Reconstruction utilizing the original muscles of facial expression is ideal, if possible. If the facial nerve is not available to power these muscles, other nerve sources may be utilized.
Direct Nerve Repair
In certain scenarios, a traumatic injury may have resulted in a sharp cut to the facial nerve, creating a facial paralysis to all or part of the face. These injuries are sometimes able to be repaired, particularly if managed within a few days from the injury. These injuries often require a nerve graft, or a segment of another nerve (usually the sural nerve from the calf) to span a gap between the two cut ends.
Cross-Facial Nerve Grafts
If only one side of the face is affected by facial paralysis, the normal, unaffected facial nerve from the opposite side of the face may be utilized as a nerve source. Appropriate expendable (or extra) branches of the working facial nerve can be identified and connected to the opposite side of the face via a cross-face nerve graft, which acts somewhat like an extension cord. The nerve graft is an expendable sensory nerve, typically the sural nerve in the calf. Removal of the sural nerve from the calf results in a numb patch on the outer surface of the foot and does not affect the ability to walk. The sural nerve removal usually requires two or three small scars on the leg. The sural nerve is then connected from the unaffected, normal facial nerve to the affected side. The nerve fibers then slowly grow across the nerve graft to provide a nerve source to the paralyzed muscle(s).
In cases of bilateral facial paralysis, it is not possible to connect nerves from one side of the face to the other because both sides are affected. In these cases, other motor nerves that are nearby may be used to provide a nerve source. We commonly use the masseteric branch of the trigeminal nerve, which is the motor nerve to the masseter muscle, a muscle used in chewing. The nerve branch is expendable (extra), and its use does not result in chewing difficulties. The masseteric nerve can be connected to the affected facial nerve to provide a nerve source to the paralyzed muscles. This nerve transfer does not require use of a nerve graft, meaning no surgery is required in the leg.
To schedule an appointment with Dr. Snyder-Warwick, please call 314-362-7388 or 1-800-454-KIDS.