Five Muscles Affected by Bell's Palsy:
- Orbicularis oculi: This muscle closes the eye.
- Orbicularis oris: This muscle closes the mouth and puckers the lips.
- Zygomaticus major: This muscle raises the corners of the mouth.
- Temporalis: This muscle closes the jaw.
- Platysma: This muscle pulls the corners of the mouth downward.
Mechanism of the Muscle Weakness:
The muscles listed above are all controlled by the facial nerve or the cranial nerve VII. When a patient is diagnoses with Bell's Palsy, their facial nerves are damaged, meaning, it cannot send signals to these muscles anymore resulting to weakness or paralysis as observed in the drooping of the side of the face.
Other Symptoms:
- Difficulty closing the eye
- Difficulty in smiling, frowning, and raising the eyebrows
- Difficulty in chewing and swallowing
- Excessive tearing
- Drooping mouth corners