Innervation options for gracilis free muscle transfer in facial reanimation

Gracilis free muscle transfer (GFMT) is considered the gold standard in dynamic smile reanimation in patients with long-standing facial paralysis. There are multiple motor nerves in the head and neck that can be used to provide innervation to the GFMT, either alone or in combination. In this article, we review the literature about these donor nerve options and discuss their advantages and disadvantages in terms of smile excursion, spontaneity, reliability, and timing. Furthermore, we discuss the use of multiple donor nerve sources in dually-innervated GFMT and areas for future investigation.