Method for constructing maxillary sinus lifting model through reverse three-dimensional finite element and hydraulic lifting method

Abstract

The invention provides a method for constructing a maxillary sinus lifting model through a reverse three-dimensional finite element and a hydraulic lifting method, and the method comprises the steps: collecting a maxillary bone CBCT image, extracting a maxillary sinus three-dimensional model contour, and carrying out three-dimensional reverse reconstruction to generate a cortical bone, cancellous bone and mucous membrane three-dimensional model. And then, establishing a maxillary sinus lifting channel model, assembling the maxillary sinus lifting channel model into a complete maxillary sinus three-dimensional model, endowing material parameters and a contact relationship, obtaining a finite element model by adopting tetrahedral mesh division, and finally obtaining a maxillary sinus lifting model by simulating hydraulic lifting loading and iterative solution. Compared with a traditional impact method, the method has the advantages that the operation difficulty and risk are lower, the method is safer, the problem of nonlinear large deformation and complex contact behaviors are solved, and therefore the accuracy and stability of a simulation result are improved.

Description

Technical Field

[0001] The invention relates to the technical field of maxillary sinus lifting, and in particular to a method for constructing a maxillary sinus lifting model by using a reverse three-dimensional finite element and hydraulic lifting method. Background Art

[0002] In the field of oral medicine, sinus lift is used to increase the bone height in the maxillary posterior area to facilitate implant placement. Traditional sinus lift techniques mainly use the impact method, which is to directly act on the maxillary sinus floor mucosa or bone blocks through tools such as punches to indirectly or directly lift the maxillary sinus floor mucosa. However, this method has some obvious shortcomings: First, during the implementation of the impact method, the operator needs to constantly adjust the force and rhythm of the tapping according to the feel of the hand, which not only requires high skills from the operator, but also makes it difficult to accurately control the height and force of the lift, thereby increasing the risk and uncertainty of the operation. In addition, when there are complex shapes such as intervals or slopes in the maxillary sinus floor, the application of the impact method is more difficult, which also increases the risk of the operation.

[0003] With the development of computer technology, finite element analysis (FEA) methods have been widely used in oral biomechanics research. By constructing a three-dimensional finite element model of the maxillary sinus, the process of maxillary sinus lift surgery can be simulated and the biomechanical effects of different methods on the maxillary sinus mucosa can be analyzed. However, in addition to being related to the accuracy of the finite element model, the results are also closely related to the structural research of the model-related material properties and the setting of the model boundary conditions. Although in vitro experiments have already had a certain understanding of the mechanical properties and deformation characteristics of the maxillary sinus mucosa, the maxillary sinus mucosa is a complex soft tissue material with large deformation nonlinearity, and the finite element modeling and calculation methods are more complicated. The main reasons are reflected in the following aspects: First, hyperelastic materials have nonlinear stress-strain relationships, and their behavior is difficult to describe with simple linear models. This requires the use of more complex material models to accurately capture the behavior of the material, such as the Mooney-Rivlin, Yeoh model, or Arruda-Boyce model; second, hyperelastic membrane materials may experience large deformations during loading, which not only puts forward requirements for the material model, but also challenges the numerical method of the solver. Large deformation problems involve the updating of material configurations, the processing of nonlinear geometry, and other issues, and specific numerical algorithms are required to ensure the accuracy and stability of the calculations. Third, when the membrane material contacts other objects or folds itself, it becomes particularly complicated to deal with contact problems. Contact analysis needs to consider the friction, adhesion and other behaviors between the contact surfaces, which increases the nonlinearity of the model and the difficulty of solving. Fourth, the implementation of boundary conditions and loading: For membrane materials, their boundary conditions and loading methods may be relatively special, such as the application of prestress, boundary constraints, etc., which requires special attention when modeling and applying loading to ensure the accuracy of the analysis. Fifth, due to the nonlinear problems and large deformation processing mentioned in the above points, the three-dimensional finite element analysis of hyperelastic membrane materials usually requires higher computing resources, including longer computing time and larger memory requirements, which is particularly obvious for large problems or problems that require fine meshing.

[0004] Therefore, the existing technical solution of constructing the maxillary sinus lift model using the impact method has the disadvantages of high difficulty in operation, high risk and inaccurate simulation results. At the same time, FEA also faces challenges in constructing the maxillary sinus lift model, such as complex material models, time-consuming calculation process and unstable results. In order to solve these problems, it is necessary to develop a more accurate, reliable and easy-to-operate method for constructing the maxillary sinus lift model. Summary of the invention

[0005] In view of the above problems, the present invention is proposed to provide a method for constructing a maxillary sinus lift model using the inverse three-dimensional finite element and hydraulic lifting method, which overcomes the above problems or at least partially solves the above problems, and a corresponding device for constructing a maxillary sinus lift model using the inverse three-dimensional finite element and hydraulic lifting method, an electronic device and a computer-readable medium.

[0006] The present invention discloses a method for constructing a maxillary sinus lifting model by using a reverse three-dimensional finite element and hydraulic lifting method, the method comprising:

[0007] Acquiring a maxillary CBCT image, and extracting a maxillary sinus three-dimensional model contour from the maxillary CBCT image;

[0008] Performing three-dimensional reverse reconstruction on the contour of the maxillary sinus three-dimensional model to generate a cortical bone three-dimensional model, a cancellous bone three-dimensional model, and a mucosa three-dimensional model, and performing feature recognition and surface diagnosis on the cortical bone three-dimensional model, the cancellous bone three-dimensional model, and the mucosa three-dimensional model to repair the defective surface;

[0009] A three-dimensional model of the maxillary sinus lifting channel is established, and the three-dimensional model of the cortical bone, the three-dimensional model of the cancellous bone, the three-dimensional model of the mucosa, and the three-dimensional model of the maxillary sinus lifting channel are assembled into a three-dimensional model of the maxillary sinus;

[0010] Assigning corresponding material parameters and contact relationships to the cortical bone three-dimensional model, the cancellous bone three-dimensional model, the mucosa three-dimensional model, and the maxillary sinus lifting channel three-dimensional model of the maxillary sinus three-dimensional model, respectively, and dividing the maxillary sinus three-dimensional model by tetrahedral meshing to obtain a maxillary sinus three-dimensional finite element model;

[0011] A loading surface is formed on the mucosal surface of the maxillary sinus three-dimensional finite element model by using channel projection, and hydraulic lifting is simulated to apply load to the loading surface. At the same time, the Mooney-Rivlin model and updated Lagrangian method are used in finite element analysis for iterative solution until the calculation converges to obtain the maxillary sinus lifting model.

[0012] Optionally, the mucosa is set to the C10 and C01 parameters of Hyperelastic; the cortical bone and the cancellous bone are in bound contact, and the cortical bone and the mucosa are in frictionless contact; when simulating different degrees of separation of the mucosa, the unseparated mucosal area and the corresponding maxillary area are treated as having common nodes, and the nodes of the separated mucosal area and the corresponding maxillary area are not in contact and are not treated as having common points.

[0013] Optionally, the loading mode is a force load; the force load mode is a quasi-static loading mode starting from 0 kPa and with a rate of 0.1 mm / s; the direction in which the liquid applies uniform pressure on the loading surface is vertical and lateral.

[0014] Optionally, the three-dimensional model of the maxillary sinus lifting channel is a cylindrical hole with a diameter of 4 mm.

[0015] Optionally, at the beginning of lifting, the stress concentration point of the maxillary sinus mucosa is in the center of the force application point, and as the lifting height increases, the stress concentration point spreads from the center to the surrounding areas.

[0016] Optionally, performing three-dimensional reverse reconstruction on the contour of the three-dimensional model of the maxillary sinus to generate a three-dimensional model of cortical bone, a three-dimensional model of cancellous bone, and a three-dimensional model of mucosa includes:

[0017] Finely segmenting the contour of the maxillary sinus three-dimensional model to distinguish the cortical bone area, the cancellous bone area and the mucosal area;

[0018] The cortical bone region, cancellous bone region and mucosal region were subjected to smooth denoising, surface construction, gridding and solidification operations respectively to generate the cortical bone 3D model, cancellous bone 3D model and mucosal 3D model; the mucosal thickness was set to 1 mm.

[0019] Optionally, acquiring a maxillary CBCT image, and extracting a maxillary sinus three-dimensional model contour from the maxillary CBCT image, comprises:

[0020] Scan the maxillary bone to obtain the maxillary CBCT image;

[0021] The maxillary CBCT image is automatically thresholded according to the grayscale values ​​of different tissues, the tissues surrounding the maxillary sinus are preliminarily separated, and the redundant parts are erased or the missing parts are supplemented, and smoothing is performed to obtain the contour of the maxillary sinus three-dimensional model.

[0022] The present invention also discloses a device for constructing a maxillary sinus lifting model using a reverse three-dimensional finite element and hydraulic lifting method, the device comprising:

[0023] A maxillary sinus contour extraction module is used to collect a maxillary CBCT image and extract a maxillary sinus three-dimensional model contour from the maxillary CBCT image;

[0024] A three-dimensional reverse reconstruction module is used to perform three-dimensional reverse reconstruction on the contour of the three-dimensional model of the maxillary sinus, generate a three-dimensional model of cortical bone, a three-dimensional model of cancellous bone, and a three-dimensional model of mucosa, and perform feature recognition and surface diagnosis on the three-dimensional model of cortical bone, the three-dimensional model of cancellous bone, and the three-dimensional model of mucosa to repair the defective surface;

[0025] A physical assembly module is used to establish a three-dimensional model of the maxillary sinus lifting channel, and assemble the cortical bone three-dimensional model, the cancellous bone three-dimensional model, the mucosa three-dimensional model, and the maxillary sinus lifting channel three-dimensional model into a maxillary sinus three-dimensional model;

[0026] a maxillary sinus three-dimensional finite element model construction module, for respectively assigning corresponding material parameters and contact relationships to the cortical bone three-dimensional model, the cancellous bone three-dimensional model, the mucosa three-dimensional model, and the maxillary sinus lifting channel three-dimensional model of the maxillary sinus three-dimensional model, and dividing the maxillary sinus three-dimensional model by tetrahedral meshing to obtain a maxillary sinus three-dimensional finite element model;

[0027] The hydraulic lifting and finite element analysis module is used to form a loading surface on the mucosal surface of the three-dimensional finite element model of the maxillary sinus by using channel projection, and simulate hydraulic lifting to apply load to the loading surface. At the same time, the Mooney-Rivlin model and the updated Lagrangian method are used in the finite element analysis to perform iterative solution until the calculation converges to obtain the maxillary sinus lifting model.

[0028] Optionally, the mucosa is set to the C10 and C01 parameters of Hyperelastic; the cortical bone and the cancellous bone are in bound contact, and the cortical bone and the mucosa are in frictionless contact; when simulating different degrees of separation of the mucosa, the unseparated mucosal area and the corresponding maxillary area are treated as having common nodes, and the nodes of the separated mucosal area and the corresponding maxillary area are not in contact and are not treated as having common points.

[0029] Optionally, the loading mode is a force load; the force load mode is a quasi-static loading mode starting from 0 kPa and with a rate of 0.1 mm / s; the direction in which the liquid applies uniform pressure on the loading surface is vertical and lateral.

[0030] Optionally, the three-dimensional model of the maxillary sinus lifting channel is a cylindrical hole with a diameter of 4 mm.

[0031] Optionally, at the beginning of lifting, the stress concentration point of the maxillary sinus mucosa is in the center of the force application point, and as the lifting height increases, the stress concentration point spreads from the center to the surrounding areas.

[0032] Optionally, the three-dimensional reverse reconstruction module includes:

[0033] A region segmentation submodule is used to finely segment the contour of the maxillary sinus three-dimensional model to distinguish the cortical bone region, the cancellous bone region and the mucosal region;

[0034] The 3D model generation submodule is used to perform smooth denoising, surface construction, gridding, and solidification operations on the cortical bone area, cancellous bone area, and mucosal area, respectively, to generate a cortical bone 3D model, a cancellous bone 3D model, and a mucosal 3D model; the mucosal thickness is set to 1 mm.

[0035] Optionally, the maxillary sinus contour extraction module includes:

[0036] The maxillary CBCT image acquisition submodule is used to scan the maxillary bone to obtain the maxillary CBCT image;

[0037] The maxillary sinus contour extraction submodule is used to perform automatic threshold segmentation on the maxillary CBCT image according to the grayscale values ​​of different tissues, preliminarily separate the tissues around the maxillary sinus, erase the redundant parts or fill in the missing parts, and perform smoothing to obtain the maxillary sinus 3D model contour.

[0038] The present invention also discloses an electronic device, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0039] The memory is used to store computer programs;

[0040] The processor is used to implement the method of constructing a maxillary sinus lifting model by using the reverse three-dimensional finite element and hydraulic lifting method as described in the present invention when executing the program stored in the memory.

[0041] The present invention also discloses one or more computer-readable media having instructions stored thereon, which, when executed by one or more processors, enable the processors to execute the method of constructing a maxillary sinus lifting model by using the inverse three-dimensional finite element and hydraulic lifting method as described in the present invention.

[0042] The present invention includes the following advantages:

[0043] The method of constructing a maxillary sinus lifting model by using the reverse three-dimensional finite element and hydraulic lifting method of the present invention collects the maxillary CBCT image, extracts the contour of the maxillary sinus three-dimensional model, and performs three-dimensional reverse reconstruction to generate a three-dimensional model of the cortical bone, cancellous bone and mucosa. Subsequently, a maxillary sinus lifting channel model is established, assembled into a complete maxillary sinus three-dimensional model, and material parameters and contact relationships are assigned. The finite element model is obtained by tetrahedral meshing, and then the maxillary sinus lifting model is finally obtained by simulating hydraulic lifting loading and iterative solution. Compared with the traditional impact method, this method has lower operating difficulty and risk, is safer, and solves the problem of nonlinear large deformation and complex contact behavior, thereby improving the accuracy and stability of the simulation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a flowchart of the steps of the method for constructing a maxillary sinus lifting model by using the reverse three-dimensional finite element and hydraulic lifting method provided by the present invention;

[0045] Figure 2 It is a reference schematic diagram of the outline of the maxillary sinus three-dimensional model provided by the present invention;

[0046] Figure 3 It is a reference schematic diagram of the three-dimensional figure of the maxillary bone provided by the present invention;

[0047] Figure 4It is a reference schematic diagram of the three-dimensional solid model of cancellous bone and mucosa provided by the present invention;

[0048] Figure 5 is a reference schematic diagram of an osteotome provided by the present invention;

[0049] Figure 6 is a reference schematic diagram of the maxillary sinus assembly entity provided by the present invention;

[0050] Figure 7 is a reference schematic diagram of the other side of the maxillary sinus assembly entity provided by the present invention;

[0051] Figure 8 is a reference schematic diagram of the maxillary sinus finite element model provided by the present invention;

[0052] Fig. 9 is a reference schematic diagram of the other side of the maxillary sinus finite element model provided by the present invention;

[0053] Fig.10 is a reference schematic diagram of the contact surface structure provided by the present invention;

[0054] Fig.11 It is the finite element cross-sectional view of M1 provided by the present invention;

[0055] Fig.12 It is the M1 calculation convergence diagram provided by the present invention;

[0056] Fig.13 It is the finite element cross-sectional view of M2 provided by the present invention;

[0057] Fig.14 It is the M2 calculation convergence diagram provided by the present invention;

[0058] Fig.15 It is the finite element cross-sectional view of M3 provided by the present invention;

[0059] Fig.16 It is the M3 calculation convergence diagram provided by the present invention. DETAILED DESCRIPTION

[0060] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0061] Reference Figure 1 , shows a flowchart of the steps of the method for constructing a maxillary sinus lifting model using the reverse three-dimensional finite element and hydraulic lifting method provided in an embodiment of the present invention, which may specifically include the following steps:

[0062] Step 101, acquiring a maxillary CBCT image, and extracting a maxillary sinus three-dimensional model contour from the maxillary CBCT image;

[0063] Step 102, performing 3D reverse reconstruction on the contour of the maxillary sinus 3D model to generate a cortical bone 3D model, a cancellous bone 3D model, and a mucosa 3D model, and performing feature recognition and surface diagnosis on the cortical bone 3D model, the cancellous bone 3D model, and the mucosa 3D model to repair the defective surface;

[0064] Step 103, establishing a three-dimensional model of the maxillary sinus lifting channel, and assembling the cortical bone three-dimensional model, the cancellous bone three-dimensional model, the mucosa three-dimensional model, and the maxillary sinus lifting channel three-dimensional model into a maxillary sinus three-dimensional model;

[0065] Step 104, respectively assigning corresponding material parameters and contact relationships to the cortical bone three-dimensional model, the cancellous bone three-dimensional model, the mucosa three-dimensional model, and the maxillary sinus lifting channel three-dimensional model of the maxillary sinus, and dividing the maxillary sinus three-dimensional model by tetrahedral meshing to obtain a maxillary sinus three-dimensional finite element model;

[0066] Step 105, using channel projection to form a loading surface on the mucosal surface of the maxillary sinus three-dimensional finite element model, and simulating hydraulic lifting to apply load to the loading surface. At the same time, the Mooney-Rivlin model and the updated Lagrangian method are used in the finite element analysis to perform iterative solution until the calculation converges to obtain the maxillary sinus lifting model.

[0067] The present invention collects CBCT images of the maxillary bone, which are the basic data required to construct a three-dimensional model of the maxillary sinus. From the CBCT image, the contour of the three-dimensional model of the maxillary sinus can be accurately extracted. Next, the contour of the three-dimensional model of the maxillary sinus can be three-dimensionally reverse reconstructed to generate a three-dimensional model of the cortical bone, cancellous bone and mucosa. In order to ensure the accuracy and reliability of the model, the geometric model can be further subjected to feature recognition and surface diagnosis, the problematic surfaces can be repaired, and then the remaining models of the maxillary sinus can be established, and a three-dimensional model of the maxillary sinus lifting channel can be established, and then the assembly interface can be entered to adjust the position, and the cortical bone, maxillary sinus membrane, and osteotome can be assembled into a complete entity according to the grouping.

[0068] In the assembled maxillary sinus 3D model, each component is assigned corresponding material parameters and contact relationships, which reflect the physical properties of the tissue. Afterwards, the entire maxillary sinus 3D model is divided using a tetrahedral mesh to obtain a maxillary sinus 3D finite element model.

[0069] Finally, the loading surface is formed on the mucosal surface by using the hole projection, and the hydraulic lifting is simulated to apply the load to the loading surface. The elastic modulus is a physical quantity that describes the elasticity of solid materials. It reflects the ease with which the shape or size of the material changes when it is subjected to external force. The main characteristic of liquid is its fluidity. Therefore, when the liquid is subjected to external force, it will not resist this force by restoring its original shape, but will flow to adapt to the direction of the external force. Therefore, from the perspective of physics, liquids do not have elastic modulus in the traditional sense because they do not have the ability to restore their original shape like solids. In the three-dimensional finite element model, the pressure load can be directly applied to the boundary of the liquid. In the finite element analysis, the Mooney-Rivlin model and the updated Lagrangian method are used for iterative solution until the calculation converges. This process simulates the actual hydraulic lifting surgery and obtains the maxillary sinus lifting model. The role of this step is to predict the effect of the surgery and provide valuable reference information for doctors.

[0070] The method of the present invention can generate a high-precision three-dimensional model of the maxillary sinus by collecting maxillary CBCT images and performing three-dimensional reverse reconstruction, including key structures such as cortical bone, cancellous bone, mucosa, and maxillary sinus lifting channel, greatly improving the accuracy and reliability of the model, and providing a solid foundation for subsequent finite element analysis. Secondly, the maxillary sinus three-dimensional model is divided into tetrahedral meshes, and combined with the Mooney-Rivlin model and the updated Lagrangian method for iterative solution, which can more accurately simulate the biomechanical changes during the maxillary sinus lifting procedure. This method not only takes into account the nonlinear stress-strain relationship of the material, but also can handle large deformation problems and complex contact behaviors, thereby improving the accuracy and stability of the simulation results.

[0071] In one embodiment of the present invention, the mucosa is set to the C10 and C01 parameters of Hyperelastic; the cortical bone and the cancellous bone are in bound contact, and the cortical bone and the mucosa are in frictionless contact; when simulating different degrees of separation of the mucosa, the unseparated mucosal area and the corresponding maxillary area are treated as having common nodes, and the nodes of the separated mucosal area and the corresponding maxillary area are not in contact and are not treated as having common points.

[0072] The maxillary sinus mucosa is a complex soft tissue material with large deformation and nonlinearity. In this embodiment, the mucosa is set to the C10 and C01 parameters of Hyperelastic. For the contact settings of cortical bone, cancellous bone, and mucosa, the following settings are adopted: the cortical bone and cancellous bone are in binding contact, and the cortical bone and mucosa are in frictionless contact to ensure the true transmission of force. When simulating the separation of mucosa to different degrees, the unseparated mucosa area and the corresponding maxillary area are treated as common nodes, and the mucosa of the separated area and the corresponding maxillary area are not in contact or treated as common points.

[0073] In one embodiment of the present invention, the load mode is a force load; the force load mode is a quasi-static loading mode starting from 0 kPa and with a rate of 0.1 mm / s; the direction in which the liquid applies uniform pressure on the loading surface is vertical and lateral.

[0074] The three-dimensional finite element loading methods are mainly divided into force loading and displacement loading. Force loading mainly studies the strain of the material when different forces are applied to the material, and displacement loading mainly studies the strain of the material after the material is forced to be displaced to a specified position. According to preliminary experiments in the early stage, displacement loading is not suitable for three-dimensional finite element research of the hydraulic lifting method. Displacement loading requires setting the bottom area and height of the loading. During the loading process, the bottom area does not change, and all nodes of the material are forced to the specified height. During the hydraulic lifting process, the bottom area changes continuously due to the strong fluidity of the liquid; the sinus floor is irregular in shape, and the superelastic properties of the mucosa make the lifting height different in different parts, and the displacement loading model is significantly different from the actual one. Therefore, the present invention selects the force loading mode as the main loading method of the present invention.

[0075] In the loading process, it is usually divided into dynamic loads, static loads and quasi-static loads, which describe the nature and effect of the forces acting on an object. Dynamic loads refer to loads that change in magnitude, direction or point of application over time. The characteristic of this load is that it will cause a dynamic response of the structure, that is, the deformation and stress distribution of the structure will change over time. Dynamic loads are usually applied in a very short time. Static loads refer to loads that are slowly applied to the structure and do not change in magnitude and direction during the action process. The characteristic of this load is that the response of the structure is basically static during the action time, that is, the deformation and stress distribution of the structure remain unchanged over time. Quasi-static loading is a method used to simulate static problems. By applying slowly changing loads to the finite element model, it can be ensured that the structural response is close to a static equilibrium state at any given moment. The key to this method is to set appropriate parameters, such as loading speed and analysis step time, to prevent local deformation problems that may occur due to excessive loading. Today, dynamic loads are more frequently used to study the effects of chewing processes and traumatic impacts. Static loads mainly evaluate the stress distribution of implants or restorations under different directions such as vertical loading and buccolingual loading. Since the hydraulic lifting process requires a slower liquid injection speed, the quasi-static load is more in line with the characteristics of the hydraulic lifting process.

[0076] This embodiment adopts a quasi-static load method of mechanical loading, applies uniform pressure to the liquid boundary, and performs quasi-static load on the model. Specifically, the force load mode is a quasi-static loading mode starting from 0 kPa and a rate of 0.1 mm / s; the direction in which the liquid applies uniform pressure on the loading surface is vertical and lateral, and finally the calculation is smooth and convergent experimental results are obtained.

[0077] In one embodiment of the present invention, at the initial stage of lifting, the stress concentration point of the maxillary sinus mucosa is at the center of the force application point, and as the lifting height increases, the stress concentration point spreads from the center to the surrounding areas.

[0078] According to the results of finite element analysis, when the maxillary sinus mucosa is lifted to the same height, the horizontal strain of the maxillary sinus mucosa in the hydraulic lifting method is significantly greater than that in the impact method, and the equivalent stress, tensile stress, compressive stress, and shear stress are all less than those in the impact method, and the difference is statistically significant. In the early stage of lifting, the stress concentration point of the maxillary sinus mucosa in the hydraulic lifting method is in the center of the force point, and as the lifting height increases, the stress concentration point spreads from the middle to the surrounding areas; while in the early stage of lifting, the stress concentration point of the impact method is around the force point, and as the lifting height increases, the stress concentration point gathers from the surrounding areas to the center. It can be seen that the hydraulic lifting method is safer than the impact method.

[0079] In one embodiment of the present invention, the three-dimensional reverse reconstruction of the contour of the maxillary sinus three-dimensional model is performed to generate a three-dimensional model of cortical bone, a three-dimensional model of cancellous bone, and a three-dimensional model of mucosa, including:

[0080] Finely segmenting the contour of the maxillary sinus three-dimensional model to distinguish the cortical bone area, the cancellous bone area and the mucosal area;

[0081] The cortical bone region, cancellous bone region and mucosal region were subjected to smooth denoising, surface construction, gridding and solidification operations respectively to generate the cortical bone 3D model, cancellous bone 3D model and mucosal 3D model; the mucosal thickness was set to 1 mm.

[0082] In one embodiment of the present invention, the three-dimensional model of the maxillary sinus lifting channel is a cylindrical hole with a diameter of 4 mm.

[0083] In an embodiment of the present invention, a three-dimensional reverse reconstruction technology is used to construct a three-dimensional model of the maxillary sinus, and the extracted contour of the three-dimensional model of the maxillary sinus can be finely segmented to clearly distinguish the cortical bone area, the cancellous bone area and the mucosal area. Then, smooth denoising, surface construction, gridding and solidification operations are performed on these three areas respectively to generate a three-dimensional model of cortical bone, a three-dimensional model of cancellous bone and a three-dimensional model of mucosa, wherein the thickness of the mucosa can be set to 1mm. In addition, in the process of constructing the three-dimensional model of the maxillary sinus, a cylindrical hole with a diameter of 4mm is designed as a three-dimensional model of the maxillary sinus lifting channel. Thus, the three-dimensional model of the frontal sinus can be assembled using these established three-dimensional models.

[0084] In one embodiment of the present invention, acquiring a maxillary CBCT image and extracting a maxillary sinus three-dimensional model contour from the maxillary CBCT image includes:

[0085] Scan the maxillary bone to obtain the maxillary CBCT image;

[0086] The maxillary CBCT image is automatically thresholded according to the grayscale values ​​of different tissues, the tissues surrounding the maxillary sinus are preliminarily separated, and the redundant parts are erased or the missing parts are supplemented, and smoothing is performed to obtain the contour of the maxillary sinus three-dimensional model.

[0087] In an embodiment of the present invention, the maxillary bones of volunteers are scanned by CT, and the obtained DICOM format file is input into the three-dimensional reconstruction software, and the following processes are performed in sequence: 1) Automated threshold segmentation is performed according to the grayscale values ​​of different tissues to preliminarily separate the tissues surrounding the maxillary sinus; 2) The manual editing layer tool is used to erase the redundant parts or fill in the missing parts, smooth the model, extract the contour of the entire maxillary sinus three-dimensional model, and export it in an STL format file.

[0088] The following is a specific example to introduce the experimental process of constructing a maxillary sinus lifting model using the reverse three-dimensional finite element and hydraulic lifting method of the present invention, as well as a comparative analysis with the maxillary sinus lifting model constructed by the impact method:

[0089] This experiment reconstructed the maxillary sinus 3D model by using CBCT scanning data, making full use of various modeling software, simplifying the tedious process of image processing and conversion, and significantly improving the accuracy of the model. The experiment used Mimics software to quickly and accurately establish a preliminary model of the human maxillary sinus, and then used Geomagic software to optimize and smooth the model, successfully establishing a 3D finite element model of the maxillary sinus, and finally imported ANSYS finite element software for related stress analysis, which can measure the stress of each point or surface, and can also simulate any form of pressure.

[0090] 1.1 Experimental Purpose

[0091] The maxillary sinus lifting model of reverse three-dimensional finite element and hydraulic lifting method, and the maxillary sinus lifting model of impact method were established, analyzed and verified for subsequent research.

[0092] 1.2. Experimental subjects

[0093] The imaging data of the maxillary sinus of a 26-year-old female patient with missing left maxillary first molar was selected as the research object. The maxillary sinus morphology of this patient was C3 type maxillary sinus.

[0094] Materials and methods

[0095] 1.3.1 Experimental equipment

[0096] Laptop: Basic configuration is Intel i7, 32G memory, 256G high-speed solid-state drive, 1T mechanical hard drive, operating system Windows 10

[0097] 1.3.2 Experimental Grouping

[0098] M1: Hydraulic lifting method; M2: The impactor performs direct impact on the maxillary sinus floor mucosa; M3: The impactor is used to directly impact the maxillary sinus floor mucosa.

[0099] 1.3.3 Modeling process

[0100] (1) CT file processing

[0101] The maxillary bones of volunteers were scanned by CT, and the obtained DICOM format files were input into the 3D reconstruction software, and the following processes were performed in sequence: 1) Automated threshold separation was performed according to the grayscale values ​​of different tissues to preliminarily separate the tissues around the maxillary sinus; 2) The manual editing layer tool was used to erase the redundant parts or fill in the missing parts, smooth the model, extract the contour of the entire maxillary sinus 3D model, and export it in STL format, such as Figure 2 shown.

[0102] (2) 3D entity reconstruction

[0103] Import the STL file obtained above into the reverse engineering software. Perform a series of image processing such as smoothing and denoising, surface construction, gridding, and solidification on the 3D models one by one to generate the maxillary 3D graphics IGES file format, such as Figure 3 The same method was used to obtain a three-dimensional solid model of cancellous bone and mucosa, as shown in Figure 4 As shown in the figure, the mucosal thickness is set to 1 mm, and a cylindrical hole with a diameter of 4.0 mm is established as the maxillary sinus lifting channel.

[0104] (3) Model assembly

[0105] Impact method: Two different diameters ( and ) of Summers osteotome, such as Figure 5 shown.

[0106] Import the geometric model format file generated by the 3D solid reconstruction software into the SolidWorks software, perform feature recognition and surface diagnosis on the geometric model, repair the problematic surfaces, and then use the feature / surface modules in the part interface to build the rest of the maxillary sinus model. Enter the assembly interface to adjust the position, and assemble the cortical bone, cancellous bone, maxillary sinus membrane, maxillary sinus lifting channel or osteotome into a complete entity according to the grouping. Figure 6 and Figure 7 .

[0107] (4) Grid division

[0108] The cortical bone, pine bone, and mucosal assembly models are assigned corresponding material parameters and contact relationships are set, and then meshing is performed. Tetrahedral meshing is used, and the mesh size is 0.5 mm. The final three-dimensional finite element model is established. Figure 8 and Fig. 9 The statistical numbers of nodes and elements are shown in Table 1.

[0109] Table 1 Statistics of the number of nodes and elements

[0110]

[0111] (5) Material properties

[0112] Import the IGES format data into the three-dimensional finite element analysis software. Assign values ​​to the cortical bone, cancellous bone, maxillary sinus mucosa, and the punch, as shown in Table 2. In this study, the maxillary sinus mucosa was set to the C10 and C01 parameters of Hyperelastic. In order to improve the calculation accuracy, convergence, and calculation efficiency, the cortical bone, cancellous bone, and mucosa were divided into tetrahedral grid units, and the punch was divided into tetrahedral grid units.

[0113] Table 2 Material elastic modulus, Poisson's ratio and element type

[0114]

[0115] (6) Contact settings

[0116] The cortical bone and cancellous bone are in binding contact, the cortical bone and mucosa are in frictionless contact, the top of the punch and the mucosa are in friction contact, and the friction coefficient is 0.2; the periphery of the punch does not contact the maxillary hole area, and the separated mucosa and the unseparated mucosa are treated as common nodes to ensure the true transmission of force. When simulating different degrees of separation of mucosa, the unseparated mucosa area and the corresponding maxillary area are treated as common nodes, and the mucosa of the separated area does not contact the nodes of the corresponding maxillary area and is not treated as common points.

[0117] (7) Constraints and loads

[0118] Assume that the maxillary bone and the punch are isotropic, uniform, and continuous linear elastic materials; the mucosa is set as a hyperelastic material. During the simulated impact process, the punch is only allowed to have vertical displacement in the height direction, and the lateral displacement limits its freedom. During the hydraulic lifting process, the liquid is allowed to have vertical and lateral displacement. The load mode is selected as force load.

[0119] (8) Solution

[0120] The large deformation nonlinear iterative solution is adopted and the solution process is completed in the solution module of ANSYS.

[0121] Description of strain and stress under large deformation conditions:

[0122] ①Green strain is defined as

[0123]

[0124] In the formula, δ ij is the Kronecher symbol; u i =x i (X i ,t)-X j is the displacement vector defined in the initial configuration.

[0125] The material derivative of Green's strain is:

[0126]

[0127] ② The Cauchy stress has a directed element n on the current configuration i The force ΔT acting on ΔA i , in the limit state,

[0128]

[0129] Surf n i Stress vector t on dA i (n) , expressed by stress vectors on three plane elements perpendicular to the coordinate axis, we have t i (n) =σ ij n j is the Cauchy stress tensor, σ ij To define the stress per unit area in the current configuration, it is the true stress associated with the deformation.

[0130] Contact interface algorithm selection: The symmetric penalty function method is mainly used in the calculation of this invention. All contact units use penalty stiffness (contact stiffness to ensure the coordination of the contact interface). Fig.10 .

[0131] (9) Three-dimensional finite element analysis

[0132] The three-dimensional finite element simulation process of the hydraulic impact method: ① The construction of the loading surface: The loading surface is formed on the mucosal surface by using the hole projection. ② By applying uniform pressure to the constructed loading surface, the direction is perpendicular to the loading surface (the pressure of the liquid on the surface is perpendicular to the contact surface). The quasi-static loading mode starts from 0kPa and the rate is 0.1mm / s.

[0133] Impact method 3D finite element simulation process: The impact method does not need to construct a loading surface, and directly applies pressure on the punch. Here, pressure = punch area x hydraulic pressure value.

[0134] 1.4 Results

[0135] The liquid and the impact device simulated the upward movement of the maxillary sinus floor mucosa and produced deformation, achieving an effect similar to the mucosal lifting in clinical maxillary sinus lift surgery, and obtained convergent experimental results. The hydraulic lifting method and impact method maxillary sinus lifting model were successfully constructed.

[0136] M1 finite element simulation diagram:

[0137] Fig.11 A in the middle is the total strain of the maxillary sinus mucosa (X-axis); B is the von Mises stress distribution (coronal plane); C is the von Mises stress distribution (viewed from above).

[0138] The calculation convergence diagram of M1 is as follows Fig.12 shown.

[0139] M2 finite element simulation diagram:

[0140] Fig.13 A in the middle is the total strain of the maxillary sinus mucosa (X-axis); B is the von Mises stress distribution (coronal plane); C is the von Mises stress distribution (viewed from above).

[0141] The calculation convergence diagram of M2 is as follows Fig.14 shown.

[0142] M3 finite element simulation diagram:

[0143] Fig.15 A in the middle is the total strain of the maxillary sinus mucosa (X-axis); B is the von Mises stress distribution (coronal plane); C is the von Mises stress distribution (viewed from above).

[0144] The calculation convergence diagram of M3 is as follows Fig.16 shown.

[0145] According to the results of finite element analysis, when the maxillary sinus mucosa is lifted to the same height, the horizontal strain of the maxillary sinus mucosa in the hydraulic lifting method is significantly greater than that in the impact method, and the equivalent stress, tensile stress, compressive stress, and shear stress are all less than those in the impact method, and the difference is statistically significant. In the early stage of lifting, the stress concentration point of the maxillary sinus mucosa in the hydraulic lifting method is in the center of the force point, and as the lifting height increases, the stress concentration point spreads from the middle to the surrounding areas; in the early stage of lifting, the stress concentration point of the impact method is around the force point, and as the lifting height increases, the stress concentration point gathers from the surrounding areas to the center. From this study, it can be seen that the hydraulic lifting method is safer than the impact method.

[0146] This study used the Mooney-Rivlin model and the Updated Lagrangian Approach in the calculation. These methods can handle the large deformation of materials and structures during loading. Adaptive mesh refinement technology was used to ensure that there was sufficient mesh density in areas with large deformation to capture details, while reducing the number of meshes in areas with small deformation to save computing resources. The C10 and C01 parameters of Hyperelastic, which were similar, were obtained by fitting. The effects of different lifting methods on the stress characteristics of the maxillary sinus mucosa were studied from a qualitative perspective. Finally, the calculation was smooth and converged experimental results were obtained. The trend of the stress and displacement values ​​generated at the interface also showed that the design of the experimental parameters was reasonable, and it also played a certain guiding role in clinical operations. At the same time, it was verified that the model established by the hydraulic lifting method had good geometric similarity and biomechanical similarity.

[0147] It should be noted that, for the sake of simplicity, the method embodiments are described as a series of action combinations, but those skilled in the art should be aware that the embodiments of the present invention are not limited by the order of the actions described, because according to the embodiments of the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.

[0148] The present invention also provides a device for constructing a maxillary sinus lifting model using a reverse three-dimensional finite element and hydraulic lifting method, which may specifically include the following modules:

[0149] A maxillary sinus contour extraction module is used to collect a maxillary CBCT image and extract a maxillary sinus three-dimensional model contour from the maxillary CBCT image;

[0150] A three-dimensional reverse reconstruction module is used to perform three-dimensional reverse reconstruction on the contour of the three-dimensional model of the maxillary sinus, generate a three-dimensional model of cortical bone, a three-dimensional model of cancellous bone, and a three-dimensional model of mucosa, and perform feature recognition and surface diagnosis on the three-dimensional model of cortical bone, the three-dimensional model of cancellous bone, and the three-dimensional model of mucosa to repair the defective surface;

[0151] A physical assembly module is used to establish a three-dimensional model of the maxillary sinus lifting channel, and assemble the cortical bone three-dimensional model, the cancellous bone three-dimensional model, the mucosa three-dimensional model, and the maxillary sinus lifting channel three-dimensional model into a maxillary sinus three-dimensional model;

[0152] a maxillary sinus three-dimensional finite element model construction module, for respectively assigning corresponding material parameters and contact relationships to the cortical bone three-dimensional model, the cancellous bone three-dimensional model, the mucosa three-dimensional model, and the maxillary sinus lifting channel three-dimensional model of the maxillary sinus three-dimensional model, and dividing the maxillary sinus three-dimensional model by tetrahedral meshing to obtain a maxillary sinus three-dimensional finite element model;

[0153] The hydraulic lifting and finite element analysis module is used to form a loading surface on the mucosal surface of the three-dimensional finite element model of the maxillary sinus by using channel projection, and simulate hydraulic lifting to apply load to the loading surface. At the same time, the Mooney-Rivlin model and the updated Lagrangian method are used in the finite element analysis to perform iterative solution until the calculation converges to obtain the maxillary sinus lifting model.

[0154] Optionally, the mucosa is set to the C10 and C01 parameters of Hyperelastic; the cortical bone and the cancellous bone are in bound contact, and the cortical bone and the mucosa are in frictionless contact; when simulating different degrees of separation of the mucosa, the unseparated mucosal area and the corresponding maxillary area are treated as having common nodes, and the nodes of the separated mucosal area and the corresponding maxillary area are not in contact and are not treated as having common points.

[0155] Optionally, the loading mode is a force load; the force load mode is a quasi-static loading mode starting from 0 kPa and with a rate of 0.1 mm / s; the direction in which the liquid applies uniform pressure on the loading surface is vertical and lateral.

[0156] Optionally, the three-dimensional model of the maxillary sinus lifting channel is a cylindrical hole with a diameter of 4 mm.

[0157] Optionally, at the beginning of lifting, the stress concentration point of the maxillary sinus mucosa is in the center of the force application point, and as the lifting height increases, the stress concentration point spreads from the center to the surrounding areas.

[0158] Optionally, the three-dimensional reverse reconstruction module includes:

[0159] A region segmentation submodule is used to finely segment the contour of the maxillary sinus three-dimensional model to distinguish the cortical bone region, the cancellous bone region and the mucosal region;

[0160] The 3D model generation submodule is used to perform smooth denoising, surface construction, gridding, and solidification operations on the cortical bone area, cancellous bone area, and mucosal area, respectively, to generate a cortical bone 3D model, a cancellous bone 3D model, and a mucosal 3D model; the mucosal thickness is set to 1 mm.

[0161] Optionally, the maxillary sinus contour extraction module includes:

[0162] The maxillary CBCT image acquisition submodule is used to scan the maxillary bone to obtain the maxillary CBCT image;

[0163] The maxillary sinus contour extraction submodule is used to perform automatic threshold segmentation on the maxillary CBCT image according to the grayscale values ​​of different tissues, preliminarily separate the tissues around the maxillary sinus, erase the redundant parts or fill in the missing parts, and perform smoothing to obtain the maxillary sinus 3D model contour.

[0164] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0165] In addition, an embodiment of the present invention further provides an electronic device, including a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus.

[0166] Memory, used to store computer programs;

[0167] The processor is used to implement the method of constructing a maxillary sinus lifting model by using the reverse three-dimensional finite element and hydraulic lifting method as described in the above embodiment when executing the program stored in the memory.

[0168] The communication bus mentioned in the above terminal can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0169] The communication interface is used for communication between the above terminal and other devices.

[0170] The memory may include a random access memory (RAM) or a non-volatile memory, such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0171] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0172] In another embodiment provided by the present invention, a computer-readable storage medium is also provided, in which instructions are stored. When the computer-readable storage medium is run on a computer, the computer executes the method of constructing a maxillary sinus lifting model by using the reverse three-dimensional finite element and hydraulic lifting method described in the above embodiment.

[0173] In another embodiment provided by the present invention, a computer program product containing instructions is also provided. When the computer is run on the computer, the computer executes the method of constructing a maxillary sinus lifting model by using the reverse three-dimensional finite element and hydraulic lifting method described in the above embodiment.

[0174] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk Solid State Disk (SSD)), etc.

[0175] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0176] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0177] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A method for constructing a maxillary sinus lifting model using a reverse three-dimensional finite element and hydraulic lifting method, characterized in that: The method comprises: Acquiring a maxillary CBCT image, and extracting a maxillary sinus three-dimensional model contour from the maxillary CBCT image; Performing three-dimensional reverse reconstruction on the contour of the maxillary sinus three-dimensional model to generate a cortical bone three-dimensional model, a cancellous bone three-dimensional model, and a mucosa three-dimensional model, and performing feature recognition and surface diagnosis on the cortical bone three-dimensional model, the cancellous bone three-dimensional model, and the mucosa three-dimensional model to repair the defective surface; A three-dimensional model of the maxillary sinus lifting channel is established, and the three-dimensional model of the cortical bone, the three-dimensional model of the cancellous bone, the three-dimensional model of the mucosa, and the three-dimensional model of the maxillary sinus lifting channel are assembled into a three-dimensional model of the maxillary sinus; Assigning corresponding material parameters and contact relationships to the cortical bone three-dimensional model, the cancellous bone three-dimensional model, the mucosa three-dimensional model, and the maxillary sinus lifting channel three-dimensional model of the maxillary sinus three-dimensional model, respectively, and dividing the maxillary sinus three-dimensional model by tetrahedral meshing to obtain a maxillary sinus three-dimensional finite element model; A loading surface is formed on the mucosal surface of the maxillary sinus three-dimensional finite element model by using channel projection, and hydraulic lifting is simulated to apply load to the loading surface. At the same time, the Mooney-Rivlin model and updated Lagrangian method are used in finite element analysis for iterative solution until the calculation converges to obtain the maxillary sinus lifting model.

2. The method according to claim 1, characterized in that The mucosa was set to the C10 and C01 parameters of Hyperelastic; the cortical bone and cancellous bone were in bound contact, and the cortical bone and mucosa were in frictionless contact; when simulating different degrees of separation of the mucosa, the unseparated mucosa area and the corresponding maxillary area were treated as having common nodes, and the nodes of the separated mucosa area and the corresponding maxillary area were not in contact and not in common.

3. The method according to claim 1, characterized in that The loading mode is force loading; the force loading mode is a quasi-static loading mode starting from 0 kPa and with a rate of 0.1 mm / s; the direction in which the liquid applies uniform pressure on the loading surface is vertical and lateral.

4. The method according to claim 1, characterized in that: The three-dimensional model of the maxillary sinus lifting channel is a cylindrical hole with a diameter of 4 mm.

5. The method according to claim 1, characterized in that In the early stage of lifting, the stress concentration point of the maxillary sinus mucosa is in the center of the force application point. As the lifting height increases, the stress concentration point spreads from the center to the surrounding areas.

6. The method according to claim 1, characterized in that Performing three-dimensional reverse reconstruction on the contour of the maxillary sinus three-dimensional model to generate a cortical bone three-dimensional model, a cancellous bone three-dimensional model, and a mucosa three-dimensional model, including: Finely segmenting the contour of the maxillary sinus three-dimensional model to distinguish the cortical bone area, the cancellous bone area and the mucosal area; The cortical bone region, cancellous bone region and mucosal region were subjected to smooth denoising, surface construction, gridding and solidification operations respectively to generate the cortical bone 3D model, cancellous bone 3D model and mucosal 3D model; the mucosal thickness was set to 1 mm.

7. The method according to claim 1, characterized in that Acquiring a maxillary CBCT image and extracting a maxillary sinus three-dimensional model contour from the maxillary CBCT image, including: Scan the maxillary bone to obtain the maxillary CBCT image; The maxillary CBCT image is automatically thresholded according to the grayscale values ​​of different tissues, the tissues surrounding the maxillary sinus are preliminarily separated, and the redundant parts are erased or the missing parts are supplemented, and smoothing is performed to obtain the contour of the maxillary sinus three-dimensional model.

8. A device for constructing a maxillary sinus lifting model using reverse three-dimensional finite element and hydraulic lifting methods, characterized in that: The device comprises: A maxillary sinus contour extraction module is used to collect a maxillary CBCT image and extract a maxillary sinus three-dimensional model contour from the maxillary CBCT image; A three-dimensional reverse reconstruction module is used to perform three-dimensional reverse reconstruction on the contour of the three-dimensional model of the maxillary sinus, generate a three-dimensional model of cortical bone, a three-dimensional model of cancellous bone, and a three-dimensional model of mucosa, and perform feature recognition and surface diagnosis on the three-dimensional model of cortical bone, the three-dimensional model of cancellous bone, and the three-dimensional model of mucosa to repair the defective surface; A physical assembly module is used to establish a three-dimensional model of the maxillary sinus lifting channel, and assemble the cortical bone three-dimensional model, the cancellous bone three-dimensional model, the mucosa three-dimensional model, and the maxillary sinus lifting channel three-dimensional model into a maxillary sinus three-dimensional model; a maxillary sinus three-dimensional finite element model construction module, for respectively assigning corresponding material parameters and contact relationships to the cortical bone three-dimensional model, the cancellous bone three-dimensional model, the mucosa three-dimensional model, and the maxillary sinus lifting channel three-dimensional model of the maxillary sinus three-dimensional model, and dividing the maxillary sinus three-dimensional model by tetrahedral meshing to obtain a maxillary sinus three-dimensional finite element model; The hydraulic lifting and finite element analysis module is used to form a loading surface on the mucosal surface of the three-dimensional finite element model of the maxillary sinus by using channel projection, and simulate hydraulic lifting to apply load to the loading surface. At the same time, the Mooney-Rivlin model and the updated Lagrangian method are used in the finite element analysis to perform iterative solution until the calculation converges to obtain the maxillary sinus lifting model.

9. An electronic device, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; The memory is used to store computer programs; The processor is used to implement the method of constructing a maxillary sinus lifting model by using the reverse three-dimensional finite element and hydraulic lifting method as described in any one of claims 1 to 7 when executing the program stored in the memory.

10. One or more computer-readable media having instructions stored thereon, which, when executed by one or more processors, enable the processors to execute the method of constructing a maxillary sinus lifting model using the inverse three-dimensional finite element and hydraulic lifting method as described in any one of claims 1 to 7.

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