Sectional neuroanatomy of the face.

Needle electromyography and the injection procedures of the face are difficult because of the small size and close anatomic relations of the facial structures. Local injections of the face have increased in frequency since the introduction of botulinum toxin. This article intends to provide anatomically accurate schematics of innervation of the muscles of facial expression that can be used to interpret magnetic resonance images of the muscles and nerves. Cross-sectional schematics of the face were drawn as they appear in imaging projections. The relevant cranial and spinal nerves were color coded. The muscles and skin surfaces were labeled and assigned the color of the appropriate nerves. An organized comprehensive map of the motor innervation of the face allows the physician to increase the accuracy and efficacy of interventional procedures. This could also assist the electromyographer in correlating the clinical and electrophysiologic findings with magnetic resonance images.