There are more than 10m 3D printed hearing aids in circulation around the world

"The potential for transforming manufacturing business models is most evident in healthcare, an industry that requires mass customization because every person’s body is different. Wohlers estimated the 2009 revenues from 3-D-printed medical devices at $157 million. British manufacturing expert Phil Reeves says more than 10 million 3-D-printed hearing aids are in circulation worldwide (it takes just an hour and a half to fabricate one), along with more than 500,000 3-D-printed dental implants. Medical researchers are using fabricators to turn CT and MRI scans into 3-D models and, at a still very experimental level, to “bioprint” artificial bones, blood vessels, and even kidneys layer by layer from living tissue. Established manufacturers still have the upper hand when it comes to larger quantities or complex assembly. That could change, however, as the devices foster new waves of experimentation."

Source:  A Strategist’s Guide to Digital Fabrication, Strategy + Business, 23rd August 2011