title: Influence of individual brightness and contrast adjustment on accuracy of radiographic measurements of infrabony defects.
abstract: OBJECTIVE
  To assess the accuracy of radiographic measurements of infrabony defects and to compare the accuracy with and without individual digital adjustment of brightness and contrast.
  
  
  METHODS
  In 41 periodontitis patients (19 females, 22 males; age range 23-73 years), 50 radiographs of 50 infrabony defects were obtained. All radiographs were digitized. Using a personal computer program, the linear distances between cemento-enamel junction (CEJ) and alveolar crest (AC) and between CEJ and bony defect (BD), and the depth of the infrabony defect (INFRA), were measured twice, according to the individual judgement of the radiographic examiner: (1) without digital adjustment (W) and (2) after use of contrast and brightness adjustment (A). Intrasurgical bone measurements served as the gold standard. The accuracy of measurements with or without digital adjustment was compared.
  
  
  RESULTS
  Radiographic measurements underestimated the gold standard for CEJ-BD (W: 1.1 mm ± 1.8 mm, P < 0.001; A: 1.0 mm ± 1.9 mm, P = 0.001). Both CEJ-AC (W: 0.2 mm ± 2.5 mm; A: 0.5 mm ± 2.6 mm) and INFRA (W: -0.4 mm ± 2.4 mm; A: -0.6 mm ± 2.5 mm) measurements came close to the gold standard. Statistically significant differences between W and A regarding accuracy were not observed.
  
  
  CONCLUSIONS
  The measurement tool used in this study provided high-accuracy measurements of periodontal bone loss in INFRA. Individual brightness and contrast adjustment failed to improve accuracy.
authors.affiliation: Department of Periodontology, Semmelweis University, Budapest, Hungary.
authors.forename: D
authors.initials: D
authors.lastname: Tihanyi
authors.forename: I
authors.initials: I
authors.lastname: Gera
authors.forename: P
authors.initials: P
authors.lastname: Eickholz
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011857:Radiographic Image Interpretation, Computer-Assisted; D019252:Radiography, Dental, Digital / Q000379:methods*; D012016:Reference Values; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D019237:Tooth Cervix / Q000000981:diagnostic imaging; D055815:Young Adult
chemical_list: D003287:Contrast Media