Objectives: To determine the prevalence of dental fluorosis, and factors associated with its occurrence in two cohorts of children exposed to different fluoride concentrations in the Malaysian water supply.
Methods: A cross-sectional study was conducted among lifelong residents (n = 1,155) aged 9 and 12 years old living in fluoridated and nonfluoridated areas. Malaysian children aged 12 years were born when the level of fluoride in the public water supply was 0.7 ppm while those aged 9 years were born after the level was reduced to 0.5 ppm. Fluorosis was blind scored using standardized photographs of maxillary central incisors using Dean’s criteria. Fluoride exposures and other factors were assessed by parental questionnaire. Data were analyzed using descriptive statistics, Chi-squared analyses, and logistic regression.
Results: Fluorosis prevalence was lower (31.9 percent) among the younger children born after the reduction of fluoride concentration in the water, compared to a prevalence of 38.4 percent in the older cohort. Early tooth brushing practices and fluoridated toothpaste were not statistically associated with fluorosis status. However, the prevalence of fluorosis was significantly associated with parents’ education level, parents’ income, fluoridated water, type of infant feeding method, age breast feeding ceased, use of formula milk, duration of formula milk intake, and type of water used to reconstitute formula milk via simple logistic regression. Fluoridated water remained a significant risk factor for fluorosis in multiple logistic regression.
Conclusions: Fluorosis was lower among children born after the adjustment of fluoride concentration in the water. Fluoridated water remained as a strong risk factor for fluorosis after downward adjustment of its fluoride concentration.
Keywords: dental fluorosis; dietary fluoride; risk factors; water fluoridation.
- Spencer AJ, Do LG. Caution needed in altering the ‘optimum’ fluoride concentration in drinking water. Commun Dent Oral Epidemiol. 2016;44(2):101-8.
- Hong L, Levy SM, Broffitt B, Warren JJ, Kanellis MJ, Wefel JS, Dawson DV. Timing of fluoride intake in relation to development of fluorosis on maxillary central incisors. Commun Dent Oral Epidemiol. 2006;34(4):299-309.
- Mascarenhas AK. Risk factors for dental fluorosis: a review of the recent literature. Pediatr Dent. 2000;22(4):269-77.
- Molina-Frechero N, Gaona E, Angulo M, Pérez LS, González RG, Rascón MN, Bologna-Molina R. Fluoride exposure effects and dental fluorosis in children in Mexico City. Med Sci Monit. 2015;21:3664-70.
- Wong MCM, Glenny AM, Tsang BWK, Lo ECM, Worthington HV, Marinho VCC. Topical fluoride as a cause of dental fluorosis in children. Cochrane Database Syst Rev. 2010;1:CD007693.
*Original abstract online at https://onlinelibrary.wiley.com/doi/10.1111/jphd.12448