Multivector functioning muscle transfer using superficial subslips of the serratus anterior muscle for longstanding facial paralysis

Various donor muscles have been identified for restoring facial function due to longstanding facial paralysis. Donor muscles such as the gracilis and latissimus dorsi are frequently used and often produce one or two reliable vectors of force. However, there are drawbacks of using these muscles, including the instability of separating multivector functioning muscle units and limited amount of muscle contraction. Serratus anterior muscle transfer has the advantages of multiple independently functioning motor units that can be created with a single neurovascular pedicle. This article describes multivector muscle transfer using two or three superficial subslips of the serratus anterior muscle on a single neurovascular pedicle to produce an esthetic smile that is customized to imitate the function of the contralateral mimetic muscles. Twelve patients who had longstanding unilateral facial paralysis underwent muscle transfer consisting of multivector superficial subslips of the serratus anterior muscle innervated by the ipsilateral masseteric nerve. The procedure had an uneventful postoperative course, and patients obtained excellent results, with sufficient upper lip excursion, mouth angle, and lower lip working simultaneously. Functioning muscle transfer using multivector superficial subslips of the serratus anterior muscle is effective for treating longstanding facial paralysis. This technique avoids postoperative bulkiness of the cheek muscle and achieves a more natural and symmetrical smile.