title: Triple images on panoramic radiographs.
abstract: OBJECTIVE
  To explain the formation of triple images on panoramic radiographs.
  
  
  METHODS
  A metal test object was placed in defined positions in relation to movement path of a panoramic X-ray beam.
  
  
  RESULTS
  The test object was portrayed once, twice or three times with varying degrees of distortion depending on its location. Triple images were formed when the test object was located in a specific diamond-shaped area distal to the path of the rotation centre of the X-ray beam.
  
  
  CONCLUSIONS
  The formation of triple images on panoramic radiographs can be explained on the basis of known projection geometry.
authors.affiliation: Institut für Zahnärztliche Röntgenologie, Zentrum für Zahn- Mund- und Kieferheilkunde, Westf. Wilhelms-Universität, Münster, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Reuter
authors.forename: W
authors.initials: W
authors.lastname: Ritter
authors.forename: G
authors.initials: G
authors.lastname: Kaeppler
mesh_terms: D016477:Artifacts; D006801:Humans; D055095:Optics and Photonics; D011862:Radiography, Panoramic