In February 2007, 23-year-old Katie Salomonsen woke up with the right side of her face red and swollen. She went to Fairview Southdale Hospital, where doctors found an abscessed wisdom tooth. Three days later, an oral surgeon extracted the tooth. During the surgery, he discovered that the entire roof of Salomonsen’s mouth was black and scattered with ulcers. He had never seen anything like it and he biopsied the tissue.