Social and biological early life influences on the prevalence of open bite in Brazilian 6-year-olds

Objective. Little is known about the effects of social and biological risk factors for open bite on the primary dentition. The aim of this study was to assess the early-life risk factors affecting anterior open bite. Methods. A cross-sectional study using a birth cohort was carried out in Pelotas, Brazil. A sample of 400, 6-year-old children was employed. The Foster and Hamilton criteria were used to classify open bite. Data concerning social conditions, and perinatal and childhood health and behaviour were obtained from birth to 12 months of age and during the fifth year of the children's lives. Unconditional bivariate and multiple logistic regression analysis were performed. Results. The prevalence of anterior open bite was 46.3%. Risk factors included: a maternal age of between 30 and 39 years, as compared with children whose mothers were younger; breast-feeding for <9 months; dental caries experience; pacifier sucking between 12 months and 5 years, as compared to no sucking or a shorter duration of sucking; and the presence of finger-sucking at 6 years of age. Conclusion. Open bite in the primary dentition was associated with older mothers, early weaning, dental caries occurrence, long-term use of a pacifier and finger-sucking at 6 years of age. These findings support the common risk approach for intervention to prevent open bite in the primary dentition.