(82) Management of Temporomandibular Joint Ankylosis Using Total Joint Replacement: A 20-Year Institutional Experience

Abstract: Temporomandibular joint (TMJ) ankylosis is a debilitating condition characterized by limited mandibular movement resulting from fibrous or bony fusion of the joint structures. This condition significantly impairs essential functions such as mastication, speech, and oral hygiene, and in some cases, may lead to facial asymmetry and psychological distress. Surgical management with alloplastic total joint replacement (TJR) offers an effective solution in severe or recurrent cases. This study aims to evaluate the long-term functional and clinical outcomes of patients with TMJ ankylosis treated with TJR at a single tertiary care center over a 20-year period.

We conducted a retrospective analysis of 91 patients diagnosed with TMJ ankylosis who underwent alloplastic joint replacement between 2000 and 2023. Data were extracted from a departmental registry and operative notes, including patient demographics, surgical laterality (unilateral or bilateral), implant type, maximum interincisal opening (MIO) before and after surgery, duration of follow-up, postoperative complications, and the need for revision surgery. Pain levels were assessed using the visual analogue scale (VAS).

The mean age at surgery was 43.4 years. Most cases (87%) involved bilateral joint replacement, and 60% of cases used Biomet custom prostheses. The average preoperative MIO was 13 mm, which improved to 32 mm postoperatively, reflecting a mean gain of 16.6 mm. Postoperative VAS scores indicated a near-complete resolution of pain in the majority of patients, with most reporting 0/10 pain levels at follow-up. The mean follow-up duration was approximately 172 months, with several patients followed for over 20 years. Reankylosis or significant heterotopic bone formation requiring revision was observed in 17% of patients. Facial nerve weakness was documented in a minority of cases, but most complications were transient or managed conservatively.

These findings suggest that TJR provides consistent and durable improvements in jaw mobility and pain relief for patients suffering from TMJ ankylosis. The results also emphasize the importance of long-term follow-up to monitor for delayed complications such as reankylosis or hardware-related issues. Bilateral reconstruction was often necessary, and custom prosthetic designs appeared to be the most frequently utilized and effective treatment modality in this complex patient population.

This study represents one of the largest long-term cohorts of TMJ ankylosis patients treated with TJR. It underscores the role of surgical intervention in restoring function and quality of life and highlights the importance of implant selection, careful operative technique, and sustained follow-up in optimizing outcomes. Further research comparing different implant systems and perioperative protocols may help refine future treatment strategies.

1. Mercuri LG. Alloplastic temporomandibular joint replacement: rationale for the use of custom devices. Int J Oral Maxillofac Surg. 2012 Sep;41(9):1033-40. doi: 10.1016/j.ijom.2012.05.032. Epub 2012 Jul 4. PMID: 22771166.
2. Boyo A, McKay J, Lebovic G, Psutka DJ. Temporomandibular joint total replacement using the Zimmer Biomet Microfixation patient-matched prosthesis results in reduced pain and improved function. Oral Surg Oral Med Oral Pathol Oral Radiol. 2019 Dec;128(6):572-580. doi: 10.1016/j.oooo.2019.04.012. Epub 2019 Apr 26. PMID: 31227450.