Pit bulls have jaws that physically lock, so once they bite down they literally cannot let go until they decide to, thanks to some special hinge or muscle other dogs do not have. It is repeated constantly in arguments about the breed.
No dog has a locking jaw, pit bulls included. Veterinary anatomists have examined the skulls and musculature and found nothing unusual: a pit bull's jaw works the same way as any other dog's, with the same bones and the same joint, and there is no latch, hinge, or locking mechanism anywhere in canine anatomy. A determined dog of any breed may be tenacious and hard to pull off once it has committed to a bite, which is a behaviour, not a structural lock, and studies of bite force do not show pit bulls topping the charts either. The 'locking jaw' is a piece of folklore that gets cited as if it were biology. Whatever you think about the breed debate, the locking jaw is not a fact you can build the argument on, because the mechanism it describes does not exist in any dog.
Reception
- Wikipedia: Pit bullREFERENCE
- Wikipedia: Pit bull (locking jaw myth)REFERENCE