Muscles that are affected by Bell's Palsy include:
- Frontalis - Raises the eyebrows and wrinkles the skin of the forehead
- Orbicularis oculi - Closes the eyelids
- Orbicularis oris - Closes and protrudes the lips, compresses the lips against the teeth
- Buccinator - Presses the cheeks against teeth and lips, assists in mastication
- Platysma - Draws outer part of lower lip inferiorly and posteriorly, and depresses the mandible
Mechanism of muscle weakness:
- Bell's palsy is a form of facial paralysis or weakness on one side of the face. It is caused by the dysfunction of the seventh cranial nerve, which is also known as the facial nerve. The facial nerve is responsible for facial expressions, eye blinking, carrying nerve impulses to tear and saliva glands, and transmitting taste sensations from the tongue which is why damage to this nerve can cause several problems.
Other symptoms:
- Other than having difficulty speaking and drooping of the mouth, other symptoms may include disordered movement of the muscles that control facial expressions, muscle twitches, drooling, altered taste, intolerance to loud noise, and excessive tearing in one eye due to the inability of closing it.