Just my $0.02....
As we age, certain parts to our body continue to grow due to the tug exerted by gravity. Particular to our faces/heads, our nose and ears continue to lengthen. This is because of gravity, not actual growth. As you age, gravity causes the cartilage in your ears and nose to break down and sag. This results in droopier, longer features. I remember reading that on Discovery's website somewhere.
His hairline might have also receded a tad and that can also make his forehead appear bigger/wider.
Aging is a bitch gentlemen.
"1"