Risk factors associated with dental fluorosis in Central Plateau State, Nigeria

Objectives: Dental fluorosis is known to occur in some parts of Plateau State, but the factors responsible for its occurrence are unknown. The purpose of this study, therefore, was to determine the factors associated with the occurrence of dental fluorosis in Central Plateau. Methods: The study was cross-sectional and comparative in design. Subjects were selected using the multi-stage sampling technique. One Local Government Area each was randomly selected from the high and low altitude parts of the district, and from each selected Local Government Area two health districts were randomly selected with probability proportional to size. From each of the selected health districts two major settlements were selected again with probability proportional to size. Twelve- to fifteen-year-old lifelong residents of the selected settlements were then selected for study. Each respondent completed an interviewer-administered questionnaire after which he/she was clinically examined to ascertain his/her fluorosis status. Samples of water were collected from water sources consumed by the respondents in each settlement. Results: One thousand one hundred children aged 12-15 years were studied, 554 (50.4%) of which lived in the high altitude part of the district and 546 (49.6%) in the low altitude part of the district. Fluorosis prevalence was significantly associated with altitude and the fluoride level of water. The prevalence of fluorosis was significantly associated with altitude (chi(2) = 85.735, d.f. = 1, P < 0.0001) and the fluoride level of water (chi(2) for trend = 8.009, d.f. = 1, P < 0.05) in the low altitude parts of the district. None of the respondents had used fluoride-containing toothpaste before 4 years of age and none used fluoride supplements. Conclusion: The occurrence of dental fluorosis in Central Plateau could be because of the high altitude of the area and the fluoride concentration of the waters consumed in the district.