According to animal planet dogs 101.The rottie has the strongest set of jaws with around 400 pounds psi..2nd would be the german shepard and pit bull.I've have breed rotties for more than 22 yrs..My male's JC, stone cold and grizz weighted about 200 pounds each.And my female around 120 to 125.I breed for the bloodline as well at there temperment.As for the size of there heads.Look at a big rigs streeing wheel and thats about the size of there head.It is a fact that you would go by the size of the dog's head to get the bite pressure.Any of you non believers go to animal planets web site and check it out.
Thats a very great question really I don't know
The bite force of a boerbole is so strong that they must not use standard body protection while training them ,, the boerbole mastiff can bite through armor that is ok to be used training a rotty. Boerbole mastifs have been known to overpower and kill healthy adault hyenas,,a rotty would be a meal for any hyena ,,just like a pittbull would! Some where in the large breeds of the molossar group ,,my money goes on the french masstiff this time,,the french mastiff has a confermed kills over jaguars ,,in single combat. There strength and jaw bite must be incredible
Not a pitbull that is not even a registerd breed its a staffershire terrier
The Kurdish shepard or Kangal dog, is a flock guardian who has a bite force of over 700 pounds per square inch...more powerful than a wolf, an english mastiff, rottweiler, dutch shepard,
,bulldog, or pitbull...in that order...
,bulldog, or pitbull...in that order...