affected muscles:
- orbiculis oculi - closes eye
- occipitofrontalis - draws scalp anteriorly, raises eyebrows, and wrinkles skin of forehead
- zygomaticus minor - raises upper lip, exposing maxillary teeth
- levator labii superioris - raises upper lip
- orbicularis oris - closes and protrudes lips; compresses lips against teeth; and shapes lips during speech
mechanism of muscle weakness
Conditions like viral infections or bacterial infections causes damage to the VII facial nerve, which results to Bell’s palsy or paralysis of the facial muscles.
other symptoms:
- loss of taste
- decreased salivation
- loss of ability to close the eyes, even during sleep
- headache
- drooling
- increased sensitivity to sound on the affected side