trench mouth, common term for Vincent's infection, an ulcerative membranous infection of the gums and mouth, by noncontagious infection, associated with a fusiform bacillus and a spirochete. Poor oral hygiene, nutritional deficiencies, insufficient rest, heavy smoking, and debilitating diseases are predisposing factors to the disease. Epidemics often occur in crowded unsanitary environments, and in former years among soldiers in the field, hence the name "trench mouth." In addition to ulcerations on the gums and mouth, which are painful and bleed freely, there are usually foul breath, increased salivation, and difficulty in swallowing and talking. The acute phase of the disease yields to antibiotic treatment and oxygenating mouth rinses, but attention must also be paid to the underlying dental and medical factors.