Association Between Duration of Breastfeeding and Malocclusion in Primary Dentition in Brazil

Purpose: To evaluate the relationship between type and duration of breastfeeding and the development of malocclusion in primary dentition. Methods: A cross-sectional observational study was conducted with children of both sexes, aged 30 to 48 months, who attended to a dental program for maternal and child care. The mothers completed a questionnaire about the form (exclusive breastfeeding or not) and duration of breastfeeding, their children's non-nutritive sucking habits, and their sociodemographic information. The clinical examination was done by a calibrated examiner in the knee-to-knee position and under indirect light to evaluate the primary occlusion. Pearson's chi-square test or Fisher's exact test and Poisson regression were performed for statistical analysis. Results: Over 45 percent of 252 children who were evaluated had malocclusion, such as anterior open bite (13.6 percent), posterior crossbite (3.6 percent), anterior crossbite (2.8 percent), midline shift (21.5 percent), overbite (19.8 percent), and overjet (32.9 percent). Children who were exclusively breastfed for less than six months had a 50 percent higher prevalence of anterior open bite (P=0.009) compared to those who had exclusive breastfeeding for more than six months. Conclusion: Exclusive breastfeeding for less than six months was associated with anterior open bite. The other malocclusion types were not associated with the time and type of feeding the children received in the early phase of the primary dentition.