A German man was able to chow down on a bratwurst sandwich after surgeons grew a new jaw bone on his back muscle and transplanted the bone to his mouth.

The 56-year-old man had part of his lower jaw removed because of mouth cancer. Until the transplant, his diet was limited to soft food and soup for nine years.

Dr. Patrick Warnke, a reconstructive facial surgeon at the University of Kiel in Germany and his colleagues used CT scans and computer-aided designs to build a virtual jaw replacement.

Doctors in Kiel, Germany have rebuilt a man's face using a new jaw grown on his back.(AP PHOTO)

The researchers used the model to construct a mesh cage, which they filled with bone mineral, protein and stem cells from the patient's bone marrow. They then transplanted the implant below his right shoulder blade.

Seven weeks later, surgeons transplanted the new bone graft into the mouth gap in the patient's face.

A month after the surgery, he was able to eat his celebratory supper.

The experiment is described in Saturday's issue of the medical journal The Lancet.

"We suggest that our results represent a proof of principle," Warnke said in a release, noting the patient needs to be followed in the long term before drawing conclusions.

Researchers need to investigate appropriate combinations of biomaterials, growth factors and "blank slate" stem cells needed to build strong, resilient substitutes for bone, said Stan Gronthos, a stem cell expert at the Hanson Institute in Adelaide, Australia.

"A patient who had previously lost his mandible through the result of a destructive tumour can now sit down to chew his first solid meals in nine years ... resulting in an improved quality of life for that individual," Gronthos wrote in a commentary accompanying the study.