Modified method of analysis for surgical correction of facial asymmetry

The aim of this article was to present a new method of analysis using a three dimensional (3D) model of an actual patient with facial asymmetry, for the assessment of her facial changes and the quantification of the deformity. This patient underwent orthodontic and surgical treatment to correct a severe facial asymmetry.

The surgical procedure was complex and the case was challenging. The treatment procedure required an orthodontic approach followed by Le Fort I osteotomy, bilateral sagittal split osteotomy, septorhinoplasty and chin advancement. The imaging devices used in this paper is the 3dMDface system (Atlanta, GA) and the Kodak 9500 Cone Beam 3D system device (Atlanta, GA). 3D digital stereophotogrammetric cameras were used for image acquisition and a reverse modeling software package, the Rapidform 2006 Software (INUS Technology, Seoul, Korea) was applied for surface registration. The images were also combined and analyzed using the 3dMD vultus (Atlanta, GA) software and InVivoDental 5.2.3 (San Jose, CA). All data gathered from previously mentioned sources were adjusted to the patient's natural head position.

The 3D images of the patient were taken and analyzed in three time frames; before orthodontics and surgical treatment (T1), at the end of orthodontic therapy and before surgery (T2) and about 2 months after surgery (T3). The patient showed significant improvement of her skeletal discrepancy between T1 and T3. In addition, there were some dentoalveolar changes between T1 and T2 as expected. The 3D analysis of surgical changes on the 3D models correlated very well to the actual surgical movements.

The use of these 3D imaging tools offer a reliable accuracy to accessing and quantifying changes that occur after surgery. This study shows supportive evidence for the use of 3D imaging techniques.