Has the vet actually looked at his teeth? My first port of call would be to get a specialised equine dentist out to look at them, as he might have hooks or points that are causing pain in his mouth, leading to him rearing when you pulled him up sharply, and the reluctance to be bridled.
You could put him in a hackamore to see if it suits him, and this might temporarily cover up the issue, as his teeth wouldn't directly be affected. If his teeth are bad however, this won't solve the issue, and it will still be there if you ever wanted to bit him again.
Hope that helped!
P.S - Hope you're feeling okay after your fall!