Tooth Decay Is Partly Genetic, Study Says
July 21, 2010

By Nancy Volkers
InteliHealth News Service

INTELIHEALTH - Your likelihood of getting cavities is driven by your genes, says a study of identical twins. But that doesn't mean you should stop brushing and flossing.

Researchers from the University of Helsinki, Finland, did a study involving 3,065 adult twins born in the 1970s. Some were identical and others were not.

Researchers asked the twins whether they had fillings, cavities or bleeding gums. Because identical twins have the same genes, researchers could compare twins with each other to see how similar they were in numbers of fillings and bleeding gums.

They also compared non-identical twins, who share half their genes, on average. Researchers then were able to estimate how strongly genes affect some aspects of oral health.

The researchers found that genes were strong predictors of the number of fillings a person had. In men, the number of fillings was about one-half genetic and one-half environmental. In women, the number of fillings was two-thirds genetic and one-third environmental. This means that a woman with "healthy teeth" genes is likely to have fewer fillings than a woman who has "unhealthy teeth" genes. The researchers did not study specific genes.

The researchers also looked at how genes influenced bleeding gums. They found that in both men and women, the genetic effect was weaker than with fillings. Bleeding gums were about one-third genetic and two-thirds environmental.

Many studies have confirmed that genes play a role in oral health. A May 2010 study found that genes could explain up to 70% of cavities in baby teeth and up to 55% in permanent teeth. A 2005 study of twins found that genes explained 33% to 39% of periodontal disease.

The Finnish study appears in the July issue of the Journal of Dental Research.