Association Between Temporomandibular Disk Position and Condylar and Fossa Morphology in Adolescents

Objective: The aim of this study was to determine the association between the disk position and the condyle and mandibular fossa morphology in adolescents. Materials and methods: In this retrospective cross-sectional study magnetic resonance imaging (MRI) and computed tomography (CT) images of adolescents TMJ were evaluated. The TMJ disk position in each joint was determined in the MRI images normal disk position (N), disk displacement with reduction (DDwR) and disk displacement without reduction (DDwoR). The condylar and fossa morphology were evaluated by CT, and were classified into condylar dimension (condylar height, antero-posterior condylar length and, latero-medial condylar length); condylar inclination (horizontal, sagittal, and coronal condylar inclination) and fossa dimension variables (antero-posterior fossa length, and fossa depth). One-way ANOVA, t-test, and chi-square test were used to assess the statistical association. Statistical significance was defined as P < .05. Results: One hundred TMJs of 51 patients (15 males and 36 females) aged between 11 and 18 years old (12.46 ± 2.28) were evaluated. The latero-medial condylar length was on average 1.17 mm greater in the normal disk position than in DDwoR (P = .041). The horizontal condylar inclination was on average 9.15° lower in DDwoR (P = .001). The depth of the fossa was on average 1.02 lower in DDwoR (P = .046). Conclusions: The horizontal condylar inclination, latero-medial condylar length and fossa depth appears to be associated with articular disk position in adolescents. These results could contribute to a better understanding the complexity of anatomical changes related to the temporomandibular disk position in growing patients.