The same thing happened with my boy. He actually looked like he had a double row of teeth where the canines were. I called him Jaws for a while.
He had to have 4 teeth pulled this week when he was being neutered. The roots were actually longer than the tooth by at least 150%. The vet said they would have never fallen out on their own. On your next trip to the vet, mention it to them and see what their opinion is.