No More Dentures

We all get the warning, brush your teeth or lose them forever because once adult teeth come in, we're done growing any more. Why is that? And can we change this so that lost teeth can be regrown. New research shows one day that looks likely.

In humans, tooth growth is strictly programmed to a set number and that's thirty-two adult teeth. In rare cases, some people grow extra teeth called supernumerary. Researchers have been studying the genes and molecular functions that stop extra teeth. They found a single gene behind it, the Usag-one. It produces a protein that inhibits two signaling molecules necessary for tooth growth. These two molecules are Wnt and BMP but they do not only control tooth growth, they provide a green or red light for other tissue growth as well. But when the gene Usag-one is present, these two signaling molecules cannot work.

Here's where it gets interesting. Since both Wnt and BMP are essential for tooth development, researchers tried removing USAG-one to see whether BMP would become active and promote new tooth growth? Researchers used ferrets in the study since they have more human like teeth than mice. When they stopped USAG-one from interacting with BMP, allowing it to activate, extra teeth began to grow in ferrets. So, maybe it could work in people but these are powerful molecules that could promote tissue growth where we don't want it. So, the challenge is to only direct growth of missing teeth. Ask anyone with dentures and they'll tell you this technology would be a godsend.