Morfologia e morfometria dos componentes ósseos da articulação temporomandibular e a presença de deslocamento do disco articular: Avaliação por ressonância magnética

Abstract

The aim of this was to evaluate the relationships between morphology and morphometry of the Temporomandibular Joints (TMJ) osseous structures and articular disc displacement using magnetic resonance imaging (MRI) of symptomatic patients. Patients that had MRI of TMJ done in an Oral and Maxillofacial private practice in the city of Salvador-BA were evaluated. Articular disc position for each TMJ in closed- mouth position was classified as normal or displaced, and if the presence of displacement was verified, they were then divided in eight possible displacement types. Qualitative analyses were done for the glenoid fossa and articular eminence using templates printed in transparency papers. The glenoid fossa was classified in concave, angled, sigmoid and plane; while que articular eminence was categorized as box, sigmoid, plane and deformed. Quantitative analyses were done by linear measurements for the following features: eminence height (EH), articular spaces in sagittal view (anterior-AS, superior-SS, posterior-PS) articular spaces in coronal view (lateral – LS, central – CS, medial – MS); and by angular measurements: articular eminence inclination (AEI) and condyle excursion (CEA). Associations between the articular eminence’s morphology with AEI and EH were assessed. Glenoid fossa morphology and articular spaces possible association were also assessed. Numerical variables were associated to age and gender groups, disc displacement presence, types of disc displacement in closed-mouth position and disc reduction. For statistical analysis, significant differences were considered for p<0.05. After inclusion and exclusion criteria, the final sample was composed of 104 patients, totalizing 199 evaluated condyles. The highest prevalence was for female patients (82.69%) than males (17.30%). The age groups with higher prevalence were 60-69 years (25.96%) and equal to above 70 years (27.88%). Articular disc displacement was observed in 69 TMJs (66.34%), and bilateral displacement was more common (78.26%). Higher AEI and EH values were associated to box shaped eminences, and lower values were associated to flattened shaped eminences. AEI and EH have no relationship with disc displacement in opened-mouth position, but a higher AEI were associated to disc reduction in opened- mouth position. Among female patients, EH reduced with the advancement of age, and in age group equal to or above 70 years EH significant differences were observed between gender. Higher SS and MS values are associated to angled glenoid fossa. Male patients have a tendency to have larger SS, PS, CS, and those measurements are associated to normal positioned discs. Larger articular spaces are associated to disc reduction. CEA was only associated to disc reduction during mouth opening. This study concluded that TMJs osseous morphology has an influence on the articular disc position and some morphological parameters are associated with gender and specific age groups.