An<unk>  or canker sore is a type of mouth ulcer which presents as a painful open sore inside the mouth, caused by a break in the mucous membrane.  The condition is also known as<unk>  stomatitis, and alternatively as "Sutton's Disease," especially in the case of multiple or recurring ulcers.
Aphthous ulcer
Buruli ulcer
Stasis ulcer
Venous ulcer
Tropical ulcer
Angina bullosa haemorrhagica
Genital ulcer
Hunner's ulcer