Preservation of the mandibular branch of the facial nerve is of great importance for surgeons during surgical procedure involving the submandibular region. To identify the nerve under direct vision seems to be the best method. Direct visualization of the nerve, however, is rather difficult, because the mandibular branch is very thin in diameter. Therefore, the following new technique was employed not to damage the mandibular branch: electrical stimulation is applied preoperatively on the submandibular region as an indicator of muscle twitch of the lip angle and the underlying nerve is marked on the skin; the skin is incised 1cm below the marked skin. The platysma and cervical fascia are incised through the same skin incision; the upper flap is stripped and elevated upward. The mandibular branch lies within the elevated flap.
This operative procedure was performed in 15 patients in this fashion. Facial palsy was not observed except for one patient with metastatic tumor in the submandibular region.
