Evaluation of the soft and hard tissue changes after anterior segmental osteotomy on the maxilla and mandible.

Purpose: The purpose of this study was to determine the relationship between the changes of soft and hard tissues after modified anterior segmental osteotomy on the maxilla and mandible and to evaluate unintended facial changes using cephalometric and photometric analyses.
Materials and Methods: The subjects included 29 women and 1 man (22 to 50 years of age) who were diagnosed as bialveolar or bimaxillary protrusion and underwent modified anterior segmental osteotomy on the maxilla and mandible. Lateral cephalograms and lateral and frontal photographs taken preoperatively and postoperatively were analyzed.
Results: There was a significant change in all soft and hard tissue parameters except the labiomental angle. The ratio of upper lip to maxillary incisor retraction was 0.67:1 and the ratio of lower lip to mandibular incisor retraction was 0.89:1. Nasolabial angle and philtrum length were increased, and vermilion length and lip width were decreased. Nasal change could be kept as small as possible, although slight widening of the nasal width and anti-tip rotation of the nasal tip were observed.
Conclusion: Anterior segmental osteotomy might be recommended as the treatment modality of choice in patients with bimaxillary and/or dentoalveolar protrusion. Because the technique is simple, postoperative complications are minimal, relapse is limited, and soft tissue changes in response to surgery are more predictable.