Abstract
Clinical examination of enamel white flecks and urinanalysis were carried out on 1678 schoolchidren, aged from 6 to 11 years, who grew up in a city which supplied city water containing low fluoride (less than 0.24ppm).
Findings were as follows: -
1) Individuals with one or more teeth in“Very mild”or higher grade condition were found to be about 25.6% of the sample. On the contrary, according to the criterion for dental fluorosis rating as the two teeth showing the most severe grade developed by Dean (1934), “Very mild or mild” was about 11.1%; however, according to the criterion as the two teeth showing the most severe rating among the several teeth (four or more teeth) distributed symmetrically developed by the authors (1973), “Very mild or mild”was about 4.5% only. Thus, the authors considered that it is important to take into accout the symmetrical distribution of several mottled teeth and to examine children aged about ten or more years for the assessment of dental fluorosis in specific areas.
2) Fluoride concentration, as well as protein, glucose and pH of urine samples collected immediately after arising in the morning were analysed. A relatively higher level of fluoride concentration was found in the higher school years than in the lower school years.
Fluoride concentration in samples was ranged widely (2.5-0.10 ppm), a little variation, however, was observed at the level of minimum urinary fluoride level fraction (about 0.1ppm-0.15ppm). Thus, the increasing of minimum urinary fluoride level of residents would be recommended for the assessment of pollution by fluoride. Besides, a positive correlation between slight (or questionable) albuminuria and urinary fluoride concentration was observed.
