Body Mass Index and Dental Caries: A Systematic Review and Meta-analysis

Objectives: To investigate the relationship between Body Mass Index (BMI) and dental caries in children and adolescents aged up to 18 years, by conducting a systematic review and meta-analysis of the published literature.
Methods: A search of the literature published between 1980 to June 2014, using electronic bibliographic databases and manual searching of bibliography lists from relevant publications was conducted. Assessment of study quality (internal and external validity) was based on the validated Methodological Evaluation of Observational Research checklist (MEVORECH) against predetermined criteria to identify research specific flaws. Reporting quality was also assessed using the same checklist. Two independent reviewers conducted the appraisal and any disagreements were resolved by consensus.
Results: The initial search identified 4208 potential studies. After de-duplication and exclusion by title/abstract and full text, 67 papers met the inclusion criteria and were included in the review. Three main types of association between BMI and dental caries were found, with some of the studies showing more than one pattern of association: 23 studies found a positive relationship between BMI and caries, 14 showed an inverse association, and 33 found no association between the variables of interest. Confounder assessment was the domain most commonly found to be flawed, followed by sampling and research specific bias domains. Among the seven studies which were found to be of better methodological quality, four found no association between BMI and dental caries and three showed a positive association between the two variables; that is, children with higher BMI had a higher burden of dental caries.
Conclusions: The evidence for a positive association between BMI and dental caries was inconsistent even in those studies found to be of better quality. A quantitative analysis of the findings (meta-analysis) will be presented.