Risk Factors for Early Childhood Caries: A Systematic Review and Meta-Analysis of Case Control and Cohort Studies.

The purpose of this study was to perform a systematic review to assess current evidence for association between various risk factors and the prevalence or incidence of early childhood caries (ECC). Two reviewers searched various databases until January 2019. The Newcastle-Ottawa scale was used to perform risk of bias assessment. The included studies were categorized according to the World Bank classification. Data were summarized in a meta-analysis using fixed and random effects inverse-generic meta-analyses. A total of 7,034 records involving 89 studies that evaluated 1,352,097 individuals were included; 23 were high, 46 were moderate, and 20 were of low quality. A total of 123 risk factors were found. Meta-analysis revealed that the strongest risk factors found in the high-income countries were presence of dentinal caries (dmft greater than zero; odds ratio [OR] equals 4.21 [2.18 to 8.16]) and high levels of mutans streptococci (OR equals 3.83 [1.81 to 8.09]). In upper-middle-income countries, presence of enamel defects (OR equals 14.62 [6.10 to 35.03]) was found to be the strongest risk factor. The strongest risk factors associated with early childhood caries was the presence of enamel defects, presence of dentinal caries and high levels of mutans streptococci.