Actually, there has been no conclusive study that shows exact bite pressures of the Pit Bull and if it's even worse than any other bite. The UGA apparantly did a study on it and couldn't get an aparatus that would measure bite pressures. Pit Bull jaws are the same as any other dog, no "Locking Jaw" mechanism.

It seems to be all about tenacity and willingness to just not let go. The heavily muscled heads of Pits will naturally give you more bite pressures. But nothings proven.