Answer:
Regional muscle transfers have been used for years to achieve support of the mouth and produce a smile. The most frequently used muscles are the temporalis and masseter. The temporal muscle is harvested from its bed in the temporal fossa and turned over the zygomatic arch to extend to the oral commissure. It may be necessary to dissect the fascia off the muscle to allow it to reach the commissure. Disadvantages include the creation of a hollow at the donor site (which can be avoided by leaving a portion of the muscle anterior to the hairline) and the bulge of muscle over the zygoma. The transfer provides excellent static positioning as well as voluntary activity. It is activated by the voluntary action of clenching the teeth. It produces a more vertical lift to the corner of the mouth and greater movement than the masseter muscle.