Early Childhood Exposures to Fluorides and Child Behavioral Development and Executive Function: A Population-Based Longitudinal Study

Abstract

It is important to both protect the healthy development and maintain the oral health of the child population. The study examined the effect of early childhood exposures to water fluoridation on measures of school-age executive functioning and emotional and behavioral development in a population-based sample. This longitudinal follow-up study used information from Australia’s National Child Oral Health Study 2012–14. Children aged 5 to 10 y at baseline were contacted again after 7 to 8 y, before they had turned 18 y of age. Percent lifetime exposed to fluoridated water (%LEFW) from birth to the age 5 y was estimated from residential history and postcode-level fluoride levels in public tap water. Measures of children’s emotional and behavioral development were assessed by the Strength and Difficulties Questionnaire (SDQ), and executive functioning was measured by the Behavior Rating Inventory of Executive Function (BRIEF). Multivariable regression models were generated to compare the associations between the exposure and the primary outcomes and controlled for covariates. An equivalence test was also conducted to compare the primary outcomes of those who had 100% LEFW against those with 0% LEFW. Sensitivity analysis was also conducted. A total of 2,682 children completed the SDQ and BRIEF, with mean scores of 7.0 (95% confidence interval, 6.6–7.4) and 45.3 (44.7–45.8), respectively. Those with lower %LEFW tended to have poorer scores of the SDQ and BRIEF. Multivariable regression models reported no association between exposure to fluoridated water and the SDQ and BRIEF scores. Low household income, identifying as Indigenous, and having a neurodevelopmental diagnosis were associated with poorer SDQ/BRIEF scores. An equivalence test confirmed that the SDQ/BRIEF scores among those with 100% LEFW were equivalent to that of those who had 0% LEFW. Exposure to fluoridated water during the first 5 y of life was not associated with altered measures of child emotional and behavioral development and executive functioning.