Could orthodontic fixed appliances and excess weight affect gingival health in adolescents?

INTRODUCTION: The aim of this study was to evaluate the impact of being overweight or obese while wearing orthodontic fixed appliances on the prevalence of gingivitis in adolescents. METHODS: A total of 334 adolescents, aged between 12 and 18 years, were recruited from 3 public schools in Cuiaba, Brazil. Participants were divided in dichotomized categories of body mass index (BMI) (under and normal weight or overweight and obesity) and fixed orthodontic appliance usage (yes or no). Gingival inflammation was evaluated by Loe & Silness index. Socioeconomic status was determined by the criteria of the Brazilian Association of Research Companies, and sugar consumption was assessed by a questionnaire of dietary habits. The statistical analysis was performed with P <0.05 considered significant. RESULTS: In a multivariate linear regression model, gingivitis was directly related to BMI (%) variation and orthodontic appliance use. In addition, excess weight seemed to be 2 times more relevant in predicting gingivitis than orthodontic fixed appliance usage. A strong positive correlation was observed between BMI (%) variation and gingival index (rho = 0.97, P <0.001). CONCLUSIONS: Orthodontic fixed appliance usage and excess weight were associated with increased gingivitis in adolescents; BMI (%) variation was the most significant predictor of gingival inflammation.