risorius muscle (anatomy)
Last reviewed 01/2018
Risorius is one of the muscles of facial expression. Bilaterally, it arises from deep fascia of the parotid gland. Passing anteriorly, it inserts into the modiolus and the skin at the angle of the mouth.
It is innervated by the buccal branch of the facial nerve (CN VII).
Risorius acts to retract the angle of the mouth.