[Determining the average posteruptive age of teeth from the results of cross-sectional studies (author's transl)].

If results of cross-sectional studies must be used as a basis for setting up models of development of caries in permanent teeth, then the average rather than individual posteruptive age of teeth has to be resorted to. Data available for this purpose had been obtained from a total of 54,000 children living in two G.D.

Distribution of caries among tooth types in fluoride and non-fluoride areas.

A method is described for estimating the preferential caries protective action of fluoride on certain morphological types of permanent teeth. The results of an analysis by this method, applied to data for 1164 Austrian school-children aged 6--14 years, are reported. There was no indication that fluoride would exert its caries inhibitory effect selectively on certain types of teeth.