title: 3-dimensional facial simulation in orthognathic surgery: is it accurate?
abstract: OBJECTIVE
  The purpose of this study was to measure the accuracy of 3D computer simulation of soft tissue changes after orthognathic surgery.
  
  
  METHODS
  Consecutive patients who underwent orthognathic surgery were studied by photogrammetric facial scanning and cone-beam computed tomography before and after surgery. The photogrammetric scan was then fused to the cone-beam computed tomogram, creating a patient-specific image. The surgery was simulated in 3D form and the simulated soft tissue face was compared with the actual facial scan obtained 6 months postoperatively. Absolute millimeter differences between the simulated and actual postoperative changes in selected cephalometric skin markings were computed.
  
  
  RESULTS
  The study was composed of 23 subjects (mean age, 31 yr; 13 women and 10 men). Eighteen different cephalometric landmarks were measured (total, 28). For 15 landmarks, the difference between actual and simulated measurements was smaller than 0.5 mm. Only 3 landmarks had a difference of 0.5 mm, and these were in the region of the labial landmarks.
  
  
  CONCLUSIONS
  Based on the present study, 3-dimensional computer surgical simulation of the soft tissue of the face for routine orthognathic surgery is accurate enough for routine clinical use.
authors: Department of Surgery, Stanford University, Stanford, CA, USA. sschendel@stanford.edu
authors: Stephen A
authors: SA
authors: Schendel
authors: Richard
authors: R
authors: Jacobson
authors: Sadri
authors: S
authors: Khalessi
mesh_terms: D000328:Adult; D002508:Cephalometry / Q000592:standards*; D003198:Computer Simulation; D054893:Cone-Beam Computed Tomography; D061827:Dimensional Measurement Accuracy; D005145:Face / Q000033:anatomy & histology*; D005147:Facial Bones / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008953:Models, Anatomic; D057909:Orthognathic Surgery; D010780:Photogrammetry; D063173:Retrognathia / Q000000981:diagnostic imaging / Q000473:pathology