What are symmetry correction procedures?
Sometimes in the setting of facial paralysis, there may be only partial paralysis affecting a portion of the face. This can cause asymmetry that can be unfavorable for many patients. This can also occur after smile reanimation or other types of facial paralysis reconstruction where correcting one deficiency may unmask an asymmetry somewhere else on the face.
The facial nerve has 5 main branches that give innervation to all of the facial muscles of expression. Any one of these branches or combination of branches can produce facial asymmetry when not functioning. Asymmetry correction is aimed at reversing or camouflaging these areas, thereby, restoring balance to the face.
There are several possible surgical and non-surgical procedures for correcting asymmetry in facial paralysis. Treatment is individualized depending on various factors, including degree of muscle function, severity of asymmetry, or age of the patient. The surgical procedures address asymmetry in a permanent fashion, whereas non-surgical options may need to be repeated. Some of the options are listed below:
- Contralateral (opposite side of paralysis) lower lip depressor muscle excision
- Contralateral marginal mandibular nerve excision
- Ipsilateral (same side as paralysis) browlift or browpexy
- Contralateral frontalis muscle excision
- Debulking of the cheek after gracilis muscle transplant
- Readjustment of temporalis tendon insertion
- Targeted Botox® injection
The most common asymmetry correction is a combination of excising the opposite side lower lip depressor muscle and marginal mandibular nerve, which is responsible for stimulating the depressors. The depressor muscles consist of The opposite side depressor is targeted because there is currently no acceptable way to dynamically reanimate the downward pulling action of the lower lip depressor muscles. Balancing the lower lip by removing the muscle activity of the opposite side improves symmetry both at rest and when smiling. An incision is placed inside the lip on the side with the active lip depressor muscles. These are a pair of muscles: depressor anguli oris and depressor labii inferiors. The muscle fibers are then located and a strip of the muscle is removed to disrupt its function. Through the same incision, the terminal branches of the marginal mandibular nerve (branch of the facial nerve) is also removed. Occasionally, a separate tiny incision underneath the jawline is placed to locate this nerve and divide it. In preparing the face, an incision is placed in the pattern of a facelift with a small extension underneath the jaw.
What is the recovery from asymmetry correction for facial paralysis?
On their own, asymmetry correction procedures are outpatient procedures. However, most often, they are combined with other symmetry procedures or reanimation surgery. A common combination is smile reanimation with lower lip depressor muscle excision, for example. Other combinations are also possible. There may be moderate swelling of the lips, lower face, forehead, or eyelids. A short course of antibiotics may be required, and a soft diet is necessary for 2 weeks. All sutures are absorbable and do not need to be removed. Contact sports and heavy lifting are avoided for 3-4 weeks.
What are the risks and complications of asymmetry correction for facial paralysis?
Bleeding, infection, and complications from anesthesia are possible during or after surgery, as with all types of surgical procedures. These are rare risks; however, other risks are related more specifically. For example, asymmetry is possible either in the resting position or with smiling. Also, there may be minor contour issues. In some cases of muscle excision, there may be partial recurrence of muscle function.
To minimize your risk, pay close attention to instructions before and after surgery. Dr. Panossian’s staff is available at all times to clarify any pre- or postoperative instructions that you are given.