Association between orthodontic treatment and periodontal diseases: Results from a national survey.

OBJECTIVE: To investigate the association between orthodontic treatment and periodontitis in a nationally representative sample of South Korea. MATERIALS AND METHODS: Data from the Fifth and Sixth Korean National Health and Nutrition Examination Survey (KNHANES V, VI-1, and VI-2), conducted from 2012 to 2014, were used in this study. The final sample size consisted of 14,693 adults aged >/=19 years. Logistic regression analysis was performed to assess the association between orthodontic treatment and periodontitis. RESULTS: The orthodontic treatment group exhibited a lower prevalence of periodontitis compared with the nonorthodontic treatment group. The adjusted odds ratios for periodontitis in subjects with a history of orthodontic treatment compared with those with no history of orthodontic treatment were 0.553, 0.614, and 0.624, when adjusted for various confounding variables (P < .0001). The subjects with periodontitis were of higher age, body mass index, waist circumference, and white blood cell counts compared with the subjects without periodontitis regardless of history of orthodontic treatment. CONCLUSIONS: History of orthodontic treatment was associated with a decreased rate of periodontitis.