Genetic and environmental factors in oral health among twins.

To date, studies on the contributions of genetic factors to oral health have been inconclusive. We hypothesized that major dental diseases show a significant genetic component. The study was based on self-reported oral health among young adult twins. The data were derived from the fourth wave of the longitudinal FinnTwin16 study, in which participants completed a questionnaire in 2000-2002 enquiring about the number of filled teeth and the prevalence of gingival bleeding. We used quantitative genetic modeling, based on the genetic similarity of identical and non-identical twins, to calculate the most probable model for both filled teeth and gingival bleeding. The models revealed a strong genetic component behind the number of filled teeth, differing between males (49%) and females (68%), and a weaker genetic component affecting gingival bleeding, being similar for males and females (32%). Genetic factors contribute to inter-individual differences in oral health among young adults.