taking into account a number of patient- and dental-related factors. Multidisciplinary care, involving paediatric dentistry, orthodontics or oral and maxillofacial surgery may be indicated. Decisions should also be informed by a sound understanding of the exact nature and prognosis of the presenting dental injury. Poor primary management of dental trauma may have lifelong consequences for the young patient.

Radiologically determined orthodontically induced external apical root resorption in incisors after non-surgical orthodontic treatment of class II division 1 malocclusion: a systematic review.

PubMed

Tieu, Long D; Saltaji, Humam; Normando, David; Flores-Mir, Carlos

2014-07-23

This study aims to critically evaluate orthodontically induced external apical root resorption (OIEARR) in incisors of patients undergoing non-surgical orthodontic treatment of class II division 1 malocclusion by a systematic review of the published data. An electronic search of two databases was performed; the bibliographies of relevant articles were also reviewed. Studies were included if they examined the amount of OIEARR in incisors produced during non-surgical orthodontic treatment of individuals with class II division I malocclusion in the permanent dentition. Individuals had no previous history of OIEARR, syndromes, pathologies, or general diseases. Study selections, risk of bias assessment, and data extraction were performed in duplicate. Eight studies of moderate methodological quality were finally included. An increased prevalence (65.6% to 98.1%) and mild to moderate severity of OIEARR (<4 mm and <1/3 original root) were reported. No sex difference in root resorption was found. For the maxillary incisors, there was no evidence that either the central or lateral incisor was more susceptible to OIEARR. A weak to moderate positive correlation between treatment duration and root resorption, and anteroposterior apical displacement and root resorption was found. Current limited evidence suggests that non-surgical comprehensive orthodontic treatment to correct class II division 1 malocclusions causes increased prevalence and severity of OIEARR the more the incisor roots are displaced and the longer this movement takes.

Eruption of first permanent incisors and live weight gain in grazing yearling Angora goats.

PubMed

McGregor, B A; Butler, K L

2013-05-01

To investigate the effects of the timing and duration of eruption of the first permanent incisors, live weight, sex and other factors on contemporaneous live weight gain in Angora goats. Goats were previously part of a pen study on the effects of energy intake of Angora does during pregnancy and lactation on kid development. The design was 3 levels of nutrition in mid-pregnancy by 2 levels of postnatal nutrition in 17 randomised blocks. Artificial insemination, ultrasound examination and feeding does in pens enabled accurate conduct of the study. After weaning, goats were grazed in sex groups. Live weight change between 14 and 20 months of age was related to deciduous first incisor loss and permanent first incisor development and other attributes assessed before the study. Live weight change was related to the elapsed time for first permanent incisors to commence eruption and to the length of time for first permanent incisors to erupt. This response was affected by sex. Over summer and autumn, entire males with short eruption intervals gained 2-3 kg more than entire males with long eruption intervals. Females that reached first permanent incisor eruption by mid-summer had a live weight gain of 3 kg more than those that reached the same development 3 months later. Live weight change in yearling Angora goats was associated with the process of first permanent incisor eruption. In females, live weight gain was greater when first permanent incisor eruption was earlier. In males, live weight gain was greater when first permanent incisor eruption was faster. © 2013 The Authors. Australian Veterinary Journal © 2013 Australian Veterinary Association.

The efficacy of infiltration anaesthesia for adult mandibular incisors: a randomised double-blind cross-over trial comparing articaine and lidocaine buccal and buccal plus lingual infiltrations.

PubMed

Jaber, A; Whitworth, J M; Corbett, I P; Al-Baqshi, B; Kanaa, M D; Meechan, J G

2010-11-01

To compare the efficacy of 2% lidocaine and 4% articaine both with 1:100,000 adrenaline in anaesthetising the pulps of mandibular incisors. Thirty-one healthy adult volunteers received the following local anaesthetic regimens adjacent to a mandibular central incisor: 1) buccal infiltration of 1.8 mL lidocaine plus dummy lingual injection (LB), 2) buccal plus lingual infiltrations of 0.9 mL lidocaine (LBL), 3) buccal infiltration of 1.8 mL articaine plus dummy lingual injection (AB), 4) buccal plus lingual infiltrations of 0.9 mL articaine (ABL). Pulp sensitivities of the central incisor and contralateral lateral incisor were assessed electronically. Anaesthetic efficacy was determined by two methods: 1) Recording the number of episodes with no responses to maximal electronic pulp tester stimulation during the course of the study period, 2) recording the number of volunteers with no response to maximal pulp tester stimulation within 15 min and maintained for 45 min (defined as sustained anaesthesia). Data were analysed by McNemar, chi-square, Mann-Whitney and paired t-tests. For both test teeth, the number of episodes of no sensation on maximal stimulation was significantly greater after articaine than lidocaine for both techniques. The split buccal plus lingual dose was more effective than the buccal injection alone for both solutions (p <0.001). 4% articaine was more effective than 2% lidocaine when comparing sustained anaesthesia in both teeth for each technique (p <0.001), however, there was no difference in sustained anaesthesia between techniques for either tooth or solution. 4% articaine was more effective than 2% lidocaine (both with 1:100,000 adrenaline) in anaesthetising the pulps of lower incisor teeth after buccal or buccal plus lingual infiltrations.

The assessment of dentofacial esthetics in restorative dentistry: a review of the literature.

PubMed

Frese, Cornelia; Staehle, Hans Joerg; Wolff, Diana

2012-05-01

The authors conducted a literature review to determine how dentofacial esthetics can be evaluated in restorative dentistry and which quantifiable clinical parameters can be used for this assessment of dentofacial esthetics. The authors selected 35 studies that focused on assessment strategies for dental professionals. The primary inclusion criteria were intraoral and extraoral esthetic assessment methods and indexes or rating scales evaluating esthetics in restorative dentistry. The studies' protocols and assessment methods were heterogeneous. The authors grouped the studies into six categories according to topic: golden proportion, soft-tissue measurement, smile and smile line assessment, orofacial indexes and scales, incisor proportion and angulation, and facial esthetics. These categories included various esthetic parameters, including the smile line, lip line, incisal offset, location of dental and facial midline, incisor angulations and width to height ratios of the maxillary anterior teeth, gingival contour, and root coverage and papilla height. These parameters should be considered when providing dental treatment in the anterior area, as they allow for quantification and objective judgment. The findings of this review might increase interest in a comprehensive dental esthetic index that allows for objective quantification and intrastudy and interstudy comparison of dental treatment outcomes.

A Conservative Approach to the Management of a Dental Trauma for Immediate Natural Esthetics.

PubMed

Mahesh Patni, Pallav; Jain, Pradeep; Jain Patni, Mona

2016-06-01

The fracture of front teeth is one of the routine presentations of traumatic injuries. The treatment of a fractured tooth involving the pulp includes root canal therapy and post placement followed by core build-up or by the extraction of the fractured tooth if it is not restorable. We report a case of an adult male who had traumatized both his maxillary central incisors following a blow experienced during domestic violence. He had lost a fractured fragment of the right central incisor, while the left incisor had complicated fractures with fragments retained attached to the soft tissue. Following radiovisiography (RVG), both incisors were conservatively treated in a single visit by reattachment and post and core techniques. The treatment reported for reattachment of the tooth fractures and post and core techniques are reasonably easy while providing immediate and lasting results in patients' regaining of social confidence and functionality.

Lower incisor inclination regarding different reference planes.

PubMed

Zataráin, Brenda; Avila, Josué; Moyaho, Angeles; Carrasco, Rosendo; Velasco, Carmen

2016-09-01

The purpose of this study was to assess the degree of lower incisor inclination with respect to different reference planes. It was an observational, analytical, longitudinal, prospective study conducted on 100 lateral cephalograms which were corrected according to the photograph in natural head position in order to draw the true vertical plane (TVP). The incisor mandibular plane angle (IMPA) was compensated to eliminate the variation of the mandibular plane growth type with the formula "FMApx.- 25 (FMA) + IMPApx. = compensated IMPA (IMPACOM)". As the data followed normal distribution determined by the KolmogorovSmirnov test, parametric tests were used for the statistical analysis, Ttest, ANOVA and Pearson coefficient correlation test. Statistical analysis was performed using a statistical significance of p <0.05. There is correlation between TVP and NB line (NB) (0.8614), Frankfort mandibular incisor angle (FMIA) (0.8894), IMPA (0.6351), Apo line (Apo) (0.609), IMPACOM (0.8895) and McHorris angle (MH) (0.7769). ANOVA showed statistically significant differences between the means for the 7 variables with 95% confidence level, P=0.0001. The multiple range test showed no significant difference among means: APoNB (0.88), IMPAMH (0.36), IMPANB (0.65), FMIAIMPACOM (0.01), FMIATVP (0.18), TVPIMPACOM (0.17). There was correlation among all reference planes. There were statistically significant differences among the means of the planes measured, except for IMPACOM, FMIA and TVP. The IMPA differed significantly from the IMPACOM. The compensated IMPA and the FMIA did not differ significantly from the TVP. The true horizontal plane was mismatched with Frankfort plane in 84% of the sample with a range of 19°. The true vertical plane is adequate for measuring lower incisor inclination. Sociedad Argentina de Investigación Odontológica.

Executive Function as a Risk Factor for Incisor Trauma.

PubMed

Nyquist, Jillian M; Phillips, Ceib; Stein, Margot; Koroluk, Lorne D

2018-05-08

Executive function is the ability to guide behavior to achieve goals or complete tasks. This study explored the relationship between executive function, as assessed by the Behavior Rating Inventory of Executive Function Parent Form Questionnaire (BRIEF ® ) and incisor trauma. This study included children in the mixed dentition with recent incisor trauma (n=28) and a control group (n=30) without recent incisor trauma. Subjects' parents completed the BRIEF ® , while a clinical examination assessed subjects' occlusal relationships. Parents also completed a custom questionnaire that investigated their child's medical history and daily activities. Fisher Exact and unpaired t-tests compared BRIEF ® scores, occlusal characteristics, medical history, and reported daily activities of the two groups. The trauma group had a greater percentage of participants with a Class II dental relationship (p=0.01). There was no significant difference between groups with respect to mean BRIEF ® t-scores within the Global Executive Composite. There was a statistically significant difference between groups with respect to the percentage of subjects with clinically significant (≥65) BRIEF ® t-scores within the Inhibit (p=0.05) and Emotional Control (p=0.02) subscales and Behavioral Regulation Index (p=0.02). There were no statistically significant differences between groups with respect to age, gender, overbite, overjet, medical history, body mass index, or daily activities. Children in the mixed dentition with a Class II dental relationship are at greater risk for incisor injury, as well as those involved in outdoor activities. Specific executive dysfunctions such as impulsivity and poor emotional control may increase the risk for incisor trauma. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Projected Impacts of Climate, Urbanization, Water Management, and Wetland Restoration on Waterbird Habitat in California's Central Valley.

PubMed

Matchett, Elliott L; Fleskes, Joseph P

2017-01-01

The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006-2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the "existing" landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

Orthodontic management of congenitally missing maxillary lateral incisors: a case report.

PubMed

Paduano, Sergio; Cioffi, Iacopo; Rongo, Roberto; Cupo, Antonello; Bucci, Rosaria; 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.

Correction of Malpositioned Implants through Periodontal Surgery and Prosthetic Rehabilitation Using Angled Abutment

PubMed Central

de Avila, Érica Dorigatti; de Barros-Filho, Luiz Antônio Borelli; de Andrade, Marcelo Ferrarezi; Mollo, Francisco de Assis; de Barros, Luiz Antônio Borelli

2014-01-01

When dental implants are malpositioned in relation to the adjacent teeth and alveolar bone or in an excessive buccal or lingual position, the final prosthesis rehabilitation impairs the peri-implant health of the gingival tissues and the aesthetics of the patient. Thus, the purpose of this case was to report and discuss a multidisciplinary protocol for the treatment of a compromised maxillary tooth in a patient with an abscess in his right central incisor due to an excessive buccal implant position. The patient presented with an implant-supported provisional restoration on his right maxillary central incisor and a traumatic injury in his left central incisor. The treatment protocol consisted in (i) abutment substitution to compensate the incorrect angulation of the implant, (ii) clinical crown lengthening, (iii) atraumatic extraction of the left central incisor, and (iv) immediate implant placement. Finally, (v) a custom abutment was fabricated to obtain a harmonious gingival contour around the prosthetic crown. In conclusion, when implants are incorrectly positioned in relation to the adjacent teeth, associated with soft-tissue defects, the challenge to create a harmonious mucogingival contours may be achieved with an interdisciplinary approach and with the placement of an appropriate custom abutment. PMID:24955259

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

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

PubMed

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

2006-03-01

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

Esthetic evaluation of incisor inclination in smiling profiles with respect to mandibular position.

PubMed

Zarif Najafi, Hooman; Oshagh, Morteza; Khalili, Mohammad Hassan; Torkan, Sepideh

2015-09-01

The smile is a key facial expression, and a careful assessment of the facial profile in smiling is an essential part of a complete orthodontic diagnosis. The aim of this study was to determine the preferred maxillary incisor inclination in the smile profile with regard to different mandibular positions. A smiling profile photograph of a man with normal facial profile features was altered digitally to obtain 3 different mandibular sagittal positions in 4-mm decrements or increments from -4 to +4 mm. In each mandibular position, the inclination of the maxillary incisors was changed from -10° to +10° in 5° increments. A total of 234 raters (72 senior dental students, 24 orthodontists, 21 maxillofacial surgeons, 25 prosthodontists, and 92 laypeople) were asked to score each photograph using a Likert-type rating scale. Mann-Whitney, Kruskal-Wallis, and intraclass correlation coefficient tests were used to analyze the data. In retruded and protruded mandibles, normal incisor inclination and the most retroclined incisors were selected as the most and the least attractive images, respectively, by almost all groups. With an orthognathic mandible, the image with the most retroclined incisors was selected as the least attractive, but the raters were not unanimous regarding the most attractive image. The intraclass correlation coefficient was 0.82 (high level of agreement). Also, the sex of the raters had no effect on the rating of the photographs. It is crucial to establish a normal incisor inclination, especially in patients with a mandibular deficiency or excess. An excessive maxillary incisor lingual inclination should be avoided regardless of the mandibular position. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Camouflage of Severe Skeletal Class II Gummy Smile Patient Treated Nonsurgically with Mini Implants

PubMed Central

Qamruddin, Irfan; Shahid, Fazal; Alam, Mohammad Khursheed; Zehra Jamal, Wafa

2014-01-01

Skeletal class II has always been a challenge in orthodontics and often needs assistance of surgical orthodontics in nongrowing patients when it presents with severe discrepancy. Difficulty increases more when vertical dysplasia is also associated with sagittal discrepancy. The advent of mini implants in orthodontics has broadened the spectrum of camouflage treatment. This case report presents a 16-year-old nongrowing girl with severe class II because of retrognathic mandible, and anterior dentoalveolar protrusion sagittally and vertically resulted in severe overjet of 13 mm and excessive display of incisors and gums. Both maxillary central incisors were trimmed by general practitioner few years back to reduce visibility. Treatment involved use of micro implant for retraction and intrusion of anterior maxillary dentoalveolar segment while lower incisors were proclined to obtain normal overjet, and overbite and pleasing soft tissue profile. Smile esthetics was further improved with composite restoration of incisal edges of both central incisors. PMID:25548686

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

PubMed

Nanekrungsan, Kamonporn; Patanaporn, Virush; Janhom, Apirum; Korwanich, Narumanus

2012-09-01

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. 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. 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. 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.

Force Eruption of Mandibular Second Incisor in an 11- Year Old Boy: A Technical Report

PubMed Central

Sobhnamayan, F; Moazami, F; Hamedi, S; Meshki, R

2013-01-01

There is a great challenge in the treatment of deeply fractured and un-restorable teeth among dentists. Orthodontic force eruption is a method of treatment for these teeth to preserve natural root system and periodontal structures. This technical report is a new modification of this procedure presented in an 11- year old boy with deeply fractured left second mandibular incisor. The fractured teeth were treated with root canal therapy and a file #80 was modified to become a hook cemented into the fractured tooth. Anterior teeth were splinted and used as anchorage to help the root extrusion. 1-year follow up of the tooth showed the convenience of the treatment. This simple and low-cost method can be an acceptable alternative to the current high cost techniques, achieving the same results. PMID:24724126

Influence of photoactivation method and mold for restoration on the Knoop hardness of resin composite restorations.

PubMed

Brandt, William Cunha; Silva-Concilio, Lais Regiane; Neves, Ana Christina Claro; de Souza-Junior, Eduardo Jose Carvalho; Sinhoreti, Mario Alexandre Coelho

2013-09-01

The aim of this study was to evaluate in vitro the Knoop hardness in the top and bottom of composite photo activated by different methods when different mold materials were used. Z250 (3M ESPE) and XL2500 halogen unit (3M ESPE) were used. For hardness test, conical restorations were made in extracted bovine incisors (tooth mold) and also metal mold (approximately 2 mm top diameter × 1.5 mm bottom diameter × 2 mm in height). Different photoactivation methods were tested: high-intensity continuous (HIC), low-intensity continuous (LIC), soft-start, or pulse-delay (PD), with constant radiant exposure. Knoop readings were performed on top and bottom restoration surfaces. Data were submitted to two-way ANOVA and Tukey's test (p = 0.05). On the top, regardless of the mold used, no significant difference in the Knoop hardness (Knoop hardness number, in kilograms-force per square millimeter) was observed between the photoactivation methods. On the bottom surface, the photoactivation method HIC shows higher means of hardness than LIC when tooth and metal were used. Significant differences of hardness on the top and in the bottom were detected between tooth and metal. The photoactivation method LIC and the material mold can interfere in the hardness values of composite restorations.

Projected Impacts of Climate, Urbanization, Water Management, and Wetland Restoration on Waterbird Habitat in California’s Central Valley

PubMed Central

Fleskes, Joseph P.

2017-01-01

The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006–2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the “existing” landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

Projected impacts of climate, urbanization, water management, and wetland restoration on waterbird habitat in California’s Central Valley

USGS Publications Warehouse

Matchett, Elliott L.; Fleskes, Joseph

2017-01-01

The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006–2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the “existing” landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

Ectopic eruption of permanent incisors after predecessor pulpectomy: five cases.

PubMed

Tannure, Patricia Nivoloni; Fidalgo, Tatiana Kelly da Silva; Barcelos, Roberta; Gleiser, Rogerio; Primo, Laura Guimaraes

2011-01-01

Pulpectomy in primary teeth is a common technique that preserves teeth in the oral environment and maintains or recovers periapical tissues to a healthy condition. This article describes the ectopic eruption of permanent incisors whose primary predecessors underwent pulpectomy using ZOE filler paste. In a group of 135 teeth that received pulpectomy therapy due to caries, 10 primary maxillary incisors had overretention and were followed for at least 3.5 years (mean time of 4.2 years), both clinically and radiographically, until the permanent teeth erupted. The proposed treatment included extraction of the overretained primary incisors based on permanent successor eruption chronology and contralateral eruption. Seven permanent teeth erupted ectopically. Autocorrection of the permanent tooth positions was observed in five cases. It can be concluded that periodic clinical and radiographic assessments are essential to verify radicular and filling paste resorptions and to avoid overretention and any subsequent malocclusion.

Release of Suppressed Red Spruce Using Canopy Gap Creation--Ecological Restoration in the Central Appalachians

Treesearch

J.S. Rentch; W.M. Ford; Thomas Schuler; Jeff Palmer; C.A. Diggins

2016-01-01

Red spruce (Picea rubens) and red spruce-northern hardwood mixed stands once covered as much as 300,000 ha in the Central Appalachians, but now comprise no more than 21,000 ha. Recently, interest in restoration of this forest type has increased because red spruce forests provide habitat for a number of rare animal species. Our study reports the...

Using SaudiVeg Ecoinformatics in assessment, monitoring and proposing environmental restoration tools in central Saudi Arabia

NASA Astrophysics Data System (ADS)

El-Sheikh, Mohamed; Hennekens, Stephan; Alfarhan, Ahmed; Thomas, Jacob; Schaminee, Joop; El-Keblawy, Ali

2017-04-01

Successful restoration of degraded habitats requires information about the history and factors led to the deterioration of these habitats. This study analyzed SaudiVeg Ecoinformatics, which is a big phytosociological database about plant communities and other environmental factors affecting them in the Najd-Central Region of Saudi Arabia. A phytosociological survey with more than 3000 vegetation relevés was conducted during 2013. The data were used to correlate the plant community attributes, such as abundance and species diversity in natural and ruderal habitats with environmental factors, such as human impacts, soil physical and chemical properties, and land uses. The data were subjected to multivariate analyses using programs, such as TWINSPAN, DCA and CCA, via Juice package. Fourteen vegetation associations were described under provisional classification of the Central Saudi Arabia deserts. These associations were broadly grouped into desert vegetation types. One alliance group, Haloxylonion salicornici, is the most widespread and contains four associations on the wadis and desert plains. Three associations are dominant on the depression habitats (raudhas) and two associations of Tamarixidetum spp. on the wetland and salt pan habitats. Four associations inhabit the man-made habitat and abandoned field habitats and one association, the Neurado procumbentis-Heliotropietum digyni, dominates the overgrazed sandy dunes. As human impact is huge and increasing, the vegetation ecoinformatics of the present study would form a baseline description that could be used as a vital tool for future monitoring and for proposing environmental restoration processes in central Saudi Arabia. It could also help both Governmental and Non-governmental organizations (NGO) in formulating strategies and on-ground plans for protection, management and restoration of the natural vegetation.

Characteristics of Teeth: A Review of Size, Shape, Composition, and Appearance of Maxillary Anterior Teeth.

PubMed

McGowan, Steve

2016-03-01

Although digital technologies play an increasingly integral role in dentistry, there remains a need for dental professionals to understand the fundamentals of tooth anatomy, form, occlusion, and color science. In this article, the size, shape, composition, and appearance of maxillary anterior teeth will be discussed from esthetic and functional perspectives. A total of 600 extracted maxillary incisors were studied: 200 each of central incisors, lateral incisors, and cuspids. The purpose of the article is to exhibit and discuss factors that make teeth unique and diverse. Understanding these aspects of teeth aids dental professionals in more effectively creating realistic and highly esthetic restorations for patients.

[Postfire restoration of organic substance in the ground cover of the larch forests in the permafrost zone of central Evenkia].

PubMed

Prokushkin, S G; Bogdanov, V V; Prokushkin, A S; Tokareva, I V

2011-01-01

The role of ground fires in transformation of organic substances in the ground cover of larch stands in the permafrost zone of Central Siberia was studied, as was the postfire restoration dynamics of organic substances. Ground fires lead to a considerable decrease in concentrations and resources of organic carbon and its individual fractions in the ground cover, and restoration takes many decades.

Width/Length Ratio in Maxillary Anterior Teeth. Comparative Study of Esthetic Preferences among Professionals and Laypersons.

PubMed

Álvarez-Álvarez, Lorena; Orozco-Varo, Ana; Arroyo-Cruz, Gema; Jiménez-Castellanos, Emilio

2017-05-17

Many studies have examined the esthetic preferences of professionals in the maxillary anterior region; however, only a few have taken into account the ratios that are more frequent within the population or other ratios suggested in the literature as ideal. Previous studies also failed to compare them with the esthetic preferences of the lay population with regards to the smile. The purpose of this study is to highlight the differences when perceiving the esthetics of smiles between general dentists and laypersons, and linking them with the width/length of the maxillary anterior teeth. Photographs of the full face of a female subject were modified with Photoshop CS regarding the length/width relationships of the 6 maxillary anterior teeth. The three modifications made were: (a) 80% length/width, (b) 85%, length/width, and (c) 85% length/width in central incisors, 80% length/width in lateral incisors and canines. Three sequences of photograph pairs were created with different ratios and presented in PowerPoint to a sample of 100 general dentists and 100 laypersons. The ratio considered as the most esthetic by the majority of the judges was 85% for central incisors and 80% for lateral incisors and canines, with a statistically significant difference (p < 0.01). There was no statistically significant difference in the esthetic preferences of the studied populations either due to gender or professional experience of the dentists (p > 0.01). According to the results obtained in this study, professionals and laypersons considered a width/length ratio of 85% for maxillary central incisors and 80% for lateral incisors and canines as the most esthetic for maxillary anterior teeth. These results do not support findings from other studies previously published with similar ratios in central incisors, lateral incisors, and canines. Today clinicians practice in a treatment environment where not only function and utility but also esthetics is demanded in almost every procedure

Comparison of incisor inclination in patients with Class III malocclusion treated with orthognathic surgery or orthodontic camouflage.

PubMed

Troy, Beth A; Shanker, Shiva; Fields, Henry W; Vig, Katherine; Johnston, William

2009-02-01

Reports comparing Class III patients treated by camouflage and those treated by orthognathic surgery are not numerous. The purpose of this study was to compare the dental and skeletal values of Class III patients treated with these methods against normative data and over the course of treatment. Thirty-three surgical and 39 camouflage Class III patients were selected from a graduate orthodontic clinic and regional private practices, and lateral cephalograms were digitized. Skeletal and dental values were obtained, and mean and efficacy evaluations referenced to ethnic norms were calculated. At pretreatment, the surgery patients had more severe skeletal discrepancies and more compensated incisors. During presurgical orthodontic treatment, most of the surgery group's mandibular incisors were significantly decompensated, although half of the maxillary incisors remained compensated. The surgical move improved 90% of these patients but to only 60% to 65% of the norm. The camouflage group was compensated at pretreatment, and they became more compensated in the end. After treatment, there were no differences between the incisor positions of the 2 groups. There was no statistical difference in incisor inclination and position between the Class III surgical and camouflage groups after treatment; there was a significant difference in the pretreatment and posttreatment incisor inclination and position compared with normative values for both the surgical and the camouflage groups; the maxillary and mandibular incisors were not adequately decompensated in the surgical group, but significant improvement in mandibular incisor position and axial inclination was achieved presurgically. The outcome of the surgical correction was limited by the inadequate presurgical orthodontic incisor decompensation, and orthodontic compensation of incisors occurred postsurgically to achieve an optimal occlusal result.

Dental development of Didelphis albiventris (Marsupialia): I--incisors and canines.

PubMed

Fonseca, C T; Alves, J B

2006-02-01

The formation of incisors and canines in marsupials of D. albiventris was studied at various stages of development. Seventy-six specimens, with ages varying from 0 to 100 days, were used in this investigation. Serial sections of the maxilla were obtained in the transverse plane and stained with hematoxylin and eosin. Histological analyses were made to verify the pattern of teeth development, as well as their chronology of eruption. The period of time from birth to 100 days comprised the entire process of teeth development, from epithelial bud formation to early eruption of the teeth. Oral epithelium thickening gave rise to the functional incisors and canines. In addition, a secondary dental lamina emerged in different phases of development in the outer epithelium of incisors and canines, which degenerated when it reached the bud stage. No evidence of deciduous dentition was observed. The results of this investigation suggest that secondary dental lamina represents remnants of a primitive condition in which secondary dentition used to be present.

[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.

Mandibular Symmetrical Bilateral Canine-Lateral Incisors Transposition: Its Early Diagnosis and Treatment Considerations.

PubMed

Shapira, Yehoshua; Finkelstein, Tamar; Kadry, Rana; Schonberger, Shirley; Shpack, Nir

2016-01-01

Bilateral mandibular tooth transposition is a relatively rare dental anomaly caused by distal migration of the mandibular lateral incisors and can be detected in the early mixed dentition by radiographic examination. Early diagnosis and interceptive intervention may reduce the risk of possible transposition between the mandibular canine and lateral incisor. This report illustrates the orthodontic management of bilateral mandibular canine-lateral incisor transposition. Correct positioning of the affected teeth was achieved on the left side while teeth on the right side were aligned in their transposed position. It demonstrates the outcome of good alignment of the teeth in the dental arch.

Apical root resorption of incisors after orthodontic treatment of impacted maxillary canines: a radiographic study.

PubMed

Brusveen, Elin Marie Gravdal; Brudvik, Pongsri; Bøe, Olav Egil; Mavragani, Maria

2012-04-01

The purpose of the study was to evaluate impacted maxillary canines as risk factor for orthodontic apical root resorption. The sample comprised 66 patients treated with fixed appliances. Thirty-two patients with a unilateral impacted maxillary canine, which was distanced from the roots of the incisors at a preliminary phase of treatment before bonding, formed the impaction group, and 34 patients without impactions served as the controls. Root shortening was calculated by using pretreatment and posttreatment intraoral radiographs. Inclination of the eruption path of the impacted canine relative to the midline, axis of the lateral incisor, and nasal line, root development, and the medial and vertical positions of the impacted tooth were recorded on orthopantomograms and lateral cephalometric films. The follicle/tooth ratio was evaluated by using periapical radiographs. No significant difference in apical resorption of the maxillary incisors was detected between the impaction and control groups, or between the incisors of the impacted and contralateral sides in the same subject. Likewise, no difference in the severity of root resorption was found between the incisors of impacted side alone and the incisors of the control group. Mesial and vertical inclinations of the impacted canines were negatively related to a lateral incisor's root resorption. No correlations were found between resorption and medial or vertical position of the crown of the canine. The follicle/tooth ratio was significantly related to the mesial inclination of the impacted canine, but not to root resorption. An impacted maxillary canine, after being distanced from the incisor roots, does not seem to be a risk factor for apical root resorption during orthodontic treatment. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

A randomized clinical trial comparing mandibular incisor proclination produced by fixed labial appliances and clear aligners.

PubMed

Hennessy, Joe; Garvey, Thérèse; Al-Awadhi, Ebrahim A

2016-09-01

To compare the mandibular incisor proclination produced by fixed labial appliances and third generation clear aligners. Patients underwent a course of orthodontic treatment using either fixed labial appliances or clear aligners (Invisalign). Mandibular incisor proclination was measured by comparing pretreatment and near-end treatment lateral cephalograms. Eligibility criteria included adult patients with mild mandibular incisor crowding (<4 mm) and Class I skeletal bases (ANB, 1-4°). The main outcome was the cephalometric change in mandibular incisor inclination to the mandibular plane at the end of treatment. Eligible patients picking a sealed opaque envelope, which indicated their group allocation, was used to achieve randomization. Data was analyzed using a Welch two-sample t-test. Forty-four patients (mean age, 26.4 ± 7.7 years) were randomized in a 1:1 ratio to either the fixed labial appliance or the clear aligner group. Baseline characteristics were similar for both groups: Fixed appliance mean crowding was 2.1 ± 1.3 mm vs clear aligner mean crowding, 2.5 ± 1.3 mm; pretreatment mean mandibular incisor inclination for the fixed appliance group was 90.8 ± 5.4° vs 91.6 ± 6.4° for the clear aligner group. Fixed appliances produced 5.3 ± 4.3° of mandibular incisor proclination. Clear aligners proclined the mandibular incisors by 3.4 ± 3.2°. The difference between the two groups was not statistically significant (P > .05). There was no difference in the amount of mandibular incisor proclination produced by clear aligners and fixed labial appliances in mild crowding cases.

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

Differential expression of syndecan isoforms during mouse incisor amelogenesis.

PubMed

Muto, Taro; Miyoshi, Keiko; Munesue, Seiichi; Nakada, Hiroshi; Okayama, Minoru; Matsuo, Takashi; Noma, Takafumi

2007-08-01

Syndecans are transmembranous heparan sulfate proteoglycans (HSPGs) with covalently attached glycosaminoglycan side-chains located on the cell surface. The mammalian syndecan family is composed of four types of syndecans (syndecan-1 to -4). Syndecans interact with the intracellular cytoskeleton through the cytoplasmic domains of their core proteins and membrane proteins, extracellular enzymes, growth factors, and matrix components, through their heparan-sulfate chains, to regulate developmental processes.Here, as a first step to assess the possible roles of syndecan proteins in amelogenesis, we examined the expression patterns of all syndecan isoforms in continuously growing mouse incisors, in which we can overview major differentiation stages of amelogenesis at a glance. Understanding the expression domain of each syndecan isoform during specific developmental stages seems useful for investigating their physiological roles in amelogenesis. Immunohistochemical analysis of syndecan core proteins in the lower incisors from postnatal day 1 mice revealed spatially and temporally specific expression patterns, with syndecan-1 expressed in undifferentiated epithelial and mesenchymal cells, and syndecan-2, -3, and -4 in more differentiated cells. These findings suggest that each syndecan isoform functions distinctly during the amelogenesis of the incisors of mice.

Switch to restoration therapy in a testosterone treated central hypogonadism with erythrocytosis.

PubMed

Cangiano, B; Cacciatore, C; Persani, L; Bonomi, M

2017-01-01

We describe a case of severe erythrocytosis caused by testosterone replacement therapy in a 66-year-old man affected with hypogonadotropic hypogonadism (HH) determining osteoporosis, resolved by switching to restoration therapy with clomiphene citrate. The patient complained fatigue, loss of libido and defective erections and a spontaneous vertebral fracture despite bisphosphonate therapy and vitamin D supplementation. The examinations proved isolated HH and he was therefore treated with testosterone gel with regression of specific manifestations but elevated hemoglobin and hematocrit values. Therefore, it was decided to switch to a restoration therapy with clomiphene citrate 25 mg/die, which resulted in the resolution of symptoms without evident side effects. In a couple of months, the patient showed normalization of testosterone levels and increment of testicular volume. Since secondary hypogonadism is the consequence of an insufficient stimulation of the gonads by hypothalamic-pituitary axis, therapeutic approaches aimed to restore endogenous testosterone production should be considered in alternative to testosterone replacement, particularly if side effects intervene. Among these strategies, clomiphene citrate seems to have a high efficacy and safety profile also in the elderly with isolated HH and no evident pituitary lesion. Hypogonadism should always be assessed in patients with severe loss in BMD and undergo appropriate medical treatment.In hypogonadotropic hypogonadism, more approaches are available other than testosterone replacement therapy alone.In patients with severe late-onset central hypogonadism presenting with erythrocytosis even at low doses of replacement therapy, restoration therapy with clomiphene could prove to be an effective solution, particularly in patients with a reversible disruption of GNRH/gonadotropin functions.Clomiphene citrate increases gonadotropin levels and testicular volume and should therefore be considered in hypogonadal

Shovel-shaped incisors and associated invagination in some Asian and African populations.

PubMed

Kharat, D U; Saini, T S; Mokeem, S

1990-08-01

Shovelling of the incisors is considered to be a polygenic inheritable trait. Shovelling differs considerably between groups of racial populations but is relatively stable within each group. Presence or absence of shovelling helps in racial identification and in exploration of ancestry. Periapical radiographs of patients of several nationalities from Asian and African continents were obtained. Shovelling and invaginations associated with the shovel-shaped incisors was studied according to nationality. Results indicated that the incidence of shovelling in Syrians, Jordanians, Palestinians and Filipinos was 5-6 per cent. In Saudi Arabians, Pakistanis and Indians, the incidence of shovelling was 10-12 per cent. Among Yemenis, Sudanese and Egyptians, the incidence of shovelling was 20-25 percent. The occurrence of invaginations in shovel-shaped incisors was 11 per cent.

Fracture behavior of single-structure fiber-reinforced composite restorations

PubMed Central

Nagata, Kohji; Garoushi, Sufyan K.; Vallittu, Pekka K.; Wakabayashi, Noriyuki; Takahashi, Hidekazu; Lassila, Lippo V. J.

2016-01-01

Abstract Objective: The applications of single-structure fiber-reinforced composite (FRC) in restorative dentistry have not been well reported. This study aimed to clarify the static mechanical properties of anterior crown restorations prepared using two types of single-structure FRC. Materials and methods : An experimental crown restoration was designed for an upper anterior incisor. The restorations were made from IPS Empress CAD for CEREC (Emp), IPS e.max® CAD (eMx), experimental single-structure all-FRC (a-FRC), Filtek™ Supreme XTE (XTE), and commercially available single-structure short-FRC (everX Posterior™) (n = 8 for each material) (s-FRC). The a-FRC restorations were prepared from an experimental FRC blank using a computer-aided design and manufacturing (CAD/CAM) device. A fracture test was performed to assess the fracture load, toughness, and failure mode. The fracture loads were vertically applied on the restorations. The surface micromorphology of the FRC restorations was observed by scanning electron microscopy (SEM). The data were analyzed by analysis of variance (p = .05) followed by Tukey's test. Results : s-FRC showed the highest mean fracture load (1145.0 ± 89.6 N) and toughness (26.2 ± 5.8 Ncm) among all the groups tested. With regard to the micromorphology of the prosthetic surface, local crushing of the fiberglass was observed in s-FRC, whereas chopped fiberglass was observed in a-FRC. Conclusions : The restorations made of short-FRC showed a higher load-bearing capacity than those made of the experimental all-FRC blanks for CAD/CAM. The brittle-like fractures were exhibited in the recent dental esthetic materials, while local crushing fractures were shown for single-structure FRC restorations. PMID:28642921

Frontonasal dysplasia: oral features, restorative and orthodontic dental treatment in a child.

PubMed

Valério, R A; Scatena, C; Santos, F R R; Romano, F L; Queiroz, A M; Paula-Silva, F W G

2017-04-01

Frontonasal dysplasia is a complex rare malformation, characterised by abnormalities involving the central portion of the face, especially the eyes, nose and forehead. It can manifest independently or associated with other abnormalities as part of some syndromes. The purpose of this case report was to describe a 5-year-old patient, diagnosed with frontonasal dysplasia. Among the abnormalities characterised with this disorder were ocular hypertelorism, broad nose tip with median notch, median facial cleft, bifid anterior skull, low set hairline, Poland's syndactyly and ankyloglossia. Consisted of behavioural management, oral hygiene instruction, prophylaxis, topical fluoride application, extraction of primary teeth, composite resin restorations and sealants in pits and fissures. Preformed metal crowns were also applied to the right and left primary maxillary second molars. Currently, the patient is 11 years-old in the permanent dentition and therefore was referred for corrective orthodontic and periodontal treatments due to the persistence of gingival retraction of the permanent mandibular right central incisor. The treatment in this case was directed to the promotion of oral health and orthodontic corrections, which are of fundamental importance due to medical, physical and social limitations of children affected by this syndrome, hindering healing and rehabilitative treatment. Paediatric dentists should be included in multidisciplinary teams providing care to patients with special needs, improving their quality of life.

Investigation of Clinical Characteristics and Etiological Factors in Children with Molar Incisor Hypomineralization

PubMed Central

Giuca, Maria Rita; Cappè, Maria; Carli, Elisabetta; Lardani, Lisa

2018-01-01

Aim The purpose of the present study was to evaluate the clinical defects and etiological factors potentially involved in the onset of MIH in a pediatric sample. Methods 120 children, selected from the university dental clinic, were included: 60 children (25 boys and 35 girls; average age: 9.8 ± 1.8 years) with MIH formed the test group and 60 children (27 boys and 33 girls; average age: 10.1 ± 2 years) without MIH constituted the control group. Distribution and severity of MIH defects were evaluated, and a questionnaire was used to investigate the etiological variables; chi-square, univariate, and multivariate statistical tests were performed (significance level set at p < 0.05). Results A total of 186 molars and 98 incisors exhibited MIH defects: 55 molars and 75 incisors showed mild defects, 91 molars and 20 incisors had moderate lesions, and 40 molars and 3 incisors showed severe lesions. Univariate and multivariate statistical analysis showed a significant association (p < 0.05) between MIH and ear, nose, and throat (ENT) disorders and the antibiotics used during pregnancy (0.019). Conclusions Moderate defects were more frequent in the molars, while mild lesions were more frequent in the incisors. Antibiotics used during pregnancy and ENT may be directly involved in the etiology of MIH in children. PMID:29861729

Euglycemia Restoration by Central Leptin in Type 1 Diabetes Requires STAT3 Signaling but Not Fast-Acting Neurotransmitter Release.

PubMed

Xu, Yuanzhong; Chang, Jeffrey T; Myers, Martin G; Xu, Yong; Tong, Qingchun

2016-04-01

Central leptin action is sufficient to restore euglycemia in insulinopenic type 1 diabetes (T1D); however, the underlying mechanism remains poorly understood. To examine the role of intracellular signal transducer and activator of transcription 3 (STAT3) pathways, we used LepRs/s mice with disrupted leptin-phosphorylated STAT3 signaling to test the effect of central leptin on euglycemia restoration. These mice developed streptozocin-induced T1D, which was surprisingly not associated with hyperglucagonemia, a typical manifestation in T1D. Further, leptin action on euglycemia restoration was abrogated in these mice, which was associated with refractory hypercorticosteronemia. To examine the role of fast-acting neurotransmitters glutamate and γ-aminobutyric acid (GABA), two major neurotransmitters in the brain, from leptin receptor (LepR) neurons, we used mice with disrupted release of glutamate, GABA, or both from LepR neurons. Surprisingly, all mice responded normally to leptin-mediated euglycemia restoration, which was associated with expected correction from hyperglucagonemia and hyperphagia. In contrast, mice with loss of glutamate and GABA appeared to develop an additive obesity effect over those with loss of single neurotransmitter release. Thus, our study reveals that STAT3 signaling, but not fast-acting neurotransmitter release, is required for leptin action on euglycemia restoration and that hyperglucagonemia is not required for T1D. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Dental preparation with sonic vs high-speed finishing: analysis of microleakage in bonded veneer restorations.

PubMed

Faus-Matoses, Ignacio; Solá-Ruiz, Fernanda

2014-02-01

To compare marginal microleakage in porcelain veneer restorations following dental finishing using two types of instruments to test the hypothesis that microleakage will be less when teeth are prepared with sonic oscillating burs than when prepared with high-speed rotating burs. Fifty-six extracted human maxillary central incisors were selected and divided randomly into two groups. Group 1 samples underwent dental finishing using high-speed rotating diamond burs, while group 2 used sonic oscillating diamond burs. Buccal chamfer preparation was carried out for both groups. Forty eight of the samples (24 per group) were restored using IPS Empress ceramic veneers. 2% methylene blue was used to evaluate microleakage at the tooth/composite veneer interface. Teeth were sectioned lengthwise into three parts and microleakage was measured at two points - cervical and incisal - on each section. Before bonding, four teeth per group underwent SEM examination. Evaluation of microleakage at the cervical dentin margin showed a value of 10.5% in group 1 and 6.6% in group 2, which was statistically significantly different (p < 0.05). Incisal microleakage was 1.3% for group 1 and 1.2% for group 2, which was not significantly different. SEM revealed different patterns of surface texture in both areas according to the instrument used. Group 1 exhibited parallel horizontal abrasion grooves with a milled effect and thick smear layers; group 2 showed abrasive erosion, discontinuous perpendicular depressions, and thin smear layers. Tooth preparations finished with sonic burs produced significantly less microleakage in the cervical dentin area of bonded veneer restorations. No differences were found in the incisal enamel area.

Ras Signaling Regulates Stem Cells and Amelogenesis in the Mouse Incisor.

PubMed

Zheng, X; Goodwin, A F; Tian, H; Jheon, A H; Klein, O D

2017-11-01

The role of Ras signaling during tooth development is poorly understood. Ras proteins-which are activated by many upstream pathways, including receptor tyrosine kinase cascades-signal through multiple effectors, such as the mitogen-activated protein kinase (MAPK) and PI3K pathways. Here, we utilized the mouse incisor as a model to study how the MAPK and PI3K pathways regulate dental epithelial stem cells and amelogenesis. The rodent incisor-which grows continuously throughout the life of the animal due to the presence of epithelial and mesenchymal stem cells-provides a model for the study of ectodermal organ renewal and regeneration. Utilizing models of Ras dysregulation as well as inhibitors of the MAPK and PI3K pathways, we found that MAPK and PI3K regulate dental epithelial stem cell activity, transit-amplifying cell proliferation, and enamel formation in the mouse incisor.

Fractographic features of glass-ceramic and zirconia-based dental restorations fractured during clinical function.

PubMed

Oilo, Marit; Hardang, Anne D; Ulsund, Amanda H; Gjerdet, Nils R

2014-06-01

Fractures during clinical function have been reported as the major concern associated with all-ceramic dental restorations. The aim of this study was to analyze the fracture features of glass-ceramic and zirconia-based restorations fractured during clinical use. Twenty-seven crowns and onlays were supplied by dentists and dental technicians with information about type of cement and time in function, if available. Fourteen lithium disilicate glass-ceramic restorations and 13 zirconia-based restorations were retrieved and analyzed. Fractographic features were examined using optical microscopy to determine crack initiation and crack propagation of the restorations. The material comprised fractured restorations from one canine, 10 incisors, four premolars, and 11 molars. One crown was not categorized because of difficulty in orientation of the fragments. The results revealed that all core and veneer fractures initiated in the cervical margin and usually from the approximal area close to the most coronally placed curvature of the margin. Three cases of occlusal chipping were found. The margin of dental all-ceramic single-tooth restorations was the area of fracture origin. The fracture features were similar for zirconia, glass-ceramic, and alumina single-tooth restorations. Design features seem to be of great importance for fracture initiation. © 2014 Eur J Oral Sci.

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. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

Three-dimensional analysis of the change in the curvature of the smiling line following orthodontic treatment in incisor class II division 1 malocclusion.

PubMed

Mah, Michael; Tan, Wei Chuan; Ong, Sim Heng; Chan, Yiong Huak; Foong, Kelvin

2014-12-01

To investigate the different effects of changes in the occlusal plane, incisors inclination, and maxillary intercanine width on the curvature of the smiling line. Records of 46 subjects (28 females and 18 males, mean age 16.6 ± 4.2 years) with incisor class II division 1 malocclusions were selected. All subjects had four premolar extractions and were treated with preadjusted edgewise appliances. Pre- and post-treatment maxillary dental digital models were virtually aligned via corresponding landmarks to the respective lateral cephalograms. Subsequent two-dimensional superimposition of the aligned cephalograms facilitated the three-dimensional superimposition of the pre- and post-treatment models. This process allowed the quantification of the curvature from a frontal perspective of the models. The change in curvature was then correlated with changes in the cephalometric inclination of the anterior occlusal plane (AOP), functional occlusal plane (FOP), maxillary central incisor (U1), and the intercanine width. Orthodontic correction in this sample resulted in the clockwise rotation of the anterior occlusal plane (5.84 degrees), reduction in proclination of the incisors (-14.39 degrees), increase in intercanine width (2.48mm), and a corresponding increase in the curvature of the smiling line (6.83 degrees). The change in curvature of the smiling line in these subjects was found to be related more significantly to the magnitude of difference in the inclination between the pre-treatment AOP and FOP than to the change in the inclination of the maxillary incisors. With orthodontic treatment, the smiling line can be correlated with cephalometric data to improve or maintain the curvature. © The Author 2013. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Strontium-90 content of deciduous human incisors.

PubMed

ROSENTHAL, H L; GILSTER, J E; BIRD, J T

1963-04-12

The concentrations of strontium-90 in deciduous incisor teeth of children born in St. Louis between 1949 to 1957 are in accord with estimated bone levels, suggesting that human deciduous teeth are useful as an index of strontium-90 accumulation during the time the teeth are formed.

Maxillary incisors changes during space closure with conventional and skeletal anchorage methods: a systematic review.

PubMed

Jayaratne, Yasas Shri Nalaka; Uribe, Flavio; Janakiraman, Nandakumar

2017-01-01

The objective of this systematic review was to compare the antero-posterior, vertical and angular changes of maxillary incisors with conventional anchorage control techniques and mini-implant based space closure methods. The electronic databases Pubmed, Scopus, ISI Web of knowledge, Cochrane Library and Open Grey were searched for potentially eligible studies using a set of predetermined keywords. Full texts meeting the inclusion criteria as well as their references were manually searched. The primary outcome data (linear, angular, and vertical maxillary incisor changes) and secondary outcome data (overbite changes, soft tissue changes, biomechanical factors, root resorption and treatment duration) were extracted from the selected articles and entered into spreadsheets based on the type of anchorage used. The methodological quality of each study was assessed. Six studies met the inclusion criteria. The amount of incisor retraction was greater with buccally placed mini-implants than conventional anchorage techniques. The incisor retraction with indirect anchorage from palatal mini-implants was less when compared with buccally placed mini-implants. Incisor intrusion occurred with buccal mini-implants, whereas extrusion was seen with conventional anchorage. Limited data on the biomechanical variables or adverse effects such as root resorption were reported in these studies. More RCT's that take in to account relevant biomechanical variables and employ three-dimensional quantification of tooth movements are required to provide information on incisor changes during space closure.

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.

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

PubMed Central

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

2015-01-01

ABSTRACT 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. PMID:26604544

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

[Finite element analysis of mechanical characteristics during retracting mandibular incisors through sliding mechanics].

PubMed

Gu, Yong-Jia; Wu, Yan-Ping; Gao, Mei-Qin; Yao, Ning; Chen, Wen-Jing

2008-10-01

To analyze the mechanical characteristic changes of teeth and arch under different loading direction during retracting mandibular incisors through implant, simulating clinical loading system. Three- dimensional finite element model, including brackets, archwire, crampable hooks and implants, was reconstructed. The force direction was determined by connecting the points in crampable hook and the center point of implant, and the force point and force direction were changed with the adjustment of the height of crampable hook and the height of implant. Then three-dimensional movement trend of teeth, stress distribution in periodontal membrane and the largest displacement of archwire nodes in each group were calculated and analyzed. SPSS13.0 software package was used for statistical analysis. It was found that the height of implant and the height of crampable hook were correlated with the movement of teeth and stress distribution in periodontal membrane (P<0.01). The movement trend of teeth in the condition of different height of implant and different height of crampable hook was illustrated as follows:(1)with the height increase of crampable hook, the movement trend of the central and lateral incisors varied from mesial lingual tipping to mesial labial tipping. However, canines tipped distally and lingually; the second premolars tipped mesially and lingually, and the first molar roots tipped distally and buccally with decreasing tipping angle. (2) The largest stress distribution in the whole arch was located in the labial apical one-third area of the lateral incisors, while that of canines and the first molars was located in the alveolar ridges and root bifurcations. These findings indicate that the different movement trend during retracting anterior teeth can be achieved through the adjustment of the height of crampable hook, and implant, anchorage can effectively control anterior movement of the posterior teeth. Supported by Research Fund of Bureau of Science and

"Maxillary lateral incisor partial anodontia sequence": a clinical entity with epigenetic origin.

PubMed

Consolaro, Alberto; Cardoso, Maurício Almeida; Consolaro, Renata Bianco

2017-01-01

The relationship between maxillary lateral incisor anodontia and the palatal displacement of unerupted maxillary canines cannot be considered as a multiple tooth abnormality with defined genetic etiology in order to be regarded as a "syndrome". Neither were the involved genes identified and located in the human genome, nor was it presumed on which chromosome the responsible gene would be located. The palatal maxillary canine displacement in cases of partial anodontia of the maxillary lateral incisor is potentially associated with environmental changes caused by its absence in its place of formation and eruption, which would characterize an epigenetic etiology. The lack of the maxillary lateral incisor in the canine region means removing one of the reference guides for the eruptive trajectory of the maxillary canine, which would therefore, not erupt and /or impact on the palate. Consequently, and in sequence, it would lead to malocclusion, maxillary atresia, transposition, prolonged retention of the deciduous canine and resorption in the neighboring teeth. Thus, we can say that we are dealing with a set of anomalies and multiple sequential changes known as sequential development anomalies or, simply, sequence. Once the epigenetics and sequential condition is accepted for this clinical picture, it could be called "Maxillary Lateral Incisor Partial Anodontia Sequence."

Dental anomalies in an orthodontic patient population with maxillary lateral incisor agenesis.

PubMed

Citak, Mehmet; Cakici, Elif Bahar; Benkli, Yasin Atakan; Cakici, Fatih; Bektas, Bircan; Buyuk, Suleyman Kutalmış

2016-01-01

The purpose of this study was to evaluate the prevalence of dental anomalies in a subpopulation of orthodontic patients with agenesis of maxillary lateral incisors (MLI). The material of the present study included the records of the 1964 orthodontic patients. Panoramic radiographs and dental casts were used to analyze other associated eight dental anomalies, including agenesis of other teeth, dens invaginatus, dens evaginatus, peg shaped MLI, taurodontism, pulp stone, root dilaceration and maxillary canine impaction. Out of the 1964 patients examined, 90 were found to have agenesis of MLI, representing a prevalence of 4.6%. The most commonly found associated-anomalies were agenesis of other teeth (23.3%), peg-shaped MLIs (15.6%), taurodontism (42.2%), and dilacerated teeth (18.9%). Permanent tooth agenesis, taurodontism, peg-shaped maxillary lateral incisor, and root dilacerations are frequently associated with maxillary lateral incisor agenesis.

Canine substitution for missing maxillary lateral incisors: the influence of canine morphology, size, and shade on perceptions of smile attractiveness.

PubMed

Brough, Elaine; Donaldson, Ana Nora; Naini, Farhad B

2010-12-01

This study was conducted to determine whether variations in the morphology, size, or shade of maxillary canines would influence perceptions of smile attractiveness in patients with canines substituted for missing maxillary lateral incisors. A smiling photograph of a hypodontia patient who had had orthodontic space closure with maxillary canines replacing the lateral incisors was digitally modified to create a bilaterally symmetrical image. Four groups of images were created, digitally altering canine gingival height, crown tip height, canine width, and canine shade. Three groups of judges (40 orthodontists, 40 dentists, and 40 laypeople) ranked the images for smile attractiveness, also scoring the most and the least attractive of each of the 4 groups, and the most and least attractive of all images. Canine gingival height was the most attractive 0.5 mm below the gingival margin of the maxillary central incisor and progressively less attractive with increasing gingival height. Increasing canine width, increased canine tip height, and pointed canines were perceived to be unattractive. Brighter than normal shades of canines were preferred to darker shades. Narrow canine crowns were most frequently ranked as the most attractive overall, 1.5 mm narrower was preferred by the orthodontists and dentists, and 3.0 mm narrower was preferred by the laypeople. All 3 groups ranked the darkest image, 20 times darker than the original, most frequently as the least attractive image overall. There was good general agreement between orthodontists, dentists, and laypeople for all 4 parameters of smile attractiveness, although laypeople demonstrated greater intragroup variations. The morphology, size, and shade of the maxillary canine in patients having orthodontic space closure and lateral incisor substitution can have a marked effect on perceived smile attractiveness. Copyright © 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Assessing the value of the Central Everglades Planning Project (CEPP) in Everglades restoration: an ecosystem service approach

USGS Publications Warehouse

Richardson, Leslie A.; Keefe, Kelly; Huber, Christopher C.; Racevskis, Laila; Gregg, Reynolds; Thourot, Scott; Miller, Ian

2014-01-01

This study identifies a full range of ecosystem services that could be affected by a restoration project in the central Everglades and monetizes the economic value of a subset of these services using existing data. Findings suggest that the project will potentially increase many ecosystem services that have considerable economic value to society. The ecosystem services monetized within the scope of this study are a subset of the difference between the future-with the Central Everglades Planning Project (CEPP) and the future-without CEPP, and they totaled ~ $1.8 billion USD at a 2.5% discount rate. Findings suggest that the use of ecosystem services in project planning and communications may require acknowledgment of the difficulty of monetizing important services and the limitations associated with using only existing data and models. Results of this study highlight the need for additional valuation efforts in this region, focused on those services that are likely to be impacted by restoration activities but were notably challenging to value in this assessment due to shortages of data.

Effects of Different Treatments of Pasture Restoration on Soil Trace Gas Emissions in the Cerrados of Central Brazil

EPA Science Inventory

Planted pastures ( mainly Brachiaria spp) are the most extensive land use in the cerrado (savannas of central Brazil) with an area of approximately 50 x 10(6) ha. The objective of the study was to assess the effects of pasture restoration on the N dynamics ( net N mineralization/...

External apical root resorption in maxillary root-filled incisors after orthodontic treatment: a split-mouth design study.

PubMed

Llamas-Carreras, José María; Amarilla, Almudena; Espinar-Escalona, Eduardo; Castellanos-Cosano, Lizett; Martín-González, Jenifer; Sánchez-Domínguez, Benito; López-Frías, Francisco Javier

2012-05-01

The purpose of this study was to compare, in a split mouth design, the external apical root resorption (EARR) associated with orthodontic treatment in root-filled maxillary incisors and their contralateral teeth with vital pulps. The study sample consisted of 38 patients (14 males and 24 females), who had one root-filled incisor before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the root resortion and the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the endodontically treated incisor and that in its contralateral incisor with a vital pulp. The student's t-test, chi-square test and logistic regression analysis were used to determine statistical significance. There was no statistically significant difference (p > 0.05) between EARR in vital teeth (1.1 ± 1.0 mm) and endodontically treated incisors (1.1 ± 0.8 mm). Twenty-six patients (68.4%) showed greater resorption of the endodontically treated incisor than its homolog vital tooth (p > 0.05). The mean and standard deviation of PPR were 1.0 ± 0.2. Multivariate logistic regression suggested that PRR does not correlate with any of the variables analyzed. There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root-filled incisors and their contralateral teeth with vital pulps.

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.

Five-minute Apgar score ≤ 5 and Molar Incisor Hypomineralisation (MIH) - a case control study.

PubMed

Sidaly, Rivan; Schmalfuss, Andreas; Skaare, Anne B; Sehic, Amer; Stiris, Tom; Espelid, Ivar

2016-07-22

The aetiology of molar incisor hypomineralisation (MIH) is unclear. The asymmetric distribution of MIH in the dentition may indicate that an insult of short duration that affects ameloblasts at a vulnerable stage could be a causative factor. Apgar ≤ 5 at 5 min may indicate asphyxia (hypoxic-ischemic insult) during birth. It was hypnotised that low Apgar score during birth may cause MIH. The present study aimed to examine a possible association between Apgar ≤ 5 at 5 min and the occurrence of MIH. Two study groups were selected for examination. The cases comprised 67 children aged 8-10 years born with Apgar score equal to or below 5 after 5 min. The control group comprised 157 age-matched healthy children. First permanent molars, second primary molars and all permanent incisors were examined in all children. Clinical examination was undertaken by two calibrated examiners and intraoral close-up photographs of the teeth were later evaluated by three calibrated and blinded clinicians. Demarcated opacities, post-eruptive breakdown, atypical restorations and extractions due to MIH, according to the criteria of the European Association of Paediatric Dentistry, were assessed. The prevalence of MIH did not differ between the two groups. A chi-square test failed to confirm any statistically significant relationship between 5-min Apgar scores and MIH occurrence. In addition, there was no statistically significant relationship between the number of affected first permanent molars in cases and controls. There was no association between Apgar ≤ 5 at 5 min and the occurrence of MIH.

Prevalence of molar incisor hypomineralization (MIH) in Singaporean children.

PubMed

Ng, Jing Jing; Eu, Oy Chu; Nair, Rahul; Hong, Catherine Hsu Ling

2015-03-01

There is a lack of data on molar incisor hypomineralization (MIH) in Asia, but this is not an indication that MIH is rare in the Asian population. Early identification of MIH is important as affected teeth frequently display post-eruptive enamel loss which would result in rapid caries progression. This objective of this study was to assess the prevalence of MIH in Singaporean children. Patients were recruited from 30 schools across Singapore. All children were examined by a single dentist, and the judgement criteria used were based on the 2003 European Academy of Paediatric Dentistry criteria. A total of 1083 children; average age of 7.7 ± 0.3 years were examined. One hundred and thirty-five children (12.5%) had MIH. A significantly higher proportion of children of the Malay ethnicity had MIH, compared to Chinese children (P = 0.02). Post-eruptive enamel breakdown and the presence of atypical restorations were correlated with increasing number of MIH teeth/child (Rho= 0.599, P < 0.001) and the cumulative enamel opacity colour score (Rho = 0.601, P < 0.001). Our findings suggest the role of ethnicity in MIH occurrence and that MIH severity may be influenced by the number of MIH teeth/child and the cumulative enamel opacity colour score. © 2014 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

External apical root resorption in maxillary root-filled incisors after orthodontic treatment: A split-mouth design study

PubMed Central

Amarilla, Almudena; Espinar-Escalona, Eduardo; Castellanos-Cosano, Lizett; Martín-González, Jenifer; Sánchez-Domínguez, Benito; López-Frías, Francisco J.

2012-01-01

Introduction: The purpose of this study was to compare, in a split mouth design, the external apical root resorption (EARR) associated with orthodontic treatment in root-filled maxillary incisors and their contralateral teeth with vital pulps. Methodology: The study sample consisted of 38 patients (14 males and 24 females), who had one root-filled incisor before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the root resortion and the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the endodontically treated incisor and that in its contralateral incisor with a vital pulp. The student’s t-test, chi-square test and logistic regression analysis were used to determine statistical significance. Results: There was no statistically significant difference (p > 0.05) between EARR in vital teeth (1.1 ± 1.0 mm) and endodontically treated incisors (1.1 ± 0.8 mm). Twenty-six patients (68.4%) showed greater resorption of the endodontically treated incisor than its homolog vital tooth (p > 0.05). The mean and standard deviation of PPR were 1.0 ± 0.2. Multivariate logistic regression suggested that PRR does not correlate with any of the variables analyzed. Conclusions: There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root-filled incisors and their contralateral teeth with vital pulps. Key words:Endodontics, orthodontics, root canal treatment, root resorption. PMID:22143731

Molar incisor hypomineralization: proportion and severity in primary public school children in Graz, Austria.

PubMed

Buchgraber, Barbara; Kqiku, Lumnije; Ebeleseder, Kurt A

2018-03-01

The aim of this study was to determine the proportion and severity of molar incisor hypomineralization (MIH) in primary school children in Graz (southeast of Austria). In 1111 children aged 6 to 12 years (mean age 9.0 ± 1.2), a wet examination of all teeth was performed by three trained examiners using a dental chair, optimal illumination, a dental mirror, and a dental explorer. All teeth with MIH lesions were registered so that different definitions of MIH were applicable. According to the European Academy of Pediatric Dentistry criteria that were considered valid at the time of the investigation, MIH was diagnosed when at least one first primary molar (FPM) was affected. MIH was present in 78 children (7.0%). In 64 children (5.8%), at least one molar and one incisor were affected (so-called M + IH). Additionally, in 9 children, only incisors were affected. In 7 affected children, teeth other than FPMs and incisors had MIH lesions. Almost an equal number of males (38) and females (40) were affected. The upper and lower molars were equally affected. The upper incisors were more frequently affected than the lower ones. Demarcated enamel opacities were the predominant types of defects. The proportion of MIH was 7.0% in Graz, which is similar to other comparable trials. This study has proven that MIH is an existing dental problem in Graz.

Euglycemia restoration by central leptin in type 1 diabetes requires STAT3 signaling but not fast-acting neurotransmitter release

USDA-ARS?s Scientific Manuscript database

Central leptin action is sufficient to restore euglycemia in insulinopenic type 1 diabetes (T1D); however, the underlying mechanism remains poorly understood. To examine the role of intracellular signal transducer and activator of transcription 3 (STAT3) pathways, we used LepRs/s mice with disrupted...

“Maxillary lateral incisor partial anodontia sequence”: a clinical entity with epigenetic origin

PubMed Central

Consolaro, Alberto; Cardoso, Maurício Almeida; Consolaro, Renata Bianco

2017-01-01

ABSTRACT The relationship between maxillary lateral incisor anodontia and the palatal displacement of unerupted maxillary canines cannot be considered as a multiple tooth abnormality with defined genetic etiology in order to be regarded as a “syndrome”. Neither were the involved genes identified and located in the human genome, nor was it presumed on which chromosome the responsible gene would be located. The palatal maxillary canine displacement in cases of partial anodontia of the maxillary lateral incisor is potentially associated with environmental changes caused by its absence in its place of formation and eruption, which would characterize an epigenetic etiology. The lack of the maxillary lateral incisor in the canine region means removing one of the reference guides for the eruptive trajectory of the maxillary canine, which would therefore, not erupt and /or impact on the palate. Consequently, and in sequence, it would lead to malocclusion, maxillary atresia, transposition, prolonged retention of the deciduous canine and resorption in the neighboring teeth. Thus, we can say that we are dealing with a set of anomalies and multiple sequential changes known as sequential development anomalies or, simply, sequence. Once the epigenetics and sequential condition is accepted for this clinical picture, it could be called “Maxillary Lateral Incisor Partial Anodontia Sequence.” PMID:29364376

Simian immunodeficiency virus infection induces severe loss of intestinal central memory T cells which impairs CD4+ T-cell restoration during antiretroviral therapy.

PubMed

Verhoeven, D; Sankaran, S; Dandekar, S

2007-08-01

Simian immunodeficiency virus (SIV) infection leads to severe loss of intestinal CD4(+) T cells and, as compared to peripheral blood, restoration of these cells is slow during antiretroviral therapy (ART). Mechanisms for this delay have not been examined in context of which specific CD4(+) memory subsets or lost and fail to regenerate during ART. Fifteen rhesus macaques were infected with SIV, five of which received ART (FTC/PMPA) for 30 weeks. Viral loads were measured by real-time PCR. Flow cytometric analysis determined changes in T-cell subsets and their proliferative state. Changes in proliferative CD4(+) memory subsets during infection accelerated their depletion. This reduced the central memory CD4(+) T-cell pool and contributed to slow CD4(+) T-cell restoration during ART. There was a lack of restoration of the CD4(+) central memory and effector memory T-cell subsets in gut-associated lymphoid tissue during ART, which may contribute to the altered intestinal T-cell homeostasis in SIV infection.

Gingival zenith positions and levels of the maxillary anterior dentition.

PubMed

Chu, Stephen J; Tan, Jocelyn H-P; Stappert, Christian F J; Tarnow, Dennis P

2009-01-01

The location of the gingival zenith in a medial-lateral position relative to the vertical tooth axis of the maxillary anterior teeth remains to be clearly defined. In addition, the apex of the free gingival margin of the lateral incisor teeth relative to the gingival zeniths of the adjacent proximal teeth remains undetermined. Therefore, this investigation evaluated two clinical parameters: (1) the gingival zenith position (GZP) from the vertical bisected midline (VBM) along the long axis of each individual maxillary anterior tooth; and (2) the gingival zenith level (GZL) of the lateral incisors in an apical-coronal direction relative to the gingival line joining the tangents of the GZP of the adjacent central incisor and canine teeth under healthy conditions. A total of 240 sites in 20 healthy patients (13 females, 7 males) with an average age of 27.7 years were evaluated. The inclusion patient criteria were absence of periodontal disease, gingival recession, or gingival hypertrophy as well as teeth without loss of interdental papillae, spacing, crowding, existing restorations, and incisal attrition. GZP dimensions were measured with calibrated digital calipers for each individual tooth and within each tooth group in a medial-lateral direction from the VBM. GZLs were measured in an apical-coronal direction from a tangent line drawn on the diagnostic casts from the GZPs of the adjacent teeth. This study demonstrated that all central incisors displayed a distal GZP from the VBM, with a mean average of 1 mm. Lateral incisors showed a deviation of the gingival zenith by a mean of 0.4 mm. In 97.5% of the canine population, the GZP was centralized along the long axis of the canine. The mean distance of the contour of the gingival margin in an apical-coronal direction of the lateral incisors (GZL) relative to gingival line joining the tangent of the adjacent central and canine GZPs was approximately 1 mm. This investigation revealed a GZP mean value of 1 mm distal from

Assessment of a prototype computer colour matching system to reproduce natural tooth colour on ceramic restorations.

PubMed

Kristiansen, Joshua; Sakai, Maiko; Da Silva, John D; Gil, Mindy; Ishikawa-Nagai, Shigemi

2011-12-01

The aim of this study was to assess the accuracy of a prototype computer colour matching (CCM) system for dental ceramics targeting the colour of natural maxillary central incisors employing a dental spectrophotometer and the Kubelka-Munk theory. Seventeen human volunteers with natural intact maxillary central incisors were selected to participate in this study. One central incisor from each subject was measured in the body region by a spectrophotometer and the reflectance values were used by the CCM system in order to generate a prescription for a ceramic mixture to reproduce the target tooth's colour. Ceramic discs were fabricated based on these prescriptions and layered on a zirconia ceramic core material of a specified colour. The colour match of each two-layered specimen to the target natural tooth was assessed by CIELAB colour coordinates (ΔE(*), ΔL(*), Δa(*) and Δb(*)). The average colour difference ΔE(*) value was 2.58±84 for the ceramic specimen-natural tooth (CS-NT) pairs. ΔL(*) values ranged from 0.17 to 2.71, Δa(*) values ranged from -1.70 to 0.61, and Δb(*) values ranged from -1.48 to 3.81. There was a moderate inverse correlation (R=-0.44, p-value=0.0721) between L(*) values for natural target teeth and ΔE(*) values; no such correlation was found for a(*) and b(*) values. The newly developed prototype CCM system has the potential to be used as an efficient tool in the reproduction of natural tooth colour. Copyright © 2011. Published by Elsevier Ltd.

Effect of surface sealants on microleakage of Class II restorations after thermocycling and long-term water storage.

PubMed

Lima, Adriano Fonseca; Soares, Giulliana Panfiglio; Vasconcellos, Pedro Henrique; Ambrosano, Gláucia Maria; Marchi, Giselle Maria; Lovadino, José Roberto; Aguiar, Flávio Henrique

2011-06-01

To evaluate interface degradation leading to marginal microleakeage in Class II restorations that had received an application of surface sealant at the tooth/restoration interface or not. Eighty bovine incisors were used, and the teeth were split obliquely, 10 mm from the amelodentinal proximal junction, and finished with water abrasive papers to obtain a smooth, flat incisal surface. Cavities were made to simulate Class II preparations (8 mm high, 4 mm wide and 1.5 mm deep), and the restorations were performed with a composite resin. Teeth were then randomly allocated into 8 groups according to the surface sealant (none, Fortify, Single Bond 2, or Scothbond MP Plus) and aging process (none or thermocycling and storage for 6 months). Microleakage was then evaluated using a dye penetration method immediately after the restoration or after aging. The samples were triturated and assessed by spectrophotometer. Microleakage was statistically similar in all groups when assessed immediately after the restorative procedure. After aging, teeth sealed with Fortify presented better results than the other groups. Aging causes interface degradation and increased microleakage. Surface sealant can reduce these effects and decrease microleakage in Class II restorations.

Effect of Crown Angulation of Maxillary Incisor on Effective Arch Perimeter.

PubMed

Jain, Megha; Vyas, Matrishva; Singh, Johar Rajvinder

2017-06-01

It has been postulated that crown angulation and inclination has potential space implication within the arch. With the insight of space implication of the axial relations of teeth, cases of genuine tooth size discrepancies can be dealt with improved stability. This in vitro study was designed to investigate and quantify the influence of angulation and inclination of maxillary incisors on the effective arch perimeter. Acrylic teeth were arranged over typhodont frame with spaced maxillary anterior segment. Known value of tip and torque in increments were incorporated to maxillary incisors through bracket positioning and corresponding consumption of the interdental spaces were measured using coordinate measuring machine. Study revealed that increase in maxillary incisor crown angulation by 1o results in consumption of approximately 0.012 mm of arch perimeter. Similarly, there is a consumption of 0.021 mm of arch perimeter with each degree increase in labial crown inclination. The knowledge of the space implication can be included in the space analysis during the orthodontic treatment planning. Depending upon the amount of space discrepancy, an accurate degree of required alteration in the axial relation of one or more teeth can be planned.

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

An Innovative Approach to Treat Incisors Hypomineralization (MIH): A Combined Use of Casein Phosphopeptide-Amorphous Calcium Phosphate and Hydrogen Peroxide-A Case Report.

PubMed

Mastroberardino, Stefano; Campus, Guglielmo; Strohmenger, Laura; Villa, Alessandro; Cagetti, Maria Grazia

2012-01-01

Molar Incisor Hypomineralization (MIH) is characterized by a developmentally derived deficiency in mineral enamel. Affected teeth present demarcated enamel opacities, ranging from white to brown; also hypoplasia can be associated. Patient frequently claims aesthetic discomfort if anterior teeth are involved. This problem leads patients to request a bleaching treatment to improve aestheticconditions.Nevertheless, hydrogen peroxide can produce serious side-effects, resulting from further mineral loss. Microabrasion and/or a composite restoration are the treatments of choice in teeth with mild/moderate MIH, but they also need enamel loss. Recently, a new remineralizing agent based on Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) has been proposed to be effective in hypomineralized enamel, improving also aesthetic conditions. The present paper presents a case report of a young man with white opacities on incisors treated with a combined use of CPP-ACP mousse and hydrogen peroxide gel to correct the aesthetic defect. The patient was instructed to use CPP-ACP for two hours per day for three months in order to obtain enamel remineralization followed by a combined use of CPP-ACP and bleaching agent for further two months. At the end of this five-month treatment, a noticeable aesthetic improvement of the opacities was observed.

Reversal of diet-induced obesity increases insulin transport into cerebrospinal fluid and restores sensitivity to the anorexic action of central insulin in male rats.

PubMed

Begg, Denovan P; Mul, Joram D; Liu, Min; Reedy, Brianne M; D'Alessio, David A; Seeley, Randy J; Woods, Stephen C

2013-03-01

Diet-induced obesity (DIO) reduces the ability of centrally administered insulin to reduce feeding behavior and also reduces the transport of insulin from the periphery to the central nervous system (CNS). The current study was designed to determine whether reversal of high-fat DIO restores the anorexic efficacy of central insulin and whether this is accompanied by restoration of the compromised insulin transport. Adult male Long-Evans rats were initially maintained on either a low-fat chow diet (LFD) or a high-fat diet (HFD). After 22 weeks, half of the animals on the HFD were changed to the LFD, whereas the other half continued on the HFD for an additional 8 weeks, such that there were 3 groups: 1) a LFD control group (Con; n = 18), 2) a HFD-fed, DIO group (n = 17), and 3) a HFD to LFD, DIO-reversal group (DIO-rev; n = 18). The DIO reversal resulted in a significant reduction of body weight and epididymal fat weight relative to the DIO group. Acute central insulin administration (8 mU) reduced food intake and caused weight loss in Con and DIO-rev but not DIO rats. Fasting cerebrospinal fluid insulin was higher in DIO than Con animals. However, after a peripheral bolus injection of insulin, cerebrospinal fluid insulin increased in Con and DIO-rev rats but not in the DIO group. These data provide support for previous reports that DIO inhibits both the central effects of insulin and insulin's transport to the CNS. Importantly, DIO-rev restored sensitivity to the effects of central insulin on food intake and insulin transport into the CNS.

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.

Resorption of maxillary incisors after orthodontic treatment--clinical study of risk factors.

PubMed

Elhaddaoui, Rajae; Benyahia, Hicham; Azeroual, Mohamed-Faouzi; Zaoui, Fatima; Razine, Rachid; Bahije, Loubna

2016-03-01

External apical root resorption (EARR) is one of the major problems associated with orthodontic treatment. Such lesions represent an iatrogenic risk that must be detected as early as possible, with regular radiological follow-up and appropriate therapeutic precautions. The causes and mechanisms leading to susceptibility to root resorption following the application of an orthodontic force are often not clear and are generally said to be of multifactorial origin. The aim of this clinical study was to analyze the factors linked to the occurrence of moderate to severe resorption (MSR) of upper incisors during orthodontic treatment in a group of Moroccan patients treated in the Dento-Facial Orthopedic Department of the Dental Consultation and Treatment Center (Centre de consultation et de traitements dentaires [CCTD]) in Rabat. A total of 82 patients (28% males, 72% females) aged between 12 and 27, with various malocclusions, who had been treated with fixed appliances for at least 1 year and for whom panoramic X-rays at the start, during and at the end of treatment were available, were selected randomly. The reduction in maxillary incisor root length was evaluated using resorption scores. The factors studied in relation to the risk of occurrence of MSR were: age, sex, treatment duration, extraction or non-extraction, type of malocclusion (Class I arch-length discrepancy, Class II, Class III), the vertical diagnosis (normal, supraocclusion, open bite), presence of dysfunction, impacted canines and root morphology. Statistical analysis was performed using SPSS software, version 18.0. Statistical tests used were: Kaplan-Meier analysis and the univariate and multivariate Cox models for the study of factors associated with MSR. The threshold of significance adopted was 0.05. The factors that were significantly associated with the occurrence of MSR at the level of the upper incisors were: tooth type, with a greater risk for the lateral incisor (HR=3.2 95% CI [2.3-4.5] P<0

A laboratory comparison of individual Targis/Vectris posts with standard fiberglass posts.

PubMed

Corsalini, Massimo; Genovese, Katia; Lamberti, Luciano; Pappalettere, Carmine; Carella, Mauro; Carossa, Stefano

2007-01-01

This article presents an in vitro analysis of a specific occlusal loading test on endodontically treated teeth restored with 2 different composite post materials. Individual, customized posts (IFPs) were compared to standard fiberglass posts (SFPs). The selected IFPs (standard cylindric Targis/Vectris posts) were compared to SFPs (Conic 6% Post, Ghimas). The posts were first subjected to a 3-point bending test to compare their flexural elastic properties. They were then used to restore 22 endodontically treated artificial maxillary central incisors and subjected to a specific occlusal loading simulation test. The loading test showed that IFP restorations performed better than SFP restorations. A clinical evaluation of this laboratory observation is suggested.

Staged Hard and Soft Tissue Reconstruction Followed by Implant Supported Restoration in the Aesthetic Zone: A Case Report.

PubMed

Parthasarathy, Harinath; Ramachandran, Lakshmi; Tadepalli, Anupama; Ponnaiyan, Deepa

2017-04-01

Alveolar ridge deficiency is a common clinical consequence following tooth loss due to chronic periodontitis complicating ideal implant placement. Advanced hard and soft tissue augmentation procedures have been developed in the recent past with predictable clinical outcomes. A male patient presented with a Grade III mobile upper right central incisor associated with advanced bone loss and soft tissue deficit. Following extraction of tooth #11, socket augmentation was done using an autogenous cortico-cancellous block graft and subsequent soft tissue augmentation was done with palatal connective tissue graft. At the end of six months, a tapered self tapping implant fixture was placed with adequate primary stability and after eight weeks, second stage implant surgery was done with the Misch technique in order to recreate papillae and the implant was prosthetically restored. The alveolar ridge was adequately recontoured following the staged surgical protocol. The implant was well integrated at the end of 15 months. Execution of sequential surgical procedures in a highly deficient edentulous site made it possible to achieve of optimal pink and white aesthetics with stable implant supported fixed prosthesis.

Bat activity following restoration prescribed burning in the central Appalachian Upland and riparian habitats

USGS Publications Warehouse

Austin, Lauren V.; Silvis, Alexander; Ford, W. Mark; Muthersbaugh, Michael; Powers, Karen E.

2018-01-01

After decades of fire suppression in eastern North America, land managers now are prioritizing prescribed fire as a management tool to restore or maintain fire-adapted vegetation communities. However, in long—fire-suppressed landscapes, such as the central and southern Appalachians, it is unknown how bats will respond to prescribed fire in both riparian and upland forest habitats. To address these concerns, we conducted zero-crossing acoustic surveys of bat activity in burned, unburned, riparian, and non-riparian areas in the central Appalachians, Virginia, USA. Burn and riparian variables had model support (ΔAICc < 4) to explain activity of all bat species. Nonetheless, parameter estimates for these conditions were small and confidence intervals overlapped zero for all species, indicating effect sizes were marginal. Our results suggest that bats respond to fire differently between upland and riparian forest habitats, but overall, large landscape-level prescribed fire has a slightly positive to neutral impact on all bats species identified at our study site post—fire application.

Ten-Year Follow-Up of a Fragment Reattachment to an Anterior Tooth: A Conservative Approach.

PubMed

Mendes, Luiz; Laxe, Laisa; Passos, Leandro

2017-01-01

This report describes the 10-year follow-up data of a patient who underwent fragment reattachment to the maxillary central incisor after coronal fracture with pulp exposure as well as the procedures followed for functional and esthetic adjustments. A 9-year-old female patient presented at the clinic of dentistry at the State University of Rio de Janeiro with a coronal fracture and pulp exposure of the right maxillary central incisor that had occurred immediately after an accident. The intact tooth fragment was recovered at the accident site and stored in milk. The treatment plan followed was to perform direct pulp capping and tooth fragment reattachment. When the patient was 14 years old, adhesion between fragment and remaining tooth was lost, and fragment reattachment was performed. Five years later, the same tooth presented clinical discoloration and absence of sensitivity during pulp vitality tests. Subsequently, a new treatment plan was formulated, which included endodontic treatment, followed by nonvital tooth bleaching and light-cured composite resin restoration. An esthetic and natural-looking restoration was achieved. Tooth fragment reattachment is not a temporary restorative technique and requires functional and esthetic adjustments over time to maintain the biomimetic characteristics of traumatized anterior teeth and predictable outcomes.

Ten-Year Follow-Up of a Fragment Reattachment to an Anterior Tooth: A Conservative Approach

PubMed Central

Mendes, Luiz; Laxe, Laisa

2017-01-01

This report describes the 10-year follow-up data of a patient who underwent fragment reattachment to the maxillary central incisor after coronal fracture with pulp exposure as well as the procedures followed for functional and esthetic adjustments. A 9-year-old female patient presented at the clinic of dentistry at the State University of Rio de Janeiro with a coronal fracture and pulp exposure of the right maxillary central incisor that had occurred immediately after an accident. The intact tooth fragment was recovered at the accident site and stored in milk. The treatment plan followed was to perform direct pulp capping and tooth fragment reattachment. When the patient was 14 years old, adhesion between fragment and remaining tooth was lost, and fragment reattachment was performed. Five years later, the same tooth presented clinical discoloration and absence of sensitivity during pulp vitality tests. Subsequently, a new treatment plan was formulated, which included endodontic treatment, followed by nonvital tooth bleaching and light-cured composite resin restoration. An esthetic and natural-looking restoration was achieved. Tooth fragment reattachment is not a temporary restorative technique and requires functional and esthetic adjustments over time to maintain the biomimetic characteristics of traumatized anterior teeth and predictable outcomes. PMID:28740741

Dens invaginatus with necrotic pulp in a right maxillary lateral incisor with preserved vitality.

PubMed

Alessandro, Lanza; Fabrizio, Di Francesco; Gennaro, De Marco; Dario, Di Stasio; Eugenio, Guidetti; Letizia, Perillo; Luigi, Femiano; Felice, Femiano

2018-01-01

Dens invaginatus (DI) is a dental malformation occurring in several morphologic types. Consequently, treatment of teeth affected by DI can get complicated because of the complex root canal anatomy. The aim is to describe how to manage a rare report of a DI with necrotic pulp held within the vital pulp of a maxillary lateral incisor. Oral fistula was found on the buccal mucosa of the apex of the vital maxillary lateral incisor with a DI having necrotic pulp. Endodontic treatment of the maxillary lateral incisor and of the tract canal of DI was realized. Clinical disappearance of oral sinus tract was observed after 10 days. On the contrary, the disappearance of radiolucent area occurred after 6 months. A proper and prompt diagnosis is necessary to carry out effective prevention protocols or prevent consequences generating nonrecoverable endo-perio diseases.

Differences between dentitions with palatally and labially located maxillary canines observed in incisor width, dental morphology and space conditions.

PubMed

Artmann, L; Larsen, H J; Sørensen, H B; Christensen, I J; Kjaer, I

2010-06-01

To analyze the interrelationship between incisor width, deviations in the dentition and available space in the dental arch in palatally and labially located maxillary ectopic canine cases. Size: On dental casts from 69 patients (mean age 13 years 6 months) the mesiodistal widths of each premolar, canine and incisor were measured and compared with normal standards. Dental deviations: Based on panoramic radiographs from the same patients the dentitions were grouped accordingly: Group I: normal morphology; Group IIa: deviations in the dentition within the maxillary incisors only; Group IIb: deviations in the dentition in general. Descriptive statistics for the tooth sizes and dental deviations were presented by the mean and 95% confidence limits for the mean and the p-value for the T-statistic. Space: Space was expresses by subtracting the total tooth sizes of incisors, canines and premolars from the length of the arch segments. Size of lateral maxillary incisor: The widths of the lateral incisors were significantly different in groups I, IIa and IIb (p=0.016) and in cases with labially located ectopic canines on average 0.65 (95% CI:0.25-1.05, p=0.0019) broader than lateral incisors in cases with palatally located ectopic canines. Space: Least available space was observed in cases with labially located canines. The linear model did show a difference between palatally and labially located ectopic canines (p=0.03). Space related to deviations in the dentition: When space in the dental arch was related to dental deviations (groups I, IIa and IIb), the cases in group IIb with palatally located canines had significantly more space compared with I and IIa. Two subgroups of palatally located ectopic maxillary canine cases based on registration of space, incisor width and deviations in the morphology of the dentition were identified.

Canines are affected in 16-year-olds with molar-incisor hypomineralisation (MIH): an epidemiological study based on the Tromsø study: "Fit Futures".

PubMed

Schmalfuss, A; Stenhagen, K R; Tveit, A B; Crossner, C-G; Espelid, I

2016-04-01

This was to determine the prevalence, distribution of affected teeth and severity of MIH in adolescents from Northern Norway. It was part of a cross-sectional health survey Fit Futures including 16-year-olds from two neighbouring municipalities, Tromsø and Balsfjord. The prevalence of MIH was 13.9% (110 of 794). The maxillary first permanent molars (FPMs) were 1.6 times more frequently affected than in the mandible (P < 0.001). The FPMs on the right side were 1.2 times more often affected than the FPMs on the left side (P = 0.038). The maxillary incisors were 2.5 times more often affected than the incisors in the mandible (P < 0.001). The proportions of participants whose canines and incisors were involved were 22.8 and 41.8%, respectively. Altogether 201 FPMs were affected; 54.0% of these had opacities only, 24.3% had posteruptive breakdown (PEB), 18.8% had atypical restorations, and 3.0% had been extracted due to MIH. The buccal surfaces were most often affected in FPMs. More severe lesions were found in the mandibular FPMs compared with the maxillary FPMs (P = 0.002). In the lower canines, only opacities were recorded, while in the upper jaw 13.0% of the affected canines showed PEBs. The distribution of MIH in the dentition was not symmetrical. The prevalence of MIH (13.9%) in the study population of 16-year-olds from Northern Norway is consistent with previous Scandinavian reports. The distribution pattern shows that one participant in four with MIH had at least one affected canine. Further studies are needed to describe the localisation of defects on the enamel surface and to relate these findings to enamel thickness and the duration of amelogenesis.

Effect of Crown Angulation of Maxillary Incisor on Effective Arch Perimeter

PubMed Central

Vyas, Matrishva; Singh, Johar Rajvinder

2017-01-01

Introduction It has been postulated that crown angulation and inclination has potential space implication within the arch. With the insight of space implication of the axial relations of teeth, cases of genuine tooth size discrepancies can be dealt with improved stability. Aim This in vitro study was designed to investigate and quantify the influence of angulation and inclination of maxillary incisors on the effective arch perimeter. Materials and Methods Acrylic teeth were arranged over typhodont frame with spaced maxillary anterior segment. Known value of tip and torque in increments were incorporated to maxillary incisors through bracket positioning and corresponding consumption of the interdental spaces were measured using coordinate measuring machine. Results Study revealed that increase in maxillary incisor crown angulation by 1o results in consumption of approximately 0.012 mm of arch perimeter. Similarly, there is a consumption of 0.021 mm of arch perimeter with each degree increase in labial crown inclination. Conclusion The knowledge of the space implication can be included in the space analysis during the orthodontic treatment planning. Depending upon the amount of space discrepancy, an accurate degree of required alteration in the axial relation of one or more teeth can be planned. PMID:28764302

[Orthodontic effects of tooth injury to the permanent and temporary incisors of children and the adolescent [corrected].

PubMed

Bassigny, F

1990-01-01

Traumatisms on the deciduous upper incisors could induce orthodontic indirect consequences on the permanent germ, dependent on his growth level and his malleability, dependent on connection between the root of deciduous incisor and the crown of permanent germ and according to the type of traumatism. According to those various data, it should be observed on the permanent incisor: germination of two germs, multiple odontoma, crown dilaceration, severe tipping of the crown with facial angulation, retention of the permanent germ with lack of root resorption of the deciduous teeth or simple cross-bite, without speaking of enamel defect.

Gingival Zenith Positions and Levels of Maxillary Anterior Dentition in Cases of Bimaxillary Protrusion: A Morphometric Analysis.

PubMed

Gowd, Snigdha; Shankar, T; Chatterjee, Suravi; Mohanty, Pritam; Sahoo, Nivedita; Baratam, Srinivas

2017-08-01

To investigate the two clinical parameters, such as gingival zenith positions (GZPs) and gingival zenith levels (GZLs), of maxillary anterior dentition in bimaxillary protrusion cases and collate it with severiety of crown inclination. Gingival zenith position and GZL in 40 healthy patients (29 females and 11 males) with an average age of 21.5 years were assessed. Inclusion criteria involved absence of periodontal diseases, Angle's class I molar relationship, and upper anterior proclination within 25 to 45° based on Steiner's analysis; exclusion criteria included spacing, crowding, anterior restoration and teeth with incisor attrition or rotation. The GZP was evaluated using digital calipers from voxel-based morphometry (VBM), and GZL was assessed from the tangent drawn from GZP of central incisor and canines to the linear vertical distance of GZP of lateral incisor. All the central incisors showed a GZP distal to VBM with a mean average of 1 mm. Severe proclination between 40 and 45° showed a statistically significant variation. Lateral incisors displayed a mean of 0.5 mm deviation of GZP from the vertically bisected midline. In 80% of canine population, GZP was centralized. We conclude that the degree of proclination of maxillary anterior dentition was correlated to the gingival contour in bimaxillary cases. The investigation revealed that there is a variation in the location of GZP as the severity of proclination increases. This study highlights the importance of microesthetics in fixed orthodontic treatment. The gingival contour should be unaltered while retraction during management of bimaxillary protrusion.

Comparison of Ferric Sulfate Combined Mineral Trioxide Aggregate Pulpotomy and Zinc Oxide Eugenol Pulpectomy of Primary Maxillary Incisors: An 18-month Randomized, Controlled Trial.

PubMed

Nguyen, Trang D; Judd, Peter L; Barrett, Edward J; Sidhu, Nicole; Casas, Michael J

2017-01-15

The purpose of this study was to compare outcomes and survival of ferric sulfate with mineral trioxide aggregate (FS+MTA) pulpotomy and root canal therapy (RCT) in carious vital primary maxillary incisors. In this parallel group noninferiority trial, asymptomatic carious vital primary incisors with pulp exposure in healthy 18- to 46-month-olds were allocated randomly to receive FS+MTA pulpotomy or RCT between September 2010 and September 2012. Each incisor was classified into one of the following radiographic outcomes: N (incisor without pathologic change); Po (pathologic change present, follow-up recommended); Px (pathologic change present, extract.) Clinical findings and incisor survival were secondary outcomes. Seventy subjects were enrolled with a total of 172 incisors. Twelve- and 18-month radiographic outcomes demonstrated no statistical difference between FS+MTA pulpotomy and RCT incisors for Px outcomes (P=0.38; odds ratio equals 0.60; 95 percent confidence interval equals 0.19 to 1.89; chi-square test). There was no statistical differences in clinical outcomes for FS+MTA pulpotomy and RCT at 12 and 18 months (P=0.51; Fisher's exact test) or survival for FS+MTA pulpotomy and RCT incisors (P=0.11; log-rank test). Ferric Sulfate with Mineral Trioxide Aggregate (FS+MTA) is an alternative to RCT for vital primary incisors.

High dose urokinase for restoration of patency of occluded permanent central venous catheters in hemodialysis patients.

PubMed

Shavit, L; Lifschitz, M; Plaksin, J; Grenader, T; Slotki, I

2010-10-01

Catheter thrombosis is common and results in inadequate dialysis treatment and, frequently, in catheter loss. Since dialysis treatment runs on a strict schedule, occluded catheters need to be restored in a timely and cost effective manner. We present a new shortened protocol of urokinase infusion that allows hemodialysis to be performed within 90 minutes. To chronic hemodialysis patients, who developed complete catheter occlusion, urokinase was infused simultaneously through both lumens of the catheter (125,000 units to each lumen) over 90 minutes. Technical success was defined as restoring blood pump speed to at least 250 ml/min. We determined the average time from catheter placement to first clot event (primary patency PP), recurrent clot event after urokinase treatment (secondary patency SP), catheter salvage rate and cause for removal. 37 catheters developed total thrombosis and urokinase was used to restore patency one or more times (total 47 treatments). Catheter salvage rate was 97 %. The average time of PP was 152 ± 56 days (7 - 784 days). Nine patients (30%) developed recurrent occlusion and the average time of SP was 64 ± 34 days (2 - 364 days). One catheter was removed because of dysfunction due to thrombosis. Other catheters were removed due to infection, fistula maturation or fell out spontaneously. Hemodialysis was performed immediately after treatment with blood speed of 250 ml/min in all patients. Our protocol is highly effective, short, and allows to restore patency of totally occluded central venous catheters with minimal disruption of the dialysis session.

On the relevance of "ideal" occlusion concepts for incisor inclination target definition.

PubMed

Knösel, Michael; Jung, Klaus

2011-11-01

The concept of "ideal" occlusion in harmony with craniofacial structures is often proposed as an ultimate goal of orthodontic treatment. The aim of this study was to assess the impact of slight variations in posterior occlusion and the history of straight-wire orthodontic treatment on the predictability of incisor inclination and third-order angles. Axial incisor inclinations, third-order angles, and craniofacial relationships were assessed on lateral headfilms and corresponding dental casts of 75 healthy white subjects, 16 to 26 years old, selected by the general inclusion criterion of a good interincisal relationship. Four groups were formed: group A (n = 17), Angle Class I occlusion subjects with no orthodontic treatment; group B (n = 20), Angle Class I occlusion subjects treated with standardized straight-wire orthodontics; group C (n = 20), up to a half-cusp distal occlusion after straight-wire treatment; and group D (n = 18), up to a half-cusp distal occlusion and no orthodontic treatment. Regression analysis was used to insert predictor angles into selected regression equations of the subjects with "ideal" occlusion, and the absolute differences between predicted and observed response angles were determined. Small differences in incisor inclination were found between subjects with "ideal" occlusion and those who slightly deviated from "ideal" with a mild occlusion of the Angle Class II category. Posterior occlusion was not relevant to the validity of the vast majority of predictor-response pairs. Straight-wire treatment produced incisor inclination that was slightly protruded compared with subjects who had good natural occlusion. The "ideal" posterior occlusion concepts as a general orthodontic treatment goal should be reconsidered. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Release of suppressed red spruce using canopy gap creation—Ecological restoration in the Central Appalachians

USGS Publications Warehouse

Rentch, J.S.; Ford, W. Mark; Schuler, T.S.; Palmer, J.; Diggins, Corinne A.

2016-01-01

Red spruce (Picea rubens) and red spruce-northern hardwood mixed stands once covered as much as 300,000 ha in the Central Appalachians, but now comprise no more than 21,000 ha. Recently, interest in restoration of this forest type has increased because red spruce forests provide habitat for a number of rare animal species. Our study reports the results of an understory red spruce release experiment in hardwood-dominated stands that have a small component of understory red spruce. In 2005, 188 target spruce were identified in sample plots at six locations in central West Virginia. We projected a vertical cylinder above the crown of all target spruces, and in 2007, we performed a release treatment whereby overtopping hardwoods were treated with herbicide using a stem injection technique. Release treatments removed 0–10% (Control), 11–50% (Low), 51–89% (Medium), and ≤90% (High) of the basal area of overtopping trees. We also took canopy photographs at the time of each remeasurement in 2007, 2010, and 2013, and compared basal removal treatments and resulting 2010 canopy openness and understory light values. The high treatment level provided significantly greater six-year dbh and height growth than the other treatment levels. Based on these results, we propose that a tree-centered release approach utilizing small canopy gaps that emulate the historical, gap-phase disturbance regime provides a good strategy for red spruce restoration in hardwood forests where overstory spruce are virtually absent, and where red spruce is largely relegated to the understory.

Botulinum neurotoxin type A in the masseter muscle: Effects on incisor eruption in rabbits

PubMed Central

Navarrete, Alfonso L.; Rafferty, Katherine L.; Liu, Zi Jun; Ye, Wenmin; Greenlee, Geoffrey M.; Herring, Susan W.

2015-01-01

Introduction Botulinum neurotoxins are responsible for the paralytic food poisoning, botulism. Commercial formulations such as botulinum neurotoxin type A are increasingly used for various conditions, including cosmetic recontouring of the lower face by injection of the large masseter muscles. The paralysis of a major muscle of mastication lowers occlusal force and thus might affect tooth eruption. The purpose of this study was to investigate the effects of unilateral masseter muscle injection of botulinum neurotoxin type A on the rate of eruption of incisors in a rabbit model. We hypothesized that the teeth would overerupt in an underloaded environment. Methods Forty rabbits were injected with either botulinum neurotoxin type A or saline solution in 1 masseter muscle. Mastication and muscle force production were monitored, and incisor eruption rate was assessed by caliper measurement of grooved teeth. Results The injection of saline solution had no effect. The masseter muscle injected with botulinum neurotoxin type A showed a dramatic loss of force 3 weeks after injection despite apparently normal mastication. Incisor eruption rate was significantly decreased for the botulinum neurotoxin type A group, an effect attributed to decreased attrition. Conclusions This study has implications for orthodontics. Although findings from ever-growing rabbit incisors cannot be extrapolated to human teeth, it is clear that botulinum neurotoxin type A caused a decrease in bite force that could influence dental eruption. PMID:23561411

[Indirect usage of miniscrew anchorage to intrude overerupted mandibular incisors in a Class II patient with a deep overbite].

PubMed

Ishihara, Yoshihito; Kuroda, Shingo; Sugawara, Yasuyo; Balam, Tarek A; Takano-Yamamoto, Teruko; Yamashiro, Takashi

2016-06-01

Vertical dentoalveolar discrepancies are a common problem in orthodontic patients but are often difficult to treat with traditional mechanics. This case report illustrates the successful treatment of overerupted mandibular incisors via the indirect use of miniscrew anchorage. A woman (age, 22 years 9 months) had chief complaints of maxillary incisor protrusion and crooked teeth. An excessive curve of Spee caused by elongation of the mandibular incisors was also found. The patient was diagnosed with a severe Class II Division 1 malocclusion and a deep overbite. After extraction of the mandibular first premolars and the subsequent leveling phase, the elongated incisors were intruded with a novel method, which involved the combined use of sectional archwires and miniscrews placed in the premolar areas. After the procedure, the mandibular incisors had been intruded by 6.5 mm with no undesirable side effects. The total active treatment period was 42 months. The resultant occlusion and satisfactory facial profile were maintained after 30 months of retention. Our novel intrusion approach shows potential for correcting a deep overbite. © EDP Sciences, SFODF, 2016.

Polytetrafluoroetylene tape as temporary restorative material: a fluid filtration study.

PubMed

Olcay, Keziban; Steier, Liviu; Erdogan, Hilal

2015-01-01

The purpose of this study was to compare the sealing ability of temporary restorative materials at 24 hrs and 1 week. Endodontic access cavities were prepared in 56 extracted lower incisor-teeth and divided into 5 groups (n=10). Standard 5 mm deep access preparations were completed and root canals were prepared to size ISO #30 file. The access cavities were restored as follows: Group 1: temporary restorative material (Ceivitron); Group 2: glass ionomer cement (Fuji II); Group 3: zinc oxide-eugenol cement (IRM); Group 4: zinc phosphate cement (Adhesor); Group 5: polytetrafluoroetylene tape (PTFE). The quality of the coronal sealing of each specimen was measured (24 hrs and 1 week) using fluid transport model. The data was analyzed with repeated measurements ANOVA, Tukey' HSD and Paired samples T-Tests. A significant difference was found among the groups at all time-periods (p<0.05). At 24 hrs, PTFE showed similar leakage with Ceivitron, IRM, and Fuji II but it showed higher leakage than Adhesor. At 1 week, Ceivitron showed higher leakage than PTFE, meanwhile PTFE showed similar leakage with IRM, Fuji II, and Adhesor (p>0.05). Sealing ability of IRM and PTFE groups significantly increased by time (p<0.05 and p<0.001 respectively). Within the limitations of this study, PTFE showed an acceptable short-term sealing capability when compared to the other commonly used temporary restorative materials at 1 week measurements.

Assessment of the Effect of Orthodontic Treatment on the Periodontal Health of Endodontically Restored Tooth.

PubMed

Jalaluddin, Md; Goyal, Vinod; Naqvi, Zuber A; Gupta, Bhaskar; Asnani, Mohil M; Sonigra, Hitesh M

2017-07-01

Intorduction: Patients usually undergo orthodontic treatment for achieving ideal interocclusal relationship between the dental tissue and bony tissue along with improving the speech, mastication, and facial esthetic appearance. Literature quotes paucity in the studies evaluating the effect of orthodontic treatment on the periodontal health of endodontically treated teeth. Hence, we planned the present study to assess the effect of orthodontic treatment on the periodontal health of endodonti-cally restored tooth. The present study included assessment of 80 patients who underwent orthodontic treatment. All the patients were divided broadly into two study groups: groups I and II. Group I included patients with the absence of endodontically treated teeth, while group II included patients which maxillary central incisors were resorted endodontically. Examination of the periodontal health of the patients was done using the community periodontal index of treatment need (CPITN) around the selected teeth. All the values were recorded during the preorthodontic time, postorthodontic time, and after the first 6 months of starting of the orthodontic treatment. All the results were recorded separately and analyzed. In the groups I and II, 28 and 25 patients respectively, had score of 1, while 10 patients in group I and 12 patients in group II had score of 2. Nonsignificant results were obtained while comparing the CPITN score in between the two study groups when measured at the pre-, intra-, and postortho time. In patients undergoing orthodontic treatment, having endodontically resorted teeth, no difference exists in relation to the periodontal health. Orthodontic treatment can be safely carried in patients with endodontically restored teeth.

Restoration of outer segments of foveal photoreceptors after resolution of central serous chorioretinopathy.

PubMed

Ojima, Yumiko; Tsujikawa, Akitaka; Yamashiro, Kenji; Ooto, Sotaro; Tamura, Hiroshi; Yoshimura, Nagahisa

2010-01-01

To study morphologically and functionally the prognosis of damaged outer segments of the foveal photoreceptor layer in eyes with resolved central serous chorioretinopathy (CSC). We studied retrospectively the medical records of 70 patients (74 eyes) with resolved CSC. Optical coherence tomography was used to detect the junctions between inner and outer segments of the photoreceptors (IS/OS) as a hallmark of the integrity of the outer photoreceptor layer. In 53 eyes (71.6%), the IS/OS line was clearly detected beneath the fovea immediately after resolution of the retinal detachment, with good visual acuity (VA). In the remaining 21 eyes (28.4%), however, the foveal IS/OS line could not be detected shortly after resolution of CSC, and VA was variable, ranging from 0.1 to 1.5 (median, 0.9). Of these 21 eyes, 15 had a follow-up examination with OCT, and in four the foveal IS/OS line was not detected at the follow-up and vision in these eyes remained poor. However, nine eyes showed recovery of the foveal IS/OS line during follow-up, and these eyes had substantial visual recovery. Immediately after resolution of active CSC, although the IS/OS line cannot be detected beneath the fovea, it often shows restoration over time, with visual recovery, though in some eyes no restoration takes place and the prognosis remains poor.

Decisions on repositioning of intruded permanent incisors; a review and case presentation.

PubMed

Hurley, E; Stewart, C; Gallagher, C; Kinirons, M

2018-06-01

Traumatic intrusion is a luxation type of injury where the tooth is displaced along the axis of the tooth, into the alveolus. This injury is regarded as serious because of the tissue damage that it causes. The traumatic movement is associated with severe damage to the periodontal ligament, pulpal tissue, root and alveolar socket. Despite its severity, the rare occurrence of this injury in permanent teeth has resulted in limited studies of immature and mature permanent incisors. The purpose of this paper is to review this luxation injury of permanent immature incisors, and to describe its diagnosis, treatment and management. In particular, we describe the repositioning strategies used in cases of intrusion injury. These include (i) monitoring spontaneous re-eruption, (ii) active orthodontic repositioning and (iii) surgical repositioning. Firstly, monitoring spontaneous re-eruption is observing and waiting for the intruded tooth to return to its original position. This process is not a normal developmental eruption and the outcome is not always predictable, nor is the time needed for this to happen. Secondly, active orthodontic repositioning is used to describe the process of rapidly moving the intruded tooth to its original position with the aid of an orthodontic appliance. Active orthodontic repositioning is often misunderstood as normal orthodontic movement. Orthodontic movement allows for periodontal ligament remodelling, using light intermittent forces. In contrast the active orthodontic repositioning used to move intruded incisors is rapid, and the primary aim is to achieve correct tooth position as rapidly as possible. Thirdly, surgical repositioning uses surgical intervention to bring the tooth back to its original position. A case of an intruded immature permanent incisor is presented, with a particular emphasis on these critical decisions on repositioning and showing the use of the three modalities of treatment in sequence, in order to achieve an outcome.

Factors affecting biological recovery of wetland restorations

DOT National Transportation Integrated Search

1999-06-01

This report describes a long-term study to monitor and evaluate the ecosystem recovery of seven wetland restorations in south central Minnesota. The study looks at the impact of planting on wetland restoration success in inland wetlands and develops ...

A phase III, open-label, single-arm study of tenecteplase for restoration of function in dysfunctional central venous catheters.

PubMed

Tebbi, Cameron; Costanzi, John; Shulman, Robert; Dreisbach, Luke; Jacobs, Brian R; Blaney, Martha; Ashby, Mark; Gillespie, Barbara S; Begelman, Susan M

2011-08-01

To evaluate, in a phase III, single-arm study, the safety and efficacy of the thrombolytic agent tenecteplase in restoring function to dysfunctional central venous catheters (CVCs). Pediatric and adult patients with dysfunctional CVCs were eligible to receive as much as 2 mL (2 mg) of intraluminal tenecteplase, which was left to dwell in the CVC lumen for a maximum of 120 minutes. If CVC function was not restored at 120 minutes, a second dose was instilled for an additional 120 minutes. Tenecteplase was administered to 246 patients. Mean patient age was 44 years (range, 0-92 y); 72 patients (29%) were younger than 17 years of age. Chemotherapy was the most common reason for catheter insertion. Restoration of CVC function was achieved in 177 patients (72%) within 120 minutes after the first dose. After instillation of a maximum of two doses of tenecteplase, CVC function was restored in 200 patients (81%), with similar frequencies in pediatric (83%) and adult (80%) patients. Adverse events (AEs) were reported in 31 patients (13%); fever (2%), neutropenia (1%), and nausea (0.8%) were most common. One serious AE, an allergic hypersensitivity reaction, was judged to be related to tenecteplase and/or a chemotherapeutic agent that the patient was receiving concurrently. Consecutive administration of one or two doses of tenecteplase into CVCs showed efficacy in the restoration of catheter function in patients with dysfunctional CVCs. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

Evaluating the Association of Tooth Form of Maxillary Central Incisors with Face Shape Using AutoCAD Software: A Descriptive Study.

PubMed

Mehndiratta, Aditi; Bembalagi, Mahantesh; Patil, Raghunath

2017-12-27

To assess the different forms of maxillary central incisors (MCI) and determine their association with the shape of the face for men and women. A total of 200 subjects (100 women, 100 men) aged between 18 and 30 years with healthy dentition were randomly selected from K.L.E. V.K Institute of Dental Sciences, Belagavi, India. Two standardized photographs (portrait and shape of the MCI) were taken for each subject and opened in AutoCAD 2009 software that was used to prepare technical drawings of face and tooth forms. The dental ratios (extent of line TA: extent of line TB) obtained after the tracings, were classified as tapered (≤0.61), ovoid (>0.61 and <0.69), or square (≥0.70). This classification was used to relate tooth form to the shape of the face and compare the form of MCI between men and women. Association between the shape of the MCI and the face was determined by Chi-square test using R 3.3.1 software. The most prevalent tooth form among the subjects was ovoid (women, 32%; men, 31%) followed by tapered (women, 13%; men, 16%). The least prevalent shape was square (women, 5%; men, 3%). The most prevalent face shape was tapered (women, 34%; men, 25%) followed by ovoid (women, 15%; men, 22%) and the least prevalent was square (women, 1%; men, 3%). An association between face shape and tooth form was statistically not significant. The most prevalent tooth form in both men and women was ovoid, and the least prevalent was square. The association between face shape and tooth form was not significant and did not abide by William's "Law of Harmony." However, there was an association between face shape and gender. © 2017 by the American College of Prosthodontists.

The effect of canine characteristics and symmetry on perceived smile attractiveness when canine teeth are substituted for lateral incisors.

PubMed

Rayner, Wendy Jane; Barber, Sophy K; Spencer, Richard James

2015-03-01

To determine the effect of canine tooth characteristics and symmetry on perceived smile attractiveness when maxillary canine teeth are substituted for missing lateral incisors. Prospective, cross-sectional study. Non-clinical study undertaken from Leeds Dental Institute, UK. A composite full-face image of a smiling female was used to display various dentitions; a control image with an 'ideal' smile, plus six further images substituting the maxillary lateral incisors with canine teeth either unilaterally or bilaterally with varying size, shape, colour and gingival margin level. The seven images were shown to orthodontists (n = 30), dentists (n = 30) and lay people (n = 30) who were asked to rate smile attractiveness using a visual analogue scale. Dental professionals rated smiles with canine substitution for lateral incisor agenesis to be significantly less attractive than an ideal smile unless the substituted canine teeth approximated the lateral incisor in terms of size, shape, colour and gingival margin. Lay people did not find smiles where canine teeth were substituted for lateral incisors significantly more or less attractive than an ideal smile regardless of the canine tooth characteristics. Dental professionals were significantly more perceptive than lay people to the deviation from ideal smile aesthetics due to canine substitution. Smiles with unilateral canine substitution were not found to be significantly less attractive than bilateral canine substitution by all groups. Canine characteristics and observer status will affect how canine substitution for lateral incisor agenesis is viewed in terms of aesthetic outcome.

The effect of baking soda when applied to bleached enamel prior to restorative treatment.

PubMed

Tostes, Bhenya Ottoni; Mondelli, Rafael Francisco Lia; Lima-Arsati, Ynara Bosco de Oliveira; Rodrigues, Jose Augusto; Costa, Leonardo Cesar

2013-08-01

This in vitro study evaluated the effect of 10% baking soda solution and sodium bicarbonate powder (applied with jets) when applied to bleached enamel prior to restorative treatment. The surfaces of 40 bovine incisors were flattened and divided into 5 groups (n = 8): Group B (bleached and restored, negative control), Group W (bleached, stored in distilled water for 7 days, and restored), Group BSJ (bleached, abraded with baking soda jet for 1 min, and restored), Group BSS (bleached, application of 10% baking soda solution for 5 min, and restored), and Group R (restored, without bleaching, positive control). The samples were bleached in 1 session with 3 applications of 35% HP-based gel and activated with a LED appliance for 9 min each. Resin composite cylinders (2 mm height and 0.8 mm diameter) were made on the enamel surface after the acid etching and a conventional 1-step single vial adhesive application was performed. After storage in distilled water (37 ± 1°C, 24 hr), the microshear bond test was performed (1 mm/min). ANOVA and Tukey tests were applied to compare the results. The mean results of these tests showed that Groups W, BBS, and R were not statistically different. These groups also indicated a higher bond strength when compared with Groups B and BSJ. The application of 10% baking soda solution for 5 min may be an alternative pre-restorative treatment for bleached enamel, but further studies are needed to consider whether or not this treatment may be effectively used in clinical practice.

Fracture resistance of endodontically treated teeth restored with Zirconia filler containing composite core material and fiber posts.

PubMed

Jeaidi, Zaid Al

2016-01-01

To assess the fracture resistance of endodontically treated teeth with a novel Zirconia (Zr) nano-particle filler containing bulk fill resin composite. Forty-five freshly extracted maxillary central incisors were endodontically treated using conventional step back preparation and warm lateral condensation filling. Post space preparation was performed using drills compatible for fiber posts (Rely X Fiber Post) on all teeth (n=45), and posts were cemented using self etch resin cement (Rely X Unicem). Samples were equally divided into three groups (n=15) based on the type of core materials, ZirconCore (ZC) MulticCore Flow (MC) and Luxacore Dual (LC). All specimens were mounted in acrylic resin and loads were applied (Universal testing machine) at 130° to the long axis of teeth, at a crosshead speed of 0.5 mm/min until failure. The loads and the site at which the failures occurred were recorded. Data obtained was tabulated and analyzed using a statistical program. The means and standard deviations were compared using ANOVA and Multiple comparisons test. The lowest and highest failure loads were shown by groups LC (18.741±3.02) and MC (25.16±3.30) respectively. Group LC (18.741±3.02) showed significantly lower failure loads compared to groups ZC (23.02±4.21) and MC (25.16±3.30) (p<0.01). However groups ZC (23.02±4.21) and MC (25.16±3.30) showed comparable failure loads (p=0.23). Fracture resistance of endodontically treated teeth restored with Zr filler containing bulk fill composite cores was comparable to teeth restored with conventional Zr free bulk fill composites. Zr filled bulk fill composites are recommended for restoration of endodontically treated teeth as they show comparable fracture resistance to conventional composite materials with less catastrophic failures.

Evaluation of accuracy of shade selection using two spectrophotometer systems: Vita Easyshade and Degudent Shadepilot.

PubMed

Kalantari, Mohammad Hassan; Ghoraishian, Seyed Ahmad; Mohaghegh, Mina

2017-01-01

The aim of this in vitro study was to evaluate the accuracy of shade matching using two spectrophotometric devices. Thirteen patients who require a full coverage restoration for one of their maxillary central incisors were selected while the adjacent central incisor was intact. 3 same frameworks were constructed for each tooth using computer-aided design and computer-aided manufacturing technology. Shade matching was performed using Vita Easyshade spectrophotometer, Shadepilot spectrophotometer, and Vitapan classical shade guide for the first, second, and third crown subsequently. After application, firing, and glazing of the porcelain, the color was evaluated and scored by five inspectors. Both spectrophotometric systems showed significantly better results than visual method ( P < 0.05) while there were no significant differences between Vita Easyshade and Shadepilot spectrophotometers ( P < 0.05). Spectrophotometers are a good substitute for visual color selection methods.

Optimizing Maxillary Aesthetics of a Severe Compromised Tooth through Orthodontic Movement and Dental Implants

PubMed Central

de Avila, Erica Dorigatti; Cirelli, Joni Augusto; Cardoso, Mauricio de Almeida; Capelozza-Filho, Leopoldino; Borelli Barros, Luiz Antonio

2014-01-01

Treatment of severe compromised tooth in the maxillary anterior area still poses great challenge to the clinicians. Several treatment modalities have been proposed to restore the function and aesthetics in teeth with advanced periodontal disease. The present study aims to report a case of traumatic injury of a left-maxillary central incisor with ridge preservation, orthodontic movement, and implant therapy. A 45-year-old woman underwent the proposed treatment for her left central incisor: basic periodontal therapy, xenogenous bone graft, and guided bone regeneration (GBR). Six months after the graft procedure, orthodontic movement by means of alignment and leveling was made and a coronal displacement of the gingival margin and vertical bone apposition could be observed after 13 months of active movement. Afterwards, a dental implant was placed followed by a connective tissue graft and immediate provisionalization of the crown. In conclusion, orthodontic movement was effective to improve the gingival tissue and alveolar bone prior to implant placement favoring the aesthetic results. Six years postoperatively, the results revealed height and width alveolar bone gain indicating that the treatment proposed was able to restore all the functional and aesthetic parameters. PMID:24523969

Developing a unified monitoring and reporting system: a key to successful restoration of mixed-oak forests throughout the central hardwood region

Treesearch

Daniel A. Yaussy; Gregory J. Nowacki; Thomas M. Schuler; Daniel C. Dey

2008-01-01

Many national forests and grasslands in the Central Hardwoods region of the United States recently have undergone Land Management Plan revision, which include management areas that promote restoration through a variety of management activities. Monitoring is a vital component of adaptive management whereby the effects from a variety of treatments (including controls)...

Treatment modalities in children with teeth affected by molar-incisor enamel hypomineralisation (MIH): A systematic review.

PubMed

Lygidakis, N A

2010-04-01

This was to review the literature concerning the treatment of permanent teeth with molar-incisor hypomineralised enamel (MIH), comment about possible shortcomings and propose areas of future research. A search of MedLine, Scopus, ResearchGate, Isis and Google Scholar databases was conducted using all terms relevant to the subject. Relevant papers published in English were identified after a review of their titles, abstracts or full reading of the papers. Of 189 references initially found, 66 papers were included; 34 directly relevant to the subject. From the latter, only 14 concerned laboratory or clinical studies dealing with treatment for MIH. Since 2000 11 reviews evaluated, to a certain extent, treatment options for affected teeth. Analysis of the proposed treatment modalities indicated options for prevention, restorations, and adhesion to hypomineralised enamel, full coronal coverage and extraction followed by orthodontics. Based on these findings, a treatment decision plan is proposed. Although treatment approaches for MIH have started to be clearer, long-term clinical trials, supported by laboratory studies, should be conducted to further facilitate the clinical management of this dental defect.

Community based ecological restoration of peatland in Central Mongolia for climate change mitigation and adaptation

NASA Astrophysics Data System (ADS)

Minayeva, Tatiana; Chultem, Dugarjav; Grootjans, Ab; Yamkhin, Jambaljav; Sirin, Andrey; Suvorov, Gennady; Batdorj, Oyunbileg; Tsamba, Batdorj

2017-04-01

Peatlands cover almost 2 % of Mongolia. They play crucial role in regulation of key natural processes in ecosystems and provide unique resources to maintain traditional way of life and livelihoods of herders. During the last decades, Mongolian peatlands severely degraded both due to the climate related events and due to overgrazing. The peat degradation causes significant losses of carbon store, GHG emissions and is followed by changes in water balance and water composition. The issue arises if such a type of ecosystems as peatlands could be a subject for ecosystem restoration in this arid and subhumid climate. Could it be considered as measure for climate change mitigation and adaptation? With funding opportunities from the Asian Development Bank a pilot project for peatland restoration had been launched in 2016 in Khashaat soum, Arkhangai aimag in Central Mongolia. The pilot aimed to merge local interests of herders with global targets of climate change mitigation. The following questions are addressed: what are the losses of natural functions and ecosystem services of peatland; what are expectations and demands of local communities and incentives for their involvement; how should and could look the target ecosystem; what are the technical solutions in order to achieve the target ecosystem characteristics; and what are the parameters for monitoring to assess the success of the project? The comprehensive baseline study addressed both natural and social aspects. The conclusions are: most of peat in the study area had been mineralised and has turned to organic rich soil with carbon content between 20 to 40 %, the key sources of water - small springs - are partly destroyed by cattle; the permafrost disappeared in this area and could not be the subject for restoration; local herders understand the value of peatland as water source and had carried out some voluntary activities for water storage and regulation such as dam construction; nevertheless there is no

Tooth shape preferences in an esthetic smile.

PubMed

Anderson, Kurt M; Behrents, Rolf G; McKinney, Thomas; Buschang, Peter H

2005-10-01

The purpose of this study was to evaluate the contributions of tooth shape to the esthetic smile. Restorative dentists (120), laypeople (102), and orthodontists (113) evaluated a series of color photographs of men's and women's smiles. The photographs were randomly presented to test the effects of 3 different shapes of maxillary incisors and canines on the same patient. For women, orthodontists preferred round and square-round incisors (P < .01), and restorative dentists preferred round incisors (P < or = .03). Laypeople did not discriminate between incisor shapes. For men, all 3 groups preferred square-round incisors (P < or = .042). There was also a tendency for male judges to rate female images more attractive than did female judges. Restorative dentists, orthodontists, and laypeople share similarities and display differences when considering esthetic preferences in tooth shape. Although there was no consensus in preference among the laypeople as a group, their preferences differed from those of the dental professionals.

Integrating a facial scan, virtual smile design, and 3D virtual patient for treatment with CAD-CAM ceramic veneers: A clinical report.

PubMed

Lin, Wei-Shao; Harris, Bryan T; Phasuk, Kamolphob; Llop, Daniel R; Morton, Dean

2018-02-01

This clinical report describes a digital workflow using the virtual smile design approach augmented with a static 3-dimensional (3D) virtual patient with photorealistic appearance to restore maxillary central incisors by using computer-aided design and computer-aided manufacturing (CAD-CAM) monolithic lithium disilicate ceramic veneers. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Assessment of the golden ratio in pleasing smiles.

PubMed

Nikgoo, Arash; Alavi, Kamiar; Alavi, Kavah; Mirfazaelian, Ali

2009-01-01

The golden ratio is a guideline to help harmoniously restore or replace missing teeth. However, this concept is controversial. This study assesses the validity of the golden ratio between the widths of the maxillary anterior teeth in individuals presenting with an attractive/nonattractive smile. A double-stage random cluster sample cross-sectional study included 903 students whose ages ranged from 18 to 30 years and met the inclusion criteria. Image-measurement software was used to assess the perceived mesiodistal widths of the maxillary anterior teeth on scanned photographs. A jury of two dental professionals, a portrait photographer, and a painter, along with the respective subject as the fifth judge, determined the attractiveness of each smile on a visual analog scale. The mean value determined whether an individual was allocated to the attractive or nonattractive smile group. Finally, the prevalence of the golden ratio was investigated in these two groups. Intraobserver correlation coefficient was 0.966. Cochran's chi-square test was used for data analysis. According to the jury, 143 individuals had an attractive smile and 289 had a nonattractive smile. Maxillary central to lateral incisor ratio showed the golden proportion in 50.3% of the students with an attractive smile as compared to 38.1% in the nonattractive smile group (P =.014). However, the golden ratio between the maxillary lateral incisors and the canines existed in only 16.8% of the individuals with an attractive smile as compared to 12.1% in the nonattractive smile group (P =.223). The golden ratio can be useful to achieve esthetic restorations of the maxillary central and lateral incisors. However, the golden ratio between the perceived widths of the maxillary lateral incisors to the canines does not seem to be decisive for an attractive smile and other factors should be considered. © 2009 BY QUINTESSENCE PUBLISHING CO, INC.

Sox2 and Lef-1 interact with Pitx2 to regulate incisor development and stem cell renewal.

PubMed

Sun, Zhao; Yu, Wenjie; Sanz Navarro, Maria; Sweat, Mason; Eliason, Steven; Sharp, Thad; Liu, Huan; Seidel, Kerstin; Zhang, Li; Moreno, Myriam; Lynch, Thomas; Holton, Nathan E; Rogers, Laura; Neff, Traci; Goodheart, Michael J; Michon, Frederic; Klein, Ophir D; Chai, Yang; Dupuy, Adam; Engelhardt, John F; Chen, Zhi; Amendt, Brad A

2016-11-15

Sox2 marks dental epithelial stem cells (DESCs) in both mammals and reptiles, and in this article we demonstrate several Sox2 transcriptional mechanisms that regulate dental stem cell fate and incisor growth. Conditional Sox2 deletion in the oral and dental epithelium results in severe craniofacial defects, including impaired dental stem cell proliferation, arrested incisor development and abnormal molar development. The murine incisor develops initially but is absorbed independently of apoptosis owing to a lack of progenitor cell proliferation and differentiation. Tamoxifen-induced inactivation of Sox2 demonstrates the requirement of Sox2 for maintenance of the DESCs in adult mice. Conditional overexpression of Lef-1 in mice increases DESC proliferation and creates a new labial cervical loop stem cell compartment, which produces rapidly growing long tusk-like incisors, and Lef-1 epithelial overexpression partially rescues the tooth arrest in Sox2 conditional knockout mice. Mechanistically, Pitx2 and Sox2 interact physically and regulate Lef-1, Pitx2 and Sox2 expression during development. Thus, we have uncovered a Pitx2-Sox2-Lef-1 transcriptional mechanism that regulates DESC homeostasis and dental development. © 2016. Published by The Company of Biologists Ltd.

Comparison of intrusion effects on maxillary incisors among mini implant anchorage, j-hook headgear and utility arch.

PubMed

Jain, Ravindra Kumar; Kumar, Sridhar Prem; Manjula, W S

2014-07-01

Intrusion of maxillary incisors is one of the most important and difficult tooth movements to achieve as a part of orthodontic therapy. A variety of techniques were used in the past to intrude the maxillary incisors before the emergence of mini implants in Orthodontics. Mini implants are temporary anchorage devices used to produce various tooth movements. The research was carried out to evaluate and compare the efficiency of producing intrusion of maxillary incisors using mini implants, utility arch and j- hook headgear. The study was conducted on 30 subjects divided into 3 Groups equally. Group 1- mini implant anchorage, Group 2 - j- hooks headgear and Group 3- utility arch were used for intrusion of the maxillary incisors. Conventional lateral cephalograms were taken before treatment and at the end of intrusion. Five cephalometric parameters were used to measure the amount of intrusion attained in each Group. Intra Group comparisons were done using student t-test and inter Group comparisons were done using ANOVA The duration of intrusion was four months in all the three Groups. In Group 1 the mean average intrusion attained was 2.1 mm, the mean average intrusion attained in Group 2 was 0.7 mm, and the mean average intrusion achieved in Group 3 was 1.4 mm with a side effect of 0.75 mm of molar extrusion. Although, both mini implants and utility arch can be used to attain significant amounts of incisor intrusion but using mini implants will produce true intrusion without any other side effects.

[Effect of incisor retraction on three-dimensional morphology of upper airway and fluid dynamics in adult class Ⅰ patients with bimaxillary protrusion].

PubMed

Sun, F C; Yang, W Z; Ma, Y K

2018-06-09

Objective: To investigate the effect of incisor retraction on three-dimensional morphology of upper airway and fluid dynamics in class Ⅰ adult patients with bimaxillary protrusion. Methods: Thirty class Ⅰ patients with bimaxillary protrusion that received fixed orthodontic treatment in Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University from January 2011 to September 2014 were selected using random number table. All the patients were treated with extraction of four first premolars and retraction of anterior teeth using implant anchorage. Cone-beam CT (CBCT) scans were performed before and after incisor retraction for all patients. The CBCT data of the upper airway were constructed using Mimics 16.0, and the flow field characteristics inside the upper airway were simulated using Ansys 14.0. The changes of volume (V), mean cross-sectional area (mCSA), maximum lateral diameters/maximum anteroposterior diameters (LP/AP) of cross section, the maximum pressure of airflow (P(max)), the minimum pressure of airflow (P(min)) and pressure drop (△P) of nasopharynx, oropharynx and hypopharynx before and after incisor retraction were measured and compared using paired t test. The correlation between the variation of △P in the most significant pharyngeal part and the morphological variables after incisor retraction was analyzed using Pearson correlation test. Results: No statistical differences were observed in the morphology and flow field in nasopharynx before and after incisor retraction ( P> 0.05). Before incisor retraction, the oropharyngeal volume and mCSA were (7 580±622) mm(3) and (217±40) mm(2), respectively, and the hypopharyngeal volume and mCSA were (2 564±162) mm(3), and (239±43) mm(2), respectively. After incisor retraction, the volumes of oropharynx and hypopharynx were (6 885±601) mm(3) and (2 535±156) mm(3), respectively, and mCSA of oropharynx and hypopharynx were (197±37) mm(2) and (236±42) mm(2), respectively

Accelerated eruption of rat lower incisor. Relationship between impeded and unimpeded eruption rates, rate of attrition, tooth length, and production of dentin and enamel.

PubMed

Risnes, S; Septier, D; Goldberg, M

1995-01-01

The present investigation studies the effects of persistently cutting one lower rat incisor out of occlusion. Within four days, the rate of eruption of the cut (unimpeded) incisor increased to 216% and that of the uncut (impeded) contralateral to 136% of the baseline rate. While the former remained high, the latter decreased gradually to about 90% within three weeks. The rate of attrition of the impeded incisor increased to 233% of the baseline rate within two days, then fell abruptly, and remained at a slightly lower level than the rate of eruption. Accordingly, the length of the erupted part of the impeded incisor decreased initially, but increased gradually after about four days. Measurements made on SEM micrographs of the series of transverse tooth segments obtained when cutting the incisor out of occlusion, showed that growth-related increase in mesiodistal tooth width was arrested from the 10th segment, dentin thickness decreased gradually to about 50% in the 12th segment, and enamel thickness, after an initial increase, decreased to about 80% in the 11th segment. The present study provides experimental evidence that accelerated eruption affects morphogenesis and histogenesis of the rat lower incisor. An impeded incisor, especially the contralateral, may not serve as an ideal control.

Rehabilitation of molar-incisor hypomineralization (MIH) complicated with localized tooth surface loss: a case report.

PubMed

Lam, Walter Y H; Ho, Edward H T; Pow, Edmond H N

2014-05-01

Molar-incisor hypomineralization (MIH) is a developmental enamel hypomineralized condition characteristically involving the first permanent molars and sometimes also the incisors. The affected teeth are predisposed to tooth surface loss (TSL) which may not only compromise the esthetics and function but also endanger the pulp and longevity of the teeth. This report describes the management of a patient with MIH complicated with localized TSL and lack of occlusal clearance due to dentoalveolar compensation. The atypical TSL pattern involved all anterior teeth and required the placement of Dahl appliances on both arches.

Reactive correction of a maxillary incisor in single-tooth crossbite following periodontal therapy.

PubMed

Huang, Chih-Hao; Brunsvold, Michael A

2005-05-01

The reactive correction of a single tooth anterior crossbite following periodontal therapy is described. This case report provides new information regarding correction of a crossbite relationship and con- firms existing reports of tooth movement following periodontal therapy. A 39-year-old woman in good general health presented with a history of recurrent periodontal abscesses of a maxillary incisor. Probing depths of the abscessed tooth ranged from 5 to 12 mm, and class 1 mobility was noted. Radiographs revealed that the tooth had previously been treated endodontically. The patient's periodontal diagnosis was generalized chronic moderate to severe periodontitis. Treatment considerations were complicated by a single-tooth crossbite relationship of the involved incisor and clinical evidence that the periodontal abscess communicated with an apical infection. Treatment of the abscess consisted of cause-related therapy, bone grafting, and occlusal adjustment. Five months after surgical treatment, an edge-to-edge incisal relationship was observed, the first indicator of tooth movement. Further correction to a normal incisal relationship resulted 1 year after modification of the proximal contact. At this time, there was normal probing depth with only slight recession and mobility. Bone fill was radiographically noted. It appears that some cases of maxillary incisor crossbite that are complicated by periodontal disease may be corrected, without orthodontic appliances, following periodontal treatment.

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

PubMed

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

2017-11-01

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

Restoring riparian forests in the Missouri Ozarks

Treesearch

Kyle L. Steele; John M. Kabrick; Daniel C. Dey; Randy G. Jensen

2013-01-01

Restoring the function of riparian forest ecosystems has become a primary objective of many land management agencies throughout the central hardwood region, and consequently, much emphasis has been placed on planting native hardwood tree species in former bottomland agricultural fields. However, there is little information providing successful restoration techniques in...

[Chromatic study of all-ceramic restorations--influence of abutment tooth color on color tone of copings].

PubMed

Hata, Utako; Yamamura, Osamu; Kawauchi, Daisuke; Fujii, Teruhisa

2006-01-01

Recently, the use of all-ceramic crowns has spread widely in clinical applications to meet the demand for both functional and esthetically-pleasing restorations. In making all-ceramic crowns, it is necessary to reproduce the shape and color near to those of the natural teeth. However, the color shades of abutments might influence the color of the copings which are made of material with high transparency. This study examined the influence of the color shades of the abutments on the final color of copings for three kinds of all-ceramic core materials: Empress, Empress 2 (IVOCLAR VIVADENT), and Procera AllCeram (Nobel Biocare). Copings with 0.5 mm in thickness were fabricated by using Empress (TC1), Empress 2 (100), and Procera AllCeram (white) core materials for an upper-right central incisor. Abutments were made by using six kinds of die materials of the Empress system (ST1, ST2, ST3, ST5, ST8, ST9), gold-silver-palladium alloy, gold alloy, and experimental black body. Copings were inserted in each abutment and the final color of the central part of the buccal surface was measured using a spectrophotometer according to the L*a*b* color system. Regardless of the color shades of the abutments, the chroma values of the copings rose in the order of Empress, Empress 2, and Procera, and the values of lightness rose in the order of Empress, Procera, and Empress 2. When the final color of each coping measured under the wet and dry conditions were compared, the difference in chroma was great. Within the limitations of this study, the results suggest that the influence of the color shades of the abutments on the final color of the three kinds of copings is small in the order of Empress, Procera, and Empress 2. In clinical and dental laboratory operations, it is hoped to observe and measure the color of copings and restorations under the wet condition.

12 years' preservation of maxillary permanent incisors with cervical root fractures adjacent to aggressive periodontitis: Report of a case.

PubMed

Tobiska, Sandra; Krastl, Gabriel

2018-05-17

This case report presents long-term results following horizontal root fracture of both maxillary central incisors in a 19-year-old woman with aggressive periodontitis. Due to extensive marginal bone loss and the close proximity of the fracture lines to the bottoms of the periodontal pockets, the prognosis of both teeth was uncertain at the time of the accident. Nevertheless, a conservative treatment strategy consisting of splinting and nonsurgical periodontal therapy was initiated. Follow-up at 12 years after the start of treatment revealed a stable situation from clinical and radiologic perspectives. Permanent fixation to the adjacent teeth and regular supportive periodontal care were the basis for a favorable long-term prognosis.

Shear bond strength of brackets on restorative materials: Comparison on various dental restorative materials using the universal primer Monobond® Plus.

PubMed

Ebert, Thomas; Elsner, Laura; Hirschfelder, Ursula; Hanke, Sebastian

2016-03-01

The purpose of this work was to analyze surfaces consisting of different restorative materials for shear bond strength (SBS) and failure patterns of metal and ceramic brackets. Bonding involved the use of a universal primer (Monobond® Plus, Ivoclar Vivadent). Six restorative materials were tested, including one composite resin (Clearfil Majesty™ Posterior, Kuraray Noritake Dental), one glass-ceramic material (IPS Empress® Esthetic, Ivoclar Vivadent), one oxide-ceramic material (CORiTEC Zr transpa Disc, imes-icore), two base-metal alloys (remanium® star, Dentaurum; Colado® CC, Ivoclar Vivadent), and one palladium-based alloy (Callisto® 75 Pd, Ivoclar Vivadent). Bovine incisors served as controls. Both metal and ceramic brackets (discovery®/discovery® pearl; Dentaurum) were bonded to the restorative surfaces after sandblasting and pretreatment with Monobond® Plus. A setup modified from DIN 13990-2 was used for SBS testing and adhesive remnant index (ARI)-based analysis of failure patterns. The metal brackets showed the highest mean SBS values on the glass-ceramic material (68.61 N/mm(2)) and the composite resin (67.58 N/mm(2)) and the lowest mean SBS on one of the base-metal alloys (Colado® CC; 14.01 N/mm(2)). The ceramic brackets showed the highest mean SBS on the glass-ceramic material (63.36 N/mm(2)) and the lowest mean SBS on the palladium-based alloy (38.48 N/mm(2)). Significant differences between the metal and ceramic brackets were observed in terms of both SBS values and ARI scores (p < 0.05). Under both bracket types, fractures of the composite-resin and the glass-ceramic samples were observed upon debonding. Opaque restorative materials under metal brackets were found to involve undercuring of the adhesive. Monobond® Plus succeeded in generating high bond strengths of both bracket types on all restorative surfaces. Given our observations of cohesive fracture (including cases of surface avulsion) of the composite-resin and the glass

Forced orthodontic extrusion and use of CAD/CAM for reconstruction of grossly destructed crown: A multidisciplinary approach

PubMed Central

Kumar, Rahul; Patil, Suvarna

2012-01-01

The aim of this study is to present a report of a case where forced orthodontic extrusion and computer-aided design and computer-aided manufacturing (CAD/CAM) technique was used for reconstruction of right maxillary central incisor with grossly destructed crown. Aesthetic rehabilitation of a fractured maxillary right central incisor was performed employing a multidisciplinary approach i.e. conventional endodontic treatment followed by orthodontic extrusion and final restoration using CAD-CAM and one piece milled zirconia post and core with full coverage zirconia crown. After the procedure being completed, periapical radiographs taken at 3 month follow up period demonstrated that the post and core remained well adapted to post space and there was a complete healing of periapical lesion. This technique can provide a complete aesthetic rehabilitation of a grossly destructed tooth without hampering the biological width and thus has a better prognosis. PMID:22557823

Evaluation of accuracy of shade selection using two spectrophotometer systems: Vita Easyshade and Degudent Shadepilot

PubMed Central

Kalantari, Mohammad Hassan; Ghoraishian, Seyed Ahmad; Mohaghegh, Mina

2017-01-01

Objective: The aim of this in vitro study was to evaluate the accuracy of shade matching using two spectrophotometric devices. Materials and Methods: Thirteen patients who require a full coverage restoration for one of their maxillary central incisors were selected while the adjacent central incisor was intact. 3 same frameworks were constructed for each tooth using computer-aided design and computer-aided manufacturing technology. Shade matching was performed using Vita Easyshade spectrophotometer, Shadepilot spectrophotometer, and Vitapan classical shade guide for the first, second, and third crown subsequently. After application, firing, and glazing of the porcelain, the color was evaluated and scored by five inspectors. Results: Both spectrophotometric systems showed significantly better results than visual method (P < 0.05) while there were no significant differences between Vita Easyshade and Shadepilot spectrophotometers (P < 0.05). Conclusion: Spectrophotometers are a good substitute for visual color selection methods. PMID:28729792

Withdrawal and restoration of central vagal afferents within the dorsal vagal complex following subdiaphragmatic vagotomy.

PubMed

Peters, James H; Gallaher, Zachary R; Ryu, Vitaly; Czaja, Krzysztof

2013-10-15

Vagotomy, a severing of the peripheral axons of the vagus nerve, has been extensively utilized to determine the role of vagal afferents in viscerosensory signaling. Vagotomy is also an unavoidable component of some bariatric surgeries. Although it is known that peripheral axons of the vagus nerve degenerate and then regenerate to a limited extent following vagotomy, very little is known about the response of central vagal afferents in the dorsal vagal complex to this type of damage. We tested the hypothesis that vagotomy results in the transient withdrawal of central vagal afferent terminals from their primary central target, the nucleus of the solitary tract (NTS). Sprague-Dawley rats underwent bilateral subdiaphragmatic vagotomy and were sacrificed 10, 30, or 60 days later. Plastic changes in vagal afferent fibers and synapses were investigated at the morphological and functional levels by using a combination of an anterograde tracer, synapse-specific markers, and patch-clamp electrophysiology in horizontal brain sections. Morphological data revealed that numbers of vagal afferent fibers and synapses in the NTS were significantly reduced 10 days following vagotomy and were restored to control levels by 30 days and 60 days, respectively. Electrophysiology revealed transient decreases in spontaneous glutamate release, glutamate release probability, and the number of primary afferent inputs. Our results demonstrate that subdiaphragmatic vagotomy triggers transient withdrawal and remodeling of central vagal afferent terminals in the NTS. The observed vagotomy-induced plasticity within this key feeding center of the brain may be partially responsible for the response of bariatric patients following gastric bypass surgery. Copyright © 2013 Wiley Periodicals, Inc.

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

PubMed

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

2014-02-01

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 micro-RNAs. 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. Copyright © 2013 Wiley Periodicals, Inc.

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

Resolving stem and progenitor cells in the adult mouse incisor through gene co-expression analysis

PubMed Central

Seidel, Kerstin; Marangoni, Pauline; Tang, Cynthia; Houshmand, Bahar; Du, Wen; Maas, Richard L; Murray, Steven; Oldham, Michael C; Klein, Ophir D

2017-01-01

Investigations into stem cell-fueled renewal of an organ benefit from an inventory of cell type-specific markers and a deep understanding of the cellular diversity within stem cell niches. Using the adult mouse incisor as a model for a continuously renewing organ, we performed an unbiased analysis of gene co-expression relationships to identify modules of co-expressed genes that represent differentiated cells, transit-amplifying cells, and residents of stem cell niches. Through in vivo lineage tracing, we demonstrated the power of this approach by showing that co-expression module members Lrig1 and Igfbp5 define populations of incisor epithelial and mesenchymal stem cells. We further discovered that two adjacent mesenchymal tissues, the periodontium and dental pulp, are maintained by distinct pools of stem cells. These findings reveal novel mechanisms of incisor renewal and illustrate how gene co-expression analysis of intact biological systems can provide insights into the transcriptional basis of cellular identity. DOI: http://dx.doi.org/10.7554/eLife.24712.001 PMID:28475038

Restorative outcomes for endodontically treated teeth in the Practitioners Engaged in Applied Research and Learning network.

PubMed

Spielman, Howard; Schaffer, Scott B; Cohen, Mitchell G; Wu, Hongyu; Vena, Donald A; Collie, Damon; Curro, Frederick A; Thompson, Van P; Craig, Ronald G

2012-07-01

The authors aimed to determine the outcome of and factors associated with success and failure of restorations in endodontically treated teeth in patients in practices participating in the Practitioners Engaged in Applied Research and Learning (PEARL) Network. Practitioner-investigators (P-Is) invited the enrollment of all patients seeking care at participating practices who had undergone primary endodontic therapy and restoration in a permanent tooth three to five years earlier. P-Is classified endodontically reated teeth as restorative failures if the restoration was replaced, the restoration needed replacement or the tooth was cracked or fractured. P-Is from 64 practices enrolled in the study 1,298 eligible patients who had endodontically treated teeth that had been restored. The mean (standard deviation) time to follow-up was 3.9 (0.6) years. Of the 1,298 enrolled teeth, P-Is classified 181 (13.9 percent; 95 percent confidence interval [CI], 12.1-15.8 percent) as restorative failures: 44 (3.4 percent) due to cracks or fractures, 57 (4.4 percent) due to replacement of the original restoration for reasons other than fracture and 80 (6.2 percent) due to need for a new restoration. When analyzing the results by means of multivariate logistic regression, the authors found a greater risk of restorative failure to be associated with canines or incisors and premolars (P = .04), intracoronal restorations (P < .01), lack of preoperative proximal contacts (P < .01), presence of periodontal connective-tissue attachment loss (P < .01), younger age (P = .01), Hispanic/Latino ethnicity (P = .04) and endodontic therapy not having been performed by a specialist (P = .04). These results suggest that molars (as opposed to other types of teeth), full-coverage restorations, preoperative proximal contacts, good periodontal health, non-Hispanic/Latino ethnicity, endodontic therapy performed by a specialist and older patient age are associated with restorative success for

[Veneer computer aided design based on reverse engineering technology].

PubMed

Liu, Ming-li; Chen, Xiao-dong; Wang, Yong

2012-03-01

To explore the computer aided design (CAD) method of veneer restoration, and to assess if the solution can help prosthesis meet morphology esthetics standard. A volunteer's upper right central incisor needed to be restored with veneer. Super hard stone models of patient's dentition (before and after tooth preparation) were scanned with the three-dimensional laser scanner. The veneer margin was designed as butt-to-butt type. The veneer was constructed using reverse engineering (RE) software. The technique guideline of veneers CAD was explore based on RE software, and the veneers was smooth, continuous and symmetrical, which met esthetics construction needs. It was a feasible method to reconstruct veneer restoration based on RE technology.

Dentists' perception, knowledge, and clinical management of molar-incisor-hypomineralisation in Kuwait: a cross-sectional study.

PubMed

Alanzi, Abrar; Faridoun, Anfal; Kavvadia, Katerina; Ghanim, Aghareed

2018-03-07

Molar-incisor Hypomineralisation (MIH) is considered as a global dental problem. There is little knowledge of general dental practitioners (GDPs) and dental specialists (DSs) about this condition in different parts of the world, particularly in Gulf Cooperation Council (GCC) countries. Hence, this study has been carried out to assess the knowledge of GDPS and DSs in Kuwait about MIH condition, its clinical presentation and management. Findings would help national school oral health program (SOHP) to promote good oral healthcare. A structured questionnaire was distributed to 310 attendees of the 18th Kuwait Dental Association Scientific Conference, Kuwait. Data concerning demographic variables, prevalence, diagnosis, severity, training demands and clinical management of MIH were collected. A response rate of 71.3% (221/310) was reported. 94% of respondents noticed MIH in their practice. Yellow/brown demarcation has been observed as a common clinical presentation (> 50%). Almost 10-20% of MIH prevalence has been reported by the participants. Resin composite was the dental material often used in treating MIH teeth (~ 65%), and fewer than half would use it for treating moderately affected molars. Most respondents would use preformed metal crowns for severe MIH (63%). Dental journals were the information source for DSs; whereas, the internet was the information source for GDPs. Child's behaviour was the main reported barrier for treatment of MIH affected children. Many GDPs felt unconfident when diagnosing MIH compared to dental specialists. Respondents supported the need to investigate MIH prevalence and to receive a clinical training. Molar incisor hypomineralisation is a recognised dental condition by practitioners in Kuwait. Yellow/brown demarcated opacities were the most reported clinical presentation, and the composite resin was the most preferred dental material for restoring MIH teeth. Most GDPs and dental specialists would use preformed metal crowns for

Photoconductive method for measuring light transmission to the root of metal-ceramic and all-ceramic restorations.

PubMed

Hsieh, Yun-Lin; Lai, Yu-Lin; Chen, Hui-Lin; Hung, Cheng-Yuan; Chen, Xiu-Ling; Lee, Shyh-Yuan

2008-09-01

In this study, the authors attempted to develop a photoconductive method for measuring light transmission through a crown restoration to the root dentin; metal-ceramic crowns with four coping designs (metal collar, and metal framework ending 0, 1, and 2mm coronal to the axiogingival line angle) and two all-ceramic crowns (Empress II and In-Ceram Alumina) were compared. According to pre-registered templates, 36 crowns were fabricated for an extracted central incisor. A cadmium sulfide (CdS) photoconductive cell was secured onto the root of a tooth, which was fixed in a light box. The validity and reliability of the experimental design were verified, and the impedance of the cell was recorded when the crowns were placed on the prepared tooth with or without try-in pastes under a constant luminance. A significant correlation (r= -0.99, p<0.001) was found between the light intensity and impedance of the CdS cell, and a 1.15% coefficient of variation between repeated measurements was observed. In this study, Empress II crowns had the smallest impedance, indicating that they provided the best light transmission. Conventional metal-ceramic crowns had the least light transmission, which was significantly improved by reducing the metal collar (p<0.05). The framework of metal-ceramic crowns which ended 2mm coronal to the axiogingival line angle showed as much light transmission as the In-Ceram crowns. The impedance increased when try-in pastes were employed in all test groups. The photoconductive method was proven to be a reliable technique for measuring the light transmitted through restorations into the adjacent tissue.

Effects of posttreatment skeletal maturity measured with the cervical vertebral maturation method on incisor alignment relapse.

PubMed

Fudalej, Piotr; Rothe, Laura E; Bollen, Anne-Marie

2008-08-01

Our aim was to test the hypothesis that relapse of incisor alignment is associated with skeletal maturity at the end of treatment, as assessed with the cervical vertebral maturation (CVM) method. This was a case-control study with information from the postretention database at the University of Washington. Mandibular incisor irregularity (II) at least 10 years out of retention (T3) was used to define the subjects (II >6 mm, relapse group) and the controls (II <3.5 mm, stable group). The following model measurements were made: II at pretreatment (T1), II at posttreatment (T2), and intercanine width at T1 and T2. On cephalograms taken T2, the CVM status was determined. Logistic regression analyses were used to determine the association between relapse and CVM status after treatment. The models were adjusted for potentially confounding variables (II at pretreatment and posttreatment, intercanine width change during treatment, sex, age at T2, and treatment alternatives). No association between CVM stage at T2 and relapse was found (P = 0.89). Both groups had similar distributions of the CVM stages (P >0.05). Pretreatment II and postretention time were found to be correlated with long-term incisor stability (P = 0.007 and 0.034, respectively). Sex was not related to relapse (P = 0.33). Maturity of craniofacial structures at the end of treatment evaluated with the CVM method is not associated with long-term stability of incisor alignment.

Weak central coherence in weight-restored adolescent anorexia nervosa: Characteristics and remediation.

PubMed

Weinbach, Noam; Perry, Amit; Sher, Helene; Lock, James D; Henik, Avishai

2017-08-01

Weak central coherence (WCC) refers to a bias towards processing details (local processing) at the expense of paying attention to the bigger picture (global processing). Multiple studies reported WCC in adults with anorexia nervosa (AN). Evidence for WCC in adolescents with AN has been inconsistent. The current study characterizes WCC in weight-restored adolescents with AN (WR-AN) using a direct measure of WCC, and examines whether WCC can be remediated by increasing alertness level-a manipulation that was found useful in enhancing global processing in healthy individuals and clinical populations. 40 adolescents (18 WR-AN and 22 healthy adolescents) performed a global/local processing task (Navon task). Auditory alerting cues that elevate alertness level were integrated into the task. Both groups processed global information faster than local information. However, compared with controls, adolescents with WR-AN were better at ignoring an irrelevant bigger picture while attending to details (smaller global interference) and had greater difficulty ignoring irrelevant details while attending to the bigger picture (larger local interference). These differences were attenuated when adolescents with WR-AN were under a state of high alertness. Additionally, the local interference effect was positively correlated with three independent self-report questionnaires assessing eating disorders symptomatology. This study suggests that abnormal interference by irrelevant global and local information is a central characteristic of WCC in adolescents with WR-AN that cannot be accounted for by enduring illness or malnourishment. Additionally, this study demonstrates that WCC can be temporarily remediated by encouraging a state of high alertness. © 2017 Wiley Periodicals, Inc.

Restoration of euglycemia after duodenal bypass surgery is reliant on central and peripheral inputs in Zucker fa/fa rats.

PubMed

Jiao, Jian; Bae, Eun Ju; Bandyopadhyay, Gautam; Oliver, Jason; Marathe, Chaitra; Chen, Michael; Hsu, Jer-Yuan; Chen, Yu; Tian, Hui; Olefsky, Jerrold M; Saberi, Maziyar

2013-04-01

Gastrointestinal bypass surgeries that result in rerouting and subsequent exclusion of nutrients from the duodenum appear to rapidly alleviate hyperglycemia and hyperinsulinemia independent of weight loss. While the mechanism(s) responsible for normalization of glucose homeostasis remains to be fully elucidated, this rapid normalization coupled with the well-known effects of vagal inputs into glucose homeostasis suggests a neurohormonally mediated mechanism. Our results show that duodenal bypass surgery on obese, insulin-resistant Zucker fa/fa rats restored insulin sensitivity in both liver and peripheral tissues independent of body weight. Restoration of normoglycemia was attributable to an enhancement in key insulin-signaling molecules, including insulin receptor substrate-2, and substrate metabolism through a multifaceted mechanism involving activation of AMP-activated protein kinase and downregulation of key regulatory genes involved in both lipid and glucose metabolism. Importantly, while central nervous system-derived vagal nerves were not essential for restoration of insulin sensitivity, rapid normalization in hepatic gluconeogenic capacity and basal hepatic glucose production required intact vagal innervation. Lastly, duodenal bypass surgery selectively altered the tissue concentration of intestinally derived glucoregulatory hormone peptides in a segment-specific manner. The present data highlight and support the significance of vagal inputs and intestinal hormone peptides toward normalization of glucose and lipid homeostasis after duodenal bypass surgery.

Traumatic dental injuries to primary incisors and the terminal or occlusal plane relationship in Indian preschool children.

PubMed

Shekhar, M G; Mohan, R

2011-03-01

To determine the prevalence of traumatic dental injuries to primary incisors in 3-5 year-old preschool children and to study the relationship between dental injuries and age, gender and terminal plane relation. A cross-sectional study was conducted in 1,126 preschool children aged three to five years enrolled in eleven private and public nursery schools, randomly selected in Chennai, India. Data regarding the age, gender, cause and type of trauma and terminal plane relation were recorded. Maxillary and mandibular primary incisors were examined for traumatic injuries and were recorded according to the method described by Andreasen & Andreasen (1994). Data were analyzed through descriptive analysis and chi-square test. Traumatic injuries to primary incisors were identified in 6.2% of children. No significant gender differences in prevalence were seen (p > 0.05). Enamel fractures (57.3%) dominated amongst the type of injuries. Majority of children who sustained traumatic dental injuries to their primary incisors were associated with mesial step molar relation. Mesial step molar relation may be considered one of the possible predisposing factors to trauma in primary dentition. Further, there is need to intensify oral health education targeted at both parents and teachers at nursery schools to inform them about consequences of primary teeth injuries on permanent dentition and emphasize the importance of prevention of dental injuries in children.

Hedgehog signaling regulates the generation of ameloblast progenitors in the continuously growing mouse incisor

PubMed Central

Seidel, Kerstin; Ahn, Christina P.; Lyons, David; Nee, Alexander; Ting, Kevin; Brownell, Isaac; Cao, Tim; Carano, Richard A. D.; Curran, Tom; Schober, Markus; Fuchs, Elaine; Joyner, Alexandra; Martin, Gail R.; de Sauvage, Frederic J.; Klein, Ophir D.

2010-01-01

In many organ systems such as the skin, gastrointestinal tract and hematopoietic system, homeostasis is dependent on the continuous generation of differentiated progeny from stem cells. The rodent incisor, unlike human teeth, grows throughout the life of the animal and provides a prime example of an organ that rapidly deteriorates if newly differentiated cells cease to form from adult stem cells. Hedgehog (Hh) signaling has been proposed to regulate self-renewal, survival, proliferation and/or differentiation of stem cells in several systems, but to date there is little evidence supporting a role for Hh signaling in adult stem cells. We used in vivo genetic lineage tracing to identify Hh-responsive stem cells in the mouse incisor and we show that sonic hedgehog (SHH), which is produced by the differentiating progeny of the stem cells, signals to several regions of the incisor. Using a hedgehog pathway inhibitor (HPI), we demonstrate that Hh signaling is not required for stem cell survival but is essential for the generation of ameloblasts, one of the major differentiated cell types in the tooth, from the stem cells. These results therefore reveal the existence of a positive-feedback loop in which differentiating progeny produce the signal that in turn allows them to be generated from stem cells. PMID:20978073

Prevalence of an unusual hypoplastic defect of the permanent maxillary lateral incisor in great apes.

PubMed

Hannibal, Darcy L

2017-02-01

In this article, I describe a previously unreported maxillary lateral incisor defect (MLID) of the enamel in great apes and evaluate potential general causes (genetic, systemic stress, or localized disturbance), as well as examine differences in prevalence among the represented taxa. This defect occurred only on the labial surface of the maxillary lateral incisor and extended from the cervical-mesial quarter of the crown to the mesial edge of the cementoenamel junction (CEJ). The study sample consisted of 136 great ape specimens, including 41 gorillas, 25 chimpanzees, and 70 orangutans from the Smithsonian's National Museum of Natural History great ape collection. I used logistic regression to assess the prevalence of this defect in the sample and a binomial probability test for bilaterality. This defect of the maxillary lateral incisor is the second most common defect I observed in the study sample (30.1% of individuals affected), and was more likely to occur in individuals with linear enamel hypoplasia (LEH) and pit defects than those without these defects. Among specimens with both maxillary lateral incisors present, the defect was mostly bilateral. Pan and Pongo were significantly more likely to exhibit the defect than Gorilla. Between Pongo species, Pongo pygmaeus was significantly more likely to exhibit the defect than Pongo abelii. Between subspecies of Gorilla, although Gorilla gorilla gorilla exhibited the defect and Gorilla gorilla beringei did not, the difference was not significant. No sex differences were evident in this sample. The prevalence of this defect indicates it is not hereditary. The bilateral trend indicates a systemic cause, although the high inter-tooth specificity suggests a local disturbance and a combination of both is possible. © 2016 Wiley Periodicals, Inc.

Restoring Fossil Creek

ERIC Educational Resources Information Center

Flaccus, Kathleen; Vlieg, Julie; Marks, Jane C.; LeRoy, Carri J.

2004-01-01

Fossil Creek had been dammed for the past 90 years, and plans were underway to restore the stream. The creek runs through Central Arizona and flows from the high plateaus to the desert, cutting through the same formations that form the Grand Canyon. This article discusses the Fossil Creek monitoring project. In this project, students and teachers…

Restoration of Long Standing Traumatized Teeth: A Case Report

PubMed Central

Kadkol, Prasanna Kumar; Reddy, K. Veera Kishore Kumar; Ainapur, Raghavendra

2015-01-01

Children are uniquely susceptible to craniofacial trauma. Injuries to the teeth occur often as a result of falls and sport activities. The pulp often gets infected after dental trauma resulting in to numerous complications. The authors present a case report of successful restoration of traumatized teeth with open apex which were weakened due to long standing infection and internal resorption. Initially antibiotic combination of 3- mix was used to disinfect the root canals. One tooth is treated with conventional endodontic treatment and the other tooth with open apex and perforation is managed by MTA apexification followed by canal reinforcement using glass ionomer cement and fiber reinforced composite post. Core build up is done using light cure composite resin followed by aesthetic crowns. The patient also presented with the peg shaped lateral incisors, which were built to an aesthetic appearance using light cure composite resins. PMID:26436062

Root resorption of permanent incisors during three months of active orthodontic treatment.

PubMed

Batool, Iffat; Abbas, Hasnain; Abbas, Assad; Abbas, Iram

2010-01-01

Root resorption is one of the most common and undesirable sequelea of orthodontic treatment. The aim of this study was to evaluate the amount of root resorption in permanent incisors during 3 month active period of fixed orthodontic appliance therapy using periapical radiographs. Periapical radiographs of a total of 138 permanent teeth (n = 138, mandibular n1 = 52, maxillary n2 = 86) were evaluated for root resorption. All patients were treated with 3M MBT multi-bonded, pre-adjusted appliances with 0.022 inch slots. Initial levelling and alignment was achieved with 0.0175 inch co-axial wires. All four incisors (maxillary and mandibular) were measured for any change in root length. The change in root length between T0 (pre-treatment) and T1 (post-treatment) was measured in millimetres and expressed in terms of percentage of original root length. The mean pre treatment (T0) root length for the maxillary teeth (n1 = 62) was 19.27 +/- 2.86 mm and 20.01 +/- 2.57 mm for the mandibular teeth (n2 = 31). The post-treatment (T1) root length for the maxillary teeth was 18.96 +/- 2.85 mm and 19.49 +/- 2.4 mm for the mandibular teeth showing a mean resorption of 0.31 mm and 0.52 mm for the maxillary and mandibular teeth respectively. Root resorption was strongly correlated with active orthodontic appliance therapy with maxillary and mandibular incisors being most susceptible. It was found that root resorption can be detected even in the early levelling and alignment stages of orthodontic treatment.

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.

Severe incisor resorption by impacted maxillary canines: case report and literature review.

PubMed

Nute, S J

2004-11-01

This paper reviews the literature relating to incisor resorption caused by impacted maxillary canines, and describes the presentation and management of a patient with unusually severe early resorption. This case highlights the need for careful monitoring of maxillary canine eruption for all paediatric patients.

Antiviral therapy during primary simian immunodeficiency virus infection fails to prevent acute loss of CD4+ T cells in gut mucosa but enhances their rapid restoration through central memory T cells.

PubMed

Verhoeven, David; Sankaran, Sumathi; Silvey, Melanie; Dandekar, Satya

2008-04-01

Gut-associated lymphoid tissue (GALT) is an early target of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) and a site for severe CD4+ T-cell depletion. Although antiretroviral therapy (ART) is effective in suppressing HIV replication and restoring CD4+ T cells in peripheral blood, restoration in GALT is delayed. The role of restored CD4+ T-cell help in GALT during ART and its impact on antiviral CD8+ T-cell responses have not been investigated. Using the SIV model, we investigated gut CD4+ T-cell restoration in infected macaques, initiating ART during either the primary stage (1 week postinfection), prior to acute CD4+ cell loss (PSI), or during the chronic stage at 10 weeks postinfection (CSI). ART led to viral suppression in GALT and peripheral blood mononuclear cells of PSI and CSI animals at comparable levels. CSI animals had incomplete CD4+ T-cell restoration in GALT. In PSI animals, ART did not prevent acute CD4+ T-cell loss by 2 weeks postinfection in GALT but supported rapid and complete CD4+ T-cell restoration thereafter. This correlated with an accumulation of central memory CD4+ T cells and better suppression of inflammation. Restoration of CD4+ T cells in GALT correlated with qualitative changes in SIV gag-specific CD8+ T-cell responses, with a dominance of interleukin-2-producing responses in PSI animals, while both CSI macaques and untreated SIV-infected controls were dominated by gamma interferon responses. Thus, central memory CD4+ T-cell levels and qualitative antiviral CD8+ T-cell responses, independent of viral suppression, were the immune correlates of gut mucosal immune restoration during ART.

The relationships between the arrangement of teeth, root resorption, and dental maturity in bovine mandibular incisors

PubMed Central

An, Jin-kyu; Ono, Takashi

2017-01-01

Objective The objective of this study is to investigate the eruption pattern and root resorption of the bovine anterior dentition in relation to growth-related parameters based on dental maturity. Methods A cross-sectional study was conducted on 110 bovine anterior mandibles by using standard radiography, cone-beam computed tomography (CBCT), and actual measurements. We determined the relationships between the stages of dental maturity by using a modification of Demirjian's method and various growth-related parameters, such as the activity of the root-resorbing tissue and mobility of the deciduous teeth. The correlation of growth-related parameters with interdental spacing and distal unusual root resorption (DRR) of the deciduous fourth incisor was assessed. The cause of mesial unusual root resorption (MRR) of the deciduous fourth incisor was determined on the basis of the arrangement of the permanent third incisor. Results An independent t-test and chi-square test indicated significant differences in growth-related parameters associated with dental arch length discrepancy and factors related to the shedding of deciduous teeth between the low and high dental maturity groups. The samples with interdental spacing and DRR showed a larger sum of mesiodistal permanent crown widths and higher dental maturity than did the respective controls. Samples with MRR tended to show a lingually rotated distal tip of the adjacent tooth crown. Conclusions Dental maturity has relevance to the interdental spaces and unusual root resorption of mixed dentition. The position of the adjacent tooth crown on CBCT may be correlated with the occurrence of unusual root resorption of the incisor. PMID:29090124

[Relationships between vegetation characteristics and soil properties at different restoration stages on slope land with purple soils in Hengyang of Hunan Province, South-central China].

PubMed

Yang, Ning; Zou, Dong-Sheng; Yang, Man-Yuan; Hu, Li-Zhen; Zou, Fang-Ping; Song, Guang-Tao; Lin, Zhong-Gui

2013-01-01

By using space series to replace time series, this paper studied the relationships between the vegetation characteristics and soil properties at different restoration stages on the slope land with purple soils in Hengyang of Hunnan Province South-central China. There existed obvious differences in the soil physical and chemical properties at different restoration stages. From grassplot, grass-shrub, shrub to shrub-arbor, the soil organic matter, total and available N, and moisture contents increased markedly, soil bulk density had an obvious decrease, soil total and available P contents changed little, and soil pH decreased gradually, but no significant differences were observed among different restoration stages. At different restoration stages, the biomass of plant community had effects on the quantity and composition of soil microbes. The quantities of soil bacteria and fungi had significant positive correlations with the aboveground biomass of plant community, but the quantity of soil actinomycetes had less correlation with plant community's aboveground biomass. At different restoration stages, the activities of soil urease, protease, alkaline phosphatase, invertase, cellulase, catalase, and polyphenol oxidase decreased with increasing soil layer, and had significant positive correlations with plant community's richness and aboveground biomass.

Functional anatomy of incisal biting in Aplodontia rufa and sciuromorph rodents - part 2: sciuromorphy is efficacious for production of force at the incisors.

PubMed

Druzinsky, Robert E

2010-01-01

The protrogomorph condition of the rodent masticatory apparatus is thought to be present in only one living species, the mountain beaver Aplodontia rufa. The major anatomical difference between protrogomorphs and sciuromorphs is that the relative size of one part of the masseter muscle, the anterior lateral masseter, is much greater in sciuromorphs than in protrogomorphs. The mechanics of force production at the incisors were compared in A. rufa and six sciuromorph rodents. Is the sciuroid masticatory apparatus more effective for production of forces at the incisors during biting than the primitive, protrogomorph condition? To answer this question, three measures of mechanical ability were employed and three hypotheses were tested: (1) the mechanical advantage of the adductor musculature is greater in sciuromorphs than in A. rufa; (2) the relative force produced at the incisors is greater in sciuromorphs than in A. rufa, and (3) the relative amount of force produced that can be used to drive the incisors into an object, is greater in sciuromorphs than in A. rufa. The results demonstrated that the protrogomorph, A. rufa, is not as efficient at generating bite forces at the incisors as the sciuromorphs. Copyright 2010 S. Karger AG, Basel.

Long-term observation of endodontic surgical intervention to treat root perforation and apical periodontitis: a case report of an amalgam-restored tooth.

PubMed

Tsurumachi, Tamotsu; Hayashi, Makoto

2003-10-01

A case of crestal root perforation and periapical lesion in a maxillary left lateral incisor is reported. Teeth with root perforation present technical difficulties in their clinical management because of their complex defects. In the present case, surgical endodontic treatment was chosen. The apical and lateral pathology was curetted, the tooth root was resected, and a retrograde root restoration of amalgam was placed in a root-end cavity and perforation site. A 10-year follow-up clinical and radiographic examination showed an asymptomatic tooth with osseous healing proceeding.

Root resorption of maxillary incisors retracted with and without skeletal anchorage.

PubMed

Barros, Sérgio Estelita; Janson, Guilherme; Chiqueto, Kelly; Baldo, Vitor Oliveira; Baldo, Taiana Oliveira

2017-02-01

Our objective was to compare root resorption degree of the maxillary central incisors retracted with and without skeletal anchorage. This nonrandomized historical control study included 37 patients requiring maximum anterior retraction and treated with extraction of 2 maxillary premolars. Group 1 consisted of 22 patients (11 male, 11 female) in whom anterior retraction was performed without skeletal anchorage, and group 2 included 15 patients (3 male, 12 female) treated with skeletally anchored anterior retraction. Periapical radiographs were used to evaluate root resorption degree by a scoring system. The groups were compared regarding the resorption score and resorption degree distribution with the Mann-Whitney U test, chi-square test, and Z test on proportions. There was no statistically significant intergroup difference regarding root resorption, but the number of patients with severe and extreme root resorption degrees was significantly greater in group 2. Although the root resorption degree of the skeletal anchorage group was not significantly different from the group without skeletal anchorage, the number of patients with severe to extreme resorption in the first group was significantly greater. Therefore, careful clinical monitoring of skeletally anchored anterior retraction is needed, especially when there are known root resorption predisposing factors. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Restoration of Endodontically Treated Molars Using All Ceramic Endocrowns

PubMed Central

Carlos, Roopak Bose; Thomas Nainan, Mohan; Pradhan, Shamina; Roshni Sharma; Benjamin, Shiny; Rose, Rajani

2013-01-01

Clinical success of endodontically treated posterior teeth is determined by the postendodontic restoration. Several options have been proposed to restore endodontically treated teeth. Endocrowns represent a conservative and esthetic restorative alternative to full coverage crowns. The preparation consists of a circular equigingival butt-joint margin and central retention cavity into the entire pulp chamber constructing both the crown and the core as a single unit. The case reports discussed here are moderately damaged endodontically treated molars restored using all ceramic endocrowns fabricated using two different systems, namely, CAD/CAM and pressed ceramic. PMID:24455318

Effect of Er,Cr:YSGG laser irradiation on eruption of rat mandibular incisor after disturbance of the enamel organ in the pulp.

PubMed

Masuda, Yoshiko Murakami; Hossain, Mozammal; Wang, Xiaogu; Matsuoka, Emi; Okano, Tomohiro; Matsumoto, Koukichi

2006-09-01

To investigate the efficacy of Er,Cr:YSGG (erbium,chromium:yttrium scandium gallium garnet) laser irradiation in root canal preparation and to evaluate its effect on eruption of rat incisors after disturbance of the enamel organ in the pulp, 20 canals of lower left incisor teeth were prepared by K-files followed by Er,Cr:YSGG laser irradiation, and 20 canals of right incisors were subjected to K-files only (control). At 1 week after irradiation, both sides of incisors erupted at the same level from the gingival margin. Histological findings showed that laser irradiation produced a slightly larger damage in the pulp than that of control. Scanning electron microscope observation revealed that laser-treated surface revealed a rough, irregular, and very clean surface; there was almost no evidence of debris or smear layer, and dentinal tubules were opened. Adequate power of Er,Cr:YSGG laser irradiation is effective in root canal preparation without disturbance of the eruption.

Central and peripheral effects of chronic food restriction and weight restoration in the rat.

PubMed

Kinzig, Kimberly P; Hargrave, Sara L; Tao, Erin E

2009-02-01

Previous studies have demonstrated that some endocrine consequences of long-term caloric restriction persist after weight restoration in human subjects. Here we evaluate effects of chronic food restriction in rats that were restricted to 70% of control kcal for 4 wk and subsequently weight restored. Measures were taken from rats at 80% (chronically restricted; CR), 90% (partially weight restored; PR), 100% (fully weight restored; FR), and after 4 wk at 100% body weight of controls (extended weight restored; ER). Plasma insulin and leptin were decreased, and ghrelin was increased in CR compared with controls. Leptin and ghrelin normalized with weight restoration at PR, FR, and ER; however, baseline insulin was not normalized until the ER state. Hypothalamic mRNA expression levels for proopiomelanocortin (POMC), agouti-related protein (AgRP), and neuropeptide Y (NPY) revealed significantly less POMC mRNA expression in CR and PR rats, and significantly less arcuate NPY mRNA in PR and FR. In the dorsomedial hypothalamus, CR, PR, and FR rats had significantly increased NPY expression that was not normalized until the ER state. In response to a test meal, insulin and ghrelin release patterns were altered through the FR stage, and ghrelin remained affected at ER. Collectively, these data demonstrate that mere weight restoration is not sufficient to normalize hypothalamic gene expression levels and endocrine responses to a meal, and that meal-related ghrelin responses persist despite weight restoration for up to 4 wk.

Human permanent teeth are divided into two parts at the cemento-enamel junction in the divine golden ratio.

PubMed

Anand, Rahul; Sarode, Sachin C; Sarode, Gargi S; Patil, Shankargouda

2017-01-01

The aim of this study is to find out whether tooth length (crown length + root length) follows the rule of most divine and mysterious phi (ϕ) or the golden ratio. A total of 140 teeth were included in the study. The crown-root ratio was manually calculated using vernier caliper and its approximation to golden ratio or the divine number phi (ϕ) was examined. The average root-crown ratio (R/C) for maxillary central incisor was 1.627 ± 0.04, and of its antagonist, mandibular central incisor was 1.628 ± 0.02. The tooth-root ratio (T/R) for the same was 1.609 ± 0.016 and 1.61 ± 0.008, respectively. Similar values were appreciated for lateral incisors where the R/C ratio in the maxillary and mandibular teeth was 1.632 ± 0.015 and 1.641 ± 0.012 and the T/R ratio was 1.606 ± 0.005 and 1.605 ± 0.005, respectively. On measuring the tooth length in linear fashion from the cusp tip to the root apex, we found that the tooth was divided into two parts at the cemento-enamel junction in the golden ratio. This information can be exploited in restorative and implant dentistry in future.

Responses to riparian restoration in the Spring Creek watershed, Central Pennsylvania

USGS Publications Warehouse

Carline, R.F.; Walsh, M.C.

2007-01-01

Riparian treatments, consisting of 3- to 4-m buffer strips, stream bank stabilization, and rock-lined stream crossings, were installed in two streams with livestock grazing to reduce sediment loading and stream bank erosion. Cedar Run and Slab Cabin Run, the treatment streams, and Spring Creek, an adjacent reference stream without riparian grazing, were monitored prior to (1991-1992) and 3-5 years after (2001-2003) riparian buffer installation to assess channel morphology, stream substrate composition, suspended sediments, and macroinvertebrate communities. Few changes were found in channel widths and depths, but channel-structuring flow events were rare in the drought period after restoration. Stream bank vegetation increased from 50% or less to 100% in nearly all formerly grazed riparian buffers. The proportion of fine sediments in stream substrates decreased in Cedar Run but not in Slab Cabin Run. After riparian treatments, suspended sediments during base flow and storm flow decreased 47-87% in both streams. Macroinvertebrate diversity did not improve after restoration in either treated stream. Relative to Spring Creek, macroinvertebrate densities increased in both treated streams by the end of the posttreatment sampling period. Despite drought conditions that may have altered physical and biological effects of riparian treatments, goals of the riparian restoration to minimize erosion and sedimentation were met. A relatively narrow grass buffer along 2.4 km of each stream was effective in improving water quality, stream substrates, and some biological metrics. ?? 2007 Society for Ecological Restoration International.

Lower incisor dentoalveolar compensation and symphysis dimensions among Class I and III malocclusion patients with different facial vertical skeletal patterns.

PubMed

Molina-Berlanga, Núria; Llopis-Perez, Jaume; Flores-Mir, Carlos; Puigdollers, Andreu

2013-11-01

To compare lower incisor dentoalveolar compensation and mandible symphysis morphology among Class I and Class III malocclusion patients with different facial vertical skeletal patterns. Lower incisor extrusion and inclination, as well as buccal (LA) and lingual (LP) cortex depth, and mandibular symphysis height (LH) were measured in 107 lateral cephalometric x-rays of adult patients without prior orthodontic treatment. In addition, malocclusion type (Class I or III) and facial vertical skeletal pattern were considered. Through a principal component analysis (PCA) related variables were reduced. Simple regression equation and multivariate analyses of variance were also used. Incisor mandibular plane angle (P < .001) and extrusion (P  =  .03) values showed significant differences between the sagittal malocclusion groups. Variations in the mandibular plane have a negative correlation with LA (Class I P  =  .03 and Class III P  =  .01) and a positive correlation with LH (Class I P  =  .01 and Class III P  =  .02) in both groups. Within the Class III group, there was a negative correlation between the mandibular plane and LP (P  =  .02). PCA showed that the tendency toward a long face causes the symphysis to elongate and narrow. In Class III, alveolar narrowing is also found in normal faces. Vertical facial pattern is a significant factor in mandibular symphysis alveolar morphology and lower incisor positioning, both for Class I and Class III patients. Short-faced Class III patients have a widened alveolar bone. However, for long-faced and normal-faced Class III, natural compensation elongates the symphysis and influences lower incisor position.

Development of the oxytalan fiber system in the periodontal space of rat incisors.

PubMed

Inoue, Kouji; Hara, Yaiko; Kuroda, Noriyuki; Sato, Tetsuji

2013-10-01

The present study clarifies developmental organization of the oxytalan fiber system in the periodontal space of both the enamel (labial) and cementum (lingual) sides of rat incisors. The number of oxytalan fibers per unit area (μm(2)) was counted in rat incisors at stages of embryonic day 20 (E20) to postnatal day 35 (P35). Oxytalan fibers in the periodontal space of the enamel side were apt to decrease in number during the postnatal period, whereas their number remained almost unchanged on the cementum side during the developmental period. When the incisor emerged through the gum at P11, thinner oxytalan fibers distributed in the apical growing periodontium of the cementum side seemed to be fused with one another to become thicker fibers as has been reported for rat molars (Inoue et al., 2012). Thus, the oxytalan fiber system in the periodontal space represented significant differences in its distributional density between the enamel and cementum sides after E23. At the stage of P35, oxytalan fibers presented significantly denser distribution in all territories of the periodontal ligament of the cementum side versus the enamel side. The present findings claim that the oxytalan fiber system might bind the tooth to the periodontal ligament and provide equilibrium of vascular system and control of blood flow in the periodontal ligament of the cementum side, while it might exclusively regulate the high level of physiologically adapted vasculature in the periodontal space of the enamel side. Copyright © 2013 Elsevier GmbH. All rights reserved.

Effect of aluminum chloride hemostatic agent on microleakage of class V composite resin restorations bonded with all-in-one adhesive

PubMed Central

Mohammadi, Narmin; Bahari, Mahmood; Pournaghi-Azar, Fatemeh; Mozafari, Aysan

2012-01-01

Objectives: Since hemostatic agents can induce changes on enamel and dentin surfaces and influence composite resin adhesion, the aim of the present study was to evaluate the effect of the aluminum chloride hemostatic agent on the gingival margin microleakage of class V (Cl V) composite resin restorations bonded with all-in-one adhesive. Study design: Cl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors. Gingival margins of the cavities were placed 1.5 mm apical to the cemento-enamel junction (CEJ). The teeth were randomly divided into two groups of 30. In group 1, the cavities were restored without the application of a hemostatic agent; in group 2, the cavities were restored after the application of the hemostatic agent. In both groups all-in-one adhesive and Z250 composite resin were used to restore the cavities with the incremental technique. After finishing and polishing, the samples underwent a thermocycling procedure, followed by immersion in 2% basic fuschin solution for 24 hours. The samples were sectioned and gingival microleakage was evaluated under a stereomicroscope. The non-parametric Mann-Whitney U test was used to compare microleakage between the two groups. Statistical significance was defined at P<0.05. Results: A statistically significant difference was observed in microleakage between the two groups (P<0.001). Conclusions: Contamination of Cl V composite resin restorations bonded with all-in-one adhesive with aluminum chloride hemostatic agent significantly increases restoration gingival margin microleakage. Key words:All-in-one adhesive resin, composite resin restoration, hemostatic agent, microleakage. PMID:22322497

A rare occurrence of supplementary maxillary lateral incisors and a detailed review on supernumerary teeth

PubMed Central

Chalakkal, Paul; Krishnan, Ramesh; De Souza, Neil; Da Costa, Godwin Clovis

2018-01-01

This article highlights a rare occurrence of nonsyndromic supplemental maxillary lateral incisors in a 11-year-old boy. It also includes a detailed literature review of supernumerary teeth. PMID:29731581

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.

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.

A new methodology for fluorescence analysis of composite resins used in anterior direct restorations.

PubMed

de Lima, Liliane Motta; Abreu, Jessica Dantas; Cohen-Carneiro, Flavia; Regalado, Diego Ferreira; Pontes, Danielson Guedes

2015-01-01

The aim of this study was to use a new methodology to evaluate the fluorescence of composite resins for direct restorations. Microhybrid (group 1, Amelogen; group 2, Opallis; group 3, Filtek Z250) and nanohybrid (group 4, Filtek Z350 XT; group 5, Brilliant NG; group 6, Evolu-X) composite resins were analyzed in this study. A prefabricated matrix was used to prepare 60 specimens of 7.0 × 3.0 mm (n = 10 per group); the composite resin discs were prepared in 2 increments (1.5 mm each) and photocured for 20 seconds. To establish a control group of natural teeth, 10 maxillary central incisor crowns were horizontally sectioned to create 10 discs of dentin and enamel tissues with the same dimensions as the composite resin specimens. The specimens were placed in a box with ultraviolet light, and photographs were taken. Aperture 3.0 software was used to quantify the central portion of the image of each specimen in shades of red (R), green (G), and blue (B) of the RGB color space. The brighter the B shade in the evaluated area of the image, the greater the fluorescence shown by the specimen. One-way analysis of variance revealed significant differences between the groups. The fluorescence achieved in group 1 was statistically similar to that of the control group and significantly different from those of the other groups (Bonferroni test). Groups 3 and 4 had the lowest fluorescence values, which were significantly different from those of the other groups. According to the results of this study, neither the size nor the amount of inorganic particles in the evaluated composite resin materials predicts if the material will exhibit good fluorescence.

Control of lower incisor inclination with a completely customized lingual appliance for dentoalveolar compensation of class III malocclusion.

PubMed

Lossdörfer, Stefan; Schwestka-Polly, Rainer; Wiechmann, Dirk

2013-09-01

Bracket slots and orthodontic archwires offering high dimensional precision are needed for fully customized lingual appliances. We aimed to investigate whether high-precision appliances of this type enable dentoalveolar compensation of class III malocclusion so that lower incisor inclination at the end of treatment will closely match the anticipated situation as defined in a pretreatment setup. This retrospective study included a total of 34 consecutive patients who had worn a fully customized lingual appliance to achieve dentoalveolar compensation for class III malocclusion by intermaxillary elastics, or proximal enamel reduction, or extraction of teeth in one or both jaws. Casts fabricated at different points in time were three-dimensionally scanned to analyze how precisely the lower incisor inclinations envisioned in the setup were implemented in clinical practice. Aside from minor deviations of ±3.75°, the lower incisor inclinations were clinically implemented as planned even in patients with major sagittal discrepancies. Treatment goals predefined in a setup of dentoalveolar compensation for class III malocclusion can be very precisely achieved via a customized lingual appliance. Correct planning can prevent undesirable lingual tipping of the lower incisors. This finding should not encourage a more liberal use of dentoalveolar compensation, but it should heighten clinicians' awareness of how essential it is to sufficiently consider the individual anatomy of the dentoalveolar complex during treatment planning.

The prevalence of Molar Incisor Hypomineralisation (MIH) in a group of Italian school children.

PubMed

Calderara, P C; Gerthoux, P M; Mocarelli, P; Lukinmaa, P L; Tramacere, P L; Alaluusua, S

2005-06-01

This epidemiological study in a group of Italian children was undertaken in order to increase our knowledge of the prevalence of Molar Incisor Hypomineralisation (MIH) in different European countries. A population of school children aged 7.3 - 8.3 years, living in Lissone, Northern Italy, was examined for the presence and severity of MIH. Of a total of 227 children (113 females), 31 (13.7%) had MIH, the tooth prevalence in the permanent first molars being 5.8%. Fifteen children (6.6%) had demarcated opacities in the incisors with a tooth prevalence of 2.1%. The defects in the molars were mild with the exception of one child who had severe defects. MIH was quite common in this Italian town, and the prevalence figures were near those reported in Scandinavian countries but clearly higher than those from Dresden, Germany.

Identifying Societal Preferences for River Restoration in a Densely Populated Urban Environment: Evidence from a Discrete Choice Experiment in Central Brussels

NASA Astrophysics Data System (ADS)

Chen, Wendy Y.; Liekens, Inge; Broekx, Steven

2017-08-01

One of the major challenges facing river restoration in densely populated urban areas has been the disparity between the expectations of policy-makers and societal preferences. This study aimed to elicit public preferences and elucidate underlying sources of preference heterogeneity, using the Zenne River in central Brussels, Belgium, as a case study. A discrete choice experiment was administered to a representative sample of the Brussels population. Five attributes were specified, including water quality, ecological status, hydromorphological features of channels, recreational opportunities, and monetary cost. Our econometric analysis based on mixed logit models revealed that overall public would like to have a more natural river (open and naturalized channel, good water quality, and with rich species diversity), while achieving good water quality was the most preferred attribute. Respondents categorized as male, non-Belgian citizen, or not being a member of an environmental organization constituted an inclination to prefer the status quo. Belgian citizens showed a pronounced preference for good biodiversity, and being a member of an environmental organization could moderate the strong preference for good water quality. This study provided insights into the relative attractiveness of key attributes pertaining to river restoration, in general, and served as a useful input to the ongoing discussion concerning the future plan for the Zenne River in Brussels, specifically. Possible implications also exist for other urban river restorations in the rest of Europe, where the Water Framework Directive has become a major impetus for the expansion of freshwater ecosystem restoration from rural and peri-urban areas to densely populated urban areas. Particularly, the cultural heterogeneity of societal preferences should be tested and accounted for to compare the welfare impacts of river restoration and to facilitate benefit transfer, within and between river basins, in the

Identifying Societal Preferences for River Restoration in a Densely Populated Urban Environment: Evidence from a Discrete Choice Experiment in Central Brussels.

PubMed

Chen, Wendy Y; Liekens, Inge; Broekx, Steven

2017-08-01

One of the major challenges facing river restoration in densely populated urban areas has been the disparity between the expectations of policy-makers and societal preferences. This study aimed to elicit public preferences and elucidate underlying sources of preference heterogeneity, using the Zenne River in central Brussels, Belgium, as a case study. A discrete choice experiment was administered to a representative sample of the Brussels population. Five attributes were specified, including water quality, ecological status, hydromorphological features of channels, recreational opportunities, and monetary cost. Our econometric analysis based on mixed logit models revealed that overall public would like to have a more natural river (open and naturalized channel, good water quality, and with rich species diversity), while achieving good water quality was the most preferred attribute. Respondents categorized as male, non-Belgian citizen, or not being a member of an environmental organization constituted an inclination to prefer the status quo. Belgian citizens showed a pronounced preference for good biodiversity, and being a member of an environmental organization could moderate the strong preference for good water quality. This study provided insights into the relative attractiveness of key attributes pertaining to river restoration, in general, and served as a useful input to the ongoing discussion concerning the future plan for the Zenne River in Brussels, specifically. Possible implications also exist for other urban river restorations in the rest of Europe, where the Water Framework Directive has become a major impetus for the expansion of freshwater ecosystem restoration from rural and peri-urban areas to densely populated urban areas. Particularly, the cultural heterogeneity of societal preferences should be tested and accounted for to compare the welfare impacts of river restoration and to facilitate benefit transfer, within and between river basins, in the

Comparison of the effect of labiolingual inclination and anteroposterior position of maxillary incisors on esthetic profile in three different facial patterns

PubMed Central

Chirivella, Praveen; Singaraju, Gowri Sankar; Mandava, Prasad; Reddy, V Karunakar; Neravati, Jeevan Kumar; George, Suja Ani

2017-01-01

Objective: To test the null hypothesis that there is no effect of esthetic perception of smiling profile in three different facial types by a change in the maxillary incisor inclination and position. Materials and Methods: A smiling profile photograph with Class I skeletal and dental pattern, normal profile were taken in each of the three facial types dolichofacial, mesofacial, and brachyfacial. Based on the original digital image, 15 smiling profiles in each of the facial types were created using the FACAD software by altering the labiolingual inclination and anteroposterior position of the maxillary incisors. These photographs were rated on a visual analog scale by three panels of examiners consisting of orthodontists, dentists, and nonprofessionals with twenty members in each group. The responses were assessed by analysis of variance (ANOVA) test followed by post hoc Scheffe. Results: Significant differences (P < 0.001) were detected when ratings of each photograph in each of the individual facial type was compared. In dolichofacial and mesofacial pattern, the position of the maxillary incisor must be limited to 2 mm from the goal anterior limit line. In brachyfacial pattern, any movement of facial axis point of maxillary incisors away from GALL is worsens the facial esthetics. The result of the ANOVA showed differences among the three groups for certain facial profiles. Conclusion: The hypothesis was rejected. The esthetic perception of labiolingual inclination and anteroposterior of maxillary incisors differ in different facial types, and this may effect in formulating treatment plans for different facial types. PMID:28197396

Prescribed burning for oak savanna restoration in central Minnesota.

Treesearch

Alan S. White

1986-01-01

Low intensity, spring prescribed burns have been used since 1964 at the Cedar Creek Natural History Area in Minnesota in an attempt to restore the area to an oak savanna. Burned areas are now more savanna like (having greater grass and forb and lower shrub and lower tree representation) than unburned areas but still have higher overstory densities than apparently...

TROPICS 1: a phase III, randomized, double-blind, placebo-controlled study of tenecteplase for restoration of function in dysfunctional central venous catheters.

PubMed

Gabrail, Nashat; Sandler, Eric; Charu, Veena; Anas, Nick; Lim, Eduardo; Blaney, Martha; Ashby, Mark; Gillespie, Barbara S; Begelman, Susan M

2010-12-01

To evaluate the efficacy and safety of the thrombolytic tenecteplase, a fibrin-specific recombinant tissue plasminogen activator, for restoring function to dysfunctional central venous catheters (CVCs). In this double-blind, placebo-controlled study, eligible patients with dysfunctional nonhemodialysis CVCs were randomly assigned to two treatment arms. In the first arm (TNK-TNK-PBO), patients received an initial dose of intraluminal tenecteplase (TNK) (up to 2 mg), a second dose of tenecteplase if indicated, and a third placebo (PBO) dose. In the PBO-TNK-TNK arm, placebo was instilled first followed by up to two doses of tenecteplase, if needed, for restoration of catheter function. After administration of each dose, CVC function was assessed at 15, 30, and 120 minutes. There were 97 patients who received either TNK-TNK-PBO (n = 50) or PBO-TNK-TNK (n = 47). Within 120 minutes of initial study drug instillation, catheter function was restored to 30 patients (60%) in the TNK-TNK-PBO arm and 11 patients (23%) in the PBO-TNK-TNK arm, for a treatment difference of 37 percentage points (95% confidence interval 18-55; P = .0002). Cumulative restoration rates for CVC function increased to 87% after the second dose of tenecteplase in both study arms combined. Two patients developed a deep vein thrombosis (DVT) after exposure to tenecteplase; one DVT was considered to be drug related. No cases of intracranial hemorrhage, major bleeding, embolic events, catheter-related bloodstream infections, or catheter-related complications were reported. Tenecteplase was efficacious for restoration of catheter function in these study patients with dysfunctional CVCs. Copyright © 2010 SIR. Published by Elsevier Inc. All rights reserved.

Molar-incisor hypomineralization and the association with childhood illnesses and antibiotics in a group of Finnish children.

PubMed

Wuollet, Emma; Laisi, Sakari; Salmela, Eija; Ess, Anneli; Alaluusua, Satu

2016-07-01

Molar-incisor hypomineralization (MIH) is a developmental enamel defect affecting 1-4 first permanent molars (FPMs) and often also incisors. The aim of this study was to assess whether childhood illnesses or medication are associated with MIH. FPMs and incisors of 287 Finnish children were examined for MIH in line with the criteria of the EAPD. Health data from the first 3 years of life was collected from medical records and the associations with MIH and MIH2 (lesions in at least one FPM and incisor) were assessed using simple and multiple logistic regression analyses. The prevalence of MIH and MIH2 were 11.5% and 6.3%, respectively. During the first 3 years of life, the children with MIH had sought care for infectious illnesses more often than the children without MIH (mean number of visits (SD) 7.9(6.4) vs. 6.0(5.1), p = 0.045, independent samples t-test). After adjustment for confounding factors, children who had received penicillin or macrolides within the first year, or amoxicillin within the first 3 years had a higher risk for MIH (2.61, 4.07 and 2.58 times, adjusted OR, respectively) or MIH2 (3.16 times, aOR for penicillin and amoxicillin) compared to those who had not received that antibiotic. Of the illnesses, children with at least one episode of otitis within the first year had a higher risk for MIH (2.28 times, aOR) than those who had not suffered from otitis. Acute otitis media and the use of certain antibiotics were associated with the elevated risk of MIH/MIH2.

Prevalence of traumatic dental injuries to permanent incisors among 12-year-old school children in Davangere, South India.

PubMed

Ravishankar, Telgi Lingesh; Kumar, Mohapatra Ashok; Ramesh, Nagrajappa; Chaitra, Telgi Ravishankar

2010-01-01

To assess the prevalence and factors associated with traumatic injuries to permanent incisors of 12-year-old school children in Davangere, India. In total, 1020 12-year-old school children were selected. Two trained and calibrated clinicians examined the children in the school environment using the World Health Organization Classification of Tooth Fracture (1978). Examination was also done for lip coverage and maxillary overjet using the Community Periodontal Index probe. Children were then interviewed using a structured questionnaire for demographic data and history of the injury. The overall prevalence rate of traumatic dental injuries (TDI) to permanent incisor teeth was 15.1%. The prevalence of TDI was higher in boys compared to girls. The major cause of TDI was falling followed by collision. The maxillary incisors were commonly injured, involving mainly enamel fracture. Children with excessive overjet and inadequate lip coverage were more likely to have injuries. TDI could be a serious dental public health problem among children. Thus, there is an urgent need to collect local data on dental injuries in order to obtain a more comprehensive picture of dental health.

Perception of molar-incisor hypomineralisation (MIH) by Iraqi dental academics.

PubMed

Ghanim, Aghareed; Morgan, Michael; Mariño, Rodrigo; Manton, David; Bailey, Denise

2011-07-01

The understanding and detection of molar-incisor hypomineralisation (MIH) is linked to its recognition by clinicians. No study has investigated dental clinicians' level of perception regarding MIH in the Middle East region including Iraq. To determine the perception of Iraqi academic clinicians about MIH prevalence, severity and aetiological factors. A questionnaire, based on previous European and Australian/New Zealand studies was administered to the academic dental staff of Mosul University. A response rate of 77.7% was reported. General dental practitioners represented 30.8% of the total respondents, whilst 65.1% were dentists with post-graduate qualification. The majority of the respondents (81.2%) encountered MIH in their clinical activities and 37.3% of them identified that the prevalence appeared to have increased in recent years. Fewer than half of the respondents observed MIH affected teeth on a monthly basis. The condition was less commonly seen in primary second molars than the first permanent molars. A variation in views was recorded about MIH specific aetiological factor/s. Respondents advocated the need for clinical training regarding MIH-aetiological and therapeutic fields. Molar-incisor hypomineralisation is a condition commonly diagnosed by Iraqi dental academics. No apparent consensus existed between the general and specialist dentists regarding the anticipated prevalence, severity and aetiology of this condition. © 2011 The Authors. International Journal of Paediatric Dentistry © 2011 BSPD, IAPD and Blackwell Publishing Ltd.

The effect of epidermal growth factor on neonatal incisor differentiation in the mouse.

PubMed

Topham, R T; Chiego, D J; Gattone, V H; Hinton, D A; Klein, R M

1987-12-01

The effect of epidermal growth factor (EGF) on cellular differentiation of the neonatal mouse mandibular incisor was examined autoradiographically using tritiated thymidine ([3H]TDR) and tritiated proline ([3H]PRO). On days 0 (day of birth), 1, and 2, EGF was administered (3 micrograms/g body wt) sc to neonates. Mice were killed on Days 1, 4, 7, 10, and 13 after birth and were injected with either [3H]TDR or [3H]PRO 1 hr before death. [3H]TDR was used to analyze cell proliferation in eight cell types in the developing mouse incisor including upper (lingual) and lower (buccal) pulpal fibroblasts, preodontoblasts, inner and outer enamel epithelial cells (IEE and OEE), stratum intermedium (SI), stellate reticulum (SR), and periodontal ligament (PDL) fibroblasts. [3H]PRO was used to analyze protein synthesis in ameloblasts, and their secretion products (enamel and dentin), as well as PDL fibroblasts. The selected EGF injection scheme elicited acceleration of incisor eruption with minimal growth retardation. At Day 1, the upper and lower pulp, preodontoblasts, SI, and SR showed a significant decrease in labeling index (LI) 24 hr after a single EGF injection. After multiple injections (Days 0, 1, 2), two LI patterns were observed. In lower pulp, preodontoblasts, IEE, SI, SR, and OEE, a posteruptive change in LI was observed. In contrast, the upper pulp and PDL regions demonstrated a direct temporal relationship with eruption. Autoradiographic analysis with [3H]PRO indicated that EGF treatment caused significant increases in grain counts per unit area in ameloblast, odontoblast, and PDL regions studied. Significant differences were found in all four regions studied (ameloblasts, enamel, odontoblasts, dentin) at the 45-microns-tall ameloblast level as well as ameloblasts and odontoblasts at the 30-microns level at 13 days of age. The PDL demonstrated significant differences at all locations studied (base, 30 microns, 45 microns,) in 4-, 7-, and 13-day-old mice

Central memory CD4 T cells are associated with incomplete restoration of the CD4 T cell pool after treatment-induced long-term undetectable HIV viraemia.

PubMed

Rallón, Norma; Sempere-Ortells, José M; Soriano, Vincent; Benito, José M

2013-11-01

It is unclear to what extent T cell reconstitution may be possible in HIV-1-infected individuals on continuous successful highly active antiretroviral therapy (HAART). Herein, we analysed distinct phenotypic markers of immune recovery in patients with undetectable viraemia for 8 years, taking as reference untreated patients and healthy controls. Seventy-two subjects were examined: 28 HIV-1+ patients on successful long-term HAART, 24 HIV-1+ untreated viraemic patients and 20 age-matched healthy controls. Analysis of naive and memory CD4 and CD8 T cells was combined with measurements of activation status (expression of CD38) and with thymic function (expression of CD31). Statistical significance was determined by non-parametric tests. After long-term HAART, the majority of parameters were normalized compared with age-matched control values, including T cell activation and thymic function. However, absolute counts of naive and central memory CD4 T cells remained below normal levels. The only parameters significantly associated with CD4 counts at the end of follow-up were the pre-HAART CD4 count ( β ± SD = 0.54 ± 0.16, P = 0.003) and the level of CD4 central memory cells at the end of follow-up (β ± SD = 1.18 ± 0.23, P < 0.0001). Only patients starting HAART with CD4 counts >350 cells/mm(3) reached a complete normalization of CD4 counts. Even after long-term successful HAART, complete CD4 restoration may be attainable only in patients starting therapy with moderately high CD4 counts, prompting early initiation of antiretroviral therapy. Incomplete CD4 restoration may be associated with a defective restoration of central memory CD4 T cells, a cell subset with a pivotal role in T cell homeostasis.

Molar-incisor hypomineralization (MIH) in a group of school-aged children in Benghazi, Libya.

PubMed

Fteita, D; Ali, A; Alaluusua, S

2006-06-01

Molar-incisor hypomineralization (MIH) is common in many countries and it has significant impact on treatment need. The aim of the present study was to assess developmental enamel defects with an emphasis to MIH in children from four primary schools in Benghazi, Libya. Permanent first molars of a total of 378 (188 females) 7.0-8.9-year-old children were examined for demarcated opacities, diffuse opacities and hypoplasia in their schools using a portable light, a mirror, and a probe. A subgroup of children attending two of the four schools and having all incisors and first molars erupted (N = 154) was examined for enamel defects in these teeth. Eleven children (2.9%) had MIH. The mean value of demarcated opacities in their first molars was 1.5. MIH lesions were found only in 1.1% of the children's first molars (tooth prevalence) and all lesions were mild. Six children (1.6%) had diffuse opacities and 3 (0.8%) had hypoplastic defects in their first molars. Fourteen out of 154 children (9%) who had both incisors and molars examined had some kind of developmental enamel defect: 11 children (7.1%) had demarcated opacities, 3 (1.9%) had diffuse opacities, and none had hypoplasia. MIH was rare in Benghazi, Libya. The prevalence was clearly lower than in comparable studies performed in Italy or in Nordic countries, where, according to the earlier reports, MIH is seen in every fifth or sixth child. Our result may be valuable when so far mostly unknown etiology behind MIH is investigated.

Alveolar bone thickness and lower incisor position in skeletal Class I and Class II malocclusions assessed with cone-beam computed tomography

PubMed Central

Ucar, Faruk Izzet; Buyuk, Suleyman Kutalmis; Ozer, Torun; Uysal, Tancan

2013-01-01

Objective To evaluate lower incisor position and bony support between patients with Class II average- and high-angle malocclusions and compare with the patients presenting Class I malocclusions. Methods CBCT records of 79 patients were divided into 2 groups according to sagittal jaw relationships: Class I and II. Each group was further divided into average- and high-angle subgroups. Six angular and 6 linear measurements were performed. Independent samples t-test, Kruskal-Wallis, and Dunn post-hoc tests were performed for statistical comparisons. Results Labial alveolar bone thickness was significantly higher in Class I group compared to Class II group (p = 0.003). Lingual alveolar bone angle (p = 0.004), lower incisor protrusion (p = 0.007) and proclination (p = 0.046) were greatest in Class II average-angle patients. Spongious bone was thinner (p = 0.016) and root apex was closer to the labial cortex in high-angle subgroups when compared to the Class II average-angle subgroup (p = 0.004). Conclusions Mandibular anterior bony support and lower incisor position were different between average- and high-angle Class II patients. Clinicians should be aware that the range of lower incisor movement in high-angle Class II patients is limited compared to average- angle Class II patients. PMID:23814708

Alveolar bone thickness and lower incisor position in skeletal Class I and Class II malocclusions assessed with cone-beam computed tomography.

PubMed

Baysal, Asli; Ucar, Faruk Izzet; Buyuk, Suleyman Kutalmis; Ozer, Torun; Uysal, Tancan

2013-06-01

To evaluate lower incisor position and bony support between patients with Class II average- and high-angle malocclusions and compare with the patients presenting Class I malocclusions. CBCT records of 79 patients were divided into 2 groups according to sagittal jaw relationships: Class I and II. Each group was further divided into average- and high-angle subgroups. Six angular and 6 linear measurements were performed. Independent samples t-test, Kruskal-Wallis, and Dunn post-hoc tests were performed for statistical comparisons. Labial alveolar bone thickness was significantly higher in Class I group compared to Class II group (p = 0.003). Lingual alveolar bone angle (p = 0.004), lower incisor protrusion (p = 0.007) and proclination (p = 0.046) were greatest in Class II average-angle patients. Spongious bone was thinner (p = 0.016) and root apex was closer to the labial cortex in high-angle subgroups when compared to the Class II average-angle subgroup (p = 0.004). Mandibular anterior bony support and lower incisor position were different between average- and high-angle Class II patients. Clinicians should be aware that the range of lower incisor movement in high-angle Class II patients is limited compared to average- angle Class II patients.

Gemination or fusion? - challenge for dental practitioners (case study).

PubMed

Chipashvili, N; Vadachkoria, D; Beshkenadze, E

2011-05-01

Gemination and fusion are anomalies in size, shape and structure of teeth. Gemination more frequently affects the primary teeth, but it may occur in permanent dentitions, usually in the incisor region. Geminated teeth are typically disfigured in appearance due to irregularities of the enamel. Fused teeth can have separated pulpal space, one pulp chamber and two canals or take the form of a large bifid crown with one pulpal space. It is hard to differentiate between fusion and gemination, especially if the supernumerary tooth bud is fused with the adjacent one. Usually, fusion may be differentiated from germination by a reduced number of teeth. An exception is in the unusual case in which the fusion is between a supernumerary tooth and normal tooth. A 20-year-old male referred to us at - "UniDent" - Dental Clinic, Training and Research Center. The patient complained about the large, unusual maxillary central incisors, lip irritation and aesthetic problems. According clinical examination and radiological findings, clinical diagnose was - bilateral germination of central incisors. Several treatment methods have been described in the literature with respect to the different types and morphological variations of fused and geminated teeth, including endodontic, direct\\indirect restorative, surgical, periodontal and/or orthodontic treatment. Our patient has demanded for better aesthetics and he choose the treatment option to make two separate PFM crowns. In the beginning of treatment, the length of tooth 11 was 9.5mm, after prosthodontic treatment it has become 11.5mm. For tooth 21, it was 9.9 millimeter and became - 10.8 mm, while the primary width of right central incisor appeared 13.2 millimeter and was narrowed until 10.8 mm. 12.8 mm was the - width of left central incisor, which finally became - 10.4 mm. Despite the considerable number of cases reported in the literature, the differential diagnosis between these abnormalities is very difficult, as well as, to find

Prevalence of lesions in incisors of mule deer from Colorado Springs, Colorado

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

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 (generalizedmore » 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.« less

Delayed orthodontic extrusion of a traumatically intruded immature upper permanent incisor - a case report.

PubMed

Umesan, Uday Kumar; Chua, Kui Lay; Kok, Ei Chuen

2014-10-01

Dental injuries are probably the most common orofacial injuries sustained during sports and play. Intrusion or intrusive luxations occur when the teeth are driven into the alveolus by an axially directed impact. This article describes the clinical case of an 8-year-old patient who suffered complete intrusive luxation of an immature permanent central incisor following an accident. An attempt at spontaneous re-eruption failed to facilitate re-emergence of the tooth beyond 2 mm. The recommended wait-and-see strategy in anticipation of spontaneous re-eruption should cease to be an option when no further elongation can be observed. Orthodontic extrusion or surgical re-positioning is a valid treatment alternative when the former fails. In this case, although the recommended time period for effecting orthodontic extrusion had elapsed, this procedure was undertaken successfully presumably owing to the application of controlled, biologically optimal forces. A review of the extruded tooth a year later revealed no clinical or radiographic signs of loss of vitality. This was confirmed radiographically by the completion of root development, an intact lamina dura and no evident signs of resorption. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of Fluoride and Simplified Adhesive Systems on the Bond Strength of Primary Molars and Incisors.

PubMed

Firoozmand, Leily Macedo; Noleto, Lawanne Ellen Carvalho; Gomes, Isabella Azevedo; Bauer, José Roberto de Oliveira; Ferreira, Meire Coelho

2015-01-01

The aim of this study was evaluate in vitro the influence of simplified adhesive systems (etch-and-rinse and self-etching) and 1.23% acidulated phosphate fluoride (APF) on the microshear bond strength (μ-SBS) of composite resins on primary molars and incisors. Forty primary molars and forty incisors vestibular enamel was treated with either the self-etching Clearfil SE Bond (CSE, Kuraray) or etch-and-rinse Adper Single Bond 2 (SB2, 3M/ESPE) adhesive system. Each group was subdivided based on the prior treatment of the enamel with or without the topical application of 1.23% APF. Thereafter, matrices were positioned and filled with composite resin and light cured. After storage in distilled water at 37 ± 1°C for 24 h, the specimens were submitted to μ-SBS in a universal testing machine. Kruskal-Wallis and Mann-Whitney tests (p < 0.05) showed that the prior application of 1.23% APF led to a significant reduction in bond strength. The type of adhesive exerted no significant influence bond strength. In the inter-group analysis, however, significantly bond strength reduction was found for the incisors when CSE was employed with APF. Adhesive failure was the most common type of fracture. The bond strength was affected by the prior application of 1.23% APF and type of tooth.

[How does sleeping restore our brain?].

PubMed

Wigren, Henna-Kaisa; Stenberg, Tarja

2015-01-01

The central function of sleep is to keep our brain functional, but what is the restoration that sleep provides? Sleep after learning improves learning outcomes. According to the theory of synaptic homeostasis the total strength of synapses, having increased during the day, is restored during sleep, making room for the next day's experiences. According to the theory of active synaptic consolidation, repetition during sleep strengthens the synapses, and these strengthened synapses form a permanent engram. According to a recent study, removal of waste products from the brain may also be one of the functions of sleep.

Effect of tooth brush abrasion and thermo-mechanical loading on direct and indirect veneer restorations.

PubMed

Rosentritt, Martin; Sawaljanow, Alexander; Behr, Michael; Kolbeck, Carola; Preis, Verena

2015-01-01

This study investigated toothbrush abrasion and in vitro aging on ceramic (indirect technique) and composite veneers (direct technique). Identical composite and individual human incisors were restored with industrially preformed composite veneers, indirectly produced ceramic veneers, and direct composite restorations. Surface roughness was determined before and after tooth brushing. A 5-year period of oral service was simulated by thermal cycling and mechanical loading (TCML). After TCML, all specimens were examined with microscopy and scanning electron microscopy. Specimens without failures during TCML were loaded until failure. analysis of variance; Bonferroni's post hoc analysis, Kaplan-Meier-Log Rank test (α = 0.05). Tooth brushing yielded a non-significant increase (p = 0.560) in roughness in all materials (industrial veneer, 0.12+/-0.07 μm, direct restoration, 0.18+/-0.14 μm, ceramic, 0.35+/-0.16 μm). No significant differences in roughness could be determined between the materials, neither before nor after testing (p < 0.001). After TCML of artificial teeth, direct and preformed composite veneers on composite teeth showed no failures or damages. Two ceramic veneers showed cracking in the labial area. After TCML of human teeth, transmission microscopy indicated a facial crack in a ceramic veneer and chipping in the cervical area of a preformed veneer. Two direct composite veneers lost retention. No significantly different survival rates were found between the three veneer groups. Fracture force on human teeth varied between 527.8+/-132.4 N (ceramic), 478.3+/-165.4 N (preformed composite), and 605.0+/-263.5 N (direct composite). All materials revealed comparable wear resistance. Indirect ceramic, direct restorative composite, and preformed composite veneers showed comparable failure rates and satisfying longevity. The results indicate similar longevity of the chosen materials for veneer restorations.

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

Bilateral Complete and Incomplete Fusion of Incisors and its Management.

PubMed

Da Costa, Godwin Clovis; Chalakkal, Paul; De Souza, Neil; Gavhane, Sanket

2017-01-01

This case report highlights the management of a case of bilateral complete and incomplete fusion of maxillary incisors in a 10-year-old child. A mock-up was done on the diagnostic cast. Pretreatment esthetic evaluation was done using bis-acryl composite temporaries which were transferred intraorally from the diagnostic cast using a putty index. An incisal overlap veneer preparation was done, following which, an IPS e-max veneer was cemented. A digital mock-up was carried out using the Adobe Photoshop and Corel Draw softwares to aid in laboratorial fabrication of the veneer.

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

The Effect of Resection Angle on Stress Distribution after Root-End Surgery.

PubMed

Monteiro, Jaiane Bandoli; Dal Piva, Amanda Maria de Oliveira; Tribst, João Paulo Mendes; Borges, Alexandre Luiz Souto; Tango, Rubens Nisie

2018-01-01

This study aimed to investigate the influence of the resection angle on the stress distribution of retrograde endodontic treated maxillary incisors under oblique-load application. A maxillary central incisor which was endodontically treated and restored with a fiber glass post was obtained in a 3-dimensional numerical model and distributed into three groups according to type of resection: control; restored with fiber post without retrograde obturation, R45 and R90 with 45º and 90º resection from tooth axial axis, respectively and restored with Fuji II LC (GC America). The numerical models received a 45 º occlusal load of 200 N/cm 2 on the middle of lingual surface. All materials and structures were considered linear elastic, homogeneous and isotropic. Numerical models were plotted and meshed with isoparametric elements, and the results were analyzed using maximum principal stress (MPS). MPS showed greater stress values in the bone tissue for control group than the other groups. Groups with apicectomy showed acceptable stress distribution on the fiber post, cement layer and root dentin, presenting more improved values than control group. Apicectomy at 90 º promotes more homogeneity on stress distribution on the fiber post, cement layer and root dentin, which suggests less probability of failure. However, due to its facility and stress distribution also being better than control group, apicectomy at 45 ° could be a good choice for clinicians.

[The supportive outcome of periodontal non-surgical therapy to severe chronic periodontitis accompanied with malformed lingual groove in lateral incisor for 6 years: a case report].

PubMed

Li, Zheng; Kang, Jun

2011-06-01

To track the initiating and developing process of one case diagnosed as chronic periodontitis accompanied with malformed lingual groove in maxillary lateral incisor and report the long-term prognosis to the periodontal conservative and supportive therapy. The patient was diagnosed with mild chronic periodontitis 6 years ago and accepted routine periodontal scaling and root planning (SRP) plus supportive periodontal therapy (SPT) one time. Two years later the periodontal condition deteriorated by deep pockets in molars and severe bone destruction around the maxillary lateral incisor with malformed lingual groove. After SRP in sites which pocket depth more than 4mm plus root canal therapy and lingual groove plasty of maxillary right lateral incisor, the SPT regularly proceeded at 3rd, 6th and 12th month. At present the whole periodontal tissue was healthy, the bone lesion around maxillary lateral incisor recovered well, the tooth had no mobile, the cosmetic effect andtooth function was in good state, and the patient was very satisfied.

How can prescribed burning and harvesting restore shortleaf pine-oak woodland at the landscape scale in central United States? Modeling joint effects of harvest and fire regimes

Treesearch

Wenchi Jin; Hong S. He; Stephen R. Shifley; Wen J. Wang; John M. Kabrick; Brian K. Davidson

2018-01-01

Historical fire regimes in the central United States maintained open-canopy shortleaf pine-oak woodlands on xeric sites. Following large-scale harvest and fire suppression, those woodlands grew denser with more continuous canopy cover, and they gained mesic species at the expense of shortleaf pine. There is high interest in restoring shortleaf pine-oak woodlands; most...

Trajectories of ecosystem service change in restored peatlands

NASA Astrophysics Data System (ADS)

Evans, Martin; Shuttleworth, Emma; Pilkington, Mike; Allott, Tim; Walker, Jonathan; Spencer, Tom

2017-04-01

Peatlands provide a wide range of ecosystem services but across the world degradation of these systems through a range of human impacts has had a negative effect on the provision of these services. A wide variety of peatland restoration approaches have been developed with the aim of mitigating these impacts. Understanding of trajectories of change in ecosystem structure and function is central to evaluating the efficacy of these restoration methods. This paper considers data on post-restoration trajectories of water table change, vegetation recovery, runoff production and water quality based on extensive data from peatland restoration work in the southern Pennines of the U.K. Data have been compiled from multiple restoration initiatives undertaken across the region, spanning up to 12 years post restoration. The data show variations in the time scale of ecosystem change which are indicative of the process basis of the ecosystem trajectories. Rapid changes in runoff are controlled by physical changes to the peatland surface. These are contrasted with longer term evolution of vegetation and water table behaviour which suggest ongoing recovery as the ecosystem adjusts to the restoration process. In order to assess restoration of ecosystem function, and so of ecosystem services, it is important that the process links between ecosystem structure and function are well understood. Establishing typical restoration trajectories can be of practical use in determining restoration project milestones, and can also provide insight into the nature of these process links.

New method of assessing the relationship between buccal bone thickness and gingival thickness

PubMed Central

2016-01-01

Purpose The aim of this study was to determine the relationship between buccal bone thickness and gingival thickness by means of a noninvasive and relatively accurate digital registration method. Methods In 20 periodontally healthy subjects, cone-beam computed tomographic images and intraoral scanned files were obtained. Measurements of buccal bone thickness and gingival thickness at the central incisors, lateral incisors, and canines were performed at points 0–5 mm from the alveolar crest on the superimposed images. The Friedman test was used to compare buccal bone and gingival thickness for each depth between the 3 tooth types. Spearman's correlation coefficient was calculated to assess the correlation between buccal bone thickness and gingival thickness. Results Of the central incisors, 77% of all sites had a buccal thickness of 0.5–1.0 mm, and 23% had a thickness of 1.0–1.5 mm. Of the lateral incisors, 71% of sites demonstrated a buccal bone thickness <1.0 mm, as did 63% of the canine sites. For gingival thickness, the proportion of sites <1.0 mm was 88%, 82%, and 91% for the central incisors, lateral incisors, and canines, respectively. Significant differences were observed in gingival thickness at the alveolar crest level (G0) between the central incisors and canines (P=0.032) and between the central incisors and lateral incisors (P=0.013). At 1 mm inferior to the alveolar crest, a difference was found between the central incisors and canines (P=0.025). The lateral incisors and canines showed a significant difference for buccal bone thickness 5 mm under the alveolar crest (P=0.025). Conclusions The gingiva and buccal bone of the anterior maxillary teeth were found to be relatively thin (<1 mm) overall. A tendency was found for gingival thickness to increase and bone thickness to decrease toward the root apex. Differences were found between teeth at some positions, although the correlation between buccal bone thickness and soft tissue thickness was

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.

A patient with mandibular deviation and 3 mandibular incisors treated with asymmetrically bent improved superelastic nickel-titanium alloy wires.

PubMed

Ikeda, Yuhei; Kokai, Satoshi; Ono, Takashi

2018-01-01

Skeletal and dental discrepancies cause asymmetric malocclusions in orthodontic patients. It is difficult to achieve adequate functional occlusion and guidance in patients with congenital absence of a mandibular incisor due to the tooth-size discrepancy. Here, we describe the orthodontic treatment of a 22-year-old woman with an asymmetric Angle Class II malocclusion, mandibular deviation to the left, and 3 mandibular incisors. The anterior teeth and maxillary canines were crowded. We used an improved superelastic nickel-titanium alloy wire (Tomy International, Tokyo, Japan) to compensate for the asymmetric mandibular arch and an asymmetrically bent archwire to move the maxillary molars distally. A skeletal anchorage system provided traction for intermaxillary elastics, and extractions were not needed. We alleviated the crowding and created an ideal occlusion with proper overjet, overbite, and anterior guidance with Class I canine and molar relationships. This method of treatment with an asymmetrically bent nickel-titanium alloy wire provided proper Class I occlusion and anterior guidance despite the mandibular deviation to the left and 3 mandibular incisors, without the need for extractions. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

A study of root canal morphology of human primary incisors and molars using cone beam computerized tomography: an in vitro study.

PubMed

Gaurav, Vivek; Srivastava, Nikhil; Rana, Vivek; Adlakha, Vivek Kumar

2013-01-01

Variations in morphology of root canals in primary teeth usually leads to complications during and after endodontic therapy. To improve the success in endodontics, a thorough knowledge of the root canal morphology is essential. The aim of this study was to assess the variation in number and morphology of the root canals of primary incisors and molars and to study the applicability of cone beam computerized tomography (CBCT) in assessing the same. A total of 60 primary molars and incisors with full root length were collected and various parameters such as the number of roots, number of canals, diameter of root canal at cementoenamel junction and middle-third, length and angulations of roots of primary molars and incisors were studied using CBCT. The observations were put to descriptive statistics to find out the frequency, mean, standard deviation and range for all four subgroups. Further, unpaired t-test was used to compare these parameters between subgroups and analysis of variance test was implemented to evaluate the parameters within the subgroups. The CBCT showed the presence of bifurcation of root canal at middle third in 13% of mandibular incisors while 20% of mandibular molars had two canals in distal root. The diameter of distobuccal root canal of maxillary molars and mesiolingual canal of mandibular molars was found to be minimum. CBCT is a relatively new and effective technology, which provides an auxiliary imaging modality to supplement conventional radiography for assessing the variation in root canal morphology of primary teeth.

Prevalence and characteristics of Molar Incisor Hypomineralisation (MIH) in the child population residing in Gandhinagar, Gujarat, India.

PubMed

Parikh, D R; Ganesh, M; Bhaskar, V

2012-02-01

Most prevalence studies on Molar Incisor Hypomineralisation (MIH) have been carried out in European countries and data from Asia especially south Asian populations are lacking. To investigate the prevalence and clinical characteristics of MIH in children residing in a western region of India. A cross-sectional survey including 1,366 children from 5 age cohorts, 8-12 years, studying in primary schools or attending the University Department, was carried out in the area of Gandhinagar, Gujarat, India. The dental examination was performed by a single well-trained and calibrated examiner in day light conditions. Full mouth inspection of wet teeth was conducted using the EAPD 2003 criteria for diagnosis of MIH. Results were recorded and statistically analysed using Chi-square test, independent sample t-test and Pearson correlations. Prevalence of MIH was 9.2% in the examined population. Males and females were equally affected. Among 12 index teeth involved in the examination, the most commonly affected were in descending order 46, 36, 16, 11 [FDI] and the least 42, 32, and 22. 17.4% of the cases revealed only molars involved, the remaining 72.6% having both molars and incisors affected; all four first permanent molars showed in 23% of the cases while no cases of only affected incisors were found. Of the MIH teeth 77.3% revealed mild defects and 22.7% severe defects. All incisors were mildly affected, as compared with only 67.1% of the molars, the remaining 32.9% being severely affected. As age increased, a statistically significant larger total number and severity level of affected teeth were recorded. Prevalence of MIH using EAPD 2003 criteria was found to be similar to other studies evaluating children in different geographic locations such as Europe, South America etc. Using the EAPD standardised criteria, more studies should be conducted in other Indian regions, in order to further evaluate prevalence, characteristics and treatment needs for this clinically demanding

Onset of molar incisor hypomineralization (MIH).

PubMed

Fagrell, Tobias G; Salmon, Phil; Melin, Lisa; Norén, Jörgen G

2013-01-01

The etiological factors and timing of the onset of molar incisor hypomineralization (MIH) are still not clear. The aim of this study was to examine ground radial and sagittal sections from teeth diagnosed with MIH using light microscopy, polarized light microscopy and X-ray micro-computed tomography (XMCT) and to estimate the onset and timing of the MIH and to relate the hypomineralized enamel to the incremental lines. Thirteen extracted permanent first molars diagnosed MIH, were analyzed with light microscopy and XMCT. The hypomineralized areas were mainly located in the mesio-buccal cusps, starting at the enamel-dentin-junction and continuing towards the enamel surface. In a relative gray scale analysis the values decreased from the EDJ towards the enamel surface. The findings indicate that the ameloblasts in the hypomineralized enamel are capable of forming an enamel of normal thickness, but with a substantial reduction of their capacity for maturation of enamel. Chronologically, it is estimated that the timing of the disturbance is at a period during the first 6-7 months of age.

Central obscuration effects on optical synthetic aperture imaging

NASA Astrophysics Data System (ADS)

Wang, Xue-wen; Luo, Xiao; Zheng, Li-gong; Zhang, Xue-jun

2014-02-01

Due to the central obscuration problem exists in most optical synthetic aperture systems, it is necessary to analyze its effects on their image performance. Based on the incoherent diffraction limited imaging theory, a Golay-3 type synthetic aperture system was used to study the central obscuration effects on the point spread function (PSF) and the modulation transfer function (MTF). It was found that the central obscuration does not affect the width of the central peak of the PSF and the cutoff spatial frequency of the MTF, but attenuate the first sidelobe of the PSF and the midfrequency of the MTF. The imaging simulation of a Golay-3 type synthetic aperture system with central obscuration proved this conclusion. At last, a Wiener Filter restoration algorithm was used to restore the image of this system, the images were obviously better.

[Esthetic restoration for anterior teeth with the hot pressed porcelain laminate veneers].

PubMed

Xu, Shao-ping; Luo, Xiao-ping; Shi, Yu-juan

2012-10-01

To evaluate the esthetic effect of anterior porcelain veneers fabricated with the heat pressed glass ceramic. Thirty-two patients, who wanted to receive a aesthetic restorative treatment for 206 anterior teeth were selected. Among them, 20 were for dental fluorosis, 8 were for light tetracycline stained teeth, the other 4 were labial enamel hypoplasia or obvious crack on the surface of enamel. According to the color of adjacent teeth,skin and lips, heat pressed IPS e.max ingots of different color were chosen to mold the restorations. Afterwards, special straining technique was conducted on the marginal ridge and incisor ridge of the veneers after carefully trimmed in the mouth. Restorations were them bonded with Variolink II resin cement. After 7 years of follow-up, a modified USPHS criterion was used to evaluate the esthetic effect. The translucency of veneers was superior. Marginal integrity of the veneers was perfect and it docked well with the marginal terminate line of the abutment. There was no edge coloring after the veneers were used for 7 years, and the veneers produce an excellent chameleon effect by absorbing the color of adjacent teeth and gums, at the same time, veneers could produce a feature of surface morphology of natural enamel after careful carve. In the long-term clinical observation, 5 of the 206 veneers were fractured or fell off. This porcelain laminate veneers fabricated from the heat pressed IPS e.max Press ingots include the following advantages, such as simple operating procedure, high mechanical strength, very little dental tissue was ground off and nice aesthetic effect. Ultra-thin veneers are especially suitable for aesthetic practice to dental fluorosis, light tetracycline and natural worn teeth.

Effect of Fluoride Varnish on Enamel Remineralization in Anterior Teeth with Molar Incisor Hypomineralization.

PubMed

Restrepo, Manuel; Jeremias, Fabiano; Santos-Pinto, Lourdes; Cordeiro, Rita Cl; Zuanon, Angela Cc

The objective of this study was to investigate the effect of fluoride varnish on remineralization of anterior teeth affected by Molar-Incisor Hypomineralization (MIH) by means of Quantitative Light-Induced Fluorescence- QLF. Fifty-one healthy 9 - 12- year-old children were selected according to different clinically diagnosed levels of MIH, proposed by the European Academy of Pediatric Dentistry (2003) (considering the most severe lesion per patient, n= 51 lesions), and randomly divided into two groups: (1) four applications of 5% NaF varnish, with one-week interval, and (2) usual home care- control. At each visit, the mean change in fluorescence and area of lesion were measured by QLF. The data were analyzed by repeated measures ANOVA and Tukey's test. All patients showed enamel alterations in first permanent molars and incisors, frequently with two molars affected by MIH (41.1%). There was no statically significant difference in the mean of fluorescence and area of lesion between groups over the studied time. We observed no favorable effect on the remineralization of MIH lesions in anterior teeth after four applications of fluoride varnish.

Strategic planning for instream flow restoration: a case study of potential climate change impacts in the central Columbia River basin.

PubMed

Donley, Erin E; Naiman, Robert J; Marineau, Mathieu D

2012-10-01

We provide a case study prioritizing instream flow restoration activities by sub-basin according to the habitat needs of Endangered Species Act (ESA)-listed salmonids relative to climate change in the central Columbia River basin in Washington State (USA). The objective is to employ scenario analysis to inform and improve existing instream flow restoration projects. We assess the sensitivity of late summer (July, August, and September) flows to the following scenario simulations - singly or in combination: climate change, changes in the quantity of water used for irrigation and possible changes to existing water resource policy. Flows for four sub-basins were modeled using the Water Evaluation and Planning system (WEAP) under historical and projected conditions of 2020 and 2040 for each scenario. Results indicate that Yakima will be the most flow-limited sub-basin with average reductions in streamflow of 41% under climate conditions of 2020 and 56% under 2040 conditions; 1.3-2.5 times greater than those of other sub-basins. In addition, irrigation plays a key role in the hydrology of the Yakima sub-basin - with flow reductions ranging from 78% to 90% under severe to extreme (i.e., 20-40%) increases in agricultural water use (2.0-4.4 times the reductions in the other sub-basins). The Yakima and Okanogan sub-basins are the most responsive to simulations of flow-bolstering policy change (providing salmon with first priority water allocation and at biologically relevant flows), as demonstrated by 91-100% target flows attained. The Wenatchee and Methow sub-basins do not exhibit similar responsiveness to simulated policy changes. Considering climate change only, we conclude that flow restoration should be prioritized first in the Yakima and Wenatchee sub-basins, and second in the Okanogan and Methow. Considering both climate change and possible policy changes, we recommend that the Yakima sub-basin receive the highest priority for flow restoration activities to sustain

Perception of altered smile esthetics among Moroccan professionals and lay people.

PubMed

Ousehal, L; Aghoutan, H; Chemlali, S; Anssari, I Filali; Talic, N

2016-10-01

To evaluate and compare the impact of altered smile characteristics on the perception of smile esthetics between Moroccan dentists and lay people. Thirty-four digital smile photographs displaying alterations in crown length and width, lateral incisor gingival margin position, gingival exposition, midline diastema, and upper midline deviation were presented to a sample of 30 dentists and 30 lay people. The ratings were assessed with a visual analog scale. Compared to that of lay people, Moroccan dentists' evaluation of the gingival smile was more critical when the decrease in central incisor crown length was 2.5 mm ( p  < 0.001) or greater and when the increase in gingival exposition was 4 mm or greater ( p  < 0.01). Moroccan dentists were also critical in their evaluation of maxillary lateral incisor crown width alterations ( p  < 0.05) and incisal midline deviations ( p  < 0.05). However, the professionals and lay people similarly evaluated irregularities in the incisor gingival margin position. Increases in the midline diastema were judged critically by both Moroccan dentists and lay people. In this sample, Moroccan dentists evaluate smile esthetic alterations more critically than Moroccan lay people. This difference in perception of smile discrepancies must be taken into account during the finishing phases of orthodontic treatment and restoration of the anterior teeth in Moroccan patients.

Central Anticholinergic Syndrome due to Hypoxia-Induced Bradycardia in a Child with Difficult Intubation Undergoing Complete Dental Restoration: A Case Report.

PubMed

Gharavifard, Mohamad; Razavi, Majid; Ghandehari Motlagh, Mehdi; Ziyaeifard, Mohsen

2014-09-01

Central anticholinergic syndrome (CAS) following general anesthesia (GA) is a well known syndrome in children and adults. Many cases of CAS have been previously reported in the literature. However, there are only two reports of post resuscitation CAS after administration of small doses of atropine. Hereby, we report a case of CAS in a child undergoing complete dental restoration under GA after receiving a small dose of atropine to reverse hypoxia induced bradycardia. Intraoperative events such as hypoxia or cardiac arrest may play a role as triggers for CAS. However, we cannot establish a causal relationship between the occurrence of CAS and such critical events.

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

Forest restoration, biodiversity and ecosystem functioning.

PubMed

Aerts, Raf; Honnay, Olivier

2011-11-24

Globally, forests cover nearly one third of the land area and they contain over 80% of terrestrial biodiversity. Both the extent and quality of forest habitat continue to decrease and the associated loss of biodiversity jeopardizes forest ecosystem functioning and the ability of forests to provide ecosystem services. In the light of the increasing population pressure, it is of major importance not only to conserve, but also to restore forest ecosystems. Ecological restoration has recently started to adopt insights from the biodiversity-ecosystem functioning (BEF) perspective. Central is the focus on restoring the relation between biodiversity and ecosystem functioning. Here we provide an overview of important considerations related to forest restoration that can be inferred from this BEF-perspective. Restoring multiple forest functions requires multiple species. It is highly unlikely that species-poor plantations, which may be optimal for above-ground biomass production, will outperform species diverse assemblages for a combination of functions, including overall carbon storage and control over water and nutrient flows. Restoring stable forest functions also requires multiple species. In particular in the light of global climatic change scenarios, which predict more frequent extreme disturbances and climatic events, it is important to incorporate insights from the relation between biodiversity and stability of ecosystem functioning into forest restoration projects. Rather than focussing on species per se, focussing on functional diversity of tree species assemblages seems appropriate when selecting tree species for restoration. Finally, also plant genetic diversity and above - below-ground linkages should be considered during the restoration process, as these likely have prominent but until now poorly understood effects at the level of the ecosystem. The BEF-approach provides a useful framework to evaluate forest restoration in an ecosystem functioning context, but

The survival of direct composite restorations in the management of severe tooth wear including attrition and erosion: A prospective 8-year study.

PubMed

Milosevic, A; Burnside, G

2016-01-01

Survival of directly placed composite to restore worn teeth has been reported in studies with small sample sizes, short observation periods and different materials. This study aimed to estimate survival for a hybrid composite placed by one clinician up to 8-years follow-up. All patients were referred and recruited for a prospective observational cohort study. One composite was used: Spectrum(®) (DentsplyDeTrey). Most restorations were placed on the maxillary anterior teeth using a Dahl approach. A total of 1010 direct composites were placed in 164 patients. Mean follow-up time was 33.8 months (s.d. 27.7). 71 of 1010 restorations failed during follow-up. The estimated failure rate in the first year was 5.4% (95% CI 3.7-7.0%). Time to failure was significantly greater in older subjects (p=0.005) and when a lack of posterior support was present (p=0.003). Bruxism and an increase in the occlusal vertical dimension were not associated with failure. The proportion of failures was greater in patients with a Class 3 or edge-to-edge incisal relationship than in Class 1 and Class 2 cases but this was not statistically significant. More failures occurred in the lower arch (9.6%) compared to the upper arch (6%) with the largest number of composites having been placed on the maxillary incisors (n=519). The worn dentition presents a restorative challenge but composite is an appropriate restorative material. This study shows that posterior occlusal support is necessary to optimise survival. Copyright © 2015 Elsevier Ltd. All rights reserved.

Polyethylene glycol restores axonal conduction after corpus callosum transection.

PubMed

Bamba, Ravinder; Riley, D Colton; Boyer, Richard B; Pollins, Alonda C; Shack, R Bruce; Thayer, Wesley P

2017-05-01

Polyethylene glycol (PEG) has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In this current experiment, coronal sectioning of the brains of Sprague-Dawley rats was performed after animal sacrifice. 3Brain high-resolution microelectrode arrays (MEA) were used to measure mean firing rate (MFR) and peak amplitude across the corpus callosum of the ex-vivo brain slices. The corpus callosum was subsequently transected and repeated measurements were performed. The cut ends of the corpus callosum were still apposite at this time. A PEG solution was applied to the injury site and repeated measurements were performed. MEA measurements showed that PEG was capable of restoring electrophysiology signaling after transection of central nerves. Before injury, the average MFRs at the ipsilateral, midline, and contralateral corpus callosum were 0.76, 0.66, and 0.65 spikes/second, respectively, and the average peak amplitudes were 69.79, 58.68, and 49.60 μV, respectively. After injury, the average MFRs were 0.71, 0.14, and 0.25 spikes/second, respectively and peak amplitudes were 52.11, 8.98, and 16.09 μV, respectively. After application of PEG, there were spikes in MFR and peak amplitude at the injury site and contralaterally. The average MFRs were 0.75, 0.55, and 0.47 spikes/second at the ipsilateral, midline, and contralateral corpus callosum, respectively and peak amplitudes were 59.44, 45.33, 40.02 μV, respectively. There were statistically differences in the average MFRs and peak amplitudes between the midline and non-midline corpus callosum groups ( P < 0.01, P < 0.05). These findings suggest that PEG restores axonal conduction between severed central nerves, potentially representing axonal fusion.

Polyethylene glycol restores axonal conduction after corpus callosum transection

PubMed Central

Bamba, Ravinder; Riley, D. Colton; Boyer, Richard B.; Pollins, Alonda C.; Shack, R. Bruce; Thayer, Wesley P.

2017-01-01

Polyethylene glycol (PEG) has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In this current experiment, coronal sectioning of the brains of Sprague-Dawley rats was performed after animal sacrifice. 3Brain high-resolution microelectrode arrays (MEA) were used to measure mean firing rate (MFR) and peak amplitude across the corpus callosum of the ex-vivo brain slices. The corpus callosum was subsequently transected and repeated measurements were performed. The cut ends of the corpus callosum were still apposite at this time. A PEG solution was applied to the injury site and repeated measurements were performed. MEA measurements showed that PEG was capable of restoring electrophysiology signaling after transection of central nerves. Before injury, the average MFRs at the ipsilateral, midline, and contralateral corpus callosum were 0.76, 0.66, and 0.65 spikes/second, respectively, and the average peak amplitudes were 69.79, 58.68, and 49.60 μV, respectively. After injury, the average MFRs were 0.71, 0.14, and 0.25 spikes/second, respectively and peak amplitudes were 52.11, 8.98, and 16.09 μV, respectively. After application of PEG, there were spikes in MFR and peak amplitude at the injury site and contralaterally. The average MFRs were 0.75, 0.55, and 0.47 spikes/second at the ipsilateral, midline, and contralateral corpus callosum, respectively and peak amplitudes were 59.44, 45.33, 40.02 μV, respectively. There were statistically differences in the average MFRs and peak amplitudes between the midline and non-midline corpus callosum groups (P < 0.01, P < 0.05). These findings suggest that PEG restores axonal conduction between severed central nerves, potentially representing axonal fusion. PMID:28616031

Immunocytochemical localization of amelogenin in rat incisor ameloblasts using ultrathin frozen sections.

PubMed

Nishikawa, S; Takagi, T; Sasa, S

1990-01-01

The localization of amelogenin, an enamel matrix protein, was examined by ultrastructural immunocytochemistry using unembedded ultrathin frozen sections of undecalcified rat incisor ameloblasts. Antibody against bovine amelogenin labeled Golgi complexes, secretory granules, and lysosomal structures in the preameloblasts and inner enamel-secretory ameloblasts as well as the enamel. The antibody also labeled dentin matrix facing preameloblasts. These results support the findings in previous reports using conventional epon embedded specimens. However, rough-surfaced endoplasmic reticulum failed to be labeled by this antibody.

A fine-structural survey of the pulpal innervation in the rat mandibular incisor.

PubMed

Bishop, M A

1981-02-01

The innervation of the rat incisor pulp has been studied using transmission electron microscopy and light microscopy. Transverse sections of mandibular incisor pulp (380-460 gm rats) from numerous positions in the long axis of the tooth were examined systematically in the electron microscopy. Quantitative data on total axon populations were obtained. The nerve fibers were found to pass through the lingual half of the pulp from the apical end to within 2 mm of the incisal tip. Although the nerve fibers were seen to lie amongst the connective tissue cells between the blood vessels, the electron microscopic observations showed that the blood vessels are not innervated. Throughout their pulpal course the nerve fibers showed no trace of perineurial investment. Virtually all the axons were unmyelinated. Total numbers of axons were small (233-328) and peak diameters of 0.3-0.4 microM confirmed the observed immature appearance of the nerve supply. Obvious nerve endings were seldom observed and the axons showed no structural association with odontoblasts. The evidence indicates that, although most axons terminate near the incisal end of the tooth, no specific structure is supplied. The qualitative features of the axons do not suggest autonomic function; however, they are consistent with a sensory role.

Bird monitoring as an aid to riparian restoration: Findings from the Trinity River in northwestern California

Treesearch

C. Klamath Bird Observatory and USFS Pacific Southwest Research Station

2013-01-01

The Trinity River Restoration Program began in 2000 with the goal of restoring the Trinity River's salmon and steelhead fisheries, which were severely degraded during the last half-century as a result of dams, water diversions under the Central Valley Project, and land-use practices such as gold mining. The restoration program, as outlined in the U.S. Department...

Early Restoration | NOAA Gulf Spill Restoration

Science.gov Websites

Early Restoration Plan. On April 20, 2011 we reached an agreement with BP to start restoration planning draft plan for the third phase of early restoration in December 2013. We are considering your comments : All Phase III information and documents Phase II Useful Links: Phase II Early Restoration Plan &

Effect of Different Esthetic Post-Core Materials on Color of Direct-Composite Restorations: A Preliminary Clinical Study.

PubMed

Ayna, Buket; Yılmaz, Berivan D; Izol, Bozan S; Ayna, Emrah; Tacir, İbrahim Halil

2018-06-15

BACKGROUND The purpose of this study was to determine the influence of 2 different esthetic post materials on the final color of direct-composite restorations by using a digital technique under in vivo conditions. MATERIAL AND METHODS We included 22 pulpless incisor teeth treated with conventionally cemented zirconia (n=11) and polyethylene fiber (n=11) posts in the study. Teeth were restored with a hybrid resin. The color of direct-composite restorations and contralateral control teeth was measured using a digital technique. The Commission Internationale de L'Eclairage, or CIE, L*a*b* and RGB color systems were investigated. Descriptive statistical analysis was performed for the CIE L*a*b* values. Color differences (ΔE) for the average L*, a*, and b* color parameters between every pair of groups were calculated (P>.05). RESULTS Significant differences were not found in the color difference luminosity (lum), R, G, B, and L* a* b* values between the zircon-rich glass fiber post (Z) and contralateral control teeth (Cz) (P>.05) and between the polyethylene fiber post (P) and contralateral control teeth (Cp) (P>.05). However, there was a statistically significant difference between the color a* values of the polyethylene fiber post (P) and contralateral control teeth (Cp) (p<0.05). Color differences (ΔE) between the zircon-rich glass fiber post (Z) and contralateral control teeth, and the polyethylene fiber post (P) and contralateral teeth were not statistically significant (P>.05). CONCLUSIONS Definitive restorations were equally affected by the 2 materials. Both materials can be used reliably in clinical practice. However, further research that focuses on the effect of intraoral conditions is needed.

Effect of restoration technique on stress distribution in roots with flared canals: an FEA study.

PubMed

Belli, Sema; Eraslan, Öznur; Eraslan, Oğuz; Eskitaşcıoğlu, Gürcan

2014-04-01

The aim of this finite element analysis (FEA) study was to test the effect of different restorative techniques on stress distribution in roots with flared canals. Five three-dimensional (3D) FEA models that simulated a maxillary incisor with excessive structure loss and flared root canals were created and restored with the following techniques/materials: 1) a prefabricated post: 2) one main and two accessory posts; 3) i-TFC post-core (Sun Medical); 4) the thickness of the root was increased by using composite resin and the root was then restored using a prefabricated post; 5) an anatomic post was created by using composite resin and a prefabricated glass-fiber post. Composite cores and ceramic crowns were created. A 300-N static load was applied at the center of the palatal surface of the tooth to calculate stress distributions. SolidWorks/Cosmosworks structural analysis programs were used for FEA analysis. The analysis of the von Mises and tensile stress values revealed that prefabricated post, accessory post, and i-TFC post systems showed similar stress distributions. They all showed high stress areas at the buccal side of the root (3.67 MPa) and in the cervical region of the root (> 3.67 MPa) as well as low stress accumulation within the post space (0 to 1 MPa). The anatomic post kept the stress within its body and directed less stress towards the remaining tooth structure. The creation of an anatomic post may save the remaining tooth structure in roots with flared canals by reducing the stress levels.

Effect of two prophylaxis methods on marginal gap of Cl Vresin-modified glass-ionomer restorations.

PubMed

Kimyai, Soodabeh; Pournaghi-Azar, Fatemeh; Daneshpooy, Mehdi; Abed Kahnamoii, Mehdi; Davoodi, Farnaz

2016-01-01

Background. This study evaluated the effect of two prophylaxis techniques on the marginal gap of CI V resin-modified glass-ionomer restorations. Methods. Standard Cl V cavities were prepared on the buccal surfaces of 48 sound bovine mandibular incisors in this in vitro study. After restoration of the cavities with GC Fuji II LC resin-modified glass-ionomer, the samples were randomly assigned to 3 groups of 16. In group 1, the prophylactic procedures were carried out with rubber cup and pumice powder and in group 2 with air-powder polishing device (APD). In group 3 (control), the samples did not undergo any prophylactic procedures. Then the marginal gaps were measured. Two-way ANOVA was used to compare marginal gaps at the occlusal and gingival margins between the groups. Post hoc Tukey test was used for two-by-two comparisons. Statistical significance was set at P < 0.05. Results. There were significant differences in the means of marginal gaps in terms of prophylactic techniques (P < 0.001), with significantly larger marginal gaps in the APD group compared to the pumice and rubber cup group, which in turn exhibited significantly larger marginal gaps compared to the control group (P < 0.0005). In addition, the means of marginal gaps were significant in terms of the margin type (P < 0.001), with significantly larger gaps at gingival margins compared to the occlusal margins (P < 0.0005). Conclusion. The prophylactic techniques used in this study had a negative effect on the marginal gaps of Cl V resin-modified glass-ionomer restorations.

The Effect of Resection Angle on Stress Distribution after Root-End Surgery

PubMed Central

Monteiro, Jaiane Bandoli; Dal Piva, Amanda Maria de Oliveira; Tribst, João Paulo Mendes; Borges, Alexandre Luiz Souto; Tango, Rubens Nisie

2018-01-01

Introduction: This study aimed to investigate the influence of the resection angle on the stress distribution of retrograde endodontic treated maxillary incisors under oblique-load application. Methods and Materials: A maxillary central incisor which was endodontically treated and restored with a fiber glass post was obtained in a 3-dimensional numerical model and distributed into three groups according to type of resection: control; restored with fiber post without retrograde obturation, R45 and R90 with 45º and 90º resection from tooth axial axis, respectively and restored with Fuji II LC (GC America). The numerical models received a 45º occlusal load of 200 N/cm2 on the middle of lingual surface. All materials and structures were considered linear elastic, homogeneous and isotropic. Numerical models were plotted and meshed with isoparametric elements, and the results were analyzed using maximum principal stress (MPS). Results: MPS showed greater stress values in the bone tissue for control group than the other groups. Groups with apicectomy showed acceptable stress distribution on the fiber post, cement layer and root dentin, presenting more improved values than control group. Conclusion: Apicectomy at 90º promotes more homogeneity on stress distribution on the fiber post, cement layer and root dentin, which suggests less probability of failure. However, due to its facility and stress distribution also being better than control group, apicectomy at 45° could be a good choice for clinicians. PMID:29707013

Planning for Large Scale Habitat Restoration in the Socorro Valley, New Mexico

Treesearch

Gina Dello Russo; Yasmeen Najmi

2006-01-01

One initiative for large scale habitat restoration on the Rio Grande in central New Mexico is being led by a nonprofit organization, the Save Our Bosque Task Force. The Task Force has just completed a conceptual restoration plan for a 72-kilometer reach of river. The goals of the plan were to determine the potential for enhanced biological diversity through improved...

75 FR 12562 - Central Utah Project Completion Act

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-16

... DEPARTMENT OF THE INTERIOR THE UTAH RECLAMATION MITIGATION AND CONSERVATION COMMISSION Central...-- Water and Science; Utah Reclamation Mitigation and Conservation Commission; and the Central Utah Water... of Public Scoping for the proposed Provo River Delta Restoration, Utah County, Utah. SUMMARY...

Central insulin-like growth factor-1 (IGF-1) restores whole-body insulin action in a model of age-related insulin resistance and IGF-1 decline.

PubMed

Huffman, Derek M; Farias Quipildor, Gabriela; Mao, Kai; Zhang, Xueying; Wan, Junxiang; Apontes, Pasha; Cohen, Pinchas; Barzilai, Nir

2016-02-01

Low insulin-like growth factor-1 (IGF-1) signaling is associated with improved longevity, but is paradoxically linked with several age-related diseases in humans. Insulin-like growth factor-1 has proven to be particularly beneficial to the brain, where it confers protection against features of neuronal and cognitive decline. While aging is characterized by central insulin resistance in the face of hyperinsulinemia, the somatotropic axis markedly declines in older humans. Thus, we hypothesized that increasing IGF-1 in the brain may prove to be a novel therapeutic alternative to overcome central insulin resistance and restore whole-body insulin action in aging. Utilizing hyperinsulinemic-euglycemic clamps, we show that old insulin-resistant rats with age-related declines in IGF-1 level demonstrate markedly improved whole-body insulin action, when treated with central IGF-1, as compared to central vehicle or insulin (P < 0.05). Furthermore, central IGF-1, but not insulin, suppressed hepatic glucose production and increased glucose disposal rates in aging rats (P < 0.05). Taken together, IGF-1 action in the brain and periphery provides a 'balance' between its beneficial and detrimental actions. Therefore, we propose that strategies aimed at 'tipping the balance' of IGF-1 action centrally are the optimal approach to achieve healthy aging and longevity in humans. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Multidisciplinary approach in the management of a complicated crown root fracture.

PubMed

Shin, J H; Kim, J E; Kim, R J

2013-06-01

This article describes the management of a complicated crown root fracture. A young patient presented with a crown root fracture of the maxillary left central incisor with an oblique subgingival fracture line. A multidisciplinary treatment approach including endodontic treatment, orthodontic extrusion, surgical extraction and intra-alveolar repositioning was used to gain sufficient crown length of the fractured maxillary incisor. The coronally repositioned maxillary left central incisor was stabilised by sutures and a resin wire splint. A resin core was built up followed by fabrication of an all-ceramic crown. Clinical and radiographic follow-up of the maxillary left central incisor after 24 months showed no signs of bone resorption or pathology and good aesthetics and functions were maintained.

Allometric equations for estimating tree biomass in restored mixed-species Atlantic Forest stands

Treesearch

Lauro Rodrigues Nogueira; Vera Lex Engel; John A. Parrotta; Antonio Carlos Galvão de Melo; Danilo Scorzoni Ré

2014-01-01

Restoration of Atlantic Forests is receiving increasing attention because of its role in both biodiversity conservation and carbon sequestration for global climate change mitigation. This study was carried out in an Atlantic Forest restoration project in the south-central region of São Paulo State – Brazil to develop allometric equations to estimate tree biomass of...

Dental fragment embedded in the lower lip after facial trauma: Brief review literature and report of a case

PubMed Central

Lauritano, Dorina; Petruzzi, Massimo; Sacco, Gerardo; Campus, Guglielmo; Carinci, Francesco; Milillo, Lucio

2012-01-01

Upper incisors are the most frequently involved teeth in traumatic dental injuries. Soft tissues (lips and/or oral mucosa) adjacent to incisal edge can receive direct and/or indirect traumas. Laceration of the lower lip is a not rare eventuality and teeth fragments could be embedded in labial soft tissue. The reattachment of these fragments, if possible, is the elective treatment choice, thanks to the modern adhesive and restorative techniques. The authors present a case of a white Caucasian 10-year-old child, who attended the dental clinic for the treatment of both upper central incisors’ crown fractures. The fragment of the left incisor was retrieved embedded in the lower lip. It was successfully surgically removed and reattached using a composite adhesive technique. A careful clinical and radiographic examination with the surgical removal of tooth fragments could prevent undesirable foreign body reaction, infection and scarring. The authors also reviewed the most relevant literature concerning tooth fragment reattachment after removal from oral soft tissues. PMID:23814592

Where to restore ecological connectivity? Detecting barriers and quantifying restoration benefits.

PubMed

McRae, Brad H; Hall, Sonia A; Beier, Paul; Theobald, David M

2012-01-01

Landscape connectivity is crucial for many ecological processes, including dispersal, gene flow, demographic rescue, and movement in response to climate change. As a result, governmental and non-governmental organizations are focusing efforts to map and conserve areas that facilitate movement to maintain population connectivity and promote climate adaptation. In contrast, little focus has been placed on identifying barriers-landscape features which impede movement between ecologically important areas-where restoration could most improve connectivity. Yet knowing where barriers most strongly reduce connectivity can complement traditional analyses aimed at mapping best movement routes. We introduce a novel method to detect important barriers and provide example applications. Our method uses GIS neighborhood analyses in conjunction with effective distance analyses to detect barriers that, if removed, would significantly improve connectivity. Applicable in least-cost, circuit-theoretic, and simulation modeling frameworks, the method detects both complete (impermeable) barriers and those that impede but do not completely block movement. Barrier mapping complements corridor mapping by broadening the range of connectivity conservation alternatives available to practitioners. The method can help practitioners move beyond maintaining currently important areas to restoring and enhancing connectivity through active barrier removal. It can inform decisions on trade-offs between restoration and protection; for example, purchasing an intact corridor may be substantially more costly than restoring a barrier that blocks an alternative corridor. And it extends the concept of centrality to barriers, highlighting areas that most diminish connectivity across broad networks. Identifying which modeled barriers have the greatest impact can also help prioritize error checking of land cover data and collection of field data to improve connectivity maps. Barrier detection provides a

Where to Restore Ecological Connectivity? Detecting Barriers and Quantifying Restoration Benefits

PubMed Central

McRae, Brad H.; Hall, Sonia A.; Beier, Paul; Theobald, David M.

2012-01-01

Landscape connectivity is crucial for many ecological processes, including dispersal, gene flow, demographic rescue, and movement in response to climate change. As a result, governmental and non-governmental organizations are focusing efforts to map and conserve areas that facilitate movement to maintain population connectivity and promote climate adaptation. In contrast, little focus has been placed on identifying barriers—landscape features which impede movement between ecologically important areas—where restoration could most improve connectivity. Yet knowing where barriers most strongly reduce connectivity can complement traditional analyses aimed at mapping best movement routes. We introduce a novel method to detect important barriers and provide example applications. Our method uses GIS neighborhood analyses in conjunction with effective distance analyses to detect barriers that, if removed, would significantly improve connectivity. Applicable in least-cost, circuit-theoretic, and simulation modeling frameworks, the method detects both complete (impermeable) barriers and those that impede but do not completely block movement. Barrier mapping complements corridor mapping by broadening the range of connectivity conservation alternatives available to practitioners. The method can help practitioners move beyond maintaining currently important areas to restoring and enhancing connectivity through active barrier removal. It can inform decisions on trade-offs between restoration and protection; for example, purchasing an intact corridor may be substantially more costly than restoring a barrier that blocks an alternative corridor. And it extends the concept of centrality to barriers, highlighting areas that most diminish connectivity across broad networks. Identifying which modeled barriers have the greatest impact can also help prioritize error checking of land cover data and collection of field data to improve connectivity maps. Barrier detection provides a

A Clinical Evaluation of Deproteinization and Different Cavity Designs on Resin Restoration Performance in MIH-Affected Molars: Two-Year Results.

PubMed

Sönmez, Hayriye; Saat, Sinem

The aim of this study was to evaluate the clinical effects of deproteinization of the hypomineralized enamel and different cavity designs on the performance of the composite resin restorations(CRRs) placed into the cavities of MIH (molar incisor hypomineralization)-affected molars. 95 MIH-affected permanent first molars (PFMs) and 31 caries but not MIH-affected PFMs (126 teeth in total) were included in the study. The MIH-affected molars were divided into three groups. In Group I, all hypomineralized tissue was removed until healthy enamel was reached. In Group II, carious and cheesy hypomineralized tissue was removed until a reasonable resistance was detected in the hypomineralized tissue. In Group III, cavities designed as Group II, differently from this group deproteinization of the left hypomineralized tissue was performed prior to the placement of CRRs. Group IV served as the control group consisting of unaffected carious PFMs. Restorations were evaluated according to modified USPHS criteria for 24 months. The retention rates were 93.7% for Group I, 80.7% for Group II, 93.5% for Group III and 100% for Group IV. The success rate for the restorations in Group II proved significantly lower (p<0.05) than that of the other three groups. No significant difference in success rates was observed between Group I, Group III and Group IV (p>0.05) at the end of 24 months. Failure of the restorations was predominant in the group that the hypomineralized tissue was left surrounding the cavities. Deproteinization of the hypomineralized enamel was found to enhance the retention rates of CRRs.

Orthodontic-periodontic intervention of pathological migration of maxillary anterior teeth in advanced periodontal disease.

PubMed

Panchal, Anita H; Patel, Vasumati G; Bhavsar, Neeta V; Mehta, Hardik V

2013-05-01

This case report presents a female patient whose chief complaint was of mobile and palatally drifted upper left central incisor which led to malalignment of upper anterior teeth. Orthodontic treatment of upper left central incisor was done with the help of 'Z' spring for the alignment of the upper anterior teeth. It was followed by splinting of upper anterior teeth to improve the stability and masticatory comfort. Regenerative periodontal surgery with Decalcified freeze dried bone allograft was done in relation to upper left central incisor.

Central leptin action on euglycemia restoration in type 1 diabetes: Restraining responses normally induced by fasting?

PubMed

Xu, Yuanzhong; Tong, Qingchun

2017-07-01

Leptin monotherapy is sufficient to restore euglycemia in insulinopenic type 1 diabetes (T1D), yet the underlying mechanism remains poorly understood. Accumulating evidence demonstrates that the brain mediates the leptin action on euglycemia restoration. Here, we first review evidence supporting that symptoms in T1D resemble an uncontrolled response to fasting. Then, we discuss recent research progress on brain neurons and their neurotransmitters that potentially mediate the leptin action. Finally, peripheral effective pathways, which are normally involved in fasting responses and associated with leptin action on euglycemia restoration in T1D, will also be discussed. This summary complements several previous excellent reviews on this topic (Meek and Morton, 2016; Perry et al., 2016; Fujikawa and Coppari, 2015). A deep understanding of neurocircuitry and the peripheral effective pathways that mediate the leptin action on euglycemia restoration will likely lead to novel targets for an insulin-independent therapeutics against T1D. Copyright © 2016 Elsevier Ltd. All rights reserved.

Restoring proximal caries lesions conservatively with tunnel restorations

PubMed Central

Chu, Chun-Hung; Mei, May L; Cheung, Chloe; Nalliah, Romesh P

2013-01-01

The tunnel restoration has been suggested as a conservative alternative to the conventional box preparation for treating proximal caries. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique-sensitive and can be particularly challenging for inexperienced restorative dentists. Recent advances in technology, such as the contemporary design of dental handpieces with advanced light-emitting diode (LED) and handheld comfort, offer operative dentists better vision, illumination, and maneuverability. The use of magnifying loupes also enhances the visibility of the preparation. The advent of digital radiographic imaging has improved dental imaging and reduced radiation. The new generation of restorative materials has improved mechanical properties. Tunnel restoration can be an option to restore proximal caries if the dentist performs proper case selection and pays attention to the details of the restorative procedures. This paper describes the clinical technique of tunnel restoration and reviews the studies of tunnel restorations. PMID:24019754

Restoring proximal caries lesions conservatively with tunnel restorations.

PubMed

Chu, Chun-Hung; Mei, May L; Cheung, Chloe; Nalliah, Romesh P

2013-07-30

The tunnel restoration has been suggested as a conservative alternative to the conventional box preparation for treating proximal caries. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique-sensitive and can be particularly challenging for inexperienced restorative dentists. Recent advances in technology, such as the contemporary design of dental handpieces with advanced light-emitting diode (LED) and handheld comfort, offer operative dentists better vision, illumination, and maneuverability. The use of magnifying loupes also enhances the visibility of the preparation. The advent of digital radiographic imaging has improved dental imaging and reduced radiation. The new generation of restorative materials has improved mechanical properties. Tunnel restoration can be an option to restore proximal caries if the dentist performs proper case selection and pays attention to the details of the restorative procedures. This paper describes the clinical technique of tunnel restoration and reviews the studies of tunnel restorations.

Periodontal probing of an impacted tooth recovered through a surgical-orthodontic approach: a case report.

PubMed

Dinoi, Maria Teresa; Lacarbonara, Mariano; Dimartino, Salvatore; Monaco, Annalisa; Marzo, Giuseppe

2014-01-27

The aim of this work was to assess the periodontal support of a central upper incisor recovered through a surgical-orthodontic approach compared to the spontaneously erupted contralateral incisor. This case study describes an 8-year-old Caucasian female with an impacted upper right central incisor. Surgical-orthodontic treatment was performed to reset the impacted dental element in the arch. Periodontal probing was performed of all sites (mesio-buccal, central-buccal, disto-buccal, mesio-palatal, central-palatal and disto-palatal) of the recovered impacted tooth and the contralateral tooth. The results were compared to determine whether the treated element showed signs of periodontal injury. Most of the probing results on both her right and left incisors gave values of approximately 3mm, which were not considered pathological. Both dental elements had adequate and physiological osseous attachments.

1. N elevation of Tender Frame Shop showing restored, standing ...

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

1. N elevation of Tender Frame Shop showing restored, standing seam metal roof. - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Tender Frame Shop, Bounded by West Broad, Jones, West Boundary & Hull Streets, Savannah, Chatham County, GA

Management of an uncomplicated crown fracture by reattaching the fractured fragment-Case report.

PubMed

Martos, Josué; Pinto, Karoline V A; Miguelis, Tiago M F; Xavier, Cristina B

2017-12-01

Coronal fractures of the anterior teeth are common sequelae of traumatic dental injuries. Reattachment of fractured tooth fragments using dental adhesive techniques offers some advantages, including restoration of the function, esthetics, shape, texture, and brightness of the surface. The present report describes a clinical case of reattachment with a 4-year clinical and radiographic follow up in a permanent maxillary central incisor with an uncomplicated crown fracture. Fragment reattachment is a conservative procedure, preserving esthetics and functionality, and it can provide an immediate positive emotional response from the patient. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Shade determination using camouflaged visual shade guides and an electronic spectrophotometer.

PubMed

Kvalheim, S F; Øilo, M

2014-03-01

The aim of the present study was to compare a camouflaged visual shade guide to a spectrophotometer designed for restorative dentistry. Two operators performed analyses of 66 subjects. One central upper incisor was measured four times by each operator; twice with a camouflaged visual shade guide and twice with a spectrophotometer Both methods had acceptable repeatability rates, but the electronic shade determination showed higher repeatability. In general, the electronically determined shades were darker than the visually determined shades. The use of a camouflaged visual shade guide seems to be an adequate method to reduce operator bias.

Rubber dam may increase the survival time of dental restorations.

PubMed

Keys, William; Carson, Susan J

2017-03-01

Data sourcesCochrane Oral Health's Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, LILACS, SciELO, Chinese BioMedical Literature Database, VIP, China National Knowledge Infrastructure, ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform, OpenGrey and Sciencepaper Online databases. Handsearches in a number of journals.Study selectionRandomised controlled trials, including split-mouth studies assessing the effects of rubber dam isolation for restorative treatments in dental patients.Data extraction and synthesisTwo review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies.ResultsFour studies involving a total of 1,270 patients were included. The studies were at high risk of bias. One trial was excluded from the analysis due to inconsistencies in the presented data. Restorations had a significantly higher survival rate in the rubber dam isolation group compared to the cotton roll isolation group at six months in participants receiving composite restorative treatment of non-carious cervical lesions (risk ratio (RR) 1.19, 95% confidence interval (CI) 1.04 to 1.37, very low-quality evidence). The rubber dam group had a lower risk of failure at two years in children undergoing proximal atraumatic restorative treatment in primary molars (hazard ratio (HR) 0.80, 95% CI 0.66 to 0.97, very low-quality evidence). One trial reported limited data showing that rubber dam usage during fissure sealing might shorten the treatment time. None of the included studies mentioned adverse effects or reported the direct cost of the treatment, or the level of patient acceptance/satisfaction. There was also no evidence evaluating the effects of rubber dam usage on the quality of the restorations.ConclusionsWe found some very low-quality evidence, from single studies, suggesting that rubber dam usage in dental direct

Excessive fluoride reduces Foxo1 expression in dental epithelial cells of the rat incisor.

PubMed

Gao, Jianghong; Ruan, Jianping; Gao, Liping

2014-10-01

Enamel fluorosis is characterized by hypomineralization, and forkhead box O1 (Foxo1) is essential for mouse enamel biomineralization. This study investigated the effect of fluoride on Foxo1 expression and its implications for enamel fluorosis. Mandibular incisors were extracted from Sprague Dawley rats treated for 3 months with water containing 0, 50, or 100 p.p.m. F⁻. Immunohistochemistry was used to localize and quantify FOXO1 expression in dental epithelial layer cells of the incisors. The effect of fluoride on expression of Foxo1, kallikrein-4 (Klk4), and amelotin (Amtn) mRNAs was analyzed by real-time RT-PCR, and western blotting was used to measure total and nuclear FOXO1 protein levels in mature dental epithelial cells. The results revealed that nuclear FOXO1 was mainly localized in the transition and the mature ameloblasts and exhibited weaker expression in the rats exposed to fluoride. In addition to the reduced levels of Foxo1, Klk4, and AmtnmRNAs, the protein levels of total and nuclearFOXO1 were decreased in the mature dental epithelial cells exposed to fluoride. Thus, excessive fluoride may have an effect on the expression levels of Foxo1 in dental epithelial cells and thereby affect hypomineralization of the enamel during fluorosis. © 2014 Eur J Oral Sci.

Clinical measurement of the height of the interproximal contact area in maxillary anterior teeth.

PubMed

Sghaireen, Mohd G; Al-Zarea, Bader K; Al-Shorman, Hisham M; Al-Omiri, Mahmoud K

2013-11-01

To clinically quantify the apicoincisal height of interproximal areas directly in patients' mouths. Thirty participants (11 females and 9 males, mean age=26±1.5 years) were recruited into this study. Measurement of interproximal contact areas was carried out directly in patients' mouths using digital caliper (TERENSA, USA) with measuring accuracy of 0.01 mm. The interproximal contact areas that were measured are: central incisor to central incisor, central incisor to lateral incisor, lateral incisor to canine, and canine to first premolar on both sides of the jaw. Statistical significance was based on probability values less than 0.05 (p<0.05). The largest contact point was the one present between central incisors and it ranged from 2.9 to 6.5 mm. On the other hand, the contact point between canine and first premolar was the smallest on both sides of the arch and ranged from 0.6 to 2.5 mm. The dimensions of the contact points declined as we move from anterior area backwards. Statistical analysis using t-test showed that there were significant differences between the measurements of interproximal points of each tooth (P<0.05). the apicogingival dimension of the contact point decreased as we moved from anterior to posterior teeth. The contact area between the central incisors was largest and the one between canine and premolar was the smallest. This study is the first to report direct intra-oral clinical measurement of contact points. Clinical evaluation of contact point dimensions using digital caliber is a viable, quick and accurate method to use.

Characteristics of the Papua New Guinean dentition. I Shovel-shaped incisors and canines associated with lingual tubercles.

PubMed

Doran, G A

1977-10-01

The prevalence of shovel-shaped and lingual tubercles in maxillary incisors and canines in four groups of people in Papua New Guinea is reported. The shovel shape was not common among the people of Highland New Guinea but its presence in Papuans was comparable with that in Mongoloid races.

Conservative treatment of an ankylosed tooth after delayed replantation: a case report.

PubMed

Díaz, Jaime Andrés; Sandoval, Hector Paulo; Pineda, Patricia Irene; Junod, Pablo Antonio

2007-10-01

An 8-year-old boy sustained avulsion of his upper right maxillary central incisor and lateral luxation of his upper left maxillary incisors. Subsequently, the upper right maxillary central incisor developed replacement resorption, and both upper left maxillary incisors developed pulpal canal obliteration. In the ankylosed tooth, decoronation procedure was performed, and in the 44-month follow-up period the involved alveolar site showed vertical apposition of bone and continuing replacement resorption. Decoronation is a surgical procedure that allows preservation of the bone volume for the future, avoiding aesthetic disturbances and more aggressive treatments in cases where other therapeutic alternatives are not feasible.

Management of geminated maxillary lateral incisor using cone beam computed tomography as a diagnostic tool.

PubMed

James, Elizabeth Prabha; Johns, Dexton Antony; Johnson, Ki; Maroli, Ramesh Kumar

2014-05-01

Geminated teeth are consequences of developmental anomalies leading to joined elements, due to incomplete attempt of one tooth germ to divide into two. This case report describes successful endodontic treatment of an unaesthetic geminated permanent maxillary lateral incisor tooth and its esthetic rehabilitation using all ceramic crowns. Newer imaging technique like cone beam computed tomography was taken for the better understanding of the complicated root canal morphology.

Factors affecting re-vegetation dynamics of experimentally restored extracted peatland in Estonia.

PubMed

Karofeld, Edgar; Müür, Mari; Vellak, Kai

2016-07-01

Increasing human activity continues to threaten peatlands, and as the area of natural mires declines, our obligation is to restore their ecosystem functions. Several restoration strategies have been developed for restoration of extracted peatlands, including "The moss layer transfer method", which was initiated on the Tässi extracted peatland in central Estonia in May 2012. Three-year study shows that despite the fluctuating water table, rainfall events can compensate for the insufficient moisture for mosses. Total plant cover on the restoration area attained 70 %, of which ~60 % is comprised of target species-Sphagnum mosses. From restoration treatments, spreading of plant fragments had a significant positive effect on the cover of bryophyte and vascular plants. Higher water table combined with higher plant fragments spreading density and stripping of oxidised peat layer affected positively the cover of targeted Sphagnum species. The species composition in the restoration area became similar to that in the donor site in a natural bog. Based on results, it was concluded that the method approved for restoration in North America gives good results also in the restoration of extracted peatland towards re-establishment of bog vegetation under northern European conditions.

[Central hypomyelination, hypogonadotrophic hypogonadism and hypodontia: a new leukodystrophy].

PubMed

Vázquez-López, M; Ruiz-Martín, Y; de Castro-Castro, P; Garzo-Fernández, C; Martín-del Valle, F; Márquez-de la Plata, L

To report one patient with slowly progressive encephalopathy, ataxia, central hypomyelination, hypodontia and hypogonadotropic hypogonadism, the 4H syndrome. This clinical picture has been described recently and there are only four patients reported previously. A girl with a previously normal early psychomotor development, presented a slowly progressive deterioration since 15 months of age. Now, she is 14 years old, and has a severe cerebellar ataxia, with tremor and dysmetria. She can't neither walk nor remain standing alone. She has lost the sphincter control and has an immature expressive language. She has no puberal development and definitive hypodontia of upper central incisors. The brain magnetic resonance imaging shows a diffuse hypomyelination, that is confirmed with diffusion and spectroscopy studies. The hypomyelinating leukoencephalopathies are disorders with abnormally low amount of myelin. The diagnosis is difficult in most of the patients. The hypomyelinating leukoencephalopathies include classic disorders and new leukoencephalopathies, described in the past few years.

Gingival health associated with porcelain veneers on maxillary incisors.

PubMed

Reid, J S; Kinane, D F; Adonogianaki, E

1991-12-01

The possible detrimental effect of acid-etched resin-bonded prostheses and porcelain veneers on plaque accumulation and gingival health is currently disputed. Some workers recommend no tooth preparation prior to veneering whilst others recommend tooth preparation to prevent adverse gingival soft tissue reactions. In order to test the possible gingival effects of veneers placed without tooth preparation, this study was set up to compare gingival health on veneered and non-veneered maxillary incisors within the same individual during periods of normal tooth cleaning and of no tooth cleaning. No significant differences were noted in plaque or gingival indices, or in gingival crevicular fluid volume, between the 72 veneered and non-veneered sites during either study period. The results of this study suggest that placing porcelain veneers on unprepared teeth does not increase the risk of gingivitis.

Direct bonding in diastema closure--high drama, immediate resolution.

PubMed

Blitz, N

1996-07-01

Aesthetic rehabilitation in complex diastema closure cases is guided by the principles of proportion. The width to length ratio of the centrals must be pleasing. Achievement of this proper balance dictates treatment. It determines the following: 1) the amount of distal proximal reduction; 2) the decision to completely veneer the incisors vs. just adding to the interproximal; 3) the number of teeth to be treated; 4) the placement and location of naturally occurring prominences and concavities to create the illusion of a narrower tooth. The proper accommodation of these four topics will permit the maintenance or restoration of acceptable dimensions in the centrals. If they are made to appear harmonious then the principle of "golden proportion" (1.6:1:0.6) can be achieved among the centrals, laterals and cuspids. Direct bonding in diastema closure cases allow the dentist and the patient complete control in the formation of that smile. This treatment modality is challenging and ultimately rewarding for the patient and the dentist. At times it enables us to restore form and function and to make our patients whole again not just figuratively but literally.

Fracture Resistance of Endodontically Treated Teeth Restored with Biodentine, Resin Modified GIC and Hybrid Composite Resin as a Core Material.

PubMed

Subash, Dayalan; Shoba, Krishnamma; Aman, Shibu; Bharkavi, Srinivasan Kumar Indu; Nimmi, Vijayan; Abhilash, Radhakrishnan

2017-09-01

The restoration of a severely damaged tooth usually needs a post and core as a part of treatment procedure to provide a corono - radicular stabilization. Biodentine is a class of dental material which possess high mechanical properties with excellent biocompatibility and bioactive behaviour. The sealing ability coupled with optimum physical properties could make Biodentine an excellent option as a core material. The aim of the study was to determine the fracture resistance of Biodentine as a core material in comparison with resin modified glass ionomer and composite resin. Freshly extracted 30 human permanent maxillary central incisors were selected. After endodontic treatment followed by post space preparation and luting of Glass fibre post (Reforpost, Angelus), the samples were divided in to three groups based on the type of core material. The core build-up used in Group I was Biodentine (Septodont, France), Group II was Resin-Modified Glass Ionomer Cement (GC, Japan) and Group III was Hybrid Composite Resin (TeEconom plus, Ivoclar vivadent). The specimens were subjected to fracture toughness using Universal testing machine (1474, Zwick/Roell, Germany) and results were compared using One-way analysis of variance with Tukey's Post hoc test. The results showed that there was significant difference between groups in terms of fracture load. Also, composite resin exhibited highest mean fracture load (1039.9 N), whereas teeth restored with Biodentine demonstrated the lowest mean fracture load (176.66 N). Resin modified glass ionomer exhibited intermediate fracture load (612.07 N). The primary mode of failure in Group I and Group II was favourable (100%) while unfavourable fracture was seen in Group III (30%). Biodentine, does not satisfy the requirements to be used as an ideal core material. The uses of RMGIC's as a core build-up material should be limited to non-stress bearing areas. Composite resin is still the best core build-up material owing to its high fracture

Effect of turpentine-induced fever during the enamel formation of rat incisor.

PubMed

Tung, Kuochung; Fujita, Haruko; Yamashita, Yasuo; Takagi, Yuzo

2006-06-01

Some epidemiological studies have indicated that diseases resulting in prolonged and sustained fever, such as exanthemata, respiratory infections and otitis media in infantile period or childhood are likely to have a marked deleterious effect on enamel formation, but the relationship between fever and enamel defects is unknown. The purpose of the present study was to induce a persistent high fever and examine the effects on the developing tooth enamel. Twenty male Wistar rats weighting 140+/-10 g were used in this study. For the experimental group, a dose of 2.3 ml/kg steam-distilled turpentine was subcutaneously injected into both hind limbs five times at 12h intervals. Control rats received 2.3 ml/kg of sterile saline into the same injection site. The rectal temperatures of animals were measured at the febrile period. After constant periods, the animals were sacrificed, and the mandibular incisors were examined by contact microradiography (CMR) and histological observation. The febrile state lasted for 57 h and the average temperature rose 1.51 degrees C higher than that of the control group. The ground sections, semi-thin and ultra-thin sections of mandibular incisors were prepared and the enamel was observed. The microradiographs showed a radiolucent line along with the incremental line in the enamel. Moreover, microscopic examination indicated disorientation of enamel prism and crystal-free area within this radiolucent lesion. Persistent high fever pattern was established firmly by the turpentine injections and the process of enamel formation was influenced by the febrile period.

Antibacterial agents in composite restorations for the prevention of dental caries.

PubMed

Pereira-Cenci, Tatiana; Cenci, Maximiliano S; Fedorowicz, Zbys; Azevedo, Marina

2013-12-17

Dental caries is a multifactorial disease in which the fermentation of food sugars by bacteria from the biofilm (dental plaque) leads to localised demineralisation of tooth surfaces, which may ultimately result in cavity formation. Resin composites are widely used in dentistry to restore teeth. These restorations can fail for a number of reasons, such as secondary caries, and restorative material fracture and other minor reasons. From these, secondary caries, which are caries lesions developed adjacent to restorations, is the main cause for restorations replacement. The presence of antibacterials in both the filling material and the bonding systems would theoretically be able to affect the initiation and progression of caries adjacent to restorations. This is an update of the Cochrane review published in 2009. To assess the effects of antibacterial agents incorporated into composite restorations for the prevention of dental caries. We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 23 July 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 6), MEDLINE via OVID (1946 to 23 July 2013) and EMBASE via OVID (1980 to 23 July 2013). We searched the US National Institutes of Health Trials Register (http://clinicaltrials.gov), the metaRegister of Controlled Trials (www.controlled-trials.com) and the World Health Organization International Clinical Trials Registry platform (www.who.int/trialsearch) for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised controlled trials comparing resin composite restorations containing antibacterial agents with composite restorations not containing antibacterial agents. Two review authors conducted screening of studies in duplicate and independently, and although no eligible trials were identified, the two authors had planned to extract data independently and

Restoration | NOAA Gulf Spill Restoration

Science.gov Websites

comprehensive look at the types of restoration that may be required to offset impacts from the spill during this long-term injury assessment continues. Types of possible early restoration projects include: Creating

[Wetlands of priority restoration in Northeast China based on spatial analysis].

PubMed

Dong, Zhang-Yu; Liu, Dian-Wei; Wang, Zong-Ming; Ren, Chun-Ying; Tang, Xu-Guang; Jia, Ming-Ming; Wang, Yan

2013-01-01

By using GIS/RS technology, and from the aspects of landscape structure, river- and road densities, wetness index, geomorphology, and cultivated land productivity, a spatial analysis was made on the potentiality of wetland restoration in Northeast China, with the regions of priority and secondary priority restoration wetlands determined. Then, by using the coordinated development index of crop production and wetland as well as the landscape indices, the wetland restoration effect was verified. In Northeast China, the wetland area of priority restoration was 1.78 x 10(6) hm2, among which, farmland and grassland were the main types for restoration, accounting for 96.7% of the total, and mainly located in the Sanjiang Plain in the northeastern part and the Songnen Plain in the central part of Northeast China. The wetland area of secondary priority restoration was 1.03 x 10(6) hm2. After the restoration of the wetlands, the wetland area in Northeast China would be increased by 37.4%, compared with the present wetland area, and the value of the coordinated development index of crop production and wetland would increase from 0.539 before restoration to 0.733 after restoration. The landscape pattern would be more benefit to the performance of the ecological functions of the wetlands. This study revealed that the restoration scheme of the wetlands in Northeast China based on spatial analysis was practicable, which could provide data support for the implement of wetland restoration and the improvement of ecological environment in Northeast China.

Conservative treatment of a cervical horizontal root fracture and a complicated crown fracture: a case report.

PubMed

Belobrov, I; Weis, M V; Parashos, P

2008-09-01

Abstract This case report describes successful long-term conservative management of a cervical root fracture and a complicated crown fracture of the maxillary central incisors in a 12-year-old patient. A mineral trioxide aggregate partial pulpotomy was performed on the maxillary right central incisor, while the maxillary left central incisor was splinted to the neighbouring lateral incisor using an acid-etch technique. Both teeth remained asymptomatic throughout the 3.5 years of a review period, with the cervical root fracture having mostly healed with the formation of a calcified tissue between the fragments. Two different treatment methods were used for two different injuries that resulted in pulp preservation in both cases. This in turn has provided for normal root development to occur while also allowing for preservation of bone.

Post-endodontic treatment of incisors and premolars among dental practitioners in Saarland: an interactive Web-based survey.

PubMed

Mitov, Gergo; Dörr, Michael; Nothdurft, Frank P; Draenert, Florian; Pospiech, Peter R

2015-06-01

The aim of the present study was to evaluate the trend of dental practitioners in the federal state of Saarland in Germany in regard to restoring endodontically treated teeth using a Web-based survey. An interactive Web-based survey instrument was developed, including seven clinical scenarios, presented by photographs of natural incisor and premolar with different types of cavities. Following a decision tree adapted to the clinical treatment, questions on different aspects of the post-endodontic treatment were asked. All 615 members of the Saarland Dental Association (SDA) were asked to participate in the survey. A total of 33 % completed the survey. The majority of the participants believed in the reinforcement effect of the ferrule design, as well as the post placement. The vast majority of the responding practitioners (92 %) adapted their treatment strategies to a high extent to the destruction degree of the endodontically treated tooth. Fiber-reinforced composite (FRC) posts are the most popular prefabricated post type, regardless of the cavity size and tooth localization. Significant differences between the dentists according to the degree of experience were detected only for the use of glass-ionomer cements as core buildup material. The predominant post-endodontic treatment strategies of German dental practitioners are only partly in agreement with the current literature. There is a clear trend toward the increasing use of metal-free post and core materials. Although the participants showed a general adoption of modern materials and techniques, different patterns of post-endodontic treatment were revealed that were not consistent with approaches supported by the literature.

Advanced Protection & Service Restoration for FREEDM Systems

NASA Astrophysics Data System (ADS)

Singh, Urvir

A smart electric power distribution system (FREEDM system) that incorporates DERs (Distributed Energy Resources), SSTs (Solid State Transformers - that can limit the fault current to two times of the rated current) & RSC (Reliable & Secure Communication) capabilities has been studied in this work in order to develop its appropriate protection & service restoration techniques. First, a solution is proposed that can make conventional protective devices be able to provide effective protection for FREEDM systems. Results show that although this scheme can provide required protection but it can be quite slow. Using the FREEDM system's communication capabilities, a communication assisted Overcurrent (O/C) protection scheme is proposed & results show that by using communication (blocking signals) very fast operating times are achieved thereby, mitigating the problem of conventional O/C scheme. Using the FREEDM System's DGI (Distributed Grid Intelligence) capability, an automated FLISR (Fault Location, Isolation & Service Restoration) scheme is proposed that is based on the concept of 'software agents' & uses lesser data (than conventional centralized approaches). Test results illustrated that this scheme is able to provide a global optimal system reconfiguration for service restoration.

Atraumatic restorative treatment versus conventional restorative treatment for managing dental caries.

PubMed

Dorri, Mojtaba; Martinez-Zapata, Maria José; Walsh, Tanya; Marinho, Valeria Cc; Sheiham Deceased, Aubrey; Zaror, Carlos

2017-12-28

Dental caries is a sugar-dependent disease that damages tooth structure and, due to loss of mineral components, may eventually lead to cavitation. Dental caries is the most prevalent disease worldwide and is considered the most important burden of oral health. Conventional treatment methods (drill and fill) involve the use of rotary burs under local anaesthesia. The need for an electricity supply, expensive handpieces and highly trained dental health personnel may limit access to dental treatment, especially in underdeveloped regions.To overcome the limitations of conventional restorative treatment, the Atraumatic Restorative Treatment (ART) was developed, mainly for treating caries in children living in under-served areas of the world where resources and facilities such as electricity and trained manpower are limited. ART is a minimally invasive approach which involves removal of decayed tissue using hand instruments alone, usually without use of anaesthesia and electrically driven equipment, and restoration of the dental cavity with an adhesive material (glass ionomer cement (GIC), composite resins, resin-modified glass-ionomer cement (RM-GICs) and compomers). To assess the effects of Atraumatic Restorative Treatment (ART) compared with conventional treatment for managing dental caries lesions in the primary and permanent teeth of children and adults. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 22 February 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 1), MEDLINE Ovid (1946 to 22 February 2017), Embase Ovid (1980 to 22 February 2017), LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 22 February 2017) and BBO BIREME Virtual Health Library (Bibliografia Brasileira de Odontologia; 1986 to 22 February 2017). The US National Institutes of Health Trials Registry (Clinical

Plant composition in oak savanna and woodland restoration at Prairie Fork Conservation Area in Missouri

Treesearch

Nadia E. Navarrete-Tindall; J.W. Van Sambeek; Jamie Coe; Warren Taylor

2007-01-01

The wooded areas of the Prairie Fork Conservation Area in central Missouri are typical of the oak/hickory forest/prairie transition zone that will require active management to restore pre-settlement, grass dominated savannas and open woodlands to improve habitat for wildlife. We initiated a management program to restore savannas and woodlands by reducing the midstory (...

[Root resorption after orthodontic treatment: a study of age factor and prevalence in anterior teeth].

PubMed

Tian, Yu-lou; Wang, Kun; Wang, Jing; Liu, Fang; Piao, Mei-ling

2013-04-01

To investigate the impact of age factor on root resorption and the prevalence in anterior teeth during orthodontic treatment. Sixty extraction cases treated with straight wire appliance were divided into adult group and child group, with 30 cases in each group.The panoramic radiographs pre-treatment and post-treatment were examined to measure the degrees of root resorption. A total of 360 anterior teeth in each group were evaluated. SPSS 13.0 software package was applied to perform statistical analysis. There was significant difference in root resorption index before and after treatment(P<0.01). The incidence of root resorption increased remarkably after orthodontic treatment. There was significant difference in the degree of root resorption in two groups (P<0.01). The prevalence of root resorption in anterior teeth was: upper central incisors, upper lateral incisors, lower central incisors, lower lateral incisors, upper canines and lower canines. The root resorption in adult patients are more obvious than child patients. The prevalence of root resorption in anterior teeth is different. Moderate or severe root resorption is prone to happen in upper central incisors or lateral incisors in adult patients.

To evaluate the validity of Recurring Esthetic Dental proportion in natural dentition

PubMed Central

Shetty, Shilpa; Pitti, Varun; Satish Babu, CL; Surendra Kumar, GP; Jnanadev, KR

2011-01-01

Background: Different proportions are described in the literature for smile designing, such as Golden proportion, Golden percentage, Preston's proportion, and recently, Recurring Esthetic Dental (RED) proportion. Aims and Objectives: To evaluate the existence of RED proportion in natural dentition. To determine the relative height of maxillary lateral incisor and canine occurring in natural dentition so that it can be used in any of the above proportions. Materials and Methods: Fifteen male subjects and 15 female subjects in each of the different age groups of 18–23 years, 24–29 years and 30–35 years were selected for this study (total 90). Photographs of the subjects were taken using Nikon D200 camera with 135 mm lens and analyzed using Adobe Photoshop CS4 extended software. The height and width of maxillary central incisors, lateral incisors and canines were found out using the measuring tool provided in the software. Results: Average width ratio and height ratio of maxillary lateral incisor to central incisor and maxillary canine to lateral incisor were calculated to check the existence of RED proportion in natural dentition. Average lateral incisor to central incisor height ratio for “small”- and “medium”-sized teeth was found to be 88% and for “tall”-sized teeth was found to be 84%. Average canine to lateral incisor height ratio for “small”- and “medium”-sized teeth was found to be 106% and for “tall”-sized teeth was found to be 105%. Conclusions: Within the limitations of the study, RED proportion was not seen in natural dentition. PMID:22025841

[Alveolar bone thickness in A point area : how to avoid periodontal failures in front of upper incisors].

PubMed

Chevalier, Émilie; Philip-Alliez, Camille; Le Gall, Michel

2016-03-01

Studies on orthodontic-periodontics relationships are numerous but few have benefited from the contribution of new 3D imaging techniques that emphasize iatrogenic effects that orthodontics may have on the periodontium. Periodontal risk in terms of fenestration, bone dehiscences next maxillary incisors are real during or after orthodontic treatment. The accurate assessment of the initial situation in terms of bone quantity in this dental arch anterior segment is thus very important. Our study aimed to evaluate the reliability of conventional lateral cephalograms to quantify alveolar bone thickness in relation to the maxillary incisors by comparing it with data from CT scans. The second objective was to identify an at risk patient profile by assessing possible correlations between this thickness and dysmorphia components. The results revealed a half of assessment error in the estimation of bone thickness and increased risk in case of hyperdivergence typology, Class III skeletal relationships and dento-alveolar protrusion. Finally, in view of these data, we discussed the clinical procedures to avoid such periodontal failures in this anterior segment of the dental arch. © EDP Sciences, SFODF, 2016.

[Measurement and analysis of smile line of 62 Han-Chinese].

PubMed

Hu, Xiu-lian; Heberer, Susanne; Nelson, Katja; Lin, Ye

2011-11-01

To analyze smile features in maximum lip-dynamic in Chinese. Sixty-two Han-Chinese, travelling in Germany, with a mean age of 28.5 years were enrolled and photographed. Standardized digital photos were made to measure the height of displayed maxillary gingiva, papilla and tooth during an enjoyment smile. Statistical analysis was performed using Mann-Whitney-U Test and non-parametric analysis. The mean height of tooth display for the central incisors was 10 mm, with no significant difference between the gender (P > 0.05). The mean height of gingival display was 1.3 mm and the mean papilla height was 3.4 mm. There was no significant difference between the genders (P > 0.05). 31% (19/62) of the subjects belonged to high smile line type, 50% (31/62) to medium smile line type and 19% (12/62) to low smile line type. The red esthetics is a paramount factor for Chinese men and women in the esthetic restoration. 81% of the Chinese studied showed various degree of gingival exposure from central incisor to the premolars, which defined the esthetic area for Chinese people. Papilla is a critical parameter for esthetic evaluation and treatment design. The ratio of high smile line in Chinese may be higher than that in Caucasian.

Perception of smile esthetics by laypeople of different ages.

PubMed

Sriphadungporn, Chompunuch; Chamnannidiadha, Niramol

2017-12-01

Age is a factor affecting smile esthetics. Three variables of smile esthetics associated with the maxillary anterior teeth and age-related changes have recently received considerable attention: (i) the incisal edge position of the maxillary central incisors, (ii) the maxillary gingival display, and (iii) the presence of a black triangle between the maxillary central incisors. The aim of this study was to evaluate the influence of age on smile esthetic perception based on these three variables in a group of Thai laypeople. The smiles were constructed from a photograph of a female smile. Smile photographs were altered in various increments using three variables: the incisal edge position of the maxillary incisors, gingival display, and a black triangle between the maxillary central incisors. The photographs were shown to a group of 240 Thai laypeople. The subjects were divided into two groups: a younger group, 15-29 years old (n = 120) and an older group, 36-52 years old (n = 120). Each subject was asked to score the attractiveness of each smile separately using a visual analog scale. Smile attractiveness scores concerning the incisal edge positions of the maxillary central incisors were similar between the two groups. However, upper lip coverage was rated as unattractive by the younger group. A gingival display of 0 and 2 mm was rated as most attractive by the younger group. Upper lip coverage and gingival display of 0 and 2 mm were considered attractive by the older group. Excessive gingival display (6 mm) was scored as unattractive by both groups. A black triangle ranging from 1 to 2.5 mm between the maxillary central incisors was scored differently between the two groups. The older group was more tolerant of the black triangle size. Age impacts smile perception based on maxillary gingival display and the presence of a black triangle between the maxillary central incisors, but not of the incisal edge position of the maxillary central incisors. Due to

Root resorption during orthodontic treatment with self-ligating or conventional brackets: a systematic review and meta-analysis.

PubMed

Yi, Jianru; Li, Meile; Li, Yu; Li, Xiaobing; Zhao, Zhihe

2016-11-21

The aim of this study was to compare the external apical root resorption (EARR) in patients receiving fixed orthodontic treatment with self-ligating or conventional brackets. Studies comparing the EARR between orthodontic patients using self-ligating or conventional brackets were identified through electronic search in databases including CENTRAL, PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) and SIGLE, and manual search in relevant journals and reference lists of the included studies until Apr 2016. The extraction of data and risk of bias evaluation were conducted by two investigators independently. The original outcome underwent statistical pooling by using Review Manager 5. Seven studies were included in the systematic review, out of which, five studies were statistically pooled in meta-analysis. The value of EARR of maxillary central incisors in the self-ligating bracket group was significantly lower than that in the conventional bracket group (SMD -0.31; 95% CI: -0.60--0.01). No significant differences in other incisors were observed between self-ligating and conventional brackets. Current evidences suggest self-ligating brackets do not outperform conventional brackets in reducing the EARR in maxillary lateral incisors, mandible central incisors and mandible lateral incisors. However, self-ligating brackets appear to have an advantage in protecting maxillary central incisor from EARR, which still needs to be confirmed by more high-quality studies.

Osteoarchaeological evidence for leprosy from western Central Asia.

PubMed

Blau, Soren; Yagodin, Vadim

2005-02-01

Published reports of palaeopathological analyses of skeletal collections from Central Asia are, to date, scarce. During the macroscopic examination of skeletal remains dating to the early first millennium AD from the Ustyurt Plateau, Uzbekistan, diagnostic features suggestive of leprosy were found on one individual from Devkesken 6. This adult female exhibited rhinomaxillary changes indicative of leprosy: resorption of the anterior nasal spine, rounding and widening of the nasal aperture, erosion of the alveolar margin, loss of a maxillary incisor, and inflammatory changes in the hard palate. While it is unclear whether the bones of the hands and the feet from this individual were absent as a result of collection strategy or poor preservation, lesions affecting the tibia and fibula were recorded, and the ways in which they may be related to a diagnosis of leprosy are discussed. This is the first skeletal evidence of leprosy from Central Asia and raises questions not only about the spread of the disease in the past, but also about the living conditions of what traditionally were thought of as nomadic peoples. 2004 Wiley-Liss, Inc.

15 CFR 990.53 - Restoration selection-developing restoration alternatives.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 3 2011-01-01 2011-01-01 false Restoration selection-developing... OIL POLLUTION ACT REGULATIONS NATURAL RESOURCE DAMAGE ASSESSMENTS Restoration Planning Phase § 990.53 Restoration selection—developing restoration alternatives. (a) General. (1) If the information on injury...

15 CFR 990.53 - Restoration selection-developing restoration alternatives.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Restoration selection-developing... OIL POLLUTION ACT REGULATIONS NATURAL RESOURCE DAMAGE ASSESSMENTS Restoration Planning Phase § 990.53 Restoration selection—developing restoration alternatives. (a) General. (1) If the information on injury...

Coordinating bracket torque and incisor inclination : Part 3: Validity of bracket torque values in achieving norm inclinations.

PubMed

Zimmer, Bernd; Sino, Hiba

2018-03-19

To analyze common values of bracket torque (Andrews, Roth, MBT, Ricketts) for their validity in achieving incisor inclinations that are considered normal by different cephalometric standards. Using the equations developed in part 1 (eU1 (BOP) = 90° - BT (U1) - TCA (U1) + α 1 - α 2 and eL1 (BOP) = 90° - BT (L1) - TCA (L1) + β 1 - β 2 ) (abbreviations see part 1) and the mean values (± SD) obtained as statistical measures in parts 1 and 2 of the study (α 1 and β 1 [1.7° ± 0.7°], α 2 [3.6° ± 0.3°], β 2 [3.2° ± 0.4°], TCA (U1) [24.6° ± 3.6°] and TCA (L1) [22.9° ± 4.3°]) expected (= theoretically anticipated) values were calculated for upper and lower incisors (U1 and L1) and compared to targeted (= cephalometric norm) values. For U1, there was no overlapping between the ranges of expected and targeted values, as the lowest targeted value of (58.3°; Ricketts) was higher than the highest expected value (56.5°; Andrews) relative to the bisected occlusal plane (BOP). Thus all of these torque systems will aim for flatter inclinations than prescribed by any of the norm values. Depending on target values, the various bracket systems fell short by 1.8-5.5° (Andrews), 6.8-10.5° (Roth), 11.8-15.5° (MBT), or 16.8-20.5° (Ricketts). For L1, there was good agreement of the MBT system with the Ricketts and Björk target values (Δ0.1° and Δ-0.8°, respectively), and both the Roth and Ricketts systems came close to the Bergen target value (both Δ2.3°). Depending on target values, the ranges of deviation for L1 were 6.3-13.2° for Andrews (Class II prescription), 2.3°-9.2° for Roth, -3.7 to -3.2° for MBT, and 2.3-9.2° for Ricketts. Common values of upper incisor bracket torque do not have acceptable validity in achieving normal incisor inclinations. A careful selection of lower bracket torque may provide satisfactory matching with some of the targeted norm values.

Effect of Industry Sponsorship on Dental Restorative Trials.

PubMed

Schwendicke, F; Tu, Y-K; Blunck, U; Paris, S; Göstemeyer, G

2016-01-01

Industry sponsorship was found to potentially introduce bias into clinical trials. We assessed the effects of industry sponsorship on the design, comparator choice, and findings of randomized controlled trials on dental restorative materials. A systematic review was performed via MEDLINE, CENTRAL, and EMBASE. Randomized trials on dental restorative and adhesive materials published 2005 to 2015 were included. The design of sponsored and nonsponsored trials was compared statistically (risk of bias, treatment indication, setting, transferability, sample size). Comparator choice and network geometry of sponsored and nonsponsored trials were assessed via network analysis. Material performance rankings in different trial types were estimated via Bayesian network meta-analysis. Overall, 114 studies were included (15,321 restorations in 5,232 patients). We found 21 and 41 (18% and 36%) trials being clearly or possibly industry sponsored, respectively. Trial design of sponsored and nonsponsored trials did not significantly differ for most assessed items. Sponsored trials evaluated restorations of load-bearing cavities significantly more often than nonsponsored trials, had longer follow-up periods, and showed significantly increased risk of detection bias. Regardless of sponsorship status, comparisons were mainly performed within material classes. The proportion of trials comparing against gold standard restorative or adhesive materials did not differ between trial types. If ranked for performance according to the need to re-treat (best: least re-treatments), most material combinations were ranked similarly in sponsored and nonsponsored trials. The effect of industry sponsorship on dental restorative trials seems limited. © International & American Associations for Dental Research 2015.

A comparison of wire- and Kevlar-reinforced provisional restorations.

PubMed

Powell, D B; Nicholls, J I; Yuodelis, R A; Strygler, H

1994-01-01

Stainless steel wire 0.036 inch in diameter was compared with Kevlar 49 polyaramid fiber as a means of reinforcing a four-unit posterior provisional fixed restoration with 2 pontics. Three reinforcement patterns for wire and two for Kevlar 49 were evaluated and compared with the control, which was an unreinforced provisional restoration. A central tensile load was placed on the cemented provisional restoration and the variables were measured: (1) the initial stiffness; (2) the load at initial fracture; and (3) the unit toughness, or the energy stored in the beam at a point where the load had undergone a 1.0-mm deflection. Statistical analysis showed (1) the bent wire configuration had a significantly higher initial stiffness (P < or = .05), (2) there was no difference between designs for load at initial fracture, and (3) the bent wire had a significantly higher unit toughness value (P < or = .05).

15 CFR 990.55 - Restoration selection-developing restoration plans.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 3 2011-01-01 2011-01-01 false Restoration selection-developing... POLLUTION ACT REGULATIONS NATURAL RESOURCE DAMAGE ASSESSMENTS Restoration Planning Phase § 990.55 Restoration selection—developing restoration plans. (a) General. OPA requires that damages be based upon a...

15 CFR 990.55 - Restoration selection-developing restoration plans.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Restoration selection-developing... POLLUTION ACT REGULATIONS NATURAL RESOURCE DAMAGE ASSESSMENTS Restoration Planning Phase § 990.55 Restoration selection—developing restoration plans. (a) General. OPA requires that damages be based upon a...

Response characteristics of periodontal mechanoreceptors to mechanical stimulation of canine and incisor teeth in the cat.

PubMed

Tabata, T; Suzuki, T; Watanabe, M

1995-09-01

The alveolar bone that overlies the labial aspect of the root of the right lower canine tooth was pared down until paper thin. Thirty-five periodontal mechanosensitive (PM) units sensitive to stimulation of the canine and incisor and to punctate stimulation through the thinned bone of the periodontal ligament of the canine were recorded from the inferior alveolar nerve rostral to the masseter muscle. The units showed a sustained and directionally selective response to pressure applied to the teeth. The optimal directions of stimulation for each tooth in the receptive field were parallel and oriented linguolabially. When the canine was stimulated mechanically in the optimal stimulus direction, the interspike intervals of the responses were relatively regular in most PM units (91%). The conditioning and test stimuli were applied to the adjacent canine and third incisor. The conditioning stimulus (0.10 N) was given to one of these teeth in the optimal stimulus direction. The test stimulus (0.02 N or 0.05 N) was applied to the adjacent tooth in the opposite direction in order to examine the effect of mechanical spreading of the conditioning stimulus on the adjacent tooth. In most PM units, the spike discharges evoked by the conditioning stimulus given to the incisor were stopped by the test stimulus given to the canine. When the given stimuli were reversed, the firings evoked by the conditioning stimulus were slightly depressed by the test stimulus. After removing the spot-like PM receptor site(s) in the paper-thin area of bone, all units but one did not respond to stimulation. These results provide evidence that neurones with multiple-tooth receptive fields and regular spike-interval responses recorded from the inferior alveolar nerve come from the mechanical spreading effect of the stimulation of one tooth on an adjacent tooth through the trans-septal fibre system and that neurones with irregular-interval responses are due to the ramification of PM fibres

Evaluation of Bone Thickness and Density in the Lower Incisors' Region in Adults with Different Types of Skeletal Malocclusion using Cone-beam Computed Tomography.

PubMed

Al-Masri, Maram M N; Ajaj, Mowaffak A; Hajeer, Mohammad Y; Al-Eed, Muataz S

2015-08-01

To evaluate the bone thickness and density in the lower incisors' region in orthodontically untreated adults, and to examine any possible relationship between thickness and density in different skeletal patterns using cone-beam computed tomography (CBCT). The CBCT records of 48 patients were obtained from the archive of orthodontic department comprising three groups of malocclusion (class I, II and III) with 16 patients in each group. Using OnDemand 3D software, sagittal sections were made for each lower incisor. Thicknesses and densities were measured at three levels of the root (cervical, middle and apical regions) from the labial and lingual sides. Accuracy and reliability tests were undertaken to assess the intraobserver reliability and to detect systematic error. Pearson correlation coefficients were calculated and one-way analysis of variance (ANOVA) was employed to detect significant differences among the three groups of skeletal malocclusion. Apical buccal thickness (ABT) in the four incisors was higher in class II and I patients than in class III patients (p < 0.05). There were significant differences between buccal and lingual surfaces at the apical and middle regions only in class II and III patients. Statistical differences were found between class I and II patients for the cervical buccal density (CBD) and between class II and III patients for apical buccal density (ABD). Relationship between bone thickness and density values ranged from strong at the cervical regions to weak at the apical regions. Sagittal skeletal patterns affect apical bone thickness and density at buccal surfaces of the four lower incisors' roots. Alveolar bone thickness and density increased from the cervical to the apical regions.

Forest restoration paradigms

Treesearch

John Stanturf; Brian J. Palik; Mary I. Williams; R. Kasten Dumroese

2014-01-01

An estimated 2 billion ha of forests are degraded globally and global change suggests even greater need for forest restoration. Four forest restoration paradigms are identified and discussed: revegetation, ecological restoration, functional restoration, and forest landscape restoration. Restoration is examined in terms of a degraded starting point and an ending point...

Wear, strength, modulus and hardness of CAD/CAM restorative materials.

PubMed

Lawson, Nathaniel C; Bansal, Ritika; Burgess, John O

2016-11-01

To measure the mechanical properties of several CAD/CAM materials, including lithium disilicate (e.max CAD), lithium silicate/zirconia (Celtra Duo), 3 resin composites (Cerasmart, Lava Ultimate, Paradigm MZ100), and a polymer infiltrated ceramic (Enamic). CAD/CAM blocks were sectioned into 2.5mm×2.5mm×16mm bars for flexural strength and elastic modulus testing and 4mm thick blocks for hardness and wear testing. E.max CAD and half the Celtra Duo specimens were treated in a furnace. Flexural strength specimens (n=10) were tested in a three-point bending fixture. Vickers microhardness (n=2, 5 readings per specimen) was measured with a 1kg load and 15s dwell time. The CAD/CAM materials as well as labial surfaces of human incisors were mounted in the UAB wear device. Cusps of human premolars were mounted as antagonists. Specimens were tested for 400,000 cycles at 20N force, 2mm sliding distance, 1Hz frequency, 24°C, and 33% glycerin lubrication. Volumetric wear and opposing enamel wear were measured with non-contact profilometry. Data were analyzed with 1-way ANOVA and Tukey post-hoc analysis (alpha=0.05). Specimens were observed with SEM. Properties were different for each material (p<0.01). E.max CAD and Celtra Duo were generally stronger, stiffer, and harder than the other materials. E.max CAD, Celtra Duo, Enamic, and enamel demonstrated signs of abrasive wear, whereas Cerasmart, Lava Ultimate, Paradigm MZ100 demonstrated signs of fatigue. Resin composite and resin infiltrated ceramic materials have demonstrated adequate wear resistance for load bearing restorations, however, they will require at least similar material thickness as lithium disilicate restorations due to their strength. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Analysis of the width ratio and wear rate of maxillary anterior teeth in the Korean population.

PubMed

Oh, Yeon-Ah; Yang, Hong-So; Park, Sang-Won; Lim, Hyun-Pil; Yun, Kwi-Dug; Park, Chan

2017-04-01

The purpose of this study was to compare the width ratio of maxillary anterior teeth according to age in the Korean population and to evaluate the maxillary central incisor width-to-length (W/L) ratio, given differences in age and gender. Ninety-three Korean adults were divided into 3 groups (n = 31) by age. Group I was 20 - 39 years old, Group II was 40 - 59 years old, and Group III was over 60 years of age. After taking an impression and a cast model of the maxillary arch, the anterior teeth width ratio and central incisor W/L ratio were calculated from standard digital images of the cast models using a graph paper with a digital single lens reflex (DSLR) camera. The calculated ratios were compared among all groups and central incisor W/L ratio were analyzed according to age and gender. All comparative data were statistically analyzed with one-sample t-tests, one-way ANOVAs with Tukey tests, and independent t-tests. No significant differences in maxillary anterior teeth ratios were found among the age groups. The maxillary central incisor W/L ratios in Group III were the greatest and were significantly higher than those in the other groups. The central incisor W/L ratio of men was higher than that of women in Group II. Maxillary anterior teeth width ratios were similar in all age groups in the Korean population. The maxillary central incisor was observed as worn teeth in the group over 60 years of age, and a significant difference between genders was found in 40 to 50 year olds.

Healing process of incisor teeth of diabetic rats replanted after storage in milk.

PubMed

Ricieri, Camila Benez; Sonoda, Celso Koogi; Aranega, Alessandra Marcondes; Panzarini, Sônia Regina; Poi, Wilson Roberto; Sundefeld, Maria Lúcia Marçal Mazza; Okamoto, Tetuo

2009-06-01

Several local factors that influence the healing process of replanted teeth have been investigated. However, it remains unclear how systemic alterations, such as diabetes mellitus, affect the prognosis of these cases. The purpose of this study was to evaluate the healing process of incisors of non-controlled diabetic rats replanted after storage in bovine long shelf-life (UHT) whole milk. Thirty-two rats were randomly assigned to receive an endovenous injection of either citrate buffer solution (group I - control; n = 16) or streptozotocin dissolved in citrate buffer solution to induce diabetes (group II; n = 16). After confirmation of the diabetic status by analysis of the glycemic levels, the maxillary right incisor of each animal was extracted and immersed in milk for 60 min. The root canals of teeth were then instrumented, and were filled with a calcium hydroxide-based dressing and replanted into their sockets. All animals received systemic antibiotic and were killed by anesthetic overdose 10 and 60 days after replantation. The specimens containing the replanted teeth were removed, fixed, decalcified, and embedded in paraffin. Semi-serial 6-microm-thick sections were obtained and stained with hematoxylin and eosin for histologic and histometric analyses. The results showed that the connective tissue adjacent to the root surface was less organized in the diabetic animals than in the control animals in both periods; the root dentin was less severely affected by root resorption in the diabetic rats; there were no significant differences between the control and diabetic groups regarding the occurrence of replacement resorption and inflammatory resorption.

Phase III Early Restoration Public Meetings | NOAA Gulf Spill Restoration

Science.gov Websites

Archive Home Phase III Early Restoration Public Meetings Phase III Early Restoration Public Meetings share Posted on December 6, 2013 | Assessment and Early Restoration Restoration Area Title: Phase III Early on the draft plan for the third phase of Early Restoration, which proposes more than $625 million in

Rubber dam isolation for restorative treatment in dental patients.

PubMed

Wang, Yan; Li, Chunjie; Yuan, He; Wong, May Cm; Zou, Jing; Shi, Zongdao; Zhou, Xuedong

2016-09-20

Successful restorations in dental patients depend largely on the effective control of moisture and microbes during the procedure. The rubber dam technique has been one of the most widely used isolation methods in dental restorative treatments. The evidence on the effects of rubber dam usage on the longevity of dental restorations is conflicting. Therefore, it is important to summarise the available evidence to determine the effects of this method. To assess the effects of rubber dam isolation compared with other types of isolation used for direct and indirect restorative treatments in dental patients. We searched the following electronic databases: Cochrane Oral Health's Trials Register (searched 17 August 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 7) in the Cochrane Library (searched 17 August 2016), MEDLINE Ovid (1946 to 17 August 2016), Embase Ovid (1980 to 17 August 2016), LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 17 August 2016), SciELO BIREME Virtual Health Library (1998 to 17 August 2016), Chinese BioMedical Literature Database (CBM, in Chinese) (1978 to 30 August 2016), VIP (in Chinese) (1989 to 30 August 2016), and China National Knowledge Infrastructure (CNKI, in Chinese) (1994 to 30 August 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform, OpenGrey and Sciencepaper Online (in Chinese) for ongoing trials. There were no restrictions on the language or date of publication when searching the electronic databases. We included randomised controlled trials (including split-mouth trials) assessing the effects of rubber dam isolation for restorative treatments in dental patients. Two review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies. We resolved disagreement by discussion. We included four studies

Alabama Public Scoping Meeting | NOAA Gulf Spill Restoration

Science.gov Websites

: Mobile, AL Start Time: 6:30 p.m. Central Time Description: As part of the public scoping process, the co open at 6:30 p.m. and the meeting will begin at 7:30 p.m. Location: The Battle House Renaissance Mobile Hotel & Spa 26 North Royal Street Mobile, AL 36602 (google map of location) Gulf Spill Restoration

Coordinating ecological restoration options analysis and risk assessment to improve environmental outcomes.

PubMed

Kapustka, Lawrence A; Bowers, Keith; Isanhart, John; Martinez-Garza, Cristina; Finger, Susan; Stahl, Ralph G; Stauber, Jenny

2016-04-01

Ecological risk assessment as currently practiced has hindered consideration of ecosystem services endpoints and restoration goals in the environmental management process. Practitioners have created barriers between procedures to clean up contaminated areas and efforts to restore ecosystem functions. In this article, we examine linkages between contaminant risk assessment approaches and restoration efforts with the aim of identifying ways to improve environmental outcomes. We advocate that project managers and other stakeholders use an ecological planning framework, with restoration options included upfront in the risk assessment. We also considered the opportunities to incorporate ecosystem services as potential assessment endpoints in the Problem Formulation stages of a risk assessment. Indeed, diverse perspectives of stakeholders are central to understand the relevance of social, cultural, economic, and regional ecology as influences on future use options for the landscape being restored. The measurement endpoints used to characterize the existing ecological conditions for selected ecosystem services can also be used to evaluate restoration success. A regional, landscape, or seascape focus is needed throughout the risk assessment process, so that restoration efforts play a more prominent role in enhancing ecosystem services. In short, we suggest that practitioners begin with the question of "how can the ecological risk assessment inform the decision on how best to restore the ecosystem?" © 2015 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC.

Die spacer thickness reproduction for central incisor crown fabrication with combined computer-aided design and 3D printing technology: an in vitro study.

PubMed

Hoang, Lisa N; Thompson, Geoffrey A; Cho, Seok-Hwan; Berzins, David W; Ahn, Kwang Woo

2015-05-01