What is the definition or description of: aphthous ulcers?

Canker sores: Apthous ulcers affect the loose mucosal surfaces of the oral cavity (cheeks, lips, tongue, etc). They appear as a circular white ulcer with a red halo around the edges. The cause is unknown, but thought to be viral. The most common type, apthous minor, lasts about 10-14 days, are painful for the first 7-10 days, and heal on their own. There is also apthous major and herpetiform apthous.

Free Mucosa virus: A non infectious viral infection of the superficial layers of oral mucosal cells. It is always in the free mucosal not attached. Can be secondarily infected by bacteria. Lasts about ten days. Many go unnoticed.Believedd to of viral origins instigated by abrsion of the tissues.