Method and device for filling undercuts and occlusal avoidance in digital tooth models

Abstract

The present invention provides a method and device for avoiding undercuts in a digital tooth model. The method comprises: obtaining a digital tooth model and undercut grids of adjacent teeth of the upper and lower jaws, determining a first influence area of ​​the undercut grid of the upper jaw in the lower jaw and a second influence area of ​​the undercut grid of the lower jaw in the upper jaw; performing collision detection on the teeth in the first influence area of ​​the lower jaw and the undercut grid of the upper jaw to obtain a first collision detection result, and cyclically updating the undercut grid of the upper jaw according to the first collision detection result to obtain an optimized undercut grid; after the optimized undercut grid of the upper jaw is completed, performing collision detection on the undercut grid of the lower jaw to obtain a second collision detection result, and cyclically updating the undercut grid of the lower jaw according to the second collision detection result to obtain an optimized undercut grid. The present invention optimizes the undercuts of the digital tooth model to ensure that no interference is caused to tooth occlusion, thereby improving the wearing comfort of the orthodontic appliance.

Description

Technical Field

[0001] The present invention relates to the technical field of tooth correction, and in particular to a method and a device for avoiding occlusion by filling an undercut in a tooth digital model. Background Art

[0002] Malocclusion is one of the three major oral diseases, with a high prevalence rate. Most malocclusions occur during growth and development, and are caused by congenital genetic factors or acquired environmental factors, such as diseases, bad oral habits, abnormal tooth replacement, uneven tooth arrangement, and abnormal jaw relationship development between the upper and lower dental arches. Malocclusion can cause great harm to the oral cavity or even the whole body, affecting maxillofacial development, oral health and function, and appearance. At present, it is generally corrected by fixed appliances and invisible appliances. With the development of technology and the improvement of aesthetics, based on the development of computer technology and materials, invisible appliances are increasingly accepted by patients. By wearing a series of invisible appliances, the teeth are continuously moved in a small range to correct the misaligned teeth.

[0003] In the process of making a digital model of a dental brace, the digital tooth model obtained by an intraoral scanner needs to be filled with undercuts first. However, when the upper and lower teeth are too deeply bitten, if the undercuts are filled without considering the occlusion, the patient will not be able to bite his teeth tightly after wearing the brace. The current undercut filling method does not consider the opposing jaw occlusion when generating the undercut filling grid, which will cause occlusal interference, affect the wearing feeling of the brace, and thus affect the treatment effect.

[0004] Therefore, it is necessary to provide a new method and device for filling undercuts and avoiding occlusions in a digital tooth model to solve the above-mentioned problems in the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for avoiding occlusion by filling undercuts in a digital tooth model, to optimize the filling undercuts in a digital tooth model to ensure that no interference is caused to tooth occlusion, and to improve the comfort of wearing an orthodontic appliance.

[0006] To achieve the above-mentioned purpose, the method for avoiding undercuts and occlusions in a digital tooth model of the present invention comprises:

[0007] Get a digital model of your teeth;

[0008] Select two adjacent teeth at preset occlusal positions in the upper and lower jaws of the digital tooth model, respectively, and obtain undercut grids of the adjacent teeth in the upper and lower jaws according to the digital tooth grids of the adjacent teeth;

[0009] Adjusting the upper and lower jaws of the digital dental model to a preset occlusal position, and determining a first influence area of ​​the undercut grid of the upper jaw in the lower jaw according to the occlusal position, and determining a second influence area of ​​the undercut grid of the lower jaw in the upper jaw according to the occlusal position;

[0010] performing collision detection on the teeth in the first influence area of ​​the mandible and the undercut mesh of the maxilla to obtain a first collision detection result, and after determining that the teeth in the first influence area and the undercut mesh of the maxilla will collide according to the first collision detection result, cyclically updating the undercut mesh of the maxilla to obtain an optimized undercut mesh, so that the teeth in the first influence area of ​​the mandible do not collide with the optimized undercut mesh of the maxilla;

[0011] After the optimized undercut mesh of the maxilla is completed, collision detection is performed on the teeth in the second influence area of ​​the maxilla and the optimized undercut mesh of the maxilla with the undercut mesh of the mandible according to the digital tooth model to obtain a second collision detection result. After determining that the teeth in the second influence area or the optimized undercut mesh of the maxilla and the undercut mesh of the mandible will collide according to the second collision detection result, the undercut mesh of the mandible is cyclically updated to obtain the optimized undercut mesh, so that the teeth in the second influence area and the optimized undercut mesh of the maxilla do not collide with the optimized undercut mesh of the mandible.

[0012] The beneficial effect of the tooth digital model filling undercut occlusion avoidance method described in the present invention is: according to the two adjacent teeth in the preset occlusal position of the tooth digital model, the first influence area of ​​the maxillary undercut filling grid in the mandible and the second influence area of ​​the mandibular undercut filling grid in the maxilla are determined, and then the optimized maxillary undercut filling grid is obtained by cyclically updating by successively performing collision detection on the maxillary undercut filling grid and the tooth model in the first influence area, and on the above basis, the mandibular undercut filling grid is optimized according to the collision detection results of the mandibular undercut filling grid with the optimized maxillary undercut filling grid and the teeth in the second influence area to obtain the optimized mandibular undercut filling grid, thereby completing the optimization process of the maxillary and mandibular undercut filling grids, effectively avoiding the collision of the undercut filling grid with the maxillary teeth or mandibular teeth of the tooth digital model during the filling process to affect the occlusal effect, thereby avoiding the interference of the undercut filling grid on tooth occlusion and ensuring the subsequent correction effect.

[0013] Optionally, the collision detection process includes:

[0014] Select a first collision detection object and a second collision detection object;

[0015] Calculate the shortest distance between the triangle mesh of the first collision detection object and the triangle mesh of the second collision detection object;

[0016] When the shortest distance is less than a preset distance, determining that a collision occurs between the first collision detection object and the second collision detection object;

[0017] When the shortest distance is greater than the preset distance, it is determined that the first collision detection object and the second collision detection object do not collide. The beneficial effect is that the collision detection is performed on the two collision detection objects to be detected through the above collision detection process to quickly determine the collision between the maxillary undercut model and the teeth in the first influence area, and the collision between the mandibular undercut model and the teeth in the second influence area and the maxillary optimized undercut grid, so as to timely optimize and adjust the maxillary undercut grid and the mandibular undercut grid.

[0018] Optionally, the preset distance satisfies the following formula:

[0019]

[0020] Wherein, L represents the preset distance, h represents the thickness of the dental appliance membrane, N represents the number of layers of the dental appliance membrane, and B represents the initial deviation value. Its beneficial effect is that on the basis of determining the preset distance according to the thickness and number of layers of the dental appliance membrane, the accuracy of the preset distance is further improved by increasing the initial deviation value, so as to ensure the accuracy of the collision detection result.

[0021] Optionally, the process of cyclically updating the undercut mesh of the maxilla to obtain an optimized undercut mesh or the process of cyclically updating the undercut mesh of the mandible to obtain an optimized undercut mesh includes:

[0022] S201, obtaining an initial undercut grid of two adjacent teeth in a target affected area, obtaining a first midpoint of a line connecting the centers of the digitized grids of the two adjacent teeth according to the initial undercut grid, and using the first midpoint as an initial midpoint;

[0023] S202, updating the adjustment times, and obtaining the adjustment distance according to the adjustment times;

[0024] S203, moving the initial midpoint in the gum direction to adjust the distance to obtain a middle midpoint, and obtaining a middle undercut grid according to the middle midpoint;

[0025] S204, determining the difference between the shortest distance between the target collision object and the middle undercut grid of the opposing jaw and a preset distance, if the shortest distance is greater than the preset distance, executing step S206, otherwise executing step S205;

[0026] S205, taking the current middle midpoint as the initial midpoint of the next round, and executing steps S202 to S204;

[0027] S206, taking the middle undercut-filling grid obtained last time as the target optimized undercut-filling grid;

[0028] Wherein, when the target impact area is the second impact area, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the maxilla, and the target collision object is the tooth mesh in the first impact area;

[0029] When the target impact area is the first impact area, the target optimized undercut mesh is the optimized undercut mesh of the mandible, and the target collision object is the tooth mesh in the second impact area and the optimized undercut mesh of the maxilla. The beneficial effect is that the initial undercut mesh is cyclically updated by the above method to obtain the target optimized undercut mesh that will not collide with the opposing tooth mesh, so as to complete the optimization processing of the undercut mesh, and effectively avoid the interference of the orthodontic appliance on the tooth occlusion after the undercut is filled.

[0030] Optionally, the adjustment distance satisfies the following formula:

[0031]

[0032] Wherein, n is the number of adjustments, n is a positive integer, M represents the preset adjustment distance of the nth adjustment of the undercut grid, A represents the initial adjustment distance of the undercut grid, and X represents the increase ratio of each adjustment of the preset adjustment distance.

[0033] Optionally, the method further includes determining, based on the first collision detection result, that the teeth in the first impact area do not collide with the undercut grid of the maxilla, and the position of the undercut grid of the maxilla remains unchanged.

[0034] The present invention also provides a tooth digital model filling undercut occlusion avoidance device, comprising:

[0035] A tooth model acquisition module is used to acquire a tooth digital model;

[0036] An undercut acquisition module is used to select two adjacent teeth at preset occlusal positions in the upper and lower jaws of the digital tooth model, and acquire the undercut grids of the adjacent teeth in the upper and lower jaws according to the digital tooth grids of the adjacent teeth;

[0037] An influence region determination module, used for adjusting the upper and lower jaws of the digital tooth model to a preset occlusal position, and determining a first influence region of the undercut grid of the upper jaw in the lower jaw according to the occlusal position, and determining a second influence region of the undercut grid of the lower jaw in the upper jaw according to the occlusal position;

[0038] an upper jaw adjustment module, configured to perform collision detection on the teeth in the first influence area of ​​the lower jaw and the undercut mesh of the upper jaw to obtain a first collision detection result, and after determining according to the first collision detection result that the teeth in the first influence area and the undercut mesh of the upper jaw will collide, cyclically update the undercut mesh of the upper jaw to obtain an optimized undercut mesh, so that the teeth in the first influence area of ​​the lower jaw do not collide with the optimized undercut mesh of the upper jaw;

[0039] A mandibular adjustment module is used to perform collision detection on the teeth in the second influence area of ​​the maxilla, the optimized undercut grid of the maxilla and the undercut grid of the mandible respectively according to the tooth digital model after the optimized undercut grid of the maxilla is completed to obtain a second collision detection result; after determining that the teeth in the second influence area or the optimized undercut grid of the maxilla will collide with the undercut grid of the mandible according to the second collision detection result, the undercut grid of the mandible is cyclically updated to obtain the optimized undercut grid, so that the teeth in the second influence area and the optimized undercut grid of the maxilla will not collide with the optimized undercut grid of the mandible.

[0040] The beneficial effects of the tooth digital model undercut occlusal avoidance device described in the present invention are: the influence area determination module determines the first influence area of ​​the undercut filling grid of the upper jaw in the lower jaw and the second influence area of ​​the undercut filling grid of the lower jaw in the upper jaw according to two adjacent teeth in the preset occlusal position of the tooth digital model; the upper jaw adjustment module obtains the optimized undercut filling grid of the upper jaw by cyclically updating by successively performing collision detection on the undercut filling grid of the upper jaw with the tooth model in the first influence area; and on the above basis, the lower jaw adjustment module optimizes the undercut filling grid of the lower jaw according to the collision detection results of the undercut filling grid of the lower jaw with the optimized undercut filling grid of the upper jaw and the teeth in the second influence area to obtain the optimized undercut filling grid of the lower jaw, thereby completing the optimization process of the undercut filling grids of the upper jaw and the lower jaw, effectively avoiding the collision of the undercut filling grid with the maxillary teeth or the mandibular teeth of the tooth digital model during the undercut filling process to affect the occlusal effect, thereby avoiding the interference of the undercut filling grid on tooth occlusion and ensuring the subsequent correction effect.

[0041] Optionally, the upper jaw adjustment module and the lower jaw adjustment module are also used to implement the following process:

[0042] S201, obtaining an initial undercut grid of two adjacent teeth in a target affected area, obtaining a first midpoint of a line connecting the centers of the digitized grids of the two adjacent teeth according to the initial undercut grid, and using the first midpoint as an initial midpoint;

[0043] S202, updating the adjustment times, and obtaining the adjustment distance according to the adjustment times;

[0044] S203, moving the initial midpoint in the gum direction to adjust the distance to obtain a middle midpoint, and obtaining a middle undercut grid according to the middle midpoint;

[0045] S204, determining the difference between the shortest distance between the target collision object and the middle undercut grid of the opposing jaw and a preset distance, if the shortest distance is greater than the preset distance, executing step S206, otherwise executing step S205;

[0046] S205, taking the current middle midpoint as the initial midpoint of the next round, and executing steps S202 to S204;

[0047] S206, taking the middle undercut-filling grid obtained last time as the target optimized undercut-filling grid;

[0048] Wherein, when the target impact area is the second impact area, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the maxilla, and the target collision object is the tooth mesh in the first impact area;

[0049] When the target impact region is the first impact region, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the mandible, and the target collision object is the tooth mesh in the second impact region and the optimized undercut-filling mesh of the maxilla.

[0050] Optionally, the upper jaw adjustment module and the lower jaw adjustment module are also used to implement the following process:

[0051] Select a first collision detection object and a second collision detection object;

[0052] Calculate the shortest distance between the triangle mesh of the first collision detection object and the triangle mesh of the second collision detection object;

[0053] When the shortest distance is less than a preset distance, determining that a collision occurs between the first collision detection object and the second collision detection object;

[0054] When the shortest distance is greater than the preset distance, it is determined that the first collision detection object and the second collision detection object do not collide.

[0055] Optionally, the maxillary adjustment module is further used to determine, based on the first collision detection result, that the teeth in the first impact area do not collide with the undercut grid of the maxillary, and the position of the undercut grid of the maxillary remains unchanged. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1A flowchart of a method for avoiding undercuts and occlusions in a digital tooth model according to an embodiment of the present invention;

[0057] Figure 2 A schematic diagram of a process of cyclically updating the undercut mesh of the maxilla to obtain an optimized undercut mesh or a schematic diagram of a process of cyclically updating the undercut mesh of the mandible to obtain an optimized undercut mesh in the tooth digital model undercut occlusal avoidance method according to an embodiment of the present invention;

[0058] Figure 3 For the embodiment of the present invention Figure 2 Schematic diagram of process execution;

[0059] Figure 4 It is a structural block diagram of the device for filling undercuts and occlusal avoidance of a digital tooth model according to an embodiment of the present invention. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the present invention belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0061] In view of the problems existing in the prior art, an embodiment of the present invention provides a method for avoiding undercuts in a digital tooth model. Figure 1 As shown, the following steps are included:

[0062] S101, obtaining a digital tooth model.

[0063] S102, selecting two adjacent teeth at preset occlusal positions in the upper and lower jaws of the digital tooth model, respectively, and obtaining undercut grids of the adjacent teeth in the upper and lower jaws according to the digital tooth grids of the adjacent teeth.

[0064] S103 adjusts the upper and lower jaws of the digital dental model to a preset occlusal position, and determines a first influence area of ​​the undercut grid of the upper jaw in the lower jaw according to the occlusal position, and determines a second influence area of ​​the undercut grid of the lower jaw in the upper jaw according to the occlusal position.

[0065] S104, performing collision detection on the undercut mesh of the maxilla and obtaining a first collision detection result, and optimizing the undercut mesh of the maxilla according to the first collision detection result to obtain an optimized undercut mesh of the maxilla.

[0066] Specifically, a collision detection is performed on the teeth in the first influence area of ​​the mandible and the undercut grid of the maxilla to obtain a first collision detection result. After determining that the teeth in the first influence area and the undercut grid of the maxilla will collide based on the first collision detection result, the undercut grid of the maxilla is cyclically updated to obtain an optimized undercut grid, so that the teeth in the first influence area of ​​the mandible do not collide with the optimized undercut grid of the maxilla.

[0067] S105, performing collision detection on the undercut mesh of the mandible and obtaining a second collision detection result, and optimizing the undercut mesh of the mandible according to the second collision detection result to obtain an optimized undercut mesh of the mandible.

[0068] Specifically, after the optimized undercut mesh of the maxilla is completed, collision detection is performed on the teeth in the second influence area of ​​the maxilla and the optimized undercut mesh of the maxilla with the undercut mesh of the mandible according to the digital model of the teeth to obtain a second collision detection result. After determining that the teeth in the second influence area or the optimized undercut mesh of the maxilla and the undercut mesh of the mandible will collide according to the second collision detection result, the undercut mesh of the mandible is cyclically updated to obtain the optimized undercut mesh, so that the teeth in the second influence area and the optimized undercut mesh of the maxilla do not collide with the optimized undercut mesh of the mandible.

[0069] Since the situation of the opposing jaw is not taken into consideration during the process of filling the undercuts on the digital tooth model, which may interfere with the tooth occlusion process, the undercut filling mesh of the maxilla is optimized and adjusted by the above method, taking into full consideration the collision of the undercut filling mesh of the maxilla with the tooth mesh in the first influence area of ​​the mandible, as well as the collision of the undercut filling mesh of the mandible with the tooth mesh in the second influence area of ​​the maxilla and the optimized undercut filling mesh of the maxilla, the undercut filling mesh of the maxilla and the mandible are respectively updated to the optimized undercut filling mesh, so that the optimized undercut filling mesh of the maxilla and the optimized undercut filling mesh of the mandible will not interfere with the tooth occlusion, thereby effectively improving the wearing feeling of the braces and the correction effect of the braces.

[0070] In some embodiments, the process of performing collision detection on the teeth in the first influence area of ​​the mandible and the undercut mesh of the maxilla in step S104, and the process of performing collision detection on the undercut mesh of the mandible and the teeth in the second influence area of ​​the maxilla and the optimized undercut mesh of the maxilla in step S105 are the same collision detection process, and the collision detection process includes the following steps:

[0071] Select a first collision detection object and a second collision detection object;

[0072] Calculating the shortest distance between the triangle mesh of the first collision detection object and the triangle mesh of the second collision detection object;

[0073] When the shortest distance is less than a preset distance, determining that a collision occurs between the first collision detection object and the second collision detection object;

[0074] When the shortest distance is greater than the preset distance, it is determined that the first collision detection object and the second collision detection object do not collide.

[0075] In the above collision detection process, the shortest distance between the triangular mesh of the first collision detection object and the triangular mesh of the second collision detection object is determined, and whether a collision will occur between the first collision detection object and the second collision detection object is determined based on the size between the calculated shortest distance and the preset distance.

[0076] In this embodiment, the calculation process of the shortest distance between the triangular mesh of the first collision detection object and the triangular mesh of the second collision detection object is as follows: the centroid line between the centroid of the triangular mesh of the first collision detection object and the centroid of the triangular mesh of the second collision detection object is used as a separation axis, and the projections of the grid points of the triangular mesh of the first collision detection object and the grid points of the triangular mesh of the second collision detection object on the separation axis are calculated respectively, and the overlapping length between the projections of the grid points of the triangular mesh of the first collision detection object and the projections of the grid points of the triangular mesh of the second collision detection object are calculated, and the overlapping distance is used as the shortest distance between the triangular mesh of the first collision detection object and the triangular mesh of the second collision detection object.

[0077] Specifically, when the tooth mesh within the first influence area is selected as the first collision detection object, the undercut mesh of the upper jaw is selected as the second collision detection object, thereby completing the collision detection process of the teeth within the first influence area of ​​the mandible and the undercut mesh of the upper jaw based on the shortest distance between the triangular mesh of the first collision detection object and the triangular mesh of the second collision detection object.

[0078] When the undercut mesh of the mandible is selected as the first collision detection object, the tooth mesh within the second influence area of ​​the maxilla and the optimized undercut mesh of the maxilla are selected as the second collision detection objects respectively to complete the collision detection process for the undercut mesh of the mandible, which will not be repeated here.

[0079] In some embodiments, during the above-mentioned detection process, the method also includes determining, based on the first collision detection result, that the teeth in the first impact area do not collide with the undercut grid of the upper jaw, and the position of the undercut grid of the upper jaw remains unchanged. After determining that no collision will occur, there is no need to adjust the undercut grid of the upper jaw, thereby reducing the operation process.

[0080] In some embodiments, the preset distance satisfies the following formula:

[0081]

[0082] Among them, L represents the preset distance, h represents the thickness of the dental appliance diaphragm, N represents the number of layers of the dental appliance diaphragm, and B represents the initial deviation value. While determining the preset distance according to the thickness and number of layers of the dental appliance diaphragm, the preset distance is also optimized by the initial deviation value to effectively reduce the error of the preset distance, thereby ensuring that the result of judging whether a collision will occur between the first collision detection object and the second collision detection object by the size of the shortest distance and the preset distance is more accurate.

[0083] In some embodiments, the process of cyclically updating the undercut mesh of the maxillary cavity to obtain an optimized undercut mesh or the process of cyclically updating the undercut mesh of the mandibular cavity to obtain an optimized undercut mesh is as follows: Figure 2 As shown, the following steps are included:

[0084] S201, obtaining an initial undercut grid of two adjacent teeth in a target affected area, obtaining a first midpoint of a line connecting the centers of the digitized grids of the two adjacent teeth according to the initial undercut grid, and using the first midpoint as an initial midpoint;

[0085] S202, updating the adjustment times, and obtaining the adjustment distance according to the adjustment times;

[0086] S203, moving the initial midpoint in the gum direction to adjust the distance to obtain a middle midpoint, and obtaining a middle undercut grid according to the middle midpoint;

[0087] S204, determining the difference between the shortest distance between the target collision object and the middle undercut grid of the opposing jaw and a preset distance, if the shortest distance is greater than the preset distance, executing step S206, otherwise executing step S205;

[0088] S205, taking the current middle midpoint as the initial midpoint of the next round, and executing steps S202 to S204;

[0089] S206, taking the middle undercut-filling grid obtained last time as the target optimized undercut-filling grid;

[0090] Wherein, when the target impact area is the second impact area, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the maxilla, and the target collision object is the tooth mesh in the first impact area;

[0091] When the target impact region is the first impact region, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the mandible, and the target collision object is the tooth mesh in the second impact region and the optimized undercut-filling mesh of the maxilla.

[0092] In some other embodiments, the second influence area is selected as the target influence area, the optimized undercut mesh of the maxilla is used as the target optimized undercut mesh, and the target collision object is the tooth mesh in the first influence area, to illustrate the above process.

[0093] Please refer to Figure 3 First, obtain the initial undercut grid of two adjacent teeth in the second influence area, that is, the undercut grid of the maxilla, and obtain the first midpoint of the line connecting the centers of the digitized grids of the two adjacent teeth based on the initial undercut grid, and use the first midpoint as the initial midpoint, and then update the number of adjustments. Since this is the first adjustment, the number of adjustments is updated to 1, and the number of adjustments is the initial value 1 at this time. Each subsequent update of the number of adjustments is incremented by 1, and then the current distance to be adjusted is obtained based on the number of adjustments. After obtaining the adjustment distance, move the current initial midpoint toward the gingival direction by the adjustment distance to obtain the middle midpoint, and then the middle undercut grid can be obtained based on the middle midpoint.

[0094] Among them, the process of obtaining the middle undercut grid based on the middle midpoint includes: first, the middle midpoint is used as the center of the sampling circle, and the plane perpendicular to the line connecting the centers of the digitized grids of the two adjacent teeth is used as the plane where the sampling circle is located, and then according to the preset radius, a complete sampling circle can be obtained, and then a group of sampling points are uniformly sampled on the circumference of the initial sampling circle, and then the distances between each vertex in the digital grid of the teeth of the two adjacent tooth models and each of the sampling points are calculated, and the points with the smallest distance are selected from the two tooth models as corresponding points, thereby obtaining two groups of corresponding points, and then interpolation circles are added between the two groups of corresponding points, and the interpolation points in the interpolation circles and the two groups of target corresponding points are connected through triangular meshes to form a closed grid of tooth undercuts, thereby obtaining the middle undercut grid.

[0095] It should be noted that the initial filling grid and the intermediate filling grid can be obtained by the method in the prior art. This solution does not involve improvement on the method of obtaining the filling grid, which will not be described here.

[0096] After obtaining the middle undercut grid, step S400 is executed to determine the size of the shortest distance between the tooth digital grid in the first influence area and the middle undercut grid of the maxilla and the preset distance, so as to determine whether the current middle undercut grid will collide with the tooth digital grid of the opposite jaw. If it is determined that the shortest distance is less than the preset distance, it is determined that the currently adjusted middle undercut grid will collide with the tooth digital grid of the opposite jaw, that is, it will collide with the tooth grid in the first influence area, and the current maxillary undercut grid needs to be further optimized, and step S500 is executed, and the current middle midpoint is used as the initial midpoint of the next round, and steps S200 to S400 are continued; and when the shortest distance is greater than the preset distance, step S600 is executed, and it can be determined that the current middle undercut grid will not collide with the tooth digital grid in the first influence area of ​​the opposite jaw, so the current middle undercut grid can be used as the final undercut grid, and the middle undercut grid is used as the optimized undercut grid of the maxilla, thereby completing the optimization process of the maxillary undercut grid.

[0097] In some other embodiments, the first influence area is selected as the target influence area, and the optimized undercut mesh of the mandible is selected as the target optimized undercut mesh, and the target collision object is the tooth mesh in the second influence area and the optimized undercut mesh of the maxilla.

[0098] First, obtain the initial undercut grid of two adjacent teeth in the first influence area, that is, the initial undercut grid of the mandible, and obtain the first midpoint of the line connecting the digitized grid centers of the two adjacent teeth of the initial undercut grid of the mandible based on the initial undercut grid, and use the first midpoint as the initial midpoint, then update the number of adjustments, and since this is the first adjustment, the number of adjustments is updated to 1, and then the current distance to be adjusted is obtained based on the number of adjustments. After obtaining the adjustment distance, move the current initial midpoint toward the gum direction by the adjustment distance to obtain the middle midpoint, and then the middle undercut grid can be obtained based on the middle midpoint.

[0099] After the middle undercut grid is obtained, step S400 is executed to determine the size of the shortest distance between the target collision object and the middle undercut grid of the opposing jaw and the preset distance, that is, the size of the shortest distance between the tooth grid in the second influence area and the optimized undercut grid of the maxilla and the middle undercut grid of the mandible and the preset distance, so as to determine whether the current middle undercut grid will collide with the tooth grid in the second influence area and the optimized undercut grid of the maxilla. If it is determined that at least one of the shortest distances of the tooth grid in the second influence area and the optimized undercut grid of the maxilla is less than the preset distance, then the tooth grid in the second influence area or the optimized undercut grid of the maxilla is determined to be less than the preset distance. The optimized undercut grid will collide with the digital grid of the teeth of the opposite jaw, and the current undercut grid of the maxilla needs to be further optimized, and step S500 is executed, and the current middle midpoint is used as the initial midpoint of the next round, and steps S200 to S400 are continued; and when the shortest distance is greater than the preset distance, step S600 is executed, and it can be determined that the current middle undercut grid will not collide with the tooth grid in the second influence area and the optimized undercut grid of the maxilla, so the current middle undercut grid can be used as the final undercut grid, and the middle undercut grid is used as the optimized undercut grid of the mandible, thereby completing the optimization process of the undercut grid of the mandible.

[0100] In some embodiments, the adjustment distance satisfies the following formula:

[0101]

[0102] Among them, n is the number of adjustments, n is a positive integer, M represents the preset adjustment distance of the nth adjustment of the undercut grid, A represents the initial adjustment distance of the undercut grid, and X represents the increase ratio of each adjustment of the preset adjustment distance, so that when the undercut grid is adjusted according to the adjustment distance, the adjustment accuracy is higher each time.

[0103] The present invention also provides a tooth digital model filling undercut occlusion avoidance device, such as Figure 4 As shown, including:

[0104] A tooth model acquisition module 401 is used to acquire a tooth digital model;

[0105] An undercut acquisition module 402 is used to select two adjacent teeth at preset occlusal positions in the upper and lower jaws of the digital tooth model, and acquire undercut grids of the adjacent teeth in the upper and lower jaws according to the digital tooth grids of the adjacent teeth;

[0106] The influence area determination module 403 is used to adjust the upper and lower jaws of the digital tooth model to a preset occlusal position, and determine the first influence area of ​​the undercut mesh of the upper jaw in the lower jaw according to the occlusal position, and determine the second influence area of ​​the undercut mesh of the lower jaw in the upper jaw according to the occlusal position;

[0107] The maxillary adjustment module 404 is configured to perform collision detection on the teeth in the first influence area of ​​the mandible and the undercut mesh of the maxillary to obtain a first collision detection result, and after determining that the teeth in the first influence area and the undercut mesh of the maxillary will collide according to the first collision detection result, cyclically update the undercut mesh of the maxillary to obtain an optimized undercut mesh, so that the teeth in the first influence area of ​​the mandible and the optimized undercut mesh of the maxillary will not collide;

[0108] The mandibular adjustment module 405 is used to perform collision detection on the teeth in the second influence area of ​​the maxilla and the optimized undercut grid of the maxilla with the undercut grid of the mandibular according to the tooth digital model after the optimized undercut grid of the maxilla is completed, and obtain a second collision detection result; after determining that the teeth in the second influence area or the optimized undercut grid of the maxilla will collide with the undercut grid of the mandibular according to the second collision detection result, the undercut grid of the mandibular is cyclically updated to obtain the optimized undercut grid, so that the teeth in the second influence area and the optimized undercut grid of the maxilla will not collide with the optimized undercut grid of the mandibular.

[0109] In some embodiments, the upper jaw adjustment module 404 and the lower jaw adjustment module 405 are also used to implement the following process:

[0110] S201, obtaining an initial undercut grid of two adjacent teeth in a target affected area, obtaining a first midpoint of a line connecting the centers of the digitized grids of the two adjacent teeth according to the initial undercut grid, and using the first midpoint as an initial midpoint;

[0111] S202, updating the adjustment times, and obtaining the adjustment distance according to the adjustment times;

[0112] S203, moving the initial midpoint in the gum direction to adjust the distance to obtain a middle midpoint, and obtaining a middle undercut grid according to the middle midpoint;

[0113] S204, determining the difference between the shortest distance between the target collision object and the middle undercut grid of the opposing jaw and a preset distance, if the shortest distance is greater than the preset distance, executing step S206, otherwise executing step S205;

[0114] S205, taking the current middle midpoint as the initial midpoint of the next round, and executing steps S202 to S204;

[0115] S206, taking the middle undercut-filling grid obtained last time as the target optimized undercut-filling grid;

[0116] Wherein, when the target impact area is the second impact area, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the maxilla, and the target collision object is the tooth mesh in the first impact area;

[0117] When the target impact region is the first impact region, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the mandible, and the target collision object is the tooth mesh in the second impact region and the optimized undercut-filling mesh of the maxilla.

[0118] In some embodiments, the upper jaw adjustment module 404 and the lower jaw adjustment module 405 are also used to implement the following process:

[0119] Select a first collision detection object and a second collision detection object;

[0120] Calculate the shortest distance between the triangle mesh of the first collision detection object and the triangle mesh of the second collision detection object;

[0121] When the shortest distance is less than a preset distance, determining that a collision occurs between the first collision detection object and the second collision detection object;

[0122] When the shortest distance is greater than the preset distance, it is determined that the first collision detection object and the second collision detection object do not collide.

[0123] In some embodiments, the maxillary adjustment module 404 is further used to determine, based on the first collision detection result, that the teeth in the first impact area do not collide with the undercut grid of the maxilla, and the position of the undercut grid of the maxilla remains unchanged.

[0124] Since the various modules of the above-mentioned tooth digital model filling undercut occlusion avoidance device correspond one to one with the working principles of the above-mentioned tooth digital model filling undercut occlusion avoidance method, they will not be described in detail here.

[0125] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. A method for avoiding undercuts in a digital tooth model, characterized in that: include: Get a digital model of your teeth; Select two adjacent teeth at preset occlusal positions in the upper and lower jaws of the digital tooth model, respectively, and obtain undercut grids of the adjacent teeth in the upper and lower jaws according to the digital tooth grids of the adjacent teeth; Adjusting the upper and lower jaws of the digital dental model to a preset occlusal position, and determining a first influence area of ​​the undercut grid of the upper jaw in the lower jaw according to the occlusal position, and determining a second influence area of ​​the undercut grid of the lower jaw in the upper jaw according to the occlusal position; performing collision detection on the teeth in the first influence area of ​​the mandible and the undercut mesh of the maxilla to obtain a first collision detection result, and after determining that the teeth in the first influence area and the undercut mesh of the maxilla will collide according to the first collision detection result, cyclically updating the undercut mesh of the maxilla to obtain an optimized undercut mesh, so that the teeth in the first influence area of ​​the mandible do not collide with the optimized undercut mesh of the maxilla; After the optimized undercut mesh of the maxilla is completed, collision detection is performed on the teeth in the second influence area of ​​the maxilla and the optimized undercut mesh of the maxilla with the undercut mesh of the mandible according to the digital tooth model to obtain a second collision detection result. After determining that the teeth in the second influence area or the optimized undercut mesh of the maxilla and the undercut mesh of the mandible will collide according to the second collision detection result, the undercut mesh of the mandible is cyclically updated to obtain the optimized undercut mesh, so that the teeth in the second influence area and the optimized undercut mesh of the maxilla do not collide with the optimized undercut mesh of the mandible.

2. The method for avoiding undercuts in a digital tooth model according to claim 1, characterized in that: The collision detection process includes: Select a first collision detection object and a second collision detection object; Calculate the shortest distance between the triangle mesh of the first collision detection object and the triangle mesh of the second collision detection object; When the shortest distance is less than a preset distance, determining that a collision occurs between the first collision detection object and the second collision detection object; When the shortest distance is greater than the preset distance, it is determined that the first collision detection object and the second collision detection object do not collide.

3. The method for avoiding undercuts in a digital tooth model according to claim 2, characterized in that: The preset distance satisfies the following formula: Wherein, L represents the preset distance, h represents the thickness of the dental appliance membrane, N represents the number of layers of the dental appliance membrane, and B represents the initial deviation value.

4. The method for avoiding undercuts in a digital tooth model according to any one of claims 1 to 3, characterized in that: The process of cyclically updating the undercut mesh of the maxilla to obtain the optimized undercut mesh or the process of cyclically updating the undercut mesh of the mandible to obtain the optimized undercut mesh comprises: S201, obtaining an initial undercut grid of two adjacent teeth in a target affected area, obtaining a first midpoint of a line connecting the centers of the digitized grids of the two adjacent teeth according to the initial undercut grid, and using the first midpoint as an initial midpoint; S202, updating the adjustment times, and obtaining the adjustment distance according to the adjustment times; S203, moving the initial midpoint in the gum direction to adjust the distance to obtain a middle midpoint, and obtaining a middle undercut grid according to the middle midpoint; S204, determining the difference between the shortest distance between the target collision object and the middle undercut grid of the opposing jaw and a preset distance, if the shortest distance is greater than the preset distance, executing step S206, otherwise executing step S205; S205, taking the current middle midpoint as the initial midpoint of the next round, and executing steps S202 to S204; S206, taking the middle undercut-filling grid obtained last time as the target optimized undercut-filling grid; Wherein, when the target impact area is the second impact area, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the maxilla, and the target collision object is the tooth mesh in the first impact area; When the target impact region is the first impact region, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the mandible, and the target collision object is the tooth mesh in the second impact region and the optimized undercut-filling mesh of the maxilla.

5. The method for avoiding undercuts in a digital tooth model according to claim 4, characterized in that: The adjustment distance satisfies the following formula: Wherein, n is the number of adjustments, n is a positive integer, M represents the preset adjustment distance of the nth adjustment of the undercut grid, A represents the initial adjustment distance of the undercut grid, and X represents the increase ratio of each adjustment of the preset adjustment distance.

6. The method for avoiding undercuts in a digital tooth model according to claim 1, characterized in that: The method also includes determining, based on the first collision detection result, that the teeth in the first impact area do not collide with the undercut grid of the maxilla, and the position of the undercut grid of the maxilla remains unchanged.

7. A tooth digital model filling undercut occlusion avoidance device, characterized in that: include: A tooth model acquisition module is used to acquire a tooth digital model; An undercut acquisition module is used to select two adjacent teeth at preset occlusal positions in the upper and lower jaws of the digital tooth model, and acquire the undercut grids of the adjacent teeth in the upper and lower jaws according to the digital tooth grids of the adjacent teeth; An influence region determination module, used for adjusting the upper and lower jaws of the digital tooth model to a preset occlusal position, and determining a first influence region of the undercut grid of the upper jaw in the lower jaw according to the occlusal position, and determining a second influence region of the undercut grid of the lower jaw in the upper jaw according to the occlusal position; an upper jaw adjustment module, configured to perform collision detection on the teeth in the first influence area of ​​the lower jaw and the undercut mesh of the upper jaw to obtain a first collision detection result, and after determining according to the first collision detection result that the teeth in the first influence area and the undercut mesh of the upper jaw will collide, cyclically update the undercut mesh of the upper jaw to obtain an optimized undercut mesh, so that the teeth in the first influence area of ​​the lower jaw do not collide with the optimized undercut mesh of the upper jaw; A mandibular adjustment module is used to perform collision detection on the teeth in the second influence area of ​​the maxilla, the optimized undercut grid of the maxilla and the undercut grid of the mandible respectively according to the tooth digital model after the optimized undercut grid of the maxilla is completed to obtain a second collision detection result; after determining that the teeth in the second influence area or the optimized undercut grid of the maxilla will collide with the undercut grid of the mandible according to the second collision detection result, the undercut grid of the mandible is cyclically updated to obtain the optimized undercut grid, so that the teeth in the second influence area and the optimized undercut grid of the maxilla will not collide with the optimized undercut grid of the mandible.

8. The tooth digital model filling undercut occlusion avoidance device according to claim 7, characterized in that: The upper jaw adjustment module and the lower jaw adjustment module are also used to implement the following process: S201, obtaining an initial undercut grid of two adjacent teeth in a target affected area, obtaining a first midpoint of a line connecting the centers of the digitized grids of the two adjacent teeth according to the initial undercut grid, and using the first midpoint as an initial midpoint; S202, updating the adjustment times, and obtaining the adjustment distance according to the adjustment times; S203, moving the initial midpoint in the gum direction to adjust the distance to obtain a middle midpoint, and obtaining a middle undercut grid according to the middle midpoint; S204, determining the difference between the shortest distance between the target collision object and the middle undercut grid of the opposing jaw and a preset distance, if the shortest distance is greater than the preset distance, executing step S206, otherwise executing step S205; S205, taking the current middle midpoint as the initial midpoint of the next round, and executing steps S202 to S204; S206, taking the middle undercut-filling grid obtained last time as the target optimized undercut-filling grid; Wherein, when the target impact area is the second impact area, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the maxilla, and the target collision object is the tooth mesh in the first impact area; When the target impact region is the first impact region, the target optimized undercut-filling mesh is the optimized undercut-filling mesh of the mandible, and the target collision object is the tooth mesh in the second impact region and the optimized undercut-filling mesh of the maxilla.

9. The tooth digital model filling undercut occlusion avoidance device according to claim 7, characterized in that: The upper jaw adjustment module and the lower jaw adjustment module are also used to implement the following process: Select a first collision detection object and a second collision detection object; Calculate the shortest distance between the triangle mesh of the first collision detection object and the triangle mesh of the second collision detection object; When the shortest distance is less than a preset distance, determining that a collision occurs between the first collision detection object and the second collision detection object; When the shortest distance is greater than the preset distance, it is determined that the first collision detection object and the second collision detection object do not collide.

10. The tooth digital model filling undercut occlusion avoidance device according to claim 7, characterized in that: The maxillary adjustment module is further used to determine, based on the first collision detection result, that the teeth in the first impact area do not collide with the undercut grid of the maxillary, and the position of the undercut grid of the maxillary remains unchanged.

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