I have done some research and found more useful Fact vs. Fiction info on Pit Bulls and debunking Pit Bull myths:
Locking Jaw
"Q: A friend of mine told me that Pit
[Pit] Bulls have a special enzyme that allow
them to lock their jaws. Is this true?
A: This is a very common myth. Pit Bulls are members
of the canine species and have the same jaw structure
as any other dog. If they had a special enzyme or other
mechanism allowing them to lock their jaws, we would
have to reclassify them as a different species.
However, Pit Bulls do seem to have an above average
amount of determination for obtaining and retaining
objects they are interested in. In fact, they were
selectively bred to never give up. Their focus may be
chasing squirrels or fetching rocks or sticks, but
whatever they do, it's done with a great deal of
enthusiasm. If they happen to grab on to something they
don't want to release, it can be quite difficult to extract it
from them."
Why Spay or Neuter topic
"It is estimated that 200 pit bulls are killed
EVERYDAY in Los Angeles, CA shelters alone
because there are not enough homes for them.
Many people have no idea how desperate the situation
is for millions of homeless companion animals,
especially Pit Bulls. These dogs have a lot more going
against them than any other breed. They are: regularly
maligned by the media; feared and misunderstood by
the public; too often owned by abusive or irresponsible
individuals; innocent victims of kill policies in shelters;
the target of municipal bans and breed specific
restrictions, etc.
It is estimated that 20 million unwanted and
homeless dogs and cats will be destroyed in the
U.S. this year. This is 1.6 million dogs and cats
KILLED per month every month of the year.
Anyone who cares about these dogs should try to save
a homeless Pit Bull before they consider adding more
dogs to a completely saturated market. This is a plea
for those of you who are thinking about breeding Pit
Bulls--please think again!
Remember that many animal shelters have a kill policy
for Pit Bulls. These dogs and puppies are destroyed
because they are Pit Bulls. The shelters that give Pit
bulls a chance are completely overloaded with these
dogs and must often euthanize them because they are
not able to find them good homes. The *lucky* ones
spend months and sometimes years rotting behind bars
lying on a cold cement floor. Before you breed, we urge
you to spend some time volunteering at your local
shelter so you can witness pet homelessness first hand."
http://www.pbrc.net/misc/pbrcbrochure.pdf