Validation of ICMR index for identification of dental fluorosis in epidemiological studies

BACKGROUND & OBJECTIVES: The Indian Council of Medical Research (ICMR) formulated a Task Force on dental fluorosis and recommended the subgroup to develop a simplified index for identification and grading of dental fluorosis to be used by the health workers. This study was conducted to pre-test the ‘ICMR Index for Dental Fluorosis’ in the field to check its reliability and reproducibility. METHODS: A total of 600 photographs were taken, 150 in each grade of fluorosis by screening 14-17 yr school children from eight schools of Hisar (Haryana) and South west Delhi. Eighty photographs were finalized (20 in each grade) before calibration to be used for training of field workers. Calibration exercise was conducted involving the five member survey team on 100 diagnosed cases of dental fluorosis. The members again screened 74 children with dental fluorosis in the field to categorize in to different grades of fluorosis for assessment of inter-examiner reliability. RESULTS: The ICMR criteria showed more difference in agreement in very mild and mild categories during calibration. The inter-examiner reliability (κ) ranged from 0.59-1. The criteria was further modified and inter- examiner reliability (κ) found to be 0.83-0.98 which was almost perfect agreement. INTERPRETATION & CONCLUSIONS: The tool developed by the ICMR to assess dental fluorosis can be used in a field set up by non-dental personnel reliably with high degree of reproducibility.