Malocclusions in young children Does breast-feeding really reduce the risk? A systematic review and meta-analysis

Background. Researchers have purported that breast-feeding can decrease the risk of malocclusions. The authors studied the relationship of breast-feeding on malocclusions in young children by means of conducting a systematic review of association (etiology). Types of Studies Reviewed. The authors used a 3-step search strategy, including electronic searches. They considered studies whose investigators included healthy children with primary dentition with a history of breast-feeding and in which the study investigators had assessed specific malocclusion outcomes to be eligible for inclusion in this review. The authors considered prospective and retrospective (longitudinal) studies, case-control studies, and analytical cross-sectional studies. Two of the authors, using standardized instruments, independently assessed the methodological quality and extracted data from the included studies. For situations for which there were a sufficient number of studies, the authors conducted meta-analyses using the random-effects model, supplemented with the fixed-effects model in situations for which statistical heterogeneity was 50% or less, assessed using the I-2 statistic. Results. The authors identified 7 studies that were included in the review. They found that children who had breast-fed suboptimally had an increased risk of developing malocclusions and that a strong and significant association existed between a shorter duration of breast-feeding (less than 12 months) and the development of an anterior open bite (n = 1,875; risk ratio, 3.58; 95% confidence interval, 2.55 to 5.03; P <.00001) and a class II canine relationship (n = 1,203; risk ratio, 1.65; 95% confidence interval, 1.38 to 1.97; P <.00001). Conclusions. Young children with a history of suboptimal breastfeeding have a higher prevalence and risk ratio for malocclusions. These children have an increased risk of developing a class II canine relationship, posterior crossbite, and anterior open bite.