A canker sore is a painful, open sore in the mouth. Canker sores are white or yellow and surrounded by a bright red area. They are benign (not cancer. See also: Herpes, Fever blisters and Canker sores
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Canker sore (aphthous ulcer)
Mouth anatomy
Canker sore
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Doctor Type Dentist Pediatrician Internist
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