The reason John Cena has a square jaw is because he does steroids.
Now, I do know quite a bit about WWE and their policy on drugs. If the man had taken/is taking steroids, then he would not/no longer be a part of said organization. The WWE has an amazingly strict rules on drugs. Another thing is genetics. Both John Cena's; grandfather, brother, and father, all have square jaws. It is in his genes to have one. Then there is bone structure, which other than the premature shortening of bones, I know little about.
The only thing that I am aware of that effects your bone structure is 'human growth hormone'; another thing WWE screens for.





























