OBJECTIVETo investigate the differences in the condylar position of subjects with skeletal class I and skeletal class II. To provide a basis of diagnosis and treatment.

METHODSGroup A was composed of 50 subjects with skeletal class I (27 males and 26 females; age range = 18 years to 30 years; mean age=26 years). Group B comprised 50 subjects with skeletal class II (24 males and 26 females; age range = 18 years to 28 years; mean age=25 years). The condylar position and the shapes of the condyle and the glenoid fossa were linearly measured on the sagittal and coronal sections by cone-beam computed tomography (CBCT). Data were analyzed by SPSS 19.0.

RESULTSNo statistically significant differences were found in the measurements of the condylar position between the sides of each group on the sagittal plane and the coronal plane (P > 0.05). There were significant differences on the anterior space and the posterior space between group A and B (P < 0.05). The A/P joint space ratio of group A was larger than that of group B (P < 0.05).

CONCLUSIONThe subjects of skeletal class I show an anterior condyle position. The subjects of skeletal class II show a posterior condyle position.