Cross-face Graft Research Articles

A Rapid Protocol for Intraoperative Assessment of Peripheral Nerve Myelinated Axon Count and Its Application to Cross-Facial Nerve Grafting.

Donor nerve myelinated axon counts correlate with functional outcomes in reanimation procedures; however, there exists no reliable means for their intraoperative quantification. In this article, the authors report a novel protocol for rapid quantification of myelinated axons from frozen sections, and demonstrate its applicability to surgical practice. The impact of various fixation and FluoroMyelin Red staining strategies on resolved myelin sheath morphology from cryosections of rat and rabbit femoral and sciatic nerves was assessed. A protocol comprising fresh cryosection and rapid staining was developed, and histomorphometric results were compared against conventional osmium-postfixed, resin-embedded, toluidine blue-stained sections of rat sciatic nerve. The rapid protocol was applied for intraoperative quantification of donor nerve myelinated axon count in a cross-facial nerve grafting procedure. Resolution of myelinated axon morphology suitable for counting was realized within 10 minutes of tissue harvest. Although mean myelinated axon diameter appeared larger using the rapid fresh-frozen as compared to conventional nerve processing techniques (mean ± SD; rapid, 9.25 ± 0.62 μm; conventional, 6.05 ± 0.71 μm; p < 0.001), no difference in axon counts was observed on high-power fields (rapid, 429.42 ± 49.32; conventional, 460.32 ± 69.96; p = 0.277). Whole nerve myelinated axon counts using the rapid protocol herein (8435.12 ± 1329.72) were similar to prior reports using conventional osmium processing of rat sciatic nerve. A rapid protocol for quantification of myelinated axon counts from peripheral nerves using widely available equipment and techniques has been described, rendering possible intraoperative assessment of donor nerve suitability for reanimation.

Anatomical study of the zygomatic and buccal branches of the facial nerve: Application to facial reanimation procedures.

The facial nerve is responsible for any facial expression channeling human emotions. Facial paralysis causes asymmetry, lagophthalmus, oral incontinence, and social limitations. Facial dynamics may be re-established with cross-face-nerve-grafts (CFNG). Our aim was to reappraise the zygomaticobuccal branch system relevant for facial reanimation surgery with respect to anastomoses and crossings. Dissection was performed on 106 facial halves of 53 fresh frozen cadavers. Study endpoints were quantity and relative thickness of branches, correlation to "Zuker's point", interconnection patterns and crossings. Level I and level II branches were classified as relevant for CFNG. Anastomoses and fusion patterns were assessed in both levels. The zygomatic branch showed 2.98 ± 0.86 (range 2-5) twigs at level II and the buccal branch 3.45 ± 0.96 (range 2-5), respectively. In the zygomatic system a single dominant branch was present in 50%, two co-dominant branches in 9% and three in 1%. In 66% of cases a single dominant buccal twig, two co-dominant in 12.6%, and three in 1% of cases were detected. The most inferior zygomatic branch was the most dominant branch (P = 0.003). Using Zuker's point, a facial nerve branch was found within 5 mm in all facial halves. Fusions were detected in 80% of specimens. Two different types of fusion patterns could be identified. Undercrossing of branches was found in 24% at levels I and II. Our study describes facial nerve branch systems relevant for facial reanimation surgery in a three-dimensional relationship of branches to each other. Clin. Anat. 32:480-488, 2019. © 2019 Wiley Periodicals, Inc.

Restoration of V2 and V3 trigeminal-distribution cutaneous sensation with cross-face nerve grafts

Restoration of V2 and V3 trigeminal-distribution cutaneous sensation with cross-face nerve grafts

Blink Restoration in Long-standing Facial Paralysis: Use of Free Neurovascular Platysma Transfer.

Since 2004, microneurovascular platysma transfer has been used for dynamic eye closure in long-standing facial palsy. The idea was initially presented by Lee and Terzis in 1984 but abandoned owing to its transfer difficulty. This muscle transfer allows forceful closure and blink restoration. This study included 24 patients operated between 2004 and 2014 for long-standing facial palsy. In the first step of the procedure, a cross-facial nerve graft was employed to transfer the motor nerve fibers from the normal side to the paralyzed side responsible for eye closure. Simultaneously, a dynamic reanimation of the mouth was conducted. After 9 months, a 4 × 9-cm platysma was transferred on its neurovascular pedicle. Revascularization was performed on the temporal vessels. Nerve coaptation between the cross-facial nerve graft and motor nerve of the platysma was also performed. Twenty-one (88%) newly reconstructed orbicularis oculis displayed a good to excellent function. In 62% of the patients, a natural appearance and closure of the previously paralyzed eye and a return of spontaneous blinking were observed. Compared with classical techniques (eg, gold weight implantation and temporalis transfer), platysma transfer is the only feasible method of restoring eye closure because of its special architecture and fiber-type distribution.

Per-oral cross-facial sural nerve graft for facial reanimation

BackgroundCross-facial nerve graft is considered the treatment of choice for facial reanimation in patients with unilateral facial palsy caused by central facial nerve damage. In most cases, a traditional parotidectomy skin incision is used to locate the buccal and zygomatic branches of the facial nerve.MethodsIn this study, cross-facial nerve graft with the sural nerve was planned for three patients with facial palsy through an intraoral approach.ResultsAn incision was made on the buccal cheek mucosa, and the dissection was performed to locate the buccal branch of the facial nerve. The parotid papillae and parotid duct were used as anatomic landmarks to locate the buccal branch.ConclusionsThe intraoral approach is more advantageous than the conventional extraoral approach because of clear anatomic marker (parotid papilla), invisible postoperative scar, reduced tissue damage from dissection, and reduced operating time.

Differential Reanimation of the Midface and Lower Face Using the Masseteric and Hypoglossal Nerves for Facial Paralysis

Hypoglossal nerve transfer is frequently employed to reanimate the paralyzed facial muscles after irreversible proximal facial nerve injury. However, it can cause significant postoperative synkinesis because it involves the reinnervation of the whole mimetic musculature using a single motor source. To describe our experience with differential reanimation of the midface and lower face using separate motor sources in patients with short-term facial paralysis after brain surgery. Seven patients underwent combined nerve transfer (the masseteric nerve to the zygomatic branch and the hypoglossal nerve to the cervicofacial division of the facial nerve) and cross-facial nerve grafting with the aim of achieving a spontaneous smile. The median duration of paralysis before surgery was 7 mo and follow-up ranged from 7 to 31 mo (mean: 18 mo). For evaluation, both physical examination and video analysis were performed. In all patients, reanimation of both the midface and the lower face was successful. A nearly symmetrical resting lip was achieved in all patients, and they were able to voluntarily elevate the corners of their mouths without visible synkinesis and to close their eyes while biting. No patient experienced impairment of masticatory function or tongue atrophy. Differential reanimation of the midface and lower face with the masseteric and hypoglossal nerves is an alternative method that helps to minimize synkinetic mass movement and morbidity at the donor site.

Descriptive study and functional results of smile reanimation surgery in patients with facial palsy with gracilis flap in a tertiary hospital

Surgery in facial palsy aims to restore the face's symmetry in rest as well as reanimation of the smile. Gracilis flap is a therapeutic option for patients with long-term facial palsy. Our objective is to describe evolution and functional results of patients treated surgically through gracilis transposition. 27 patients with chronic (> 12 months) unilateral facial palsy were treated with gracilis transposition to reanimate smile. Demographic information such as age, gender and personal history was gathered, as well as onset of facial palsy, affected side, etiology, date and kind of surgery, complications and initiation of movement. Functional results were evaluated with the Facial Disability Index and the smile item on the Sunnybrook Scale. Mean age was 50 years old and a slight prevalence of women over men and right-sided palsy over left was observed. Most prevalent etiology was iatrogenic after acoustic neuroma surgery (33.3%). Fifty-nine percent of palsies were less than 5 years old in evolution. Donor nerve most frequently used was the masseter (48%), followed by the cross-face sural nerve graft with masseter babysitter (33.4%) and lastly, cross-face nerve graft (18.6%). Four patients required a second reanimation surgery. Most common complication was scar retraction at the angle of the mouth. Majority of patients initiated smile around 2–4 months after surgery, being a complete or almost complete movement in 66.6% of patients. Facial Disability Index Global Score was less than 100/200 in 20% of patients and more than 150/200 in 44% of them. Functional results were good in more than half the patients, with mild-moderate facial disability. There is a tendency to associate the use of masseter donor with better smile movements and facial disability indexes, even though results are not statistically significant was scar retraction at the angle of the mouth.

Mixed facial reanimation technique to treat paralysis in medium-term cases

Recent facial paralyses, in which fibrillations of the mimetic muscles are still detectable by electromyography (EMG), allow facial reanimation based on giving new neural stimuli to musculature. However, if more time has elapsed, mimetic muscles can undergo irreversible atrophy, and providing a new neural stimulus is simply not effective. In these cases function is provided by transferring free flaps into the face or transposing masticatory muscles to reinstitute major movements, such as eyelid closure and smiling.In a small number of cases, patients affected by paralysis are referred late — more than 18 months after onset. In these cases, reinnervating the musculature carries a high risk of failure because some or all of the mimetic muscles may atrophy irreversibly while axonal ingrowth is taking place. A mixed reanimation technique to address this involves a neurorrhaphy between the masseteric nerve and a facial nerve branch for the orbicularis oculi, to ensure a stronger innervation to that muscle, associated with the transposition of the temporalis muscle to the nasiolabial sulcus. This gives good symmetry in the rest of the midface, while smiling movement is achievable, but not guaranteed. This one-time facial reanimation is particularly indicated for those who refuse major free-flap surgery or when that may be risky, as in previously operated and irradiated fields. More extensive procedures based on utilizing a free flap to recover smiling, while adding a cross-face nerve graft to restore blinking, may be proposed for motivated patients.Between 2010 and 2015, five patients affected by complete unilateral facial palsy underwent this technique in the Maxillofacial Surgery Department, San Paolo Hospital (Milan, Italy).Symmetry of the middle-third of the face at rest and recovery of smiling was quite good. Complete voluntary eyelid closure was obtained in all cases.Combining temporalis flap rotation and a masseteric-to-orbicularis-oculi-facial-nerve branch neurorrhaphy seems to be a valid solution for those medium-term referred patients.

Triple innervation for re-animation of recent facial paralysis

Recent facial palsies are those in which fibrillations of the mimetic musculature remain detectable by electromyography (EMG). Such fibrillations generally cease 18–24 months after palsy onset. During this period, facial re-animation surgery seeks to supply new neural inputs to the facial nerve.Neural usable sources were divided into qualitative (contralateral facial nerve) and quantitative (hypoglossus and masseteric nerve), depending on the type of stimulus provided.To further improve the extent and quality of facial re-animation, we here describe a new surgical technique featuring triple neural inputs: the use of the masseteric nerve and 30% of the hypoglossus nerve fibres as quantitative sources was associated with the contralateral facial nerve (incorporated via two cross-face nerve grafts) as a qualitative source in order to restore facial movements in 24 consecutive patients.The use of two quantitative motor nerve sources together with a qualitative neural source appears to improve re-animation after facial paralysis, despite earlier doubts as to whether patients could use different nerves to produce facial movements. In fact, movement was much improved. Smiling according to emotions and blinking seem to be better assured if cross-face nerve grafting is performed in two steps rather than one.

The Distal Stump of the Intramuscular Motor Branch of the Obturator Nerve Is Useful for the Reconstruction of Long-Standing Facial Paralysis Using a Double-Powered Free Gracilis Muscle Flap Transfer.

Double innervation of the transferred muscle with the contralateral facial nerve and the ipsilateral masseteric nerve has recently been reported by some authors. The aim of this study was to assess the utility of our procedure of double innervation of free gracilis muscle for reconstruction of long-standing facial palsy. In our department, 6 cases of long-standing facial paralysis (4 cases of complete palsy and 2 of incomplete palsy) were reconstructed using a free gracilis muscle double innervated with the masseteric and contralateral facial nerves. The patient age ranged from 37 to 79 years (average 56.7 ± 15.7). In our procedure, the intramuscular motor branch of the transferred muscle was identified and sutured to the ipsilateral masseteric nerve in an end-to-end fashion, and the obturator nerve of the transferred muscle was sutured to the cross-facial nerve graft, which was coapted with the contralateral facial nerve by end-to-end suturing. All patients were followed up for >18 months and recovered their smiling function. The voluntary movement of the transferred muscle with teeth clenching was observed at approximately 4.7 months, and this movement combined with contralateral mouth angle elevation was observed at approximately 9.5 months after the surgery. Our experience suggests that the distal stump of the intramuscular motor branch of the obturator nerve may be useful for facial reanimation via double-powered free gracilis muscle flap transfer.

The split hypoglossal nerve versus the cross-face nerve graft to supply the free functional muscle transfer for facial reanimation: A comparative study

Long-standing cases of facial paralysis are currently treated with free functional muscle transfer. Several nerves are mentioned in the literature to supply the free muscle transfer. The aim of this study is to compare the split hypoglossal nerve and the cross-face nerve graft to supply the free functional muscle transfer in facial reanimation. Of 94 patients with long-standing, unilateral facial palsy, 49 were treated using the latissimus dorsi muscle supplied by the split hypoglossal nerve, and 45 patients were treated using the latissmus dorsi muscle supplied by healthy contralateral buccal branch of the facial nerve. The excursion gained by the free muscle transfer supplied by the split hypoglossal nerve (mean 19.20 ± 6.321) was significantly higher (P value 0.001) than that obtained by the contralateral buccal branch of the facial nerve (mean 14.59 ± 6.245). The split hypoglossal nerve appears to be a good possible option to supply the free vascularised muscle transfer in facial reanimation. It yields a stronger excursion in less time than the contralateral cross-face nerve graft.

Masseteric cooptation and crossfacial nerve grafting: Is it still applicable 22months after the onset of facial palsy?

Eighteen months is usually considered the cutoff time within which recovery of the mimic muscle remains possible using facial nerve cooptation. Few reports on the use of cooptation after this interval have appeared. Purpose of this study is to investigate the feasibility of this procedure also after 22months. Six patients treated via crossfacial nerve grafting between healthy and paralyzed middle and middle-upper facial nerve branches and masseteric cooptation of the main trunk of the paralyzed facial nerve between 20 and 24months after the onset of palsy were analyzed. Population consisted of two males and four females ages 8-42years (mean 24years). Facial palsy developed after acoustic neuroma resection in three patients, after the removal of a cerebellopontine angle astrocytoma in one, and as a consequence of Bell's palsy or cerebral hemorrhage in the other two (one each). House-Brackman and Sunnybrook clinical evaluation systems and FDI questionnaire were used to assess results. House-Brackman scores changed from VI before the operation for all patients to II for two patients and III for four patients. Sunnybrook scores were 0-10 before the operation, but 62-84 at the last visit. Mean FDI scores moved from 24 to 38.5 meaning a statistical high significant improvement (P<.01). Masseteric/crossfacial nerve grafting is feasible for patients with palsies 20-24months in duration, affording satisfactory functional and esthetic results and a dramatic improvement in quality of life.

Reanimation of the paralyzed lids by cross-face nerve graft and platysma transfer

Alterations of facial muscles may critically humper patients' quality of life. One of the worst conditions is the reduction or abolition of eye blinking. To prevent these adverse effects, surgical rehabilitation of eyelid function is the current treatment choice. In the present paper, we present a modification of the technique devised by Nassif to recover lids from long-standing paralysis. In our modification, the upper lid is rehabilitated by a platisma graft innervated by the contralateral facial nerve branches using a cross-face sural nerve graft. The lower lid is pulled upward by a fascia lata string suspension. Fourteen patients with unilateral facial paralysis were operated on consecutively. For each patient, two sets of frontal photographs with open and closed eyes were available, before and after the surgical rehabilitation. On average, eyelid lumen with closed eyes decreased by 2.6 mm (SD 2.4) after surgical rehabilitation (37% of the initial value). With open eyes, the decrement was 1.5 mm (SD 1.6, 15%). The modifications were highly significant (p < 0.01), with very large effect sizes. Reanimation of the paralyzed eye by mean of cross-face nerve graft followed by platisma neurotization can restore natural eyelid closure and blink reflex.

Eyelid reanimation using crossface nerve graft: Relationship between surgical outcome and preoperative paralysis duration.

To reanimate the mimetic muscles, crossface nerve graft (CFNG) is an effective surgical option. However, muscle atrophy after facial paralysis may influence the surgical result. We analyzed the relationship between surgical result and preoperative paralysis duration. We performed CFNG on 15 patients. The sural nerve was transferred between the affected and nonaffected sides of the zygomatic branch. Eyelid function and eyelid lid were evaluated using the modified House-Brackmann scale. The effects of age, sex, cause of facial paralysis, graft nerve length, and preoperative paralysis duration were evaluated. The mean follow up period was 9.3 ± 3.3 (range 4-14) years. Eyelid closure was excellent in four patients, good in six, fair in one, and poor in four. Statistically, no significant difference was observed between those patients with excellent or good outcomes and fair or poor outcomes regarding age (40.9 ± 11.0 years vs. 22.6 ± 20.8; P = .067), sex (male/female = 2/8 vs. 3/2; P = .250), cause (tumor/trauma = 10/0 vs. 3/2; P = .095), and length of nerve graft (14.4 ± 0.8 cm vs. 13.8 ± 1.6 cm; P = .375). The average preoperative paralysis duration in the excellent/good patients was significantly shorter than that in the fair/poor patients (P = .005). All eight cases with preoperative paralysis of less than 6 months showed a marked excellent/good result. Two of the seven patients with preoperative paralysis was 6 months or longer marked fair/poor result. (P = .007). To achieve successful results with CFNG, surgery should be performed within 6 months of the onset of paralysis.

Lengthening Temporalis Myoplasty vs Free Gracilis Muscle Transfer with Cross Face Nerve Graft for Long-Standing Facial Paralysis in Children: An Objective Measure of Outcomes Using Oral Commissure Excursion

Lengthening Temporalis Myoplasty vs Free Gracilis Muscle Transfer with Cross Face Nerve Graft for Long-Standing Facial Paralysis in Children: An Objective Measure of Outcomes Using Oral Commissure Excursion

Surgical treatment of synkinesis between smiling and eyelid closure

Synkinetic movements are common among patients with incomplete recovery from facial palsy, with reported rates ranging from 9.1% to almost 100%.The authors propose the separation of the neural stimulus of the orbicularis oculi from that of the zygomatic muscular complex to treat eyelid closure/smiling synkinesis. This technique, associated with an anastomosis between the masseteric nerve and a central branch of the facial nerve, as well as with the use of a cross-facial nerve graft, resolves most of the spasms of the midface musculature, leading to a more relaxed tone when the mimic muscle is at rest and enhancing muscle excursion during voluntary and spontaneous smiling.Between 2011 and 2016, 18 patients affected by segmental paresis of the middle of the face underwent surgical treatment at the Maxillofacial Surgery Department of the San Paolo Hospital (Milan, Italy). Of these patients, 72.22% of cases with hypertone obtained partial to complete relaxation. Synkinesis was completely resolved in 83.33% of cases, and a significant improvement in facial movement was achieved in all patients.Neurorrhaphy of the masseteric nerve and the central branch of the facial nerve appears to produce favorable results. These initial data should be confirmed by further studies.

A higher quality of life with cross-face-nerve-grafting as an adjunct to a hypoglossal–facial nerve jump graft in facial palsy treatment

Nerve reconstructions are the preferred technique for short-standing facial paralysis, most commonly using the contralateral facial nerve or ipsilateral hypoglossal nerve. The hypoglossal nerve provides a strong motor signal, whereas the signal of a cross-face nerve graft is weaker but spontaneous. Spontaneity in facial expression is believed to be important for psychological wellbeing. Therefore, a combination of the two procedures incorporates the best of both: a strong motor signal and a spontaneous smile. This study aimed to objectify this expected benefit. Of the 20 patients who received a hypoglossal-facial nerve anastomosis from 1995 to 2015 in our institutions, 12 patients were included in this study, 5 with and 7 without a cross-face nerve graft. The outcomes were compared using photographs, disease-specific quality of life (Facial Clinimetric Evaluation (FaCE) scale), a self-reported synkinesis scale (Synkinesis Assessment Questionnaire) and the presence of a spontaneous smile. Significant differences were found in preoperative excursion of the affected side of the mouth and the change in excursion. Median Total FaCE scores were considerably larger (18.3 points) for patients who underwent the combined procedure. A spontaneous smile was observed both with (n=2) and without (n=1) a cross-face nerve graft. The addition of a cross-face nerve graft to a hypoglossal-facial nerve anastomosis resulted in a positive trend in disease-specific quality of life. This benefit could also be present with the combination of a cross-face nerve graft with another nerve transfer such as a masseteric-facial nerve anastomosis.

Correlation between Facial Nerve Axonal Load and Age and Its Relevance to Facial Reanimation.

Two-stage facial reanimation procedures with a cross-facial nerve graft often have unsatisfactory results in the older patient. Although the cause of result variability is likely multifactorial, some studies suggest that increased donor nerve axonal load improves function of a free muscle transfer after a cross-facial nerve graft. This study attempts to characterize the relationship between age and facial nerve axonal load. Sixty-three fresh cadaveric heads were dissected to expose the facial nerve. For each hemiface, two facial nerve samples were taken: one proximal as the nerve exits the stylomastoid foramen, and one distal at the buccal branch (at a point 1 cm proximal to the anterior parotid border). Nerve samples were stained and quantified. Correlation analysis was completed using a Pearson correlation coefficient. Thirty-six female and 27 male cadavers were dissected; their average age was 71 years (range, 22 to 97 years). At the proximal (r = -0.26; p < 0.01; n = 104) and distal (r = -0.45; p < 0.0001; n = 114) sampling points, there was a significant negative correlation between age and axonal load. As age increases, the axonal load of the facial nerve decreases at the buccal and zygomatic branches approximately 1 cm proximal to the anterior parotid border. The authors previously suggested this location as significant for cross-facial nerve coaptation. These results propose that decreasing axonal load can be a factor in the unsatisfactory outcomes of cross-facial grafting in the aging population. Moreover, this underscores the importance of recruiting more donor axons in attempting to improve facial reanimation in the older patient.

Facial Reanimation: Basic Surgical Tools and Creation of an Effective Toolbox for Treating Patients with Facial Paralysis. Part A: Functional Muscle Transfers in the Long-Term Facial Palsy Patient.

The literature on facial paralysis is vast; however, detailed videos of the basic tools of dynamic reanimation within the context of patient scenarios accompanied by detailed narrative emphasizing both technique and thought processes are not common. Although not all scenarios of facial paralysis can be discussed in one setting, videographic visualization of basic surgical procedures, including facial marking, facial dissection, donor nerve preparation, cross-facial nerve graft, nerve transfers, and muscle harvest and inset, may provide a strong toolbox. Using these tools in various combinations depending on the unique case details enables the surgeon to treat a great majority of facial palsy patients. Part A, with the first of two videos, concentrates on free functional muscle transfer in the setting of longstanding facial paralysis. It includes preoperative markings, preparation of the patient in the operating room before incision, facial dissection including exposure of the masseter nerve, partial gracilis muscle harvest, and perhaps most importantly, the inset of the muscle on the paralyzed side. Part B (with the second video) concentrates on the cross-facial nerve graft and nerve transfers, used in the context of acute facial palsy, providing the short-term goal of mimetic musculature salvage in addition to longer term specific regional reinnervation by means of cross-facial nerve grafting. We hope that these videos provide a strong learning tool for enthusiastic novice medical students, residents, and fellows wishing to prepare for their cases, and faculty level physicians who wish to use them as a refresher before surgery.

Analysis of the ideal muscle weight of gracilis muscle transplants for facial reanimation surgery with regard to the donor nerve and outcome

Free functional muscle transfers represent the 'criterion standard' for smile reconstruction in facial paralysis. The gracilis muscle is a common donor muscle; however, no data exist regarding the volume of the muscle tissue that is necessary for symmetric commissure excursion. All patients with facial paralysis receiving a free functional muscle transfer for facial reanimation surgery between January 2009 and November 2015 were retrospectively analysed. Only patients with unilateral facial paralysis and documented weight of the muscle portion were included. The extent of oral commissure amplitude was determined from standardised photographs. In total, 42 free functional gracilis transfers were performed during the study period, of which 22 met the inclusion criteria. Eight muscles were innervated by a cross-facial nerve graft (CFNG) and 14 by the masseteric nerve. Segments between 19 and 50g of weight (mean: CFNG, 33.9g and masseteric nerve, 31.7g; p=0.59) were transferred. Coaptation to the masseteric nerve led to increased commissure excursion compared to coaptation to the CFNG. We observed a significant increase in commissure excursion with increasing muscle weight in the masseteric nerve group. In this group, four patients underwent secondary flap debulking in flaps weighing ≥27g. In the CFNG group, only one patient, who had an initial flap weight of 50g, underwent secondary flap reduction. Thinning reduced the oral commissure movement but improved the symmetry of commissure excursion and the aesthetic result. The ideal muscle weight depends on the donor nerve and should be smaller for masseteric nerve than for CFNG coaptation in adults.