title: Comparison between panoramic and intra-oral radiographs for the assessment of alveolar bone levels in a periodontal maintenance population.
abstract: BACKGROUND
  Information about the agreement between intra-oral (I-O) and panoramic (OPG) radiographs is limited.
  
  
  OBJECTIVE
  : (1) To assess the agreement between I-Os and OPGs for direct measurements of the distance between the cemento-enamel junction (CEJ) and the alveolar bone level (BL) as well as the proportional values in relation to the root length (CEJ-BL/root length), and (2) to explore the symmetry between the left- and right-side measurements.
  
  
  METHODS
  I-Os and OPGs were studied in 292 periodontal maintenance subjects (mean age 55.5 years, SD+/-12.6) with on average 22.4 teeth (SD+/-4.1 range: 6-28). The images were measured using a PC software program. Site-based I-O and OPG values for CEJ-BL as well as CEJ-BL/root length were compared. OPG values of CEJ-BL/root length values between the left and right sides were also studied.
  
  
  RESULTS
  A total of 11,395 linear distances (CEJ-BL plus CEJ-apex) from the I-Os and 21,462 linear distances from the OPGs were measured. The intra-class correlation coefficients (ICCs) between sets of readings of CEJ-BL varied between 0.80 and 0.89 (p<0.001), with the best agreement for tooth 22 (ICC: 0.89; 95% CI: 0.83-0.92). The ICCs for CEJ-BL/root length varied between 0.54 and 0.92. Mean differences between I-O and OPG values were in the 0.00-0.04 mm range for the CEJ-BL/root length comparisons. The maxillary anterior sextant demonstrated a 1.4 x enlargement by OPG for the CEJ-BL/root length comparisons. No distortions were observed for mandibular sextants. Left- and right-side symmetry of periodontal bone loss was demonstrated. ICC varied between 0.79 (95.00% CI: 0.71-0.84, p<0.01) and 0.53 (95.00% CI: 0.36-0.65, p< 0.01).
  
  
  CONCLUSIONS
  I-O and OPG radiograph readings are in great agreement. Alveolar bone loss appeared to have a symmetrical distribution pattern. Hence for periodontal assessments, OPG radiographic readings may, at least in part, substitute for full-mouth periapical radiographic evaluation.
authors.affiliation: School of Dental Medicine, University of Berne, Switzerland.
authors.forename: Rigmor E
authors.initials: RE
authors.lastname: Persson
authors.forename: Sappho
authors.initials: S
authors.lastname: Tzannetou
authors.forename: Andreas G
authors.initials: AG
authors.lastname: Feloutzis
authors.forename: Urs
authors.initials: U
authors.lastname: Brägger
authors.forename: G Rutger
authors.initials: GR
authors.lastname: Persson
authors.forename: Niklaus P
authors.initials: NP
authors.lastname: Lang
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging; D000539:Alveolar Process / Q000000981:diagnostic imaging*; D002508:Cephalometry; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010510:Periodontal Diseases / Q000517:prevention & control; D016300:Radiography, Bitewing; D011862:Radiography, Panoramic; D019227:Tooth Apex / Q000000981:diagnostic imaging; D019237:Tooth Cervix / Q000000981:diagnostic imaging; D014092:Tooth Root / Q000000981:diagnostic imaging