I’ve never dreamt that my teeth fell out but there were two memorable dreams that involved teeth. In the first, I bit the thumb off of a one-fingered bum who was using it to attack me and felt rather bad about it after.
The second involved a dog jumping up and biting me in the face. For some reason I was sleeping with my hand on my face that night and it twitched. The nocturnal scream woke everybody in the house. I’m surprised it didn’t wake everybody in the neighborhood.