Efficacy of the "Baby-Sitter" Procedure After Prolonged Denervation

Abstract

This study was undertaken to evaluate whether 40 percent of the hypoglossal nerve, which showed optimal efficacy in restoring orbicularis oculi muscle (OOM) function after different percentages of partial neurectomy in a previous study would be effective after prolonged denervation time. Twenty Sprague-Dawley rats were divided into four groups. In first-stage surgery the left facial nerve of all animals was transected at the level of the stylomastoid foramen and main zygomatic branch. Group A (controls) consisted of animals with only left facial nerves transected (no repair). In Groups B, C, and D the facial nerve was transected and the facial musculature was denervated for a period of 4, 8, and 12 weeks respectively. During a second-stage procedure, a 40 percent neurectomy was performed on the hypoglossal nerve. Subsequently, a nerve transfer was performed by coaptations of a saphenous nerve graft to the neurectomized hypoglossal nerve and the main zygomatic branch of the facial nerve that innervated the OOM. Behavioral analysis of blink reflex, electrophysiology, and axon and motor end-plate counts in Groups B, C, and D showed superior results compared to Group A. There was no statistically significant difference observed among Groups B, C, and D (p > 0.05). Despite the diminished number of axons in the zygomatic branch and motor end-plates in the orbicularis oculi muscle after 12 weeks of denervation, there was still sufficient muscle target recovery to effect some eye closure in all groups except the controls. This study demonstrated in this model that the 40 percent partial neurectomy of the XII to VII component of the "baby-sitter" procedure was effective even after prolonged denervation.

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.…”

Comparison of hemihypoglossal-facial nerve transposition with a cross-facial nerve graft and muscle transplant for the rehabilitation of facial paralysis using the Facial clima method

“…These operations can be classified according to their purpose as static rehabilitation techniques that improve the facial symmetry in rest, and dynamic rehabilitation techniques that restore the normal tone and facial function. There are several surgical options for dynamic rehabilitation of facial paralysis, such as neurorrhaphy of the facial nerve [1], with the interposition of nerve grafts [2], cross-facial nerve grafts (CFNG) [3], nerve transpositions with the hypoglossal nerve [4], CFNG plus hypoglossal nerve as a "babysitter" procedure [5], local muscle transfers such as lengthening temporalis myoplasty [6], and finally free muscle transfers (gracilis [7] or latissimus dorsi [8]). The choice of one or other technique will depend on many factors, among which are the time that has passed since the paralysis set in, the patient's age, the facial morphotype, and the surgeon's preferred technique.…”

Lengthening Temporalis Myoplasty Versus Hypoglossal-Facial Nerve Coaptation in the Surgical Rehabilitation of Facial Palsy

“…Surgical rehabilitation aims at restoring the symmetry of the face not only during rest but also during emotional and voluntary motions such as smiling and eye closure. Different procedures of dynamic reanimation have been attempted, such as nerve transposition with the hypoglossal nerve (1Y6), cross-face nerve graft (7,8) that could be associated to the Bbabysitter[ technique (9), muscle transposition (temporalis, masseter) (10Y13), and free muscle flap (14Y19). Lengthening temporalis myoplasty and hypoglossalYfacial (XIIYVII) coaptation are both popular techniques, although no procedure achieves perfect cosmetic results.…”