Table 4. Unadjusted Association Between Fluoride Exposure and Fluorosis^a.

Fluoride exposure	Odds ratio (95% CI)
	2013-2014 Cycle	2015-2016 Cycle	2013-2016 Cycles
Fluoride supplement
None	1 [Reference]	1 [Reference]	1 [Reference]
Children	0.511 (0.252-1.037)	0.812 (0.441-1.496)	0.716 (0.456-1.125)
Adolescents	0.684 (0.324-1.441)	0.712 (0.329-01.542)	0.747 (0.459-1.041)
Water fluoride level, mg/L
≤0.30	1 [Reference]	1 [Reference]	1 [Reference]
Children
0.31-0.50	2.005 (1.098-3.660)	1.406 (0.470-4.205)	1.498 (0.699-3.210)
0.51-70	2.464 (1.060-5.729)	1.702 (0.713-4.062)	2.313 (1.281-4.179)
>0.70	2.465 (1.119-5.429)	2.362 (1.035-5.388)	2.520 (1.271-4.999)
Adolescents
0.31-0.50	1.071 (0.314-3.653)	0.884 (0.244-3.197)	0.954 (0.569-2.580 )
0.51-0.70	1.305 (0.415-4.099)	2.397 (0.707-8.315)	2.372 (1.243-4.179)
>0.70	1.795 (0.603-5.344)	3.299 (1.351-8.053)	3.457 (1.472-5.077)
Plasma fluoride level, μmol/L
≤0.30	1 [Reference]	1 [Reference]	1 [Reference]
Children
0.31-0.40	0.964 (0.525-1.770)	1.110 (0.768-1.605)	1.195 (0.831-1.712)
0.41-0.50	1.713 (0.759-3.868)	1.659 (0.912-3.019)	2.086 (1.204-3.614)
>0.50	0.844 (0.445-1.601)	1.217 (0.705-2.100)	1.341 (0.907-1.981)
Adolescents
0.31-0.40	0.824 (0.282-2.402)	1.451 (0.595-3.450)	1.582 (0.849-2.948)
0.41-0.50	0.604 (0.175-2.077)(	0.924 (0.400-2.132)	1.182 (0.601-2.322)
>0.50	0.852 (0.370-1.964)	4.822 (1.904-12.214)	3.059 (1.469-6.369)

^a Children are aged 6 to 11 years; adolescents, aged 12 to 15 years.