I received this from my grandfather.

My grandpa was a cardiovascular surgeon and he told me that he got this skull when the university he was at changed their skeleton models over to resins. The jaw is held together with pins and very strong springs and they still work. The top of the cranium was removable but one of the pins fell out at some point so someone glued it closed. Found this sub by accident in my feed today, figured I would share it with you all.