title: Can nonstandardized bitewing radiographs be used to assess the presence of alveolar bone loss in epidemiologic studies?
abstract: OBJECTIVE
  To compare periodontitis-associated alveolar bone loss assessment by standardized and nonstandardized radiographs in clinical and epidemiologic studies.
  
  
  METHODS
  Participants included 37 patients aged 21-66 years with prior nonstandardized bitewing radiographs scheduled to receive bitewing radiographs as part of their next routine dental care visit. Standardized bitewing radiographs were taken with a Rinn film holder to position the film in the mouth and align the X-rays so that they were at 90 degrees to the film. Before taking the radiograph the bite was registered in centric relation using a polyether impression material. One registered dental hygienist took and processed all the standardized radiographs. One dentist read all radiographs using a viewing box, magnifying lens, and periodontal probe with William's markings. Radiographic bone loss was measured to the closest millimeter at mesial and distal sites of the posterior teeth excluding third molars. The examining dentist was blinded to the participant's name, age, gender, or if the radiograph was standardized or nonstandardized.
  
  
  RESULTS
  Mean bone loss (+/- SD) was similar in the standardized and nonstandardized groups (1.60 +/- 0.72 mm versus 1.64 +/- 0.85 mm), and the correlation was high (r = 0.95). Periodontitis was defined as present if the participant had at least one site with 3, 4 and 5 mm bone loss. The Kappa statistics for concordance using these three cutoffs were good and ranged from 0.60 to 0.65. The sensitivity ranged from 72.7 to 80.8% and specificity from 88.5 to 90.9%.
  
  
  CONCLUSIONS
  Periodontitis assessed as mean alveolar bone loss or the prevalence of disease based on alveolar bone loss can be accurately and reliably evaluated from nonstandardized radiographs.
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada. merchant@ccc.mcmaster.ca
authors.forename: Anwar T
authors.initials: AT
authors.lastname: Merchant
authors.forename: Waranuch
authors.initials: W
authors.lastname: Pitiphat
authors.forename: Jessica
authors.initials: J
authors.lastname: Parker
authors.forename: Kaumudi
authors.initials: K
authors.lastname: Joshipura
authors.forename: Mary
authors.initials: M
authors.lastname: Kellerman
authors.forename: Chester W
authors.initials: CW
authors.lastname: Douglass
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000175:diagnosis / Q000000981:diagnostic imaging*; D016302:Centric Relation; D016021:Epidemiologic Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007574:Jaw Relation Record; D008297:Male; D008875:Middle Aged; D010517:Periodontics / Q000295:instrumentation; D010518:Periodontitis / Q000453:epidemiology*; D016300:Radiography, Bitewing; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method