Jaw guard plate design method and device, storage medium and program product

Abstract

The invention discloses a jaw guard plate design method and device, a storage medium and a program product, relates to the technical field of jaw guard plate design, and aims to improve the design accuracy of a jaw guard plate buffer layer. The method comprises the following steps: extracting a palate profile curve from a smooth palate three-dimensional digital model of a patient; inwards shifting the palate profile curve by a preset safety distance to generate a jaw guard plate basic boundary; calculating the normal contact force distribution of the palate side tooth surface based on the occlusal contact data of the patient at the maximum apical interlacing position; projecting the normal contact force distribution to the surface of the palate model to form a palate pressure distribution diagram; identifying a high-pressure region with a pressure value greater than a preset threshold value in the palate pressure distribution diagram; establishing a local thickness control vector along the normal direction of the palate surface by taking the geometric center of the high-pressure area as a reference point; mapping the pressure value corresponding to each local thickness control vector into a local thickness increment by adopting a piecewise linear function; and superposing the local thickness increments to a preset basic thickness to generate a jaw guard plate model.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of jaw guard design, and particularly relates to a jaw guard design method, a jaw guard design device, a storage medium and a program product. BACKGROUND

[0002] The palatal guard is mainly used in oral and maxillofacial trauma repair, temporomandibular joint functional disorder treatment and postoperative protection of cleft palate repair, and its core functions include protecting the wound, compressing hemostasis, promoting healing, relieving pain and facilitating early recovery of eating for patients.

[0003] In the related art, the design and manufacture of the palatal guard has entered the digital stage, mainly using the process flow of intraoral scanning combined with 3D printing. Specifically, the technology first uses an intraoral scanner to digitally scan the palate of the patient to obtain a three-dimensional digital model. Then, the basic parameters such as the coverage range and overall thickness of the palatal guard are controlled in the computer-aided design software. Finally, a medical-grade flexible resin material is used for manufacturing.

[0004] However, the related art mainly adopts a simplified design mode with a uniform thickness, and for the occlusal cushioning function required by patients with temporomandibular joint functional disorders, it is usually necessary to achieve it through post-adjustment and grinding, and it is difficult to accurately adjust the cushioning layer of the palatal guard. SUMMARY

[0005] The present application provides a jaw guard design method, a jaw guard design device, a storage medium and a program product, to improve the design accuracy of the cushioning layer of the palatal guard.

[0006] In a first aspect, a method for designing a mouthguard is provided, and the method is applied to a design device. The method comprises: obtaining a three-dimensional digital model of a smooth palate of a patient; extracting a palate profile curve from the three-dimensional digital model of the palate; generating a basic boundary of the mouthguard by offsetting the palate profile curve inward by a preset safety distance; calculating a normal contact force distribution on a palatal tooth surface based on occlusal contact data of the upper and lower jaws of the patient at a maximum intercuspation position; projecting the normal contact force distribution onto the surface of the three-dimensional digital model of the palate to form a palate pressure distribution map; identifying a high-pressure area in the palate pressure distribution map, wherein the pressure value of the high-pressure area is greater than a preset threshold; establishing a local thickness control vector along the normal direction of the surface of the palate with the geometric center of the high-pressure area as a reference point; mapping the pressure value corresponding to each local thickness control vector to a local thickness increment by using a piecewise linear function, wherein the piecewise linear function has a first preset slope in a preset low-pressure segment and a second preset slope in a high-pressure segment, and the first preset slope is smaller than the second preset slope; and adding each local thickness increment to a preset basic thickness to generate a three-dimensional model of the mouthguard with a continuously changing thickness distribution, wherein the preset basic thickness is determined according to the average radius of curvature of the surface of the palate within the basic boundary of the mouthguard. This is because a flat palate with a large average radius of curvature is more likely to deform in a curved shape under stress, and a thicker basic thickness is needed to provide sufficient structural rigidity. On the other hand, a dome-shaped palate with a small radius of curvature has a relatively stable structure, and a slightly thinner basic thickness can be used.

[0007] By using the above technical solution, the design device calculates the normal contact force distribution of the patient at the maximum intercuspation position, projects it onto the palate to form a pressure distribution map, and then non-linearly maps the pressure value of the identified high-pressure area to a local thickness increment by using a piecewise linear function, so that the thickness of the mouthguard is more matched with the occlusal pressure distribution of the individual patient. Thus, the thickness of the buffer layer is effectively strengthened at the required position, while remaining thin at the non-critical area, thereby improving the design accuracy of the buffer layer of the mouthguard.

[0008] In combination with some embodiments of the first aspect, in some embodiments, before the step of calculating the normal contact force distribution on the palatal tooth surface based on the occlusal contact data of the upper and lower jaws of the patient at the maximum intercuspation position, the method further comprises: obtaining a lower jaw movement trajectory of the patient during a preset action template recorded by a four-dimensional dynamic jaw-face motion tracking system; simulating the contact state of the upper and lower teeth at each time in the lower jaw movement trajectory based on a virtual articulator algorithm to obtain a dynamic contact point sequence; calculating an instantaneous contact force vector acting on the palatal tooth surface at each contact point in the dynamic contact point sequence; and decomposing the instantaneous contact force vector to extract a normal force component perpendicular to the contact point surface and a shear force component parallel to the contact point surface.

[0009] By adopting the technical scheme, the design device records the actual mandibular movement trajectory of the patient by introducing a four-dimensional dynamic jaw movement tracking system, and performs dynamic contact simulation based on the same, and then decomposes the normal force and shear force components. Thus, the complex dynamic stress conditions of the patient in actual functional movements such as mastication and tooth grinding are taken into account in the design, and more accurate and more personalized mechanical data than static data are obtained.

[0010] In combination with some embodiments of the first aspect, in some embodiments, the preset action template specifically includes: protrusive movement, left lateral movement, right lateral movement, and tooth grinding movement.

[0011] By adopting the technical scheme, the preset action template is specifically protrusive movement, left lateral movement, right lateral movement, and tooth grinding movement, thereby improving the comprehensiveness of the mandibular movement trajectory.

[0012] In combination with some embodiments of the first aspect, in some embodiments, the step of superimposing each local thickness increment on the preset base thickness to generate the three-dimensional model of the mouthguard with a continuously changing thickness distribution specifically includes: determining a mouthguard design region according to the average radius of curvature of the patient's palate surface within the mouthguard base boundary and the patient's needs; dividing the mouthguard design region into three-dimensional grid cells; mapping the normal force component and the shear force component of each contact point into the three-dimensional grid cells; determining the relative density of the lattice cell based on the size of the normal force component in the three-dimensional grid cell, the relative density of the lattice cell being proportional to the size of the normal force component; regarding the grid cell in which the shear force component is greater than a preset shear force threshold as a shear force dominant region; in the shear force dominant region, determining the inclination direction of the inclined rod in the lattice structure according to the direction angle of the shear force component; in the non-shear force dominant region, setting a standard symmetrical lattice structure; determining the geometric size of the inclined rod according to the relative density of the lattice cell; and spatially splicing the lattice structure of each grid cell to generate a three-dimensional model of the mouthguard with a gradient microstructure.

[0013] By adopting the technical scheme, the design device divides the design region into three-dimensional grid cells, and determines the lattice density based on the normal force and the inclined rod direction based on the shear force, thereby converting the macroscopic entity thickness design into a microscopic structure topology optimization. This gradient microstructure design not only more accurately allocates the amount of material according to the size of the compressive stress, but also actively resists and conducts shear force by optimizing the arrangement direction of the rods inside the lattice, thereby improving the overall mechanical properties and fatigue resistance of the mouthguard.

[0014] In some embodiments of the first aspect, in the shear force dominant region, the step of determining the inclination direction of the inclined rods in the lattice structure according to the direction angle of the shear force component specifically comprises: calculating the standard deviation of the direction angle of the shear force component in the shear force dominant region; determining a single-direction shear region as a region with a standard deviation less than a preset angle threshold; determining a multi-direction shear region as a region with a standard deviation not less than the preset angle threshold; setting a lattice structure with single-direction inclined rods in the single-direction shear region, the angle of the single-direction inclined rods being the average of the direction angle of the shear force component in the single-direction shear region; and setting a lattice structure with multi-direction inclined rods in the multi-direction shear region, the angle of the multi-direction inclined rods being the direction angle of a preset number of large shear force components in the multi-direction shear region.

[0015] By adopting the above technical solution, the design equipment distinguishes single-direction shear regions and multi-direction shear regions by calculating the standard deviation of the direction angle of the shear force, and sets different forms of inclined rod structures accordingly, thereby further refining the lattice topology of the shear force dominant region. The lattice structure can resist shear loads of different properties in a more optimized manner, thereby reducing the setting of unnecessary multi-direction support rods in the single-direction stress region, improving the mechanical properties in the multi-direction stress region, and further improving the accuracy of the design of the jaw guard.

[0016] In some embodiments of the first aspect, after the step of superimposing each local thickness increment on the preset base thickness to generate a three-dimensional model of the jaw guard with a continuously changing thickness distribution, the method further comprises: reserving a gas permeable hole in a non-biting area of the three-dimensional model of the jaw guard.

[0017] By adopting the above technical solution, a gas permeable hole is reserved in the non-biting area of the three-dimensional model of the jaw guard, thereby enhancing the air and saliva flow of the jaw guard without sacrificing the mechanical properties of the key area.

[0018] In some embodiments of the first aspect, after the step of reserving a gas permeable hole in the non-biting area of the three-dimensional model of the jaw guard, the method further comprises: virtually assembling the three-dimensional model of the jaw guard with a three-dimensional digital model of the palate to determine a fit clearance; when the fit clearance is greater than a preset clearance threshold, establishing a local coordinate system in the area where the fit clearance is greater than the preset clearance threshold, adjusting the inner surface profile of the three-dimensional model of the jaw guard along the normal direction of the surface of the palate, and synchronously adjusting the edge curvature of the three-dimensional model of the jaw guard, until the fit clearance is not greater than the preset clearance threshold.

[0019] By adopting the above technical solution, virtual assembly and fit clearance analysis are performed after design is completed, and adaptive digital adjustment is performed on the over-limit area, thereby checking and optimizing the fit of the inner surface of the jaw guard before entering the physical manufacturing stage. The success rate of the first time wearing of the jaw guard is improved.

[0020] In a second aspect, the embodiments of the present application provide a design device, comprising: one or more processors and a memory; the memory is coupled to the one or more processors, and the memory is configured to store computer program codes, the computer program codes comprising computer instructions, and the one or more processors are configured to invoke the computer instructions to cause the design device to perform the method described in the first aspect and any possible implementation manner of the first aspect.

[0021] In a third aspect, the embodiments of the present application provide a computer program product comprising instructions which, when executed on a design device, cause the design device to perform the method described in the first aspect and any possible implementation manner of the first aspect.

[0022] In a fourth aspect, the embodiments of the present application provide a computer-readable storage medium comprising instructions which, when executed on a design device, cause the design device to perform the method described in the first aspect and any possible implementation manner of the first aspect.

[0023] It can be understood that the design device provided in the second aspect, the computer program product provided in the third aspect, and the computer storage medium provided in the fourth aspect are all used to execute the method provided in the embodiments of the present application. Therefore, the beneficial effects that can be achieved thereby can refer to the beneficial effects in the corresponding method, which will not be described here again.

[0024] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. The design device projects the normal contact force distribution of the patient at the maximum intercuspation position to the palate to form a pressure distribution map, and then uses a piecewise linear function to nonlinearly map the pressure value of the identified high-pressure area to a local thickness increment, so that the thickness of the jaw guard is more matched with the individual bite pressure distribution of the patient. Thus, the thickness of the buffer layer is effectively strengthened at the required position, while remaining light and thin in the non-critical area, thereby improving the design accuracy of the jaw guard buffer layer.

[0025] 2. The design device divides the design area into three-dimensional grid units, and determines the lattice density based on the normal force and the inclined rod direction based on the shear force, thereby converting the macroscopic solid thickness design into a microscopic structure topology optimization. This gradient microstructure design not only more accurately allocates the amount of material according to the size of the compressive stress, but also actively resists and conducts shear force by optimizing the arrangement direction of the rods inside the lattice, thereby improving the overall mechanical properties and fatigue resistance of the jaw guard.

[0026] 3. Because the design equipment distinguishes between unidirectional and multidirectional shear regions by statistically analyzing the standard deviation of the shear force direction angle, and specifically sets up different shaped oblique bar structures, the lattice topology of the shear force-dominant region is further refined. This allows the lattice structure to resist shear loads of different natures in a more optimized way, thereby reducing the need for unnecessary multidirectional support members in the unidirectional stress region and improving the mechanical performance in the multidirectional stress region, thus further enhancing the accuracy of the jaw guard plate design. Attached Figure Description

[0027] Figure 1 This is a schematic flowchart of a jaw guard design method in an embodiment of this application.

[0028] Figure 2 This is another schematic flowchart illustrating a design method for a jaw guard in an embodiment of this application.

[0029] Figure 3 This is a schematic diagram of the physical device structure of the designed equipment in the embodiments of this application. Detailed Implementation

[0030] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0031] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0032] This application provides a design method, design equipment, storage medium, and program product for jaw protectors to improve the design accuracy of the jaw protector buffer layer.

[0033] Please see Figure 1 This is a flowchart illustrating a design method for a jaw guard in an embodiment of this application.

[0034] S101. Obtain a smooth three-dimensional digital model of the patient's palate.

[0035] Wherein, the patient refers to an individual who needs to design and wear a mouthguard for the purpose of oral and maxillofacial trauma repair, temporomandibular joint disorder treatment, or postoperative protection after cleft palate repair. The palatal three-dimensional digital model refers to a collection of three-dimensional geometric data that can represent the morphology of the patient's maxillary inner side, including the hard and soft palate regions, and adjacent gingival and dental tissue, obtained through digital scanning technology, usually in the form of point cloud or mesh (such as STL format). A smooth palatal three-dimensional digital model indicates that the model surface has been processed, for example, by filtering algorithms to remove noise, artifacts, or discontinuous protrusions that may occur during the scanning process, thus presenting a continuous and gently curved surface characteristic.

[0036] Specifically, this step is the data input and basic preparation stage of the entire digital design process of the mouthguard. The technical personnel use three-dimensional scanning equipment to capture the surface morphology information of the patient's palate and related teeth. The original scanning data can be point cloud data or a preliminary generated mesh model. Since the original scanning data may contain noise points, data voids, or local rough areas caused by factors such as saliva reflection, scanning probe movement jitter, or model minor flaws, in order not to affect the accuracy of subsequent design and the wearing comfort of the final product, a specific filtering algorithm (such as Laplace smoothing, Gaussian filtering, or moving average algorithm) is applied in a dedicated computer-aided design (CAD) software or three-dimensional model processing software to process the mesh model. Under the premise of preserving the macroscopic anatomical features of the palate, small surface concave-convex that do not affect the wearing function are eliminated, and finally a three-dimensional digital model with a continuous and smooth surface that can reflect the overall contour of the patient's palate is output.

[0037] S102, extracting a palatal contour curve from the palatal three-dimensional digital model.

[0038] Wherein, the palatal contour curve refers to a closed or open curve identified on the palatal three-dimensional digital model, which defines the boundary of the palatal region to be covered by the mouthguard. This curve usually extends along the junction of the palate and the gum margin of the teeth or at a certain specific height (such as the maximum perimeter line) on the palatal side of the teeth.

[0039] Specifically, this step is executed after the design device obtains a smooth palatal model that can be used for design. The mouthguard needs to cover the specified palatal region and form a stable retention relationship with the adjacent teeth, so it is necessary to first define the mouthguard coverage boundary. The design device loads the palatal three-dimensional digital model in a computer-aided design (CAD) software environment, and according to the clinical treatment needs (for example, whether to cover the whole palate or only part of the palate; whether to extend to the tooth surface to obtain retention or limited to the soft tissue area) and anatomical landmarks, the palatal contour curve is drawn on the three-dimensional model interactively or automatically.

[0040] S103, offsetting the palatal contour curve inward by a preset safety distance to generate a basic boundary of the mouthguard.

[0041] Wherein, the inward offset means that each point on the palatal contour curve is moved along the surface of the palatal model at the location of the point to the direction of the central palatal region enclosed by the curve by a specified preset safety distance. The preset safety distance is a value pre-set according to clinical experience and material properties, for example, 0.5 to 2 mm, and the purpose is to keep a small gap between the edge of the mouthguard and the sensitive gum tissue to avoid gum damage or discomfort caused by edge compression. The basic boundary of the mouthguard refers to the new curve generated after the inward offset, which will be used as the final outer boundary to generate the solid model of the mouthguard.

[0042] Specifically, this step is immediately after the contour curve extraction. Directly using the contour line close to the gum as the edge of the mouthguard may press or rub the gum tissue in actual wearing due to manufacturing errors, material deformation or slight movement in the mouth, causing inflammation or pain. Therefore, by uniformly shrinking the contour line to the central direction of the palate, a safety zone can be created between the edge of the mouthguard and the gum. This offset operation is designed in the CAD software, which calculates the tangent plane and normal vector of each point on the curve on the surface of the three-dimensional model of the palate, and then offsets along the two-dimensional direction pointing to the center of the palate in the tangent plane to generate a new smooth curve inside the original contour line, which is the basic boundary of the mouthguard.

[0043] S104, calculating the normal contact force distribution of the palatal tooth surface based on the occlusal contact data of the patient's upper and lower jaws in the maximum intercuspation position.

[0044] Wherein, the maximum intercuspation position refers to the state where the tooth cusps and fossae contact points are the most, the occlusion is the tightest, and the most stable, which is the reference position for evaluating static occlusal force. The occlusal contact data refers to a data set describing the position, area and pressure of the contact between the upper and lower jaws in the maximum intercuspation position, which is usually obtained by physical bite paper, pressure sensor or virtual occlusion simulation. The normal contact force distribution refers to the distribution of the force component perpendicular to the tooth contact point surface (i.e. along the surface normal direction) on the entire palatal tooth surface after the total contact force occurring at the tooth contact point is decomposed, which directly reflects the pushing action of the occlusal force on the teeth.

[0045] Specifically, the purpose of this step is to quantify how the bite force is transmitted through the maxillary teeth in the most critical state of static occlusion, and possibly affect the palatal guard. The first requirement for the design device is to obtain the occlusal contact data of the patient in the maximum intercuspation state. This can be done by positioning the patient's maxillary and mandibular three-dimensional digital models in their actual maximum intercuspation relationship in a virtual environment (virtual articulator), and then detecting the contact points and contact areas between the two. Then, based on biomechanical models or finite element analysis (FEA) methods, simulate the typical bite force applied by the patient in this state (e.g. average masticatory muscle force estimated according to patient age, gender), calculate the force vector at each contact point. Finally, the design device decomposes these force vectors acting on the cusps or slopes into normal force components perpendicular to the contact surface and shear force components along the tangent of the surface, forming a data set describing the size and location of these normal forces, i.e. the normal contact force distribution.

[0046] S105, projecting the normal contact force distribution to the surface of the palatal three-dimensional digital model to form a palatal pressure distribution map.

[0047] The palatal pressure distribution map refers to a two-dimensional map displayed on the palatal three-dimensional digital model in pseudo-color, contour or other visualization form, indicating the corresponding pressure distribution on the palatal soft tissue caused by the normal contact force transmitted by the teeth.

[0048] Specifically, after the teeth are stressed, the stress will be transmitted to the adjacent palatal tissue through the periodontal membrane and alveolar bone. This step simulates this force transmission effect through a simplified mapping method. The design device iterates through each normal force data point on the surface of the teeth on the palatal side, and then finds a corresponding point on the surface of the palatal three-dimensional digital model according to a predetermined projection rule, and assigns the value of the normal contact force to this corresponding point. A commonly used projection rule can be the reverse extension line along the normal direction of the tooth surface. After all the force data points are projected, the palatal surface obtains a discrete pressure value field, which can be processed by interpolation and smoothing to generate a continuous and visual palatal pressure distribution map.

[0049] S106, identifying high pressure areas with pressure values greater than a preset threshold in the palatal pressure distribution map.

[0050] The preset threshold is a pressure threshold value set according to biomechanical knowledge and clinical experience, representing a pressure threshold value that may cause tissue discomfort or require special attention.

[0051] Specifically, the palate guard does not need equal buffering capacity in all areas. Strengthening the design of high-pressure areas can improve the utilization of materials. The device traverses each data point (or grid cell) in the palate pressure distribution map and compares its pressure value with the preset pressure threshold. If the pressure value of a point is greater than the threshold, it is marked as a high-pressure point. These marked points, if spatially connected, form a high-pressure area. According to the differences in the individual occlusion of patients, a single, large-scale high-pressure area may be identified (for example, when the main occlusal force is concentrated on a few teeth), or multiple separate, scattered high-pressure areas may be identified (for example, when multiple tooth pairs have high-intensity contact).

[0052] S107, Establish a local thickness control vector along the normal direction of the palate surface with the geometric center of the high-pressure area as the reference point.

[0053] Wherein, the normal direction of the palate surface refers to the direction perpendicular to the surface of the palate three-dimensional digital model at the reference point position. The local thickness control vector is a vector with a starting point, direction and size, with the starting point at the reference point and the direction being the normal direction of the palate surface.

[0054] Specifically, for each high-pressure area identified in S106 (whether it is a single area or one of multiple areas), first calculate its geometric center point. This geometric center point is considered as the representative point of the high-pressure area. Then, with the geometric center point as the reference point, determine the normal direction of the palate three-dimensional digital model surface at this point. This normal vector defines the direction of increasing thickness in this area, ensuring that the thickness grows outward perpendicular to the palate surface, thereby achieving effective buffering. This vector from the reference point along the normal direction, whose properties (size) will be determined by the pressure value, is the local thickness control vector. For multiple independent high-pressure areas, this process is repeated to establish a local thickness control vector for each high-pressure area.

[0055] S108, Map the pressure value corresponding to each local thickness control vector to the local thickness increment using a piecewise linear function.

[0056] Specifically, a simple linear relationship (i.e. thickness increment is directly proportional to pressure) can not be optimal, as it can result in unnecessary thickness increase in low pressure zones, or insufficient thickness increase in high pressure zones. A more sophisticated control can be achieved by designing the device to employ a piecewise linear function. This function defines two or more pressure intervals: a low pressure interval and a high pressure interval. When the pressure value corresponding to the local thickness control vector in S107 falls in the low pressure interval, the corresponding local thickness increment is calculated according to a smaller slope (first pre-set slope), and the thickness increases relatively slowly. When the pressure value exceeds a certain inflection point and enters the high pressure interval, the local thickness increment is calculated according to an increased slope (second pre-set slope), and the thickness increases more rapidly.

[0057] S109, superimpose each local thickness increment to the pre-set base thickness to generate a 3D model of the bite guard with continuously varying thickness distribution.

[0058] Specifically, first, the design device calculates the average radius of curvature of the surface of the patient's palate in the region within the base boundary of the bite guard, based on the 3D digital model of the patient's palate, and determines a suitable pre-set base thickness in combination with the clinical requirement for rigidity. For example, a relatively flat palate (large average radius of curvature) can require a slightly thicker base thickness to resist deformation. Then, in the CAD software, based on the base boundary of the bite guard generated in S103, the surface of the palate model is offset outward by the pre-set base thickness to form a base guard model with uniform thickness. Next, the local thickness increments associated with each high pressure region calculated in S108 are superimposed on the outer surface of this base guard model in the direction of the local thickness control vector established in S107. In order to achieve continuous variation of thickness, the design device uses interpolation or blending algorithms so that the thickness reaches the maximum increment at the center of the high pressure region and smoothly transitions to the surrounding area until it seamlessly connects with the base thickness region. The final 3D model of the bite guard is a personalized 3D model of the bite guard with an inner surface that fits the patient's palate and an outer surface with continuously varying cushioning thickness customized according to the bite pressure.

[0059] In some embodiments, after generating the 3D model of the bite guard with continuously varying thickness distribution according to the above method, the design device can also identify non-bite areas and low pressure areas on the model, which are usually located in the central palate or non-functional areas between teeth. Finally, in these identified areas, a series of array or randomly distributed hole structures are created by Boolean subtraction operation to generate a 3D model of the bite guard with both functional thickness distribution and good air permeability.

[0060] In some embodiments, after generating a three-dimensional model of the palatal guard with both functional thickness distribution and good air permeability, the design device can further virtually assemble the three-dimensional model of the palatal guard with the three-dimensional digital model of the palate and perform gap analysis to calculate the distance between the inner surface of the palatal guard and the surface of the palate model, and generate a fitting gap cloud map. If it is found that there are regions with a gap greater than a preset gap threshold (such as 0.1 millimeters), a local coordinate system is established at the center of these regions, and the position of the corresponding vertex of the inner surface of the palatal guard is fine-tuned in the normal direction of the palate surface to reduce the gap, while the design device automatically adjusts the curvature of the surface and the edge arc of the adjacent region to ensure overall smoothness. Finally, the gap analysis and adjustment process is repeated until the fitting gap of all regions meets the requirements, thereby obtaining a final three-dimensional model of the palatal guard with higher fitting degree.

[0061] In the above embodiments, a palatal guard optimization design method based on static bite analysis is provided. The method identifies the high-pressure areas of the palate of the patient at the maximum intercuspation position, and uses a piecewise linear function to establish a mapping relationship between pressure and thickness increment, thereby achieving local reinforcement of the buffer layer of the palatal guard and generating a design model with a continuously varying thickness distribution, thereby improving the accuracy of the buffer design.

[0062] However, although the design of the entity variable thickness is effective, it may have problems of material redundancy and excessive weight under the premise of achieving equivalent mechanical performance, affecting the long-term comfort of wearing. With the increasing maturity of four-dimensional dynamic jaw and facial movement tracking systems and the continuous reduction of costs, as well as the rapid development of artificial intelligence (AI) enabled computing design and analysis software capabilities, it has become possible to acquire and process personalized dynamic jaw and facial data of patients. At the same time, the vigorous development of 3D printing technology (additive manufacturing) has made it no longer limited to manufacturing simple solid shapes, but can accurately build complex internal microstructures (such as lattices, dot arrays). Therefore, in order to design the next generation of high-performance palatal guards that can better adapt to the dynamic functions of patients, are more lightweight, and have better mechanical performance in the context of rapid development of various technologies, a more advanced palatal guard design method is proposed in the following embodiments.

[0063] Please refer to Figure 2 for another flowchart of a palatal guard design method in the embodiments of the present application.

[0064] S201, acquire a smooth three-dimensional digital model of the palate of the patient.

[0065] S202, extract the palate contour curve from the three-dimensional digital model of the palate.

[0066] S203, generate a palatal guard base boundary by offsetting the palate contour curve inward by a preset safety distance.

[0067] Step S201 is similar to step S101, step S202 is similar to step S102, and step S203 is similar to step S103, which will not be described here.

[0068] S204, acquiring the mandibular movement trajectory of the patient during the preset action template recorded by the four-dimensional dynamic jaw movement tracking system.

[0069] The four-dimensional dynamic jaw movement tracking system refers to a device capable of capturing and recording the movement (translation and rotation) of the mandible in three-dimensional space over time (fourth dimension), which is usually composed of optical markers, high-speed cameras and data processing software. The preset action template refers to a series of standardized mandibular movement tasks set to comprehensively evaluate the patient's jaw function, which can specifically include protrusion movement, left lateral movement, right lateral movement and molar movement.

[0070] Specifically, this step aims to obtain personalized mandibular movement data of the patient when performing functional movements, instead of relying solely on static occlusion or simplified, non-personalized articulator simulation. This step is performed after obtaining the three-dimensional digital model of the patient's upper and lower jaws. When operating the four-dimensional dynamic jaw movement tracking system, the technician fixes the tracking markers on the patient's mandible (for example, by attaching a tray on the lower anterior teeth) and the head reference frame. The patient completes the preset action template in sequence within the field of view of the camera, such as maximum protrusion and return of the mandible, maximum lateral movement to the left and right, and molar movement simulating chewing. The high-speed camera captures the spatial position of the markers at a high frame rate, and calculates the six-degree-of-freedom movement trajectory of the mandible relative to the maxilla (or skull), i.e. three-direction translation and three-axis rotation, and stores these data in time sequence. The design device obtains these time sequence data, i.e. the mandibular movement trajectory.

[0071] S205, simulating the upper and lower jaw tooth contact state at each time in the mandibular movement trajectory based on the virtual articulator algorithm to obtain a dynamic contact point sequence.

[0072] The virtual articulator algorithm can simulate the function of a real mechanical articulator in a three-dimensional digital environment, and can import and play back the real mandibular movement trajectory recorded in S204. The upper and lower jaw tooth contact state refers to the specific position of the upper and lower jaw tooth models that collide or contact at any time during the simulation movement. The dynamic contact point sequence refers to the set of all contact points during the entire simulation movement, which includes the position coordinates of each contact point and the time information of its occurrence.

[0073] Specifically, the design device imports the patient's upper and lower jaw three-dimensional digital model into the computer-aided design software, and aligns them according to the initial occlusal relationship (such as the maximum intercuspation position). Then, the lower jaw movement trajectory data recorded in S204 is loaded into the virtual articulator module. According to the trajectory data, the module drives the lower jaw model to reproduce the patient's real movement in the software. At each frame or each micro-time step of the simulation playback, the software performs a collision detection algorithm to determine whether there is contact between the upper and lower jaw tooth models. Once contact is detected, the precise three-dimensional coordinates of the contact point are recorded, and a time sequence containing thousands of contact points, i.e. a dynamic contact point sequence, is finally formed.

[0074] S206, at each contact point of the dynamic contact point sequence, the instantaneous contact force vector acting on the palatal tooth surface is calculated.

[0075] Specifically, after obtaining the dynamic contact point sequence, the design device can call the built-in mechanical estimation module (such as the advanced module of exocad and 3Shape) in the advanced dental design software to calculate the instantaneous contact force. For example, in one embodiment, the magnitude of the instantaneous contact force can be estimated according to the contact area at the contact point, the relative motion speed and the preset material contact parameters, and the direction of the force is initially set as the common normal direction of the contact surface. In another more detailed embodiment, the lower jaw kinematics data obtained from the virtual articulator can be combined with a standardized masticatory muscle force model to calculate more accurate instantaneous contact force vectors at each contact point through a multi-body dynamics solver. Through this step, each geometric contact point generated by S205 is given a specific mechanical property (a three-dimensional force vector), i.e. an instantaneous contact force vector.

[0076] S207, the instantaneous contact force vector is decomposed into a normal force component perpendicular to the contact point surface and a shear force component parallel to the contact point surface.

[0077] Specifically, for each instantaneous contact force vector calculated by S206, the normal direction of the tooth surface at the point of action needs to be determined first. Then, using the mathematical method of vector projection, the total contact force vector is projected onto the normal direction to obtain the normal force component. The total contact force vector minus its normal force component, i.e. the shear force component in the tangent plane perpendicular to the normal, is obtained. By decomposing all contact forces in the dynamic contact point sequence, two sets of dynamic data corresponding to each other are finally obtained: one is the normal force component sequence, and the other is the shear force component sequence (including magnitude and direction).

[0078] S208, based on the occlusal contact data of the patient's upper and lower jaws in the maximum intercuspation position, the normal contact force distribution of the palatal tooth surface is calculated.

[0079] S209, project the normal contact force distribution to the surface of the palatal 3D digital model to form a palatal pressure distribution map.

[0080] S210, identify the high pressure area in the palatal pressure distribution map where the pressure value is greater than a preset threshold value.

[0081] S211, establish a local thickness control vector along the normal direction of the palatal surface with the geometric center of the high pressure area as the reference point.

[0082] S212, map the pressure value corresponding to each local thickness control vector to a local thickness increment using a piecewise linear function.

[0083] Step S208 is similar to step S104, step S209 is similar to step S105, step S210 is similar to step S106, step S211 is similar to step S107, and step S212 is similar to step S108. Here, no longer described.

[0084] S213, determine the design area of the jaw guard according to the average radius of curvature of the patient's palatal surface within the jaw guard base boundary and the patient's needs.

[0085] Specifically, in the method of S101-S109, the thickness is directly superimposed on the surface. In this embodiment, a clear container or mold space needs to be created first, and then the optimized microstructure is used to fill it. First, based on the jaw guard base boundary generated in S203, the relevant curved surface on the palatal 3D digital model is framed. Then, two factors are considered to determine the thickness of the region and thus define its three-dimensional volume: one is to determine a basic thickness according to the average radius of curvature of the palatal surface in the region to ensure the basic structural stiffness. Two, the specific needs of the patient can be combined, such as patients with temporomandibular joint disorders may need a thicker buffer layer, and postoperative protective guards may hope to be lighter and thinner. These two factors together determine the outer surface profile of the design area, which together with the inner surface of the palate forms the final jaw guard design area.

[0086] S214, divide the jaw guard design area into three-dimensional grid elements.

[0087] Specifically, the basic geometric elements obtained after discretization of the jaw guard design area determined in S213 include common elements such as cubes (voxels) or tetrahedrons.

[0088] S215, map the normal force component and shear force component of each contact point to the three-dimensional grid element.

[0089] Specifically, the normal force and shear force data obtained in S207 are attached to the tooth surface, while the microstructure design needs to know the stress distribution inside the shield volume. This step transfers the mechanical data on the tooth surface to each three-dimensional grid element in the shield design area through a mature data mapping algorithm in engineering. For example, an inverse distance weighting algorithm based on the influence radius can be used. First, define an influence radius for each tooth contact point, which can be associated with the anatomical size of the tooth it is in, such as the length of the tooth root. For example, the contact point of a large molar can be set to a larger influence radius. Second, for each three-dimensional grid element within the influence radius, the force value assigned to it from the contact point is inversely proportional to the distance from the center of the element to the contact point. The final force vector that a grid element bears is the vector sum of the influences of all relevant contact points. In this way, the discrete surface force data is smoothly mapped to the continuous force field data in the shield volume.

[0090] S216, determining the relative density of the lattice unit based on the size of the normal force component in the three-dimensional grid element.

[0091] wherein the relative density of the lattice unit refers to the proportion of the volume occupied by the solid material (i.e. the rod) in the volume of a standard lattice unit (such as a cube), which is between 0 (completely hollow) and 1 (completely solid).

[0092] Specifically, the normal force component mainly causes compressive stress, and the most effective way to resist compression is to increase the amount of material. Therefore, this step directly links the size of the normal force component mapped to each three-dimensional grid element in S215 to the relative density of the lattice structure to be generated in that element. Specifically, the larger the normal force, the higher the target relative density of the element; the smaller the normal force, the lower the target relative density of the element. This proportional relationship ensures that the material is precisely used where it is most needed to resist compression, thereby achieving lightweight while ensuring mechanical performance.

[0093] In some embodiments, the determination of the relative density of the lattice unit based on the size of the normal force component in the three-dimensional grid element can be achieved in various ways: optionally, the first way is linear mapping. First, determine the maximum and minimum normal forces F_max and F_min of all grid elements in the entire design area, as well as the desired relative density range [p_min, p_max]. Second, for any element with a normal force F_i, its relative density p_i can be calculated by linear interpolation: p_i = p_min + (p_max - p_min) * (F_i - F_min) / (F_max - F_min). Optionally, the second way is a non-linear mapping based on a power law. In order to save more material in the low stress area and quickly increase the stiffness in the high stress area, a power law relationship p_i = C * (F_i) nwhere C is a scaling factor, and the exponent n is typically greater than 1. This relationship can more efficiently distribute the material.

[0094] S217, marking the grid cells in the three-dimensional grid whose shear force component is greater than a preset shear force threshold as shear force dominant regions.

[0095] Specifically, in order to concentrate optimization resources on key areas, it is necessary to screen out cells that bear significant shear forces. This step is achieved by setting a preset shear force threshold. The threshold is not fixed and can be determined according to the following manner: Optionally, a relative threshold can be set, for example, when the size of the shear force component in a cell exceeds 20% of the normal force component, the cell is determined to be a shear force dominant region.

[0096] Optionally, an absolute threshold based on material properties can also be set, for example, according to the shear strength or fatigue limit of the selected 3D printing resin material, a critical stress value under a safety factor is set.

[0097] The design device traverses all three-dimensional grid cells and marks the cells that meet the above conditions as shear force dominant regions.

[0098] S218, in the shear force dominant region, the inclination direction of the diagonal rods in the lattice structure is determined according to the direction angle of the shear force component.

[0099] Specifically, in the shear force dominant region identified in S217, the topology of the lattice structure needs to be optimized to more effectively resist shear forces. A better way is to arrange the rods in the lattice, especially the diagonal rods, along the direction of the force. Therefore, this step determines the inclination direction of the diagonal rods in the lattice according to the direction angle of the shear force component in each shear force dominant cell. Further, by counting the dispersion degree (standard deviation) of the shear force direction angle in a shear force dominant region, it can be distinguished whether the region bears unidirectional, stable shear force or multidirectional, complex shear force, and different diagonal rod arrangement strategies are adopted accordingly.

[0100] In some embodiments, the determination of the orientation of the diagonal rods in the lattice structure according to the direction angle of the shear force component in the shear force dominant region can be implemented in various ways: optionally, first, the standard deviation of the direction angle of the shear force of all cells in a shear force dominant region is calculated. If the standard deviation is less than a preset angle threshold (such as 10 degrees), it is determined to be a unidirectional shear region. Second, the arithmetic mean of the direction angle of all shear forces in the region is calculated. Finally, in all lattice cells in the region, a unidirectional diagonal rod structure is generated along the average angle direction. Optionally, first, if the standard deviation is not less than the preset angle threshold, it is determined to be a multidirectional shear region. Second, in the region, all shear force vectors are sorted by size, and the direction angles corresponding to the top N (N is a preset number, such as 2 or 3) largest shear force vectors are selected. Finally, in the lattice cells in the region, multiple groups of diagonal rods are set, and the directions of the groups of diagonal rods are respectively aligned with the N main direction angles, forming a cross or star-shaped shear-resistant structure.

[0101] S219, in the non-shear force dominant region, a standard symmetric lattice structure is set.

[0102] The non-shear force dominant region refers to those three-dimensional grid cells in S217 that are not marked as shear force dominant. The standard symmetric lattice structure refers to a lattice type with isotropic or approximately isotropic mechanical properties, and the arrangement of its rods has high geometric symmetry, such as body-centered cubic (BCC) or face-centered cubic (FCC) derived structure.

[0103] Specifically, this step deals with regions that are relatively simple in stress and mainly dominated by compression. In these non-shear force dominant regions, there is no specific shear direction to resist, so there is no need to design a complex, anisotropic lattice structure. The use of a standard, symmetric lattice structure can meet the mechanical requirements. The mechanical properties of these symmetric structures are the same or similar in all directions, and their main mechanical contribution comes from the provision of compression stiffness through the adjustment of relative density (i.e. rod thickness). This design strategy of separate processing simplifies the calculation and improves the stability of the structure.

[0104] S220, the geometric size of the diagonal rod is determined according to the relative density of the lattice cell.

[0105] The geometric size of the diagonal rod mainly refers to the diameter or cross-sectional length of the rod, which is a direct parameter that determines the relative density and mechanical strength of the lattice cell.

[0106] Specifically, the thickness of the rods needs to be determined, whether it is the directional diagonal rods designed in S218 or the symmetric structure set in S219. This step reverses the geometric size of all rods in the unit according to the target relative density value calculated in S216 for each unit. For a given lattice topology (such as BCC), there is a certain mathematical relationship between the relative density and the rod diameter. Therefore, the design device can calculate the required rod diameter according to the target density.

[0107] In some embodiments, the geometric size of the diagonal rods can be determined according to the relative density of the lattice unit in various ways: optionally, the first way is based on an analytical formula. For many standard lattices, the relationship between the relative density p and the rod radius r and the unit edge length L can be represented as an analytical formula, for example, for BCC structure, p≈C*(r / L)^2 (C is a constant). The software can directly use this formula to inversely solve r according to the known p and L. Optionally, the second way is based on a lookup table. First, for each type of lattice used, a lookup table is generated by calculation or simulation, which records the relative density corresponding to different rod sizes. Second, during design, the software quickly finds the closest rod geometric size according to the target relative density through table lookup and interpolation.

[0108] S221, spatially splice the lattice structures of each grid unit to generate a three-dimensional model of the jaw shield with gradient microstructure.

[0109] Among them, spatial splicing refers to the process of connecting all independently designed lattice units with different microstructure parameters into a whole in three-dimensional space. Gradient microstructure refers to a macroscopic object whose internal microstructure (such as lattice density, topology, direction) changes smoothly and continuously in space, rather than abruptly.

[0110] Specifically, after the previous steps, the design device obtains a set consisting of parameters such as the lattice type, density, and direction of each unit. Then the design device generates the corresponding solid lattice geometry in each three-dimensional grid unit divided by the set in S214. And through geometric fusion or smooth transition processing at the unit boundary, all discrete lattice units are finally fused into a coherent whole, forming a jaw shield with gradient characteristics whose internal microstructure changes with stress distribution.

[0111] In some embodiments, the lattice structures of the grid cells can be spatially stitched in various ways to generate a three-dimensional model of the bite guard with gradient microstructure: optionally, a first way is based on implicit modeling. First, each bar is represented as an implicit function (e.g., a band distance field). Second, the field functions of all bars are fused into a single implicit function describing the entire bite guard through field function operations (e.g., Boolean union). Finally, the isosurface is extracted from the implicit function using algorithms such as marching cubes to generate the final closed and smooth triangular mesh model. This method can naturally handle gradient changes and smooth connections. Optionally, a second way is based on explicit modeling of grid operations. First, a grid model of the lattice is generated for each three-dimensional grid cell separately. Second, the grid models of all cells are placed in their correct positions in the global coordinate system. Finally, the grid Boolean operations and subsequent grid repair and smoothing algorithms are used to connect all independent grid models into a single, watertight whole model.

[0112] In the above embodiments, a bite guard design method based on dynamic mechanical analysis and gradient microstructure design is provided. The method more comprehensively captures the normal and shear combined load of the patient in functional movement by introducing four-dimensional dynamic jaw-face movement data. The bite guard design area is discretized into a three-dimensional grid, and a customized lattice microstructure is designed for each cell: the relative density of the lattice (i.e., the thickness of the bars) is controlled by the normal force to achieve the on-demand distribution of materials and the matching of the compression resistance. The inclination direction of the lattice diagonal bar is controlled by the size and direction of the shear force to achieve active resistance and efficient conduction of the shear load. The final three-dimensional model of the bite guard with gradient microstructure improves the mechanical properties, lightweight degree and biological functional adaptability of the bite guard.

[0113] The above describes a bite guard design method in the embodiments of the present application, and the following introduces an exemplary design device 300 provided in the embodiments of the present application.

[0114] Figure 3is an exemplary hardware structure schematic diagram of the design device 300 provided in the embodiments of the present application. In some embodiments, the design device 300 is a computer device. The computer device includes a processor, a memory and a network interface connected through a system bus. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for running the operating system and the computer program in the non-volatile storage medium. The database of the computer device is configured to store data. The network interface of the computer device is configured to communicate with other terminals or servers outside through a network connection. In some embodiments, the network interface can be a wired network interface, and in some embodiments, the network interface can also be a wireless network interface. The computer program is executed by the processor to implement the design method of the jaw guard in the embodiments of the present application.

[0115] Those skilled in the art can understand that, Figure 3 The structure shown in the above-mentioned figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. Specifically, the computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0116] In some embodiments of the present application, a computer readable storage medium is also provided, including instructions which, when executed on the design device 300, can cause the design device 300 to perform the design method of the jaw guard in the embodiments of the present application.

[0117] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit the technical solutions thereof; even though the technical solutions recorded in the foregoing embodiments have been described in detail, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some technical features thereof; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0118] In the above-described embodiments, according to the context, the term "when" can be interpreted as meaning "if" or "after" or "in response to determining" or "in response to detecting". Similarly, according to the context, the phrase "upon determining" or "if detecting (the stated condition or event)" can be interpreted as meaning "if determining" or "in response to determining" or "upon detecting (the stated condition or event)" or "in response to detecting (the stated condition or event)".

[0119] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented 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, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. 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 one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line) or wireless (such as infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk) and the like.

[0120] Those of ordinary skill in the art understand that all or part of the processes in the above embodiments can be implemented by a computer program to instruct the relevant hardware, which can be stored in a computer readable storage medium. The program can include the processes of the above method embodiments when executed. The aforementioned storage medium includes ROM or random access memory (RAM), magnetic disk or optical disk, and various media that can store program codes.

Claims

1. A design method for a jaw guard, characterized in that, Applied to the design of equipment, the method includes: Obtain a smooth three-dimensional digital model of the patient's palate; Extract the palatal contour curve from the three-dimensional digital model of the palate; The palatal contour curve is shifted inward by a preset safety distance to generate the basic boundary of the palatal guard plate. The normal contact force distribution on the palatal tooth surface is calculated based on the occlusal contact data of the patient's upper and lower jaws at the maximum cusp intersection position. The normal contact force distribution is projected onto the surface of the three-dimensional digital model of the palate to form a palatal pressure distribution map. Identify high-pressure areas where the pressure value is greater than a preset threshold in the palatal pressure distribution map; Using the geometric center of the high-pressure region as a reference point, a local thickness control vector is established along the normal direction of the palatal surface; A piecewise linear function is used to map the pressure value corresponding to each local thickness control vector to a local thickness increment. The piecewise linear function has a first preset slope in the preset low pressure segment and a second preset slope in the high pressure segment. The first preset slope is less than the second preset slope. Each of the aforementioned local thickness increments is superimposed onto a preset base thickness to generate a three-dimensional model of a jaw guard with a continuously varying thickness distribution. The preset base thickness is determined based on the average radius of curvature of the patient's palate surface within the base boundary of the jaw guard.

2. The method according to claim 1, characterized in that, Prior to the step of calculating the normal contact force distribution on the palatal tooth surface based on the occlusal contact data of the patient's maxilla and mandible at the maximum cusp intercuspal position, the method further includes: The mandibular movement trajectory of the patient during the process of the preset action template is recorded by a four-dimensional dynamic maxillofacial motion tracking system; The contact state of the upper and lower teeth at each moment in the mandibular movement trajectory is simulated based on the virtual articulation algorithm to obtain a dynamic contact point sequence. At each contact point in the dynamic contact point sequence, the instantaneous contact force vector acting on the palatal tooth surface is calculated; The instantaneous contact force vector is decomposed to extract the normal force component perpendicular to the contact point surface and the shear force component parallel to the contact point surface.

3. The method according to claim 2, characterized in that, The preset action templates specifically include: forward extension movement, leftward movement, rightward movement, and teeth grinding movement.

4. The method according to claim 2, characterized in that, The step of superimposing each of the local thickness increments onto a preset base thickness to generate a three-dimensional model of a jaw guard with a continuously varying thickness distribution specifically includes: The jaw shield design area is determined based on the average radius of curvature of the patient's palate surface within the basic boundary of the jaw shield and the patient's needs. The jaw guard design area is divided into three-dimensional mesh units; The normal force component and the shear force component at each contact point are mapped to the three-dimensional mesh element; The relative density of the lattice unit is determined based on the magnitude of the normal force component in the three-dimensional mesh unit, and the relative density of the lattice unit is proportional to the magnitude of the normal force component; The mesh cells in the three-dimensional mesh where the shear force component is greater than a preset shear force threshold are defined as the shear force dominant region. Within the region dominated by shear force, the tilting direction of the slant bar in the lattice structure is determined based on the direction angle of the shear force component; In regions not dominated by shear force, a standard symmetric lattice structure is set; The geometric dimensions of the inclined rod are determined based on the relative density of the lattice units; The lattice structures of each grid unit are spatially spliced ​​to generate a three-dimensional model of the jaw guard with a gradient microstructure.

5. The method according to claim 4, characterized in that, The step of determining the tilt direction of the inclined rods in the lattice structure based on the direction angle of the shear force component within the shear force-dominant region specifically includes: The standard deviation of the direction angle of the shear force component within the dominant shear force region is calculated. The region whose standard deviation is less than a preset angle threshold is defined as the unidirectional shearing region; The region whose standard deviation is not less than the preset angle threshold is defined as the multi-directional shearing region; A lattice structure with unidirectional tilted bar is provided in the unidirectional shear region, and the angle of the unidirectional tilted bar is the average value of the direction angle of the shear force component in the unidirectional shear region; A lattice structure with multi-directional tilted bar is provided in the multi-directional shear region, and the angles of the multi-directional tilted bar are the direction angles of the shear force components that are preset in the multi-directional shear region.

6. The method according to claim 1, characterized in that, After the step of superimposing each of the local thickness increments onto a preset base thickness to generate a three-dimensional model of a jaw guard with a continuously varying thickness distribution, the method further includes: Ventilation holes are reserved in the non-occlusal area of ​​the three-dimensional model of the jaw guard.

7. The method according to claim 6, characterized in that, After the step of reserving ventilation holes in the non-occlusal area of ​​the three-dimensional model of the jaw guard, the method further includes: The three-dimensional model of the jaw guard is virtually assembled with the three-dimensional digital model of the palate to determine the fitting gap; When the fitting gap is greater than a preset gap threshold, a local coordinate system is established in the region where the fitting gap is greater than the preset gap threshold. The inner surface contour of the three-dimensional model of the jaw guard is adjusted along the normal direction of the palate surface, and the edge curvature of the three-dimensional model of the jaw guard is adjusted simultaneously until the fitting gap is not greater than the preset gap threshold.

8. A design device, characterized in that, The design device includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code including computer instructions, and the one or more processors invoke the computer instructions to cause the design device to perform the method as described in any one of claims 1-7.

9. A computer program product containing instructions, characterized in that, When the computer program product is run on a design device, the design device performs the method as described in any one of claims 1-7.

10. A computer-readable storage medium comprising instructions, characterized in that, When the instructions are executed on the design device, the design device performs the method as described in any one of claims 1-7.

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