title: Automatic Superimposition of Palatal Fiducial Markers for Accurate Integration of Digital Dental Model and Cone Beam Computed Tomography.
abstract: OBJECTIVE
  Obtaining a detailed dentition image is important for 3-dimensional orthognathic surgical simulation. The purpose of the present study was to evaluate the accuracy of a method using automatic superimposition of intraoral fiducial markers for integrating the digital dental model with the cone beam computed tomography (CBCT) scan.
  
  
  METHODS
  A preliminary test was performed on a plastic skull model for the proper selection of the size and number of the fiducial markers fixed to the palatal plate. Five patients were enrolled in the present study. Plaster dental models were taken and scanned. Integration of the upper dental and occlusion dental image with the CBCT scan was performed by superimposition of the markers. The occlusion dental image was used to connect the lower dental image and the corresponding position of the CBCT mandibular dentition. The root mean square difference (RMSD) was used to evaluate the accuracy of fiducial marker superimposition, and the Euclidean distances were measured between 2 occlusion surfaces to evaluate the registration accuracy.
  
  
  RESULTS
  The RMSD was less than 0.13 mm in the superimposition of fiducial markers, and the Euclidean distance was less than 0.28 mm in the occlusal surface deviation. The results showed high accuracy on integration. The patients reported good tolerance to the markers.
  
  
  CONCLUSIONS
  This superimposition method provided high accuracy for the replacement of dentition using CBCT and was patient- and user-friendly for clinical application.
authors.affiliation: Attending Staff, Department of Dentistry, Chang Gung Memorial Hospital, Chiayi, Taiwan.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Yang
authors.affiliation: Assistant Professor, Department of Orthodontics, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Cheng-Ting
authors.initials: CT
authors.lastname: Ho
authors.affiliation: Professor, Department of Plastic and Reconstructive Surgery, and Craniofacial Research Center, and Chairman, Department of Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan. Electronic address: lunjoulo@cgmh.org.tw.
authors.forename: Lun-Jou
authors.initials: LJ
authors.lastname: Lo
mesh_terms: D001331:Automation; D054893:Cone-Beam Computed Tomography; D006801:Humans; D008953:Models, Anatomic; D003765:Models, Dental; D010159:Palate / Q000000981:diagnostic imaging*