Prosthetic total temporomandibular joint (TMJ) replacement (TJR) is well established in the United Kingdom, with clear guidelines for indications and nationally published outcomes. CAD/CAM technology has made it possible to push the boundaries of custom-made TJR to include extended versions (eTJR), which may replace segmental mandibular defects or defects in the skull base with extended components for the ramus and fossa, respectively. Such prostheses are uncommon, and published reports are restricted to isolated cases and series of cases. We know of no previous attempts to classify such prostheses, and here we suggest a bipartite classification system for use in communications between surgeons and manufacturers based on a review of 19 prostheses provided by one manufacturer (TMJ Concepts, Ventura, CA)
