Automatic tooth alignment method and system for generating a personalized dental arch based on an ideal dental arch

Abstract

The present application relates to an automatic tooth arrangement method and system for generating a personalized dental arch based on an ideal dental arch, fitting polynomial coefficients according to a dental arch form given by medicine as template data, generating an ideal dental arch curve in a two-dimensional space according to the template data, projecting the ideal dental arch curve to a three-dimensional space, generating initial tooth hanging points on the dental arch line according to tooth width and FACC center point position, taking tooth No. 6 as a reference tooth position if there is no designated fitting tooth position, taking the designated fitting tooth position as a reference if there is a designated fitting tooth position, and generating a personalized tooth arrangement dental arch curve. The present application generates a tooth arrangement dental arch that fits the teeth according to the ideal dental arch constructed and different tooth forms, thereby realizing automatic tooth arrangement. The tooth arrangement method proposed in the present application can automatically generate a reasonable and beautiful tooth arrangement dental arch, greatly reducing the time length of manual tooth arrangement.

Description

Technical Field

[0001] This invention relates to the field of orthodontics, and more particularly to an automated tooth alignment method, system, and application for generating a personalized dental arch based on an ideal dental arch. Background Technology

[0002] Dentofacial deformity is an oral disease. Malformed teeth can affect the development of the dentofacial region, impacting oral health and function, and consequently affecting facial appearance.

[0003] Currently, in invisible orthodontic treatment, teeth alignment is mostly done manually by a designer based on the doctor's instructions, which is very time-consuming and unstable. This invention provides a solution to the problems of time-consuming and unstable teeth alignment in existing methods. Summary of the Invention

[0004] The technical problem to be solved by this invention is to design an automatic tooth arrangement method and system for generating personalized dental arches based on ideal dental arches, thereby solving the existing technical problems.

[0005] To solve the above-mentioned technical problems, the automatic tooth arrangement method of the present invention, which generates a personalized dental arch based on an ideal dental arch, includes the following steps:

[0006] Step S1: Based on the dental arch morphology given by medical orthodontics, use mathematical methods to fit the polynomial coefficients, as well as the width of the teeth and the position of the FACC center point, to generate an ideal dental arch curve. The polynomial coefficients are the parameters of the dental arch.

[0007] Step S2: Generate a personalized dental arch. If no tooth position is specified, tooth number 6 is used as the reference tooth position by default. If a tooth position is specified, the tooth arrangement curve is generated based on the position of the specified tooth.

[0008] Step S3: Dental arch generation and tooth attachment. This step is a coarse-grained arrangement. After the coarse arrangement, there are still some collisions and gaps between the teeth. Therefore, the OBB Tree (Oriented Bounding Box Tree) hierarchical bounding box detection method is used to eliminate collisions and gaps. The OBB Tree algorithm is briefly described as follows: an intersection detection method based on the separating axis theorem. According to the separating axis theorem, it projects onto 15 axes respectively, and determines the positional relationship of the OBB Tree bounding boxes based on different projection intervals.

[0009] Furthermore, step S1 includes the following steps:

[0010] Step S11: Based on the dental arch morphology provided by medical experts, pixel information of the dental arch is obtained using pixel extraction methods. The least squares method is then used to fit polynomial coefficients, which serve as template data for the dental arch and also as parameters for fitting the arch. The polynomial function is shown in the formula below, and the fitted coefficients a, b, c, and d are used as parameters of the dental arch.

[0011] b ;

[0012] Step S12: Generate the ideal dental arch curve in two-dimensional space based on the template data;

[0013] Step S13: Based on the data from the jaw plane, project the ideal dental arch curve into three-dimensional space;

[0014] Step S14: Based on the known tooth width and FACC center point position, generate the initial tooth attachment points on the dental arch line;

[0015] Step S15: Take the data of the attachment points of certain teeth in the dental arch (such as teeth 13, 16, and 18) and the intersection of the line connecting the center points of the FACC of two teeth No. 1 in the mid-incisal plane as the control point of the dental arch.

[0016] Furthermore, in step S14, the position of a single tooth on the dental arch is determined by the distance method, namely the start index and the end index; then, the midpoint is found by the range of each tooth on the dental arch, and this midpoint is the attachment point of the tooth on the dental arch line.

[0017] Furthermore, step S2 includes the following steps:

[0018] Step S21: If no tooth position is specified for cladding, calculate the distance from the center point of the FACC of the two initial No. 6 teeth to the incisal plane, and take the one with the larger distance as the reference tooth position A; if a tooth position is specified for cladding, select the tooth with the largest locked tooth position ID in a single quadrant as the reference tooth position A.

[0019] Step S22: Based on the reference tooth position A known in step S21, calculate the tooth position in the same position in another quadrant as the reference tooth position B;

[0020] Step S23: Based on the dental arch data generated in steps S22 and S1, extract the dental arch origin and the FACC center points of the two reference tooth positions, and construct plane P;

[0021] Step S24: Reproject the dental arch onto the new plane P so that its height matches the actual height of the FACC center point of the tooth;

[0022] Step S25: Perform arch expansion and contraction operations on the dental arch;

[0023] Step S26: If the initial dental arch data has a Spee curve, add the dental arch deformation of the Spee curve; this deformation is also applied to the TPS algorithm for deformation;

[0024] Step S27: Finally, generate a personalized dental arch as the tooth arrangement curve.

[0025] Furthermore, the steps of the arch expansion and contraction operation in Step S25 are as follows:

[0026] Step S25a: Calculate the points on the dental arch curve, the point a that is closest to the FACC center point of the reference tooth position A, loop through the points on the dental arch, and calculate the closest point to the specified tooth position;

[0027] Step S25b: Calculate the distance between point a and the FACC center point of the reference tooth position, and this distance is used as the reference distance for arch expansion and contraction;

[0028] Step S25c: Calculate the distance dist1 between point a and the mid-sagittal plane, and calculate the distance dist2 between the FACC center point of the reference tooth position and the mid-sagittal plane. If dist1 > dist2, perform arch contraction; if dist1 < dist2, perform arch expansion;

[0029] Step S25d: For dental arch deformation, use the TPS thin plate spline deformation process, calculate the ratio according to the distance of arch expansion and contraction and the distance from the mid-sagittal plane, denoted as ratio; the algorithm input has control points and target points, and the input control points are the attachment point data generated by the initial dental arch (ideal dental arch), and the attachment point data is as shown in Step S14;

[0030] Step S25e: For the initial attachment point data, calculate the distance from the mid-sagittal plane, and then calculate the new attachment points according to the ratio of the distance ratio, and the new attachment points are used as target points;

[0031] Step S25f: Based on the TPS algorithm, obtain the dental arch data after arch expansion and contraction.

[0032] Furthermore, if the medical order indicates that slice preparation is required, use the methods of collision detection and tooth movement to automatically perform slice preparation and meet the required amount of slice preparation by the doctor.

[0033] Furthermore, if there is tooth extraction operation, perform the post-processing operation of the anchorage threshold. If the anchorage is 1.0 mm, set the distance of the 6th tooth moving 1 mm in the labial direction in the sagittal plane. The 6th tooth movement matrix is also used for the overall tooth movement at other tooth positions to arrange a reasonable tooth extraction case tooth arrangement plan.

[0034] The present invention also provides an automatic tooth arrangement system for generating a personalized dental arch based on an ideal dental arch, including:

[0035] One or more processors; and

[0036] One or more memories storing a computer-executable program, wherein the aforementioned method is performed when the processor executes the computer-executable program.

[0037] The beneficial effects of this invention are as follows: The automatic tooth arrangement method and system based on an ideal dental arch to generate personalized dental arches generate tooth arrangement arches that fit the teeth according to different tooth morphologies, thereby achieving automatic tooth arrangement. This invention can greatly reduce the workload of manual tooth arrangement and provide better tooth arrangement solutions, enabling medical designers to better arrange teeth. The tooth arrangement method proposed in this invention can automatically generate reasonable and aesthetically pleasing dental arches, greatly reducing the time required for manual tooth arrangement. Attached Figure Description

[0038] The specific embodiments of the present invention will be further explained below with reference to the accompanying drawings.

[0039] Figure 1 A flowchart for generating a personalized dental arch;

[0040] Figure 2 This is a schematic diagram of the initial dental arch and tooth positions;

[0041] Figure 3 A schematic diagram for determining the expansion and contraction of the dental arch based on the distance relationship between the initial dental arch and the specified tooth position;

[0042] Figure 4 A diagram illustrating how a personalized dental arch fits the actual tooth position;

[0043] Figure 5 This is a schematic diagram of the initial tooth position in a tooth extraction case;

[0044] Figure 6 This is a schematic diagram of the target tooth position with an anchorage of 1.0 mm. Detailed Implementation

[0045] Combination Figures 1-6 The automatic tooth arrangement method of the present invention, which generates a personalized dental arch based on an ideal dental arch, includes the following steps:

[0046] Step S1: Based on the dental arch morphology provided by medical orthodontics, mathematical methods are used to fit polynomial coefficients, tooth widths, and the position of the FACC center point to generate an ideal dental arch curve. The polynomial coefficients represent the parameters of the dental arch, such as... Figure 2 As shown;

[0047] Step S1 includes the following steps:

[0048] Step S11: Based on the dental arch morphology provided by medical experts, pixel information of the dental arch is obtained using pixel extraction methods. The least squares method is then used to fit polynomial coefficients, which serve as template data for the dental arch and also as parameters for fitting the arch. The polynomial function is shown in the formula below, and the fitted coefficients a, b, c, and d are used as parameters of the dental arch.

[0049] b ;

[0050] Step S12: Generate the ideal dental arch curve in two-dimensional space based on the template data;

[0051] Step S13: Based on the data from the jaw plane, project the ideal dental arch curve into three-dimensional space;

[0052] Step S14: Based on the known tooth width and FACC center point position, generate the initial attachment points of the teeth on the dental arch line; determine the position of a single tooth on the dental arch using the distance method, i.e., the start index and end index; then find the midpoint of each tooth within the range of the dental arch, which is the attachment point of the tooth on the dental arch line.

[0053] Step S15: Take the data of the attachment points of certain teeth in the dental arch (such as teeth 13, 16, and 18) and the intersection of the line connecting the center points of the FACC of two teeth No. 1 in the mid-incisal plane as the control point of the dental arch.

[0054] Step S2: Generate a personalized dental arch. If no specific tooth position is specified, tooth #6 is used as the reference tooth position by default. If a specific tooth position is specified, the tooth alignment curve is generated based on the position of the specified tooth, such as... Figure 4 As shown; step S2 includes the following steps:

[0055] Step S21: If no tooth position is specified for cladding, calculate the distance from the center point of the FACC of the two initial No. 6 teeth to the incisal plane, and take the one with the larger distance as the reference tooth position A; if a tooth position is specified for cladding, select the tooth with the largest locked tooth position ID in a single quadrant as the reference tooth position A.

[0056] Step S22: Based on the reference tooth position A known in step S21, calculate the tooth position in the same position in another quadrant as the reference tooth position B;

[0057] Step S23: Based on the dental arch data generated in steps S22 and S1, extract the dental arch origin and the FACC center points of the two reference tooth positions, and construct plane P;

[0058] Step S24: Reproject the dental arch onto the new plane P so that its height matches the actual height of the FACC center point of the tooth;

[0059] Step S25: Perform arch expansion and constriction operations on the dental arch; the steps of the arch expansion and constriction operations are as follows:

[0060] Step S25a: Calculate the points on the dental arch curve, and find the point a that is closest to the FACC center point of the reference tooth position A. As Figure 2 shown, loop through the points on the dental arch to calculate the closest point to the specified tooth position;

[0061] Step S25b: Calculate the distance between point a and the FACC center point of the reference tooth position, and this distance is used as the reference distance for arch expansion and constriction;

[0062] Step S25c: Calculate the distance dist1 from point a to the mid-sagittal plane, and calculate the distance dist2 from the FACC center point of the reference tooth position to the mid-sagittal plane. If dist1 > dist2, perform constriction treatment on the arch; if dist1 < dist2, perform expansion treatment on the arch. As Figure 3 shown;

[0063] Step S25d: For the deformation of the dental arch, use the TPS thin plate spline deformation method to perform proportional calculation based on the distance of arch expansion and constriction and the distance from the mid-sagittal plane, denoted as ratio; the input of the algorithm includes control points and target points, and the input control points are the attachment point data generated by the initial dental arch (ideal dental arch), and the attachment point data is as shown in Step S14;

[0064] Step S25e: For the initial attachment point data, calculate the distance from the mid-sagittal plane, and then calculate the new attachment point according to the ratio ratio of the distance. The new attachment point is used as the target point;

[0065] Step S25f: Based on the TPS algorithm, obtain the dental arch data after arch expansion and constriction. As Figure 4 shown.

[0066] Step S26: If the initial dental arch data has a Spee curve, add the dental arch deformation of the Spee curve; this deformation also uses the TPS algorithm for deformation; the principle of the TPS algorithm is as follows:

[0067] (a) Input a set of three-dimensional control point sets C;

[0068] (b) Construct matrix P, ;

[0069] (c) The form of the basis function is: , where r is the Euler distance between two points;

[0070] Construct matrix K, ;

[0071] (d) Construct matrix L, ;

[0072] (e) Then set the target point coordinates to form a matrix as follows: , = That is, LW=Y; given L and Y, the transformation matrix W is obtained;

[0073] Step S27: Finally, generate a personalized dental arch as the tooth arrangement curve.

[0074] Step S3: Dental arch generation and tooth attachment. This step is a coarse-grained arrangement. After the coarse arrangement, there are still some collisions and gaps between the teeth. Therefore, the OBB Tree (Oriented Bounding Box Tree) hierarchical bounding box detection method is used to eliminate collisions and gaps. The OBB Tree algorithm is briefly described as follows: an intersection detection method based on the separating axis theorem. According to the separating axis theorem, it projects onto 15 axes respectively, and determines the positional relationship of the OBB Tree bounding boxes based on different projection intervals.

[0075] In this preferred embodiment, if the doctor's order indicates that a slicing operation is required, the slicing amount is automatically provided using collision detection and tooth movement methods, and the slicing amount is met as required by the doctor.

[0076] In this preferred embodiment, if a tooth extraction is performed, a post-processing operation of the anchorage threshold is performed. If the anchorage is 1.0 mm, tooth 6 is moved 1 mm labially in the sagittal direction. The tooth 6 movement matrix is ​​also used to move the entire tooth in other tooth positions to generate a reasonable tooth arrangement plan for the extraction case.

[0077] This embodiment also provides an automated tooth alignment system that generates a personalized dental arch based on an ideal dental arch, including:

[0078] One or more processors; and

[0079] One or more memories storing a computer-executable program, wherein the aforementioned method is performed when the processor executes the computer-executable program.

[0080] This embodiment of the automatic tooth arrangement method and system, based on an ideal dental arch to generate personalized dental arches, automatically arranges teeth by constructing an ideal dental arch and generating a dental arch that fits the teeth according to different tooth morphologies. This invention can significantly reduce the workload of manual tooth arrangement and provides better tooth arrangement solutions, enabling medical designers to better arrange teeth. The proposed method for generating tooth arrangement that fits various teeth can automatically generate reasonable and aesthetically pleasing dental arches, greatly reducing the time required for manual tooth arrangement.

[0081] Many specific details have been set forth in the foregoing description to provide a thorough understanding of the present invention. However, the above description is merely a preferred embodiment of the present invention, and the present invention can be implemented in many other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed above. Furthermore, any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, using the methods and techniques disclosed above, without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. An automated tooth arrangement method for generating a personalized dental arch based on an ideal dental arch, characterized in that: It includes the following steps: Step S1: According to the dental arch form given by medical orthodontics, use mathematical methods to fit the polynomial coefficients, the width of the teeth, and the position of the FACC center point, generate an ideal dental arch curve, and the polynomial coefficients are the parameters of the dental arch; Step S2: Generate a personalized dental arch. If there is no specified tooth position to fit, default to use the 6th tooth as the reference tooth position; if there is a specified tooth position to fit, then use the position of the specified tooth to fit as the reference to generate a tooth arrangement curve that fits the current teeth; Step S3: Generate the dental arch, hang the teeth. This step is a rough arrangement operation. After the rough arrangement, there are certain collisions and gaps between the teeth, then use the method of OBB Tree hierarchical bounding box tree detection to eliminate the collision gaps; Step S2 includes the following steps: Step S21: If there is no specified tooth position to fit, calculate the distance from the FACC center points of the initial two 6th teeth to the median plane, and take the one with the larger distance as the reference tooth position A; if there is a specified tooth position to fit, then select the tooth with the largest locked tooth position ID in a single quadrant as the reference tooth position A; Step S22: According to the reference tooth position A known in Step S21, calculate the tooth position in the same position in another quadrant as the reference tooth position B; Step S23: According to the dental arch data generated in Step S22 and Step S1, take out the origin of the dental arch and the FACC center points of the two reference tooth positions to construct a plane P; Step S24: Reproject the dental arch onto the new plane P so that the height fits the height of the FACC center points of the actual teeth; Step S25: Perform arch expansion and contraction operations on the dental arch; Step S26: If the initial dental arch data has a Spee curve, add a Spee curve dental arch deformation; this deformation is also applied to the TPS algorithm for deformation; Step S27: Finally, generate a personalized dental arch as the tooth arrangement curve; The steps of the arch expansion and contraction operation in Step S25 are as follows: Step S25a: Calculate the points on the dental arch curve, the point a closest to the FACC center point of the reference tooth position A, loop through the points on the dental arch, and calculate the closest point to the specified tooth position; Step S25b: Calculate the distance from point a to the FACC center point of the reference tooth position A, and this distance is used as the reference distance for arch expansion and contraction; Step S25c: Calculate the distance dist1 from point a to the median plane, and calculate the distance dist2 from the FACC center point of the reference tooth position to the median plane. If dist1 > dist2, perform a contraction arch operation; if dist1 < dist2, perform an expansion arch operation; Step S25d: For the dental arch deformation, use the TPS thin plate spline deformation processing, calculate the ratio according to the distance of arch expansion and contraction and the distance to the median plane, denoted as ratio; Among them, the algorithm input has control points and target points, and the input control points are the hanging point data generated by the initial dental arch; Step S25e: For the initial hanging point data, calculate the distance to the median plane, and then calculate the new hanging point according to the ratio ratio of the distance, and the new hanging point is used as the target point; Step S25f: Based on the TPS algorithm, obtain the dental arch data after arch expansion and contraction; 2. The automatic tooth arrangement method for generating a personalized dental arch based on an ideal dental arch according to claim 1, characterized in that: Step S1 includes the following steps: Step S11: Based on the dental arch morphology provided by medical experts, pixel information of the dental arch is obtained using pixel extraction methods. The least squares method is then used to fit polynomial coefficients, which serve as template data for the dental arch and also as parameters for fitting the arch. The polynomial function is shown in the formula below, and the fitted coefficients a, b, c, and d are used as parameters of the dental arch. b ； Step S12: Generate the ideal dental arch curve in two-dimensional space based on the template data; Step S13: Based on the data from the jaw plane, project the ideal dental arch curve into three-dimensional space; Step S14: Based on the known tooth width and FACC center point position, generate the initial tooth attachment points on the dental arch line; Step S15: Take the data of the attachment points of certain teeth in the dental arch and the intersection of the line connecting the center points of the two first teeth FACC in the mid-incisal plane as the control point of the dental arch.

3. The automatic tooth arrangement method for generating a personalized dental arch based on an ideal dental arch according to claim 2, characterized in that: In step S14, the position of a single tooth on the dental arch is determined by the distance method, namely the start index and the end index; then, the midpoint is found by the range of each tooth on the dental arch, and this midpoint is the attachment point of the tooth on the dental arch line.

4. The automatic tooth arrangement method for generating a personalized dental arch based on an ideal dental arch according to claim 1, characterized in that: If the doctor's order indicates that a chipping procedure is required, the chipping procedure will be automatically generated using collision detection and tooth movement methods, and the amount of chipping required by the doctor will be met.

5. The automatic tooth arrangement method for generating a personalized dental arch based on an ideal dental arch according to claim 1, characterized in that: If tooth extraction is performed, post-processing of the anchorage threshold is performed. If the anchorage is 1.0 mm, tooth #6 is moved 1 mm labially in the sagittal direction. The tooth #6 movement matrix is ​​also used to move the entire tooth in other positions to generate a reasonable tooth arrangement plan for the extraction case.

6. An automated tooth arrangement system for generating personalized dental arches based on an ideal dental arch, characterized in that: include: One or more processors; as well as One or more memories storing a computer-executable program, which, when executed by the processor, performs the method of any one of claims 1-5.

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