A Surgeon's Armamentarium for Ocular Management in Facial Paralysis: A Comprehensive Review.

OBJECTIVE: To review the current management paradigm of the eye in patients with facial paralysis. METHODS: A PubMed and Cochrane search was done with no date restrictions for English-language literature on facial synkinesis. The search terms used were "ocular," "facial," "synkinesis," "palsy," "neurotization," and various combinations of the terms. A total of 65 articles were included. RESULTS: Facial paralysis may result in devastating ocular sequelae. Therefore, assessment of the eye in facial paralysis is a critical component of patient management. Although the management should be individualized to the patient, the primary objective should include an ophthalmologic evaluation to implement measures to protect the ocular surface and preserve visual acuity. The degree of facial paralysis, lacrimal secretion, corneal sensation, and position of the eyelids should be assessed thoroughly. Patients with the anticipated recovery of facial nerve function may respond to more conservative temporizing measures to protect the ocular surface. Conversely, patients with expected prolonged paralysis should be appropriately identified as they will benefit from surgical reconstruction and rehabilitation of the periorbital complex. The majority of reconstructive measures within a facial surgeon's armamentarium augment coverage of the eye but are unable to restore blink. Eyelid reanimation restores the esthetic proportionality of the eye with blinking and reestablishes protective functions necessary for ocular preservation and function. CONCLUSIONS: Ocular preservation is the primary priority in the initial management of the patient with facial paralysis. An accurate assessment is a critical component in identifying the type of paralysis and developing an individualized treatment plan.

Selective Neurectomy for Treatment of Post-Facial Paralysis Synkinesis: A Systematic Review.

BACKGROUND: Synkinesis is commonly encountered after flaccid facial paralysis and can have a detrimental impact on a patient's life. First-line treatment of synkinesis is chemodenervation with botulinum toxin (Botox) and neuromuscular retraining. Surgical options include selective myectomy, selective neurectomy (SN), cross-facial nerve grafting, nerve substitution, and free gracilis muscle transfer. Data on surgical management of synkinesis using SN is limited. EVIDENCE REVIEW: PubMed, Embase, Cochrane CENTRAL, Cochrane Neuromuscular Register, Clinicaltrials.gov, and World Health Organization International Clinical Trials Registry Platform were searched using a comprehensive keyword strategy in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All English-only texts published in the past 20 years were included. Two independent investigators reviewed 906 abstracts and 7 studies met inclusion criteria. Demographics, etiology of paralysis, time to surgery, and primary outcomes studied were collected. FINDINGS: A total of 250 patients were included across 7 studies. In 6 out of 7 studies, Botox was used prior to surgical intervention. Two studies showed significant reduction in Botox dosage postoperatively, while one study showed no difference. Other primary outcomes included the House-Brackmann Score, palpebral fissure width, electronic clinician-graded facial function scale (eFACE) score, Facial Clinimetric Evaluation (FaCE) scale, and Synkinesis Assessment Questionnaire (SAQ). Three studies showed significant improvement in the eFACE score, two studies showed significant improvement in the FaCE scale, while one study showed improvement in quality of life measured by the SAQ. CONCLUSION: SN can be considered as an adjunct to other management options including neuromuscular retraining, Botox, selective myectomy, and reanimation procedures. While there is great heterogeneity of study design in the studies included, many cohorts showed improvement in facial symmetry, facial function, and quality of life. There remains a great gap in knowledge in this subject matter and a need for large well-designed prospective studies comparing this technique to other management options.

Depressor Anguli Oris Myectomy versus Transfer to Depressor Labii Inferioris for Facial Symmetry in Synkinetic Facial Paralysis.

BACKGROUND: Postparalytic synkinesis presents with a combination of hypo- and hypertonic muscles, leading to facial asynchrony with animation and at rest. One ubiquitous finding is a hypertonic depressor anguli oris (DAO) muscle and a weak depressor labii inferioris (DLI) muscle. The goal of this study was to evaluate the utility of DAO myectomy with or without its transfer to the weakened DLI in improving critical components of the dynamic smile. METHODS: From 2018 to 2020, this single-center, prospective study included of postparetic facial synkinetic patients with evidence of DAO hypertonicity who underwent DAO myectomy with or without transfer to DLI. Objective facial measurements were used to compare the effectiveness of DAO to DLI transfer to pure DAO myectomy in improving asymmetry of the synkinetic hemiface. RESULTS: Twenty-one patients with unilateral postparetic facial synkinesis with DAO hypertonicity were included; 11 underwent DAO myectomy, while 10 underwent DAO to DLI transfer. Baseline demographics and facial measurements were similar between the groups. DAO myectomy resulted in increased modiolus resting position, closed-mouth smile modiolus angle and excursion, open-mouth smile modiolus angle, excursion, dental show, and decreased lower lip height deviation. DAO to DLI transfer demonstrated similar findings but lacked significant increase in excursion and resulted in worsened lower lip height deviation. CONCLUSION: These findings illustrate the utility of DAO myectomy in improving imbalance in the synkinetic patient and necessitate further technical refinements for DAO transfers or a different approach for improving lower lip depression in this subgroup of patients.

Epineurectomy of Facial Nerve Trunk for Refractory Oral-Ocular and Oculo-Oral Synkinesis Following Bell Palsy.

BACKGROUND: Synkinesis is a common sequelae after incomplete recovery from Bell palsy. Current first-line treatments include botulinum toxin injection and physical therapy. However, patients unresponsive to these treatments may require further surgery. Various surgical treatments have been reported, but no consensus has been reached for the optimal surgery. In a guinea pig model of synkinesis, the facial nerve trunk (FNT) was observed using a scanning electron microscope. Based on the results of scanning electron microscope and clinical ultrasonography, the authors chose FNT as the therapeutic target. METHODS: The authors performed epineurectomy of FNT for 11 patients with refractory oral-ocular and oculo-oral synkinesis under abnormal muscle response and facial electromyography monitoring. The postoperative assessments at 1 year were conducted using Sunnybrook Facial Grading System and Facial Disability Index scale. Furthermore, the epineurium excised during the operation was collected as the specimen and submitted for histopathological examination; the cadaveric FNT served as the control group. RESULTS: The follow-up results showed significant relief from synkinesis (4.91 ±â€Š0.37 versus 10.18 ±â€Š0.64, P < 0.01), improvement of physical (84.55 ±â€Š1.96 versus 73.18 ±â€Š3.65, P < 0.01) and social functions (77.09 ±â€Š3.24 versus 61.82 ±â€Š6.28, P < 0.01), with no worsening of facial paralysis in the patients. The histopathological examination revealed many nerve fibers in the epineurium, suggesting that FNT was the area of aberrant axon regeneration. CONCLUSIONS: Epineurectomy of FNT is a safe and effective surgical remedy. It can be considered as a surgical option for patients with refractory oral-ocular and oculo-oral synkinesis following Bell palsy.

Masseteric-zygomatic nerve transfer for the management of eye closure-smile excursion synkinesis.

OBJECTIVE: The purpose of this study is to illustrate the efficacy of masseteric-to-zygomatic nerve transfer to address eye closure-smile excursion synkinesis after facial nerve paralysis. BACKGROUND: Synkinesis after facial nerve paralysis represents a wide range of facial movement disability. One manifestation is involuntary smiling with eye closure and a concomitant reduction of oral commissure movement with attempted smile ("frozen smile") - arising as a result of aberrant fibers populating the zygomatic branch-muscle complex. This is a particularly difficult area to treat with conservative management. We propose a single-stage procedure to sever the dysfunctional zygomatic nerve and perform a masseteric-zygomatic nerve coaptation to recover a voluntary smile. METHODS: We present a case series of eight patients with eye closure/smile excursion synkinesis who underwent single-stage masseteric-zygomatic nerve transfer by a single surgeon. The surgical technique and indications for surgery were reviewed. Patients underwent facial movement analysis using Emotrics. RESULTS: We analyzed the pre- and post- surgical photographic images of 8 patients with synkinesis (7 female, 1 male). Masseteric-facial nerve transfer was performed from 18 months to 22 years after the initial facial paralysis. Eyelid and brow positioning were more symmetric after surgery, with discrepancy between affected and unaffected side decreasing from 2.1 to 1.0 mm (p < .05) and 1.74 to 1.29 mm (p < .05), respectively. Symmetry of smile excursion postoperatively was also improved with commissure excursion discrepancy decreasing from 8.8 to 3.78 mm (p < .05). Discrepancy in the smile angle when comparing affected to unaffected side improved postoperatively from 10.3 to 5.2 degrees (p < .05). Improvement in oral commissure height was noted, but not statistically significant. CONCLUSIONS: The masseteric-zygomatic nerve transfer is a useful technique for the treatment of eye closure/smile excursion synkinesis after failure of chemodenervation and/or physical therapy.

Facial nerve repair: the impact of technical variations on the final outcome.

OBJECTIVES: To analyze the outcome of facial nerve (FN) reconstruction, the impact of technical variations in different conditions and locations, and the importance of additional techniques in case of suboptimal results. STUDY DESIGN: Retrospective study. SETTING: University-based tertiary referral center. PATIENTS: Between 2001 and 2017, reconstruction of the FN was performed on 36 patients with varying underlying diseases. INTERVENTIONS: FN repair was performed by direct coaptation (n = 3) or graft interposition (n = 33). Microsurgical sutures were used in 17 patients (47%) and fibrin glue was used in all cases. Additional reinnervation techniques (hypoglossal-facial or masseter-facial transfers) were performed in five patients with poor results after initial reconstruction. MAIN OUTCOME MEASURES: FN function was evaluated using the House-Brackmann (HB) and the electronic clinician-graded facial function (eFACE) grading systems. Minimum follow-up was 12 months. RESULTS: FN reconstruction yielded improvement in 83% of patients, 21 patients (58.3%) achieving a HB grade III. The eFACE median composite, static, dynamic and synkinesis scores were 69.1, 78, 53.2, and 88.2 respectively. A tendency towards better outcome with the use of sutures was found, the difference not being significant. All patients undergoing an additional reinnervation procedure achieved a HB grade III, eFACE score being 74.8. CONCLUSIONS: FN reconstruction offers acceptable functional results in most cases. No significant differences are expected with technical variations, different locations or conditions. In patients with poor initial results, additional reinnervation techniques should be always considered. The eFACE adds substantial information to the most used HB scale.

Oculo-zygomatic nerve transfer for facial synkinesis: An anatomical feasibility study.

BACKGROUND: Patients with severe oro-ocular synkinesis often present with concomitant inefficient smile excursion on the affected site. In theory, oculo-zygomatic nerve transfer may decrease synkinesis and improve smile by redirecting nerve fibers to their target muscle. The aim of this study was to explore the feasibility of nerve transfer in human cadavers between a caudal branch innervating the orbicularis oculi to a cephalad branch innervating the zygomaticus major muscles. METHODS: Eighteen hemi-faces were dissected. Reach for direct coaptation of a caudal nerve branch innervating the orbicularis oculi muscle to a cephalad nerve branch innervating the zygomaticus major muscle was assessed. Measurements included total number of nerve branches as well as maximum dissection length. Nerve samples were taken from both branches at the site of coaptation and histomorphometric analysis for axonal count was performed. RESULTS: The number of sub-branches to the orbicularis oculi muscle was 3.1 ± 1.0 and to the zygomaticus major muscle 4.7 ± 1.2. The maximal length of dissection of the caudal nerve branch to the orbicularis oculi muscle was 28.3 ± 7.3 mm and for the cranial nerve branch to the zygomaticus major muscle 23.8 ± 6.5 mm. Transection and tension-free coaptation was possible in all cases but one. The average myelinated fiber counts per mm2 was of 5,173 ± 2,293 for the caudal orbicularis oculi branch and 5,256 ± 1,774 for the cephalad zygomaticus major branch. CONCLUSION: Oculo-zygomatic nerve transfer is an anatomically feasible procedure. The clinical value of this procedure, however, remains to be proven.

Nerve Switch for Reducing Synkinesis After Gracilis Muscle Transfer Innervated Via the Masseter Nerve.

BACKGROUND: In surgical treatment for longstanding facial paralysis, muscle transplantation is considered a useful and important method. To obtain a spontaneous smile, the use of the facial nerve of the healthy side as a motor source is better, but use of the masseter nerve allows prompt reinnervation and powerful movement. However, in some patients in whom the masseter nerve is used, separating masticatory movement and commissure contraction is difficult. Solutions for such patients have not been determined. CASE HISTORY AND DISCUSSION: A 46-year-old female patient presented with longstanding complete facial paralysis after resection of a right acoustic neurinoma. As initial surgery, free gracilis transfer was performed on the cheek, but the patient experienced commissure movement during meals postsurgery. Secondary corrective surgery was performed to detach the motor nerve of the gracilis from the masseter nerve and suture it to the facial nerve of the healthy side via cross-face nerve graft. The symptom improved but partially recurred. Improvement in synkinetic movement can be obtained by performing cross-face nerve grafting and subsequent nerve switch.

Idiopathic Synkinesis of the Facial Musculature: Oculo-Nasal, Oculo-Zygomatic, and Fronto-Nasal Synkinesis.

Facial synkinesis is the simultaneous contraction of the certain facial musculature accompanying a motion of designated muscle in the face. With the exception of rare afflictions that are congenital in origin, most patients develop as a sequel to facial nerve paralysis due to trauma, tumor, and surgical injury. As an idiopathic congenital form, oculo-nasal synkinesis which reveals co-contraction of orbicularis oculi and the compressor narium minor muscles which are innervated by separate branches of the facial nerve have been already reported. In addition to oculo-nasal synkinesis, the authors describe 2 more rare patients with facial synkinesis; oculo-zygomatic and fronto-nasal synkinesis with video documentation, which to the best of our knowledge, have not been reported previously in detail. This will help plastic surgeons prevent being involved in legal issues when they might neglect these rare phenomena in preoperative evaluation during cosmetic surgery.

Oculonasal Synkinesis: Video Report and Surgical Solution of a Rare Phenomenon.

BACKGROUND: Synkinesis represents involuntary muscular movements that occur in association with voluntary contraction of other muscle groups. Oculonasal synkinesis is a rare phenomenon. OBJECTIVES: In a series of videos, the authors present clinical findings and surgical correction of oculonasal synkinesis. METHODS: Two women who underwent surgical procedures to correct oculonasal synkinesis were evaluated in a prospective study. One patient presented with bilateral synkinesis after 2 previous rhinoplasties. She underwent open rhinoplasty in our office. The other patient had unilateral synkinesis of the left side and received endonasal rhinoplasty. RESULTS: The patients' mean age was 27.5 years, and follow-up was conducted for 6 months. Both patients experienced complete, stable resolution of synkinesis after surgical correction. No complications were recorded. CONCLUSIONS: Patients with oculonasal synkinesis may not notice it preoperatively and may regard these muscle movements as an unfavorable result of rhinoplasty. Therefore, careful preoperative evaluation is crucial.

Selective neurolysis in post-paralytic facial nerve syndrome (PFS).

UNLABELLED: Post-paralytic facial nerve syndrome (PFS) summarizes specific symptoms that result from an incomplete or poor recovery of the facial nerve after peripheral facial palsy. Selective chemodenervation using botulinum toxin A (Btx A) and mime therapy represent the therapeutic standard for treating PFS. We report on a 35-year-old male who was suffering greatly from unilateral PFS-specific movement disorders, including periorbital contractions and oculofacial synkinesis that did not respond to Btx A administration. We present a surgical alternative to overcome periorbital movement disorders by selective neurolysis and review therapeutic options for this rare syndrome. In conclusion, selective neurolysis appears to be an efficient alternative treatment method of PFS in which the quality of life is severely impacted due to movement disorders and there was no therapeutic benefit from Btx A. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Pre-Operative Factors May Predict Outcome in Selective Neurectomy for Synkinesis.

Background: While there has been great interest in offering selective neurectomy (SN) to patients with nonflaccid facial palsy (NFFP), postoperative outcomes are inconsistent. Objective: To assess overall SN outcome in NFFP patients and to examine correlation between preoperative factors and SN outcome. Methods: SN cases were retrospectively identified between 2019 and 2021. Patient factors and facial function were assessed using chart review, the Facial Clinimetric Evaluation (FaCE), the electronic clinician-graded facial function tool (eFACE), and an automated computer-aided facial assessment tool (Emotrics). Correlations between preoperative factors and patients outcome were established. Results: Fifty-eight SN cases were performed; 88% were females, and median age was 53 years (range 11-81). Outcome assessment was 8 months on average (1-24 months). Postoperatively, multiple eFACE and Emotrics parameters improved significantly, including ocular, perioral, and synkinesis metrics. In preoperative factors assessment, age >50, facial palsy (FP) duration >2 years, poor preoperative facial function, and nontrauma etiology all correlated with greater improvements compared with younger patients, those with shorter duration facial palsy, trauma etiology, and better preoperative facial function. Conclusions: SN can significantly improve facial function; we have identified several preoperative factors that correlated to outcome.

Chemodenervation Algorithm: Functional and Aesthetic Considerations for Facial Harmony in Patients with Post-Facial Paralysis Synkinesis.

Management of post-facial paralysis synkinesis has evolved for the past decade with diversification of neuromuscular retraining, chemodenervation, and advanced surgical reanimation techniques. Chemodenervation with botulinum toxin-A is a commonly used treatment modality for synkinesis patients. Treatment has shifted from solely weakening the unaffected contralateral facial musculature for rote symmetry to selective reduction of undesired or overactive synkinetic muscles, allowing for a more organized motion of the recovered musculature. Facial neuromuscular retraining should be considered a crucial component of treating patients with synkinesis along with soft tissue mobilization, but specifics of these are beyond the scope of this article. Our goal was to create a descriptive platform for our method of chemodenervation treatment in the evolving field of post-facial paralysis synkinesis. A multi-institutional and multidisciplinary comparison of techniques was performed with photograph and video creation, review, and discussion over an electronic platform with all authors. Anatomic specifics of each region of the face and individual muscles were considered. A muscle by muscle algorithm for synkinesis therapy was created to include chemodenervation with botulinum toxin that should be considered for patients suffering from post-facial paralysis synkinesis.

Modified Selective Neurectomy for Post Facial Paralysis Synkinesis Smile Dysfunction.

Following incomplete facial nerve injury, patients may develop aberrant facial nerve reinnervation, which can result in facial synkinesis. The treatment goals for patients with postfacial paralysis synkinesis are to improve resting oral commissure position, oral competence, facial and cervical tightness, and smile symmetry and spontaneity. Modified selective neurectomy of the facial nerve as described by Azizzadeh and colleagues is a targeted surgical method that allows the surgeon to eliminate the antagonist movements of the face and allow the favorable movements of the face to predominate, resulting in a more natural smile.

Outcome evaluation using an artificial intelligence-based facial measurement software for facial nerve grafting in head and neck and skull base surgery.

BACKGROUND: Interposition nerve grafting is an indispensable technique for facial nerve reconstruction in head and neck, and skull base surgery. The prognostic factors are inconclusive, partly due to limited objective assessment systems for facial nerve function. This study aimed to apply an artificial intelligence (AI)-based facial asymmetry measurement system to assess facial nerve grafting outcomes. METHODS: We retrospectively reviewed data of 23 patients who underwent facial nerve grafting between 2011 and 2020. Oral asymmetry and synkinesis severity were measured using AI. RESULTS: Oral movement recovered at 12-18 months postoperatively. Postoperative radiotherapy and a larger number of anastomosed distal stumps were significantly associated with poor and good final oral symmetry, respectively. Synkinesis severity was weakly correlated with the degree of oral movement recovery. CONCLUSIONS: Oral function recovered without a strong correlation with synkinesis. Caution should be exercised in facial nerve grafting for cases with postoperative radiotherapy.

Selective neurectomy for nonflaccid facial palsy.

PURPOSE OF REVIEW: To review the evolving role of selective neurectomy in the management of patients with synkinesis including the history of selective neurectomy, operative techniques, and clinical outcomes. RECENT FINDINGS: Modified selective neurectomy alone or in conjunction with other procedures achieves more durable outcomes based on objective measures such as time to recurrence of symptoms and units of botulinum toxin required postoperatively. This is also reflected on patient reported quality of life outcome measures. Regarding operative technique, lower rates of oral incompetence are reported with division of an average of 6.7 nerve branches as opposed to more branches. SUMMARY: Chemodenervation has long been the mainstay of treatment in facial synkinesis, but in recent years, the paradigm has begun to shift in favor of incorporating interventions with more durable outcomes such as modified selective neurectomy. Modified selective neurectomy is often performed with other simultaneous surgeries such as nerve transfer, rhytidectomy, lid surgery and static facial reanimation primarily to address periocular synkinesis and synkinetic smile. The outcomes have been favorable with improvement in quality-of-life measures and a decrease in botulinum toxin requirements.

Do Preoperative Depressor Anguli Oris Muscle Blocks Predict Myectomy Outcomes? A Single-Cohort Comparison in Postparetic Facial Synkinesis.

SUMMARY: The complexity of facial synkinesis will likely benefit from an individualized approach to intervene on discrete synkinetic facial subunits. This overarching treatment algorithm requires understanding each synkinetic mimetic subunit. The depressor anguli oris muscle, because of its antagonistic relationship to the zygomaticus major, is of particular interest. This study aims to provide outcomes of depressor anguli oris muscle myectomies and the predictive value of preoperative lidocaine blocks. Preoperative depressor anguli oris muscle lidocaine blocks were administered to patients with postparetic facial synkinesis, and subsequent isolated depressor anguli oris muscle myectomies were performed on those who showed improvement and elected to proceed. Twenty synkinetic patients underwent isolated depressor anguli oris myectomies after lidocaine blockade, with an average follow-up of 9 months. Facial mimetic parameters and measurements were recorded and analyzed by Massachusetts Eye and Ear Infirmary Emotrics and National Institutes of Health ImageJ software to compare results from both blocks and myectomies. Both lidocaine block and depressor anguli oris myectomy improved dental show by 14.42 mm 2 and 23.012 mm 2 , respectively, and open mouth smile angles above a horizontal plane by 4.66 and 3.32 degrees, respectively. There was no statistical difference between the groups in terms of improvements noted in closed and open mouth smile angles above a horizontal plane, or in dental show ( p = 0.695, p = 0.351, and p = 0.242, respectively). Preoperative lidocaine blockade accurately predicts the improvement in dental show and modiolus smile angle that is provided by isolated depressor anguli oris muscle myectomy. This furthers our understanding of depressor anguli oris muscle abnormality in the overall spectrum of facial synkinesis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Synkinetic Brow Dysfunction: Diagnosis and Treatment Algorithm.

Importance: The diagnosis and management of brow dysfunction in patients with postfacial paralysis with synkinesis can be perplexing and challenging for the treating physician. Objective: To describe a novel diagnostic and treatment algorithm for brow dysfunction in patients with postfacial paralysis with synkinesis. Design: Surgical pearls-description of novel surgical technique. Setting: A private practice. Participants: Patients who underwent the operation.

Surgical Treatment for Postparalytic Facial Synkinesis: A 35-Year Experience.

BACKGROUND: Surgical intervention with combined myectomy and neurectomy followed by functioning free muscle transplantation has been proposed to effectively resolve the problem of postparalytic facial synkinesis since 1985, and it continues to be the authors' standard of care. The authors aim to provide evidence that this surgical strategy is effective for treatment of synkinesis and smile quality. METHODS: One hundred three patients with postparalytic facial synkinesis were investigated (1985 to 2020). They all underwent extensive removal of the synkinetic muscles and triggered facial nerve branches in the cheek, nose, and neck regions, followed by gracilis functioning free muscle transplantation for facial reanimation. Ninety-four patients (50 with type II and 44 with type III postparalytic facial synkinesis), all of whom had at least 1 year of postoperative follow-up, were included in the study. Patient demographics and functional and aesthetic evaluations before and after surgery were collected. RESULTS: In the yearly distribution of the facial paralysis reconstruction, the incidence of surgical intervention increased from 15 percent before 2012 up to 24 percent in the years after. Young adults (79 percent) and female patients (63 percent) were the dominant population. Results showed a significant improvement of the facial smile quality, with more teeth visible while smiling, and a long-lasting decrease of facial synkinesis. Ninety-six percent of patients did not require botulinum toxin type A injection after surgery. Revision surgery for secondary deformity was 53 percent. CONCLUSIONS: Combined myectomy and neurectomy followed by functioning free muscle transplantation for type II and III synkinetic patients leads to promising and long-lasting results despite high revision rates. Refined techniques to decrease the revision rates are needed in the future. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Modified Selective Neurectomy: A New Paradigm in the Management of Facial Palsy with Synkinesis.

All patients with postparalytic facial paralysis are at risk of developing synkinesis due to aberrant nerve regeneration. Synkinesis can result in smile dysfunction, tension, and eyelid aperture narrowing due to overactive and uncoordinated muscle activity. When the synkinesis causes an asymmetric smile, there are several treatment modalities including neurotoxin, neuromuscular retraining, and surgery. Modified selective neurectomy of the facial nerve is a treatment option that potentially can improve the smile mechanism by reducing the activity of counterproductive facial muscles while preserving the natural neural pathway.