title: Geometric accuracy of the NewTom 9000 Cone Beam CT.
abstract: OBJECTIVE
  To determine the geometric accuracy of digital volume tomograms to assess their usability for implant planning.
  
  
  METHODS
  A measuring object with 216 measuring points, whose geometry is exactly known, is X-rayed with a NewTom 9000 cone beam scanner; thereafter the geometry of the volume tomogram of the object is compared with the original body.
  
  
  RESULTS
  Considering all three coordinate axes, geometric mean deviations of 0.13 +/- 0.09 mm with a maximum deviation of 0.3 mm were determined. These geometric deviations are below the resolution power of the volume tomograph.
  
  
  CONCLUSIONS
  The digital volume tomographies of NewTom 9000 present images which are geometrically correct and, from a geometrical point of view, suitable for three-dimensional implant planning.
authors.affiliation: Department of Cranio-Maxillofacial Surgery, University of Heidelberg, Im Neuenheimer Feld 400, D-69120 Heidelberg, Germany. Ruediger_Marmulla@med.uni-heidelberg.de
authors.forename: R
authors.initials: R
authors.lastname: Marmulla
authors.forename: R
authors.initials: R
authors.lastname: Wörtche
authors.forename: J
authors.initials: J
authors.lastname: Mühling
authors.forename: S
authors.initials: S
authors.lastname: Hassfeld
mesh_terms: D003758:Dental Implantation, Endosseous; D010347:Patient Care Planning; D019047:Phantoms, Imaging; D019252:Radiography, Dental, Digital / Q000379:methods*; D015203:Reproducibility of Results; D015898:Tomography Scanners, X-Ray Computed / Q000592:standards*; D036542:Tomography, Spiral Computed / Q000295:instrumentation*