Page 756 - My FlipBook

754 ORTHODONTIA AS AN OPERATIVE PROCEDURE.

"If tile power tube is extended forward to the first bieiispid and
its anterior end allowed to rest u})on a narrow })rojection soldered to
the bicuspid band, it will add greatly to tlu; stability of the anchorage.
" It w'ill be seen that any tendency of the molar to tip forward
will curry the anterior end of the tube almost directly toward the

Fig. 741.

Author's combination for expansion.

root of the bicuspid, the movement being prevented by the rest. Nor
will any such device offer any special obstruction to the movement of
the bicuspid, the rest sliding along the tube."
The " power bar," or drag-screw^, should end in a hook engaged in
a tube on the canine or any other tooth tliat needs to be moved.

Matteson caps in place of bands in ay)pliance for expansion.
Spreading the Arch.—For spreading the arch an appliance
should be firmly fixed upon the teeth and should have sufficient power,
which can be well regulated. For such an appliance the writer has
made a combination of Magill bands. Angle's jack-screw, and the coil