What’s so wise about wisdom teeth? Even oral surgeons seem to think that these crooked, painful molars are quite worthless, since they remove them from the mouths of 85 percent of Americans to prevent infection and orthodontist bills. But researchers in Japan may have finally found a smart use for these third molars: making stem cells.
In 2007, scientists succeeded in transforming specialized human cells, like bone or skin cells, into stem cells, blank slates with the potential to grow into any tissue in the body. These converted cells, called induced pluripotent stem cells (iPSCs), have so far been made from bone, skin, muscle and fat cells. But the reprogramming process isn’t always efficient; researchers may remove a large chunk of a patient’s bone or skin as a source of cells, yet fail to produce any iPSCs.
In a paper published in September in the Journal of Biological Chemistry, cell engineer Hajime Ohgushi and his research team at the National Institute of Advanced Industrial Science and Technology in Hyogo, Japan, explore the possibility of using wisdom teeth as alternative sources of iPSCs. Similarly to studies by the U.S. National Institutes of Health, which produced iPSCs from children’s “baby” teeth, the team injected donated tooth cells with proteins that reversed the cells’ specialization and made them into iPSCs.
Importantly, the researchers found that wisdom tooth cells could be reprogrammed much more readily than other cells — up to 100 times faster. “We can easily generate the iPSCs from the third molar due to high efficiency,” said Ohgushi. This could make wisdom teeth into consistent stem cell sources, he notes, since most are discarded as medical waste anyway.
Geneticist In-Hyun Park from the Yale University Stem Cell Center in New Haven, Connecticut, said increased efficiency will be important in for scientists to create better stem cells and learn how best to use them. More research is needed to make stem cells safer and more reliable for human use, he said.
Despite current handicaps, several companies in the U.S., Europe, and India have opened tooth banks, which, for monthly or yearly fees, store a customer’s “baby” and wisdom teeth. Theoretically, these cells can be unfrozen years later and used to repair and regrow the customer’s damaged tissue — with no waiting for an organ donor and no risk of immune rejection, since the donor and the receiver are the same person.
Although Park still has all his wisdom teeth, he’s not rushing to the nearest dental surgeon or tooth bank. “If I really needed cells, I would let them take a skin biopsy, or my blood or hair,” he said. Until scientists develop real-world medical applications for stem cells, it may be a better investment to leave your dislodged teeth under your pillow for the tooth fairy.