Methods: Six databases were systematically searched to the end of October 2014.
Observational and interventional studies were included. Breastfeeding was evaluated in
three categories: (i) ever versus never; (ii) exclusive versus absence of exclusive; and (iii)
longer periods versus shorter periods. All types of malocclusion were considered as the
outcome. Pooled adjusted odds ratio and its 95% confidence interval (95%CI) were
obtained from meta-analyses. Heterogeneity was assessed with both the Q-test and the Isquare.
Funnel plots and Egger’s test were employed to assess publication bias.
Results: Forty-eight studies were included in the systematic review, and 41 were included
in the overall meta-analysis (n = 27 023 participants). Subjects who were ever breastfed
were less likely to develop malocclusions than those never breastfed (OR 0.34; 95% CI
0.24; 0.48), those who were exclusively breastfed presented lower risk to present
malocclusion than those with absence of exclusive breastfeeding (OR 0.54; 95% CI 0.38;
0.77), and subjects longer breastfed were less likely to have malocclusions than those
shorter breastfed (OR 0.40; 95% CI 0.29; 0.54).
Conclusion: Breastfeeding decreases the risk of malocclusions