Multiple Choice: Chapter 78 The patient in pain

Question 1. A 55-year-old female patient presents with a history of severe, sharp, shooting pain involving her left cheek. The pain is spontaneous in origin and each episode lasts for approximately 30 seconds. The pain does not respond to routine non-steroidal anti-inflammatory drugs. There are no remarkable findings on clinical and radiographic examination. What is the most likely cause of her pain?