Dr Brisbin PhD (Georgia University) has compared skulls weight for weight in dog breeds, with examinations of dog jaws and all are the same construction.

Dr. Brisbin states:
"The few studies which have been conducted of the structure of the skulls, mandibles and teeth of pit bulls show that, in proportion to their size, their jaw structure and thus its inferred functional morphology, is no different than that of any breed of dog. There is absolutely no evidence for the existence of any kind of 'locking mechanism' unique to the structure of the jaw and/or teeth of the American Pit Bull Terrier."

In regard to claims of massive 1200 P.S.I., 1500 P.S.I., 1800 P.S.I. jaw strength
he says: there are no published scientific studies that would allow any meaningful comparison to be made of the biting power of various breeds of dogs. There are, moreover, compelling technical reasons why such data describing biting power in terms of 'pounds per square inch' can never be collected in a meaningful way. All figures describing biting power in such terms can be traced to either unfounded rumor or, in some cases, to newspaper articles with no foundation in factual data."

Toledo, Ohio Court Trial:

I.Lehr Brisbin, who studies animal ecology in South Carolina, took the witness stand first. With the aid of a pit bull skull in a jar that both the defense and prosecuting attorneys seemed scared to touch, he explained that examinations of pit bull bodies show that they do not have more powerful jaws than other dogs

Dr. Brisbin said pit bull bites are less dangerous to people than bites by other breeds because pit bulls tend to hold on, while other dogs often slash and tear the skin, causing excessive bleeding.

Dr. Stur (Vienna University):

Valuable scientific studies showing significant differences in jaw strength among breeds does not exist (Dr. Stur, 2000).