We chopped most of my hair off today (the surgeons are going to do a more thorough job in a few days), & it reminded me of the size of my dent.
On the top half of the photo, you can see a lighter arc in my hair. That’s my scalp, behind the chunk the surgeon removed. The ridge itself is a bit over a cm tall, the dent it surrounds gets as deep as a couple of cm.
In the bottom half, imagine a round head rather than the squared-off one pictured; the removed bit is everything between squared-off & rounded. The top of the squared bit is soft.
I’m amazed (no wise-backside comments, thanks) that there’s so much redundancy in a head. It’s only an inch or so, but it still speaks well for our ability to survive head impacts & perhaps hints at how early trepanning/trephining operations succeeded.