Enhanced Surgical Outcomes in Patients With Skeletal Class III Facial Asymmetry by 3-Dimensional Surgical Simulation.

PURPOSE: With the advance of image fusion techniques, the creation of 3-dimensional (3D) virtual head and 3D surgical simulations has provided previews of surgical procedures. The aim of this study was to investigate the surgical outcomes in patients receiving orthognathic surgery (OGS) with the guidance of 3D computer-assisted surgical simulation. PATIENTS AND METHODS: The study included 34 consecutive patients (15 men and 19 women; age, 18.1 to 33.0 yr) with skeletal Class III facial asymmetry who underwent bimaxillary OGS. One-week postoperative cone-beam computed tomographic craniofacial images (Ta) were constructed and superimposed on preoperative simulated virtual images (Ts) at the cranial base and surfaces of the frontal and periorbital regions. The 3D cephalometric landmarks were measured relative to 3 reference planes. The outcomes among different experience levels of surgeons also were compared. RESULTS: Although the mean values between Ta and Ts were small, statistical differences were observed in the center of maxillary and mandibular incisors and the B point relative to the midline and in the maxillary first molar in vertical distances, sagittal dentoskeletal dimensions, and pitch angles. The root mean square deviations (RMSD(L)) of measurement variables relative to center landmark accuracy were 1.5 and less than 2 mm at the maxilla and mandible, respectively. RMSD(L) greater than 2 mm was located at the maxillary first molar in the vertical distance and in the sagittal dimension at the anterior nasal spine and B point. Variables related to centering the midline structures were highly inter-related. The roll angle deviation was associated with centering the midline landmarks. The yaw angle deviation was not associated with midline correction. CONCLUSION: With guidance from 3D surgical simulation, surgeons could achieve similar outcomes to correct facial asymmetry regardless of their years of practice.