Abstract:

In the long-term performance ofthe temporomaridibular joint (TMJ) implant, wear must be considered. Thus retrieved and laboratory test implants were examined both optically and in a scanning electron microscope (SEM). In laboratory testing, the volumetric wear of metal-on-metal was about an order of magnitude less than that of acrylic-on-metal TMJ implants. This metal-on-metal wear was also about half of that reported in the literature for a laboratory test of polyethylene-on-metal TMJ implants, The retrieved TMJ implants showed some abrasive wear occurred during multi-directional articulation with smaller wear zones for the metal-on-metal compared to the acrylic-on-metal configuration. Further efforts to characterize and minimize wear were recommended as prudent in the continuing development of TMJ arthroplasty.

Authors:

Albert L. Lippincott III, B.C.E., Judith M. Dowling, D. Phil, C.Eng., John B. Medley, Ph.D., P.Eng., Robert W. Christensen, D.D.S.

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Abstract:

The increase in patients with multiply operated temporomandibular joints (TMJs) has led to an increase in associated complications that respond unfavorably to additional attempts at correction. These can present as ankylosis and/or heterotopic bone formation. This has been recognized in other joint reconstruction, to a much more significant degree, and related to decreased vascularity, increased fibrosis and scarring, and decreased cellularity of the tissue in the joint space following multiple surgical procedures. Attempted correction of this problem can often lead to an increase in the etiology and to recurrence of the bone formation in spite of its debridement. Correction in other joints has evolved to include the use of thorough debridement of the heterotopic bone, alloplastic joint reconstruction, autologous fat grafting, and use of NSAIDs and low-dose radiatíon to decreaserecurrence.

Authors:

William R. Garrett, D.D.S., Patrick A. Abbey, D.M.D.

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