These procedures are typically used when nerve grafting is not possible due to degradation of distal nerve fibers. Transposition of the temporalis or masseter muscles can provide tone and dynamic reanimation to the lower face. The temporalis muscle transfer requires the movement of the temporalis belly over the zygomatic arch. This can result in significant cosmetic deformity in the temporal and zygomatic region. Using the temporalis tendon transfer technique will avoid this possible deformity. The temporalis tendon is disinserted from its attachment to the coronoid process and transferred to the lateral commissure or melolabial fold. Masseter can be used as well if the surgeon prefers to avoid a large facial incision. However, there is less muscle to use and the vector of force provides less superior angulation to the corner of the mouth [15, 45, 46].
Free muscle flaps
Microvascular free flaps utilize free tissue transfer, including soft tissue and corresponding nerve and vascular supply, to rehabilitate the paralyzed face. These flaps have the possibility to allow for emotional animation in addition to better tone. The procedure is typically two staged in which a cross-facial nerve graft is performed approximately 9-12 months prior to the flap. The most common is the gracilis flap [15, 47, 48].