From a 1911 textbook on orthopedic medicine, this is an illustration of a handmade leather brace used for fractures of the jaw, no longer in use.
The original image was a tiny photograph from an out of copyright publication:
Scudder, Charles. The Treatment of Fractures. Philadelphia: 1927.
Polymer print, 2013, artist proof, 10"h x 8 "w.