title: Cross-sectional tomograms obtained with four panoramic radiographic units in the assessment of implant site measurements.
abstract: OBJECTIVE
  The aim of this study was to evaluate the ability of four panoramic X-ray units to produce cross-sectional images and to assess the effect of interexaminer and intraexaminer variations on the results.
  
  
  METHODS
  Cross-sectional tomograms of a human cadaver mandible were taken from two edentulous and one dentate area using four different X-ray units: OP-100 Ortho Trans (Instrumentarium Imaging Co, Tuusula, Finland), Proscan (Planmeca Co, Helsinki, Finland), Cranex-Tome and Scanora (Soredex, Orion Co, Espoo, Finland). Four different linear distances were measured from each radiograph. The mandible was then cut into 4 mm thick slices at three marked places. These slices were microradiographed and used as the gold standard for measurements made from each cross-sectional tomogram.
  
  
  RESULTS
  Of all measurements only the thickness of the mandible in the radiographs taken with the OP-100 differed significantly (P < 0.021) from the gold standard. In the interexaminer variation, the agreement was 85% and Kappa index 0.68. In the intraexaminer reproducibility, the agreement was 76.7% and Kappa indices 0.52 and 0.50.
  
  
  CONCLUSIONS
  The X-ray units studied were found to be similar in terms of image performance and the produced images were acceptable for dental implant placement planning. Interexaminer and intraexaminer variations can be large and the main source of error can be the interpreter him or herself.
authors.affiliation: Department of Oral Radiology, Institute of Dentistry, University of Helsinki, Finland. jaakko.peltola@helsinki.fi
authors.forename: J S
authors.initials: JS
authors.lastname: Peltola
authors.forename: M
authors.initials: M
authors.lastname: Mattila
mesh_terms: D019412:Anatomy, Cross-Sectional; D002102:Cadaver; D002508:Cephalometry; D015921:Dental Implants; D006801:Humans; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging; D008334:Mandible / Q000000981:diagnostic imaging*; D008852:Microradiography; D015588:Observer Variation; D011856:Radiographic Image Enhancement; D019252:Radiography, Dental, Digital / Q000295:instrumentation; D011862:Radiography, Panoramic / Q000295:instrumentation*; D015203:Reproducibility of Results; D014056:Tomography, X-Ray; D014962:X-Ray Film; D014963:X-Ray Intensifying Screens
chemical_list: D015921:Dental Implants