Bells' Palsy or facial paralysis is a condition caused by the dysfunction of the facial nerve (cranial nerve VII) resulting in the loss of control of facial muscles on the affected side.  Generally, it affects only one side of the face, but in rare cases, it can affect both sides.  It can begin suddenly and reach peak symptoms within 48 hours.  Symptoms range from mild weakness to total loss of control (paralysis). They may also include twitching, drooping of the eyelid or corner of the mouth, drooling, dry eye or mouth, loss of taste, or inability to completely close the eye.  It is common to have distorted facial expression.