Assertion: mouth ulcer | /r/Synonym | canker sores
Facets:
Source sentences:
text: They are also known as canker sores.
text: Mouth ulcers, also known as oral ulcers, aphthous ulcers, or canker sores, are breaks in the tissue lining of your mouth, often along the base of the gums or inside the cheeks or lips, but can form in the floor of the mouth or on the tongue.