Association between body mass index and caries among 13-year-old population in Castelo de Paiva, Portugal

ObjectivesThe purpose of this study was to evaluate the association between dental caries and body mass index-for-age (BMI-for-age) in a 13-year-old population.MethodsA cross-sectional study was carried out with a birth-cohort of 181 voluntary 13 year-old adolescents belonging to a grouping of schools in Castelo de Paiva. BMI-for-age, DMFT and oral hygiene habits were recorded. The Z-test, Mann–Whitney and the Kruskal–Wallis tests were used for univariate comparisons. Multivariate association between independent factors and DMFT>0 or DMFT>6 was assessed using backward stepwise binary logistic multivariate regression analysis (0.05 for covariate inclusion and 0.10 for exclusion).ResultsThe mean DMFT was 4.04 (±2.79) with caries experience affecting 90.1% of adolescents and the majority had normal BMI-for-age (69.1%), 3.3% below normal and 27.6% had weight over normal.DiscussionNo significant differences were found for DMFT according to gender, school attendance, oral hygiene frequency or BMI-for-age. In multivariate analysis the oral hygiene frequency was shown to be significantly associated with DMFT higher than zero (p=0.041). For a more severe DMFT value (DMFT>6) this frequency was not statistically important, whereas the lack of performing oral hygiene at night showed to be a significant risk factor for severe DMFT (p=0.006). The oral hygiene habits showed to be a better predictor than BMI-for-age for the development of caries disease prediction.ConclusionThis study confirms that no association could be assigned between BMI-for-age and dental caries in children especially in permanent dentition