Review of Dental Literature and Art. [Volume: 2, Issue: 4, November, 1860, pp. 228-234]

REVIEW OF DENTAL LITERATURE AND ART.

229

it is in contact. If, on the other hand, it is too soft and yielding, it will
not react or expand quickly enough, but will be liable to be clogged by
food and the viscid fluids of the mouths; nor will it long sustain, as it
must do, not only the ordinary pressure upon it in speaking and swallowing, but also the more violent and spasmodic efforts of coughing, sneezing, vomiting, etc.
"I will now proceed to explain, as clearly as I am able to do in words,
the plans and methods I have used in adapting artificial vela to relieve
the different forms of palatine fissure already described; and trust, by the
aid of the accompanying drawings, to make myself understood by those
who may happen to be especially interested in the subject.
"All cases require, in the first place, a plate or roof of gold, or some
other convenient substance, to be prepared, to the posterior margin of
which the flexible and elastic velum is to be attached. Where the fissure
does not extend into the bony roof, as in cases belonging to the first class,
a narrow arch of gold plate from the molar teeth on one side to those on
the other, will be sufficient for our purpose. But when, as in cases of the
second class, the opening reaches far forward, then an artificial roof has
also to be supplied; and plates made of gold are found too heavy; but
the vulcanized hard rubber, by its combined lightness and strenth, is
much to be preferred. The plate or artificial roof having been properly
fitted to the bony surface, the making of the velum is next to be proceeded
with.
"As the velum is to be fitted to the fleshy, and therefore mobile region
of the fissure, its shape and size must be determined by a resort to some
expedients other than what are used to get a cast of the bony portions;
for it is manifest that however soft and plastic the wax or other substance
might be, the sensitiveness of the fleshy parts would cause them to retract
instantly from contact with a foreign substance; so that the form of the
fissure must, for the moment, be changed to something different from what
it is while in a state of rest. Added to this, the degree of pressure, however slight, required for taking an impression of parts that in fact have
no more solidity than the lips or the tongue, must of necessity cause some
displacement; I therefore resort to other means for getting the shape of
the lower portion; but for the upper portion, say half or three-quarters
of an inch above and below the point where the muscular fibres are.
attached to the bones, I am enabled to get pretty accurate plastic impressions. I have always found much greater irregularity in the form of the
soft parts, behind the edges of the opening, and which are out of view,
than is seen on the anterior surfaces, which are pretty symmetrical. This
irregularity of the shape of the posterior surfaces is caused by the abnormal position and form of the palatine bones, to the edges of which the
long, slender muscles forming the columns of the soft palate are superiorly
attached. The artificial roof being extended backward to a point where the
fleshy tissue begins, I first get the form and breadth of the opening from that
point as far down as the little pendant, nipple-like processes, by using a lamina of wax, not softened, attached obliquely to the end of a stick, paring
the edges with a knife until the wax can be passed backward and forward,
through the fissure, and is seen to correspond in shape. This lamina of
wax, thus brought to the required shape, I afterwards extend downward
by the addition of another and broader piece, which reaches as low as the
union of the slender palatine muscles with the base of the tongue and the
pharyngeus. The pattern thus obtained represents the flat, central por