I don’t see any scars - just a vague line or two seemingly caused by irregularities in the graying process, or perhaps from a slightly uneven haircut.
Wow, where have you been. There are pictures of this everywhere. It runs from the left side all the way down the right side and into his neck.
There are some good picture of it on this site.
http://www.disclose.tv/forum/mystery-scar-on-obama-s-head-t41940.html