OBJECTIVES, DESIGN AND SUBJECTS: Earlier results on the effect of breastfeeding on the one hand, and non-nutritive sucking habits (pacifier and/or digit sucking) on the other, on the orofacial development of infants are inconclusive. Thus we studied the prevalence of malocclusions and their relationship to the duration of breastfeeding and to non-nutritive sucking habits in a group of randomly selected 3-year-old children (n = 148).
Results: Posterior crossbite was detected in 13%, anterior open bite in 18% and large overjet (> 3 mm) in 26% of the children. The proportion of children with anterior vertical open bite was significantly larger among children with non-nutritive sucking habits than among the other children (P < 0.001). Neither posterior crossbite nor large overjet were associated with non-nutritive sucking habits. The duration of exclusive breastfeeding was 5.8 +/- 3.6 months while that of total breastfeeding was 7.3 +/- 3.8 months on average. The exclusive and total breastfeeding periods of children with posterior crossbite were both significantly shorter than those of the other children (P < 0.01 and P < 0.002, respectively). Children's height and weight were unrelated to the duration of breastfeeding or occlusal anomalies.
Conclusion: We suggest that an early introduction of bottlefeeding, indicating a pattern of low-impact muscular activity, may interfere with the normal development of alveolar ridges and hard palate, and hence lead to posterior crossbite.