Images of Memorable Cases: Cases 51 & 52 A 42-year-old woman (above left) complained of a painless sore beneath her jaw. The sore had discharged pus intermittently during the previous four years, but numerous trials of antibiotic therapy had been ineffective. A 29-year-old woman (above right) noticed an occasional serosanguineous discharge from a red spot near the angle of her jaw. The drainage was painless and had been present for six months. 51 & 52. Dental sinus tract Dental radiographs in the first patient (left image) showed a periapical abscess of a mandibular molar. After the tooth was extracted, the discharge stopped, and the sore healed. In the other patient, radiographs showed a periapical radiolucency at the root of a maxillary premolar, suggesting pulpal necrosis. Conventional endodontic therapy saved the tooth and cured the discharge. These two cases illustrate an important clinical point: Most chronically draining sinuses of the face or neck have a dental origin. And because dental symptoms are often absent, diagnosis can be delayed for years.