Dental fluorosis in 12-and 15-year-olds at high altitudes in above-optimal fluoridated communities in Mexico

Objective: The purpose of this study was to determine the prevalence and severity of dental fluorosis in Mexican adolescents. Materials and Methods: A cross-sectional epidemiological study was carried out in 1,024 adolescents 12 and 15 years old residing in three naturally fluoridated locales at high altitudes above sea level (> 2,000 m or > 6,560 ft) in Tula de Allende, Hidalgo, Mexico. Participants had lived in those communities from birth to their sixth birthday. Both the Modified Dean Index and the Community Fluorosis Index were calculated. Results: The overall fluorosis prevalence was 83.8 percent. Fluorosis prevalence in El Llano (3.07 ppmF), San Marcos (1.38 ppmF), and Tula Centro (1.42 ppmF) was 94.7, 89.8, and 81.9 percent, respectively. Overall, the Community Fluorosis Index was 1.85. We observed a high prevalence of dental fluorosis - mostly very mild (35.9 percent), but also uncommonly severe (20.6 percent). Conclusions: At least 8 out of 10 adolescents had some level of fluorosis, and such prevalence is considered to be a dental public health problem. A relationship between fluoride concentration in water in each community and fluorosis was observed. The high fluorosis prevalence and severity might possibly be associated with the high altitude of the communities.