Incidence of Recurrent Aphthous Ulcer among Vape and Cigarette Smokers European Journal of Dental and Oral Health Incidence of Recurrent Aphthous Ulcer among Vape and Cigarette Smokers European Journal of Dental and Oral Health Canker sores are small, painful ulcers that develop inside the mouth. This JAMA Patient Page describes the types of canker sores and how they can be treated. https: ja.ma 4g2Qc3u Recurrent Oral Ulceration British Association of Oral and Maxillofacial Surgeons