Structural Characteristics of the Temporomandibular Joint in Temporomandibular Joint Disorder Syndrome: A Cross- sectional Study Based on MRI

Background​: Temporomandibular joint disorder syndrome (TMD) is a prevalent oral-maxillofacial condition. The Diagnostic Criteria serve as a widely used diagnostic framework for TMD with high specificity, yet its sensitivity requires further optimization. In contrast, magnetic resonance imaging (MRI) is a non-invasive imaging modality that enables clear visualization of temporomandibular joint (TMJ) structures. Therefore, this study aimed to analyze the association between TMJ structural characteristics and TMD, and evaluate the predictive value of MRI-based morphological parameters for TMD. Methods​: 214 patients (428 joints) were divided into TMD (108 patients) and control (106 patients) groups. MRI was used to measure condylar size, morphology, joint space, position, horizontal condylar angle (HCA), and the inclination of the glenoid fossa (IGF). Group differences were compared, and multivariate logistic regression identified parameters associated with TMD. Results​: TMD group had smaller condylar sizes, superior joint space, higher proportions of beak-like condyles and posterior condylar position (all P<0.001). Multivariate regression showed condylar mediolateral diameter, superior joint space were protective factors (OR<1, P<0.05); anterior joint space was risk factors (OR>1, P<0.05). HCA/IGF had no differences.​ Conclusion​: Reduced condylar size and altered joint space predict TMD. Quantitative MRI provides a reliable basis for TMD early identification and risk assessment.