Scientists Grow Teeth in the Lab from Single Cells

Researchers in Japan have grown mice teeth from single cells and successfully transplanted the teeth into the mice's mouths.

Exciting as this news is, don't throw away your bridges and your dentures just yet. It will take some time before teeth can be grown for humans.

The research was conducted in the Tokyo University of Science. The scientists took two kinds of cells from mouse embryos. These weren't stem cells, but early cells from a slightly later stage in development, and they were the type of cells that in an embryo would later develop into teeth.

The researchers put the cells in a collagen gel, and the cells grew into tooth buds, which are an early stage of tooth development. The researchers then transplanted the tooth buds into the mouths of adult mice who had had teeth extracted. The tooth buds then grew, within the mouths of the mice, into normal, healthy teeth.

One obstacle in replicating this procedure in humans is that the researchers used embryonic cells, and that wouldn't be possible when working with humans rather than lab animals. Study co-author Yasuhiro Tomooka told The Scientist Magazine that his group was searching for adult cells that could be used instead. "The adult brain has stem cells making neurons," he said. "Maybe somewhere in your mouth we can find such cells." He believes that there is a "high possibility" that such cells do exist in adults' mouths.

Pamela C. Yelick, an associate professor at Tufts University who has done similar bioengineering work, told HealthDay News that the biggest stumbling block was that nobody has yet been able to grow teeth to be a predetermined specific size and shape. She said that developing adequate tooth root formation was also a problem. Even though the Japanese group's implanted teeth did develop some root structures, it wasn't enough to hold the teeth in place as well as you would want in a fully functional mouth.

She said, however, that she is optimistic. She believes that some day it will be possible to bioengineer tissues to repair damaged organs and to grow whole organs outside of the body.

Sources

Japanese scientists grow teeth from single cells, Feb. 18, 2007, Reuters

Scientists Grow Mouse Teeth From Single Cells, by Steven Reinberg, Feb. 19, 2007, HealthDay News

Teeth, whiskers bioengineered, by Jeffrey M. Perkel, Feb. 19, 2007, The Scientist, www.the-scientist.com

Lab-grown replacement teeth fill the gap, by Emma Young and Roxanne Khamsi, Feb. 18, 2007, NewScientist.com news service