Depending on the status of the facial muscles, a patients with facial paralysis can be classified into one of 3 clinical categories. The clinical category helps us determine what treatment option is likely to achieve the best outcome.
Longstanding facial paralysis and paralysis present at birth such as Mobius syndrome are examples of irreversible complete paralysis. In this category, functional facial muscle are absent either from atrophy, trauma or developmentally. Patients in this category often require functional muscle transfer procedures to restore symmetry and smile. Examples of functional muscle transfer procedures are the temporalis muscle tendon unit transfer, gracilis muscle transfer, pectorals minor muscle transfer , etc.
As injured nerves recover, there is almost always so aberrancy in their regeneration. This aberrancy may manifest as too much much function in one area, not enough function in other areas or groups of the innervated muscles moving together when not desired. Two different muscles ( for example eyelid and smile muscles ) moving unwantedly together is termed synkinesis. The causes of these abberant nerve regeneration and their clinical manifestations vary and include changes occurring within the brain, the facial nerve branches and facial muscles. Reeducating the facial nerve - muscle network is an important aspect of rehabilitating the face after facial paralysis surgery.
Our patients work with our specially trained physical therapist using specific facial exercises to improve their facial balance. By suppressing unwanted movements, patients learn to enhance desired ones. This therapy is aided by video recordings of desired facial movements such as a learned smile in a system known as self-modeling and social implementation.
Targeted chemodenervation with injection of Botulinum toxin
Botulinum toxin is a neuropeptide that blocks nerve impulse from activating muscle fibers. The effect of botulinum on muscles are temporary since muscles recover from this near blockade. can be injected into specific muscle groups to help correct assymetry, muscle spasms, over contraction, synkinesis and is also used to facilitate the results of physical therapy.
Highly selective neurectomy
In selected cases of synkinesis, nerve branches reponsible for the unwanted facial movement or spasm are resected. The facial nerve is first explored and isolated. The branches are stimulated and the associated movement recorded. The branch or branches that appear to strongly cause synkinetic movement are identified.The nerve branches are then tagged through tiny incision in the skin.The patient then wakes up from anesthesia. In the early recovery period, the previously tagged nerve branches are sequentially blocked with micro injections of lidocaine to see if the synkinesis will resolve without negatively affecting eyelid closure or smile. The responsible nerve branch is then tied off and divided.
Highlyselective neurectomy is an important technique in the management of difficult to control
ocular synkinesis. It is however the last resort procedure after we have
exhausted less-invasive procedures.
selective neurectomy is usually performed as an outpatient procedure under general
anesthesia. The success of the procedure depends on identifying potential
candidate nerve branches for division while maintaining adequate innervation to allow
eyelid function and smile. We sometimes combine selective neurectomy with selective
myectomy (muscle resection) to optimize the outcome.
Selective myectomy is the division of an overactive facial muscle that is causing unbalanced facial movement. This is seen in extreme forms of synkinesis. In our practice, the most commonly divided muscle for facial balance is the platysma muscle. The platysma muscle is a broad paper thin muscle that starts over the lower face and extends to the clavicle. It is the muscle that tightens up in the neck when one tries to grimace. It acts to pull down the lower face and lip. When hyperactive, a tight platysma muscle tends to pull the lips down and counters the effects of the upper lip elevators needed for a smile. This tug of war between a depressor muscle ( platysma ) and an elevator muscle ( smile muscle ) can result in a strained appearance. Platysma resection is performed through a 2 to 3 cm neck incision and has the potential of relieving part of the facial tightness and imbalance common after Bells Palsy or synkinesis resulting from other causes of facial paralysis.
Another form of myectomy is the division of the lower lip depressor commonly used to correct asymmetric movement of the paralyzed lower lip that results in a distorted sile. In this procedure, a small segment of the active lower lip muscle the pulls the lip down in an unbalanced manner is removed. This results in a more balanced symmetric lower lip when smiling.
The hyperactive orbicularis oculi muscle may also be partially resected to partly control the effects of ocular synkinesis and extreme cases of blepharospasm
We often consider selective myectomy after a trial period of selective botulinum toxin injection.
Dynamic muscle and tendon transfer procedures ( temporalis tendon transfer, diagastric muscle tendon transfer).
Tendon transfer procedures are common in hand surgery. We have used the same principles to design minimally invasive techniques from transposing the temporalis tendon to acheive immediate improvement in facail symmetry and to improve smile after facial paralysis.With this special and minimally invasive technique that we have helped advance, we are able to restore movement to the face and allow one to relearn the ability to smile. This is one of the most rewarding procedures we perform for facial paralysis because the result is almost immediate. Infact, with muscle stimulators, we can record movement of the face minutes after the procedure is completed. The patient then learns to harness the power of the transfered temporalis muscle for smiling. Read more about the minimally invasive temporalis tendon transfer by Dr. Boahene. There are important biomechanical principles that guide the successful transfer on muscle tendon units. These principles must be carefully adopted to ensure optimized movement after a T3 ( temporalis muscle tendon transfer procedure). Read more about Dr Boahene's publication on muscle transfer correction of facial paralysis.
Nerve grafting ( facial nerve-hypoglossal nerve, masseter to facial nerve transfer, cross facial nerve grafting).
In cases where the facial muscles are determined to be electrically viable, the facial paralysis may be reversed with a nerve graft procedure. The nerve graft supplies a new source of nerve fibers (axons) that grow through nerve channels to the facial muscle to restore tone and movement. Nerve sources include the hypoglossal nerve, the masseter nerve and the facial nerve on the unparalyzed side of the face. Excellent result may be obtained from each of these methods with timing of intervention being the most critical factor. We have been able to restore movement using nerve grafting techniques in partial paralysis cases that have been present for 2 to 20 years. In these longstanding paralysis cases, we were able to determine that, although the paralysis was old, some intact nerve fibers were able to keep the facial muscle alive leaving them electrically responsive and thus reversible. In complete paralysis of shorter duration, the results are predictable and we seen recovery as early as 4 months following the surgery. We select which donor nerve after carefully considering the goals and individual patient attributes.
Types of nerve transposition for facial paralysis. 12 hypoglossal nerve, 7 facial nerve, 5 masseteric nerve, 7 to 7 cross facial nerve. While each example of the above nerve transposition can be done alone, occasionally we recommend a combination of nerve transpositions to take advantage of the unique features of each donor nerve.
Dr, Boahene has pioneered a minimally invasive method of transfering the masseter nerve to the facial nerve for facial reanimation.
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|The subzygomatic triangle by Dr. Boahene|| Through a small incision that leaves minimal scar, the masseter nerve is identified ( nerve seen under yellow band. Notice that the work area is very small which minimizes swelling and scar. || Using an endoscope through this small opening, we are able to trace a long segment of the masseter nerve (average 3cm). ||The masseter nerve is then transferred to the facial nerve under high magnification and carefully connected to the facial nerve using microsurgical techniques |
| Before||After ||After |
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3 months after complete facial
4 months after masster nerve
transfer to the facial nerve showing
symmetry at rest.
4 months after masster nerve
transfer to the facial nerve showing
excellent, natural and unstrained smile.
| Before||After || ||Before ||After |
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| Results after hypoglossal nerve transfer to the facial nerve for correction of facial paralysis|| ||Results after hypoglossal nerve transfer to the facial nerve for correction of facial paralysis |
| Hypoglossal nerve transfer|
|Combination of masseteric nerve graft and interposition facial nerve graft following |
complete resection of the facial nerve with complete reversible paralysis. Recovery
from the masseteric nerve was noted first with restoration of tone and symmetry. This was
followed by recovery of the interposition facial nerve grafts which restored spontaneous
movement when laughing and smiling.
Upgrading partially recovered facial nerves
An important concept in facial paralysis treatment is the ability to improve nerve and muscle function in individuals who have incomplete facial nerve recovery or paralysis. The typical case is a patient who develops Bells palsy and recovers only partially. They have improved symmetry but an asymmetric smile. The challenge is to improve their smile without disturbing the partial recovery they regained. We use a technique called "supercharging" whereby through nerve grafting techniques more movement is restored to the smile muscles while preserving the partial gains.
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Improved smile following a nerve super charge procedure to correct incomplete recovery of facial paralysis. Facial paralysis resulting from Bells palsy or surgery can recover fully without residual asymmetry. Occasionally, the recovery is incomplete. This young lady had surgery to remove a brain tumor (acoustic neuroma). She had complete paralysis of her face which recovered partially after one year. At rest, her face was symmetric but crooked when she smiles. To improve her smile as well as eyelid closure a supercharge procedure was performed. The goal of a supercharge procedure is to upgrade the nerve signal to the partially recovered or paralyzed facial muscles without adversely affecting the regenerated nerve fibers. The nerve transfer supercharge technique by Dr. Boahene preserves the partial recovery but upgrades the nerve signal to facial muscles resulting in improved movement, tone and a better smile. Results shown here is 3 months after the supercharge signal upgrading surgery. The surgery is done through a small incision placed in front of the ear crease. The procedure takes about 3 hours to perform and patients are usually discharged home the same day.
Free functional muscle transfer.
( gracilis muscle, vastus lateralis muscle, pectoralis muscle, serratus muscle transfer, latissimus musle transfer)
When nerve repair or muscle tendon transfer is not feasible, we have the option of transplanting a muscle and nerve from other parts of the body to the face; connect the nerves to other nerves in the face to restore facial movement. The muscle being transferred does not leave a noticeable deficit. Common donor sites for transferring muscle include the thigh, chest wall or back. Presently we commonly transfer the gracillis muscle to correct longstanding facial paralysis. This procedure has been refined over many years and can now yield predictable results. Specific techniques we use to improve results include transferring a small segment of the gracillis muscle to minimize bulk. We can perform this procedure in a single stage fashion using the masseter nerve to power the gracillis muscle. In a 2 stage fashion, we use a combination of a cross facial nerve graft that borrows nerve fibers from the normal face and the masseter nerve to produce a reliable result. There are other muscle besides the gracillis that may be transferred. We are constantly involved in research looking at other donor muscles and methods of enhancing results in facial muscle transfer.
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The thin muscle segment is segment of the gracilis muscle can be harvested with its artery, veins (white arrow) and nerve (blue arrow). Guided by nerve stimulation, the muscle is carefully debulked. The thin muscle segment is transplanted to replace the smile muscles (large blue arrows) to restore symmetry and smile. In a single stage gracilis transfer, the nerve is connected to the masseter nerve. In a 2 stage gracilis transfer procedure; we first perform a cross facial nerve graft followed 6 months later by the muscle transfer. In selected cases, we innervated the gracilis with both a cross facial nerve and masseter nerve. To achieve a nice result, it is important to apply the biomechanical principle of muscle tendon unit transfer. The vector of muscle contraction, site of muscle insertion, tension of muscle insertion and a bed of fat on both sides of the transplanted gracilis muscle are all important technical details essential in achieving a muscle that glides smoothly to restore a nice smile.
Example of a gracilis flap in a young boy for reanimation of a left facial paralysis. Notice before surgery( left image) there was asymmetry at rest, the lips were uneven and no smile crease defined on the left cheek. After the gracilis flap ( center and right images) there is excellent symmetry, even lips, no excessive bulk from the muscle flap and restored smile crease and movement of the lip. The gracilis flap was innervated by a cross-facial and masseteric nerves.
Example of a gracilis flap reanimation of a left facial paralysis. Notice smile asymmetry before the gracilis flap ( left images) with unequal teeth exposure (dental show) . After the gracilis flap ( right images) there is excellent symmetry, even lips, no excessive bulk from the muscle flap and restored smile with equal teeth showing. The gracilis flap was innervated with masseteric nerve only as a single stage procedure.
Gracilis flap innervated by mastered nerve for right-sided congenital facial paralysis in a young boy.
Note result at rest with restore symmetry ( left ), symmetric Mona Lisa smile ( middle ) and
spontaneous smile showing nearly symmetric lip elevation and dental ( teeth) show.
One of the most bothersome consequences of facial paralysis (Bells palsy) is synkinesis. Synkinesis is the unwanted movement that accompanies a desired movement and is usually a sign of aberrant regrowth of the facial nerve. A common example is eye closure when one smiles or laughs. The reason why this occurs following nerve injury varies and includes nerve fibers reaching the wrong target, changes in the myelin sheath that covers a regenerating nerve and changes in nerve fiber connections in the facial nucleus within the brain stem. Treatment options for facial synkinesis include nerve-muscle retraining aided by biofeedback techniques, selective disruption of nerve signals to the muscle group one desires to suppress either by injections (chemo denervation with botulinum neuropeptide), nerve division (neurectomy) or selective removal of muscle (myectomy). The most distressing form of synkinesis usually involves the eyelid muscles and can be severe enough to obstruct vision. The involved eye looks smaller and cosmetically unappealing. We use a combination of the above methods to achieve long-lasting improvement. See before and after photos of surgical correction of synkinesis and blepharospasm of the eye after Bells palsy.
The platysma muscle is a broad thin muscle which is an extension of the facial muscles in the neck. It is innervated by the facial nerve and acts to pull down the lower face when grimacing. During recovery of an injured or repaired facial nerve, precious fibers of the regenerating nerve may end up in the platysma muscle diverting nerve fibers from desired targets in the upper face. In addition to this, cross talk between these platysma fibers and nerves to the midfacial and eyelid muscles may contribute to diminished lip evelation during smile and synkinesis. This may also result in tightness in the face and can occasionally be painful. Dividing the offending platysma fibers ( platysmoplasty) has the potential of immediately relieving the facial tightness, improving lip movement and minimizing synkinesis. Platysmoplasty for facial paralysis can be done under local anesthesia and is usually well tolerated.
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|Neck and facial tightness from |
|Relaxed face and resolved neck |
tightness after platysma resection
Smile recovery scale
We grade our procedure outcomes both subjectively and objectively. Our smile recovery scale is based on measures of symmetry, lip elevation and dental show. An abbreviated version of the smile recovery scale is shown here.
Static reanimation ( facelift, eyelid sling, midfacelift, Fascia lata slings)
The droopiness seen in the paralyzed face can be corrected with various procedures that even out the face and actually helps the face look younger. Brow lift procedures even out the droopy brow correcting the angry look.
Facelift many be used to improve the neckline, midface and the overall facial symmetry. The droopy cheek is sometimes lifted ( midface lift) to help support and suspend the lower eyelid which improves eye closure.
Platinum chain eyelid implants are flexible low profile implants that we place within the upper eyelid to aid in eye closure. Because of their low profile, they are usually invisble where they are implanted. Lower eyelid suspension using free fascia slings or temporalis muscle slings helps suspend the retracted eyelids up which aids in eye closure, tear distribution and thus reducing excessive tearing. Combinations of spacer grafts( tissue grafts placed within the lower eyelid) and eyelid suspension techniques ( medial and lateral canthopxey) are key in protecting the eye from irritation, drying and ulceration.
Facial weakness in FSH dystrophy
Facioscapulohumeral (FSH) dystrophy is a common muscular dystrophy in which there is progressive weakness of the face, upper arms and shoulder regions as well as the legs. The symptoms of FSH dystrophy may appear during childhood with severe facial and limb weakness or develop slowly and gradually in adulthood with difficulty such as eye closure, lifting or tripping. The disease is caused by degeneration of muscle due to a specific chromosomal deletion. This deletion is inherited from one generation to the next. FSH dystrophy is the third most common dystrophy with an estimated prevalence of 1 in 20,000. In spite of this high prevalence, research and treatment options are at a suboptimal level. We are collaborating with neurologists and therapist who focus in the care of this disease. We have focused on facial manifestation of FSH dystrophy and made several observations that have lead to treatment options for our patients.The muscles of facial animation are small skeletal muscles that mostly originate and insert on the soft tissues of the face. Facial expression is an important part of human communication allowing us to reflect emotions and project non-verbal cues. The facial muscles also support the facial skin and fat giving it shape and form. Blinking, whistling, blowing out candles, drinking from a straw are simple day to day actions that depend of the fine action of the facial muscles. These functions are severely affected when the facial muscle become progressively weak as seen in FSH dystrophy.FSH dystrophy patient often complain of changes in their speech. They are unable to generate the intraoral pressure to pronounce plosive sounds such as "P" "B". As the facial muscle become weaker, midfacial fat descends the corner of the mouth turns downwards giving a falsely sad appearance. Read more.