Analysis of three-dimensional changes of facial soft tissue after setback surgeryusing the non-contacting three-dimensional optical surface scanner

Abstract

Mandibular prognathic patients who underwent sagittal splitting ramus osteotomy were examined for soft tissue changes after the surgery using a non-contacting three-dimensional optical surface scanner. Eleven females and 7 males without severe facial asymmetry or open-bite were included in this study. Optical surface scans were obtained from all patients preoperatively and 6 months postoperatively, and then evaluated by three-dimensional analyzing software. In all the cases, the soft tissue changes were exclusively found at areas from the lower lip to the border of the chin and were classified into two types: one was focused on the center of the chin, and the other on the lower border of the chin. To access factors associated with the soft tissue changes, the cephalographs taken pre- and postoperatively were three-dimensionally analyzed. The results indicated that the amount of set-back is a significant factor that determines the patterns of soft tissue changes.