D32. Long-term Outcomes Comparing Between Single Versus Dual Innervated Free Functional Gracilis Muscle Transfer in Longstanding Facial Paralysis Patients

Abstract

PURPOSE: Comparing long-term outcomes between single versus dual innervated free functional muscle transfer (FFMT) in patients with longstanding facial paralysis. METHODS: Included were longstanding flaccid facial palsy patients between 2013-2020 treated with a FFMT innervated either by a nerve-to-masseter (single innervation group - SIG) or by nerve-to-masseter and cross-facial-nerve graft (dual innervation group - DIG). One year minimal follow up was required. Outcome measures, based on professional standardized photos, included excursion, smile angle, teeth exposure in repose and in closed and open teeth smile preoperatively, and at 3 months, 1-year, 3-years, and 5-years postoperatively as available. Emotrics software (Massachusetts Eye and Ear Infirmary, Boston, MA) and ImageJ (Rasband, W.S., ImageJ, U.S, National Institutes of Health, Bethesda, MD) were used for all measurements. Between group and within group longitudinal comparisons at each timepoint were analyzed using Wilcoxon Two-Sample Testing. RESULTS: Preoperatively (SIG=33, DIG=14) and 3-months-postoperatively (SIG=28, DIG=14) parameters were similar between groups. At one-year (SIG=32, DIG=13) modiolus angle in repose was increased in the DIG (SIG=99.245 degrees, DIG=105.91 degrees, p=0.0146). At three years (SIG=24, DIG=13),significance was found in modiolus position (SIG=26.42mm, DIG=31.51mm, p=0.0001), commissure excursion with open mouth smile (SIG=31.21mm, DIG=30.915mm, p=0.0005), modiolus angle in repose (SIG=98.14 degrees, DIG=105.06 degrees, p=0.0344), and modiolus angle with open mouth smile(SIG=111.025 degrees, DIG=99.47 degrees, p=0.0001). Midface parameters at 5-year follow up (SIG=14, DIG=6) were similar between groups. CONCLUSION: Dually innervated FFMT did not reveal any clear long-term measurable benefit for midface reanimation albeit synchrony and spontaneity were not assessed.