Affected Muscles
- Occipitofrontalis
- Action: Produces horizontal wrinkles on the forehead by lifting the eyebrow and upper eyelids
- Action: closes eye
- Action: closes and protrudes lips for kissing; compresses lips against teeth; and shapes lips during speech.
- Action: Presses cheeks against teeth and lips, as in whistling, blowing, and sucking; draws corner of mouth laterally; and assists in mastication (chewing) by keeping food between the teeth (and not between teeth and cheeks).
- Action: Draws outer part of lower lip inferiorly and posteriorly as in pouting; depresses mandible.
Mechanism of Muscle weakness:
- The unilateral paralysis (weakening) of the muscles of facial expression due to damage or disease of the facial (VII) nerve.
Other Symptoms
- Headache
- Tearing
- Drooling
- Loss of the sense of taste on the front 2/3 of the tongue
- Hypersensitivity to sound in the affected ear (hyperacusis)