• Ashraf Raslan, Gerd Fabian Volk, Martin Möller, Vincent Stark, Nikolas Eckhardt, and Orlando Guntinas-Lichius.
• Department of Otorhinolaryngology and Facial Nerve Center Jena, Jena University Hospital, Jena, Germany.
• Laryngoscope. 2017 Jun 1; 127 (6): 1288-1295.

Objectives/HypothesisTo examine by intraoperative electric stimulation which peripheral facial nerve (FN) branches are functionally connected to which facial muscle functions.Study DesignSingle-center prospective clinical study.MethodsSeven patients whose peripheral FN branching was exposed during parotidectomy under FN monitoring received a systematic electrostimulation of each branch starting with 0.1 mA and stepwise increase to 2 mA with a frequency of 3 Hz. The electrostimulation and the facial and neck movements were video recorded simultaneously and evaluated independently by two investigators.ResultsA uniform functional allocation of specific peripheral FN branches to a specific mimic movement was not possible. Stimulation of the whole spectrum of branches of the temporofacial division could lead to eye closure (orbicularis oculi muscle function). Stimulation of the spectrum of nerve branches of the cervicofacial division could lead to reactions in the midface (nasal and zygomatic muscles) as well as around the mouth (orbicularis oris and depressor anguli oris muscle function). Frontal and eye region were exclusively supplied by the temporofacial division. The region of the mouth and the neck was exclusively supplied by the cervicofacial division. Nose and zygomatic region were mainly supplied by the temporofacial division, but some patients had also nerve branches of the cervicofacial division functionally supplying the nasal and zygomatic region.ConclusionsFN branches distal to temporofacial and cervicofacial division are not necessarily covered by common facial nerve monitoring. Future bionic devices will need a patient-specific evaluation to stimulate the correct peripheral nerve branches to trigger distinct muscle functions.Level Of Evidence4 Laryngoscope, 127:1288-1295, 2017.© 2016 The American Laryngological, Rhinological and Otological Society, Inc.

31 keywords...

hide…