Necrotizing ulcerative gingivitis has been observed for centuries. Xenophon observes sore mouth and foul smelling breath in Greek soldiers in the 4th century BC. Hunter describes the clinical features of ANUG in 1778, differentiating it from scurvy (avitaminosis C) and chronic periodontitis . Jean Hyacinthe Vincent , a French physician working at the Paris Pasteur Institute describes a fusospirochetal infection of the pharynx and palatine tonsils , causing "ulcero-membranous pharyngitis and tonsillitis",  which later became known as Vincent's angina . Later in 1904, Vincent describes the same pathogenic organisms in "ulceronecrotic gingivitis". Vincent's angina is sometimes confused with NUG, however the former is tonsillitis and pharyngitis, and the latter involves the gums, and usually the two conditions occur in isolation from each other.