Methods of designing and manufacturing an attachment and an appliance, apparatuses, devices, and media

Abstract

The application relates to the technical field of tooth orthodontics, and discloses an accessory and orthodontic appliance design method, a manufacturing method, a device, equipment and a medium. The method comprises the following steps: acquiring a dental finite element model provided with an accessory; acquiring a finite element model of an orthodontic appliance, the orthodontic appliance comprising an accessory accommodating cavity accommodating the accessory; obtaining the orthodontic force of the orthodontic appliance according to the current position and the target position after single correction of the target tooth provided with the accessory; acquiring the first displacement of the target tooth and the strain of the target periodontal membrane covering the target tooth under the action of the orthodontic force; determining the alveolar bone reconstruction amount after a preset time length according to the strain of the target periodontal membrane, and acquiring the second displacement of the target tooth according to the alveolar bone reconstruction amount; acquiring the actual position of the target tooth after the preset time length according to the first displacement and the second displacement; and acquiring the tooth correction deviation according to the target position and the actual position, and then optimizing the accessory design parameters. The accuracy of the accessory and the orthodontic appliance design and manufacturing is improved, and the design efficiency and the correction effect are improved.

Description

Technical Field

[0001] This application relates to the field of orthodontic technology, and in particular to a design method, manufacturing method, device, equipment and medium for accessories and orthodontic appliances. Background Technology

[0002] With the continuous development of society, orthodontic treatment is being adopted by more and more people. Orthodontics is used to treat malocclusion or malalignment of teeth. It uses fixed orthodontic appliances consisting of archwires and brackets, or removable invisible orthodontic appliances (hereinafter referred to as appliances), to apply three-dimensional corrective forces and torques to the teeth, adjusting the balance and coordination between facial bones, teeth, and maxillofacial muscles. After a period of treatment, it improves facial appearance, aligns teeth, and enhances chewing efficiency. Compared with fixed orthodontic appliances, appliances have advantages such as aesthetics and removability, making them an increasingly popular choice for orthodontic treatment.

[0003] To achieve better orthodontic results, engineers and clinicians typically design orthodontic appliances to correct the patient's teeth based on the treatment process and target outcomes. However, using appliances alone sometimes cannot provide sufficient corrective force or a suitable force system. Therefore, attachments are often bonded to the teeth, and the appliances are then fabricated on top of these attachments. These attachments, as protruding geometric shapes on the tooth crown, interact with the appliances to provide additional corrective force. This force, combined with the force provided by the appliance itself and the tooth crown, forms a force system that achieves the desired movement.

[0004] The commonly used design method for orthodontic appliances and accessories is based on the finite element method to calculate the movement of teeth under the action of appliances and accessories, so as to design appliances and accessories that meet the expected orthodontic effect. Existing design methods sometimes fail to consider the role of the alveolar bone, leading to significant discrepancies between the expected tooth movement trend and the actual tooth movement during treatment, potentially resulting in unsatisfactory treatment outcomes for the corresponding orthodontic appliances. Other methods simulate the role of the alveolar bone by creating a finite element model (FEM). However, these FEM models typically exhibit high stiffness, resulting in minimal deformation during tooth movement. This means that while the FEM model is included, its impact on tooth movement is far less than the actual influence of the alveolar bone during treatment, again leading to significant discrepancies between the expected and actual tooth movement trends. Constructing an FEM model based on the patient's actual alveolar bone properties can more accurately simulate the influence of the alveolar bone on tooth movement. However, due to individual patient differences, each patient's alveolar bone requires scanning and analysis, which is time-consuming. Furthermore, simulating the role of the alveolar bone through FEM modeling involves significant computational load, resulting in long processing times and low design efficiency for orthodontic appliances and accessories. Summary of the Invention

[0005] The main objective of this application is to propose a design method, manufacturing method, device, equipment, and medium for attachments and orthodontic appliances, and to solve the technical problems of how to improve the accuracy of the design and manufacturing of attachments and orthodontic appliances during orthodontic treatment, how to achieve better orthodontic results, and how to improve the design efficiency of attachments and orthodontic appliances.

[0006] To at least achieve the above objectives, embodiments of this application provide an accessory design method, comprising: obtaining a finite element model of a jaw with accessories, the finite element model of the jaw including finite element models of multiple teeth, a finite element model of the periodontal ligament, and a finite element model of the accessories; obtaining a finite element model of an orthodontic appliance, the orthodontic appliance including an accessory receiving cavity for accommodating the accessories; assembling the finite element model of the orthodontic appliance onto the finite element model of the jaw; obtaining the orthodontic force of the orthodontic appliance based on the current position of the target tooth and the target position after a single treatment; obtaining the first displacement of the target tooth and the strain of the target periodontal ligament covering the target tooth under the action of the orthodontic force, the target tooth being a tooth with accessories; determining the amount of alveolar bone reconstruction after a preset time based on the strain of the target periodontal ligament, and obtaining the second displacement of the target tooth based on the amount of alveolar bone reconstruction; obtaining the actual position of the target tooth after the preset time based on the first displacement and the second displacement; obtaining the orthodontic deviation of the target tooth based on the target position and the actual position; and optimizing the design parameters of the accessories based on the orthodontic deviation.

[0007] Furthermore, optimizing the design parameters of the accessory based on the corrective deviation includes: adjusting the placement of the accessory and / or adjusting the shape and size of the accessory; wherein the corrective deviation re-obtained based on the optimized accessory is less than the current deviation; if the corrective deviation re-obtained based on the optimized accessory meets preset conditions, the current parameters are used as the optimized design parameters of the accessory. By adjusting the placement and / or shape of the accessory in the direction that reduces the corrective deviation, the accuracy and effectiveness of the accessory design are improved.

[0008] Furthermore, the preset conditions include that the correction deviation is less than a preset threshold, or that the correction deviation is the minimum deviation obtained after traversing all parameter optimization schemes. By setting the requirements for correction deviation during the optimization process of the appendix parameters, the correction deviation can be minimized, thereby improving the degree of consistency between the correction effect and the expected result.

[0009] Further, based on the strain of the target periodontal ligament, the amount of alveolar bone reconstruction of the target tooth after a preset time is determined, including: acquiring each principal strain of the target periodontal ligament, and acquiring the alveolar bone reconstruction rate in each principal strain direction according to a pre-established relationship function between the alveolar bone reconstruction rate and the periodontal ligament strain; and acquiring the amount of alveolar bone reconstruction in each principal strain direction after the preset time based on the alveolar bone reconstruction rate. By accurately acquiring the amount of alveolar bone reconstruction in each principal direction after the preset time based on the preset relationship function and the strain of the periodontal ligament in different principal directions, it is convenient to accurately obtain the actual position of the target tooth after the preset time.

[0010] Further, obtaining the alveolar bone reconstruction rate in each of the principal strain directions includes: obtaining the alveolar bone reconstruction rate according to the following formula.

[0011]

[0012] Where e is the principal strain corresponding to the principal strain direction, c and l are constants, a is the lower limit of the strain for alveolar bone reconstruction, and b is the upper limit of the strain for alveolar bone reconstruction. Based on the formula, the alveolar bone reconstruction rate in each direction can be accurately obtained.

[0013] Furthermore, obtaining the actual position of the target tooth after the preset time period based on the first displacement and the second displacement includes: obtaining the rebound displacement of the target tooth after the orthodontic force is stopped and the target periodontal ligament rebounds to a stress-free state; and obtaining the actual position of the target tooth after the preset time period based on the first displacement, the second displacement, and the rebound displacement. By considering the rebound displacement caused by the periodontal ligament rebound, the accuracy of predicting the actual position of the target tooth after the preset time period is further improved.

[0014] Further, based on the target position and the actual position, the orthodontic deviation of the target tooth is obtained, including: based on the spatial relationship between the target position and the actual position, obtaining the deviation of the target tooth along three coordinate axes of a preset spatial coordinate system; wherein the three coordinate axes of the preset spatial coordinate system are the mesial-distal axis, the long axis, and the labial-lingual axis; summing the deviations along the three coordinate axes, and using the summation result as the orthodontic deviation. By decomposing the deviation into coordinate axis directions based on the spatial relationship between the target position and the actual position, the orthodontic deviation can be accurately quantified and calculated.

[0015] Furthermore, obtaining the deviations of the target tooth along the three coordinate axes of the local tooth coordinate system includes: obtaining the translational deviations and rotational deviations of the target tooth along the three coordinate axes of the preset spatial coordinate system; summing the deviations along the three coordinate axes includes: performing dimensionless summation on each of the translational and rotational deviations. By comprehensively considering the translational and rotational deviations and obtaining the total deviation through dimensionless summation, the accuracy of deviation calculation is improved.

[0016] Further, obtaining the finite element model of the orthodontic appliance includes: obtaining the initial design parameters of the attachments; obtaining the finite element model of the jaw after assembling the attachments based on the initial design parameters; wherein the target tooth in the finite element model of the jaw is located at the target position after the single orthodontic treatment; and obtaining the finite element model of the orthodontic appliance based on the finite element model of the jaw after assembling the attachments. The orthodontic appliance model is accurately obtained by using the jaw model with the target tooth at the target position and the initial design parameters of the attachments.

[0017] Furthermore, obtaining the initial design parameters of the attachment includes: determining the movement type of the target tooth based on its current initial position and the target position after a single orthodontic treatment; and determining the initial shape, size, and placement position of the attachment based on the movement type and the projection of the target tooth onto a preset plane. By accurately obtaining the initial design parameters of the attachment based on the movement type of the target tooth and its projection onto the preset plane, the attachment's initial design parameters are thus determined.

[0018] Furthermore, the preset plane is a plane formed by any two of the following axes: the mesial-distal axis of the target tooth, the long axis of the tooth, and the labial-lingual axis. Multiple projection acquisition methods ensure the practicality of the accessory design.

[0019] To at least achieve the above objectives, embodiments of this application also provide an orthodontic appliance design method, which involves obtaining the accessory with optimized design parameters according to the above accessory design method; adjusting the design parameters of the accessory receiving cavity of the orthodontic appliance according to the optimized design parameters of the accessory, and obtaining the orthodontic appliance with updated design parameters.

[0020] Furthermore, after adjusting the design parameters of the accessory cavity of the orthodontic appliance, the procedure further includes: obtaining the stress of the target periodontal ligament based on its strain; adjusting the designed movement of the target tooth of the orthodontic appliance based on the relationship between the stress of the target periodontal ligament and the upper and lower limits of a preset stress range, until the re-obtained stress of the target periodontal ligament is within the preset stress range; and adjusting the design parameters of the tooth cavity of the orthodontic appliance that accommodates the target tooth based on the adjusted designed movement of the target tooth. By adjusting the design parameters of the tooth cavity of the orthodontic appliance that accommodates the target tooth according to the preset stress range, the designed movement of the target tooth is accurately calculated, avoiding root resorption or ineffective orthodontic treatment.

[0021] Furthermore, based on the relationship between the stress of the target periodontal ligament and the upper and lower limits of the preset stress range, the designed movement of the target tooth in the orthodontic appliance is adjusted. This includes: obtaining the maximum designed movement of the tooth in a single treatment session based on the upper limit of the preset stress range; and adjusting the design parameters of the orthodontic appliance so that the designed movement of the target tooth is equal to the maximum designed movement. By adjusting the design parameters of the orthodontic appliance based on the maximum designed movement, the treatment effect is guaranteed while improving treatment efficiency and reducing the treatment cost for patients.

[0022] Furthermore, before adjusting the design parameters of the orthodontic appliance to make the target tooth movement equal to the maximum designed movement, the procedure further includes: obtaining the target tooth movement based on the target orthodontic effect; if the target movement is greater than the maximum designed movement, adjusting the design parameters of the orthodontic appliance to make the target tooth movement equal to the maximum designed movement; and if the target movement is not greater than the maximum designed movement, adjusting the design parameters of the orthodontic appliance to make the target tooth movement equal to the target movement. By adjusting the orthodontic appliance parameters based on the relationship between the required tooth movement distance and the maximum designed movement, overcorrection is avoided.

[0023] To at least achieve the above objectives, embodiments of this application also provide an accessory manufacturing method, comprising: obtaining an accessory model with updated design parameters according to the above accessory design method; manufacturing a negative mold of the accessory according to the accessory model; and fabricating the accessory by filling the negative mold of the accessory with light-cured resin.

[0024] To at least achieve the above objectives, embodiments of this application also provide an accessory manufacturing method, comprising: obtaining an accessory model with updated design parameters according to the above accessory design method; and manufacturing the accessory by additive manufacturing process according to the data information corresponding to the accessory.

[0025] To at least achieve the above objectives, embodiments of this application also provide a method for manufacturing an orthodontic appliance, comprising: obtaining an orthodontic appliance model with updated design parameters according to the above-described orthodontic appliance design method; manufacturing a male mold of the orthodontic appliance according to the orthodontic appliance model; obtaining a shell-shaped dental instrument containing a tooth shape on the male mold of the orthodontic appliance by thermoforming; and cutting a shell-shaped orthodontic appliance capable of accommodating teeth on the shell-shaped dental instrument along the gingival line or adjacent to the gingival line.

[0026] To at least achieve the above objectives, embodiments of this application also propose a method for manufacturing an orthodontic appliance, comprising: obtaining an orthodontic appliance model with updated design parameters according to the above-described orthodontic appliance design method; and manufacturing a shell-shaped orthodontic appliance by additive manufacturing process based on the data information corresponding to the orthodontic appliance.

[0027] To at least achieve the above objectives, embodiments of this application also propose an accessory design device, comprising: a first acquisition module for acquiring a finite element model of a dentition with accessories, the finite element model of the dentition including finite element models of multiple teeth, a finite element model of the periodontal ligament, and a finite element model of the accessories; a second acquisition module for acquiring a finite element model of an orthodontic appliance, the orthodontic appliance including an accessory receiving cavity for accommodating the accessories; and a third acquisition module for assembling the finite element model of the orthodontic appliance onto the dentition finite element model, obtaining the orthodontic force of the orthodontic appliance based on the current position of the target tooth and the target position after a single treatment, and acquiring the orthodontic force of the accessory. The system includes a first displacement of the target tooth under the action of a force-applying device and the strain of the target periodontal ligament covering the target tooth, wherein the target tooth is a tooth with attachments; a fourth acquisition module is used to determine the amount of alveolar bone reconstruction after a preset time based on the strain of the target periodontal ligament, and to acquire the second displacement of the target tooth based on the amount of alveolar bone reconstruction, and to acquire the actual position of the target tooth after the preset time based on the first displacement and the second displacement; a fifth acquisition module is used to acquire the orthodontic deviation of the target tooth based on the target position and the actual position; and an adjustment module is used to optimize the design parameters of the attachments based on the orthodontic deviation.

[0028] To at least achieve the above objectives, embodiments of this application also propose an orthodontic appliance design apparatus, comprising: an acquisition module, configured to acquire the accessory with optimized design parameters according to the above-described accessory design method; and a design module, configured to adjust the design parameters of the accessory receiving cavity of the orthodontic appliance according to the optimized design parameters of the accessory, and acquire the orthodontic appliance with updated design parameters.

[0029] To at least achieve the above objectives, embodiments of this application also propose an electronic device, the device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the accessory design method or the orthodontic design method as described above.

[0030] To at least achieve the above objectives, embodiments of this application also propose a computer-readable storage medium storing a computer program that, when executed by a processor, implements the accessory design method or orthodontic appliance design method as described above.

[0031] The attachment design method provided in this application involves obtaining a dentition model and an orthodontic appliance model including attachments, teeth, and periodontal ligaments. The orthodontic appliance is then fitted onto the dentition. Based on the current position of the target tooth and the target position after a single treatment, the orthodontic force under the orthodontic appliance is determined. Then, the first displacement of the target tooth with attachments and the strain of the target periodontal ligament covering the target tooth are obtained under the orthodontic force. The amount of alveolar bone reconstruction after a preset time is determined based on the periodontal ligament strain, and the second displacement of the target tooth is determined based on the amount of alveolar bone reconstruction. The actual position of the target tooth after a preset time is determined by combining the first and second displacements. Based on the relationship between the target position and the actual position, the orthodontic deviation of the target tooth is obtained, and the design parameters of the attachment are optimized based on the orthodontic deviation. By calculating the alveolar bone reconstruction amount after a preset time based on the first displacement of the target tooth when the appliance is fitted, the amount of alveolar bone reconstruction is determined based on the periodontal ligament strain, and the second displacement is determined based on the amount of alveolar bone reconstruction, the actual position of the tooth after a single orthodontic treatment is accurately obtained. Using periodontal ligament strain to calculate the amount of alveolar bone reconstruction ensures the accuracy of the calculation results and reduces the computational difficulty and time compared to establishing a finite element model of the alveolar bone, thereby improving design efficiency. The orthodontic deviation is determined based on the relationship between the actual position and the target position, and the design parameters of the attachments are optimized based on the orthodontic deviation, so that the parameters of the designed attachments are as accurate as possible, thereby ensuring that the actual orthodontic effect is as consistent as possible with the expected orthodontic effect. Attached Figure Description

[0032] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0033] Figure 1 This is a flowchart of the attachment design method in the first embodiment of this application;

[0034] Figure 2 This is a schematic diagram of the horizontal projection of the target tooth in the first embodiment of this application;

[0035] Figure 3 This is a schematic diagram of the mechanical analysis of the target tooth in the first embodiment of this application.

[0036] Figure 4 This is a schematic diagram showing the placement of the target tooth in the first embodiment of this application;

[0037] Figure 5 This is a flowchart of the attachment design method in the second embodiment of this application;

[0038] Figure 6 This is a flowchart of the orthodontic appliance design method in the third embodiment of this application;

[0039] Figure 7 This is a flowchart of the attachment manufacturing method in the fourth embodiment of this application;

[0040] Figure 8 This is a flowchart of the attachment manufacturing method in the fifth embodiment of this application;

[0041] Figure 9 This is a flowchart of the orthodontic appliance manufacturing method in the sixth embodiment of this application;

[0042] Figure 10 This is a flowchart of the orthodontic appliance manufacturing method in the seventh embodiment of this application;

[0043] Figure 11 This is a schematic diagram of the accessory design device in the eighth embodiment of this application;

[0044] Figure 12 This is a schematic diagram of the orthodontic appliance manufacturing apparatus according to the ninth embodiment of this application.

[0045] Figure 13 This is a schematic diagram of the structure of the electronic device in the tenth embodiment of this application. Detailed Implementation

[0046] As the background technology shows, when designing attachments and appliances for orthodontic treatment based on current methods, and then performing orthodontic treatment using these designs, the results often deviate from the expected outcomes, resulting in poor treatment outcomes. Furthermore, the design process for attachments and appliances is computationally intensive, time-consuming, and inefficient. Therefore, improving the accuracy of the design and manufacturing of attachments and appliances for orthodontic treatment, achieving better orthodontic results, and increasing the design efficiency of attachments and appliances are urgent technical problems that need to be solved.

[0047] To address the aforementioned problems, some embodiments of this application provide an accessory design method, comprising: obtaining a finite element model of a jaw with accessories, the finite element model of the jaw including finite element models of multiple teeth, a finite element model of the periodontal ligament, and a finite element model of the accessories; obtaining a finite element model of an orthodontic appliance, the orthodontic appliance including an accessory receiving cavity for accommodating the accessories; assembling the finite element model of the orthodontic appliance onto the jaw finite element model; obtaining the orthodontic force of the orthodontic appliance based on the current position of the target tooth and the target position after a single treatment; obtaining the first displacement of the target tooth and the strain of the target periodontal ligament covering the target tooth under the orthodontic force; the target tooth being a tooth with accessories; determining the amount of alveolar bone reconstruction after a preset time based on the strain of the target periodontal ligament, and obtaining the second displacement of the target tooth based on the amount of alveolar bone reconstruction; obtaining the actual position of the target tooth after a preset time based on the first displacement and the second displacement; obtaining the orthodontic deviation of the target tooth based on the target position and the actual position; and optimizing the design parameters of the accessories based on the orthodontic deviation.

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the various embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the various embodiments below is for ease of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0049] The implementation details of the appendix design method described in this application will be specifically described below with reference to specific embodiments. The following implementation details are provided for ease of understanding only and are not necessary for implementing this solution.

[0050] The first embodiment of this application provides an attachment design method, the flow of which can be referred to... Figure 1 In some embodiments, the accessory design method is applied to terminals with communication, computing, and data storage capabilities, such as computers, mobile phones, and other electronic devices. This embodiment takes its application in a computer as an example for illustration. The accessory design includes the following steps:

[0051] Step 101: Obtain a finite element model of the jaw with attachments. The finite element model of the jaw includes finite element models of multiple teeth, a finite element model of the periodontal ligament, and a finite element model of the attachments.

[0052] Specifically, when designing attachments, the processor first obtains a finite element model of the patient's jaw based on the patient's dental information, either by generating data in real time or by reading externally imported data. This finite element model includes finite element models of multiple teeth and the periodontal ligament covering the teeth. Then, based on the patient's orthodontic treatment plan, the processor designs initial attachments and constructs finite element models of the attachments. Finally, the finite element models of the attachments are assembled onto the jaw model to obtain a finite element model of the jaw with attachments.

[0053] For example, when generating a finite element model of the jaw, an oral scan is performed on the patient to obtain information such as the arrangement, shape, and number of teeth in the patient's mouth. Then, based on the scan data, the patient's teeth are reconstructed in three dimensions to generate a digital model of the patient's teeth. The periodontal ligament is then covered on the outer surface of the digital model of the teeth to obtain a digital model of the periodontal ligament. When obtaining the finite element model of the periodontal ligament, a pre-defined stacking algorithm is used to stack the mesh on the processed digital model of the teeth along the external normal direction to form a digital model of the periodontal ligament surrounding the teeth. The thickness of the periodontal ligament ranges from 0.15mm to 0.38mm, with 0.2mm typically used as a reference thickness for the periodontal ligament in healthy adults. Appropriate meshing is then performed to complete the construction of the finite element model of the periodontal ligament. After performing CBCT on the teeth, three-dimensional reverse reconstruction is performed based on the scan results to ensure the accuracy of the obtained digital model of the teeth. Stacking along the external normal direction improves the accuracy of the obtained digital model of the periodontal ligament, thereby improving the degree of consistency between the finite element model and the actual patient situation.

[0054] The methods for performing oral scans on patients include computed tomography (CAT) scans, digital computed tomography (CT) scans, cone-beam computed tomography (CBCT) scans, magnetic resonance imaging (MRI), intraoral optical scans, and three-dimensional laser scans based on standard tooth models, etc. This embodiment does not limit these methods.

[0055] It should be noted that, in addition to teeth and periodontal ligament, the dental finite element model may also include meshed models of other bones or muscles in the patient's oral cavity. This embodiment does not limit the specific number of models included in the dental finite element model, or the method of obtaining other models.

[0056] In addition, the dental finite element model mainly includes three elements: mesh model, material properties, and constraints and loading conditions. To ensure that the changes in the dental finite element model match the actual orthodontic process, appropriate material properties, constraints, and loading conditions need to be set for each mesh model in the finite element model. Among them, the material properties of the teeth can include the elastic modulus and Poisson's ratio; the material properties of the periodontal ligament are determined based on the viscoelastic constitutive model or the hyperelastic constitutive model, so that the periodontal ligament mesh model can fit the actual biological stress mechanism of the periodontal ligament as closely as possible; the constraints can be set to ensure that the outer surface of the tooth root is in close contact with the periodontal ligament without relative slippage; the constraints of the periodontal ligament can be set to be that the outer surface of the periodontal ligament is fixed during the instant of application of the orthodontic force, subjected to the corresponding reconstruction displacement load during the alveolar bone reconstruction stage, and in a free state during the periodontal ligament stress release stage.

[0057] The elastic modulus of teeth, Poisson's ratio, and specific material properties of the periodontal ligament can be calculated by inputting the constituent data into the corresponding model, or obtained by consulting relevant literature resources, which will not be elaborated here.

[0058] Step 102: Obtain the finite element model of the orthodontic appliance, which includes an accessory receiving cavity for accommodating accessories.

[0059] Specifically, when designing attachments, the processor also needs to design an orthodontic appliance finite element model that has an attachment receiving cavity that can accommodate the attachments and whose orthodontic distance matches the target orthodontic effect, based on the finite element model of the jaw with attachments and the target orthodontic effect of the patient's teeth.

[0060] In one example, obtaining the finite element model of the orthodontic appliance includes: obtaining the initial design parameters of the attachments; obtaining the finite element model of the jaw after the attachments are assembled based on the initial design parameters; wherein the target tooth in the finite element model of the jaw is in the target position after a single orthodontic treatment; and obtaining the finite element model of the orthodontic appliance based on the finite element model of the jaw after the attachments are assembled.

[0061] Specifically, when obtaining the finite element model of the orthodontic appliance, the initial design parameters of the attachments are first obtained. Based on these parameters, the attachments are assembled onto the pre-obtained finite element model of the jaw. Then, according to the patient's target orthodontic effect, the target teeth requiring treatment are moved to their target positions after a single treatment session, resulting in a finite element model of the jaw with attachments after a single treatment session. The target teeth can be one or more. Based on this finite element model, a shell-shaped orthodontic appliance model with thickness is constructed by selecting and outwardly expanding and stretching the crown surface and redesigning some connection areas. Alternatively, the finite element model can undergo geometric processing to obtain thermoforming mold data, and a diaphragm model with thickness information is established. Using actual material and process parameters (such as temperature, pressure, and speed) as input, the thermoforming process is simulated using the finite element method. The finite element model is then exported and subjected to geometric processing such as trimming to obtain an orthodontic appliance model that approximates the real-world state. The orthodontic appliance model is accurately obtained by using a dental model of the target teeth in the target position as needed and the initial design parameters of the attachments.

[0062] In obtaining the orthodontic appliance model through finite element simulation, the dental mold can use real material parameters or rigid body elements to improve computational efficiency. The element type of the diaphragm can be selected as solid elements to obtain orthodontic appliance models with different thickness distributions, or shell elements can be selected to improve computational efficiency. This embodiment does not limit the specific simulation process.

[0063] In another example, the initial design parameters of the attachment are obtained, including: determining the movement type of the target tooth based on its current initial position and the target position after a single orthodontic treatment; and determining the initial shape, size, and initial placement of the attachment based on the movement type and the projection of the target tooth onto a preset plane.

[0064] Specifically, when obtaining the initial design parameters for the attachments, for the target tooth, the doctor's experience or an automatic tooth alignment algorithm can be used to determine the target position of the target tooth after a single orthodontic treatment based on the target treatment effect. Then, based on the spatial relationship between the target tooth's current initial position and the target position after a single treatment, the type of movement of the target tooth during the single treatment can be determined, such as rotation, translation, or a combination of both. Then, based on the type of movement of the target tooth in a single treatment, the direction of the orthodontic force and torque to be applied to the target tooth is determined. Combined with the projection of the target tooth onto a preset plane, the initial shape, size, and placement of the attachments are determined. Specifically, a preliminary mechanical analysis is performed within the projection plane to determine the direction and placement of the initial force-applying surface of the attachments (i.e., the surface that interacts with the appliance). The size of the attachments and the shape of the non-force-applying surface are designed in conjunction with clinical feasibility and the removability of the appliance.

[0065] Furthermore, the preset plane is a plane formed by any two of the following axes: the mesial-distal axis (Y-axis), the long axis (Z-axis), and the labiolingual axis (X-axis). Different planes are selected for projection analysis for different tooth movement types, as shown in Table 1. By providing multiple projection acquisition methods, the practicality of the attachment design method is ensured.

[0066] Table 1. Preset projection planes corresponding to different tooth movement types

[0067]

[0068]

[0069] Note: The origin O is the impedance center CR of the tooth.

[0070] For example, taking canine rotation of the target tooth as a specific example, the preset plane is the plane formed by the long axis of the tooth and the labiolingual axis. The projection of the target tooth on the horizontal plane can be referenced. Figure 2 F represents the force exerted on the attachment's force-applying surface. This surface, perpendicular to the crown plane, provides torsional torque around the impedance center. The greater the distance between the force-applying surface and the impedance center, the greater the torsional torque. Therefore, the attachment is placed mesially near the gingiva according to spatial characteristics. To counteract tooth overturning during torsion, the force-applying surface is designed as an incline. The projection of the occlusal model onto the pre-defined plane and the mechanical analysis after adding the attachment can be referenced. Figure 3CR is the impedance center of the target tooth, Z is the long axis of the tooth, X is the labial-lingual lateral axis intersecting the long axis of the tooth Z at the impedance center CR, M indicates the desired tooth movement as a counterclockwise rotation around the long axis of the tooth, α is the angle between the force plane and the horizontal plane, F can be decomposed into a force F1 in the horizontal plane and a force F2 in the sagittal plane according to α, the distance between F1 and the impedance center is h1, the distance between F2 and the impedance center is d1, and according to the force and distance, a clockwise torque M1 = F*sin(α)*h1 in the coronal plane, a counterclockwise torque M2 = F*cos(α)*d1, and a torque M in the counterclockwise direction along the long axis of the tooth can be formed respectively. M represents the orthodontic torque required for the tooth to rotate around its long axis. M1 and M2 represent the additional torques generated after the attachments are installed, which will cause the tooth to rotate in the mesiodistal direction. When designing the attachment force application surface, M1 and M2 should be made as equal in size and opposite in direction as possible to eliminate this additional rotational torque. Based on the results of the above mechanical analysis, the initial placement parameters of the attachments are obtained, including the distance H1 between the highest point of the target tooth and the lowest point of the attachment, the distance D1 between the lowest point of the attachment and the outermost vertex that is closest to the tooth and the attachment, and the attachment force application surface angle parameter α. Combining existing clinical design experience of attachments and the removability of the orthodontic appliance, the initial size of the attachment force application surface and the shape of the non-force application surface, such as a hemisphere, are determined, thus obtaining the initial design parameters of the attachments.

[0071] Step 103: Determine the actual position of the target tooth after a single orthodontic treatment based on the displacement of the target tooth and the strain of the target periodontal ligament under the action of the orthodontic appliance.

[0072] Specifically, after obtaining the finite element model of the jaw with attachments and the finite element model of the orthodontic appliance containing the attachment cavity, the finite element model of the orthodontic appliance is assembled onto the finite element model of the jaw with attachments through simulation. The target position of the tooth with attachments, i.e., the target tooth after a single orthodontic treatment, is determined under the action of the orthodontic appliance. Based on the current position of the target tooth and the target position after a single treatment, the deformation of the orthodontic appliance model is determined, and the orthodontic force applied to the target tooth by the appliance in the rebound state is determined based on the deformation of the orthodontic appliance model. Then, the first instantaneous displacement of the target tooth under the orthodontic force and the strain of the target periodontal ligament covering the target tooth are obtained. Based on the strain of the target periodontal ligament, the amount of alveolar bone reconstruction of the target tooth after a preset time is calculated, and the second displacement of the target tooth within the preset time is obtained based on the calculated alveolar bone reconstruction amount. Based on the first instantaneous displacement of the target tooth and the second displacement obtained from the alveolar bone reconstruction amount, the actual position of the target tooth after the preset time is determined.

[0073] In one example, the amount of alveolar bone reconstruction of the target tooth after a preset time is determined based on the strain of the target periodontal ligament. This includes: obtaining each principal strain of the target periodontal ligament, and obtaining the alveolar bone reconstruction rate in each principal strain direction according to a pre-created relationship function between the alveolar bone reconstruction rate and the periodontal ligament strain; and obtaining the amount of alveolar bone reconstruction in each principal strain direction after a preset time based on the alveolar bone reconstruction rate.

[0074] Specifically, after obtaining the strain of the target periodontal ligament, the strain is analyzed, and the direction vector of the principal strain direction is used as the alveolar bone reconstruction direction. Then, based on the specific strain magnitude of the principal strain of the periodontal ligament in each principal strain direction, and the pre-created relationship function between the alveolar bone reconstruction rate and the periodontal ligament strain, the alveolar bone reconstruction rate in each principal strain direction is obtained. Combining the preset duration and the alveolar bone reconstruction rate in each principal strain direction, the amount of alveolar bone reconstruction in each principal strain direction after the preset duration is obtained. Finally, the amount of alveolar bone reconstruction in each principal strain direction is decomposed and summed in the global coordinate system to obtain the amount of alveolar bone reconstruction in the global coordinate system. By using the preset relationship function between alveolar bone reconstruction rate and periodontal ligament strain, combined with the specific strain magnitude of the principal strain of the target periodontal ligament in different principal strain directions, the amount of alveolar bone reconstruction in each principal strain direction after a preset time is accurately obtained. The alveolar bone reconstruction is characterized by the displacement of the outer nodes of the periodontal ligament using a finite element model, and the amount of alveolar bone reconstruction in the global coordinate system is accurately predicted, avoiding the complex calculation process when calculating the reconstruction amount based on a rigid alveolar bone model.

[0075] Step 104: Obtain the orthodontic deviation of the target tooth based on the target position and the actual position.

[0076] Specifically, after determining the actual position of the target tooth after a preset duration based on the first displacement of the target tooth at the instant of the orthodontic force and the second displacement determined based on the amount of alveolar bone reconstruction, the orthodontic deviation of the target tooth is calculated based on the spatial relationship between the target position and the actual position after a single orthodontic treatment, and the orthodontic deviation of the target tooth is obtained.

[0077] In one example, the orthodontic deviation of the target tooth is obtained based on the target position and the actual position, including: obtaining the deviation of the target tooth along three coordinate axes of a preset spatial coordinate system based on the spatial relationship between the target position and the actual position; wherein, the three coordinate axes of the preset spatial coordinate system are the mesial-distal axis, the long axis, and the labial-lingual axis of the target tooth; the deviations along the three coordinate axes are summed, and the summation result is used as the orthodontic deviation.

[0078] Specifically, when calculating the orthodontic deviation of the target tooth based on its target position and actual position after a single treatment, a pre-defined spatial coordinate system is constructed using the tooth's mesial-distal axis, long axis, and labiolingual axis as three axes. Then, based on the target tooth's coordinates at its target position and its actual position, the displacement deviation of the target tooth along each of the three axes is obtained. These displacement deviations are then summed, and the sum is taken as the orthodontic deviation of the target tooth. By decomposing the deviation along the coordinate axes according to the spatial relationship between the target and actual positions, the orthodontic deviation is accurately quantified.

[0079] Furthermore, the deviations of the target tooth in the three coordinate axes of the preset spatial coordinate system are obtained, including: obtaining the translational deviations and rotational deviations of the target tooth in the three coordinate axes of the preset spatial coordinate system; and summing the deviations along the three coordinate axes, including: performing dimensionless summation on each translational deviation and rotational deviation.

[0080] Specifically, when obtaining the deviations of the target tooth along the three coordinate axes of a preset spatial coordinate system, based on the spatial relationship between the target position and the actual position of the target tooth, the translational deviations along the three coordinate axes and the rotational deviations around the coordinate axes are obtained. The translational deviations are represented by displacement, and the rotational deviations are represented by radians. Taking the counterclockwise rotation of the canine around the Z-axis as an example, the translational deviations Dx, Dy, and Dz along the X, Y, and Z axes, and the rotational deviations Rx, Ry, and Rz around the X, Y, and Z axes are calculated by decomposing and summing the deviations. Then, when determining the orthodontic deviation of the target tooth, the obtained translational and rotational deviations are summed dimensionlessly, and the dimensionless summation result S is obtained according to the following formula: S = |Dx| + |Dy| + |Dz| + |Rx| + |Ry| + |Rz|, and the obtained dimensionless summation result S is taken as the orthodontic deviation of the target tooth. By comprehensively considering the translational and rotational deviations of the target teeth and obtaining the total deviation through dimensionless summation, the accuracy of orthodontic deviation calculation is improved.

[0081] Step 105: Optimize the design parameters of the attachments based on the correction deviation.

[0082] Specifically, after calculating the orthodontic deviation of the target tooth, the design parameters of the attachments are adjusted according to the relationship between the size of the force plane and the magnitude of the orthodontic force, and the relationship between the angle between the force plane and the horizontal or vertical plane and the direction of the orthodontic force. The parameters are then recalculated to determine the smallest possible orthodontic deviation and thus optimize the design parameters.

[0083] In one example, optimizing the design parameters of the attachments based on the correction deviation includes: adjusting the placement of the attachments, and / or adjusting the shape and size of the attachments; wherein the correction deviation re-obtained based on the optimized attachments is less than the current deviation; if the correction deviation re-obtained based on the optimized attachments meets preset conditions, the current parameters are used as the optimized design parameters of the attachments.

[0084] Specifically, during the optimization of accessory design parameters based on correction deviations, the placement and / or shape and size of the accessories can be adjusted according to a preset step size. The shape and size of the accessories include the angle between the force-applying surface and the horizontal or vertical plane, the size of the force-applying surface, and the shape of the non-force-applying surface. Then, based on the updated accessory design parameters, a new mechanical analysis of the correction process is performed. Combining the results of the mechanical analysis with the correction deviation calculation method, the correction deviation in a single correction process after the accessory design parameters are updated is calculated. The obtained correction deviation is then checked to see if it meets preset conditions. If the newly obtained correction deviation meets the preset conditions, the current parameters are used as the optimized design parameters for the accessories. If the newly obtained correction deviation does not meet the preset conditions, the placement and / or shape and size of the accessories are adjusted again according to the preset step size until the newly obtained correction deviation meets the preset conditions. By adjusting the placement and / or shape and size of the accessories in the direction that reduces correction deviation, the accuracy and effectiveness of the accessory design are improved.

[0085] Furthermore, the preset conditions include that the correction deviation is less than a preset threshold, or that the correction deviation is the minimum deviation obtained after traversing all parameter optimization schemes.

[0086] Specifically, during design parameter optimization, the design parameters can be gradually adjusted according to a preset step size to obtain the corrective deviation after parameter updates. Alternatively, multiple parameter update schemes within the adjustable range can be directly calculated, and the corrective deviation for each scheme can be calculated separately. Then, the corrective deviation of each parameter update scheme is checked to see if it meets preset conditions. These preset conditions can be that the corrective deviation is less than a preset threshold, or that the current corrective deviation is the minimum deviation after traversing all optimized parameter schemes. This check can be performed after each calculated parameter update scheme. Therefore, using a preset threshold as a preset condition can improve the speed of determining the parameter update scheme while maximizing the corrective effect. Using the minimum deviation among all schemes as a preset condition ensures the best corrective effect. By setting requirements for corrective deviation during the parameter optimization process, the corrective deviation can be minimized, improving the degree of agreement between the corrective effect and expectations.

[0087] For example, taking the aforementioned canine rotation as an example, when determining the optimal placement, for easier and more intuitive understanding, one can refer to... Figure 4 The projection of the target tooth onto the plane formed by the tooth's long axis and mesiodistal axis is explained. Using the calculation method described above, the appropriate range for the distance H1 between the highest point of the target tooth and the lowest point of the attachment when completing canine rotation is 3mm to 5mm; the appropriate range for the distance D1 between the lowest point of the attachment and the outermost vertex closest to the tooth and attachment is 2mm to 3mm; and the appropriate range for the angle between the attachment's force application plane and the horizontal plane is 30° to 45°. An example of determining the placement position is provided. Similarly, the shape and size of the attachment can be used as design variables. Based on the relationship between the attachment's shape and size and the angle between the force application plane and the horizontal or vertical plane, various moments during the orthodontic process, and the magnitude of the applied orthodontic force, the orthodontic deviation can be calculated to obtain the appropriate range for the shape and size.

[0088] It's worth noting that when adjusting the placement and size of accessories based on preset step sizes, one parameter can be kept constant while adjusting the other. For example, the size can be kept constant initially, and the placement position with the smallest corrective deviation can be found. Then, the placement position can be kept constant, and the size and shape with the smallest corrective deviation can be found. Alternatively, multiple combinations of size and placement can be calculated directly, and the corrective deviation of each combination can be determined. The accessory design parameters can then be updated based on the combination with the smallest corrective deviation or the deviation being less than a preset threshold.

[0089] It should be noted that the process of updating the attachment design parameters can be completed in steps. For example, after determining the appropriate placement information for the attachment, the placement position can be updated and optimized; after obtaining the appropriate range for the shape and size of the attachment, the shape and size can be updated to obtain the attachment with optimized design parameters. Alternatively, the process of updating the attachment design parameters can involve calculating the appropriate range for all design parameters and then updating all parameters at once to obtain the attachment with optimized design parameters. This embodiment does not limit the specific design optimization method.

[0090] In this embodiment, a finite element model of the jaw with attachments and a finite element model of the orthodontic appliance capable of accommodating the attachments are constructed. Periodontal ligament strain is used as the stimulus condition for alveolar bone reconstruction. This fully considers the physiological characteristics and changes that may occur at various locations in the oral cavity under biomechanical mechanisms, thus obtaining the amount of alveolar bone reconstruction more accurately. Compared to direct calculation based on the alveolar bone finite element model, this significantly reduces computational complexity. By accurately obtaining the actual position of the target tooth after a single orthodontic treatment based on the instantaneous first displacement and the second displacement corresponding to the amount of alveolar bone reconstruction, the orthodontic deviation can be accurately obtained. This facilitates the optimization of attachment design parameters based on the orthodontic deviation, improving the accuracy and effectiveness of attachment design, and ultimately ensuring the consistency between the orthodontic treatment effect and the expected result.

[0091] The second embodiment of this application provides an accessory design method. When determining the amount of alveolar bone reconstruction, by setting the upper and lower limits of periodontal ligament strain, the calculation efficiency of the amount of alveolar bone reconstruction is improved, while ensuring that the obtained amount of alveolar bone reconstruction is more in line with the actual situation. When obtaining the actual position, the influence of periodontal ligament rebound on orthodontic treatment is also taken into consideration, which further improves the accuracy of obtaining the orthodontic deviation after a single treatment, thereby improving the accuracy of accessory design parameter optimization.

[0092] The flowchart of the attachment design method in this embodiment can be referred to Figure 5 This includes the following steps:

[0093] Step 501: Obtain the finite element model of the jaw with attachments.

[0094] Step 502: Obtain the finite element model of the orthodontic appliance.

[0095] Steps 501 and 502 in this embodiment are similar to steps 101 and 102 in the first embodiment, and will not be described in detail here.

[0096] Step 503: Determine the actual position of the target tooth after a single orthodontic treatment based on the displacement of the target tooth under the action of the orthodontic appliance and the displacement of the target tooth during the periodontal ligament stress release process.

[0097] Specifically, the method involves acquiring the first displacement of the target tooth instantaneously under orthodontic force, as well as the strain of the target periodontal ligament covering the target tooth. Based on the relationship between the strain of the target periodontal ligament and its upper and lower limits, the alveolar bone remodeling rate in each principal strain direction is obtained. Then, the amount of alveolar bone remodeling of the target tooth after a preset time is calculated, and the second displacement of the target tooth within the preset time is obtained based on the calculated amount of alveolar bone remodeling. Finally, the rebound displacement of the target tooth during the stress release phase of the target periodontal ligament is acquired. Based on the first displacement, the second displacement, and the rebound displacement, the actual position of the target tooth after the preset time is determined.

[0098] In one example, when obtaining the alveolar bone reconstruction rate in each principal strain direction, the alveolar bone reconstruction rate r· can be calculated according to the following formula:

[0099]

[0100] Where e represents the principal strain corresponding to the principal strain direction, c and l are constants, a is the lower limit of the alveolar bone reconstruction strain, and b is the upper limit of the alveolar bone reconstruction strain. The alveolar bone reconstruction rate in each principal strain direction is accurately obtained according to the preset formula, avoiding the calculation of an additional alveolar bone reconstruction rate when the periodontal ligament strain is insufficient, and preventing the calculated alveolar bone reconstruction rate from exceeding the maximum actual reconstruction rate when the periodontal ligament strain is excessive, thus further improving the accuracy of alveolar bone reconstruction calculation.

[0101] In another example, obtaining the actual position of the target tooth after a preset time based on the first displacement and the second displacement includes: obtaining the rebound displacement of the target tooth after the target periodontal ligament rebounds to a stress-free state after the application of orthodontic force is stopped, and obtaining the actual position of the target tooth after a preset time based on the first displacement, the second displacement and the rebound displacement.

[0102] Specifically, after the orthodontic appliance is removed, the periodontal ligament gradually springs back to a stress-free state as the orthodontic force ceases to apply. During this springback, the teeth move. Therefore, by acquiring the springback displacement of the target tooth during the periodontal ligament's return to a stress-free state after the orthodontic force is stopped, and then summing the first displacement of the tooth at the moment the orthodontic force is applied, the second displacement under the orthodontic force, and the springback displacement of the tooth during the periodontal ligament springback procedure, the summed result is taken as the actual displacement of the target tooth. The actual position of the target tooth after a single treatment is then determined based on the acquired actual displacement. By considering the impact of periodontal ligament springback on the orthodontic treatment of the target tooth, the accuracy of orthodontic deviation calculation is further improved, thereby enhancing the accuracy of subsequent attachment design parameter optimization.

[0103] Step 504: Obtain the orthodontic deviation of the target tooth based on the target position and the actual position.

[0104] Step 505: Optimize the design parameters of the attachments based on the correction deviation.

[0105] Steps 504 and 505 in this embodiment are similar to steps 104 and 105 in the first embodiment, and will not be described in detail here.

[0106] In this embodiment, the alveolar bone reconstruction rate is calculated by combining the upper and lower limits of strain, which further improves the accuracy of obtaining the amount of alveolar bone reconstruction. By introducing the rebound displacement of the target tooth during the periodontal ligament rebound to a stress-free state, it is more in line with the actual orthodontic process, which greatly improves the accuracy of calculating the actual position of the target tooth after a single orthodontic treatment, thereby improving the accuracy of obtaining orthodontic deviation and optimizing accessory design parameters.

[0107] The third embodiment of this application provides a method for designing an orthodontic appliance. This method can be applied to terminals with communication, computing, and data storage capabilities, such as computers, mobile phones, and other electronic devices. This embodiment uses an application in a computer as an example for illustration. The flowchart of the orthodontic appliance design method in this embodiment can be found in [reference needed]. Figure 6 This includes the following steps:

[0108] Step 601: Obtain the attachment with optimized design parameters.

[0109] Specifically, during the orthodontic appliance design process, the processor obtains the accessories after the design parameters have been optimized using the accessory design method in the above embodiments, and uses the obtained accessories as the accessories that the orthodontic appliance receiving cavity needs to contain.

[0110] Step 602: Based on the optimized design parameters of the attachments, adjust the design parameters of the attachment receiving cavity of the orthodontic appliance to obtain the orthodontic appliance with updated design parameters.

[0111] Specifically, when optimizing the parameters of the orthodontic appliance, the design parameters of the accessory receiving cavity in the appliance are adaptively adjusted based on the obtained design parameters of the accessories, so that the adjusted accessory receiving cavity can accommodate the obtained accessories, resulting in an orthodontic appliance with updated design parameters.

[0112] In one example, after adjusting the design parameters of the attachment cavity of the orthodontic appliance, the process further includes: obtaining the stress of the target periodontal ligament based on the strain of the target periodontal ligament; adjusting the designed movement of the target tooth based on the relationship between the stress of the target periodontal ligament and the upper and lower limits of the preset stress range, until the stress of the target periodontal ligament obtained again is within the preset stress range; and adjusting the design parameters of the tooth cavity of the orthodontic appliance that accommodates the target tooth based on the adjusted designed movement of the target tooth.

[0113] Specifically, after updating the design parameters of the attachment housing in the orthodontic appliance, the strain of the target periodontal ligament during the orthodontic process is obtained based on the current design parameters of the attachments and the appliance, and the stress of the target periodontal ligament is obtained based on the strain. Then, based on the pre-obtained preset stress range, the relationship between the stress of the target periodontal ligament and the upper and lower limits of the preset stress range is detected. The lower limit of the preset stress range corresponds to the minimum stress that can cause tooth movement, and the upper limit of the preset stress range corresponds to the minimum stress that can cause the maximum tooth movement speed. The upper and lower limits of the preset stress range can be human capillary pressure and human systolic pressure, respectively, i.e., 4.7 kPa to 17 kPa. Therefore, after obtaining the stress of the target periodontal ligament, when the stress of the target periodontal ligament is less than the lower limit of the preset stress range, the designed movement of the target tooth in a single treatment with the orthodontic appliance is increased; when the stress of the target periodontal ligament is greater than the upper limit of the preset stress range, the designed movement of the target tooth in a single treatment with the orthodontic appliance is decreased, so that the stress of the target periodontal ligament obtained again is within the preset stress range. Then, based on the change in the designed movement of the target tooth with the orthodontic appliance, the design parameters of the tooth receiving cavity that accommodates the target tooth are updated.

[0114] In another example, the designed movement of the target tooth is adjusted based on the relationship between the stress of the target periodontal ligament and the upper and lower limits of the preset stress range. This includes: obtaining the maximum designed movement of the tooth in a single orthodontic treatment based on the upper limit of the preset stress range; and adjusting the design parameters of the orthodontic appliance so that the designed movement of the target tooth is equal to the maximum designed movement.

[0115] Specifically, during the update of orthodontic appliance design parameters, the maximum designed movement of the teeth in a single treatment session can be calculated based on the upper limit of the preset stress range. Then, based on this calculated maximum designed movement, the design parameters of the tooth cavity and / or attachment cavity of the appliance are adjusted so that the designed movement of the target tooth under the appliance's action equals the maximum designed movement. For example, during canine rotation, the maximum rotation angle in a single treatment session can be calculated to be 2 degrees using the above method. By calculating the maximum designed movement in a single treatment session based on the upper stress limit and adjusting the appliance's design parameters accordingly, the treatment effect is guaranteed while improving treatment efficiency and reducing the cost of orthodontic treatment for patients.

[0116] Furthermore, before adjusting the design parameters of the orthodontic appliance to make the designed movement of the target tooth equal to the maximum designed movement, the procedure also includes: obtaining the target movement of the target tooth based on the target orthodontic effect; if the target movement is greater than the maximum designed movement, adjusting the design parameters of the orthodontic appliance to make the designed movement of the target tooth equal to the maximum designed movement; and if the target movement is not greater than the maximum designed movement, adjusting the design parameters of the orthodontic appliance to make the designed movement of the target tooth equal to the target movement.

[0117] Specifically, before adjusting the target tooth movement of the orthodontic appliance to the maximum designed movement, it is necessary to determine the current target tooth movement based on the desired treatment outcome. Then, the relationship between the target movement and the maximum designed movement is examined. If the target movement exceeds the maximum designed movement, the appliance's design parameters are adjusted to make the target tooth movement equal to the maximum designed movement. If the target movement is not greater than the maximum designed movement, the appliance's design parameters are adjusted to make the target tooth movement equal to the target movement. By adjusting the appliance parameters based on the relationship between the required tooth movement distance and the maximum designed movement, overcorrection is avoided, and the treatment effect is maximized.

[0118] Furthermore, it should be understood that the step divisions of the various methods described above are only for clarity. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of the algorithm and process, are also within the scope of protection of this patent.

[0119] The fourth embodiment of this application relates to a method for manufacturing an accessory, see reference. Figure 7 ,include:

[0120] Step 701: Obtain the attachment model after the design parameters are updated.

[0121] Specifically, during the accessory manufacturing process, the processor obtains the updated digital accessory model with design parameters obtained through the scheme in the above accessory design method embodiment, based on the instructions input by the administrator.

[0122] Step 702: Manufacture the female mold of the attachment based on the attachment model.

[0123] Specifically, after obtaining the updated digital attachment model with the design parameters, the data of the digital attachment model is extracted and transformed into the specification data for manufacturing the attachment female mold. Then, the manufacturing of the attachment female mold is completed based on the obtained specification data.

[0124] It is worth mentioning that when manufacturing the female mold of the attachment based on the specifications of the female mold in the attachment, rapid prototyping technology can be used. The specifications of the female mold of the attachment are converted into the data format corresponding to the rapid prototyping technology used, and then the manufacturing is completed using rapid prototyping technology. Among them, the rapid prototyping technologies used include: stereolithography (STL), stereolithography apparatus (SLA), laminated object manufacturing (LOM), selected laser sintering (SLS), fused deposition modeling (FDM), three-dimensional printing (3DP), etc. This embodiment does not limit the specific rapid prototyping technology used.

[0125] Step 703: The accessory is made by filling the negative mold of the accessory with light-cured resin.

[0126] Specifically, after obtaining the negative mold of the accessory, a light-curing resin, preferably an ultraviolet-curing resin, is filled into the negative mold. After filling, the resin is cured by light to form the accessory. This method can greatly improve manufacturing efficiency and accuracy.

[0127] The fifth embodiment of this application relates to a method for manufacturing an accessory, see reference. Figure 8 ,include:

[0128] Step 801: Obtain the attachment model after the design parameters are updated.

[0129] Specifically, during the accessory manufacturing process, the processor obtains the updated digital accessory model with design parameters obtained through the scheme in the above accessory design method embodiment, based on the instructions input by the administrator.

[0130] Step 802: Based on the data information corresponding to the attachment, the attachment is manufactured using additive manufacturing technology.

[0131] Specifically, after obtaining the digital attachments, the data of the digital attachments is extracted and transformed into specific specification data. Then, based on the obtained specification data of the digital attachments, the attachments are manufactured using additive manufacturing technology.

[0132] It is worth mentioning that when manufacturing accessories based on the specifications of the digital accessories, rapid prototyping technology can be used. The specifications of the accessories are converted into the data format corresponding to the rapid prototyping technology used, and then manufacturing is completed using rapid prototyping technology. The rapid prototyping technologies used include: stereolithography, laser rapid prototyping, layered solid modeling, selective laser sintering, fused deposition modeling, 3D printing, etc. This embodiment does not limit the specific rapid prototyping technology used.

[0133] This embodiment utilizes rapid prototyping technology to accurately and efficiently manufacture accessories based on digital attachments.

[0134] The sixth embodiment of this application relates to a method for manufacturing an orthodontic appliance, see reference... Figure 9 ,include:

[0135] Step 901: Obtain the orthodontic appliance model with updated design parameters.

[0136] Specifically, during the manufacturing process of orthodontic appliances, the computer first acquires the digital orthodontic appliance designed using the above-mentioned orthodontic appliance design method, and analyzes the digital orthodontic appliance to obtain the relevant parameters and data of the manufactured orthodontic appliance.

[0137] Step 902: Manufacture the positive mold of the orthodontic appliance based on the appliance model.

[0138] Specifically, after obtaining the model of the digital orthodontic appliance, the data of the digital orthodontic appliance model is extracted and converted into the specification data for manufacturing the positive mold of the orthodontic appliance. Then, the positive mold of the orthodontic appliance is manufactured according to the obtained specification data.

[0139] Step 903: A shell-shaped dental instrument containing the shape of teeth is obtained by thermoforming on the male mold of the orthodontic appliance.

[0140] Specifically, after obtaining the male mold of the orthodontic appliance, a diaphragm made of a transparent polymer material (an elastic polymer, such as polycarbonate) can be pressed onto the male mold using a thermoforming device and positive pressure molding technology to form a shell, thereby producing a shell-shaped dental instrument containing the shape of teeth. The thermoforming method greatly improves manufacturing efficiency and accuracy.

[0141] Step 904: Cut a shell-shaped orthodontic appliance along or near the gingival line on the shell-shaped dental instrument to obtain a shell-shaped orthodontic appliance that can accommodate the teeth.

[0142] Specifically, in order for the manufactured orthodontic appliance to play a good orthodontic role, it is necessary to ensure that the orthodontic appliance can be used normally. Therefore, the shell-shaped dental instrument is cut along the gingival line or adjacent to the gingival line on the thermo-pressed shell-shaped dental instrument so that the cut shell-shaped dental instrument can accommodate the patient's teeth, thereby completing the manufacturing of the shell-shaped orthodontic appliance.

[0143] It is worth mentioning that when manufacturing shell-shaped orthodontic appliances based on the specifications of digital orthodontic appliances, rapid prototyping technology can be used. This involves converting the specifications of the digital orthodontic appliance into the data format corresponding to the rapid prototyping technology used, and then completing the manufacturing process using rapid prototyping technology. The rapid prototyping technologies used include: stereolithography, laser rapid prototyping, layered solid fabrication, selective laser sintering, fused deposition modeling, and 3D printing. This embodiment does not limit the specific rapid prototyping technology used.

[0144] This embodiment utilizes rapid prototyping technology to accurately and efficiently manufacture the orthodontic appliance based on a digital orthodontic appliance.

[0145] The seventh embodiment of this application relates to a method for manufacturing an orthodontic appliance, see reference... Figure 10 ,include:

[0146] Step 1001: Obtain the orthodontic appliance model with updated design parameters.

[0147] Specifically, during the manufacturing process of the orthodontic appliance, the processor obtains the digital orthodontic appliance model with updated design parameters obtained through the scheme in the above-described orthodontic appliance design method embodiment, based on the instructions input by the administrator.

[0148] Step 1002: Based on the data information corresponding to the orthodontic appliance, a shell-shaped orthodontic appliance is manufactured using additive manufacturing technology.

[0149] Specifically, after obtaining the digital orthodontic appliance, the data of the digital orthodontic appliance is extracted and converted into specific specification data. Then, based on the obtained specification data of the digital orthodontic appliance, a shell-shaped dental appliance is manufactured using additive manufacturing technology.

[0150] It is worth mentioning that when manufacturing the orthodontic appliance based on the specifications of the digital orthodontic appliance, rapid prototyping technology can be used. This involves converting the appliance's specifications into the data format corresponding to the rapid prototyping technology used, and then completing the manufacturing process using this technology. The rapid prototyping technologies employed include: stereolithography, laser rapid prototyping, layered solid modeling, selective laser sintering, fused deposition modeling, and 3D printing. This embodiment does not limit the specific rapid prototyping technology used.

[0151] The eighth embodiment of this application relates to an accessory design device, referencing... Figure 11 ,include:

[0152] The first acquisition module 1101 is used to acquire a finite element model of the jaw with attachments. The finite element model of the jaw includes finite element models of multiple teeth, a finite element model of the periodontal ligament, and a finite element model of the attachments.

[0153] The second acquisition module 1102 is used to acquire the finite element model of the orthodontic appliance, which includes an accessory receiving cavity for accommodating accessories.

[0154] The third acquisition module 1103 is used to assemble the finite element model of the orthodontic appliance onto the finite element model of the jaw, obtain the orthodontic force of the appliance based on the current position of the target tooth and the target position after a single treatment, obtain the first displacement of the target tooth and the strain of the target periodontal ligament covering the target tooth under the action of the orthodontic force, the target tooth being a tooth with attachments; determine the amount of alveolar bone reconstruction after a preset time based on the strain of the target periodontal ligament, obtain the second displacement of the target tooth based on the amount of alveolar bone reconstruction, and obtain the actual position of the target tooth after a preset time based on the first displacement and the second displacement.

[0155] The fourth acquisition module 1104 acquires the orthodontic deviation of the target tooth based on the target position and the actual position.

[0156] Adjustment module 1105 is used to optimize the design parameters of the accessories based on the correction deviation.

[0157] It is not difficult to see that this embodiment is a device embodiment corresponding to the method embodiment, and this embodiment can be implemented in conjunction with the method embodiment. The relevant technical details mentioned in the method embodiment are still valid in this embodiment, and will not be repeated here to reduce repetition. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the method embodiment.

[0158] It is worth mentioning that all modules involved in this embodiment are logical modules. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this invention, this embodiment does not introduce units that are not closely related to solving the technical problem proposed by this invention; however, this does not mean that other units are absent from this embodiment.

[0159] The ninth embodiment of this application provides an orthodontic appliance design device, with reference to... Figure 12 ,include:

[0160] The acquisition module 1201 is used to acquire the attachment with optimized design parameters according to the attachment design method described above;

[0161] Design module 1202 is used to adjust the design parameters of the accessory receiving cavity of the orthodontic appliance according to the optimized design parameters of the accessories, and obtain the orthodontic appliance with updated design parameters.

[0162] It is not difficult to see that this embodiment is a device embodiment corresponding to the method embodiment, and this embodiment can be implemented in conjunction with the method embodiment. The relevant technical details mentioned in the method embodiment are still valid in this embodiment, and will not be repeated here to reduce repetition. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the method embodiment.

[0163] It is worth mentioning that all modules involved in this embodiment are logical modules. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this invention, this embodiment does not introduce units that are not closely related to solving the technical problem proposed by this invention; however, this does not mean that other units are absent from this embodiment.

[0164] The tenth embodiment of this application provides an electronic device, with reference to... Figure 13 The method includes: at least one processor 1301; and a memory 1302 communicatively connected to at least one processor 1301; wherein the memory 1302 stores instructions that can be executed by at least one processor 1301, the instructions being executed by at least one processor 1301 to enable at least one processor 1301 to perform the accessory design method or orthodontic device design method described in any of the above method embodiments.

[0165] The memory 1302 and processor 1301 are connected via a bus. This bus can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors 1301 and memory 1302. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. A bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by processor 1301 is transmitted over a wireless medium via an antenna, which further receives data and transmits it to processor 1301.

[0166] Processor 1301 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory 1302 can be used to store data used by processor 1301 during operation.

[0167] The eleventh embodiment of this application also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the above-described method embodiments.

[0168] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0169] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. An accessory design method, characterized in that, include: Obtain a finite element model of the jaw with attachments, the finite element model of the jaw includes finite element models of multiple teeth, finite element models of the periodontal ligament, and finite element models of attachments; Obtain a finite element model of the orthodontic appliance, the orthodontic appliance including an accessory receiving cavity for accommodating the accessory; The finite element model of the orthodontic appliance is assembled on the finite element model of the jaw. The orthodontic force of the orthodontic appliance is obtained according to the current position of the target tooth and the target position after a single treatment. The first displacement of the target tooth and the strain of the target periodontal ligament covering the target tooth are obtained under the action of the orthodontic force. The target tooth is a tooth with attachments. Based on the strain of the target periodontal ligament, the amount of alveolar bone reconstruction after a preset time is determined, and the second displacement of the target tooth is obtained based on the amount of alveolar bone reconstruction. Based on the first displacement and the second displacement, the actual position of the target tooth after the preset time is obtained. Based on the target position and the actual position, the orthodontic deviation of the target tooth is obtained; The design parameters of the accessory are optimized based on the corrective deviation.

2. The accessory design method according to claim 1, characterized in that, The optimization of the design parameters of the accessory based on the correction deviation includes: Adjust the placement of the attachments, and / or adjust the shape and size of the attachments; wherein the corrective deviation re-acquired based on the attachments optimized according to the parameters is less than the current deviation; If the correction deviation obtained again based on the optimized attachment meets the preset conditions, the current parameters are used as the optimized design parameters of the attachment.

3. The accessory design method according to claim 2, characterized in that, The preset conditions include the correction deviation being less than a preset threshold, or the correction deviation being the minimum deviation obtained after traversing all parameter optimization schemes.

4. The accessory design method according to claim 1, characterized in that, The step of determining the amount of alveolar bone remodeling in the target tooth after a preset time period based on the strain of the target periodontal ligament includes: Obtain the principal strains of the target periodontal ligament, and obtain the alveolar bone reconstruction rate in each principal strain direction according to the pre-created relationship function between alveolar bone reconstruction rate and periodontal ligament strain; Based on the alveolar bone reconstruction rate, the amount of alveolar bone reconstruction in each principal strain direction after the preset time is obtained.

5. The accessory design method according to claim 4, characterized in that, The step of obtaining the alveolar bone reconstruction rate in each of the principal strain directions includes: obtaining the alveolar bone reconstruction rate according to the following formula. Where e is the principal strain corresponding to the principal strain direction, c and l are constants, a is the lower limit of the alveolar bone reconstruction strain, and b is the upper limit of the alveolar bone reconstruction strain.

6. The accessory design method according to claim 1, characterized in that, The step of obtaining the actual position of the target tooth after the preset time based on the first displacement and the second displacement includes: After the orthodontic force is stopped, the target periodontal membrane rebounds to a stress-free state, and the rebound displacement of the target tooth is obtained. Based on the first displacement, the second displacement, and the rebound displacement, the actual position of the target tooth after the preset time is obtained.

7. The accessory design method according to claim 1, characterized in that, The step of obtaining the orthodontic deviation of the target tooth based on the target position and the actual position includes: Based on the spatial relationship between the target position and the actual position, the deviation of the target tooth along the three coordinate axes of a preset spatial coordinate system is obtained; wherein, the three coordinate axes of the preset spatial coordinate system are the mesial-distal axis, the long axis, and the labial-lingual axis. The deviations along the three coordinate axes are summed, and the summation result is taken as the corrective deviation.

8. The accessory design method according to claim 7, characterized in that, The step of obtaining the deviation of the target tooth in the three coordinate axes of the preset spatial coordinate system includes: The translational deviation and rotational deviation of the target tooth in the three coordinate axes of the preset spatial coordinate system are obtained. The summation of the deviations along the three coordinate axes includes: The translational and rotational deviations are summed in dimensionless form.

9. The accessory design method according to any one of claims 1 to 8, characterized in that, The acquisition of the finite element model of the orthodontic appliance includes: Obtain the initial design parameters of the attachment; Based on the initial design parameters, a finite element model of the jaw is obtained after the attachments are assembled; wherein, the target tooth in the finite element model of the jaw is located at the target position after the single orthodontic treatment; Based on the finite element model of the jaw after the attachments are assembled, the finite element model of the orthodontic appliance is obtained.

10. The accessory design method according to claim 9, characterized in that, The process of obtaining the initial design parameters of the attachment includes: The type of movement of the target tooth is determined based on the current initial position of the target tooth and the target position after a single orthodontic treatment. Based on the movement type and the projection of the target tooth onto a preset plane, the initial shape, size, and initial placement position of the attachment are determined.

11. The accessory design method according to claim 10, characterized in that, The preset plane is a plane formed by any two of the following axes: the mesial-distal axis of the target tooth, the long axis of the tooth, and the labial-lingual axis.

12. A method for designing an orthodontic appliance, characterized in that, include: According to any one of claims 1 to 11, the attachment with optimized design parameters is obtained; Based on the optimized design parameters of the attachments, the design parameters of the attachment receiving cavity of the orthodontic appliance are adjusted to obtain the orthodontic appliance with updated design parameters.

13. The orthodontic appliance design method according to claim 12, characterized in that, After adjusting the design parameters of the accessory receiving cavity of the orthodontic appliance, the method further includes: The stress of the target periodontal ligament is obtained based on the strain of the target periodontal ligament. Based on the relationship between the stress of the target periodontal ligament and the upper and lower limits of the preset stress range, the designed movement amount of the target tooth is adjusted until the stress of the target periodontal ligament that is re-obtained is within the preset stress range. The design parameters of the tooth cavity of the orthodontic appliance that accommodates the target tooth are adjusted according to the adjusted target tooth design movement.

14. The orthodontic appliance design method according to claim 13, characterized in that, The step of adjusting the designed movement of the target tooth based on the relationship between the stress of the target periodontal ligament and the upper and lower limits of the preset stress range includes: Based on the upper limit of the preset stress range, the maximum designed movement of the teeth in a single orthodontic treatment is obtained; Adjust the design parameters of the orthodontic appliance so that the designed movement of the target tooth is equal to the maximum designed movement.

15. The orthodontic appliance design method according to claim 14, characterized in that, Before adjusting the design parameters of the orthodontic appliance to make the designed movement of the target tooth equal to the maximum designed movement, the procedure further includes: Based on the target orthodontic effect of the target tooth, the target movement amount of the target tooth is obtained; If the target tooth movement is greater than the maximum designed movement, the design parameters of the orthodontic appliance are adjusted so that the target tooth movement is equal to the maximum designed movement. If the target tooth movement is not greater than the maximum designed movement, the design parameters of the orthodontic appliance are adjusted so that the designed tooth movement is equal to the target movement.

16. A method for manufacturing an accessory, characterized in that, include: The attachment design method according to any one of claims 1 to 11 obtains the attachment model with updated design parameters; Manufacture the female mold of the attachment according to the attachment model; The accessory is manufactured by filling a negative mold with light-cured resin.

17. A method for manufacturing an accessory, characterized in that, include: The attachment design method according to any one of claims 1 to 11 obtains the attachment model with updated design parameters; The attachment is manufactured using additive manufacturing processes based on the data information corresponding to the attachment.

18. A method for manufacturing an orthodontic appliance, characterized in that, include: The orthodontic appliance design method according to any one of claims 12 to 15 obtains an orthodontic appliance model with updated design parameters; Manufacture a positive mold of the orthodontic appliance based on the orthodontic appliance model; A shell-shaped dental instrument containing the shape of teeth is obtained by thermoforming on the male mold of the orthodontic appliance; A shell-shaped orthodontic appliance capable of accommodating teeth is obtained by cutting along or near the gingival line on the shell-shaped dental instrument.

19. A method for manufacturing an orthodontic appliance, characterized in that, include: The orthodontic appliance design method according to any one of claims 12 to 15 obtains an orthodontic appliance model with updated design parameters; Based on the data information corresponding to the orthodontic appliance, a shell-shaped orthodontic appliance is manufactured using additive manufacturing technology.

20. An accessory design device, characterized in that, include: The first acquisition module is used to acquire a finite element model of a jaw with attachments, wherein the finite element model of a jaw includes finite element models of multiple teeth, a finite element model of the periodontal ligament, and a finite element model of the attachments. The second acquisition module is used to acquire the finite element model of the orthodontic appliance, which includes an accessory receiving cavity for accommodating the accessory. The third acquisition module is used to assemble the finite element model of the orthodontic appliance onto the finite element model of the jaw, obtain the orthodontic force of the orthodontic appliance based on the current position of the target tooth and the target position after a single treatment, and obtain the first displacement of the target tooth and the strain of the target periodontal ligament covering the target tooth under the action of the orthodontic force, wherein the target tooth is a tooth with attachments. The fourth acquisition module is used to determine the amount of alveolar bone reconstruction after a preset time based on the strain of the target periodontal ligament, and to obtain the second displacement of the target tooth based on the amount of alveolar bone reconstruction, and to obtain the actual position of the target tooth after the preset time based on the first displacement and the second displacement. The fifth acquisition module is used to acquire the orthodontic deviation of the target tooth based on the target position and the actual position; An adjustment module is used to optimize the design parameters of the accessory based on the correction deviation.

21. A device for designing an orthodontic appliance, characterized in that, include: The acquisition module is used to acquire the attachment with optimized design parameters according to the attachment design method according to any one of claims 1 to 11; The design module is used to adjust the design parameters of the accessory receiving cavity of the orthodontic appliance according to the optimized design parameters of the accessory, and obtain the orthodontic appliance with updated design parameters.

22. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the accessory design method as described in any one of claims 1 to 11, or the orthodontic appliance design method as described in any one of claims 12 to 15.

23. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the accessory design method of any one of claims 1 to 11, or the orthodontic appliance design method of any one of claims 12 to 15.

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