Scientists say they have replaced a 65-year-old patient's upper jaw with a bone transplant cultivated from stem cells isolated from his own fatty tissue and grown inside his abdomen.

The Finnish researchers say this opens up new ways to treat severe tissue damage and makes the prospect of custom-made living spares parts a step closer.

"There have been a couple of similar sounding procedures before, but these didn't use the patient's own stem cells that were first cultured and expanded in laboratory and differentiated into bone tissue," says Professor Riitta Suuronen of the Regea Institute of Regenerative Medicine, part of the University of Tampere.

She says the patient is recovering more quickly than he would have if he had received a bone graft from his leg.

The team used no materials from animals, preventing the risk of transmitting viruses than can be hidden in an animal's DNA, and followed European Union guidelines, she says.