Profiling of innervations of mimetic muscles in fresh human cadavers using a modified Sihler's technique

The nerve map of the human face, although important in guiding facial surgery, has not been well defined. In this study we applied a modified Sihler's technique to profile intramuscular innervation of human mimetic muscles. Six fresh cadaveric heads were used. The intramuscular distribution of the facial nerve in human mimetic muscles was visualized using a modified Sihler's technique. Modified Sihler's staining revealed a three-dimensional picture of the clearly purple-black intramuscular facial and sensory nerves. The nerve branching patterns of both facial halves were asymmetrical. None of the fine nerve branches crossed over the midline. The facial nerve branches divided into secondary rami and formed a mesh-like plexus before entering the target muscles at a right angle. The modified Sihler's technique can profile intramuscular innervation of human mimetic muscles. Our nerve map of the face offers valuable guidance for facial reanimation surgery, facial cosmetic surgery, and parotid surgery.