title: Accuracy of virtual models in the assessment of maxillary defects.
abstract: OBJECTIVE
  This study aimed to assess the reliability of measurements performed on three-dimensional (3D) virtual models of maxillary defects obtained using cone-beam computed tomography (CBCT) and 3D optical scanning.
  
  
  METHODS
  Mechanical cavities simulating maxillary defects were prepared on the hard palate of nine cadavers. Images were obtained using a CBCT unit at three different fields-of-views (FOVs) and voxel sizes: 1) 60×60 mm FOV, 0.125 mm(3) (FOV60); 2) 80×80 mm FOV, 0.160 mm(3) (FOV80); and 3) 100×100 mm FOV, 0.250 mm(3) (FOV100). Superimposition of the images was performed using software called VRMesh Design. Automated volume measurements were conducted, and differences between surfaces were demonstrated. Silicon impressions obtained from the defects were also scanned with a 3D optical scanner. Virtual models obtained using VRMesh Design were compared with impressions obtained by scanning silicon models. Gold standard volumes of the impression models were then compared with CBCT and 3D scanner measurements. Further, the general linear model was used, and the significance was set to p=0.05.
  
  
  RESULTS
  A comparison of the results obtained by the observers and methods revealed the p values to be smaller than 0.05, suggesting that the measurement variations were caused by both methods and observers along with the different cadaver specimens used. Further, the 3D scanner measurements were closer to the gold standard measurements when compared to the CBCT measurements.
  
  
  CONCLUSIONS
  In the assessment of artificially created maxillary defects, the 3D scanner measurements were more accurate than the CBCT measurements.
authors: Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey.
authors: Kıvanç
authors: K
authors: Kamburoğlu
authors: Division of Dentomaxillofacial Radiology, Ministry of Health, Oral and Dental Health Center, Bolu, Turkey.
authors: Şebnem
authors: Ş
authors: Kurşun
authors: Department of Anatomy, Gülhane Military Medical Academy, Ankara, Turkey.
authors: Cenk
authors: C
authors: Kılıç
authors: Department of Dentomaxillofacial Radiology, Dental Science Center, Gülhane Military Medical Academy, Ankara, Turkey.
authors: Tuncer
authors: T
authors: Özen
keywords: Cone-beam Computed Tomography; Dimensional Measurement Accuracy; Maxillofacial Prosthesis; Radiology