Diagnosis of mild enamel fluorosis in permanent maxillary incisors using two scoring systems

The main purpose of this study was to compare the diagnosis of mild enamel fluorosis as established by two scoring systems, that of Dean based primarily on quantitative aspects and that of Thylstrup & Fejerskov with a preferentially qualitative approach. A further aim was to study the prevalence of fluorosis in permanent maxillary incisors after intake of fluoride tablets for a minimum of 5 yr between 1/2 and 6 yr of age in accordance with recommendations from the National Swedish Board of Health and Welfare. Maxillary incisors were examined in 118 13-yr-old children; 49 constituted a tablet group and the remaining 69 a control group who had never consumed tablets. Scored according to Dean, the difference in enamel fluorosis between the two groups was statistically not significant at the 5% level, whereas the system of Thylstrup & Fejerskov did give a significant difference. The frequency of fluorosis was substantially lower than that resulting from consumption of drinking water in Uppsala, Sweden, containing 1-1.2 ppm F. A probable relationship was found between the scoring systems, particularly if the Dean score 0.5 ("questionable") was converted to score 1. To ensure correct diagnosis, the tooth surface should be exposed to prolonged drying and apply relevant criteria for the differential diagnosis of disturbances of other origin. The higher sensitivity of Thylstrup & Fejerskov's system relates to score 1, narrow white lines located corresponding to perikymata. Here there seems to be a risk of over- or underdiagnosing. Recommendations are given for epidemiologic surveys and for experimental trials of limited size.