阅读说明：本技术 一种3d牙模自动摆正方法、系统、装置及存储介质 (Automatic 3D dental model straightening method, system, device and storage medium ) 是由 冯伟 王勇 李鸣 黄鹤源 于 2020-05-21 设计创作，主要内容包括：本发明公开了一种3D牙模自动摆正方法、系统、装置及存储介质,其中方法包括获取3D牙模,识别3D牙模的最大底面,并输出最大底面的法向量；结合3D牙模最大底面法向量和预设第一法向量获取第一旋转数据,根据第一旋转数据旋转3D牙模至第一平面；获取第一平面上3D牙模的轮廓,根据轮廓确定牙齿骨架曲线方程,并输出3D牙模的方向向量；结合3D牙模的方向向量和预设第二法向量获取第二旋转数据,根据第二旋转数据旋转3D牙模至目标位置,将3D牙模通过两次旋转摆放在目标位置,极大的缩短了牙齿模型数据预处理的时间,大大地提高了整个牙齿诊疗流程的效率,从而增强了用户体验,实现了牙齿正畸矫正的自动化流程处理。(The invention discloses a method, a system, a device and a storage medium for automatically righting a 3D dental model, wherein the method comprises the steps of obtaining the 3D dental model, identifying the maximum bottom surface of the 3D dental model and outputting the normal vector of the maximum bottom surface; combining the maximum bottom surface normal vector of the 3D dental model and a preset first normal vector to obtain first rotation data, and rotating the 3D dental model to a first plane according to the first rotation data; acquiring the contour of the 3D dental model on the first plane, determining a tooth skeleton curve equation according to the contour, and outputting a direction vector of the 3D dental model; the direction vector of the 3D dental model and the preset second normal vector are combined to obtain second rotation data, the 3D dental model is rotated to the target position according to the second rotation data, the 3D dental model is placed at the target position through twice rotation, the time for preprocessing the dental model data is greatly shortened, the efficiency of the whole tooth diagnosis and treatment process is greatly improved, orthodontic user experience is enhanced, and automatic process processing of tooth correction is realized.)

1. A3D dental model automatic setting method is characterized by comprising the following steps:

acquiring a 3D dental model, identifying the maximum bottom surface of the 3D dental model, and outputting a normal vector of the maximum bottom surface;

combining the maximum bottom surface normal vector of the 3D dental model and a preset first normal vector to obtain first rotation data, and rotating the 3D dental model to a first plane according to the first rotation data;

acquiring the contour of the 3D dental model on the first plane, determining a tooth skeleton curve equation according to the contour, and outputting a direction vector of the 3D dental model;

and combining the direction vector of the 3D dental model and a preset second normal vector to obtain second rotation data, and rotating the 3D dental model to a target position according to the second rotation data.

2. The method for automatically straightening the 3D dental model according to claim 1, wherein the step of obtaining the contour of the 3D dental model on the first plane and determining the tooth skeleton curve equation according to the contour includes the following steps:

projecting the 3D dental model on the first plane by adopting a projection technology to generate a contour picture;

extracting a target tooth skeleton curve from the 3D dental model contour picture;

denoising and fitting the target tooth skeleton curve to generate a tooth skeleton curve equation.

3. The method for automatically straightening the 3D dental model according to claim 1, wherein the 3D dental model is a three-dimensional body consisting of a plurality of triangular surfaces, and the step of obtaining the 3D dental model and identifying the largest bottom surface of the 3D dental model specifically comprises the following steps:

performing included angle matching on a plurality of triangular surfaces of the acquired 3D dental model by adopting a set triangular surface to generate a target bottom surface set;

and traversing the area of the target bottom surface set to obtain the maximum bottom surface with the maximum area of the 3D dental model.

4. The method for automatically aligning a 3D dental model according to claim 1, wherein the step of obtaining first rotation data by combining the maximum bottom surface normal vector of the 3D dental model and a preset first normal vector, and rotating the 3D dental model to a first plane according to the first rotation data specifically comprises the steps of:

performing cross multiplication on the obtained maximum bottom surface normal vector of the 3D dental model and a preset first normal vector to generate first rotation data;

the 3D dental model is rotated to a first plane according to the first rotation data.

5. The method for automatically aligning a 3D dental cast according to claim 2, wherein the step of obtaining second rotation data by combining the direction vector of the 3D dental cast and a preset second normal vector, and rotating the 3D dental cast to a target position according to the second rotation data specifically comprises the steps of:

performing cross multiplication on the obtained direction vector of the 3D dental model and a preset second normal vector to generate second rotation data;

and rotating the 3D dental model to the target position according to the second rotation data.

6. A3D dental model automatic setting system is characterized by comprising:

the identification module is used for acquiring the 3D dental model, identifying the maximum bottom surface of the 3D dental model and outputting a normal vector of the maximum bottom surface;

the first rotation module is used for acquiring first rotation data by combining the maximum bottom surface normal vector of the 3D dental model and a preset first normal vector, and rotating the 3D dental model to a first plane according to the first rotation data;

the determining module is used for acquiring the contour of the 3D dental model on the first plane, determining a tooth skeleton curve equation according to the contour and outputting a direction vector of the 3D dental model;

and the second rotating module is used for acquiring second rotating data by combining the direction vector of the 3D dental model and a preset second normal vector, and rotating the 3D dental model to a target position according to the second rotating data.

7. The system of claim 6, wherein the determining module comprises:

the generating unit is used for projecting the 3D dental model on the first plane by adopting a projection technology to generate a contour picture;

the extraction unit is used for extracting a target tooth skeleton curve from the 3D dental model outline picture;

and the fitting unit is used for denoising and fitting the target tooth skeleton curve to generate a tooth skeleton curve equation.

8. The system of claim 6, wherein the identification module comprises:

the matching unit is used for carrying out included angle matching on a plurality of acquired triangular surfaces of the 3D dental model by adopting the set triangular surfaces to generate a target bottom surface set;

and the traversing unit is used for traversing the area of the target bottom surface set to obtain the maximum bottom surface with the maximum area of the 3D dental model.

9. An apparatus comprising a memory for storing at least one program and a processor for loading the at least one program to perform the method of any one of claims 1-5.

10. A storage medium having stored therein processor-executable instructions, which when executed by a processor, are configured to perform the method of any one of claims 1-5.

Technical Field

The invention relates to the technical field of measurement control, in particular to a method, a system, a device and a storage medium for automatically aligning a 3D dental model.

Background

Dental medicine is an inevitable problem for most people, such as orthodontic correction, dental implant restoration, tooth filling and the like, and not only does traditional dental medicine require doctors to have very high professional skills and abundant clinical experience, but also the purely manual treatment process is relatively slow and the success rate of healing is low. With the progress of science and technology and the development of society, the fusion and cooperation between different scientific technologies in the application field become a great trend, wherein the deep fusion of computer technology, measurement technology and 3D digital printing technology has been widely applied to various aspects in the medical field, and dental medicine is one of hot applications, so that people's eyesight has shifted from the traditional purely artificial dental medicine to the digital dental medicine. The prior knowledge provided by a high-new digital technology and the 3D digital tooth model can be used for observing the condition of the teeth in the oral cavity more visually and stereoscopically, so that the safety and the success rate of tooth treatment are greatly improved.

In the application scene of present tooth diagnosis and treatment, especially orthodontic correction, for the digital 3D tooth model of fine application is diagnose, need carry out data preprocessing to the tooth model earlier to carry out accurate correction to the tooth in the follow-up, wherein the preprocessing of 3D tooth model putting is just orthodontic correction's key step, has occupied the most time of whole diagnosis and treatment flow moreover, in order to improve the efficiency of whole diagnosis and treatment flow, strengthen user experience, need shorten the preprocessing time of tooth model data, orthodontic correction's automation technology still belongs to the blank at present.

Disclosure of Invention

In order to solve the above technical problems, an object of the present invention is to provide a method, a system, an apparatus and a storage medium for automatically aligning a 3D dental model.

The first technical scheme adopted by the invention is as follows:

A3D dental model automatic setting method comprises the following steps:

acquiring a 3D dental model, identifying the maximum bottom surface of the 3D dental model, and outputting a normal vector of the maximum bottom surface;

combining the maximum bottom surface normal vector of the 3D dental model and a preset first normal vector to obtain first rotation data, and rotating the 3D dental model to a first plane according to the first rotation data;

acquiring the contour of the 3D dental model on the first plane, determining a tooth skeleton curve equation according to the contour, and outputting a direction vector of the 3D dental model;

and combining the direction vector of the 3D dental model and a preset second normal vector to obtain second rotation data, and rotating the 3D dental model to a target position according to the second rotation data.

Optionally, the step of acquiring the contour of the 3D dental model on the first plane and determining the tooth skeleton curve equation according to the contour specifically includes the following steps:

projecting the 3D dental model on the first plane by adopting a projection technology to generate a contour picture;

extracting a target tooth skeleton curve from the 3D dental model contour picture;

denoising and fitting the target tooth skeleton curve to generate a tooth skeleton curve equation.

Optionally, the step of denoising and fitting the curve of the target tooth skeleton to generate a tooth skeleton curve equation specifically includes the following steps:

carrying out iterative denoising processing on the target tooth skeleton curve to generate a continuous target tooth skeleton curve;

and traversing each target tooth of the continuous target tooth skeleton curve to generate a tooth skeleton curve equation.

Optionally, the 3D dental model is a three-dimensional body composed of a plurality of triangular surfaces, and the step of acquiring the 3D dental model and identifying the largest bottom surface of the 3D dental model specifically includes the following steps:

performing included angle matching on a plurality of triangular surfaces of the acquired 3D dental model by adopting a set triangular surface to generate a target bottom surface set;

and traversing the area of the target bottom surface set to obtain the maximum bottom surface with the maximum area of the 3D dental model.

Optionally, the step of obtaining first rotation data by combining the maximum bottom surface normal vector of the 3D dental model and a preset first normal vector, and rotating the 3D dental model to a first plane according to the first rotation data specifically includes the following steps:

performing cross multiplication on the obtained maximum bottom surface normal vector of the 3D dental model and a preset first normal vector to generate first rotation data;

the 3D dental model is rotated to a first plane according to the first rotation data.

Optionally, the step of obtaining second rotation data by combining the direction vector of the 3D dental model and a preset second normal vector, and rotating the 3D dental model to the target position according to the second rotation data specifically includes the following steps:

performing cross multiplication on the obtained direction vector of the 3D dental model and a preset second normal vector to generate second rotation data;

and rotating the 3D dental model to the target position according to the second rotation data.

The second technical scheme adopted by the invention is as follows:

A3D dental model automatic setting system comprises:

the identification module is used for acquiring the 3D dental model, identifying the maximum bottom surface of the 3D dental model and outputting a normal vector of the maximum bottom surface;

the first rotation module is used for acquiring first rotation data by combining the maximum bottom surface normal vector of the 3D dental model and a preset first normal vector, and rotating the 3D dental model to a first plane according to the first rotation data;

the determining module is used for acquiring the contour of the 3D dental model on the first plane, determining a tooth skeleton curve equation according to the contour and outputting a direction vector of the 3D dental model;

and the second rotating module is used for acquiring second rotating data by combining the direction vector of the 3D dental model and a preset second normal vector, and rotating the 3D dental model to a target position according to the second rotating data.

Optionally, the determining module includes:

the generating unit is used for projecting the 3D dental model on the first plane by adopting a projection technology to generate a contour picture;

the extraction unit is used for extracting a target tooth skeleton curve from the 3D dental model outline picture;

and the fitting unit is used for denoising and fitting the target tooth skeleton curve to generate a tooth skeleton curve equation.

Optionally, the identification module comprises:

the matching unit is used for carrying out included angle matching on a plurality of acquired triangular surfaces of the 3D dental model by adopting the set triangular surfaces to generate a target bottom surface set;

and the traversing unit is used for traversing the area of the target bottom surface set to obtain the maximum bottom surface with the maximum area of the 3D dental model.

Optionally, the first rotation module comprises:

the first cross multiplication unit is used for performing cross multiplication on the obtained maximum bottom surface normal vector of the 3D dental model and a preset first normal vector to generate first rotation data;

and the first rotating unit is used for rotating the 3D dental model to the first plane according to the first rotating data.

Optionally, the second rotation module comprises:

the second cross multiplication unit is used for performing cross multiplication on the obtained direction vector of the 3D dental model and a preset second normal vector to generate second rotation data;

and the second rotating unit is used for rotating the 3D dental model to the target position according to the second rotating data.

The third technical scheme adopted by the invention is as follows:

an apparatus, the memory for storing at least one program, the processor for loading the at least one program to perform the method described above.

The fourth technical scheme adopted by the invention is as follows:

a storage medium having stored therein processor-executable instructions for performing the method as described above when executed by a processor.

The invention has the beneficial effects that: the 3D dental model is placed at a target position through twice rotation by determining the normal vector and the preset first normal vector of the maximum bottom surface of the 3D dental model and acquiring the direction vector and the preset second normal vector of the 3D dental model determined by the contour of the 3D dental model on the first plane, so that the time for preprocessing the dental model data is greatly shortened, the efficiency of the whole tooth diagnosis and treatment process is greatly improved, the user experience is enhanced, and the automatic process treatment of the tooth orthodontic correction is realized.

Drawings

FIG. 1 is a flow chart illustrating the steps of a 3D dental cast automatic setting method according to the present invention;

FIG. 2 is a block diagram of the automatic 3D dental cast straightening system according to the present invention;

FIG. 3 is a detailed flow chart of the 3D dental cast automatic setting method of the present invention.

Detailed Description

As shown in fig. 1, the automatic 3D dental cast setting method provided in this embodiment includes the following steps:

s1, obtaining the 3D dental model, identifying the maximum bottom surface of the 3D dental model, and outputting a normal vector of the maximum bottom surface;

s2, combining the maximum bottom surface normal vector of the 3D dental model and a preset first normal vector to obtain first rotation data, and rotating the 3D dental model to a first plane according to the first rotation data;

s3, acquiring the contour of the 3D dental model on the first plane, determining a tooth skeleton curve equation according to the contour, and outputting a direction vector of the 3D dental model;

and S4, combining the direction vector of the 3D dental model and a preset second normal vector to obtain second rotation data, and rotating the 3D dental model to the target position according to the second rotation data.

A dental model, i.e. a model of teeth, is a model used by doctors for analyzing tooth shaping schemes, and is generally made by mixing dentifrice and water, occluding the teeth by patients, solidifying the occluded model, taking down the whole body and making the model with other materials. The maximum bottom surface is a maximum plane of a tooth model, the first plane is a set plane which takes the maximum bottom surface of the 3D dental model as a reference and places the 3D dental model to a corresponding target position, the preset first normal vector is a normal vector which is set according to the normal vector of the maximum bottom surface of the 3D dental model and is used for rotating the 3D dental model to a required rotating direction of the first plane, the direction vector of the 3D dental model is a direction vector of the 3D dental model which is made based on a tooth skeleton curve, the preset second preset normal vector is a normal vector which is set according to the direction vector of the 3D dental model and is used for rotating the 3D dental model to the required rotating direction of the target position, the first rotating data comprises a first rotating angle and a first rotating shaft, and the second rotating data comprises a second rotating angle and a second rotating shaft; the normal vector and the preset first normal vector of the maximum bottom surface of the 3D dental model are identified and output, the direction vector and the preset second normal vector of the 3D dental model are determined according to the profile picture of the 3D dental model on the first plane, and the 3D dental model is placed at the target position through twice rotation, so that the tooth diagnosis and treatment process dental model data preprocessing time is greatly shortened, the whole tooth diagnosis and treatment process efficiency is greatly improved, the automatic process treatment of tooth orthodontic correction is realized, and the user experience is greatly enhanced.

Optionally, the 3D dental cast is a three-dimensional body composed of a plurality of triangular surfaces, and the step S1 specifically includes the following steps:

s10, matching included angles of the plurality of triangular surfaces of the acquired 3D dental model by adopting the set triangular surface to generate a target bottom surface set;

s11, traversing the size of the target bottom surface set area to obtain the maximum bottom surface of the 3D dental model.

Specifically, a set triangular surface is adopted to carry out included angle matching on a plurality of acquired triangular surfaces of the 3D dental model, wherein the triangular plate is optional, if the triangular plate is initially set as the triangular plate i, firstly, the adjacent triangular plate i +1 of the triangular plate i is judged, if the triangular plate i is matched with the adjacent triangular plate i +1, the triangular plate i is determined to be coplanar with the adjacent triangular plate i +1, then, the triangular plate i is continuously matched with other adjacent triangular surface plates, meanwhile, the triangular surface plate i +1 is also matched with the adjacent triangular surface plates [ (i +1) +1], similarly, the triangular surface plates [ (i +1) +1] are also matched with the adjacent triangular surface plates and analogized, and the successfully matched triangular surface plates are superposed together to serve as a continuous target bottom surface; when an initially set triangular patch i is not matched with an adjacent triangular patch [ (i +1) +1], determining that the triangular patch i is different from the adjacent triangular patch [ (i +1) +1], taking the triangular patch [ (i +1) +1] as a new set triangular patch, matching the adjacent triangular patch of the triangular patch [ (i +1) +1] to judge a new bottom surface, and so on, traversing all the triangular patches to obtain a set consisting of a plurality of target bottom surfaces, wherein each target bottom surface at least consists of one triangular patch; the target bottom surface with the largest area is the largest bottom surface of the 3D dental model, in the embodiment, the 3D dental model is a three-dimensional dental model which is processed and repaired by design software and is provided with a bottom surface and is composed of a plurality of triangular surfaces in any direction, and the three-dimensional dental model has the characteristics of accurate data, high precision and smooth dental model surface.

Optionally, the step S2 specifically includes the following steps:

s20, performing cross multiplication on the obtained maximum bottom surface normal vector of the 3D dental model and a preset first normal vector to generate first rotation data;

and S21, rotating the 3D dental model to a first plane according to the first rotation data.

Specifically, in the process of identifying the maximum bottom surface of the 3D dental model at the position, a plane equation corresponding to the maximum bottom surface of the 3D dental model can be obtained by using the existing computer technology and mathematical methods, so as to obtain a normal vector of the maximum bottom surface of the 3D dental model, a preset first normal vector is set according to the normal vector of the maximum bottom surface of the 3D dental model, cross multiplication operation is performed on the normal vector of the maximum bottom surface of the 3D dental model and the preset first normal vector to obtain first rotation data, and the 3D dental model is rotated to a first plane according to the first rotation data.

Optionally, the step S3 specifically includes the following steps:

s30, projecting the 3D dental model on the first plane by adopting a projection technology to generate a contour picture;

s31, extracting a target tooth skeleton curve from the 3D dental model contour picture;

s32, denoising and fitting the target tooth skeleton curve to generate a tooth skeleton curve equation.

The steps S1 and S2 are completed by rotating the 3D dental model to the first plane with the maximum bottom surface as the reference, and after rotating to the first plane, performing a second rotation based on the maximum bottom surface of the 3D dental model of the first plane, specifically, projecting the 3D dental model located on the first plane by a projection technique to generate a picture containing a contour of the target tooth skeleton, extracting a curve of the target tooth skeleton from the picture of the contour of the 3D dental model, denoising the obtained curve of the tooth skeleton, and generating a curve equation of the tooth skeleton by using a conventional computer fitting algorithm.

Optionally, the step S32 specifically includes:

s320, carrying out iterative denoising treatment on the target tooth skeleton curve to generate a continuous target tooth skeleton curve;

s321, traversing each target tooth of the continuous target tooth skeleton curve to fit and generate a tooth skeleton curve equation.

Specifically, the target tooth skeleton curve extracted from the profile usually has an additional branch, i.e., noise, so that iterative denoising processing needs to be performed on the obtained target tooth skeleton curve until a smooth continuous target tooth skeleton curve is generated, and after the obtained continuous target tooth skeleton curve is subjected to traversal processing, a tooth skeleton curve equation is generated by fitting processing on the continuous target tooth skeleton curve.

Optionally, the step S4 specifically includes the following steps:

s40, performing cross multiplication on the obtained direction vector of the 3D dental model and a preset second normal vector to generate second rotation data;

s41 rotating the 3D dental model to the target position according to the second rotation data.

Specifically, a direction vector of the 3D dental model is obtained according to the generated tooth skeleton curve equation, a preset second normal vector is set according to the direction vector of the 3D dental model, cross multiplication processing is carried out on the direction vector of the 3D dental model and the preset second normal vector to generate second rotation data, the second rotation data comprise a second rotation angle and a second rotation axis, and the 3D dental model is rotated to the target position according to the second rotation angle and the second rotation axis.

Fig. 2 is a block diagram of a 3D dental cast automatic setting system according to the present invention, which includes:

the identification module is used for acquiring the 3D dental model, identifying the maximum bottom surface of the 3D dental model and outputting a normal vector of the maximum bottom surface;

the first rotation module is used for acquiring first rotation data by combining the maximum bottom surface normal vector of the 3D dental model and a preset first normal vector, and rotating the 3D dental model to a first plane according to the first rotation data;

the determining module is used for acquiring the contour of the 3D dental model on the first plane, determining a tooth skeleton curve equation according to the contour and outputting a direction vector of the 3D dental model;

and the second rotating module is used for acquiring second rotating data by combining the direction vector of the 3D dental model and a preset second normal vector, and rotating the 3D dental model to a target position according to the second rotating data.

Optionally, the determining module includes:

the generating unit is used for projecting the 3D dental model on the first plane by adopting a projection technology to generate a contour picture;

the extraction unit is used for extracting a target tooth skeleton curve from the 3D dental model outline picture;

and the fitting unit is used for denoising and fitting the target tooth skeleton curve to generate a tooth skeleton curve equation.

Optionally, the fitting unit includes:

the first generation subunit is used for performing iterative denoising processing on the target tooth skeleton curve to generate a continuous target tooth skeleton curve;

and the second generation subunit is used for traversing each target tooth of the continuous target tooth skeleton curve to generate a tooth skeleton curve equation in a fitting manner.

Optionally, the identification module comprises:

the matching unit is used for carrying out included angle matching on a plurality of acquired triangular surfaces of the 3D dental model by adopting the set triangular surfaces to generate a target bottom surface set;

and the traversing unit is used for traversing the area of the target bottom surface set to obtain the maximum bottom surface with the maximum area of the 3D dental model.

Optionally, the first rotation module comprises:

the first cross multiplication unit is used for performing cross multiplication on the obtained maximum bottom surface normal vector of the 3D dental model and a preset first normal vector to generate first rotation data;

and the first rotating unit is used for rotating the 3D dental model to the first plane according to the first rotating data.

Optionally, the second rotation module comprises:

the second cross multiplication unit is used for performing cross multiplication on the obtained direction vector of the 3D dental model and a preset second normal vector to generate second rotation data;

and the second rotating unit is used for rotating the 3D dental model to the target position according to the second rotating data.

The 3D dental cast automatic straightening system of the embodiment can execute the 3D dental cast automatic straightening method provided by the embodiment of the method of the invention, can execute any combination of the implementation steps of the embodiment of the method, and has corresponding functions and beneficial effects of the method.

An apparatus, the memory for storing at least one program, the processor for loading the at least one program to perform the method of the method embodiments.

The device of the embodiment can execute the automatic 3D dental cast straightening method provided by the embodiment of the method of the invention, can execute any combination of the implementation steps of the embodiment of the method, and has corresponding functions and beneficial effects of the method.

A storage medium having stored therein processor-executable instructions for performing method embodiments when executed by a processor.

The storage medium of this embodiment can execute the 3D dental cast automatic setting method provided in the first embodiment of the method of the present invention, can execute any combination of the implementation steps of the method embodiments, and has corresponding functions and advantages of the method.

As shown in fig. 3, it is a detailed flow diagram of the 3D dental model automatic setting method of the present invention, and the specific flow is as follows:

firstly, introducing a 3D dental model, wherein the 3D dental model is a three-dimensional body consisting of a plurality of triangular surfaces and is provided with a smooth bottom surface, and a tooth model manufactured based on a 3D printing technology is randomly placed on the smooth bottom surface;

identifying a plane normal vector of the 3D dental model, specifically, matching plane included angles of a plurality of triangular surfaces of the 3D dental model by adopting a set triangular surface patch, and when the included angle between the set triangular surface and a certain triangular surface on the 3D dental model is greater than a preset error threshold value e, determining that the triangular surface is not matched with the set triangular surface and is eliminated; when the included angle between a set triangular surface and a certain triangular surface on the 3D dental model is smaller than a preset error threshold value e, the triangular surface is determined to be matched with the set triangular surface, the two surfaces are overlapped and marked as a target bottom surface for storage, the next triangular surface is continuously searched and whether the triangular surface is matched with the set triangular surface is judged, all the target bottom surfaces with the included angles smaller than the preset error threshold value with the set triangular surface are stored to generate a target bottom surface area, a maximum value function is mostly adopted to traverse a target bottom surface set, and the target bottom surface with the largest area is taken as a plane of the 3D dental model; and outputting a normal vector (Xn, Yn, Zn) of the maximum bottom surface of the 3D dental model, specifically, obtaining a plane equation aX + bY + cZ corresponding to the maximum bottom surface of the 3D dental model as 0 bY adopting the existing computer technology and mathematical methods, obtaining the normal vector (a, b, c) of the plane equation, uniformly expressing, and setting (a, b, c) as (Xn, Yn, Zn) for expression.

Setting a preset first normal vector (Xd1, Yd1, Zd1), and obtaining a first rotation angle and a first rotation axis through cross multiplication processing, wherein the first rotation angle and the first rotation axis are specifically as follows: p is taken as the normal vector (Xn, Yn, Zn) of the maximum bottom surface of the 3D dental model₁Setting a preset first normal vector (Xd1, Yd1, Zd1) as Q₁To P₁And Q₁Performing cross multiplication to obtain a first rotation angle theta₁＝cos^-1(P₁·Q₁/|P₁||Q₁And the first axis of rotation C1 ═ C11, C12, C13, (C11, C12, C13) ═ Yn × Zd1-Zn × Yd1, Zn × Xd1-Xn × Zd1, Xn × Yd1-Yn × Xd 1.

Rotating the 3D dental model to a first plane, specifically, according to a first rotation angle theta₁And the first rotation axis C1 rotates the 3D dental model to the first plane.

And projecting the 3D dental model to generate a contour picture, and solving a tooth skeleton curve equation, specifically, projecting the 3D dental model on a first plane to generate a picture containing the contour of the target tooth skeleton.

And extracting a tooth skeleton from the contour picture, specifically, extracting a target tooth skeleton curve from the contour picture by adopting an Average function, denoising the obtained tooth skeleton curve, and generating a tooth skeleton curve equation by adopting the existing computer fitting algorithm.

And outputting the direction vector (Xm, Ym, Zm) of the 3D dental model, specifically, obtaining the direction vector (Xm, Ym, Zm) of the 3D dental model on the first plane through the obtained tooth skeleton curve equation.

Setting preset second normal vectors (Xd2, Yd2, Zd2), and obtaining a second rotation angle and a second rotation axis by cross product combing, specifically, setting P according to the direction vector (Xm, Ym, Zm) of the 3D dental model in the first plane₂Setting a preset second normal vector (Xd2, Yd2, Zd2) as Q₂To P₂And Q₂Performing cross multiplication to obtain a first rotation angle theta₂＝cos^-1(P₂·Q₂/|P₂||Q₂And the first axis of rotation C2 ═ (C21, C22, C23), (C21, C22, C23) ═ Ym × Zd2-Zm ═ Yd2, Zm × Xd2-Xm × Zd2, Xm × Yd2-Ym × 2).

Rotating the 3D dental model to a target position, specifically, according to a second rotation angle theta₂And the second rotation axis C2 rotates the 3D dental cast to the target position, ending.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.