He still lacks a lower set of teeth, but a German man who had his jaw removed during a painful battle with mouth cancer just received a replacement. What makes his story unusual, however, is how his jaw was created. The risk of infection and the patient’s medication prevented doctors from taking the standard approach—constructing a substitute out of bone material grafted from other parts of his body. Instead surgeons at the University of Kiel in Germany grew a new jaw in the man’s back. Here is the simplified recipe.