Criteria for Radiographic Diagnosis of Periodontitis in Epidemiological Studies

Objective: This study aimed to compare four radiographic methods for interpreting the periodontitis in epidemiological studies on associations with systemic conditions.Methods: A database from a case-control study evaluating the association between osteoporosis and periodontitis was used to compare four different radiographic criteria (RC) with the clinical criteria (CC) for interpreting the presence of periodontal disease (PD): RC-1, one tooth; RC-2, at least two teeth; RC-3, at least three teeth; RC-4, at least four teeth, with one or more sites on the mesial or distal face presenting bone loss ≥ 3 mm, in relation to the cement-enamel junction. PD frequency and diagnostic values were calculated, along with the main association measurements (odds ratios), for the two criteria presenting highest specificity.Results: PD frequency varied according to the RC used, from 76.6% to 95.6%. RC-4 and RC-3 presented the highest specificity (30.5% and 21.0%, respectively). The sensitivity was 100% for all criteria tested. The unadjusted and adjusted odds ratios for RC-3 and RC-4 ranged from 1.13 to 1.52, without statistical significance.Conclusions: The findings showed that PD frequency may be influenced by different RCs, as well as indicating variation in the strength of the association between osteoporosis and periodontitis.