Sociodemographic and behavioural correlates of severe dental fluorosis

The aim of this study was to identify sociodemographic and behavioural factors associated with the prevalence of severe dental fluorosis in moderate- and high-fluoride areas of the Ethiopian Rift Valley.

Three hundred and six adolescents (12-15 years) and 233 mothers participated in the study. The children were examined for dental fluorosis according to the Thylstrup-Fejerskov Index (TFI). The children and their mothers were subsequently interviewed. Sixty mothers had more than one participating child. In order to perform a paired parent/child analysis, a total of 73 younger siblings had to be excluded.

Among the remaining 233 children, the prevalence of severe dental fluorosis (TFI >or= 5) was 24.1% and 75.9% in the moderate- and high-fluoride areas, respectively. According to bivariate as well as multivariate analyses, a number of sociodemographic and behavioural factors were related to severe fluorosis. The odds for having severe fluorosis varied according to the fluoride concentration of the drinking water, age, consumption of tea, length of breastfeeding and method of storing water. The adjusted odds ratios ranged from 2.6 to 26.1. Breastfeeding for > 18 months and the use of clay pots for storing drinking water helped protect against severe dental fluorosis. Bivariate analyses indicated that being male and consuming fish might be associated with higher TFI scores.

In order to avoid dental fluorosis, low-fluoride drinking water should be provided in the relevant villages. A prolonged period of breastfeeding, the use of clay pots for storing water, and possibly a reduced intake of tea and whole fish in infants might also help to avoid severe fluorosis in children growing up in traditionally fluoride-endemic areas.