Nonnutritive sucking habits and anterior open bite in Brazilian children: a longitudinal study.

PURPOSE The purpose of this longitudinal study was to assess the relationship between nonnutritive sucking habits and anterior open bite in 305 4- to 5-year-old children attending state schools in the city of Recife, Brazil. METHODS The data were collected by interviewing the children's mothers or guardians and through clinical examinations carried out by 1 calibrated examiner (K = 1). Bivariate analyses (Pearson chi-square, McNemar, and Stuart-Maxwell tests) were used for the statistical analysis. RESULTS The prevalence of sucking habits was low, and the sample showed reductions after 1 year of follow-up. The prevalence of anterior open bite decreased from 33% to 29% after 1 year. A significant association was found between anterior open bite and sucking habits. Open bite self-correction was associated with the abandoning of deleterious habits. CONCLUSIONS The low prevalence of nonnutritive sucking habits and its reduction during the period studied seem to reflect a natural tendency in preschool children. Even presenting a slight reduction, the high prevalence of anterior open bite draws attention to the importance of longitudinal studies to support scientific evidences for early clinical intervention.