Method of manufacturing a working model of belonging together maxillas and mandibles

Abstract

A correlator for a working dental model comprises a hinged two-part body having a pair of abutting planar faces and a pivot axis lying in the common plane of the abutting faces. Each of the hinged parts has a set of mounting pins extending from it; the pins on one of the parts being parallel to the common plane, while the pins on the other are perpendicular to the common plane. These pins are so located that, when previously-made casting from dental impressions are further cast to the two-part body to include the respective mounting pins, an adjustable, articulated working model of a patient's entire mouth, capable of disassembly and reassembly without introduction of inaccuracies is obtained.

Description

The present invention relates to a method of manufacturing a working model of belonging together maxillas and mandibles, by which casts of a patient's teeth in the upper-and lower part of the mouth are attached to a jointing member.

By crown and bridge works it is necessary to use a working model matching a patient's maxilla and mandible, as it is hereby possible to make, by way of example, checks and adjustments during the work without patient's presence.

Such a working model is made on a basis of casts of the patient's teeth in the upper-or lower part of the mouth with appurtenant antagonist model or reproduction index, and the two casts are held together by means of a suitable member, an occludator, in mutually correct position.

In a known method the two casts are cast to each its own of two hinged arms, while held in mutually correct position. These two arms of the occludator are rotatable about a common axis and possess co-operating adjustable stopping members, so as to prevent the arms from moving nearer to each other than by the casting.

The use of known occludators is rather troublesome and in many cases it does not secure a satisfactory accuracy. By mailing of the working model, e.g., from a dentist to a dental technician and when stored the two jaws are cast to the occludator, and the model is consequently bulky. In use there is further a risk, that a mutually correct position of the two casts is not obtained every time when the two arms have been moved, partly because the stopping members of the arms may have been displaced, and partly because it is difficult to recognize whether the position is correct.

The object of the present invention is to provide a method of manufacturing a working model of the said type, in which two jaw casts or a jaw cast and an antagonist model, reproduction-or articulation index can be fixed on and removed from a jointing member at any time, with the security of always obtaining a mutually correct position.

This is according to the invention achieved by the method provided in the claim.

A working model made according to the method with two jaw casts can be taken apart in the two jaw casts with cast in bushings and the jointing member, which may simply be e.g., a plastic block. When taking apart the one cast must first be removed in the direction away from the joint face. When reassembling the model, till the casts rest against the abutting faces of the jointing member, the two casts are with security in mutually correct position.

The invention will now be explained in details below with reference to the drawing, which illustrates in perspective the three main parts of a taken apart working model.

In the drawing is illustrated a cast 1 of a part of a patient's mandible and a cast 2 of the matching part of the maxilla. With two surfaces of a jointing member 3 as abutting faces the two jaw casts 1, 2 are cast over bushings 5' and 5", on which are mounted pins 4', 4", which are protruding from the abutting surfaces. The one set of pins 4" is essentially standing at right angles to the joint face of the jaw casts. When the casting material has hardened, first the one jaw cast 2 with the bushings 5" can be removed from the jointing member 3 and then the other cast 1, so that the two casts can be mailed or stored taken apart from the jointing member 3.

When the two jaw casts are later on placed on the jointing member 3 or a copy hereof, it is directly possible by considering the joint between the abutting surfaces of the jointing member 3 and the surfaces of the casts 1 and 2 resting here against to check, whether the mutual position of the casts is correct. Furthermore parallel raising or lowering of the patient's bite can be made.

By the method according to the invention has thus been made a working model, which can be taken apart and easily reassembled and with security for correct assembling. The working model is furthermore easy to store and to mail, because the jointing member can be removed and not has to be enclosed when the recipient has a matching member at disposal.

It appears from the above that the one jaw cast can be replaced by various index or antagonist models. The method is also very suitable for the manufacture of duplicate models.

Finally should be noted, that the said bushings can be replaced by corresponding co-operating slide guides.

According to the invention the jointing member can as indicated in the drawing be composed of two parts with each its own of the two abutting surfaces mentioned, which parts are embedded on a common pivot 6. Located on such a member the two casts 1 and 2 can be moved reciprocatingly in a manner corresponding to normal movement of the jaws. The mutually correct position of the castings 1, 2 in what is corresponding to the patient's biting his teeth together can be checked by considering the joint faces between the two parts of the jointing member.

Claims

I claim:

1. A method of producing a working dental model of related maxillas and mandibles of a patient's upper and lower jaws whereby cast of a patient's teeth and gum tissue on the upper and lower jaws are attached to an articulated correlator, said method comprising:

a. providing a two-part body having abutting planar faces, said parts being pivotable about an axis parallel to and lying within the plane of said abutting faces;

b. providing castings of impressions of a patient's upper and lower jaws;

c. aligning a first of said jaw castings with its occlusal plane in the plane of the abutting faces of said first named body and casting a base for said first jaw against a surfae of said body which includes fixed mounting means parallel to said abutting faces; and

d. aligning the second of said jaw castings with its occlusal plane in the plane of the abutting faces of said first named body and casting a base for said second jaw against a surface of said body which includes fixed mounting means perpendicular to said abutting faces, thereby producing a dental model which is capable of pivoting about said axis to simulate the patient's biting action, which is capable of disassembly and reassembly without altering the proper relative positions of said upper and lower jaw castings, and which is also capable of separate adjustment in directions parallel to and perpendicular to said occlusal plane to permit correction of a faulty occlusion and to permit adjustment and correction of prosthetic restorations without requiring the presence of the patient.

2. A correlator for a working dental model comprising:

a. a two-part body having abutting planar faces, said parts being pivotable about a common axis parallel to the common plane of said abutting faces, said common plane comprising the occlusal plane of related upper and lower jaws;

b. hinge means connecting said parts for mutual rotation of said parts about said common axis;

c. first mounting means extending from a first of said two-part body in a direction parallel to the common plane of the abutting faces for slidably and removably mounting a first of a pair of related jaw castings, whereby the position of said first jaw is adjustable in a direction parallel to said common plane;

d. second mounting means extending from the second of said two-part body in a direction perpendicular to the common plane of the abutting faces for slidably and removably mounting the second of a pair of related jaw castings, whereby the position of said second jaw is adjustable in a direction perpendicular to said common plane, said first and second mounting means being so located that when said jaw castings abut the respective parts upon which they are mounted, the edges of the teeth on said castings will lie in said common plane, said jaw castings being slidably adjustable on said mounting means to permit correction of a faulty occlusion, said hinged, two-part body simulating the articulated jaws of the patient when said jaw castings are mounted thereon, and being capable of disassembly and reassembly without alteration of critical locations of the respective parts.

3. A correlator as in claim 2 wherein the common axis lies in the common plane of the abutting faces.