Method and Apparatus for Articulating Human and Animal Jaw Structures

Dental articulators are used to simulate the jaw and jaw hinge mechanism for use in the analysis and diagnosis of dental related problems and creation of various appliances and prostheses and thereby provide according to a patient's particular bite. To accomplish this, upper and lower frame units are generally employed to simulate the upper and lower jaws. Further, condyle ball and socket arrangements are employed in a great many of these devices which were intended to correspond to the actual jaw hinges of humans. Such a device is shown in U.S. Pat. Nos. 3,409,986 to Freeman, 3,478,431 to Depetrio and 3,206,852 to Swanson. To facilitate the description of the present invention, and to promote an understanding of the prior art of articulators in general, the aforementioned patent is referenced in the present description. It will readily appear and be understood by those skilled in the art that the present invention can be incorporated with various other articulators.

U.S. Pat. No. 3,409,986 shows an articulator which permits both angular and vertical adjustments. The upper base member is elevated and supported by pin elements, two of which rest on vertically adjustable platforms. The flexibility of adjustment is not present in this articulator that is present in Applicant's.

The condyle ball and socket joints employed in arcon dental articulators generally provide for significant controlled adjustment to border positions to better reflect actual jaw movements. Consequently, the joints are not interlocking and will not support the upper frame when it is rotated to disengage the false teeth mounted on the articulator. As a result, it has been found useful to provide a secondary mechanism for holding the upper frame on the lower frame when the upper frame is pivoted from the engagement position. Further, the permitted relative lateral displacement of the condyle ball and sockets creates a second operational closed, occludent position when efforts are made to work on the subject teeth with both the upper and lower portions engaged.

There are two general classes of dental articulating instruments, arcon and non-arcon. The arcon articulation concept designates a mechanical feature whereby the anatomy of the jaw joints is reproduced more or less. Condylar spheres are attached to the lower beam and the fossa or condylar housings are attached to the upper beam. In the past, the articulator condyle has been provided with close and intimate contact with the fossa. This was considered necessary in order to guide the instrument to follow adjustable restraints built into the articulator in an attempt to allow reproduction of the various eccentric jaw positions and reliably return models of the jaws to a predetermined "centric" position.

Non-arcon articulators include those which incorporate the condylar spheres on the upper beam and the condylar housings in the lower beam. It has been determined that in most circumstances the arcon and non-arcon articulators produce identical results in the end, but the arcon is considered more easily understood. However, all articulator systems devised have failed to address the fact that in a large percentage of cases there is an unphysiologic relationship between the condyles and fossae which can be corrected or treated by permitting the condyle/fossa spatial relationship to be adjusted. In other words, it may be determined that a particular case may benefit from a decompression of the temporo mandibular joint space. No articulator has yet been devised which offers this possibility.

This invention relates to an apparatus for articulating models of human or animal jaw structrues for the purpose of orthoenathic surgical diagnosis, fabricating prostheses, fabricating construction bites, analyzing occlusion, and diagnosing and treating temporomandibular joint problems.

The object of the present invention, the lokus articulator, is to provide a range of adjustment for the decompression and/or repositioning of the condylefossa relationship. This dramatically simplifies diagnosis and treatment especially in cases with problems relating to malpositions or dislocations of the jaw joints.

In addition, the unique capability of this new device to be adjusted in three planes of space for each condyle allows for positive diagnosis and repositioning of patient models for reconstructive or orthoenathic jaw surgery.

With the above and other objects in view, the present invention consists of the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawing and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportions and minor details of construction without departing from the spirit or sacrificing any of the advantages of the invention.

FIG. 1 is an isometric view of the articulator according to the invention with a face bow shown in phantom.

FIG. 2 is an enlarged side view of part of the articulator.

FIG. 3 is an enlarged top view of a part of FIG. 1.

FIG. 4 is a side view of the articulator.

FIG. 5 is an enlarged side view of a part of the articulator.

FIG. 6 is an enlarged partial side view of a part of the articulator.

FIG. 7 is a top view of the articulator.

FIG. 8 is a front view of the articulator.

FIG. 9 is a rear view of the articulator.

FIG. 10 is an enlarged partial top view of another embodiment of the invention.

FIG. 11 is an enlarged partial front view of the embodiment of FIG. 10.

FIG. 12 is an enlarged partial side view of the embodiment of FIGS. 10 and 11.

FIG. 13 is an enlarged partial side view of the embodiment of FIGS. 10-12.

FIG. 14 is an enlarged partial side view of the embodiment of FIGS. 10-13.

FIG. 15 is a side view of another embodiment of the articulator.

FIG. 16 is a top view of the embodiment of FIG. 15.

FIG. 17 is a front view of the articulator of FIG. 15.

FIG. 18 is a rear view of the articulator shown in FIG. 17.

Now with more particular reference to the drawings, the articulator 10 comprises the upper frame 11 and the lower frame 12. The upper frame 11 is made up of the upper beam 13 having an upper arm 15 attached thereto and extending forwardly therefrom. An incisal pin 17 is fixed to the forward end of the upper arm 15 and extends downwardly therefrom. The first downwardly extending bracket 20 is fixed to the first end of the upper beam 13 and a second downwardly extending bracket 21 is fixed to the second end of the upper beam 13. A first support or model ring 29, a dental mounting plate is fixed to upper arm 15 and a second support 30, a dental mounting plate is fixed to lower arm 16.

The lower frame 12 is made up of a laterally extending beam 14 having a first end and a second end and a lower arm 16 is fixed to the lower beam 14 and extends forwardly generally parallel to the upper beam 15. Lower beam 14 has upwardly extending posts 22 and 23 fixed to its ends and slider joints 21' are slidably received in posts 22 and 23. Spaced, preferably conical shaped, orifices 24 are formed in the first downwardly extending bracket 20. In the examples shown, the sliders are dovetail shaped but they could be of different shapes such as T-shaped, cylindrical or square. FIG. 5 shows a downwardly extending bracket 21 with two rows of conical orifices spaced 1 mm apart, the lower orifices staggered to be disposed between the upper row. The two rows are 4 mm apart. FIG. 6 shows a bracket 20 with eight rows with staggered orifices 2 mm apart. The styluses 18 and 19 are threadably received in the dovetail shaped slider 21' which slides vertically in slot 22' which is complementary in shape to the slide. The points of the styluses 18 and 19 are received selectively in the orifices 24, 24A, 25, 25A-25G. The vertical position of the styluses 18 and 19 can be controlled by moving the dovetail shaped slider 21' up or down by loosening the set screws 31 and 31A and allowing the dovetail shaped slider 21' to slide variably in the slots 52. Thus the ends of the upper beam can be individually adjusted horizontally relative to the lower beam by adjusting the styluses 18 and 19 to the desired orifice in the rows of orifices 24 and 25. The beams can also be adjusted vertically to the desired position by adjusting the dovetail shaped slider 21 up or down, and locking it in this position by the set screws 31 and 31A and with the double hex nuts. The adjustment is made to raise the ends of the beam 13 simultaneously or to raise one end relative to the other, to achieve the exact desired position of the styluses 18 and 19 to the support brackets. In addition, the styluses can be adjusted laterally by loosening the double hex nuts and turning one stylus clockwise and the other counter clockwise. This allows the alignment of midlines of mounted models. Loosening of hex screws allows the model ring 29 to be rotated thus allowing rotation only of the maxillary model.

In the embodiment of the invention shown in FIGS. 10 through 14, I show an adjustment for each end of beams 113. Downwardly extending brackets 120 and 121 are provided with adjustments similar to the adjustments on a sight of a rifle. Brackets 120 and 121 have orifices 124, similar to the orifices in brackets 20 and 21 in the embodiment of FIGS. 1-9.

The styluses 118 and 119 are simliar to the stylus 18 shown in the embodiments of FIGS. 1-8 are threadably received in vertical slides 132 and are locked in position by lock nuts 127 and 128 which are similar to the lock nuts 27 and 28. A stylus carrier 132 and 133 replace the sliders 21 of the first embodiment. The horizontal slides 133 are carried on vertical slide 132. Horizontal slide 133 is slidably supported on vertical slide 132 and moves up and down with it. The vertical slide 132 is slidably supported on each upwardly extending post 122.

When the instrument is assembled, each of the points of each of the styluses 118 and 119 engage the selected orifices 124 in the bracket 120. The styluses 118 and 119 may be both adjusted individually to the horizontal plane, the vertical plane and the lateral plane.

In the embodiment of the invention shown in FIGS. 15 through 18, I show an articulator 210 that uses both a vertically slidable dovetail member and a horizontally slidable dovetail member and pivot means for connecting the lower beam to the upper support posts. This embodiment shows an articulator 210 which has styluses 218 and 219, vertical dovetail shaped sliders 251. The styluses 218 and 219 are supported on the dovetail slider members 251 in the slots in the downwardly extending brackets and the points of styluses 218 and 219 engage the horizontal siders 232 provide a pivot means. Each slider and each slot which receives it could be made in any suitable shape.

The upper frame 211 is made up of upper beam 213 having upper arm 215 fixed to it and brackets 220 and 221 fixed to its ends. Lower frame 212 is made up of lower beam 214 with upwardly extending brackets 222 and 223. The first mounting plate 229 is fixed to the upper arm 215 and the second mounting plate 230 is fixed to the lower arm 216. An incisal pin 217 is fixed to the forward end of the arm 215 and extends downwardly therefrom and rests on arm 216. Vertical dovetail shaped slider members 251 are verticaly slidably received in dovetail shaped slots 254 formed in posts 222 and 223. The styluses 218 and 219 are threadably received in dovetail slider member 251. The points of the styluses 218 and 219 engage the horizontally extending horizontal dovetail slider members 232 which may be made of a relatively soft metal, such as aluminum, so that the points of the styluses 218, in effect, when tightened form orifices in the aluminum material slider member 252 which are locked in position by set screw 231. The points of the styluses have a friction fit in the aluminum dovetail slider material when they are tightened. The vertical position of the styluses 218 and 219 can be controlled by moving the vertical slider members 251 up and down by first loosening the set screws 231 and moving the dovetail shaped sliders 251 upwardly or downwardly in the slots 254. The upper beam 211 can be adjusted horizontally by sliding horizontal dovetail members 252 forwardly or rearwardly in slots 253 and can be adjusted horizontally relative to the lower beam by adjusting horizontal dovetail sliders 252 in their slots in brackets 220 and 221. Thus the articulator can be used with universal adjustment and can be readily made.

The instrument is set according to radiographic and gnathologic considerations. A transcranial radiograph of the patient's temporomandibular joints is first obtained. Clinical examination, radiographic evaluation, and past history will determine if the patient requires condylar repositioning or decompression. The transcranial radiograph is then traced on acetate and a point is inserted on the condyle for reference. The corrected condylar position is obtained by superimposing a second condylar tracing in the desired position. The difference in position of the two points can be easily determined, converted into vertical and horizontal components, and the stylus repositioned vertically and horizontally to instantly obtain the same corrected relationship between the upper beam 13 and lower beam 14. This in turn would reposition jaw models previously mounted on the supports in the intercuspal position, to a corrected therapeutic position which would reflect the clinically and radiographically determined repositioning. A cephalometric evaluation can be used to adjust the incisal guide pin for the correct anterior vertical dimension. Thus it is possible to correct each condyle to its appropriate vertical dimension on an individual basis and simultaneously incorporate the ideal anterior vertical dimension. The models of any patient can ben then mounted on this articulator and manipulated at will to any jaw position. This can be done repeatedly, is reproduceable, and the models can be returned to their exact original position with no difficulty. No other device or articulator yet devised allows this ease of adjustment, reproduceability of settings or the potential to adjust for posterior and anterior vertical dimension.

Once the corrected position is obtained and the jaw models are related in a therapeutic position, a compound or wax occlusion record is fabricated by softening the material, placing it between the models, and gently closing the articulator. The cooled record is then transferred to the patient's mouth and he is directed to carefully close into the record. Minor fine tuning adjustments can be accomplished by carefully heating the maxillary occlusal surface and manipulating the patient to close in the desired position. Additional transcranial films are taken to confirm that the condyles are in the desired position and the above procedure is repeated as needed until the desired result is obtained. The articulator is readjusted and the instrument is locked. If the patient is edentulous, the procedure can easily be performed on wax occlusion rims.

This invention can accept facebow registrations from any major make of facebow, such as the facebow shown in phantom in FIG. 1, and can be adapted to accept any type of mounting rings. It is designed in such a way that the upper model with mounting ring attached can be transferred to another articulator intact. This would require remounting the lower model only, utilizing the therapeutic record. The appliance or prosthesis is then completed on the articulator of choice. In many instances the work can be completed on the lokus articulator.

The foregoing specification sets forth the invention in its preferred, practical forms but the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood is broadly novel as is commensurate with the appended claims.