Three-dimensional analysis of mandibular condyle position in patients with deviated mandibular prognathism

The purpose of this study was to evaluate the bilateral difference in condyle position in patients with deviated mandibular prognathism. Patients with asymmetrical (n=28) and symmetrical mandibular prognathism (n=23) were compared using the three-dimensional (3D) reformatted image from cone beam computed tomography. Significant positional differences in the condyle and subcondyle region (sigmoid notch) were found between the deviated and contralateral sides in the group with asymmetrical mandibular prognathism, but not in the control group. The lateral condyle was more laterally and inferiorly positioned on the contralateral side than on the deviated side (P<0.05). The sigmoid notch was more laterally, superiorly, and posteriorly positioned on the deviated side (P<0.01). Interestingly, condyle width and height on the deviated side was narrower and shorter than on the contralateral side and in the control group. Menton deviation was closely correlated with the bilateral difference in condyle height and 3D position of the sigmoid notch (P<0.01). The degree of asymmetry was more highly correlated with condyle height than with the spatial orientation of the condyle head. The results demonstrated that mandibular prognathism with asymmetry is associated with bilateral differences in 3D morphology and orientation of the condyle. Therefore, clinicians should consider these variations during surgical planning.