Validation of an extended total joint replacement (eTJR) classification system for the temporomandibular joint (TMJ).

The aim of this paper was to validate a previously described classification system for extended total joint replacements (eTJRs) of the temporomandibular joint (TMJ). We engaged an expert panel to review 60 TMJ eTJR devices and classify them using the system, examining their responses for inter-rater agreement and concordance with the correct response as determined by the authors. Conger's kappa was 0.34 for the fossa (F) component sub-classification and 0.67 for the mandibular (M) component. A posthoc analysis showed improvements in inter-rater agreement for a modified three-tiered F sub-classification system which is suggested in a revised version of the TMJ eTJR classification system

Review of emerging temporomandibular joint total joint replacement systems.

Total temporomandibular joint (TMJ) replacement has been documented as a viable option for the management of end-stage TMJ disease, but data on long-term outcomes have been reported for only two established systems: TMJ Concepts, and Zimmer Biomet. Other devices are now emerging globally, but reports of preclinical laboratory and clinical outcomes are limited. We retrieved information on the design, material composition, preclinical laboratory tests, regulatory status, and clinical outcomes of new TMJ replacement systems from PubMed and Google, and from personal correspondence with surgeons worldwide. Fifteen countries have developed, or are developing, 27 TMJ replacement systems, of which 21 are custom-designed, but to date, only four have been given regulatory approval. All the devices are designed to have both a skull-based glenoid fossa component and a mandibular ramus or condyle, and 22/27 are similar to the designs of the two established systems. Twenty-one devices use an ultra-high-molecular-weight polyethylene (UHMWPE) fossa-bearing surface, and 10 have a titanium alloy condyle. Nineteen manufacturers report that a titanium alloy is used for the ramus portion of the condyle/ramus component. Preclinical laboratory tests on 12 of the systems have been reported but, to our knowledge, no outcomes have yet been reported on nine of the 27 reviewed. Not all systems are equal in terms of design, material composition, preclinical laboratory testing, manufacturing methods, regulatory status, and reports of clinical outcomes