L5.5.1: Facial Muscles

• FACIAL MUSCLES

  [a] Frontalis

  [b] Temporalis

  [c] Occipitalis

  [d] Orbicularis Oculi

  [e] Zygomaticus

  [f] Buccinator

  [g] Risorius

  [h] Levator Labii Superioris

  [i] Orbicularis Oris

  [j] Masseter

  
• Frontalis

  ○ Covers the frontal bone

  ○ Runs from the cranial aponeurosis to the skin of the eyebrows where it inserts

  ○ Movement: allows to raise the eyebrows and wrinkle the forehead
• Temporalis

  ○ Fan-shaped muscle overlying the temporal bone

  ○ Inserts into the mandible

  ○ Movement: Acts as a synergist (assistant) of the masseter in closing the jaw
• Occipitalis

  ○ Found at the posterior end of the cranial aponeurosis

  ○ Covers the posterior aspect of the skull and pulls the scalp posteriorly
• Orbicularis Oculi

  ○ Its fibers run in circles around the eye

  ○ Movement: allows closing, squinting, blinking, and winking of the eyes
• Zygomaticus

  ○ Extends from the corner of the mouth to the cheek bone

  ○ The “smiling muscle”

  ○ Movement: Raises the corners of the mouth
• Buccinator

  ○ Runs horizontally across the cheek

  ○ Inserts into the orbicularis oris

  ○ Flattens the cheek

  ○ A chewing muscle because it compresses the cheek to hold food between the teeth during chewing
• Risorius

  ○ Pull at the corner of the mouth to generate smile
• Levator Labii Superioris

  ○ Functions with nasalis muscle in snarling

  ○ Elevates the side of the nose
• Orbicularis Oris

  ○ Circular muscle of the lips

  ○ The “kissing muscle”

  ○ Movement: closes the mouth and protrudes the lips
• Masseter

  ○ Runs from the zygomatic process of the temporal bone to the mandible

  ○ Covers the angle of the lower jaw

  ○ Movement: Elevates the mandible to close the jaw