What triggers the appearance of canker sores?

I had some minor oral surgery on Monday, and two or three canker sores have come up since then.





This isn't the first time canker sores followed a dental appointment. Are there dental procedures that might trigger the outbreak of the sores?





They're on the same side of my mouth as the surgery, but not actually where the surgery took place. Neither are they the points where novocaine was injected.

What triggers the appearance of canker sores?
For one thing, nervousness and stress can cause them. When I was really stressed out from my bf and school I got one. Google it. Also, after your mouth has gone through some stress it's possible that it's just not healing very well. =) To help the pain, Tanac numbs it and works great. I used that and mine went away in a day (stress related ones can stay for weeks).
Reply:Stress and trauma are the two most common causes of aphthae. Good Luck