Page 143 - My FlipBook

POSITIONS AT THE CHAIR. 59

Turning now to the lower teeth, Figure 39 shows a position
which, when corrected by dropping tlie chair a few inches lower,
is excellent for doing much of the work of excavating and filling
cavities in the teeth of the right side of the lower jaw. The face
of the patient is turned rather too much away from the camera
to show the left hand, which is holding the lips away. It is a
position that should be carefully cultivated. In Figure 40 the
operator has run the chair up too high so that he could not well
assume the desired position of right side behind. The patient is
also tilted too far back. This is in part corrected in Figure 41
by turning the chair forward and lowering it. But it is still a
little too high for easy operating. A few inches lower would
give an easier position. When thus corrected this is the best
position for the greater amount of operating on the lower teeth.
The head of the patient should always be so well forward that
the light will fall full upon the lower teeth. This position will
depend somewhat upon whether the source of light is a high
window or a low one. The angle of light, when from a high
window, will allow the head of the patient to be farther back, and
relieve the operator from some of the bending of the back
required when the source of light is low.
While this position has the widest range of usefulness for
operations on the lower teeth, every operator should be able to
relieve tired muscles by changing occasionally. For the teeth of
the left side, the position shown in Figure 42 may be used tem-
porarily for some part of the woi'k, but this is not good for any
considerable work at one time. The position in Figure 43 is
better and can often be very effectively used for operations in
the buccal surfaces of the lower bicuspids and molars of the left
side, when one has learned to hold the tissues away in part with
the unemployed fingers of the instrument hand. Figure 44 is
the true left side behind position. This gives a very desirable
position for operations in the occlusal surfaces of the lower
molars of the right side, when these teeth have not too much
lingual inclination. It is especially a favorable position for the
use of great force, when that is I'equired, in chipping enamel from
the buccal walls of cavities in these teeth with the straight or
binangle chisel, for various things in excavating, and for a part
of the packing of gold. Figure 45, the full left side in front posi-
tion, is especially useful for distal cavities in the lower incisors
and cuspids, and for buccal cavities in the bicuspids and often
also in the first and second molars.
From the foregoing statements it is seen that one may work