IMPROVED MEANS FOR TAKING IMPRESSIONS OF THE MOUTH FOR DENTAL PURPOSES
Year: 1878

page_text: LETTERS PATENT to Michael Eugene Toomey, of Rathbone Place, in the
County of Middlesex, for the Invention of "IMPROVED MEANS FOR TAKING
IMPRESSIONS OF THE MOUTH FOR DENTAL PURPOSES."
Scaled the 12th July 1876, and dated the 7th May 1878.
PROVISIONAL SPECIFICATION left by the said Michael Eugene Toomey at
the Office of the Commissioners of Patents on the 7th May 1878.
MICHAEL EUGENE TOOMEY, of Rathbone Place, in the County of Middlesex.
"IMPROVED MEANS FOR TAKING IMPRESSIONS OF THE MOUTH FOR DENTAL
PURPOSES."
My Invention relates to an improved dentist's tray used in taking wax or other
impressions of the teeth, gums, and palate for dental purposes; and the Invention
consists in a tray so constructed as to enable perfect impressions, both of the upper
and lower jaws and palate, and also of the bitc, to be obtained at one operation, and
by the patient thereby saving time and avoiding the necessity for a special visit to
the dentist for the purpose.
Hitherto two trays of rather different form have been used for obtaining at two
separate operations the impression of the upper and lower jaws and the bite has
been obtained by biting a separate piece of wax. It will thus be seen that to obtain
hitherto a complete impression of the mouth with the ordinary form of trays three
operations were required.
My improved tray consists of an outer rim of semicircular form with handle
attached, the upper and lower edges of the said rim being preferably slightly flared
in opposite directions, so that the rim is shaped in cross section in order to assist
in retaining the wax in place. Within this rim and at the usual distance therefrom
is the convex plate, as employed in the upper tray above referred to, to support the
wax intended to take the impression of the palate, but this convex plate is separated
from the outer rim by a space sufficient to hold the wax, and to allow the teeth of
..מ

page_text: the two jaws to meet between the outer rim and the inner convex plate. For this
purpose the said convex plate is only attached to the outer rim and held in position
by curved wires soldered or otherwise fixed to the extremities of the outer rim and
passing behind the wisdom teeth.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Michael Eugene Toomey in the Great Seal Patent Office on the 7th
November 1878.
MICHAEL EUGENE TOOMEY, of Rathbone Place, in the County of Middlesex.
"IMPROVED MEANS FOR TAKING IMPRESSIONS OF THE MOUTH FOR DENTAL
PURPOSES."
My Invention relates to an improved dental tray to be used in taking wax or
other impressions of the teeth, guns, and palate for dental purposes; and the
Invention consists in a tray so constructed as to enable a complete impression of the
mouth, that is to say, of the upper and lower jaws, the palate, and also of the "bite,"
to be obtained at one operation and by the patient himself, thereby saving time and
avoiding the necessity for a special visit to the dentist for the purpose
37
Hitherto three trays of different form have been used, one called an "upper
tray for obtaining the impression of the upper jaw, another called the "lower" tray
for obtaining that of the lower jaw, and another called the "bite" tray for obtaining
the impression of the "bite" or meeting of the upper and lower jaws. Thus to
obtain a complete impression of the mouth, together with the bite by the ordinary
form of trays, three separate impressions were required. From the first two of
these impressions plaster casts or models are obtained, which are adjusted to their
proper relative position from the impression of the bite, and retained in that position
by being united to a plaster slab. To these models the dental operator works in
the construction of bases for artificial teeth.
Owing to the fact that three separate impressions are required, it has been
practically impossible for a patient himself to obtain a perfect impression of his own
inouth, a perfect impression being absolutely essential to ensure a proper fit of the
teeth.
My improved tray consists in the combination with the ordinary "bite" tray
(slightly modified, as hereafter described) of a "palate" piece, which is a domed or
convex plate (like that employed heretofore in the "upper" tray above referred to),
serving to support the wax intended to take the impression of the roof of the
mouth, this domed plate or "palate" piece being separated from the outer rim of
the tray by a space sufficient to hold the wax by which the impression is taken, and
to allow the teeth or gums of the two jaws to meet together naturally, thus giving
the correct "bite." For this purpose the said convex plate or "palate" piece is only
held in position by being attached to the outer rim by curved wires fixed to the

page_text: DESCRIPTION OF DRAWINGS.
Figure 1 is a perspective view of my improved dental tray empty; Figure 2, a
top plan; and Figure 3, a back view of the same.
Figure 4 is a section of the tray on line 1-1, Figure 1; and Figure 5 is a similar
section of the tray with a wax impression contained therein.
a is the outer rim of the tray, similar in form to the outer rim of the old "bite "
tray, but deeper and straighter from the upper to the lower edge, so as to hold the
wax up against the gums and ensure an accurate impression thereof. It is provided
with the usual handle b. c is the "palate" piece or domed plate to carry the wax by
which the impression of the roof of the mouth is taken. This "palate" piece c takes
the place of the inner rim of the old "bite" tray, and forms in effect a combined
inner rim and palate piece; this palate piece rises to a sufficient height and its lower
edge descends to a sufficient depth to afford the wax the necessary support to ensure
an accurate impression of the roof of the mouth and of the lower gums. This
palate piece c may be slit along the central line 1-1, so as to be readily pressed up
or down to raise or lower it according to the height of the roof of the mouth. This
palate pieco c is soldered to a wire d which runs round it and round the exterior of
the outer rim a as usual, the said wire being carried sufficiently far forward at d¹ to
pass behind the wisdom teeth or "tuberositics." This palate piece c is hollow on
the under side. to give space for the tongue when an impression is being taken.
In cases when only a small "base" for the upper teeth is required the palate
piece c need not extend so far back as I have shown in the Drawings, but its back
odge may be shaped as indicated by the dotted line in Figure 2 for example.
In Figure 5 e is the wax impression of the mouth, giving, as shown, an exact
impression at once of the two jaws and of the "bite." In order to retain the wax
more securely in place I slightly roughen the surfaces of the outer rim a and palate
piece like a rasp, as indicated in Figure 1. To take an impression the wax or other
material is softened by heat in the usual way andi nserted in the tray, which is then
placed in the mouth and the latter closed until the teeth or gums meet through the
wax. The tray is made of tin or other metal usually employed for the purpose.
Having now described my Invention, and the manner of performing the same, I
declare that what I claim as my Invention to be protected by the herein-before in
part recited Letters Patent is,―
1st. A dental tray constructed of an outer rim, and a combined inner rim and
palate piece connected to the outer rim, but separated therefrom by a through
opening, substantially as and for the purpose herein shown and described.
2nd. In a dental tray constructed as above described, the wires d' curved or
arranged to pass behind the wisdom teeth or tuberosities, as shown and described.
In witness whereof, I, the said Michael Eugene Toomey, have hereunto set my
hand and seal, this Sixth day of November, in the year of our Lord One
thousand eight hundred and seventy-eight.
Witness,
WM CLARK,
Patent Agent,
Chancery Lane.
M. E. TOOMEY. (L.S.)