Nutritional and non-nutritional habits and occurrence of malocclusions in the mixed dentition.

Malocclusions are changes in the development of craniofacial structures of high prevalence. Associated risk factors are diverse and nutritional and non-nutritional suction habits are the most reported. The aim of this study was to estimate the prevalence of malocclusions in the mixed dentition and to study possible association with practices of breastfeeding and suction habits among Brazilian schoolchildren. A cross-sectional study involving a sample of 664 6-year-old children and their families was carried out. Data collection was done through interviews with mothers in the homes and oral examinations of children in schools. Multivariate analyses were performed using the Poisson regression with a robust estimator. The prevalence of overjet over 4 mm was 21.1% and of posterior crossbite was 12.2%; 91.9% of the children were breastfed, 79.0% used a nursing bottle and 49.4% used a pacifier. Significant and independent associations were observed between father's unemployment, private school, interruption of breastfeeding before the fourth month and pacifier use with certain malocclusions. High rates of malocclusion were found in the studied sample. Socioeconomic conditions, breastfeeding practices and suction habits were shown to be statistically associated with their occurrence.