Dental 21 Cities Study by Dean is done for? A Checking hypothesis of 1 ppm is minimum threshold in water than not leads to fluorosis B Check first fluoridated water supply city in USA C Check severity of mottling enamel in different regions of USA D Checking best city with least caries % of affected tooth in 0-5 years of children 💡 Explanation 21 Cities Study by Dean is done for? ✓ Correct Answer: A. Checking hypothesis of 1 ppm is minimum threshold in water than not leads to fluorosis