Do dental implant therapies arouse signs and symptoms of temporomandibular disorders? A scoping review.

OBJECTIVE: To delineate and discuss the literature about TMD in the context of dental implantology. METHODS: The PRISMA-ScR and Joanna Briggs guidelines for scoping reviews were used as methodological parameters. In vivo studies published in the English language showing interplay between dental implant therapy and TMD were included. A systematic screen strategy was applied in two platforms to obtain a broad range of relevant literature published in English. RESULTS: The literature review indicated that prolonged surgical procedure may be a risk for TMD. Conversely, implant-supported prostheses were found to contribute to the mitigation of some TMD aspects. Empirical principles for the best practice in implant dentistry concerning the TMD were discussed in the present study. CONCLUSION: The included clinical studies suggest that factors associated with the implant placement, such as long duration of surgical procedures, may represent risk factors for TMD. They also indicate long-term benefits of implant-supported restorations.

Ocorrência simultânea de cisto dentígero e odontoma composto-complexo causando impacção dentária / Simultaneous occurrence of dentigerous cyst and compound-complex odontoma causing dental impaction

O presente trabalho ilustra e discute essa doença que representa o tumor odontogênico mais comum da prática clínica, o Odontoma. Para tal, apresenta um caso clínico com imagens clínicas e radiográficas esclarecedoras dos aspectos dessa doença, bem como discussão a partir de revisão narrativa de literatura direcionada para a carac-terização da doença. Relata-se o caso de um odontoma composto-complexo, uma forma incomum de odontoma, mas que mantém os demais aspectos usuais, sendo uma mulher de 21 anos com lesão radiopaca em maxila de-tectada devido à não erupção do 23. A remoção cirúrgica seguiu a partir de acesso anterior na maxila e o exame histopatológico mostrou os aspectos típicos de um Odontoma composto e complexo juntos. Independentemente da variante, nota-se que o Odontoma é quase sempre indolente, porém requer cuidados de remoção precoce devido à possibilidade de crescimento, de desenvolvimento de cistos e comprometimento de estruturas adjacentes devido a sua localização e possibilidade de crescimento (AU)

The present work illustrates and discusses this disease that represents the most common odontogenic tumor in clinical practice, the Odontoma. However, an unusual variation of the same is included here in the literature, char-acterized by the exams as a form of compound-complex odontoma additionally causing dentigerous cyst formation and dental impaction. The unusual case occurred in a 21-year-old woman, complaining of missing the tooth 23. The details of the exams allowed the visualization of compound and complex areas in the lesion, cystic formation and dental impaction. The histopathological findings confirmed the diagnosis of the Odontoma, and the interpreta-tion with the set of other exams led to the final diagnosis of Compound-complex odontoma with dentigerous cyst. The present case highlights the need for early removal of Odontoma due to the possibility of developing cysts, compromising adjacent structures, in addition to its growth potential already reported in the literature (AU)

In-vitro comparison of mechanical resistance between two straight plates and a Y-plate for fixation of mandibular condyle fractures.

OBJECTIVE: To compare the mechanical resistance of conventional plates with a modified Y-plate in mandibular condyle fracture. MATERIALS AND METHODS: 40 synthetic hemi-mandibular polyurethane replicates were used. Two groups of fixing materials were included: 20 mandibles fixed with 40 straight plates with four roles each (2.0 mm system) and 20 mandibles fixed with 20 Y-shaped plates (2.0 mm system and 1.5 mm thickness). The samples were submitted to linear loading in the following directions: 10 mandibles from each group from lateral to medial and 10 mandibles from each group from anterior to posterior. A universal loading machine, Instron Universal 4411, was used to performed the tests, and the resistance of each fixed mandible was assessed at displacements of 1 mm, 3 mm, and 5 mm. The t-test for independent samples was performed. The p value was set at <0.05. RESULTS: The worst mechanical resistance was found in the Y-plates loaded from anterior to posterior. The best mechanical resistance was in two straight hole plates loaded from lateral to medial. The Y-plates and two straight hole plates showed similar resistance when a lateral to medial load was applied. CONCLUSION: There was no difference between the plates when lateral to medial loading was tested.

Reabilitação de fratura complexa de mandíbula atrófica com placa tipo locking ­ relato de caso / Atrophic mandible complex fracture rehabilitation with locking type plate ­ case report

A atrofia óssea devido a perdas dentárias ocasiona diminuição da altura e espessura do reordo, tornando a mandíbula susceptível a fraturas. Pode-se considerar atrófica, quando a altura óssea não ultrapassa 20 mm. Essas fraturas acometem principalmente a população idosa, porque além da atrofia óssea subsequente ao edentulismo, a redução da vascularização contribui para o enfraquecimento da mandíbula nos pacientes desse grupo etário. O tratamento dessas fraturas permanece um desafio cirúrgico e não há consenso quanto à melhor técnica de tratamento. Isso devido a fatores inerentes a essa patologia, a relativa raridade da mesma, o que gera inexperiência dos cirurgiões e a escassez de informação sobre o tema na literatura cirúrgica. O objetivo deste trabalho consiste em descrever um caso de tratamento de fratura em mandíbula atrófica, no qual foi realizada a correção cirúrgica da fratura através da técnica de redução aberta com acesso intrabucal que se estendeu da região retromolar direita à mesma região contralateral e de segmentos ósseos fixados com uma placa de reconstrução do sistema 2.0 mm, tipo locking e parafusos bicorticais (AU).

Bone atrophy due to tooth loss causes a decrease in bone height and thickness, making jaw susceptible to fractures. It can be considered atrophic when the bone height does not exceed 20 mm. These fractures mainly occlude the elderly population, because in addition to bone atrophy subsequent to edentulism, the reduction of vascularization contributed to mandible weakening in the patients of this age group. The treatment of these fractures remains a surgical challenge and there is no consensus in relation to the best treatment technique. This is due to factors inherent to this pathology, its relative rarity, which generates surgeon's inexperience, and scarcity of information on the subject in surgical literature. The aim of this work is to describe a clinic case of fracture treatment in an atrophic mandible, in which surgical fracture correction was performed through the technique of open reduction and intrabuccal access that extended from the right retromolar region to the same contralateral region and the bone segments fixed with a 2.0mm system rebuilding plate, locking type and bicortical screws (AU).

Influence of degree of edentulism in mandible fractures / Influência do grau de edentulismo em fraturas mandíbulas

Objective ­ To characterize epidemiologically the aspects of incidence, treatment and complications of mandibular fractures in dentate, partially dentate and edentulous patients. Methods ­ Data were collected from medical records of patients seen by the department of Oral and Maxillofacial Surgery, Piracicaba School of Dentistry/UNICAMP, from January 1999 to October 2009. Results ­ Were selected 738 adult patients, grouped into three age groups (18 to 30 years, 31-64 years and over 64 years), whose degree of edentulism was informed, being 330 dentition (45%), 367 partially serrated (50%) and 41 edentulous (5%). The ratio between male and female was 4:1, mean age of 31 years, with higher incidence in caucasians, and 81% were economically active. The most common causes were traffic accidents (54%), followed by assault (20%), falls (15%), sports accidents (4%) and work (4%). Condylar fractures accounted for 29% of all fractures, followed by fractures of the body (25%), symphysis (24%) and angle (19%). The only significant difference between the sites of fracture was found in the edentulous, which presented a low incidence of angle fractures. Conclusions ­ It was observed that this population, homogeneous as to the cultural and socio-environmental factors, the dentate, partially dentate and edentulous behaved similarly as to the mandibular fractures resulting from trauma energies of similar intensities.

Objetivo ­ Caracterizar epidemiologicamente os aspectos de incidência, tratamento e complicações de fraturas mandibulares em pacientes dentados, parcialmente dentados e edêntulos. Métodos ­ Os dados foram coletados de prontuários de pacientes atendidos pelo departamento de Cirurgia Oral e Maxilofacial, Faculdade de Odontologia de Piracicaba/UNICAMP, de janeiro de 1999 a outubro de 2009. Resultados ­ Foram selecionados 738 pacientes adultos, agrupados em três faixas etárias (18 a 30 anos, 31-64 anos e mais de 64 anos), cujo grau de edentulismo foi informado, sendo 330 dentições (45%), 367 parcialmente serrilhadas (50%) e 41 edêntulas (5%). A proporção entre homens e mulheres foi de 4:1, idade média de 31 anos, com maior incidência em caucasianos e 81% economicamente ativas. As causas mais comuns foram os acidentes de trânsito (54%), seguidos pelo assalto (20%), quedas (15%), acidentes esportivos (4%) e trabalho (4%). As fraturas condilares representaram 29% de todas as fraturas, seguidas de fraturas do corpo (25%), sínfise (24%) e ângulo (19%). A única diferença significativa entre os locais de fratura foi encontrada no edêntulo, que apresentou baixa incidência de fraturas angulares. Conclusões ­ Observou-se que esta população, homogênea quanto aos fatores culturais e socioambientais, dentada, parcialmente dentada e edêntula, comporta-se de forma semelhante às fraturas mandibulares resultantes de energias de trauma de intensidades semelhantes.

Evaluation of cyclic and linear mechanical resistance of prebent and manually-bent plates used for maxillary advancement in orthognathic surgery.

The aim of the present study was to compare prebent and manually-bent plates used in maxillary advancement. The prebent plates were fixed in polyurethane blocks for the linear test and aluminium blocks for the cyclic test, and the manually-bent plates were fixed in polyurethane and aluminium blocks. The linear load tests were done using an Instron® 4411 mechanical testing machine and the cyclic test with an Instron® E3000 testing machine. The linear mechanical test showed that there was no significant difference between the plates. In the cyclic test the prebent plates reached the limit of 500000 cycles without fracturing whereas the manually-bent plate group fractured before reaching the limit of cycles (p=0.008). The decision to use prebent or manually-bent plates during operations should be influenced by the production of the bends and their consequent brittleness.

Mechanical and photoelastic analysis of conventional screws and cannulated screws for sagittal split osteotomy fixation: a comparative study.

PURPOSE: The aim of the present study was to use mechanical and photoelastic tests to compare the performance of cannulated screws with solid-core screws in sagittal split osteotomy fixation. METHODS: Ten polyurethane mandibles, with a prefabricated sagittal split ramus osteotomy, were fixed with an L inverted technique and allocated to each group as follows: cannulated screw group (CSG), fixed with three 2.3-cannulated screws; and solid-core screw group (SCSG), fixed with three 2.3-solid-core screws. Vertical linear loading tests were performed. The differences between mean values were analyzed through T test for independent samples. The photoelastic test was carried out using a polariscope. RESULTS: The results revealed differences between the two groups only at 1 mm of displacement, in which the cannulated-screw revealed more resistance. Photoelastic test showed higher stress concentration close to mandibular branch in the solid-core group. CONCLUSIONS: Cannulated screws performed better than solid-core ones in a mechanical test at 1-mm displacement and photoelastic tests.

Mechanical and photoelastic analysis of four different fixation methods for mandibular body fractures.

OBJECTIVE: The aim of the present study was to compare four methods of fixation in mandibular body fractures. STUDY DESIGN: Mechanical and photoelastic tests were performed using polyurethane and photoelastic resin mandibles, respectively. The study groups contained the following: (I), two miniplates of 2.0 mm; (II) one 2.0 mm plate and an Erich arch bar; (III) one 2.4 mm plate and an Erich arch bar, and (IV) one 2.0 mm plate and one 2.4 mm plate. The differences between the mean values were analyzed using Tukey's test, the Mann-Whitney test and the Bonferroni correction. RESULTS: Group II recorded the lowest resistance, followed by groups I, IV and III. The photoelastic test confirmed the increase of tension in group II. CONCLUSION: The 2.4 mm system board in linear mandibular body fractures provided more resistance and the use of only one 2.0 mm plate in the central area of the mandible created higher tension.

Development plates for stable internal fixation: Study of mechanical resistance in simulated fractures of the mandibular condyle.

OBJECTIVE: To develop Y-shaped plates with different thicknesses to be used in simulated fractures of the mandibular condyle. Ten plates were developed in Y shape, containing eight holes, and 30 synthetic polyurethane mandible replicas were developed for the study. MATERIAL AND METHODS: The load test was performed on an Instron Model 4411 universal testing machine, applying load in the mediolateral and anterior-posterior positions on the head of the condyle. Two-way ANOVA with Tukey testing with a 5% significance level was used. RESULTS: It was observed that when the load was applied in the medial-lateral plate of greater thickness (1.5 mm), it gave the highest strength, while in the anteroposterior direction, the plate with the highest resistance was of the lesser thickness (0.6 mm). A plate with a thickness of 1.5 mm was the one with the highest average value for all displacements. In the anteroposterior direction, the highest values of resistance were seen in the displacement of 15 mm. CONCLUSION: After comparing the values of the biomechanical testing found in the scientific literature, it is suggested that the use of Y plates are suitable for use in subcondylar fractures within the limitations of the study.

Perception of oral and maxillofacial surgeons, orthodontists and laypersons in relation to the harmony of the smile.

OBJECTIVE: Harmony is one of the main objectives in surgical and orthodontic treatment and this harmony must be present in the smile, as well as in the face. The aim of the present study was to assess the perceptions of professionals and laypersons in relation to the harmony of the smile of patients with or without vertical maxillary alterations. MATERIALS AND METHODS: Sixty observers (oral and maxillofacial surgeons, orthodontists and laypersons) reported the degree of harmony of six smiles using an objective questionnaire and the participants indicated if there was a need for corrective surgery or not. The classification of observers was recorded on a Likert scale from 1 to 5. Mixed regression was used to determine differences between the three groups. RESULTS: Statistically significant differences were found only for the harmony of the smile between the oral and maxillofacial surgeons and laypersons, with laypersons being more critical when assessing the smile. There was no statistical difference between the other groups for the harmony of the smile or the indication of corrective surgery. The patterns of greater or lesser harmony determined by observers during the smile were similar to those found in the literature as the ideal standard in relation to vertical maxillary positioning. CONCLUSIONS: Laypersons had a tendency to be more critical in relation to facial harmony than surgeons, although no statistical differences were found in the other groups in relation to the harmony of the smile or indication for the corrective surgery. In addition, the patterns of greater or lesser harmony of the smile determined by the participants were similar to those found in the literature as the ideal standard in relation to vertical maxillary positioning. Overall, the present study demonstrates that adequate interaction between surgeons, orthodontists and laypersons is essential in order to achieve facial harmony with orthodontic and/or surgical treatment. CLINICAL RELEVANCE: Opinion of specialists and laypersons about the smile in relation to the vertical positioning of the maxilla.

Assessment of the fixation of mandibular symphysis fractures using conical cannulated screws: mechanical and photoelastic tests.

OBJECTIVE: The aim of this study was to use mechanical and photoelastic tests to compare the performance of cannulated screws with other fixation methods in mandibular symphysis fractures. STUDY DESIGN: Ten polyurethane mandibles were allocated to each group and fixed as follows: group PRP, 2 perpendicular miniplates; group PLL, 1 miniplate and 1 plate, parallel; and group CS, 2 cannulated screws. Vertical linear loading tests were performed. The differences between mean values were analyzed with the Tukey test. The photoelastic test was carried out using a polariscope. RESULTS: The results revealed differences between the CS and PRP groups at 1, 3, 5, and 10 millimeters of displacement. The photoelastic test confirmed higher stress concentration in all groups close to the mandibular base, whereas the CS group showed it throughout the region assessed. CONCLUSIONS: Conical cannulated screws performed well in mechanical and photoelastic tests.

Fractographic analysis of 2.0-mm plates with a screw locking system in simulated fractures of the mandibular body.

PURPOSE: The purpose of the present study was to analyze the fractured plates from 2 brands of 2.0-mm locking fixation systems submitted to axial linear load testing. MATERIALS AND METHODS: Four aluminum hemimandibles with linear sectioning to simulate a mandibular body fracture were used as a substrate and fixed with 2 fixation techniques from 2 national brands: Tóride and Traumec. The techniques were as follows: one 4-hole plate, with four 6-mm screws in the tension zone, and one 4-hole plate, with four 10-mm screws in the compression zone; and one 4-hole plate, with four 6-mm holes in the neutral zone. The hemimandibles were submitted to vertical linear load tests using an Instron 4411 mechanical test machine. The system was submitted to the test until complete failure had occurred. Next, a topographic analysis of the surface of the plates was performed using a stereomicroscope and an electronic scanning microscope. The samples were evaluated using different magnifications, and images were obtained. RESULTS: The surface of the fracture analyzed in scanning electron microscopy demonstrated a ductile-type fracture, usually found in the traction test bodies of ductile materials, such as titanium. No evidence of failure was observed in any fracture surface from a change in the structure or composition of the material. CONCLUSIONS: The plates were fractured by a ductile rupture mechanism, as expected, suggesting that the manufacturing of the national brand name plates used in the present study has been under adequate quality control, with no structural changes produced by the manufacturing process that could compromise their function.

Biomechanical strength analysis of mini anchors for the temporomandibular joint.

INTRODUCTION: The usage of mini anchors for the treatment of internal derangements of the temporomandibular joint (TMJ) is considered an innovative treatment, and it has presented excellent clinical results in the stabilization of the articular disc. This study aimed to evaluate, through mechanical tensile testing, the resistance of mini anchors for TMJ articular disc repositioning. MATERIALS AND METHODS: Ten thermoplastic polymer poly-ether-ether-ketone (PEEK) mini anchors were tested in artificial polyurethane blocks with a pullout test in a mechanical Instron™ machine, model 4411. The mini anchors were pulled out until failure and the force and displacement were recorded for each specimen. A small standard deviation was noted, which indicated reproducibility. RESULTS: The findings indicate that Cillen™ mini anchors presented a mean force at failure up to 46.1 N with similar values in the scientific literature. Nevertheless, further studies should be conducted for a comparison of PEEK mini anchors with other commercially available anchors, in addition to studies related to PEEK, a scarcely known material in the dentistry field.

Hipertrofia unilateral do músculo master: relato de caso / Unilateral Masseter Muscle Hypertrophy: Case Repor

A hipertrofia do músculo masseter é um crescimento excessivo uni ou bilateral do músculo, de etiopatogenia ainda não definida que, na maioria das vezes, gera um desconforto estético e em alguns casos, funcional. Os indivíduos afetados frequentemente exibem um aumento em volume ósseo em região de ramo e ângulo mandibular e o tratamento pode ser através de métodos cirúrgicos ou não cirúrgicos. A abordagem cirúrgica envolve intervenções que são realizadas, apenas, na musculatura comprometida, na estrutura óssea do ângulo mandibular ou ambos. O presente artigo descreve um caso de hipertrofia unilateral do músculo masseter, onde optou-se pela intervenção cirúrgica intraoral com ressecção de fibras musculares e osteotomia do ângulo mandibular. Após um período de dois meses de acompanhamento, observa-se que a modalidade cirúrgica para tratamento de hipertrofia do masseter está bem indicada pois proporciona ótimo resultado estético... (AU)

Masseter muscle hypertrophy is a unilateral or bilateral enlargement of the masseter muscle, of undefined etiology, which in most cases generates an aesthetic discomfort, and in some cases a functional one as well. The affected individuals often exhibit an increase in bone mass in the region of the branch and mandibular angle, and the treatment can use surgical or nonsurgical methods. The surgical approach involves intervetions performed in either the compromised muscle or the mandibular angle bone structure, or in both. This article describes a case of unilateral masseter muscle hypertrophy, where the surgical resection of the muscle fibers in an intraoral approach and a osteotomy with a reciprocating saw were performed in the mandibular angle region. After a two-month follow-up, it was observed that the surgical approach for the treatment of masseter hypertrophy is well advised, since the aesthetic results are excellent, with similarity to the contralateral side of mandibular angle... (AU)