title: Virtual variation simulation of CAD/CAM template-guided surgeries performed on human cadavers: Part II.
abstract: BACKGROUND
  CAD/CAM template-guided surgery has gained attention as a method of improving the predictability of dental implant placement. However, due to possible variations during the manufacturing process and in the robustness of the template design, a virtual prediction of the potential positioning of the implants is needed.
  
  
  OBJECTIVE
  The purpose of this study was to perform virtual variation simulations on virtually planned implant placements and to compare them with corresponding results from actual surgeries performed on human cadavers in a previous study.
  
  
  METHODS
  Seventeen computer-aided plans were used for virtual variation simulation of surgeries conducted on 17 human cadavers and 145 implants placed in the cadavers. For each surgery, 10,000 virtual surgeries were performed, resulting in 1,450,000 implant placements. The results from the virtual variation simulations were statistically compared with the results from the actual surgeries. The Mann-Whitney U test was used to compare the implant distributions (alpha=.05).
  
  
  RESULTS
  In the maxillae, the difference between the simulated average mean of the mean and the compared surgical average of the median was 0.22 mm (apex) and -0.35 mm (hex), and for the mandible, the corresponding values were -0.19 mm (apex) and -0.69 mm (hex). The simulated average mean of the range compared to the mean range of the maximum deviation results from the surgeries of the maxillae was 2.96 mm (apex) and 0.44 mm (hex), and 2.3 mm (apex) and 0.26 mm (hex) for the mandible. The implant distributions between the simulations and the surgeries were significantly different at both the hex (P<.001) and apex (P<.001).
  
  
  CONCLUSIONS
  The implant distributions were neither static nor normally distributed. Thus, within the limitations of this study, the definitive geometrical variations of the implants were not static, as they depend on the individual anatomy of the jaws and the ability to place the CAD/CAM-guided surgical template in the proper position.
authors.affiliation: Department of Product and Production Development, Chalmers University of Technology, Göteborg, Sweden.
authors.forename: Timo
authors.initials: T
authors.lastname: Kero
authors.forename: Andreas
authors.initials: A
authors.lastname: Pettersson
authors.forename: Jenny
authors.initials: J
authors.lastname: Fäldt
authors.forename: Matts
authors.initials: M
authors.lastname: Andersson
authors.forename: Luc
authors.initials: L
authors.lastname: Gillot
authors.forename: Bernard
authors.initials: B
authors.lastname: Cannas
authors.forename: Karin
authors.initials: K
authors.lastname: Näsström
authors.forename: Rikard
authors.initials: R
authors.lastname: Söderberg
mesh_terms: D002102:Cadaver; D003198:Computer Simulation; D017076:Computer-Aided Design / Q000706:statistics & numerical data*; D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D015921:Dental Implants / Q000706:statistics & numerical data*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007575:Jaw, Edentulous / Q000473:pathology / Q000601:surgery; D008334:Mandible / Q000473:pathology / Q000601:surgery; D008437:Maxilla / Q000473:pathology / Q000601:surgery; D008953:Models, Anatomic; D009010:Monte Carlo Method; D010347:Patient Care Planning / Q000706:statistics & numerical data*; D025321:Surgery, Computer-Assisted / Q000706:statistics & numerical data*; D014057:Tomography, X-Ray Computed / Q000379:methods; D014584:User-Computer Interface
chemical_list: D015921:Dental Implants