title: Multichannel computed tomography versus cone-beam computed tomography: linear accuracy of in vitro measurements of the maxilla for implant placement.
abstract: OBJECTIVE
  Accurate measurement of alveolar bone and adjacent anatomic structures is of paramount importance in implant insertion. This study was conducted to compare the linear measurement accuracy of 64-channel computed tomography (CT) and cone-beam CT (CBCT).
  
  
  METHODS
  Twenty-seven sites were marked on three dry human skulls, with the positions of the buccal and palatal fiducial markers ensuring the representation of one plane by each buccal-palatal pair. The skulls were imaged using Somatom Sensation 64-channel CT (Siemens) and Pro Max 3D CBCT (Planmeca). The two fiducial markers and alveolar bone height were measured on the printed films of the cross-sectional views representing the best buccal and palatal markers. The maxillae were then sawed in marked locations, and direct measurements of the fiducial markers and alveolar bone height were then made. The Wilcoxon signed rank test was employed for statistical analysis.
  
  
  RESULTS
  The measurement errors for the buccal fiducial markers, palatal fiducial markers, and crest height for CBCT were 0.38 +/- 0.39 mm, 0.37 +/- 0.33 mm, and 0.58 +/- 0.45mm, respectively; for the 64-channel CT they were 0.59 +/- 0.61 mm, 0.37 +/- 0.42 mm, and 0.72 +/- 0.92 mm, respectively. There was no statistically significant difference in measurement error between the two methods (P > .05).
  
  
  CONCLUSIONS
  There was no statistically significant difference in terms of linear measurement accuracy between the two systems; it could, therefore, be concluded that CBCT is a useful tool for a preliminary assessment of anticipated implant sites.
authors.affiliation: Department of Oral and Maxillofacial Radiology, School of Dental Sciences, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed Ahmad
authors.initials: SA
authors.lastname: Fatemitabar
authors.forename: Arash
authors.initials: A
authors.lastname: Nikgoo
mesh_terms: D000539:Alveolar Process / Q000000981:diagnostic imaging; D019412:Anatomy, Cross-Sectional; D002102:Cadaver; D054893:Cone-Beam Computed Tomography; D003758:Dental Implantation, Endosseous / Q000379:methods*; D006801:Humans; D008437:Maxilla / Q000000981:diagnostic imaging*; D010347:Patient Care Planning; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*