Made available in DSpace on 2014-07-29T15:21:57Z (GMT). No. of bitstreams: 1 dissertacao luciana pimenta e silva machado.pdf: 1454474 bytes, checksum: 09a4d7c1496bba377b1749ce79194bbc (MD5) Previous issue date: 2011-02-28 / The aim of this study was to investigate the opinion of specialists in radiology, from different parts of the world, regarding to the proposed criteria for image acquisition and interpretation by Computed Tomography (CT), Cone Beam Computed Tomography (CBCT) and Resonance imaging (MRI) in diagnosing temporomandibular joint disorders (DATM) as part of Diagnostic Criteria for Research of Temporomandibular Disorders (RDC/TMD). Radiology specialists were invited by email to participate as volunteers in the study from three different eligible populations: researchers with publication DATM indexed on PubMed, ORADLIST members and individual contact. The link to access the questionnaire was mailed to volunteers interested in participating who matched the inclusion criteria. The sample was composed of specialists in radiology with experience in the interpretation of sectional images (CT, CBCT and/or MRI) of the temporomandibular joint (TMJ) who answered a questionnaire in English, which was developed and maintained online (LimeSurvey 1.87+). In a three months period, two recalls were sent and a period of 40 days after the last notification was given for responses submission. The questionnaire was divided into three parts with closed and open questions. Part I was related to issues of participant identification (gender, age, country of activity, area of activity, time and experience as a radiologist in the interpretation of sectional images of the TMJ and monthly time dedicated to the activity of interpreting sectional images of ATM). Part II contained questions related to the adequacy of the proposed criteria for the interpretation of sectional images of the ATM as part of the RDC/TMD. The criteria were presented into two columns' tables and the participants were asked whether that set of criteria was considered adequate or not for assessement and diagnosis of TMJ osseous and non-osseous tissues according to each imaging modality. If the respondent not considered criteria appropriate, he/she should indicate what type of suggestion: if insertion of new items, the modification or deletion of existing items. Part III had questions related to the need to include a minimal technical protocol for TMJ CT, CBCT and MRI acquisition as part of the RDC/TMD. If deemed necessary, the respondent should indicate which would be his/her suggestion protocol for acquisition of each imaging technique (CT, CBCT and MRI). Fifty-seven radiologists from different countries completed the questionnaire. The results indicate that 87 to 98% of radiologists considered the criteria adequate and that 81.6% of respondents considered necessary to include a minimal technical protocol for CT, CBCT and MRI acquisition as part of the RDC/TMD. Two to thirteen percent of respondents suggested insertion, modification and deletion of items in the proposed criteria. Ninety percent of respondents considered necessary to include a minimal technical protocol for CT/CBCT and 81.7% for MRI. We conclude that, according to the opinion of the worldwide community of specialists in radiology, the need for adjustments in the criteria for assessment of sectional images of the ATM is minimal, however, the need for the inclusion of a protocol to acquire minimal technical parameters of those images as part of protocol standardization of studies using the RDC/TMD is clear. / O objetivo desse estudo foi investigar a opinião de especialistas em radiologia, de várias partes do mundo, quanto aos critérios propostos para aquisição e interpretação de imagens por Tomografia Computadorizada (TC), Tomografia Computadorizada por Feixe Cônico (TCFC) e Ressonância Magnética (RM) no diagnóstico das desordens da articulação temporomandibular (DATM) como parte dos Critérios de Diagnóstico para Pesquisa das Desordens emporomandibulares (RDC/TMD). Especialistas em radiologia foram convidados por meio de e-mail a participar como voluntários do estudo a partir de três diferentes populações elegíveis: pesquisadores com publicação indexada sobre DATM no PubMed, membros da ORADLIST e contato individual. O link de acesso ao questionário foi enviado por email aos voluntários interessados em participar os quais preencheram os critérios de inclusão. A amostra foi composta por especialistas em radiologia com experiência na interpretação de imagens seccionais (TC, TCFC e/ou RM) da articulação temporomandibular (ATM) que responderam um questionário na língua inglesa, desenvolvido e mantido online (LimeSurvey 1.87+). Num período de três meses, duas notificações foram enviadas e um prazo de 40 dias após a última notificação foi estabelecido para o envio das respostas. O questionário foi dividido em três partes com perguntas fechadas e abertas. A parte I relacionava-se às questões de identificação do participante (gênero, idade, país de atuação, área de atividade, tempo de experiência como radiologista e na interpretação de imagens seccionais da ATM e o tempo de dedicação mensal à atividade de interpretar imagens seccionais da ATM). A parte II continha questões relacionadas à adequação dos critérios propostos para interpretação das imagens seccionais da ATM como parte do RDC/TMD. Os critérios foram apresentados em tabelas de duas colunas e os participantes eram questionados se aquele conjunto de critérios era considerado adequado ou não para a interpretação e diagnóstico dos tecidos ósseos e não-ósseos da ATM de acordo com cada modalidade de imagem. Caso não os considerasse adequado, deveria indicar qual o tipo de sugestão: se inserção de novos items, a modificação ou eliminação de itens existentes. A parte III continha perguntas relacionadas à necessidade de se incluir um protocolo técnico mínimo para a aquisição de TC, TCFC e RM como parte do RDC/TMD. Caso considerasse necessário, deveria indicar qual seria sua sugestão de protocolo para aquisição de cada uma das técnicas de imagem (TC, TCFC e RM). Cinqüenta e sete radiologistas de vários países responderam o questionário. Os resultados indicam que 87 a 98% dos radiologistas consideraram os critérios adequados e que 81,6% dos respondentes consideram necessária a inclusão de um protocolo técnico mínimo para aquisição das imagens por TC, TCFC e RM como parte do RDC/TMD. Dois a treze porcento dos respondentes sugeriram inserção, modificação e eliminação de items nos critérios propostos. Noventa porcento dos respondentes consideram necessária a inclusão de protocolo técnico mínimo para TC/TCFC e 81.7% para a RM. Conclui-se que, de acordo com a opinião da comunidade mundial de especialistas em radiologia, é mínima a necessidade de ajustes nos critérios para interpretação de imagens seccionais da ATM, entretanto, é clara a necessidade da inclusão de um protocolo técnico mínimo para a aquisição das referidas imagens como parte do protocolo de normatização das pesquisas que utilizam o RDC/TMD.

No presente estudo realizou-se a avaliação da eficácia do exame de imagem por ressonância magnética (IRM) e de reconstruções digitais bi e tridimensionais da ATM, em diferentes estágios de desenvolvimento. Foi criado um protocolo próprio de exame de IRM, o qual foi aplicado em embriões e fetos humanos, entre 22 a 160mm de comprimento céfalo-caudal (CRL), correspondendo da 7 a a 18 a semana de vida intra-uterina (IU). Em cada amostra foram realizadas duas seqüências de imagens sagitais da cabeça inteira, com distância de 1,0mm entre os cortes. Em seguida, as imagens foram intercaladas digitalmente, gerando uma seqüência de cortes de 0,5mm distância. Estas imagens foram importadas para um programa específico que realizou a reconstrução digital, criando modelos bi e tridimensionais. Para avaliar a formação e desenvolvimento das estruturas articulares de cada uma das amostras, foram realizados cortes histológicos da ATM. O exame histológico determinou o grau de maturação da ATM e a qualidade da matriz colágena presente. Os resultados demonstraram que o protocolo desenvolvido foi capaz de capturar e processar as imagens de IRM, principalmente após a 13 a semana de vida IU, em seu estágio de maturação articular. Os cortes histológicos comprovaram que, a partir desta fase, pode-se identificar melhor as estruturas articulares no exame de IRM devido a uma maior diferenciação celular e da matriz colágena, que passa de uma composição predominante de fibras colágenas tipo III para fibras do tipo I. A criação de modelos bi e tridimensionais mostrou ser uma ferramenta eficiente no diagnóstico do desenvolvimento facial, além de facilitar sua compreensão e aprendizado, embora ainda sejam necessários maiores avanços tecnológicos para a sua aplicação na formação das estruturas da ATM. / The present study was carried out to evaluate the effectiveness of Magnetic Resonance Imaging (MRI) and bi and three-dimensional digital reconstructions of the TMJ in different stages of development, by the comparison with histological sections. A proper protocol of IRM examination was developed, which was applied in formalin-preserved human embryos and fetuses, ranging from 22 to 160mm of crown-rump length (CRL), between 7 and 18 weeks of intrauterine life (IU). Two sequences of sagital images of the entire head of each specimen were performed, with interslice gap of 1,0mm. Consequently, images were digitally intercalated, creating a slice sequence of 0,5mm of interslice gap. These images were imported to the MRIcro Ò program for bi and three-dimensional digital reconstruction. In order to evaluate the development of the articular structures of each one of the specimens, histological sections of the TMJ were obtained. The maturation’s degree and the quality of the collagen matrix of the TMJ were determined by the histological sections . The results showed that the developed protocol was capable of capture and process MR images, mainly in the articular maturation stage, after the 13 th week of IU. Histological findings also showed that articular structures are better identified in this stage by RMI examination. This can be explained due to an increase of cellular and collagen matrix differentiation, which undergoes conversion from collagen type III to type I. Bi and three-dimensional models seem to be an efficient tool for the diagnosis of facial development, facilitating its understanding and learning. Further studies and technological advances may be necessary for its application in TMJ’s structures in intrauterine period.

Le but de ce travail était la mise en place d’une chaîne méthodologique de planification virtuelle d’une ostéotomie sagittale des branches mandibulaires (OSBM) et son transfert au bloc opératoire. Dans la première partie, les méthodes classiques de planification et de transfert sont exposées. Habituellement réalisées à partir de modèles en plâtre sur articulateur, la planification et la production de guides occlusaux chirurgicaux souffrent d’une imprécision potentiellement à l’origine de troubles fonctionnels temporo-­‐mandibulaires. Le contrôle per-­‐opératoire du condyle mandibulaire lors de l’OSBM est un élément de stabilité squelettique dont dépend la qualité du résultat fonctionnel. Une évaluation des pratiques professionnelles des chirurgiens maxillo-­‐faciaux a été réalisée sur ce point. Une méthode de positionnement condylien utilisant un dispositif, moins fréquemment utilisée que la méthode empirique, est proposée comme présentant le meilleur rapport bénéfice/risque. Cette méthode a été reproduite virtuellement à travers les différents maillons de la chaîne méthodologique. Des techniques innovantes informatisées d’acquisition, de conception et modélisation, et d’impression en 3 dimensions ont été utilisées. Dans la seconde partie, la méthodologie de chacun des maillons de la chaîne a été présentée et évaluée, soit sur sujets cadavériques, soit sur patients. L’objectif était de démontrer la faisabilité de la chaîne. Le maillon « acquisition et extraction de surface » a mis en exergue le problème des artéfacts dus aux matériaux métalliques dentaires ou orthodontiques. Dans 90% des cas le maillage obtenu était satisfaisant, permettant de s’affranchir des modèles en plâtre. Le maillon « planification chirurgicale virtuelle » a montré une valorisation par rapport à la technique classique en terme de prévention des interférences des pièces osseuses déplacées. Le maillon « modélisation et impression du guide chirurgical » a décrit les étapes d’invention d’un guide de positionnement occlusal et condylien (OCPD : occlusal and condylar positionning device). Ses caractéristiques techniques, ses modalités de production par impression 3D ainsi que son utilisation peropératoire, ont été précisées. Enfin le maillon « évaluation de l’OCPD » a permis de montrer la faisabilité de la méthode et l’équivalence clinique, technique et biologique de ce dispositif médical sur mesure par rapport à ceux utilisés dans la méthode classique. Enfin le positionnement condylien obtenu grâce à ce dispositif a été évalué de manière préliminaire et comparé aux données de la littérature. Grâce à l’OCPD, nous avons montré la possibilité de transférer au bloc opératoire la planification virtuelle d’une OSBM contrôlant la position des condyles / The purpose of this work was the implementation of a methodological chain for bilateral sagittal split osteotomy (BSSO) virtual planning and its transfer in the operating room. In the first part of the work, usual methods for planning BSSO are exposed. Usually realized from plaster models on articulator, the planning and the occlusal surgical guides production are at risk of temporo-­‐mandibular functional disorders. The quality of the functional result depends on the correct positioning of the mandibular condyle, considered as a skeletal stability element. An assessment of the maxillofacial surgeons practices was realized regarding intra-­‐operative condyle positioning. Using a condylar positioning device (CPD),less frequently employed than the empirical method, meets an acceptable benefit/risk balance. This method was virtually reproduced through various steps of the methodological chain described. Computerized innovative techniques for three-­‐dimensional acquisition, design and manufacturing were used. In the second part of the work, the methodology of each step of the chain was presented and estimated, either on cadaveric subjects, or on patients. The aim was to demonstrate the feasibility of the whole chain. The “acquisition and surface extraction” step pointed the issue of artefacts due to dental or orthodontic metallic devices. Ninety % of the obtained meshes were satisfactory, allowing not to use plaster models. The “virtual surgical planning” step allowed reproducing the usual method and showed great interest in bone interferences prevention. The “modelling and printing of the surgical guide” step described the stages of occlusal and condylar positioning device (OCPD) invention. Its technical characteristics, its methods of manufacturing by 3D printing, and its intraoperative use were specified. The step “OCPD evaluation” showed the method feasibility and the clinical, technical and biological equivalence of this custom-­‐made medical device as compared to those used in the usual method. Finally the condylar position obtained with this device was estimated in a preliminary clinical study and compared with the literature. Thanks to the OCPD, we showed the possibility of transferring in the operating room an OSBM virtual planning controlling condyles position.

This thesis deals with the cartilage imaging using magnetic resonance. At first, there is mentioned physical principle of the magnetic resonance phenomenon and the most commonly used excitation sequences, followed by the description of the 9.4 T MR imaging system Bruker BioSpec 94/30 USR, which was used for measurement in the practical part. The next part is dedicated to the composition of cartilages and describes the temporomandibular joint, due to its suitability as an object for cartilage imaging. The series of MR scans of temporomandibular joint were taken with different acquisition parameters and evaluated by program designed through the MATLAB software. The program can be used for viewing scanned images, evaluating their contrast and determining the T1 relaxation time of the tissues by creating T1 maps.