He wore braces didn't he, I remember a photo of him in school wearing them. I can't find it now but I found this one
http://media.tumblr .com/452a434333091b45aee707b65fa67d8c/tumblr_inline_mserxqaZV41qz4rgp.jpg

The shape of his teeth looks the same to me, but they weren't straight. From the way he always pushes his tongue against his upper front teeth I'd say he had atypical deglutition as a child and that's why his front teeth were separated. But I could be wrong and he just needed braces like most of us.