Dental Fluorosis vs. IQ of Children of Bagalkot District, India

This study was conducted on 160 children, aged 7-11 years, in the Bagalkot district of Karnataka state, India, between August and October 2010, with the aim of determining if a relationship exists between the degree of dental fluorosis and scores on Intelligence Quotient (IQ) tests. Among 120 randomly sampled and examined children of the Bagalkot taluk (water fluoride = 0.5 ppm), 80 children without dental fluorosis were selected for the study. They were compared to a selection (based upon the presence of dental fluorosis) among 80 (of 150 randomly sampled and examined) children of the Hungund taluk (water fluoride 2.5-3.5 ppm). Intelligence testing was done using the Raven's Coloured Progressive Matrices. The following observations were derived from the data. The mean IQ score of children without dental fluorosis (76.36 plus or minus 20.84) was significantly higher (P = 0.0019) than that of children with dental fluorosis (66.62 plus or minus 18.09). The mean IQ scores did not vary with the severity of dental fluorosis as classified by Dean's fluorosis index. It was also found that a higher percentage of children with dental fluorosis was in the "Extremely Low" and "Low" IQ categories, whereas a higher percentage of children without dental fluorosis was in the "Average" and "High Average" IQ categories. Table 1 of the paper reveals the largest effect among female children (64.36 plus or minus 19.94 vs. 78.29 plus or minus 17.36, with and without dental fluorosis, respectively; P = 0.0032), whereas among males the effect was smaller (68.67 plus or minus 16.21 vs. 75.14 plus or minus 22.86; P = 0.1285). Previous studies have indicated decreased intelligence in children exposed to high levels of fluoride, and our study confirms such an effect.