[Comparison of skeletal structure of temporomandibular joint through cone-beam CT between Angle ClassⅠ, Ⅱ, Ⅱ, Ⅲ malocclusion patients with permanent dentition].

Purpose: To compare characteristics of temporomandibular joint and related structures according to gender and Angle Ⅰ, Ⅱ, Ⅱ and Ⅲ class.

Methods: Cone-beam CT (CBCT) was performed in 123 patients with malocclusion, and three-dimensional reconstruction was performed with Mimics 19.0 software. The anterior, upper, and posterior spaces of temporomandibular joint, width and depth of acetabulum, height and horizontal angle of condyle, radius of condyle, and anteroposterior and long-axis diameter of condyle were analysed on sagittal plane. The position of condyle in the joint fossa was analyzed using Pullinger methods. SPSS 22.0 software package was used for statistical analysis.

Results: Significant differences were found in the long axis and radius of the condyles between Class Ⅰ and Ⅲ, Class Ⅰ and Ⅱ, respectively (P<0.05). The widest acetabulum was observed in Class Ⅲ, followed by Class Ⅰ, Ⅱ, and Ⅱ. Moreover, the deepest acetabulum was found in Class Ⅱ, followed by Class Ⅱ, Ⅰ, and Ⅲ. No significant differences were detected in the left and right condyle-related structures among different temporomandibular articulation. In addition, the anterior articular space was significantly larger in Class Ⅰ patients, compared with Class Ⅱ patients.

Conclusions: There are significant differences in condylar morphology, joint space, joint fossa morphology and condylar position between different Angle classifications.