title: Comparison of the accuracy of the three-dimensional virtual method and the conventional manual method for model surgery and intermediate wafer fabrication.
abstract: OBJECTIVE
  The aim was to compare the accuracy of 3-dimensional virtual (3D-VMS) and conventional manual methods (MMS) for model surgery and intermediate wafer (IW) fabrication.
  
  
  METHODS
  Twenty-five patients were divided according to presence or absence of anteroposterior movement (groups 1 and 2, respectively) and canting correction (groups 3 and 4, respectively) of the maxilla. After MMS and 3D-VMS, conventional IW and 3D virtual IW (3D-VIW) were fabricated. Additional maxillary casts were mounted on the articulator using these IWs and 3D positions, and the 3D positions were statistically analyzed.
  
  
  RESULTS
  In model surgery, although 3D-VMS was more accurate than MMS, the errors of both methods were less than 1 mm in all groups. In wafer fabrication, vertical change only was significant in groups 1, 2, and 3. Model surgery and wafer fabrication methods did not show significant differences in accuracy.
  
  
  CONCLUSIONS
  Three-dimensional VMS was more accurate than MMS. However, the accuracy of 3D-VIW fabrication needs to be improved.
authors.affiliation: Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Kyu-Gin
authors.initials: KG
authors.lastname: Song
authors.forename: Seung-Hak
authors.initials: SH
authors.lastname: Baek