One-Stage 2-Vector Reconstruction for Facial Paralysis and Hypoplasia in Hemifacial Microsomia Using Dual Latissimus Dorsi Adipo-Muscular Flap Transfer

Hemifacial microsomia (HFM) is characterized by unilateral craniofacial hypoplasia and is frequently associated with facial paralysis. Dynamic reanimation, in addition to facial augmentation, is important for aesthetic and functional improvement. Most publications on dynamic reanimation have focused on oral commissure elevation during smiling. However, severe lower lip depressor paralysis, often observed in patients with HFM, also requires reconstruction to improve aesthetic symmetry. Here, we report the simultaneous reconstruction of oral commissure elevation, lower lip depression, and cheek augmentation in a patient with HFM. A 19-year-old woman with HFM presented with incomplete facial paralysis and cheek hypoplasia. She demonstrated mildly impaired oral commissure elevation and nearly absent lower-lip depression. Reconstruction was performed using a dual latissimus dorsi adipomuscular flap. Muscle A, including adipose tissue, was used for midfacial augmentation and oral commissure elevation and was innervated by the ipsilateral facial nerve. Muscle B, used for lower lip depressor reanimation, was dually innervated by the ipsilateral facial nerve and the contralateral marginal mandibular branch (CLMMB) of the facial nerve. The selective division of the CLMMB offered a motor source for muscle B while simultaneously attenuating the contralateral depressor. A fascia lata graft was used to prevent deviation of the lower lip. Six months postoperatively, the patient demonstrated satisfactory facial contour and lip symmetry both at rest and during smiling. To the best of our knowledge, this is the first report of simultaneous reconstruction combining 2-vector dynamic reanimation of lip elevation and depression with cheek augmentation in a patient with HFM.