Soft tissue profile changes in the mandibular retrognathic patients: mandibular advancement versus anterior segmental maxillary osteotomy

Purpose Thepurpose of this study was to investigate and compare the effectiveness ofanterior segmental maxillary osteotomy (ASMO) with that of surgical mandibular advancement (SMA) in improving the softtissue profiles of Japanese patients with mandibularretrognathia.Materials and methods In total, 24 Japanese patients (12 SMA and 12 ASMO) were included in this study. Cephalometric radiographs taken before (T0) and after (T1) surgical orthodontic treatment were used to measure the angular and linear measurements of hard and soft tissues. Between-group differences at T0 and T1 and correlations between soft and hard tissue measurements for each group were calculated.Results AtT0, there were no significant between-group differences in any parameter exceptupper lip protrusion, which wassignificantly greater in the ASMO group. From T0 to T1, retractive movement ofthe lower nose and upper and lower lips was observed in the ASMO group, while retractivemovement of upper lip and protrusive movement of the chin were observed in theSMA group. Consequently, facial convexity, Z-angle, and upper lip protrusion,which represent the convexity of the lateral profile, were improved in bothgroups, with no significant differences at T1.Conclusion In Japanese patients with mandibularretrognathia, although the region of soft tissue changes differed between ASMO and SMA, the lateral profile convexity was significantly improved in both groups. Thus, both procedures can result in favourable outcomes.