Temporomandibular condylar morphology in diverse maxillary-mandibular skeletal patterns: A 3-dimensional cone-beam computed tomography study.

BACKGROUND: The authors evaluated the morphology and symmetry of the temporomandibular joint in participants with normodivergent and hyperdivergent skeletal class I, II, and III patterns.

METHODS: A total of 80 participants were divided into 4 groups on the basis of their sagittal and vertical skeletal patterns. Cone-beam computed tomographic images were used to evaluate the condyle-fossa relationship and the morphology and symmetry of the mandibular condyle. One-way analysis of variance and Tukey post hoc tests were used to compare the mean values among the different groups.

RESULTS: Participants with class II hyperdivergent patterns had the smallest anteroposterior (mean [standard deviation {SD}], 4.4 [1.6] millimeters) and mediolateral (10.5 [3.0] mm) condylar process widths among all 4 groups. The mean (SD) axial condylar angle was flatter in patients with class III hyperdivergent patterns (19.8° [5.1°]) compared with the other groups. The mean (SD) anteroposterior differences of the condylar processes (2.9 [1.4] mm) in patients with class III hyperdivergent patterns were the greatest in all 4 groups.

CONCLUSION: Participants in the group with class II hyperdivergent patterns have a smaller and narrower condyle compared with the other groups measured. Asymmetry was found among all groups, with participants with skeletal class III patterns having the most asymmetry. The most common condylar morphology in all groups examined was convex.

PRACTICAL IMPLICATIONS: These results support the concept that morphology and symmetry of the temporomandibular joint varies in different skeletal patterns, presumably as an adaptive response to functional demands.