This study quantifies the mandibular movements of opening and close, laterotrusion and protrusion, obtained from 20 healthy subjects and 20 TMD subjects subdivided into 10 individuals with myopathy and 10 individuals with arthropaty, selected by Research Diagnostic Criteria (RDC) protocols. These movements of all subjects were captured and measured at maximum length, medium velocity and acceleration and deviation during your trajectories, were captured by three infrared cameras and measured by a computational system previously developed by the University Federal of Uberlândia, which, in this research was named Jaw Capture. This system receives images simultaneously from nine reflective markers and send and process this data to a computer using a firewire system through a mathematical approach to analyze and quantify in 3D (at X, Y and Z axis), the marker trajectories. The reflective markers were positioned by supporting systems fixed on vestibular face of lower incisives and skin surface of face. The movement ranges are similar among all individuals, meanwhile the deviation and the medium velocity and acceleration are very different between target and control group after statistical analysis. This system being proves reliable and efficient. / Este estudo quantifica os movimentos mandibulares de abertura e fechamento, lateralidade e protrusão, de 20 indivíduos saudáveis, e 20 indivíduos com DTM, sendo, 10 indivíduos portadores de miopatia e 10 indivíduos portadores de artropatia, triados segundo o protocolo de Research Diagnostic Criteria (RDC). Os movimentos mandibulares, de cada um deles, foram capturados e medidos em suas amplitudes máximas, velocidade e aceleração médias, bem como os desvios durante os mesmos, por um sistema de reconstrução de imagens, desenvolvido na Universidade Federal de Uberlândia, o qual foi chamado neste trabalho de Jaw Capture. O sistema recebe imagens simultâneas de nove marcadores de alta refletividade, capturadas por três câmeras de infravermelho, conectadas a um computador pelo sistema firewire, através de uma abordagem matemática para analisar e quantificar as trajetórias dos marcadores em três dimensões (3D), nos eixos X, Y e Z. Os sensores foram posicionados em suportes afixados nos incisivos inferiores e na pele do rosto, sem considerar os movimentos das cabeças da mandíbula. A amplitude dos movimentos em todos os indivíduos mostrou-se semelhante, entretanto os desvios e a velocidade e aceleração médias foram muito diferentes, após a análise estatística. O método provou ser confiável e eficiente. / Doutor em Ciências

Cette thèse aborde une étude biomécanique de l’Articulation Temporo Mandibulaire (ATM), dont l’un des objectifs est la définition d’une approche complète, faisant appel à des outils modernes, permettant la conception d’une prothèse d’ATM personnalisée. Tout d’abord, nous avons conçu et réalisé un tribomètre reproduisant les conditions physiologiques de fonctionnement de l’ATM, afin d’étudier les interactions entre un matériau prothétique et de l’os porcin et de quantifier leurs usures respectives. La conception prothétique personnalisée passe par la réalisation d’un « état des lieux ». Nous avons donc défini un protocole de caractérisation non invasif de l’ATM. Il correspond à l’acquisition de sa géométrie actuelle et des mouvements élémentaires de la mandibule. Dans un deuxième temps, des simulations numériques en dynamique des corps rigides et/ou en éléments finis ont été réalisées pour accéder à des grandeurs mécaniques, telles que contraintes et déformations, nécessaires à la conception d’une prothèse. La totalité du protocole a été menée sur deux sujets d’étude : un sujet présentant une résorption condylienne et un sujet asymptomatique. Des modèles numériques personnalisés ont été construits pour chaque cas. Ces modèles nous ont permis d’étudier le fonctionnement articulaire de chaque individu. Nous avons effectué des comparaisons entre ces deux sujets et nous avons pu constater des différences notables concernant le fonctionnement articulaire. Il s’est avéré que les changements morphologiques occasionnés par la résorption osseuse ont des conséquences sur l’activité musculaire, ainsi que sur les efforts articulaires. Ce travail a permis d’enrichir les connaissances fondamentales par rapport au fonctionnement de l’ATM. Il a également permis de valider des outils d’évaluation de l’état fonctionnel de l’articulation. L’approche développée durant cette thèse est mise en pratique au sein de la société OBL, spécialisée dans la conception et la réalisation de prothèses maxillo-faciales sur mesure. Elle peut également être utilisée comme outil d’évaluation de solutions prothétiques existantes et à venir / This thesis deals with a biomechanical study of the Temporo-Mandibular Joint (TMJ); one of the objectives of this work is the definition of a complete approach, using modern tools, allowing the design of a personalized TMJ prosthesis. First of all, a tribometer reproducing the TMJ physiological conditions was designed and built, in order to study the interactions between porcine bone and a prosthetic material and to quantify their respective wears. Through this device, the relationships between the contact parameters and bone wear were determined. Personalized prosthetic design needs first to carry out “a state-of-the-art”. We defined a non invasive protocol for TMJ characterization. It corresponds to the acquisition of its current geometry and of the mandible elementary motions. In a second step, numerical simulations of rigid bodies and/or finite elements were achieved to obtain the mechanical quantities, such as stresses and strains, necessary for the prosthesis design. The entire protocol was conducted on two subjects: an asymptomatic one and a second one with condylar resorption. Personalized numerical models were built for each case. These models allowed us study the joint functioning of each subject. We made comparisons between these subjects and significant differences were found. It was proved that the changes produced by bone resorption have an impact on muscle activity, as well as contact forces in joints. This work allowed enhancing the fundamental knowledge regarding TMJ operating conditions. It also enabled to validate evaluation tools of the functional state of the joint. The approach developed during this thesis is applied by OBL society, specialized in the design of customed maxillofacial prostheses. The approach proposed in this work can also be used as an evaluation tool of existing prosthetic solutions, as well as future solutions