We investigated the clinical status of third molars in 876 Finnish conscripts aged 19.9 years (SD, 1.1 years) and compared the findings with data on male students of the same age from 40 years before. Significantly more partially erupted and fewer totally erupted lower third molars were found in the present study than 40 years earlier: 29% (95% confidence interval +/- 3%) versus 19% were partially erupted (p > 0.001), and 13% (confidence interval +/- 3%) versus 23% were totally erupted (p