Nerve transfers to the facial nerve

Nerve transfers to the facial nerve are utilized in acute and subacute facial paralysis patients with intact facial mimetic musculature where the proximal facial nerve cannot be directly repaired. Denervation time of the facial mimetic musculature should generally not have exceeded 18 months. Several non-facial donor nerves can be used, but currently the masseteric nerve is the preferred donor nerve because rapid reinnervation from the masseteric to facial nerve transfer salvages the facial mimetic musculature and provides voluntary motions with negligible donor-site morbidity. However, nerve transfers using non-facial donor nerves cannot be relied upon to consistently reestablish tone, spontaneity, or synchrony. Therefore, cross-facial nerve grafts as an adjunct to masseteric to facial nerve transfer is often used to theoretically optimize the chance of improved tone, and perhaps even synchroneity, although no strong data currently exists to support this. This book chapter is a review of nerve transfers to the facial nerve covering the goals, indications, and rationale behind these procedures. Further, we describe technical aspects of masseteric to facial nerve transfer as well as adjunct cross-facial nerve grafting.