Contemporary techniques for nerve transfer in facial reanimation

Nerve transfer procedures have the potential to restore innervation and function to the native facial musculature. This review summarizes the existing literature on facial nerve injury, regeneration, and reinnervation techniques with a focus on nerve transfer and its various options. Utilizing nerve transfer as early as possible, and ideally during the first 12 months of paralysis, is recommended. Prolonged paralysis is frequently not amenable to nerve transfer. The masseteric nerve provides excellent smile restoration after coapation to midfacial nerve branches with minimal morbidity. Several modifications to the hypoglossal nerve transfer have been described to limit its morbidity in speech and swallowing. The cross facial nerve, while appealing and able to achieve a true spontaneous smile, has limitations in terms of axonal load, time to reinnervation, unpredictable outcomes, and utility in older patients, who have less regenerative potential. Finally, there are exciting new developments in the field, combining reanimation techniques to harness advantages of various donor nerves, and research in peripheral nerve regeneration