Head muscles

The muscles of the head can be grouped into two categories: the muscles of mastication (masticatory muscles), which are derivatives of the first pharyngeal arch, and the muscles of facial expression (facial muscles), which are derivatives of the second pharyngeal arch.

Because of their different embryological development the two groups of head muscles are supplied by two different cranial nerves. Most of the muscles of the head belong to the facial muscles and are innervated by the facial nerve (CN VII), while the four masticatory muscles are innervated by the mandibular nerve (CN V3).