Use of the masseter motor nerve in facial animation with free muscle transfer.

Facial paralysis is either congenital or acquired, and of varying severity, which leads to an asymmetrical or absent facial expression. It is an important disability both from the aesthetic and functional points of view. Between 2003 and 2008, at the Department of Maxillofacial Surgery, University of Parma, Italy, 21 patients with facial paralysis had their faces reanimated with a gracilis transplant reinnervated by the masseter motor nerve. All free-muscle transplants survived the transfer, and no flap was lost. Facial symmetry at rest and while smiling was excellent or good in most cases, and we found an appreciable improvement in both speech and oral competence. We consider that the masseter motor nerve is a powerful and reliable donor nerve, which allows us to obtain movement of the commissure and upper lip similar to those of the normal site for degree and direction. There may be a role for the masseter motor nerve in innervation of patients with facial paralysis.