Virtual gingiva generation method, device, and computer-readable storage medium

Abstract

The application discloses a virtual gum generation method, equipment and computer readable storage medium, and relates to the field of virtual gum generation. The virtual gum generation method comprises the following steps: acquiring dental arch model data of teeth at multiple tooth positions in a patient's oral cavity; identifying tooth position neck edge lines of the teeth at the multiple tooth positions based on the dental arch model data; fitting the tooth position neck edge lines to obtain a virtual gum base contour line; sequentially determining feature points of the tooth position neck edge lines, wherein the feature points at least comprise a papilla area point, and the papilla area point is on the tooth position neck edge; performing point set sampling on the tooth position neck edge lines between the feature points in the tooth position neck edge lines to obtain sampling points, and determining connecting points corresponding to the sampling points; and fitting the sampling points and the connecting points of the tooth position neck edge lines to generate a virtual gum. The application optimizes the generation mode of the virtual gum.

Description

Technical Field

[0001] This invention relates to the field of image processing, and more particularly to a method, apparatus, and computer-readable storage medium for generating virtual gums. Background Technology

[0002] Orthodontic treatment is one of the most basic procedures in prosthodontics. Currently, clinicians use orthodontic software for orthodontic treatment because the gingival area on the original model is difficult to visualize during the treatment process, while virtual gingiva can better demonstrate these changes. However, current virtual gingiva generation does not distinguish between the papilla areas and directly calculates the lateral curve, making it impossible to control the overall shape from multiple perspectives, resulting in poor virtual gingiva morphology. Summary of the Invention

[0003] The main objective of this invention is to provide a method, device, and computer-readable storage medium for generating virtual gingiva, aiming to solve the technical problem of how to optimize the generated morphology of virtual gingiva.

[0004] To achieve the above objectives, the present invention provides a method for generating virtual gingiva, comprising the following steps:

[0005] Obtain dental arch model data of teeth at multiple positions in the patient's oral cavity, and identify the cervical margin line of each tooth position based on the dental arch model data;

[0006] A virtual gingival base contour line is obtained by fitting the cervical margin line of each tooth position, and the feature points of each cervical margin line of each tooth position are determined in sequence, wherein the feature points include at least the papillary point, which is located on the cervical margin of the tooth position;

[0007] Point set sampling is performed on the cervical margin lines of each tooth position between the characteristic points to obtain sampling points, and the connection points corresponding to the sampling points are determined. The connection points include at least the point with the maximum curvature of the gingival margin region, the lowest point of the lateral gingival margin, and the point closest to the contour line. The point closest to the contour line is on the contour line of the virtual gingival base.

[0008] The sampling points and connection points of each tooth position's cervical margin are fitted to generate a virtual gingiva.

[0009] Optionally, the step of fitting the cervical margin line of each of the teeth to obtain the virtual gingival base contour line includes:

[0010] Determine the cervical margin plane where all the tooth positions are located, and translate the cervical margin plane with a preset gingival height to obtain a virtual gingival base plane;

[0011] Projecting all the cervical margin lines of the teeth onto the virtual gingival base plane yields the first cervical margin line, and extracting the gingival margin vertices of all the first cervical margin lines;

[0012] Fit all the gingival margin vertices to obtain a virtual gingival base contour.

[0013] Optionally, the gingival margin apex includes the innermost point and the outermost point, and the step of extracting all gingival margin apexes of the first cervical margin line includes:

[0014] Determine the center of the cervical margin of each of the first cervical margin lines, and fit all the centers of the cervical margin lines to obtain the virtual gingival base midline;

[0015] Each of the first cervical margin lines is traversed sequentially, and the point set of the traversed first cervical margin lines is sampled to obtain the first cervical margin line point set. It is determined that the first cervical margin line points are concentrated on the inner first cervical margin line points inside the midline of the virtual gingival base, and the first cervical margin line points are concentrated on the outer first cervical margin line points outside the midline of the virtual gingival base.

[0016] Determine the first distance from each of the inner first cervical margin points to the midline of the virtual gingival base, and take the inner first cervical margin point corresponding to the largest first distance among the first distances as the innermost point of the traversed first cervical margin.

[0017] Determine the second distance from each of the outer first cervical margin points to the midline of the virtual gingival base, and take the outer first cervical margin point corresponding to the largest second distance among the second distances as the outermost point of the traversed first cervical margin.

[0018] Optionally, the nipple region point includes the highest point of the target nipple region, and the step of sequentially extracting the feature points of each tooth's cervical margin line includes:

[0019] The cervical margins of each tooth position are traversed sequentially, and the traversed cervical margins of the tooth positions are compared with the target tooth position cervical margins. The adjacent tooth position cervical margins corresponding to the target tooth position cervical margins are then determined.

[0020] Determine the target plane corresponding to the cervical margin line of the target tooth position, perform point set sampling on the cervical margin line of the target tooth position, and obtain the target tooth position cervical margin line point set corresponding to the target tooth position cervical margin line, wherein the target tooth position cervical margin line point set includes multiple target tooth position cervical margin line points;

[0021] Determine the third distance from each target tooth cervical margin point in the target tooth position cervical margin point set to the target plane. Select the target tooth cervical margin point corresponding to the smallest third distance from each third distance as the initial papillary region high point, and use the initial papillary region high point as the target papillary region high point.

[0022] Optionally, before the step of using the initial nipple region elevation as the target nipple region elevation, the following steps are included:

[0023] Point set sampling is performed on the adjacent tooth neck edge line to obtain the adjacent tooth neck edge line point set corresponding to the adjacent tooth neck edge line, wherein the adjacent tooth neck edge line point set includes multiple adjacent tooth neck edge line points.

[0024] The target tooth cervical margin point is traversed sequentially from each target tooth cervical margin point in the target tooth position cervical margin point set. The fourth distance from each target tooth cervical margin point to each adjacent tooth cervical margin point is determined. The fourth distance with the largest distance among the fourth distances is selected as the target distance.

[0025] If the target distance is less than the preset grid distance, the traversed target tooth cervical margin line points are marked as adjacent points. After traversing all target tooth cervical margin line points in the target tooth cervical margin line point set, an adjacent point set composed of the adjacent points is obtained.

[0026] If there are at least two adjacent points in the set of adjacent points, select two adjacent points from the set of adjacent points as the target nipple region high points.

[0027] Optionally, the nipple area point includes the low point of the target nipple area, and the high point of the target nipple area includes the high point of the inner target nipple area and the high point of the outer target nipple area.

[0028] Following the step of using the initial nipple region elevation as the target nipple region elevation, the following steps are included:

[0029] Determine the target gingival margin vertex of the cervical margin line of the target tooth position, wherein the target gingival margin vertex includes the innermost point and the outermost point of the target;

[0030] From the innermost point of the target tooth to the highest point of the inner target papilla area, select one target tooth cervical margin point as the low point of the inner target papilla area;

[0031] From the outermost point of the target tooth to the highest point of the outer target papilla region, select one target tooth cervical margin point as the low point of the outer target papilla region;

[0032] The low point of the inner target nipple region and the low point of the outer target nipple region are taken as the low point of the target nipple region.

[0033] Optionally, the step of determining the connection point corresponding to the sampling point includes:

[0034] Determine the first coordinates of the sampling point in a preset coordinate system, wherein the first coordinates include a first horizontal coordinate and a first vertical coordinate;

[0035] A reference horizontal coordinate is obtained by multiplying the preset gingival margin thickness by the first horizontal coordinate, and a target horizontal coordinate is obtained by multiplying the preset gingival margin thickness ratio by the reference horizontal coordinate. The sum of the target horizontal coordinate and the first horizontal coordinate is used as the second horizontal coordinate.

[0036] The sum of the reference horizontal coordinate and the first horizontal coordinate is taken as the third horizontal coordinate;

[0037] The target vertical coordinate is obtained by multiplying the preset gingival margin height by the first vertical coordinate, and the sum of the target vertical coordinate and the first vertical coordinate is used as the second vertical coordinate;

[0038] The coordinate points corresponding to the second horizontal coordinate and the second vertical coordinate are taken as the points with the maximum curvature of the gingival margin region.

[0039] The coordinate point corresponding to the third horizontal coordinate and the first vertical coordinate is taken as the lowest point of the lateral gingival margin.

[0040] The projection point is obtained by projecting the low point of the outer gingival margin onto the virtual gingival base plane where the virtual gingival base contour line is located. The contour point with the shortest distance to the projection point on the virtual gingival base contour line is determined, and the contour point is taken as the closest point of the contour line corresponding to the sampling point.

[0041] Optionally, the step of generating a virtual gingiva by fitting the sampling points and connection points of each of the tooth positions includes:

[0042] The lateral connection curve is obtained by sequentially fitting the lowest point of the lateral gingival margin of each tooth position to the nearest point of the contour line; the papillary region curve is obtained by sequentially fitting the sampling point, the maximum curvature point of the gingival margin region, and the lowest point of the lateral gingival margin.

[0043] A virtual gingiva is obtained by sequentially connecting the lateral connecting curves of each tooth position with the papillary region curve.

[0044] In addition, to achieve the above objectives, the present invention also provides a virtual gingival generation device, comprising: a memory, a processor, and a virtual gingival generation program stored in the memory and executable on the processor, wherein the virtual gingival generation program, when executed by the processor, implements the steps of the virtual gingival generation method as described above.

[0045] In addition, to achieve the above objectives, the present invention also provides a computer-readable storage medium storing a virtual gingival generation program, which, when executed by a processor, implements the steps of the virtual gingival generation method as described above.

[0046] This application obtains dental arch model data from the patient's oral cavity, identifies the cervical margin lines of teeth at each position based on the dental arch model data, extracts papilla points on the cervical margin lines of each tooth position, performs point set sampling on the cervical margin lines between papilla points to obtain sampling points, and then determines the corresponding connection points. After that, the sampling points and connection points are fitted to generate virtual gingiva, avoiding the phenomenon in the prior art where the generation of virtual gingiva does not distinguish the papilla area, resulting in poor virtual gingiva morphology. This application optimizes the generation morphology of virtual gingiva by extracting papilla points on the cervical margin line and then distinguishing the papilla area to generate virtual gingiva. Attached Figure Description

[0047] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0048] Figure 1 This is a schematic diagram of the terminal / device structure of the hardware operating environment involved in the embodiments of the present invention;

[0049] Figure 2 This is a flowchart illustrating the first embodiment of the virtual gingiva generation method of the present invention;

[0050] Figure 3 This is a schematic diagram of the virtual gingival base outline of the virtual gingival generation method of the present invention;

[0051] Figure 4 This is an illustrative diagram of the virtual gum in the virtual gum generation method of the present invention;

[0052] Figure 5 This is a flowchart illustrating the virtual gingiva generation method of the present invention. Detailed Implementation

[0053] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0054] Reference Figure 1 , Figure 1 This is a schematic diagram of the structure of a virtual gingival generation device in the hardware operating environment of an embodiment of the present invention.

[0055] like Figure 1As shown, the virtual gum generation device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen and an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface). The memory 1005 may be a high-speed random access memory (RAM) or a stable non-volatile memory (NVM), such as a disk drive. The memory 1005 may also optionally be a storage device independent of the aforementioned processor 1001.

[0056] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on the virtual gingival generation device and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0057] like Figure 1 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a data storage module, a network communication module, a user interface module, and a virtual gum generation program.

[0058] exist Figure 1 In the virtual gum generation device shown, the network interface 1004 is mainly used for data communication with other devices; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the virtual gum generation device of the present invention can be set in the virtual gum generation device, and the virtual gum generation device calls the virtual gum generation program stored in the memory 1005 through the processor 1001 and executes the virtual gum generation method provided in the embodiment of the present invention.

[0059] Reference Figure 2 This invention provides a method for generating virtual gingiva. In a first embodiment of the method, the method includes the following steps:

[0060] Step S10: Obtain dental arch model data of multiple teeth in the patient's oral cavity, and identify the cervical margin line of each tooth based on the dental arch model data;

[0061] In this embodiment, multiple tooth positions, including at least one tooth in a specific position, are included. This means that multiple tooth positions at least include one or more teeth requiring orthodontic treatment. A scanning device is used to uniformly scan the teeth in the patient's oral cavity, accurately and quickly capturing the actual intraoral situation and acquiring dental arch model data that clearly distinguishes the gingiva, crowns, and gingival margin. The dental arch model data can be three-dimensional digital image data, and the scanning device can be any device capable of acquiring three-dimensional digital images of the oral cavity, such as cone-beam computed tomography (CBCT), UP600 intraoral scanner, intraoral scanner, or UP scanner. Furthermore, the dental arch model data may also include a tooth model for each tooth position, the local coordinate system of the tooth model, and the occlusal direction of the dental arch.

[0062] For example, the cervical margin of each tooth position can be identified from the dental arch model data. This can be achieved by obtaining the maximum set of boundary points in the dental model and using it as the cervical margin. It should be noted that for a vertex v in the triangular mesh of the dental model, if there is only one edge (v, vi) for each neighboring vertex vi of v, then v is a boundary vertex. Thus, the maximum set of boundary points is obtained from all vertices in the triangular mesh of the dental model that satisfy this condition. Furthermore, the direction of the cervical margin of each tooth position can be unified, such as sequential counterclockwise or sequential clockwise.

[0063] In another scenario, a plaster model of the target tooth can be created. After obtaining the plaster model, a scanning device is used to perform maxillary, mandibular, and occlusal scans on the target tooth in the plaster model to obtain plaster model data in STL or DCM format, including maxillary, mandibular, and occlusal data. Then, a preset recognition algorithm can be used to identify the reference cervical margin line in the plaster model data. Next, a preset registration algorithm is used to register the tooth position cervical margin line with the reference cervical margin line. The data deviation domain obtained from the registration can be manually adjusted until the tooth position cervical margin line matches the reference cervical margin line. The adjusted cervical margin line is then used as the cervical margin line for each tooth position. The preset recognition algorithm can be a recognition algorithm set by the user in advance. In one embodiment, the recognition algorithm can be a one-point recognition algorithm. The preset registration algorithm is also a registration algorithm set by the user in advance. In one example, the registration algorithm can be the Iterative Closest Points (ICP) algorithm. The ICP algorithm registers two point sets (i.e. model data) by optimizing rigid body transformation.

[0064] Step S20: Fit the cervical margin lines of each tooth position to obtain a virtual gingival base contour line, and sequentially determine the feature points of each cervical margin line of each tooth position, wherein the feature points include at least the papilla points, which are located on the cervical margin of the tooth position.

[0065] It's important to understand that real gingiva has a certain height. Before fitting the cervical margin lines of the teeth, these lines can be projected onto a base plane. A virtual gingival contour can then be obtained by fitting the cervical margin lines onto this base plane. For example, the occlusal direction of the dental arch can be obtained from the dental arch model data. Based on this occlusal direction, the plane containing all the cervical margin lines of the teeth can be determined. This plane is then translated using a preset gingival height (e.g., 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, etc.) to obtain the base plane, which is then designated as the virtual gingival base plane. All the cervical margin lines of the teeth are then projected onto this virtual gingival base plane, and the virtual gingival base contour is obtained by fitting the projected cervical margin lines onto this virtual gingival base plane.

[0066] Furthermore, the outermost and innermost points of the cervical margin line of each tooth position are determined as the gingival apex of each tooth position. It should be noted that for the innermost tooth position (i.e., the tooth with only one adjacent tooth), point sets can be sampled along the cervical margin line of teeth where the innermost and outermost points are not in adjacent regions, obtaining the outermost point sets of the two innermost teeth. Thus, based on the gingival apex of each tooth position and the outermost point sets of the innermost tooth position's cervical margin line, a point set in a preset direction (e.g., counterclockwise) is sequentially combined. Then, a virtual gingival base contour line is fitted using cubic B-splines, as shown below. Figure 3 The virtual gingival contour line is obtained by fitting the cervical margin line of each tooth position.

[0067] The coordinates of feature points corresponding to different cervical margin morphologies of teeth can be preset. Based on the morphology of each cervical margin, the coordinates of feature points matching that morphology can be determined. These feature points include at least the papilla points on the cervical margin of each tooth. The papilla points on the cervical margin of each tooth are located on its own cervical margin. Understandably, the papilla points include the high point and low point of the papilla area. Each cervical margin can be divided into four regions based on the cervical margin centerline and the occlusal direction: upper left region, lower left region, upper right region, and lower right region (or left medial, left lateral, right medial, and right lateral). Each region has its own high and low points on the cervical margin of the tooth position. From this, at least eight feature points can be extracted on the cervical margin of each tooth position, namely, [high point of the upper left papilla, low point of the upper left papilla, high point of the lower left papilla, low point of the lower left papilla, high point of the upper right papilla, low point of the upper right papilla, high point of the lower right papilla, low point of the lower right papilla] (or [high point of the left medial papilla, low point of the left medial papilla, high point of the left lateral papilla, low point of the left lateral papilla, high point of the right medial papilla, low point of the right medial papilla, high point of the right lateral papilla, low point of the right lateral papilla]).

[0068] Step S30: Sampling is performed on the cervical margin lines of each tooth position between the feature points to obtain sampling points, and the connection points corresponding to the sampling points are determined. The connection points include at least the point with the maximum curvature of the gingival margin region, the lowest point of the lateral gingival margin, and the point closest to the contour line. The point closest to the contour line is on the contour line of the virtual gingival base.

[0069] Point set sampling is performed on the cervical margin line of each tooth position, between the feature points, to obtain sampling points. It should be noted that the process of generating a virtual gingiva for each tooth position by sampling the point set of the cervical margin line is similar. In this embodiment, a tooth position and a cervical margin line are used as an example for explanation.

[0070] Point set sampling is performed on the cervical margin line between characteristic points on the tooth position cervical margin line. Understandably, there are at least 8 papillary points on the cervical margin line. Point set sampling can be performed on the cervical margin lines between the lowest points of the same papillary region, such as the cervical margin lines between the lowest points of the same medial papillary region (between the lowest points of the left and right medial papillary regions) and between the lowest points of the same lateral papillary region (between the lowest points of the left and right lateral papillary regions). Sampling points are obtained, and for each sampling point, the local coordinate system of the tooth at that position can be obtained from the dental arch model data. This process determines the coordinates of the sampling point in the local coordinate system. Then, based on a preset mapping table, the coordinates of the corresponding connection point can be determined. This preset mapping table can be the connection point coordinates corresponding to each sampling point coordinate pre-set by the user. In other words, the connection point corresponding to the sampling point is determined based on the preset mapping table. It can be understood that these coordinates are all in the local coordinate system corresponding to the tooth position, and can be connection point coordinates corresponding to different coordinate ranges. Therefore, after obtaining the specific coordinates of the sampling point, the coordinates of the connection point are obtained by matching them with the preset mapping table. Alternatively, in another embodiment, the coordinates of the connection point can also be calculated using a preset formula.

[0071] Step S40: Fit the sampling points and connection points of each tooth position cervical margin line to generate a virtual gingiva.

[0072] Therefore, virtual gingiva is generated by fitting the sampling points and connection points of the cervical margin line of each tooth position. Optionally, the lateral curve and papillary curve of each tooth position are obtained by interpolation fitting the connection points and sampling points using cubic Hermite curves. Thus, the virtual gingiva of each tooth position is obtained by connecting the lateral curve and papillary curve of each tooth position.

[0073] In one embodiment, the step of generating a virtual gingiva by fitting the sampling points and connection points of each of the tooth cervical margin lines includes:

[0074] Step a: sequentially fit the lowest point of the lateral gingival margin of each tooth position to the nearest point of the contour line to obtain the lateral connection curve; sequentially fit the sampling point, the point of maximum curvature of the gingival margin region to the lowest point of the lateral gingival margin to obtain the papillary region curve.

[0075] In this embodiment, the connection point includes at least the point of maximum curvature of the gingival margin, the lowest point of the lateral gingival margin, and the point closest to the contour line. The point closest to the contour line is on the virtual gingival contour line. Optionally, the point closest to the lowest point of the lateral gingival margin can be the point on the virtual gingival contour line closest to the lowest point of the lateral gingival margin to generate a virtual gingiva with height. The sampling point is denoted as Po, the point of maximum curvature of the gingival margin is denoted as P1, the lowest point of the lateral gingival margin is denoted as P2, and the point closest to the contour line is P3. The lateral curve is obtained by interpolation using cubic Hermite curves based on Po, P1, P2, and P3 and their directions. It should be noted that the lateral curve here is divided into two parts: one part is the gingival papilla area and the other part is the lateral connection area. The lateral connection area is obtained by fitting the midpoint between P2 and P2 on both sides of the tooth position. The point set between P3 is used to obtain the lateral connection curve. Optionally, the lateral curve is obtained by interpolation fitting using cubic Hermite curves. Then, the midpoint set between the two sides of P2 and P3, the midpoint between P1 at the low point of the two papilla regions, and the cervical margin line between the midpoint of the cervical margin line between the high point of the inner papilla region of adjacent teeth and the cervical margin line between the high point of the outer papilla region are taken. A curve passing through the gap between adjacent teeth is obtained by fitting a cubic B-spline. Then, the point set of the cervical margin line between the low points of the inner and outer papilla regions of adjacent teeth is sampled, as well as the point set between P0, P1 and P2 at the low point of the papilla region on both the inner and outer sides. According to the curve passing through the gap between teeth fitted above, it is divided into left and right sides. Then, several curves are fitted from left to right as the papilla region curve.

[0076] Step b: Connect the lateral connection curves of each tooth position with the papillary region curve in sequence to obtain a virtual gingiva.

[0077] By sequentially connecting the lateral connecting curves of each tooth position with the papillary region curve, the curves are combined into a surface to obtain a virtual gingiva, such as... Figure 4 The middle image shows the final generated virtual gum.

[0078] In this embodiment, the side connection curve and the papillary region curve are respectively fitted by the sampling points and the connection points, that is, the papillary region is distinguished to generate virtual gingiva. Thus, the overall shape of the virtual gingiva can be controlled from multiple directions to optimize the generation effect of the virtual gingiva.

[0079] To aid in understanding the virtual gingival generation method in this embodiment, an example is provided below.

[0080] Reference Figure 5The dental arch model data of the target tooth is input into the orthodontic software. This data includes the tooth model of each tooth position and its local coordinate system. Based on the tooth model, the location of the cavity in each tooth position is initially identified, and the cavity information is initialized. The cervical margin line of each tooth position is then obtained to obtain the cervical margin line of the target tooth, and its direction is standardized (e.g., counterclockwise). The cervical margin line data is then projected onto a virtual gingival base plane. Further, the center of the cervical margin line of each tooth position after projection can be fitted to obtain the center of the virtual gingival base. The gingival margin vertex of each tooth position after projection is calculated, and the gingival margin vertex is fitted to obtain the contour line of the virtual gingival base. The contour line of each tooth position is then calculated. The adjacency relationship of teeth, the high point and low point of the papilla, the cervical margin line between the low point of the ipsilateral papilla is sampled to obtain sampling points, and the corresponding connection points are determined. The lateral curve is obtained by cubic Hermite interpolation fitting between the sampling points and the connection points. The lateral curve is divided into two parts: one part is the lateral connection area, and the other part is the papilla area. For the lateral connection area, the point set between P2 and P3 (lateral point set) is calculated and fitted to obtain the lateral connection curve. For the papilla area, the point set between P0, P1 and P2 (papillary area point set) is calculated and fitted to obtain the papilla area curve. The lateral connection curve and the papilla area curve are combined into a surface to obtain the virtual gingiva.

[0081] In this embodiment, dental arch model data is acquired from the patient's oral cavity. Based on the dental arch model data, the cervical margin lines of each tooth position are identified, and papillary points on the cervical margin lines of each tooth position are extracted. Point set sampling is performed on the cervical margin lines between the papillary points to obtain sampling points. After determining the connection points corresponding to the sampling points, the sampling points and connection points are fitted to generate virtual gingiva. This avoids the phenomenon in the prior art where the generation of virtual gingiva does not distinguish the papillary region, resulting in poor virtual gingiva morphology. This embodiment achieves the distinction of papillary region in the generation of virtual gingiva by extracting papillary points on the cervical margin line, thereby optimizing the generation morphology of virtual gingiva.

[0082] Furthermore, based on the first embodiment of the present invention described above, a second embodiment of the virtual gingival generation method of the present invention is proposed. In this embodiment, the refinement of step S20 of the above embodiment, which uses the cervical margin line of each tooth position as the cervical margin line of the target tooth and fits the cervical margin line to obtain the virtual gingival base contour line, includes:

[0083] Step c: Determine the cervical margin plane where all the tooth positions are located, and translate the cervical margin plane with a preset gingival height to obtain a virtual gingival base plane;

[0084] Step d: Project all the cervical margin lines of the teeth onto the virtual gingival base plane to obtain the first cervical margin line, and extract the gingival margin vertices of all the first cervical margin lines;

[0085] Step e: Fit all the gingival margin vertices to obtain a virtual gingival base contour.

[0086] The first cervical margin line is obtained by projecting all tooth position cervical margin lines onto the virtual gingival base plane. The gingival margin vertex of the first cervical margin line is extracted. It can be understood that each first tooth position cervical margin line projected onto the virtual gingival base plane has its own gingival margin vertex. The process of fitting the gingival margin vertex to obtain the virtual gingival base contour line is described in part of the first embodiment of this application, and will not be detailed here.

[0087] In this embodiment, the cervical margin lines of all teeth are projected onto the virtual gingival base plane to obtain the first cervical margin line, so that the generated virtual gingiva can have a certain height. The gingival margin apex of the first cervical margin line is extracted, and the gingival margin apex is fitted to obtain the virtual gingival base contour line, thereby improving the accuracy of the virtual gingival base contour.

[0088] In one embodiment, the gingival margin apex includes the innermost point and the outermost point, and the step of extracting all gingival margin apexes of the first cervical margin line includes:

[0089] Step f: Determine the center of the cervical margin of each of the first cervical margin lines, and fit all the centers of the cervical margin lines to obtain the virtual gingival base midline;

[0090] Step g: sequentially traverse each of the first cervical margin lines, perform point set sampling on the traversed first cervical margin lines to obtain the first cervical margin line point set, determine that the first cervical margin line points are concentrated on the inner first cervical margin line points inside the midline of the virtual gingival base, and determine that the first cervical margin line points are concentrated on the outer first cervical margin line points outside the midline of the virtual gingival base.

[0091] The process involves sequentially traversing the cervical margins of each first tooth position, sampling a point set for each traversed cervical margin to obtain the first cervical margin point set. Alternatively, point sampling can be performed on all first cervical margins before traversing them. Therefore, when traversing the cervical margins of a first tooth position, the corresponding first cervical margin point set can be directly obtained. Understandably, the medial first cervical margin points include the point set concentrated inside the virtual gingival base midline, and the lateral first cervical margin points include the point set concentrated outside the virtual gingival base midline. Thus, after traversing all first cervical margins, the gingival apex of each first cervical margin can be extracted. Optionally, the medial and lateral sides can be distinguished by the reverse of the dental arch occlusion. In this embodiment, the side of the tooth closer to the tongue is considered medial, and the side closer to the buccal surface is considered lateral.

[0092] Step h: Determine the first distance from each of the inner first cervical margin points to the midline of the virtual gingival base, and take the inner first cervical margin point corresponding to the largest first distance among the first distances as the innermost point of the traversed first cervical margin.

[0093] Step i: Determine the second distance from each of the outer first cervical margin points to the midline of the virtual gingival base, and take the outer first cervical margin point corresponding to the largest second distance among the second distances as the outermost point of the traversed first cervical margin.

[0094] The inner cervical margin point of each tooth position is determined by selecting the inner cervical margin point corresponding to the largest first distance from the midline of the virtual gingival base. This innermost point of the cervical margin of that tooth position is then determined sequentially.

[0095] The outermost point of the cervical margin line of each tooth position is selected from the second distances from the midline of the virtual gingival base. The second distance with the largest distance is selected as the outermost point of the cervical margin line of that tooth position. Thus, the outermost point of the cervical margin line of each tooth position is determined in turn.

[0096] Furthermore, to ensure the effectiveness of the innermost and outermost points of each tooth position, a point can be selected on the virtual gingival base line that is closest to the center point of the cervical margin of the tooth position. A fan-shaped region with an angle of 2θ is obtained by shifting the occlusal direction of the tooth position to both sides of the central axis. The innermost and outermost points of each tooth position are determined by selecting the innermost and outermost points of the cervical margin of the tooth position concentrated in this fan-shaped region.

[0097] In this embodiment, the innermost and outermost points of the cervical margin line of each tooth position are determined to obtain the gingival margin vertex of the cervical margin of each tooth position, and then the gingival margin vertex of the first cervical margin is obtained. The cervical margin point set of each tooth position is divided into inner and outer cervical margin point sets by the dental arch occlusal direction and the midline of the virtual gingival base. The point with the longest distance from the midline in the inner cervical margin point set is selected as the innermost point of this tooth position, and the point with the longest distance from the midline in the outer cervical margin point set is selected as the outermost point of this tooth position, thereby improving the accuracy of the gingival margin vertex.

[0098] In one embodiment, the nipple region point includes the highest point of the target nipple region, and the step of sequentially extracting the feature points of each tooth's cervical margin line includes:

[0099] Step j: sequentially traverse each of the tooth position cervical margin lines, and determine the adjacent tooth position cervical margin line corresponding to the target tooth position cervical margin line.

[0100] Before extracting feature points from each tooth position, it's possible to calculate malformed tooth positions within the target teeth. Three teeth at consecutive positions are selected for malformation assessment. For example, let's define consecutive tooth positions A, B, and C. V1 is the direction vector from the center of the cervical margin of tooth position B to the center of the cervical margin of tooth position A, and V2 is the direction vector from the center of the cervical margin of tooth position B to the center of the cervical margin of tooth position C. If the angle between V1 and V2 is less than a preset angle (e.g., 130°, 135°, 140°, 145°, etc.), it's considered a malformed tooth position. Furthermore, if the cross product of V1 and V2 is the same as the occlusal direction of the dental arch, it's a concave type; otherwise, it's a convex type. For example... Figure 3 , Figure 4 The number at the center of the cervical margin of each tooth position is the angle between V1 and V2 calculated for this tooth position.

[0101] Feature points are extracted for each tooth's cervical margin line, including at least papilla points. The extraction process for papilla points on each tooth's cervical margin line is similar. In this embodiment, the extraction process for papilla points is illustrated using the target tooth's cervical margin line as an example. Adjacent cervical margin lines are those adjacent to the target cervical margin line. For a target cervical margin line with two adjacent cervical margin lines, papilla points are determined on the corresponding side of each adjacent tooth's cervical margin line. The extraction process for papilla points on each side of the target tooth's cervical margin line is similar. In this embodiment, the extraction process for papilla points on the target tooth's cervical margin line on either side of the target tooth's cervical margin line is illustrated using the adjacent tooth's cervical margin line on that side as an example.

[0102] It should be noted that, in another embodiment, if the adjacent tooth is in a malformed position, the cervical margin line of the tooth immediately adjacent to this adjacent tooth can be used as the cervical margin line of the target tooth (adjacent in the same direction). If the target tooth is in a normal position (i.e., not malformed), the cervical margin line of the tooth immediately adjacent to the target tooth is used as the cervical margin line of the adjacent tooth. If the target tooth is in a malformed position, the cervical margin line of the tooth immediately adjacent to the target tooth is used as the cervical margin line of the adjacent tooth. This optimizes the gingival generation effect of the virtual gingiva at malformed tooth positions.

[0103] Step k: Determine the target plane corresponding to the cervical margin line of the target tooth position, and perform point set sampling on the cervical margin line of the target tooth position to obtain the target tooth position cervical margin line point set corresponding to the target tooth position cervical margin line, wherein the target tooth position cervical margin line point set includes multiple target tooth position cervical margin line points;

[0104] Step 1: Determine the third distance from each target tooth cervical margin point in the target tooth position cervical margin point set to the target plane. Select the target tooth cervical margin point corresponding to the smallest third distance from the set of third distances as the initial papillary region high point, and use the initial papillary region high point as the target papillary region high point.

[0105] In this example, the nipple region point includes the nipple region elevation point. The nipple region elevation point of the target tooth cervical margin line is denoted as the target nipple region elevation point. To determine the target plane corresponding to the target tooth cervical margin line, optionally, the target plane is fitted according to the occlusal direction of the target tooth corresponding to the target tooth cervical margin line and the line connecting the center of the cervical margin line of the target tooth and the center of the cervical margin line of the adjacent tooth. The direction from the center of the cervical margin line of the adjacent tooth to the center of the cervical margin line of the target tooth is taken as the first direction of the target tooth cervical margin line. A direction vector is obtained by using the right-hand rule from the occlusal direction of the target tooth cervical margin line to the first direction. The target plane is obtained by passing through the center point of the target tooth cervical margin line and using this direction vector as the normal vector. The point on the target tooth cervical margin line closest to the target plane is determined as the initial nipple region elevation point.

[0106] Optionally, a point set sampling is performed on the cervical margin of the target tooth to obtain a point set of the cervical margin of the target tooth corresponding to the cervical margin of the target tooth. The distance from each cervical margin point of the target tooth to the target plane is determined. The cervical margin point of the target tooth corresponding to the shortest distance from each cervical margin point of the target tooth to the target plane is selected as the high point of the target papilla region corresponding to the cervical margin of the target tooth. It should be noted that the cervical margin midline can be obtained by fitting the center point of the cervical margin of each tooth position. The cervical margin midline divides the cervical margin of each tooth position into two parts: the inner cervical margin of the tooth position and the outer cervical margin of the tooth position. For the target tooth position cervical margin, there are also inner and outer target tooth position cervical margins. Correspondingly, the target tooth position cervical margin point set is also divided into inner and outer target tooth position cervical margin point sets. The inner target tooth position cervical margin point corresponding to the shortest distance from the inner target tooth position cervical margin point set to the target plane is selected as the inner target papilla high point corresponding to the target tooth position cervical margin. The outer target tooth position cervical margin point corresponding to the smallest third distance from the outer target tooth position cervical margin point set to the target plane is selected as the outer target papilla high point corresponding to the target tooth position cervical margin. The inner and outer target papilla high points are selected as the target papilla high points. Thus, the high point of the target papilla region on the cervical margin of the target tooth was extracted.

[0107] In this embodiment, a target plane is determined where the cervical margin of the target tooth is located. Point set sampling is performed on the cervical margin of the target tooth to obtain the point set of the cervical margin of the target tooth. The cervical margin point of the target tooth with the shortest distance from each point of the cervical margin of the target tooth to the target plane is selected as the initial papillary region high point corresponding to the cervical margin of the target tooth. The initial papillary region high point is used as the target papillary region high point. A target plane is determined. After one point set sampling, the target papillary region high point can be quickly calculated and determined based on the distance from the point to the line, which improves the determination speed of the target papillary region high point and further improves the generation speed of virtual gingiva.

[0108] In one embodiment, prior to the step of using the initial nipple region elevation as the target nipple region elevation, the method includes:

[0109] Step m: Sampling of the cervical margin of the adjacent tooth position is performed to obtain the cervical margin point set of the adjacent tooth position corresponding to the cervical margin of the adjacent tooth position, wherein the cervical margin point set of the adjacent tooth position includes multiple cervical margin points of the adjacent tooth position.

[0110] Step n: Iterate through each target tooth cervical margin point in the target tooth position cervical margin point set, determine the fourth distance from the traversed target tooth cervical margin point to each of the adjacent tooth cervical margin points, and select the fourth distance with the largest distance among the fourth distances as the target distance.

[0111] Step o: If the target distance is less than the preset grid distance, mark the traversed target tooth cervical margin line points as adjacent points. After traversing all target tooth cervical margin line points in the target tooth cervical margin line point set, a set of adjacent points composed of the adjacent points is obtained.

[0112] Step p: If there are at least two adjacent points in the set of adjacent points, select two adjacent points from the set of adjacent points as the target nipple region high points.

[0113] In this embodiment, based on the Euclidean distance D between the points set of the cervical margins of two tooth positions, if D is less than a preset grid distance, it is recorded as an adjacent point. The preset grid distance can be a preset multiple (e.g., 0.05, 0.1, 0.15, 0.2, etc.) of the average side length of all tooth grids in the dental arch model data. Then, a new target papilla elevation point is determined from the adjacent point set. For tooth positions that are not adjacent (i.e., have a gap), the initial papilla elevation point is used as the target papilla elevation point.

[0114] For each neck edge point in the target neck edge point set, determine the distance from this neck edge point (i.e., the traversed target tooth neck edge point) to each adjacent neck edge point in the adjacent neck edge point set. If the longest distance among all distances is less than the preset grid distance, mark this neck edge point as an adjacent point. After traversing all neck edge points in the target neck edge point set, all adjacent points form an adjacent point set. If the adjacent point set is empty or has only one, select the initial nipple region high point as the target nipple region high point. If there are at least two adjacent points in the adjacent point set, select two adjacent points from the adjacent point set as the target nipple region high points. Optionally, traverse all adjacent points in the adjacent point set in a preset direction (such as clockwise or counterclockwise), and select the starting adjacent point and the ending adjacent point (i.e., the adjacent nodes at both ends) as the target nipple region high points. It should be noted that the adjacent points at both ends are used as the inner target nipple region high point and the other as the outer target nipple region high point according to their actual positions. If the starting neighbor is on the inside, then the starting neighbor is taken as the high point of the inner target nipple region; if the ending neighbor is on the outside, then the ending neighbor is taken as the high point of the outer target nipple region.

[0115] In this embodiment, the longest distance among all distances from the target cervical margin points to the adjacent tooth cervical margin points in the set of adjacent tooth cervical margin points is determined as the target distance. If the target distance is less than the preset grid distance, the traversed target tooth cervical margin points are marked as adjacent points. After traversing all target tooth cervical margin points in the set of target tooth cervical margin points, an adjacent point set composed of the adjacent points is obtained. If there are at least two adjacent points in the adjacent point set, two adjacent points are selected from the adjacent point set as target papillary region high points. Thus, the target papillary region high points on the cervical margin of each tooth are extracted, further ensuring the effectiveness of extracting the papillary region high points.

[0116] In one embodiment, the nipple region point includes the target nipple region low point, and the target nipple region high point includes the inner target nipple region high point and the outer target nipple region high point. Following the step of using the initial nipple region high point as the target nipple region high point, the method further includes:

[0117] Step q: Determine the target gingival margin vertex of the cervical margin line of the target tooth position, wherein the target gingival margin vertex includes the innermost point and the outermost point of the target;

[0118] In this example, the papilla point includes the papilla low point. The high and low points of the papilla on the cervical margin line of the target tooth position are denoted as the target papilla low point. Similar to the process of calculating the gingival margin apex on the cervical margin line of each tooth position projected onto the virtual gingival base plane, the gingival margin apex on the cervical margin line of the target tooth position can also be determined and denoted as the target gingival margin apex. Alternatively, it can be understood that once the gingival margin apex on the cervical margin line of each tooth position projected onto the virtual gingival base plane has been determined, the gingival margin apex on the cervical margin line of each tooth position before projection can also be determined accordingly. The target gingival margin apex also includes the target innermost point and the target outermost point.

[0119] Step r: Select one target tooth position cervical margin point from the target innermost point to the high point of the inner target papilla region as the low point of the inner target papilla region.

[0120] Step s: Select one target tooth position cervical margin point from the target outermost point to the high point of the outer target papilla region as the low point of the outer target papilla region.

[0121] From the innermost point of the target neckline, select one point as the low point of the inner target nipple region from the set of target neckline points between the innermost point and the high point of the inner target nipple region. Further, the selected low point of the inner target nipple region can be any target neckline point in the set of target neckline points between the innermost point and the high point of the inner target nipple region that meets a preset condition. The preset condition can be: starting from the innermost point of the target, traverse the target neckline points sequentially in a preset direction until the high point of the inner target nipple region is reached, ending the traversal. Determine the distance from the traversed target neckline points to all target neckline points on the opposite side (e.g., the opposite side of the left inner side is the left outer side, and the opposite side of the right inner side is the right outer side). If the distances from the traversed target neckline points to all target neckline points on the opposite side are all less than a preset distance, where the preset distance can be n times the preset gingival margin thickness (e.g., 1.5 times the preset gingival margin thickness, 2 times the preset gingival margin thickness, 2.5 times the preset gingival margin thickness, etc.), mark the traversed target neckline points as the initial low point of the inner nipple region. After the traversal is completed, the following conditions are met: To the initial set of low points in the medial papilla region, the same method is used to determine the initial set of low points in the medial papilla region of the adjacent tooth cervical margin line that is adjacent to the target tooth position cervical margin line. From each of the two initial sets of low points in the medial papilla region, two initial low points in the medial papilla region are selected. If the angle between the line connecting the two low points projected onto the virtual gingival base plane and the line connecting the nearest point on the virtual base outline of the same side (same medial side) is less than a preset angle (such as 8 degrees, 9 degrees, 10 degrees, 11 degrees, 12 degrees, etc.), then these two points are marked. Thus, from the two initial sets of low points in the medial papilla region, the initial low points in the medial papilla region that satisfy the projection angle being less than the preset angle are selected again. If there are multiple initial low points in the medial papilla region with projection angles less than the preset angle, then the longest distance from each initial low point in the medial papilla region with a projection angle less than the preset angle to all target cervical margin line points on the opposite side is recorded as the actual distance. From all actual distances, the initial low point in the medial papilla region corresponding to the smallest actual distance is selected as the target medial papilla region high point.

[0122] Correspondingly, the high point of the lateral nipple area can also be determined in the same way.

[0123] Step t: The low point of the inner target nipple region and the low point of the outer target nipple region are taken as the low point of the target nipple region.

[0124] In this embodiment, a point is selected from the target cervical margin points between the innermost point of the target and the high point of the inner target papilla region as the low point of the inner target papilla region, and a point is selected from the target cervical margin points between the outermost point of the target and the high point of the outer target papilla region as the low point of the outer target papilla region. The low points of the inner and outer target papilla regions are used as the low points of the target papilla regions corresponding to the tooth in the target position, thereby improving the speed of determining the low points of the target papilla regions.

[0125] In one embodiment, the step of determining the connection point corresponding to the sampling point includes:

[0126] Step u: Determine the first coordinates of the sampling point in a preset coordinate system, wherein the first coordinates include a first horizontal coordinate and a first vertical coordinate;

[0127] Step v: Multiply the preset gingival margin thickness by the first horizontal coordinate to obtain the reference horizontal coordinate, multiply the preset gingival margin thickness ratio by the reference horizontal coordinate to obtain the target horizontal coordinate, and use the sum of the target horizontal coordinate and the first horizontal coordinate as the second horizontal coordinate.

[0128] Step w: The sum of the reference horizontal coordinate and the first horizontal coordinate is taken as the third horizontal coordinate;

[0129] Step x: Multiply the preset gingival margin height by the first vertical coordinate to obtain the target vertical coordinate, and use the sum of the target vertical coordinate and the first vertical coordinate as the second vertical coordinate;

[0130] Step y: Take the coordinate point corresponding to the second horizontal coordinate and the second vertical coordinate as the point with the maximum curvature of the gingival margin region;

[0131] Step z: The coordinate point corresponding to the third horizontal coordinate and the first vertical coordinate is taken as the low point of the lateral gingival margin;

[0132] In this example, the maximum curvature point of the gingival margin region corresponding to the sampling point can also be determined based on the first preset formula, wherein the first preset formula is: P1=Po+Vref*R1*r*r1+Vh*R2*r2, where Po is the coordinate of the sampling point in the preset coordinate system, Vh is the occlusal direction of the teeth, Vref is perpendicular to the occlusal direction Vh, R1 is the preset gingival margin thickness, R2 is the preset gingival margin height, r1 is the preset gingival margin thickness ratio, r2 is the preset gingival margin height ratio, r is the preset gingival margin maximum curvature point position ratio, and P1 is the coordinate of the maximum curvature point of the gingival margin region in the preset coordinate system;

[0133] Understandably, multiple sampling points are obtained by sampling the cervical margin points between the lowest points of the papilla region on the same side (same medial or same lateral) of the cervical margin line for each tooth position. For each sampling point, a corresponding point of maximum curvature of the gingival margin region can be determined based on the first preset formula. It should be noted that r1 and r2 are proportional values ​​that change with the position of point Po. The values ​​of r1 and r2 decrease as they approach the lowest point of the papilla region. It should also be noted that if the x-coordinate of the position of the point of maximum curvature of the gingival margin region is X, then X / R1 = r. Understandably, the preset coordinate system can be the local coordinate system of the tooth model corresponding to each tooth position included in the dental arch model data.

[0134] In addition, the lateral gingival margin low point corresponding to the sampling point can also be determined based on the second preset formula, wherein the second preset formula is: P2=Po+Vref*R1*r, where P2 is the coordinate of the lateral gingival margin low point in the preset coordinate system, which is the same as the point with the maximum curvature of the gingival margin region. For each sampling point, a corresponding lateral gingival margin low point can be determined based on the second preset formula.

[0135] Step z0: Project the low point of the outer gingival margin onto the virtual gingival base plane where the virtual gingival base contour line is located to obtain the projection point. Determine the contour point on the virtual gingival base contour line that has the shortest distance to the projection point, and take the contour point as the closest point on the contour line corresponding to the sampling point.

[0136] In this embodiment, the maximum curvature point of the gingival margin region and the lowest point of the lateral gingival margin corresponding to the sampling point are determined based on the first preset formula and the second preset formula, respectively. The lowest point of the lateral gingival margin is projected onto the virtual gingival base plane where the virtual gingival base contour line is located to obtain the projection point. The contour point with the shortest distance to the projection point on the virtual gingival base contour line is determined, and the contour point is taken as the closest point on the contour line corresponding to the sampling point. The maximum curvature point of the gingival margin region and the lowest point of the lateral gingival margin are points close to the papilla region. In this way, the papilla region and the lateral connecting region can be distinguished to generate virtual gingiva. The generation morphology of virtual gingiva can be controlled from multiple aspects such as gingival margin height and gingival margin thickness, optimizing the generation morphology of virtual gingiva. Furthermore, the sampling and fitting of point sets to generate virtual gingiva improves the generation speed of virtual gingiva.

[0137] Furthermore, this invention also proposes a virtual gingival generation device, which includes a memory, a processor, and a virtual gingival generation program stored in the memory and executable on the processor. When the virtual gingival generation program is executed by the processor, it implements the steps of the virtual gingival generation method described above.

[0138] The specific implementation of the virtual gingival generation device in this application is basically the same as the embodiments of the virtual gingival generation method described above, and will not be repeated here.

[0139] In addition, to achieve the above objectives, the present invention also provides a computer-readable storage medium storing a virtual gingival generation program, which, when executed by a processor, implements the steps of the virtual gingival generation method as described above.

[0140] The specific implementation of the computer-readable storage medium in this application is basically the same as the embodiments of the virtual gingiva generation method described above, and will not be repeated here.

[0141] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system 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 system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0142] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0143] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0144] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for generating virtual gingiva, characterized in that, The virtual gingiva generation method includes the following steps: Obtain dental arch model data of teeth at multiple positions in the patient's oral cavity, and identify the cervical margin line of each tooth position based on the dental arch model data; A virtual gingival base contour line is obtained by fitting the cervical margin line of each tooth position, and the feature points of each cervical margin line of each tooth position are determined in sequence, wherein the feature points include at least the papillary point, which is located on the cervical margin of the tooth position; Point set sampling is performed on the cervical margin lines of each tooth position between the characteristic points to obtain sampling points, and the connection points corresponding to the sampling points are determined. The connection points include at least the point with the maximum curvature of the gingival margin region, the lowest point of the lateral gingival margin, and the point closest to the contour line. The point closest to the contour line is on the contour line of the virtual gingival base. The sampling points and connection points of each tooth position's cervical margin are fitted to generate a virtual gingiva.

2. The virtual gingiva generation method as described in claim 1, characterized in that, The step of fitting the cervical margin lines of each tooth to obtain the virtual gingival base contour line includes: Determine the cervical margin plane where all the tooth positions are located, and translate the cervical margin plane with a preset gingival height to obtain a virtual gingival base plane; Projecting all the cervical margin lines of the teeth onto the virtual gingival base plane yields the first cervical margin line, and extracting the gingival margin vertices of all the first cervical margin lines; Fit all the gingival margin vertices to obtain a virtual gingival base contour.

3. The virtual gingiva generation method as described in claim 2, characterized in that, The gingival margin apex includes the innermost point and the outermost point. The step of extracting all gingival margin apexes of the first cervical margin line includes: Determine the center of the cervical margin of each of the first cervical margin lines, and fit all the centers of the cervical margin lines to obtain the virtual gingival base midline; Each of the first cervical margin lines is traversed sequentially, and the point set of the traversed first cervical margin lines is sampled to obtain the first cervical margin line point set. It is determined that the first cervical margin line points are concentrated on the inner first cervical margin line points inside the midline of the virtual gingival base, and the first cervical margin line points are concentrated on the outer first cervical margin line points outside the midline of the virtual gingival base. Determine the first distance from each of the inner first cervical margin points to the midline of the virtual gingival base, and take the inner first cervical margin point corresponding to the largest first distance among the first distances as the innermost point of the traversed first cervical margin. Determine the second distance from each of the outer first cervical margin points to the midline of the virtual gingival base, and take the outer first cervical margin point corresponding to the largest second distance among the second distances as the outermost point of the traversed first cervical margin.

4. The virtual gingiva generation method as described in claim 1, characterized in that, The nipple area point includes the highest point of the target nipple area. The step of sequentially determining the characteristic points of the cervical margin of each tooth position includes: The cervical margins of each tooth position are traversed sequentially, and the traversed cervical margins of each tooth position are taken as the target tooth position cervical margins. The adjacent tooth position cervical margins corresponding to the target tooth position cervical margins are then determined. Determine the target plane corresponding to the cervical margin line of the target tooth position, perform point set sampling on the cervical margin line of the target tooth position, and obtain the target tooth position cervical margin line point set corresponding to the target tooth position cervical margin line, wherein the target tooth position cervical margin line point set includes multiple target tooth position cervical margin line points; Determine the third distance from each target tooth cervical margin point in the target tooth position cervical margin point set to the target plane. Select the target tooth cervical margin point corresponding to the smallest third distance from each third distance as the initial papillary region high point, and use the initial papillary region high point as the target papillary region high point.

5. The virtual gingiva generation method as described in claim 4, characterized in that, Before the step of using the initial nipple region elevation as the target nipple region elevation, the following steps are included: Point set sampling is performed on the adjacent tooth neck edge line to obtain the adjacent tooth neck edge line point set corresponding to the adjacent tooth neck edge line, wherein the adjacent tooth neck edge line point set includes multiple adjacent tooth neck edge line points. The target tooth cervical margin point is traversed sequentially from each target tooth cervical margin point in the target tooth position cervical margin point set. The fourth distance from each target tooth cervical margin point to each adjacent tooth cervical margin point is determined. The fourth distance with the largest distance among the fourth distances is selected as the target distance. If the target distance is less than the preset grid distance, the traversed target tooth cervical margin line points are marked as adjacent points. After traversing all target tooth cervical margin line points in the target tooth cervical margin line point set, an adjacent point set composed of the adjacent points is obtained. If there are at least two adjacent points in the set of adjacent points, select two adjacent points from the set of adjacent points as the target nipple region high points.

6. The virtual gingiva generation method as described in claim 4, characterized in that, The nipple region points include the low point of the target nipple region, and the high points of the target nipple region include the high points of the inner and outer target nipple regions. Following the step of using the initial nipple region elevation as the target nipple region elevation, the following is included: Determine the target gingival margin vertex of the cervical margin line of the target tooth position, wherein the target gingival margin vertex includes the innermost point and the outermost point of the target; From the innermost point of the target tooth to the highest point of the inner target papilla area, select one target tooth cervical margin point as the low point of the inner target papilla area; From the outermost point of the target tooth to the highest point of the outer target papilla region, select one target tooth cervical margin point as the low point of the outer target papilla region; The low point of the inner target nipple region and the low point of the outer target nipple region are taken as the low point of the target nipple region.

7. The virtual gingival generation method according to any one of claims 1-6, characterized in that, The step of determining the connection point corresponding to the sampling point includes: Determine the first coordinates of the sampling point in a preset coordinate system, wherein the first coordinates include a first horizontal coordinate and a first vertical coordinate; A reference horizontal coordinate is obtained by multiplying the preset gingival margin thickness by the first horizontal coordinate, and a target horizontal coordinate is obtained by multiplying the preset gingival margin thickness ratio by the reference horizontal coordinate. The sum of the target horizontal coordinate and the first horizontal coordinate is used as the second horizontal coordinate. The sum of the reference horizontal coordinate and the first horizontal coordinate is taken as the third horizontal coordinate; The target vertical coordinate is obtained by multiplying the preset gingival margin height by the first vertical coordinate, and the sum of the target vertical coordinate and the first vertical coordinate is used as the second vertical coordinate; The coordinate points corresponding to the second horizontal coordinate and the second vertical coordinate are taken as the points with the maximum curvature of the gingival margin region. The coordinate point corresponding to the third horizontal coordinate and the first vertical coordinate is taken as the lowest point of the lateral gingival margin. The projection point is obtained by projecting the low point of the outer gingival margin onto the virtual gingival base plane where the virtual gingival base contour line is located. The contour point with the shortest distance to the projection point on the virtual gingival base contour line is determined, and the contour point is taken as the closest point of the contour line corresponding to the sampling point.

8. The virtual gingiva generation method as described in claim 7, characterized in that, The step of generating a virtual gingiva by fitting the sampling points and connection points of the cervical margin lines of each tooth position includes: The lateral connection curve is obtained by sequentially fitting the lowest point of the lateral gingival margin of each tooth position cervical margin line with the nearest point of the contour line; the papillary region curve is obtained by sequentially fitting the sampling point, the maximum curvature point of the gingival margin region with the lowest point of the lateral gingival margin. The virtual gingiva is obtained by sequentially connecting the lateral connecting curves of the cervical margins of each tooth position with the papillary region curve.

9. A virtual gum generation device, characterized in that, The virtual gingival generation device includes: a memory, a processor, and a virtual gingival generation program stored in the memory and executable on the processor, wherein the virtual gingival generation program, when executed by the processor, implements the steps of the virtual gingival generation method as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a virtual gingival generation program, which, when executed by a processor, implements the steps of the virtual gingival generation method as described in any one of claims 1 to 8.

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