Page 272 - My FlipBook

240 HISTORY OF DENTAL SURGERY

altogether. This movable portion of the back should be retained, when put
up, by tvo strong brass snaps, which, by touching a spring attached to each,
will allow it readily to fall down. On the left hand side of the chair should
be placed a half oval flat cushion, stutfed to the shape of the head, and about
a foot in circumference; this is for the patient's head to rest against, and
should be capable of being raised or depressed by means of a brass rack or
groove, through which the back part of the cushion should traverse, and for
wliich purpose it should lie provided with corresponding projections made of
brass, the cushion being retained in any situation that may Ije recpiired by
means of a small spring and snap. Another of these flat cushions should be
attached to the top of the chair, which should be capable of traversing from
right to left, along the upper part of the chair; this upper cushion should
also take ofE and when occasion requires, should be affixed to the lower part
of the back of the chair when the upper and movable part which falls down
is removed. It sliould further be capable of moving from or towards the
operator.
Wlien the whole hack part of the chair is allowed to slope, wliich is almost
always the case in a greater or less degree, the patient being seated, and lean-
ing back, the shoulders alone would touch ; the back and loins would there-
fore be without support. To remedy this, a large cushion should be placed
between the patient's back, and the back of the chair; this cushion should
be the height of the chair, at that part where it is separated. It should be
about twenty inches in length and eighteen inches in breadth. It is requisite
that this cushion should be most carefully made; it should be of leather and
\-ery exactly stuffed to the shape of the back, that in whatever position the
patient may sit or recline, it may be felt equally from the shoulders downward.
On the proper shape and stuffing of this cushion depend much of the ease of
the patient.
"All patients have not the same length of back ; * * * (^q remedy this,
the cushion should be no longer than will lie necessary to reach the shoulders
of a middle-sized man, and should he flat at the top, to admit of a smaller
cushion the length of the lireadfh of the chair, of a triangular form, the an-
terior part being rounded. Two or three of these little cushions should be
provided of different depths, so that the patient's head may lie placed in any
position, from the perpendicular to the horizontal.
"Many operations on the upper teeth require that the patient's head
should be considerably above the operator. * * * It is desirable, there-
fore, in such cases, that the seat of the chair should be raised in order that