Biomaterials and Medical Devices: An Industry in Transition The Impact of Healthcare Reform, Product Liability, Regulatory Issues, and Raw Materials Shortages

Biomaterials and Medical Devices: An Industry in Transition The Impact of Healthcare Reform, Product Liability, Regulatory Issues, and Raw Materials Shortages
Background of TMJ Research and Treatment "Dr. Enid Neidle, former director of scientific affairs for the American Dental Association (ADA), has described TMJ as "dentistry's hottest area of unorthodoxy and out-and-out quackery."1
Perhaps the historical perspective of the temporomandibular joint (TMJ) implant disaster is most effectively given by examining the state of the art of research and treatment of TMJ disorders over the past several decades. This could well prove to be a case study of how every professional organization and governmental agency fell down on the job of protecting the TMJ patients of this country.
In the thirties, temporomandibular joint disorders were turned over to the dental "turf" by James Costen, an ENT specialist, who believed that TMJ disorders stemmed from occlusal factors. From that time, research and treatment of these disorders remained in the dental realm.
In the late seventies, "TMJ" became the buzz word and catch-all for many complaints that didn't fall into any specific disease. Dentists took to TMJ disorders like fleas on a dog. Treatment modalities proliferated in number until today 49 can be listed. Dental specialists touted the benefits of their particular treatments and expertise. As a dentist once told me, "At my dental school, you received TMJ treatment depending upon where the elevator stopped -- sixth floor, oral surgery; fourth, prosthodontics; third, orthodontics, etc." Even now, we don't have one standard of care; we have many standards of care.
The American Dental Association (ADA) has never made TMJ disorders a specialty. Thus, dental or continuing education criteria are nonexistent. As Dr. Harold Perry, orthodontist and professor at Northwestern University, states, many self-professed TMJ specialists received their education at "sporadic, single-concept 'Hilton University' weekend seminars."2 Treatment of this joint has been largely based on anecdotal information and trial and error. Because there was no scientific evidence to repudiate the proclaimed advantages of these treatments, dental professionals dogmatically defended them -- even in the face of failure.
The lack of hard science and the financial rewards of multi-modality treatment practices have no doubt contributed to what Dr. Perry sees as a greater proportion of iatrogenic problems resulting from misdiagnosis and mistreatment."3 In the early eighties, TMJ received a new nickname -- "The Money Joint." Advertisements acknowledged that taking on TMJ was one way to "increase, revitalize, and inflation-proof" dental practices.4 What evolved was a cottage industry profession whose members lacked not only the skills and knowledge necessary to understand and do scientific research, but scientific curiosity as well. As Dr. Enid Neidle, former director of scientific affairs for the ADA, so succinctly put it: "Where dental schools have done an exceedingly poor job, and continue to do so, is to incorporate those things into the curriculum that will create in their graduates an inquiring mind, a respect for science, a comprehension of what research means, and a deep understanding of how fundamental to the practice of dentistry scientifically generated knowledge is."5 These are the people who took on the treatment of the most complex joint in the body.
At the National Institute of Dental Research (NIDR), TMJ disorders were placed in the Craniofacial Anomalies, Pain Control, and Behavioral Research Branch. Through the years, this disorder has been a low priority where funding is concerned. Even in the nineties, approximately 2 percent of the NIDR budget is directed toward TMJ disorders which, conservatively speaking, affect approximately 30 million people, the majority of whom are women. There has been no serious attempt to fund basic research into these disorders. Most of the funding has been directed toward the "psychosocial" components of this problem. As with many disorders, until etiology is scientifically established, the patient is perceived to cause or propagate the problem. However, with TMJ disorders, the psychological cause is usually pulled out of the hat of tricks after all the patient's money has been spent on those other 49 treatment modalities and/or the disorder is iatrogenically induced. To this date, not one grant has been funded to support studies of TMJ implants.
TMJ Implants -- Historical Perspective
The lack of basic research in the TMJ area has permitted what one researcher calls "the Great American Medical Disaster" -- TMJ implants.
Since the mid-sixties, professionals have been using various materials to replace all or part of the temporomandibular joint. Sometimes, surgeons replace the disc with what is frequently called an interpositional implant (IPI). In other instances, the condyle (the head of the mandible, or lower jaw), fossa (the skull, or socket, of the jaw joint), or both, are replaced with prosthetic devices. The total number of implant recipients is unknown; however, a conservative estimate would be that 150,000 Americans have received biomaterial jaw joint parts.
Most biomaterials for jaw joint reconstruction were introduced on the market before the 1976 Medical Devices Amendment Act was passed requiring manufacturers to provide evidence that their devices were safe and effective. The TMJ implants that were first marketed after 1976 were allowed on the market without testing, because of a legal loophole which required manufacturers to prove only that their devices were substantially equivalent" to a pre-Amendment device.
Two products that have been widely used as disc replacements for torn and/or displaced natural discs are Dow Corning's Silastic and Vitek's Proplast-Teflon.
Silastic
Silastic implants appeared in several forms. The first, introduced in the mid-sixties, was a block of Silastic, or silicone rubber, carved to shape. Another was Silastic HP Sheeting, which was reinforced with dacron. This was followed by the Wilkes design, marketed in 1985. Designed for temporary use only, this implant was made with "tabs" to allow for easy removal after several months.
Short-term studies in the early seventies looked good. Reports after one to five years, however, showed substantial problems, including ankylosis, arthritis, and lymph node swelling. One 1982 study warned doctors that particle migration meant they should be alerted to possible systemic reactions and foreign body synovitis, speeding failure.6 A 1986 article reported "fragmentation, perforation, and deterioration of the (Silastic) material."7 And another stated, "silicone may not be a totally inert material and that its biomechanical properties are not ideal for use in the TMJ."8 By the end of the 198Os, enough failures had occurred for some researchers to call for strict limits on the use of Silastic.9
Dr. Mark Lappe, professor of Health Policy and Ethics at the University of Illinois, stated in testimony before Congress that, from Dow Corning's public documents and a review of the literature, it is clear that Dow Corning knew decades earlier what doctors found in 1985-that Silastic is intrinsically flawed as a biomaterial for long-term implantation into the human body." 10 As early as the sixties, they saw foreign body giant cell reaction and knew it induced fibrosis and calcification. But even in the late seventies and early eighties, with the knowledge of the adverse effects of the wear particles, Dow Corning issued no adequate warning in the package insert and continued marketing the implants." Dr. Lappe further stated that Dow Corning "knowingly allowed their silicone sheeting to be used for repairing the damaged TMJ even though it was highly likely that the sheeting, even when reinforced, could not stand up to the stresses typical of a major, pressure-bearing, inflammation-damaged joint."12
As late as 1989, there was not one long-term study of the use of Silastic in animals or humans. As a matter of fact, a single study in 1965 "served as the principal impetus to encourage the marketing of Silastic sheeting for this new, and untested purpose."13 In 1991, when sheep studies were conducted, severe bony destruction and foreign body giant cell reaction were found. Finally, after 20 years of use, it was decided that Silastic isn't appropriate for long-term use and that even short-term use is highly experimental.14
Dr. Lappe describes the development of Silastic and other implant materials for the TMJ as "marked by a pattern of haphazard development, entrepreneuralism, unverified assertions in the absence of animal testing, and a silent FDA. In 1992," he states, "we are left with no truly suitable implant material, in part because the most commonly used one -- Silastic brand reinforced sheeting -- was only belatedly subjected to testing. And then, it was found to be deficient for just the properties which were known to its manufacturer fully twenty years earlier."15
Proplast-Teflon
In the seventies, Vitek developed and sold Proplast Sheeting (Teflon FEP film laminated to a porous composite material made from polytetrafluoroethylene (PTFE) and carbon). The implant was modified in the early eighties, and Teflon film was then laminated to PTFE and aluminum oxide. These implants, usually no larger than a thumbnail, were manufactured individually or custom cut from sheets in the operating room by the surgeon, and then sutured to the fossa or condyle.
As with the Silastic implants, early reports claimed success, and in 1983, the FDA allowed Vitek to market a pre-cut disc. Under the law, the company's president, Charles Homsy, merely had to convince the Food and Drug Administration (FDA) that the device was "substantially equivalent" to Dow Corning's Silastic disc, marketed years earlier.
At the 1986 meeting of the American