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 superior-posterior 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.