Reuse of the Masseteric Nerve for Dynamic Reanimation in Facial Palsy Patients with Previously Failed One-Stage Dynamic Smile Reanimation.

Abstract

Failed primary dynamic smile reanimation procedures present significant challenges for the patient and surgeon alike. This is particularly true in older patients with a history of previous neck dissection and radiation therapy who underwent previous reconstruction with a free functional muscle transfer innervated with an ipsilateral masseter nerve. The objective of this study was to demonstrate feasibility, describe surgical technique, and assess results of reusing the masseter nerve to reinnervate a new free functional muscle transfer. Patients presenting between 2007 and 2017 to a single center after previously failed dynamic smile reanimation using the masseteric nerve who underwent a salvage dynamic procedure involving reuse of the masseteric nerve were analyzed for demographics, history of radiation therapy or chemotherapy, surgical techniques, and objective measurements using the MEEI Facegram software. The average age was 50 years, the average duration of palsy was 6.2 years, and the average preoperative House-Brackmann score was 6. Causes of palsy included Bell palsy in one, parotid malignancies in two, and a seventh cranial nerve schwannoma in one patient, with two patients requiring radiation therapy preoperatively. Three patients failed to achieve any motion after the first reanimation, and the fourth patient initially achieved excursion; however, because of cancer recurrence and resection of free functional muscle transfer, motion was subsequently lost. Average smile excursion after salvage was 11.32 mm and philtral deviation correction was 1.3 mm. Reusing the masseter nerve for dynamic smile restoration with free functional muscle transfer in previously failed reanimation patients is feasible and may provide successful reanimation. Careful patient evaluation and clear understanding of previous procedures are essential for success. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.