A longitudinal study of time trends in the eruption of permanent teeth in Danish children

The purpose was: (1) to estimate mean eruption times of permanent teeth in Danish schoolchildren for the birth cohorts from 1969 to 1982; and (2) to determine any time trends in eruption. For teeth with a low proportion of aplasia, the distribution of the the eruption time was close to normal. For teeth with a higher proportion of aplasia there was a slight deviation from the normal distribution ill the right-hand part of the distribution. For erupted teeth, the time to eruption was, however, again very close to the normal distribution. A small, but statistically significant, increase in mean eruption times was Found For both sexes and almost all teeth. Averaged over all teeth the increase was 1.5 days pet. year (95% CI: 0.9-2.2) for boys and 2.6 days per year (95% CI: 2.2-2.9) for girls. (C) 2001 Elsevier Science Ltd. All rights reserved.