What is masseter to facial nerve transfer surgery?
The masseter to facial nerve transfer or trigeminal nerve transfer can significantly improve smile in select patients with facial paralysis. Your surgeon will be able to guide you through the process to see if you would benefit from this procedure. The masseteric nerve brings movement to a chewing muscle, called the masseter on the side of the face. Using the masseteric nerve leaves nearly no deficit, because multiple muscles are responsible for that chewing and biting.
A major advantage of using masseteric nerve is that it results in quicker return of movement, usually within 3 months of surgery. In contrast, a cross-face nerve transplant takes 6-12 months to grow across the face. In certain time-sensitive situations, where patients have had long history of paralysis with significant wasting of facial muscles, your surgeon may recommend masseter to facial nerve transfer in order to improve the chances of retaining the movement in your smile muscles. Another advantage of connecting a smile branches to masseteric nerve is the expected decrease in synkinesis, which is movement of multiple facial muscles at the same time, in patients who undergo additional nerve transplant surgeries.
The smile obtained from this technique is triggered by biting down. Initially, patients have to think to bite down to smile on the paralyzed smile, but through work with our facial physiotherapists, patients learn to smile more naturally. A simultaneous cross-face nerve transplant with masseter to facial nerve transfer can create a more natural spontaneous smile within 6-12 months of surgery.
Patients with paralysis of more than 2 years may no longer have functional facial muscles, because the muscles waste away if they are not used. In rare cases, smile muscles may be removed during cancer surgery. In those circumstances, patients do need both a nerve transplant and a muscle transplant in order to achieve the most natural movement on the paralyzed side. Your surgeon may recommend dual nerve transfer to bring most natural smile using both masseter nerve as well as cross facial nerve graft to power the transplanted smile muscle. The muscle from the inner thigh, called the gracilis muscle can be used as a free flap to replace missing or wasted smile muscles. A free flap means that the muscle is moved from one area of the body to another with its own artery, vein and nerve like a transplant. It is then connected to nerves in the face and the arteries and veins in the neck under a microscope. The muscle transplant then slowly learns movement from the nerve transplant over the next 8-12 months.
When do I need masseter to facial nerve transfer surgery?
Facial paralysis surgery is different in all patients, your surgeon will be able to create a custom plan for your unique situation in order to get the best results. Patients with flaccid facial paralysis of less than 2 years in duration may benefit from nerve to masseter transfer with or without a cross-face nerve graft. If paralysis has been present for over 2 years patients often need both a cross-face nerve graft and a muscle transplant from their inner thigh.
During cancer surgery of the parotid gland or tumor removal operations a segment of the facial nerve may have to be removed with the tumor or cancer. These patients will need substitute nerve transplants during their cancer removal operation in order to maintain facial movement. In order to reduce synkinesis, your surgeon may combine that surgery with masseter to facial nerve transfer surgery if it is safe from cancer treatment perspective. Sometimes cancer that involved the facial nerve may also affect the masseteric nerve as they are located close to each other. If a nerve transplant is performed for a missing piece of the facial nerve, it generally takes 6-12 months for the nerves to regrow. Time to being able to smile again can be reduced by the use of masseter to facial nerve transfer to 3 months.
How do I prepare for masseter to facial nerve transfer surgery?
Prior to masseter of facial nerve transfer surgery, your surgeon may get an electromyography (EMG) study of your facial muscles to determine if you are a candidate for the nerve transfers. Some patients will have a few sessions of facial physiotherapy (link to facial physiotherapy article) before surgery.
Your surgeon will discuss the procedure with you including risks, benefits and alternative treatments. They will review your medications including herbal and over-the-counter drugs and supplements. Many herbal products and pain relievers make it harder for you blood to clot and should be discontinued before surgery. You will sign informed consents and get your instructions for before and after surgery.
You will see your own personal physician for a medical clearance to make sure they feel it is safe for you to have surgery. Your physician may order laboratory blood tests, an EKG or a chest X-ray. You need to stop smoking as this delays healing. You should have nothing to eat or drink after midnight before your procedure. You will be told when to arrive at the surgery center before your surgery. You are signed in, change into a gown, given an IV, and talk to the nurse and anesthesiologist. You will then talk to your surgeon before you get any medication at the hospital so you can ask questions.
What happens during masseter to facial nerve transfer surgery?
You are taken in to the operating room, lie down on your back, and the anesthesiologist will put you to sleep with a breathing tube to make sure your airway is safe. The area to be operated on is sterilely prepared with a cleaning solution and drapes. Nerve monitoring system is used to help in identification of the nerve to the masseter muscle. Once identified masseteric nerve is isolated and connected to smile branch of the non-functioning facial nerve. The nerves are sutured together under a high-powered microscope using sutures smaller than the size of human hair. Special nerve sheaths are also placed on suture connections in order to facilitate nerve growth. The nerves do not function right away, but the surgery creates new pathways or conduits for nerves to grow and therefore create movement on the paralyzed side of the face.
What is the follow-up for masseter to facial nerve transfer surgery?
The procedure is generally not very painful, but you may take oral pain medicine the doctor has given you or acetaminophen (Tylenol). If you need a narcotic pain medicine you should take them with food in your stomach and start on a mild stool softener like Senna. You will be often given antibiotic to prevent infection. There will be a surgical drain under the skin in the face. It will generally be removed on day 3-5 after surgery depending on your recovery.
Keeping your head elevated will decrease pressure on the incision. You should take it easy for at least two weeks and your doctor will let you know what level of activity you can resume. Call your doctor if you have increasing redness of the incision, fever, bleeding, pus, drainage, the incision opens or you have worsening pain. Also, let your doctor know if you have any other concerns. You will see your doctor one week after surgery and sutures will be removed. You usually can be performing normal activities within two weeks of surgery.
What are the risks of masseter to facial nerve transfer surgery?
The risks of surgery will vary depending on what nerve transplant or transfer surgery is performed. The general risks of facial surgery include bleeding, bruising, infection, injury to the movement nerves on the donor sites, numbness, the need for additional surgery, chronic pain, numbness, temporary or permanent loss of facial movement on the functional side risks of general anesthesia. Preparing for surgery and following your doctor’s instructions are useful to help minimize risks.
The Surgeons of Norelle Health are highly trained and skilled in the diagnosis, management, and treatment of facial paralysis. Dr. Araslanova can provide the optimal treatment for facial paralysis in your situation. The field of facial paralysis is growing rapidly and our surgeons are at the forefront of research and most modern surgical treatment options. As out-of-network providers, we will check your benefits for you and let you know if there are costs are so there are no surprises. We use an individualized treatment plan for your concerns to provide a personalized holistic plan of care. If you would like assistance, please feel free to contact us.