[Table/Fig-9]:

Comparison of results of similar studies conducted in various parts of the world with the present study

S.No.	Authors’ Name & Year of Study	Place of Study	Sample Size	Results	Results of the present study
1	Karimzade S et al., [21] (2014)	Azerbaijan, Iran	39	The results showed that the mean IQ of children living in high drinking water fluoride region (81.21±16.17) was lower than that of children living in low drinking water fluoride region (104.25±20.73).	The present study showed that the mean IQ scores of fluorosis free children was found to be 110.1+9.0 which is much higher than the mean IQ score of 62.4±2.4 for severe fluorosis children.
2	Nagarajappa R et al., [1] (2013)	Gujrat, India	100	This study concluded that chronic exposure to high levels of fluoride and water is associated with lower IQ.	The present study showed that children living in high fluoride area had lower IQ grades than the children living in low fluoride area.
3	Seraj B et al., [10] (2012)	Makoo, Iran	293	Results showed that the average IQ scores decreased from the normal fluoride group (97.77+18.91) to medium fluoride group (89.03±12,99) to high fluoride group (88.58±16.01)..	Results from the present study showed that the mean IQ scores decreased from fluorosis free children (110.1±9.0) to children having mild fluorosis (85.9±9.2) to children having severe fluorosis (62.4±2.4).
4	Shivaprakash PK et al., [4] (2011)	Karnataka, India	160	Results of this study revealed that children with dental fluorosis had lower IQ (66.63±18.09) than those without dental fluorosis (76.36±20.84).	In the present study, with increase in fluorosis grade, a statistically significant increase in grade of IQ (decrease in intelligence) was observed.
5	Pourlesami HR et al., [22] (2011)	Kerman, Iran	120	Results of this study confirmed that average IQ of high fluoride group (91.37±16.63) was significantly lower than the average IQ of low fluoride group (97.80±15.95).	In the present study, IQ score of normal fluorosis index level children was found to be higher than that of children with other grades of fluorosis, and this difference was found to be statistically significant.
6	Eswar P et al., [23] (2011)	Karnataka, India	133	They arrived at the result that 63.2% of children in high fluoride village had IQ less than 90, versus 47.7% of children in low fluoride village but this difference was not found to be statistically significant.	Statistically significant differences were found between the IQ grades of children living in high & low fluoride areas.
7	Sudhir KM et al., [24] (2009)	Andhra Pradesh, India	1000	Findings of the study suggested that the overall IQ levels in children exposed to high fluoride level were significantly lower than the low fluoride areas.	The present study showed that 100% children with severe fluorosis had IQ Grade 5 whereas all the children with IQ Grade 1 were fluorosis free.
8	Amador DR et al., [25] (2007)	Durango, Mexico	132	The results showed that both fluoride in urine and fluoride in water were significantly correlated with lower IQ in children.	The present study found that fluorosis and IQ levels were affected by drinking water fluoride concentrations as suggested by the significant deficit in IQ of children living in the high fluoride area as compared to those living in low fluoride area.
9	Xiang Q et al., [26] (2003)	Jiangsu, China	512	The mean IQ score of high F village (92.02±13.00) was found to be lower than the mean IQ score of low F village (100.41±13.21). It was therefore concluded that higher drinking water fluoride is significantly associated with higher rates of mental retardation and borderline intelligence, thus lower IQ.	The present study demonstrated that the children living in high fluoride area had lower IQ grades than the children living in low fluoride area.
10	Lu Y et al., [27] (2000)	Tianjin Xiqing, China	118	The mean IQ scores were found to be significantly low in high fluoride area (3.15± 0.61mg/l) than in the low fluoride area (0.37± 0.04mg/l) and hence it was concluded that a real relationship exists between fluoride exposure and intelligence.	The results from the present study confirm that children living in high fluoride area had lower IQ Grades than the children living in low fluoride area.
11	Wang G et al., [28] (1996)	Xinjiang, China	230	Results showed that the average IQ of high F group (95.64±14.34) was lower than in control group (101.23±15.84).	Results from the present study also showed that IQ grades of children with severe fluorosis were higher than those of children with moderate, mild & no fluorosis.
12	Li XS et al., [29] (1995)	Guizhou, China	907	The results demonstrated that the IQ of children living in areas with a medium (79.7±12.7) or severe (80.3±12.9) prevalence of fluorosis was lower than that of children living in areas with slight fluorosis (89.7±12.7) or low fluorosis (89.9±10.4).	Results of the present study showed that majority of the fluorosis free children (76.3%) had Grade 2 IQ scores, majority of children with mild fluorosis (65.9%) had Grade 3 IQ scores, Majority of children with moderate fluorosis (37.2%) had Grade 4 IQ scores whereas all the children with severe fluorosis (100%) had Grade 5 IQ scores.