sagittal crest?

[trigeminalneuralgia]

have you guys read about this

http://en.wikipedia.org/wiki/Sagittal_crest

my dad says he has strong jaw muscles because he has this.  his jaw doesn't look particularly strong to me, i think he's just got a bump in his head 

[Marisama]

I have a little bit of what the picture shows but my jaw muscles are very weak