An acute inflammatory condition of the supporting tissues of the teeth resulting in permanent tissue destruction and characterized by a change in gingival contour, bleeding, pain, and the loss of the apex of the gingival papilla, producing a punched-out appearance. Tissue death (necrosis) frequently produces a grey slough (pseudomembrane) on the gingival surface, accompanied by halitosis. There may also be swollen lymph glands and pyrexia. Destruction of the tissues may progress to necrosis of the alveolar bone, which can become a detached fragment (sequestrum). General predisposing factors include increased stress, malnutrition, fatigue, suppression of the immune system, and systemic diseases such as leukaemia and HIV. Local predisposing factors include poor oral hygiene, cigarette smoking, and pre-existing gingivitis. Treatment is by the removal of surface deposits, oral hygiene instruction, the prescription of mouth rinses such as hydrogen peroxide and chlorhexidine, and possibly antibiotics if there are systemic symptoms. See also periodontitis, chronic.