Breast and Bottle Feeding as Risk Factors for Dental Caries: A Systematic Review and Meta-Analysis

Abstract

Understanding the role that breastfeeding and bottle feeding play in the development of dental caries during childhood is essential in helping dentists and parents and care providers prevent the disease, and also for the development of effective public health policies. However, the issue is not yet fully understood. The aim of this systematic review and meta-analysis was to search for scientific evidence in response to the question: Do bottle fed children have more dental caries in primary dentition than breastfed children? Seven electronic databases and grey literature were used in the search. The protocol number of the study is PROSPERO CRD 42014006534. Two independent reviewers selected the studies, extracted data and evaluated risk of bias by quality assessment. A random effect model was used for meta-analysis, and the summary effect measure were calculated by odds ratio (OR) and 95% CI. Seven studies were included: five cross-sectional, one case-control and one cohort study. A meta-analysis of cross-sectional studies showed that breastfed children were less affected by dental caries than bottle fed children (OR: 0.43; 95%CI: 0.23-0.80). Four studies showed that bottle fed children had more dental caries (p<0.05), while three studies found no such association (p>0.05). The scientific evidence therefore indicated that breastfeeding can protect against dental caries in early childhood. The benefits of breastfeeding until age two is recommended by WHO/UNICEF guidelines. Further prospective observational cohort studies are needed to strengthen the evidence.

Fig 1. Screening of articles.

Four-phase PRISMA flow-diagram for study collection, showing number of studies identified, screened, eligible, included in review and meta-analysis [26].

Fig 2. Newcastle-Ottawa quality assessment summary.

¹For cross-sectional and case-control studies. ²For case-control study only. ³For cohort study only. ⁴For all study designs. †This item was allocated a maximum of 2 points. †† This item was allocated a maximum of 2 point for cross-sectional and 3 points for cohort and case-control studies. NR = not rated.

Fig 3. Forest plot of meta-analysis for four cross-sectional studies.

Evaluates bottle or breast feeding practices and dental caries (outcome: presence of dental caries vs. absence of dental caries). Pooled effect measures [odds ratio (OR) and 95% confidence interval (CI)] indicated no statistically significant difference between breast and bottle fed children. I² = 33.14%. Fixed effect model used.