[Exposure of the facial nerve in the masseteric region during parotid surgery. Technical aspects and value].

With an accurate understanding of facial soft-tissue anatomy, deep plane rithydectomy can be performed in safe and precise fashion. We report our experience of 19 cases of parotidectomy using this superficial musculo-aponeurotic system mobilization anterior to the gland. In all cases (two recurrences), it was thus possible to safely expose at least two terminal branches of the lower facial nerve in the masseteric area without jeopardizing the facial nerve. During a second operation for recurrent tumor or in the case of some lesions as inferior and anterior intraglandular cyst, the distant branches of the nerve can be uncovered by a backward dissection. The easiest to identify seems to be the terminal branches in the masseteric area, as it is directly accessible after cutaneous undermining in an area generally not dissected during previous operations and with preserved anatomic relations. In other cases this technique enables one to expose the parotid gland completely and facilitates anterograde facial nerve dissection by its terminal exposure. The superficial musculo-aponeurotic system dissection allows its backward transposition, in the absence of any contraindication, so as to prevent retromandibular depression following a parotidectomy.