5 Muscles Affected:
Occipitofrontalis | Action: Draws scalp anteriorly
orbicularis oculi | Action: Closes eye
orbicularis oris | Action: Closes and protrudes lips; compresses lips against teeth; and shapes lips during speech
buccinator | Action: Presses cheeks against teeth and lips; draws corner of mouth laterally; and assists in mastication (chewing)
platysma | Action: Draws outer part of lower lip inferiorly and posteriorly; depresses mandible
Mechanism of Muscle Weakness:
Bell's Palsy is a disorder that affects the facial (VII) nerve. It is often a result of decreased blood flow within the area or a compression on the nerve to warrant unilateral facial paralysis. Causes range from viral infection, head or face trauma, and inflammation of the nerve. This greatly affects the nerves handling the movements of the muscles on the face as the inflammation may lead to damaging the integrity of these nerves responsible for sensory, motor, and parasympathetic functions, especially as muscles of facial expression.
Symptoms:
- loss of sense of taste
- sound hypersensitivity
- facial twitches
- difficulty closing eyes, eating, or drinking