Temporomandibular joint alloplastic replacement failure

Abstract

Temporomandibular joint disorders are common, with alloplastic temporomandibular joint replacement (TMJR) being one method of addressing chronic pain and movement limitations that cannot otherwise be managed. Despite this, TMJR has known complications that can lead to failure. We present our experience of managing these cases and review the current evidence on the management and outcomes of alloplastic TMJR failures. Until 2015 our unit regularly used Dundee full metal prostheses, and encountered multiple issues such as infection, heterotopic bone formation, and progression of osteoarthritis beneath the condylar element. We also present our experience with other standard TMJR implants. One common cause of failure we observed is improper placement of a prosthesis due to poor technique, for instance, placement of the fossa implant too close to the ear canal can cause unresolved postoperative pain. There is no consensus on the management of TMJR, but non-surgical measures are preferred initially and surgical intervention is reserved for later stages. Recently our unit has managed numerous failure cases, employing a multidisciplinary approach combined with thorough preoperative planning and postoperative care, which has proven effective in reducing complications and improving outcomes. Based on our experience, we do not recommend the use of Dundee full metal prostheses for TMJR. Appropriate training in the placement of contemporary implants remains crucial. Suboptimal alignment of the implant in some cases does not need surgical intervention, but surgical management is justifiable in cases of persistent symptoms and functional limitations. When placing stock implants or designing a custom-made implant for an adult, we recommend that the posterior edge of the fossa component is at least 3 mm away from the bone of the ear canal.