Deformed Alligator eating fish

Below is a sequence of images depicting a 6' Alligator eating a fish at the Viera Wetlands. At first glance it appears to be just another average Alligator at the wetlands until it raises its snout out of the water. You can then see that its lower jaw is about 3 inches short! I don't know what causes that deformity, but I have seen it on other Alligators at Viera.

1.
http://i587.photobucket.com/albums/s...gator_8981.jpg

2.
http://i587.photobucket.com/albums/s...gator_8988.jpg

3.
http://i587.photobucket.com/albums/s...gator_8992.jpg

4.
http://i587.photobucket.com/albums/s...gator_8993.jpg

5.
http://i587.photobucket.com/albums/s...gator_8995.jpg

6.
http://i587.photobucket.com/albums/s...gator_9028.jpg

7.
http://i587.photobucket.com/albums/s...gator_9040.jpg

8. A better look at the deformity.....
http://i587.photobucket.com/albums/s...edjaw_8985.jpg

very interesting. Do you think it was a birth defect or posible a very old injury from it's first year of life?

I'm not sure..... could be ether of those possibilities. Another alligator could have caused the injury when it was young.