Page 164 - My FlipBook

152 MECHANICAL DENTISTRY AND METALLURGY.

apparatus, it consists of two parts. For the lower part, I
made a brass plate to fit the chin, havini;' arms with hooked
ends reaching to a point just below the point of the chin.
These arms were arranged in such a way that the distance
between them could be altered at will by simply pressing
them apart or together. The upper part consisted of a
simple network, going over the head and having two hooks
on each side, one hook being above and the other below the
Fic

ear. When this apparatus was completed and in use, there
were four ligatures of ordinary elastic rubber pulling in such
a way as to force the lower jaw almost directly backward.
The work proceeded very rapidly, so that at the end of two
months the irregularity was almost entirely cured."
A very good method of making the chin piece—Dr. Guil-
ford's method—is to take a plaster impression of the chin
and from this make a model. The model is then overlaid