Muscle | Origin | Insertion | Action |
Frontalis | O- galea aponeurotica | I- skin of eyebrows and root of nose | With aponeurosis fixed, raises the eyebrows (as in surprise); wrinkles forehead skin horizontially. |
Occipitalis | O- occipital and temporal bones | I- galea aponeurotica | Fixes aponeurosis and pulls scalp posteriorly. |
Corrugator Supercilli | O- arch of frontal bone above nasal bone | I- skin of eyebrow | Draws eyebrows together and inferiorly; wrinkles skin of forehead vertically (as in frowning). |
Zygomatics- major and minor | O- zygomatic bone | I- skin and muscle at corner of mouth | Raises lateral corners of mouth upward (smiling muscle). |
Risorius | O- lateral fascia associated with masseter muscle | I- skin at angle of mouth | Draws corner of lip laterally; tenses lips; synergist of zygomaticus. |
Orbicularis Oris | O- arises indirectly from maxilla and mandible; fibers blended with fibers of other facial muscles associated with the lips | I- encircles mouth; inserts into muscle and skin at angles of mouth | Closes lips; purses and protudes lips; kissing and whistling muscle. |
Mentalis | O- mandible below incisors | I- skin of chin | Protrudes lower lip; wrinkles chin. |
Buccinator | O- molar region of maxilla and mandible | I- orbicularis oris | Draws corner of mouth laterally; compresses cheek (as in whistling and sucking); holds food between teeth during chewing; well developed in nursing infants. |
Platysma | O- fascia of chest (over pectoral muscles and deltoid) | I- lower margin of mandible, and skin and muscle at corner of mouth | Helps depress mandible; pulls lower lip back and down, i.e., produces downward sag of mouth; tenses skin of neck (e.g., during shaving). |
Masseter | O- zygomatic arch and maxilla | I- angle and ramus of mandible | Prime mover of jaw closure; elevates mandible. |
Temporalis | O- temporal fossa | I- coranoid process of mandible via a tendon that passes deep to zygomatic arch | Closes jaw; elevates and retracts mandible; synergist of pterygoids in side-to-side movements; maintains posistion of the mandible at rest. |