I've just finished my second Parkrun and am sat with all my front teeth, top and bottom are aching. I know it will go away in a little while and I was wondering myself what was causing this and I never thought of cool air until your post.i would hazard a very uneducated guess that it is caused by taking in more air than you do normally. if you have a cavity sucking air across it causes reaction and perhaps when you run you repeat this.