BASIC RESEARCH: Don't Sell Them to the Tooth Fairy.

Remember those teeth that came out with such trauma when you were a child, and your mama told you to put them under the pillow, and the next morning there was a dollar where your tooth had been? Well, the tooth fairy was ripping you off! Scientists from the National Institute of Dental and Craniofacial Research (NIDCR, National Institutes of Health, Bethesda, MD 20892-2190; Tel: 301/496-4261; Website: www.nidcr.nih.gov) report that "baby" teeth" contain a rich supply of pluripotent stem cells in their dental pulp. The researchers say this unexpected discovery could have important implications because the stem cells remain alive inside the tooth for a short time after it falls out of a child's mouth, suggesting the cells could be readily harvested for research or medical therapies.

According to the scientists, who published their findings online in the Proceedings of the National Academy of Sciences, the stem cells are unique compared with many "adult" stem cells in the body. They are long-lived, grow rapidly in culture, and, with careful prompting in the laboratory, have the potential to induce the formation of specialized dentin, bone, and neuronal cells. The scientists speculate they may have identified an important and easily accessible source of stem cells that possibly could be manipulated to repair damaged teeth, induce the regeneration of bone, and treat neural injury or disease.

"Doctors have successfully harvested stem cells from umbilical cord blood for years," says Songtao Shi, a scientist at NICDR and the senior author on the paper. "Our finding is similar in some ways, in that the stem cells in the tooth are likely latent remnants of an early developmental process."

Shi and colleagues named the cells SHED, which stands for Stem Cells from Human Exfoliated Deciduous teeth. Children normally develop a set of 20 deciduous teeth, which appear after 6 months of life and generally are replaced, one tooth at a time, between age 6 and 12.

The discovery of SHED came after Shi's then-6-year-old daughter, Julia, asked for help in pulling out a loose baby tooth. "Once it ...