Methods: The Community based Case Control study was carried out in villages having different fluoride levels (high 2.21 ppm, optimum 1.10ppm, and low 0.56ppm) in drinking water in north Karnataka, India. 352 school Children {12-15 years, male 58 %) with severe grades of dental fluorosis classified by Thylstrup & Fejerskov Index were selected as cases. 428 school children (12 to 15 years, male 48.8%) with no dental fluorosis were selected randomly from the same area as controls. Exposure ascertainment of Jowar consumption was done by 24-hour diet recall and Food frequency Questionnaire. Ion selective electrode method was used to estimate the fluoride level in spot urine samples of subjects and drinking water. Logistic regression analysis was done using SPSS version 11.
Results: Children who consumed jowar had 2.67 times more chance of getting severe dental fluorosis compared to those who did not [adjusted (OR) 2.67, 95% CI 1.98 to 3.62)]. The risk was higher in optimum (OR 3.18 95% CI 2.01 to 5.07) and high fluoride villages (OR 3.76, 95% CI 2.05 to 6.91) compared to low fluoride villages. Daily jowar consumers had higher risk for dental fluorosis (OR 3.15, 95% CI 2.20 to 4.52) compared to weekly consumers (OR 2.06, 95% CI 1.41 to 3.01). Children who started consuming jowar before eight years had significantly higher proportion of severe dental fluorosis compared to their counterparts. Urinary fluoride excretion among jowar consumers was significantly lower than non-jowar consumers.
Conclusions: Jowar consumption was positively associated with severity of dental fluorosis in this population.