Digital tooth bridge generation method, device and system, and computer readable storage medium

Abstract

The invention relates to the technical field of oral clinical medicine, and discloses a digital tooth bridge generation method which comprises the following steps: inputting a tooth three-dimensional mesh model and an occlusion direction; establishing a tooth local coordinate system based on the occlusion direction; on the basis of the tooth local coordinate system and the tooth restoration type, calculating a connector placement area between adjacent tooth models; generating a connector control line based on the connector placement area; constructing a connector grid according to the connector control lines; and fusing the connector grid and the tooth three-dimensional grid model to generate a tooth bridge model. Through a small amount of necessary input of the model and the direction, full-chain self-adaptive processing is driven, dependence on a preset template and manual intervention of a user is reduced, and therefore the tooth bridge model meeting the clinical function and attractiveness requirements is generated, the situations that the shape is abrupt and transition is unnatural after fusion are reduced, and the repairing effect is improved. The invention further discloses a digital tooth bridge generation device, a digital tooth bridge generation system and a computer readable storage medium.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oral clinical medicine, for example to a digital dental bridge generation method and device, a digital dental bridge generation system, and a computer readable storage medium. BACKGROUND

[0002] At present, in the field of oral clinical medicine, tooth loss is a common oral problem, which not only affects the mastication function and stability of the patient's teeth, but also can cause damage to the appearance of the face and inaccurate pronunciation. As an important repair scheme, the dental bridge is especially suitable for patients whose alveolar bone conditions are not suitable for implantation or adjacent teeth have caries. However, the traditional dental bridge design mainly relies on manual operation, and the doctor or technician needs to manually adjust the shape and position of the connecting body according to experience, which not only takes a long time, but is also greatly affected by subjective factors, and it is difficult to ensure the consistency and standardization of the shape of the dental bridge among different cases.

[0003] In order to solve the problems of low efficiency and poor consistency of manual design, the related technology introduces computer-aided design, obtains a three-dimensional mesh model of the teeth, combines with preset repair parameters such as the approximate size range of the connecting body, and generates the dental bridge structure by template matching or simple geometric operation. For example, based on a fixed connecting body shape template, it is fitted into the gap between adjacent teeth, and then a preliminary digital design is realized through manual fine adjustment.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related technology: The related technology reduces the manual intervention to a certain extent and improves the design efficiency. However, in actual application, due to the use of fixed templates or simple geometric operations, the structural feature differences of different tooth repair types are not considered, which leads to insufficient fitting between the generated connecting body and the teeth, and the fusion is prone to have a prominent shape and unnatural transition. In addition, it is difficult to meet the requirements of the connecting body stability and functionality, which affects the repair effect.

[0005] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] In order to have a basic understanding of some aspects of the disclosed embodiments, the following is a simple summary. The summary is not a general review, nor is it intended to determine the key / important elements or describe the protection scope of these embodiments, but as a prelude to the detailed description below.

[0007] The embodiment of the present disclosure provides a digital tooth bridge generation method and device, a digital tooth bridge generation system and a computer readable storage medium, so that the fitting degree between the connecting body and the tooth is improved, the appearance is not abrupt after fusion, the transition is not natural, the requirements of the connecting body stability and functionality in the clinic are met, and the repair effect is improved.

[0008] In some embodiments, the method comprises: inputting a tooth three-dimensional mesh model and a bite direction; establishing a tooth local coordinate system based on the bite direction; calculating a connecting body placeable region between adjacent tooth models based on the tooth local coordinate system and a tooth restoration type; generating a connecting body control line based on the connecting body placeable region; constructing a connecting body mesh according to the connecting body control line; and fusing the connecting body mesh with the tooth three-dimensional mesh model to generate a tooth bridge model.

[0009] Optionally, the tooth local coordinate system is established based on the bite direction, comprising: unitizing the bite direction vector as the Z-axis reference direction of the tooth local coordinate system; calculating the difference value of the position vector of the bounding box center points of the adjacent tooth models on both sides of the edentulous gap; projecting the position vector difference onto a direction perpendicular to the Z-axis reference direction to obtain a projection vector; unitizing the projection vector as the Y-axis reference direction; and determining the X-axis reference direction through the cross product of the Z-axis reference direction and the Y-axis reference direction.

[0010] Optionally, the connecting body placeable region between the adjacent tooth models is calculated based on the tooth local coordinate system and the tooth restoration type, comprising: based on the tooth local coordinate system and the tooth restoration type, calculating the connecting body placeable region between the adjacent tooth models, comprising: marking the protection area and the collision area of each tooth model in the adjacent tooth models; wherein the protection area comprises a neck margin area and / or a tooth inner layer area; determining an initial placeable region of the adjacent tooth models based on the tooth local coordinate system and the restoration type; wherein the vertex set of the initial placeable region avoids the protection area; merging the collision area and the initial placeable region, and expanding the neighborhood for the merged region to obtain the connecting body placeable region.

[0011] Optionally, the connector control line is generated based on the connector placement area, including: taking the average of the connector placement area center points of the adjacent tooth models as the origin, and the X-axis reference direction, the Y-axis reference direction and the Z-axis reference direction of the tooth local coordinate system as the corresponding coordinate system directions, to establish a control line coordinate system; projecting the connector placement area boundaries of the adjacent tooth models to the least square surfaces of the respective boundaries respectively, and rotating to the plane with the control line coordinate system origin as the plane point and the Y-axis reference direction as the normal direction, to obtain a first polygon and a second polygon; calculating the intersection of the first polygon and the second polygon, and sorting and sparsifying the intersection boundary point set to generate an initial control boundary; determining the connector shape according to the user selection or the tooth position of the adjacent tooth model; and generating the connector control line of the corresponding shape based on the tooth restoration type and the control line coordinate system, and taking the initial control boundary as the basis.

[0012] Optionally, the connector mesh is constructed according to the connector control line, including: when the adjacent tooth models have a collision area, projecting the collision area boundary and the connector control line to the least square surface, and rotating the point sets projected by the collision area boundary and the connector control line to the plane with the control line coordinate system origin as the plane point and the Y-axis reference direction as the normal direction, to obtain a first collision boundary and a first control boundary; scaling the first collision boundary to obtain a second collision boundary, and making the second collision boundary located within the first control boundary; calculating the convex hull of the second collision boundary and the first control boundary to obtain an optimized control line, and making the optimized control line located within the initial placement area; calculating the plane normal of the connector placement area of the adjacent tooth models, and rotating the optimized control line to the placement area surface with the plane normal of the two-side connector placement area as the z direction, to obtain a first control line and a second control line; calculating the center point set of the first control line and the second control line as a third control line, and according to the collision state, performing interpolation sampling and mesh triangulation on the first control line, the second control line and / or the third control line to generate the connector mesh.

[0013] Optionally, the connector mesh is fused with the tooth three-dimensional mesh model to generate a bridge model, including: performing triangulation and closure processing on the connector mesh; identifying and separating the protection area and the non-protection area in the tooth three-dimensional mesh model; determining a fusion area in the non-protection area based on the intersection relationship between the connector mesh and the tooth three-dimensional mesh model; performing Boolean operation on the connector mesh and the tooth three-dimensional mesh model based on the fusion area to generate a preliminary fusion mesh; integrating the protection area into the preliminary fusion mesh; and performing mesh optimization processing on the interface area of the integrated mesh to generate the bridge model.

[0014] Optionally, the digital dental bridge generation method further comprises: in response to the dragging instruction, re-generating the connector mesh according to the current connector control line; and / or, in response to the morphology switching instruction, re-calculating the connector control line according to the current initial control boundary, and generating the connector mesh; and / or, in response to the control point displacement instruction, re-fitting the connector control line, and generating a new connector mesh.

[0015] In some embodiments, the apparatus comprises a processor and a memory storing program instructions, the processor is configured to execute the digital dental bridge generation method when executing the program instructions.

[0016] In some embodiments, the digital dental bridge generation system comprises a digital dental bridge generation system body, and the digital dental bridge generation apparatus is installed in the digital dental bridge generation system body.

[0017] In some embodiments, the computer readable storage medium stores program instructions, the program instructions execute the digital dental bridge generation method when running.

[0018] The digital dental bridge generation method and apparatus, the digital dental bridge generation system, and the computer readable storage medium provided by the embodiments of the present disclosure can achieve the following technical effects: By inputting the tooth three-dimensional mesh model and the occlusion direction, the complexity of user input is reduced, a unified tooth local coordinate system is established based on the occlusion direction, a standardized space reference is provided for subsequent steps, and then the connector placement area between adjacent tooth models is adaptively calculated in combination with the coordinate system and the tooth restoration type, so as to ensure that the area meets the spatial constraints of a specific restoration type and avoids a protection area. Then, the connector control line is generated based on the connector placement area, accurate guidance is provided for constructing the morphology-adaptive connector mesh, and finally the connector mesh is constructed according to the connector control line and is fused with the tooth three-dimensional mesh model to generate a dental bridge model. Only a small amount of necessary input of the model and the direction drives the whole-chain adaptive processing from the establishment of the standardized coordinate system, the calculation of the safe area, the generation of the control line, to the mesh fusion, reduces the dependence on the preset template and manual intervention of the user, and thus the dental bridge model meeting the clinical functional and aesthetic requirements is efficiently and stably generated. The fit between the connector and the tooth is improved, the situation that the morphology is abrupt and the transition is unnatural after fusion is reduced, and the restoration effect is improved.

[0019] The general description above and the following description below are exemplary and explanatory only and are not intended to be limiting. BRIEF DESCRIPTION OF DRAWINGS

[0020] One or more embodiments are illustrated by way of example in the figures that are not intended to be limiting of the embodiments. Like numbers refer to like elements throughout the drawings, which are not necessarily to scale, and in which: Figure 1 is a schematic diagram of a digital dental bridge generation method provided by an embodiment of the present disclosure; Figure 2 is a schematic diagram of a connector placement area when the dental restoration type is an inlay; Figure 3 is a schematic diagram of a connector placement area when the dental restoration type is a full crown; Figure 4 is a schematic diagram of the highest projection point A, the second highest projection point B, and the lowest projection point C of a dental model; Figure 5 is a schematic diagram of a connector placement area when the dental restoration type is a veneer; Figure 6 is a schematic diagram of a connector mesh after mesh optimization when the dental restoration type is a full crown; Figure 7 is a schematic diagram of a connector with a circular cross-section; Figure 8 is a schematic diagram of a connector with a square cross-section; Figure 9 is a schematic diagram of a connector with a triangular cross-section; Figure 10 is another schematic diagram of a connector with a triangular cross-section provided by an embodiment of the present disclosure; Figure 11 is a schematic diagram of a dental bridge effect when the dental restoration type is a veneer provided by an embodiment of the present disclosure; Figure 12 is a schematic diagram of a full mouth dental bridge generation effect provided by an embodiment of the present disclosure; Figure 13 is a schematic diagram of a digital dental bridge generation device provided by an embodiment of the present disclosure.

[0021] Reference signs: 800: digital dental bridge generation device; 801: processor; 802: memory; 803: communication interface; 804: bus.

[0022] Embodiment Mode In order to enable a more detailed understanding of the features and technical content of the embodiments of the present disclosure, the implementation of the embodiments of the present disclosure is described in detail below, and the accompanying drawings are used for reference only and do not limit the embodiments of the present disclosure. In the following technical description, in order to facilitate explanation, a plurality of details are provided to provide a full understanding of the disclosed embodiments. However, one or more embodiments can still be implemented without these details. In other cases, well-known structures and devices can be simplified to facilitate the drawings.

[0023] The terms "first", "second", and the like in the specification and claims of the embodiments of the present disclosure and the above drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0024] In the embodiments of the present disclosure, the terms "upper", "lower", "inner", "middle", "outer", "front", "back", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the embodiments of the present disclosure and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. In addition, in addition to indicating the orientation or positional relationship, the above-mentioned terms can also be used to indicate other meanings, for example, the term "upper" can also be used to indicate a certain attachment relationship or connection relationship in some cases. For those skilled in the art, the specific meaning of these terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0025] In addition, the terms "set", "connected", "fixed" should be broadly understood. For example, "connected" can be fixedly connected, detachably connected, or integrally configured; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or internal communication between two devices, elements or components. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0026] Unless otherwise specified, the term "a plurality of" means two or more.

[0027] In the embodiments of the present disclosure, the character " / " represents an "or" relationship between the objects before and after it. For example, A / B represents: A or B.

[0028] The term "and / or" is a description of the association between objects, which means that there can be three relationships. For example, A and / or B, which means: A or B, or, A and B, the three relationships.

[0029] The term "corresponding" can refer to a kind of association or binding relationship, A corresponding to B means that there is an association or binding relationship between A and B.

[0030] It should be noted that the embodiments in the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0031] Figure 1 is a schematic diagram of the digital dental bridge generation method provided by the embodiments of the present disclosure, any one of the following methods can be executed in the digital dental bridge generation system, or in the server or terminal device connected in communication with the digital dental bridge generation system.

[0032] In combination with Figure 1 The embodiments of the present disclosure provide a digital dental bridge generation method, which comprises: S01, input a tooth three-dimensional mesh model and a bite direction.

[0033] S02, establish a tooth local coordinate system based on the bite direction.

[0034] S03, calculate the connecting body pluggable region between adjacent tooth models based on the tooth local coordinate system and the tooth restoration type.

[0035] S04, generate a connecting body control line based on the connecting body pluggable region.

[0036] S05, construct a connecting body mesh according to the connecting body control line.

[0037] S06, fuse the connecting body mesh with the tooth three-dimensional mesh model to generate a dental bridge model.

[0038] The digital dental bridge generation method provided in the embodiment of the disclosure reduces the complexity of user input by inputting a tooth three-dimensional mesh model and a bite direction, establishes a unified tooth local coordinate system based on the bite direction, provides a standardized spatial reference for subsequent steps, and then adaptively calculates a connecting body pl acement area between adjacent tooth models in combination with the coordinate system and the tooth restoration type, ensures that the area meets the spatial constraints of a specific restoration type and avoids a protection area, generates a connecting body control line based on the connecting body placement area, provides accurate guidance for constructing a connecting body mesh that is morphologically adapted, and finally constructs a connecting body mesh according to the connecting body control line and fuses the connecting body mesh with the tooth three-dimensional mesh model to generate a dental bridge model. Only a small amount of necessary input of the model and the direction drives the whole chain adaptive processing from the establishment of the standardized coordinate system, the calculation of the safe area, the generation of the control line to the mesh fusion, reduces the dependence on the preset template and user manual intervention, and thus efficiently and stably generates a dental bridge model that meets the clinical functional and aesthetic requirements. The fit between the connecting body and the tooth is improved, the situation of abrupt shape and unnatural transition after fusion is reduced, and the restoration effect is improved.

[0039] Optionally, the tooth local coordinate system is established based on the bite direction, including: unitizing the bite direction vector as the Z-axis reference direction of the tooth local coordinate system; calculating the difference value of the position vector of the bounding box center points of the adjacent tooth models on both sides of the edentulous gap; projecting the difference value of the position vector onto a direction perpendicular to the Z-axis reference direction to obtain a projection vector; unitizing the projection vector as the Y-axis reference direction; and determining the X-axis reference direction through the cross product of the Z-axis reference direction and the Y-axis reference direction.

[0040] In this way, by directly using the bite direction (reflecting the clinically expected tooth arrangement direction) input by the user as the Z-axis reference, the coordinate system is ensured to be aligned with the real bite requirement, and the Y-axis is calculated by projecting the difference value of the bounding box center points of the adjacent tooth models, and the X-axis is automatically derived through the cross product, so that a unified and adaptive tooth local coordinate system is established. This avoids relying on artificial preset or experience adjustment, provides a standardized spatial reference for subsequent connecting body placement area calculation, enables the subsequent steps to perform adaptive processing based on consistent directions, reduces the problems of connecting body shape misalignment or insufficient fit caused by coordinate system deviation, and improves the accuracy of dental bridge generation and the naturalness of the overall restoration effect.

[0041] Optionally, based on the tooth local coordinate system and the tooth restoration type, a connecting body placeable region between adjacent tooth models is calculated, including: marking a protection region and a collision region of each tooth model in the adjacent tooth models; wherein the protection region includes a cervical margin region and / or a tooth inner layer region; determining an initial placeable region of the adjacent tooth models based on the tooth local coordinate system and the restoration type; wherein the initial placeable region vertex set avoids the protection region; merging the collision region with the initial placeable region, and expanding the neighborhood of the merged region to obtain the connecting body placeable region.

[0042] In the embodiments of the present disclosure, the initial placeable region vertex set not only avoids the protection region vertex set, but also avoids the jaw side, part of the lingual side and / or the buccal side.

[0043] In the embodiments of the present disclosure, when the tooth restoration type is a full crown or an inlay, the restoration type corresponding screening operation includes: screening a candidate vertex subset with an angle of 45°±5° between the vertex normal and the Y-axis reference direction (connecting body generation direction); performing a contraction operation once and an expansion operation twice on the candidate vertex subset to generate an optimized vertex subset (which can be based on the adaptive adjustment of the mesh vertex curvature); topologically fusing the optimized vertex subset with the neighborhood vertex set; and excluding jaw surface region vertices based on the Z-axis reference direction to obtain the screened region vertex set corresponding to the inlay as shown in Figure 2 or the full crown restoration type as shown in Figure 3 When the tooth restoration type is a veneer, the restoration type corresponding screening operation includes: calculating the highest projection point, the second highest projection point and the lowest projection point of each tooth model based on the Z-axis reference direction projection as shown in Figure 4 ; constructing a first screening plane based on the highest projection point and the X-axis reference direction; constructing a second screening plane based on the lowest projection point and the Z-axis reference direction; performing a double-plane screening on the merged region vertex set using the first screening plane and the second screening plane; and correcting the region curvature continuity based on the second highest projection point to obtain the screened region vertex set corresponding to the veneer restoration type as shown in Figure 5 . The calculation of the second highest projection point includes: taking the highest projection point as a reference point; taking the Z-axis reference direction and the Y-axis reference direction to form a cross-sectional plane normal; calculating the vertex farthest from the reference point in the cross-sectional plane as the second highest projection point; and / or using the second highest projection point to correct the normal direction of the first screening plane. Using the first screening plane and the second screening plane, the double-plane screening on the merged region vertex set includes: retaining the vertices located on the positive side of the first screening plane; and retaining the vertices located on the positive side of the second screening plane.

[0044] In the embodiments of the present disclosure, the expansion of the neighborhood for the merging region includes: taking the collision region boundary vertex as the starting point, traversing outward along the topological grid connection relationship, extracting the grid vertices directly adjacent to the collision region boundary vertex on the topological grid; and merging the extracted vertices with the collision region vertices and marking them as a neighborhood vertex set. The neighborhood is a 1-ring neighborhood or a 2-ring neighborhood in the sense of grid topology, and the specific selection can be made according to actual needs.

[0045] In actual application, based on the tooth local coordinate system and the tooth restoration type, the connecting body placement region between adjacent tooth models is calculated, including: traversing the vertices of the tooth three-dimensional grid model, marking the vertex patches with the neck region attribute or the tooth inner layer region attribute as the protection region; detecting the collision between adjacent tooth models, calculating the vertex set of tooth model A inside tooth model B and the intersection line of the collision, marking the vertex set and the intersection line vertex as the collision region attribute; expanding the spherical neighborhood space for the collision region vertex, and marking the vertices in the neighborhood space as the collision region attribute; performing adjacent face screening calculation based on the tooth local coordinate system and the restoration type; based on the tooth local coordinate system and the tooth restoration type, the connecting body placement region between adjacent tooth models is calculated, including: when the restoration type is a full crown or an inlay, traversing the vertices of the tooth three-dimensional grid model, screening the vertices with the vertex normal and the Y-axis reference direction of the tooth local coordinate system at an angle of 45 degrees for marking; performing a contraction operation and two expansion operations on the marked vertex set, which is based on the curvature of the grid vertex for adaptive region growth or reduction to connect sparse or discontinuous regions; calculating the maximum connected region in the processed vertex set, screening out small connected regions formed by the jaw surface or other special shapes to obtain the screened region vertex set corresponding to the inlay as shown in Figure 2 or the full crown restoration type as shown in Figure 3 , the maximum connected region vertex set is taken as the initial placement region; when there is a collision region, the collision region vertex set is merged with the initial placement region vertex set, and two neighborhood spaces are expanded for the merged vertex set to ensure complete coverage of the collision region, and the expanded region is cropped to generate a placement region grid; the boundary point set of the placement region grid is calculated and sorted; for the other adjacent tooth model, the same process is calculated, but the vertex normal is used in the screening vertex at an angle of 45 degrees with the opposite direction of the Y-axis reference direction of the tooth local coordinate system; when the restoration type is a veneer, six target direction vectors are defined; traversing the vertices of the tooth three-dimensional grid model, calculating the dot product of the vertex normal and the six target direction vectors, and distributing the vertices to the direction category with the largest dot product; screening the vertices distributed to the category closest to the Y-axis reference direction of the tooth local coordinate system and marking them; performing three contraction operations and two expansion operations on the marked vertex set; calculating the maximum connected region vertex set as the candidate region; based on the Z-axis reference direction projection of the tooth local coordinate system, the calculation of the veneer placement region is as shown in Figure 4The highest projection point A and the lowest projection point C of the tooth model shown; taking the highest projection point A as the reference point, the cross product of the Z-axis reference direction and the Y-axis reference direction of the tooth local coordinate system as the profile normal direction, a profile plane is constructed, and the distance from the profile plane to the highest projection point A is calculated as Figure 4 The vertex farthest from the point A is shown as the second highest projection point B; the direction is judged by the lowest projection point C, and the positive direction is determined on the side of point C; point A1 is obtained by offsetting point A by 0.5mm in the negative direction of the Y-axis reference direction of the tooth local coordinate system, point A1 is taken as the plane point, and the first screening plane is constructed by taking the profile normal after direction correction as the plane normal, and the vertices in the candidate region located on the positive side of the first screening plane are retained; point C1 is obtained by offsetting point C by 1mm in the Z-axis reference direction of the tooth local coordinate system, point C1 is taken as the plane point, and the second screening plane is constructed by taking the Z-axis reference direction of the tooth local coordinate system as the normal, and the vertices in the candidate region located on the positive side of the second screening plane are retained, and the obtained Figure 5 The screened region vertex set corresponding to the veneer restoration type is taken as the initial placeable region; the subsequent collision region merging, neighborhood expansion, clipping and boundary sorting operations are the same as those of the full crown or inlay restoration type; for the adjacent tooth model, the same process is calculated, but in the direction classification, the category closest to the negative direction of the Y-axis reference direction of the tooth local coordinate system is selected.

[0046] In this way, by marking the protection area (including the cervical margin area and the inner layer area of the tooth) and the collision area of each tooth model in the adjacent tooth model based on the established tooth local coordinate system and the tooth restoration type, and further determining the initial placeable region (whose vertex set actively avoids the protection area) based on the coordinate system and the restoration type, then merging the collision region with the initial placeable region and expanding the neighborhood for the merged region, and finally obtaining the connector placeable region, the generation range of the connector is effectively constrained, which not only meets the specific morphological requirements of different restoration types, but also avoids interference with key tooth structures such as the cervical margin and the inner layer of the tooth, and also fully considers the possible collision situation in actual application, thereby providing an accurate, safe and clinically required spatial basis for the subsequent shape generation and fusion of the connector, and improving the fit and naturalness of the final dental bridge model and the restoration effect.

[0047] Optionally, the connector control line is generated based on the connector placement area, including: taking the average of the center points of the connector placement areas of the adjacent tooth models as the origin, and the X-axis reference direction, the Y-axis reference direction and the Z-axis reference direction of the tooth local coordinate system as the corresponding coordinate system directions, to establish a control line coordinate system; projecting the boundaries of the connector placement areas of the adjacent tooth models to the least square surfaces of the respective boundaries respectively, and rotating to the plane with the control line coordinate system origin as the plane point and the Y-axis reference direction as the normal direction, to obtain a first polygon and a second polygon; calculating the intersection of the first polygon and the second polygon, and sorting and sparsifying the intersection boundary point set to generate an initial control boundary; determining the connector shape according to the user selection or the tooth position of the adjacent tooth model; and generating the connector control line of the corresponding shape based on the tooth restoration type and the control line coordinate system, and taking the initial control boundary as the basis.

[0048] In the embodiments of the present disclosure, based on the tooth restoration type and the control line coordinate system, the connecting body control line of a corresponding shape (triangle, rectangle or circle) is generated based on the initial control boundary, including: calculating the area of the polygon formed by the initial control boundary; if the area is less than 10 mm2, there is no collision between adjacent tooth models, and the distance between the connecting body placement area of each tooth model in the adjacent tooth model in the Y-axis reference direction is greater than 0.5 mm, the control line generation strategy of the veneer restoration type (fitting a smooth curve based on the initial control boundary) is adopted; otherwise, the control line generation strategy of the full crown or inlay restoration type is adopted. The control line generation strategy of the full crown or inlay restoration type includes: calculating the maximum area rectangle inside the polygon formed by the initial control boundary, the rectangle direction is along the Z-axis reference direction of the control line coordinate system, projecting the polygon to the plane with the Y-axis reference direction of the control line coordinate system as the normal direction, constructing a rectangular local coordinate system, wherein the Z-axis reference direction of the control line coordinate system is taken as the Y-axis direction of the rectangular local coordinate system, by calculating the inner product of the X-axis reference direction of the control line coordinate system and the lingual direction, if the inner product is positive, the X-axis reference direction of the control line coordinate system is taken as the X-axis direction of the rectangular local coordinate system, if the inner product is negative, the opposite direction of the X-axis reference direction of the control line coordinate system is taken as the X-axis direction of the rectangular local coordinate system, and the Z-axis direction is obtained by the cross product of the X-axis direction and the Y-axis direction of the rectangular local coordinate system and the three directions are unitized; calculating the minimum circumscribed rectangle of the polygon formed by the initial control boundary, dividing the grid points with a step length of 0.2 mm, checking whether each grid point is located inside the polygon, marking the grid points in the range of 0 to 1 / 4 along the X-axis direction of the rectangular local coordinate system in the minimum circumscribed rectangle grid as 0 to screen out the buccal area point set, and marking the remaining grid points as 1 if they are located inside the polygon or as 0 if they are not, to form a two-dimensional matrix; based on the dynamic programming algorithm, the largest rectangular area point set composed of elements marked as 1 is found in the two-dimensional matrix, which is taken as the maximum area rectangle inside the irregular polygon of the initial control boundary, and the center of the rectangle is taken as the center point of the connecting body control line. The length and width ratio of the rectangle and the minimum area limit are used to calculate the connecting body control line of a circle or a rectangle; or based on the dynamic programming algorithm, the maximum area upper triangle or lower triangle along the Z-axis reference direction of the control line coordinate system is calculated, and the minimum area limit is used to calculate the connecting body control line of the upper triangle or lower triangle. When the tooth restoration type is veneer. The control line generation strategy of the veneer restoration type includes: fitting and approximating the initial control boundary to generate a smooth transition connecting body control line, or generating a connecting body control line of a specified shape according to the full crown or inlay restoration type strategy in response to a user instruction.Specifically, the initial control boundary point set can be sparsified, retaining points with a spacing of not less than 0.1 mm to reduce redundant data. Based on the sparsified initial control boundary point set, a cubic B-spline curve is fitted, allowing the fitted curve to naturally approximate the initial control boundary shape, ensuring a smooth visual transition. If tooth misalignment causes boundary discontinuity, the fitted curve is piecewise interpolated, and the curve slope is adjusted using least-squares optimization at the misalignment points to ensure a smooth transition. The area of ​​the polygon formed by the fitted curve is calculated using the shoelace formula; if the area is less than 4 mm², it is scaled proportionally to not less than 4 mm² to meet clinical stability requirements. The scaled curve is projected onto the surface where the connector can be placed, and the control point position is corrected using minimum distance query to ensure the curve falls entirely within the connector's placement area, generating the connector control line for veneer restorations. Furthermore, when responding to a shape switching command, the control line for veneer restorations is used as a reference, and the shape constraints of the initial control boundary are consulted to recalculate triangular, rectangular, or circular control lines, ensuring the new shape boundary does not exceed the connector's placement area.

[0049] In this embodiment of the disclosure, the shape of the cross-section of the connector is determined based on the tooth position, such as a connector with a circular, square, or triangular cross-section. Figure 7 , 8 Figures 9 and 1 are schematic diagrams illustrating a connecting body with a circular, square, and triangular cross-section, respectively, provided by embodiments of this disclosure. Typically, the two sides of the connecting body have the same shape. In some cases, the two sides of the connecting body may have different shapes, such as one side being a triangle and the other a square; or one side being a rectangle and the other a circle, etc. The shapes on both sides of the connecting body may have the same or different orientations, such as one side being a rectangle with its long side facing the X-axis reference direction, and the other side being a rectangle with its long side facing the Z-axis reference direction; or, as... Figure 10 As shown, the cross-section of the anterior teeth is an upward-facing triangle, while the cross-section of the posterior teeth is a downward-facing triangle.

[0050] Thus, by taking the average of the center points of the connective placement regions of the adjacent tooth models as the origin and using the reference direction of the established tooth local coordinate system to construct a unified control line coordinate system, a stable spatial reference framework is provided for subsequent processing. By projecting the placement regions on both sides to the least squares plane and rotating them to the same reference plane, the geometric data from different teeth is effectively aligned, reducing misalignment caused by initial position differences. By calculating the intersection of the two polygons to generate an initial control boundary, and sorting and sparsifying it, the symmetry and data rationality of the control line basis are ensured. Finally, the initial control boundary is used as the basis to adaptively generate connective control lines of specific shapes in combination with the tooth restoration type and user selection or tooth position information, so that the final generated control lines can adapt to the morphological constraints and clinical aesthetic requirements of the two sides of the teeth, laying a foundation for subsequent construction of connective meshes with high fit and natural shape.

[0051] Optionally, the connective mesh is constructed according to the connective control line, comprising: when there is a collision region between the adjacent tooth models, projecting the collision region boundary and the connective control line onto the least squares plane, and rotating the point sets after projecting the collision region boundary and the connective control line onto the plane with the origin of the control line coordinate system as the plane point Y-axis reference direction and the normal direction as the normal direction, to obtain the first collision boundary and the first control boundary; scaling the first collision boundary to obtain the second collision boundary, and making the second collision boundary located within the first control boundary; calculating the convex hull of the second collision boundary and the first control boundary to obtain the optimized control line, and making the optimized control line located within the initial placement region; calculating the plane normal of the connective placement region of the adjacent tooth models, and rotating the optimized control line to the placement region surface with the plane normal of the connective placement region on both sides as the z direction to obtain the first control line and the second control line; calculating the center point set of the first control line and the second control line as the third control line, and according to the collision state, interpolating sampling and mesh triangulation are performed on the first control line, the second control line and / or the third control line to generate the connective mesh.

[0052] In the embodiments of the present disclosure, in order to obtain a required optimization control line, a first least square plane is obtained by fitting the collision region boundary point set through the least square method, the collision region boundary point set is projected onto the plane in the normal direction of the first least square plane, and then the projected point set is rotated onto a plane with the control line coordinate system origin point as a plane point and the control line coordinate system Y axis reference direction as a normal direction, to obtain a first collision boundary; a second least square plane is obtained by fitting the connecting body control line point set through the least square method, the connecting body control line point set is projected onto the plane in the normal direction of the second least square plane, and then the projected point set is rotated onto a plane with the control line coordinate system origin point as a plane point and the control line coordinate system Y axis reference direction as a normal direction, to obtain a first control boundary; the first collision boundary is scaled by 1.3 times in the scaling direction of the control line coordinate system Y axis reference direction to obtain a second collision boundary; when the second collision boundary is not inside the polygon formed by the first control boundary, the vector difference between the center points of the first control boundary and the second collision boundary is calculated, the vector difference is multiplied by 0.5 to obtain a displacement offset, and the first control boundary is moved by the displacement offset, so that the second collision boundary is located inside the polygon formed by the moved first control boundary; the convex hull point set of the second collision boundary and the moved first control boundary is calculated as an optimization control line; the optimization control line point set is sparsified to remove points with too close distances, the intervals of point sets with too large distances are interpolated, a cubic B-spline curve is used to fit the optimization control line point set, and the optimization control line point set is resampled at a fixed step length; the cross product direction of the order of the optimization control line point set is calculated to ensure that the direction is the same as the control line coordinate system Y axis reference direction.

[0053] In the disclosed embodiment, in order to obtain a qualified connector mesh, the spatial position of the optimized control line point set can be adjusted by translation or scaling matrix transformation to make the optimized control line point set as a whole located within the boundary range of the initial placeable region; the average normal of the mesh of the left and right connector placeable regions is calculated respectively as the plane normal of each; the optimized control line point set is rotated respectively to the plane with the plane normal of the left connector placeable region as the Z-axis direction to obtain the first control line, and to the plane with the plane normal of the right connector placeable region as the Z-axis direction to obtain the second control line; the point set is moved to the nearest mesh surface position found by the minimum distance query based on the mesh surface of the corresponding side of the connector placeable region for the first control line and the second control line point set, and then a cubic spline curve is fitted by the approximation method and the curve is resampled with a fixed step to obtain the first control line and the second control line point set which are smooth and close to the mesh surface; the center points of each corresponding sequential point in the first control line point set and the second control line point set are calculated to form the third control line point set; when there is a collision region, the first control line point set and the second control line point set are directly interpolated and sampled; when there is no collision region, the first control line point set, the third control line point set and the second control line point set are sequentially interpolated and sampled; the area of the polygon surrounded by the third control line point set is calculated by the Shoelace formula, and if the area is less than 4 mm2, the third control line point set is scaled in proportion to the area; the point set obtained after all interpolation sampling is triangulated to generate the connector mesh.

[0054] In this way, by projecting the collision region boundary and the generated connector control line to the least squares plane and rotating to the unified reference plane when there is a collision region between adjacent tooth models, the spatial positions of the collision region and the preset control line are effectively aligned in the same comparable reference system. By scaling the first collision boundary to generate the second collision boundary and ensuring that it is located inside the first control boundary, the connector form can fully wrap the collision region. By calculating the convex hull of the second collision boundary and the first control boundary to obtain the optimized control line and constraining it within the initial placeable region, conflicts with the protection region are avoided, and the natural transition of the connector form is ensured. By rotating the optimized control line to the plane with the plane normal of the left and right connector placeable regions as the reference, the first control line and the second control line are generated to fit the tooth surface. Finally, the third control line is obtained by calculating the center point set, and the control line is adaptively selected for interpolation sampling and triangulation according to the collision state, so that the finally generated connector mesh can adaptively avoid collision interference while maintaining good fitting and natural form with the tooth surfaces on both sides, providing a high-quality mesh basis for subsequent fusion operations.

[0055] Optionally, the connector mesh is fused with the tooth three-dimensional mesh model to generate a bridge model, including: performing a triangulation closing process on the connector mesh; identifying and separating a protection area and a non-protection area in the tooth three-dimensional mesh model; determining a fusion area in the non-protection area based on the intersection relationship between the connector mesh and the tooth three-dimensional mesh model; performing a Boolean operation on the connector mesh and the tooth three-dimensional mesh model based on the fusion area to generate a preliminary fusion mesh; integrating the protection area into the preliminary fusion mesh; performing a mesh optimization process on the interface area of the integrated mesh to generate the bridge model.

[0056] In the embodiments of the present disclosure, the connector mesh is fused with the tooth three-dimensional mesh model to generate a bridge model, including: calculating a boundary point set of the connector mesh and sorting the boundary point set; extending a boundary center point in a reverse direction along the connector based on the sorted boundary point set to obtain an extended vertex; performing a triangulation closing process on the connector mesh based on the extended vertex and the boundary point set; separating a protection area and a non-protection area of the tooth three-dimensional mesh model; wherein the protection area includes a cervical margin area and a tooth inner layer area; detecting a collision area of the tooth three-dimensional mesh model and the connector mesh, and marking tooth mesh vertices inside the collision area as a fusion point set; expanding neighborhood vertices of the fusion point set, and marking the expanded area as a connection area; based on the connection area, the tooth three-dimensional mesh model is divided into a connection area and a non-connection area; wherein tooth models located at both ends of a tooth sequence are divided into one connection area and one non-connection area, and tooth models located in the middle of the tooth sequence are divided into two connection areas and one non-connection area; the connection area mesh is fused with the connector mesh to remove self-intersecting surface patches and non-manifold edges, to obtain an intermediate fusion mesh; the intermediate fusion mesh and the non-connection area mesh are executed to remove duplicate vertices, remove duplicate surface patches, remove very close vertices, re-mesh, and smooth processing, to optimize the mesh form of the interface area, to obtain an optimized mesh; the separated protection area is integrated into the optimized mesh to generate a bridge model.

[0057] Specifically, the boundary vertices of the connector mesh are calculated and sorted; the center points of the left and right boundary vertex sets of the connector mesh are calculated respectively, new vertices are obtained by extending a preset distance in the opposite direction of the connector generation direction, and the connector mesh is triangulated and closed using the new vertices and the ordered boundary vertices; the cervical margin area and the inner layer area of the tooth three-dimensional mesh model are identified as protection areas, the protection areas are separated from the tooth three-dimensional mesh model, and the remaining part is a non-protection area; the connector placement area is taken as a basic connection area, the collision area between the connector mesh and the tooth three-dimensional mesh model is detected, the tooth mesh vertices located inside the collision area are marked as a fusion point set and set as a connection area; the connection area is expanded to a spherical neighborhood vertex, and the neighborhood vertex is marked as a connection area; the vertices inside the collision area in the connector mesh and the boundary vertices on both sides of the connector mesh are marked as a fusion point set; the tooth three-dimensional mesh model is divided according to the sequence position of the tooth in the dental bridge, the tooth models at both ends of the sequence are divided into one connection area and one non-connection area, the tooth models in the middle of the sequence are divided into two connection areas and one non-connection area, and the neighborhood vertices of the connection areas are expanded during the division process; the connector mesh is fused with the connection area mesh of the tooth models on both sides, the self-intersecting facets are eliminated, the non-manifold edges are screened and removed, and the triangular facets that do not belong to the point set inside the collision area and do not contain non-manifold edges are screened out, to obtain a preliminary fusion mesh; the non-connection area is integrated with the preliminary fusion mesh, the repeated vertices and repeated facets are removed, the extremely close vertices of the Boolean operation boundary area are deleted, the re-meshing and fairing operations are performed on the boundary area, the mesh form at the junction is optimized, and an optimized mesh is obtained, such as shown in FIG. 8, which is an optimized mesh of a tooth restoration type of a full crown; the separated protection area is integrated into the optimized mesh to generate a final dental bridge model, such as shown in FIG. 9, which is a dental bridge model of a tooth restoration type of a veneer, and such as shown in FIG. 10, which is a multi-bridge dental bridge model generated for a full mouth. Figure 6 Figure 11 Figure 12

[0058] ​​​Thus, by first performing a triangulation closing process on the connector mesh, the integrity and closure of the connector mesh itself are ensured, providing a structurally complete geometric object for subsequent fusion operations. By identifying and separating the protected and non-protected areas in the tooth three-dimensional mesh model, the key structures of the teeth that cannot be modified (such as the neck margin and the inner layer of the teeth) and the safe area that can be fused are effectively distinguished, preventing accidental modification of the key structures. Based on the intersection relationship between the connector mesh and the tooth three-dimensional mesh model, the fusion area is accurately determined in the non-protected area, so that the subsequent Boolean operation can accurately act on the target area, avoiding unnecessary mesh interference. Based on the fusion area, the Boolean operation is performed to generate a preliminary fusion mesh, realizing the preliminary seamless combination of the connector and the main structure of the tooth. Finally, by re-integrating the protected area into the preliminary fusion mesh and optimizing the mesh at the junction area, the original protected structure of the tooth is restored while the mesh quality at the fusion junction is improved, making the final generated dental bridge model transition naturally in form and complete and reliable in structure, effectively improving the overall aesthetics and clinical applicability of the restoration.

[0059] Optionally, the digital dental bridge generation method further comprises: in response to a dragging instruction, re-generating a connector mesh according to a current connector control line; and / or, in response to a form switching instruction, re-calculating a connector control line according to a current initial control boundary, and generating a connector mesh; and / or, in response to a control point displacement instruction, re-fitting a connector control line, and generating a new connector mesh.

[0060] Thus, by responding to the dragging instruction to directly re-generate the connector mesh based on the current connector control line, repeated coordinate system establishment and placeable area calculation are avoided. In response to the form switching instruction, the connector control line is recalculated and the mesh is generated using the existing geometric reference. In response to the control point displacement instruction, only the connector control line is refitted and a new mesh is generated, maintaining the repair type constraint. Using the established high-quality geometric basis, local updating is used instead of global reconstruction, ensuring that the connector form meets the clinical constraints, improving user interaction editing efficiency, and avoiding form mutations or fit degradation caused by full-flow recalculation, providing flexible and stable technical support for personalized adjustment.

[0061] In combination Figure 13As shown, the embodiment of the present disclosure provides a digital dental bridge generation device 800, which comprises a processor 801 and a memory 802. Optionally, the device can further comprise a communication interface 803 and a bus 804. The processor 801, the communication interface 803 and the memory 802 can complete mutual communication through the bus 804. The communication interface 803 can be used for information transmission. The processor 801 can invoke the logical instructions in the memory 802 to execute the digital dental bridge generation method of the above-mentioned embodiment.

[0062] In addition, the logical instructions in the memory 802 described above can be realized in the form of a software functional unit and sold or used as an independent product, which can be stored in a computer readable storage medium.

[0063] The memory 802 as a computer readable storage medium can be used to store software programs, computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 801 executes the program instructions / modules stored in the memory 802, thereby performing functional applications and data processing, i.e. realizing the digital dental bridge generation method in the above-mentioned embodiment.

[0064] The memory 802 can include a program storage area and a data storage area, wherein the program storage area can store an operating system and application programs required by at least one function; the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory 802 can include a high-speed random access memory, and can also include a non-volatile memory.

[0065] The embodiment of the present disclosure provides a digital dental bridge generation system 900, which comprises a digital dental bridge generation system body and the above-mentioned digital dental bridge generation device 800. The digital dental bridge generation device 800 is installed in the digital dental bridge generation system body. The installation relationship described herein is not limited to placing in the digital dental bridge generation system, but also includes installation connection with other components of the digital dental bridge generation system, including but not limited to physical connection, electrical connection or signal transmission connection, etc. Those skilled in the art can understand that the digital dental bridge generation device 800 can be adapted to a feasible digital dental bridge generation system body, and thus realize other feasible embodiments.

[0066] The embodiment of the present disclosure provides a computer readable storage medium, which stores computer executable instructions, and the computer executable instructions are set to execute the above-mentioned digital dental bridge generation method.

[0067] The technical solutions of the embodiments of the present disclosure can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes one or more instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method disclosed in the embodiments of the present disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0068] The above description and drawings sufficiently illustrate the embodiments of the present disclosure to enable one skilled in the art to practice them. Other embodiments can include structural, logical, electrical, process, and other changes. The embodiments represent only a few of the possible variations. Individual components and functions are optional unless explicitly required, and the order of operations can be changed. Parts and features of some embodiments can be included or replaced by parts and features of other embodiments. Also, the words used in this application are used only to describe the embodiments and not to limit the claims. As used in the description of the embodiments and the claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Similarly, the term "and / or" as used in this application refers to any and all possible combinations of one or more associated listed items. In addition, when used in this application, the term "comprise" and its variants "comprises" and / or comprises" and the like mean the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Without more limitations, the element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the process, method, or device that includes the stated element. In this document, each embodiment focuses on the differences from other embodiments, and the same or similar parts between embodiments can be referred to each other. For the method, product, etc. disclosed in the embodiments, if it corresponds to the method part disclosed in the embodiments, the relevant part can be referred to the description of the method part.

[0069] Those skilled in the art can understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods for each specific application to realize the described functions, but such implementation should not be considered beyond the scope of the embodiments of the present disclosure. The skilled person can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0070] In the embodiments disclosed herein, the disclosed methods, products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the above-described device embodiments are only schematic, for example, the division of the units can only be a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms. The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to implement the embodiments. In addition, each functional unit in the embodiments of the present disclosure can be integrated in one processing unit, or each unit can be a physically independent unit, or two or more units can be integrated in one unit.

[0071] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other processing device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other processing device to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

Claims

1. A method for generating a digital denture, characterized in that, The method comprises the following steps: inputting a three-dimensional mesh model of teeth and a bite direction; establishing a local coordinate system of the teeth based on the bite direction; calculating a connective body placeable region between adjacent tooth models based on the local coordinate system of the teeth and a tooth restoration type; generating a connective body control line based on the connective body placeable region; constructing a connective body mesh according to the connective body control line; fusing the connective body mesh with the three-dimensional mesh model of the teeth to generate a dental bridge model.

2. The method of claim 1, wherein, The method for establishing a local coordinate system of the teeth based on the bite direction comprises the following steps: unitizing the bite direction vector as a Z-axis reference direction of the local coordinate system of the teeth; calculating a difference value of position vector of the center points of the bounding boxes of the adjacent tooth models on both sides of the edentulous space; projecting the difference value of the position vector onto a direction perpendicular to the Z-axis reference direction to obtain a projection vector; unitizing the projection vector as a Y-axis reference direction; determining an X-axis reference direction through the cross product of the Z-axis reference direction and the Y-axis reference direction.

3. The method of claim 1, wherein, The method for calculating a connective body placeable region between adjacent tooth models based on the local coordinate system of the teeth and a tooth restoration type comprises the following steps: marking a protection region and a collision region of each tooth model in the adjacent tooth models; wherein the protection region comprises a neck region and / or a tooth inner layer region; determining an initial placeable region of the adjacent tooth models based on the local coordinate system of the teeth and the restoration type; wherein the vertex set of the initial placeable region avoids the protection region; merging the collision region and the initial placeable region, and expanding the neighborhood of the merged region to obtain the connective body placeable region.

4. The method of claim 1, wherein, The method for generating a connective body control line based on the connective body placeable region comprises the following steps: establishing a control line coordinate system with the average value of the center points of the connective body placeable regions of the adjacent tooth models as the origin, and the X-axis reference direction, the Y-axis reference direction and the Z-axis reference direction of the local coordinate system of the teeth as the corresponding coordinate system directions; projecting the boundaries of the connective body placeable regions of the adjacent tooth models onto the least square planes of the respective boundaries, and rotating them to the planes with the origin of the control line coordinate system as the plane point and the Y-axis reference direction as the normal direction to obtain a first polygon and a second polygon; calculating the intersection of the first polygon and the second polygon, and sorting and sparsifying the boundary point set of the intersection to generate an initial control boundary; determining the shape of the connective body according to the user selection or the tooth position of the adjacent tooth models; generating a connective body control line of the corresponding shape based on the tooth restoration type and the control line coordinate system, and taking the initial control boundary as the basis.

5. The method of claim 1, wherein, The method for constructing a connective body mesh according to the connective body control line comprises the following steps: when the adjacent tooth models have collision regions, projecting the collision region boundaries and the connective body control line onto the least square planes, and rotating the point sets of the projected collision region boundaries and the connective body control line onto the planes with the origin of the control line coordinate system as the plane point and the Y-axis reference direction as the normal direction to obtain a first collision boundary and a first control boundary; scaling the first collision boundary to obtain a second collision boundary, and making the second collision boundary located within the first control boundary; calculating the convex hull of the second collision boundary and the first control boundary to obtain an optimized control line, and making the optimized control line located within the initial placeable region; A normal of the connecting body placeable region of the adjacent tooth model is calculated, and the optimization control lines are rotated to the placeable region surface with the normal of the connecting body placeable region of the two sides as the z direction, to obtain a first control line and a second control line; A center point set of the first control line and the second control line is calculated as a third control line, and interpolation sampling and mesh triangulation are performed on the first control line, the second control line and / or the third control line according to the collision state, to generate a connecting body mesh.

6. The method of claim 1, wherein, The connecting body mesh is fused with the tooth three-dimensional mesh model to generate a dental bridge model, including: Triangulation and closing processing are performed on the connecting body mesh; The protection area and the non-protection area in the tooth three-dimensional mesh model are identified and separated; Based on the intersection relationship between the connecting body mesh and the tooth three-dimensional mesh model, a fusion area is determined in the non-protection area; Based on the fusion area, the connecting body mesh and the tooth three-dimensional mesh model are subjected to Boolean operation to generate a preliminary fusion mesh; The protection area is integrated into the preliminary fusion mesh; The interface area of the integrated mesh is subjected to mesh optimization processing to generate a dental bridge model.

7. The method according to any one of claims 1 to 6, characterized in that, Further comprising: In response to a dragging instruction, the connecting body mesh is regenerated according to the current connecting body control line; And / or, In response to a mode switching instruction, the connecting body control line is recalculated according to the current initial control boundary, and the connecting body mesh is generated; and / or, In response to a control point displacement instruction, the connecting body control line is refitted, and a new connecting body mesh is generated.

8. A digital denture generation apparatus comprising a processor and a memory having stored program instructions, wherein, The processor is configured to execute the digital dental bridge generation method of any one of claims 1 to 7 when running the program instructions.

9. A digital denture generation system, characterized by, Including: A digital dental bridge generation system body; And, The digital dental bridge generation device of claim 8 is installed in the digital dental bridge generation system body.

10. A computer readable storage medium storing program instructions, wherein the program instructions comprise instructions for causing a computer to perform the method of any one of claims 1-9. The program instructions, when running, are used to make the computer execute the digital dental bridge generation method of any one of claims 1 to 7.

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