Three-dimensional investigation of facial surface asymmetries in skeletal malocclusion patients before and after orthodontic treatment combined with orthognathic surgery

Abstract

The goal of the following study was to quantify facial soft-tissue asymmetry in patients with pronounced skeletal malocclusion anomalies before and after orthodontic treatment combined with orthognathic surgery. In addition, the facial attractiveness of these patients was rated by dental specialists and laypersons both before and after treatment based on the three-dimensional (3D) data. An optical sensor was used to noninvasively capture the 3D facial surface data of 60adult patients including two groups of 20patients with skeletal ClassII or III anomalies and a control group of another 20subjects with ClassI relationships. Facial surface asymmetries were evaluated immediately before the surgical procedure and 1year thereafter. In addition, subjective ratings of facial attractiveness were obtained based on a questionnaire from orthodontists, maxillofacial surgeons, and laypersons. No differences in facial soft-tissue asymmetry were observed between the ClassII and III patients either pre- or postoperatively, but asymmetry was found to be more pronounced in the skeletal malocclusion groups than in the ClassI control group both pre- and postoperatively. The subjective ratings of facial attractiveness by the various rater groups yielded more favorable results for the post- than preoperative patient images, reflecting differences that reached overall statistical significance. Quantitative analysis of facial soft-tissue asymmetry and calculating a cutoff value allowed us to distinguish patients with skeletal malocclusion from a control group solely on the basis of asymmetry. Combined regimens of orthodontic treatment and orthognathic surgery go some way in reducing asymmetry toward the levels seen in untreated control subjects, while the asymmetry pattern characteristic of this type of malocclusion will persist. Nevertheless, the asymmetry reduction is noticeable enough to result in more favorable ratings of attractiveness.