Page 33 - Demo

Historical evolution of the TMJ prosthesis312when Smith and Robinson (OCEBM LOE IV) developed stainless steel custom-made bent plates for gap arthroplasty.(11,12,19,21) Compared to the previous plethora of gap inserts, this new concept was revolutionary because their approach initially focused on joint dynamics. By bending the plate, a pivoting point for the mandible was created, allowing better movement of the lower jaw.(18,19) This concept brought a new stimulus to the field of TMJ prosthesis design, and 3 years later, Robinson developed a ‘false’ fossa implant out of stainless steel that covered the glenoid fossa and articular eminence and was fixed to the zygomatic arch using two screws. This design was meant to improve implant and joint stability, and as such, achieved success and longevity.(12,18,19) Due to the box-like design of the fossa, the posterior slope of the articular eminence was absent, allowing for increased forward movement of the mandible.(19) In 1963, Christensen, inspired by Robinson’s idea to create a fossa prosthesis, created a 0.5-mm Vitallium (a cobalt-chromium (CoCr) alloy) plate covering the fossa and articular eminence.(11,12,18,19) Christensen’s plate incorporated screw holes over the zygomatic arch and lateral articular tubercle.(19) A portfolio of initially 20, and later 33 and 44, different templates was produced to assist the surgeon in selecting the ‘best fit’ stock implant. Not only was this the first approach that allowed the surgeon to select the best fitting prosthesis without having to worry about peri-operative reshaping of bony structures, it was also the first interpositioning prosthesis used on a more significant scale, and it is still used today.(18–20) In 1964, despite previously reported negative outcomes, Hellinger made use of tantalum foil. While results were not noteworthy, Hellinger left a mark on the history of the TMJ implantology by being the first to consider physical therapy as a keystone component of rehabilitation.(11) In 1965, Morgan made further modifications to Christensen’s original design and limited coverage to the articular eminence, providing five different stock implants. As the implant was only meant to be used in cases of osteoarthrosis and arthritis, the risk of recurring ankylosis due to covering only the articular eminence instead of the entire fossa was minimal.(18,19) Nikolas de Meurechy NW.indd 31 05-06-2024 10:14