Jaw transplant allows man to chew after nine years

A man has been able to savour his first proper meal in nine years after surgeons successfully created and transplanted a jawbone for him.

A jaw, grown on a titanium frame, enabled the man to chew for the first time since he lost his lower jaw in radical surgery for cancer. The functional jawbone was created using a combination of computer aided design and bone stem cells.

The 56-year-old German man underwent surgery to remove cancerous tumours on his jawbone in 1997, and since then he was able to eat only soup and soft foods. But just four weeks after a pioneering jaw-creation and transplantation procedure, he tucked into a meal of sausages and bread.

Current techniques for replacing lost bone usually rely on a painful, slow-healing bone graft from another part of the body, causing loss of bone density in the donor area and a secondary site of possible infection. Flat areas, such as the shoulder blade, are often used, which are far from ideal replicates for a complex three-dimensional structure like jawbone.

Now, doctors at the University of Kiel in Germany have neatly bypassed the initial bone removal procedure and instead grown the required bone from stem cells in the patient's own bone marrow.

"We created a titanium mesh cage to a three-dimensional shape and fit, for his lower jaw, using computer-aided design, based on CT scans of his face," explains Patrick Warnke from the Department of Oral and Maxillofacial Surgery, who carried out the jaw transplant.

Liquid bone marrow

Warnke and colleagues then filled the mesh with bone mineral blocks of bovine origin, that would act as a scaffold for the growing bone. On to the blocks were poured a mixture of recombinant human bone morphogenic protein (BMP) powder - a genetically engineered protein that causes cells to ossify or become bone - and liquid bone marrow containing stem cells.

The titanium frame with its bone-growing ingredients were then implanted into a layer of muscle on the patient's right shoulder blade to form tissue and blood vessel connections to the muscle. "He actually didn't find this uncomfortable at all and was able to sleep on that side with no problems," Warnke comments.

Seven weeks later, when the implant was removed it showed evidence of bone remodelling and mineralisation, and CT scans revealed bone formation. The jaw structure, with its newly created envelope of muscle tissue was then transplanted into the patient's face and microsurgery was performed to connect it to his existing jaw muscle and to blood vessels at the base of his neck. Skin was closed around the new jaw as much as possible.

"He is very happy with the result," Warnke told New Scientist . "He can chew food again and his speech is much more easy to understand, especially on the phone."

Nose structure

Ken Lavery, a maxillofacial consultant, who is carrying out similar research at Queen Victoria Hospital in East Grinstead, UK, says the technique offers huge potential for victims of gunshot or facial tumours.

"It's a sophisticated procedure, but it depends on the patient being in a condition to wait long enough to grow the new bone. We are currently in the process of developing a nose structure for a patient whose nose has been lost though cancer, using a resorbable plate mesh, rather than titanium which needs to be removed after."

Lavery believes that bone marrow is unnecessary for such transplants, since the BMP will grow into bone itself.

In a year's time, when the German patient's bone density has improved further, Warnke hopes to remove the titanium and implant teeth.

Journal reference: The Lancet (vol 364 p 766)

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