Page 165 - My FlipBook

FINGER POSITIONS. 65
of the teeth of the left side of the mouth, the operator standing
to the left in front. By the use of these positions, the necessity
for the contra-angle hand piece is very much diminished. In
fact, that instrument should rarely be used in buccal cavities.
Left side behind. Lower teeth. Turning now to Figure
54, we find a most excellent position for operating upon the occlu-
sal surfaces of the lower molars and bicuspids of the right side.
In opening cavities particularly, this position is especially good
when the teeth are not inclined too much to the lingual. It is
often an excellent position for packing gold. It will sometimes
happen that a lingual inclination of the teeth will defeat any
effort at operating in the position shown. Generally in the molar
teeth the cutting of the enamel away from the buccal side of a
cavity with the chisel will be best done from this position, while
the lingual side will be cut more easily from a position to the
right side in front, using the enamel hatchets. In this case, the
right side in front will give the left hand a better position for
exposing the field of operation to view. This position is shown
in Figure 47. Sometimes in this work a position on the left side
in front, with the patient 's face turned toward the operator, will
give the left hand a much better position in which to both expose
the field of operations and support the lower jaw.
Left side behind. Upper teeth. In Figure 55 is repre-
sented a position obtained on the left side behind, which is occa-
sionally useful. In this the inverted pen grasp is illustrated
particularly. The instrument point is directed in almost the
opposite direction from its usual position by the bending of the
fingers. Hence the term, inverted pen grasp. The grasp may be
considerably varied to suit different positions. Notice that the
third finger is on the upper incisors, forming a rest that is safe
and the control very accurate for doing any delicate thing in
operating, while the forefinger of the left hand, with the first joint
sharply bent, is holding the tissues away. It is easy to expose
the teeth much more perfectly than is shown in this picture by
holding the lower lip away with the second finger, or by holding
the upper lip with the thumb and the lower lip with the first
finger. In using this position as shown, the head of the operator,
in order to see the progress of the work, would generally be
between the camera and the instrument hand. The grasp is not
one of great power, but one in which very accurate work may be
done after a little practice. Positions calling for its use are not
very frequent.
Left side in front. Upper teeth. Figure 56 illustrates a