Temporomandibular joint disorders: artificial joint replacements and future research needs

Temporomandibular disorders (TMD) affect a significant section of the American population. According to the National Institutes of Health (NIH), an estimated 3% to 5% of Americans suffer from temporomandibular disorders. Majority of TMDs can be treated by conservative methods, albeit surgical interventions are indicated for some pathological/clinical conditions (according to the American Association of Temporomandibular Joint Surgeons). A distinction can be made between the TMD and the TMJ disease/dysfunction. In the case of TMD, it most correctly relates to a neuromuscular type of problem in the general area of the Temporomandibular Joint (TMJ), but may not intrinsically be related to the TM joint itself. However, TMJ disease/dysfunction relates to a true joint type of pathology, which ultimately may lead to the use of either a partial or a total joint reconstruction. Degeneration of the meniscus and the actual bony portions of the joint is often seen in cases of true TMJ pathology. The use of custom made or predesigned partial and/or total artificial TMJ replacement remains one of the surgical alternatives for treating various TMJ diseases when other conservative treatments fail. The purpose of this article is to provide an overview of currently existing TMJ implants and to discuss relevant issues, including some of the challenges and current needs facing TMJ research. Additionally, this article describes some of the currently available TMJ surgical procedures, the use of autografts and alloplastic materials (with primary emphasis on TMJ implants) for TMJ reconstruction, and some suggestions for future research. Past incidents of clinical failures of TMJ implants have been attributed to several reasons. The important factors that are responsible for the past failures include lack of a sound scientific approach and inadequate basic research to study the underlying causes for pathologies and their remedies of the TMJ. All these previously mentioned concerns have prompted current biomedical researchers to address many overlooked issues in relation to studying temporomandibular disorders and TMJ implants. Future research should be aimed toward addressing TMJ problems with a multidisciplinary approach, emphasizing simultaneous involvement from clinical (i.e., dentists and physicians) and nonclinical personnel (i.e., oral biologists, bioengineers, biostatisticians, physiotherapists, and pain management specialists).