Severe dental fluorosis and jowar consumption in Karnataka, India

Dental fluorosis is a major public health problem in 17 states of India. Earlier studies have reported that Jowar (a type of millet) consumption interacts with fluoride (F) in the body and enhances fluorosis. We conducted this study to determine the association between jowar consumption and severity of dental fluorosis.A community based case control study was carried out in villages having different F levels (low, medium, and high) in drinking water in North Karnataka, India. 352 school Children (12-15 years, male 58%) with severe dental fluorosis classified by ThylstrupFejerskov Index (1988) were selected as cases. 428 school children (12-15 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-h diet recall and food frequency questionnaire. Ion selective electrode method was used to estimate the F level in spot urine samples of subjects and in drinking water. Multiple logistic regression analysis was done using SPSS V. 11.01Children who consumed jowar had 2.67 times more chance of getting severe dental fluorosis compared to those who did not [Odds Ratio (OR) 2.67, CI 1.98-3.62]. Children from high F level villages (OR 1.91, CI 1.27-2.85) had higher odds of severe dental fluorosis compared to children from medium and low F level villages. Daily jowar consumers (OR 2.14, CI 1.64-3.09) and weekly consumers (OR 1.68, CI 1.31-3.45) had higher risk for dental fluorosis compared to non jowar consumers. Children who started consuming jowar before 8 years of age had significantly higher proportion of severe dental fluorosis compared to their counterparts. Urinary F excretion among jowar consumers was significantly lower than non-jowar consumers.Jowar consumption was positively associated with severity of dental fluorosis in this population.