B. Cross-face grafting
Although atypical for repair of the nerve, anastomosis of 30-50% of the buccal and zygomatic branches from the unaffected side is used to innervate contralateral paralyzed nerve branches by way of an interposition graft . These healthy nerve branches are sacrificed (theoretically causing minimal deformity on the normal side), with the ultimate goal of restoring symmetry and some mimetic function on the injured side. This potential to gain improvements on the injured side outweighs this minimal negative consequence. Typically this procedure is only chosen if the period of degeneration has been less than 6 months [37-40].
C. Cable grafting
Interpositional facial nerve grafting is used when the proximal and distal ends of the nerve cannot be coapted without tension. Techniques have been developed for grafting anywhere along the length of the facial nerve, from the cerebellopontine angle to the parotid gland. In cases in which less than 10 cm of lengths of nerve graft is used, a contralateral greater auricular nerve graft is harvested . Larger lengths will require sural nerve harvesting.
D. Hypoglossal nerve transfer
The transfer of the hypoglossal nerve is a dependable and effective treatment for situations in which the proximal facial nerve is unavailable but the distal nerve remains anatomically intact. Advantages of this procedure include relatively low degree of technical difficulty and relative short time to movement (usually 4-6 months). The major disadvantage includes donor-site morbidity, specifically ipsilateral paralysis of tongue musculature [41-44].