[Dental caries in 280 pairs of same-sex twins]

The dental caries in 280 pairs of like-sex twins (186 monozygotic, 94 dizygotic) were studied. Then, comparisons of variability of dental caries, missing and filled surface (DMFS), concordance, and correlation in the two types of twins were made. The heritability index (HI) was also calculated. There were less variance, higher concordance and higher correlation in monozygotic twins, but the results were not statistically significant. The HI of dental caries was 8.7% according to this study. It was suggested that environmental influence was dominant in caries initiation: whereas heredity was of little influence.