Masseteric Nerve as "Baby Sitter" Procedure in Incomplete Facial Paralysis.

Supplemental Digital Content is available in the text.

Sir:

The author presents a case of an incomplete facial paralysis, which was treated with masseteric to selective zygomatic branch transfer combined with cross-facial nerve grafting. The masseteric nerve was used as “baby sitter”[1] in this procedure.

A 69-year-old man who underwent surgical removal of the intraparotid facial nerve schwannoma at another hospital was referred to our hospital. He had had incomplete facial paralysis for 13 months due to damage of the upper trunk of the facial nerve during the surgery. He showed drooping of his oral commissure and lower lid ectropion; however, the resting brow position remained normal and the lower lip depressor remained functioning (Fig. 1). In the first stage, 2 zygomatic branches that are responsible for smiling were identified by electrostimulation into the parotid gland. The masseteric nerve was anastomosed to 1 of these in an end-to-end fashion. Using the same procedure, a sural nerve graft was connected to the zygomatic branch of the unaffected hemiface that is responsible for smiling. The distal end of the sural nerve graft was left in the paralyzed side. The patient was able to produce voluntary smiling while biting in 3 months without deteriorating preoperative mimetic function. After confirming the existence of Tinel sign in the paralyzed side, the end of the cross-facial nerve graft was connected to 1 of the peripheral zygomatic branches that are located anterior to the parotid gland in an end-to-end fashion, so that previously performed masseteric zygomatic branch anastomosis remained undisturbed. With this procedure, an attempt was made to produce a spontaneous smile with the cross-facial nerve graft. After 12 months from the second procedure, the patient showed good symmetry at rest (Fig. 2), spontaneous smiling, and oral commissure elevation with biting (see Supplemental Digital Content 1, which shows pre- and postoperative facial appearances, http://links.lww.com/PRSGO/A187).

Fig. 1.

Preoperative facial appearance. Reprinted with permission from Yoshioka N. Masseteric–to-facial nerve transfer combined with cross-facial nerve grafting for reanimation of incomplete facial paralysis: a case report. The Japanese J of Plastic Surgery. 2015;58:431–437.

Fig. 2.

The facial appearance 18 months after secondary neurorrhaphy and additional upper and lower blepharoplasty. Reprinted with permission from Yoshioka N. Masseteric–to-facial nerve transfer combined with cross-facial nerve grafting for reanimation of incomplete facial paralysis: a case report. The Japanese J of Plastic Surgery. 2015;58:431–437.

There are several advantages in using the masseteric nerve rather than the hypoglossal nerve, including the proximity of the masseteric nerve to the facial nerve and the fact that it is associated with negligible donor site morbidity and a rapid recovery. Although effortless spontaneous smiles due to cerebral adaptation have been reported by some authors who used the masseteric nerve for facial reanimation,[2] such adaptation does not occur in all patients, especially in elderly patients. There are several articles which describe the use of masseteric nerve transfer combined with cross-facial nerve grafting to treat facial paralysis.[2,3] However, the cross-facial nerve grafting was used for eyelid animation, and the masseteric nerve was the only nerve used for smiling in those procedures. Our technique is similar to that described in a case report by Hontanilla et al,[4] in which they applied masseteric nerve as a “baby sitter” procedure in complete facial paralysis. Although the main zygomatic branch can be used without deteriorating any mimetic function in complete paralysis, incomplete paralysis needs to restore motion without damaging the remaining function. In conclusion, incomplete facial paralysis with prominent midfacial asymmetry, which still has functioning mimetic muscles, seems to be the best candidate for masseteric to selective zygomatic branch transfer combined with cross- facial nerve grafting.

DISCLOSURE

The author has no financial interest to declare in relation to the content of this article. The Article Processing Charge was paid for by the author.

PATIENT CONSENT

The patient provided written consent for the use of his image.