Skeletodental factors affecting chin point deviation in female patients with class III malocclusion and facial asymmetry: a three-dimensional analysis using computed tomography

Objective. Three- dimensional computed tomography (CT) was used to investigate which skeletodental factors are related to chin point deviation of facial asymmetry in skeletal class III malocclusion (SCIII) patients. Study design. Forty Korean adult female patients with SCIII, who had a three- dimensional CT taken 1 month before orthognathic surgical surgery, were assigned to group 1 (symmetry) or group 2 (asymmetry) according to the amount of chin point deviation from facial midline. Midfacial, mandibular, and cranial base variables were measured with software and statistically analyzed. Results. Group 2 showed higher positions of the upper canine and first molar, shorter ramus height, more superiorposterior positioning of gonion (Go) on the deviated side, and more mesial inclination of the ramus and medial positioning of Go on the opposite side. Conclusion. Facial asymmetry in SCIII patients occurs due to greater growth and mesial inclination of the ramus and greater maxillary vertical excess in the opposite side.