Page 45 - Demo

Historical evolution of the TMJ prosthesis432with a lower wear resistance will undergo wear and develop wear debris. As a result, the implant will have a shortened total life span and the wear debris formed can possibly result in an inflammatory or allergic reaction.(52–54) Third, the materials must be biocompatible. When this is not the case, adverse reactions such as foreign body giant cell reactions (FBGCR) or metallosis can be seen.(53,55)A more in-depth discussion of these critical biomaterial properties can be found several excellent articles.(56–59) This paper will focus on the more significant materials that have left their mark on the history of the TMJ prosthesis.Earliest materialsSome of the earliest materials used for the TMJ prosthesis were wood (Carnochan(10)) in 1840, ivory (Gluck(24)) in 1890, and tantalum (Eggers(16) and Goodsell(17)) in 1946-1947. Although there are no other reports of wood being used in the TMJ, several animal studies evaluated wood as a potential biomaterial. Kristen et al.(60) implanted alcohol pretreated ash wood into the dorsal part of the calcaneus of rabbits in 1979, and on explantation noticed soft tissue growth of the Achilles tendon as well as bony ingrowth into the pores, had occurred. Gross and Ezerietis implanted juniper wood femur prostheses into rabbits.(61) Juniper wood was chosen because of its stiffness that approaches that of bone and its porous structure allowing for bony ingrowth. It also releases a natural oil that prevents infection. Before implantation, the wood was treated by placement in boiling water for 10 minutes. During the 3 year follow-up no foreign body cell reaction was found, and no signs of hindrance due to the prosthesis were observed in the rabbits. The authors concluded that the bone showed ingrowth into the wood and that the implant was capable of withstanding functional forces. While these studies might indicate that certain types of wood could be suitable for implantation after being treated before implantation, no human in vivo studies have ever been undertaken, thus the possibility of success is impossible to predict. Furthermore, it would be safe to assume that Carnochan(10) was unaware of these essential factors. Since 1840, there have been no reports of the use of wood as an interpositioning material in the TMJ. Nikolas de Meurechy NW.indd 43 05-06-2024 10:14