5 muscles affected by Bell’s Palsy:
- Frontalis - raises eyebrows and wrinkles forehead
- Orbicularis oculi – closes eye
- Orbicularis oris - controls the shape and movements of the lips (closes, protrudes, and compresses the lips)
- Buccinator – assists in whistling, blowing, and sucking as it presses the cheeks against teeth and lips; aids in mastication when chewing; laterally draws corner of the mouth
- Platysma – depresses mandible; inferiorly and posteriorly draws the outer part of the lower lip
The mechanism of his muscle weakness results from the damaged facial (VII) nerve, which hinders the person from furrowing his brows, shutting an eye, or pouting the lips on the affected side. Thus, in extreme cases of this facial paralysis, the entire side of the face droops. In some instances, it might also result in drooling, difficulty swallowing, hyperacusis, and loss of taste. Furthermore, some Bell’s palsy signs resemble stroke symptoms.