阅读说明：本技术 旋转中心设计检验方法、壳状牙科器械设计及制备方法 (Rotation center design inspection method, shell-shaped dental instrument design and preparation method ) 是由 於路 王心军 姚峻峰 于 2020-04-01 设计创作，主要内容包括：本发明提供旋转中心设计检验方法、壳状牙科器械设计及制备方法,其中,旋转中心设计检验方法包括步骤：单颗数字化牙冠模型的分类、单颗数字化牙冠模型长轴的拟合、数字化牙冠模型阻抗中心的确定、模拟数字化牙冠模型排牙设计、及旋转中心的优化调整,其中,基于施加到数字化牙冠模型上产生的力矩与施加到数字化牙齿矫治器上产生的平衡力矩的比值与排牙设计中的旋转量设计检验旋转中心的预设位置,以实现旋转中心的优化调整。通过对单颗数字化牙冠模型分类、牙冠模型长轴拟合、阻抗中心确定、排牙设计、旋转中心优化调整,使得,设计的牙齿旋转中心和实际矫治过程中的旋转中心基本一致,使牙齿治疗效果符合预期效果,进一步避免了医疗事故的发生。(The invention provides a method for designing and checking a rotation center, a method for designing and manufacturing a shell-shaped dental instrument, wherein the method for designing and checking the rotation center comprises the following steps: the method comprises the steps of classifying single digital dental crown models, fitting a long shaft of the single digital dental crown model, determining an impedance center of the digital dental crown model, simulating a tooth arrangement design of the digital dental crown model and optimizing and adjusting a rotation center, wherein the preset position of the rotation center is checked based on the ratio of the torque generated by applying the digital dental crown model to the balance torque generated by applying the digital dental crown model to a digital dental appliance and the rotation amount design in the tooth arrangement design so as to realize the optimizing and adjusting of the rotation center. Through the classification of a single digital dental crown model, the fitting of a long shaft of the dental crown model, the determination of an impedance center, the design of tooth arrangement and the optimization and adjustment of a rotation center, the designed rotation center of the tooth is basically consistent with the rotation center in the actual correcting process, so that the treatment effect of the tooth accords with the expected effect, and the occurrence of medical accidents is further avoided.)

1. A design and inspection method for a rotation center based on a digital dental crown model is characterized by comprising the following steps:

classification of single digital crown model: carrying out classification and labeling on the single digital dental crown model according to the classification standard of the standard digital dental crown model;

fitting of a long shaft of a single digital dental crown model: fitting a long axis of the single digital dental crown model based on the classified and labeled single digital dental crown model;

determination of the impedance center of the digital dental crown model: calculating the position of an impedance center point of the digital dental crown model based on the point of each point on the single digital dental crown model projected to the long axis and the classification marking information of the digital dental crown model;

simulating a digital dental crown model tooth arrangement design: simulating a digital dental crown model tooth arrangement design based on the initial position and the target correction position of the digital dental crown model, and calculating a single-step movement amount of the digital dental crown model, wherein the single-step movement amount comprises a translation amount and a rotation amount of the digital dental crown model, and the rotation amount is a pose change amount generated by the digital dental crown model with a rotation center as a rotation point;

optimizing and adjusting the rotation center: respectively superposing impedance center points corresponding to the initial position and the target position of the digital dental crown model based on the translation amount, and calculating the rotation amount of the digital dental crown model; the preset position of the center of rotation is then verified based on the ratio of the torque applied to the digital crown model to the balancing torque applied to the digital dental appliance and the amount of rotation design.

2. The digital dental crown model based design verification of center of rotation method according to claim 1, wherein the classification method of the single digital dental crown model comprises:

acquiring a digital dental model: acquiring a digital dental model, wherein the digital dental model comprises a digital dental crown model;

segmenting the digital dental model: dividing the digital dental model into a single digital dental crown model and a digital gum model;

classification of single digital crown model: and carrying out classification labeling on the single digital dental crown model according to the classification standard of the standard digital dental crown model.

3. The digital crown model rotation center based design verification method according to any one of the claims 1 or 2, wherein the fitting method of the single digital crown model long axis comprises:

repairing a single digital dental crown model: performing digital mesh repairing on two side surfaces of two adjacent single digital dental crown models in the near-far direction and the bottom surface close to the digital gum model after classification and marking, wherein a plane formed after the digital mesh repairing of the bottom surface is a gum line fitting plane;

fitting of a long shaft of a single digital dental crown model: fitting a long axis of the single digital crown model based on a normal vector of the gum line fitting plane.

4. The design verification method for rotation center based on digital dental crown model according to claim 3, characterized in that the determination method for impedance center of digital dental crown model comprises:

and calculating the height of the single digital dental crown model along the long axis direction based on the distance between the cusp of the single digital dental crown model and the projection point of the gum line fitting plane which is respectively mapped to the long axis, wherein the point which is mapped to the long axis by the gum line fitting plane is taken as a starting point, and the position which extends to the direction of the digital dental crown model by half of the height of the single digital dental crown model is taken as the position of an impedance center.

5. The digital dental crown model-based design verification of center of rotation method according to claim 3, further comprising the step of virtually generating a digital dental root model: and according to the single digital dental crown model after classification and marking, generating a digital dental root model by matching and adjusting with a standard digital dental crown model, and fitting the digital dental crown model and the digital dental root model into the single digital dental model.

6. The design verification method for rotation center based on digital dental crown model according to claim 5, characterized in that the determination method for impedance center of digital dental crown model comprises:

based on the distance between the apex of the single digital tooth model and the projection point of the gum line fitting plane which is respectively mapped to the long axis, the point which is mapped to the long axis by the gum line fitting plane is taken as the starting point, and the position which extends to the direction of the digital tooth root model by half of the distance is taken as the position of the impedance center.

7. The digital dental crown model-based rotational center design verification method according to claim 6, wherein the direction of the long axis is set to be directed to the digital dental crown model by the digital dental root model or to be directed to the digital dental root model by the digital dental crown model.

8. The digital dental crown model-based design verification method for rotation center according to claim 7, wherein the ratio of the difference of the rotation center to the impedance center to the difference of the apical point to the impedance center is set to a predetermined range to determine the accuracy of one-step movement amount design of the digital dental crown model.

9. The method for designing and verifying the rotation center based on the digital dental crown model according to claim 8, wherein when the ratio of the difference from the rotation center to the impedance center to the difference from the apical point to the impedance center is 0 or more, the ratio of the moment generated by applying the digital dental crown model to the balance moment generated by applying the digital dental appliance is 1-Exp [ - (D-C)/(B-C) ], wherein C is the impedance center relative coordinate position, D is the rotation center relative coordinate position, and B is the apical point relative coordinate position.

10. The digital dental crown model-based design verification method for rotation center according to claim 8, wherein when the ratio of the difference from the rotation center to the impedance center to the difference from the apical point to the impedance center is less than 0, the ratio of the moment generated by the application to the digital dental crown model to the balance moment generated by the application to the digital dental appliance is more than 1.

11. The digital dental crown model-based rotation center design verification method according to any one of claims 8 to 10, wherein a ratio of a moment generated to be applied to the digital dental crown model and a balance moment generated to be applied to the digital dental appliance based on the pose change amount in the analog digital dental crown model tooth arrangement design method and a ratio of a moment generated to be applied to the digital dental appliance and a balance moment generated to be applied to the digital dental appliance generated when the standard digital dental crown model is moved are subjected to a uniformity test; if the two ratios are uniform, the adjustment of the rotation center is not needed; if the two ratios are not uniform, the rotation center needs to be adjusted until the two ratios are uniform.

12. The digital dental crown model-based design verification method for rotation center according to claim 11, wherein the pose change of the digital dental crown model is translation when the ratio of the moment generated by applying the standard digital dental crown model to the digital dental crown model generated by moving the standard digital dental crown model to the balance moment generated by applying the standard digital dental crown model to the digital dental appliance is 1.

13. The digital dental crown model-based design verification method for rotation center according to claim 11, wherein the pose of the digital dental crown model is changed to rotation when the ratio of the moment generated when the standard digital dental crown model is moved and applied to the digital dental crown model to the balance moment generated when the standard digital dental crown model is applied to the digital dental appliance is 0, or between 0 and 1, or greater than 1.

14. The digital crown model rotation center based design verification method according to claim 1, wherein the method for acquiring the digital dental model is intraoral scan acquisition data or impression acquisition data.

15. The digital dental crown model rotation center-based design inspection method according to claim 1, wherein the single digital dental crown model is classified and labeled by FDI labeling, Palmer tooth position representation or general registration.

16. The digital dental crown model rotation center-based design inspection method according to claim 3, wherein the single digital dental crown model has a segmentation boundary comprising a segmentation boundary between two adjacent single digital dental crown models and a bottom surface segmentation boundary adjacent to the digital gum model, the single digital dental crown model repairing method comprising:

initial repairing of a segmentation boundary, namely performing initial repairing on the side surface in the near-far direction of two adjacent digital dental crown models so as to perform initial fitting on two adjacent surfaces between the two adjacent single digital dental crown models, wherein the segmentation boundary is completely repaired, and the single digital dental crown model is initially repaired near the bottom segmentation boundary of the digital gum model so as to completely repair the bottom segmentation boundary of the single digital dental crown model and obtain an initial repairing grid of the single digital dental crown model;

optimizing and adjusting the initialized repairing mesh, and performing optimizing and adjusting the preset distance between the vertexes of the initialized repairing mesh of two adjacent digital dental crown models by adopting a quadratic programming method so as to prevent two adjacent surfaces between the two adjacent digital dental crown models from colliding with each other; and simultaneously, initializing a repairing grid of the single digital dental crown model close to the bottom surface of the digital gum model for optimization and adjustment.

17. The digital crown model-based design verification of rotation center according to claim 16, wherein the initial repairing of the segmentation boundary is a digital mesh repairing of the segmentation boundary using a minimum angle method.

18. The digital dental crown model rotation center based design verification method according to claim 16, wherein the method of optimally trimming the bottom surface of the single digital dental crown model adjacent to the digital gum model comprises a method of extending the bottom surface of the initially trimmed digital dental crown model in an extension axis direction.

19. The digital dental crown model-based design verification method for rotation center according to claim 16, wherein v is set for the coordinates of the digital mesh vertex of the bottom surface of the digital dental crown model extending from the long axis direction of the tooth to the root direction h_k＝v_k0+ h × m, wherein k ∈ digitizes the crown base part, wherein v_k0And (3) representing the coordinates of the vertex of the digital mesh after the initial trimming of the segmentation boundary of the bottom surface part of the digital dental crown, wherein h is the translation distance, and m is the direction of the dental axis.

20. A tooth arrangement method based on a digital dental crown model is characterized in that: performing a tooth arrangement design of the digital dental crown model after passing the verification of the rotational center design verification method based on the digital dental crown model according to any one of claims 1 to 19.

21. A method of designing a shell-like dental instrument, comprising:

acquiring a digital dental model: acquiring a digital dental model, wherein the digital dental model comprises a digital dental crown model;

obtaining a post-dentition digital crown model based on a method of dentition performed based on a digital crown model according to claim 20;

design of shell-like dental instruments: designing a shell-shaped dental instrument having the digital dental crown model accommodated therein based on the arranged digital dental crown model, wherein the ratio of the moment generated by the shell-shaped dental instrument applied to the digital dental crown model to the balance moment generated by the digital dental crown model applied to the shell-shaped dental instrument is controlled within a predetermined value or range to adjust the pose change of the digital dental model.

22. A method of making a shell-like dental instrument, comprising: the shell-shaped dental instrument designed according to the method for designing a shell-shaped dental instrument of claim 21 is manufactured accordingly, and the specific manufacturing method comprises the following steps: 3D printing is carried out on the digital dental model after the pose change, a solid dental model is prepared, then shell-shaped dental appliances containing tooth shapes are obtained on the solid dental model in a hot press forming mode, and then the shell-shaped dental appliances containing the tooth shapes are obtained by cutting along a gum line or at a position close to the gum line on the shell-shaped dental appliances containing the tooth shapes.

23. A method for manufacturing a shell-shaped dental instrument, wherein the designed shell-shaped dental instrument is manufactured based on the method for designing a shell-shaped dental instrument according to claim 21, and the method comprises: and printing and preparing the designed shell-shaped dental instrument by adopting a direct 3D printing method.

Technical Field

The invention belongs to the technical field of tooth correction, and particularly relates to a shell-shaped tooth corrector manufacturing technology, in particular to a design and inspection method for a rotation center based on a digital dental crown model, a tooth arrangement method based on the digital dental crown model, a shell-shaped dental appliance design method and a shell-shaped dental appliance preparation method.

Background

In the process of designing orthodontic treatment, a single digital tooth model of a patient needs to be moved and arranged in a three-dimensional space, namely, the process of simulating digital tooth arrangement. However, in the current orthodontic treatment of teeth, actual intraoral information of a patient is converted into a digitized tooth three-dimensional model, then the digitized tooth three-dimensional model is segmented to obtain a digitized dental crown model, the surface of the digitized dental crown model is repaired to enable the shape of the repaired digitized dental crown model to be closer to the real tooth shape of the patient, then the digitized dental crown model is subjected to rotational translation operation to gradually change the arrangement mode to a target correction position, and finally a series of tooth correctors are manufactured according to each step of the gradually changed digitized dental crown model.

Because of different data acquisition modes, the digital tooth models are not provided with digital tooth root models, so that the rotation center of the digital tooth models can only be designed on the digital tooth crown models or the repaired digital tooth crown models, parameters of the digital tooth root models need to be simulated and estimated, and the accuracy of the mode has certain deviation, so that the actual corrected position of the teeth is probably not consistent with the expected target correction position in the actual correction process, the correction effect is not ideal for light persons, and the correction period is prolonged; even in severe cases, the tooth root is removed from the alveolar bone in the process of correcting the tooth, which causes serious medical accidents.

Therefore, the invention provides a corresponding technical scheme aiming at the problem that the selected rotation center is tested in the tooth arrangement designing process to ensure that the rotation center is closer to and better than the real intraoral condition of a patient.

Disclosure of Invention

The invention mainly aims to overcome the defects of the prior art, and provides a design inspection method for a rotary center based on a digital dental crown model, a tooth arrangement method based on the digital dental crown model, a shell-shaped dental appliance design method and a shell-shaped dental appliance preparation method, which solve the problem that the rotary center selected in the digital tooth arrangement process is deviated from the rotary center in the actual correction process.

The technical scheme provided by the invention is as follows:

the invention provides a design and inspection method for a rotation center based on a digital dental crown model, which comprises the following steps:

classification of single digital crown model: carrying out classification and labeling on the single digital dental crown model according to the classification standard of the standard digital dental crown model;

fitting of a long shaft of a single digital dental crown model: fitting a long axis of the single digital dental crown model based on the classified and labeled single digital dental crown model;

determination of the impedance center of the digital dental crown model: calculating the position of an impedance center point of the digital dental crown model based on the point of each point on the single digital dental crown model projected to the long axis and the classification marking information of the digital dental crown model;

simulating a digital dental crown model tooth arrangement design: simulating a digital dental crown model tooth arrangement design based on the initial position and the target correction position of the digital dental crown model, and calculating a single-step movement amount of the digital dental crown model, wherein the single-step movement amount comprises a translation amount and a rotation amount of the digital dental crown model, and the rotation amount is a pose change amount generated by the digital dental crown model with a rotation center as a rotation point;

optimizing and adjusting the rotation center: respectively superposing impedance center points corresponding to the initial position and the target position of the digital dental crown model based on the translation amount, and calculating the rotation amount of the digital dental crown model; the preset position of the center of rotation is then verified based on the ratio of the torque applied to the digital crown model to the balancing torque applied to the digital dental appliance and the amount of rotation design.

Further preferably, the classification method of the single digital dental crown model comprises the following steps:

acquiring a digital dental model: acquiring a digital dental model, wherein the digital dental model comprises a digital dental crown model;

segmenting the digital dental model: dividing the digital dental model into a single digital dental crown model and a digital gum model;

classification of single digital crown model: and carrying out classification labeling on the single digital dental crown model according to the classification standard of the standard digital dental crown model.

Further preferably, the method for fitting the long axis of the single digital dental crown model comprises the following steps:

repairing a single digital dental crown model: performing digital mesh repairing on two side surfaces of two adjacent single digital dental crown models in the near-far direction and the bottom surface close to the digital gum model after classification and marking, wherein the plane formed after the bottom surface digital mesh repairing is a gum line fitting plane;

fitting of a long shaft of a single digital dental crown model: fitting a long axis of the single digital crown model based on a normal vector of the gum line fitting plane.

Further preferably, the method for determining the impedance center of the digital dental crown model specifically comprises the following steps:

and calculating the height of the single digital dental crown model along the long axis direction based on the distance between the cusp of the single digital dental crown model and the projection point of the gum line fitting plane which is respectively mapped to the long axis, wherein the point which is mapped to the long axis by the gum line fitting plane is taken as a starting point, and the position which extends to the direction of the digital dental crown model by half of the height of the single digital dental crown model is taken as the position of an impedance center.

Further preferably, the method for determining the impedance center of the digital dental crown model specifically comprises the following steps:

based on the distance between the apex of the single digital tooth model and the projection point of the gum line fitting plane which is respectively mapped to the long axis, the point which is mapped to the long axis by the gum line fitting plane is taken as the starting point, and the position which extends to the direction of the digital tooth root model by half of the distance is taken as the position of the impedance center.

Further preferably, the direction of the long axis is set to be directed by the digitized tooth root model to the digitized tooth crown model or by the digitized tooth crown model to the digitized tooth root model.

Further preferably, the ratio of the difference from the rotation center to the impedance center to the difference from the apical point to the impedance center is set to a predetermined range to determine the accuracy of the single step movement amount design of the digital crown model.

Further preferably, when the ratio of the difference between the rotation center and the impedance center to the difference between the apical point and the impedance center is greater than or equal to 0, the ratio of the moment generated by the digital crown model to the balance moment generated by the digital appliance is 1-Exp [ - (D-C)/(B-C) ] where C is the impedance center relative coordinate position, D is the rotation center relative coordinate position, and B is the apical point relative coordinate position.

Further preferably, when a ratio of a difference between the rotation center and the impedance center to a difference between the apical point and the impedance center is less than 0, a ratio of a moment generated by the digital crown model to a balance moment generated by the digital appliance is greater than 1.

Further preferably, a uniformity check is performed on the basis of a ratio of a moment generated by applying the pose change amount to the digital dental crown model and a balance moment generated by applying the pose change amount to the digital dental appliance in the analog-digital dental crown model arrangement design method, and a ratio of a moment generated by applying the standard digital dental crown model to the digital dental appliance when moving; if the two ratios are uniform, the adjustment of the rotation center is not needed; if the two ratios are not uniform, the rotation center needs to be adjusted until the two ratios are uniform.

Further preferably, the pose of the digital dental crown model changes to translation when the ratio of the moment generated by the standard digital dental crown model when moving and the balance moment generated by the standard digital dental crown model when moving and the balance moment generated by the standard digital dental crown model when moving is 1.

Further preferably, when the ratio of the moment generated by the standard digital dental crown model when moving and applied to the digital dental crown model to the balance moment generated by the standard digital dental crown model when moving and applied to the digital dental appliance is 0, or between 0 and 1, or greater than 1, the pose of the digital dental crown model changes to rotation.

Further preferably, the method of acquiring a digital dental model is intraoral scanning acquisition data or impression acquisition data.

Further preferably, the single digital crown model is classified and labeled by an FDI labeling method, a Parmer tooth position representation method or a general recording method.

Further preferably, the method for repairing the single digital dental crown model comprises the following steps:

dividing the digital dental crown model into a single digital dental crown model with a dividing boundary, wherein the dividing boundary comprises a dividing boundary between two adjacent digital dental crown models and a bottom surface dividing boundary close to the digital gingival model;

initial repairing of a segmentation boundary, namely performing initial repairing on the side surface in the near-far direction of two adjacent digital dental crown models so as to perform initial fitting on two adjacent surfaces between the two adjacent single digital dental crown models, wherein the segmentation boundary is completely repaired, and the single digital dental crown model is initially repaired near the bottom segmentation boundary of the digital gum model so as to completely repair the bottom segmentation boundary of the single digital dental crown model and obtain an initial repairing grid of the single digital dental crown model;

optimizing and adjusting the initialized repairing mesh, and performing optimizing and adjusting the preset distance between the vertexes of the initialized repairing mesh of two adjacent digital dental crown models by adopting a quadratic programming method so as to prevent two adjacent surfaces between the two adjacent digital dental crown models from colliding with each other; and simultaneously, initializing a repairing grid of the single digital dental crown model close to the bottom surface of the digital gum model for optimization and adjustment.

Further preferably, the initial repairing method of the segmentation boundary is to perform digital mesh repairing on the segmentation boundary by using a minimum angle method.

Further preferably, the method for optimally trimming the bottom surface of the single digital dental crown model adjacent to the digital gum model comprises a method for performing extension setting on the bottom surface of the initially trimmed digital dental crown model in the direction of the extension axis.

Further preferably, v is set in such a manner that the coordinates of the digital mesh vertexes of the bottom surface of the digital crown model extend in the tooth root direction along the tooth long axis direction by h_k＝v_k0+ h × m, wherein k ∈ digitizes the crown base part, wherein v_k0And (3) representing the coordinates of the vertex of the digital mesh after the initial trimming of the segmentation boundary of the bottom surface part of the digital dental crown, wherein h is the translation distance, and m is the direction of the dental axis.

The invention also provides a tooth arrangement method based on the digital dental crown model, which comprises the following steps: and performing tooth arrangement design of the digital dental crown model after the rotational center design inspection method based on the digital dental crown model is qualified.

The invention also provides a design method of the shell-shaped dental instrument, which comprises the following steps:

acquiring a digital dental model: acquiring a digital dental model, wherein the digital dental model comprises a digital dental crown model;

obtaining a digital dental crown model after tooth arrangement based on the tooth arrangement method based on the digital dental crown model;

design of shell-like dental instruments: designing a shell-shaped dental instrument having the digital dental crown model accommodated therein based on the arranged digital dental crown model, wherein the ratio of the moment generated by the shell-shaped dental instrument applied to the digital dental crown model to the balance moment generated by the digital dental crown model applied to the shell-shaped dental instrument is controlled within a predetermined value or range to adjust the pose change of the digital dental model.

The invention also provides a preparation method of the shell-shaped dental instrument, which is used for correspondingly preparing the designed shell-shaped dental instrument based on the design method of the shell-shaped dental instrument, and the specific preparation method comprises the following steps: 3D printing is carried out on the digital dental model after the pose change, a solid dental model is prepared, then shell-shaped dental appliances containing tooth shapes are obtained on the solid dental model in a hot press forming mode, and then the shell-shaped dental appliances containing the tooth shapes are obtained by cutting along a gum line or at a position close to the gum line on the shell-shaped dental appliances containing the tooth shapes.

The invention also provides a preparation method of the shell-shaped dental instrument, which is used for correspondingly preparing the designed shell-shaped dental instrument based on the design method of the shell-shaped dental instrument, and the specific preparation method comprises the following steps: and printing and preparing the designed shell-shaped dental instrument by adopting a direct 3D printing method.

According to the design and inspection method for the rotation center based on the digital dental crown model, the design and inspection of the rotation center of the digital dental crown model are carried out through the steps of classifying the single digital dental crown model, fitting the long shaft of the digital dental crown model, determining the impedance center, designing the tooth arrangement, optimizing and adjusting the rotation center and the like, the subsequent tooth arrangement design and the design and preparation of the shell-shaped dental appliance are carried out on the rotation center meeting the inspection requirement, the consistency of the rotation center designed aiming at the digital dental crown model and the actual correction process is ensured, and the tooth treatment effect is ensured to meet the expected target correction effect. Specifically, the impedance center of the digital dental crown model is determined only by adopting the digital dental crown model in the provided determination mode of the impedance center of the digital dental crown model, the intraoral collected data only contains intraoral information obtained by the digital dental crown model, the position of the impedance center of the individualized teeth of a patient can be accurately determined, then the digital dental crown model is simulated to perform tooth arrangement design, the tooth pose change is generated in the tooth arrangement design, the preset position of the rotation center is adjusted, the rotation center after the inspection is adjusted to accord with the optimal scheme of the tooth arrangement design, the subsequently prepared shell-shaped teeth correcting device can align the teeth of the patient to the target correcting position, and the phenomenon of bone windowing or bone cracking is avoided in the process of tooth movement.

Drawings

The foregoing features, technical features, advantages and embodiments are further described in the following detailed description of the preferred embodiments, which is to be read in connection with the accompanying drawings.

FIG. 1 is a flow chart of a design verification method for a rotational center based on a digital crown model according to the present invention;

FIG. 2 is a flowchart of a method for repairing a triangular mesh by a minimum inclusion angle method according to the present invention;

FIG. 3 is a schematic diagram of adding a triangular mesh patch;

FIG. 4 is a schematic diagram of adding two triangular mesh patches;

FIG. 5 is a flowchart illustrating optimization and adjustment of vertices of a mesh to be repaired according to the present invention;

FIG. 6 is a schematic diagram of the structure of a single digitized tooth model generated by the fitting of the present invention;

FIG. 7 is a flow chart of a digital crown model based tooth arrangement design provided by the present invention;

FIG. 8 is a flow chart of a shell-like dental instrument design provided by the present invention;

FIG. 9 is a flow chart illustrating the preparation of a shell-shaped dental instrument according to the present invention.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

For the tooth correction of an orthodontic patient, the method that a doctor needs to align the teeth of the patient is that actual intraoral information of the patient is converted into a digital tooth three-dimensional model, then the digital tooth three-dimensional model is segmented to obtain a digital dental crown model, the surface of the digital dental crown model is repaired to enable the shape of the repaired digital dental crown model to be closer to the real tooth shape of the patient, then the digital dental crown model is rotated and translated to gradually change the arrangement mode to a target correction position, and finally a series of tooth correctors are manufactured according to each step of the digital dental crown model which gradually changes.

Because of different data acquisition modes, the digital tooth models are not provided with digital tooth root models, so that the rotation center of the digital tooth models can only be designed on the digital tooth crown models or the repaired digital tooth crown models, parameters of the digital tooth root models need to be simulated and estimated, and the accuracy of the mode has certain deviation, so that the actual corrected position of the teeth is probably not consistent with the expected target correction position in the actual correction process, the correction effect is not ideal for light persons, and the correction period is prolonged; even in severe cases, the tooth root is removed from the alveolar bone in the process of correcting the tooth, which causes serious medical accidents.

Aiming at the problems, the invention provides a corresponding solution, and the technical scheme provided by the invention solves the problem that the selected rotation center in the digital tooth arrangement process is deviated from the rotation center in the actual correction process. The technical scheme provided by the invention is as follows: