Page 38 - Demo

Chapter 236Total TMJ replacementHaving developed one of the first serial-produced fossa prosthesis in 1963, Christensen also created the first total TMJ prosthesis in 1965 by combining his Vitallium fossa-eminence implant, which was first reported in 1970, with a standardized cast Vitallium ramus component with a PMMA condylar head.(11,12,18) Inspired by Christensen’s fossa prosthesis and Hahn’s ramus prosthesis, Kiehn et al. designed a total TMJ replacement consisting of a Vitallium mandibular fossa plate and a Vitallium ramuscondyle prosthesis in 1974.(11,18) Both components were fitted and fixed using PMMA cement. Burr holes in the mandibular ramus and the lateral part of the glenoid fossa increased the cement contact area between the prosthesis and bone, thus improving retention. However, as previously mentioned, the use of PMMA cement was abandoned, and thus the prosthesis as well. Two years later, Morgan designed a condylar prosthesis to be used in combination with his previously designed fossaeminence prosthesis. The mandibular component consisted of a Vitallium plate that was screwed to the mandible and an acrylic condylar head to articulate with the fossa component.(12,19) In 1984 House, Morgan, et al. (34) (OCEBM LOE IV) published a follow-up study, discussing the results of the implant system. Although 41.7% of the responding patients reported excellent results, fair to poor results were reported by as many as 29.4% of the patients. Momma was the first to make use of a metal-on-metal total TMJ replacement system, using screw fixation, in 1977. Both the mandibular component and fossa of the Protasul were made out of Vitallium. While anterior-posterior movement was possible, movement in other directions was limited.(19) During the same year Kummoona(35) (OCEBM LOE IV) introduced his CoCr metal-on-metal TJR. Similar to the condylar prosthesis of Silver et al.(31), Kummoona’s condylar component was fixated using both an intramedullary stem and PMMA cement. A second significant difference between the prostheses of Momma and Kummoona, other than the materials used, was found in the fossa. The fossa component covered the glenoid fossa, zygomatic arch, and zygomatic process of the temporal bone and was fixed with screws. The key part of the design, a flattened condylar head, was to encourage fibrous tissue penetration across the head of the prosthesis from the joint capsule.(18,19) The idea was that Nikolas de Meurechy NW.indd 36 05-06-2024 10:14