Method for determining the facial midline and the position of teeth for orthodontic treatment, manufacturing method and system

Abstract

The application discloses a method for determining a facial midline and a tooth correction position, a manufacturing method and a system. The method for determining the facial midline comprises the following steps: acquiring a position of a first facial midline and a position of a first tooth midline of a target object in a target two-dimensional photo; acquiring a position of a second tooth midline of the target object in a three-dimensional dental model, acquiring a second size value of a target tooth in the three-dimensional dental model; acquiring a first size value of the target tooth in the target two-dimensional photo, establishing a mapping relationship between the first size value and the second size value; obtaining a first deviation value between the first facial midline and the first tooth midline; obtaining a second deviation value between a second facial midline and the second tooth midline of the target object in the three-dimensional dental model; and obtaining the position of the second facial midline in the three-dimensional dental model based on the position of the second tooth midline and the second deviation value. The application realizes automatic determination of the position of the facial midline in the three-dimensional dental model, and improves the accuracy and efficiency of determining the facial midline.

Description

Technical Field

[0001] This application relates to the field of orthodontic technology, and in particular to a method, manufacturing method and system for determining the midline of the face and the position of teeth for orthodontic treatment. Background Technology

[0002] Based on the concept of oral aesthetics, more and more people have higher pursuit of their own tooth shape, and orthodontic treatment (or oral orthodontics) has emerged. In the process of orthodontic treatment, the position of each tooth needs to be adjusted according to certain rules. For example, the position of the midline of the patient's face is used as a reference. Based on the relative relationship between the position of the patient's tooth midline and the midline of the face, it is determined whether the teeth should be adjusted to the left or right relative to the midline of the face.

[0003] The current orthodontic process requires orthodontic designers to observe two-dimensional photos of the patient's exposed teeth and, based on their personal experience, roughly estimate the position of the facial midline in the dentition. Then, they manually estimate the position of the facial midline in a three-dimensional dental model that includes the patient's crowns and gingiva. This method is not only cumbersome, but also results in low accuracy of the determined facial midline, with a certain degree of randomness and error. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art in the process of orthodontic treatment, which requires manual estimation of the position of the facial midline in the three-dimensional dental model, the determination process of the facial midline is cumbersome, and the accuracy of the determined facial midline is low, with a certain degree of randomness and error. The present invention provides a method, manufacturing method and system for determining the facial midline and orthodontic treatment.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] Firstly, a method for determining the midline of a three-dimensional dental model is provided, the method comprising:

[0007] Obtain the position of the target object's first face midline and the position of its first tooth midline in the target 2D photograph;

[0008] The target two-dimensional photograph includes the face of the target object with the target teeth exposed;

[0009] Based on the target tooth, the position of the second tooth midline of the target object in the three-dimensional dental model is obtained, and the second dimension value of the target tooth in the three-dimensional dental model is obtained;

[0010] Obtain the first dimension value of the target tooth in the target two-dimensional photograph, and establish a mapping relationship between the first dimension value and the second dimension value;

[0011] A first deviation value between the first surface midline and the first tooth midline is obtained based on the position of the first surface midline and the position of the first tooth midline;

[0012] Based on the mapping relationship and the first deviation value, the second deviation value between the second surface midline and the second tooth midline of the target object in the three-dimensional dental model is obtained;

[0013] The position of the second surface midline in the three-dimensional dental model is obtained based on the position of the second tooth midline and the second deviation value.

[0014] Preferably, obtaining the position of the first face midline and the position of the first tooth midline of the target object in the target two-dimensional photograph includes:

[0015] Obtain the target two-dimensional photograph of the target object;

[0016] Obtain the facial region from the target 2D photograph;

[0017] Obtain facial feature localization points of the facial region;

[0018] The position of the midline of the first face is obtained based on the facial feature positioning points;

[0019] The position of the midline of the first tooth is obtained based on the position of the target tooth in the target two-dimensional photograph;

[0020] The target teeth include at least one of the two maxillary central incisors or at least one of the two mandibular central incisors.

[0021] Preferably, after the step of obtaining the facial feature localization points of the facial region, the method further includes:

[0022] Based on the position of the facial feature positioning points, determine whether the face of the target object in the target 2D photo is tilted;

[0023] If so, then perform a rotation correction operation on the facial feature positioning points, and execute the operation of obtaining the position of the first face midline based on the facial feature positioning points;

[0024] If not, then perform the operation of obtaining the position of the first face midline based on the facial feature positioning points.

[0025] Preferably, the step of obtaining the position of the midline of the first face based on the facial feature localization points includes:

[0026] Facial feature key points are selected from the facial feature positioning points, and the position of the first face midline is obtained based on the facial feature key points;

[0027] The facial feature positioning points include positioning points corresponding to the eyes, eyebrows, bridge of the nose, lips, and outer contour of the face; the facial feature key points include at least three of the following: the center of the eyebrows, the corners of the eyes, the tip of the nose, the base of the nose, and the philtrum.

[0028] Preferably, the step of obtaining the facial region in the target two-dimensional photograph includes:

[0029] The facial region is obtained by performing image recognition on the target two-dimensional photo based on a facial region recognition algorithm.

[0030] And / or, the step of obtaining facial feature localization points of the facial region includes:

[0031] The facial region is identified based on a facial feature recognition algorithm to obtain the facial feature localization points;

[0032] And / or, the method for obtaining the position of the first face midline based on the facial feature localization points includes:

[0033] The facial feature localization points are fitted using a fitting algorithm to obtain the position of the midline of the first face;

[0034] And / or, the step of obtaining the position of the first tooth midline based on the position of the target tooth in the target two-dimensional photograph includes:

[0035] Obtain the midline between the two central incisors in the upper jaw or the midline between the two central incisors in the lower jaw, and use the midline as the first tooth midline to obtain the position of the first tooth midline.

[0036] Preferably, the step of obtaining the position of the second tooth midline of the target object in the three-dimensional dental model based on the target tooth, and obtaining the second dimension value of the target tooth in the three-dimensional dental model includes:

[0037] Obtain the three-dimensional dental model of the target object, including the crown and gingiva;

[0038] In the three-dimensional dental model, the midline between the two central incisors in the upper jaw or the midline between the two central incisors in the lower jaw is used as the position of the second tooth midline, and the corresponding second size value of the central incisor is obtained.

[0039] Preferably, the step of obtaining the position of the second tooth midline of the target object in the three-dimensional dental model based on the target tooth, and obtaining the second dimension value of the target tooth in the three-dimensional dental model includes:

[0040] Obtain the three-dimensional dental model of the target object, including the crown and gingiva;

[0041] In the three-dimensional dental model, the midline between the two central incisors in the upper jaw or the midline between the two central incisors in the lower jaw is used as the position of the second tooth midline, and the corresponding second size value of the central incisor is obtained based on the preset size value.

[0042] Preferably, the step of obtaining the first size value of the target tooth in the target two-dimensional photograph and establishing a mapping relationship between the first size value and the second size value includes:

[0043] The first size value of the target tooth in the target two-dimensional photograph is obtained based on an image recognition algorithm;

[0044] A mapping relationship between the first size value and the second size value corresponding to the target tooth is established.

[0045] Preferably, the step of obtaining the first size value of the target tooth in the target two-dimensional photograph and establishing a mapping relationship between the first size value and the second size value includes:

[0046] The first size value of the target tooth in the target two-dimensional photograph is obtained based on the preset scale corresponding to the target two-dimensional photograph.

[0047] A mapping relationship between the first size value and the second size value corresponding to the target tooth is established.

[0048] Preferably, the step of obtaining the position of the second surface midline in the three-dimensional dental model based on the position of the second tooth midline and the second deviation value includes:

[0049] The relative position of the second surface midline with respect to the second tooth midline is obtained based on the second deviation value;

[0050] The position of the second surface midline in the three-dimensional dental model is obtained based on the relative position.

[0051] Secondly, a method for determining the position of teeth for orthodontic treatment is also provided, the method comprising:

[0052] The position of the second surface midline of the target object in the three-dimensional dental model is obtained by using the method for determining the midline of the surface in the three-dimensional dental model described above;

[0053] A three-dimensional coordinate system is established in the three-dimensional dental model based on the position of the midline of the second surface.

[0054] The orthodontic position for each tooth of the target object is determined based on the three-dimensional coordinate system and the position of the second tooth midline of the target object in the three-dimensional dental model.

[0055] Thirdly, a method for manufacturing a dental orthodontic appliance is also provided, the method comprising:

[0056] The target orthodontic position of the target object's teeth is obtained by using the method for determining the orthodontic position described above;

[0057] The shape of the orthodontic appliance for the target object is determined based on the target orthodontic position, so as to manufacture an orthodontic appliance with the corresponding shape.

[0058] Fourthly, a system for determining the midline of a three-dimensional dental model is also provided, the system comprising:

[0059] The first acquisition module is used to acquire the position of the first face midline and the position of the first tooth midline of the target object in the target two-dimensional photograph;

[0060] The target two-dimensional photograph includes the face of the target object with the target teeth exposed;

[0061] The second acquisition module is used to acquire the position of the second tooth midline of the target object in the three-dimensional dental model based on the target tooth, and to acquire the second dimension value of the target tooth in the three-dimensional dental model;

[0062] A mapping relationship establishment module is used to obtain the first size value of the target tooth in the target two-dimensional photograph and establish a mapping relationship between the first size value and the second size value;

[0063] The first deviation value acquisition module is used to obtain a first deviation value between the first surface midline and the first tooth midline based on the position of the first surface midline and the position of the first tooth midline.

[0064] The second deviation value acquisition module is used to obtain the second deviation value between the second surface midline and the second tooth midline of the target object in the three-dimensional dental model based on the mapping relationship and the first deviation value.

[0065] The third acquisition module is used to obtain the position of the second surface midline in the three-dimensional dental model based on the position of the second tooth midline and the second deviation value.

[0066] Preferably, the first acquisition module includes:

[0067] A two-dimensional photo acquisition unit is used to acquire the target two-dimensional photo of the target object;

[0068] A facial region acquisition unit is used to acquire the facial region in the target two-dimensional photograph;

[0069] The positioning point acquisition unit is used to acquire the facial feature positioning points of the facial region;

[0070] The first face midline acquisition unit is used to obtain the position of the first face midline based on the facial feature positioning points;

[0071] The first tooth midline acquisition unit is used to obtain the position of the first tooth midline based on the position of the target tooth in the target two-dimensional photograph;

[0072] The target teeth include at least one of the two maxillary central incisors or at least one of the two mandibular central incisors.

[0073] Preferably, the first acquisition module further includes:

[0074] A facial tilt determination unit is used to determine whether the face of the target object in the target two-dimensional photograph is tilted based on the position of the facial feature positioning points.

[0075] The correction unit is used to perform a rotation correction operation on the facial feature positioning points and run the first face midline acquisition unit when the face tilt judgment unit determines that the face of the target object in the target two-dimensional photo is tilted.

[0076] If the facial tilt determination unit determines that the face of the target object in the target two-dimensional photo is not tilted, then the first face centerline acquisition unit is run.

[0077] Preferably, the first face midline acquisition unit is specifically used to select facial feature key points from the facial feature positioning points, and obtain the position of the first face midline based on the facial feature key points;

[0078] The facial feature positioning points include positioning points corresponding to the eyes, eyebrows, bridge of the nose, lips, and outer contour of the face; the facial feature key points include at least three of the following: the center of the eyebrows, the corners of the eyes, the tip of the nose, the base of the nose, and the philtrum.

[0079] Preferably, the facial region acquisition unit is specifically used to perform image recognition on the target two-dimensional photograph based on a facial region recognition algorithm to obtain the facial region.

[0080] Preferably, the positioning point acquisition unit is specifically used to identify the facial region based on a facial feature recognition algorithm to obtain the facial feature positioning points.

[0081] Preferably, the first face midline acquisition unit is specifically used to perform fitting processing on the facial feature positioning points based on a fitting algorithm to obtain the position of the first face midline.

[0082] Preferably, the first dental midline acquisition unit is specifically used to acquire the midline between the two central incisors of the upper jaw or the midline between the two central incisors of the lower jaw, and use the midline as the first dental midline to obtain the position of the first dental midline.

[0083] Preferably, the second acquisition module includes:

[0084] A three-dimensional dental model acquisition unit is used to acquire the three-dimensional dental model of the target object, including the crown and gingiva.

[0085] The second dimension value acquisition unit is used to take the midline between the two central incisors in the upper jaw or the midline between the two central incisors in the lower jaw as the position of the second tooth midline in the three-dimensional dental model, and obtain the corresponding second dimension value of the central incisor.

[0086] Preferably, the second acquisition module includes:

[0087] A three-dimensional dental model acquisition unit acquires the three-dimensional dental model of the target object, including the crown and gingiva.

[0088] The second dimension value acquisition unit is used in the three-dimensional dental model to take the midline between the two central incisors in the upper jaw or the midline between the two central incisors in the lower jaw as the position of the second tooth midline, and obtain the corresponding second dimension value of the central incisor based on the preset dimension value.

[0089] Preferably, the mapping relationship establishment module includes:

[0090] The first size value acquisition unit is used to acquire the pixel value of the target tooth in the target two-dimensional photograph based on an image recognition algorithm, and use the pixel value as the first size value;

[0091] The mapping relationship establishment unit is used to establish a mapping relationship between the first size value and the second size value based on the first size value and the second size value corresponding to the target tooth.

[0092] Preferably, the mapping relationship establishment module includes:

[0093] The first size value acquisition unit is used to acquire the scale value of the target tooth in the target two-dimensional photograph based on a preset scale corresponding to the target two-dimensional photograph, and use the scale value as the first size value;

[0094] The mapping relationship establishment unit is used to establish a mapping relationship between the first size value and the second size value based on the first size value and the second size value corresponding to the target tooth.

[0095] Preferably, the third acquisition module includes:

[0096] A relative position determination unit is used to determine the relative position of the second surface midline relative to the second tooth midline based on the second deviation value;

[0097] The second surface midline determination unit is used to determine the position of the second surface midline in the three-dimensional dental model based on the relative position.

[0098] Fifthly, a system for determining the position of teeth during orthodontic treatment is also provided, the system comprising:

[0099] The midline acquisition module is used to obtain the position of the midline of the target object in the three-dimensional dental model using the midline determination system in the three-dimensional dental model described above.

[0100] A coordinate system establishment module is used to establish a three-dimensional coordinate system in the three-dimensional dental model based on the position of the midline of the surface.

[0101] The orthodontic position determination module is used to determine the orthodontic position corresponding to each tooth of the target object based on the three-dimensional coordinate system and the position of the tooth midline of the target object in the three-dimensional dental model.

[0102] Sixthly, a manufacturing system for orthodontic appliances is also provided, the manufacturing system comprising:

[0103] The orthodontic position acquisition module is used to obtain the target orthodontic position of the target object's teeth using the orthodontic position determination system described above.

[0104] The orthodontic appliance manufacturing module is used to determine the shape of the orthodontic appliance for the target object based on the target orthodontic position, so as to manufacture an orthodontic appliance with the corresponding shape.

[0105] In a seventh aspect, an electronic device is also provided, including a memory, a processor, and a computer program stored in the memory and used to run on the processor. When the processor executes the computer program, it implements the method for determining the midline of the three-dimensional dental model, the method for determining the orthodontic position, or the method for manufacturing the orthodontic appliance.

[0106] Eighthly, a computer-readable storage medium is also provided, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the method for determining the midline of a three-dimensional dental model, the method for determining the position of a tooth orthodontic treatment, or the method for manufacturing a tooth orthodontic appliance as described above.

[0107] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0108] The positive and progressive effects of this invention are as follows:

[0109] The method, manufacturing method, and system for determining the facial midline and orthodontic position of the present invention can automatically acquire the position of the first facial midline and the position of the first dental midline of the target object in a target two-dimensional photograph. Based on the first dimension value of the target tooth in the target two-dimensional photograph and the second dimension value of the target tooth in a three-dimensional dental model, a mapping relationship between the first dimension value and the second dimension value is established. Then, based on the first deviation value between the first facial midline and the first dental midline, the second deviation value between the second facial midline and the second dental midline of the target object in the three-dimensional dental model is obtained. Finally, based on the position of the second dental midline in the three-dimensional dental model and the second deviation value, the position of the second facial midline in the three-dimensional dental model is obtained. This achieves automatic determination of the facial midline position in the three-dimensional dental model, improving the accuracy and efficiency of determining the facial midline. Attached Figure Description

[0110] Figure 1 This is a schematic diagram of the first process of the method for determining the midline of a three-dimensional dental model provided in Embodiment 1 of the present invention;

[0111] Figure 2 This is a schematic diagram of the second process of the method for determining the midline of a three-dimensional dental model provided in Embodiment 1 of the present invention;

[0112] Figure 3 This is a schematic diagram of facial feature positioning points in the method for determining the midline of the face in a three-dimensional dental model provided in Embodiment 1 of the present invention;

[0113] Figure 4 This is a schematic diagram showing the positions of the first surface midline and the tooth midline in the target two-dimensional photograph of the method for determining the surface midline in a three-dimensional dental model provided in Embodiment 1 of the present invention.

[0114] Figure 5 This is a schematic diagram of the three-dimensional dental model in the method for determining the midline of the three-dimensional dental model provided in Embodiment 1 of the present invention;

[0115] Figure 6 This is a flowchart illustrating the method for determining the position of teeth in orthodontic treatment provided in Embodiment 2 of the present invention.

[0116] Figure 7 This is a schematic flowchart of the manufacturing method of the orthodontic appliance provided in Embodiment 3 of the present invention;

[0117] Figure 8 This is a schematic diagram of the structure of the midline determination system in the three-dimensional dental model provided in Embodiment 4 of the present invention;

[0118] Figure 9 This is a schematic diagram of the structure of the tooth orthodontic position determination system provided in Embodiment 5 of the present invention;

[0119] Figure 10 This is a schematic diagram of the structure of the electronic device provided in Embodiment 7 of the present invention. Detailed Implementation

[0120] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0121] Example 1

[0122] This embodiment provides a method for determining the midline of a three-dimensional dental model, such as... Figure 1 As shown, the determination method includes:

[0123] S101. Obtain the position of the first face midline and the position of the first tooth midline of the target object in the target 2D photograph.

[0124] The target 2D photograph includes the target object's face with the target teeth exposed.

[0125] S102. Based on the target tooth, obtain the position of the second tooth midline of the target object in the three-dimensional dental model, and obtain the second dimension value of the target tooth in the three-dimensional dental model.

[0126] S103. Obtain the first dimension value of the target tooth in the target two-dimensional photograph, and establish the mapping relationship between the first dimension value and the second dimension value.

[0127] S104. Based on the position of the first surface midline and the position of the first tooth midline, obtain the first deviation value between the first surface midline and the first tooth midline.

[0128] S105. Based on the mapping relationship and the first deviation value, the second deviation value between the second surface midline and the second tooth midline of the target object in the three-dimensional dental model is obtained.

[0129] S106. Based on the position of the second tooth midline and the second deviation value in the three-dimensional dental model, the position of the second surface midline in the three-dimensional dental model is obtained.

[0130] The first tooth midline is the tooth midline of the target object in the target 2D photograph, and the first surface midline is the surface midline of the target object in the target 2D photograph; the second tooth midline is the tooth midline of the target object in the 3D dental model, and the second surface midline is the surface midline of the target object in the 3D dental model.

[0131] The second dimension value is the actual physical dimension value of the target tooth of the target object. It can be obtained by means of a three-dimensional dental model or by means of statistical laws of teeth.

[0132] The method for determining the midline of a three-dimensional dental model in this embodiment can automatically obtain the position of the first midline and the position of the first tooth midline of the target object in the target two-dimensional photograph. Based on the first dimension value of the target tooth in the target two-dimensional photograph and the second dimension value of the target tooth in the three-dimensional dental model, a mapping relationship between the first dimension value and the second dimension value is established. Then, based on the first deviation value between the first midline and the first tooth midline, the second deviation value between the second midline and the second tooth midline of the target object in the three-dimensional dental model is obtained. Finally, based on the position of the second tooth midline and the second deviation value in the three-dimensional dental model, the position of the second midline of the face in the three-dimensional dental model is obtained. This achieves automatic determination of the midline position in the three-dimensional dental model, improving the accuracy and efficiency of determining the midline.

[0133] In an alternative implementation, such as Figure 2 As shown, step S101 above includes:

[0134] S1011. Obtain a two-dimensional photograph of the target object.

[0135] S1012. Obtain the facial region from the target 2D photograph.

[0136] S1013. Obtain facial feature localization points of the facial region.

[0137] S1014. Obtain the position of the midline of the first face based on the facial feature localization points.

[0138] S1015. The position of the first tooth midline is obtained based on the position of the target tooth in the target two-dimensional photograph.

[0139] The target teeth include at least one of the two maxillary central incisors or at least one of the two mandibular central incisors.

[0140] If the target is a person, the target 2D photograph can be a front-facing smiling photograph showing the target's teeth.

[0141] The central incisors are commonly known as front teeth. The dental midline can also be called the dental midline. For example, the dental midline is an imaginary line that passes between the two upper or two lower central incisors.

[0142] In step S1012 above, the target two-dimensional photo is specifically image-recognized based on a facial region recognition algorithm to obtain the facial region.

[0143] This method uses facial region recognition algorithms to perform image recognition on target 2D photographs, detecting the presence of faces and marking facial regions. Facial region recognition algorithms can be traditional machine learning methods, such as Haar Cascade, Eigenfaces, and Fisherfaces, or they can be methods based on convolutional neural networks.

[0144] The Haar Cascade algorithm is an object detection algorithm for locating objects in images. Based on machine learning, the algorithm learns from a large number of positive and negative samples. The former contains objects of interest, while the latter contains anything other than the object to be found. A cascade function is trained from a large number of positive and negative images and then used to detect objects in other images.

[0145] The Eigenfaces algorithm determines a set of "standardized facial components" through statistical analysis of a large number of facial images. Facial features are assigned constant values ​​because this algorithm does not use digital images but rather a statistical database; any facial image is a combination of different percentages of these values. It uses Principal Component Analysis (PAC) to process high-dimensional facial data into low-dimensional data before performing data analysis and processing to obtain recognition results. The algorithm uses PCA to reduce the dimensionality of the original data and extract the principal component information, thus achieving facial recognition.

[0146] Fisherfaces is an eigenface-based method that finds a linear combination of features that maximizes the variance in data. Eigenface is the name of a set of feature vectors used in computer vision problems for face recognition. Eigenfaces is based on PCA (Principal Component Analysis).

[0147] If the facial region cannot be identified in the target 2D image, a new target 2D image needs to be acquired.

[0148] In step S1013 above, the facial region is specifically identified based on a facial feature recognition algorithm to obtain facial feature localization points.

[0149] Facial feature localization points can also be called facial key feature points.

[0150] After identifying the facial region, a facial feature recognition algorithm is used to identify the facial feature localization points. The facial feature recognition algorithm can be a model-based ASM (Active Shape Model) and AAM (Active Appearance Model), or an algorithm based on cascaded shape regression, or an algorithm based on deep learning.

[0151] ASM is a variable model that models shapes (such as facial feature localization points) in an image. The resulting shape model can be used to analyze new shapes, such as fitting a model to obtain a new shape, or to generate shapes, such as searching for shapes in a given image.

[0152] AAM is an image segmentation algorithm based on active appearance models. This method can be divided into two parts. The first part is the training part, which constructs an active appearance model of an object. This part requires a training set, which is used to let the program remember the shape and appearance features of the image to be segmented. The second part is the image segmentation stage. This part searches for the features of the object collected in the training set in the image to be segmented, finds the outline and appearance of the object image similar to the training set, and then segments it from the whole image.

[0153] Figure 3 A schematic diagram of facial feature localization points provided for this embodiment. (See diagram below.) Figure 3 As shown, facial feature positioning points +1 to +17 are facial feature positioning points corresponding to the outer contour of the face, facial feature positioning points +18 to +27 are facial feature positioning points corresponding to the two eyebrows, facial feature positioning points +28 to +36 are facial feature positioning points corresponding to the bridge of the nose, facial feature positioning points +37 to +48 are facial feature positioning points corresponding to the two eyes, and facial feature positioning points +49 to +68 are facial feature positioning points corresponding to the lips.

[0154] In step S1014 above, the facial feature localization points are specifically fitted using a fitting algorithm to obtain the position of the midline of the first face.

[0155] Fitting algorithms include, but are not limited to, the least squares method and the Hough transform method.

[0156] The basic principle of Hough transform is to transform curves (including straight lines) in image space into parameter space, and by detecting extreme points in parameter space, determine the descriptive parameters of the curve, thereby extracting regular curves from the image.

[0157] The facial feature localization points are symmetrically distributed on both sides of the midline of the first face, with the midline of the first face as the axis of symmetry.

[0158] In step S1015 above, the position of the first tooth midline is obtained by acquiring the midline between the two upper central incisors or the two lower central incisors and using the midline as the first tooth midline.

[0159] That is, the midline of the first tooth can be the midline between the two central incisors in the upper jaw or the midline between the two central incisors in the lower jaw.

[0160] If the target tooth is only one central incisor, the boundary line of the central incisor closest to the adjacent central incisor in the same occlusal direction is called the mesial boundary line, and this mesial boundary line is used as the first dental midline. The boundary line of the central incisor furthest from the adjacent central incisor in the same occlusal direction is called the distal boundary line.

[0161] The first dental midline can be obtained using traditional image recognition methods, such as edge detection, or using deep learning methods, such as convolutional neural networks. Simultaneously, based on the mesial and distal boundary lines, the first dimension value of the corresponding central incisor in the target two-dimensional photograph can be calculated.

[0162] Figure 4 This is a schematic diagram showing the positions of the midline of the first surface and the midline of the teeth in the target two-dimensional photograph provided in this embodiment. Figure 4 The image shows the location of the first dental midline and the first facial midline. The location of the first dental midline is the midline between the two maxillary central incisors.

[0163] The method for determining the midline of a three-dimensional dental model in this embodiment automatically obtains the position of the first midline and the position of the first tooth midline of the target object in the target two-dimensional photograph according to a corresponding algorithm. Based on the first dimension value of the target tooth in the target two-dimensional photograph and the second dimension value of the target tooth in the three-dimensional dental model, a mapping relationship between the first dimension value and the second dimension value is established. Then, based on the first deviation value between the first midline and the first tooth midline, the second deviation value between the second midline and the second tooth midline of the target object in the three-dimensional dental model is obtained. Finally, based on the position of the second tooth midline and the second deviation value in the three-dimensional dental model, the position of the second midline of the face in the three-dimensional dental model is obtained. This achieves automatic determination of the midline position in the three-dimensional dental model, improving the accuracy and efficiency of midline determination.

[0164] In an optional implementation, the step S1013 above is followed by:

[0165] S10131. Determine whether the face of the target object in the target 2D photo is tilted based on the position of the facial feature positioning points.

[0166] If yes, proceed to step S10132; otherwise, proceed to step S1014.

[0167] S10132, Perform rotation correction operation on facial feature positioning points.

[0168] After performing the rotation correction operation, proceed to step S1014.

[0169] To prevent facial tilting in 2D target photos caused by changes in shooting angle or facial posture, rotation correction can be performed based on the facial feature positioning points obtained above. Taking a human as an example, a facial image coordinate system is established with the center of the line connecting the inner corners of the left and right eyes as the origin. By rotating the image to keep the inner corners of the eyes horizontal, the rotation matrix can be obtained, thereby realizing the rotation correction operation of the facial feature positioning points.

[0170] The method for determining the midline of the face in the three-dimensional dental model of this embodiment performs a rotation correction operation on the facial feature positioning points so that the facial area of ​​the target object is no longer tilted, and the face in the target two-dimensional photograph remains upright, which makes it easier to mark the position of the first tooth midline and the position of the first face midline in the target two-dimensional photograph.

[0171] In an optional implementation, step S1014 includes:

[0172] Facial feature key points are selected from the facial feature localization points, and the position of the first face midline is obtained based on the facial feature key points.

[0173] Among them, facial feature positioning points include positioning points corresponding to the eyes, eyebrows, bridge of the nose, lips, and outer contour of the face; facial feature key points include at least three of the following: center of the eyebrows, corner of the eye, tip of the nose, base of the nose, and philtrum.

[0174] like Figure 3 As shown, facial feature positioning points +20 and +25 are the facial feature key points corresponding to the center of the eyebrows; facial feature positioning points +37 and +46 are the facial feature key points corresponding to the outer corner of the eye; facial feature positioning points +40 and +43 are the facial feature key points corresponding to the inner corner of the eye; facial feature positioning point +31 is the facial feature key point corresponding to the tip of the nose; facial feature positioning point +34 is the facial feature key point corresponding to the base of the nose. The midpoint between facial feature positioning points +34 and +52 is taken as the philtrum.

[0175] At least three facial feature key points are selected, and the facial feature localization points are fitted based on a fitting algorithm to obtain the position of the midline of the first face.

[0176] In an optional implementation, step S102 includes:

[0177] S1021. Obtain a three-dimensional dental model of the target object, including the crown and gingiva.

[0178] S1022. In a three-dimensional dental model, the midline between the two central incisors in the upper jaw or the midline between the two central incisors in the lower jaw is used as the position of the second dental midline, and the corresponding second dimension value of the central incisor is obtained.

[0179] By scanning the oral cavity of the target subject, a three-dimensional dental model including the crowns and gingiva is created. In the three-dimensional dental model, the midline between the two upper central incisors or the midline between the two lower central incisors is used as the location of the second dental midline.

[0180] The distribution and size of each tooth of the target object can be obtained from the three-dimensional dental model, and then the second size value of the central incisor can be determined.

[0181] Figure 5 This is a schematic diagram of the three-dimensional dental model provided in this embodiment. Figure 5 The location of the second tooth midline and the second surface midline is shown in the figure.

[0182] The method for determining the midline of a three-dimensional dental model in this embodiment automatically determines the position of the second midline in the three-dimensional dental model, improving the accuracy and efficiency of determining the midline.

[0183] In an optional implementation, step S102 includes:

[0184] S1023. Obtain a three-dimensional dental model of the target object, including the crown and gingiva.

[0185] S1024. In the three-dimensional dental model, the midline between the two central incisors of the upper jaw or the midline between the two central incisors of the lower jaw is used as the position of the second tooth midline, and the corresponding second size value of the central incisor is obtained based on the preset size value.

[0186] By scanning the oral cavity of the target subject, a three-dimensional dental model including the crowns and gingiva is created. In the three-dimensional dental model, the midline between the two upper central incisors or the midline between the two lower central incisors is used as the location of the second dental midline.

[0187] Based on statistical principles, tooth size information can be derived. For example, based on the target subject's age, gender, and the approximate shape and size of their teeth, the second size value of the central incisor can be obtained from preset size values ​​stored in a tooth database.

[0188] The method for determining the midline of a three-dimensional dental model in this embodiment automatically determines the position of the second midline in the three-dimensional dental model, improving the accuracy and efficiency of determining the midline.

[0189] In an optional implementation, step S103 includes:

[0190] S1031. Obtain the pixel value of the target tooth in the target two-dimensional photograph based on the image recognition algorithm, and use the pixel value as the first size value.

[0191] S1032. Establish a mapping relationship between the first dimension value and the second dimension value based on the first dimension value and the second dimension value corresponding to the target tooth.

[0192] After obtaining the mesial and distal boundaries of a central incisor, the pixel value of the central incisor in the target 2D photograph is calculated based on an image recognition algorithm. This pixel value is then used as the first dimension value of the target tooth in the 2D photograph. Simultaneously, the second dimension value of the central incisor can be obtained from the 3D dental model. A mapping relationship between the first and second dimension values ​​of the central incisor is established based on the first dimension value of the central incisor in the target 2D photograph and the second dimension value of the central incisor in the 3D dental model.

[0193] The method for determining the midline in a three-dimensional dental model according to this embodiment automatically acquires the first dimension value of the target tooth in the target two-dimensional photograph, and establishes a mapping relationship between the first dimension value and the second dimension value based on the first dimension value and the second dimension value corresponding to the target tooth, thereby automatically determining the position of the second midline in the three-dimensional dental model, improving the accuracy and efficiency of determining the midline.

[0194] In an optional implementation, step S103 includes:

[0195] S1033. Obtain the scale value of the target tooth in the target two-dimensional photograph based on the preset scale corresponding to the target two-dimensional photograph, and use the scale value as the first size value.

[0196] S1034. Establish a mapping relationship between the first dimension value and the second dimension value based on the first dimension value and the second dimension value corresponding to the target tooth.

[0197] When the target 2D photograph has a corresponding preset scale, the scale value of the target tooth in the target 2D photograph can be obtained according to the value defined by the preset scale, and the scale value is used as the first size value.

[0198] The method for determining the midline in a three-dimensional dental model according to this embodiment automatically acquires the first dimension value of the target tooth in the target two-dimensional photograph, and establishes a mapping relationship between the first dimension value and the second dimension value based on the first dimension value and the second dimension value corresponding to the target tooth, thereby automatically determining the position of the second midline in the three-dimensional dental model, improving the accuracy and efficiency of determining the midline.

[0199] In an optional implementation, step S105 includes:

[0200] S1051. Based on the second deviation value, the relative position of the midline of the second surface with respect to the midline of the second tooth is obtained.

[0201] S1052. Based on the relative position, the position of the midline of the second surface in the three-dimensional dental model is obtained.

[0202] After obtaining the first deviation value between the first surface midline and the first tooth midline, the first deviation value can be converted into the corresponding second deviation value according to the mapping relationship between the first dimension value and the second dimension value. Since the position of the second tooth midline has been determined, the relative position of the second surface midline with respect to the second tooth midline can be obtained according to the second deviation value. Then, the position of the second surface midline in the three-dimensional dental model can be obtained based on the relative position.

[0203] The method for determining the midline in a three-dimensional dental model in this embodiment automatically obtains the position of the second midline in the three-dimensional dental model by using the second deviation value between the second midline of the target object and the second midline of the second tooth, the mapping relationship between the first dimension value and the second dimension value, and the position of the second midline of the second tooth in the three-dimensional dental model, thereby improving the accuracy and efficiency of determining the midline.

[0204] Example 2

[0205] This embodiment provides a method for determining the position of teeth during orthodontic treatment, such as... Figure 6 As shown, the methods for determining the position of teeth during orthodontic treatment include:

[0206] S201. The position of the second midline of the target object in the three-dimensional dental model is obtained by using the method for determining the midline of the three-dimensional dental model in Example 1.

[0207] S202. Establish a three-dimensional coordinate system in the three-dimensional dental model based on the position of the midline of the second surface.

[0208] S203. Determine the orthodontic position for each tooth of the target object based on the three-dimensional coordinate system and the position of the second tooth midline of the target object in the three-dimensional dental model.

[0209] The method for determining the orthodontic position in this embodiment automatically obtains the position of the midline of the target object in the three-dimensional dental model based on the method for determining the midline of the face in the three-dimensional dental model in Embodiment 1. Then, a three-dimensional coordinate system is established based on the position of the second midline of the face. According to the position of the second midline of the target object in the three-dimensional dental model in the three-dimensional coordinate system, the orthodontic position corresponding to each tooth of the target object is determined. For example, whether a certain tooth is moved to the left or to the right relative to the second midline of the face.

[0210] The method for determining the orthodontic position in this embodiment can quickly determine the orthodontic position corresponding to each tooth of the target subject, thereby flexibly designing and adjusting the orthodontic treatment plan.

[0211] Example 3

[0212] This embodiment provides a method for manufacturing a dental appliance, such as Figure 7 As shown, the manufacturing method of orthodontic appliances includes:

[0213] S301. The target orthodontic position of the target object's teeth is obtained by using the method for determining the orthodontic position in Example 2.

[0214] S302. Determine the shape of the orthodontic appliance for the target object based on the target orthodontic position, so as to manufacture an orthodontic appliance with the corresponding shape.

[0215] Specifically, the data on the target orthodontic position of the teeth can be transmitted to the orthodontic appliance manufacturing equipment, which can form a mold (e.g., a positive mold) for the orthodontic appliance according to the data using general engineering methods, thereby manufacturing an orthodontic appliance with the corresponding shape from the mold.

[0216] Of course, orthodontic appliance manufacturing equipment can also utilize 3D printing technology to form a positive mold of the orthodontic appliance based on data of the target orthodontic position of the teeth, and further manufacture orthodontic appliances with the corresponding shape from the positive mold.

[0217] Furthermore, the orthodontic appliance manufacturing equipment can also utilize 3D printing technology to determine the corresponding orthodontic appliance data based on the data of the target orthodontic position of the teeth, and directly form the orthodontic appliance based on the data of the orthodontic appliance.

[0218] In an alternative embodiment, the orthodontic appliance is made of a tough, transparent polymer material, thereby forming a bracketless clear aligner.

[0219] The method for manufacturing a dental appliance in this embodiment can quickly and accurately determine the shape of the dental appliance for the target object based on the target orthodontic position of the target object's teeth, and then manufacture a dental appliance with the corresponding shape.

[0220] Example 4

[0221] This embodiment provides a system for determining the midline of a three-dimensional dental model, such as... Figure 8 As shown, the system for determining the midline in a three-dimensional dental model includes:

[0222] The first acquisition module 1 is used to acquire the position of the first face midline and the position of the first tooth midline of the target object in the target two-dimensional photograph;

[0223] Among them, the target 2D photograph includes the face of the target object showing the target teeth;

[0224] The second acquisition module 2 is used to acquire the position of the second tooth midline of the target object in the three-dimensional dental model based on the target tooth, and to acquire the second dimension value of the target tooth in the three-dimensional dental model.

[0225] The mapping relationship establishment module 3 is used to obtain the first size value of the target tooth in the target two-dimensional photograph and establish the mapping relationship between the first size value and the second size value.

[0226] The first deviation value acquisition module 4 is used to obtain the first deviation value between the first surface midline and the first tooth midline based on the position of the first surface midline and the position of the first tooth midline;

[0227] The second deviation value acquisition module 5 is used to obtain the second deviation value between the second surface midline and the second tooth midline of the target object in the three-dimensional dental model based on the mapping relationship and the first deviation value.

[0228] The third acquisition module 6 is used to obtain the position of the second surface midline in the three-dimensional dental model based on the position of the second tooth midline and the second deviation value in the three-dimensional dental model.

[0229] In an optional implementation, the first acquisition module 1 includes a two-dimensional photo acquisition unit 11 for acquiring a target two-dimensional photo of the target object; a facial region acquisition unit 12 for acquiring a facial region in the target two-dimensional photo; a positioning point acquisition unit 13 for acquiring facial feature positioning points of the facial region; a first face midline acquisition unit 14 for obtaining the position of the first face midline based on the facial feature positioning points; and a first tooth midline acquisition unit 15 for obtaining the position of the first tooth midline based on the position of the target tooth in the target two-dimensional photo; wherein the target tooth includes at least one of the two maxillary central incisors or at least one of the two mandibular central incisors.

[0230] In an optional embodiment, the first acquisition module 1 further includes a facial tilt judgment unit 16, used to determine whether the face of the target object in the target two-dimensional photo is tilted based on the position of the facial feature positioning points; and a correction unit 17, used to perform a rotation correction operation on the facial feature positioning points and run the first face midline acquisition unit 14 when the facial tilt judgment unit 16 determines that the face of the target object in the target two-dimensional photo is tilted; and to run the first face midline acquisition unit 14 if the facial tilt judgment unit 16 determines that the face of the target object in the target two-dimensional photo is not tilted.

[0231] In an optional embodiment, the first face midline acquisition unit 14 is specifically used to select facial feature key points from the facial feature positioning points, and obtain the position of the first face midline based on the facial feature key points; wherein, the facial feature positioning points include positioning points corresponding to the eyes, eyebrows, bridge of the nose, lips, and outer contour of the face; the facial feature key points include at least three of the following: the center of the eyebrows, the corner of the eye, the tip of the nose, the base of the nose, and the philtrum.

[0232] In an optional implementation, the face region acquisition unit 12 is specifically used to perform image recognition on the target two-dimensional photograph based on a face region recognition algorithm to obtain the face region.

[0233] In an optional implementation, the positioning point acquisition unit 13 is specifically used to identify the facial region based on a facial feature recognition algorithm to obtain facial feature positioning points.

[0234] In an optional implementation, the first face midline acquisition unit 14 is specifically used to perform fitting processing on facial feature positioning points based on a fitting algorithm to obtain the position of the first face midline.

[0235] In an optional embodiment, the first dental midline acquisition unit 15 is specifically used to acquire the midline between the two upper central incisors or the midline between the two lower central incisors, and use the midline as the first dental midline to obtain the position of the first dental midline.

[0236] In an optional implementation, the second acquisition module 2 includes a three-dimensional dental model acquisition unit 21, used to acquire a three-dimensional dental model of the target object including the crown and gingiva; and a second size value acquisition unit 22, used to take the midline between the two upper central incisors or the midline between the two lower central incisors in the three-dimensional dental model as the position of the second tooth midline, and obtain the corresponding second size value of the central incisor.

[0237] In an optional embodiment, the second acquisition module 2 includes a three-dimensional dental model acquisition unit 21, used to acquire a three-dimensional dental model of the target object including the crown and gingiva; and a second size value acquisition unit 22, used to obtain the second size value of the corresponding central incisor based on a preset size value, taking the midline between the two central incisors of the upper jaw or the midline between the two central incisors of the lower jaw as the position of the second tooth midline in the three-dimensional dental model.

[0238] In an optional implementation, the mapping relationship establishment module 3 includes a first size value acquisition unit 31, used to acquire the first size value of the target tooth in the target two-dimensional photograph based on an image recognition algorithm; and a mapping relationship establishment unit 32, used to establish a mapping relationship between the first size value and the second size value based on the first size value and the second size value corresponding to the target tooth.

[0239] In an optional implementation, the mapping relationship establishment module 3 includes a first size value acquisition unit 31, which is used to acquire the first size value of the target tooth in the target two-dimensional photograph based on a preset scale corresponding to the target two-dimensional photograph; and a mapping relationship establishment unit 32, which is used to establish a mapping relationship between the first size value and the second size value based on the first size value and the second size value corresponding to the target tooth.

[0240] In an optional implementation, the third acquisition module 6 includes a relative position determination unit 61, used to obtain the relative position of the second surface midline relative to the second tooth midline based on the second deviation value; and a second surface midline determination unit 62, used to obtain the position of the second surface midline in the three-dimensional dental model based on the relative position.

[0241] The working principle of the system for determining the midline of the three-dimensional dental model in this embodiment is the same as that of the method for determining the midline of the three-dimensional dental model in Embodiment 1, and will not be repeated here.

[0242] The midline determination system in the 3D dental model of this embodiment can automatically obtain the position of the first midline and the position of the first tooth midline of the target object in the target 2D photograph. Based on the first dimension value of the target tooth in the target 2D photograph and the second dimension value of the target tooth in the 3D dental model, a mapping relationship between the first dimension value and the second dimension value is established. Then, based on the first deviation value between the first midline and the first tooth midline, the second deviation value between the second midline and the second tooth midline of the target object in the 3D dental model is obtained. Finally, based on the position of the second tooth midline and the second deviation value in the 3D dental model, the position of the second midline in the 3D dental model is obtained. This achieves automatic determination of the midline position in the 3D dental model, improving the accuracy and efficiency of midline determination.

[0243] Example 5

[0244] This embodiment provides a system for determining the position of teeth during orthodontic treatment, such as... Figure 9 As shown, the system for determining the position of teeth during orthodontic treatment includes:

[0245] The midline acquisition module 7 is used to obtain the position of the midline of the target object in the three-dimensional dental model using the midline determination system in the three-dimensional dental model of embodiment 4;

[0246] Coordinate system establishment module 8 is used to establish a three-dimensional coordinate system in the three-dimensional dental model based on the position of the midline of the face;

[0247] The orthodontic position determination module 9 is used to determine the orthodontic position of each tooth of the target object based on the three-dimensional coordinate system and the position of the tooth midline of the target object in the three-dimensional dental model.

[0248] The working principle of the tooth orthodontic position determination system in this embodiment is the same as that of the tooth orthodontic position determination method in embodiment 2, and will not be repeated here.

[0249] The tooth orthodontic position determination system of this embodiment automatically obtains the position of the midline of the target object in the three-dimensional dental model based on the midline determination system in the three-dimensional dental model of embodiment 4. It can quickly determine the orthodontic position corresponding to each tooth of the target object, and then flexibly design and adjust the orthodontic treatment plan.

[0250] Example 6

[0251] This embodiment provides a manufacturing system for orthodontic appliances, the manufacturing system for orthodontic appliances includes:

[0252] The orthodontic position acquisition module is used to obtain the target orthodontic position of the target object's teeth using the orthodontic position determination system in Example 5;

[0253] The orthodontic appliance manufacturing module is used to determine the shape of the orthodontic appliance for the target object based on the target orthodontic position, so as to manufacture an orthodontic appliance with the corresponding shape.

[0254] The working principle of the manufacturing system for the orthodontic appliance in this embodiment is the same as that of the manufacturing method for the orthodontic appliance in Embodiment 3, and will not be repeated here.

[0255] The manufacturing system for the orthodontic appliance in this embodiment determines the target orthodontic position of the target object's teeth based on the orthodontic position determination system in embodiment 5, quickly and accurately determines the shape of the orthodontic appliance for the target object, and then manufactures an orthodontic appliance with the corresponding shape.

[0256] Example 7

[0257] This embodiment provides an electronic device. Figure 10 This is a schematic diagram of the structure of the electronic device provided in this embodiment. The electronic device includes a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the computer program, it implements the method for determining the midline of the three-dimensional dental model in Embodiment 1, or the method for determining the position of the teeth in Embodiment 2, or the method for manufacturing the orthodontic appliance in Embodiment 3. Figure 10 The electronic device 70 shown is merely an example and should not be construed as limiting the functionality or scope of the embodiments of the present invention. Figure 10As shown, the electronic device 70 can be manifested as a general-purpose computing device, such as a server device. The components of the electronic device 70 may include, but are not limited to: at least one processor 71, at least one memory 72, and a bus 73 connecting different system components (including memory 72 and processor 71).

[0258] Bus 73 includes a data bus, an address bus, and a control bus.

[0259] The memory 72 may include volatile memory, such as random access memory (RAM) 721 and / or cache memory 722, and may further include read-only memory (ROM) 723.

[0260] The memory 72 may also include a program tool 725 (or utility) having a set (at least one) program module 724, such program module 724 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0261] The processor 71 executes various functional applications and data processing by running computer programs stored in the memory 72, such as the method for determining the midline of the three-dimensional dental model in Embodiment 1 above, the method for determining the position of the teeth in the orthodontic treatment in Embodiment 2 above, or the method for manufacturing the orthodontic appliance in Embodiment 3 above.

[0262] Electronic device 70 can also communicate with one or more external devices 74. This communication can be performed via input / output (I / O) interface 75. Furthermore, the model-generated electronic device 70 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 76. Figure 10 As shown, network adapter 76 communicates with other modules of electronic device 70 via bus 73. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with electronic device 70, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, and data backup storage systems.

[0263] It should be noted that although several units / modules or sub-units / modules of the electronic device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more units / modules described above can be embodied in one unit / module. Conversely, the features and functions of one unit / module described above can be further divided and embodied by multiple units / modules.

[0264] Example 8

[0265] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method for determining the midline of the three-dimensional dental model in Embodiment 1, the method for determining the position of the teeth in Embodiment 2, or the method for manufacturing the orthodontic appliance in Embodiment 3.

[0266] The readable storage medium may be more specifically adopted, including but not limited to: portable disk, hard disk, random access memory, read-only memory, erasable programmable read-only memory, optical storage device, magnetic storage device, or any suitable combination thereof.

[0267] In possible implementations, the present invention can also be implemented as a program product, which includes program code. When the program product is run on a terminal device, the program code is used to cause the terminal device to perform the steps in the method for determining the midline of the three-dimensional dental model in Embodiment 1 above, or the steps in the method for determining the orthodontic position in Embodiment 2 above, or the steps in the method for manufacturing the orthodontic appliance in Embodiment 3 above.

[0268] The program code for executing the present invention can be written in any combination of one or more programming languages. The program code can be executed entirely on the user device, partially on the user device, as a standalone software package, partially on the user device and partially on a remote device, or entirely on a remote device.

[0269] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for determining a facial midline in a three-dimensional dental model, characterized in that, The determining method comprises: obtaining a position of a first facial midline and a position of a first dental midline of a target object in a target two-dimensional photo; wherein the target two-dimensional photo comprises a face of the target object exposing target teeth; obtaining a position of a second dental midline of the target object in the three-dimensional dental model based on the target teeth, and obtaining a second size value of the target teeth in the three-dimensional dental model; obtaining a first size value of the target teeth in the target two-dimensional photo, and establishing a mapping relationship between the first size value and the second size value; obtaining a first deviation value between the first facial midline and the first dental midline based on the position of the first facial midline and the position of the first dental midline; obtaining a second deviation value between a second facial midline and the second dental midline of the target object in the three-dimensional dental model based on the mapping relationship and the first deviation value; obtaining the position of the second facial midline in the three-dimensional dental model based on the position of the second dental midline in the three-dimensional dental model and the second deviation value.

2. The determination method according to claim 1, characterized in that, The obtaining of the position of the first facial midline and the position of the first dental midline of the target object in the target two-dimensional photo comprises: obtaining the target two-dimensional photo of the target object; obtaining a face region in the target two-dimensional photo; obtaining facial feature positioning points of the face region; obtaining the position of the first facial midline based on the facial feature positioning points; obtaining the position of the first dental midline based on the position of the target teeth in the target two-dimensional photo; wherein the target teeth comprise at least one of two maxillary central incisors or at least one of two mandibular central incisors.

3. The determination method according to claim 2, characterized in that, The obtaining of the facial feature positioning points of the face region further comprises: judging whether a face of the target object in the target two-dimensional photo is tilted based on the positions of the facial feature positioning points; if yes, performing a rotation correction operation on the facial feature positioning points, and performing the operation of obtaining the position of the first facial midline based on the facial feature positioning points; if no, performing the operation of obtaining the position of the first facial midline based on the facial feature positioning points.

4. The determination method according to claim 2, characterized in that, The operation of obtaining the position of the first facial midline based on the facial feature positioning points comprises: selecting facial feature key points from the facial feature positioning points, and obtaining the position of the first facial midline based on the facial feature key points; wherein the facial feature positioning points comprise positioning points corresponding to eyes, eyebrows, a nose bridge, lips, and a face contour; and the facial feature key points comprise at least three of a brow center point, a canthus point, a nose tip point, a nose bottom point, and a philtrum point.

5. The determination method according to claim 2, characterized in that, The obtaining of the face region in the target two-dimensional photo comprises: performing image recognition on the target two-dimensional photo based on a face region recognition algorithm to obtain the face region. And / or, the obtaining of the facial feature positioning points of the face region comprises: performing recognition on the face region based on a facial feature recognition algorithm to obtain the facial feature positioning points. And / or, the method of obtaining the position of the first facial median line based on the facial feature positioning points comprises: fitting the facial feature positioning points based on a fitting algorithm to obtain the position of the first facial median line; And / or, the step of obtaining the position of the first tooth median line based on the position of the target tooth in the target two-dimensional photo comprises: Obtaining the median line between the two central incisors of the upper jaw or the median line between the two central incisors of the lower jaw, and taking the median line as the first tooth median line to obtain the position of the first tooth median line.

6. The determination method according to claim 2, characterized in that, The step of obtaining the position of the second tooth median line of the target object in the three-dimensional dental model based on the target tooth and obtaining the second size value of the target tooth in the three-dimensional dental model comprises: Obtaining the three-dimensional dental model of the target object containing the crown and the gum; In the three-dimensional dental model, taking the median line between the two central incisors of the upper jaw or the median line between the two central incisors of the lower jaw as the position of the second tooth median line, and obtaining the second size value of the corresponding central incisor.

7. The determination method according to claim 2, characterized in that, The step of obtaining the position of the second tooth median line of the target object in the three-dimensional dental model based on the target tooth and obtaining the second size value of the target tooth in the three-dimensional dental model comprises: Obtaining the three-dimensional dental model of the target object containing the crown and the gum; In the three-dimensional dental model, taking the median line between the two central incisors of the upper jaw or the median line between the two central incisors of the lower jaw as the position of the second tooth median line, and obtaining the second size value of the corresponding central incisor based on the preset size value.

8. The determination method of claim 1, wherein, The step of obtaining the first size value of the target tooth in the target two-dimensional photo and establishing the mapping relationship between the first size value and the second size value comprises: Obtaining the pixel value of the target tooth in the target two-dimensional photo based on an image recognition algorithm, and taking the pixel value as the first size value; Establishing the mapping relationship between the first size value and the second size value based on the first size value and the second size value corresponding to the target tooth.

9. The determination method of claim 1, wherein, The step of obtaining the first size value of the target tooth in the target two-dimensional photo and establishing the mapping relationship between the first size value and the second size value comprises: Obtaining the scale value of the target tooth in the target two-dimensional photo based on the preset scale corresponding to the target two-dimensional photo, and taking the scale value as the first size value; Establishing the mapping relationship between the first size value and the second size value based on the first size value and the second size value corresponding to the target tooth.

10. The determination method of claim 1, wherein, The step of obtaining the position of the second facial median line in the three-dimensional dental model based on the position of the second tooth median line in the three-dimensional dental model and the second deviation value comprises: Obtaining the relative position of the second facial median line relative to the second tooth median line based on the second deviation value; Obtaining the position of the second facial median line in the three-dimensional dental model based on the relative position.

11. A method for determining the position of teeth in orthodontic treatment, characterized in that, The determination method comprises: The method comprises: The method comprises: The system comprises:

12. A method of manufacturing a dental appliance, characterized by, The system comprises: The system comprises: The system comprises:

13. A system for determining the midline of a three-dimensional dental model, characterized in that, The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises:

14. A system for determining the position of a tooth alignment position, characterized by The system comprises: The system comprises: The system comprises: The system comprises:

15. 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The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system 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The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: 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comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises: The system comprises:

16. An electronic device comprising a memory, a processor, and a computer program stored on the memory for running on the processor, characterized in that, The processor implements the method for determining the facial midline in the three-dimensional dental model according to any one of claims 1-10, or the method for determining the dental correction position according to claim 11, or the manufacturing method of the dental appliance according to claim 12 when the computer program is executed.

17. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the method for determining the facial midline in the three-dimensional dental model according to any one of claims 1-10, or the method for determining the dental correction position according to claim 11, or the manufacturing method of the dental appliance according to claim 12.

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