Association between gingival bleeding and gingival enlargement and oral health-related quality of life (OHRQoL) of subjects under fixed orthodontic treatment: a cross-sectional study

BACKGROUND: There are scarce evidences that evaluated the impact of periodontal disease on oral health-related quality of life (OHRQoL) taking marginal gingival alterations into consideration. Thus, this study aimed to verify the association between OHRQoL and gingival enlargement and gingival bleeding in subjects under fixed orthodontic treatment (FOT). METHODS: 330 participants under FOT for at least 6 months were examined by a single, calibrated examiner for periodontal variables and dental aesthetic index. Socio-economic background, body mass index, time with orthodontic appliances, and use of dental floss were assessed by oral interviews. OHRQoL was evaluated using the oral health impact profile (OHIP-14) questionnaire. The assessment of associations used unadjusted and adjusted Poisson regression models. RESULTS: Higher impacts on the OHIP-14 overall were observed in subjects who presented higher levels of anterior gingival enlargement (RR 2.83; 95% CI 2.60-3.09), were non-whites (RR 1.29; 95% CI 1.15-1.45), had household income lower than five national minimum wages (RR 1.85; 95% CI 1.30-2.61), presented body mass index > 25 (RR 1.14; 95% CI 1.01-1.29), and showed a dental aesthetic index > 30 (RR 1.32; 95% CI 1.20-1.46). CONCLUSIONS: Anterior gingival enlargement seems to influence the OHRQoL in subjects receiving orthodontic treatment.