Skeletal Stability After Simultaneous Mandibular Angle Resection and Sagittal Split Ramus Osteotomy for Correction of Mandible Prognathism

Purpose

Simultaneous mandibular angle resection with bilateral sagittal split ramus osteotomy (BSSRO) is a useful modification of conventional BSSRO in patients with prominent mandibular angles. The purpose of this study is to prove whether simultaneous mandibular angle resection and BSSRO can influence the tendency of postoperative skeletal instability by means of shortening the pterygomasseteric sling.

Patients and Methods

This study was based on 26 cases of mandible prognathism. The experimental group consisted of 12 patients (average age, 24.6 ± 3.9) who underwent BSSRO and mandibular angle resection simultaneously. Fourteen patients (average age, 21.4 ± 3.4) served as a control group where only BSSRO was carried out. In lateral cephalometric tracings, horizontal and vertical changes of B point, pogonion, and menton were measured to determine the amount of postoperative instability. The amount of skeletal instability was compared between 2 groups.

Results

In the experimental group, point B and pogonion moved posteriorly 1.86 mm and 1.21 mm, respectively. In the control group they moved anteriorly 1.04 mm and 0.96 mm, respectively.

Conclusions

Simultaneous mandibular angle resection and BSSRO proved to be a useful modification of the conventional BSSRO to reduce the tension in the pterygomasseteric muscle sling and to obtain more esthetic results clinically.