US2754588A

US2754588A - Articulator

Info

Publication number: US2754588A
Application number: US324999A
Authority: US
Inventors: Finton M Cordell
Original assignee: HARRY B SCHWARTZ Inc
Current assignee: HARRY B SCHWARTZ Inc
Priority date: 1952-12-09
Filing date: 1952-12-09
Publication date: 1956-07-17
Anticipated expiration: 1973-07-17

Description

y 17, 1956 F. M. CORDELL 2,754,588

ARTICULATOR Filed Dec; 9, 1952 4 Sheets-Sheet 1 11\ VENTOR Van. UT): KS

July 17, 1956 F. M. CORDELL 2,754,588

ARTICULATOR Filed Dec. 9, 1952 4 Sheets-Sheet 2 INVENTOR aim/1M,

ATTORNEY July 17, 1956 F. M. CORDELL 2,754,588

ARTICULATOR Filed Dec. 9, 1952 4 Sheets-Sheet 3 INVENTOR J1 fouls,

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ATTORNEY July 17, 1956 F. M. CORDELL 2,754,538

ARTICULATOR Filed Dec. 9, 1952 4 Sheets-Sheet 4 INVENTOR ATTORNEY United States Patent Ofi ce Patented July 17, 1956 ARTICULATOR Finton M. Cordell, Baltimore, Md., assignor to Harry B. Schwartz, Inc., Baltimore, Md., a corporation of Mary land Application December 9, 1952, Serial No. 324,999

22 Claims. (Cl. 32-32) The present invention relates to a method and the apparatus employed in the construction of artificial dentures. More particularly, the present invention relates to the method and apparatus employed in constructing artificial dentures whereby an exact fitting of the finished dentures is obtained.

It is now generally recognized that oral discomfort resulting from inadequate dental prosthesis is injurious to the nervous system and can result in general organic malfunction. It is extremely important, therefore, that considerable time and effort be expended and the best available equipment be utilized in the construction of dentures for an individual case, particularly since it is possible that inadequate or ill fitting dentures can result in the physical breakdown of an individual.

The science and art of dental prosthesis have been developed to a degree whereby adequate artificial dentures are provided for those individuals who have unfortunately lost their natural dentition. With the aid of artificial dentures, these latter individuals have been able to continue in their ordinary course of life without undue tooth consciousness. However, the science and art of dental prosthesis, although having developed techniques to construct artificial dentures which are adequate, have not, prior to the instant invention, discovered a process whereby artificial dentures can be constructed and then fitted in the patients mouth without various adjustments having to be made to conform the dentures to the particular characteristics of the patients mouth.

It has become the general procedure in the field of dental prosthetics to utilize a mechanical device or articulator to aid in the construction of the artificial dentures. Articulators are constructed with the view that if the patients jaw or mandible movements can be translated to a mechanical movement, the complete denture can be formed thereon in conformance with the patients natural jaw movements. Unfortunately, the mandible as it moves forward in protrnsive position and to the side laterally does not open and close purely as a hinge, but in opening and closing also moves forward and backward due to the inclined plane of the bony fossa combined with the action of the meniscus and muscular attachments. Moreover, the angle of inclination of the inclined plane, or condylar indication, will vary for some individuals with each side of the head. These variations, if not compensated for in the completed dentures, will often result in improper maxillomandibular relation or disharmony of the teeth in function.

Prior to the instant invention, the heretofore known methods which have employed articulators have not succeeded in solving the problem of accurately transferring the natural movements of the patients jaw to the articulator. Even though the heretofore known articulators can be adjusted to simulate some of the human mandible movements, dentures constructed on these articulators do not have correct occlusion initially and have to be custom-fitted in the patients month. More than often additional grinding and fittings are necessary before the dentures properly fit the patients mouth, and even then post fittings and adjustments are frequently required. Not only are the heretofore known denture techniques using articulators not capable of producing correctly fitting dentures in the first instance, but they are of little value for those edentulous patients who have different angles of inclination or variations in the condylar indications on either side of the head. For these individuals who have heretofore been considered dental cripples, there is no means or method heretofore known by which correctly fitting dentures can be constructed without considerable difficulty.

It is therefore an object of the present invention to provide a method of constructing artificial dentures whereby the finished dentures will correctly fit the patients mouth.

Another object of the present invention is to provide a method of utilizing articulating apparatus that will correctly transfer the human mandible movements onto an articulator.

Still another object of the present invention is to provide a method of utilizing articulating apparatus that results in the exact reproduction of the desired movements of the human mandible.

Still another object of the present invention is to provide an adjustment plate by which the mandible cast is adjusted in accordance with the patients mandibular movements.

Other objects and the nature and advantages of the instant invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a side elevational view of an articulator with the maxillary bracket hinged out of position and illustrating the position in which the mandibular cast is positioned in the articulator;

Fig. 2 is a side elevational view of the articulator illustrated in Fig. 1 showing a primary bite being utilized to correctly position the mandibular and maxillary cast in the articulator;

Fig. 3 is a partial view in side elevation of the articulator illustrating an element for recording a Gothic arch positioned on the mandibular cast;

Fig. 4 is a vertical sectional view of an element for tracing a Gothic arch positioned on the maxillary cast;

Fig. 5 is a plan view of the articulator with the maxillary cast hinged out of position and the recording element positioned on the mandibular cast prior to adjustment of the mandibular cast adjustment plate;

Fig. 6 is a plan view of the articulator similar to Fig. 6 after adjustment of the mandibular cast by means of the mandibular cast adjustment plate;

Fig. 7 is a plan view of the articulator, illustrating locking means for locking the mandibular cast in centric relation, the tracing and recording elements shown in Figs. 3 and 4 positioned in the articulator prior to the final mounting of the maxillary cast;

Fig. 8 is a plan view of the articulator illustrating a locking means for locking the maxillary and mandibular casts in protrnsive position, the maxillary cast being shown in canted position;

Fig. 9 is an exploded view in perspective of the adjustable mandibular mounting plate upon which the mandibular cast is mounted; and

Fig. 10 is a view taken along the line 10-10 of Fig. 2.

It is a generally accepted fact that if the articulator employed in the construction of artificial dentures is able to exactly duplicate the movements of the patients lower jaw or mandible, the dentures will be constructed in conformity with the patients oral characteristics. One of the techniques employed in attempting to reproduce the movement of the lower jaw utilizes a Gothic arch tracing device. The Gothic arch tracing device records the movements of the patients lower jaw in the form of an arch. If the arch recorded on the tracing device is exactly duplicated by the articulator, the dentures constructed on that articulator will be in conformance with the movements of the lower jaw of the patient and will thereby be in proper occlusion when placed in the patients mouth. The present invention is designed to position the maxillary and mandibular casts, which duplicate the patients upper and lower gum impressions, in such a manner that the Gothic arch recorded by the patient will be exactly duplicated. The dentures thus formed on the articulator described in the present invention will, when inserted in the patients mouth, be in proper occlusion and any additional adjustments or grinding of the dentures is thereby obviated.

Referring to Figs. 1 and 2 of the drawings, the articulator embodies in the present invention is illustrated therein generally at and includes a base 12. integrally formed on the underside of the base 12 and located at the corners thereof are feet 14. Positioned at the rear corners of the base 12 are vertical or condylar posts 16 which extend upwardly, terminating in circular or condylar heads 18. The condylar heads 18 are adapted to simulate the position of the human condyles and are provided with adjustments to compensate for condylar inclination deviations as will hereinafter be described. Each of the conylar posts 16 is rotatably positioned in the base 12 and is engaged by a stud 20 which secures the posts 16 in any desired adjusted position.

Mounted for rotation in each of the condylar heads 18 is a rotatable element 22 which has a slot 24 formed therein. Each of the rotatable elements 22 is adjusted in a condylar head 18 by means of a lock nut 26. Each of the lock nuts 26 threadedly engages a screw stud 28 which extends through a slot 29 formed in the upper portion of the condylar heads 18 and which is secured to the rotatable element 22. It is apparent that the lock nut 26 locks the rotatable element 22 in any desired position which, in effect, adjusts the position of the slot 24 with respect to the horizontal. Positioned in each of the slots 24 is a condylar ball 30 which is adapted to be movable lengthwise in the slot 24 but is prevented from moving laterally therein. A suitable locking device 32 is secured to the rotatable element 22 and firmly locks the condylar ball 30 in the slot 24. Each of the balls 30 is secured to an end of a shaft 35 which defines the hinge axis of a maxillary bracket 38 formed integral with the shaft 35 and located perpendicular thereto. Referring to Fig. 2, the maxillary bracket 38 is shown including a mounting plate 40 which is attached to the bracket 38 by a mounting nut 42. Secured to the front portion of the bracket 33 and depending downwardly therefrom is an incisal pin 3-4 which forms the front guide or stop for the bracket 38 as it is hingedly moved on the condylar balls 30 secured to the ends of the shaft 35. Secured to the base 12 is a lower mounting plate generally indicated at 59, which is adapted to have mounted thereon a cast of the patients lower jaw or mandible. The plate is adjustable, as will hereinafter be described, and cooperates with the upper mounting plate 40 to secure the upper and lower casts of the patient in the correct mounting position in the articulator.

It is apparent that in the articulator described hereinabove, the basic elements of the human jaw are reproduced therein. If an impression or cast of the patients jaws is made and fixed to the lower mounting plate 5% and the uppermounting plate 49, the upper bracket 33 of the articulator may be hinged upwardly and downwardly along the hinge axis extending through the condylar balls 30 and thereby simulate the opening and closing of the patients jaws. However, it is obvious that the exact movement of the patients jaws may not be reproduced on the articulator without making additional adjustments to compensate for the special characteristics of the patients jaws in movement. It is a known fact that there are certain characteristics that are common to all patients and, therefore, if these known facts are applied, the individual case may be solved with relative simplicity.

It is an accepted anatomical fact that the high points of the natural lower anterior teeth, as they theoretically appear in the patients mouth, lie in a horizontal plane that includes the high points of the natural lower posterior teeth, assuming that there has been no wear or abrasion of the teeth. Therefore, theoretically, if an individual is positioned upright, and if there are no interfering teeth, a plane extending from the high points of the natural lower anterior teeth to the high points of the natural lower posterior teeth will be horizontal. It follows that if a model or cast of the patients lower jaw or mandible,

in riding the natural anterior and posterior teeth, is reproduced and placed in an articulator and positioned such that the high points of the natural lower anterior teeth and the high points of the natural lower posterior teeth are located in a horizontal plane, then the mandibular cast will be located in a substantially correct vertical position in the articulator. The positioning of the mandibular or lower cast in the articulator in the true horizontal position will be described in detail hereinafter. However, for the purpose of initially locating the lower cast horizontally in the articulator, the average distance from the natural lower anterior teeth in the head to a line extending through the condyles or intercondylar axis is utilized. The average length of the natural lower anterior teeth, the average length of the natural lower posterior teeth, and the average distance of these teeth from the condylar axis can be determined from known anatomical reference points and can be accurately indicated on an edentulous lower model or cast. There fore, if a model or cast of a patients edentulous jaw or mandible is reproduced and placed in an articulator and positioned such that calibrated reference positions, which correspond to the high points of the natural lower anterior teeth and the natural lower posterior teeth, lie in a horizontal plane at the average distance from the condylar axis of the articulator, then the mandibular cast indicated at 52 in Fig. 1 will be located in a substantially correct vertical position in the articulator. In order to obtain the correct vertical position of the mandibular cast 52, whereby the high points of the natural lower and anterior teeth will lie in a horizontal plane, any convenient means or method, such as an ordinary spirit or bubble level can be employed. The location of the edentulous mandibular cast in the proper vertical plane on the articulator will hereinafter be referred to as the correct anatomical average vertical and horizontal position. Once the correct anatomical average vertical and horizontal position of the mandibular cast is obtained, plaster is injected beneath the cast, thereby sealing it to the lower mounting plate 50.

Although the lower cast 52 is fixed in the anatomical average vertical and horizontal position in the articulator, it is necessary to obtain the centric relation of the upper and lower jaws which can then be transferred to the articulator to produce the true horizontal location of the lower east 52. With the lower cast 52 correctly positioned in centric relation in the articulator, an upper cast indicated at 54 in Fig. 2 can then be correctly mounted in the articulator. Centric relation is defined as the most retruded unstrained position of the condylar heads in the glenoid fossae at a given degree of opening and is obtained in the present invention by utilizing a Gothic arch tracer. The Gothic arch tracer includes a tracing device that is placed in the patients mouth, the tracing device being adapted to have the lateral and protrusive movements of the patients lower jaw recorded thereon. In recording the movements of the patients jaw, an arch is tracedthat is produced by one condylar head moving laterally, the other condylar head acting as a universal pivot. The tracing :ofthis movement produces .a line arses-es starting from a point which is the most retruded position of the moving condylar head. Moving the opposite condylar head laterally traces a line that begins from the most retruded position of the moving condylar head and which cuts across the tracing of the first line at an angle. The lines thus traced are recorded on the tracing device in the form of an arch, the apex of which defines centric relation.

Since the tracing device is actually placed in the patients mouth, it is constructed from the impression formed on the lower cast 52 and on the upper cast 54 which is a model of the patients upper jaw. However, before the tracing device can be constructed, the upper and lower casts must be positioned relative to the position of the patients' upper and lower jaws. Referring again to Fig. 2, the upper cast 54 is shown mounted in the articulator on the upper mounting plate 40 and engaging a primary bite plate 56. The primary bite plate 56 is formed from an impression of the patients upper and lower jaws and when placed in the articulator between the upper cast 54 and the lower cast 52 will cause the upper and lower casts to approximate the natural position of the patients upper and lower jaws. The upper cast 54 is then preliminarily secured to the upper mounting plate 40 by suitable means, such as quicksetting plaster, and the primary bite plate 56 is removed from the articulator. It is apparent that the upper and lower casts are now mounted in the articulator in such a manner so as to approximate the anatomical position of the patients upper and lower jaws.

The tracing or recording device utilized in recording the patients jaw movements may be of any conventional type. However, an intraoral type is illustrated and is formed in individual elements comprising a lower recording element 66 (Fig. 3) and an upper tracing element 62 (Fig. 4). The lower recording element 60 is constructed by using the lower cast 52 as a model and shaping the body of the element 60 in accordance with the impression formed thereon. The upper tracing element 62 is similarly formed by using the upper cast as a model and shaping the body of the upper element in accordance with the impression of the upper cast 54. The lower recording element 60 is formed such that when positioned on the lower cast 52, the upper surface thereof lies in a horizontal plane. Securely fixed to the upper surface of the recording element 60 is a recording plate 64 which forms the surface upon which the Gothic arch produced by the movements of the patients jaws is recorded. The recording plate 64, when located in the lower cast, lies in a horizontal plane that corresponds to the plane extending through the high points of the natural anterior and posterior teeth as these teeth theoretically appear in the patients mouth. The recording plate 64 is thereby located in the correct anatomical average vertical and horizontal position. A plate 66 is secured to the lowermost surface of the tracing element 62 and a tracing pin 68 is secured thereto. The tracing pin 68 is located at approximately the mid point of the upper tracing element 62 and is adapted to contact the recording plate 64 at approximately the mid point thereof when the tracing device is mounted in the articulator or placed in the patients mouth.

It is apparent that when the tracing device is placed in the patients mouth, lateral movements of the patients jaws will produce a recording in the form of an arch on the plate 64, as traced by the tracing pin 68. Protrusive movement of the patients jaw will produce a straight line that, theoretically, if extended, would extend from the center of the horizontal projection of the hinge axis of the articulator through the apex of the Gothic arch. In order to obtain a permanent record of the centric relation recorded by the tracing device, a plaster lock is formed around the upper tracing element 62 and the lower recording element 60 with the tracing pin 68 resting on the apex of the Gothic arch. For convenience,

this lock is referred to as the C or centric loclr. Sim ilarly, with the patients jaws in the most protrusive position, a plaster impression is taken between the upper and lower jaws and forms a permanent record of the protrusive position of the patients jaws. The protrusive bite or lock is referred to as the P lock and will be more completely described hereinafter.

When the lower cast 60 was initially mounted on the lower mounting plate 54 of the articulator it was mounted in accordance with average measurements for the average person. However, the jaw measurements of individuals vary. That is to say, the condylar width of all persons will not always be the same and similarly, the distance from the intercondylar axis to the high point of the lower anterior teeth will vary from person to person. It follows, therefore, that a person with a wide condylar width will trace a Gothic arch that has an apex that is relatively a greater distance from the center of the horizontal projection of a line drawn through the condylar balls 30 or hingle axis of the articulator than a patient having a narrow condylar width. Referring now to Figs. 5 and 6, the lower recording element 60 of the Gothic arch tracing device is illustrated positioned in the articulator with the Gothic arch recorded thereon. The line a of the Gothic arch represents the movement of the lower condylar ball 30, as seen in Fig. 5, whereas the line b represents the movement of the upper condylar ball 30. The lines a and b intersect at the point 0 which is the apex of the Gothic arch. A substantially straight line d is formed on the tracing plate 64 by the forward movement of the patients lower jaw and represents the protrusive tracing thereof. As discussed above, a Gothic arch tracing represents the extreme lateral and the centric position from which all movements of the lower jaw are made. If the articulator reproduces this Gothic arch tracing with the tracing device disposed on the upper and lower casts, then it may be assumed that the movements of the patients lower jaw are duplicated by the articulator. However, in order for the tracing point 68 of the upper tracing element 54 to reproduce the lines a and b in the articulator, it is necessary to first reposition the lower east 52 in the articulator in accordance with the actual measurement of the angle of the Gothic arch. Since the angle of the Gothic arch tracing anatomically is related to the distance between the apex of the arch and the intercondylar axis and the horizontal projection of a line drawn through the hinge axis of the articulator, this distance can be obtained by utilizing a chart, the data for which has been compiled from actual case histories. Thus, by compiling data from a series of cases, the relation between the measurement of the angle of the Gothic arch traced by an individual and the distance from the apex of the arch to the midpoint of the horizontal projection of the hinge axis will be determined. Consequently, by referring to the chart, the distance for an individual case can be readily determined if the angle of the arch that is traced is measured. It is apparent then that the distance obtained will be the distance that the apex of the Gothic arch traced by the patient must be positioned from the midpoint of the horizontal projection of the line drawn through the hinge axis of the articulator in order to compensate for the deviations from the average condylar width.

An example of a chart is indicated below, the distance from the apex of the arch that is traced to the midpoint of the horizontal projection of the hinge axis of the articulator being indicated in millimeters:

Angle in degrees: Distance in millimeters By utilizing the protrusive line d formed by the patient on the tracing plate 64, the lateral position of the lower cast 60 can also be obtained. The example of the Gothic arch tracing illustrated in Fig. 5 shows the protrusive line d deviated from a line extending from the apex c of the Gothic arch to the midpoint of the line drawn through the hinge axis of the articulator. By laterally moving the lower cast 60 until the line d coincides with the line drawn through the apex c of the Gothic arch to the midpointof the horizontal projection of the articulator hinge axis, the lower cast is positioned in the same relationship to the line drawn through the articulator hinge axis that the lower jaw is to the intercondylar ax In order to effect the necessary lateral adjustments of the lower east 60, the mounting plate 59 illustrated in Fig. 9 is employed. The mounting plate 50 comprises a movable upper plate 7t) which is generally rectangular in configuration and which is formed with rounded corners. A slotted plate 72 normally employed in articu lators is secured in an appropriate recess 7% formed in the upper plate 70 by means of set screws 76 which extend through the ends of the upper plate 79 and into the recess 74. Downwardly extending elongated screws 78 are secured in the upper plate 70 and are formed flush with the upper surface thereof. A fixed lower plate it is adapted to engage the upper plate 70 and has a generally rectangular configuration with rounded corners similar to plate 70. Large openings 82 are formed in the plate 80 and are adapted to receive the elongated screws 78 therein. A threaded opening 84 is formed in the center of the lower plate 80 and receives a mounting screw 86 which extends through the base 12 of the articulator, thereby fixedly securing the plate 89 to the articulator. Adjustment nuts 88 formed with eccentric openings in the body thereof are positioned in the openings 32 of the lower plate 80, as seen in Fig. 1G, and are adapted to receive the elongated screws 73. Lock nuts 9%) are formed with threaded openings in the body thereof and are adapted to threadedly engage the screws 78 for locking the movable plate 70 to the fixed plate it As shown in Fig. 10, the locknuts 90, when tightened, force the shoulder of the adjustment nuts 83 against the plate 80 and the uppermost end thereof against the plate 7%, thereby firmly securing the upper plate 76 to the fixed lower plate 80. In laterally adjusting the lower east 52 to move the protrusive line d of the Gothic arch tracing so that it conforms to the line extending from the apex of the Gothic arch to the center of the horizontal pro jection of the hinge'axis of the articulator, it is only necessary to loosen thelock nuts 96 and rotate the nuts 88. Since the body of the adjustment nuts has eccentrically located openings formed therein, rotation of the nuts 83 will cause the movable plate 7% to move laterally with respect to the fixed plate 89. The adjustable mounting plate 50 thereby provides a simple method of laterally repositioning thelower cast 52 as requiret by the Gothic arch tracing.

Referring now to Fig. 6, the lower east 52 is shown after it has been laterally repositioned in accordance with the reading of the chart discussed hercinabove. The lower cast 52 has been adjusted laterally by the lower mounting plate 50 so that the protrusive line (2 lies a line extending from the apex c of the Gothic arch to the center of the horizontal projection of the hinge axis of the articulator. With the lower east 52 mounted in the correct horizontal position in the articulator, the upper and lower elements of'the Gothic arch tracing device are locked together with-the C" lock as shown in Fig. 7 and placed on the lower east 52. The upper east 54 is then mounted permanently to the upper mounting plate 4'9, utilizing the upper element 62 of the Gothic arch tracing device as a guide. It is apparent that the upper and lower casts will then be mounted in centric relation in the articulator. Since the Gothic arch tracing represents the extreme lateral and centric position from which all movements of the lower jaw are made, it should follow that .if .a tracing is-made by.moving the articulator to the right and then to the left laterally, the tracing recorded by the articulator should identically duplicate the tracing made by the patient. However, in some instances, due to variations in the condylar inclinations of the patients head, this tracing will not be duplicated and, therefore, further adjustments in the articulator are necessary.

The inclined plane or the condylar inclination of the average person measures approximately 22 on both sides of the head. However, many individuals have different condylar inclinations on either side of the head and it is for these individuals that the condylar slots 24 must be adjusted in the articulator to compensate for any deviations in the condylar inclinations. The deviations in the condylar inclinations of the patient are recorded by havthe patient move the lower jaw in a protrusive position and then filling up the space between the upper and lower casts with plaster to form the P or protrusive bite or lock (see Fig. 8). The P lock actually records the space between the upper and lower jaws with relationship to the condyles when the jaws are moved in the protrusive position and will determine the amount of adjustment of the condylar slots 24 that is necessary to reproduce the tracing on the Gothic arch tracing device. The protrusive adjustment of the articulator is obtained after the upper and lower casts have been mounted on the articulator in centric relationship. The lock nuts 26 for the rotating element 22 are loosened and the upper and lower elements of the Gothic arch tracer are placed on the upper and lower casts and the protrusive lock P" is accurately fitted on the lower element of the Gothic arch tracing device. Pressure is exerted on the upper bracket 38 and at the same time one of the rotating elements 22, which includes the condylar slots 24, is loosened and moved back and forth until the upper element of the Gothic arch tracer firmly and precisely fits protrusive lock P. The process is repeated with the other rotating element 22 and condylar slot 24 until an overall precise and secure seat of the upper tracing clement attached to the upper cast is achieved. The rotating elements 22 are then locked in the position thus obtained. Referring to Fig. 8, the condylar slots have been so adjusted that the shaft 35 has been slightly canted as seen in the plan view.

In some instances, when the loss of teeth has been irregular over a period of years, the lower jaw or mandible usually has been shunted into a protrusive and lateral position which varies considerably from normal. In these cases, correction for the proper condylar inclination of the condyles will not always result in an exact reproduction of the Gothic arch tracing by the articulator. Therefore, it is necessary to loosen the screws 29 located along the rear side of the articulator and then to rotate each condylar post 16. The condylar posts 16 are rotated as the upper cast 54 is moved laterally to the left and right over the lower cast 52. The proper position of the condylar posts 16 will be ascertained when the articulator is caused to exactly duplicate the tracing traced by the patient. The rotation of the condylar posts 16 thus enables the articulator to exactly duplicate the patients tracing recorded on the Gothic arch tracing device. As shown in Fig. 8, the lower post has been retated to the position shown in dotted lines. Once the Gothic arch tracing is duplicated by the articulator, the teeth can be set up and waxed, invested and processed in the conventional manner. The completed dentures, when placed back on the articulator, are finished and polished and then removed for insertion into the patients mouth. Since the method described above enables the articulator to exactly duplicate the Gothic arch tracing scribed by the patient, occlusal adjustments or grinding of the dentures are unnecessary, the dentures exactly fitting the patients mouth when initially inserted therein.

it is apparentthatthe methodof constructing artificial dentures set forth above will produce dentures that will correctly fit the patient in the first instance and the necessity for additional grinding or adjusting or post fitting is thereby completely obviated. Actual clinical results have proved that the method and apparatus described hereinabove produce dentures that fit the patient with proper occlusion and even those patients who have been edentulous for long periods of time have been accurately fitted with little dilficulty. Moreover, the dilficulty in constructing dentures for those patients who are partially or completely edentulous and who have different angles of inclination or variations in the condylar indications on both sides of the head has been overcome by the application of the method taught by the present invention. Since clinical results and analysis have proved that the method of constructing artificial dentures taught by the present invention does produce correctly fitting dentures which do not require further adjustment, it is apparent that the present invention presents a real solution to a very difiicult problem that has existed for many years.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and, therefore, the invention is not limited to what is shown in the drawings and described in the specification, but only as indicated in the appended claims.

What is claimed is:

1. In a method of construction artificial dentures comprising the steps of mounting a lower east in an articulator in the correct anatomical average vertical and horizontal position, constructing a Gothic arch tracing device to record the patients mandibular movements, mounting the lower element of said tracing device on said lower cast so that the upper surface thereof lies in a horizontal plane, placing said Gothic arch tracing device in the patients mouth and recording the mandibular movements thereof in the form of a Gothic arch, measuring the angle formed by said Gothic'arch, adjusting the position of said lower cast in centric relation in accordance with the reading of said angle, mounting an upper cast in said articulator in a position determined by the adjusted position of said lower cast, moving said upper cast in protrusive position, adjusting the condylar heads and posts of said articulator so that the Gothic arch traced by the mandibular movements of the patient will be reproduced when said upper cast is moved relative to said lower east in said articulator, and mounting teeth in said casts, said teeth being arranged to properly occlude due to the proper alignment of said upper and lower casts.

2. In a method of constructing artificial dentures, comprising the steps of forming the maxillary and mandibular casts of the patient, mounting said mandibular cast on an articulator so that a horizontal plane extends through reference points corresponding to the high points of the natural lower anterior and posterior teeth, thereby simulating the location of the mandible as it appears in the patients mouth, constructing a tracing device in accordance with the formation of the maxillary and mandibular casts, recording the lateral and protrusive mandibular movements of the patient on said tracing device, measuring the angle formed by said recording, adjusting the position of said mandibular cast in accordance with the reading of said angle, mounting said maxillary cast in said articulator in a position determined by the adjusted position of said mandibular cast, moving the upper cast in the most protrusive position, adjusting the condylar heads and posts of said articulator so that the arch traced by the mandibular movements of the patient will be reproduced when said maxillary cast is moved relative to said mandibular cast, and mounting teeth in said casts, said teeth being arranged to properly occlude due to the proper alignment of said maxillary and mandibular casts.

3. In a method of constructing artificial dentures comprising mounting a lower east of the patients mandible in an articulator in the correct anatomical average vertical and horizontal position, recording the movements of said mandible on a tracing device, adjusting the position of said lower cast in said articulator in accordance with the record of the patients mandibular movements, mounting an upper cast of the patients maxillary in said articulator in centric relation with said lower cast, moving said upper cast in the protrusive position and then adjusting the condylar reading of said articulator so that said articulator will reproduce the maxillomandibular movements of the patient, and mounting teeth in said casts, said teeth being arranged to properly occlude due to the correct positioning of said upper and lower casts.

4. In a method of constructing artificial dentures comprising the steps of mounting a lower cast in an articulator in the correct anatomical average vertical and horizontal position, adjusting said lower cast in said articulator in centric relation in accordance with a record of the patients mandibular movements, mounting an upper cast in said articulator in proper relation to said lower cast, and mounting teeth in said upper and lower casts, said teeth being arranged to properly occlude due to the correct positioning of said upper and lower casts.

5. In a method of constructing artificial dentures comprising the steps of mounting a lower east in an articulator in the correct anatomical average vertical and horizontal position, recording the lateral and protrusive mandibular movements of the patient in the form of a Gothic arch, measuring the angle of said Gothic arch, adjusting the position of said lower cast in accordance with the measurement of said angle, mounting an upper cast in said articulator to conform to the position of said lower east, moving said upper cast in the most protrusive position and then adjusting the condylar reading of said articulator so that the Gothic arch traced by the manibular movements of the patient will be reproduced when said upper cast is moved relative to said lower cast, and mounting teeth in said casts, said teeth being arranged to properly occlude due to the correct alignment of said upper and lower casts.

6. In a method of constructing artificial dentures comprising the steps of forming an upper and lower cast of a patients jaws in the correct anatomical average vertical and horizontal position, constructing recording means for recording the movements of the patients lower jaw, recording the movements of the patients lower jaw on said recording means, adjusting said lower east in said articulator in accordance with the recorded reading, mounting an upper cast of the patients upper jaw in said articulator in a position determined by the adjusted position of said lower cast, moving the casts in the most protrusive position, and adjusting articulating means thereby causing said articulator to reproduce the patients recording.

7. In a method of constructing artificial dentures comprising the steps of constructing an upper and a lower cast of a patients jaws, mounting said lower east in an articulator utilizing leveling means, said leveling means locating said lower cast in said articulator in the correct anatomical average vertical and horizontal position, adjusting said lower cast in said articulator in accordance with the recorded movements of the patients jaws, mounting said upper cast in said articulator in centric relation with said lower cast, moving said upper cast in protrusive position, and adjusting articulating means thereby causing said articulator to reproduce the patients recorded movements.

8. In a method of constructing artificial dentures comprising the steps of mounting a lower cast of the patients mandible in an articulator in the correct anatomical average vertical and horizontal position, recording the movements of the patients mandible, measuring the recording of the patients mandible, adjusting said lower cast laterally and protrusively in accordance with said recording, mounting an upper cast in said articulator in proper position as determined by the position of said lower cast, and mounting teeth in said casts, said teeth properly occluding due to correct alignment of said upper and lower casts.

9. In a method of constructing artificial dentures comprising the steps of mounting a lower cast of a patients mandible in an articulator, recording the movement of the patients mandible, measuring said recording, adjusting said lower cast laterally and protrusively in accordance with said recording, mounting an upper cast in said articulator in proper position as determined by the position of said lower east, moving said upper cast in the protrusive position, and adjusting articulating means to cause said articulator to reproduce said recording, and mounting teeth in said casts.

10. In a method of constructin" artificial dentures comprising forming an upper and lower east of a patients jaws, mounting said upper and lower casts in an articulator in centric relation, said last step comprising recording the movements of the patients mandible, adjusting said lower cast laterally and protrusiveiy in accordance with the recorded reading and mounting said upper cast in said articulator in a position determined by said lower east, moving said upper east in protrusive position and adjusting the condylar readings in said articulator to cause said recording to be reproduced by said articulator, and mounting teeth in said casts, said teeth properly occluding because of the correct alignment of said upper and lower casts.

11. In an articulator, a base, vertical condylar posts mounted at the rear of said base, said condylar posts ter minating in condylar heads, said condylar heads including rotatable elements having slots formed therein, a maxillary bracket formed integral with a shaft, said shaft including means engaging said slots thereby pivotally securing said maxillary bracket in said articulator, an upper mounting plate secured to said maxillary bracket, said upper mounting plate having an upper cast secured thereto, a lower mounting plate secured to said base and adapted to receive a lower east, said lower mounting plate adjustably moving said lower east laterally and protrusively and comprising a movable top plate, elongated screws secured to said top plate, a fixed bottom plate engaging said top plate, said bottom plate having wide slots formed therein receiving said elongated screws, ad-- justment nuts extending into said slots, said adjustment nuts having openings formed eccentrically therein, said openings receiving said screws, lock nuts having threaded openings formed therein for receiving said screws, said adjustment nuts adapted to move said top plate relative to said fixed bottom plate thereby adjusting the position of said top plate, said lock nuts adapted to lock said top plate to said bottom plate in a fixed position.

12. In an articulator, a base, vertical condylar posts mounted at the rear of said base, said condylar posts terminating in condylar heads, said condylar heads including rotatable elements having slots formed therein, a maxillary bracket mounted in said articulator formed integral with a. shaft, the ends of said shaft extending into said slots thereby pivotally securing said maxillary bracket in said articulator, an upper mounting plate secured to said maxillary bracket, said upper mounting plate adapted to have an upper cast secured thereto, a lower mounting plate secured to said base and adapted to have a lower cast secured thereto, said lower mounting plate being adjustable laterally and protrusively and comprising a movable top member and a fixed bottom member, screw means secured to said movable top member, means engaging said screw means for adjusting said top member thereby adjusting the position of said lower mounting plate.

13. in an articulator as set forth in claim 12, wherein said engaging means comprises a pair of adjustment nuts, each of said adjustment nuts having an opening formed eccentricaliy therein, said eccentric openings cooperating with said screw means to move said top plate laterally.

14. In an adjustment plate for an articulator, a fixed bottom plate having enlarged openings disposed at opposite sides ofthe plate thereof, a movable top plate engaging said bottom plate, said top plate having elongated screws secured thereto and extending through said enlarged openings in said bottom plate, adjustment nuts having a body portion which extends into an opening in said bottom plate, each of said adjustment nuts having an opening formed eccentrically therein, each of said eccentrically formed openings receiving an elongated screw therein, and lock nuts having threaded openings formed therein adapted to receive said screws, said movable plate being moved laterally upon rotation of said adjustment nuts and said lock nuts being adapted to secure said movable top plate to said bottom plate when tightened on said screws.

15. In an adjustment plate for an articulator, a fixed bottom plate, said bottom plate having an opening formed therein, a movable top plate engaging said bottom plate, screw means secured to said top plate and extending through the opening in said bottom plate, adjustment means having an opening formed eccentrically therein and receiving'said screw means, said adjustment means extending into the opening in said bottom plate, and lock means engaging said screw means, said adjustment means adapted to move said topplate laterally with respect to said bottom plate and said lock mean adapted to lock said top plate securely to said bottom plate.

16. In an adjustment plate for an articulator, a fixed bottom plate having openings formed therein, a movable top plate having screw means secured thereto and extending through said openings in said bottom plate, means having-openings formed eccentrically therein, said lastnamed openings engaging said screw means, said means being adapted to move said top plate relative to said bottom plate, and means having threaded openings formed therein engaging said screw means for securing said top plate to said bottom plate in locked position.

17. In a method of constructing artificial dentures comprising the steps of mounting a lower east in an articulator in the correct anatomical average vertical and horizontal position, recording the mandibular movements of the patient in the form of a Gothic arch, measuring the angle of said Gothic arch, adjusting said lower cast relative to the center of the hinge axis of said articulator in accordance with said measurements, mounting an upper cast in said articulator to conform to the position of said lower east, moving said upper cast in the protrusive position and adjusting the condylar readings of said articulator so that the articulator will reproduce the Gothic arch traced by the patient, and mounting teeth in said casts, said teeth being arranged to properly occlude due to the correct alignment of saidupper and lower casts.

13. In a method of constructing artificial dentures comprising the steps of mounting a lower cast in an articulator in the correct anatomical average vertical and horizontal position, recording the mandibular movements of the patient in the form of a Gothic arch, measuring the angle of said Gothic arch, adjusting said lower cast so that the distance from the apex of said Gothic arch to the midpoint of the horizontal projection of the hinge axis of said articulator is in accordance with the measurement of said angle, mounting an upper cast in said articulator in accordance with the position of said lower east, adjusting the condylar reading of said articulator so that the articulator will reproduce the Gothic arch traced by the patient, and mounting teeth in said casts, said teeth being arranged to properly occlude because of the correct alignment of said upper and lower casts.

19. In a method of constructing artificial dentures comprising the stcps of mounting a lower cast in an articulator in the correct anatomical average vertical and horizontal position, recording the movements of the patients lower jaw in the form of a Gothic arch, measuring the angle of said Gothic arch, adjusting said lower east in said articulator so that the distance from the center of the horizontal projection-of the hinge axis of said articulator to the apex of said arch conforms to the measurement of said angle, mounting an upper cast in said articulator in accordance with the position of said lower cast, adjusting the condylar readings of said articulator so that the Gothic arch traced by the patient will be reproduced by said articulator, and mounting teeth in said casts, said teeth being arranged to properly occlude due to the correct alignment of said upper and lower casts.

20. In a method of constructing artificial dentures comprising mounting a lower east of the patients mandible in an articulator in the correct anatomical average vertical and horizontal position, recording the lateral and protrusive mandibular movements of the patient in the form of a Gothic arch by a Gothic arch tracing device,

locking together upper and lower elements of said Gothic arch tracing device utilizing a centric lock, thereby establishing centric relation, removing said centric lock from between said tracing elements, recording the protrusive relationship of the patients mouth by inserting a lock between said tracing elements after the patient has moved the mandible in a protrusive position, measuring the angle formed by the Gothic arch tracing, adjusting the position of said lower cast in accordance with the reading of said angle, mounting an upper cast in said articulator in a position determined by the adjusted position of said lower east so that the Gothic arch traced by the mandibular movements of the patient will be reproduced when said upper cast is moved relative to said lower cast in said articulator.

21. In a method of constructing artificial dentures as set forth in claim 20, rotating one or both of the articulator condylar posts to a proper position when an irregular Gothic arch tracing has been traced by a patient whose mandible has been shunted in a protrusive and lateral position which varies considerably from normal, the proper position of rotation of said condylar posts being determined when said articulator duplicates the tracing traced by said patient, moving the upper cast in a protrusive position to seat in said protrusive lock, thereby causing said articulator to duplicate the patients condylar inclination, whereby all mandibular movements of said patient will be reproduced when said maxillary cast is moved relative to said mandibular cast.

22. In an articulator, a base, vertical condylar posts mounted at the rear of said base, said condylar posts terminating in condylar heads and being rotatable to compensate for variations in the protrusive and lateral position of the patients mandible, a maxillary bracket mounted in said articulator, an upper mounting plate secured to said maxillary bracket, an adjustable lower mounting plate secured to said base and adapted to laterally and protrusively adjust the position of a lower cast mounted thereon, said condylar heads including rotatable elements mounted thereon, said elements being rotatable about an axis normal to the axis of said posts to compensate for various condylar inclinations of the patient, whereby rotation of said condylar posts and rotatable elements mounted on said posts enable a tracing by the patient to be duplicated on said articulator.

References Cited in the file of this patent UNITED STATES PATENTS 1,799,528 Phillips Apr. 7, 1931 2,220,734 Shanahan Nov. 5, 1940 2,510,152 Stoll June 6, 1950 2,521,599 Neil Sept. 5, 1950