Data sources: Medline, government reports and conference proceedings were searched.
Study selection: Case-control, cohort or cross sectional studies were included if they provided relevant and applicable quantitative information on the relation between asthma and caries, had an independent study population and adequate definitions of asthma and caries and appropriate measurement of caries.
Data extraction and synthesis: Data were extracted independently by two reviewers and quality was assessed using the Newcastle-Ottawa Quality Assessment Scale. Fixed- and random-effects models were used for the analyses. Heterogeneity and publication bias were evaluated.
Results: Eighteen articles were included; 11 provided information on primary dentition and 15 on permanent dentition. Random-effects models showed a significant association between asthma and caries for both primary and permanent dentition, the odds ratios being 2.73 (95% CI: 1.61, 4.64) and 2.04 (95% CI: 1.44, 2.89), respectively.
Conclusions: Evidence from this analysis suggests that asthma doubles the risk of caries in both primary and permanent dentition. Publication bias diagnostics and simulation suggested possible overestimation of the summary odds ratio for permanent dentition but not for primary dentition. Physicians and dentists should recommend preventive measures against caries for people with asthma.