Posted on July 23, 2004 at 3:45 p.m.
BIRMINGHAM, Ala. – An estimated 10 million Americans suffer from symptoms of TMJ-related disorders, according to the National Institute of Dental and Craniofacial Research (NIDCR). Diseases and disorders of the temporomandibular joint (TMJ) are a complex and poorly understood set of conditions, manifested by pain in the area of the jaw and associated muscles. It limits a person’s ability to make normal jaw movements.
An interdisciplinary research team from the University of Alabama at Birmingham (UAB) has received a four-year, $1.3 million grant from the National Institute of Dental and Craniofacial Research (NIDCR), a division of the National Institutes of Health (NIH), to develop new, more functional TMJ implants that will promote integration with surrounding bone and tissue.
“From 1988 to 1998, at least 100,000 TMJ patients received plastic alloy implants and another 300,000 patients received bone grafts to help ease TMJ symptoms,” said Yogesh Vohra, Ph.D., UAB physics professor and grant principal investigator. “These implants were designed to take the place of the patient’s own damaged disc but have shown significant failure rates. It is now clear that TMJ implant designs must include highly wear-resistant surfaces combined with materials that easily integrate into existing bone. Keeping this design focus in mind, the TMJ implants we are now working on should have success and longevity, and should reduce the need for multiple or revision surgeries.”
The UAB research team will employ nanotechnology approaches to improve integration of TMJ implants. The new implants will have a core of metal that gradually transitions to a smooth, nanostructured ceramic surface on the outside. In addition, the screws that attach the implant to the bone will be coated with a nanostructured hydroxyapatite coating to help existing bone better adhere to the implant.
“The nanostructured hydroxyapatite coating on the screws is especially important to help the implant withstand the shear stresses during placement of the implant and to promote growth of new bone that will help in the overall implant stability and integration,” Vohra said. “In many cases with current implants, the hydroxyapatite coating on screws shows poor adhesion when the implant is placed in the jaw and bone has less chance to adhere to the implant, which can be the cause of implant failure.”
The interdisciplinary team working on the project brings together researchers from the UAB schools of Natural Science and Mathematics, Engineering, Dentistry and the Department of Joint Health Sciences. The team, under the direction of Vohra, also includes: Alan W. Eberhardt, Ph.D., associate professor of biomedical engineering, who will perform wear testing on the new implants; Patrick Louis, D.D.S., associate professor of dentistry, and Jack E. Lemons, Ph.D., professor of dentistry, who will perform in vivo testing and coordinate with industry on more extensive testing; Shane A. Catledge, Ph.D., physics research assistant professor, who along with Vohra will fabricate the actual implant; Andrei Stanishevsky, Ph.D., assistant professor of physics, who is designing the hydroxyapatite coating; and Susan L. Bellis, Ph.D., assistant professor of physiology and biophysics, who will study how cells attach and multiply on the implant’s surface.
Vohra said it is hoped that once the TMJ implant design is optimized and validated by mechanical and other testing, the new device would be ready for clinical trials.