No, this is completely false. There are absolutely no scientific studies proving that a Pit Bull’s jaws are any different than other breeds’ jaws. There is no “locking mechanism” in a pit bull’s jaws.
Chuck U. Farley writes:
The American Pit Bull Terrier (and their predecessors) were originally bred as “gripping dogs”. Before dogfighting was widely practiced the dogs were used in bullbaiting, in which they would grip and hold a bull by the nose, ears or neck to subdue it. After bullbaiting was banned and dogfighting took it’s place as “entertainment” and “sport”, the gripping ability and the tenacity of the best bullbaiting dogs was highly prized by dogfighters as well.
The stucture and function of the APBT’s jaws is the same as any other dog. They do not have a “locking mechanism” in their jaws and they do not have an “enzyme” that prevents the release of a bite.
What IS different about the bite and grip of an APBT is the same ability and tenacity mentioned above. When an APBT is seen hanging by its’ mouth with a strong grip on something, be it a springpole, a tug toy or a tree branch, it is not letting go because it is unable to…it is not letting go because it does not WANT TO.