A ATM pode ser afetada por lesões que alteram sua morfologia e comprometem sua função, levando o cirurgião, algumas vezes, a ter a necessidade de ressecá-la e reconstruí-la. A reconstrução dos defeitos ósseos articulares, congênitos ou adquiridos, é um desafio para o Cirurgião Buco-Maxilo-Facial, podendo ser realizado com materiais aloplásticos, que excluem a necessidade de área doadora, minimizando a morbidade. Entre estes destacamos as próteses totais da articulação temporo-mandibular, estudados até sua forma e composição atual e que possibilitou o estabelecimento de protocolos bem definidos para sua utilização. Destacamos a prótese de estoque da W. Lorenz, com componentes de alta tecnologia e indicações precisas que possibilita grande melhora clínico e funcional. Este estudo avaliou clínico e funcionalmente 15 pacientes tratados no período de oito anos, demonstrando que apesar da melhoria funcional evidente observada, em especial para os casos de anquilose em ATM, ainda muitos estudos e acompanhamento devem ser realizados para se estabelecer, ao longo do tempo, se estas próteses suprem de forma eficiente e duradoura a fisiologia estomatognática ideal. / The TMJ can be affected by injuries that alter its morphology and compromise its normal function, leading the surgeon, sometimes, to have the need to resect it and rebuild it. The reconstruction of the bone articular defects, congenital or acquired, which has been a challenge for the maxillofacial surgeon can be achieved by using aloplastic materials. The use of aloplastics materials precludes the need for a donor area, minimizing the morbidness. Among these, we highlight the temporo-mandibular joint total prosthesis, studied until achieving its current form and composition, and which enabled the establishment of clear protocols for its use. Among these, we highlight the W.Lorenz prosthesis with high technology and specific details that enable a large clinical and functional improvement. This study evaluated important clinical and functional aspects observed in 15 patients treated over a period of eight years, showing that despite the clear functional improvement, particularly observed in cases of TMJ ankylosis, many more studies and monitoring should be conducted to establish, especially in the long term, that these prosthesis supply the stomatognathic system with an effective and durable physiology.

A ATM pode ser afetada por lesões que alteram sua morfologia e comprometem sua função, levando o cirurgião, algumas vezes, a ter a necessidade de ressecá-la e reconstruí-la. A reconstrução dos defeitos ósseos articulares, congênitos ou adquiridos, é um desafio para o Cirurgião Buco-Maxilo-Facial, podendo ser realizado com materiais aloplásticos, que excluem a necessidade de área doadora, minimizando a morbidade. Entre estes destacamos as próteses totais da articulação temporo-mandibular, estudados até sua forma e composição atual e que possibilitou o estabelecimento de protocolos bem definidos para sua utilização. Destacamos a prótese de estoque da W. Lorenz, com componentes de alta tecnologia e indicações precisas que possibilita grande melhora clínico e funcional. Este estudo avaliou clínico e funcionalmente 15 pacientes tratados no período de oito anos, demonstrando que apesar da melhoria funcional evidente observada, em especial para os casos de anquilose em ATM, ainda muitos estudos e acompanhamento devem ser realizados para se estabelecer, ao longo do tempo, se estas próteses suprem de forma eficiente e duradoura a fisiologia estomatognática ideal. / The TMJ can be affected by injuries that alter its morphology and compromise its normal function, leading the surgeon, sometimes, to have the need to resect it and rebuild it. The reconstruction of the bone articular defects, congenital or acquired, which has been a challenge for the maxillofacial surgeon can be achieved by using aloplastic materials. The use of aloplastics materials precludes the need for a donor area, minimizing the morbidness. Among these, we highlight the temporo-mandibular joint total prosthesis, studied until achieving its current form and composition, and which enabled the establishment of clear protocols for its use. Among these, we highlight the W.Lorenz prosthesis with high technology and specific details that enable a large clinical and functional improvement. This study evaluated important clinical and functional aspects observed in 15 patients treated over a period of eight years, showing that despite the clear functional improvement, particularly observed in cases of TMJ ankylosis, many more studies and monitoring should be conducted to establish, especially in the long term, that these prosthesis supply the stomatognathic system with an effective and durable physiology.

The thesis deals with the edge detection in the magnetic resonance images and their segmentation. There are adduced the gradient based methods, methods based on zero-crossing in the Laplacian images and also methods combined both of the methods adduced above. These methods are compared to find the best one for the temporo-mandibular joint detection. Consequently sufficient segmentation method for particular parts of the temporo-mandibular joint (the condyle, the acetabulum and the articular disk) separation is chosen.

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