Comparison of different methods for estimating human tooth-eruption time on one set of Danish National Data.

The prevalence of congenitally missing teeth and the eruption times for the teeth in the human permanent dentition, defined as the mean age at which the teeth emerge in the mouth, were calculated from cross-sectional records of 760,108 children. A computation method based on probit analysis and Kärber's method based on dosage/response curves were compared and their estimates related to figures obtained by direct interpolation in the data. Kärber's method was less precise than probit analysis especially when data were not corrected for frequency of congenitally missing teeth or the number of observation points decreased. As the advantage of the Kärber method of easy computation is now reduced by the use of computers, probit analysis is recommended.