A Bayesian analysis of multivariate doubly-interval-censored dental data

A Bayesian survival analysis is presented to examine the effect of fluoride-intake on the time to caries development of the permanent first molars in children between 7 and 12 years of age using a longitudinal study conducted in Flanders.Three problems needed to be addressed.Firstly, since the emergence time of a tooth and the time it experiences caries were recorded yearly, the time to caries is doubly interval censored.Secondly, due to the setup of the study, many emergence times were left-censored.Thirdly, events on teeth of the same child are dependent.Our Bayesian analysis is a modified version of the intensity model of Härkänen et al.(2000, Scandinavian Journal of Statistics27, 577.588).To tackle the problem of the large number of left-censored observations a similar Finnish data set was introduced.Our analysis shows no convincing effect of fluoride-intake on caries development.