Fluoride, Thyroid Hormone Derangements and its Correlation with Tooth Eruption Pattern Among the Pediatric Population from Endemic and Non-endemic Fluorosis Areas.

AIM: To comparatively evaluate the status of fluoride in the body with thyroid activity in the pediatric population of endemic fluorosis areas. The present study also attempted to elucidate whether any correlation exists between fluoride and thyroid hormone derangement with delayed tooth eruption.

MATERIALS AND METHODS: A total of 400 pediatric subjects were included in the present study. All the patients were divided into two broad groups; groups A and B. Group A included 200 subjects who belonged to the endemic fluorosis area while Group B included remaining 200 subjects, who belonged to the fluorosis non-endemic area. Group B subjects were taken as control. Group A subjects were further divided into two study groups as follows: Group A1: 100 Pediatric subjects with dental fluorosis, and Group A 2: A total of one hundred pediatric subjects without dental fluorosis. Dean's index of fluorosis was calculated in all the patients. Blood samples were collected and were sent to a laboratory for assessment of thyroid hormone levels. All the results were subjected to statistical analysis by Statistical Package for the Social Sciences (SPSS) software.

RESULTS: Mean thyroid stimulating hormone (TSH), water fluoride levels, urine fluoride levels and serum fluoride levels of subjects in group 1 were found to be significantly higher than that of subjects of group 2. Delayed tooth eruption was absent in subjects of group B while it was present in 100 subjects of group A. Thyroid hormone level derangement was seen in 54 percent subjects of group B, while it was seen in 67.5% subjects of group A.

CONCLUSION: Positive correlation exists between fluorosis and thyroid functional activity. However; the tooth eruption pattern is independent up on the thyroid hormone derangement.

CLINICAL SIGNIFICANCE: Delayed tooth eruption and alteration in thyroid hormone levels can occur in subjects of the endemic fluoride areas. Therefore, adequate measures should be taken for controlling such adverse effects.