title: Assessment of the reliability of root angulations on panoramic radiographs.
abstract: OBJECTIVE
  To check the reliability of panoramic radiographs in assessing mesiodistal angulations while considering the true long axes of teeth in relation to a horizontal reference archwire.
  
  
  METHODS
  A clear anatomical typodont with removable teeth was used with 0.8-mm chromium steel balls glued over the incisal/occlusal and apical/furcal portions of teeth to serve as reference markers for representing true long axes of teeth on radiographs and photographs. A photograph of each tooth was taken with a particular technique to serve as a medium through which to measure true mesiodistal angulations of teeth.
  
  
  RESULTS
  Only overall maxillary teeth angulations significantly correlated to true mesiodistal angulations. Radiographic relationship of the long axes of adjacent teeth (convergence or divergence) in the mandibular as well as the maxillary arch did not show any significant correlation to true degree of convergence or divergence and displayed a tendency to accentuate the maxillary canine to premolar divergence and mandibular lateral incisor to canine convergence.
  
  
  CONCLUSIONS
  Panoramic radiographs provide a poor representation of the mesiodistal angulations of teeth and require cautious use with clinical judgment and adjunctive procedures to ascertain root angulations.
authors.affiliation: Department of Orthodontics, Nair Hospital Dental College, Mumbai Central, Mumbai, Maharashtra, India. dholakia_kartik@rediffmail.com
authors.forename: Kartik D
authors.initials: KD
authors.lastname: Dholakia
authors.forename: Shweta R
authors.initials: SR
authors.lastname: Bhat
mesh_terms: D006801:Humans; D008310:Malocclusion / Q000000981:diagnostic imaging*; D008334:Mandible; D008437:Maxilla; D003765:Models, Dental; D009811:Odontometry / Q000295:instrumentation* / Q000379:methods; D019047:Phantoms, Imaging; D011862:Radiography, Panoramic / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012399:Rotation; D019227:Tooth Apex / Q000000981:diagnostic imaging; D014092:Tooth Root / Q000000981:diagnostic imaging*