Dental fluorosis and altitude: a preliminary study.

PURPOSE: Previous studies have reported higher dental fluorosis prevalence in high-altitude communities than in low-altitude communities. This investigation determined and compared dental fluorosis prevalence in populations of children living at high and low altitudes in Mexico. MATERIALS AND METHODS: Fluorosis prevalence was determined in 7 to 10-year-old children: 67 in Mexico City (2,240 m) and 71 in Veracruz (sea level). Previous fluoride exposure of those children was surveyed by retrospective, questionnaire data. The fluoride content of water and salt from those communities was also documented. RESULTS: Fluorosis prevalence in Mexico City (53.0%) was significantly higher than in Veracruz (24.3%) (p < 0.0001). While there were statistical differences in one of the fluorosis risk factors between the two communities, the observed difference in fluorosis prevalence was still significant when data were analyzed after adjusting for the reported differences in that factor. CONCLUSION: Our results led to the conclusion that the difference in fluorosis prevalence in Mexico City and Veracruz could not be explained by differences in fluoride content of the salt or water samples, self-reported exposure to fluorosis risk factors or estimated fluoride intake.

Fluoride intake from foods, beverages and dentifrice by children in Mexico.

OBJECTIVES: This investigation monitored fluoride ingestion in Mexican children who were susceptible to developing dental fluorosis. METHODS: Total fluoride intake, from dietary and toothpaste samples, was determined in 15-36-month-old children from Mexico City and Veracruz, Mexico. A duplicate plate technique was used. Plasma fluoride levels were also determined in this group of children. RESULTS: The children ingested a mean (+/-SD) of 0.20 +/- 0.08 and 0.18 +/- 0.07 mg fluoride/kg/day, in Mexico City and Veracruz, respectively. There was no statistically significant difference between the fluoride ingested by children in the two cities (P > 0.9). Plasma from children in Mexico City and Veracruz contained a mean of 1.30 +/- 0.81 and 0.87 +/- 0.72 micro mol fluoride/l, respectively, and these values were not significantly different. CONCLUSIONS: Our results lead to the conclusion that mean fluoride ingested from the combination of foods and beverages was within the proposed safe threshold for fluoride intake of 0.05-0.07 mg F/kg/day. Most of the fluoride intake by these children was derived from the ingestion of fluoridated toothpaste. When all sources of ingested fluoride were added and total fluoride intake was calculated, the children, both in Mexico City and Veracruz, were ingesting amounts of fluoride well above the upper limits of the proposed safe threshold for fluoride intake.

The fluoride content of foods and beverages from negligibly and optimally fluoridated communities.

In the spring of 1996, foods and beverages most commonly consumed by adolescents were analyzed for fluoride as part of a larger investigation. These foods were selected by interviewing 711 adolescents, 12-14 years of age, who were long-time residents of either an optimally or negligibly fluoridated community. The brand names of the identified foods and beverages most commonly purchased were determined by interviews with the parents. A total of 441 brand-name food and beverage items were purchased from both communities and were individually analyzed for fluoride. These analyses were done in order to estimate the fluoride content of various kinds of foods and beverages and to determine whether or not there was a significant difference between the two communities in the amount of fluoride ingested from these dietary sources. The food and beverage items were classified into dietary groups based on US Department of Agriculture (USDA) guidelines. Overall, the fluoride content of the sampled foods and beverages was low. In addition, there was no significant difference in the fluoride content of the same pre-packaged or ready-to-eat food or beverage items purchased in the two communities. However, a significant difference was found between the two communities in the fluoride content of fountain beverages and in cooked or reconstituted foods prepared using local water from the respective communities. Based on these results, we have estimated the mean daily, dietary fluoride intake for 3-5-year-old children who are more susceptible to developing dental fluorosis.