Challenges in Managing Post-Radiation TMJ Pseudoankylosis

Abstract

This study demonstrates the outcomes of post-radiation temporomandibular joint (TMJ) pseudoankylosis management and its challenges. A rare maxillary squamous cell carcinoma was treated with subtotal maxillary resection. Subsequent radiation therapy, failure of free flap reconstruction, and 1 year of jaw hypomobility instigated TMJ pseudoankylosis with a maximal mouth opening (MMO) of less than 5 mm. Bilateral coronoidectomy was done simultaneously with maxillary reconstruction, followed up with buccal fibrosis release and extensive jaw exercises. At 16 months of follow-up, the patient’s MMO was 20 mm. Although bilateral coronoidectomy released the attachment of the atrophic temporalis muscle, it did not correct the other causes of trismus, specifically the progressive fibrosis of masticatory muscles, loss of elasticity of the TMJ ligaments, and other soft tissue abnormalities. Radiotherapy-induced–trismus refractory to physical exercise may require further management to achieve satisfactory MMO.