A severe gangrenous process occurring predominantly in debilitated and malnourished children, especially in underdeveloped countries. It typically begins as a small vesicle or ulcer on the gingiva that rapidly becomes necrotic and spreads to produce extensive destruction of the buccal and labial mucosa and tissues of the face, which may result in severe disfigurement and even death. Various bacteria have been implicated in the etiology. (Dorland, 27th ed)

Noma is a gangrenous disease that causes severe destruction of the soft and osseous tissues of the face.

(gangrenous stomatitis) Gangrene of the mucous membranes of the mouth leading to ulcers and destruction of the soft tissues of the face and bones. It usually occurs in malnourished children in areas of poor sanitation and immunocompromised patients.