The form of Tom Brady's helmet seems to be different than most players, even from his own team. His helmet have a somewhat old-fashioned look. Is there a known reason for this?
Brady wears a Riddell VSR4. It is a common helmet in the NFL. It might be the most common. Note that this helmet has a more traditional look, unlike most Schutt helmets or the Riddell Revolution. The facemask is your run of the mill QB facemask too, so not really sure where you are going with Brady looking different.
If anything the VSR4 might be used by Brady so he looks better. It is one of the lowest rated (for concussions) new helmets. The only other reason I could think of is that the extra gear (speakers) that he needs fit better in the VSR4.
Brady wears an extremely old-fashioned helmet, the VSR4 by Riddell, which debuted in 1993.
It's not a great helmet to prevent concussion (only 1 star out of 5) but it's apparently comfortable for him.
Even though other players like Drew Brees, Adrian Peterson, Jared Allen & Jason Whitten use the VSR4, it's a helmet that is seen less and less due to said poor star ratings.