A meeting of the Dental Products Panel was held on October 6, 2000. The topic of the meeting was a premarket approval application (PMA) for the TMJ Implants, Incorporated Fossa-Eminence Prosthesis. This device is a partial joint temporomandibular joint implant that consists of the glenoid fossa portion of the temporomandibular joint. This implant is to be used with the natural condyle. The device is a preamendments device.
The Open Public Hearing was the first item on the agenda following opening remarks. A number of patients spoke during the Open Public Hearing. Two patients with the Fossa-Eminence implant spoke in favor of the device, describing successful results after having received the implants. One patient described negative experiences following implantation with a total joint implant made TMJ Implants, Inc. Although, the total joint implant was not the subject of this meeting, the patient desired to express her concern regarding these implants and urged FDA to require sufficient data before approving other temporomandibular joint implant devices. A representative from the TMJ Association (a patient advocacy group) spoke on behalf of another patient, also describing a negative experience following implantation with a total joint implant by TMJ Implants, Inc. Another representative from the TMJ Association presented general patient concerns regarding complications and adverse event reports received from patients regarding various temporomandibular prosthetic devices. The TMJ Association representative also called for FDA to require adequate data to support approval of this device.
A number of oral surgeons addressed the panel, most describing favorable results that they have obtained using the Fossa-Eminence Prosthesis. Several oral surgeons expressed concerns regarding the lack of availability of the devices. One oral surgeon expressed concerns with the lack of sufficient data available to support the use of this type of device. A representative from Senator Tom Tancredo’s office provided a statement in support of the approval of the Fossa-Eminence Prosthesis, expressing concerns regarding FDA's process for review of this device.
There were a number of questions asked by the Panel members, mostly of the clinicians who addressed the panel during the Open Public Hearing. Most of these questions focused on indications for use, patient selection, patient follow-up and other related issues.
The presentation by TMJ Implants, Inc., began with a discussion of the implant's main indication for use, which is internal derangement. The sponsor identified a commonly used classification scheme for internal derangement, the Wilkes classification system. Several clinicians presented their clinical experience using the Fossa-Eminence Prosthesis, reporting successful results in which patients demonstrated improvement in the clinical parameter of pain reduction. Sponsor presenters also noted that, in a limited number of patients where re-entry surgery was performed because of trauma to the reconstructed joint, the natural condyle did not show any degenerative changes as a result of articulation against the metal fossa implant. The sponsor also addressed engineering data regarding the device.
The FDA presentation noted concerns regarding the lack of engineering data on the potential wear of the natural condyle as a result of articulation against the metal fossa. Clinical concerns included the small number of patients with long-term follow-up and the broad nature of internal derangement as an indication for use.
In response to the FDA panel questions, the Panel provided the following comments.
The Panel expressed concerns in using the indication of internal derangement, noting that internal derangement is a broad diagnosis with many facets. In general, the Panel believed that the data did not support the effective use of the Fossa-Eminence Prosthesis for the broad diagnosis of internal derangement based on the limited clinical data (i.e., the number of patients and the short follow-up time). The Panel stated that there may be evidence to support use of the device in patients with a diagnosis of Wilkes class V internal derangement. Other indications for the device included: 1) inflammatory arthritis involving the temporomandibular joint not responsive to other modalities of treatment; 2) recurrent fibrosis and/or bony ankylosis not responsive to other modalities of treatment; 3) failed tissue graft and 4) failed alloplastic partial joint reconstruction. The panel believed that the sample size was insufficient for each of these individual indications.
The panel also believed that it was important to know the distribution of time at which the majority of failures occur and stated that the patient follow-up should be longer than this period of time. The panel also noted that it may be necessary to place restrictions on the loading for this device. During panel discussion, it was also noted that there should be a quantitative assessment of changes to the condyle based on radiographic data.
The Panel recommended that P000035 be found not approvable based on the lack of safety and effectiveness data for surgical indications as given in the PMA.
The Panel offered the following recommendations in order to place the PMA in approvable form.
- Additional fatigue testing at higher loads;
- Clarification and definition of the patient inclusion criteria in the clinical study;
- Clarification of the means of radiographic evaluation (i.e., monitoring of changes in the condyle over time);
- Clarification of the definition of adverse outcomes;
- Evaluation of failures and additional patient follow-up;
- More clearly defined indications and
- A power analysis.
Contact: Pamela D. Scott, Executive Secretary, at 301-827-5283, x127
Transcripts of this meeting may be purchased from Miller Reporting, 735 8th St., S.E., Washington, DC 20003, 202-546-6666 or 1-800-833-7947 (FAX: 202-546-1502) and from the Food and Drug Administration, Freedom of Information Staff (HFI-35), 5600 Fishers Lane, Rockville, MD 20852, 301- 827-6500 (voice), 301-443-1726 (fax).