Articulator

Abstract

To provide an articulator that reproduces progress of cooperative transition from an entire movement axis to a minimum movement axis and, thereby, is capable of accurately reproducing a path of mandibular movement.SOLUTION: An articulator capable of reproducing a unique jaw position, positional relation between upper and lower angles, and jaw movement of an individual patient with clinically sufficient accuracy is configured to be capable of reproducing human basic jaw movement by including a condylar ball forming an entire movement axis at an average condylar position of subjects having healthy mandibular movement as a first rotation center axis 1 and providing a second rotation center axis 4 in a region in which an average minimum movement axis of the subjects having healthy mandibular movement exists and by making positions of the respective rotation center axes be adjustable in the average regions.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a dental articulator used to set and fix an upper jaw model and a lower jaw model to study and diagnose a patient's jaw ridge, dentition, occlusion condition, jaw movement, etc., and / or to maintain the position between the upper and lower jaws of a patient or reproduce jaw movement in order to treat temporomandibular joint disorders and / or to fabricate prosthetic devices, orthodontic devices, etc. [Background technology]

[0002] Generally, articulators are used for various diagnoses and the production of prosthetic devices by maintaining the positional relationship of the patient's upper and lower jaws and teeth, and have a central axis of rotation for the upper and lower arches at positions corresponding to the mandibular condyles on the left and right sides of the patient's mandible. Alternatively, the upper and lower arches are connected by a hinge at an appropriate point behind the upper and lower jaws. With this type of articulator, it can be freely rotated in any direction by loosening the hinge set screw. Both types of articulators use such mechanisms to allow the upper and lower jaws to be opened and closed.

[0003] Articulators with various shapes and mechanisms have been developed depending on the purpose of use, including those that can reproduce specific occlusal positions, such as centric occlusion, and those that can reproduce jaw movements such as lateral movement and anterior gliding movement. Some devices have an adjustment mechanism on the condylar ball to reproduce the patient's specific jaw movement as needed, or to reproduce the movement of the mandible due to opening / closing or lateral movement. Depending on the number and type of adjustable parameters, they are broadly classified into simple articulators, average value articulators, semi-adjustable articulators, and fully adjustable articulators.

[0004] The simplified articulator is not intended to reproduce the exact path of jaw movement, but is suited to hold upper and lower jaw models and allow simple opening and closing movements to allow minimal movement to facilitate the prosthetic device manufacturing process.

[0005] The average value articulator fixes the elements of mandibular movement to the anatomical average value. Among adjustable articulators that can adjust and reproduce individual differences in the movement elements that make up mandibular movement, such as the condylar path and incisal path, a semi-adjustable articulator is an articulator that can reproduce only some of the mandibular movement elements.

[0006] In addition, the fully adjustable articulator is an articulator in which all elements of mandibular movement can be adjusted and reproduced. The surgeon selects and uses the necessary type of articulator from among a fully adjustable articulator, a semi-adjustable articulator, a simplified articulator, etc. according to the purpose of use. In order to manufacture a prosthetic device that matches the patient's mandibular movement, it is thought that using an articulator that can adjust and reproduce more mandibular movement elements tends to produce better results, but this is not necessarily the case. In reality, there are errors in the adjustment and reproducibility of each mandibular movement element, and as the number of mandibular movement elements handled increases, it becomes more difficult to operate the articulator, requiring more advanced knowledge and experience about occlusion, and more time is required for operation, making it extremely difficult to reproduce with a certain level of accuracy within a limited time.

[0007] When using an adjustable articulator, it is common to attach the upper jaw model to the upper arch using a face bow, and the lower jaw model to the lower arch using bite wax obtained in the intercuspal position. However, it is said that for approximately 80 percent of modern people, the intercuspal position and the condylar rest position are in different positions, and the reality is that when a mandibular model is placed in the intercuspal position, the patient's Bonwill triangle does not exist in the model on the articulator.

[0008] Regardless of the number of adjustable parameters, well-known problems that have been pointed out in the past include the inability to accurately reproduce the position of the condyles during opening and closing movements, and the occurrence of molar separation that differs from the actual movement.

[0009] For this reason, various prosthetic devices, dentures, orthodontic devices, etc., manufactured using conventional articulators in which the center of rotation is mechanically fixed are adjusted and manufactured within a mandibular movement system that is different from the patient's unique jaw movement. Therefore, when actually fitting them to a patient, adjustments and corrections must be made within the oral cavity, especially for the occlusal surfaces of the molars where the upper and lower teeth come into contact and bite.

[0010] Furthermore, when the patient's jaw movement, which is precisely reproduced using 6-DOF mandibular movement measurement data, is applied to the space reproduced on a conventional articulator, in the case of a patient with an abnormality in the temporomandibular joint, all of the movement axes do not converge near the mandibular condyle, which poses a serious problem in that the surgeon is presented with information such as opening and closing movements, occlusal planes, and occlusion of the upper and lower teeth that are completely different from reality.

[0011] Due to these issues, prosthetic devices made with a conventional articulator generally require extensive adjustment work after being fitted in the patient's mouth. It is necessary to repeat the process of making small adjustments and checking the condition, and since this work requires careful attention, it is not uncommon for it to take a long time, which places a great burden on both the patient and the surgeon. Naturally, if the amount of adjustment is large, the occlusal height will change from when it was fitted to the model on the articulator during the adjustment process, and after adjustments in the patient's mouth, when the device is returned to the articulator for final adjustments and confirmation, the occlusal height will be lower than before the adjustment, and the patient's occlusal height may not be accurately reproduced. In this case, the only option is to consider the difference in the occlusal height before and after adjustment as an error and adjust the actual dimensions in the patient's mouth.

[0012] For patients with abnormalities in the shape, movement, or path of opening and closing movement of the temporomandibular joint, it is necessary to thoroughly consider whether the occlusal plane is appropriate before fabricating a prosthetic device, and if not, where it should be set. However, as long as conventional articulators are used, there is a large room for error in the judgment and diagnosis, and in most cases it cannot be used as a basis for determining the occlusal plane that can be fully trusted for accurate treatment.

[0013] In addition, in treatment to reconstruct the occlusal plane, it is important to compare the progress of treatment before and after and to judge whether the current state is desirable or not, but conventional articulators provide insufficient information to make a well-founded judgment. In such cases, as long as an articulator that cannot accurately reproduce jaw movement is used, it is practically difficult to evaluate and set the occlusal plane based on evidence, and in practice, the surgeon has no choice but to make a subjective decision based on knowledge and experience, taking into account morphological and aesthetic factors.

[0014] There is no basis or guarantee that this is correct, and in fact, when trying it out in the patient's mouth, unexpected contact between the upper and lower teeth and incorrect occlusal movement induction phenomena often occur, so it has become common practice to make adjustments by fitting the actual product.

[0015] To solve this problem, Patent Document 1 places the junction of the upper and lower arches at the same height as a virtual plane extending backward from the occlusal plane, solving the problem that the second molar comes into contact in a different direction earlier during opening and closing movements compared to when the patient's upper and lower jaws actually open and close. However, when the mouth is closed, the upper and lower arches join at a position different from the natural position of the condyles, so if lateral movement is performed in this state, the movement will be in a different direction than in the actual patient's mouth, resulting in the problem of a new movement path that is different from the actual situation.

[0016] Furthermore, the patient's mouth opening and closing movement begins with the mandible opening around the total movement axis, and as the mouth opening amount increases, the total movement axis rotates while moving forward and downward from the mandibular head. In other words, the rotation axis moves in translation, but the mouth opening movement that can be reproduced by the articulator in Patent Document 1 is a hinge movement (hinge axis), so there is no mechanism for translating the axis in response to an increase in the mouth opening amount. Therefore, the articulator of Patent Document 1 could not be used for purposes such as designing or adjusting the occlusal surface of a prosthetic device, or for treating patients with temporomandibular joint disorders or observing their progress in treatment, even if it was necessary to accurately reproduce opening and closing movements.

[0017] Non-Patent Document 1 describes the existence of the axis of minimum movement, how to calculate its position, and its academic significance. It is an extremely useful theory and knowledge for reproducing the patient's mandibular movement more accurately than ever before, and can determine the appropriate transition time for the treatment step of temporomandibular joint disorder, and can reproduce the accurate state of separation of the molar occlusal surface, which could not be reproduced with conventional articulators. Although it is now possible to achieve the above effects through computer simulations, until now there has been no actual device capable of reproducing this theory and knowledge, and so it has not been possible to fully apply and utilize this theory and knowledge in clinical practice. [Prior art documents] [Patent documents]

[0018] [Patent Document 1] Patent No. 5688620 [Non-patent literature]

[0019] [Non-Patent Document 1] Dental Echo Vol. 188 ~ 191 (published July 2017 ~ March 2018) combined edition Summary of the Invention [Problem to be solved by the invention]

[0020] Conventional articulators could only reproduce the positional relationship between the upper and lower jaws at the time of impression taking, and as a result, the positional relationship between the upper and lower jaws could only be maintained in the terminal position during limit movements such as the intercuspal position, centric position, and lateral limit position.

[0021] Furthermore, the path of mandibular movement could not be reproduced, and the dynamic path of movement of the upper and lower jaws and the contact relationship between the teeth and the prosthetic device could not be reproduced accurately.

[0022] As a result, prosthetic devices must be manufactured based on the positional relationship between the upper and lower jaws in the terminal position. After manufacture, the prosthetic device must be tried out in the patient's mouth, and the jaw must be moved, and / or manual adjustments must be made to maintain the desired positional relationship and opening angle. This adjustment work requires skill and accurate capture and reproduction of the jaw movement of each individual patient, but it is extremely difficult for dentists to perform this adequately in an actual clinical setting due to factors such as constraints on treatment time and a lack of skill and knowledge in technical work. Even when dental technicians use conventional articulators to create prosthetic devices, they are unable to objectively confirm and reproduce the patient's jaw movement on the articulator. Therefore, even if aesthetics can be adequately reproduced, it is difficult to create a functional prosthetic device that does not impair the patient's unique jaw movement and has an occlusal surface and occlusal relationship that provides high chewing efficiency. [Means for solving the problem]

[0023] The object of the present invention is to provide an articulator that can reproduce both the total movement axis, which is the axis of rotation near the mandibular head, and the minimum movement axis which minimizes the translational movement of the entire mandible, in order to reproduce human sagittal plane movement with an articulator, which has problems with the prior art, thereby capable of reproducing the path of mandibular movement with high precision.

[0024] The articulator of the present invention is characterized in that it is an articulator having a first rotation center axis and a second rotation center axis, and the first rotation center axis indicates a condylar sphere forming a total movement axis at the average condylar position of a subject with healthy mandibular movement, and the second rotation center axis is located within an area where an average minimum movement axis of a subject with healthy mandibular movement exists.

[0025] In addition, it is preferable that the first rotational center shaft is placed on a slider and is capable of rotational movement and parallel sliding movement, the second rotational center shaft is in contact with a bracket, and the second rotational center shaft and the bracket are provided with an adjustment mechanism that can move and fix them in the vertical or front-rear direction, respectively. Here, it is preferable that the adjustment mechanism can adjust the position of the second rotational center shaft and the bracket over a width of 15 to 30 mm in the vertical or front-rear direction, respectively. The adjustment mechanism is arbitrary, and can be provided with a screw, or a ratchet mechanism, a quick release mechanism, a slide lock function, a snap button, or other appropriate locking / releasing function. As shown in Figures 5 and 6, it may be a slide-type adjustment mechanism.

[0026] During occlusal adjustment, particularly when the axis of minimum movement in the intercuspal position is used as the reference, it is preferable to provide a mechanism for releasing the fixation by removing or loosening a component that includes the first rotation axis.

[0027] In addition, it is preferable that the first rotating shaft and the second rotating shaft each have a mechanism capable of adjusting and maintaining the positional relationship. The mechanism capable of adjusting and maintaining the positional relationship is arbitrary, and examples thereof include a screw or ratchet mechanism, a quick release mechanism, a slide lock function, a snap button, and other suitable locking / releasing functions. In addition, a spring or elastic member may be interposed between the bracket, the upper bow, or the lower bow and the shaft as necessary.

[0028] It is preferable that at least one of the first rotation axis, the second rotation axis, the upper arch, the lower arch, and the mechanism for connecting the upper arch and the lower arch is provided with a mechanism capable of reproducing any positional relationship related to occlusion obtained from a patient. Specifically, it is preferable that the upper arch, the lower arch, and the mechanism for connecting the upper arch and the lower arch is provided with a mechanism capable of setting the midline, occlusal plane, and orbital base point obtained from a patient to reproduce the positional relationship of each of the above-mentioned parts of the patient, and capable of rotating the first and second rotation central axes in cooperation at a correct angle so as to accurately reproduce mandibular movement.

[0029] The device is configured to reproduce basic human jaw movements by having a first central axis of rotation that is a condylar ball that forms the total axis of movement at the average condylar position of a subject with healthy mandibular movement, and by setting a second central axis of rotation within the area where the average minimum axis of movement of a subject with healthy mandibular movement exists, and the position of each central axis of rotation is adjustable within the average area, thereby configuring an articulator that can reproduce the unique jaw position, vertical angle positional relationship, and jaw movement of each individual patient with sufficient clinical accuracy. Here, the first rotational axis is rotatable and is located on a slider capable of parallel sliding motion. The second rotational axis is equipped with a bracket that receives the second rotational axis, and the first rotational axis corresponding to the total motion axis has a rotational bearing that can move parallel along the cusp inclination angle. The bearing of the second rotational axis corresponding to the minimum motion axis is not fixed to one point, and is configured with a radius larger than the radius of the second rotational axis ball so that it can move freely within a certain area. This allows free movement within the range that can be taken within the constraints of the first rotational axis. Furthermore, the upper and lower arches can be attached and detached, opened and closed, and slid in either the minimum motion axis or the total motion axis, making it possible to accurately reproduce human jaw movement. By linking the two rotational axes in this way and allowing them to move freely within a certain range, it is possible to reproduce the path of mandibular movement. In addition, by operating this articulator using the mandibular movement data, it becomes possible to perform simulations using the actual situation. This function allows the surgeon to understand and grasp the patient's jaw movement three-dimensionally and intuitively, and it makes it possible to objectively know the goal setting and the degree of achievement of the goal in the diagnosis, treatment, production of prosthetic devices, and adjustment work. Effect of the Invention

[0030] It is possible to accurately reproduce the complex movements of the human jaw, including not only each limit position but also the path. The current occlusal plane can be evaluated morphologically and functionally when attached to an articulator. It serves as an indicator / standard for setting the occlusal plane during oral rehabilitation. Since the position and convergence range of the patient's specific axis of minimum movement (the range of movement of the axis of minimum movement) can be reproduced on the articulator, it is possible to identify areas where excessive occlusal pressure is applied and to confirm the degree of reduction in the convergence range of the axis of minimum movement over time, thereby reproducing and confirming the indicators for determining whether or not to proceed to the next treatment step outside the patient's mouth.

[0031] In indirect technique, the occlusal behavior in the functional range can be simulated. As a result, a prosthetic device that allows normal opening and closing movements without any improper tooth interference can be easily fabricated.

[0032] In the case of edentulous patients, the occlusal vertical dimension cannot be determined by taking an impression alone, so it was necessary to first set the occlusal plane using the average value. However, if the patient's specific occlusal plane can be set from the results of analytical calculations using total movement axis and minimum movement axis data, it will be possible to produce complete dentures with the occlusal plane actually reproduced using the articulator of the present invention.

[0033] There are many patients for whom the axis of least movement and the axis of total movement are not parallel, but the articulator of the present invention can reproduce the positional relationship of these two axes, and can therefore be used to plan a series of treatments to bring the axis of least movement and the axis of total movement closer to parallel, to plan treatment for temporomandibular joint disorders, to reproduce the actual treatment progress, and to create treatment tools and prosthetic devices that are optimal for that positional relationship.

[0034] The second rotation axis and bracket can be positioned independently on the left and right sides, so that the direction and distance of mandibular movement caused by the contraction and contraction of the masticatory muscles can be accurately reproduced independently on the left and right sides, making it possible to reproduce an integrated series of mandibular movements with extremely high precision. [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 is a schematic diagram showing a structure of an articulator according to the present invention. [Diagram 2] 1 is a conceptual diagram of a conventional articulator with one rotation axis. [Diagram 3] The appearance of the open mouth state reproduced by the articulator according to the present invention. [Figure 4] FIG. 13 is a comparative diagram showing the positions of the rotation center points when reproducing the closed and open states of a conventional articulator and an articulator according to the present invention, and shows that the conventional articulator cannot reproduce molar separation, but the articulator of the present invention can. [Diagram 5] Schematic diagram of a mechanism for adjusting the position of the second central axis of rotation up and down and forward and backward. [Figure 6] A conceptual diagram of the light-emitting part and indicator needle that make it easy to reproduce the patient's upper and lower jaw opening state at any given time. [Explanation of symbols]

[0036] 1. First rotation axis (total motion axis) 2 Slider 3 Bracket 4 Second rotation axis (axis of least movement) 5 Upper bow 6 lower bow 7 Incisal Pin 8 Incisor Guide Pin 9 Plaster model of the upper jaw 10. Plaster model of the lower jaw 11 Rotation axis 20 Indicator needle 21 Display section 22 Indicator needle 23 Display section 24 Display DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The device is configured to reproduce basic human jaw movements by having a first central axis of rotation that is a condylar ball that forms the total axis of movement at the average condylar position of a subject with healthy mandibular movement, and by setting a second central axis of rotation within the area where the average minimum axis of movement of a subject with healthy mandibular movement exists, and the position of each central axis of rotation is adjustable within the average area, thereby configuring an articulator that can reproduce the unique jaw position, vertical angle positional relationship, and jaw movement of each individual patient with sufficient clinical accuracy. The two rotational axes are each equipped with a slider capable of rotating and sliding in parallel, and a bracket that receives the rotational axis, and the upper and lower arches can be attached / detached, opened / closed, and slid on either the minimum movement axis or the full movement axis, thereby making it possible to accurately reproduce human jaw movement.

[0038] The effects of the articulator according to the present invention will be described below.

[0039] Because of the existence of the condylar path angle, the axis of minimum motion does not converge to a single point but has a certain range of motion. Also, the axis of minimum motion is not necessarily parallel to the axis of total motion. To recreate this When the axis of minimum movement in the intercuspal position is used as the reference, the device is equipped with a mechanism for removing and / or freeing the conventional condylar path portion that includes the first central axis of rotation during occlusal adjustment. Specifically, mechanisms for fixing a part to be fixed in a desired position, or for loosening a part to be loosened, can include a mechanism that uses a screw to loosen or tighten, a one-touch lever, a ratchet mechanism, a holding mechanism that uses a spring, and if a drive mechanism is provided, a method of braking the drive mechanism electrically, pneumatically, or hydraulically.

[0040] The display unit may be provided with a pointer that functions as an index for rotating the two rotation axes correctly and a pointer for aligning the pointer. The display unit may be provided with multiple LEDs arranged so that it has the resolution required to indicate the position by itself, or a liquid crystal display element may be used. An element at a desired position in the display unit is lit or its color tone or brightness is changed by a control signal obtained by back-calculating from the movement path data obtained by measuring the mandibular movement, and the surgeon can move the lower arch together by aligning the pointer there, so that the upper arch and the lower arch are in the correct position. FIG. 7 is a schematic diagram for explaining this situation. An indicator 20 is provided that always faces vertically from the center of the first rotation axis, and by aligning this indicator 21 with a line displayed on a display unit 21 attached to the slider, the position of the first rotation axis at a certain moment can be reproduced. At the same time, by aligning an indicator 22 attached from the slider toward the first rotation axis with a line displayed on a circular arc-shaped display unit 23 attached to the first rotation axis, the opening angle of the first rotation axis at the same moment can be reproduced. Furthermore, by aligning the horizontal line displayed on the circular display unit 24 attached to the second rotation center axis with the mesial end of the bracket and adjusting the opening of the lower arch so that the vertical line is vertical, the position and opening angle of the second rotation center axis can be reproduced. This makes it possible to accurately reproduce the relative positions of the patient's upper and lower jaws at any given moment during opening and closing movements.

[0041] An appropriate number of driving mechanisms such as motors and actuators driven by an appropriate power source such as electricity, air, hydraulics, bimetal, etc. may be attached to the rotating part, sliding part, upper arch, and lower arch of the articulator of the present invention, and the above driving mechanisms may be driven by a control signal obtained by back-calculating from the movement path data obtained by measuring the mandibular movement, thereby making it possible to automatically reproduce the patient's jaw movement without the surgeon having to manually operate the articulator of the present invention.

[0042] In addition, jaw movement measurement data obtained for research or dental treatment, shape data of the patient's oral cavity obtained by an intraoral scanner, shape data obtained by scanning a replica model of the patient's oral cavity made by taking an impression of the patient's oral cavity and pouring plaster into it and letting it harden, CT data, and other necessary data are input into an occlusion simulator reproduced on a PC to reproduce the patient's mandibular movement, chewing movement, and other biological movements, and the method of using them for treatment and research is becoming more and more popular with improved performance every year, but If a simulator with the same structure is reproduced in a PC, the same data obtained from the patient can be used to simulate treatment and conduct research, and the knowledge, diagnosis, and design results obtained there can be utilized in the articulator of the present invention for treatment, exercise therapy, and the manufacture of prosthetic devices. In this case, accurate and precise diagnosis, treatment, and research can be made possible by transferring, reproducing, and adjusting the electronic information in the PC as a real thing on the articulator of the present invention.

[0043] By providing storage areas in which multiple markers can be placed on each of the upper and lower arches, and reading the positions and movements of these markers with a camera to convert the path of the patient's mandibular movement into electronic data, the data can be used for preoperative simulations and for comparing and analyzing changes in mandibular movement before and after treatment. In this case, three or more markers are preferable. At this time, if a prosthetic device is also produced on the articulator, the improvement obtained by continuous treatment using the prosthetic device can be confirmed in advance using the actual prosthetic device that will be worn by the patient.

[0044] For example, such a method of use involves reproducing the state of a patient in which the first and second rotation axes are significantly out of parallel, performing mandibular movement, reading the movement of the marker with a camera, and calculating the mandibular movement path data, and then performing mandibular movement assuming a state in which the first and second rotation axes are almost parallel as treatment for temporomandibular joint disorder progresses, recording the movement of the marker with a camera, and calculating the mandibular movement path as well, and comparing and examining the two, thereby simulating the state of the jaw after treatment or using it as various research materials. Once the patient's jaw movement is acquired, the state can be reproduced anytime and as many times as the articulator of the present invention, and it can be used for many purposes such as effective treatment, research, and training of surgeons while predicting the state after treatment. [Industrial Applicability]

[0045] This is a dental articulator for diagnosis, treatment, and research, and is also for industrial use.

Claims

1. An articulator having a first rotation central axis and a second rotation central axis, The first rotational axis corresponds to the condylar sphere which constitutes the axis of all motion; The second rotation axis corresponds to an axis along which the translational movement of the entire mandible during mandibular movement is minimized, The first rotation axis is connected to the upper bow, The second rotation axis is connected to the lower bow, The first rotation center shaft is placed on a slider, The slider is connected to the lower bow, The second rotation axis is in contact with the bracket, The bracket is connected to the upper bow, the bracket has a radius larger than a radius of the second rotation axis; the second rotation axis is movable within the bracket; When opening around the first rotation central axis, the opening can be opened within a range limited by the second rotation central axis. Articulator.

2. An articulator as described in claim 1, having an adjustment mechanism that allows the second rotation center axis to move vertically or horizontally.

3. An articulator as described in claim 1, having an adjustment mechanism that allows the bracket to move vertically or horizontally.

4. An articulator as described in claim 2, having a mechanism that can fix the second rotation center axis after it is moved.

Images