What causes canker sores in the mouth? Home › Forums › Dental / Oral Health › What causes canker sores in the mouth? This topic has 0 replies, 1 voice, and was last updated 3 years ago by sunil. Viewing 1 post (of 1 total) Author Posts April 30, 2019 at 5:33 pm #2966 sunilParticipant Causes of canker sores Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In