83-Year-Old Woman Gets New 3D-Printed Titanium Jaw

arnodf writes "The University of Hasselt (in Belgium) announced today (Google translation of Dutch original) that Belgian and Dutch scientists have successfully replaced an 83-year-old woman's lower jaw with a 3D-printed model. According to the researchers, 'It is the first custom-made implant in the world to replace an entire lower jaw. ... The 3D printer prints titanium powder layer by layer, while a computer controlled laser ensures that the correct particles are fused together. Using 3D printing technology, less materials are needed and the production time is much shorter than traditional manufacturing. The artificial jaw is slightly heavier than a natural jaw, but the patient can easily get used to it."

Comments

How do they attach muscle/tendons to titanium?

[vyvepe]

How do they attach muscle/tendons to titanium?

Re:How do they attach muscle/tendons to titanium?

[Anonymous Coward]

From what I understand of the jaws anatomy, it's essentially cradled inside a basket of muscles, those allow it to open/close. The tendon attachment, however, is tricky, as titanium forms a bond with bone (which grows around it) and not with tendons or ligaments.

The power of Kroll!

[dbIII]

You also need to remove oxygen when exposing titanium metal powder to heat. You could make a bomb out of that stuff even more effective than the powdered aluminium ones. I got some sub-micron titanium powder in 1990 and the bag of powder was in a can full of argon, but even then the idiot that shipped it by air would be spending time in prison if he's done that today. To answer the GP poster, it wasn't a lot more expensive than the same mass of titanium metal (which isn't cheap). Some materials are actually cheaper to produce in powder form than in ingot form. With titanium the metal is first available as a porous sponge so producing a powder isn't necessarily more expensive than producing solid material (http://en.wikipedia.org/wiki/Kroll_process).

On top of that, a sintered piece won't have the same strength as a milled piece

That's true because it's not going to be 100% solid, but you can get to within 90% or more with laser sintering. However for this application being a little bit porous is an advantage because real bone can grow on it and into it. A bit over a decade ago researchers were treating milled titanium knee joints with hot caustic soda to make the surface porous and let bone grow into the portions that were in contact with bone.

Re:almost true

[trout007]

I got a (4 Interesting) so I'll continue.

There are a couple of mechanical properties that you can generalize for a metal regardless of alloy type.

Density is pretty consistent. Aluminum is about .09 lb/in^3, Titanium .16 lb/in^3, and Steels .28 lb/in^3

But the most important one is Young's Modulus. This is basically how stiff a material is so higher is stiffer.
Aluminum is 10 Mpsi
Titanium is 16 Mpsi
Steel is 29 Mpsi

What is really freaky is that the Young's Modulus numbers are almost identical to the in proportion to the densities.