It took many people donating their bodies for scientific research to allow medicine to advance to the point it is now, but 3D printing might make it easier for surgeons to gain experience.
Above is a video of a brain surgeon, or rather a brain surgeon trainee, carrying out a brain surgery on a 3D printed skull.
The skull was made by scientists from the University of Malaysia. Its purpose is to be cut, drilled and sliced by doctors seeking to gain experience in brain operations, as I said before.
It's not a perfect substitute for the real things (there's no gore, for one), but it's a lot better than nothing, and likely to make the ones who came up with the idea for the skull quite a bit of cash.