The position and branching pattern of the facial nerve and their effect on transcutaneous electrical stimulation in the orofacial region.

A significant proportion (31%) of southern (Hong Kong) Chinese patients who received therapeutic transcutaneous electrical stimulation with the Myo-Monitor experienced uncomfortable twitching of the muscles of facial expression of the upper and middle portions of the face. This can be attributed, at least in part, to anatomic variation in the position and branching pattern of the upper (temporofacial) division of the facial nerve in the sample population. Our observations of living patients support the contention that muscular contraction resulting from Myo-Monitor stimulation is neurally mediated.