Vincent's disease Painful inflammation of the mouth caused by two organisms, Bacillus fusiformis and Borrelia vincenti . These are commonly present in the mouth and cause infection only if some other factor, such as immune deficiency or vitamin B deficiency, operates. Vincent's disease features painful ulcers and an acute destructive inflammation of the gums called necrotizing gingivitis. It is treated with the antibacterial drug metronidazole, an antiseptic mouthwash and dental scaling to remove calculus. Also known as trench mouth. (Jean-Hyacinthe Vincent, 1862–1950, French bacteriologist).