New jawbone is grown for cancer patient

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LONDON -- A German who had his lower jaw cut out because of cancer has enjoyed his first solid meal in nine years -- a bratwurst sandwich -- after surgeons grew a new jaw bone in his back muscle and transplanted it to his mouth in what experts call an "ambitious" experiment.

According to this week's issue of the Lancet medical journal, the German doctors used a mesh cage, a growth chemical and the patient's own bone marrow, containing stem cells, to create a new jaw bone that fit exactly into the gap left by the cancer surgery.

Tests have not been done yet to verify whether the bone was created by the blank-slate stem cells, and it is too early to tell whether the jaw will function normally in the long term, but the operation is the first published report of a whole bone being engineered and incubated inside a patient's body and transplanted.

Stem cells are the master cells of the body that go on to become every tissue in the body. They are a popular area of research, with scientists trying to find ways to prompt them to make desired tissues and perhaps organs.

While researchers debate whether the technique resulted in a scientific advance involving stem cells, the operation has achieved its purpose and changed a life, said Stan Gronthos, a stem cell expert at the Institute of Medical and Veterinary Science in Adelaide, Australia.

"A patient who had previously lost his mandible [lower jaw] through the result of a destructive tumor can now sit down and chew his first solid meals in nine years ... resulting in an improved quality of life," said Mr. Gronthos, who was not connected with the experiment.

The operation was done by Dr. Patrick Warnke, a reconstructive facial surgeon at the University of Kiel in Germany. The patient, a 56-year-old man, had his lower jaw and half his tongue cut out almost a decade ago after getting mouth cancer. Since then, he had only been able to slurp soft food or soup from a spoon.

In similar cases, doctors can sometimes replace a lost jawbone by cutting out a piece of bone from the lower leg or from the hip and chiseling it to fit into the mouth.

This patient could not have that procedure because he was taking a potent blood thinner for another condition and doctors considered it too dangerous to harvest bone from elsewhere in his body.

Dr. Warnke and his group began by creating a virtual jaw on a computer, after making a three-dimensional scan of the patient's mouth.

The information was used to create a thin titanium micromesh cage. Several cow-derived pure bone mineral blocks the size of sugar lumps were then put inside the structure, along with a human growth factor that builds bone and a large squirt of blood extracted from the man's bone marrow, which contains stem cells.

The surgeons then implanted the mesh cage and its contents into the muscle below the patient's right shoulder blade. He was given no drugs, other than routine antibiotics to prevent infection from the surgery.

The implant was left in for seven weeks, when scans showed new bone formation. It was removed about eight weeks ago, along with some surrounding muscle and blood vessels, put in the man's mouth and connected to the blood vessels in his neck.

Scans showed new bone continued to form after the transplant.