The determinants of social disparities in trajectories of dental caries

Introduction: Conventional approaches to social disparities in dental caries experience do not capture the effects of changes in social status upon dental caries, neither do they allow the investigation of the effects of SES upon patterns, or trajectories, of dental caries. Many studies simply imitate the methods (and therefore findings) used in previous studies. Aim: To investigate the relative importance of measures of social status and deprivation for the experience of dental caries and tooth loss in adolescence and young adulthood over time. Methods: Longitudinal DMFS data from the Dunedin Multidisciplinary Health and Development Study at ages 5, 9, 15, 18, 26, and 32 years were analysed using group-based trajectory analysis (Nagin, 2005), and the methodology is described elsewhere (Broadbent and Thomson, 2005). The social determinants of the resultant DMFS trajectories were then determined using logistic regression modelling. Results: Some 953 of the original 1037 study members were included in this study. Social factors (including parental occupation) were found to have effects upon dental health that begin in childhood, and continue to act upon dental health into adulthood, thus widening social disparities with age. Conclusions: Dental caries (as measured by DMFS) is a cumulative disease, and the effect of cumulative experience of social factors over time is to cause accumulating social disparity in DMFS with increasing age. Funding for this study was provided by Grant R01 DE-015260-01A1 from the National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA 20892, the NZDA Dental Research Foundation, and the Health Research Council of New Zealand.