Restoring Facial Expression And Sensation: A Systematic Review Of Nerve Repair In Face Transplantation

PURPOSE: Since 2005, 50 face transplants have been performed worldwide, demonstrating promising outcomes in restoring facial form, function, and quality of life for patients with severe disfigurement. Desired outcomes include regained speech, facial expression, and sensation, facilitated by coaptation of the facial nerve and branches of the trigeminal nerve. This study examines motor and sensory recovery in face transplant recipients, focusing on nerves coapted and microsurgical techniques used. METHODS: A systematic review was conducted in March 2025 according to PRISMA 2020 guidelines using PubMed, Web of Science, and Scopus. Included studies reported face transplant recipients with documented nerve coaptation and motor or sensory outcomes. Extracted data included nerves coapted, microsurgical technique, recovery timelines, and functional outcomes. For both the coapted and non-coapted groups, the mean rates of recovery (function regained per month on a normalized 0-1 scale) were calculated. A Welch two-sample t-test was conducted to determine statistical significance. RESULTS: The review included 46 studies with 38 unique face transplant recipients. Sensory nerve coaptation was performed in 22 of 38 recipients. Among patients with sensory nerve repair, sensation began on average in 2.9 ± 0.7 months and complete sensation returned on average in 8.0 ± 4.5 months. From the time sensation began, sensation recovered completely with an average rate of 1.1 ± 2.2 fraction of full recovery/month. In patients without sensory nerve repair, sensation began on average in 4.0 ± 1.0 months, with complete recovery on average in 8.7 ± 3.1 months. From the time sensation began, sensation recovered completely with an average rate of 0.6 ± 0.6 fraction of full recovery/month. The differences between coapted and non-coapted were not statistically significant (p=0.6). The facial nerve was reportedly coapted in 30 of 38 patients. Initial motor recovery was observed on average in 5.7 ± 3.3 months, with "reasonable to good" recovery achieved on average in 15.5 ± 7.0 months. From the time motor recovery began, movement recovered completely with an average rate of 0.1 ± 0.05 fraction of full recovery/month. Microsurgical technique was described in 19 patients: all used suture, 10 utilized an interpositional donor nerve graft, 6 added fibrin sealant glue, and 4 placed the nerve over its respective foramina. Of note, there was no statistically significant difference between the start (p=0.97) and completion (p=0.69) of sensation or start (p=0.43) and completion (p=0.98) of motor control when using a nerve graft versus not. There was not enough sensory or motor outcome data reported to compare the other techniques. CONCLUSION: Sensory recovery after facial transplantation occurs earlier and progresses more rapidly than motor recovery. Complete sensory return occurred within two years, even without formal nerve repair, suggesting a role for spontaneous regeneration. Although nerve coaptation may influence recovery rates, variability across patients and sample size limits firm conclusions. Despite heterogeneity in functional and sensory outcome reporting, this review highlights current practices in nerve coaptation and underscores the need for standardized surgical reporting and longitudinal outcomes in face transplant recipients. *Source: https://ps-rc.org/meeting/Program/2026/EP58.cgi*