Cone-beam CT evaluation of temporomandibular joint in permanent dentition according to Angle's classification.

OBJECTIVES: To compare characteristics of temporomandibular joint (TMJ) and related structures according to Angle class I, II1, II2, and III. METHODS: 123 Chinese patients (13-36 years old, 60 males, and 63 females) were classified in four groups according to Angle's classification: skeletal class I (31 patients), skeletal class II division 1 (30 patients), skeletal class II division 2 (30 patients), and skeletal class III (32 patients). Left and right TMJs of each subject were evaluated independently with cone-beam computed tomography (CBCT). The position of condyle in the joint fossa was analyzed according to Pullinger. RESULTS: There were significant differences between class III subjects and class I, II1, II2 in the superior joint space (p < 0.05). Compared with class II1, II2, and III subjects, the height and diameter of condyle in class I was significantly larger (p < 0.05). The width of joint fossa was significantly larger in Angle class III than in Angle class I, II1, and II2, while the depth was significantly smaller. The condyle position in class III subjects was more anteriorly displaced compared with that in class I subjects. In class II2 patients, the condyle position was mainly concentric and posterior. CONCLUSIONS: There are significant differences in condylar morphology, joint space, joint fossa morphology, and condylar position between different Angle classifications.