Method of manufacturing orthodontic devices using an insertion channel

Abstract

The present invention relates to a program for designing orthodontic appliances, and includes the steps of: displaying an insertion path on a screen to determine the insertion direction of the orthodontic appliance (S01); specifying the teeth for which insertion path setting is to be performed (S02); setting an insertion path in an arbitrary direction for the specified teeth (S03); displaying the undercuts of each tooth caused by the set insertion path on a screen (S04); calculating and saving the depth value of the undercut for each tooth based on the insertion path (S05); and calculating and saving the sum of the volumes of the undercuts of each tooth based on the insertion path (S06).

Description

Technical Field

[0001] The present invention relates to a method (program) for designing a dental correction device using an electronic information processing device such as a computer. Specifically, it relates to a method for acquiring a patient's oral structure (tooth alignment information, etc.) using a 3D scanner and then manufacturing a dental correction device optimized for the oral structure.

Background Art

[0002] The conventional method for manufacturing a dental correction device is as follows. First, after the operator grasps the patient's oral structure, a tooth model having the same shape as the teeth is produced. Generally, the patient's tooth model is produced using plaster or the like after taking a mold of the oral structure. For the tooth plaster model thus produced, a sheet-like polyol material is thermocompression-bonded in the vertical direction with a molding machine to produce a transparent correction device adapted to the patient, which is a conventional general technique. On the other hand, in recent years, a method of scanning the patient's oral structure using a 3D scanner, storing the information, and then producing a tooth model based on the information has been widely used. This method is an advanced method compared to the method of directly collecting the tooth shape to produce a tooth model. That is, 3D scan data regarding the patient's tooth structure is transmitted from a dental clinic to a dental laboratory, and the dental laboratory produces a tooth model based on the received information. Furthermore, a method of directly manufacturing a transparent correction device using a 3D printer has also been proposed. This method is more advanced in that it does not require a tooth model by directly outputting a correction device using a 3D printer, unlike the conventional method of first producing a tooth model and then producing a correction device based on it. The present invention relates to a program for designing a correction device on a computer when directly outputting and manufacturing a transparent dental correction device using a 3D printer.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In removable orthodontic appliances, in transparent orthodontic appliances produced by 3D printing, The technical challenge is to manufacture orthodontic appliances optimized for the patient's teeth by ideally setting the insertion path corresponding to the direction of insertion of the orthodontic appliance. [Means for solving the problem]

[0004] The present invention provides a solution that includes the steps of: displaying an insertion path on a screen to determine the insertion direction of the orthodontic appliance (S01); specifying the teeth for which the insertion path is to be set (S02); and displaying the undercuts of each tooth caused by the set insertion path on a screen (S04). [Effects of the Invention]

[0005] This invention provides an orthodontic appliance optimized for the patient's teeth by ideally setting the insertion path corresponding to the insertion direction of the orthodontic appliance. It maximizes the orthodontic effect, enhances treatment effectiveness, and increases convenience of use by making it easier to attach and detach the orthodontic appliance. Furthermore, by making it easier to find the most ideal insertion path when designing orthodontic appliances on a computer, it has the effect of reducing the time and effort required to manufacture orthodontic appliances. Furthermore, by enabling easy setting of the optimal insertion path, the present invention is expected to significantly improve the quality of orthodontic devices even when performed by unskilled workers. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 is a flowchart of the method for manufacturing an orthodontic appliance according to the present invention. [Figure 2] Figure 2 shows the insertion path setting screen according to the present invention. [Figure 3] Figure 3 shows a menu function according to one embodiment of the present invention. [Figure 4] Figure 4 shows the state after the function related to Figure 3 (undercut removal: blockout) has been implemented. [Modes for carrying out the invention]

[0007] The present invention The best form includes the following steps: (S01) displaying the insertion path on the screen to determine the insertion direction of the orthodontic appliance; (S02) specifying the teeth for which the insertion path setting is to be performed; (S03) setting the insertion path in an arbitrary direction for the specified teeth; (S04) displaying the undercuts of each tooth caused by the set insertion path on the screen; (S05) calculating and saving the depth value of the undercut for each tooth based on the insertion path; (S06) calculating and saving the sum of the volumes of the undercuts of each tooth based on the insertion path; (S07) setting the insertion path in a direction different from the previously set direction and repeating steps S04 to S06; and (S08) selecting and saving the insertion path with the minimum value from the sum of the undercut volumes obtained in step S07. The method for manufacturing the transparent orthodontic device according to the present invention will be described in detail step by step below. The technical terms used in the present invention are used solely to describe the following embodiments and are not intended to limit the scope of the present invention. Furthermore, unless otherwise specifically defined in the present invention, the technical terms should be understood to convey the meanings that a person skilled in the art would ordinarily understand and use. This invention relates to a method (program) for designing transparent orthodontic appliances using a computer. In order to carry out this invention, a 3D scanning operation of the patient's teeth must be performed as a preliminary step. The inside of the patient's oral cavity is scanned in detail using a 3D scanner to obtain image information regarding the tooth structure, and then the patient's tooth structure is displayed on a display based on this information. Once a complete image of the patient's tooth structure is displayed, an optimized orthodontic appliance is designed using a computer in accordance with the present invention. Here, orthodontic appliances are intended for correcting the alignment of teeth (a concept that includes all changes in tooth position, such as horizontal movement, rotation, extrusion, and impaction), and are produced via a 3D printer. Furthermore, while the orthodontic device according to the present invention is preferably applied to a transparent orthodontic device that covers the entire dentition (dental model), it can also be applied to orthodontic devices that partially cover the dentition (for example, an orthodontic device that covers only a few teeth adjacent to the tooth to be corrected). Figure 1 is a flowchart of the orthodontic appliance manufacturing method according to the present invention, and Figure 2 shows a screen illustrating the setting of the insertion path and the associated undercut according to the present invention. Step S01 is the process of displaying the insertion path on the screen to determine the insertion direction of the orthodontic appliance, and step S02 is the process of specifying the teeth for which the insertion path will be set. The problem of setting the insertion direction stems from the fact that each tooth has a different upward orientation. To ensure effective orthodontic force, the orthodontic appliance must be tightly fitted to the dentition and supported by the teeth. Therefore, how the insertion direction is set directly impacts the performance of the orthodontic appliance. The insertion path refers to the direction in which the orthodontic appliance is attached to the teeth. While primarily based on the vertical direction (the Y-axis on the diagram), it must be set in a direction (incline) that efficiently ensures the application of orthodontic force. Furthermore, since the orthodontic appliance is removable rather than fixed, ease of attachment and removal must also be ensured. As shown in Figure 2, once an arbitrary insertion path is set, the undercuts of each tooth corresponding to the set insertion path are displayed. The technical feature of this invention is that the operator specifies a range of teeth and searches for the optimal insertion path for the specified group of teeth, and Figure 2 shows a screen in which the undercuts of all teeth are displayed for the set insertion path.

[0008] The insertion path is set by inputting arbitrary angle values ​​tilted from the Y-axis to the X-axis or / or Z-axis. For example, if you input 3° for the X-axis and -5° for the Z-axis, the insertion path will be displayed on the screen tilted 3° in the X-axis (+) direction and 5° in the Z-axis (-) direction. Alternatively, the insertion path can also be set (tilted) by the user placing a cursor over the insertion path and moving the cursor to tilt it. When the cursor moves near the insertion path, the function to tilt the insertion path is activated, and the user can tilt the insertion path in the desired direction by moving the cursor in the X-axis and / or Z-axis directions. Step S02 is the process of specifying the teeth to be inserted. From the patient's teeth, teeth within a certain range are selected at the discretion of the operator. The selected teeth may be a single tooth, or multiple adjacent teeth may be selected as a group. Step S03 is the process of setting an insertion path in any direction for a specified tooth (or group of teeth), and step S04 is the process of displaying the undercuts of each tooth caused by the set insertion path on the screen. Step S05 is the process of calculating and saving the depth value of the undercut for each tooth according to the insertion path. When the insertion path is set in a desired direction, the corresponding undercuts of each tooth are displayed. Teeth have different lateral diameters depending on their height, and the part with the largest diameter is called the ridge. Beyond the ridge, the lateral diameter of the tooth decreases towards the gingiva. An undercut is the recessed area of ​​the tooth after the ridge. These undercuts exist even in healthy teeth and become larger in cases of damage from external forces or caries. Figure 2 shows only the case for the lower jaw; however, in the case of the upper jaw, the undercut is located on the upper part of the tooth, and the principle is the same, so a detailed explanation and illustration are omitted. The shape of the undercut on each tooth will differ depending on how the insertion path is set up. This is because the degree of inclination of each tooth differs, as well as the position and shape of the undercut itself.

[0009] Once an insertion path is established, an undercut is visually displayed for the designated tooth, as shown in Figure 2 (Step S04). Although Figure 2 shows undercuts for all teeth, it is also possible to display undercuts only for the teeth specified before establishing the insertion path, and this display can be switched at the operator's discretion. Based on the configured insertion path, each tooth's undercut is displayed in a color different from the tooth's color for easier visibility. Furthermore, each undercut is displayed in a different color according to its depth value. Here, the depth value refers to the horizontal length of the undercut (in the X-axis or Y-axis direction in Figure 2). If the undercut depth value is small, it is displayed in yellow; if the depth value is large, it is displayed in red. Therefore, the undercut depth value for each tooth is calculated and stored continuously for each tooth. If a tooth has an undercut, that undercut will have a color corresponding to a spectrum from yellow to red, depending on its horizontal depth. This allows the user to instantly check the presence and extent of undercuts in each designated tooth relative to the set insertion path. The depth value of the undercut for each tooth based on the insertion path is calculated and stored (Step S05). Step S06 is the process of calculating and saving the sum of the undercut volumes of each tooth based on the set insertion path. Once the undercuts of each tooth are determined for a particular insertion path, the computer calculates the volume of the undercut for each tooth, sums up the calculated volumes, and saves the total value. The user can check the undercuts of each tooth and their total volume for each insertion path at any time. Step S07 is a process in which the insertion path is set in a direction different from the previously set direction, and steps S04 to S06 are executed again. The user can arbitrarily change the insertion path (specifically, change the inclination of the insertion path) and check the degree of undercutting which changes for each tooth. Step S07 may also be set to be executed automatically by pre-setting the number of times it is performed. When the inclination of the insertion path changes, the undercuts of each tooth change in shape, depth, and volume. Since the vertical inclination is different for each tooth and the shape is also different, when the inclination of the insertion path changes, the undercuts of each tooth change in shape and volume.

[0010] In the S07 step, the user sets the insertion path in a direction different from before, and each time checks the shape of the undercut of each tooth that changes accordingly, and can also check the total volume value of the undercuts each time. The S07 step may end in one go, but depending on the operator's choice, it can be repeated more than three times until the optimal insertion path is set, and it can also be carried out in various other numbers of times. On the other hand, there may be a case where a specific tooth is largely inclined in a certain direction. When a specific tooth is thus inclined in a biased manner in one direction, the degree of undercut in a specific direction of the insertion path may be maximized. This phenomenon may distort the overall undercut volume with respect to a specific insertion path. In such a case, it is desirable to go through a process of excluding the undercut volume of the tooth that is largely inclined in a specific direction from the calculation. The S08 step is a step of selecting and saving an insertion path having the minimum value from the total volume values of the undercuts obtained in the S07 step. In order for the correction device to effectively exert a correction force on the tooth, it is required to be mounted in close contact with the tooth. In order for the correction device to be mounted in close contact, a correction device capable of minimizing the degree of undercut is required. On the other hand, if only the securing of the correction force is pursued in the manufacture of the correction device, the detachable property (usability in use) of the correction device may be greatly reduced. Therefore, it is necessary to set an insertion path that can maximize the correction force while ensuring the detachable property of the correction device. The present invention proposes, as the most ideal insertion path, an insertion path obtained by summing up the volumes of the undercuts of each tooth calculated respectively, and having the minimum sum value. The design method of the correction device according to the present invention is one that can ensure the maximum correction force while being easily detachable, and aims to provide a correction device optimized for the teeth to be corrected. According to the present invention, even an unskilled person can easily find the most ideal insertion path, thereby enabling the production of an optimized correction device. Moreover, an object of the present invention is to provide a correction device that has excellent correction force while ensuring wearability by setting a plurality of insertion paths. An operator designates a first group for teeth to which one insertion path is applicable, and executes steps S04 to S06 to obtain an optimal insertion path for the designated first group. Thereafter, other teeth are designated as a second group, and steps S04 to S06 are similarly executed to obtain an optimal insertion path for the second group (S021, S031). This process can be further extended to a third group and a fourth group. Since the correction device according to the present invention has a certain elasticity, wearability is ensured even if the correction device has partially different insertion paths. Furthermore, by setting the insertion paths to be different for each group of teeth, it is expected that an optimal correction force corresponding to the characteristics of each tooth will be applied to the teeth to be corrected.

[0011] FIG. 3 shows a menu regarding the stage of executing a specific function in one embodiment of the present invention. FIG. 4 shows a state in which undercuts at each tooth are removed according to the execution of the menu shown in FIG. 3. In the menu shown in FIG. 3, the undercut removal function (Remove Undercuts) is enabled. Removing an undercut means setting that the sunken lower end portion of the tooth (corresponding to the upper end portion in the case of the upper jaw) is filled without being sunken. FIG. 4 shows a state in which the function according to FIG. 3 (removal of undercuts: Block out) is implemented. FIG. 4 shows a state in which all undercuts existing in each tooth are removed, that is, a state in which all tooth defect portions (white portions in FIG. 4) are filled. The removal of undercuts may be performed on all teeth, or may be performed only on some teeth as necessary. The S051 process involves setting each tooth's undercut to be non-existent (block out setting) for portions exceeding a specific depth value. Generally, the depth of an undercut in a tooth increases the further it is from the convex area. Designing an orthodontic appliance to account for extremely deep undercuts can make it extremely difficult to insert and remove a removable orthodontic appliance. If an orthodontic appliance is made in a shape that is too tightly fitted to the teeth, it can be difficult to insert, and even if it can be inserted, it may be difficult to remove the appliance from the teeth. For this reason, it is desirable to design orthodontic appliances by ignoring undercuts with a depth greater than a predetermined value. This invention considers the convenience of attaching and detaching orthodontic appliances while ensuring orthodontic force, and proposes that an appropriate depth value that can be ignored be set to 0.2 mm to 0.5 mm. In other words, if the depth of the undercut is approximately 0.2 mm to 0.5 mm or more, the undercuts greater than that depth are ignored (blocked out) when designing the orthodontic appliance. In this case, the orthodontic appliance is designed so that it does not come into close contact with tooth areas that have undercuts deeper than that depth. It should be noted that the above-mentioned appropriate depth value is not an absolute value, but can be freely adjusted by the practitioner according to the specific treatment situation of the patient, such as the shape of each tooth and the amount of orthodontic force, via the menu screen shown in Figure 3 (adjusted using the "Retention amount" menu shown in Figure 3). Depending on the condition of the teeth, it may be possible to ignore the entire undercut, in which case the above-mentioned appropriate depth value will be 0 (zero).

[0012] The orthodontic device according to the present invention provides additional means to facilitate its attachment and detachment. Step S052 is a step in which the bending angle of the orthodontic appliance is set so that the end of the appliance starts from a position where the undercut is considered not to exist (a position where the undercut is ignored) and is bent in the opposite direction to the tooth. After going through process S051, when the orthodontic appliance is output (using a 3D printer), the ends of the appliance will have a shape that extends straight vertically. However, for easier attachment of the orthodontic appliance, it is sometimes desirable for the ends to be slightly open. Therefore, the orthodontic appliance according to the present invention is characterized in that its end portion (the portion from the position where the undercut is ignored to the end portion) is formed to bend in the opposite direction to the tooth by a predetermined value. In other words, the end portion can be said to mean the portion from the position where the block out according to the present invention begins to the end portion. Through repeated testing, the present invention proposes an optimal bending angle of 2° to 4° for orthodontic appliances that are easy to attach and detach while not causing discomfort during wear. On the other hand, the bending at the ends may be less than 2° depending on the patient's oral environment, or in some cases, no bending may be provided at all. Since the optimal bending angle at the ends may differ for each tooth, it is also possible to set a different angle for each tooth. Furthermore, while the ends of orthodontic appliances are extended to the gingival line, in special circumstances such as very short tooth crowns, the ends of the appliance may be designed to be further extended. In this case, it is desirable that the gingival line be receded or removed. For example, if the tooth crown is very short, extending the ends allows the orthodontic appliance to be fitted more stably to the patient's dentition. Step S09 is the process of restoring the undercut corrected in step S051 back to its original shape. In other words, it means canceling the block-out. When the cursor on the screen moves to a specific tooth, the computer recognizes this and restores and saves any undercuts in that tooth or surrounding teeth to their original shape. If it is determined that there will be no major problems with the insertion or removal of the orthodontic appliance even if the undercut is accepted as the original shape, it is desirable to restore the undercut to its original shape. In fact, by restoring the undercut in this way, it is expected that the inner surface of the orthodontic appliance will be made to adhere to the tooth as closely as possible, making it easier to secure the corrective force on the tooth.

[0013] The restoration of undercuts can be carried out in various ways. This can be done by sequentially moving the cursor over each tooth, or by dragging the cursor to specify a certain area (multiple teeth at once) and restoring all undercuts within that area to their original shape. None of these various modifications deviate from the technical scope of the present invention. Furthermore, when it is stated that one component is "connected," "joined," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, or another component may be "connected," "joined," or "connected" between them. Also, unless otherwise specified, the singular form should be understood to include the plural form. The above description of the configuration and effects relates to one embodiment of the present invention and does not limit the scope of the claims of the present invention. It is obvious to those skilled in the art that various changes and modifications are possible without altering the technical concept of the present invention, and such simple design changes also fall within the technical scope of the present invention.

Claims

1. Step (S01) to display the insertion path on the screen to determine the insertion direction of the orthodontic appliance; Step (S02) to specify the tooth to be used for the insertion path setting; Step (S03) of setting the insertion path in any direction for the designated tooth; Step (S04): Displaying on the screen the undercuts of each tooth caused by the configured insertion path; Step (S05): Calculate and save the depth value of the undercut for each tooth based on the insertion path; Step (S06): Calculate and store the sum of the volumes of the undercuts of each tooth based on the insertion path; A step (S07) in which the insertion path is set in a direction different from the previously set direction, and steps S04 to S06 are executed again; and Step (S08): Select and save the insertion path with the minimum value from the total undercut volume obtained in step S07; A method for manufacturing an orthodontic device using an insertion channel, characterized by including the following:

2. In the method according to claim 1, The aforementioned step S02 includes a step (S021) of dividing the teeth into a first group and a second group, The aforementioned step S03 is characterized by including a step (S031) of setting insertion paths for the first group and the second group specified in step S021, respectively. A method for manufacturing orthodontic devices using an insertion channel.

3. In the method according to claim 1 or claim 2, The process further includes setting (S051) that there are no undercuts in the portion of each tooth that has a depth value greater than a certain value. A method for manufacturing orthodontic devices using an insertion channel.

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