(PhysOrg.com) -- Earlier this year in a report in The Lancet, Columbia professor Jeremy Mao and his team showed that a joint could be grown with a host’s own stem cells, presenting a potential alternative for the 400,000 people who receive an artificial knee or hip each year. He has also demonstrated that it is possible to regenerate a new tooth from stem cells, which offers hope that one day dentures and implants may become a thing of the past.