Facial Reanimation Using the Masseter-to-Facial Nerve Transfer

Abstract

The masseter-to-facial nerve transfer is an effective method for reanimation of the midface and perioral region in a select group of facial paralysis patients. The technique is advocated for its limited donor-site morbidity, avoidance of interposition nerve grafts, and potential for cerebral adaptation, producing a strong, potentially effortless smile.

Contemporary Solutions for the Treatment of Facial Nerve Paralysis

“…Each donor nerve varies with respect to its functional deficit and morbidity, motor power, and synergy with facial expression. [12][13][14][15] Over the past decade, anatomy and physiology knowledge of the trigeminal motor nerve branch to the masseter muscle has increased, [16][17][18][19][20][21] with masseter-to-facial nerve transfers (fifth to seventh cranial nerve) being our technique of choice for facial reanimation (Reference 17 Level of Evidence: Therapeutic, IV). This regional (subunit) approach to rehabilitation of the paralyzed face allows "babysitting" of paralyzed mimetic muscles of the midface and perioral region (Fig.…”

A Contemporary Approach to Facial Reanimation

“…A V to VII transfer using either the masseteric nerve 39 or deep temporal branches is increasing in popularity secondary to minimal donor-site morbidity, ease of volitional triggering compared with hypoglossal transfer, and superior commissure excursion compared with CFNG due to higher motor neuron counts. 40 The benefits of CFNG for smile over other nerve transfer techniques include reanimation of spontaneous (emotive) smile in addition to volitional smile, improved resting firing tone, and absence of facial twitching with mastication that may be seen with V to VII transfers. Disadvantages of CFNG include smile with less commissure excursion, on average, than that obtained using other nerve transfers (eg, V-VII) due to fewer available motor axons 40 ; a risk of causing undesired weakness in healthy hemiface, ocular synkinesis, or blink-triggered activation (because some fibers to the orbicularis oculi are often present in the donor midface branch); the typical need for a staged second procedure; and increased risk of donor-site morbidity.…”

“…40 The benefits of CFNG for smile over other nerve transfer techniques include reanimation of spontaneous (emotive) smile in addition to volitional smile, improved resting firing tone, and absence of facial twitching with mastication that may be seen with V to VII transfers. Disadvantages of CFNG include smile with less commissure excursion, on average, than that obtained using other nerve transfers (eg, V-VII) due to fewer available motor axons 40 ; a risk of causing undesired weakness in healthy hemiface, ocular synkinesis, or blink-triggered activation (because some fibers to the orbicularis oculi are often present in the donor midface branch); the typical need for a staged second procedure; and increased risk of donor-site morbidity. The CFNG procedure begins with elevation of a sub-SMAS flap over the parotidomasseteric fascia using a preauricular incision on the nonparalyzed side.…”

Facial Reanimation with Gracilis Muscle Transfer Neurotized to Cross-Facial Nerve Graft versus Masseteric Nerve

“…Not surprisingly, a considerable number of studies have been published regarding its anatomy and topographic landmarks to aid in its harvest for facial reanimation. 18,25,26 Moreover, the motor nerve to the masseter has been used not only to innervate a free muscle transfer but also as a nerve transposition and "babysitter" following the concept described by Mersa et al [27][28][29] One of the main advantages attributed to this nerve is its strength of pull, which allows, on the one hand, reanimation of strong smiles, and on the other hand, acquisition of very good symmetry at rest and when smiling. 10,30 This particularity is very likely explained by the high axonal load that can be delivered with this nerve in comparison with others, such as cross-facial nerve grafting.…”