Prevalence of retained roots in the Finnish adult population.

The prevalence of retained roots among Finnish adults was evaluated by examining a representative sample of 8000 Finnish adults aged 30 or older. The participation percentage was 89.6. Retained root was recorded when more than half the height of the tooth surfaces had been destroyed by caries. The reproducibility coefficient (kappa) for clinical recordings of retained roots was 0.79 for intraexaminer cases and 0.65 for interexaminer cases. Fifteen percent of the subjects had one or more retained roots. Prevalence was twice as great among males as among females. The mean number of retained roots was 0.4 per subject. Of all teeth in the mouth, 4.4% had only the roots left. On the population level, some 343000 adult Finns were estimated to have at least one retained root.