Dental fluorosis and fluoride mapping in Langtang town, Nigeria.

This study is aimed at measuring the fluoride concentrations of different water supplies in a Nigerian community known to have endemic fluorosis. This is with the view of mapping out a pattern and to investigate the relationship of this pattern with the distribution of dental fluorosis among residents of the community. A representative sample of 475 persons selected on the basis of criteria described in an earlier publication, constituted the study subjects. Clinical examination were carried out after obtaining sociodemographic information from the subjects. Analyses of fluoride concentrations in 136 water samples revealed, in general the highest levels in stream water range: 2.39-3.96 ppm, followed by wells (range: 1.26-2.82 ppm) and the least in pipe-borne water (range: 0.5-0.97 ppm). In plotting specific fluoride readings from the different identified sources on the geographical map of the study area, a distinctive pattern emerged. High fluoride readings were generally in the highland areas from which rivers and streams took origin. Approximately 50% of the town was supplied with water containing fluoride above the optimum. As reported in the earlier publication, the prevalence of dental fluorosis was found to be 26.1%. The age specific prevalence rate indicated the highest occurrence rate among those aged 10-19 years. Six of the participating children had involvement of deciduous teeth. Even though no correlation was established between dental fluorosis and sex on one hand and fluorosis and ethnicity on the other, there was a markedly significant association between fluorosis and source of drinking water (P < 0.05). Those who drank from streams appeared more likely to have fluorosis. It was concluded that though other sources of fluoride ingestion have been documented, it appeared that water may play a very significant role in the aetiology of fluorosis in this community.

Prevalence and distribution pattern of enamel fluorosis in Langtang town, Nigeria.

Dental fluorosis, a defect which causes white flecks or brown staining of the teeth, has been reported in some parts of the world. This study, a descriptive, cross-sectional survey was designed to determine the prevalence and distribution pattern of dental fluorosis in Langtang town, Plateau State of Nigeria between April and June 1997. Community members had recognised the discolouration of teeth as a public health problem for which solution had been sought from the near-by public health agency. A representative sample of 475 persons drawn from the 7 wards of the local government area were interviewed. Information on their age, ethnicity, occupation and source of drinking water were obtained. Intra-oral examinations were conducted to determine the status of participants' enamel using a modified version of Dean's classification of enamel mottling. Results revealed a 26.1% prevalence rate of enamel fluorosis, with 20.6% of the cases classified as mild and 5.5% as severe. While the prevalence rate was not influenced by sex and ethnicity, it was strongly associated with the source of drinking water (P < 0.05). Drinking from streams seemed to increase the likelihood of participants having dental fluorosis. A pattern of distribution with age also emerged with the highest prevalence being among the 10-19 years age group. Six cases were detected in deciduous teeth. In view of the strong indication of an environmental aetiological basis, there is need for the determination of the current levels of fluoride in water, foods beverages and other likely sources of exposure in that community.