HELSINKI (Reuters) - Scientists in Finland said they had 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. Researchers said on Friday the breakthrough opened up new ways to treat severe tissue damage and made the prospect of custom-made living spares parts for humans a step closer to reality.

"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," said Riitta Suuronen of the Regea Institute of Regenerative Medicine, part of the University of Tampere.

She told a news conference the patient was recovering more quickly than he would have if he had received a bone graft from his leg. She added, 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.

Stem cells are the body's master cells and they can be found throughout the blood and tissues. Researchers have recently found that fat contains stem cells which can be directed to form a variety of different tissues. Using a patient's own stem cells provides a tailor-made transplant that the body should not reject.