Page 244 - My FlipBook

242 EXCLUSION OF MOTSTURE.
The arrangement of the holes in the triangular piocc should differ
for each section of the mouth.
Fig. 210 shows a piece for the central incisors. The figures repre-
sent inches.
Fig. 211 shows the arrangement of holes for the uj^per bicuspids
(1 11(1 molars. It will be observed the line of holes is not parallel with
llic ujiper edge.
Fig. 210. Fig. 211. Fk;. 212.
11" .<^ ,fi

For central incisors. For upper bicuspids and For lower bicuspids and
molars. molars.

Fig. 212 shows the arrangement for the lotrer bicuspids and molars.
Here, too, the line of holes is not parallel Avith the edge, to allow for
the difference in distance from the commissure of the lips to the ante-
rior and posterior holes.
Fig. 213 shows the arrangement when the lower i)icisors and canines
are included. Here the line of the apertures
Fig. 213. is curved.
By conforming to these arrangements of
the openings in the rubber, and by extend-
ing the line in conformity with it, as well as
by increasing the size of the piece, any num-
^^cr of liolcs may be made, to include any
For lower front teeth.
])()rtion or all of the teeth of one quarter of
the denture when that may be required.
The number of apertures in the rubber should be such as to give
easy access to the operation and to permit the free entrance of light.
For the anterior teeth five to six holes are necessary, and for the pos-
terior teeth from four to six as may be needed to secure the above-stated
objects. In general, at least two teeth anterior to the one operated
upon, and when admissible the one posterior, should be included.
The Placement of the Dam.—When the teeth are not in firm con-
tact or when their attachments are flexible the adjustment of the dam
is simple. But when the teeth are rigid certain preliminary conditions
should be secured. It has been pointed out in speaking of the prepara-
tion of the teeth for a series of operations that they should be well
cleaned of any deposits Avhich may be upon them and be })olished on
their approximal surfaces. This makes easier the insertion and the
application of the rubber.