Ten million 3-D printed hearing aids are already in circulation because the unique advantages of this process cut in half the number of steps required to fit an individual with a custom device. It’s not just ear canals that make humans unique. Every hip transplant requires an exacting fit to an individual’s body. Every surgery requires precision results within a unique physiology.
http://www.mddionline.com/blog/devicetalk/3-d-printing-applications-changing-healthcare-03-11-16