HOUSTON (AP) _ An oral implant used to treat a jaw disorder was recalled by the Food and Drug Administration because it can damage the jawbone or induce an immune reaction, an agency official said Saturday.

The maker of the device is the defunct Vitek Inc., said Gerald Vince, a regional director for the FDA.

As many as 30,000 Proplast-Teflon Interpositional TMJ implants were made and distributed by the Houston company between 1983 and 1988, Vince said.

It was unknown how many people had the devices surgically implanted, but the FDA has contacted surgeons and hospitals the company listed as having purchased them.

The agency believes a large number of implants remain in stock in hospitals nationwide.

The implant is used to treat temporomandibular joint disorders, or TMJ. The ailment is caused by persistent jaw-clenching, which can cause jaw and facial pain, headaches and tooth damage.

The implants were intended to be ''relatively permanent,'' but a Teflon coating began to wear off, Vince said. Without the coating, bone degeneration can result or the body treats the device like a foreign object and the immune system tries to reject it, he said.

When patients began experiencing problems, tests were ordered and the recall ordered, Vince said.

''It was enough to make us very concerned about the longevity of the implants,'' he said.

The device has been the subject of about 400 product liability lawsuits against Vitek.

The implants are not life-threatening and the FDA doesn't suggest surgery to remove them, Vince said.

''We are just strongly recommending that the oral surgeon monitor the implants more frequently and on a more regular basis,'' he said.

Charles Homsy, former president of Vitek, said: ''There are still a lot of them implanted that are working beautifully.''

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