US2050837A - Artificial teeth - Google Patents

Description

Aug. 11, 1936. A. GYSI ARTIFICIAL T-EETH Filed July 17, 1935 2 Sheets-Sheet 1 INVENT R Patented Aug. 11,1936

UNITED STATES PATENT OFFICE aososs'z ARTIFICIAL TEETH Alfred and, Zurich, Switzerland, "minors to The Dentists Supply Company of New York. New York, N. 1., a corporation of New York Application July r1, 1935, Serial No. class 4 Claims. (01. 32-8) This invention relates to artificial teeth and particularly to artificial teeth which will articulate and, in so doing, work in harmony with the movements of the Jaws of the average human being; I

In my United States Patent No. 1,665,357, dated April 10, 1928, there were explained methods and means for making primordial forms by geometrical construction that would harmonize with the' average movements of the human mandible during mastication.

- In that patent, the cutting of the teeth from the primordial tothe finished stage was shown, 7 and the teeth were made to inter-relate on the facetsof the primordial forms, but with the elevations and deep depressions removed and rounded so as to reduce the contact areas of the original primordial forms and, at the same time, to provide fossae and sulci for the reception and go elimination of food during mastication.

The present invention relates to teeth designed from similar primordial forms but in which the fossae and sulci have been carved to present a more emcient masticating instrument. One of the objects of this invention is to provide artificial teeth which have more definite cutting and shearing contacts, upper with lower. Another object of the invention is to provide artificial teeth having such definite characteristic o primordial inter-relating contact areas retained ;as to definitely assist the dentist in the proper placement of uppers-with lowers. A still further object of the invention is to arrange or position the reliefs in the upper facets with relation to the reliefs in the lower facets as -45 position.

Another object of the invention is to so form the neck areas ormarkings of the buccal surfaces that proper identification is provided for the rec- I ognition offirst or second bicuspids or molars. so According to this invention, the facets of the upper and lower primordialforms are cut to geometrical design so as to correspond during mandibular movement with average human Jaw movements, and as the peripheries of these facets con- ;Qii tacteach other theyform definite angles which are retained as vital features of this particular, design. so thatv the teeth can eventually be set in exactly the relative position .to which they were carved, whereas the fossae and sulci are cut from the interior of the facets, not disturbing th con- 5 trolling areas, but retaining theperipheral outlines of the facets as they were cut on the primordial form.

The drawings illustrate an embodiment of the invention and the views therein are as follows: 10

Fig. 1 shows aprimordial form from which the occlusal surface of the left lower posterior teeth are to be carved, I s

Fig. 2 is a like view showing division of the primordial form into individual tooth blocks or units. 5

Fig. 3 shows the outline of the occlusal surface of one of these devices,

Fig. 4 is a like view of the finished tooth carved from-the block shown in Fig. 3, and which said tooth is the first lower left molar. 20 Fig. 5 is a top plan view showing the occlusal surface of the first left upper molar in primordial form,

Fig. 6 is a similar view showing a further development of the primordial, form of Fig. 5,.

' Fig. 7 is a still further development showing th finished first left upper molar,

Figs. 8 and 8-A represent the first upper and first'lower' molars before referred to, cross-sectioned from I to VII, said cross sections being so made in both teeth according to their position in centric articulation,

Figs. 9 to 15, inclusive, show the inter-relation of the upper to the lower first molars at the vari-- ous cross sections marked from I to VII, em- 35 phasizing the efiiciency as masticating tools,

Figs. 16 to 19, inclusive, are sections showing the movement and result progressively in the masticating of food through one of these cross sections,

Fig. 20 illustrates the continuous passage that v is formed between the two rows of teeth, upper and lower, due to the inter-relation of the cut out areas, which inter-relation facilitates the fiow of food to the outside of tooth contacts, buccally and lingually,

Figs. 21 to 31, inclusive, show the tool-like action of this form of tooth carving, and

Figs. 32 to 35,-lnclusive, are buccalviews of the lower left posterior teeth showing collar markings.

Whilenatural teeth, which are fixed by their roots in the mandible and in the maxilla, of the averagehuman do more or less deviate from a condition wherein all the teeth of the lower 'Jaw are in contact with the corre p nding teeth of the 5s upper jaw during masticating movements, it has been found that with artificial teeth on plates which are designed to take the place of lost natural teeth it is essential that these artificial teeth shall be so shaped and placed that the teeth of the lower denture will contact with the corresponding teeth of the upper denture during the masticating movement in such a way as to form tool-like cutting, grinding and shearing instruments.

While the natural supposition would be tha natural teeth themselves should be copied, research has definitely ascertained that artificial teeth made in this way have a. very limited masticating power. It has been learned through investigations and through long courses of experiments that posterior teeth should be made much more mechanically perfect in operation than natural teeth, because there is a great difference in the force or power that can be exerted by natural teeth as compared with that which can be exerted by artificial teeth. Since the natural teeth are firmly fixed in the bones of the mandible and maxilla, much greater force can be exerted in the masticating operation than can be produced by an artificial denture which is much less firmly fixed in position, because artificial teeth being. mounted on plates resting on'the mucous membrane are incapable of transmitting the same masticating force as natural teeth, and thus they should be so constructed that their cutting and grinding capacities are increased with less power than is usually available with natural teeth.

In my patent hereinbefore referred to, I have illustrated and described a method for the production of primordial forms of the posterior teeth which consists in securing to one member of an articulator two rows of cutting knives arranged in a curve corresponding to a natural back tooth row at one side of the row and in more or less parallel relation, and having cutting edges which slope backward and downwardwith a gradual lessen ing obliquity from front to rear; and thereafter, causing a relative movement between the knives corresponding to the left and right side bite movements and to the forward or protrusive movements and backward or retrusive movements, and to all possible movements of the articulator corresponding to intermediary masticatory directions,so that angular depressions and elevations are cut in and upon the primordial form which serve as the basis for the occlusal surfaces.

In the present invention, the primordial forms are obtained in like manner and, for instance, by the use of an articulator such as that shown and described in my German Patent No. 293,074, or in my United States Letters Patent No. 1,684,393, dated September 18,- 1928. This primordial form for the left posterior teeth is shown in Fig. 1 of the drawings.

Fig. 2 of the drawings shows this same primordial form divided into individual primordial forms on which the outlines'of the teeth are laid, as shown by the single first lower molar in Fig. 3.

In Fig. 3, the outline ll of the first lower left molar confines or embraces definite facets, e. g.,

42, N, U, 45, ll, etc., and these facets meet to form substantially V-shaped angulations either in the form of ridges or grooves.

In the form of teeth contemplated by my Patent lid-1,665,357, the angulations of the primordial forms were carved so that the meeting facets were slightly rounded insofar as the ridges were concerned, and the grooves were more'deeply carved to provide fissures for the eiilcient shearing and grinding of the food between the same and to also provide means for the esc'apement of the food buccally and lingually.

In the figures of the drawings, the buccal side 6 of the forms and of the teeth illustrated is indicated by the character B, and the lingual side of form, that is to say, the angulations between the facets are retained in'both the lower and upper teeth, these angulations forming surfaces for the inter-relation of the upper and lower teeth in 15 their working, balancing, protrusive and retrusive movements.

Figs. 5, 6 and 7 show the development of the first upper left molar from the primordial form to its finished condition, and Fig. 4 shows the finished condition of the lower left first molar.

These finished first molars have their buccal and lingual sides rounded to the shape of the average natural tooth and are provided with beauty marks, etc., to givethem an appearance approximating that of natural teeth.

The facets of the teeth have been provided with fossae 41 formed by removing or digging out the face of the facets within the perimeters thereof, and sulci l8 have been formed for the escapement 30 of masticated food by providing fissures through certain of the angulations or perlmeters of the facets, as clearly shown in Figs. 8 and 8--A.

In this figure, M represents the mesial side of the teeth and D represents the distal side. It will, of course, be understood that when these teeth are placed in proper plates, the tooth of Fig. 8 will be rotated forward through 180 degrees so that its occlusal surface will interact with the occlusal surface of the lower left first molar shown in Fig. 8-A which is centric position.

Now considering that these two teeth of Figs. 8 and 8A have been brought into centric coacting relation, the sections LP! to TIL-VII indicate sections cut down through both teeth in their centric position, that is to say, the line 1-1 of Fig. 8 will coincide with the line I-I of Fig. 8-A, and the other lines accordingly,

.In order to illustrate the co-action and the opposed relations of the occlusal surfaces of these teeth, Figs. 9 to 15, inclusive, have been illustrated to show the inter-relation at the points on the several bucco-lingual section lines. In these figures, the dotted lines indicate the primordial forms from which these first molars have been carved.

Figs. 16 to 19, inclusive, show the working side of the teeth in which Fig. 16 illustrates the closing of the teeth into lateral occlusion after the mandible has moved from the centric position i C to the position shown by the Fig. 17 shows the further operation of the teeth to the point shown by the arrow in that figure, and wherein the buccal and lingual parts ofthebolus offoodareseparatedfromthecen-Gfi tral portion,

In Fig. 18, the mandible has moved as shown by the arrow in that figure, and the clearance sulci begin to open more and more from the position shown in Fig. 17. '70

mandibular movements of mastication wherein the sharp-edged ridges on the occlusal surfaces of the molars fulfill different tool-like cutting actions on'the food. The arrows in these figures indicate the directions in which these sharpedged ridges of the lower molars move against the ridges of the upper molars.

The cross-wise principle of inter-action of these ridges during the mandibular movements is most efficient and the retention of .the angulations and formation of the sulci and fossae" in the facet faces provide means whereby these sharp-edged cutting ridges may be readily provided, so that cutting, shearing and grinding ismore readily accomplished with teeth of this The views shown in Figs. 28, 29,30 and 31 are intended to illustrate the movements of the mandible in the direction of the arrows, and the approach from the working bite to centric position. These particular views illustrate the shearing action with the tool-like ridges formed on teeth asdescribed in this application,

Figs. 32 to 35, inclusive, illustrate the manner of marking the buccal side of the posterior teeth to provide identifying means, whereby the dentist or other technician may properly place the teeth in a cast or mold, the first bicuspid having one collar 6!, the second bicuspid two collars 62,

the first molar one collar 63. and the second molartwo collars 64. These identifying means will also serve to identify teeth made according to the invention disclosed herein, and are intended to be used in the manufacture of these teeth for the two purposes specified.

Of course, the teeth illustrated and described herein may be changed particularly as to methads of providing the primordial form and angulations of the facets, etc., without departing from the invention herein set forth and hereafter claimed.

The invention is hereby claimed as follows:

1. A posterior tooth having facets of varying 5 angulations to accommodate average mandibular movements, said tooth having reliefs cut in the facets while retaining substantially the entire perimeters thereof, thus leaving the original meeting edges of the facets and thereby retain 1 ing the original facets angulations.

2. A posterior tooth having facets of varying angulations to accommodate average mandibular movements, said tooth having its facets provided with fossae of substantially the shape of the facets while retaining substantially the perimeters, of said facets, thus leaving the original meeting edges of the facets practically intact, and thereby retaining the original control portions of said facets, and sulci leading from some t of the fossae and extending through the perimeters buccally and lingually.

' 3. A posterior tooth made from a primordial form having facets to accommodate the average mandibular movements, said tooth having facets provided with fossae of substantially the shape of the facets while retaining substantially the perimeters of said facets, thus leaving the original meeting edges of the facets practically intact and thereby retaining the control portions which con- 3 form to average mandibular movements.

4. Posterior teeth made from primordial forms having facets to accommodate the average mandibular movements, said teeth having fossae in the facets while retaining substantially the 35 perimeters thereof; thus leaving the meeting edges of the facets practically intact and thereby retaining the control portions which conform to the average mandibular movements, sulci leading from some of the fossae and extending through the perimeters buccally and lingually, said fossae and sulci so inter-related between the upper and lower teeth during masticating movements that the food is forced against the cutting edges formed thereby -in order to cut and shear the same and expel masticated food hue- CERTIFICATE OF CORRECTION.

Patent No. 2,050,837. August 11, 1936.

ALFRED GYSI.

It is hereby certified that error appearsin the printed specification of the above numbered patent requiring correction as follows: Page 3, second column, .afterline 22, claim 2, insert the following as claims 3 and 4:

3. A posterior tooth made from a primordial form having facets to accomodate the average mandibular movements, said tooth having reliefs in the facets while retaining substantially the entire perimeters thereof, thusleaving the originalmeeting edges of the facets and thereby retaining the angulations of the primordial form.

4. A posterior tooth made from a primordial form having facets to accommodate the average mandibular movements, said tooth having reliefs in the facets while retaining substantially the perimeters thereof,- thus leaving the' meeting edges of the facets practically intact and thereby retaining the control portions which conform to" average madibular movements.

The claims now appearing in the patent as numbers "3" and "4" shopld bear the numbers 5 and 6 respectively; and that the said Letters Patent should be readwith these corrections therein that the same may conform to the record 01 the case in the Patent Office.

Signed and sealed this 29th day of December, A. D. 1956-.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

Images