US1681557A - Dental articulator - Google Patents

Description

Aug. 21, 192s. 1,681,557

G. P. PHILLIPS DENTAL ART ICULATOR Filed Aug. 29, 1924 Patented Aug. 21, 1928.

' .UNITED STATES GEORGE P. PHILLIPS, OF BOSTON, MASSACHUSETTS.

DENTAL ARTICULATOR.

Application filed August 29, 1924. Serial No. 734,930.

This invention relates to articulators utilized by dentists for making artificial dentures and is intended to provide a mechanically simple apparatus which can be readily adjusted accurately to reproduce the natural movements of the jaws of any individual patient.

This and other objects of the invention will be best understood by reference to the following description when taken in connection with the accompanying illustration of one specihc embodiment thereof, while its scope will be more particularly pointed outin the appended claims. j

j In the drawings,

Fig. 1 is a plan view of an articulator embodying one form of the invention;

Fig. 2 is a side elevation of the device shown in Fig. l; l f

Fig. 3 is a central longitudinal sectional elevation taken through the supporting attachment for one of the model carrying arms or jaws;

Fig. 4 is a transverse sectional elevation on the line t-l of Fig. 3;

Fig. 5 shows an attachment for a trial plate utilized in producing` a guide mold for accurately and readily adjusting the articulator; and i Fig. 6 shows the method of forming the guide mold.

Referring to the drawings and to the illustrated embodiment of the invention shown in Figs. 1 to L1- inclusive thereof, the same is provided with a base or rest 11 which serves as the model holding arm or jaw for holding the lower aw model. This is so constructed that when the apparatus is in use itrests upon the lower or arm as a base, the relative movement between the models being provided by movement of an upper jaw or model carrying arm 13 which is suspended on a support or carrier in the form of a casing 15, the latter hinged at 17 to the lower jaw 11 and carrying the various adjustments required. Both jaws 11 and 13 carry at their ends receptacles 19, one directly over and confronting the other, in which the models may be removablyv held with the trial plate for the upper jaw model resting on that of the lower jaw model. Each receptacle 19 consists of a dish-shaped casing, preferablv with flaring sides, in which the plaster base of the model is inserted. Preferably eachreceptaele has in its bottom or base a transverse plate 21 which may have 'one or more projections 23 adapted to seat in corresponding cavities in the bottom of the plaster base. The plate 21 has swiveled attachment to a screw 25 threaded through the bottom of the receptacle and provided with the thumb piece 27. By turning 'the screw, the plate may be either forced outwardly away from the bottom of the holder or retracted, thus assisting in expelling the plaster base when it is desired to substitute another. By this arrangement'the same apparatus, without the necessity of duplicate holders or other parts, may be used interchangeably with any number of sets ofniodels and the same set may be separately installed and removed from the articulator with assura-nce of'reproducing the same relationship.

Referring to the support for the arm 13, the latter is provided at each side within the supporting casing 15 with a lateral extension `29, the latter having a downwardly extending supporting pin 31 which rests upon an adjustable guide or cam 33. These pins reproduce the functions of the condyles and the guides', those of the condyle paths. Each condyle guide 33 is of suliicicnt length and breadth to permit the required lateral and longitudinal movement of the aw and is adjustably mounted so as to be set at any desired angle to reproduce the jaw movement of the natural mouth for any given patient. For this purpose each guide 33 is pivoted at 35 on the casing and is provided at its opposite end with a threaded pin 37 which proif trudes through an aro-shaped slot 39 in the side of the casing where it has threaded engagement with a thumb nut 41 by which it can be clamped in any desired position of adjustment, its inclination beingreadily ascertainable from the scale 42 appearing on the outside of the casing end in connection with a pointer carried by the pin 37.

In the illustrated embodiment of the invention, I have provided for the jaw 13 a system of suspension which reproduces substantially the same flexibility of aw movement afforded in the natural mouth by the ligaments and muscular attachments. For this purpose the end of the arm 13 opposite the model holder 19 has a pivotal attachment to a supporting block A13 located within the casing 15, such attachment being preferably in the form of a ball and socket joint, the ball 45 being secured to an arm 47 depending from a plate 49 attached to the arm 13.l The sides of the supporting block 43 are grooved and adapted lll to afford a longitudinal sliding movement in a guiding slot located in the bottom of the casing 15. This provides a forward and backward movement for the jaw corresponding to the forward bite. rI`he block 13 is normally forced to a neutral position against the forward end of the slot as indicated in Fig. 3 by means of the leaf spring 51 bearing against the rear wall of the casing and engaging the rear end of the jaw arm 13. The rearward movement of the supporting block L13 is limited by a stop comprising the set screw 53 which can be adjusted to any desired position and there held by a lock nut 55. The ball and socket provide a universal oint suspension for the jaw 13 about which the latter is capable of a rocking movement in any plane to afford (under the guidance of the cams or condyle guides 33) the required movement of elevation or depression, combined with lateral or forward and backward movements. The pins 31 are maintained in engagement with the `guides 33 whatever may be their inclination and whatever the position or movements of the. arm 13 by means of a .leaf spring 57 bear ingagainst the top of the casing.

The lateral movements of the arm 13 are preferably limited by adjustable stop devices such as the right and left set screws 59 and 61, each of which is provided with a suitable lock nut, so that they may be independently set to a fixed point of adjustment. Such set screws are also preferably provided each with a scale. or other device (not shown) such as will indicate the exact point to which each one has been individually set, so that its setting may be recorded and reproduced at a later time.

The spring 57 is so arranged. as to leave the arm 13 free to perform the required rocking movement about the ball joint, there being provided for this purpose a socket or seat in the spring resting on a ball shaped protrusion on the casing, the ends ofthe spring seating in groows formed at the end of the arm.

To reproduce accurately the jaw movements of the natural mouth it is frequently and usually necessary for the condyle guides to be adj usted to different slopes or different angles, which requires unequal lifts at opposite sides of the arm in executing its lateral movements. '.lhis requires in certain positions a lengthening of the radius arm with relation to the ball and socket. Tor this purpose there is provided between the arm 13 and the ball 45 a yieldable connection comprising herein the plate 49 to which the ball is attached, the plate being hinged at G3 to the arm 13, and held normally in the plane of the arm by means of the two leaf springs and 66. Normally the plate and arm move as a unit, but when a compound movement is given the arm involving unequal lift at opposite sides, the arm will be permitted to move slightly with relation to the plate to assume the position called for by the condyle guides. c

The provision of a definite point of suspension about which the movements of the jaw can take place under the guidance of the` cams 33 permits the movements of the jaw to be reproduced accurately and with a very simple form of apparatus.

iTo maintain a fixed position between the upper and lower carrying arms, I have provided a rest or bite pin G9 adjustably supported in the socket 71 and adapted to be set in any desired position by means of the set screw 73. By means of a suitable scale, the pin may be set to any desired position to open the bite anyv required amount. It will be observed that the rest 69 engages the hinged supporting casing 15 and is independent of the suspension or supporting agencies of the movable jaw 13.

In installing the models in this device, the casing 15 is caused to rest upon the bite pin 69 and the arm 17 is held in horizontal position by means of the trip pin 7 5 which engages a. lug` 77 on the bottom of the arm 13. The pin (39 may be adjusted to different heights to accommodate different sizesof models, but, in any position of adjustment of the pin 69, the trip 75, when thrown into engagement with the arm 13, holds the latter in a position corresponding to the neutral position of the con dyle guides and there retains it during the process of adjustment.

Relations having been taken in the mouth and models prepared, the latter are transferred to the articulator. The model receptacles 19 are each lled with a base of soft plaster of Paris, and the upperand lower kjaw models are placed in their respective bases in central occlusion corresponding with a median line of vthe model holders. The plaster having been allowed -to harden, the trip pin is thrown down and the instrument then adjusted to accord with the previously ascertained jaw movements of the patient. The lateral bites of the jaw are fixed by setting the set screws 59 and 61 to the required positions. The condyle guides are set at the required angles, and theset screw 53 is adjusted to give the required forward bite.

For the purpose of accurately adjusting the instrument to accord. with the forward and lateral bites7 I have provided an improved device for taking the relations in the mouth and an in'iproved method of measuring the same. For this purpose I utilize a device such for example as the clip81 shown in Fig. 5, which can be applied to the trial plate and utilized. while the latter is in the mouth of the patient, for forming a guide mold which can be made to facilitate the ad* j ust-ment of the articulator. These clips which are preferably formed of some non-corrosive metal, have an L-shaped cross-section and conform in contour generally to that portion of the edge of the trial plate to which they are to'be applied. Each clip has one or more inturned points 83 which may be pressed into the waxy material of the plate so that the clip is attached to the occlusal rim of the trial plate, as indicated in Fig. 6. Each clip is also provided with one or more outwardly extending projections 85 having rounded tips. One such clip is attached to each opposite side of the upper trial plate to gauge the relations of the lateral bite and a third one at the anterior rim thereof to determine the forward bite. contiguous portions of the lower trial plate so that when the plates are placed in the mouth of the patient adjacent upper and lower clips bear the normal relation indicated in Fig. 6. Molds of molding compound are then made in the usual manner and applied to each set of clips while the patient holds the jaws in the desired positions for the lateral and forward bites respectively, oney such mold being indicated in Fig. 6. The pins on the clips act to provide more or less complex formations in the molds so that when the trial plates with the clips attached are placed in the articulator, the three molds can be used as guides to quickly bring the trial plated to their several respective positions required for adjustment of the artieulator, the projections 85 acting like dowel pins to bring the models and plates to the precise relations assumed in the mouth when making the forward and lateral. bites.

lllhile I have herein shown and described for purposes of illustration one specific embodiment of the invention` it is to be understood that the latter is not limited to the specific construction or the relative arrangement of parts, but that extensive deviation may be made from the details herein shown, all with.- out departing from the spirit thereof.

I claim :A

l. A dental articulator comprising a lower jaw model holder, a support hinged to said holder, a stop to limit the approach of said support to said holder, an upper aw` model holding arm having connections to said support providing for mandibular movement, said connections comprising a socket and carrier movable forwardly and backwardly on the support and an adjustable stop to limit said movement of the carrier, a ball support mounted in the socket and having a yieldable connection to said arm to permit movement of the latter about the socket, a condyle guide at each side of said arm adjustable to different angles of inclination, the latter having a bearing on each guide, means adjustablv to limit the lateral movement of the arm in -each direction and means for yieldably forcing the holder into a position of central occlusion.

L2. A dental articulator comprising a model Similar clips are applied tov holder, a support hinged to said holder, a stop to limit the approach of said support to said holder, a movable model holder arm having connections to said support providing for mandibular movement, said connections comprisingr a carrier movable forwardly and backwardly on the support, an adjustable stop to limit said movement, a universal connection between said support and said arm, adjustable condyle guides on which the arm has a bearing and means adjustably to limit the lateral movement of the arm in each direction.

3. A dental articulator comprising a model holder, a support connected thereto, a movable model holder arm having connections to said support providing for mandibular movement, said connections comprising a carrier movable forwardly and backwardly on the support, a universal oint connection between the arm and said carrier and adjustable condyle guides which govern the movement of said arm about its carrier.

4. The method of adjusting a dental articulator which consists in attaching mold forming protrusions to contiguous portions of the occlusal rims of upper and lower cooperating trial plates and utilizing the same in the mouth of the patient to form guide molds by impressing the protrusions into a mass of molding material held against the same after the patient has placed his jaws in a position of extreme lateral bite.

5. The method of adjusting a dental articulator which consists in attaching mold forming protrusions to contiguous portions of the occlusal rims of upper and lower cooperating trial plates and utilizing the same in the mouth of the patient to form guide molds bv impressing the protrusions into a mass of molding material held against the same after the patient has placed his jaws in a position of extreme lateral bite for opposite lateral bites and the guide mold for the forward bite and then utilizing the molds to set the articulator.

6. A guide-mold-forming device for use with. dental articulators eomprisin g an an gled sheet metal clip provided with one or more inturned attachment points for attaching the same to the occlusal rim of the trial plate and having one or more outwardly turned guidemold-forming protrusions.

7. A guide-mold-forming device for use with dental articulators comprising an angled member with means for attaching the same to the occlusal rim of a trial plate and having one or more outwardly directed guide-moldforming protrusions.

In testimony whereof, I have signed my name to this specification.

GEORGE P. PHILLIPQ.

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