JPH06269468A - Method for measuring and displaying mandibular position - Google Patents

Abstract

PURPOSE:To distinctly recognize the positions of teeth and the positions of denture by the correct orthodontics most approximate to the natural teeth by measuring the three-dimensional positional relations of the mandibular bone relative to the cranium or a reference position in accordance with the results of the articulation measurement by an articulator. CONSTITUTION:The data on the articulation measurement of the mandibular position of a person to be measured is determined by the articulator and the resulted data on the articulation measurement is analyzed by a computer. The total six-dimensional numerical values at arbitrary three points are given as the conditions necessary and sufficient for indicating the stereoscopic positions in the space and are then inputted along input terms at the time of this analysis. The image data on the three-dimensional positional relations of the mandibular bone is then formed by the data analysis. This image data and the previously stored data indicating the position in the ideal and correct articulation state of the teeth most approximate to the articulation state of the natural teeth are synthesized and displayed in superposition on a CRT. As a result, the positions of the teeth and the positions of the denture by the corrective orthodontics are objectively recognized.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is based on the result of occlusion measurement by a so-called articulator, which is a device for taking a tooth profile and simulating the occlusal state of the mandible. The present invention relates to a mandibular position measurement / display method that measures a positional relationship and displays it three-dimensionally.

2. Description of the Related Art Conventionally, there is an articulator known as a device for taking a tooth profile and simulating how the teeth are engaged with each other. This device is used for the analysis of occlusion of teeth, and denture creation (for example, actually occlude the created model of plaster etc. with this device,
It is used when making a denture according to the temporomandibular joint in the simulation), etc., and the tooth shape, tooth sprouting direction, occlusal state, etc. are all different for all humans. Therefore, it is an indispensable device for creating the most suitable denture for each person. Currently, several articulators have been developed, but the basic mechanism of the device is almost the same. By the way, in the field of dentistry diagnosis and treatment, since the mandible is anatomically separated from the skull and controlled by the neuromuscular system, the position of the mandible relative to the skull or the position of the mandibular condyle relative to the mandibular fossa. Normalizing or monitoring is the starting point for all dental treatments. That is, in the case of conservative prosthesis treatment, TMJ treatment, orthodontic treatment, surgical orthodontic treatment, etc., diagnosis and treatment are performed based on the position of the mandibular condyle with respect to the skull, and the progress etc. is monitored while performing an appropriate evaluation. It is necessary. Therefore, an articulator, which is the above-mentioned known device, has been conventionally developed for the purpose of measuring the correct position of the mandible close to nature. However, with the above articulator alone, the dentist will infer the position of the lower jaw from the two-dimensional mark of the flag used in the occlusion measurement, and for example, obtain a three-dimensional image such as the twist of the lower jaw. Was extremely difficult. Also, when observing the dynamics of the mandibular condyle from various directions for clinical consideration, it is the actual situation that the original function of the articulator cannot be exerted with the measured data of the articulator. It was In particular, recently, orthodontic dentistry for orthodontics has been frequently used, but in the present situation, what is the best tooth alignment and occlusion for each individual patient?
The reality is that there are still some unclear points. For example, when orthodontic treatment is completed, even if the patient is in a satisfactory state, the position of the mandible with respect to the skull or the position of the mandibular condyle with respect to the mandibular fossa is not normal and the joint of the mandible is abnormal. Because of the load,
A temporomandibular disorder may occur in which the temporomandibular joint becomes painful over time (for example, 6 months after completion of orthodontic treatment). In such a case, it is important to clearly specify the goal of what kind of occlusion should be made in orthodontic treatment, but the fact is that the articulation measurement using only the articulator cannot deal with this. The above-mentioned temporomandibular disorder means that there is some abnormal symptom in the temporomandibular joint, and the symptom is pain, discomfort, joint noise, dysfunction, or the like. The most important factor in considering temporomandibular disorders is the occlusion, which is composed of the left and right temporomandibular joints and the dentition, so the three-dimensional structure of the temporomandibular joint is suitable for treating temporomandibular disorders. It is necessary to understand and grasp exactly. Furthermore, although there are various types of temporomandibular disorders, most of them all require occlusal reconstructive treatment in the end. Since most of them are prosthetic treatments, treatment of temporomandibular disorders will be a waste if a proper prosthesis cannot be performed. Therefore, also in the treatment in this case, it is necessary to properly understand and grasp the three-dimensional structure of the temporomandibular joint as a prerequisite.

SUMMARY OF THE INVENTION The present invention has been developed in view of the above-mentioned conventional circumstances, and an object thereof is to determine a lower limit for a skull or a reference position based on an occlusion measurement result by an articulator. Measure the three-dimensional positional relationship of the jawbone and display it three-dimensionally, and determine the tooth position and denture position by correct orthodontic treatment that is the most natural and correct at the beginning of orthodontic diagnosis, orthodontic treatment, and denture creation. It is not based on the judgment of individual skill and intuition, but it can be used to perform orthodontics while always objectively and swiftly confirming, and can be used to create dentures. It is also useful as a method for measuring and displaying the mandibular position, which is useful for showing the patient how the current patient's jaw is in three dimensions, and for obtaining the patient's understanding of the treatment. It is to provide.

The invention according to claim 1 is
Based on occlusal measurement data by a known so-called articulator, which is a device that takes a tooth profile and simulates the occlusal state, measures the three-dimensional positional relationship of the mandible with respect to the skull or reference position, and measures it three-dimensionally. A method for measuring and displaying the lower jaw position, which is configured to display an image, and a step of obtaining occlusal measurement data of the lower jaw position of the measurement subject by the articulator,
When performing the occlusal measurement data analysis using a computer as the information processing of the occlusal measurement data, an arbitrary 3 as a necessary and sufficient condition for representing the position of the solid in the space
After giving a total of 6-dimensional numerical values at the points, inputting the occlusal measurement data along input items and analyzing the data to create image data of the three-dimensional positional relationship of the mandible. A method for measuring and displaying the lower jaw position, in which the created image data and the data, which is stored in advance and which shows the position of the ideal correct tooth occlusal state which is the most natural and which is stored in advance, are superimposed and displayed on a CRT. Is. The invention according to claim 2 is a method for measuring and displaying the lower jaw position, in which occlusal measurement data by the articulator is sampled in the order of steps as described in this claim. In the invention according to claim 3, the composite display is capable of confirming a three-dimensional positional relationship between the created image data and the data indicating the position of the ideal correct tooth engagement state which is the most natural. It is a mandibular position measurement and display method by composite display from the direction. According to a fourth aspect of the present invention, the composite display means of the created image data and the data indicating the position of the most correct and ideal ideal tooth occlusal state that is stored in advance is displayed in different colors. Mandibular position measurement so that it can be displayed
It is a display method.

According to the present invention as described above, the image data of the three-dimensional positional relationship of the mandible should be created by analyzing the data based on the occlusal measurement data obtained by the articulator. In addition to the measurement, it is possible to synthesize the image data created as described above with the data stored in advance that shows the position of the ideal correct tooth engagement state which is the most natural and can be superimposed and displayed on the CRT. as a result,
With the synthesized image display, the position of the tooth and the denture position by the correct orthodontic treatment that is the most natural at the beginning of orthodontics and denture creation should not be determined by each dentist's skill and feeling, but always objectively. It can also be used for orthodontics with quick confirmation and for making dentures, and can be used as a guideline for correct training after completion of orthodontics and dentures. Shows three-dimensionally, and can be effectively used to obtain the patient's understanding of the treatment.

EXAMPLES Examples of the present invention will be described below. In recent years, there has been considerable debate about whether or not the cause of temporomandibular disorders is occlusal abnormality. The present inventor has paid attention to the fact that temporomandibular disorders and occlusal abnormalities are very closely related to each other, and after many years of research on occlusal inspection and examination methods, the present invention has been developed. Many researchers and clinicians other than the present inventor have reported on occlusal inspection methods, but most of them use expensive inspection equipment, and it is difficult to read data by the equipment and diagnosed as not very familiar. It was common to not be able to. Further, most of the above-mentioned conventional occlusal examination methods have the inconvenience that it is impossible to grasp the movement abnormality of the entire lower jaw body because the measurement points are only incisor points. The present inventor narrowed down the jaw kinematical pathological condition of temporomandibular arthrosis to abnormalities at the intercuspal position, and used the previously known articulator such as SA.
M or PANADENT (device name of articulator manufacturer)
MPI or CP for mandibular position measurement in articulator
I system (system name, hereinafter "MPI or CP
As a result of investigating the twist of the mandibular body at the cusp-fitting position using the “I system”), it was found that it is difficult to grasp the actual situation in the actual temporomandibular joint part only with the measurement data of the MPI system. Therefore, the above MPI or CP
When I tried to visualize the measurement data of the I system and assist in the diagnosis of occlusal abnormalities that cause temporomandibular disorders,
This was extremely useful. Therefore, the method of the present invention, as a basic device for measuring the mandibular position, utilizes the function of the conventionally known appropriate articulator, and statically and three-dimensionally records the position of the lower jaw with respect to the upper jaw. is there. Here, in the present invention, in order to realize the present invention, first, it is necessary to measure the mandibular position in the articulator appropriately for input numerical values and basic data collection, and then, in the articulator The position of a specific lower jaw with respect to the reference position is calculated from occlusal measurement raw data, and it is displayed three-dimensionally from multiple directions by computer graphics. This is displayed as an image on a CRT. It was done. More specifically, the present invention calculates the discrepancy between the measurement result of the articulator and the correct position of the mandibular position close to the natural position by a computer, and displays the discrepancy on a three-dimensional screen, and as a result, what is the mandibular position? It is a screen display that clearly shows whether the position is the most natural and correct position. Then, while the dentist or the like visually recognizes the screen display, it determines which part is abnormal and which part is normal, and the present invention is used for diagnosis and treatment of temporomandibular disorders. First, the sequence of the method for measuring the lower jaw position of the MPI or CPI system in the articulator will be described below.
The articulator used in this embodiment is SAM or PA.
A NADENT articulator and an MPI or CPI system for measuring the mandibular position in the articulator were used. However, in the present invention, the means and order for obtaining the measurement data of the lower jaw position are not limited to the following examples, and if the measurement method of the present invention can be realized, change it. Of course, it can be implemented. 1. Mount the upper and lower jaw models on the articulator in the jaw position determined by the operator. 2. Transfer the upper jaw model with mounting plate to MPI or CPI system. 3. The occlusal record to be investigated is fixed by interposing it between the upper and lower dentitions. 4. The position of the articulating paper of appropriate color is marked by sandwiching it between the condylar sphere, which is the constituent part of the articulator, and the recording part of the MPI or CPI system to which the recording paper is attached. 5. Since the reference position is in a coordinate form in which the center of the recording paper is marked with a needle or the center can be confirmed, the two jaw positions can be compared two-dimensionally on the recording paper. However, this is not a comparison at the position of the mandibular condyle, but is a comparison at the condylar bulb portion, which is a constituent part of the articulator, so there is a possibility that the slight difference may be magnified. The above operation is performed for the left and right jaw positions. 6. A gauge attached to the back of the MPI or CPI system is used to check the axial displacement of the condylar ball, which is a component of the articulator. However, this is also slightly different from the actual displacement in the mandibular head, as in the above-mentioned 5. 7. Record the difference in height pointed to by the incisal pin on the incisal table. As a result of the above, measurement data of the mandibular position in the MPI or CPI system of the articulator can be obtained. next,
As information processing of the above data, data analysis was performed using a computer. At this time, it should be noted that in order to completely three-dimensionally represent the spatial relationship of the solid in space, that is, the mandibular body with respect to the skull, the measurement item should be an incisal pin (SAM or PANADEN).
It is to change to a method that includes the length of the member in the T articulator), that is, a method that satisfies the actual three-point six-dimension. More specifically, when the data analysis is simply performed without changing to the above three-point six-dimensional method, it seems that the position of the lower jaw with respect to the upper jaw can be measured three-dimensionally, but the position of the lower jaw of the sagittal plane is Looking at it, the lower jaw is merely moving in parallel, and the deviation such as the twist of the lower jaw that should exist between the two lower jaw positions that should actually exist is not expressed. That is, the correct displacement of the lower jaw cannot be expressed. This is caused by not satisfying the necessary and sufficient conditions for representing the coordinates of a solid in space, and the coordinates of points on the incisal table can be calculated from the coordinates of the left and right condylar spheres. Because they are exactly the same,
This is the result caused by measuring only 3 points and 5 dimensions. Therefore, since the necessary and sufficient condition for representing the position of a solid in space is that the numerical values for a total of 6 dimensions at any 3 points are given, the difference in the heights of the incisal pins in the two lower jaw positions is taken as an element. Put in
The above conditions are established and it becomes possible to compare 3D objects. The input table of the measurement items in the case of measuring by the above method is not particularly limited as long as the measurement method can be realized. Next, after the data analysis was changed to the above method, the MPI of the articulator was changed.
Alternatively, as an information processing of measurement data of the lower jaw position obtained by the CPI system, a method of inputting measurement items for performing data analysis using a computer and creating image data will be described. In the measuring method of the present invention, there are input items as shown in each input item in Table 1 below. The operator inputs corresponding data along each input item, saves the input data in a file after completing the input, and ends the input screen to create image data. It should be noted that the present invention is not limited to each input item as shown in Table 1, and the input item can be changed and implemented as long as the measuring method of the present invention can be realized.

[Table 1] Next, a case where the image data is displayed on the CRT after the image data is created will be described. In the display method of the present invention, for example, as shown in Tables 2 and 3, the following A
By selecting nine display methods from 1 to I, it is possible to display an image while enlarging or reducing the entire mandibular position or the condyle head from various directions.

[Table 2]

[Table 3] A: Horizontal plane B: Right side C: Front side D: Left side E: Right front 30 degrees F: Front 30 degrees G: Left front 30 degrees H: Overall display (right side, left side, front, horizontal) I: Enlarged display (right side) Surface, left side, right front, left front, right horizontal, left horizontal). The CR display in Tables 2 and 3 above indicates the position of the ideal correct tooth occlusal state which is the most natural and which is stored in advance, and the CO display is input according to the measurement items. It shows the position of the lower jaw of each person to be measured, which is created by the above. Next, as shown in Tables 2 and 3, the 9 types of CO screens are superimposed and displayed on the CR screens corresponding to the respective CO screens in which data is stored in advance. In this case, for example, if the CR display is white and the CO display is red, the shift of each screen on the combined display can be clearly read. Here, according to the present invention, the CR display and the CO display can be overlapped and composite-displayed on the screen, and the operator (dentist) can confirm whether or not there is an abnormality in the normal lower jaw position. , If it is abnormal, for example, it is very easy and clear to visually check which part is displaced in which direction, etc.
As a result of the confirmation, the present invention can be widely used for appropriate and prompt diagnosis and treatment of dental arthritis such as temporomandibular disorders. In addition, Table 4 below shows that the present invention compares specific images by selecting the composite display of each CR screen and the CR screen from the 9 types of display methods.
It shows a state in which it can be enlarged and displayed.
Further, it goes without saying that a data file can be copied by the computer for each of the image information in the present invention. Furthermore, the computer means for implementing the lower jaw position measurement / display method according to the present invention is not particularly limited as long as it has basic functions such as input, image creation, image display, and data storage. Absent.

[Table 4] The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the gist thereof. In addition, when the data processing is performed as described above by the measuring method according to the present invention, the position of the lower jaw can be three-dimensionally grasped as described above. It seems that. 1. Make the lower jaw body three-dimensionally represented. 2. As the image representation method, both the CR and CO have been subjected to the hidden surface treatment. 3. Display the value at the measurement point of MPI or CPI system by converting it to the standard size of the mandibular body of an adult. 4. The screen to be displayed should be limited to the minimum necessary in consideration of the processing capacity of the computer. In the case of screen display, the lower jaw position that should be the reference is the tooth contact position in the center position (the position where the lower jaw head is most anterior and uppermost in the mandibular fossa through the joint disc), and the cusp fit In order to clarify the positional relationship of the mandibular body in the position, for example, the central position may be blue and the cusp fitting position may be green. The above-mentioned central position means a neutral state in which neither traction nor compression is generated in the temporomandibular joint. Based on the result of occlusal measurement by the articulator, the initial purpose of the present invention of measuring the three-dimensional positional relationship of the mandible with respect to the skull or the reference position and displaying the three-dimensional position is realized. . Next, it will be explained that the method of the present invention is useful for diagnosis and treatment of temporomandibular disorders. That is, for example, one of the causes of the development of temporomandibular disorders is an external force applied to the temporomandibular joint. In this case, in considering the relationship between chronic trauma of the temporomandibular joint and occlusion, what external force acts on the temporomandibular joint at the cusp-fitting position, which is the starting point of all occlusion functions, It is important to see the displacement. External forces applied to the temporomandibular joint include compression and traction. The above-mentioned traction refers to the case where the mandibular condyle is pulled down in either direction, but if this continues chronically, it causes the loosening of the joint capsule and joint disc supporting tissue, causing the metastasis of the joint disc, and also It causes inflammation or degeneration of the joint capsule and the synovium on its inner surface. The above-mentioned compression has different effects depending on the direction in which it occurs, but the direction that most seriously affects the temporomandibular joint is the posterior direction, and there is posterior joint disc tissue in that part, and external force such as compression is applied. Therefore, it is easily deformed, and since blood vessels and nerves are abundantly distributed in the relevant part, it is easy to react sensitively to displacement and force. Therefore, with the method of the present invention, the positional change of the mandibular body including the mandibular condyle when biting in the cuspcal position is recorded, and the image is reproduced three-dimensionally with graphics to determine the position of the condyle with respect to the skull. It is extremely important and useful for the treatment such as the above-mentioned temporomandibular joint case to monitor the progress while diagnosing and treating the patient properly and performing the appropriate evaluation.
Furthermore, it is extremely important and useful not only for temporomandibular disorders but also for general dental clinic to monitor the progress of the diagnosis and treatment based on the position of the mandibular condyle with respect to the cranium and perform an appropriate evaluation. Is. Next, it will be explained that the method of the present invention is useful for diagnosing and treating a specific case of temporomandibular disorders. A patient visited our hospital with a click on the right temporomandibular joint and spontaneous pain on the right head and neck 23 A woman of age. As a result of an interview and a medical examination, the right temporomandibular joint had a reciprocal click due to an internal temporomandibular disorder and the left temporomandibular joint had a temporomandibular disorder, which was a chronic closed lock stage. Therefore, for the above cases, the MPI or CP
Data from the I system was input to the computer, an input table and image processing were performed, and the lower jaw of the patient was image-displayed on the CRT according to Tables 2 and 3 above. From the above-mentioned image display, it was found that the lower jaw position of the patient moved parallel to the left side and further rotated rearward in the cusp-fitting position, as compared with the apparent center position.
Furthermore, it was found that the left and right mandibular condyles in the temporomandibular joint were displaced rearward and downward, and were displaced leftward overall.
In such a state, the lateral ligament is pulled in the temporomandibular joints on both sides, and the posterior disk tissue is compressed, and the inward displacement of the condyle tympani is caused by the inward displacement of the right mandibular condyle. I was able to diagnose something. Based on the above diagnostic results, a repositioning appliance was manufactured at the therapeutic position, and a treatment for mounting the repositioning appliance was performed. As a result of the treatment, recapture of the right joint disc was successful 2 months later. At this stage, we did not dare to recapture the left joint disc. After another 1.5 months, the joint disc was also stable, so the center position was recorded again and compared with the record of the center position before treatment. As a result, the right temporomandibular joint showed almost no change from that before the operation, but in the left temporomandibular joint, the mandibular condyle was displaced backward and downward, and there was not much axial displacement. Therefore, from this, even if the joint disc can be recaptured in the right temporomandibular joint, when the posterior disc tissue is interposed and when the joint disc is interposed,
It was found that the position of the mandibular condyle did not change much. Rather, the repositioning appliance has caused thickening of the posterior disc tissue of the left temporomandibular joint. Here, it has been clarified that the measurement of the lower jaw position by the method of the present invention is useful and the diagnostic result by the image display of the measurement result is useful. As described above, the method of the present invention and the three-dimensional graphics image display of the specific lower jaw position (for example, the central position and the central occlusion position) with respect to the reference position, which can be realized by the present invention, are more useful in the following cases. Is. 1. Use as confirmation of the mandibular position before and after preservation and prosthetic treatment. 2. Use as a material for considering the dynamics of the mandibular condyle and joint disc in the diagnosis and treatment of temporomandibular disorders. 3. Use as a material for determining the effect of splint therapy or monitoring it. 4. Use as a reference material for diagnosing orthodontic treatment, treatment, and monitoring of the mandibular condyle and mandible in the subsequent prosthetic treatment. 5. Use as a material for diagnosing orthodontic surgery combination therapy, and for monitoring the mandibular condyle and mandible in the subsequent prosthetic treatment. 6. It shows what kind of condition the patient's jaw is in three dimensions using the three-dimensional graphics image display of the lower jaw position or its photograph, hard copy, etc., and the dentist's diagnosis and treatment plan concerning the above 1 to 5 While explaining the above to the patient, when the patient or his / her child is a child, etc., use to obtain understanding and cooperation for treatment.

According to the present invention described in detail above, by adopting the method of measuring and displaying the mandibular position as described above, the three-dimensional shape of the mandible relative to the skull or the reference position is based on the occlusal measurement result by the articulator. It is possible to measure the physical positional relationship and display it three-dimensionally, and to judge the tooth position and denture position by correct orthodontic treatment that is the most natural at the beginning of orthodontics and denture creation, and judge the skill and intuition of each dentist. Always, rather than
It can be used to perform orthodontic treatment and denture preparation while objectively and promptly confirming it, and it can also be used as a guideline for correct training after completion of orthodontic treatment and denture. It is possible to provide a method for measuring and displaying the lower jaw position, which is useful for obtaining the patient's understanding of the treatment by showing what kind of state the jaw has in three dimensions.

Claims (4)

[Claims] 1. A three-dimensional positional relationship of a mandible with respect to a skull or a reference position is measured based on occlusal measurement data by a known so-called articulator, which is a device that takes a tooth profile and simulates the occlusal state. A method for measuring and displaying the mandibular position, which was designed to display this in a three-dimensional image.
Necessary to represent the position of a solid in space when obtaining the occlusal measurement data of the lower jaw position of the measurement subject by the articulator and performing the occlusal measurement data analysis using a computer as information processing of the occlusal measurement data. In addition, after giving a total of 6-dimensional numerical values at arbitrary 3 points as sufficient conditions, the occlusal measurement data is input along the input items and data analysis is performed to obtain image data of the three-dimensional positional relationship of the mandible. And a step of creating the above-mentioned image data, and the previously stored image data and the data indicating the position of the ideal correct tooth occlusal state which is the most natural and is stored in advance are superimposed and displayed on the CRT. A method for measuring and displaying the mandibular position, which is characterized in that 2. The occlusal measurement data by the articulator is a step of mounting the upper and lower jaw models on the articulator at a jaw position determined by the operator as a reference, and the upper jaw model is transferred to the articulator together with the mounting plate. Process, step of fixing record of occlusal to be investigated by interposing between upper and lower dentition, articulating paper of appropriate color was attached to condylar ball part which is one component of articulator and recording paper The process of marking the position by sandwiching it between the recording parts of the articulator, the two-dimensional comparison of the left and right jaw positions on the recording paper, the axial direction of the condyle ball with the dial gauge on the back of the articulator 2. The step of examining the shift to the incisal table and the step of recording the difference in length when the incisal pin comes into contact with the incisal table by using an articulating paper are obtained in the order of steps. Lower jaw position measurement and display method. 3. The composite display is from an arbitrary direction in which a three-dimensional positional relationship between the created image data and the data showing the position of the ideal correct tooth occlusal state which is the most natural can be confirmed. The method for measuring and displaying the lower jaw position according to claim 1, wherein the method is based on synthetic display. 4. The composite display of the created image data and the prestored data showing the position of the ideal correct tooth biting state which is the most natural and which is most natural is displayed in different colors. The lower jaw position measuring / displaying method according to claim 1.