A retrospective longitudinal study of caries development in an Australian Aboriginal Birth Cohort

There are a limited number of longitudinal investigations that examine the progression of dental disease in an indigenous population. Dental examinations of a cohort of indigenous Australians born in Darwin (Australia) between 1987 and 1990 were conducted at ages 6-8 and 11-13 years as part of the Child Dental Health Survey, and 18-20 years as part of the longstanding prospective Aboriginal Birth Cohort (ABC) study. Data was available at all ages for 145 participants. The percent DMFT >0 increased from 17.2 to 44.1 to 81.4%, representing a linear trajectory, whereas mean DMFT increased from 0.3 to 1.0 to 5.6, representing an exponential trajectory. Both trends were significant. At age 18-20 years, the percent DMFT >0 among ABC study participants was 1.2 times that of their counterparts at a national level. The differences were more marked when dental caries severity was considered, with mean DMFT among 18- to 20-year-old ABC study participants being 1.7 times that of similarly aged adults at a national level. Most of this disparity was constituted by the decayed component, with ABC study participants having eight times the mean DT of their national-level counterparts. The findings indicate that Aboriginal young adults in this birth cohort experience a disproportionate amount of dental disease relative to their non-indigenous counterparts, and that this pattern is consistent across the life course.