Page 840 - My FlipBook

838 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. —
In solderint>- tubes to place use a .slightly lower grade of silver solder
than that used to join the bands. Use sufficient to thoroughly unite all
the joints, and fill all V-shaped spaces, being careful to turn the joints
of the tubes toward the bands that they may be closed. Thoroughly
unite the api)roxiiiKd surfaces of the bands and reinforce the lingual V
with an extra piece. (See Fig. 894.)
In finishing the apparatus, the soldered parts should be boiled in a solu-
tion of sulfuric acid to remove the borax and oxids. After being neu-
tralized and brushed they are now ready for the trial fitting to the mouth.
In this operation the bands should be perfectly fitted to the position

Yic. 895.

Protrusion apparatus.

they are to occupy—the upright bars readjusted, if necessary, and all
surplus material cut away—sharp and rough surfaces smoothed and
polished, and the gingival and occluding edges of the bands carefully
burnished to the teeth.
In constructing the power bar the anchorage attachments should be
placed upon a plaster model of the teeth, in order to accurately deter-
mine its length and the lengths of its threaded ends, then properly
shaped to the gum over which it is to rest. It should be flattened in
the rollers to about one-half its diameter along that portion which lies
in front of the bicuspids. In this operation it may become necessary
to roll the bar so that the bent bow is flaring, to fit the gums against
which it nearly rests, and to engage perfectly with the upright bars
especially if the incisors are labially inclined.
When the apparatus is polished and heavily gold-plated it is ready
for the final cementing to the teeth. Brush the teeth with piunice stone,