An 8-year-old boy had an extensive mastoidectomy due to an infection that did not respond to antibiotics. Postoperatively he had Bell's palsy (facial paralysis), and one of the features was that saliva tended to accumulate in the vestibule of his oral cavity and dribble from the corner of his mouth. Which of the following muscles was paralyzed to allow this condition to occur?
High-Yield Explanation
Normally the tonus of the buccinator muscle prevents the accumulation of saliva and foodstuffs in the oral vestibule. Although a lesion of the facial nerve would paralyze the other muscles listed, the buccinator is the most important muscle of the cheek.