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LOCKING JAWS? IMPOSSIBLE

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The diagram above shows the correct skull structure, jaw alignment, and dentition for mesocephalic breeds of dogs. Mesocephalic refers to those breeds whose length of muzzle approximates the length of the top skull. These breeds when correctly structured have a scissors bite, with the top teeth meeting tightly in front of the bottom teeth.

Most of the breeds of dogs lumped under the ubiquitous heading of “pit bull” are mesocephalic, but some are not.

There is no supernatural structure to these breed’s skull, jaw, or teeth. That any dog is capable of locking its jaw is a myth.

Sound, correct dogs have 42 teeth after the seven month molars erupt. Dogs may exhibit malocclusions, or genetically missing teeth, usually pre-molars.

There are two more types of skull that are displayed in dogs. The brachycephalic which is the very short faced seen in breeds such as the Bulldog, Pug, Boston terrier, Pekingese, American Bulldog, etc. These breeds are predisposed to malocclusions, and to missing teeth due to crowding. These breeds are prognathous jawed, with the lower teeth protruding in front of the top teeth.

The dolichocephalic type of skull is long, and narrow, the muzzle is longer than the top skull. It is common in breeds such as the Borzoi, the Bull Terrier, and the Collie. The long narrow jaws appear to be able to hold more teeth, but these breeds also have 42 teeth.

These are the facts about dog skull configuration.

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National Geographic’s Dr. Brady Barr’s Bite Pressure Tests

Dr. Brady Barr of National Geographic (Dangerous Encounters: Bite Force, 8pm est 8/18/2005) – Dr. Barr measured bite forces of many different creatures. Domestic dogs were included in the test.

Here are the results of all of the animals tested:

Humans: 120 pounds of bite pressure

Domestic dogs: 320 LBS of pressure on avg. A German Shepherd Dog, American Pit Bull Terrier (APBT), and Rottweiler were tested using a bite sleeve equipped with a specialized computer instrument. The APBT had the least amount of pressure of the 3 dogs tested.

Wild dogs: 310 lbs

Lions: 600 lbs

White sharks: 600 lbs

Hyenas: 1000 lbs

Snapping turtles: 1000 lbs

Crocodiles: 2500 lbs
Nat. Geo actually did a follow-up on this first special, “The Big Bite II-Dangerous Encounters”. Using the same techniques, Dr. Barr tested some other
animals, including a Hyacinth McCaw(parrot), a Tasmanian Devil, a Savanah monitor lizard, a Nurse shark and a large Alpha male wolf. The wolf’s bite
was a bit over 400 pounds p.s.i, making it the strongest biter of the canids, but the two-pound McCaw nearly equaled that 100+ pound wolf, with a bite force of 375 p.s.i, and it did not appear to be doing anything more than just playing around with the bite meter instrument, as it was a tame bird! In the first bite-force special, the APBT (which DID appear to be biting that sleeve for all it was worth, a good “full-mouth” bite)managed only 127 p.s.i, just seven pounds more than the HUMAN tested! In the second special, Dr. Barr was convinced that the young crocodile he’d tested was not performing up to snuff in its bite, since all the crocodilians he’d tested had all been freshly-caught specimens, which were exhausted after a struggle. He tested the device again on a 18-foot wild male Nile croc, in the wild, unrestrained, that was brumating in a den on an African river bank to escape the daytime heat, by actually crawling down the burrow himself! That animal managed, with a single bite, to exert a pressure of over SIX THOUSAND pounds per square inch, making it the most powerful bite of any animal, ever recorded.

Nat. Geo channel does state that a DVD or CD-ROM of the programming is available upon request. The names of these two documentaries are “Dangerous Encounters: Bite Force” and “Dangerous Encounters: Bite Force 2”, both with Dr. Brady Barr. Here’s a link to Nat. Geo’s customer
service, and they might be able to help; maybe at least transcrips will be available.

http://www.nationalgeographic.com/siteindex/customer.html

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