title: Three-dimensional accuracy of measurements made with software on cone-beam computed tomography images.
abstract: BACKGROUND
  The purpose of this article was to evaluate the accuracy of measurements made on 9- and 12-in cone-beam computed tomography (CBCT) images compared with measurements made on a coordinate measuring machine (CMM), which is the gold standard.
  
  
  METHODS
  Ten markers were placed on a synthetic mandible, and landmark coordinates and linear and angular measurements were determined with the CMM. Three-dimensional CBCT images, measuring 9 and 12 in, were taken of the mandible with a CBCT machine (NewTom 3G, Aperio Services, Verona, Italy), and landmark coordinates and linear and angular measurements were obtained with AMIRA (Mercury Computer Systems, Berlin, Germany) software.
  
  
  RESULTS
  The coordinate intrareliability correlation coefficient was almost perfect between the 3-dimensional CBCT images and the CMM measurements. With the Student t test, we found no significant statistical difference between linear and angular measurements from the CMM and the NewTom 3G images, which differed less than 1 mm and 1 degrees , respectively.
  
  
  CONCLUSIONS
  The NewTom 3G produces a 1-to-1 image-to-reality ratio.
authors.affiliation: Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada. mlagravere@yahoo.com
authors.forename: Manuel O
authors.initials: MO
authors.lastname: Lagravère
authors.forename: Jason
authors.initials: J
authors.lastname: Carey
authors.forename: Roger W
authors.initials: RW
authors.lastname: Toogood
authors.forename: Paul W
authors.initials: PW
authors.lastname: Major
mesh_terms: D002508:Cephalometry / Q000379:methods* / Q000706:statistics & numerical data; D054893:Cone-Beam Computed Tomography / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods / Q000706:statistics & numerical data; D021621:Imaging, Three-Dimensional / Q000379:methods* / Q000706:statistics & numerical data; D008334:Mandible / Q000000981:diagnostic imaging; D008953:Models, Anatomic; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012984:Software / Q000706:statistics & numerical data; D014025:Titanium
chemical_list: D014025:Titanium