title: Observer variation in the radiographic assessment of the bone level on the buccal and lingual surfaces of mandibular molars.
abstract: OBJECTIVE
  To assess accuracy and precision of observers' diagnostic performance in locating the buccal/lingual bone level using conventional periapical radiographs.
  
  
  METHODS
  Standardized radiographs of molar regions of 10 dried mandibles were obtained. The bone crest on buccal and lingual surfaces of first and second molars was then marked with thin lead foil strips and fresh radiographs taken. A series of increasingly extensive furcation defects was created by sequential bone removal and radiographs with and without markers obtained after each step. The radiographs without indicators were presented to 10 observers on two separate occasions and the most apically located bone level marked on a transparent film. The distance between observers' markings and 'true' bone level on the radiographs was determined.
  
  
  RESULTS
  There was wide interobserver variation which increased as the bone loss increased. Lack of consistency was largely attributable to intra-observer variation except when a furcation defect was present. The underestimation of bone loss became more marked as the amount of bone loss increased.
  
  
  CONCLUSIONS
  Radiographic determination of bone loss on buccal and lingual surfaces is associated with a considerable lack of accuracy and precision, both of which get worse as bone loss increases.
authors.affiliation: Department of Periodontology, Faculty of Odontology, University of Göteborg, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Gürgan
authors.forename: K
authors.initials: K
authors.lastname: Gröndahl
authors.lastname: Wennström
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging*; D002983:Clinical Competence; D017823:Furcation Defects / Q000000981:diagnostic imaging; D006801:Humans; D008336:Mandibular Diseases / Q000000981:diagnostic imaging*; D008963:Molar; D015588:Observer Variation; D011861:Radiography, Dental / Q000592:standards*; D015203:Reproducibility of Results