[Federal Register Volume 59, Number 243 (Tuesday, December 20, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-31161]


[[Page Unknown]]

[Federal Register: December 20, 1994]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

21 CFR Part 872

[Docket No. 92N-0281]

 

Medical Devices; Classification of Temporomandibular Joint 
Implants

AGENCY: Food and Drug Administration, HHS.

ACTION: Final rule.

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SUMMARY: The Food and Drug Administration (FDA) is classifying four 
temporomandibular joint (TMJ) implants, the total temporomandibular 
joint prosthesis, the glenoid fossa prosthesis, the mandibular condyle 
prosthesis, and the interarticular disc prosthesis (interpositional 
implant), into class III (premarket approval). These actions are being 
taken under the Federal Food, Drug, and Cosmetic Act (the act), as 
amended by the Medical Device Amendments of 1976 (the 1976 amendments) 
and the Safe Medical Devices Act of 1990 (the SMDA).

EFFECTIVE DATE: January 19, 1995.

FOR FURTHER INFORMATION CONTACT: Joseph M. Sheehan, Center for Devices 
and Radiological Health (HFZ-84), Food and Drug Administration, 2098 
Gaither Rd., Rockville, MD 20850, 301-594-4765, ext. 157.

SUPPLEMENTARY INFORMATION:

I. Background

    In the Federal Register of September 18, 1992 (57 FR 43165), FDA 
issued a proposed rule to classify certain TMJ implants into class III. 
Initially, FDA provided for interested persons to submit written 
comments on the proposal by November 17, 1992. In response to a request 
for an extension of the comment period, in the Federal Register of 
December 1, 1992 (57 FR 56876), FDA extended the comment period until 
December 8, 1992.
    Subsequently, in the Federal Register of February 14, 1994 (59 FR 
6935), FDA reproposed to classify two TMJ implants, the mandibular 
condyle prosthesis and the glenoid fossa prosthesis, into class III 
(premarket approval) to reflect the recommendation of the Dental 
Products Panel (the panel) with respect to the classification of these 
devices.

II. Response to Comments

    The agency received 54 comments responding to the proposed rule and 
one comment responding to the reproposed rule. These comments were 
submitted by a law firm, oral and maxillofacial surgeons who placed TMJ 
implants, manufacturers and distributors of TMJ implants, and TMJ 
implant recipients.
    1. In the preamble to the proposed rule, FDA advised interested 
persons that the agency lacked evidence that the total TMJ prosthesis 
was legally in commercial distribution before May 28, 1976. If the 
device was first introduced into interstate commerce after May 28, 
1976, it would be in class III in accordance with section 513 of the 
act (21 U.S.C. 360c). FDA specifically requested comments on this 
issue. In response, FDA received several comments stating that the 
total TMJ prosthesis was legally in commercial distribution in the 
United States before May 28, 1976, and one comment to the contrary.
    FDA has determined, from information submitted in comments, that 
two firms, TMJ Implants, Inc., Golden, CO, and the Temporomandibular 
Joint Research Foundation, La Cresenta, CA, were commercially 
distributing the total TMJ prosthesis in the United States on or before 
May 28, 1976. Thus, the agency has concluded that the total TMJ 
prosthesis is, in fact, a preamendments device and should be classified 
along with the other TMJ implants.
    2. Several comments stated that classification of TMJ implants into 
class III (premarket approval) might result in the unavailability of 
these devices for clinical use or in a movement to ban them. One 
manufacturer of total TMJ implants stated that, if the total TMJ 
implant is classified into class III, the expense of preparing a PMA 
would force that manufacturer to discontinue marketing the device.
    Under the statute, FDA classifies a device into class III, and 
subsequently requires submission of PMA's for the device, when FDA has 
determined that premarket approval is necessary to provide reasonable 
assurance of the safety and effectiveness of the device. The 
classification of a device, therefore, is based on considerations 
related to the safety or effectiveness of the device.
    FDA disagrees that classifying TMJ implants into class III will 
necessarily result in the unavailability and/or the banning of these 
devices because of the procedural safeguards contained in the statute. 
The effect of classifying a device into class III is to provide each 
manufacturer of the device with sufficient time to conduct necessary 
testing of the device (a minimum of 30 months) and then to submit a PMA 
to FDA by a date to be set in a future regulation under section 515(b) 
of the act (21 U.S.C. 360e(b)(1)). That regulation is promulgated using 
notice-and-comment rulemaking, in conjunction with which manufacturers 
are permitted to petition for reclassification. Moreover, pursuant to 
section 501(f) of the act (21 U.S.C. 351(f)(1)), a preamendments device 
may continue to be sold throughout this time period and while a PMA is 
pending.
    FDA is not attempting to ban TMJ implants by classifying them into 
class III. In fact, by eventually requiring submission of PMA's for 
these devices, FDA will be giving manufacturers the opportunity to 
establish that the devices are safe and effective. The classification 
of a device into class III neither results in nor is it related to the 
banning of a device under section 516 of the act (21 U.S.C. 360f).
    3. Several comments stated that, for reconstruction of the 
temporomandibular joint, non-ProplastTM TMJ implant devices are 
superior to autogenous materials. One comment stated that partial fossa 
protheses are safe and effective. Comments from patients and TMJ 
prostheses manufacturers stated that they experienced favorable results 
following implantation of the total TMJ prosthesis.
    In classifying these devices, FDA is determining the level of 
regulatory control needed to provide reasonable assurance of their 
safety and effectiveness. Whether non-ProplastTM TMJ implants are 
superior in safety and effectiveness to autogenous materials, or 
whether partial fossa prostheses are perceived as safe and effective, 
is not relevant to this determination.
    In accordance with section 513(a)(3) of the act, the agency relies 
on valid scientific evidence to determine the classification of a 
device. According to Sec. 860.7(c)(2) (21 CFR 860.7(c)(2)), valid 
scientific evidence includes evidence from well-controlled 
investigations, partially controlled studies, studies and objective 
trials without matched controls, well-documented case histories 
conducted by qualified experts, and reports of significant human 
experience with a marketed device. Valid scientific evidence does not 
include isolated case reports, random experience, reports lacking 
sufficient details to permit scientific evaluation, or unsubstantiated 
opinions. Thus, the isolated case reports, random testimonials, and 
unsubstantiated opinions received in response to the proposed rule 
cannot be regarded as valid scientific evidence upon which the 
classification of TMJ implants can be based.
    4. One comment stated that the agency's failure to provide the 
panel information relating to TMJ devices made of materials other than 
ProplastTM limited the panel's consideration and should limit the 
scope of its classification recommendation accordingly.
    FDA disagrees with this comment. As stated in the legislative 
history of the Medical Device Amendments of 1976:
    In requiring a panel's classification recommendation to include 
a summary of the reasons for the recommendation and a summary of the 
data upon which the recommendation is based, the objective is to 
assure that the record accurately reflects the basis for the panel's 
recommendations. The use of the term ``data'' is not intended to 
refer only to the results of scientific experiments but should also 
consist of less formal evidence, other scientific information, or 
judgments of experts when available. The requirement is not intended 
to imply that a panel must have received evidence with respect to 
safety and effectiveness of a device before it can make a 
classification recommendation. Under this premise, the burden of 
providing evidence substantiating the safety and effectiveness of a 
device rests on the manufacturers, and the absence of sufficient 
data may be referred to in a panel's recommendation as the reason 
for classification of a device into class III.
    (See H. Rept. No. 94-853, 94th Cong., 2d sess. 40 (1976), p. 40).
    5. One comment asserted that the references cited by FDA in the 
proposed rule classifying the total TMJ implant did not exist at the 
time of the panel meeting and, therefore, could not have been evaluated 
by the panel when making its recommendation.
    FDA disagrees with this comment. It is true that some of the 
information cited by FDA in support of its proposed classification of 
the total TMJ implant did not exist at the time of the panel's April 
21, 1989, meeting. However, the proposed rule reflected not only the 
panel's recommendations, but also FDA's determinations regarding the 
proper classification of these devices. The proposed rule did not state 
or imply that the panel relied on all the data cited by the agency in 
support of the proposed rule.
    6. Several comments suggested that, when classifying these devices, 
FDA should distinguish TMJ prostheses containing ProplastTM from 
those not containing that material. These comments recommended that 
only devices containing ProplastTM should be classified. Some 
comments stated that the risks to health identified in the proposed 
rule are based only on data associated with the failure of TMJ 
prostheses containing ProplastTM. One comment stated that 
ProplastTM implants and non-ProplastTM implants (specifically 
cobalt chrome and polymethylmethacrylate (PMMA) prostheses) should be 
classified separately because the difference in the material used in 
these implants significantly affects their safety and effectiveness. 
Several comments stated that surgeons and TMJ implant manufacturers had 
observed no specific cases of the risks to health identified in the 
proposed rule in several patients implanted with a non-ProplastTM 
total TMJ prosthesis. Some comments stated that these risks to health 
were not observed in patients implanted with TMJ prostheses 
manufactured by specific manufacturers. In contrast, several comments 
said that these risks were observed often in patients implanted with 
TMJ implants containing ProplastTM.
    According to Sec. 860.5(c)(3), when FDA initially classifies a 
device, it may consider safety and effectiveness data developed for 
other devices of the same generic type. A generic type of device 
includes devices that do not differ significantly in purpose, design, 
material, energy source, function, or any other feature related to 
safety and effectiveness, and for which similar regulatory controls are 
sufficient to provide reasonable assurance of safety and effectiveness 
(see Sec. 860.3(i)).
    The transcript of the April 21, 1989, panel meeting demonstrates 
that the panel considered TMJ implants composed of various materials, 
i.e., silicone, ProplastTM, dural grafts, fascia, vitallium, 
acrylic, meniscle and silastic, before making its recommendations with 
respect to classification. Evidence submitted during the panel meeting 
revealed that similar risks and similar safety and effectiveness 
concerns are associated with all TMJ implants, regardless of material 
composition. Based on the evidence provided, the panel concluded that 
TMJ devices composed of different materials raise the same safety and 
effectiveness questions. Thus, the panel concluded, and FDA agrees, 
that TMJ implants of all materials should be regulated within the four 
generic types of devices identified because the devices do not differ 
significantly in the safety and effectiveness questions raised and, 
consequently, similar regulatory controls will be needed to provide 
reasonable assurance of their safety and effectiveness.
    7. Comments stated that one of the health risks identified in the 
proposed rule, loosening of the total TMJ prosthesis, is directly 
related to the health of the bone at the implant interface. These 
comments asserted that loosening of the device does not occur unless 
there is a void of suitable bone.
    As stated in the preamble to the proposed rule, FDA has determined 
that the screws used to anchor the implant may loosen, resulting in 
implant loosening or displacement which may cause changes in bite, 
difficulty in chewing, limited joint function and unpredictable wear on 
implant components (see Refs. 2 through 5). The agency has not received 
any new information to cause FDA to change its opinion.
    8. Some comments asserted that FDA should classify all the TMJ 
implants into class II because special controls would allow the agency 
to impose special conditions on these devices, such as postmarket 
surveillance. One of these comments, received from a TMJ implant 
manufacturer, recommended that FDA classify TMJ cobalt-chrome-PMMA 
implants into class II.
    FDA disagrees with these comments. FDA believes that insufficient 
information exists to establish that special controls would provide 
reasonable assurance of the safety and effectiveness of these devices. 
FDA believes that a PMA is necessary to provide such assurance. 
Furthermore, postmarket surveillance is not limited to class II 
devices. Thus, at some future time, FDA may request that manufacturers 
of TMJ implants conduct postmarket surveillance of these devices.
    9. One comment urged that the total temporomandibular joint 
prosthesis and the interarticular implant be given high priority in 
calling for PMA's. One comment disagreed, stating that FDA cannot give 
the total TMJ prosthesis high priority in calling for PMA's when the 
panel recommended low priority. Another comment expressed concern that 
manufacturers of these prostheses will not have to submit PMA's to FDA 
for at least 2\1/2\ years and will be permitted to market the devices 
in the interim.
    Pursuant to sections 501(f) and 515(b) of the act, TMJ implant 
manufacturers may continue to commercially distribute their devices 
without filing a PMA for 30 months after the effective date of the 
final rule classifying these implants into class III or until 90 days 
after FDA issues a final rule requiring premarket approval for the 
devices, whichever is later. Moreover, section 515(i) of the act shows 
a clear congressional intent that FDA move forward with requiring the 
submission of PMA's for all preamendments devices. Thus, regardless of 
the priority assigned for calling for PMA's, eventually PMA's will be 
required for all class III preamendments devices that are not 
reclassified. Furthermore, it should be noted that a panel 
recommendation is only a recommendation that FDA may adopt or reject. 
FDA believes that it is appropriate to require PMA's for all TMJ 
implants as soon as possible under the act.
    10. Two comments objected that the glenoid fossa prosthesis and the 
mandibular condyle prosthesis should not be classified into class III 
because the panel did not recommend that they be classified into class 
III.
    Subsequent to issuing the proposed rule, the panel reconvened on 
February 11, 1993, and recommended that the mandibular condyle 
prosthesis and the glenoid fossa prosthesis be classified into class 
III. Based on this recommendation, FDA issued a reproposed rule in the 
Federal Register of February 14, 1994 (59 FR 6935), to classify the 
devices into class III.
    11. One comment stated that the classification process for the TMJ 
implants was flawed and should be reinitiated because of events which 
transpired between the April 1989 panel recommendation and the issuance 
of the proposed rule. During this time, the SMDA was passed. Among 
other things, the SMDA changed the classification definitions for 
medical devices.
    FDA disagrees with this comment. It is the agency's position that 
the SMDA does not require the agency to obtain a new classification 
recommendation from a panel which had recommended classification under 
the previous standard.
    As stated previously, the agency is not bound to adopt a panel's 
recommendation. Moreover, in light of the significant risks to health 
identified by the panel, FDA believes it is extremely unlikely that the 
panel would have recommended that the devices be classified into class 
II under the new definition.
    12. On its own initiative, FDA has deleted the words, ``naturally 
occurring'' from the identifications of glenoid fossa prosthesis and 
mandibular condyle prosthesis because the standard of care now 
indicates that these devices may now interface not only with naturally 
occurring surfaces but also with artificial surfaces.

III. References

    The following referencees have been placed on display in the 
Dockets Management Branch (address above) and may be seen by interested 
persons between 9 a.m. and 4 p.m., Monday through Friday.
    1. Transcripts of the Dental Products Panel meeting, April 21, 
1989.
    2. Transcripts of the Dental Products Panel meeting, February 
11, 1993.
    3. Fontenot, M. G., and J. N. Kent, ``In-vitro and In-Vivo Wear 
Performance of TMJ Implants,'' abstract, International Association 
of Dental Research, 1991.
    4. Kent, J. N., and M. S. Block, ``Comparison of FEP and UPE 
Glenoid Fossa Prosthesis,'' abstract, International Association of 
Dental Research, 1991.
    5. ``Clinical Information on the Vitek TMJ Interpositional (IPI) 
Implant and the Vitek-Kent (VK) and Vitek-Kent 1 (VK-1) TMJ 
Implants,'' and ``Vitek Patient Notification Program,'' an FDA 
publication, 1991.
    6. Kent, J. N., ``VK Partial and Total Joint Reconstruction,'' 
Current Concepts of TMJ Total Joint Replacement, University of 
Medicine and Dentistry of New Jersey, pp. 1-8, March 1992.
    7. Primely, D., Jr., ``Histological and Radiological Evaluation 
of the ProplastTM-Teflon Interpositional Implant in 
Temporomandibular Joint Reconstruction Following Meniscectomy,'' 
thesis, Master Degree in Oral Maxillofacial Surgery, University of 
Iowa, May 1987.
    8. Westlund, K. J., ``An Evaluation Using Computerized 
Tomography of Clinically Asymptomatic Patients Following 
Meniscectomy and Temporomandibular Joint Reconstruction Using the 
ProplastTM-Teflon Interpositional Implant,'' thesis, Masters 
Degree in Oral and Maxillofacial Surgery, University of Iowa,May 
1989.
    9. Wagner, J. D., and E. L. Mosby, ``Assessment of 
ProplastTM-Teflon Disc Replacements,'' Journal of Oral and 
Maxillofacial Surgery, 48:1140-1144, 1990.
    10. Florine, B. K., et al., ``Tomographic Evaluation of 
Temporomandibular Joints Following Discoplasty or Placement of 
Polytetrafluoroethylene Implants,'' Journal of Oral and 
Maxillofacial Surgery, 48:183-188, 1988.
    11. Heffez, L., et al., ``CT Evaluation of TMJ Disc Replacement 
with a ProplastTM Teflon Laminate,'' Journal of Oral and 
Maxillofacial Surgery, 45:657-665, 1987.
    12. Ryan, D. E., ``Alloplastic Implants in the Temporomandibular 
Joint,'' Oral and Maxillofacial Surgery Clinics of North America, 
1:427, 1989.
    13. Valentine, J. D., ``Light and Electron Microscopic 
Evaluation of ProplastTM II TMJ Disc Implants,'' Journal of 
Oral and Maxillofacial Surgery, 47:689-696, 1989.
    14. Logrotteria, L., et. al., ``Patient with Lymphadenopathy 
Following Temporomandibular Joint Arthroplasty with 
ProplastTM,'' The Hour of Craniomandibular Practice, vol. 4, 
No. 2:172-178, 1986.
    15. Berarduci, J. P., et al., ``Perforation into Middle Cranial 
Fossa as a Sequel to Use of a ProplastTM-Teflon Implant for 
Temporomandibular Joint Reconstruction,'' Journal of Oral and 
Maxillofacial Surgery, 46:496-498, 1990.
    16. Berman, D. N., and S. L. Pronstein, ``Osteo Phytic Reaction 
to a Polytetrafluoroethylene Temporomandibular Joint Implant,'' Oral 
Surgery, Oral Medicine, Oral Pathology (continues the Oral Surgery 
Section of the American Journal of Orthodontics and Oral Surgery), 
69:20-23, 1990.

IV. Environmental Imapct

    The agency has determined under 21 CFR 25.24(e)(2) that this action 
is of a type that does not individually or cumulatively have a 
significant effect on the human environment. Therefore, neither an 
environmental assessment nor an environmental impact statement is 
required.

V. Analysis of Impacts

    FDA has examined the impacts of the final rule under Executive 
Order 12866 and the Regulatory Flexibility Act (Pub. L. 96-54). 
Executive Order 12866 directs agencies to assess all costs and benefits 
of available regulatory alternatives and, when regulation is necessary, 
to select regulatory approaches that maximize net benefits (including 
potential economic, environmental, public health and safety, and other 
advantages; distributive impacts; and equity). The agency believes that 
this final rule is consistent with the regulatory philosophy and 
principles identified in the Executive Order. In addition, the final 
rule is not a significant regulatory action as defined by the Executive 
Order and so is not subject to review under the Executive Order.
    The Regulatory Flexibility Act requires agencies to analyze 
regulatory options that would minimize any significant impact of a rule 
on small entities. Because this rule does not impose any new 
requirements, the agency certifies that the final rule will not have a 
significant economic impact on a substantial number of small entities. 
Therefore, under the Regulatory Flexibility Act, no further analysis is 
required.

List of Subjects in 21 CFR Part 872

    Medical devices.
    Therefore, under the Federal Food, Drug, and Cosmetic Act, and 
under authority delegated to the Commissioner of Food and Drugs, 21 CFR 
part 872 is amended as follows:

PART 872--DENTAL DEVICES

    1. The authority citation for 21 CFR part 872 continues to read as 
follows:

    Authority: Secs. 501, 510, 513, 515, 520, 701 of the Federal 
Food, Drug, and Cosmetic Act (21 U.S.C. 351, 360, 360c, 360e, 360j, 
371).

    2. New Secs. 872.3940, 872.3950, 872.3960, and 872.3970 are added 
to subpart D to read as follows:

Sec. 872.3940  Total temporomandibular joint prosthesis.

    (a) Identification. A total temporomandibular joint prosthesis is a 
device that is intended to be implanted in the human jaw to replace the 
mandibular condyle and augment the glenoid fossa to functionally 
reconstruct the temporomandibular joint.
    (b) Classification. Class III.
    (c) Date PMA or notice of completion of a PDP is required. The 
effective date of the requirement for premarket approval has not been 
established. See Sec. 872.3.

Sec. 872.3950  Glenoid fossa prosthesis.

    (a) Identification. A glenoid fossa prosthesis is a device that is 
intended to be implanted in the temporomandibular joint to augment a 
glenoid fossa or to provide an articulation surface for the head of a 
mandibular condyle.
    (b) Classification. Class III.
    (c) Date PMA or notice of completion of a PDP is required. The 
effective date of the requirement for premarket approval has not been 
established. See Sec. 872.3.

Sec. 872.3960  Mandibular condyle prosthesis.

    (a) Identification. A mandibular condyle prosthesis is a device 
that is intended to be implanted in the human jaw to replace the 
mandibular condyle and to articulate within a glenoid fossa.
    (b) Classification. Class III.
    (c) Date PMA or notice of completion of a PDP is required. The 
effective date of the requirement for premarket approval has not been 
established. See Sec. 872.3.


Sec. 872.3970  Interarticular disc prosthesis (interpositional 
implant).

    (a) Identification. An interarticular disc prosthesis 
(interpositional implant) is a device that is intended to be an 
interface between the natural articulating surface of the mandibular 
condyle and glenoid fossa.
    (b) Classification. Class III.
    (c) Date PMA or notice of completion of a PDP is required. The 
effective date of the requirement for premarket approval hasnot been 
established. See Sec. 872.3.

    Dated: November 25, 1994.
D. B. Burlington,
Director, Center for Devices and Radiological Health.
[FR Doc. 94-31161 Filed 12-19-94; 8:45 am]
BILLING CODE 4160-01-F