Google:  bone morphogenic protein

Jaw transplant allows man to chew after nine years

00:01 27 August 2004
NewScientist.com news service
Gaia Vince
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 1995, 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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Weblinks

University of Kiel, Germany<LI style="MARGIN-BOTTOM:
5px">http://www.uni-kiel.de/index-e.html
Queen Victoria Hospital, East Grinstead, UK<LI style="MARGIN-BOTTOM:
5px">http://www.qvh.nhs.uk/
The Lancet
http://www.thelancet.com/

-Sue (nondentist)

I am sorry .Please allow me to correct myself...how much progress has
stem cell research made

Very good point!

I also don't see how the teeth could be 'vital' at implantion.
Do I get to charge for the endo too?

Dartos

Titanium is one of the most biocompatible materials we have today.

As far as applications where new "natural" may not be subject to
re-disintegration due to environmental factors might be:

-teeth lost through trauma (car accident, injury etc.)
-congenital absence of teeth
-cranofacial abnormalities
-surgical removal of jaw due to cancer
etc.

Also if new teeth can be grown, then new tissue can be grown.  I
believe that Dentrix is looking at stem cell technology  that could one
day be an alterantive to  root canal therapy.

Just some thoughts,
Sue

I'm watching Hitachi... They'll prolly open a new subsiduary based in
Singapore (the current hotbed of cloning research: no limiting rules, no
religeous zealotism).
SP

regenerated teeth can also be used to replace those lost due to trauma
or a cause not related to oral hygiene.

Hello! I'm a new member  from India! A freshly passed B.D.S.(Bachelor
of Dental Surgery) Graduate!
This all seems really Great!
How many years have to go for bringing this in routine use?
It will be hell lot costly? Right!
The technology should develop so that even the poor can get advantage
of that; is what I feel.

Pankaj