Three-Dimensional Analysis of Facial Morphology of Patients with Mandibular Prognathism Undergoing Sagittal Splitting Ramus Osteotomy

Abstract

The purpose of this study was to analyze the relationship between changes of mandibular position and that of facial morphology before and after orthognathic surgery by sagittal splitting ramus osteotomy (SSRO) and to simulate the postoperative facial image.
Eleven female patients with mandibular prognathism who underwent SSRO were analyzed just before and 3 months after the operation by using a noncontact three-dimensional measuring apparatus (VOXELAN NKV-300DS, Hamano Engineering) and three-dimensional analyzing software (3-D RUGLE, Medic Engineering).
The results were as follows:
1. It was found that the system composed of VOXELAN and 3-D RUGLE was useful for three-dimensional measurement and analysis of facial figure in jaw deformity.
2. The morphological changes of facial soft tissue caused by the mandibular set back were maximum in the middle mental region. The upper lip region was slightly affected as well.
3. The anatomic measurement points in the lower face showed downward and significant backward movement. Most points of the upper and middle face showed little change.
4. Facial heights were shortened significantly.
5. By taking the direction of the mandibular movement into account, changes of facial morphology by mandibular movement were demonstrated more clearly.
6. It was found that the simulated postoperative facial image computed by the data were similar to the real one.