Is 3D printing really enabling this? If they can make the measurements, I have a hard time believing that an experienced machinist couldn't fabricate the parts necessary. This seems more like a victory of measurement technologies that allow the requirements for a replacement skull to be precisely mapped, than a triumph of 3d printing. (Though I do admit that 3d printing would probably be a lot cheaper than machining.)
Absolutely. No "experienced machinist" can reasonably make this part within spec. The time and cost for a CNC / operator / programming is exorbitant and simply beyond the reach of most people.
3D printing in this context allows for the fabrication of complex geometries that would be incredibly resource intensive otherwise.
You're correct in proposing that measurement techniques have enabled for this. But what good are the measurements if your tools do not allow for you to produce anything meaningful from the data?
Somewhere in the middle: "Typically, they use a special type of cement, but those replacements often don't have a good fit because they had to be created by hand."
I'm curious to know how they then attach that skull to the rest of her body. Is there a skin transplant that somehow lives on top of plastic? Do they just screw it into other bones to hold it into place? But what about the juncture, and how can you ensure nothing gets in at that juncture?
My wife, a surgical technician, hasn't done surgeries like this before but has mentioned how for other procedures (on the face, perhaps) that they fold back the skin and then 'flop it back on'. It is crazy when she talks about stuff she's seen/helped do.
I like to picture surgery to be very similar to working on a car, except the pipes, wires, manifolds, etc are made of organic stuff.
The blood vessels all run within the scalp, which is part of what helps it be loose. Some run up the side and some come out next to the eyes, and nothing has to go through the top half of the skull.
> Bone cement chemically is nothing more than Plexiglas (i.e. polymethyl methacrylate or PMMA).
Wow! I wonder if it's a special formulation - acrylic glass is really bad at chemical resistance (pretty much any organic solvent will damage it) and shatters pretty easily.
There have been several patients who had had custom implants designed using CT scans of their skull, then 3D printed and surgically attached to replace part of their skull: one nice report is http://thescipub.com/PDF/ajeassp.2011.169.174.pdf
> "The operation was performed by a team of neurosurgeons at the University Medical Centre Utrecht and the university claims this is this first instance of a successful 3D printed cranium that has not been rejected by the patient."
Oh man... having a skull implant rejected is horrifying. Having an arm or something rejected is one thing (you probably just go back to how you were going to be otherwise, more or less), but are there any backup plans if your body rejects a skull implant?
I'd like to think they preserved her scalp / kept it in circulation and returned it to its position, but I have no idea if skin can be kept alive across this surface. Maybe that's what those holes in the printed piece are about, though? Or are you concerned that even with skin on top it'd alter the appearance due to different subsurface scattering?
Yeah, I'd be incredibly shocked if they didn't preserve the scalp.
On the other hand, if she did have an exposed skull, I think there's like half a century or more of media which says you pretty much have to leave it transparent. You can always wear a wig or a baseball cap, but how else will people know you as an incredible (evil) super-genius without the exposed brain?
Neither she nor anybody else is going to routinely see her skull, so I don't understand why you think it would make her feel abnormal any more than an opaque one would.
