Method and apparatus for generating an orthodontic guide

Abstract

The application relates to a method and device for generating an orthodontic guide plate. The method comprises: obtaining a first tooth model; the first tooth model comprises a plurality of teeth in original tooth positions; determining target positions of the teeth after orthodontic treatment; determining first bracket positions of the teeth in the target positions; and determining target bracket positions of the teeth in the original tooth positions based on the target positions, the first bracket positions and the original tooth positions; and generating the orthodontic guide plate based on the target bracket positions. The application solves the problems of a long treatment period and a large number of fine adjustments in the later period caused by inaccurate positioning of the bracket positions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of orthodontic technology, and in particular to a generation method and device of an orthodontic guide plate. BACKGROUND

[0002] Wearing an orthodontic guide plate in the oral cavity is conducive to gradually restoring the position of teeth to normal, improving the symptoms of irregular arrangement and deformity, and improving the overall appearance of the oral cavity and face. In the process of orthodontic treatment, how much the orthodontic guide plate can play a role depends on the fitting degree of the teeth and the guide plate, and the key factor determining the fitting degree of the teeth and the guide plate is whether the positioning position of the tooth bracket is accurate.

[0003] At present, the guide plate generation system or method in the related art only simply performs data benchmarking, specifically, a digital model of the oral cavity of a patient is obtained through mouth scanning, then a corresponding bracket is selected for each tooth, the position of the bracket is modified according to manual adjustment of a doctor, and finally the guide plate is generated according to the finally determined position of the bracket. Such a technical solution is extremely dependent on the subjective experience of the doctor, and it is difficult to accurately position the position of the tooth bracket.

[0004] The traditional guide plate is made by hot pressing or 3D printing into an integral whole. Because the guide plate is worn with the bracket and the adhesive is worn from the top of the tooth, the adhesive on the bracket will flow onto the tooth when worn. In addition, there is no interaction design in the previous clinical software, and all the design is completed by the technician, and the doctor verbally tells the technician about the design modification.

[0005] In view of the problem that the inaccurate positioning position of the bracket leads to the poor fitting of the guide plate and the teeth, no effective solution has been proposed. SUMMARY

[0006] The present application provides a generation method and device of an orthodontic guide plate to solve the problems of a long correction course and a large number of fine adjustments in the later period caused by inaccurate positioning of the bracket position.

[0007] According to an aspect of an embodiment of the present application, the present application provides a method, comprising: obtaining a first tooth model; the first tooth model comprises a plurality of teeth in an original tooth position; determining a pre-arrangement target position of each tooth after treatment; determining a first bracket position of the tooth in the pre-arrangement target position, and determining a target bracket position of the tooth in the original tooth position based on the pre-arrangement target position, the first bracket position and the original tooth position; and generating an orthodontic guide plate based on the target bracket position.

[0008] According to another aspect of the embodiments of the present application, a device for generating an orthodontic guide plate is also provided, comprising a memory and a processor, the memory storing a computer program, and the computer program being executed by the processor to perform the method described above.

[0009] According to another aspect of the embodiments of the present application, a computer readable storage medium is also provided, storing a computer program, and the computer program being executed by a processor to perform the steps of the method described above.

[0010] The above technical solutions provided by the embodiments of the present application have the following advantages compared with related art.

[0011] The present application obtains a first tooth model, the first tooth model includes a plurality of teeth in original tooth positions, determines the target positions of the teeth after orthodontic treatment, determines the first bracket positions of the teeth in the target positions, and determines the target bracket positions of the teeth in the original tooth positions based on the target positions, the first bracket positions and the original tooth positions. The method for generating an orthodontic guide plate based on the target bracket positions can use the first bracket positions determined based on the target positions, the target positions and the original tooth positions to determine the target bracket positions, improve the accuracy of the determined bracket positions, further improve the adaptability of the generated orthodontic guide plate and the teeth, and solve the problems of long correction course and many fine adjustment times in the later period caused by inaccurate positioning of the bracket positions. BRIEF DESCRIPTION OF DRAWINGS

[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and serve to explain the principles of the present application together with the specification.

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the accompanying drawings needed to be used in the embodiments or the related art description will be briefly introduced. Obviously, those skilled in the art can obtain other drawings from these drawings without any creative effort.

[0014] Figure 1 A hardware environment schematic diagram of an optional method for generating an orthodontic guide plate according to the embodiments of the present application is shown in the figure.

[0015] Figure 2 A flowchart of an optional method for generating an orthodontic guide plate according to the embodiments of the present application is shown in the figure.

[0016] Figure 3 A bracket schematic diagram of an optional method for generating an orthodontic guide plate according to the embodiments of the present application is shown in the figure.

[0017] Figure 4A tooth midpoint and tooth midline diagram of an optional orthodontic guide generation method according to an embodiment of the present application;

[0018] Figure 5 A bracket attachment and retention body diagram of an optional orthodontic guide generation method according to an embodiment of the present application;

[0019] Figure 6 A diagram of fixing a retention body through a bracket attachment of an optional orthodontic guide generation method according to an embodiment of the present application;

[0020] Figure 7 A flowchart of an optional three-dimensional tooth model segmentation method according to an embodiment of the present application;

[0021] Figure 8 A wave peak point and wave valley point diagram of an optional three-dimensional tooth model according to an embodiment of the present application;

[0022] Figure 9 A tooth segmentation diagram of an optional three-dimensional tooth model according to an embodiment of the present application;

[0023] Figure 10 A flowchart of an optional gum line extraction method according to an embodiment of the present application;

[0024] Figure 11 A polygon patch diagram of an optional gum line extraction method according to an embodiment of the present application;

[0025] Figure 12 A model recognition diagram of an optional gum line extraction method according to an embodiment of the present application;

[0026] Figure 13 A convolution pooling operation diagram based on edges in a third tooth model of an optional gum line extraction method according to an embodiment of the present application;

[0027] Figure 14 A tooth segmentation diagram of an optional three-dimensional tooth model according to an embodiment of the present application;

[0028] Figure 15 A diagram of an optional combined orthodontic guide according to an embodiment of the present application;

[0029] Figure 16 A diagram of connection of an optional first and second snap-fit members according to an embodiment of the present application;

[0030] Figure 17 A diagram of a retention body rotation range according to an embodiment of the present application;

[0031] Figure 18 An optional connection arm and buckle coordination diagram provided by an embodiment of the present application;

[0032] Figure 19 An optional tooth position marker diagram provided by an embodiment of the present application;

[0033] Figure 20 An optional bracket fixing diagram provided by an embodiment of the present application;

[0034] Figure 21 A flow chart of an optional generation method of an orthodontic guide plate according to an embodiment of the present application;

[0035] Figure 22 An optional device block diagram provided by an embodiment of the present application. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0037] In the subsequent description, the suffixes such as "module", "component" or "unit" used to represent elements are only for the convenience of description of the present application, and have no specific meaning in itself. Therefore, "module" and "component" can be used interchangeably.

[0038] To solve the problems mentioned in the background, according to an aspect of an embodiment of the present application, an embodiment of a generation method of an orthodontic guide plate is provided.

[0039] Optionally, in the embodiments of the present application, the above-mentioned method can be applied in a hardware environment composed of a terminal 101 and a server 103 as shown in Figure 1 As shown in Figure 1 , the server 103 is connected with the terminal 101 through a network, which can be used to provide services for the terminal or the client installed on the terminal, and a database 105 can be set on the server or independently of the server, which is used to provide data storage services for the server 103, and the above-mentioned network includes but is not limited to a wide area network, a metropolitan area network or a local area network, and the terminal 101 includes but is not limited to a PC, a mobile phone, a tablet computer and the like.

[0040] The method in the embodiments of the present application can be executed by the server 103, and can also be executed by the server 103 and the terminal 101 jointly, as shown in the method can include the following steps: Figure 2

[0041] In step S202, a first tooth model is acquired; the first tooth model includes a plurality of teeth in original tooth positions;

[0042] In step S204, a pre-arrangement target position of each tooth after orthodontic treatment is determined;

[0043] In step S206, a first bracket position of the tooth in the pre-arrangement target position is determined, and a target bracket position of the tooth in the original tooth position is determined based on the pre-arrangement target position, the first bracket position, and the original tooth position;

[0044] In step S208, an orthodontic guide plate is generated based on the target bracket position.

[0045] Optionally, the first tooth model described above can be a three-dimensional tooth model obtained by performing a mouth scan on the inside of the user's mouth, or a model obtained by adjusting the mouth scan model. The first tooth model can be displayed through a display interface, so that the shape of the first tooth model can be viewed.

[0046] The position, orientation, size (size change considering molar grinding), etc. of each tooth on the first tooth model described above can be adjusted. Before adjustment, the position of each tooth on the first tooth model is the original tooth position described above. The position of the tooth after adjustment is the pre-arrangement target position. It can be understood that the position of the tooth on the initial first tooth model after adjustment, the pre-arrangement target position of the tooth is more healthy or more beautiful.

[0047] The first bracket position described above is the position of the bracket installed on the tooth. The bracket is fixed on the tooth. In an embodiment, as shown in the bracket is located at the center of the labial side of the tooth. Figure 3

[0048] After the first bracket position is determined, the target bracket position can be determined according to the correspondence between the original tooth position and the pre-arrangement target position, and the first bracket position described above. The target bracket position is the position of the bracket on the original tooth position. After obtaining the target bracket position, the bracket can be installed on the user's tooth according to the target bracket position of the bracket on the original tooth position.

[0049] ​​The application obtains a first tooth model; the first tooth model includes a plurality of teeth in original tooth positions; determines target positions of the teeth after orthodontic treatment; determines first bracket positions of the teeth in the target positions, and determines target bracket positions of the teeth in the original tooth positions based on the target positions, the first bracket positions and the original tooth positions; and generates an orthodontic guide plate based on the target bracket positions, so that the first bracket positions determined based on the target positions, the target positions and the original tooth positions are used to determine the target bracket positions, the accuracy of the determined bracket positions is improved, and the adaptability of the generated orthodontic guide plate and the teeth is further improved.

[0050] As an optional example, the target bracket positions of the teeth in the original tooth positions are determined, including: determining tooth position offset relationships based on the original tooth positions and the target positions; determining second bracket positions of the teeth in the original tooth positions based on the first bracket positions, relative position relationships of the teeth in the target positions and the tooth position offset relationships; transmitting the second bracket positions to the outside, receiving returned third bracket positions corresponding to the second bracket positions; and determining the third bracket positions as the target bracket positions. It should be noted that the third bracket positions can be the same as or different from the second bracket positions. In an example, the third bracket positions can be modified by a doctor end and sent.

[0051] The position offset relationships can be changes in positions of the original tooth positions and the target positions in the same three-dimensional space, for example, a position of a tooth is moved by 3 units and an angle is offset by thirty degrees. Optionally, as a way of determining the target bracket positions, if the tooth position offset relationships between the original tooth positions and the target positions are known and the positions of the first bracket positions on the teeth are unchanged, the target bracket positions of the original tooth positions can be correspondingly determined.

[0052] Optionally, in the embodiment, after the target bracket positions are obtained, the target bracket positions can be used, that is, brackets are installed on the teeth according to the target bracket positions, or the target bracket positions are adjusted and then the brackets are installed. The adjustment of the target bracket positions can be manual adjustment, that is, the adjustment is performed by receiving adjustment instructions from a doctor end, so that accurate target bracket positions are obtained.

[0053] As an optional example, determining the target bracket position of the tooth in the original tooth position comprises: sending the first tooth model and the first bracket position to the outside and receiving the fourth bracket position corresponding to the first bracket position; determining the tooth position offset relationship according to the original tooth position and the pre-treatment target position; determining the fifth bracket position of the tooth in the original tooth position according to the tooth position offset relationship, the relative position relationship between the fourth bracket position and the tooth in the pre-treatment target position; and determining the target bracket position of the tooth in the original tooth position as the fifth bracket position.

[0054] Optionally, as another way of determining the target bracket position, the first bracket position can be adjusted to obtain the fourth bracket position after obtaining the first bracket position. The fourth bracket position can be the same as or different from the first bracket position. Then, the target bracket position is determined according to the fourth bracket position. The position offset relationship can be the change of the position of the original tooth position and the pre-treatment target position in the same three-dimensional space. If the tooth position offset relationship between the original tooth position and the pre-treatment target position is known, and the position of the fourth bracket position on the tooth is unchanged, the target bracket position of the original tooth position can be correspondingly determined.

[0055] As an optional example, determining the pre-treatment target position of each tooth after treatment comprises: arranging the teeth in the first tooth model to determine the position of each tooth in the tooth row; simulating the treatment of the first tooth model according to the tooth treatment strategy, and recording the position offset information of each tooth during the simulation to obtain the pre-treatment target position after the tooth treatment; and / or receiving the adjustment instruction input by the target user and adjusting the position of each tooth in the tooth row according to the adjustment instruction to obtain the pre-treatment target position after the tooth treatment.

[0056] In the embodiment, there are different methods for adjusting the teeth in the first tooth model to obtain the pre-treatment target position. One method is automatic correction. When automatic correction is performed, the direction, size and position of the teeth on the first tooth model can be adjusted. For example, if the angle of the same direction of the surfaces of two teeth is too large, the angle can be adjusted to be smaller, and if the positions of the teeth are not aligned, the teeth can be adjusted to be aligned with the gum as the boundary. After adjustment, the teeth are more aligned. Another method is manual correction. The adjustment instruction input by the target user is received to adjust the teeth on the first tooth model to obtain the pre-treatment target position.

[0057] As an optional example, the tooth arrangement for the first tooth model includes: obtaining an intraoral photo and a facial photo of a patient corresponding to the first tooth model; determining actual original positions of teeth of the patient based on the intraoral photo and the facial photo, and determining a shift position based on the actual original positions, wherein the shift position includes a maxilla or a mandible of the patient; determining a facial midline of the patient based on the facial photo, and determining a dental midline of the maxilla or the mandible of the patient based on the intraoral photo, wherein the dental midline corresponds to the facial midline; and arranging the shift position based on the dental midline.

[0058] Optionally, the intraoral photo can be a photo of teeth taken by a user with lips open. The facial photo can be a photo containing a front of a face of the user. The purpose of obtaining the intraoral photo and the facial photo is to determine whether teeth of the maxilla or the mandible of the user are shifted through the association of the facial photo and the intraoral photo. Thus, when adjusting positions of teeth of the user, the adjusted positions of the teeth can be more accurate and fit the face of the user. The facial midline is a midline of the left and right sides of the face of the user. The dental midline of the maxilla and the dental midline of the mandible of the adjusted teeth correspond to the facial midline.

[0059] As an optional example, after determining the actual original positions of the teeth of the patient based on the intraoral photo and the facial photo, the method further includes: in a case where the actual original positions of the teeth of the patient do not completely match positions of each tooth in the first tooth model, sending a miscommunication prompt information to re-upload a tooth model matched with the patient.

[0060] Optionally, in this embodiment, since the first tooth model is a three-dimensional tooth model scanned by a mouth, if the first tooth model and the actual original positions of the teeth of the user are different, it indicates that the scanned model is incorrect. Therefore, the scanned model needs to be re-obtained.

[0061] As an optional example, the first bracket position includes a center point and a central axis of the bracket; and the determining the first bracket position of the tooth at the pre-arrangement target position includes: determining a clinical crown long axis and a clinical crown center point of the tooth at the pre-arrangement target position on the first tooth model; determining the clinical crown center point as the center point and determining the clinical crown long axis as the central axis.

[0062] Optionally, a midpoint of one face of the bracket can be used as the center point, and the bracket is axially symmetrical or close to axially symmetrical, so that the central axis of the bracket can be determined. The central axis of the bracket coincides with the clinical crown long axis of the tooth, and the center point of the bracket coincides with the clinical crown center point of the tooth. That is, the bracket is installed at the center of the tooth. For example, as shown in FIG. 2, the bracket 21 is installed at the center of the tooth 22. Figure 4 Figure 4 ​To determine the midpoint and midline of a tooth.

[0063] As an optional example, the above-mentioned generation of the target orthodontic guide based on the target bracket position includes: generating a bracket retention component according to the target bracket position; selecting a bracket attachment with a corresponding tooth position label and placing the bracket attachment on the labial / buccal surface of the corresponding tooth; and combining the retention component with the corresponding bracket attachment to obtain the target orthodontic guide.

[0064] Optionally, in this embodiment, the bracket described above is used to connect bracket attachments after being fixed to the teeth. The bracket connects to the bracket attachments, and the bracket attachments connect to retention components, which are used for orthodontic treatment. The combination of retention components for each tooth forms an orthodontic guide. For example, as... Figure 5 As shown, Figure 5 In this design, bracket attachment 502 can be connected to retention component 504, and the retention components 504 of multiple teeth together form a guide plate. Bracket attachment 502 can be fixed to the bracket, so after fixing, the guide plate fits into the tooth. Figure 6 This is a schematic diagram showing the teeth engaging on the guide plate after the bracket attachment is installed in the bracket.

[0065] As an optional example, before obtaining the orthodontic strategy and the first tooth model, the above method further includes: receiving a second tooth model; adding a base to the second tooth model to obtain a third tooth model; and performing tooth separation processing on the third tooth model to obtain the first tooth model.

[0066] Optionally, in this embodiment, the second tooth model described above can be an oral scan model obtained by scanning the inside of the user's mouth. The gingival portion of the oral scan model is uneven; therefore, a base can be added to make the gingival portion flat. The oral scan model has the contours of teeth and gums; therefore, the teeth can be segmented to determine individual teeth, thus obtaining the first tooth model.

[0067] As an optional example, the third tooth model is subjected to tooth segmentation processing to obtain the first tooth model, including: extracting the gingival line of the third tooth model, and performing tooth segmentation processing on the third tooth model according to the gingival line to obtain the first tooth model.

[0068] Optionally, in this embodiment, the third tooth model is divided into individual teeth to obtain the first tooth model. This division can be performed using the gingival line, which is the boundary between the tooth and the gum. Gingival line division involves dividing the tooth portion of the first tooth model into individual teeth.

[0069] As an optional example, the above-described extraction of the gingival line of the third tooth model and the segmentation of the third tooth model based on the gingival line to obtain the first tooth model includes: downsampling the third tooth model to obtain a fourth tooth model with a target number of sides, wherein the fourth tooth model is a tooth model composed of multiple polygonal faces, and the total number of sides of the multiple polygonal faces is the target number of sides; determining the feature parameters of each side in the fourth tooth model, wherein the feature parameters include at least one of the following: the curvature values ​​of the two endpoints of the current side, the included angle of the current side corresponding to the multiple polygonal faces, the distance from the vertices on the two polygonal faces to the current side, and the included angle between the remaining two sides of each of the two polygonal faces; inputting the feature parameters of each side into a target classification network to determine the target category to which each side belongs using the target classification network; dividing the fourth tooth model into a tooth region and a gingival region based on the target category of each side; and extracting the gingival line from the third tooth model and segmenting the teeth using the tooth region and the gingival region on the fourth tooth model to obtain the first tooth model.

[0070] As an optional example, the above-mentioned extraction of the gingival line and tooth segmentation on the third tooth model using the tooth region and gingival region on the fourth tooth model to obtain the first tooth model includes: determining the boundary vertices between the tooth region and the gingival region; projecting the boundary vertices onto the third tooth model and finding the feature point on the third tooth model that best matches each of the boundary vertices; interpolating between the key feature points on the third tooth model to obtain the gingival line; and segmenting the third tooth model using the gingival line to obtain the first tooth model.

[0071] As an optional example, the third tooth model is subjected to tooth segmentation processing, wherein the third tooth model is also a three-dimensional tooth model, hereinafter referred to as a three-dimensional tooth model, including:

[0072] like Figure 7 As shown, the method may include the following steps:

[0073] Step S212: Obtain the gingival line and tooth region of the three-dimensional tooth model;

[0074] Step S214: Extract the peaks of the gingival line and pair the peaks to obtain peak combinations;

[0075] Step S216: Based on the combination of peak points, determine the segmentation path between teeth in the tooth region;

[0076] Step S218: The tooth region is segmented according to the segmentation path to obtain the target segmented tooth.

[0077] Optionally, the purpose of the above-mentioned third tooth model segmentation method is to accurately segment each tooth on the third tooth model into individual teeth.

[0078] The aforementioned third tooth model can be an intraoral scan model, which refers to a three-dimensional model including the user's teeth, generated by scanning the inside of the user's mouth. The data of the third tooth model is stored on a computer or server, and its shape or style can be displayed on a screen for the doctor's convenience.

[0079] Optionally, the aforementioned gingival line can be the dividing line between the tooth region and the gingival region on the third tooth model. The gingival line can be determined in various ways, such as by recognition through a neural network model, or by recognizing a two-dimensional projection image of the third tooth model.

[0080] Optionally, the peak point of the third tooth model can be a point on the gingival line of the third tooth model that is higher than the adjacent points. For example, if a straight line connecting multiple points on the gingival line of the third tooth model continuously rises and then begins to decline at one of the points, then that point is a peak point. A peak point can be understood as the highest point of the gingiva located at the gap between two teeth.

[0081] In this embodiment, the pairing of peak points allows each pair of peak points to be defined as a peak point combination. The two peak points in a peak point combination are used to determine the boundary between two teeth. Each peak point combination contains two peak points.

[0082] In this embodiment, after determining the combination of peak points, the segmentation path between two teeth in the tooth region can be determined based on the two peak points.

[0083] The tooth region can be segmented according to the segmentation path to obtain individual teeth. For example... Figure 8 As shown, the gingival line between the tooth and the gum in the third tooth model has peaks and troughs. Figure 8 (The unshown portion on the other side of the middle tooth also exists). The peak point is the highest point on the gum line between two teeth (it may be the highest point, or not the highest point, but located on the gum line). The trough point is the lowest point on the gum line. By pairing peak points, the peak points at the gap between every two teeth can be combined into a peak point combination. Using this peak point combination, the segmentation path between the two teeth can be determined. Finally, the teeth are segmented using this path to obtain individual teeth. The segmentation result can be as follows: Figure 9 As shown.

[0084] This application obtains the gingival line and tooth region of the third tooth model, extracts the peak points of the gingival line, pairs the peak points to obtain peak point combinations, determines the segmentation path based on the peak point combinations, and segments the tooth region according to the segmentation path to obtain the target segmented tooth method. This method can accurately segment each tooth of the third tooth model, achieving the effect of accurately segmenting the third tooth model.

[0085] As an optional example, pairing the peak points to obtain peak point combinations includes: dividing the peak points into a first peak point group and a second peak point group according to the positional relationship between the peak points and the third tooth model; taking each peak point in the first peak point group as the first peak point, and taking the first peak point and the second peak point in the second peak point group as a peak point combination, wherein the second peak point is the peak point in the second peak point group that is closest to the first peak point, and the angle between the line connecting the first peak point and the second peak point and the tooth midline of the third tooth model is greater than a third threshold.

[0086] Optionally, in this embodiment, when pairing the peak points, two peak points that are closest to each other and whose connecting line passes through the dental midline are paired as a pair of peak points. The dental midline is the line connecting the midpoints of the teeth on the third tooth model. Peak points passing through the connecting line indicate that peak points on both sides of the tooth are paired, rather than peak points on one side of the tooth.

[0087] As an optional example, after taking each peak in the first peak group as the first peak, and combining the first peak with the second peak in the second peak group as a peak combination, the method further includes: deleting the successfully paired peaks from the first peak group and the second peak group; taking each peak in the second peak group as the third peak, and combining the third peak with the fourth peak in the first peak group as a peak combination, wherein the fourth peak is the peak in the first peak group that is closest to the third peak, and the angle between the line connecting the third peak and the fourth peak and the tooth midline of the third tooth model is greater than a third threshold.

[0088] In this embodiment, we can start from the peak points on one side of the third tooth model and pair them one by one. For each peak point on one side of the third tooth model, we select the peak point with the smallest distance from the other side of the tooth and the angle between the line connecting the two peak points and the tooth midline meets the preset threshold condition. We then combine the two peak points into a peak point combination. After the pairing is completed, we delete all the successfully paired peak points and then start from the other side of the tooth to pair them again, so as to achieve the pairing of all peak points.

[0089] Furthermore, if the minimum distance peak point is found based solely on distance, it is easy to make incorrect pairings in the case of oblique teeth or incisors. The pairing method described above can avoid pairing errors in such scenarios by using whether the included angle meets a preset threshold condition.

[0090] There may be several reasons why pairing may fail, such as the distance between the two peaks being too large, or one peak on one side being able to pair with both peaks on the other side.

[0091] As an optional example, determining the segmentation path between teeth in a tooth region based on peak point combinations includes: determining each peak point combination as the current combination; and determining the shortest distance between two peak points in the current combination on a third tooth model as a segmentation path.

[0092] Once the combination of peak points is determined, the segmentation path can be determined based on this combination. The segmentation path can be the shortest path between two peak points on the tooth.

[0093] As an optional example, determining the segmentation path between teeth in a tooth region based on peak point combinations includes: determining each peak point combination as the current combination; determining the shortest distance between two peak points in the current combination on a third tooth model as the first path; correcting the first path by superimposing curvature to obtain the target path; and determining the target path as the segmentation path.

[0094] In this embodiment, the segmentation path can be used as the path for segmenting teeth. Alternatively, the segmentation path can be adjusted. After obtaining the shortest path between two peaks on a tooth, the path can be corrected by superimposing curvature. The corrected path can then be used as the segmentation path.

[0095] As an optional example, the first path is corrected by superimposing curvature to obtain the target path, which includes: taking each point on the first path as the current point, determining the replacement point of the current point within a preset range on the third tooth model; wherein the replacement point is a point that meets the curvature threshold requirement; and taking the line connecting the replacement points as the target path.

[0096] In this embodiment, the shortest path is corrected using a superimposed curvature method. This involves locally adjusting points on the path based on curvature, correcting each point on the shortest path. Each point is treated as the current point. If, on the third tooth model, there exists a point within a preset range near the current point that meets the curvature threshold requirement, then that point replaces the current point. The replaced points are then connected to form the segmentation path.

[0097] In an optional example, such as Figure 10 The method for extracting the gingival line may include the following steps:

[0098] Step S222: Obtain the third tooth model, wherein the third tooth model includes multiple polygonal facets;

[0099] Step S224: Determine the edge categories of the edges of multiple polygonal patches, where the edge categories include tooth edges and gum edges;

[0100] Step S226: Determine the gingival line of the third tooth model based on the edge category.

[0101] The aforementioned third dental model can be an intraoral scan model, which refers to a digital 3D model including the user's teeth and gums generated by scanning the inside of the user's mouth; alternatively, it can be obtained by taking impressions of the teeth and gums, and then scanning the impressions to obtain a digital 3D model. The 3D dental model data is stored on a computer or server, and its shape or style can be displayed on a screen for the doctor's convenience.

[0102] The aforementioned polygonal facets are the facets that make up the surface of the third tooth model (both the tooth and non-tooth parts, the entire surface of the model). Specifically, they can be triangles, quadrilaterals, pentagons, etc. Each polygonal facet lies on a plane, and different polygonal facets can lie on the same or different planes. The surface of the third tooth model is composed of multiple polygonal facets, each containing multiple edges. Adjacent polygonal facets share an edge. The endpoints of the edges are the vertices of the corresponding polygonal facets, and a single vertex can be shared by multiple polygonal facets.

[0103] It should be noted that the third tooth model includes a tooth portion and a gingival portion, and the gingival line is the boundary between the tooth portion and the gingival portion. The edges that make up the polygonal facets can be located in either the tooth portion or the gingival portion, and thus can be classified as tooth edges and gingival edges. Based on this, in this embodiment, the gingival line of the third tooth model can be determined according to the edge category of the polygonal facets, and the determined gingival line is used to divide the tooth portion and the gingival portion of the third tooth model.

[0104] In this embodiment, after obtaining the third tooth model, the edge category can be determined by determining the edge category of the polygonal facet on the third tooth model, thereby determining the gingival line of the third tooth model. The edges, as components of the polygonal facet, can further refine the third tooth model, thereby improving the accuracy of gingival line extraction of the tooth model.

[0105] As an optional example, determining the edge category of multiple polygonal patches includes: obtaining target features of the edges of the multiple polygonal patches; and determining the edge category of the edges of the multiple polygonal patches based on the target features.

[0106] In this embodiment, the target features include geometric features. Of course, in other embodiments, the target features may also include non-geometric features; this is not specifically limited here. In this embodiment, the edge category can be determined by extracting the target features of the edges of polygonal patches and identifying the target features. It should be noted that when the target features include geometric features, the topological relationship of the space will be considered when classifying the edges, thereby improving the accuracy of gingival line recognition.

[0107] In this embodiment, target features of all edges on the third tooth model can be extracted, or target features of a subset of edges can be selected. The edge category is determined by identifying the extracted target features of the edges.

[0108] As an optional example, the target features of an edge include at least one of the following: a dihedral angle between a first polygonal patch and a second polygonal patch sharing the edge; a first curvature value of a first vertex of the edge; a second curvature value of a second vertex of the edge; a first distance from a vertex of the first polygonal patch furthest from the edge to the edge; a second distance from a vertex of the second polygonal patch furthest from the edge to the edge; a first diagonal of the edge in the first polygonal patch; and a second diagonal of the edge in the second polygonal patch. In one application scenario, the target features of an edge include the above seven items.

[0109] As another alternative example, the target features of an edge may include at least one of the following features: a dihedral angle between a first polygonal patch and a second polygonal patch sharing the edge, a first curvature value of a first vertex of the edge, a second curvature value of a second vertex of the edge, a first spatial coordinate of a first vertex, a second spatial coordinate of a second vertex, the length of the edge, the angle between the edge and an adjacent edge, a first distance from a vertex of the first polygonal patch away from the edge to the edge, a second distance from a vertex of the second polygonal patch away from the edge to the edge, a first diagonal of the edge in the first polygonal patch, a second diagonal of the edge in the second polygonal patch, a first normal of the first vertex, a second normal of the second vertex, a normal of the first polygonal patch, and a normal of the second polygonal patch.

[0110] The dihedral angle between the first and second polygonal faces sharing a common edge is the angle between the two polygonal faces sharing a common edge. The first and second vertices are the two endpoints of the edge, and the curvature value is the curvature of the face corresponding to that vertex at that vertex. Curvature is the rate of rotation of the tangent direction angle about the arc length at a point on a curve, defined by differentiation, indicating the degree to which the curve deviates from a straight line. It is a numerical value indicating the degree of curvature of the curve at a point. The greater the curvature, the more curved the curve at that point. The spatial coordinates are the coordinates in the three-dimensional Cartesian coordinate system where the vertex is located. The three-dimensional Cartesian coordinate system can be the coordinate system of the third tooth model; for example, the plane containing the base plate of the third tooth model can be defined as the xOy plane, and the normal direction of this plane can be defined as the z-axis. The directions of the coordinate axes can be predetermined. For example, the gingival surface of the third tooth model can be used as the plane containing the X and Y axes, and the tooth direction as the Z-axis direction. The length of a side is the distance between its two endpoints. Since a side may have multiple adjacent sides, the angle between two adjacent sides can be multiple, ranging from 0 to 180 degrees. When the polygon is quadrilateral or more polygonal, the distance from a vertex furthest from the side to the side can be more than one, and each vertex's distance to the side can be different. However, when the polygonal face is triangular, there is only one vertex furthest from the side, and therefore only one distance from that vertex to the side. Similarly, a side in a polygonal face can have one or more opposite angles, and when there are multiple angles, each opposite angle can be different. For example, as... Figure 11 As shown, the polygonal patches are triangular patch 302, quadrilateral patch 304 and pentagonal patch 306, and each side of the three polygonal patches corresponds to at least one or at least two of the above features.

[0111] Specifically, during feature extraction, the polygonal facets corresponding to the edges of the third tooth model are identified. The cross product of the normals of the polygonal facets yields the angle between the normals of two polygonal facets. Since the dihedral angle between two polygonal facets is complementary to the angle between their normals, subtracting the angle between the normals from 180° gives the dihedral angle between the two polygonal facets. The curvature values ​​of the two vertices can be obtained using curvature geometry calculations or other methods. The distance from the vertex furthest from the edge of a polygonal facet to the edge can be obtained using the point-to-line distance method. Two vectors are obtained based on the orientation of the two edges. The dot product of these two vectors yields the angle between the two edges at the vertex of the polygonal facet, i.e., the diagonal of the edge in each polygonal facet. It should be noted that the spatial coordinates of each vertex and the proximity relationships between points, edges, and faces are all known, allowing for the derivation of each target feature.

[0112] As an optional example, determining the edge category based on the target features includes: increasing the dimensionality of the target features in the initial dimension of the edge to obtain a first feature in the first dimension; reducing the dimensionality of the first feature to obtain a second feature in the target dimension; and determining whether the edge is a tooth edge or a gingival edge based on the value of the second feature. That is, in this embodiment, the target dimension can be two-dimensional, corresponding to tooth edges and gingival edges respectively. Of course, in other embodiments, it can also be multi-dimensional, as long as the edge category of the corresponding edge can be determined; this is not limited here.

[0113] Optionally, in this embodiment, after extracting the target features of the edges, the initial dimension of the target features can be determined according to the type and quantity of the extracted target features. First, the target features are increased in dimensionality to the first dimension to obtain the first feature. Then, the first feature is reduced in dimensionality to the target dimension. However, since dimensionality is increased first and then reduced, the first feature after dimensionality reduction is no longer the target feature, but rather the second feature of the target dimension. Based on this, the edge category of the corresponding edge can be determined.

[0114] Taking an initial dimension of seven as an example, the seven-dimensional target features of the corresponding edge are input into the edge classification network to classify the corresponding edge. Specifically, the input dimension is first seven dimensions, corresponding to seven geometric features. After one convolution operation, the dimension of the target feature increases to N dimensions. Then, after k identical convolution operations, the dimension of the target feature remains unchanged. Finally, a pooling operation is performed to reduce the number of edges. Then repeat the above process, i.e., one dimensionality-increasing convolution + k same-dimensional convolutions + pooling, so that the dimension of the target feature becomes 2N, 4N, and 8N respectively. It should be noted that in the last dimensionality-increasing loop, after k same-dimensional convolutions, an upper pooling operation is performed to gradually restore the number of edges, and then a dimensionality-reducing convolution is performed to reduce the feature dimension to 4N. After k more identical convolution operations, the feature dimension remains unchanged, and then the above process is repeated, i.e., upper pooling + one dimensionality-reducing convolution + k dimensionality-increasing convolutions, so that the feature dimension becomes 4N, 2N, and N respectively. It should be noted that after the last dimensionality-reducing loop, the feature dimension can be further reduced directly to 2 dimensions. Figure 12 The dashed arrow in the middle indicates the feature fusion operation. The final values ​​of the two dimensions are the probability values ​​of whether the edge is a tooth edge or a gingival edge. The category with the larger probability value can be selected as the edge category. At this point, each edge of the model is classified as a tooth edge or a gingival edge.

[0115] It should be noted that the above are merely examples and not intended to be limiting. For instance, the initial dimension is not limited to 7 dimensions, nor is the number of iterations during dimensionality increase and decrease. N is an integer not less than 7, such as 7, 8, 9, 10, etc. These can be adjusted according to the actual situation in the specific implementation plan.

[0116] It should be further noted that the convolution and pooling operations in this step differ from those in the convolution and pooling operations within the image neighborhood, such as...Figure 13 As shown, its operation is based on the edges in the third tooth model.

[0117] In the convolution operation, to eliminate the influence of different edge orders (e.g., (a,b,c,d) and (c,d,a,b)), the original edge features are processed according to the following equation (1), where f(a) and f'(a) represent the original feature and the processed feature of edge a, respectively. The definition of the convolution operation for the processed edge e is given in equation (2), where {w k |k=0,1,2,3,4} represents the weight parameters that need to be trained. The pooling operation transforms 5 edges (e,a,b,c,d) into 2 edges (h,i), as defined in equation (3). The upper pooling operation is the opposite of the pooling operation, transforming 2 edges (h,i) into (e',a',b',c',d'), as defined in equation (4).

[0118]

[0119] C(e)=w0f'(e)+w1f'(a)+w2f'(b)+w3f'(c)+w4f'(d) (2)

[0120]

[0121]

[0122] In addition, before performing edge classification, the classification network needs to be trained to obtain network weight values ​​and some hyperparameter values, such as k and N. Specifically, multiple sets of geometric feature data and the corresponding edge classification values ​​(e.g., 0 for gingiva, 1 for teeth) are input into the edge classification network for training. For example, 500, 1000, or 2000 sets of pre-classified tooth model data can be input, each set containing geometric feature data and classification data corresponding to 5000, 10000, or 20000 edges, enabling the classification network to classify the edge based on its geometric feature data. It should be noted that this embodiment combines deep learning technology, and the edge classification method can automatically identify gingival line data, which can greatly improve the accuracy and efficiency of recognition, improve the efficiency of the entire dental treatment process such as invisible orthodontics, and enhance the user's experience during treatment.

[0123] As an optional example, determining the gingival line of the third tooth model based on the edge category includes: determining the facet category of the polygon facet based on the edge category, wherein the facet category includes tooth facet and gingival facet; and extracting the gingival line based on the shared edges of adjacent polygon facets with different facet categories.

[0124] Optionally, in this embodiment, after determining the edge category, the polygonal patch category can be determined based on the edge category. Understandably, a tooth patch is a patch located on the tooth portion of a tooth model, and a gingival patch is a patch located on the gingival portion. Determining the patch category based on the edge category can be done by determining the polygonal patch category based on all edges of the polygonal patch, or by determining the polygonal patch category based on at least one edge of the polygonal patch.

[0125] As an optional example, determining the polygonal facet category based on the edge category includes: when the number of gingival edges is greater than the number of tooth edges in the polygonal facet, the polygonal facet is determined to be a gingival facet; when the number of gingival edges is less than the number of tooth edges in the polygonal facet, the polygonal facet is determined to be a tooth facet.

[0126] Optionally, in this embodiment, the polygonal patch category is determined based on the edge categories of all its edges. The polygonal patch is classified as either a tooth edge or a gingival edge based on the number of tooth edges and gingival edges within it.

[0127] Traverse all edges of the third tooth model. If the two facets corresponding to an edge are of different categories, then mark the edge as a shared edge.

[0128] As an optional example, extracting the gingival line based on the shared edges of adjacent polygonal faces of different face types includes: determining a first feature point based on the vertices of the shared edges; determining a target feature point from the first feature point according to the curvature relationship; and determining the gingival line based on the target feature point.

[0129] Optionally, in this embodiment, since the polygonal facet category can be determined based on the edge category, after determining the facet category, the shared edges of polygonal faces with different categories serve as the boundary between the tooth facet and the gingival facet. Therefore, the gingival line can be determined based on all the shared edges of the tooth facet and the gingival facet.

[0130] In this embodiment, a first feature point can be determined from the vertices of the shared edge, then a target feature point can be determined from the first feature point, and the gingival line can be determined based on the target feature point. The target feature point can be calculated based on the curvature.

[0131] In this embodiment, starting from a vertex of a shared edge, connected shared edges are found, and the vertices of each connected shared edge are recorded as feature points in a counter-clockwise or clockwise order. The first feature point can be all or part of the recorded feature points. Specifically, the first feature point is located on the initial tooth model, thus improving the accuracy of the extracted gingival line. The target feature point is a portion of the first feature points that possess specific characteristics.

[0132] As an optional example, determining the first feature point based on the vertices of the shared edge includes: when the third tooth model is a model obtained by edge shrinking the initial tooth model, determining the point on the shared edge that is closest to the initial tooth model as the first feature point; when the third tooth model is the initial tooth model, determining the vertices on the shared edge as the first feature point.

[0133] Optionally, the initial tooth model mentioned above is the first tooth model obtained. The initial tooth model can be processed by edge contraction to obtain the third tooth model, or the initial tooth model can be directly used as the third tooth model. Whether or not edge contraction is performed on the initial tooth model affects whether the vertex of the shared edge is directly used as the first feature point. In this embodiment, the first feature point is the vertex of the shared edge, or the point on the initial tooth model where the shared edge is closest.

[0134] In other words, in this embodiment, starting from the vertex of a shared edge, the connected shared edges are found, and the vertices are recorded as feature points in counterclockwise or clockwise order. Then, the recorded feature points can be projected back to the original model, and the point on the original model closest to the recorded feature point is found as the new feature point.

[0135] Specifically, a KDTree can be established using the vertices of the initial tooth model. A KDTree is a tree-like data structure that stores instance points in k-dimensional space for fast retrieval. In this embodiment, all recorded feature points can be traversed, and the nearest point in the KDTree can be found as the new feature point. This new feature point is the first feature point.

[0136] As an optional example, determining the target feature point from the first feature points based on the curvature relationship includes: identifying the first feature points whose curvature is greater than that of the neighboring first feature points as the target feature points.

[0137] After determining the first feature points based on whether the initial tooth model has undergone edge shrinkage processing, target feature points can be determined from the first feature points based on their curvature. Each first feature point corresponds to a curvature. In this embodiment, the first feature point with a curvature greater than that of its neighboring first feature points is selected as the target feature point. In other words, the point in the curve that is more curved is selected as the target feature point, which better reflects the actual trend of the curve.

[0138] After the recorded feature points are projected back to the original model, the curvature of the discrete points can be estimated using a geometric algorithm of curvature, and feature points with large curvature can be retained as target feature points. The reason for retaining feature points with large curvature is that points with large curvature are often inflection points, and inflection points have strong characteristics and are representative.

[0139] As an optional example, determining the gingival line based on target feature points includes: performing an interpolation operation on the target feature points to obtain interpolated target feature points; and connecting the interpolated target feature points in sequence to form the gingival line.

[0140] In this embodiment, interpolation is performed on the target feature points to compensate for the loss of feature points caused by determining the target feature points from the first feature points, and the interpolation operation can combine the target feature points into a closed curve. The closed curve is the gingival line.

[0141] When interpolating target feature points, B-spline curve interpolation can be performed on adjacent target feature points; connecting all points in sequence forms the gingival line. It should be noted that B-spline curves are not limited to interpolation of target feature points; other spline curves can also be used, and no specific limitation is made here.

[0142] As an optional example, obtaining the third tooth model includes: obtaining an initial tooth model, wherein the initial tooth model includes multiple polygonal patches, and the number of edges in the initial tooth model is greater than the number of edges in the third tooth model; reducing the number of edges in the initial tooth model to a preset number according to a preset method to obtain the third tooth model.

[0143] Optionally, in this embodiment, the preset method can be edge contraction or edge collapse. Performing edge contraction on the initial tooth model aims to reduce the number of edges in the initial tooth model, thereby obtaining a third tooth model, simplifying the tooth model and improving the recognition rate of the gingival line.

[0144] There are several ways to reduce the number of edges in the initial tooth model. You can reduce one edge at a time or in batches, such as reducing one edge at a time until a preset number is reached or a preset number of times is reduced. Alternatively, you can reduce edges in batches until a preset number is reached or a preset number of times is reduced.

[0145] Taking edge collapse as an example, the imported initial tooth model can be a tooth model in any direction. The initial tooth model is a digital 3D volume composed of a series of vertices and polygonal faces. After importing the initial tooth model, the tooth model is downsampled using the edge collapse method. After downsampling, the polygonal faces of the tooth model become sparser, the number of polygonal faces decreases, and the number of edges also decreases, until the specified number of edges is reached before downsampling stops.

[0146] The imported initial tooth model often has many edges with varying numbers. However, the required number of edges is usually specific when classifying the tooth using a classification network in subsequent steps. Therefore, it is necessary to downsample the imported initial tooth model, deleting some edges and retaining a specified number. The determination of the number of edges can be based on both classification speed (fewer edges mean faster speed) and the accuracy of the final gingival line (more edges mean higher accuracy and less information loss from the original model). The main process is as follows:

[0147] (1) For each vertex of the initial tooth model, record the sum of its distances to the adjacent face as the error value, with an initial value of 0; where the adjacent face refers to the face where the vertex is located; the initial error value of 0 means that before the edge shrinkage is performed, the sum of the distances from the vertex to its adjacent face is 0.

[0148] (2) Calculate the error value of the vertex after deleting the edge (here, it refers to the sum of the distances from the vertex to the adjacent face when the edge was not deleted). Sort them according to the error value from smallest to largest, and delete the edge with the smallest error first. When an edge shrinks into a vertex, delete the two adjacent face, and delete one vertex and three edges. There are multiple cases for the position of an edge shrinking into a point. For example, it can be moved from the two vertices of the edge to any point on the edge for deletion. The specific position of the point is selected in this step according to the smallest error value.

[0149] (3) Repeat the above steps, continuously calculating the error value and deleting the corresponding edges, until the number of edges reaches the specified number. At this point, the adjustment of the number of edges in the initial tooth model is complete.

[0150] As an optional example, reducing the number of edges in the initial tooth model to a preset number according to a preset method to obtain a third tooth model includes: for each edge of the tooth model to be processed, calculating the sum of distances from the vertex corresponding to each edge to the adjacent polygonal facets of the corresponding vertex in the tooth model to be processed after edge shrinkage processing according to each of a variety of shrinkage methods; wherein, in the first processing, the tooth model to be processed is the initial tooth model; determining the edge corresponding to the minimum value among the calculated sums of multiple distances and the shrinkage method; performing edge shrinkage processing on the edge corresponding to the minimum value according to the shrinkage method corresponding to the minimum value to obtain the third tooth model.

[0151] As an optional example, the edge corresponding to the minimum value is shrunk according to the shrinkage method corresponding to the minimum value to obtain the third tooth model. This includes: after the edge shrinkage process, if the number of edges in the obtained tooth model is not greater than a preset number, then the obtained tooth model is the third tooth model; if the number of edges is greater than the preset number, then the obtained tooth model is determined as the tooth model to be processed, so that the edge shrinkage process can continue.

[0152] Optionally, in this embodiment, when performing edge shrinkage processing on the initial tooth model, it is also necessary to determine which edge to shrink. This process can be a cyclical process. That is, shrinking one edge at a time and repeating, or shrinking a batch of edges at a time and repeating, until the shrunken tooth model meets the conditions. Therefore, in each shrinkage, it is necessary to determine which edge or which batch of edges to shrink.

[0153] In this embodiment, the initial model can be used as the model to be processed, and the edges to be shrunk in the model to be processed are determined. The determination method can be either simulation or calculation. Calculate the sum of distances from each vertex corresponding to that edge in the shrunk model to the adjacent polygonal faces of the corresponding vertex in the tooth model to be processed, if a certain edge is shrunk. If this sum is minimized, then the edge is shrunk according to this strategy. Each time an edge is shrunk, the calculation is repeated, and the edge shrunk is repeated until the number of edges in the tooth model to be processed meets the preset requirement. At this point, the edge shrunking is complete, and the third tooth model is obtained.

[0154] As an optional example, the edge corresponding to the minimum value is shrunk according to the shrinkage method corresponding to the minimum value to obtain the third tooth model. This includes: after the edge shrinkage process, if the number of edges in the obtained tooth model is not greater than a preset number, then the obtained tooth model is the third tooth model; if the number of edges is greater than the preset number, then the obtained tooth model is determined as the tooth model to be processed, so that the edge shrinkage process can continue.

[0155] Optionally, in this embodiment, when performing edge shrinkage processing on the initial tooth model, it is also necessary to determine which edge to shrink. This process can be a cyclical process. That is, shrinking one edge at a time and repeating, or shrinking a batch of edges at a time and repeating, until the shrunken tooth model meets the conditions. Therefore, in each shrinkage, it is necessary to determine which edge or which batch of edges to shrink.

[0156] In this embodiment, the initial model can be used as the model to be processed, and the edges to be shrunk in the model to be processed are determined. The determination method can be either simulation or calculation. Calculate the sum of distances from each vertex corresponding to that edge in the shrunk model to the adjacent polygonal faces of the corresponding vertex in the tooth model to be processed, if a certain edge is shrunk. If this sum is minimized, then the edge is shrunk according to this strategy. Each time an edge is shrunk, the calculation is repeated, and the edge shrunk is repeated until the number of edges in the tooth model to be processed meets the preset requirement. At this point, the edge shrunking is complete, and the third tooth model is obtained.

[0157] In an optional example, such as Figure 14 As shown, the third tooth model undergoes tooth separation processing, including:

[0158] Step S242: Obtain a two-dimensional projection image of the three-dimensional tooth model, and identify the two-dimensional projection image to obtain multiple tooth regions;

[0159] Step S244: In the three-dimensional tooth model, identify the original seed points corresponding to multiple tooth regions;

[0160] Step S246: Expand the original seed points within a preset range to obtain the target seed points of the teeth in the three-dimensional tooth model.

[0161] Step S248: Segment the three-dimensional tooth model based on the target seed points of each tooth to obtain segmented teeth.

[0162] Optionally, the purpose of the above-mentioned three-dimensional tooth model segmentation method is to accurately segment each tooth on the three-dimensional tooth model into individual teeth.

[0163] The aforementioned 3D dental model can be an intraoral scan model, which refers to a 3D model including the user's teeth generated by scanning the inside of the user's mouth. The data of the 3D dental model is stored on a computer or server, and its shape or style can be displayed on a screen for the doctor's convenience.

[0164] The aforementioned two-dimensional projection image can be an image obtained by projecting a three-dimensional tooth model onto a plane. The two-dimensional projection image includes both tooth and non-tooth regions. By recognizing the two-dimensional projection image, multiple tooth regions can be identified, thereby segmenting the teeth on the three-dimensional tooth model. The recognition method can employ machine vision or artificial intelligence to identify the tooth regions from the two-dimensional projection image.

[0165] The surface of a 3D tooth model is composed of polygonal patches, such as triangular patches. A triangular patch contains three vertices, and all vertices of the triangular patches can be considered seed points. The aforementioned original seed points are the seed points among all seed points in the 3D tooth model that correspond to the tooth region in the 2D projection image. In other words, the tooth region can be initially determined on the 3D tooth model using the original seed points.

[0166] Since the tooth region determined by the original seed point may not be accurate, the original seed point can be expanded to obtain the target seed point. The area covered by the target seed point can be regarded as a tooth on the 3D tooth model. Through the target seed point, the 3D tooth model can be accurately segmented.

[0167] After identifying the tooth region, it can be understood that the location and area of ​​the tooth have been determined on the 2D projection image. Then, this is mapped onto the 3D tooth model to determine the initial seed points on the 3D tooth model. Since the seed points are the vertices of the triangular facets on the surface of the 3D tooth model, the initial seed points can be understood as covering the area of ​​the tooth on the 3D tooth model. To ensure accuracy, the initial seed points are further expanded to obtain target seed points. Based on the target seed points, the 3D tooth model is segmented to obtain segmented teeth. Thus, the teeth in the 3D tooth model can be divided into individual teeth.

[0168] The above method identifies the original seed points on the three-dimensional tooth model by recognizing the two-dimensional projection image of the three-dimensional tooth model, and expands the original seed points to obtain target seed points. The range of teeth on the three-dimensional tooth model is marked by the target seed points. Furthermore, the three-dimensional tooth model can be segmented according to the target seed points to obtain segmented teeth, thereby achieving the effect of accurately segmenting teeth in the three-dimensional tooth model.

[0169] Optionally, in this embodiment, after obtaining the original seed point, the original seed point can be expanded to obtain the target seed point. The process of expanding the original seed point can be divided into one or more stages.

[0170] For example, in one stage, the original seed point can be expanded according to a preset curvature threshold to obtain the target seed point. The preset curvature threshold can be understood as a constraint used when expanding the original seed point to prevent the expansion from exceeding the limit. The preset curvature threshold can include one or more curvature values. If the preset curvature threshold includes one curvature value, the original seed point can be expanded according to that single curvature value to obtain the target seed point. If the preset curvature threshold includes multiple curvature values, the first curvature value can be used to expand the original seed point, then the second curvature value can be used to expand the result of the expansion of the first curvature value, and the third curvature value can be used to expand the result of the expansion of the second curvature value, and so on, until all curvature values ​​have been used once.

[0171] As an optional example, expanding the original seed point according to a preset curvature threshold to obtain the target seed point includes: expanding the original seed point according to an initial curvature threshold to obtain a first seed point; expanding the first seed point according to a target curvature threshold to obtain the target seed point, wherein the target curvature threshold is obtained based on the initial curvature threshold.

[0172] Taking a preset curvature threshold consisting of an initial curvature threshold and a target curvature threshold as an example, the original seed point is first expanded using the initial curvature threshold to obtain the first seed point. Then, the first seed point is expanded using the target curvature threshold to obtain the target seed point. The initial curvature threshold and the target curvature threshold can be the same or different. Through these two expansions, the target seed point is obtained.

[0173] As an optional example, expanding the original seed point according to the initial curvature threshold to obtain the first seed point includes: taking the seed point adjacent to the original seed point as the current seed point; and taking the current seed point and the original seed point as the first seed point if the curvature of the current seed point is less than or equal to the initial curvature threshold.

[0174] In this embodiment, when expanding the original seed point using an initial curvature threshold, the curvature of the seed points adjacent to the original seed point can be obtained. Curvature is the rate of rotation of the tangent direction angle with respect to the arc length at a point on the curve, defined by differentiation, indicating the degree to which the curve deviates from a straight line. It is a numerical value indicating the degree of curvature of the curve at a point. Each seed point corresponds to a curvature. By comparing the curvature with the initial curvature threshold, it is determined whether the seed points adjacent to the original seed point can be used as the first seed point. The original seed point can be used as the first seed point without comparing its curvature.

[0175] Here, "adjacent" as mentioned below can be understood as two vertices that form the same edge of the same triangular facet as the seed point. For example, "adjacent" to the original seed point means two vertices that form the same edge of the same triangular facet as the original seed point.

[0176] As an optional example, expanding the first seed point according to the target curvature threshold to obtain the target seed point includes: taking the seed point adjacent to the first seed point as the current seed point; and taking the first seed point and the current seed point as the target seed point if the curvature of the current seed point is less than or equal to the target curvature threshold.

[0177] After expanding the original seed point using an initial curvature threshold to obtain the first seed point, the first seed point can be expanded using a target curvature threshold to obtain the target seed point. The curvature of the seed points adjacent to the first seed point is determined, and then this curvature is compared with the target curvature threshold. By comparing their magnitudes, it is determined whether a seed point adjacent to the first seed point is a target seed point. This completes the process of expanding the original seed point to obtain the target seed point using the initial curvature threshold and the target curvature threshold.

[0178] As an optional example, before expanding the first seed point according to the target curvature threshold to obtain the target seed point, the above method further includes: using the sum of the initial curvature threshold and a preset value as the target curvature threshold, wherein the preset value is a positive number.

[0179] Optionally, in this embodiment, the initial curvature threshold and the target curvature threshold can be empirical values, or the initial curvature threshold can be an empirical value, and the target curvature threshold can be determined based on the initial curvature threshold. For example, the sum of the initial curvature threshold and a preset value can be used as the target curvature threshold, that is, the target curvature threshold is obtained based on the initial curvature threshold, and the target curvature threshold is greater than the initial curvature threshold. The preset value is a pre-set value that can be modified according to different three-dimensional tooth models.

[0180] As an optional example, after expanding the original seed point according to the initial curvature threshold to obtain the first seed point, or expanding the first seed point according to the target curvature threshold to obtain the target seed point, the above method further includes: if the corresponding point of the first seed point on the two-dimensional projection image does not fall into the corresponding tooth region, adjusting the first seed point to a non-first seed point; or if the corresponding point of the target seed point on the two-dimensional projection image does not fall into the corresponding tooth region, adjusting the target seed point to a non-target seed point.

[0181] Optionally, in this embodiment, when expanding the original seed point according to the initial curvature threshold or expanding the first seed point according to the target curvature threshold, it is also necessary to check whether the expanded seed point meets the requirements, that is, whether the expansion exceeds the range, and whether a seed point in a non-tooth region is used as the first seed point or a seed point in a non-tooth region is used as the target seed point. For example, when expanding the original seed point according to the initial curvature threshold, if the curvature of a seed point adjacent to the original seed point is less than or equal to the initial curvature threshold, it is also necessary to determine the region where the corresponding point of the seed point is located in the two-dimensional projection image. If it is not located in the tooth region, it means that the seed point has been removed from the tooth region of the three-dimensional tooth model, and therefore, the seed point should be regarded as a non-first seed point. When expanding the first seed point according to the target curvature threshold, if the curvature of a seed point adjacent to the first seed point is less than or equal to the target curvature threshold, it is also necessary to determine the region where the corresponding point of the seed point is located in the two-dimensional projection image. If it is not located in the tooth region, it means that the seed point has been removed from the tooth region of the three-dimensional tooth model, and therefore, the seed point should be regarded as a non-target seed point.

[0182] As an optional example, after expanding the original seed points according to the curvature threshold to obtain the target seed points, and before segmenting the three-dimensional tooth model based on the target seed points of each tooth to obtain the segmented teeth, the above method further includes: expanding the regions obtained by expanding multiple tooth regions to obtain the target region; and expanding the target seed points in the target region according to the initial curvature threshold and height.

[0183] After expanding the original seed points to obtain target seed points, the teeth of the 3D tooth model can be segmented according to the target seed points. Furthermore, the target seed points can be expanded again before segmenting the teeth. That is, in addition to the first stage of expansion using initial and target curvature thresholds to obtain target seed points, a second stage of expansion can be performed.

[0184] In the second stage of expansion, the tooth region on the 2D projection image can be adjusted first to expand the tooth region and obtain the target region. Then, using the target region as a constraint, the target seed points are expanded in the second stage using the initial curvature threshold and height. The purpose of expanding the tooth region into the target region is to ensure that all seed points located on the teeth in the 3D tooth model are marked as target seed points, avoiding omissions.

[0185] As an optional example, when expanding the target seed point according to the initial curvature threshold and height, the seed point adjacent to the target seed point can be used as the current seed point; if the height of the current seed point is greater than the preset standard height and the curvature of the current seed point is less than or equal to the target curvature threshold, the current seed point can be used as the target seed point.

[0186] The height mentioned above can be the numerical value of the seed point in a preset direction of the 3D tooth model. For example, the preset direction of the 3D tooth model can be used as the Z-axis, and the coordinate value of the seed point on the Z-axis can be used as the height of the seed point.

[0187] The preset direction can be any direction. After obtaining the 3D tooth model, the orientation of the 3D tooth model can be adjusted to the preset direction, thereby unifying the orientation of all obtained 3D tooth models.

[0188] When expanding a target seed point using an initial curvature threshold and height, a seed point adjacent to the target seed point can be used as the current seed point. If the curvature and height values ​​of the current seed point meet the requirements of the initial curvature threshold and height, then the current seed point can be used as the target seed point, thereby completing the expansion of the target seed point.

[0189] As an optional example, when the height of the current seed point is greater than a preset standard height and the curvature of the current seed point is less than or equal to a target curvature threshold, using the current seed point as a target seed point includes: when the height of the current seed point is greater than the standard height, the curvature of the current seed point is less than or equal to the target curvature threshold, and the corresponding point of the current seed point on the two-dimensional projection image is located within the target region, the current seed point is used as a target seed point, where the target region is the region obtained after enlarging multiple tooth regions; when the corresponding point of the current seed point on the two-dimensional projection image is located outside the target region, the current seed point is used as a non-target seed point.

[0190] Optionally, when expanding the target seed point using the initial curvature threshold and height, it is essential to ensure that the expanded target seed point does not exceed the target region. The target region is the area obtained after expanding the tooth region. The purpose of expanding the tooth region is to include a portion of the non-tooth region near the tooth region within the target region. This allows the target seed point to extend into the non-tooth region near the tooth region when expanding the target seed point using the initial curvature threshold and height. This ensures that the expanded target seed point covers the entire tooth region.

[0191] As an optional example, after expanding the target seed point according to the initial curvature threshold and height, the above method further includes: taking the seed point adjacent to the expanded target seed point as the current seed point; and taking the current seed point as the target seed point as well.

[0192] After expanding the target seed point using the initial curvature threshold and height, the expanded target seed point can be expanded again, with adjacent seed points also used as target seed points. The purpose of this expansion is also to ensure that the expanded target seed point covers the entire tooth area, so that when segmenting the tooth according to the expanded target seed point, the tooth remains intact.

[0193] As an optional example, before expanding the original seed points within a preset range, the method further includes: expanding multiple tooth regions to obtain a target region; marking points in the target region other than those on the three-dimensional tooth model as third seed points; and expanding the third seed points according to a curvature threshold.

[0194] In this embodiment, the target region is first expanded to include all tooth areas, as well as non-tooth areas near the teeth. Therefore, when points outside the target region on the 3D tooth model are marked as third seed points, these third seed points are not points on the teeth. Expanding the third seed points allows points near the teeth in non-tooth areas (gingival areas or gaps between teeth) to be marked as third seed points. This brings the boundary between the non-tooth and tooth areas closer to the teeth, reducing the size of the target region. While the target region includes non-tooth areas, it contains fewer non-tooth areas.

[0195] After expanding the third seed point, the dividing line between the tooth part and the part outside the tooth on the 3D tooth model will become "thinner".

[0196] As an optional example, expanding the third seed point according to the curvature threshold includes: taking the seed point adjacent to the third seed point as the current seed point; and taking the current seed point as the third seed point if the curvature of the current seed point is greater than the curvature threshold.

[0197] In this embodiment, when expanding the third seed point, it can be expanded according to curvature and a curvature threshold. The curvature of the third seed point can be calculated by differentiating the rate of rotation of the tangent direction angle with respect to the arc length at that point. The curvature threshold can be a preset threshold, and the curvature threshold can be different for different three-dimensional tooth models.

[0198] As an optional example, after taking the seed point adjacent to the third seed point as the current seed point, the method further includes: taking the current seed point as a non-third seed point if the point corresponding to the current seed point in the two-dimensional projection image is located within the target area.

[0199] After expanding the third seed point, it's necessary to check if it has expanded into the target region. Since the target region includes the tooth area, if the third seed point expands into the target region, it may have expanded into the tooth area. Therefore, any third seed points located within the target region should be reverted and treated as non-third seed points.

[0200] As an optional example, after expanding the third seed point according to the curvature threshold, the above method further includes: determining a first region composed of the third seed point; determining a sub-region from the first region; and determining the seed point in the sub-region as the target seed point if the sub-region is surrounded by the target seed point.

[0201] Optionally, in this embodiment, after expanding the third seed point, the third seed point forms a first region. The first region can be divided into multiple sub-regions. Each of the multiple sub-regions can be understood as a region composed of multiple third seed points. If a certain sub-region is surrounded by a target seed point, it means that the sub-region is located within the tooth part in the three-dimensional tooth model, but the sub-region may not be a tooth, that is, the hole part on the tooth. Therefore, the seed point of the sub-region should be used as the target seed point and divided into the tooth part.

[0202] In one optional example, the generated orthodontic guide can be used during orthodontic treatment. The brackets are fixed to the teeth via bracket attachments on the guide. The brackets and bracket attachments can then be separated, and the bracket attachments can be removed from the retention body. After the brackets are fixed to the teeth, the archwire is passed through the brackets, thereby pulling the archwire. The archwire moves the brackets, thus shifting the position of the teeth and achieving the orthodontic effect.

[0203] like Figure 15 As shown, the combined orthodontic guide plate in this embodiment includes: a retention body 102 and a bracket attachment 104. The bracket attachment 104 is provided with a receiving cavity 106 for accommodating the bracket. The bracket attachment is rotatably connected to the retention body 102.

[0204] In this embodiment, the bracket accessory and the retaining body can be fixedly connected or detachably connected, for example... Figure 1 In the diagram, the bracket attachment 104 and the retaining body 102 are detachably connected. For clarity, they are not shown in the connected state.

[0205] The combined orthodontic guide plate in this embodiment serves to assist in fixing the brackets to the teeth. Only after the brackets are fixed to the teeth can the archwire be threaded through them, and the orthodontic treatment can then be performed by adjusting the archwire.

[0206] like Figure 15 As shown, the user's teeth can bite onto the retention body 102, with the tooth surface facing the bracket attachment 104. The receiving cavity 106 on the bracket attachment 104 can accommodate the bracket, thereby fixing the bracket to the tooth surface. Since there is a rotatable connection between the retention body 102 and the bracket attachment 104, the bracket can be moved closer to or away from the tooth surface by rotating the bracket attachment 104.

[0207] After the bracket is secured to the tooth surface, the bracket attachment can be rotated again to move it away from the tooth surface, while the bracket remains fixed to the tooth. Once the bracket attachment is away from the tooth surface, the user can open their mouth and remove the retention unit and bracket attachment from their oral cavity.

[0208] Optionally, in this embodiment, the combined orthodontic guide plate further includes a snap-fit ​​assembly, which includes a first snap-fit ​​fitting disposed on the bracket attachment and a second snap-fit ​​fitting disposed on the fixation body, wherein the first snap-fit ​​fitting and the second snap-fit ​​fitting are rotatably connected.

[0209] In other words, in this embodiment, the bracket accessory and the retaining body can be connected through the mutual connection of the first snap-fit ​​component and the second snap-fit ​​component. For example, as Figure 16 As shown, the first snap-fit ​​component 202 on the bracket accessory and the second snap-fit ​​component 204 on the retaining body are rotatably connected.

[0210] Optionally, in this embodiment, the rotation angle range of the first snap-fit ​​component and the second snap-fit ​​component is 0 to 270 degrees. For each second snap-fit ​​component, its length satisfies the following condition: when the target bracket is fixed in place in the bracket accessory and the first snap-fit ​​component is rotated to the target angle, the length of the second snap-fit ​​component makes the target bracket fit against the tooth surface.

[0211] For example, such as Figure 17 As shown, Figure 3 In the diagram, the bracket accessory is enclosed by a dashed box 302. The dashed lines indicate the movable positions of the bracket accessory, while the solid lines indicate its position when the bracket is installed on the tooth. 304 represents the retention body. The first snap-fit ​​component 306 on the bracket accessory and the second snap-fit ​​component 308 on the retention body are rotatably connected. The arrow indicates the rotatable angle of the bracket accessory, which is 270 degrees.

[0212] Optionally, in this embodiment, the first and second snap-fit ​​components are detachably connected. That is, in this embodiment, the first and second snap-fit ​​components can be disassembled and separated, and after disassembly and separation, the fixing body and the bracket accessory are also separated.

[0213] Optionally, in this embodiment, the second snap-fit ​​component includes a connecting arm and a snap-fit ​​locating component. The connecting arm includes a first connecting arm and a second connecting arm. The snap-fit ​​locating component is laterally disposed in the middle of the first connecting arm and the second connecting arm to connect the first connecting arm and the second connecting arm respectively.

[0214] In other words, in this embodiment, the second snap-fit ​​component includes two connecting arms, and the second connecting arm and the first connecting arm are fixed together by the two connecting arms and the snap-fit ​​fitting between the two connecting arms. For example, as Figure 18 As shown, Figure 18In this assembly, the second snap-fit ​​component 402 of the retaining body and the first snap-fit ​​component 404 of the bracket accessory are connected. The second snap-fit ​​component 402 of the retaining body includes a connecting arm 406 and a snap-fit ​​mating component 408. There are two connecting arms 406, namely a first connecting arm and a second connecting arm. The snap-fit ​​mating component 408 is located between the two connecting arms. The snap-fit ​​mating component 408 can cooperate with the first snap-fit ​​component to rotatably connect the bracket accessory and the retaining body.

[0215] Optionally, in this embodiment, the bracket attachment corresponds one-to-one with the patient's teeth, and the bracket attachment is provided with a tooth position label, which is used to display the tooth position number of the corresponding tooth.

[0216] Optionally, in this embodiment, the number of brackets and bracket attachments is determined based on the number of the patient's teeth. Generally, one bracket corresponds to one tooth, and one bracket corresponds to one bracket attachment. Each bracket attachment is connected to the retention body via a first snap-fit ​​element and a second snap-fit ​​element. For example, as... Figure 19 As shown, Figure 19 In this system, each tooth corresponds to one bracket, and each bracket corresponds to one bracket attachment. The bracket attachment is connected to the retention body via a first and a second snap-fit ​​component. Once the user's tooth is engaged in the retention body, the bracket attachment can be rotated to fit the bracket onto the tooth surface, thus securing the bracket to the tooth surface through adhesive. Each bracket attachment is marked with a tooth position label, and the label number can be determined according to the tooth's condition, position, or the order of procedures.

[0217] Optionally, in this embodiment, the bracket attachment includes a support member and a bracket fixing member. The bottom of the support member is connected to the first snap-fit ​​member, the back of the support member is used to set the tooth position label corresponding to the tooth position, and the front of the support member is connected to the bracket fixing member near the top. The bracket fixing member includes a first support surface, a second support surface, and a third support surface. The first support surface, the second support surface, and the third support surface form a receiving cavity for accommodating the bracket. The receiving cavity is used to surround the bracket from three sides, so that the bracket can be moved closer to or away from the tooth surface by rotating the bracket attachment relative to the retention body.

[0218] Optionally, in this embodiment, the front surfaces of the first support surface, the second support surface, and the third support surface form a concave surrounding surface. When the concave surrounding surface surrounds the target bracket, the top of the concave surrounding surface exposes the target cleaning space. The target cleaning space is used to clean the adhesive that overflows around the bracket base, the occlusal side, and the gingival side when the target bracket is bonded to the tooth with adhesive.

[0219] In other words, in this embodiment, the support member connects the first snap-fit ​​component and the bracket fixing component. The bracket fixing component holds the bracket, and the support member can also have a tooth position label on its back for marking the tooth number. For example, as... Figure 20 As shown, Figure 20 In this bracket attachment, the support has a tooth position label, and the bracket retainer 602 is a concave groove that surrounds the left, front, and right sides of the bracket 604. After the bracket is placed in the bracket retainer 602 of the bracket attachment, the bracket 604 can be moved closer to or away from the tooth by rotating the bracket attachment. After the bracket 604 is close to and bonded to the tooth, the bracket 604 can be separated from the bracket retainer 602 of the bracket attachment.

[0220] By placing the bracket in the concave surrounding surface formed by the first, second, and third support surfaces of the bracket retainer, the position of the bracket can be easily moved. When it is necessary to bond the bracket to the tooth, simply rotate the bracket attachment to fix the bracket to the tooth. After the bracket is bonded to the tooth, the adhesive can be cleaned through the target cleaning space. The target cleaning space is the space above the bracket and the bracket retainer.

[0221] Optionally, in this embodiment, the second snap-fit ​​component corresponds one-to-one with the patient's teeth. The second snap-fit ​​component is positioned on the retention body and faces outward in the direction perpendicular to the target cutting plane of the corresponding tooth. The target cutting plane is a cutting plane with the center point of the clinical crown of the corresponding tooth as the cutting point. The midline of the second snap-fit ​​component coincides with the extension line of the long axis of the clinical crown of the corresponding tooth.

[0222] For example, such as Figure 6 As shown, Figure 6 This diagram illustrates the connection between the bracket attachments and the retention body to secure the bracket to the bracket. The teeth can bite into the retention body. By rotating the bracket attachments, the bracket is brought closer to the teeth. Each bracket attachment can be rotated individually; only the attachment for the desired bracket is rotated. Once the bracket attachment is close to the teeth and the bracket is fitted, adhesive can be used to bond the bracket to the teeth. After the bracket is secured, the bracket attachment can be removed by rotating it. After all brackets are bonded to the teeth, the bracket attachments and retention body can be removed.

[0223] After the dentist has pre-treated the patient's teeth, they will place the self-adaptive guide with adhesive onto the teeth in the patient's mouth. Any excess adhesive around the bracket can be scraped off with a probe and then light-cured. When separating the guide from the bracket, a probe can be used to separate the bracket from the retention body one by one from the guide's snap-fit ​​assembly. Then, the guide is removed, and the entire guide is taken out of the mouth. It is then reinforced and cured again from the occlusal side to complete the bracket bonding.

[0224] Optionally, in this embodiment, the retaining body and the second snap-fit ​​component are integrally formed structures, and the bracket accessory and the first snap-fit ​​component are integrally formed structures.

[0225] In this embodiment, the retaining body and the second snap-fit ​​component are integrally formed, as are the bracket accessory and the first snap-fit ​​component. This can increase the hardness between the retaining body and the second snap-fit ​​component, as well as between the bracket accessory and the first snap-fit ​​component. The first snap-fit ​​component and the second snap-fit ​​component can be connected or separated, which facilitates the installation and replacement of the bracket accessory and the retaining body.

[0226] Optionally, this embodiment may include a doctor's end and a technician's end. The doctor's end and the technician's end can cooperate with each other to determine the accurate target bracket position and further generate a suitable orthodontic guide plate.

[0227] Figure 21 This is a flowchart of this embodiment.

[0228] Step 1: The doctor submits the necessary data for bracket positioning. This data includes intraoral photos, facial photos, digital dental models, bracket brand information used in the cone-beam computed tomography (CBCT) imaging system, and the orthodontic plan.

[0229] The intraoral and facial photographs in the above steps are primarily for obtaining complete patient information. They allow for verification of the match between the digital dental model obtained from the intraoral scan and the actual teeth, thus checking the accuracy of the digital dental model and determining if it has been misrepresented. Furthermore, the digital dental model is a model of the upper and lower jaws; the midlines of the upper and lower teeth are not aligned, making it unclear whether the deviation is maxillary or mandibular based solely on the model. However, combining the facial or intraoral photographs can determine whether the deviation is maxillary or mandibular. During subsequent tooth alignment, normally the midlines of the upper and lower teeth are aligned, but for teeth requiring correction, the midlines are misaligned. During orthodontic treatment, it's crucial to determine whether to use the maxillary or mandibular midline for tooth alignment. Facial photographs can be used to select a dental midline corresponding to the facial midline as a reference for tooth alignment.

[0230] Step 2: The technician receives the data submitted by the doctor and adds a base to the digital dental model.

[0231] The base can be a C-shaped base to save printing material, or other types of bases; no limitation is made here. Generally, the distance between the bottom surface of the C-shaped base and the neck edge is about 4mm, but this distance can be adjusted according to actual needs. Since the digital dental model is obtained through oral scanning and the digital teeth are hollow, adjusting the position of the bottom surface of the base and the neck edge ensures that the digital dental model after adding the base is a sealed whole, facilitating subsequent guide plate design and model printing.

[0232] Step 3: Separate the teeth, that is, separate the teeth from the gums.

[0233] Specifically, the mesiodistal diameter of the tooth crown is first determined, and then a cervical margin line corresponding to the mesiodistal diameter is generated. The cervical margin line can be referenced from tooth segmentation techniques used in this field or by our company. After generation, the cervical margin line can be manually adjusted to accommodate the separation of the tooth crown and gingiva. The mesiodistal diameter refers to the straight-line distance from the mesial to the distal end of the tooth, defining its width.

[0234] Step 4: Determine the target position for the pre-arrangement of the crowns according to the orthodontic plan.

[0235] The orthodontic plan refers to the doctor's treatment requirements, such as whether tooth extraction is necessary, and what existing problems the doctor wants to address, such as extracting four fourth molars to correct crowding of the front teeth and improve facial protrusion. Based on the treatment requirements in the orthodontic plan, the technician determines the position of the tooth crowns after correction (pre-alignment target position). Note: This part can be automatically determined by the system, or it can be determined by receiving instructions from the technician. The technician's tooth alignment methods can include rotation, tilting, torque, mesiodistal or labial-buccal-lingual translation, etc., manually adjusting the position of each tooth in the dentition to ensure each tooth is in the target position. This allows the technician to access the doctor's orthodontic plan in real time for reference and alignment as needed.

[0236] Step 5: Determine the FACC and FA points of the tooth in the pre-arrangement target position, and locate the brackets according to the clinical coronal center method to determine the position of the first bracket of the tooth in the pre-arrangement target position.

[0237] FACC: Facial Axis of the Clinical Crown. For teeth other than a few, the facial axis of the clinical crown is located at the most prominent part of the central buccal lobe of the crown. For molars, the facial axis is the buccal groove between the two large buccal cusps. FA point: Facial-Axis point, the center of the clinical crown, located at the equilateral bisection of the facial axis in the gingival direction. Brackets will be placed using the pre-determined FACC and FA points. The vertical portion of the bracket's ligature wings will be parallel to the FACC, ensuring the bracket's central axis overlaps with the FACC. Then, the center point of the bracket will overlap with the FA point. Viewed from the distal surface of the tooth, the FA point of the crown, the landmark point on the bracket base, and the midpoint of the groove bottom should be on the same plane.

[0238] Step 6: Determine the position of the second bracket for the tooth in its original position based on the position of the tooth in its original position (the position of the tooth in the digital tooth model obtained by oral scan), the pre-arrangement target position of the crown, and the position of the first bracket.

[0239] The relative position of the bracket and the tooth is fixed. Based on this relative position, the position of the second bracket can be determined.

[0240] Step 7: The technician sends the digital dental model (including the base, teeth, and brackets) and the second bracket position to the doctor. The doctor performs the final review of the bracket positioning and can make corrections to the bracket tilt, mesiodistal position, and vertical translation to obtain the third bracket position. After modification, the position is saved and synchronized to the technician's end.

[0241] The third bracket position can be the same as the second bracket position, meaning the doctor has not changed the bracket position. The third bracket position is used as the target bracket position.

[0242] Step 8: Based on the location of the third bracket, the technician draws and generates the bracket retention device, and selects the attachment structure corresponding to the tooth position label to place on the labial and buccal surfaces of the tooth. The tooth retention component is created and combined with the bracket attachment to complete the adaptive indirect bonding guide design, which is then sent to the printer for printing. After post-printing processing, it can be applied to clinical bracket bonding.

[0243] The placement angle of the attachment on the labial and buccal surfaces of the bracket retention device can be manually adjusted. The steps for selecting the attachment structure are as follows: select individual teeth in sequence according to the tooth position code of the numerical marking tooth position recording method, and then select the attachment structure corresponding to the tooth position number in the database for placement.

[0244] It should be noted that steps 1 to 8 above are an optional example. In this embodiment, the doctor and technician can use the same terminal for dental adjustments, or they can use different terminals. The doctor and technician can also be the same person.

[0245] In steps 6, 7, and 8 above, determining the target bracket position can also be achieved through the following steps:

[0246] The technician sends the digital dental model (including the base, teeth, and brackets) and the first bracket position to the dentist. The dentist adjusts the first bracket position to obtain the fourth bracket position and synchronizes it back to the technician. The technician receives the fourth bracket position and, based on the position of the teeth in the original position (the position of the teeth in the digital dental model obtained from the intraoral scan), the pre-aligned target position of the crowns, and the fourth bracket position, determines the target bracket position in the original position. The target bracket position is used for guide plate design.

[0247] According to another aspect of the embodiments of this application, such as Figure 22 As shown, an apparatus is provided, including: a memory 801 and a processor 803, the memory storing a computer program, the computer program being executed by the processor to perform the above-described method for generating an orthodontic guide plate.

[0248] It should be noted that the examples and application scenarios implemented by the above modules and corresponding steps are the same, but are not limited to the content disclosed in the above embodiments. It should also be noted that the above modules, as part of a device, can operate in environments such as... Figure 1 The hardware environment shown can be implemented either through software or hardware. The device may also include other components, such as the communication interface 805 and the connecting cable 807.

[0249] According to another aspect of the embodiments of this application, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the steps of any of the above embodiments.

[0250] According to another aspect of the embodiments of this application, an electronic device is provided, including a memory, a processor, a communication interface and a communication bus. The memory stores a computer program that can run on the processor. The memory and the processor communicate with each other through the communication bus and the communication interface. When the processor executes the computer program, it implements the steps of the above-described three-dimensional tooth model segmentation method.

[0251] In specific implementation, the embodiments of this application can be referred to the above embodiments and have corresponding technical effects.

[0252] It is understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described herein, or combinations thereof.

[0253] For software implementation, the techniques described herein can be implemented by units that perform the functions described herein. The software code can be stored in memory and executed by a processor. The memory can be implemented in the processor or external to the processor.

[0254] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0255] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs. Additionally, the functional units in the various embodiments of this application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. If the function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, or the parts that contribute to the prior art, or parts of the technical solutions, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks. It should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application.Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method of generating an orthodontic guide, characterized by, The method comprises the following steps: receiving a tooth model with a base, and performing tooth separation processing on the tooth model with the base to obtain a first tooth model, the first tooth model comprising a plurality of teeth in original tooth positions; determining pre-alignment target positions of the teeth after orthodontic treatment; determining first bracket positions of the teeth in the pre-alignment target positions, and determining target bracket positions of the teeth in the original tooth positions based on the pre-alignment target positions, the first bracket positions, and the original tooth positions; generating an orthodontic guide plate based on the target bracket positions; wherein the tooth separation processing on the tooth model with the base to obtain the first tooth model comprises: obtaining a gum line and a tooth region of the tooth model with the base; extracting peak points of the gum line, and pairing the peak points to obtain a peak point combination; determining a segmentation path between the teeth in the tooth region based on the peak point combination; and performing segmentation processing on the tooth region according to the segmentation path to obtain the first tooth model; or the tooth separation processing on the tooth model with the base to obtain the first tooth model comprises: obtaining a two-dimensional projection image of the tooth model with the base, and identifying the two-dimensional projection image to obtain a plurality of tooth regions; identifying original seed points corresponding to the plurality of tooth regions in the tooth model with the base; expanding the original seed points within a preset range to obtain target seed points of the teeth in the tooth model with the base; and performing segmentation processing on the tooth model with the base based on the target seed points of the teeth to obtain the first tooth model.

2. The method of claim 1, wherein, determining the target bracket positions of the teeth in the original tooth positions comprises: determining a tooth position offset relationship according to the original tooth positions and the pre-alignment target positions; identifying second bracket positions of the teeth in the original tooth positions according to the first bracket positions, relative position relationships of the teeth in the pre-alignment target positions, and the tooth position offset relationship; transmitting the second bracket positions externally, and receiving returned third bracket positions corresponding to the second bracket positions; determining the third bracket positions as the target bracket positions.

3. The method of claim 1, wherein, determining the target bracket positions of the teeth in the original tooth positions comprises: sending the first tooth model and the first bracket positions externally, and receiving returned fourth bracket positions corresponding to the first bracket positions; determining a tooth position offset relationship according to the original tooth positions and the pre-alignment target positions; determining fifth bracket positions of the teeth in the original tooth positions according to the tooth position offset relationship, relative position relationships of the fourth bracket positions and the teeth in the pre-alignment target positions; determining the fifth bracket positions as the target bracket positions.

4. The method of claim 1, wherein, determining the pre-alignment target positions of the teeth after orthodontic treatment comprises: performing tooth arrangement on the first tooth model to determine a position of each tooth in the first tooth model in the dentition; performing simulation treatment on the first tooth model according to the tooth treatment strategy, and recording position offset information of each tooth during the simulation treatment to obtain the pre-arrangement target position after tooth treatment; and / or, receiving an adjustment instruction input by a target user, and adjusting the position of each tooth in the dentition according to the adjustment instruction to obtain the pre-arrangement target position after tooth treatment.

5. The method of claim 4, wherein, The performing tooth arrangement on the first tooth model comprises: obtaining an intraoral photograph and a facial photograph of a patient corresponding to the first tooth model; determining an actual original position of the teeth of the patient based on the intraoral photograph and the facial photograph, and determining a shift position using the actual original position, wherein the shift position includes the upper jaw or the lower jaw of the patient; determining a facial midline of the patient using the facial photograph, and determining a dental midline of the upper jaw or the lower jaw of the patient using the intraoral photograph, wherein the dental midline corresponds to the facial midline; performing tooth arrangement on the shift position based on the dental midline.

6. The method of claim 5, wherein, After determining the actual original position of the teeth of the patient based on the intraoral photograph and the facial photograph, the method further comprises: in a case where the actual original position of the teeth of the patient and the position of each tooth in the first tooth model do not completely match, sending a miscommunication prompt information.

7. The method of claim 1, wherein, The first bracket position includes a center point and a central axis of the bracket; determining the first bracket position of the tooth in the pre-arrangement target position comprises: determining a clinical crown long axis and a clinical crown center point of the tooth in the pre-arrangement target position on the first tooth model; determining the clinical crown center point as the center point and determining the clinical crown long axis as the central axis.

8. The method of claim 1, wherein, The generating a target orthodontic guide plate based on the target bracket position comprises: generating a retaining component of the bracket according to the target bracket position; selecting a bracket accessory corresponding to a tooth position label, and placing the bracket accessory on a corresponding tooth labial buccal surface; combining the retaining component with the corresponding bracket accessory to obtain the target orthodontic guide plate.

9. The method of claim 1, wherein, extracting the wave peak point of the gum line comprises: determining a coordinate value of each point on the gum line based on a target orientation of the tooth model with a base; determining the wave peak point from the gum line according to the coordinate value, wherein the coordinate value of the wave peak point is greater than the coordinate value of adjacent points of the wave peak point on the gum line.

10. The method of claim 1, wherein, pairing the wave peak points to obtain the wave peak point combination comprises: dividing the wave peak points into a first wave peak point group and a second wave peak point group according to a positional relationship between the wave peak points and the tooth model with a base; combining each of the first wave crest points as a first wave crest point with a second wave crest point in the second wave crest point group as a group of wave crest points, wherein the second wave crest point is the closest wave crest point in the second wave crest point group to the first wave crest point, and an angle between a line connecting the first wave crest point and the second wave crest point and a dental median line of the dental model with a base is greater than a third threshold value.

11. The method of generating a malguide according to claim 10, wherein, After the first wave crest point and the second wave crest point in the second wave crest point group are combined as a group of wave crest points, the method further comprises: deleting the successfully paired wave crest points from the first wave crest point group and the second wave crest point group; combining each of the second wave crest points as a third wave crest point with a fourth wave crest point in the first wave crest point group as a group of wave crest points, wherein the fourth wave crest point is the closest wave crest point in the first wave crest point group to the third wave crest point, and an angle between a line connecting the third wave crest point and the fourth wave crest point and a dental median line of the dental model with a base is greater than a third threshold value.

12. The method of claim 1, wherein, The dental model with a base comprises a plurality of polygonal patches; obtaining a gum line of the dental model with a base comprises: determining an edge category of an edge of the plurality of polygonal patches, wherein the edge category comprises a tooth edge and a gum edge; determining the gum line of the dental model with a base according to the edge category of the edge.

13. The method of claim 12, wherein: Determining the edge category of the edge of the plurality of polygonal patches comprises: obtaining a target feature of the edge of the plurality of polygonal patches, wherein the target feature comprises a geometric feature; determining the edge category of the edge according to the target feature.

14. The method of claim 13, wherein: Determining the edge category of the edge according to the target feature comprises: dimensioning the target feature of the initial dimension of the edge to obtain a first feature of a first dimension; dimension-reducing the first feature to obtain a second feature of a target dimension; determining whether the edge is a tooth edge or a gum edge according to the value of the second feature.

15. The method of claim 12, wherein: Determining the gum line of the dental model with a base according to the edge category comprises: determining a patch category of the polygonal patch according to the edge category, wherein the patch category comprises a tooth patch and a gum patch; extracting the gum line based on a common edge of the polygonal patches with different and adjacent patch categories.

16. The method of claim 1, wherein: Expanding the original seed point in a preset range to obtain a target seed point of a tooth in the dental model with a base comprises: expanding the original seed point according to an initial curvature threshold to obtain a first seed point; expanding the first seed point according to a target curvature threshold to obtain the target seed point, wherein the target curvature threshold is obtained according to the initial curvature threshold.

17. The method of claim 16, wherein: Expanding the original seed point according to an initial curvature threshold to obtain a first seed point comprises: taking a seed point adjacent to the original seed point as a current seed point; in a case where the curvature of the current seed point is less than or equal to the initial curvature threshold value, taking the current seed point and the original seed point as the first seed point; the expanding the first seed point according to the target curvature threshold value to obtain the target seed point comprises: taking a seed point adjacent to the first seed point as a current seed point; in a case where the curvature of the current seed point is less than or equal to the target curvature threshold value, taking the first seed point and the current seed point as the target seed point.

18. The method of claim 16 or 17, wherein, after the original seed point is expanded according to the initial curvature threshold value to obtain the first seed point, or the first seed point is expanded according to the target curvature threshold value to obtain the target seed point, the method further comprises: in a case where the corresponding point on the two-dimensional projection image does not fall into the corresponding tooth region, adjusting the first seed point to be a non-first seed point; or, in a case where the corresponding point on the two-dimensional projection image does not fall into the corresponding tooth region, adjusting the target seed point to be a non-target seed point; after the original seed point is expanded according to the curvature threshold value to obtain the target seed point, before the tooth model with the base is segmented based on the target seed points of the teeth to obtain segmented teeth, the method further comprises: obtaining a target region from the region obtained after the plurality of tooth regions are expanded; in the target region, expanding the target seed point according to the initial curvature threshold value and the height.

19. An apparatus for generating an orthodontic guide, the apparatus comprising: comprise: a memory and a processor, the memory stores a computer program, and the computer program is executed by the processor to perform the method in any one of claims 1 to 18.

20. 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 steps of the method in any one of claims 1 to 18. the computer program is executed by the processor to implement the steps of the method in any one of claims 1 to 18.

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