A comparison of commissure excursion following gracilis muscle transplantation for facial paralysis using a cross-face nerve graft versus the motor nerve to the masseter nerve

Functional Outcome of Dual Reinnervation with Cross-Facial Nerve Graft and Masseteric Nerve Transfer for Facial Paralysis

BACKGROUND

The combination of cross-facial nerve graft (CFNG) and masseteric nerve transfer (MNT) for reinnervation of facial paralysis may provide advantages of both neural sources. However, quantitative functional outcome reports with a larger number of patients are lacking in the literature. Here, the authors describe their 8-year experience with this surgical technique.

METHODS

Twenty patients who presented with complete facial paralysis (duration, <12 months) received dual reinnervation with CFNG and MNT. The functional outcome of the procedure was evaluated with the physician-graded outcome metric eFACE scale. The objective artificial intelligence-driven software Emotrics and FaceReader were used for oral commissure measurements and emotional expression assessment, respectively.

RESULTS

The mean follow-up was 31.75 ± 23.32 months. In the eFACE score, the nasolabial fold depth and oral commissure at rest improved significantly ( P < 0.05) toward a more balanced state after surgery. Postoperatively, there was a significant decrease in oral commissure asymmetry while smiling (from 19.22 ± 6.1 mm to 12.19 ± 7.52 mm). For emotional expression, the median intensity score of happiness, as measured by the FaceReader software, increased significantly while smiling (0.28; interquartile range, 0.13 to 0.64). In five patients (25%), a secondary static midface suspension with fascia lata strip had to be performed because of unsatisfactory resting symmetry. Older patients and patients with greater preoperative resting asymmetry were more likely to receive static midface suspension.

CONCLUSION

The authors' results suggest that the combination of MNT and CFNG for reinnervation of facial paralysis provides good voluntary motion and may lessen the use of static midface suspension in the majority of patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Task force of the Brazilian Society of Otology - evaluation and management of peripheral facial palsy

OBJECTIVE

To review key evidence-based recommendations for the diagnosis and treatment of peripheral facial palsy in children and adults.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on peripheral facial palsy were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 main parts: (1) Evaluation and diagnosis of facial palsy: electrophysiologic tests, idiopathic facial palsy, Ramsay Hunt syndrome, traumatic peripheral facial palsy, recurrent peripheral facial palsy, facial nerve tumors, and peripheral facial palsy in children; and (2) Rehabilitation procedures: surgical decompression of the facial nerve, facial nerve grafting, surgical treatment of long-term peripheral facial palsy, and non-surgical rehabilitation of the facial nerve.

CONCLUSIONS

Peripheral facial palsy is a condition of diverse etiology. Treatment should be individualized according to the cause of facial nerve dysfunction, but the literature presents better evidence-based recommendations for systemic corticosteroid therapy.

Dual-Innervated Gracilis Free Functional Muscle Transfers in Facial Palsy Patients: Comparing Long-Term Outcomes between One- versus Two-Stage Procedures

BACKGROUND

 In facial reanimation, dual-innervated gracilis free functional muscle transfers (FFMTs) may have amalgamated increases in tone, excursion, synchroneity, and potentially spontaneity when compared with single innervation. The ideal staging of dual-innervated gracilis FFMTs has not been investigated. We aim to compare objective long-term outcomes following one- and two-stage dual-innervated gracilis FFMTs.

METHODS

 Included were adult patients with facial paralysis who underwent either one- (one-stage group) or two-stage (two-stage group) dual-innervated gracilis FFMT with ≥1 year of postoperative follow-up. Facial measurements were obtained from standardized photographs of patients in repose, closed-mouth smile, and open-mouth smile taken preoperatively, 1 year postoperatively, and 3 years postoperatively. Symmetry was calculated from the absolute difference between the paralyzed and healthy hemiface; a lower value indicates greater symmetry.

RESULTS

 Of 553 facial paralysis patients, 14 were included. Five and nine patients were in the one- and two-stage groups, with mean follow-up time, respectively, being 2.5 and 2.6 years. Within-group analysis of both groups, most paralyzed-side and symmetry measurements significantly improved over time with maintained significance at 3 years postoperatively in closed and open-mouth smile (all p ≤ 0.05). However, only the two-stage group had maintained significance in improvements at 3 years postoperatively in paralyzed-side and symmetry measurements in repose with commissure position (median change [interquartile range, IQR], 7.62 [6.00-10.56] mm), commissure angle (median change [IQR], 8.92 [6.18-13.69] degrees), commissure position symmetry (median change [IQR], -5.18 [-10.48 to -1.80] mm), commissure angle symmetry (median change [IQR], -9.78 [-11.73 to -7.32] degrees), and commissure height deviation (median change [IQR], -5.70 [-7.19 to -1.64] mm; all p ≤ 0.05). In the between-group analysis, all measurements were comparable in repose, closed-mouth smile, and open-mouth smile (all p > 0.05).

CONCLUSION

 Long-term outcomes demonstrate that both one- and two-stage dual-innervated gracilis FFMTs significantly improve excursion, but only two-stage reconstruction significantly improves resting tone.

Comparison of Outcomes of Facial Reanimation Between the Use of Cross-facial Nerve Graft and the Masseteric Nerve as the Donor Nerve for Reinnervation of Gracilis Muscle Flap Transfer

BACKGROUND

In patients with facial paralysis, the free functional gracilis muscle transfer is preferred for facial reanimation. The choice of an adequate motor nerve to innervate the transplanted gracilis muscle is one of the procedure's key components. We present a comparative study between cross-facial nerve graft (CFNG) and masseteric nerve as donor nerves for reinnervated gracilis flap transfer in patients with complete facial paralysis.

MATERLALS AND METHODS

Retrospective analysis was performed on all patients with complete facial paralysis who had a free functional gracilis muscle transfer for facial reanimation between January 2014 and December 2021. Only those who received gracilis transfer reinnervated by either CFNG or masseteric nerve were included in this study. The smile excursion and lip angle were measured for evaluating the outcomes postoperatively.

RESULTS

The inclusion criteria were met by a total of 21 free functional gracilis muscle transfers, of which 11 were innervated by CFNG and 10 by the masseteric nerve. Both surgical procedures resulted in a highly considerable smile excursion of the reanimated side and postoperative improvement of static or dynamic lip angle. Masseteric nerve coaptation led to greater smile excursion and more significant improvement of dynamic lip angle than CFNG.

CONCLUSIONS

For patients who have complete facial paralysis, face reanimation can be successfully accomplished by free gracilis transfer reinnervated by the CFNG or the masseteric nerve. In particular, the masseteric nerve is a reliable choice for dynamic smile reanimation.

The masseteric nerve for facial reanimation: Macroscopic and histomorphometric characteristics in 106 human cadavers and comparison of axonal ratio with recipient nerves

Peripheral facial palsy causes severe impairments. Sufficient axonal load is critical for adequate functional outcomes in reanimation procedures. The aim of our study was to attain a better understanding of the anatomy of the masseteric nerve as a donor, in order to optimize neurotization procedures. Biopsies were obtained from 106 hemifaces of fresh frozen human cadavers. Histological cross-sections were fixed, stained with PPD, and digitized. Histomorphometry and a validated software-based axon quantification were conducted. Of the 154 evaluated branches, 74 specimens were of the main trunk (MT), 40 of the anterior branch (AB), and 38 of the descending branch (DB), while two halves of one cadaver featured an additional branch. The MT showed a diameter of 1.4 ± 0.41 mm (n = 74) with 2213 ± 957 axons (n = 55). The AB diameter was 0.9 ± 0.33 mm (n = 40) with 725 ± 714 axons (n = 30). The DB diameter was 1.15 ± 0.34 mm (n = 380) with 1562 ± 926 axons (n = 30). The DB demonstrated a high axonal capacity - valuable for nerve transfers or muscle transplants. Our findings should facilitate a balanced selection of axonal load, and are potentially helpful in achieving more predictable results while preserving masseter muscle function.

Nerve guide conduits, nerve transfers, and local and free muscle transfer in facial nerve palsy

PURPOSE OF REVIEW

To highlight the recent literature on reinnervation options in the management of facial nerve paralysis using nerve conduits, and nerve and muscle transfers.

RECENT FINDINGS

Engineering of natural and synthetic nerve conduits has progressed and many of these products are now available on the market. The use of the masseter nerve has become more popular recently as a choice in nerve transfer procedures due to various unique advantages. Various authors have recently described mimetic muscle reinnervation using more than one nerve transfer, as well as dual and triple innervation of free muscle transfer.

SUMMARY

The ideal nerve conduit continues to be elusive, however significant progress has been made with many natural and synthetic materials and designs tested and introduced on the market. Many authors have modified the classic approaches in motor nerve transfer, as well as local and free muscle transfer, and described new ones, that aim to combine their advantages, particularly the simplification to a single stage and use of multiple reinnervation to the mimetic muscles. These advances are valuable to the reconstructive surgeon as powerful tools that can be tailored to the unique challenges of patients with facial nerve palsy looking for dynamic reanimation options.

Extra- and intramuscular innervation of the masseter: Implications for facial reanimation

PURPOSE

Irreversible facial paralysis results in significant functional impairment. The motor nerve to the masseter is a reconstructive option, but despite its clinical importance, there are few parametric anatomic studies of the masseteric nerve. The purpose of this study was to investigate the extra- and intramuscular innervation of the masseter in 3D to determine the relationship of the nerve to the muscle heads and identify landmarks to aid identification.

MATERIALS AND METHODS

The nerve was dissected throughout its entire course in eight formalin-embalmed cadaveric specimens (mean age 84.9 ± 12.2 years). The nerve was digitized at 1-2 mm intervals using a MicroScribe™ digitizer and modeled in 3D in Autodesk® Maya®.

RESULTS

Two or three extramuscular nerves were found to enter the deep head (DH) of the masseter: one main "primary" nerve (n = 8) and one (n = 4) or two (n = 4) smaller primary nerve(s). The main primary nerve supplied both the deep and superficial heads, whereas the smaller primary nerve(s) only supplied the DH. Surgical landmarks for masseter nerve localization were quantified.

CONCLUSIONS

Comprehensive mapping of the innervation of the masseter muscle throughout its volume revealed neural partitioning that could provide a basis for safety planning for muscle flaps and donor nerve identification and explain why masseter functional loss is not incurred by donor nerve sacrifice. Quantified landmarks correlate to previous studies and support the constant anatomy of this nerve. Our results provide a basis to optimize surgical approaches for donor nerve and muscle flap surgery.

Age-related outcomes of facial reanimation surgery using gracilis free functional muscle transfer innervated by the masseteric nerve: A retrospective cohort study

BACKGROUND

The free functional muscle gracilis transfer is an established approach in facial reanimation surgery; however, the significance of its neurotization and the patient's age is still inconclusive. Several donor nerves are available for facial reanimation using the free functional gracilis muscle transfer.

OBJECTIVE

This retrospective cohort study investigates whether the masseteric nerve is an equally reliable donor nerve in both older and younger patients.

METHODS

We included 46 patients (13-71 years, male and female) who underwent nerve-to-masseter (NTM)-driven free functional muscle transfer (FFMT) between January 2008 and December 2019. Patients were distributed into three cohorts according to their age at surgery. We assessed the facial symmetry before and after surgery using the pupillo-modiolar angle. Commissure height and excursion deviation were measured with the Emotrics software. Patient-reported outcome measurements were taken using the Facial Clinimetric Examination (FaCE) scale.

RESULTS

All patients had successful flap innervation, except for one patient in the middle-aged cohort (31-51 years). The postoperative facial symmetry at rest, smiling, and laughing was analyzed with the pupillo-modiolar angle and the Emotrics software and showed similar results between all cohorts. The FaCE scale showed similar scores for the middle-aged (31-51 years) cohort and the senior cohort (52-71 years). The social function score in the senior cohort was higher than in the middle-aged cohort, without statistical significance. One patient in the middle-aged (31-51 years) cohort and the senior cohort (52-71 years), respectively, underwent emergency revision due to impaired flap perfusion and could be salvaged.

CONCLUSIONS

NTM-driven FFMT for facial reanimation is a safe and reliable procedure across all age groups of patients.

Anatomic Analysis of Masseteric-to-zygomatic Nerve Transfer in Rat and Pig Models

Background

Nerve transfer from the masseteric branch of the trigeminal nerve is a widely performed procedure for facial reanimation. Despite achieving powerful muscle force, clinical and aesthetic results leave room for improvement. Preclinical animal models are invaluable to establishing new therapeutic approaches. This anatomical study aimed to establish a masseteric-to-zygomatic nerve transfer model in rats and pigs.

Methods

The masseteric branch of the trigeminal nerve and the zygomatic branch of the facial nerve were dissected in 30 swine and 40 rat hemifaces. Both nerves were mobilized and approximated to achieve an overlap between the nerve ends. Over the course of dissecting both nerves, their anatomy, length, and branching pattern were documented. At the coaptation point, diameters of both nerves were measured, and samples were taken for neuromorphometric analysis.

Results

Anatomic details and landmarks were described. Tension-free coaptation was possible in all rat and pig dissections. In rats, the masseteric branch had an average diameter of 0.36 mm (±0.06), and the zygomatic branch average diameter was 0.46 mm (±0.13). In pigs, the masseteric branch measured 0.52 (±0.16) mm and the zygomatic branch, 0.59 (±0.16) mm. No significant differences were found between the diameters and axon counts of both nerves in pigs. In rats, however, their diameters, axon counts, and fascicular areas were significantly different.

Conclusion

Our study demonstrated the feasibility of direct masseteric-to-zygomatic nerve transfer in rats and pigs and provided general anatomic knowledge of both nerves.

Evidence-Based Practices in Facial Reanimation Surgery

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the causes and preoperative evaluation of facial paralysis. 2. Discuss techniques to restore corneal sensation and eyelid closure, elevation of the upper lip for smile, and depression of the lower lip for lip symmetry. 3. Outline treatment goals, surgical treatment options, timing of repair, and other patient-specific considerations in appropriate technique selection.

SUMMARY

Congenital facial paralysis affects 2.7 per 100,000 children; Bell palsy affects 23 per 100,000 people annually; and even more people are affected when considering all other causes. Conditions that impair facial mimetics impact patients' social functioning and emotional well-being. Dynamic and static reconstructive methods may be used individually or in concert to achieve adequate blink restoration, smile strength and spontaneity, and lower lip depression. Timing of injury and repair, patient characteristics such as age, and cause of facial paralysis are all considered in selecting the most appropriate reconstructive approach. This article describes evidence-based management of facial paralysis.

Gracilis Muscle-Free Flap Objective Improvement of Oral Commissure Excursion in Facial Palsy Reanimation Surgery: Systematic Review and Meta-Analysis

Background: Facial palsy patients face significant challenges. Gracilis free flap transfer is a key procedure in facial reanimation. Objective: This study aims to analyze oral commissure excursion improvement after gracilis free flap transfer and the differences regarding donor nerve: cross-facial nerve graft (CFNG), hypoglossal or spinal accessory nerves, motor nerve to masseteric (MNTM), and most recently, double anastomosis using both the MNTM and CFNG. Methods: A systematic review and meta-analysis were conducted of studies reporting oral commissure excursion improvement after free gracilis muscle transfer. Pooled proportions were calculated using a random-effects model. Results: Eighteen studies, 453 patients, and 488 free gracilis flaps were included. The mean change in perioperative oral commissure excursion was 7.0 mm, for CFNG 7.2 mm, for MNTM 7.7, and for double anastomoses 5.5 mm. Conclusions: There is a significant improvement in oral commissure excursion after gracilis muscle-free flap. Unfortunately, we could not make definitive conclusions regarding the optimal choice of donor nerve.

Histomorphometry of the Sural Nerve for Use as a CFNG in Facial Reanimation Procedures

Facial palsy (FP) is a debilitating nerve pathology. Cross Face Nerve Grafting (CFNG) describes a surgical technique that uses nerve grafts to reanimate the paralyzed face. The sural nerve has been shown to be a reliable nerve graft with little donor side morbidity. Therefore, we aimed to investigate the microanatomy of the sural nerve. Biopsies were obtained from 15 FP patients who underwent CFNG using sural nerve grafts. Histological cross-sections were fixated, stained with PPD, and digitized. Histomorphometry and a validated software-based axon quantification were conducted. The median age of the operated patients was 37 years (5-62 years). There was a significant difference in axonal capacity decrease towards the periphery when comparing proximal vs. distal biopsies (p = 0.047), while the side of nerve harvest showed no significant differences in nerve caliber (proximal p = 0.253, distal p = 0.506) and axonal capacity for proximal and distal biopsies (proximal p = 0.414, distal p = 0.922). Age did not correlate with axonal capacity (proximal: R = -0.201, p = 0.603; distal: R = 0.317, p = 0.292). These novel insights into the microanatomy of the sural nerve may help refine CFNG techniques and individualize FP patient treatment plans, ultimately improving overall patient outcomes.

Donor nerve selection in free gracilis muscle transfer for facial reanimation. A systematic review and meta-analysis of clinical outcomes

BACKGROUND

One of the critical factors in facial reanimation is selecting the donor nerve. The most favored neurotizers are the contralateral facial nerve with a cross-face nerve graft (CFNG) and motor nerve to the masseter (MNM). A relatively new dual innervation (DI) method has shown successful results. This study aimed to compare the clinical outcomes of different neurotization strategies for free gracilis muscle transfer (FGMT).

METHODS

The Scopus and WoS databases were queried with 21 keywords. Three-stage article selection was performed for the systematic review. Articles presenting quantitative data for commissure excursion and facial symmetry were included in meta-analysis, using random-effects model. ROBINS-I tool and Newcastle-Ottawa scale were used to assess bias and study quality.

RESULTS

One hundred forty-seven articles containing FGMT were systematically reviewed. Most studies indicated CFNG as the first choice. MNM was primarily indicated in bilateral palsy and in elderly. Clinical outcomes of DI studies were promising. 13 studies including 435 observations (179 CFNG, 182 MNM, 74 DI) were eligible for meta-analysis. The mean change in commissure excursion was 7.15 mm (95% CI: 4.57-9.72) for CFNG, 8.46 mm (95% CI: 6.86-10.06) for MNM, and 5.18 mm (95% CI: 4.01-6.34) for DI. In pairwise comparisons, a significant difference was found between MNM and DI (p = 0.0011), despite the superior outcomes described in DI studies. No statistically significant difference was found in resting and smile symmetry (p = 0.625, p = 0.780).

CONCLUSIONS

CFNG is the most preferred neurotizer, and MNM is a reliable second option. Outcomes of DI studies are promising, but more comparison studies are needed to draw conclusions. Our meta-analysis was limited by incompatibility of the assessment scales. Consensus on a standardized assessment system would add value to future studies.

Comparison of static and dynamic symmetry between masseter-innervated and dual-innervated free multivector serratus anterior muscle transfer for complete facial paralysis

PURPOSE

In this study, facial symmetry was compared between the masseter-innervated and dual-innervated free multivector serratus anterior muscle transfer (FMSAMT) methods.

METHODS

Eighteen patients with unilateral complete facial paralysis underwent facial reanimation surgery between April 2006 and July 2019. The masseter-innervated FMSAMT group (Group M, n = 8) underwent end-to-end coaptation with the ipsilateral masseter nerve in one stage. The dual-innervated FMSAMT group (Group D, n = 10) underwent end-to-end coaptation with the masseter nerve and end-to-side coaptation with the contralateral facial nerve via cross-face nerve graft. They were further divided into the one-stage (Group D1, n = 5) and two-stage (Group D2, n = 5) subgroups. The durations of periods until the first visible muscle contraction with clenching, first spontaneous smile, and the completion of resting tone were evaluated. The possibility of a spontaneous smile and symmetry of the midline and horizontal deviation at rest and during voluntary smiling were compared between each group.

RESULTS

Groups M and D differed significantly in the possibility of a spontaneous smile and improvement rate of midline deviation and horizontal deviation at rest (p < 0.001, p < 0.001, and p = 0.001, respectively) but not in the improvement rate of midline and horizontal deviation during voluntary smiling. The duration of the period until the completion of resting tone was significantly shorter in Group D1 than in Group D2 (p = 0.048); however, the possibility of a spontaneous smile and the improvement rate of midline and horizontal deviation were not significantly different.

CONCLUSIONS

Dual-innervated FMSAMT was effective in guaranteeing a symmetrical resting tone, voluntary smiling, and reproducing a spontaneous smile.

Integrated Approaches for Reconstruction of Facial Paralysis

BACKGROUND

Facial paralysis can affect periorbital muscles, oral competence, and facial expressions with significant facial deformities, which could occur in either children or adults with variable severity, duration, and degree of recovery.

OBJECTIVE

The present study was aimed to delineate treatment plans for facial paralysis with different clinical scenarios and to report the results of these patients.

METHODS

Patients were grouped according to different presentations as follows: (1) facial paralysis with incomplete recovery; (2) young patients of facial paralysis without recovery; (3) senile patients of facial palsy without recovery; (4) combined facial palsy with mandibular deficiency, vascularized bone reconstruction for mandible with (a) subsequent muscle transfer or (b) simultaneous sling operation or (c) simultaneous facial nerve exploration and cross nerve grafting; (5) palsy of frontal branch of facial nerve; (6) palsy of zygomatic-buccal branch of facial nerve; (7) palsy of marginal mandibular branch of facial nerve; (8) partial recovery with dyskinesia; and (9) facial paralysis with dynamic asymmetry and muscle atrophy. According to clinical scenarios, different treatment plans were provided, and clinical outcomes were evaluated and presented.

RESULTS

All patient groups achieved fair or satisfactory outcomes. Revisions using sling procedures, botulinum toxin injection, and filler or fat graft as supplement further refined the ultimate outcomes.

CONCLUSIONS

For reconstruction of facial paralysis, individualized integrated treatment plans are mandatory according to the presentation and condition of the patient. Comprehensive considerations and strategic solutions for the existing disabilities have been appreciated by the patients. The least numbers of operations with considerate correction of asymmetry were the major concerns of the patients.

Microvascular Gracilis Free Flap: Single and Double Innervation

Facial paralysis (FP) is a devastating condition that can lead to significant aesthetic, social, and emotional morbidities for patients. For some patients with FP, free gracilis muscle transfer (FGMT) is the best option for smile restoration. Masseteric-driven FGMT produces a reliable voluntary smile. Cross-face nerve graft-driven FGMT can produce a spontaneous smile, but this technique has higher failure rates. Early studies suggest dual-innervation FGMT can produce a spontaneous smile while maintaining the reliability of masseteric-driven procedures. Great care should be taken during FGMT surgery to minimize facial bulk and place medial inset sutures that create a natural-appearing smile.

Reducing Risk in Facial Reanimation Surgery

Facial reanimation surgery can greatly improve quality of life, but these procedures are not without risk. Important considerations for risk reduction in facial reanimation surgery include preoperative risk-stratification, protecting patients' clinical media, clearly and thoroughly setting expectations, and intraoperative strategies to maximize technical success and minimize operative time.

MODIFIED GRACILIS MUSCLE FLAP IN FACIAL REANIMATION: U-SHAPED DESIGN

BACKGROUND

Surgical treatment of long-term facial palsy has been reported using various techniques, including functioning muscle-free flaps. The free gracilis muscle flap is the most common because of its many advantages. Our study presents a modified way of shaping the gracilis muscle for transfer to the face to improve the restoration of natural smiles.

METHODS

This retrospective study assessed 5 patients who received the classical technique and 43 patients who received modified, U-shaped, free gracilis muscle flap for smile reanimation from 2013 to 2018. The surgery is single-staged. Preoperative and postoperative photos were taken. Functional outcomes were evaluated using the Terzis and Noah score and the Chuang smile excursion score.

RESULTS

The mean patient age at the time of operation was 31 years. The length of gracilis muscle harvested was 12-13 cm. Of the 43 patients who received U-shaped design-free gracilis muscle, results were excellent for 15 (34.9%), good for 20 (46.5%), and fair for 8 (18.6%) followed the Terzis and Noah score. The Chuang smile excursion score was 2 for 16.3%, 3 for 46.5%, and 4 for 37.2% of 43 patients. Of the 5 patients who underwent classical technique, there are no excellent results based on the Terzis and Noah score. The Chuang smile excursion score was only 1 and 2.

CONCLUSIONS

The U-shaped modification to the gracilis muscle-free flap is a simple and effective technique to help restore a symmetrical and natural smile in patients with facial palsy.

Anatomic and histomorphometric study of the nerve to the vastus lateralis in cadaver for its clinical application in facial reanimation

BACKGROUND

The innervated vastus lateralis flap (IVLF) is a barely used possibility for facial palsy reconstruction because of its thickness compared to the gracilis, latissimus dorsi, and pectoralis minor flaps. The aim of this study is to perform a precise description of the intramuscular distribution of the nerve motor branches and its relationship with the vascular pedicle in order to harvest a segmental muscle flap with the best contractile strength to restore facial reanimation.

METHODS

The study was performed on 16 adult cadaver thighs identifying the vastus lateralis muscle and the distribution and relationships of its neurovascular pedicle and branches. We evaluated where the nerve pierced the muscle and the course of the nerve within it. Transverse segments of the nerve were obtained from the proximal and distal ends of the nerve and stained using anti-ChAT (Choline acetyltransferase) antibodies which are specific of motor neurons.

RESULTS

A nerve for the vastus lateralis from the posterior division of the femoral nerve divided into 2 branches in 56% of cases; the principal branch coursed along the vascular pedicle and pierced the muscle more proximally than the respective vessels, and a minor branch that pierced the muscle 25-60 mm proximally. There were 3 main intramuscular branches. The nerve length (mean 132.65 ± 22.89 mm) allowed to reach the contralateral side of the face in almost all cases (95%). The mean ChAT positive fibers was 351.0 ± 92.4/mm² at the proximal end, and 270.3 ± 87.9/mm² at the distal end (p = 0.49). The number of ChAT negative fibers was higher than ChAT positive in both proximal and distal ends of the nerve.

CONCLUSION

We propose the IVLF as a one-step surgical flap for facial paralysis reanimation due to the constant neurovascular pattern and lengthy pedicle. The amount of motor fibers in several segments of the nerve is appropriate to produce a powerful contraction for dynamic reconstruction.

Smile Reanimation with Masseteric-to-Facial Nerve Transfer plus Cross-Face Nerve Grafting in Patients with Segmental Midface Paresis: 3D Retrospective Quantitative Evaluation

Facial paresis involves functional and aesthetic problems with altered and asymmetric movement patterns. Surgical procedures and physical therapy can effectively reanimate the muscles. From our database, 10 patients (18–50 years) suffering from unilateral segmental midface paresis and rehabilitated by a masseteric-to-facial nerve transfer combined with a cross-face facial nerve graft, followed by physical therapy, were retrospectively analyzed. Standardized labial movements were measured using an optoelectronic motion capture system. Maximum teeth clenching, spontaneous smiles, and lip protrusion (kiss movement) were detected before and after surgery (21 ± 13 months). Preoperatively, during the maximum smile, the paretic side moved less than the healthy one (23.2 vs. 28.7 mm; activation ratio 69%, asymmetry index 18%). Postoperatively, no differences in total mobility were found. The activity ratio and the asymmetry index differed significantly (without/with teeth clenching: ratio 65% vs. 92%, p = 0.016; asymmetry index 21% vs. 5%, p = 0.016). Postoperatively, the mobility of the spontaneous smiles significantly reduced (healthy side, 25.1 vs. 17.2 mm, p = 0.043; paretic side 16.8 vs. 12.2 mm, p = 0.043), without modifications of the activity ratio and asymmetry index. Postoperatively, the paretic side kiss movement was significantly reduced (27 vs. 19.9 mm, p = 0.028). Overall, the treatment contributed to balancing the displacements between the two sides of the face with more symmetric movements.

Dual-Innervated Free Gracilis Muscle Transfer for Facial Reanimation in Children

BACKGROUND

Facial palsy may have deleterious effects for pediatric patients. The most common reconstruction is 2-stage free gracilis muscle transfer (FGMT) after cross-face nerve graft (CFNG). This requires a prolonged period from time of surgery to smile. New techniques using both a CFNG and motor nerve to masseter (MNM) as dual power sources in a single-stage surgery have been described in adults. Here, we examine our experience with this technique in children.

METHODS

A retrospective study was performed examining patients who underwent dual-innervated single-stage FGMT at 2 pediatric hospitals from 2016 to 2019. Demographics, etiology, perioperative characteristics, time to mandibular and emotional smile, and Sunnybrook scores were recorded.

RESULTS

Five patients met inclusion criteria with a mean age of 11.8 (range, 8-20). Two patients had congenital facial palsy while 3 had acquired facial palsy. Four patients (80%) received dual end-to-end neural coaptations of the CFNG and MNM to the obturator nerve. One (20%) had end-to-side coaptation of the CFNG to the obturator nerve and end-to-end of the MNM to the obturator nerve. The average time to mandibular smile was 103 ± 15.4 days. The average time to emotional smile was 245 ± 48.1 days. The preoperative Sunnybrook scale was 32 ± 7.5 and improved to 55.3 ± 20.6 at 8 months postoperatively.

CONCLUSIONS

Dual-innervated FGMT is effective for facial reanimation in children with unilateral facial palsy. Patients can harness a stronger motor source (MNM) and the component of an emotional stimulus (CFNG). This approach may be the new criterion standard pediatric facial reanimation.

The Split Hypoglossal Nerve and Cross-Face Nerve Graft for Dual Innervation of the Functional Muscle Transfer in Facial Reanimation

Facial paralysis is a disabling deformity. The affected individual is seriously affected both esthetically and functionally. Free functional muscle transfer is currently the corner stone in the management of long-standing facial nerve paralysis. Several nerve options are available to supply the free muscle transfer. These nerves can be used alone or in combination. The aim of this work is to study the possibility and results of dually innervating the free functioning muscle transfer. The dual innervation is done using the split hypoglossal nerve and cross-face nerve graft (CFNG) both sutured in an end-to-end manner to the nerve to gracilis. Twenty-nine patients with unilateral long-standing facial nerve paralysis (more than 1 y) were treated using free gracilis muscle transfer dually supplied by the split hypoglossal nerve and CFNG, both sutured in an end-to-end manner. The gained excursion after the free gracilis transfer was 9 to 29 mm (mean: 17.24 mm). A statistically significant increase ( P -value=0.0001) in the distance from where the midline crosses the lower vermilion border to commissure occurred from preoperative (mean: 16.55 mm) to postoperative setting (mean: 33.79 mm). Spontaneity was achieved in 26 patients (89.6%). In conclusion, dual innervation of the free muscle transfer using both the split hypoglossal nerve and CFNG (both sutured in an end-to-end manner to the nerve to gracilis) is a good possible option to treat long-standing cases of facial nerve paralysis. It yields adequate muscle excursion with acceptable spontaneity.

Facial reanimation using free partial latissimus dorsi muscle transfer: Single versus dual innervation method

The aim of the present study was to analyze the consequences of partial free latissimus dorsi muscle flap with nerve splitting technique (Partial LD transfer) for facial reanimation and compare outcomes according to innervation method (singer versus dual innervation). Patients with complete unilateral facial paralysis underwent either the single (ipsilateral masseteric nerve only) or dual (ipsilateral masseteric nerve plus contralateral buccal branch of the facial nerve) nerve innervation method for facial reanimation. An assessment was carried out to compare the outcomes between the single and dual innervation. Total of 21 patients were involved in this study. In the single innervation group, 7 out of 8 patients developed a voluntary smile. However, none were able to achieve a spontaneous smile. On the other hand, 9 out of 13 patients developed a voluntary smile and 3 out of 13 patients achieved a spontaneous smile. The mean increases of smile excursion assessed by Emotrics software and Terzis grades showed no significant differences between two groups. Within the limitations of the study it seems that partial LD transfer approach utilizing the dual innervation method has a positive effect on achieving a spontaneous smile and could be a valuable option for facial reanimation.

Age-related outcome of facial reanimation surgery using cross face nerve graft and gracilis free functional muscle transfer-A retrospective cohort study

BACKGROUND

Free functional muscle transfer has become the criterion standard for the treatment of long-standing flaccid facial paralysis. Clinical experience suggests that a two-stage approach using a cross-face nerve graft (CFNG) as a donor nerve for free functional muscle transfers (FFMT) is less successful in older patients when compared to the pediatric population. However, clear data and scientific evidence are still rare. This study examines the age-related outcome of CFNG-driven FFMT.

METHODS

Twenty-eight patients with a mean age of 20.73 years (ranging 5-51 years) who received two-stage facial reanimation with CFNG-driven gracilis FFMT at our institution from 1998 to 2019 were included. The ipsilateral sural nerve was used as CFNG. After 12 months, the ipsilateral gracilis muscle was used as FFMT. Patients were distributed equally into three cohorts according to their age. We assessed facial symmetry before and after facial reanimation measuring the angle between the interpupillary and the intermodiolar line (pupillo-modiolar angle). Additionally, the commissure height was measured using the Emotrics software.

RESULTS

The mean follow-up of the pediatric, young adults and the middle-aged cohort was 29.5 ± 7.3, 24.9 ± 6.3, and 25.5 ± 12.4 months, respectively. One patient suffered flap loss due to flap ischemia. Four patients suffered insufficient innervation of the FFMT. Otherwise no major complication occurred. The likelihood of successful innervation of the FFMT was significantly higher in patients younger than 31 years (100% vs. 50%; p = .003). Smiling facial symmetry (pupillo-modiolar angle) significantly improved in the pediatric cohort (5-16 years; 8.68° ± 0.69° to 1.48° ± 0.67°; p < .001) and the young adults' cohort (17-30 years; 11.55° ± 1.95° to 4.62° ± 1.08°; p = .005), but improved only slightly in the middle-aged cohort (31-51 years; 11.77° ± 1.16° to 9.4° ± 1.8° p = .27). The postoperative smiling symmetry showed a significant correlation with increasing age (r = .62, p < .001). The smiling commissure height deviation significantly improved in the pediatric cohort (5-16 years; 6.5-2.3 mm; p = .006) and the postoperative result was significantly better than the middle-aged group (31-51 years; 2.3 vs. 7.5 mm; p = .02).

CONCLUSIONS

The outcome of CFNG-driven gracilis FFMT is age-related. Static as well as dynamic facial symmetry after two-stage facial reanimation was best in the pediatric and young adult population. For older patients, other approaches like the nerve-to-masseter-driven FFMT should be considered.

Releasing the Smile: Depressor Anguli Oris Excision in the Context of Managing Nonflaccid Facial Palsy

BACKGROUND

Nonflaccid facial palsy is a debilitating entity characterized by hypertonicity, synkinesis, and hypomobility. Patients with nonflaccid facial palsy often have smile asymmetry and restriction because of disruption of normal vector forces on the modiolus. Excision of the depressor anguli oris can lead to improved oral commissure excursion, smile angle, dental show, and symmetry.

METHODS

All depressor anguli oris resection cases between January 8, 2018, and December 26, 2019, were reviewed. Patients with postoperative photographs were included in this cohort study. Preoperative and postoperative photographs were analyzed using the Emotrics software program, and changes in oral commissure excursion, smile angle, and dental show were tracked. Clinician-graded facial palsy assessments and patient-reported outcome measures were compared preoperatively and postoperatively using the Electronic Facial Paralysis Assessment and Facial Clinimetric Evaluation Scale, respectively.

RESULTS

Forty-three patients were included in this study; 79 percent of patients underwent isolated depressor anguli oris resection. Depressor anguli oris resection led to a statistically significant increase in oral commissure median excursion, smile angle, and dental show [3.02 mm (p = 0.015), 1.70 degrees (p = 0.002), and 2.36 mm (p < 0.001), respectively]. Median Electronic Facial Paralysis Assessment and Facial Clinimetric Evaluation Scale instrument scores also improved [6.0 (p = 0.001) and 7.5 (p = 0.013), respectively]. Depressor anguli oris resection also led to more symmetric smiles. No correlation was seen between duration of follow-up and change in metrics.

CONCLUSION

Depressor anguli oris resection is a minimal-risk procedure that frequently results in improved smile dynamics, smile symmetry, and quality of life in patients with nonflaccid facial palsy.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Dynamic Facial Reanimation in an Overweight Patient and with Significant Comorbidities: An Objective Analysis of Labbè Technique

Gracilis free muscle transfer is considered the gold standard technique for facial reanimation in cases of facial palsy. However, it is limited by its long operative and recovery times, the need for a second surgical site, and its outcomes that can sometimes show midfacial bulk and oral commissure malposition. Facial reanimation with lengthening temporalis myoplasty (LTM)-Labbé technique- carries the advantage of having a shorter surgical time, a faster recovery, and being a less invasive surgery. Almost all patients included in studies of LTM were evaluated by subjective methods, and very little quantifiable data was available. A 64-year-old woman presented with long-standing incomplete right facial palsy secondary to acoustic neuroma surgery. Since she was overweight (body mass index [BMI]: 43.9) and had several cardiovascular comorbidities (hypertension, dyslipidemia), she was not a good candidate for gracilis free muscle transfer. She was submitted to facial reanimation with LTM. Fourteen months after surgery, she presented excellent facial symmetry, both at rest and in contraction, while smiling. She was evaluated with the Facegram-3D, a technology that we have developed for dynamic evaluation of facial muscle contraction. The analysis showed symmetry at rest and contraction, according to Terzis and Noah. Regarding vertical and horizontal displacement, the postoperative movement was synchronized and with less fluctuations when compared with the preoperative period. Notably, the anatomical pair's trajectories were smoother. Similar velocity profiles were found between anatomical pairs, with less abrupt changes in velocity values, further supporting improved movement control. Comparing the symmetry index, which takes a theoretical maximum of 1.0 for perfect 3D symmetry, its value was 0.56 for the commissures and 0.5 for the midpoints in the preoperative period, having improved to 0.91 and 0.82, respectively, 3 months postoperatively. Good aesthetic and functional results were achieved using the Labbè technique. LTM is a good option in cases of long-standing facial paralysis, if the patient desires a single-stage procedure with almost immediate dynamic function. Moreover, this technique assumes extreme importance in facial reanimation of patients of advanced age, overweight, or those who have several comorbidities.

Seminal Studies in Facial Reanimation Surgery: Consensus and Controversies in the Top 50 Most Cited Articles

ABSTRACT

Facial paralysis can impair one's ability to form facial expressions that are congruent with internal emotion. This hinders communication and the cognitive processing of emotional experience. Facial reanimation surgery, which aims to restore full facial expressivity is a relatively recent undertaking which is still evolving. Due in large part to published techniques, refinements, and clinical outcomes in the scientific literature, consensus on best practice is gradually emerging, whereas controversies still exist.Taking stock of how the discipline reached its current state can help delineate areas of agreement and debate, and more clearly reveal a path forward. To do this, the authors have analyzed the 50 seminal publications pertaining to facial reanimation surgery. In longstanding cases, the free gracilis transfer emerges as a clear muscle of choice but the nerve selection remains controversial with prevailing philosophies advocating cross facial nerve grafts (with or without the support of an ipsilateral motor donor) or an ipsilateral motor donor only, of which the hypoglossal and nerve to masseter predominate. The alternative orthodoxy has refined the approach popularized by Gillies in 1934 and does not require the deployment of microsurgical principles. Although this citation analysis does not tell the whole story, surgeons with an interest in facial reanimation will find that this is a good place to start.

Microanatomy of the Frontal Branch of the Facial Nerve: The Role of Nerve Caliber and Axonal Capacity

BACKGROUND

A commonly seen issue in facial palsy patients is brow ptosis caused by paralysis of the frontalis muscle powered by the frontal branch of the facial nerve. Predominantly, static methods are used for correction. Functional restoration concepts include the transfer of the deep temporal branch of the trigeminal nerve and cross-facial nerve grafts. Both techniques can neurotize the original mimic muscles in early cases or power muscle transplants in late cases. Because axonal capacity is particularly important in cross-facial nerve graft procedures, the authors investigated the microanatomical features of the frontal branch to provide the basis for its potential use and to ease intraoperative donor nerve selection.

METHODS

Nerve biopsy specimens from 106 fresh-frozen cadaver facial halves were obtained. Histologic processing and digitalization were followed by nerve morphometric analysis and semiautomated axon quantification.

RESULTS

The frontal branch showed a median of three fascicles (n = 100; range, one to nine fascicles). A mean axonal capacity of 1191 ± 668 axons (range, 186 to 3539 axons; n = 88) and an average cross-sectional diameter of 1.01 ± 0.26 mm (range, 0.43 to 1.74 mm; n = 67) were noted. In the linear regression model, diameter and axonal capacity demonstrated a positive relation (n = 57; r2 = 0.32; p < 0.001). Based on that equation, a nerve measuring 1 mm is expected to carry 1339 axons.

CONCLUSION

The authors' analysis on the microanatomy of the frontal branch could promote clinical use of cross-facial nerve graft procedures in frontalis muscle neurotization and free muscle transplantations.

Two-Stage Dual-Nerve Facial Reanimation: Outcomes and Complications in a Series of Pediatric Patients

Background

In facial reanimation via microneurovascular muscle transfer, dual-nerve reinnervation of the muscle capitalizes on the synergistic effects of spontaneous motion from cross facial nerve grafting (CFNG) and increased excursion from masseteric nerve transfer. Two-stage approaches that delay masseteric nerve transfer until the time of the muscle flap increase spontaneity by maximizing muscle reinnervation from the CFNG. While this 2-stage, dual-nerve approach has been described in adults, we present a series of pediatric patients who underwent this reconstructive technique.

Methods

We retrospectively reviewed all pediatric patients who underwent 2-stage, dual-nerve reconstruction with CFNG and ipsilateral masseteric nerve transfers. Procedures were performed between 2004 and 2016 by 2 surgeons at a single centre. Degree of facial paralysis before and after surgical intervention was measured using House-Brackmann scores.

Results

Nine patients with a mean age of 8.6 (range: 5-15 years) years at time of surgery underwent 2-stage, dual-nerve reconstruction. Average time between CFNG and transfer of the free gracilis with masseteric nerve transfer was 13.3 (SD 2.4) months. Mean follow-up was 27.3 months (SD 25.7). Patients demonstrated initiation of voluntary movement on paralyzed side by 3.6 months (SD 0.6) on average, with 3 patients demonstrating spontaneous movement at 3 months.

Conclusion

The 2-stage, dual innervation technique using CFNG and delayed ipsilateral masseteric nerve transfer with a free gracilis is a promising reconstructive option to maximize spontaneous expression in pediatric patients. Validated, objective scoring systems for excursion are needed before meaningful comparisons can be made to other reconstructive strategies.

Masseteric nerve transference with sling tendon for symmetry in the restoration of facial paralysis: An effective combination of dynamic and static correction

Masseteric nerve transposition has shown to be an effective technique for the treatment of facial paralysis. Due to its low morbidity at the donor site, its consistent anatomy, and one-stage operation, it constitutes a reliable option for both complete and incomplete facial paralysis. Masseteric nerve transference has proven to achieve good commissural excursion and dynamic symmetry. However, some patients with heavy faces and complete facial paralysis recover incompletely after surgery characterized by an asymmetrical smile with asymmetry at rest, affecting the cosmetic appearance. For these patients, we propose a novel combination of masseteric nerve transposition for the dynamic rehabilitation of the smile with a tendon sling suspension to create symmetry at rest. A detailed description of the surgical technique is given and results after using it with eight patients show good functional and aesthetic satisfaction. A combination of both dynamic and static techniques for complete facial paralysis rehabilitation may provide adequate symmetry with the contralateral healthy side both at rest and when smiling.

[Dynamic procedures for facial nerve reconstruction]

In this article the indications and surgical treatment options for patients with facial nerve palsy are discussed. A distinction is made between static and dynamic surgical procedures. Static reconstructions for example are used to restore the eyelid closure function. For smile reconstruction, which is important for the psychosocial life of the patient, dynamic procedures are used. Depending on the duration of the facial nerve paralysis, there are several possibilities to restore the smile. In this work the masseteric branch transposition to the buccal branch, the hypoglossal-facial nerve anastomosis, the Labbé procedure and the gracilis flap as a free muscle transplant are discussed. The surgical procedures are compared and the advantages and disadvantages of the intervention are presented. A spontaneous smile is aimed, this cannot always be achieved. With the masseteric branch transposition to the buccal branch and the Labbé procedure the smile is initially triggered by chewing. A spontaneous smile is possible through cortical adaptation. With the gracilis flap, however, a nerve anastomosis with the contralateral 'healthy' facial nerve is possible, either directly or via a so-called cross facial nerve grafting, whereby a spontaneous smile can be achieved.

Lessons from Gracilis Free Tissue Transfer for Facial Paralysis: Now versus 10 Years Ago

Outcomes following free gracilis muscle transfer have steadily improved during the past decade. Areas for continued improvement include re-creating natural smile vectors, improving midface symmetry, minimizing scarring, improving spontaneity, and increasing reliability using various neural sources. Outcome standardization, pooled data collection, and remote data acquisition methods will facilitate comparative effectiveness research and continued surgical advancements.

Strategies to Improve Cross-Face Nerve Grafting in Facial Paralysis

Cross-face nerve grafting enables the reanimation of the contralateral hemiface in unilateral facial palsy and may recover a spontaneous smile. This chapter discusses various clinically applicable strategies to increase the chances for good functional outcomes by maintaining the viability of the neural pathway and target muscle, increasing the number of reinnervating nerve fibers and selecting functionally compatible donor nerve branches. Adopting those strategies may help to further improve patient outcomes in facial reanimation surgery.

Maximizing the Smile Symmetry in Facial Paralysis Reconstruction: An Algorithm Based on Twenty Years' Experience

Over the last two decades, the senior author (B.H.) has had an extensive experience with facial paralysis reconstruction. During this period, the techniques have evolved substantially based on the experience and after observing and analyzing the surgical outcomes. The purpose of this article is to relay the lessons learned from the 20 years' experience and suggest an algorithm. In this retrospective study, we have included 343 cases of facial paralysis cases. Complete facial paralysis cases were 285 and 58 were incomplete facial paralyses, both requiring surgical procedures. Complete facial paralyses were divided in to short term (n = 83) and long term (n = 202). In total, 58% of the patients were women and 42% were men. The age range was 6 to 82 years. The techniques employed were direct suture, nerve grafts, cross-facial nerve grafts (CFNGs), masseteric-to-facial nerve transference, hypoglossal-to-facial nerve transference, free muscle transplants, and lengthening temporal myoplasty to achieve the best symmetry after reanimation of unilateral, bilateral, complete, and incomplete facial paralysis. The type of paralysis, objective measurements, the personal patient's smile, and the gender are key concepts to be considered before scheduling a dynamic facial paralysis reconstruction. For unilateral facial paralysis, the time of onset, the type of paralysis, the patient's comorbidities, and the healthy side status are some of the determining factors when selecting the correct technique. The preferred techniques for unilateral facial paralysis are direct repair, CFNG, masseteric-to-facial transposition, and free gracilis transfer. For incomplete facial paralysis, the masseteric-to-facial nerve transference is preferred. In bilateral facial paralysis, bilateral free gracilis transfer is performed in two stages using the nerve of the masseter muscle as the source of innervation. The authors provide an algorithm which simplifies facial paralysis reconstruction to achieve the greatest facial symmetry while thinking about the potential comorbidities and developing spontaneity smile according to the gender of the patient.

Evaluating Quality of Life After Facial Reanimation Using the Facial Clinimetric Evaluation Scale in a Series of Pediatric Patients

BACKGROUND

Facial palsy can have significant functional and psychological impact. Dynamic facial reanimation methods have provided means of restoration of smile. There remains a dearth of quality of life data in children. The authors aim to assess patient reported outcomes in this underreported population.

METHODS

A retrospective review was performed of pediatric patients with facial palsy who had dynamic facial reanimation from 2009 to 2017 at a single institution. Patients were sent a digital Facial Clinimetric Evaluation (FaCE) questionnaire, a validated tool to assess patient quality of life. FaCE statements are grouped into 6 categories: facial movement, facial comfort, oral function, eye comfort, lacrimal control, and social control.

RESULTS

Twenty patients met inclusion criteria. Fourteen successfully completed the survey. With normal function being 100, our cohort scored: facial movement 38.7 ± 14.3; facial comfort 67.3 ± 23, oral function 75 ± 22.7, eye comfort 68.75 ± 18.2, lacrimal control 53.6 ± 32.5, social function 64.3 ± 25.6. The overall FaCE score was 61.07 ± 10.85. The facial movement subscores were lower for brow raise 16.1 ± 33.4 relative to smiling 53.6 ± 29.2 and lip pucker, 46.4 ± 23.7. No correlation was found between facial movement scores and total scores (R2 < 0.01). There was a strong negative correlation between total scores and time since procedure (Spearman's rho R =  -0.45).

CONCLUSION

Our pediatric facial reanimation cohort demonstrated excellent social function, in contrast to a relatively lower facial movement score. The low facial movement score was mediated by low score for brow raise and was not correlated to overall FaCE score. Interestingly, overall FaCE score tended to decrease with time from procedure.

The sternohyoid muscle flap for new dynamic facial reanimation technique: Anatomical study and clinical results

BACKGROUND

Long-term facial nerve palsy has a highly negative impact on patients' quality of life. In 2016, Alam reported one case of facial reanimation with the sternohyoid muscle after publishing a preclinical study in 2013. Despite the potentially ideal characteristics of this muscle for reanimation of facial palsy, this technique is still not widely used. The objective of our description of cases was to present the clinical results obtained with the surgical procedure and the study on cadavers to confirm the anatomical findings.

METHODS

This work describes the anatomical study of the vascular and nervous pedicle of the sternohyoid muscle compared with clinical results from a series of patients with long-term facial paralysis who underwent facial reanimation between June 2016 and September 2019, through the insertion of the sternohyoid muscle into the masseteric nerve.

RESULTS

The anatomical study was conducted in eight human hemi-necks. In five cases (62%), the vascular pedicle was provided by the superior thyroid artery, and the entrance of the ansa cervicalis to the muscle was constant 1.8 cm from the distal insertion. This series included ten patients who underwent the surgery technique of facial reanimation using the sternohyoid muscle, with a 90% (n = 9) of reinnervation; 100% (n = 10) of flaps were viable, and none of the patients showed complications in the donor area.

CONCLUSIONS

The sternohyoid muscle showed itself as a reliable muscle as a free flap in facial reanimation, and alternative to the gracilis flap. The surgical technique was safe, without any complications, with excellent excursion, recovery, and aesthetic results.

Hypoglossal and Masseteric Nerve Transfer for Facial Reanimation: A Systematic Review and Meta-Analysis

Background: Hypoglossal and masseteric nerve transfer are currently the most popular cranial nerve transfer techniques for patients with facial paralysis. The authors performed a systematic review and meta-analysis to compare functional outcomes and adverse effects of these procedures. Methods: A review of online databases was performed to include studies with four or more patients undergoing hypoglossal or masseter nerve transfer without muscle transfer or other cranial nerve transposition. Facial nerve outcomes, time to reinnervation, and adverse events were pooled and studied. Results: A total of 71 studies were included: 15 studies included 220 masseteric-facial transfers, and 60 studies included 1312 hypoglossal-facial transfers. Oral commissure symmetry at rest was better for hypoglossal transfer (2.22 ± 1.6 mm vs. 3.62 ± 2.7 mm, p = 0.047). The composite Sunnybrook Facial Nerve Grading Scale was better for masseteric transfer (47.7 ± 7.4 vs. 33.0 ± 6.4, p < 0.001). Time to first movement (in months) was significantly faster in masseteric transfer (4.6 ± 2.6 vs. 6.3 ± 1.3, p < 0.001). Adverse effects were rare (<5%) for both procedures. Conclusions: Both nerve transfer techniques are effective for facial reanimation, and the surgeon should consider the nuanced differences in selecting the correct procedure for each patient.

Workhorse Free Functional Muscle Transfer Techniques for Smile Reanimation in Children with Congenital Facial Palsy: Case Report and Systematic Review of the Literature

BACKGROUND

Pediatric facial palsy represents a rare multifactorial entity. Facial reanimation restores smiling, thus boosting self-confidence and social integration of the affected children. The purpose of this paper is to present a systematic review of microsurgical workhorse free functional muscle transfer procedures with emphasis on the long-term functional, aesthetic, and psychosocial outcomes.

MATERIALS AND METHODS

We performed a literature search of the PubMed database from 1995 to 2019 using the following search strategy: "facial paralysis"[Title/Abstract] OR "facial palsy"[Title]. We used as limits: full text, English language, age younger than 18 years, and humans. Two independent reviewers performed the online screening process using Covidence. Forty articles met the inclusion criteria. The protocol was aligned with the PRISMA statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and was registered at the International Prospective Register of Systematic Reviews (PROSPERO, CRD42019150112) of the National Institute for Health Research.

RESULTS

Free functional muscle transfer procedures include mainly segmental gracilis, latissimus dorsi, and pectoralis minor muscle transfer. Facial reanimation procedures with the use of the cross-face nerve graft (CFNG) or masseteric nerve result in almost symmetric smiles. The transplanted muscle grows harmoniously along with the craniofacial skeleton. Muscle function and aesthetic outcomes improve over time. All children presented improved self-esteem, oral commissure opening, facial animation, and speech.

CONCLUSIONS

A two-stage CFNG plus an FFMT may restore a spontaneous emotive smile in pediatric facial palsy patients. Superior results of children FFMT compared to adults FFMT are probably attributed to greater brain plasticity.

Masseter nerve-based facial palsy reconstruction

Facial paralysis is a devastating disease, the treatment of which is challenging. The use of the masseteric nerve in facial reanimation has become increasingly popular and has been applied to an expanded range of clinical scenarios. However, appropriate selection of the motor nerve and reanimation method is vital for successful facial reanimation. In this literature review on facial reanimation and the masseter nerve, we summarize and compare various reanimation methods using the masseter nerve. The masseter nerve can be used for direct coaptation with the paralyzed facial nerve for temporary motor input during cross-facial nerve graft regeneration and for double innervation with the contralateral facial nerve. The masseter nerve is favorable because of its proximity to the facial nerve, limited donor site morbidity, and rapid functional recovery. Masseter nerve transfer usually leads to improved symmetry and oral commissure excursion due to robust motor input. However, the lack of a spontaneous, effortless smile is a significant concern with the use of the masseter nerve. A thorough understanding of the advantages and disadvantages of the use of the masseter nerve, along with careful patient selection, can expand its use in clinical scenarios and improve the outcomes of facial reanimation surgery.

Combining an end to side nerve to masseter transfer with cross face nerve graft for functional upgrade in partial facial paralysis-an observational cohort study

BACKGROUND

Results of a single stage technique combining cross facial nerve graft(s) (CFNG) with an ipsilateral end to side nerve to masseter transfer (NTM) in incomplete facial paralysis are assessed in a retrospective cohort study. The hypothesis is that the technique can safely improve the quality of smile in these patients. End to side coaptations for the recipient facial nerve minimise the risk of iatrogenic function loss, contrasting with the end to end neurorrhaphies used in conventional babysitting procedures.

METHODS

A series of 27 patients was studied through case note review and standardised assessments. Surgical technique involves extensive exposure of the facial nerve and the NTM on the affected side and access is by bilateral preauricular incisions. End to end coaptations are made to the facial nerve on the donor side and on the recipient a standard CFNG is combined with an end to side NTM coaptation. Follow up was a minimum of 9 months from surgery.

RESULTS

Overall improvement in the Sunnybrook scale averaged 33, from a pre-operative score of 40 (p < 0.05). Average upgrade of 4.7 mm of increased movement at the modiolus was achieved (p < 0.05), 43% improvement compared to the normal side. An improved resting symmetry of 3.8 mm was achieved in relevant cases. Where eye closure was strengthened the average improvement was 5 mm of increased lid closure. The smile achieved was spontaneous in 22 of 27 cases.

CONCLUSION

The study confirms the hypothesis that CFNG with NTM transfer offers a physiological upgrade of facial movement in partial facial paralysis, applicable in both early and longstanding cases.

Free Functional Gracilis Flaps for Facial Reanimation in Elderly Patients

Importance: The free functional gracilis flap (FFGF) is a versatile procedure in reanimating the paralyzed face, yet its application in seniors is limited by perceptions of morbidity and inefficacy. Objective: The study objective was to compare the morbidity and effectiveness of FFGF reanimation among senior and younger patients. Design, Setting, and Participants: A retrospective chart review was performed on 20 consecutive patients aged 60 years and above (seniors) and 35 patients aged 40 years and below (juniors) who underwent FFGF for facial reanimation. Among this group, 16 senior and 22 junior patients with available long-term follow-up data were analyzed for functional outcomes. Main Outcomes and Measures: The length of postoperative stay and postoperative complications were compared with assess immediate results. A second analysis for functional outcomes was assessed by resting and smile facial asymmetry index (FAI), as well as maxillary dental display to compare facial tone and lip excursion. Results: The average age of seniors was 67 ± 5 years and that of juniors was 27 ± 10 years. Mean lengths of postoperative stay were 4 ± 2 versus 3 ± 1 days in seniors versus Juniors, respectively (p = 0.16). There were no intraoperative complications and postoperative complications in one (5%) senior and four (11%) juniors (p = 0.64). There was functional muscle recovery in all cases, with more pronounced correction of both resting (Δ3.0 mm vs. Δ2.4 mm, p = 0.66) and dynamic (Δ5.2 mm vs. Δ4.2 mm, p = 0.37) FAI in seniors than in juniors. Among patients who underwent a multivector FGFF, there was an additional three versus one visualized maxillary teeth (p = 0.03) in seniors versus juniors, respectively. Conclusions and Relevance: The FFGF is effective for facial reanimation among seniors and can be performed with minimal morbidity. Age alone should not preclude the application of the FFGF in seniors with a preference for more dynamic options.

Spontaneity Assessment in Dually Innervated Gracilis Smile Reanimation Surgery

Importance

Surgeons have sought to optimize outcomes of smile reanimation surgery by combining inputs from nerve-to-masseter and cross-face nerve grafts. An objective assessment tool could help surgeons evaluate outcomes to determine the optimal neural sources for smile reanimation.

Objective

To evaluate the use of a novel video time-stamping method and standard outcome measurement tools to assess outcomes of facial reanimation surgery using various innervation strategies.

Design, Setting, and Participants

Cohort study assessing the outcomes of dually innervated gracilis free muscle transfers vs single-source innervated gracilis transfer performed at a tertiary care facial nerve center between 2007 and 2017 using a novel, video time-stamping spontaneity assessment method. The statistical analyses were performed in 2018.

Interventions

Dually innervated gracilis free muscle transfers or single-source innervated gracilis transfer.

Main Outcomes and Measures

Spontaneous smiling was assessed by clinicians and quantified using blinded time-stamped video recordings of smiling elicited while viewing humorous video clips.

Results

This retrospective cohort study included 25 patients (12 men and 13 women; median [range] age, 38.4 [29.3-46.0] years) treated with dually innervated gracilis free functional muscle graft for unilateral facial palsy between 2007 and 2017. Smile spontaneity assessment was performed in 17 patients and was compared with assessment performed in 24 patients treated with single-source innervated gracilis transfer (ie, nerve-to-masseter-driven or cross-face nerve graft-driven gracilis [n = 13]) (demographic data not available for NTM and CFNG cohorts). The use of time-stamped video assessment revealed that spontaneous synchronous oral commissure movement in a median percentage of smiles was 33% in patients with dually innervated gracilis (interquartile range [IQR], 0%-71%), 20% of smiles in patients with nerve-to-masseter-driven gracilis (IQR, 0%-50%), and 75% of smiles in patients with cross-face nerve graft-driven gracilis (IQR, 0%-100%). Clinicians graded smile spontaneity in dually innervated cases as absent in 40% (n = 6 of 15), trace in 33% (n = 5 of 15) and present in 27% (n = 4 of 15). No association was demonstrated between clinician-reported spontaneity and objectively measured synchronicity.

Conclusions and Relevance

Dually innervated gracilis free muscle transfers may improve smile spontaneity compared with masseteric nerve-driven transfers but not to the level of cross-face nerve graft-driven gracilis transfers. Quantifying spontaneity is notoriously difficult, and most authors rely on clinical assessment. Our results suggest that clinicians may rate presence of spontaneity higher than objective measures, highlighting the importance of standardized assessment techniques.

Level of Evidence

4.

Dual Coaptation of Facial Nerve Using Masseteric Branch of Trigeminal Nerve for Iatrogenic Facial Palsy: Preliminary Reports

OBJECTIVES

Immediate facial nerve substitution or graft technique has been used for the repair of facial nerve defects occurring as a result of tumour dissection. However, some patients report unsatisfactory outcomes, such as difficulty in maintaining resting or smiling symmetry, due to persistent flaccid facial palsy. Here we evaluated the functional outcomes of transferring the masseteric branch of the trigeminal nerve to the facial nerve adjunct to facial nerve graft.

METHODS

We reviewed the medical records of seven patients who underwent facial reanimation surgery between 2014 and 2016. The patients were divided into two groups according to the type of facial reanimation surgery: group A, masseteric nerve innervation with interposition graft; group B, interposition graft only. The postoperative resting symmetry and dynamic movement were compared.

RESULTS

Facial contraction was first observed in group A at 4 months and in group B at 7.3 months. Most of the patients achieved reliable resting symmetry; however, one patient in group B exhibited unsatisfactory facial weakness on the affected side. Group A patients showed better dynamic movement than group B patients. Eye closure, oral excursion and oral continence were better in group A than in group B patients. Smile symmetry in both groups was similar due to hyperkinetic movement in group A patients and flaccidity in group B patients.

CONCLUSIONS

Dual innervation of the masseteric branch of the trigeminal nerve improves the dynamic movement of paralysed facial muscles and shortens the recovery period in patients with iatrogenic facial palsy.