A good friend of mine chipped a tooth badly doing the same thing off a smaller drop. He's lucky his knee didn't slam into his jaw any harder, but there was enough soft stuff to land in.
I saw a video of a guy who attempted a real long drop but leaned back too much on take-off. Landed on his back/shoulders after rotating almost 270 degrees in flight. I can't recall where I saw it, but it looked terrifying.
Druski