Jan. 12, 2005, 11:35PM
Raising hope for relief from jaw disorder
Rice researcher works on growing TMJ patients' own cartilage
By ERIC BERGER
Copyright 2005 Houston Chronicle
Nearly 20 years ago Deanna Discher-Harm felt pain in her jaw. As the problem worsened, talking, chewing and swallowing became unbearable. Sometimes her mouth would even lock in an open position.
|TMJ symptoms include: |
?Motion: Limited movement or locking of the jaw.
?Pain: Radiating pain in the face, neck or shoulders.
?Sounds: Painful clicking, popping or grating sounds in the jaw joint when opening or closing the mouth.
?Teeth: A sudden, major change in the way the upper and lower teeth fit together.
Find out moreTo learn more about temporomandibular disorders, order a free copy of "TMD: Temporomandibular Disorders" from the National Institute of Dental and Craniofacial Research. To order a copy, write to: The National Institute of Dental and Craniofacial Research National Oral Health Information Clearinghouse 1 NOHIC Way Bethesda, MD 20892-3500
Source: National Institute of Dental and Craniofacial Research
Upon moving to Houston in the late 1980s, she met Dr. Mark Wong, a dental surgeon who eventually rebuilt her jaw with natural cartilage and tissue, bringing some relief. Discher-Harm, 40, still has constant pain of varying degrees, and she must avoid foods that stress her jaw, such as nuts. Of course, visits to the dentist are more painful than for most.
"Having to hold my mouth wide open, for a long time, that's excruciating," she says.
Although medical science has few answers for her ills, there may be cause for optimism because of a Rice University biological engineer's work in growing patients' own cartilage.
Ailment mostly a mysteryThe cause of Discher-Harm's disease, called TMJ for the temporomandibular joint that controls jaw functions, is largely unknown. No surgery for extreme cases has proved effective over the long term. And there's no known method to prevent TMJ illnesses. Such are the hard facts surrounding the diseases and disorders that afflict the joint used to chew, speak and swallow. About 11 million Americans have TMJ problems.
As many as two-thirds of TMJ problems come from a displaced or damaged sheet of cartilage within the joint. This TMJ disc, about the size of a postage stamp, cannot heal itself.
The bioengineering group at Rice led by Kyriacos Athanasiou recently received a $1.5 million, five-year grant from the National Institutes of Health to continue working toward its goal of using a patient's own cells to grow new cartilage for patients suffering from TMJ disorders.
Athanasiou, whose previous work focused largely on knee cartilage, says he became intrigued with the TMJ disc at a dentists seminar where he learned that 90 percent of those who seek treatment for the disease are young, premenopausal women. "I thought there must be something really, really unusual with this joint," he said.
'Tall order' for researcherAthanasiou said he soon learned that little research had been done on the small, but important cartilage disc. He believes this has happened because the problem falls in a gray area between dentistry and general medicine.
"This is a tall order because there is scant information about what the TMJ disc is, what it is made of, what its functions are, what its pathologies are and how its pathologies develop."
But Athanasiou thought methods used to grow other types of cartilage in his lab might be applicable to the TMJ disc. After four years of work to understand more about this different type of cartilage, he believes they can. By applying pressure and tension to cells taken from a patient's TMJ disc, Athanasiou believes, his team can induce the cells to grow new tissue in a proper form on a biodegradable scaffold.
"It's not unlike what we do to our muscles to build them up," Athanasiou said. "We exercise to make ourselves stronger and bigger."
The Rice team believes that when the grant expires, researchers will be ready for trials with human patients.
This new type of treatment is geared toward the most extreme cases, patients like Discher-Harm who lose sufficient structure in their joint, said Wong.
"The current treatments for this condition are not ideal," said Wong, chairman of the Department of Oral and Maxillofacial Surgery at the University of Texas Dental Branch at Houston. "A new type of biological implant would be very attractive."
Tissue harvested from a patient's rib or joint is an imperfect replacement, and ligaments and muscles do not attach sufficiently well to metallic implants, which can also fail over time, Wong said.
Since becoming interested in the disease, Athanasiou said, he has served as a scientific adviser to the TMJ Association.
"I realized that any contributions we could make to help with the horrible pain and conditions of this disease would be great," he said. "If somebody has a bad knee, it's a very difficult problem. But if there's terrible pain in the joint that controls eating and talking, it's much worse."