CME Contemporary Solutions for the Treatment of Facial Nerve Paralysis Ryan M. Garcia, M.D. Tessa A. Hadlock, M.D. Michael J. Klebuc, M.D. Roger L. Simpson, M.D., M.B.A. Michael R. Zenn, M.D., M.B.A. Jeffrey R. Marcus, M.D. Durham, N.C.; Boston, Mass.; Houston, Texas; and East Meadow, N.Y.
Learning Objectives: After reviewing this article, the participant should be able to: 1. Understand the most modern indications and technique for neurotization, including masseter-to-facial nerve transfer (fifth-to-seventh cranial nerve transfer). 2. Contrast the advantages and limitations associated with contiguous muscle transfers and free-muscle transfers for facial reanimation. 3. Understand the indications for a two-stage and one-stage free gracilis muscle transfer for facial reanimation. 4. Apply nonsurgical adjuvant treatments for acute facial nerve paralysis. Summary: Facial expression is a complex neuromotor and psychomotor process that is disrupted in patients with facial paralysis breaking the link between emotion and physical expression. Contemporary reconstructive options are being implemented in patients with facial paralysis. While static procedures provide facial symmetry at rest, true "facial reanimation" requires restoration of facial movement. Contemporary treatment options include neurotization procedures (a new motor nerve is used to restore innervation to a viable muscle), contiguous regional muscle transfer (most commonly temporalis muscle transfer), microsurgical free muscle transfer, and nonsurgical adjuvants used to balance facial symmetry. Each approach has advantages and disadvantages along with ongoing controversies and should be individualized for each patient. Treatments for patients with facial paralysis continue to evolve in order to restore the complex psychomotor process of facial expression. (Plast. Reconstr. Surg. 135: 1025e, 2015.)
T
his continuing medical education article intends to provide a broad perspective on the currently available treatments for patients with facial paralysis. The presentation and manifestation of facial paralysis is extremely heterogeneous, and the range of possible treatments is equally diverse. In some areas, consensus has not been determined. In this article, we merge the opinions from experts in specific subject areas, highlight the areas of consensus, and explain the areas where differences of opinion still exist. Facial expression is a complex neuromotor and psychomotor process linking physical expression with emotion. Facial nerve palsy, a broad From the Division of Plastic and Reconstructive Surgery, Department of Surgery, Duke University Medical Center; Massachusetts Eye and Ear Infirmary; the Division of Plastic and Reconstructive Surgery, Department of Surgery, Baylor College of Medicine, The Methodist Hospital; Long Island Plastic Surgical Group; and the Division of Plastic Surgery, Department of Surgery, Nassau University Medical Center. Received for publication January 23, 2013; accepted May 2, 2013. Copyright © 2015 by the American Society of Plastic Surgeons DOI: 10.1097/PRS.0000000000001273
descriptive term, describes paralysis of any structure that is innervated by the facial nerve, thus inhibiting facial expression. The most troublesome psychosocial effect of facial nerve paralysis occurs during social interactions. Facial expression, even without language, provides a participant in a social interaction with important cues and insight into another’s meanings, intentions, and emotional states. Without these clues, social interactions become severely compromised. The most extreme example, Möbius syndrome (bilateral facial nerve Disclosure: Dr. Zenn is a consultant for LifeCell and Novadaq. Dr. Marcus has received royalties from Stryker Leibinger for SmartLock Hybrid IMF. The other authors have no financial interest to declare in relation to the content of this article.
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Plastic and Reconstructive Surgery • June 2015 paralysis), manifests with symmetrically flat facial expressions, thus severely inhibiting successful social interactions and emotional expression. In addition to the nonverbal communication provided by facial expression, facial muscles are responsible for essential functions such as eyelid closure, oral competence, and phonation of labial sounds. Paralysis of the frontalis muscle leads to an obstructed gaze that is progressive with age. Paralysis of the orbicularis oculi muscle leads to exposure and drying of the cornea and an inability to protect the eye from foreign material. Nasal obstruction can be present and debilitating to patients with facial paralysis. Nasal obstruction can be unilateral or bilateral and cause the nasal base to shift toward the nonparalyzed side by an unopposed action. With regard to the lower face, the orbicularis oris muscle encircles the mouth and controls oral competence, whereas the buccinator muscle restrains food boluses by keeping the cheek reduced to the teeth. Paralysis of the lower facial muscles therefore can lead to oral drooling, pocketing of food in the buccal sulcus, severe dental caries, and an inability to phonate labial sounds such as /b/ or /p/. In the multidisciplinary management of facial paralysis, every patient should be aware of the potential problems he or she may encounter. The variability in cause and clinical presentation requires an individualized treatment plan for patients with facial nerve palsies.1,2 Classification by Westin and Zuker categorizes facial nerve paralysis into congenital and acquired deficiencies and provides ease of applicability.3 The focus of this article is to detail current procedures that provide facial movement or “reanimation.” Static procedures (i.e., soft-tissue suspensions or slings) can improve facial resting appearance but lack true “reanimation” and are most often chosen for elderly patients. We advocate that the treatment goal be restoration of facial movement whenever possible. The purpose of this article is to describe typical patient presentations and preoperative assessments followed by a detailed illustration of current dynamic treatment modalities, including neurotization procedures, contiguous muscle transfers, and microsurgical free-muscle transfers. In the final section, we discuss the role of nonoperative techniques for adjunctive treatment and for primary management in selected patients. Neurotization procedures restore function of native muscles and presuppose that the native muscles remain amenable to reinnervation; in this section, we describe the factors that allow one to determine the status of native facial muscles. Contiguous muscle transfer and microvascular
free-muscle transfer replace function when the native muscles are congenitally absent or have been subjected to prolonged denervation and are therefore not amenable to reinnervation. Contiguous muscle transfers have been practiced for over 50 years; however, over the past 10 to 20 years, many surgeons have focused on microvascular free-muscle transfer. Increasingly consistent and improved aesthetic results have made free-muscle transfer the current criterion standard in modern reanimation, particularly among children. Despite this, contiguous muscle transfer is an excellent option among adults and should remain among treatment options at facial paralysis centers. The pros and cons of these modalities are contrasted. In the final section, nonsurgical adjuvant treatments are discussed to improve existing movement or as a complement to dynamic procedures. Human interactions and the function of facial muscles do not occur in snapshots but are defined by the movement created. It is our opinion that reported facial paralysis procedures, both static and dynamic, should be demonstrated in video format; such videos are included throughout this article to capture their effect with active motion.
PREOPERATIVE EVALUATION A thorough history of patients with unilateral or bilateral facial paralysis should elicit a possible cause, duration of dysfunction, patient concerns, and clinical symptoms, including corneal irritation and oral incompetence. Duration of symptoms is important, as newly acquired deficits from neurapraxic or axonotmetic injuries may continue to resolve for 12 months or longer without surgical intervention. This becomes important when determining prognosis from neurotization procedures, as successful muscle recovery is highly correlated with denervation time (Level of Evidence: Therapeutic, IV).4 A complete facial examination should emphasize corneal status, oral competence, and facial nerve branch pattern involvement. The physical examination begins during the history, with the examiner noting facial expression and socialization capabilities. A detailed facial nerve examination is then performed. The patient is asked to raise the eyebrow (frontalis muscle, temporal branch) and close the eye forcibly (orbicularis, zygomatic branches). The ability to blink and the presence of a Bell phenomenon (involuntary upward gaze with eye closure) are observed, as both protect and lubricate the globe. Next, upper and lower eyelid position is assessed relative to the cornea, and eyelid
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis tone is gauged with a snap test. Diminished lower lid tone can result in lower lid malposition and/or paralytic ectropion. The lower face is observed at rest and with animation. Resting facial symmetry is assessed with attention toward the nasolabial fold, philtrum deviation, lack of a distinct oral commissure, and tissue laxity. Alar support and external valve collapse are evaluated with inspiration and expiration. The patient’s smile is evaluated with lips together and full dental display. For patients undergoing reanimation, the quality and strength of the normal contralateral smile are analyzed. Upper dental display resulting from upward and lateral movement of the upper lip is analyzed along with lower dental display in patients who activate lower lip depressors. On the paralyzed side, movement of the commissure and upper lip is noted along with accentuation of the nasolabial crease. A number of facial nerve grading systems are available for use,5–8 and medical centers treating facial paralysis should have an objective testing method. Examination is completed with testing of the fifth cranial nerve (temporalis and masseter muscle palpation). Electrophysiologic testing can be helpful in predicting functional recovery in recently acquired deficits9–11 (e.g., following acoustic neuroma resection with a facial nerve thought to be in-continuity). In such cases, serial electrophysiologic examinations may show early electrical
recovery before clinical recovery. Electrophysiologic testing of multiple facial muscle patterns in patients with Bell palsy can provide physicians with clinically undetectable evidence of neural recovery11 and is useful for mapping available muscle motors before contiguous muscle transfer. The most important factor in determining the optimal dynamic facial palsy reconstruction to perform is to know the viability of existing facial mimetic muscles and motor endplates, thus allowing for possible reinnervation. This situation is not relevant to patients with congenital paralysis or those with a longstanding paralysis, as the muscles are developmentally absent or irreversibly atrophied. Patients with acquired paralysis who have undergone serial clinical and/or electrophysiologic testing that has failed to show any functional recovery by 6 months can be considered for a reinnervation procedure before complete muscle and motor endplate atrophy. Depending on the age of the patient and the type of procedure intended, reinnervation can be successful up to 12 to 18 months after denervation. Increased denervation time and advancing patient age both negatively affect nerve regeneration and may lead to inferior outcomes of reinnervation procedures. To date, there is no defined cutoff limit for denervation time that is universally applicable.
Fig. 1. (Left) The branching pattern and oblique deep muscular course of the masseter nerve is depicted. (Right) The surgical anatomy of the masseter-to-facial nerve transfer is shown (fifth-to-seventh cranial nerve transfer). The descending branch of the masseter nerve is anastomosed by microsurgical techniques to selected buccal branches of the facial nerve. (Reprinted with permission from Klebuc M. Facial reanimation using the masseter-tofacial nerve transfer. Plast Reconstr Surg. 2011;127:1909–1915.)
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Video 1. Supplemental Digital Content 1, which displays a video, recorded preoperatively and 8 months postoperatively, of a patient who had facial nerve paralysis after skull base surgery and who underwent masseter-to-facial nerve transfer (fifthto-seventh cranial nerve transfer), is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B299.
Video 2. Supplemental Digital Content 2 displays a video, recorded preoperatively and 7 months postoperatively, of a patient who had a facial nerve paralysis after acoustic neuroma excision; she underwent fifth-to-seventh cranial nerve transfer in addition to a cross-face nerve graft for eye closure. This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B300.
NEUROTIZATION PROCEDURES BY MICHAEL J. KLEBUC, M.D. The use of a new motor source to restore an existing muscle (i.e., cross-face facial nerve graft or masseter nerve transfer) is termed “neurotization.” Such adjacent cranial nerve transfers can be effective for reanimating the paralyzed face. Nerve transfers are indicated when intracranial and/or intratemporal segments of the facial nerve are irreversibly damaged in the presence of intact distal facial nerve branches and viable mimetic muscles. Common clinical scenarios include ablative oncologic surgery or trauma involving the brainstem and skull base.
Fig. 2. Anatomical dissection of the masseter nerve demonstrating small proximal branches and the dominant descending branch that will be used for neurotization transfer of the masseter to facial nerve (fifth-to-seventh cranial nerve transfer).
Traditional donor nerves include the hypoglossal (twelfth cranial nerve), contralateral facial (seventh cranial nerve) with cross-face nerve grafts, spinal accessory (eleventh cranial nerve), and phrenic nerves. Each donor nerve varies with respect to its functional deficit and morbidity, motor power, and synergy with facial expression.12–15 Over the past decade, anatomy and physiology knowledge of the trigeminal motor nerve branch to the masseter muscle has increased,16–21 with masseter-to-facial nerve transfers (fifth to seventh cranial nerve) being our technique of choice for facial reanimation (Reference 17 Level of Evidence: Therapeutic, IV). This regional (subunit) approach to rehabilitation of the paralyzed face allows “babysitting” of paralyzed mimetic muscles of the midface and perioral region (Fig. 1). The fifth-to-seventh cranial nerve transfer is used as an isolated procedure in individuals with limited nerve regeneration potential (elderly patients), whereas in younger patients, the fifth-to-seventh cranial nerve transfer is often combined with cross-face nerve grafts. Strict age criteria have not been determined or specifically studied; however, we reserve isolated fifth-to-seventh cranial nerve transfer for patients aged 55 years or older. In addition, younger patients with an acute facial nerve paralysis (younger than 12 months without functional or electrophysiologic evidence of functional recovery) may be candidates for facial nerve cross-face grafting alone without a babysitting procedure, allowing adequate time for nerve regeneration before complete muscle atrophy and motor endplate degradation occurs.
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Fig. 3. (Above, left) Left facial nerve paralysis 11 months after a skull base fracture. (Above, right) Preoperative markings for masseter-to-facial nerve transfer and combined cross-face nerve graft for reestablishment of eye closure are shown. (Below, left) Microsurgical anastomosis of the descending branch of the masseter nerve to selected buccal branches and cross-face nerve grafting to the zygomatic facial nerve branches were performed. (Below, right) Facial motion during postoperative month 8. Motion at this stage is based on the masseter-to-facial nerve transfer, with the cross-face nerve graft requiring approximately 12 months for completion of the necessary neuroregeneration. (Reprinted with permission from Klebuc M. Facial reanimation using the masseter-to-facial nerve transfer. Plast Reconstr Surg. 2011;5:1909–1915.)
Fig. 4. (Left) Right facial paralysis is depicted 15 months after an acoustic neuroma excision. (Right) Postoperative result 7 months after masseter-to-facial nerve transfer.
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Fig. 5. (Left) Surgical exploration of the facial and masseter nerves by means of a limited preauricular incision. The facial nerve is shown mobilized from the parotid gland. (Right) The facial nerve divided at the stylomastoid foramen and followed by microsurgical nerve repair to the transposed, descending branch of the masseter nerve with 10-0 nylon.
The fifth-to-seventh cranial nerve transfer is associated with a number of advantages, including limited donor-site morbidity, constant nerve anatomy, dense motor fibers producing a strong and symmetric smile, direct microsurgical nerve anastomosis, rapid tone and motion recovery, and ease of cerebral adaptation creating an effortless smile. The donor-site deficit and functional loss from partial denervation of the masseter muscle is minimal, as the masseter and temporalis muscles work in concert during mastication. During the
Fig. 6. Masseter-to-facial nerve transfer is combined with crossface nerve grafts to create a synergy of power (fifth cranial nerve) and spontaneity (seventh cranial nerve). Coaptations can be performed using an end-to-end or end-to-side technique based on patient anatomy. We advocate the use of nerve stimulation and typically perform end-to-end anastomoses in areas of nerve overlap.
fifth-to-seventh cranial nerve transfer, the descending branch of the masseter nerve is divided, leaving the more proximal branches intact, preventing complete muscle paralysis and avoiding cosmetic deformities from muscle atrophy. Bite abnormalities and temporomandibular joint dysfunction have not been identified at long-term follow-up, allowing use of this technique in bilateral facial paralysis. In comparison, complete hypoglossalto-facial nerve transfers (twelfth-to-seventh cranial nerve transfer) have largely been abandoned because of postoperative difficulties with speech, eating, and motion.22,23 Although selective, partial sectioning of the hypoglossal nerve with an interposition jump graft has significantly improved the donor-site morbidity, permanent tongue dysfunction is still reported in 8 percent.24 Donor deficits of the spinal accessory (eleventh cranial nerve) or phrenic nerve include shoulder weakness and hemidiaphragmatic paralysis.25,26 Donor-site morbidity of the contralateral facial nerve is characteristically low; however, inadvertent injury during exploration can occur. The anatomy of the masseter nerve is well delineated. Topographically, the main trunk is identified 3 cm anterior to the tragus and 1 cm below the zygomatic arch. The nerve liberates proximal branches before the dominant descending branch courses obliquely in an anterior, inferior direction between the deep and middle layers of the muscle (1.5 cm deep to the superficial musculoaponeurotic system) (Fig. 2).27,28 The proximal and distal nerve segments contain approximately 2700 and 1500 myelinated fibers, respectively.27,29 The fifthto-seventh cranial nerve transfer typically produces a smile 6 months postoperatively, with a vector and
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Video 3. Supplemental Digital Content 3, which displays a video depiction of the patient presented in Figure 8, is available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B301.
Video 4. Supplemental Digital Content 4, which displays a video depiction of the patient presented in Figure 9, is available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B302.
strength comparable to those of the normal side (Figs. 3 and 4). [See Video, Supplemental Digital Content 1, which displays a video, recorded preoperatively and 8 months postoperatively, of a patient who had facial nerve paralysis after skull base surgery and who underwent masseter-to-facial nerve transfer (fifth-to-seventh cranial nerve transfer). This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B299. See Video, Supplemental Digital Content 2, which displays a video, recorded preoperatively and 7 months postoperatively, of a patient who had a facial nerve paralysis after acoustic neuroma excision; she underwent fifth-to-seventh cranial nerve transfer in addition to a cross-face nerve graft for eye closure. This video is
available in the “Related Videos” section of the fulltext article on PRSJournal.com or at http://links. lww.com/PRS/B300.] This technique also achieves a direct nerve repair without interposition grafts. During the fifth-to-seventh cranial nerve transfer, the facial nerve is identified at the stylomastoid foramen and traced through the parotid gland (Fig. 5), although the dissection could also be performed in retrograde fashion. The selected facial nerve branch is divided as proximally as possible, providing mobility for primary anastomosis to the masseter nerve. Facial nerve branches to the eye and brow are selectively transected to prevent mass motion or are used for cross face nerve grafts. Masseter nerve motor reeducation and efficient cerebral adaptation have been well described and supported neuroanatomically with electromyography (Reference 30 Level of Evidence: Therapeutic, IV).30–35 Schaverien et al. found electromyographic evidence of masseter muscle contraction in 40 percent of subjects during normal smiling.36 We also demonstrated that the majority of patients with fifth-to-seventh cranial nerve transfer could produce a smile without clenching their teeth at 2-year follow-up. The smile that frequently evolves in children and motivated patients is effortless or reflexive but not truly spontaneous. Only the facial nerve is highly modulated by the limbic system producing emotionally mediated, spontaneous mimetic facial motion.37 In patients with nerve regeneration potential, the fifth-to-seventh cranial nerve transfer can be combined with cross-face nerve grafting38 (Fig. 6), creating a combined approach for power (fifth cranial nerve) and spontaneity (seventh cranial nerve). For patients who are not candidates for neurotization (congenital or longstanding paralysis), muscle movement must be replaced. This can be performed with regional muscle transfer or microvascular free-muscle transfer. These two very different techniques are described in the following two sections. There are distinct advantages and disadvantages of each of these approaches, which are discussed subsequently.
CONTIGUOUS REGIONAL MUSCLE TRANSFER BY ROGER L. SIMPSON, M.D., M.B.A. Facial paralysis reanimation by contiguous muscle transposition uses muscles innervated by the fifth cranial nerve and is applicable for partial, complete, and bilateral facial paralysis patients (Möbius syndrome).39 The direction and strength
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Plastic and Reconstructive Surgery • June 2015
Fig. 7. (Left) Preoperative image of a patient who sustained definitive loss of left facial nerve function following resection of an acoustic neuroma. With no return anticipated, early contiguous temporalis and masseter transfers were performed with anticipated slight overcorrection. (Right) Postoperative photograph taken at 2 years shows excellent balance of the upper lip, commissure, and lower lip. Note the symmetric depth of the nasolabial fold, the balanced upward and lateral pull of the upper lip from the temporalis, and the downward balance of the lower lip from the partial masseter transfer.
Fig. 8. (Left) Congenital unilateral right facial paralysis in a 26-year-old woman. The patient retained full function of the marginal mandibular branch of the facial nerve. The lower lip showed normal tone and depression in the absence of any excursion of the commissure or the upper lip. (Center) Right temporalis muscle transfer using the zygomatic arch to set proper tension. Attachment of the contiguous muscle transfer is to the vermillion of the upper lip and commissure. Once the tension is set, the nasolabial fold is attached to the fascial portion of the transfer to produce animation and depth. The patient is shown at 18 months after reconstruction. (Right) Note the relaxation of the transfer allowing the upper lip and the commissure to return to a normal balanced position when she is not creating her smile.
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Fig. 9. (Left) A 16-year-old patient underwent resection of a hemangioma of the left upper lip resulting in a partial facial paralysis from regional muscle loss. The patient has an isolated loss of the levator labii superioris. (Center) The patient shows a broad well-balanced smile from an isolated partial temporalis transfer to the upper lip 40 years after her single-stage reconstruction. Note the retained commissure, upper lip, and nasolabial fold balance. (Right) The patient shows nearly complete relaxation of the temporalis construct when not smiling.
Fig. 10. (Left) This 46-year-old patient developed a left single episode of Bell palsy. Recovery reached a plateau at 18 months, with no further improvement noted at 6 years. Absence of symmetric elevation of the upper lip and commissure is appreciated. No restraint of the lower lip is seen despite spastic activity of lower lip and chin musculature. No prior treatment had been received. (Right) The patient underwent a partial temporalis and partial masseter transfer 8 months previously. Symmetry of upper lip excursion is noted. A gentle downward restraint of the lower lip balances the smile.
of the transferred muscles determine the quality and symmetry of the dynamic reanimation. Contiguous muscle reanimation is reliable and reproducible, and results are rapid, requiring patient
compliance, reeducation, and the presence of molar teeth for maximum strength (Figs. 7 through 10). (See Video, Supplemental Digital Content 3, which displays a video depiction of the
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Fig. 11. (Left) Patient with longstanding Bell partial right paralysis shows marked asymmetry of smile despite exerting maximum force. Note the recruitment of associated muscles of the face and neck attempting to produce a balanced excursion of the commissure. (Right) Six months after partial temporalis transfer to the right upper lip and commissure, the patient can produce a balanced smile without the intense contraction of the partially compromised facial nerve innervated muscles.
Fig. 12. (Left) Congenital left facial paralysis with intact function of the lower lip musculature. The plan was for a temporalis transfer to the commissure and upper lip, gold weight to the upper eyelid, and fascial sling support for the lower eyelid. (Right) Temporalis muscle transfer to the left upper lip and commissure at 14 months after reconstruction. Note vigorous contraction of the temporalis over the zygomatic arch. Given the patient’s hairstyle and obvious muscle prominence during contraction, secondary enhancement of the temporal fossa with acellular dermal matrix was planned to lessen the prominence of the muscle transfer. Tightening of the subsidence of the temporalis lift to the upper lip was also planned.
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Fig. 13. Surgical technique harvests the temporalis muscle and extends its reach by using the deep temporalis fascia for lengthening. The construct is drawn over the zygomatic arch through the nasolabial fold incision under tension. (Above, left) After appropriate stretch, it is inserted into defined areas of the vermillion, reproducing the exact form of the opposite normal side according to Rubin’s anatomy of the smile. (Right) Note the final overcorrection of the right commissure and upper lip anticipating a degree of subsidence over the first several months. The degree of overcorrection must allow for the maximum excursion and produce a normal position during relaxation. (Below, left) Acellular dermal matrix, as a moderately thick folded sheet, has replaced the use of a solid implant as a fill for the harvested temporalis muscle. Increased patient comfort, decreased complications, markedly improved soft contour without capsule formation, and decreased number of secondary procedures are appreciated.
patient presented in Fig. 8. This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww. com/PRS/B301. See Video, Supplemental Digital Content 4, which displays a video depiction of the patient presented in Fig. 9. This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/ PRS/B302.) Temporalis and masseter muscle transfers are chosen to reanimate the paralyzed smile. Their blood supply and innervation permit appropriate arcs of rotation without significant risk of necrosis or denervation.40 Rubin highlighted the normal lip’s dynamic contour to guide paralysis
reconstruction.41 The direction of contraction can be altered to produce symmetry of position and motion. Overcorrection of lip position and muscle edema begin to subside within 1 week, and motion is visible within 2 weeks. The concept of the spontaneous, “emotional” smile highlighted in cross-face nerve grafting is absent in contiguous transfers; however, patients are often able to smile without physically clenching their teeth.32 Temporalis transfer occurs over the zygomatic arch, allowing the surgeon to predictably set tension against a solid fixation point despite creating a visible bulge. The redirected temporalis is lengthened by its own fascia to directly reach the vermilion, allowing proper tension, a stronger
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Fig. 14. (Left) This photograph shows the degree of overcorrection of both temporalis and masseter reconstructions based on the extent of anticipated muscle subsidence. This estimation is based on the quality of the muscle and soft tissue. (Right) The atrophy of the lower lip on the paralyzed side is accentuated by the increased horizontal pull of the masseter transfer. The use of linear strips of acellular dermal matrix will increase the volume of the atrophic side, blended to the volume of the normal side. This increased volume will immediately decrease the symptoms of oral incontinence on the paralyzed side during the period of overcorrection.
upward directed pull, and a gliding surface for the cheek soft tissue (Fig. 11). The temporalis muscle can also be transferred to the upper lip as a lengthening myoplasty described by Labbé and Huault.42 The entire muscle is mobilized from the temporal fossa and the fascial portion is advanced to the upper lip and commissure deep to the zygomatic arch. The temporalis muscle is resecured at a lower level within the fossa, preserving facial contour. The masseter as a standalone muscle transfer produces an undesired horizontal pull and does not have the correct vector to lift the upper lip and increase commissure excursion.40 Rather, the masseter is best used as a secondary muscle transfer to complement the temporalis. The strong upward pull of the temporalis can be balanced by transferring the anterior third of the masseter muscle to the lower lip (medial to the commissure) with a fascial graft from the temporal fossa. The masseter produces a balanced smile with a lateral lower lip dynamic, downward pull that restrains the strong, unopposed, upward temporalis (Fig. 12). The marginal mandibular branch is often preserved in congenital unilateral paralysis, and masseter transfer is not indicated. The anterior belly of the digastrics, innervated by the fifth cranial nerve, can be transferred to the lower lip as an “antagonistic counterbalance” to the strong upward pull of normally innervated musculature (isolated marginal mandibular paralysis)
or the strong, upward pull following temporalis muscle transfer.43–45 The digastric muscle is separated from its posterior belly and rotated upward and medial to the commissure of the lower lip.46 Similar to the masseter transfer, digastric muscle transfer performs lower lip restraint and mimics normal downward motion. Contiguous muscle transfers in partial facial paralysis are dependent on residual muscle excursion following maximum nerve and muscle regeneration. Technique is based on electrophysiologic studies of muscles on the paralyzed side compared with the normal side.47 Residual muscle excursion greater than 70 percent of the levator labii superioris and zygomaticus major muscles can achieve successful smile following muscle shortening. Patients with less than 70 percent residual muscle excursion require temporalis muscle transfer to achieve upper lip and commissure motion (Figs. 13 and 14). Difficulty in objective, reproducible muscle excursion measurements makes clinical judgment essential in selecting the appropriate reanimation procedure.
MICROSURGICAL FREE-MUSCLE TRANSFER PROCEDURES BY RYAN M. GARCIA, M.D., MICHAEL R. ZENN, M.D., M.B.A., AND JEFFREY R. MARCUS, M.D. Microsurgical free tissue transfer for facial reanimation has evolved and is now considered
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Video 5. Supplemental Digital Content 5, which depicts stimulation of various branches of the facial nerve, is available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B303.
Video 6. Supplemental Digital Content 6, which depicts a face incision and recipient-site dissection, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B304.
the criterion standard for patients with longstanding, permanent facial paralysis. Technical variations exist but all have a common need for a donor muscle and recipient nerve supply.48 Reconstructions are performed in either one or two stages.49,50 The two-stage protocol requires neuroregeneration across a cross-face nerve graft before subsequent muscle transfer. The facial nerve recipient by means of a cross-face graft provides a simultaneous, bilateral stimulus when unconscious emotions are elicited.51 During the first stage, the nonparalyzed face is dissected, a nerve stimulator is used, and a redundant facial nerve branch is selected that activates the desired smile separate from other facial movements. (See
Video 7. Supplemental Digital Content 7, which displays anchoring sutures for eventual free-muscle transfer, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B305.
Video 8. Supplemental Digital Content 8, which displays dissection of the gracilis muscle, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http:// links.lww.com/PRS/B306.
Video 9. Supplemental Digital Content 9, which displays a video depiction of the patient presented in Figure 15, is available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B307.
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Video 10. Supplemental Digital Content 10, which displays a video depiction of the patient presented in Figure 16, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B308.
Video, Supplemental Digital Content 5, which depicts stimulation of various branches of the facial nerve, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B303.) The sural nerve graft is passed in a subcutaneous tunnel from the nonparalyzed side to the paralyzed side, with the end left above the canine at the upper buccal sulcus to be retrieved during the second stage. This sural nerve graft is coapted to the previously selected branch of the nonparalyzed facial nerve and matures for 9 to 12 months. Nerve maturity is followed clinically with an advancing Tinel sign, although it is not always present in appropriately regenerated nerves. The
sural nerve is an ideal donor graft secondary to its extensive length, caliber, and limited morbidity. Typically, 18 to 20 cm of graft is adequate and can be obtained from the proximal two-thirds of the calf. Newer endoscopic techniques with a vein stripper are described to decrease operative time and morbidity associated with traditional sural nerve harvest.52 The second stage consists of microvascular free-muscle transfer after donor nerve maturation. Potential donor muscles include the gracilis, pectoralis minor, latissimus dorsi, serratus anterior, extensor carpi radialis brevis, rectus abdominis, and gastrocnemius.53 We advocate using the gracilis muscle secondary to its ease of harvest, adequate length, capability of being reduced in bulk, minimal functional loss, and disguised donor-site incision. During the second-stage presurgical evaluation, the desired vector of facial movement along with the contralateral smile is studied and marked. The recipient site for muscle transfer is prepared by performing wide elevation in the sub–superficial musculoaponeurotic system plane, and buccal fat is removed to reduce bulk for anticipated muscle transfer. (See Video, Supplemental Digital Content 6, which depicts a face incision and recipient-site dissection, available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B304.) The facial artery and vein are most often used as recipient vessels because of their proximity and
Fig. 15. (Left) A 10-year-old boy with congenital, unilateral, left facial paralysis. (Right) Twoyear postoperative result following free gracilis muscle transfer and contralateral cross-face nerve innervation.
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Fig. 16. Preoperative photograph of a 9-year-old girl who presented after undergoing two surgical resections of a juvenile pilocytic astrocytoma. (Left and center) After the second resection, she had complete and unchanging facial paralysis. She had previously undergone two gold-weight procedures that were complicated by infection and extrusion. (Right) Three-year postoperative result following a two-stage reanimation procedure and placement of a low-profile platinum weight at the second stage.
vessel size match. The length of gracilis muscle needed and the preferred pedicle position relative to donor vessels are determined before harvest, with the muscle at normal resting length. Proper placement of three to four nonabsorbable inset sutures at the commissure and upper lip is crucial to mimic the normal contralateral side vector. (See Video, Supplemental Digital Content 7, which displays anchoring sutures for eventual free-muscle transfer, available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B305.) A vessel loop can be used to pass the obturator nerve from the cheek to the sural graft in the mouth.
The medial circumflex femoral vessels and the anterior branch of the obturator nerve supply the gracilis muscle and are dissected carefully. (See Video, Supplemental Digital Content 8, which displays dissection of the gracilis muscle, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http:// links.lww.com/PRS/B306.) We prefer the contralateral gracilis muscle secondary to the neurovascular pedicle orientation and ease of obturator nerve positioning. The distal muscle is inset at the oral commissure and upper lip using the previous inset sutures before microvascular anastomosis. Vascular anastomosis is performed, the
Video 11. Supplemental Digital Content 11, which displays a video depiction of the patient presented in Figure 17, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B309.
Video 12. Supplemental Digital Content 12, which displays a video depiction of the patient presented in Figure 18, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B310.
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Fig. 17. Preoperative photograph of a 28-year-old man who, 2 years previously, had undergone resection of an acoustic neuroma with reported preservation of the facial nerve. (Left) His complete paralysis was unchanged clinically, and serial electroneurographic testing showed no evidence of reinnervation. He underwent one-stage reanimation using a branch to the masseter nerve. (Right) His 1-year postoperative result is shown.
Fig. 18. (Left) Preoperative photograph of a 43-year-old woman with a history of congenital facial paralysis. Clinical examination demonstrated paralysis that primarily affected lower facial nerve branches. She required a strong vertical vector to give adequate dental display to her broad smile. She underwent a one-stage reanimation using a branch to the masseter nerve. (Right) Her 1 year postoperative result is shown.
obturator nerve is drawn through the subcutaneous tunnel, and an epineurial coaptation to the sural nerve is completed. Lastly, the proximal gracilis muscle is inset at the desired vector with slight overcorrection relative to resting tension.
The operative time of the first stage is consistently 3 hours, and patients typically are observed in the hospital overnight. Operative time following the second stage is typically 5 hours, with two simultaneous teams. Patients are monitored with
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Video 13. Supplemental Digital Content 13, which displays a video depiction of the patient presented in Figure 19, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B311.
an implantable Doppler device for 3 days before discharge on postoperative day 3. For patients with longstanding, static facial nerve paralysis, the gracilis free-muscle transfer with cross-facial nerve grafting is an ideal treatment. It results in an unconscious, emotion-elicited smile, with minimal donor-site morbidity (Figs. 15 and 16). (See Video, Supplemental Digital Content 9, which displays a video depiction of the patient presented in Fig. 15, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/ B307. See Video, Supplemental Digital Content 10, which displays a video depiction of the patient presented in Fig. 16, available in the “Related
Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B308.) Results of the two-stage procedure are best among younger and thinner patients, possibly related to improved nerve regeneration and lighter muscle load. Reasons for less-than-optimal results of an underpowered smile are multifactorial. Explanations include insufficient donor axons, poor axon regeneration across multiple coaptation sites, relative muscle ischemia with scarring and atrophy, or age-related influences on nerve regeneration. We recommend one-stage facial reanimation for bilateral facial paralysis in children or unilateral cases in adults (Figs. 17 and 18). (See Video, Supplemental Digital Content 11, which displays a video depiction of the patient presented in Fig. 17, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http:// links.lww.com/PRS/B309. See Video, Supplemental Digital Content 12, which displays a video depiction of the patient presented in Fig. 18, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww. com/PRS/B310.) We recognize that variation and controversy exist among experts when choosing between a one-stage and a two-stage approach as it relates to age. We prefer the unilateral one-stage approach in adults aged 30 years or older and recommend the two-stage approach for all children younger than 18 years. In one-stage cases, the masseteric branch of the trigeminal nerve, which is expendable and powerful, is chosen as the donor nerve.
Fig. 19. (Left) Preoperative photograph of a 6-year-old boy with Möbius syndrome (bilateral facial paralysis) and hemifacial microsomia with bilateral mandibular hypoplasia. This patient underwent bilateral free gracilis muscle transfers, performed in two separate stages, both of which were innervated by the motor branch to the masseter muscle of the respective side (fifth cranial nerve). He later underwent successful mandibular distraction with bilateral internal devices. (Center) Six-month postoperative visit following a left gracilis free-muscle transfer. (Right) Twelve-month postoperative visit after the left gracilis free-muscle transfer and 6 months after the right gracilis free-muscle transfer.
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Plastic and Reconstructive Surgery • June 2015
Fig. 20. Eyelid stretching technique is depicted. The patient is instructed to grasp the upper eye lid lashes and pull the lid downward while also offering countertraction in the center of the upper lid in the zone corresponding to the levator palpebrae superioris. This stretch is held for 60 seconds, and is repeated every 8 hours until blinking returns. The eyelid stretch is designed to mechanically disrupt the myosin chain cross-linking of the levator palpebrae superioris during the anticipated passive stretching phase from the opposing action of the orbicularis oculi.
Postoperatively, physical therapy training is necessary to achieve expression. In contrast, the twostage approach with cross-face nerve grafting delivers an automatic, responsive facial reaction to emotion without training and has power to innervate the muscle transplant. In situations of absent bilateral facial nerves (Möbius syndrome), the motor nerve to the masseter or hypoglossal nerve can be used as the donor54–56 (Reference 54 Level of Evidence: Therapeutic, IV) (Fig. 19). (See Video, Supplemental
Digital Content 13, which displays a video depiction of the patient presented in Fig. 19, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww. com/PRS/B311.) The nerve to the masseter muscle can be used with limited donor-site deficit or weakness.57 In addition, the masseter muscle contracts in 40 percent of normal individuals during natural smiling,36 thus making it a reasonable motor alternative when the facial nerve is not available. Manktelow et al. demonstrated success with onestage free gracilis muscle transfer using the motor nerve to the masseter, with 59 percent of patients smiling without cortical initiation and 85 percent of patients smiling without clenching their teeth.30
MICROVASCULAR FREE-MUSCLE TRANSFER VERSUS CONTIGUOUS MUSCLE TRANSFER Microvascular free-muscle transfer can result in consistently excellent contour and strong movement but has a longer operative time, potential vascular complications, a delay in muscle function, and a final result in smile quality that occurs several years after successful muscle transfer. Contiguous muscle transfer offers a more immediate result but requires effort and concentration to activate muscles of mastication to achieve smiling. Furthermore, depending on technique, the presence of a visible muscle bulge over the malar eminence can be problematic. Both techniques are ultimately susceptible to variability in movement magnitude. Ideally, patients should have the option to select with an objective understanding of each. Most experts in facial reanimation would
Fig. 21. The effectiveness of administration of a single dose of botulinum toxin is depicted for lip balancing after marginal mandibular nerve neurapraxia. (Left) Lower lip asymmetry following mandible surgery. (Right) Balancing of the lip following the administration of 5 IU of botulinum toxin A into the right depressor labii inferioris muscle.
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis concede that contiguous muscle transfer is the procedure of choice for those who are not candidates or those who decline free-muscle transfer.
NONSURGICAL ADJUVANT TREATMENTS BY TESSA A. HADLOCK, M.D. Nonsurgical adjunctive therapies are used in patients with facial weakness either alone or in combination with static and dynamic reconstructive procedures to optimize outcome. Adjunctive therapies include medical therapy (botulinum toxin chemodenervation), physical therapy (tailored on the degree of flaccidity and/or hypertonicity), and miscellaneous facial balancing maneuvers (minor cosmetic techniques). Medical Therapy It is now generally accepted that systemic management of acute viral facial paralysis involves treatment with corticosteroids and valacyclovir.58 In addition, patients exhibiting poor electrophysiologic profiles (electroneuronography
Learning Objectives: After reviewing this article, the participant should be able to: 1. Understand the most modern indications and technique for neurotization, including masseter-to-facial nerve transfer (fifth-to-seventh cranial nerve transfer). 2. Contrast the advantages and limitations associated with contiguous muscle transfers and free-muscle transfers for facial reanimation. 3. Understand the indications for a two-stage and one-stage free gracilis muscle transfer for facial reanimation. 4. Apply nonsurgical adjuvant treatments for acute facial nerve paralysis. Summary: Facial expression is a complex neuromotor and psychomotor process that is disrupted in patients with facial paralysis breaking the link between emotion and physical expression. Contemporary reconstructive options are being implemented in patients with facial paralysis. While static procedures provide facial symmetry at rest, true "facial reanimation" requires restoration of facial movement. Contemporary treatment options include neurotization procedures (a new motor nerve is used to restore innervation to a viable muscle), contiguous regional muscle transfer (most commonly temporalis muscle transfer), microsurgical free muscle transfer, and nonsurgical adjuvants used to balance facial symmetry. Each approach has advantages and disadvantages along with ongoing controversies and should be individualized for each patient. Treatments for patients with facial paralysis continue to evolve in order to restore the complex psychomotor process of facial expression. (Plast. Reconstr. Surg. 135: 1025e, 2015.)
T
his continuing medical education article intends to provide a broad perspective on the currently available treatments for patients with facial paralysis. The presentation and manifestation of facial paralysis is extremely heterogeneous, and the range of possible treatments is equally diverse. In some areas, consensus has not been determined. In this article, we merge the opinions from experts in specific subject areas, highlight the areas of consensus, and explain the areas where differences of opinion still exist. Facial expression is a complex neuromotor and psychomotor process linking physical expression with emotion. Facial nerve palsy, a broad From the Division of Plastic and Reconstructive Surgery, Department of Surgery, Duke University Medical Center; Massachusetts Eye and Ear Infirmary; the Division of Plastic and Reconstructive Surgery, Department of Surgery, Baylor College of Medicine, The Methodist Hospital; Long Island Plastic Surgical Group; and the Division of Plastic Surgery, Department of Surgery, Nassau University Medical Center. Received for publication January 23, 2013; accepted May 2, 2013. Copyright © 2015 by the American Society of Plastic Surgeons DOI: 10.1097/PRS.0000000000001273
descriptive term, describes paralysis of any structure that is innervated by the facial nerve, thus inhibiting facial expression. The most troublesome psychosocial effect of facial nerve paralysis occurs during social interactions. Facial expression, even without language, provides a participant in a social interaction with important cues and insight into another’s meanings, intentions, and emotional states. Without these clues, social interactions become severely compromised. The most extreme example, Möbius syndrome (bilateral facial nerve Disclosure: Dr. Zenn is a consultant for LifeCell and Novadaq. Dr. Marcus has received royalties from Stryker Leibinger for SmartLock Hybrid IMF. The other authors have no financial interest to declare in relation to the content of this article.
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Plastic and Reconstructive Surgery • June 2015 paralysis), manifests with symmetrically flat facial expressions, thus severely inhibiting successful social interactions and emotional expression. In addition to the nonverbal communication provided by facial expression, facial muscles are responsible for essential functions such as eyelid closure, oral competence, and phonation of labial sounds. Paralysis of the frontalis muscle leads to an obstructed gaze that is progressive with age. Paralysis of the orbicularis oculi muscle leads to exposure and drying of the cornea and an inability to protect the eye from foreign material. Nasal obstruction can be present and debilitating to patients with facial paralysis. Nasal obstruction can be unilateral or bilateral and cause the nasal base to shift toward the nonparalyzed side by an unopposed action. With regard to the lower face, the orbicularis oris muscle encircles the mouth and controls oral competence, whereas the buccinator muscle restrains food boluses by keeping the cheek reduced to the teeth. Paralysis of the lower facial muscles therefore can lead to oral drooling, pocketing of food in the buccal sulcus, severe dental caries, and an inability to phonate labial sounds such as /b/ or /p/. In the multidisciplinary management of facial paralysis, every patient should be aware of the potential problems he or she may encounter. The variability in cause and clinical presentation requires an individualized treatment plan for patients with facial nerve palsies.1,2 Classification by Westin and Zuker categorizes facial nerve paralysis into congenital and acquired deficiencies and provides ease of applicability.3 The focus of this article is to detail current procedures that provide facial movement or “reanimation.” Static procedures (i.e., soft-tissue suspensions or slings) can improve facial resting appearance but lack true “reanimation” and are most often chosen for elderly patients. We advocate that the treatment goal be restoration of facial movement whenever possible. The purpose of this article is to describe typical patient presentations and preoperative assessments followed by a detailed illustration of current dynamic treatment modalities, including neurotization procedures, contiguous muscle transfers, and microsurgical free-muscle transfers. In the final section, we discuss the role of nonoperative techniques for adjunctive treatment and for primary management in selected patients. Neurotization procedures restore function of native muscles and presuppose that the native muscles remain amenable to reinnervation; in this section, we describe the factors that allow one to determine the status of native facial muscles. Contiguous muscle transfer and microvascular
free-muscle transfer replace function when the native muscles are congenitally absent or have been subjected to prolonged denervation and are therefore not amenable to reinnervation. Contiguous muscle transfers have been practiced for over 50 years; however, over the past 10 to 20 years, many surgeons have focused on microvascular free-muscle transfer. Increasingly consistent and improved aesthetic results have made free-muscle transfer the current criterion standard in modern reanimation, particularly among children. Despite this, contiguous muscle transfer is an excellent option among adults and should remain among treatment options at facial paralysis centers. The pros and cons of these modalities are contrasted. In the final section, nonsurgical adjuvant treatments are discussed to improve existing movement or as a complement to dynamic procedures. Human interactions and the function of facial muscles do not occur in snapshots but are defined by the movement created. It is our opinion that reported facial paralysis procedures, both static and dynamic, should be demonstrated in video format; such videos are included throughout this article to capture their effect with active motion.
PREOPERATIVE EVALUATION A thorough history of patients with unilateral or bilateral facial paralysis should elicit a possible cause, duration of dysfunction, patient concerns, and clinical symptoms, including corneal irritation and oral incompetence. Duration of symptoms is important, as newly acquired deficits from neurapraxic or axonotmetic injuries may continue to resolve for 12 months or longer without surgical intervention. This becomes important when determining prognosis from neurotization procedures, as successful muscle recovery is highly correlated with denervation time (Level of Evidence: Therapeutic, IV).4 A complete facial examination should emphasize corneal status, oral competence, and facial nerve branch pattern involvement. The physical examination begins during the history, with the examiner noting facial expression and socialization capabilities. A detailed facial nerve examination is then performed. The patient is asked to raise the eyebrow (frontalis muscle, temporal branch) and close the eye forcibly (orbicularis, zygomatic branches). The ability to blink and the presence of a Bell phenomenon (involuntary upward gaze with eye closure) are observed, as both protect and lubricate the globe. Next, upper and lower eyelid position is assessed relative to the cornea, and eyelid
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis tone is gauged with a snap test. Diminished lower lid tone can result in lower lid malposition and/or paralytic ectropion. The lower face is observed at rest and with animation. Resting facial symmetry is assessed with attention toward the nasolabial fold, philtrum deviation, lack of a distinct oral commissure, and tissue laxity. Alar support and external valve collapse are evaluated with inspiration and expiration. The patient’s smile is evaluated with lips together and full dental display. For patients undergoing reanimation, the quality and strength of the normal contralateral smile are analyzed. Upper dental display resulting from upward and lateral movement of the upper lip is analyzed along with lower dental display in patients who activate lower lip depressors. On the paralyzed side, movement of the commissure and upper lip is noted along with accentuation of the nasolabial crease. A number of facial nerve grading systems are available for use,5–8 and medical centers treating facial paralysis should have an objective testing method. Examination is completed with testing of the fifth cranial nerve (temporalis and masseter muscle palpation). Electrophysiologic testing can be helpful in predicting functional recovery in recently acquired deficits9–11 (e.g., following acoustic neuroma resection with a facial nerve thought to be in-continuity). In such cases, serial electrophysiologic examinations may show early electrical
recovery before clinical recovery. Electrophysiologic testing of multiple facial muscle patterns in patients with Bell palsy can provide physicians with clinically undetectable evidence of neural recovery11 and is useful for mapping available muscle motors before contiguous muscle transfer. The most important factor in determining the optimal dynamic facial palsy reconstruction to perform is to know the viability of existing facial mimetic muscles and motor endplates, thus allowing for possible reinnervation. This situation is not relevant to patients with congenital paralysis or those with a longstanding paralysis, as the muscles are developmentally absent or irreversibly atrophied. Patients with acquired paralysis who have undergone serial clinical and/or electrophysiologic testing that has failed to show any functional recovery by 6 months can be considered for a reinnervation procedure before complete muscle and motor endplate atrophy. Depending on the age of the patient and the type of procedure intended, reinnervation can be successful up to 12 to 18 months after denervation. Increased denervation time and advancing patient age both negatively affect nerve regeneration and may lead to inferior outcomes of reinnervation procedures. To date, there is no defined cutoff limit for denervation time that is universally applicable.
Fig. 1. (Left) The branching pattern and oblique deep muscular course of the masseter nerve is depicted. (Right) The surgical anatomy of the masseter-to-facial nerve transfer is shown (fifth-to-seventh cranial nerve transfer). The descending branch of the masseter nerve is anastomosed by microsurgical techniques to selected buccal branches of the facial nerve. (Reprinted with permission from Klebuc M. Facial reanimation using the masseter-tofacial nerve transfer. Plast Reconstr Surg. 2011;127:1909–1915.)
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Plastic and Reconstructive Surgery • June 2015
Video 1. Supplemental Digital Content 1, which displays a video, recorded preoperatively and 8 months postoperatively, of a patient who had facial nerve paralysis after skull base surgery and who underwent masseter-to-facial nerve transfer (fifthto-seventh cranial nerve transfer), is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B299.
Video 2. Supplemental Digital Content 2 displays a video, recorded preoperatively and 7 months postoperatively, of a patient who had a facial nerve paralysis after acoustic neuroma excision; she underwent fifth-to-seventh cranial nerve transfer in addition to a cross-face nerve graft for eye closure. This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B300.
NEUROTIZATION PROCEDURES BY MICHAEL J. KLEBUC, M.D. The use of a new motor source to restore an existing muscle (i.e., cross-face facial nerve graft or masseter nerve transfer) is termed “neurotization.” Such adjacent cranial nerve transfers can be effective for reanimating the paralyzed face. Nerve transfers are indicated when intracranial and/or intratemporal segments of the facial nerve are irreversibly damaged in the presence of intact distal facial nerve branches and viable mimetic muscles. Common clinical scenarios include ablative oncologic surgery or trauma involving the brainstem and skull base.
Fig. 2. Anatomical dissection of the masseter nerve demonstrating small proximal branches and the dominant descending branch that will be used for neurotization transfer of the masseter to facial nerve (fifth-to-seventh cranial nerve transfer).
Traditional donor nerves include the hypoglossal (twelfth cranial nerve), contralateral facial (seventh cranial nerve) with cross-face nerve grafts, spinal accessory (eleventh cranial nerve), and phrenic nerves. Each donor nerve varies with respect to its functional deficit and morbidity, motor power, and synergy with facial expression.12–15 Over the past decade, anatomy and physiology knowledge of the trigeminal motor nerve branch to the masseter muscle has increased,16–21 with masseter-to-facial nerve transfers (fifth to seventh cranial nerve) being our technique of choice for facial reanimation (Reference 17 Level of Evidence: Therapeutic, IV). This regional (subunit) approach to rehabilitation of the paralyzed face allows “babysitting” of paralyzed mimetic muscles of the midface and perioral region (Fig. 1). The fifth-to-seventh cranial nerve transfer is used as an isolated procedure in individuals with limited nerve regeneration potential (elderly patients), whereas in younger patients, the fifth-to-seventh cranial nerve transfer is often combined with cross-face nerve grafts. Strict age criteria have not been determined or specifically studied; however, we reserve isolated fifth-to-seventh cranial nerve transfer for patients aged 55 years or older. In addition, younger patients with an acute facial nerve paralysis (younger than 12 months without functional or electrophysiologic evidence of functional recovery) may be candidates for facial nerve cross-face grafting alone without a babysitting procedure, allowing adequate time for nerve regeneration before complete muscle atrophy and motor endplate degradation occurs.
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Fig. 3. (Above, left) Left facial nerve paralysis 11 months after a skull base fracture. (Above, right) Preoperative markings for masseter-to-facial nerve transfer and combined cross-face nerve graft for reestablishment of eye closure are shown. (Below, left) Microsurgical anastomosis of the descending branch of the masseter nerve to selected buccal branches and cross-face nerve grafting to the zygomatic facial nerve branches were performed. (Below, right) Facial motion during postoperative month 8. Motion at this stage is based on the masseter-to-facial nerve transfer, with the cross-face nerve graft requiring approximately 12 months for completion of the necessary neuroregeneration. (Reprinted with permission from Klebuc M. Facial reanimation using the masseter-to-facial nerve transfer. Plast Reconstr Surg. 2011;5:1909–1915.)
Fig. 4. (Left) Right facial paralysis is depicted 15 months after an acoustic neuroma excision. (Right) Postoperative result 7 months after masseter-to-facial nerve transfer.
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Plastic and Reconstructive Surgery • June 2015
Fig. 5. (Left) Surgical exploration of the facial and masseter nerves by means of a limited preauricular incision. The facial nerve is shown mobilized from the parotid gland. (Right) The facial nerve divided at the stylomastoid foramen and followed by microsurgical nerve repair to the transposed, descending branch of the masseter nerve with 10-0 nylon.
The fifth-to-seventh cranial nerve transfer is associated with a number of advantages, including limited donor-site morbidity, constant nerve anatomy, dense motor fibers producing a strong and symmetric smile, direct microsurgical nerve anastomosis, rapid tone and motion recovery, and ease of cerebral adaptation creating an effortless smile. The donor-site deficit and functional loss from partial denervation of the masseter muscle is minimal, as the masseter and temporalis muscles work in concert during mastication. During the
Fig. 6. Masseter-to-facial nerve transfer is combined with crossface nerve grafts to create a synergy of power (fifth cranial nerve) and spontaneity (seventh cranial nerve). Coaptations can be performed using an end-to-end or end-to-side technique based on patient anatomy. We advocate the use of nerve stimulation and typically perform end-to-end anastomoses in areas of nerve overlap.
fifth-to-seventh cranial nerve transfer, the descending branch of the masseter nerve is divided, leaving the more proximal branches intact, preventing complete muscle paralysis and avoiding cosmetic deformities from muscle atrophy. Bite abnormalities and temporomandibular joint dysfunction have not been identified at long-term follow-up, allowing use of this technique in bilateral facial paralysis. In comparison, complete hypoglossalto-facial nerve transfers (twelfth-to-seventh cranial nerve transfer) have largely been abandoned because of postoperative difficulties with speech, eating, and motion.22,23 Although selective, partial sectioning of the hypoglossal nerve with an interposition jump graft has significantly improved the donor-site morbidity, permanent tongue dysfunction is still reported in 8 percent.24 Donor deficits of the spinal accessory (eleventh cranial nerve) or phrenic nerve include shoulder weakness and hemidiaphragmatic paralysis.25,26 Donor-site morbidity of the contralateral facial nerve is characteristically low; however, inadvertent injury during exploration can occur. The anatomy of the masseter nerve is well delineated. Topographically, the main trunk is identified 3 cm anterior to the tragus and 1 cm below the zygomatic arch. The nerve liberates proximal branches before the dominant descending branch courses obliquely in an anterior, inferior direction between the deep and middle layers of the muscle (1.5 cm deep to the superficial musculoaponeurotic system) (Fig. 2).27,28 The proximal and distal nerve segments contain approximately 2700 and 1500 myelinated fibers, respectively.27,29 The fifthto-seventh cranial nerve transfer typically produces a smile 6 months postoperatively, with a vector and
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Video 3. Supplemental Digital Content 3, which displays a video depiction of the patient presented in Figure 8, is available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B301.
Video 4. Supplemental Digital Content 4, which displays a video depiction of the patient presented in Figure 9, is available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B302.
strength comparable to those of the normal side (Figs. 3 and 4). [See Video, Supplemental Digital Content 1, which displays a video, recorded preoperatively and 8 months postoperatively, of a patient who had facial nerve paralysis after skull base surgery and who underwent masseter-to-facial nerve transfer (fifth-to-seventh cranial nerve transfer). This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B299. See Video, Supplemental Digital Content 2, which displays a video, recorded preoperatively and 7 months postoperatively, of a patient who had a facial nerve paralysis after acoustic neuroma excision; she underwent fifth-to-seventh cranial nerve transfer in addition to a cross-face nerve graft for eye closure. This video is
available in the “Related Videos” section of the fulltext article on PRSJournal.com or at http://links. lww.com/PRS/B300.] This technique also achieves a direct nerve repair without interposition grafts. During the fifth-to-seventh cranial nerve transfer, the facial nerve is identified at the stylomastoid foramen and traced through the parotid gland (Fig. 5), although the dissection could also be performed in retrograde fashion. The selected facial nerve branch is divided as proximally as possible, providing mobility for primary anastomosis to the masseter nerve. Facial nerve branches to the eye and brow are selectively transected to prevent mass motion or are used for cross face nerve grafts. Masseter nerve motor reeducation and efficient cerebral adaptation have been well described and supported neuroanatomically with electromyography (Reference 30 Level of Evidence: Therapeutic, IV).30–35 Schaverien et al. found electromyographic evidence of masseter muscle contraction in 40 percent of subjects during normal smiling.36 We also demonstrated that the majority of patients with fifth-to-seventh cranial nerve transfer could produce a smile without clenching their teeth at 2-year follow-up. The smile that frequently evolves in children and motivated patients is effortless or reflexive but not truly spontaneous. Only the facial nerve is highly modulated by the limbic system producing emotionally mediated, spontaneous mimetic facial motion.37 In patients with nerve regeneration potential, the fifth-to-seventh cranial nerve transfer can be combined with cross-face nerve grafting38 (Fig. 6), creating a combined approach for power (fifth cranial nerve) and spontaneity (seventh cranial nerve). For patients who are not candidates for neurotization (congenital or longstanding paralysis), muscle movement must be replaced. This can be performed with regional muscle transfer or microvascular free-muscle transfer. These two very different techniques are described in the following two sections. There are distinct advantages and disadvantages of each of these approaches, which are discussed subsequently.
CONTIGUOUS REGIONAL MUSCLE TRANSFER BY ROGER L. SIMPSON, M.D., M.B.A. Facial paralysis reanimation by contiguous muscle transposition uses muscles innervated by the fifth cranial nerve and is applicable for partial, complete, and bilateral facial paralysis patients (Möbius syndrome).39 The direction and strength
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Plastic and Reconstructive Surgery • June 2015
Fig. 7. (Left) Preoperative image of a patient who sustained definitive loss of left facial nerve function following resection of an acoustic neuroma. With no return anticipated, early contiguous temporalis and masseter transfers were performed with anticipated slight overcorrection. (Right) Postoperative photograph taken at 2 years shows excellent balance of the upper lip, commissure, and lower lip. Note the symmetric depth of the nasolabial fold, the balanced upward and lateral pull of the upper lip from the temporalis, and the downward balance of the lower lip from the partial masseter transfer.
Fig. 8. (Left) Congenital unilateral right facial paralysis in a 26-year-old woman. The patient retained full function of the marginal mandibular branch of the facial nerve. The lower lip showed normal tone and depression in the absence of any excursion of the commissure or the upper lip. (Center) Right temporalis muscle transfer using the zygomatic arch to set proper tension. Attachment of the contiguous muscle transfer is to the vermillion of the upper lip and commissure. Once the tension is set, the nasolabial fold is attached to the fascial portion of the transfer to produce animation and depth. The patient is shown at 18 months after reconstruction. (Right) Note the relaxation of the transfer allowing the upper lip and the commissure to return to a normal balanced position when she is not creating her smile.
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Fig. 9. (Left) A 16-year-old patient underwent resection of a hemangioma of the left upper lip resulting in a partial facial paralysis from regional muscle loss. The patient has an isolated loss of the levator labii superioris. (Center) The patient shows a broad well-balanced smile from an isolated partial temporalis transfer to the upper lip 40 years after her single-stage reconstruction. Note the retained commissure, upper lip, and nasolabial fold balance. (Right) The patient shows nearly complete relaxation of the temporalis construct when not smiling.
Fig. 10. (Left) This 46-year-old patient developed a left single episode of Bell palsy. Recovery reached a plateau at 18 months, with no further improvement noted at 6 years. Absence of symmetric elevation of the upper lip and commissure is appreciated. No restraint of the lower lip is seen despite spastic activity of lower lip and chin musculature. No prior treatment had been received. (Right) The patient underwent a partial temporalis and partial masseter transfer 8 months previously. Symmetry of upper lip excursion is noted. A gentle downward restraint of the lower lip balances the smile.
of the transferred muscles determine the quality and symmetry of the dynamic reanimation. Contiguous muscle reanimation is reliable and reproducible, and results are rapid, requiring patient
compliance, reeducation, and the presence of molar teeth for maximum strength (Figs. 7 through 10). (See Video, Supplemental Digital Content 3, which displays a video depiction of the
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Plastic and Reconstructive Surgery • June 2015
Fig. 11. (Left) Patient with longstanding Bell partial right paralysis shows marked asymmetry of smile despite exerting maximum force. Note the recruitment of associated muscles of the face and neck attempting to produce a balanced excursion of the commissure. (Right) Six months after partial temporalis transfer to the right upper lip and commissure, the patient can produce a balanced smile without the intense contraction of the partially compromised facial nerve innervated muscles.
Fig. 12. (Left) Congenital left facial paralysis with intact function of the lower lip musculature. The plan was for a temporalis transfer to the commissure and upper lip, gold weight to the upper eyelid, and fascial sling support for the lower eyelid. (Right) Temporalis muscle transfer to the left upper lip and commissure at 14 months after reconstruction. Note vigorous contraction of the temporalis over the zygomatic arch. Given the patient’s hairstyle and obvious muscle prominence during contraction, secondary enhancement of the temporal fossa with acellular dermal matrix was planned to lessen the prominence of the muscle transfer. Tightening of the subsidence of the temporalis lift to the upper lip was also planned.
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Fig. 13. Surgical technique harvests the temporalis muscle and extends its reach by using the deep temporalis fascia for lengthening. The construct is drawn over the zygomatic arch through the nasolabial fold incision under tension. (Above, left) After appropriate stretch, it is inserted into defined areas of the vermillion, reproducing the exact form of the opposite normal side according to Rubin’s anatomy of the smile. (Right) Note the final overcorrection of the right commissure and upper lip anticipating a degree of subsidence over the first several months. The degree of overcorrection must allow for the maximum excursion and produce a normal position during relaxation. (Below, left) Acellular dermal matrix, as a moderately thick folded sheet, has replaced the use of a solid implant as a fill for the harvested temporalis muscle. Increased patient comfort, decreased complications, markedly improved soft contour without capsule formation, and decreased number of secondary procedures are appreciated.
patient presented in Fig. 8. This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww. com/PRS/B301. See Video, Supplemental Digital Content 4, which displays a video depiction of the patient presented in Fig. 9. This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/ PRS/B302.) Temporalis and masseter muscle transfers are chosen to reanimate the paralyzed smile. Their blood supply and innervation permit appropriate arcs of rotation without significant risk of necrosis or denervation.40 Rubin highlighted the normal lip’s dynamic contour to guide paralysis
reconstruction.41 The direction of contraction can be altered to produce symmetry of position and motion. Overcorrection of lip position and muscle edema begin to subside within 1 week, and motion is visible within 2 weeks. The concept of the spontaneous, “emotional” smile highlighted in cross-face nerve grafting is absent in contiguous transfers; however, patients are often able to smile without physically clenching their teeth.32 Temporalis transfer occurs over the zygomatic arch, allowing the surgeon to predictably set tension against a solid fixation point despite creating a visible bulge. The redirected temporalis is lengthened by its own fascia to directly reach the vermilion, allowing proper tension, a stronger
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Plastic and Reconstructive Surgery • June 2015
Fig. 14. (Left) This photograph shows the degree of overcorrection of both temporalis and masseter reconstructions based on the extent of anticipated muscle subsidence. This estimation is based on the quality of the muscle and soft tissue. (Right) The atrophy of the lower lip on the paralyzed side is accentuated by the increased horizontal pull of the masseter transfer. The use of linear strips of acellular dermal matrix will increase the volume of the atrophic side, blended to the volume of the normal side. This increased volume will immediately decrease the symptoms of oral incontinence on the paralyzed side during the period of overcorrection.
upward directed pull, and a gliding surface for the cheek soft tissue (Fig. 11). The temporalis muscle can also be transferred to the upper lip as a lengthening myoplasty described by Labbé and Huault.42 The entire muscle is mobilized from the temporal fossa and the fascial portion is advanced to the upper lip and commissure deep to the zygomatic arch. The temporalis muscle is resecured at a lower level within the fossa, preserving facial contour. The masseter as a standalone muscle transfer produces an undesired horizontal pull and does not have the correct vector to lift the upper lip and increase commissure excursion.40 Rather, the masseter is best used as a secondary muscle transfer to complement the temporalis. The strong upward pull of the temporalis can be balanced by transferring the anterior third of the masseter muscle to the lower lip (medial to the commissure) with a fascial graft from the temporal fossa. The masseter produces a balanced smile with a lateral lower lip dynamic, downward pull that restrains the strong, unopposed, upward temporalis (Fig. 12). The marginal mandibular branch is often preserved in congenital unilateral paralysis, and masseter transfer is not indicated. The anterior belly of the digastrics, innervated by the fifth cranial nerve, can be transferred to the lower lip as an “antagonistic counterbalance” to the strong upward pull of normally innervated musculature (isolated marginal mandibular paralysis)
or the strong, upward pull following temporalis muscle transfer.43–45 The digastric muscle is separated from its posterior belly and rotated upward and medial to the commissure of the lower lip.46 Similar to the masseter transfer, digastric muscle transfer performs lower lip restraint and mimics normal downward motion. Contiguous muscle transfers in partial facial paralysis are dependent on residual muscle excursion following maximum nerve and muscle regeneration. Technique is based on electrophysiologic studies of muscles on the paralyzed side compared with the normal side.47 Residual muscle excursion greater than 70 percent of the levator labii superioris and zygomaticus major muscles can achieve successful smile following muscle shortening. Patients with less than 70 percent residual muscle excursion require temporalis muscle transfer to achieve upper lip and commissure motion (Figs. 13 and 14). Difficulty in objective, reproducible muscle excursion measurements makes clinical judgment essential in selecting the appropriate reanimation procedure.
MICROSURGICAL FREE-MUSCLE TRANSFER PROCEDURES BY RYAN M. GARCIA, M.D., MICHAEL R. ZENN, M.D., M.B.A., AND JEFFREY R. MARCUS, M.D. Microsurgical free tissue transfer for facial reanimation has evolved and is now considered
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Video 5. Supplemental Digital Content 5, which depicts stimulation of various branches of the facial nerve, is available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B303.
Video 6. Supplemental Digital Content 6, which depicts a face incision and recipient-site dissection, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B304.
the criterion standard for patients with longstanding, permanent facial paralysis. Technical variations exist but all have a common need for a donor muscle and recipient nerve supply.48 Reconstructions are performed in either one or two stages.49,50 The two-stage protocol requires neuroregeneration across a cross-face nerve graft before subsequent muscle transfer. The facial nerve recipient by means of a cross-face graft provides a simultaneous, bilateral stimulus when unconscious emotions are elicited.51 During the first stage, the nonparalyzed face is dissected, a nerve stimulator is used, and a redundant facial nerve branch is selected that activates the desired smile separate from other facial movements. (See
Video 7. Supplemental Digital Content 7, which displays anchoring sutures for eventual free-muscle transfer, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B305.
Video 8. Supplemental Digital Content 8, which displays dissection of the gracilis muscle, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http:// links.lww.com/PRS/B306.
Video 9. Supplemental Digital Content 9, which displays a video depiction of the patient presented in Figure 15, is available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B307.
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Video 10. Supplemental Digital Content 10, which displays a video depiction of the patient presented in Figure 16, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B308.
Video, Supplemental Digital Content 5, which depicts stimulation of various branches of the facial nerve, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B303.) The sural nerve graft is passed in a subcutaneous tunnel from the nonparalyzed side to the paralyzed side, with the end left above the canine at the upper buccal sulcus to be retrieved during the second stage. This sural nerve graft is coapted to the previously selected branch of the nonparalyzed facial nerve and matures for 9 to 12 months. Nerve maturity is followed clinically with an advancing Tinel sign, although it is not always present in appropriately regenerated nerves. The
sural nerve is an ideal donor graft secondary to its extensive length, caliber, and limited morbidity. Typically, 18 to 20 cm of graft is adequate and can be obtained from the proximal two-thirds of the calf. Newer endoscopic techniques with a vein stripper are described to decrease operative time and morbidity associated with traditional sural nerve harvest.52 The second stage consists of microvascular free-muscle transfer after donor nerve maturation. Potential donor muscles include the gracilis, pectoralis minor, latissimus dorsi, serratus anterior, extensor carpi radialis brevis, rectus abdominis, and gastrocnemius.53 We advocate using the gracilis muscle secondary to its ease of harvest, adequate length, capability of being reduced in bulk, minimal functional loss, and disguised donor-site incision. During the second-stage presurgical evaluation, the desired vector of facial movement along with the contralateral smile is studied and marked. The recipient site for muscle transfer is prepared by performing wide elevation in the sub–superficial musculoaponeurotic system plane, and buccal fat is removed to reduce bulk for anticipated muscle transfer. (See Video, Supplemental Digital Content 6, which depicts a face incision and recipient-site dissection, available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B304.) The facial artery and vein are most often used as recipient vessels because of their proximity and
Fig. 15. (Left) A 10-year-old boy with congenital, unilateral, left facial paralysis. (Right) Twoyear postoperative result following free gracilis muscle transfer and contralateral cross-face nerve innervation.
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Fig. 16. Preoperative photograph of a 9-year-old girl who presented after undergoing two surgical resections of a juvenile pilocytic astrocytoma. (Left and center) After the second resection, she had complete and unchanging facial paralysis. She had previously undergone two gold-weight procedures that were complicated by infection and extrusion. (Right) Three-year postoperative result following a two-stage reanimation procedure and placement of a low-profile platinum weight at the second stage.
vessel size match. The length of gracilis muscle needed and the preferred pedicle position relative to donor vessels are determined before harvest, with the muscle at normal resting length. Proper placement of three to four nonabsorbable inset sutures at the commissure and upper lip is crucial to mimic the normal contralateral side vector. (See Video, Supplemental Digital Content 7, which displays anchoring sutures for eventual free-muscle transfer, available in the “Related Videos” section of the full-text article on PRSJournal. com or at http://links.lww.com/PRS/B305.) A vessel loop can be used to pass the obturator nerve from the cheek to the sural graft in the mouth.
The medial circumflex femoral vessels and the anterior branch of the obturator nerve supply the gracilis muscle and are dissected carefully. (See Video, Supplemental Digital Content 8, which displays dissection of the gracilis muscle, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http:// links.lww.com/PRS/B306.) We prefer the contralateral gracilis muscle secondary to the neurovascular pedicle orientation and ease of obturator nerve positioning. The distal muscle is inset at the oral commissure and upper lip using the previous inset sutures before microvascular anastomosis. Vascular anastomosis is performed, the
Video 11. Supplemental Digital Content 11, which displays a video depiction of the patient presented in Figure 17, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B309.
Video 12. Supplemental Digital Content 12, which displays a video depiction of the patient presented in Figure 18, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B310.
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Fig. 17. Preoperative photograph of a 28-year-old man who, 2 years previously, had undergone resection of an acoustic neuroma with reported preservation of the facial nerve. (Left) His complete paralysis was unchanged clinically, and serial electroneurographic testing showed no evidence of reinnervation. He underwent one-stage reanimation using a branch to the masseter nerve. (Right) His 1-year postoperative result is shown.
Fig. 18. (Left) Preoperative photograph of a 43-year-old woman with a history of congenital facial paralysis. Clinical examination demonstrated paralysis that primarily affected lower facial nerve branches. She required a strong vertical vector to give adequate dental display to her broad smile. She underwent a one-stage reanimation using a branch to the masseter nerve. (Right) Her 1 year postoperative result is shown.
obturator nerve is drawn through the subcutaneous tunnel, and an epineurial coaptation to the sural nerve is completed. Lastly, the proximal gracilis muscle is inset at the desired vector with slight overcorrection relative to resting tension.
The operative time of the first stage is consistently 3 hours, and patients typically are observed in the hospital overnight. Operative time following the second stage is typically 5 hours, with two simultaneous teams. Patients are monitored with
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis
Video 13. Supplemental Digital Content 13, which displays a video depiction of the patient presented in Figure 19, is available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B311.
an implantable Doppler device for 3 days before discharge on postoperative day 3. For patients with longstanding, static facial nerve paralysis, the gracilis free-muscle transfer with cross-facial nerve grafting is an ideal treatment. It results in an unconscious, emotion-elicited smile, with minimal donor-site morbidity (Figs. 15 and 16). (See Video, Supplemental Digital Content 9, which displays a video depiction of the patient presented in Fig. 15, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/ B307. See Video, Supplemental Digital Content 10, which displays a video depiction of the patient presented in Fig. 16, available in the “Related
Videos” section of the full-text article on PRSJournal.com or at http://links.lww.com/PRS/B308.) Results of the two-stage procedure are best among younger and thinner patients, possibly related to improved nerve regeneration and lighter muscle load. Reasons for less-than-optimal results of an underpowered smile are multifactorial. Explanations include insufficient donor axons, poor axon regeneration across multiple coaptation sites, relative muscle ischemia with scarring and atrophy, or age-related influences on nerve regeneration. We recommend one-stage facial reanimation for bilateral facial paralysis in children or unilateral cases in adults (Figs. 17 and 18). (See Video, Supplemental Digital Content 11, which displays a video depiction of the patient presented in Fig. 17, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http:// links.lww.com/PRS/B309. See Video, Supplemental Digital Content 12, which displays a video depiction of the patient presented in Fig. 18, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww. com/PRS/B310.) We recognize that variation and controversy exist among experts when choosing between a one-stage and a two-stage approach as it relates to age. We prefer the unilateral one-stage approach in adults aged 30 years or older and recommend the two-stage approach for all children younger than 18 years. In one-stage cases, the masseteric branch of the trigeminal nerve, which is expendable and powerful, is chosen as the donor nerve.
Fig. 19. (Left) Preoperative photograph of a 6-year-old boy with Möbius syndrome (bilateral facial paralysis) and hemifacial microsomia with bilateral mandibular hypoplasia. This patient underwent bilateral free gracilis muscle transfers, performed in two separate stages, both of which were innervated by the motor branch to the masseter muscle of the respective side (fifth cranial nerve). He later underwent successful mandibular distraction with bilateral internal devices. (Center) Six-month postoperative visit following a left gracilis free-muscle transfer. (Right) Twelve-month postoperative visit after the left gracilis free-muscle transfer and 6 months after the right gracilis free-muscle transfer.
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Plastic and Reconstructive Surgery • June 2015
Fig. 20. Eyelid stretching technique is depicted. The patient is instructed to grasp the upper eye lid lashes and pull the lid downward while also offering countertraction in the center of the upper lid in the zone corresponding to the levator palpebrae superioris. This stretch is held for 60 seconds, and is repeated every 8 hours until blinking returns. The eyelid stretch is designed to mechanically disrupt the myosin chain cross-linking of the levator palpebrae superioris during the anticipated passive stretching phase from the opposing action of the orbicularis oculi.
Postoperatively, physical therapy training is necessary to achieve expression. In contrast, the twostage approach with cross-face nerve grafting delivers an automatic, responsive facial reaction to emotion without training and has power to innervate the muscle transplant. In situations of absent bilateral facial nerves (Möbius syndrome), the motor nerve to the masseter or hypoglossal nerve can be used as the donor54–56 (Reference 54 Level of Evidence: Therapeutic, IV) (Fig. 19). (See Video, Supplemental
Digital Content 13, which displays a video depiction of the patient presented in Fig. 19, available in the “Related Videos” section of the full-text article on PRSJournal.com or at http://links.lww. com/PRS/B311.) The nerve to the masseter muscle can be used with limited donor-site deficit or weakness.57 In addition, the masseter muscle contracts in 40 percent of normal individuals during natural smiling,36 thus making it a reasonable motor alternative when the facial nerve is not available. Manktelow et al. demonstrated success with onestage free gracilis muscle transfer using the motor nerve to the masseter, with 59 percent of patients smiling without cortical initiation and 85 percent of patients smiling without clenching their teeth.30
MICROVASCULAR FREE-MUSCLE TRANSFER VERSUS CONTIGUOUS MUSCLE TRANSFER Microvascular free-muscle transfer can result in consistently excellent contour and strong movement but has a longer operative time, potential vascular complications, a delay in muscle function, and a final result in smile quality that occurs several years after successful muscle transfer. Contiguous muscle transfer offers a more immediate result but requires effort and concentration to activate muscles of mastication to achieve smiling. Furthermore, depending on technique, the presence of a visible muscle bulge over the malar eminence can be problematic. Both techniques are ultimately susceptible to variability in movement magnitude. Ideally, patients should have the option to select with an objective understanding of each. Most experts in facial reanimation would
Fig. 21. The effectiveness of administration of a single dose of botulinum toxin is depicted for lip balancing after marginal mandibular nerve neurapraxia. (Left) Lower lip asymmetry following mandible surgery. (Right) Balancing of the lip following the administration of 5 IU of botulinum toxin A into the right depressor labii inferioris muscle.
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Volume 135, Number 6 • Treatment of Facial Nerve Paralysis concede that contiguous muscle transfer is the procedure of choice for those who are not candidates or those who decline free-muscle transfer.
NONSURGICAL ADJUVANT TREATMENTS BY TESSA A. HADLOCK, M.D. Nonsurgical adjunctive therapies are used in patients with facial weakness either alone or in combination with static and dynamic reconstructive procedures to optimize outcome. Adjunctive therapies include medical therapy (botulinum toxin chemodenervation), physical therapy (tailored on the degree of flaccidity and/or hypertonicity), and miscellaneous facial balancing maneuvers (minor cosmetic techniques). Medical Therapy It is now generally accepted that systemic management of acute viral facial paralysis involves treatment with corticosteroids and valacyclovir.58 In addition, patients exhibiting poor electrophysiologic profiles (electroneuronography
