Whole teeth grown from molar stem cells in mice

Researchers in Japan have grown functional teeth using cells taken from a mouse molar as starting material. The group grew these cells for a few days in the lab, then placed them into a tooth-shaped mold and implanted the mold into the mouse kidney where they were left to grow for about two months.

What the group found after that time looked like a tooth, had the normal structures of a tooth and was able to implant normally into the jaw of a mouse. The mouse was able to chew normally using the engineered tooth.

The work was published on July 12 in the journal PLoS ONE. In a Reuters story about the work,Takashi Tsuji, who led the research, said two things are needed before dentists can replace artificial bridges with teeth that implant and function just like the original set. One is learning how to grow the teeth in a lab rather than inside the kidney.

The other is finding the human equivalent of the cells they took from mouse molars. Molars contain a lot of cells, only some of which have the ability to create entire new teeth under the right conditions. In the Reuters story Tsuji said:

“In this case, entire tooth units could be grown because the stem cells were taken from molar teeth of mice — where they later grew into enamel, dental bones and other parts that comprised a regular tooth unit.”

As is often the case in medical research, translating discoveries from mice or rats to humans can be slow going. However, if the scientists are able to find the right cells and work out conditions to grow those cells in the lab, in could mean a future of easier chewing for older people.