Evaluation of Temporomandibular Joint Morphology According to the Occlusal Relationship Between Dental Arches Using...

Background: This study aims to evaluate the temporomandibular joint (TMJ) morphology according to the occlusal relationship of the upper and lower dental arches shown on cone-beam computed tomography (CBCT) images. Methods: A total of 131 patients were evaluated using CBCT images and categorized as Angle Class I (Cl I), Class II (Cl II), or Class III (Cl III), based on the occlusal relationship of the dental arches. Measurements included the height and inclination of the articular eminence and the width and depth of the glenoid fossa for the right and left sides, as well as the angle between the long axis of both condyles and the angle between the long axis of the condyle and the midsagittal plane. A significance level of 5% was considered for all statistical analysis. Results: The articular eminence inclination and glenoid fossa depth demonstrated significant gender-related differences, while significant side-related variations were observed for articular eminence inclination, glenoid fossa width, and depth (p < 0.05). The articular eminence height was significantly higher in the Cl II (6.93 ± 1.07 mm) than in the Cl I (6.27 ± 1.22 mm) (p < 0.05) groups. The articular eminence inclination (best-fit line/top-roof line methods) also differed significantly among groups (p ≤ 0.001), with the highest values in the Cl II (51.74 ± 5.77°/38.27 ± 5.17°), followed by the Cl I (48.54 ± 5.94°/35.83 ± 4.43°) and Cl III (47.30 ± 7.36°/34.07 ± 5.24°) groups. No statistically significant differences were found among the study groups for glenoid fossa depth or width (p > 0.05). Conclusions: These findings suggest that TMJ morphology varies, depending on the occlusal relationship of the dental arches, gender, and side. These variations should be considered in both physiological and pathological evaluations of TMJ anatomy.