Infections such as tonsillitis, retropharyngeal and peritonsillar abscesses, epiglottitis and mumps. Problems with the jaw, e.g., fracture or dislocation Radiation therapy Neurologic disorders such as Amyotrophic lateral sclerosis, myasthenia gravis, Parkinson's disease, multiple system atrophy, rabies, bulbar paralysis, bilateral facial nerve palsy, and hypoglossal nerve palsy