KUHF-FM (88.7, Houston), Oct. 10, 2009

The average American adult is missing four teeth because of gum disease, trauma or congenital defects. Norbert Herzog and David Niesel of UTMB's Medical Discovery News say that scientists have isolated a single gene called osr2 that prevents growth of extra teeth in humans and mice. The researchers eliminated the gene in mice and found that they developed extra teeth.