=Definition.=—Inflammation of the mouth.
=Etiology.=—Chemical, mechanical, thermal or parasitic irritations;
secondary to disorders of the gastro-intestinal tract, scarlet fever,
measles and variola; cachexia, due to such diseases as cancer and
phthisis; dentition; artificial feeding; hot weather and poor hygienic
surroundings are the most common causes. Lesions to the innervation
and vascular supply of the mouth are found, principally, in the upper
cervical vertebræ, occasionally in the upper dorsal vertebræ and
corresponding ribs.
=Varieties.=—Catarrhal, aphthous, ulcerative, parasitic, gangrenous.