COMPARISON OF 2 INDEXES OF DENTAL FLUOROSIS IN LOW, MODERATE AND HIGHFLUOROSIS TANZANIAN POPULATIONS

This study aimed at comparing the Thylstrup-Fejerskov index (TFI) and the Dean's Index (DI) which were applied on three communities with dif ferent severity of dental fluorosis. A total of 1565 children aged bet ween 11 and 18 yr with a mean age of 14.7 were examined for dental flu orosis with the TFI and 1155 of these children were also examined with the DI. The measurement error for the TFI was 0.50 (10 scale point) c ompared to 0.53 for DI (6 scale point). The Kappa values and the measu rement-remeasurement correlation appeared to be better for the TFI. No difficulties were encountered in applying the TFI in contrast to the DI, which caused uncertainties in assessing the ''questionable'' and ' 'very mild'' scores, and this may explain the relatively better reprod ucibility of the TFI. The correspondence between both indices was dete rmined. TFI 0 corresponded well with DIG. The conversion values for TF I 1, 2, 3 and 4 into DI scores were 0.3, 0.8, 1.4 and 2.4 respectively . The TFI 5-9 corresponded with DI score 4. TFI could discriminate the severe forms of dental fluorosis which were categorized in Dean's hig hest score 4. TFI was able to reveal more dental fluorosis than DI in communities with minor and moderate dental fluorosis. In the community with severe dental fluorosis where more than 85% of all teeth exhibit ed a DI greater than or equal to 1, both indices revealed a comparable prevalence of dental fluorosis. The TFI is considered a near ideal in strument.