title: Effect of breastfeeding on malocclusions: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The objective of this systematic review was to investigate whether breastfeeding decreases the risk of malocclusions.
  
  
  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 I-square. 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).
  
  
  CONCLUSIONS
  Breastfeeding decreases the risk of malocclusions.
authors.affiliation: Australian Research Centre for Population Oral Health - ARCPOH, University of Adelaide, Adelaide, Australia.
authors.forename: Karen Glazer
authors.initials: KG
authors.lastname: Peres
authors.affiliation: Post-graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Andreia Morales
authors.initials: AM
authors.lastname: Cascaes
authors.affiliation: Australian Research Centre for Population Oral Health - ARCPOH, University of Adelaide, Adelaide, Australia.|Post-graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Gustavo Giacomelli
authors.initials: GG
authors.lastname: Nascimento
authors.affiliation: Post-graduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Cesar Gomes
authors.initials: CG
authors.lastname: Victora
mesh_terms: D000293:Adolescent; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008310:Malocclusion / Q000453:epidemiology*; D016017:Odds Ratio; D013997:Time Factors
keywords: Breastfeeding; Malocclusion; Systematic review; Teeth