Michelle M. DeMars from Kansas City submitted this skull featuring the medical practice of trepanning or trephination.
If you are not familiar with trephination, it's the medical practice of drilling into a skull to release pressure from brain injuries. It is an ancient practice that in some cases, is still used. This piece of art either shows a split skull or the trephination is double sided. This reminds me of the wall of skulls at the Mutter Museum in Philadelphia. They also have many other medical oddities for your curious enjoyment. My favorites are the old medical supplies like hand drills (non-electric), saws and knifes. I feel like an old medical doctor any time I have use these in my skull art.