Objetivo: realizar a caracterização do sistema miofuncional orofacial de indivíduos adultos com fraturas de face, que foram submetidos à procedimentos cirúrgicos distintos para a correção das fraturas (redução aberta e fechada). Métodos: 57 participantes divididos em três grupos: G1- composto por 19 indivíduos submetidos a redução aberta de pelo menos uma das fraturas faciais; G2- composto por 19 indivíduos submetidos a redução fechada da fratura; GC - 19 indivíduos voluntários saudáveis, sem alterações no sistema miofuncional orofacial. Todos os participantes foram submetidos à avaliação que consistiu na aplicação de um protocolo clínico para a avaliação da motricidade orofacial, a amplitude dos movimentos mandibulares e a avaliação da musculatura mastigatória por meio da eletromiografia de superfície (EMGs). Resultados: os resultados indicaram que para avaliação clínica da motricidade orofacial, ambos os grupos com fratura de face se diferenciaram do grupo controle, apresentando prejuízo na mobilidade dos órgãos fonoarticulatórios e nas funções de mastigação e deglutição. Os grupos com fratura de face não se diferenciaram neste item da avaliação. Quanto às medidas de amplitude mandibular, os grupos com fratura de face também se diferenciaram do grupo controle, apresentando maior restrição da mobilidade mandibular. Nesta etapa da avaliação, o grupo submetido à redução fechada da fratura apresentou maior amplitude de movimentos, se comparado ao grupo submetido à redução aberta da mesma, principalmente para a medida de abertura oral máxima. Na avaliação eletromiográfica dos músculos mastigatórios, o grupo submetido à redução aberta da fratura apresentou menor ativação muscular se comparado aos demais grupos. Ambos os grupos com fraturas de face se diferenciaram significantemente do grupo controle quando considerado o índice de assimetria do músculo masseter, apresentando funcionamento muscular mais assimétrico na tarefa de máxima intercuspidação dentária. Conclusão: Os pacientes com trauma de face apresentam alterações significativas em postura, mobilidade, funções orofaciais, amplitude mandibular e na atividade eletromiográfica. O tipo de tratamento médico não influenciou os resultados da funcionalidade muscular no período de até seis meses após a correção da fratura / Purpose: to characterize the oral-motor sytem of adults with facial factures, comparing the performance of individuals submitted to open and closed surgical treatment. Methods: 57 adults divided into three groups: G1 - 19 individuals submitted to open surgery for the correction of at least one of the facial fractures; G2 - 19 individuals submitted to closed surgery for the correction of facial fractures; GC - 19 voluntary healthy individuals, with no alterations of the orofacial myofunctional system. All participants underwent the same assessment: clinical assessment of the orofacial myofunctional system; evaluation of the mandibular range of movements; and surface electromyography (sEMG) of the masticatory muscles. Results: the results indicated that both groups with facial fractures presented significant differences when compared to the control group, in terms of the mobility of the oral-motor organs, mastication and swallowing. However, the groups with facial fractures did not differ in performance. Regarding the measurements obtained for the mandibular movements, both groups with facial fractures presented significant differences when compared to the control group, indicating greater restrictions in mandibular movements. The group submitted to closed surgery presented better range of movements when compared to the group submitted to open surgery, especially when considering the measurement of maximal mandibular opening. When analyzing the results of the sEMG, the group submitted to open surgery presented lower muscle activation when compared to the other two groups. Both groups with facial fractures differed significantly from the control group when considering the index of asymmetry for the masseter muscle, presenting a more asymmetrical muscle function during the task of maximum voluntary teeth clenching. Conclusion: Patients with facial trauma present significant deficits in posture, mobility and function of the oral motor system. The type of medical treatment did not have an influence on the results of muscle function during the first six months after fracture reduction

A Disfunção Temporomandibular (DTM) se refere a várias doenças que envolvem os músculos da mastigação e/ou a articulação temporomandibular (ATM). Ao longo da história, o desenvolvimento de técnicas de imagem possibilitou a avaliação das disfunções intra-articulares. A Ressonância Magnética (RM) é considerada o melhor método de avaliação de imagem para diagnosticar doenças da ATM e o exame mais preciso para detectar a posição do disco articular e visualizar estruturas ósseas, como a cabeça da mandíbula e a fossa mandibular, complementando o exame clínico. A associação entre sinais e sintomas de DTM e achados na RM é controversa na literatura e a correlação entre a posição da cabeça da mandíbula dentro da fossa mandibular e a sintomatologia de pacientes diagnosticados com DTM foi pouco elucidada pelos autores. O objetivo do estudo foi analisar os achados imaginológicos da ressonância magnética quanto à posição da cabeça da mandíbula e quanto à posição do disco articular, verificando sua correlação com os sinais clínicos de estalo e de dor à palpação muscular e articular relatados pelo paciente. Foram analisados 163 prontuários contendo ficha clínica e exame de RM de pacientes com DTM. As fichas clínicas forneceram dados referentes a sinais e sintomas dos pacientes, como presença de estalo e de dor à palpação, e o exame de imagem possibilitou a classificação da posição do disco articular (em posição, deslocado com redução e deslocado sem redução) e da cabeça da mandíbula (concêntrica, posterior e anterior). As variáveis clínicas e imaginológicas foram avaliadas por meio de um método de classificação que proporcionou uma análise dos dados sob o ponto de vista holístico, levando em consideração a situação clínica das duas ATMs do mesmo paciente simultanamente. Os dados obtidos foram analisando usando o teste exato de Fischer. A classificação adotada dificultou a comparação com outros estudos, já que usualmente os autores fazem a somatória das articulações do lado direito e esquerdo, porém é válida por proporcionar uma análise das variáveis clínicas e imaginológicas dentro de um sistema, que é o indivíduo. No estudo, 20,2% dos pacientes eram homens e 79,8% eram mulheres com média de idade de aproximadamente 37 anos. Os pacientes se distribuíram em maior porcentagem quando houve a mesma posição dos discos articulares bilateralmente (65,0%), porém quanto à cabeça da mandíbula, combinações heterogêneas foram observadas em maior quantidade (60,7%). Apenas 19,1% da amostra não possuía estalo e 25,8% apresentavam dor posterior à cápsula articular. Os músculos mais álgicos foram pterigoideo lateral e masseter, já os menos álgicos foram temporal posterior e cervical. A média de dor total muscular e articular (10,56) se mostrou maior do que a média de dor muscular (9,60) nos pacientes. A dor total em pacientes com ausência de dor posterior à cápsula articular foi significativamente menor do que a dor total em pacientes que apresentam dor posterior à cápsula bilateral. Não houve correlação entre a posição do disco articular e da cabeça da mandíbula, nem entre as variáveis clínicas e imaginológicas. A nova metodologia proposta permitiu a observação de que a maioria dos pacientes apresenta discos bilateralmente concordantes quanto à posição e que a presença de artralgia está relacionada à maior quantidade de músculos álgicos à palpação. / Temporomandibular Disorder (TMD) refers to various diseases involving masticatory muscles and/or temporomandibular joint (TMJ). Throughout history, the development of imaging techniques enabled the evaluation of intra-articular disorders. Magnetic resonance imaging (MRI) is considered the best method for evaluating image to diagnose TMJ diseases and most accurate test to detect the position of the articular disc and display bone structures as the condyle and glenoid fossa, complementing the clinical examination. The association between signs and symptoms of TMD and MRI findings in the literature is controversial and the correlation between the position of the condyle within the fossa and symptoms of patients diagnosed with TMD was somewhat elucidated by the authors. The aim of the study was to analyze the findings of magnetic resonance imaging as the position of the condyle (posterior, anterior or concentric) and on the position of the articular disc (in position, displaced with or without reduction), verifying its correlation with clinical signs clicking and pain on palpation of muscle and joint reported by the patient. We analyzed 163 records containing medical records and MRI in patients with TMD. The medical records provided data for signs and symptoms of patients such as presence of clicking and pain on palpation, and imaging examination allowed the classification of the position of the articular disc (in position, displaced with reduction and displaced without reduction) and condyle (concentric, posterior and anterior). The clinical and imaging procedures were evaluated using a grading method that provided an analysis of the data under the holistic point of view, taking into account the clinical condition of the two TMJs of the same patient. Data were analyzed using the Fisher exact test. The classification adopted it was difficult to compare with other studies, since usually the authors make the sum of the joints of the right and left side, however it is valid for providing an analysis of clinical and imaging procedures within a system, that is the individual. In the study, 20.2% were men and 79.8% were women with a mean age of approximately 37 years. The patients were divided into greater percentage when there was the same position of the articular disc bilaterally (65.0%), but as condyle heterogeneous combinations were observed in greater amounts (60.7%). Only 19.1% of the sample had no clicking and 25.8% had joint pain. The muscles more algesic were lateral pterygoid and masseter muscles, the less pain conditions were already temporal posterior and cervical. The average overall muscle and joint pain (10.56) was larger than the average muscle pain (9.60) in patients. The total pain in patients with no joint pain was significantly lower than the total pain in patients with bilateral joint pain. There was no correlation between the position of the articular disc and the condyle, or between clinical and imaging procedures. The new methodology allowed the observation that the majority of patients have bilateral agreement discs considering the position and the presence of arthralgia is closely related to the amount of muscles on palpation pain conditions.

In order to investigate growth modifications of the temporomandibular joint (TMJ) during dentofacial orthopaedic treatment, various functional appliances have been used to prompt the mandible into a protrusive position in various animal experimental models. The general purpose of this project was (i) to test the effectiveness of a functional appliance specially designed for sheep; (ii) to clarify whether or not forward mandibular displacement in sheep is associated with faster and/or redirected condylar growth; (iii) to evaluate the sheep as a model for dentofacial orthopaedic research by comparing the similarities of mandibular condylar growth in sheep and humans; (iv) to detail the position of the mandible during forward mandibular posturing and the effects of mandibular forward displacement on modelling and remodelling of the mandibular condyle. The specific purpose of this project was to reveal whether functional appliance treatment increases the quantity of bone formed during the treatment, or changes the distribution of the bone, or both. Eight, 4-month old, castrated male Merino sheep were randomly assigned to experimental or control groups with 4 in each group. Cast functional appliances were fabricated for the animals in the experimental group. The treatment period was 15 weeks. Calcein (day 1) tetracycline (13 weeks) and alizarin red S (3 days before sacrifice) fluorochromes were administered to all animals. Dental casts, endosseous implant markers and cephalograms were used to analyse the 3-D displacement of the mandible. Undecalcified mid-sagittal sections of TMJ were used to evaluate the tissue responses induced by the appliances. Dynamic parameters of bone formation, static indices of bone-forming and resorbing activity as well as structural indices of trabecular bone were estimated using histomorphometry. The trabecular bone was sampled from two regions: (i) a subchondral region; (determined by 2nd and 3rd labels), believed to comprise bone newly-formed during the experimental period; and (ii) a central region (labelled by all the three fluorochromes), believed to comprise bone which existed before the experiment. The cortical bone was divided into anterior and posterior regions for analysis. The weight of the animals was measured monthly to monitor their growth. Metacarpus growth was also evaluated. During the experimental period, the animals were found to maintain their weight within the normal range and grew normally. The appliance was found to displace the mandible to a downward and forward position with a net condylar displacement of 2.4 mm. The observed adaptive responses in the TMJ induced by the appliances included; the condylar process was less tapered and rounder in the experimental group than in the controls, and anteriorly thickened condylar cartilage and a thickened compact bone layer along the anterior surface of the posterior wall of the glenoid fossa. The mandibular condylar growth vector in sheep was found to be in a postero-superior direction. Condylar growth in the control sheep during the experimental period varied from 8.8 to 11.9 mm, with the mean being 10.6 mm, which is quantitatively similar to two years of condylar growth in human adolescents. In the experimental sheep, the condylar growth varied from 8.5 to 13.3 mm, with the mean being 11.4 mm. When metacarpal growth and weight gain were taken into consideration using multivariant analysis, the coefficients for growth in the postero-superior and posterior direction were found to be high, with adjusted r2 as 0.84 and 0.82 respectively. The induced condylar growth was estimated to be largest in the posterior direction (2.3 mm), which is also similar to previous reports in humans. Regional differences in adaptive response within the mandibular condyle were found in this study. In the experimental group, bone volume fraction (BV/TV) of the subchondral regions decreased, although the specific bone surface and bone formation rates increased. This low BV/TV was associated with decreased trabecular thickness and increased trabecular separation. In the central region of the experimental group's condyle, BV/TV was unchanged. However, an increased osteoid surface (OS/BS) was defined when the eroded surface (ES/BS) was taken into consideration. The sheep were found to cope well with the experimental procedures and the appliance used in this study has been effective in inducing adaptive responses in the TMJ. Consequently, it is believed that the sheep is an appropriate animal model for quantitative histological analysis of the responses to functional appliance treatment. The first null hypothesis, that functional appliance treatment has no effect on bone matrix mineralisation was rejected. The second null hypothesis, functional appliance treatment has no effect on the mineralisation lag time, was rejected. The results indicated that the treatment effects of functional appliances involve reorganisation of the TMJ through bone modelling and remodelling. An important mechanism of functional appliance treatment is, therefore, suggested to be a change in the distribution of bone rather than an increase in the quantity of bone. Posterior rotation of the principle tensile strain angle (Et) suggested an posteriorly altered direction of the condylar growth. Increased new bone formation in the glenoid fossa suggested an anterior re-positioning of the temporomandibular joint. / Thesis (Ph.D.)--Dental School, 2002.

A distrofia muscular de Duchenne (DMD) é uma doença de caráter hereditário recessivo ligado ao cromossomo X, que determina a ausência da distrofia, a responsável pela progressiva degenaração muscular observada no DMD. Embora não expresse o fenótipo, a camundongo mdx apresenta a ausência da distrofia e o mais comum modelo animal experimental para estudar as repercursões da DMD em muitos orgãos. Este estudo foi realizado na cartilagem do processo condilar da mandíbula de mdx, um importante sítio de crescimento craniofacial. Assim, o PC dos mdx de 4 (G1) e 10 (G2) semanas e dos respectivos controles (camundongos c57BL/10 mice) foram avaliados usando as técnicas de microscopia de luz (H.E, Picrosirius e Safranina-O) e de imunohistoquímica (IGF e IGF-IR). Em ambos os grupos, não houve diferença estatísticamente significante na área do PC e comparação aos controles. O número de e a área dos condrócitos, bem como, a quantidade de matriz extracelular (MEC) forma menores nos grupos mdx. A imunorreatividade para ambos, IGF-I e IGF-IR, proporcionalmente maiores nos grupos mdx. Os dados quantitativos e predominância do colágeno tipo I nos grupos mdx, sugere um processo precoce de envelhecimento na cartilagem do PC desses animais. / The duchenne muscular dystrophy (DMD) is a recessive hereditary disease linked to X-chromossome that determines teh dystrophin abstence, the responsible for progressive muscle degeneration observed in DMD. Although not exhibit the phenotype, the MDX mouse reveal abstence of dystrophin and is the most common experimental animal model for DMD studies in many organs. This study was performed in the articular cartilage of the mandibular condylar process (PC) of MDX, an important site of craniofacial growth. Thus the PC of MDX and respective controls (C57BL/10 mice) were evaluated at the ages of 4 (G1) and 10 (G2) weeks using ligth microscopy (H.E, Picrosirius e Safranin-O) and immunohistochemical (IGF-I e IGF-IR) tecniques. In both groups, there was no statistical significant difference in PC area of the mdx and the respective controls. The number and area of the chondrocytes, as well as the amout of extracellular matrix (MEC) were lower in MDX groups. The immunoreactivity for both, IGF-I and IGF-IR, were propostionally higher im MDX groups. The quantitative data and the predominance of collagen type i fibers in the MDX groups suggest a premature aging process of the PC in these animals.

A associação entre sinais e sintomas de Disfunções Temporomandibulares (DTM) e achados em imagens de ressonância magnética (RM) tem sido controversa, dessa forma, este estudo avaliou a posição do disco, pelo método do relógio, e verificou a associação com a posição da cabeça da mandíbula, com a dor muscular à palpação, abertura passiva e ativa, presença de estalo e idade em pacientes portadores de DTM que foram submetidos ao exame de RM. O disco foi classificado em 0- posição normal (banda posterior em 11 e 12 horas); 1- início do deslocamento (posição entre 11 e 10 horas); 2- deslocamento médio (posição entre 10 e 9 horas); e 3- deslocamento avançado (posição entre 9 e 8 horas). A posição da cabeça da mandíbula foi classificada de acordo com o método de Pullinger em 1- posterior; 2- anterior; e 3- concêntrica. As classificações foram realizadas por três examinadores. A associação entre os dados clínicos e imaginológicos foi realizada utilizando o coeficiente de correlação intraclasse, coeficiente de correlação de Spearman, análise de variância, teste exato de Fisher ou teste de Kruskal-Wallis conforme a necessidade, com 5% de nível de significância. Sessenta casos foram incluídos no estudo, com predomínio de mulheres e média de 37 anos de idade. Houve concordância excelente entre os examinadores para posição do disco e da cabeça da mandíbula, porém não houve correlação entre essas duas variáveis. A presença de estalo, dor muscular à palpação e amplitude de abertura de boca também não apresentaram correlação estatisticamente significante com a posição do disco. Apenas a dor muscular à palpação foi associada a abertura de boca (p<0,05). Conclui-se que não há associação entre sinais e sintomas clínicos e posição do disco com a posição da cabeça de mandíbula em pacientes portadores de DTM. / The association between signs and symptoms of temporomandibular disorders (TMD) and findings on magnetic resonance imaging (MRI) has been controversial, thus, this study evaluated the disc position, by the clock method, and verified the association with the condyle position, muscle pain on palpation, passive and active opening, presence of temporomandibular joint (TMJ) sound and age in patients with TMD who underwent MRI. The disc position was classified as 0 - normal position (posterior band at 11 and 12 hours); 1 - mild displacement (position between 11 and 10 hours); 2 - Moderate displacement (position between 10:09 hours); and 3 - Severe displacement (position 9 to 8 hours). The condyle position was graded according to the Pullinger\'s method as 1 - posterior; 2 - anterior; and 3 - concentric. Three examiners performed the analyses. The association between clinical and imaging data was performed using the intraclass correlation coefficient ICC -, Spearman correlation coefficient, analysis of variance, Fisher\'s exact test or Kruskal-Wallis test as appropriate, with 5% significance level. Sixty cases were included in the study, with a predominance of women and average age of 37. There was excellent agreement between the examiners to disc and condyle position, but there was no significant correlation between these two variables. The presence of TMJ sound, muscle pain on palpation and range of mouth opening also showed no statistically significant correlation with the disc position. Only muscle pain on palpation was associated with mouth opening (p <0.05). It is concluded that there is no association between clinical signs and symptoms and disc position with condyle position in patients with TMD.

A região da articulação temporomandibular (ATM) possui uma limitação na obtenção de imagens pela radiografia convencional. A tomografia computadorizada é o exame mais indicado pela alta especificidade e sensibilidade, para o diagnóstico, planejamento cirúrgico e tratamento das lesões ósseas. O objetivo deste trabalho consiste na avaliação de lesões ósseas simuladas na cabeça da mandíbula pela tomografia computadorizada. Foram utilizadas 15 mandíbulas secas, onde foram criadas lesões esféricas, com o auxílio de brocas esféricas cirúrgicas de uso odontológico com tamanhos variados (nº 1, 3, 6) na cabeça da mandíbula. As lesões foram avaliadas por meio da TC multislice (64 canais), por 2 examinadores independentemente, em 02 ocasiões distintas, utilizando 2 protocolos: axial, coronal, sagital e imagens parassagitais para visualização dos pólos (anterior, lateral, posterior, medial, superior). Posteriormente, as imagens foram comparadas com as lesões presentes na mandíbula seca (Padrão Ouro) avaliando o grau de especificidade e sensibilidade da TC. Estatística de Kappa, teste de validade e teste do Qui-Quadrado foram utilizados como métodos estatísticos. Como resultados observaram a vantagem da associação dos cortes axial, coronal e sagital com cortes parassagitais para detecção de lesões na região de cabeça de mandíbula. Para determinada localização de lesões nos pólos, os tipos de protocolos não apresentaram diferenças significativas em relação as porcentagens de concordância. Os protocolos para visualização da região de cabeça da mandíbula foram estabelecidos no intuito de melhorar a visualização da presença de alterações de cada pólo da cabeça da mandíbula. No que se refere aos pólos avaliados pelos cortes parassagitais houve melhor visualização no pólo anterior e posterior no sentido látero medial. Nos pólos superior, medial e lateral foram mais bem visualizados no sentido ântero-posterior. / There are limitations for image acquisition using conventional radiography of the temporomandibular joint (ATM) region. Computerized tomography (CT) scan is a better option due to its higher specificity and sensitivity for diagnosis, surgical planning and treatment of bone injuries. The purpose of this study is to evaluate simulated bone injuries of the head of the jaw by CT scan. Spherical lesions were created in the head of 15 dry jaws with dentist drills (sizes 1, 3, and 6). Lesions were evaluated using the CT multislice (64 bits) by 2 examiners independently, in 2 different occasions, using 2 protocols: axial, coronal, and sagittal and parasagittal images for head of the mandible visualization (anterior, lateral, posterior, medial, and superior). Images were compared with the dry jaw (gold standard) regarding the presence of injuries, evaluating the degree of specificity and sensitivity of the CT. Kappa statistics, validity tests, and chi-square tests were used as statistical methods. As a result, we observed the advantage of the association of axial, coronal and sagittal slices with parasagittal slices for detection of lesions in the region of mandibles head. For some lesions localized in polar regions, protocols did not show statistically significant differences regarding the proportion of agreement. Protocols for visualization were created to improve the visualization of lesions in each polar region of the jaws head. Regarding parassagittal slices, there was better lateromedial visualization of the anterior and posterior poles and better anteroposterior visualization of superior, medial, and lateral poles.

Orientador: Marcio de Moraes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T05:16:45Z (GMT). No. of bitstreams: 1 Asprino_Luciana_D.pdf: 2820978 bytes, checksum: 12a98cf496579afbd3ea8036f938836c (MD5) Previous issue date: 2005 / Resumo: O objetivo deste estudo foi avaliar comparativamente a resistência de três técnicas de fixação interna rígida com uso de mini placas em fratura de côndilo mandibular. Foram obtidas 80 réplicas de hemimandíbulas humanas em resina de poliuretano, sendo 20 do grupo controle. As 60 hemimandíbulas restantes foram submetidas a seccionamento simulando fratura subcondilar e em seguida fixadas com três técnicas da aplicação de placas e parafusos do sistema 2,Omm, que deram origem a seis grupos experimentais, cada um com 10 hemimandíbulas. As técnicas de fixação foram: uma placa de quatro furos com quatro parafusos de 6mm; uma placa de quatro furos com quatro parafusos de 8mm; e duas placas de quatro furos com quatro parafusos de 6mm cada. Cada sistema foi submetido ao teste de carregamento com aplicação de carga no sentido médiolateral e antero-posterior em máquina de ensaio universal Instron 4411. Foram mensurados valores de carga e deslocamento de pico. Médias e desvio padrão foram avaliados aplicando-se Análise de Variância (P<.05), verificada a significância estatística, aplicou-se o teste de Tukey com nível de significância de 5%. Tanto para o valor de carga como de deslocamento de pico, as hemimandíbulas fixadas com duas placas tiveram melhor comportamento, seguidas de uma placa com quatro parafusos de 8mm e uma placa com quatro parafusos de 6mm. Os sistemas de fixação aplicados foram mais resistentes ao carregamento no sentido antero-posterior e a aplicação de parafusos de 8mm aumentou a resistência da fixação comparado à aplicação de parafusos de 6 mm somente no teste antero-posterior. Pode-se concluir, dentro das condições testadas, que a utilização do sistema de fixação com a utilização de duas placas traz maior resistência à fixação aplicada às fraturas condilares. E, pode-se sugerir, que o uso de parafusos mais longos aumentaria a resistência da fixação aplicada à fratura de côndilo mandibular / Abstract: The aim of this study was to comparatively evaluate the resistance of three plating rigid internal fixation techniques for mandibular condylar process fractures. Eighty synthetic hemi-mandible replicas made in polyurethane were used to evaluate a control, and three mandibular condyle plating techniques using 2.0mm system plates and screws. The plating techniques were fixation with a four-hole plate and four 6-mm screws, fixation with a four-hole plate and four 8-mm screws and fixation with two four-hole plates with four 6-mm screws each. Each one was subjected to linear loading in medial to lateral and anterior to posterior directions by an Instron 4411 servo hydraulic mechanical testing unit. Load peak value and peak displacement were measured. Means and standard derivations were derived and compared for statistical significance using an analyses variance (P<.05) and compared by Tukey test. Statistically significant differences were noted between fixation groups for the different mechanical measures evaluated under the different directions of linear loading. The two-plate fixation system presented better behavior, followed by one plate with four 8-mm screws and one plate with four 6-mm screws. The employed fixation systems were more resistant to antero-posterior load and the use of 8-mm screws improved the resistance of the fixation when compared to 6-mm screws only in the antero-posterior test. Under the conditions tested the two-plate fixation system provided the most favorable mechanical behavior. We can suggest that lengthy screws can increase the stability at fixation of mandibular condylar process fractures / Doutorado / Cirurgia e Traumatologia Buco-Maxilo-Faciais / Doutor em Clínica Odontológica

O Metotrexato (MTX) é utilizado em altas doses no tratamento de neoplasias e em baixas doses como antiinflamatório. O objetivo deste estudo foi avaliar a reparação da fratura de côndilo mandibular e a simetria facial em ratos tratados com MTX. Foram utilizados 100 ratos, Wistar, machos que foram submetidos a procedimento cirúrgico utilizando modelo experimental de fratura de côndilo do lado direito. Os ratos foram distribuídos em quatro grupos e receberam os seguintes tratamentos: Controle - soro (um mL/semana); Dexametasona - dexametasona (0,15 mg/Kg); MTX Baixa dose - MTX (três mg/kg/semana); MTX Alta dose - MTX (30 mg/Kg). Os períodos de sacrifício foram de um dia, sete, 15, 30 e 90 dias de pós-operatório (n=cinco). O peso dos animais foi documentado. Foi realizada coleta de sangue para análise bioquímica de proteínas totais e fosfatase alcalina. Foi realizado exame radiográfico das cabeças em norma axial para análise cefalométrica. Foram realizadas mensurações lineares da maxila e mandíbula, bem como angulares do desvio mandibular. As amostras foram processadas histologicamente sendo obtidas lâminas com cortes no sentido coronal. Os dados quantitativos foram submetidos a análises estatísticas (=0,05). Os animais recuperaram peso ao longo do tempo, exceto no grupo MTX Alta dose. Os níveis séricos de proteínas totais mostraram aumento nos períodos iniciais e os de fosfatase alcalina queda nos períodos de formação do calo ósseo no tratamento com MTX. Houve redução no comprimento mandibular com alterações também na maxila e desvio progressivo da mandíbula em relação à base do crânio no grupo MTX Alta dose. A análise histológica revelou que houve reparo da fratura, pela formação de calo ósseo, e das estruturas da articulação sendo que no grupo MTX Alta dose ocorreu um retardo neste processo, havendo desvio do côndilo e em um espécime houve anquilose fibrosa. A histomorfometria revelou que a área de neoformação óssea foi menor no grupo MTX Alta dose. Foi concluído que o tratamento com MTX em alta dose teve efeito deletério na simetria facial de ratos submetidos à fratura do processo condilar e prejudicou a formação do calo ósseo e o reparo da articulação temporomandibular, com possível indução de anquilose fibrosa. / low doses as an antiinflammatory. The aim of this study was to evaluate the healing of the mandibular condyle fracture and facial symmetry in rats treated with MTX. 100 Wistar male rats undergone surgery using an experimental model of mandibular condyle fracture of the right side. The rats were distributed in four groups and received the following treatments: Control Saline (1 ml/week); Dexamethasone dexamethasone (0,15mg/kg); MTX Low dose MTX (3 mg/kg/week); MTX High dose MTX (30 mg/kg). Animals were sacrificed at one, seven, 15, 30 and 90 days postoperatively (n=5). Animals body weight were recorded. Blood has been taken to provide the biochemical analysis of total proteins and alkaline phosphatase. Radiographic axial exams from the heads were provided to cephalometric analysis. Linear measures of jaw and mandible, as well as angular measures of the mandibular deviation were done. The samples were histologically processed and coronal sections were obtained. Quantitative data were submitted to statistical analysis (=0,05). The animals regained body weight over the time, except in MTX High dose group. Total protein serum levels demonstrated the increase in initial periods and the alkaline phosphatase levels showed decrease in the periods of bone callus formation. There was reduction in the mandibular length and also changes in the jaw and progressive deviation in the mandible in relation to the skull basis in the MTX High dose group. The histological analysis revealed that there were repair of the bone and temporomandibular joint although in the MTX High dose group there was a delay in this process, in wich there was deviation of the condyle and one specimen was fibrous ankylosis. Histomorphometry revealed that the new bone formation area was lower in MTX High dose group. It was concluded that treatment with high dose MTX had a deleterious effect on facial symmetry of rats submitted to fracture of the condylar process and damaged the bone callus formation and repair of the temporomandibular joint, with possible induction of fibrous ankylosis.

No description available.

Mucopolysaccharidosis VI (MPS VI) is a hereditary lysosomal storage disease caused by the absence of the enzyme arylsulfatase B (ARSB). Craniofacial defects are common in MPS VI patients and manifest as abnormalities of the facial bones, teeth, and temporomandibular joints. Although enzyme replacement therapy (ERT) is the treatment of choice for MPS VI, the effects on the craniofacial and dental structures are still poorly understood. In this study, we used an Arsb-deficient mouse model (Arsb m/m ) that mimics MPS VI to investigate the effects of ERT on dental and craniofacial structures and compared these results with clinical and radiological observations from three MPS VI patients. Using micro-computed tomography, we found that the craniofacial phenotype of the Arsb m/m mice was characterized by bone exostoses at the insertion points of the masseter muscles and an overall increased volume of the jaw bone. An early start of ERT (at 4 weeks of age for 20 weeks) resulted in a moderate improvement of these jaw anomalies, while a late start of ERT (at 12 weeks of age for 12 weeks) showed no effect on the craniofacial skeleton. While teeth typically developed in Arsb m/m mice, we observed a pronounced loss of tooth-bearing alveolar bone. This alveolar bone loss, which has not been described before in MPS VI, was also observed in one of the MPS VI patients. Interestingly, only an early start of ERT led to a complete normalization of the alveolar bone in Arsb m/m mice. The temporomandibular joints in Arsb m/m mice were deformed and had a porous articular surface. Histological analysis revealed a loss of physiological cartilage layering, which was also reflected in an altered proteoglycan content in the cartilage of Arsb m/m mice. These abnormalities could only be partially corrected by an early start of ERT. In conclusion, our results show that an early start of ERT in Arsb m/m mice achieves the best therapeutic effects for tooth, bone, and temporomandibular joint development. As the MPS VI mouse model in this study resembles the clinical findings in MPS VI patients, our results suggest enzyme replacement therapy should be started as early as possible.