[Fluorine and the dentition].

In order to estimate the influence of fluorine (in drinking-water and air) on the occlusion 372 twelve-year-old children have been examined in four different localities with differing fluorine concentrations of drinking water and air. Apart from the determination of the fluorosis frequency and of the DMFt index, the number of children who do not require any orthodontic treatment according to the WHO recommendation has been determined. The degree of malocclusion has been defined by means of the Eismann-Masztalerz's method. There was observed that the optimal fluorine concentration in drinking water (0.7-0.9 mg/l) decreases the degree of malocclusion except for the crowding of the teeth whereas its concentration above the optimum (4.0-7.0 mg/l) as well as fluorine polluted air are one of the causes of crowding.