Tooth defect determination method, orthodontic appliance manufacturing method, and apparatus

Abstract

Provided in the present application are a tooth defect determination method, an orthodontic appliance manufacturing method, and an apparatus. The tooth defect determination method comprises: a computing device acquiring tooth characterization data of a target object that indicates the degree of concavity and convexity of different positional regions of each tooth; using regions of an ith tooth located in a first region as candidate regions, wherein the first region indicates the labial side and / or the gingival line; and on the basis of the candidate regions and the tooth characterization data corresponding to the ith tooth, determining a defect region of the ith tooth, wherein the defect region is used for undercut filling. By means of a defect region determined on the basis of candidate regions and tooth characterization data, the present application can improve the detection efficiency of the defect region and save on labor costs; moreover, undercut filling carried out on the basis of the defect region can ensure that a constructed orthodontic appliance is more adaptable to the requirements of a target object, thereby ensuring the use experience of the target object.

Description

Tooth defect determination method, tooth aligner manufacturing method and device

[0001] Cross-reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. 202410777767.9, filed on June 14, 2024, and entitled "Tooth defect determination method, tooth aligner manufacturing method and device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of tooth correction, in particular to a tooth defect determination method, a tooth aligner manufacturing method and a device. BACKGROUND

[0004] The invisible tooth aligner is usually generated according to the tooth arrangement, profile and other conditions of the patient. The invisible tooth aligner fits the patient's tooth type and does not affect daily life and social interaction. In addition, since the patient can take off and wear it by himself, oral hygiene can be maintained normally, and the whole correction process is time-saving and labor-saving.

[0005] The manufacturing of the invisible tooth aligner includes the processes of tooth scanning, digital tooth model construction, manufacturing of physical tooth model and pressing of invisible tooth aligner. The state data of the patient's teeth can be obtained through tooth scanning. There may be a wedge-shaped defect area in the patient's teeth (an area with a concave part near the gum part of the teeth). In the digital tooth model construction stage, the wedge-shaped defect of the teeth needs to be virtually filled. Then, the physical tooth model is manufactured by correcting the state of the teeth through virtual design. Finally, the physical tooth model is used as a male mold to obtain the invisible tooth aligner through hot pressing.

[0006] In the related art, in the digital tooth model construction stage, a technician usually selects the area with the wedge-shaped defect based on experience. This method consumes human resources, and the experience values of different technicians are different, so the determined wedge-shaped defect area may be different. Based on this, after manufacturing the physical tooth model and pressing the invisible tooth aligner, the invisible tooth aligner may not fit the patient's teeth, or the invisible tooth aligner may be tightly attached to the patient's teeth, causing the patient to use it unsatisfactorily. SUMMARY

[0007] The present application provides a tooth defect determination method, a tooth aligner manufacturing method and a device to improve the determination efficiency of the tooth defect area.

[0008] In a first aspect, the present application provides a tooth defect determination method, which is executed by a computing device, which can be understood as a computer, a server or the like, and the present application does not specifically limit it. The method is executed as follows:

[0009] obtain tooth characteristic data of the target object, the tooth characteristic data indicating a degree of concave-convex of each tooth at different position regions, a value of the tooth characteristic data being positively correlated with the degree of convex of the position region; take a region of an i th tooth located at a first region as a candidate region, the first region indicating a labial side and / or a gum line, the i th tooth being any tooth of the teeth of the target object, and i being a positive integer; determine a defect region of the i th tooth according to the candidate region and tooth characteristic data corresponding to the i th tooth, the defect region being used for filling the undercut.

[0010] The present application first obtains tooth characteristic data of a target object, then selects a suitable region on the tooth surface as a candidate region, and finally determines a defect region of the tooth according to the tooth characteristic data and the candidate region. In this way, the first region is determined as the candidate region because the tooth defect part usually only appears at the position of the first region. By limiting the position of the defect region through the first region, it is ensured that the finally selected candidate region is the region that needs to be filled with the undercut. Further, the defect region is determined according to the tooth characteristic data and the candidate region, which ensures the accuracy of the determined defect region and improves the efficiency of confirming the tooth defect region and filling the undercut.

[0011] In a possible implementation, the candidate region further includes a region of the i th tooth whose tooth characteristic data is less than a first threshold value.

[0012] The present application determines the candidate region through the tooth characteristic data, and determines the part with tooth characteristic data less than a certain range as the candidate region by setting a range for the tooth characteristic data, which lays a foundation for subsequent determination of the tooth defect part and ensures that the selected candidate region is the region that may have a tooth defect.

[0013] In a possible implementation, determining the defect region of the i th tooth according to the candidate region and the tooth characteristic data corresponding to the i th tooth includes: determining a region to be filled according to the tooth characteristic data corresponding to the i th tooth; and determining the defect region according to the region to be filled and the candidate region.

[0014] The present application first determines the undercut part in the tooth according to the tooth characteristic data, and then further determines the defect region according to the region to be filled and the candidate region. In this way, the present application realizes the narrowing of the candidate region based on the region to be filled, ensures that the candidate region corresponds to the region to be filled, can fully cover the entire defect region, avoids the region that does not need to be filled with the undercut being filled, and makes the filled tooth more flat and more in line with the external appearance of the conventional tooth.

[0015] In a possible implementation, determining the defect region according to the to-be-filled region and the candidate region comprises: determining the defect region according to the to-be-filled region and the reduced candidate region.

[0016] The application can also first determine a candidate region according to the tooth characteristic data, and then reduce the candidate region through the to-be-filled region to finally determine the tooth defect region. In this way, the application can ensure that the to-be-filled region covers the entire defect region in the process of determining the tooth defect region, so that the determination of the defect region is more in line with the actual demand, and the part of the tooth that does not exist defect is avoided to be covered as the defect region.

[0017] In a possible implementation, the candidate region is the region intersection of the region whose tooth characteristic data is less than the first threshold value and the region of the i th tooth located in the first region.

[0018] The application obtains the candidate region by taking the intersection of the region whose tooth characteristic data is less than the first threshold value and the region of the tooth located in the first region. Through the region whose tooth characteristic data is less than the first threshold value, the application ensures that the obtained candidate region is the part of the tooth with large concave-convex degree and possible tooth defect; through obtaining the region of the tooth located in the first region, the application ensures that the obtained candidate region is the position where the tooth defect may occur. By taking the intersection of the two, the application can ensure that the position and concave-convex degree of the obtained candidate region are in line with the part of the tooth that may have defect, so that the determined candidate region is more accurate. In a possible implementation, determining the defect region of the i th tooth according to the candidate region and the tooth characteristic data corresponding to the i th tooth comprises: extending the candidate region outward along the tooth contour by a first preset value to obtain the defect region.

[0019] The application extends the candidate region outward along the tooth contour to obtain the defect region, realizes the expansion of the candidate region, and ensures that the obtained defect region is more in line with the actual demand in the reverse concave filling.

[0020] In a possible implementation, extending the candidate region outward along the tooth contour by a first preset value to obtain the defect region comprises: extending the candidate region outward by the first preset value, and stopping the extension at the tooth hole line to obtain an extended region, the tooth hole line being the boundary line between the tooth and the gum; and merging the extended region and the candidate region as the defect region.

[0021] When determining the defect region, the application first expands the candidate region outward, then stops the outward expansion of the candidate region at the tooth hole line to obtain an extended region, and finally merges the extended region and the candidate region as the defect region, so as to ensure that the obtained defect region is more in line with the actual demand in the reverse concave filling. At the same time, by stopping the expansion at the tooth hole line, it is ensured that the extended region is not located in the position of the gum.

[0022] In a possible implementation, if a preset condition is met, it is determined that the ith tooth does not have a defect region; the preset condition includes at least one of the following: the area of the candidate region is less than a first area threshold, the candidate region is not in the region to be filled, the number of triangular facets in the candidate region is less than a first number threshold, or the sum of the areas of the triangular facets in the candidate region is less than a second area threshold.

[0023] When determining the defect region, the application excludes the part where the area of the candidate region is less than a certain threshold, the position of the candidate region is not in the region to be filled, or the number of triangular facets in the candidate region is less than a first threshold, and the sum of the areas of the triangular facets is less than a second threshold, thereby ensuring the accuracy of the positioning of the tooth defect region. If the area of the candidate region is too small, the number of triangular facets in the candidate region is too small, or the sum of the areas of the triangular facets in the candidate region is too small, it indicates that the position of the defect is too small and can be ignored. If the position of the candidate region is not in the region to be filled, it indicates that the candidate region may be a normal recessed part of the tooth, which will not affect the wearing effect of the target object after the aligner is generated, and can be ignored. In this way, the application ensures that the selected defect part is more accurate.

[0024] In a second aspect, the application provides a method for manufacturing a dental aligner, including: obtaining oral scanning data of a target object; determining tooth representation data of the target object based on the oral scanning data, the tooth representation data indicating the concave-convex degree of each tooth at different positions, and the value of the tooth representation data being positively correlated with the convex degree of the position region; determining a defect region of the tooth of the target object according to the tooth representation data; performing filling processing on the defect region to recess, and determining a digital tooth model; pressing the dental aligner based on the digital tooth model; wherein the step of determining the defect region of the tooth of the target object according to the tooth representation data includes the following steps: taking a region of an ith tooth located in a first region as a candidate region, the first region indicating a labial side and / or a gum line, and the ith tooth being any tooth in the tooth of the target object, and i being a positive integer; determining a defect region of the ith tooth according to the candidate region and the tooth representation data corresponding to the ith tooth, the defect region being used for filling the recess.

[0025] The application first obtains the oral scanning data and determines the tooth representation data, determines the defect region according to the tooth representation data, fills the defect region, and determines the digital model after filling the recess. The dental aligner is pressed based on the digital tooth model. In this way, the application can obtain a dental aligner that accurately fills all recessed parts, which is convenient for the target object to wear and take off in daily life.

[0026] In a third aspect, the present application provides a computing device, comprising: a memory for storing program instructions; and a processor for invoking the program instructions stored in the memory to implement the method of the first aspect.

[0027] In a fourth aspect, the present application provides a computer readable storage medium, wherein computer readable instructions are stored, and when the computer readable instructions are read and executed by a computer, the method of the first aspect is implemented.

[0028] In a fifth aspect, the present application provides a computer program product, comprising computer program executable by a computing device, and when the program is run on the computing device, the computing device is caused to implement the method of the first aspect.

[0029] The technical effects achieved by the third aspect to the fifth aspect can refer to the technical effects achieved by the corresponding possible design schemes of the first aspect, which will not be repeated here.

[0030] Other features and advantages of the present application will be described in the following description, and become apparent from the description, or be learned by practice of the application. The purpose and other advantages of the present application can be achieved and obtained by the structure particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0032] Fig. 1 is an application scenario provided by an embodiment of the present application;

[0033] Fig. 2 is a flowchart of a tooth defect determination method provided by an embodiment of the present application;

[0034] Fig. 3 is an outward expansion schematic diagram of a candidate region provided by an embodiment of the present application;

[0035] Fig. 4 is a flowchart of a tooth aligner manufacturing method provided by an embodiment of the present application;

[0036] Fig. 5 is a schematic diagram of a tooth defect determination device provided by an embodiment of the present application;

[0037] Fig. 6 is a structural schematic diagram of a computing device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application.

[0039] In the following embodiments of the present application, the association relationship of the associated objects is described by “and / or”, which means that there can be three kinds of relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. The character “ / ” generally means that the associated objects before and after it have an “or” relationship. “At least one (one) of the following or similar expressions means any combination of these items, including any combination of single (one) or multiple items. For example, at least one of a, b or c can mean a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple. The singular expressions “one”, “a kind of”, “the above”, “the” and “this” are intended to also include expressions such as “one or more”, unless the context clearly indicates otherwise. In addition, unless otherwise stated, the ordinal numbers “first”, “second”, etc. mentioned in the embodiments of the present application are used to distinguish a plurality of objects, and are not used to limit the order, time sequence, priority or importance of the plurality of objects.

[0040] In the present application, the reference “one embodiment” or “some embodiments” means that the specific features, structures or characteristics described in connection with the embodiment are included in one or more embodiments of the present application. Therefore, the statements “in one embodiment”, “in some embodiments”, “in other some embodiments”, “in other some embodiments” and the like appearing in different places in the specification are not necessarily all referring to the same embodiment, but mean “one or more but not all embodiments”, unless otherwise specifically emphasized. The terms “include”, “contain”, “have” and their variants mean “include but not limited to”, unless otherwise specifically emphasized.

[0041] As the background, compared with the traditional tooth aligner, the invisible tooth aligner not only has a transparent shell to avoid social embarrassment of the target object wearing the tooth aligner, but also has a removable function, which is more in line with the daily wearing needs and is more convenient to clean compared with the traditional tooth aligner. Therefore, more and more people prefer to choose invisible tooth aligners as the first choice for tooth alignment. Since the tooth aligner needs to provide good protection for the teeth of the target object, therefore, whether it is an ordinary tooth aligner or an invisible tooth aligner, it needs to be specially designed according to the tooth condition of the target object to ensure that the tooth alignment effect is better.

[0042] Specifically, the manufacturing method of the dental appliance is shown in FIG. 1. First, the teeth of the target object are scanned to obtain the tooth state data of the target object; then, the tooth state data of the target object is corrected by a series of corrections based on the manual correction of relevant personnel, and the tooth state data is modeled to obtain a corrected digital tooth model; further, based on the digital tooth model, the corresponding physical tooth model is manufactured using the method of numerical control machine tool processing or the method of rapid prototyping, and the corresponding dental appliance is pressed according to the physical tooth model. In this way, the corresponding dental appliance can be quickly generated according to the tooth condition of the target object. However, since the dental appliance is made based on the digital tooth model of the target object, the profile of the dental appliance is in a fitted state with the profile of the teeth of the target object. This leads to some special cases, for example, when there is a defect part on the surface of the teeth of the target object, the corresponding position of the dental appliance will press the concave part of the tooth surface to form a corresponding convex part. This causes inconvenience for the extraction and wearing of the dental appliance, and at the same time, when the defective part of the tooth touches the dental appliance, it also brings negative feelings such as pain to the target object. Therefore, before generating the physical tooth model, the digital tooth model needs to be operated to fill the undercut. First, the defective part is filled with undercut in the digital tooth model, then the filled physical tooth model is obtained, and finally the dental appliance is generated according to the physical tooth model. In this way, it can be ensured that the dental appliance obtained has no corresponding convex part in the undercut position on the tooth surface, so as to prevent the dental appliance from having bad demolding, bad wearing or bad wearing experience, etc.

[0043] In one possible implementation, the positive mold of the dental appliance can be manufactured based on a rapid prototyping process. Rapid prototyping techniques can be classified into several typical forming processes, such as stereo lithography apparatus (SLA), laminated object manufacturing (LOM), selected laser sintering (SLS), fused deposition modeling (FDM), three dimensional printing (3DP), and the like. In terms of forming materials, currently, mainly organic polymer materials are used, such as photo-cured resin, nylon, wax, and the like. Among them, the laser rapid forming SLA is a method of forming by using a laser to irradiate a photo-cured resin point by point to induce a chemical change of the material to solidify, while the laminated object manufacturing LOM is a method of forming by using a laser to cut a foil (paper, ceramic foil, metal foil, and the like), and the foils are bonded by hot melt adhesive under the pressure and heat transfer action of a hot roller to form a layer by layer stack. The selective laser sintering SLS is a method of forming by using a laser to irradiate a powder material point by point to make the material powder melt, or to make the solid adhesive coated outside the powder material melt to realize the connection of the material, while the fused deposition modeling FDM is a method of forming by continuously feeding a thermoplastic forming material into a nozzle, heating and melting it in the nozzle, and then spraying it out to gradually accumulate and form. The three-dimensional printing SDP is a method of forming by using a method similar to inkjet printing to spray a molten material to accumulate and form or to spray an adhesive to bond the powder material point by point.

[0044] Further, the region to be filled includes a region in which the tooth surface near the root part has a depression, such as a triangular region of depression between two adjacent teeth and a gum edge, or a wedge-shaped defect region of the root part caused by improper brushing, and the like. Currently, filling the undercut generally includes two ways: filling the undercut of the solid tooth model, or directly filling the undercut of the digital tooth model. In the former, a technician manually processes the region to be filled of the solid tooth model by using artificial stone, plaster, or paraffin, and the like, according to the surface of the solid tooth model. However, this manual processing method for filling the undercut has some problems. For example, the process of manually determining and filling the undercut can result in low production efficiency of the dental appliance and waste of human resources. Moreover, the experience values of different technicians are different, and the regions of the undercut determined by different technicians can be different.

[0045] Further, the reverse undercut filling of the digital tooth model is usually based on the digital tooth model to generate a virtual reverse undercut grid, and fill the virtual reverse undercut grid in the filling area of the digital tooth model to realize the reverse undercut filling of the digital tooth model. Alternatively, when the digital tooth model is filled with reverse undercut, recursive method or iterative method can also be used to automatically fill the reverse undercut area. For example, after filling the reverse undercut in the first round, it is detected again whether there is a reverse undercut, if there is, the reverse undercut filling method is repeated to fill the reverse undercut again, until no reverse undercut is detected in the digital tooth model. However, although this way of filling the reverse undercut no longer needs the technician to manually find the reverse undercut in the physical tooth model and fill it, it still needs the technician to manually find the area with reverse undercut according to the digital tooth model, and this process also leads to low production efficiency of the dental appliance and waste of human resources; and the experience values of different technicians are different, and the determined reverse undercut area can be different.

[0046] Therefore, the embodiments of the present application provide a tooth defect determination method, which obtains tooth representation data, and determines a tooth defect area in combination with the tooth representation data and a corresponding candidate area. The flow of the tooth defect determination method provided by the embodiments of the present application is shown in FIG. 2. The method can be executed by a computing device, which can be understood as a computer, a processor or the like, and the present application does not specifically limit it here. The method is specifically executed as follows:

[0047] In step 201, the computing device obtains tooth representation data of a target object.

[0048] Specifically, the computing device can model the tooth state data of the target object according to the tooth state data of the target object to obtain a digital tooth model. The tooth state data of the target object can be determined by oral scanning, bite mold, nuclear magnetic resonance, CT and the like, and the present application does not limit it here.

[0049] In order to better represent the position of each tooth of the target object, the teeth of the target object can be divided into four quadrants according to the teeth, and there are at most eight teeth in each quadrant. The teeth in the first quadrant are numbered as teeth 1x, for example, the teeth in the first quadrant are numbered as teeth 11, teeth 12, teeth 13, etc. according to the distance from the incisor from near to far. Similarly, the teeth in the second quadrant are numbered as teeth 2x, for example, the teeth in the second quadrant are numbered as teeth 21, teeth 22, teeth 23, etc. according to the distance from the incisor from near to far. The teeth in the third quadrant are numbered as teeth 3x, for example, the teeth in the third quadrant are numbered as teeth 31, teeth 32, teeth 33, etc. according to the distance from the incisor from near to far. The teeth in the fourth quadrant are numbered as teeth 4x, for example, the teeth in the second quadrant are numbered as teeth 41, teeth 42, teeth 43, etc. according to the distance from the incisor from near to far. Further, a corresponding coordinate system is established for each tooth in the digital tooth model. Usually, the three coordinate axes of the tooth are calculated by principal component analysis (PCA) of the triangular facets of the digital tooth model, so as to establish the corresponding tooth coordinate system.

[0050] Specifically, after obtaining the tooth coordinate system, the candidate region can be determined according to the tooth coordinate system. For example, in the tooth coordinate system, the part of the triangular facet of each tooth in the first quadrant and the third quadrant with a Y-axis picture centroid coordinate less than 0, and the part of the triangular facet of each tooth in the second quadrant and the fourth quadrant with a Y-axis picture centroid coordinate greater than 0 are the part of the tooth close to the lip. The Y-axis picture centroid coordinate of the triangular facet is calculated according to the average value of the coordinates of the three vertices of each triangular facet. Further, the part of the triangular facet with a Z-axis component of the centroid coordinate greater than the centroid of the tooth is the part of the tooth close to the root. The Z-axis component of the centroid coordinate is obtained by averaging the coordinates of all vertices of the triangular facet.

[0051] The tooth representation data indicates the concave-convex degree of each tooth at different positions. The value of the tooth representation data is positively correlated with the convex degree of the position region (i.e. the greater the convex degree of the tooth, the greater the value of the tooth representation data, and the greater the concave degree of the tooth, the smaller the value of the tooth representation data).

[0052] In an alternative manner, after obtaining the tooth state data of the target object, a triangular facet corresponding to each tooth can be constructed (where the size of the triangular facet can be based on the medical and production requirements for the accuracy of the appliance, i.e., the accuracy at which the tooth positive mold is determined), and the SDF value obtained based on the shape diameter function value (Shape Diameter Function, SDF) of each triangular facet indicates the representation data of the tooth. Of course, the triangular facet of the tooth can also be indicated according to other manners, and the present embodiment is exemplified by the SDF value.

[0053] The SDF value represents the mapping of the three-dimensional model volume to its enclosing mesh surface, which is used to determine the concave-convex degree of each part of the digital tooth model. For example, in the digital tooth model, the parts with different SDF values can be presented by different colors, and the operator can easily judge the concave-convex degree of each part of the tooth by the depth of the color. By calculating the SDF value, an intuitive display of the concave-convex degree of each part of each tooth can be obtained, so as to determine whether there is a defect area on the tooth surface.

[0054] It should be noted that the SDF value can also be presented in other manners to represent different concave-convex degrees, for example, a part with a larger convexity can be covered by a graph A, a part with a larger concavity can be covered by a graph B, and different graphs can be used to represent different concave-convex degrees, etc., which are not limited by the present application.

[0055] In a specific implementation case, the tooth representation data SDF value can be a specific numerical value, and can also be divided into different gears based on the value range of the SDF value. Referring to Table 1 below, as shown in Table 1, when the SDF value is less than 10%, it corresponds to the first gear, when the SDF value is between 10% and 30%, it corresponds to the second gear, when the SDF value is between 30% and 50%, it corresponds to the third gear, when the SDF value is between 50% and 70%, it corresponds to the fourth gear, and when the SDF value is greater than 70%, it corresponds to the fifth gear. Table 1 below is only exemplarily described, and the gears of the SDF value are not specifically limited.

[0056] Table 1

[0057] For example, when the size of the SDF value is distinguished by color depth, the part with the largest convexity in the digital tooth model, that is, the thickest part of the tooth, can be represented by red; the part with the moderate convexity in the digital tooth model, that is, the part with the moderate thickness of the tooth, can be represented by yellow; and the part with the largest concavity in the digital tooth model, that is, the thinnest part of the tooth, can be represented by green. For the target object with a wedge-shaped defect, the middle part of the incisor is represented by red, the part transitioning outward from the middle part is represented by yellow, and the part close to the gum and the other side is represented by green in modeling. It should be noted that the above color and SDF value representation are only examples, and the present application is not limited thereto.

[0058] In step 202, the computing device takes the region of the ith tooth in the first region as a candidate region.

[0059] The first region indicates the labial side, and / or the gum line, the ith tooth is any tooth of the target object, and i is a positive integer.

[0060] Specifically, taking a single tooth as an example, the first region can be the part of the tooth close to the labial side and the gum line, or the part of the tooth close to the labial side, or the part of the tooth close to the gum line, and the present application is not limited thereto.

[0061] In one possible implementation, the candidate region further includes a region of the ith tooth whose tooth representation data is less than a first threshold value. For example, the first threshold value can be set to SDF = 20% (e.g., 0.2), and the part of the ith tooth whose tooth representation data is less than 0.2 is taken as the candidate region. For example, the first threshold value can also be set to a third gear, and the part of the ith tooth whose tooth representation data is less than the third gear is taken as the candidate region. In this example, the representation form of the first threshold value is only illustrative, and the first threshold value can be flexibly set based on the operating experience of the technician, and can also be determined based on the to-be-filled region of the tooth, and the present application is not limited thereto.

[0062] For example, the skilled person finds that the SDF value of the tooth region where the tooth has some kind of defect is less than a certain fixed value, for example, the region where the tooth has a wedge-shaped defect is usually more concave, and the SDF value is less than 20% (for example, 0.2), therefore, the skilled person usually considers the part with SDF value less than 0.2 as the part where the tooth has a wedge-shaped defect. Meanwhile, the skilled person also finds that the part where the tooth has a reverse concave is usually more concave compared with other parts of the tooth, and the SDF value is generally less than 10% (for example, 0.1), therefore, the skilled person considers the part with SDF value less than 0.1 as the part where the tooth has a reverse concave. In order to make the tooth defect region contain both the wedge-shaped defect region and the part where the tooth has a reverse concave, the skilled person sets the first threshold value of the SDF value as SDF = 20%. It should be noted that the above numerical value is only an example, and the present application does not limit the SDF value, which can be replaced by other numerical values according to actual needs.

[0063] In another possible implementation, the candidate region is the region intersection of the region where the tooth characteristic data of the ith tooth is less than the first threshold value and the region of the ith tooth located in the first region.

[0064] Specifically, the candidate region in the present application can obtain the part of the first region of each tooth, and then obtain the part of the region where the tooth characteristic data of the ith tooth is less than the first threshold value, and then perform intersection calculation on the two parts, and finally obtain the part of the first region of the tooth where the tooth characteristic data is less than the first threshold value. Alternatively, the present application can also obtain the region of the ith tooth located in the first region, and then screen the part of the region where the tooth characteristic data is less than the first threshold value. The calculation methods of the two methods are different in the implementation process, and the final results are consistent, and the present application does not limit them.

[0065] In step 203, the computing device determines the defect region of the ith tooth according to the candidate region and the tooth characteristic data corresponding to the ith tooth, and the defect region is used to fill the reverse concave.

[0066] Based on the introduction in step 202, the candidate region is the first region, the region where the tooth characteristic data of the ith tooth is less than the first threshold value, or the region intersection of the region where the tooth characteristic data of the ith tooth is less than the first threshold value and the region of the ith tooth located in the first region. The following describes how to determine the defect region of the ith tooth in combination with different cases.

[0067] Case 1, the candidate region is the first region.

[0068] Case 2, the candidate region is the region where the tooth characteristic data of the ith tooth is less than the first threshold value.

[0069] In the case 1 and the case 2, the computing device can determine the to-be-filled region according to the tooth representation data corresponding to the ith tooth; and determine the defect region according to the to-be-filled region and the candidate region.

[0070] Specifically, the computing device can regard a region, in which the tooth representation data corresponding to the ith tooth is less than a second threshold (the second threshold can be an experience value of a technician, and generally the second threshold is less than the first threshold), as the to-be-filled region, or regard a region of a tooth located in a second region (i.e., an existing undercut region, such as a concave triangular region of a gum edge of two adjacent teeth, or a wedge-shaped defect region caused by improper tooth brushing, etc.) as the to-be-filled region, regard a part in which the to-be-filled region and the candidate region exist as the defect region, or determine the defect region according to the to-be-filled region and the candidate region, which is not specifically limited herein.

[0071] Specifically, the determination of the defect region can also first obtain the candidate region, and reduce the area of the candidate region according to a region in which the undercut is located, to obtain a reduced region as the defect region; for example, the application obtains a candidate region A, and then searches for a corresponding to-be-filled region B in the candidate region A, and reduces the area of the candidate region A to a certain range according to the area of the to-be-filled region B, to obtain a reduced candidate region. Specifically, the reduced area can be set to different values according to the tooth data of a user, for example, 1 square millimeter, which is not limited by the embodiments of the application.

[0072] In this way, the embodiments of the application realize the determination of the defect region, consider various parameters from multiple aspects, and guarantee the accuracy of the tooth defect region determined by the application, thereby improving the comfort of the tooth appliance manufactured by using the method.

[0073] The case 3, the candidate region is a region intersection of a region, in which the tooth representation data of the ith tooth is less than the first threshold, and a region of the ith tooth located in the first region

[0074] In a possible implementation, the candidate region is extended by a first preset value along the tooth contour to obtain the defect region.

[0075] Specifically, after the candidate region is obtained, the candidate region is expanded along the tooth contour, as shown in FIG. 3. First, the candidate region is determined as the part of the solid line filled box in the tooth model 301 in FIG. 3, and the part of the region is expanded along the tooth to obtain the part of the dashed line filled box. In a possible implementation, the candidate region is expanded by a first preset value in all directions, and the expansion stops at the tooth hole line, which is the boundary line between the tooth and the gum, to obtain an expanded region. The expanded region and the candidate region are combined to obtain the defect region. Specifically, the first preset value can be set to different values according to the tooth data of the user. For example, the first preset value can be 1 mm, and the embodiments of the present application are not limited in this regard.

[0076] In this way, it can be ensured that the expanded candidate region completely covers the tooth defect region. As shown in FIG. 3, 302 is a side view of the defect region after the candidate region is expanded. The part of the solid line filled box is the candidate region, and the part of the dashed line filled box is the expanded region. It can be found that the combined candidate region and expanded region can obtain the complete defect region that needs to be filled.

[0077] As shown in FIG. 3, the candidate region is determined as the part of the solid line filled box in 301, and the part of the dashed line filled box is obtained by expanding the candidate region outward, and the candidate region is combined as the outwardly expanded undercut. As shown in FIG. 3, 303 is the defect region determined by combining the candidate region and the to-be-filled region. Further, as shown in FIG. 3, 304, after the defect region is determined, the defect region needs to be filled. This filling is usually to modify the model of the tooth defect part on the digital tooth model to generate a digital tooth with filled undercut, and then obtain a tooth model. As shown in FIG. 3, 304 is a digital tooth model with filled undercut. After the tooth defect region is determined, the digital tooth model is used to fill the undercut of the defect region. Alternatively, after the defect region is determined, the tooth model can be obtained first, and then a special material is used to fill the marked defect region on the tooth model. The present application does not limit how to fill the undercut.

[0078] It should be further noted that if the preset condition is met, it is determined that the i th tooth does not have a defect region. The preset condition includes at least one of the following: the area of the candidate region is less than a first area threshold, the candidate region is not in the to-be-filled region, the number of triangular facets in the candidate region is less than a first number threshold, or the area sum of the triangular facets in the candidate region is less than a second area threshold.

[0079] Specifically, if the area of the candidate region is less than a specific first area threshold, the overall area of the undercut portion is small, and the corresponding undercut will not be generated during the pressing of the dental appliance, so filling is not needed. If the candidate region is not in the region to be filled, the tooth representation data value of the region may be normal even if it is less than the first threshold, for example, it may be the thinnest position of the front teeth, etc. Or, the tooth defect in the region may not affect the generation of the dental appliance, for example, it may be a dental caries, etc. If the number of triangular facets in the candidate region is less than a first number threshold, or the area sum of the triangular facets in the candidate region is less than a second area threshold, the overall area of the undercut portion is small, and the corresponding undercut will not be generated during the pressing of the dental appliance, so filling is not needed. For example, if the area of the candidate region is less than 0.3 square millimeters, the candidate region is not filled with the undercut. It should be noted that the above scheme is only an example, and the present application does not limit this.

[0080] Based on the same technical concept, the present application provides a method for manufacturing a dental appliance. The method performs a production process of the dental appliance through the process of the tooth defect determination method. The method is executed by a computing device, which can be understood as a computer or the like. The process of the method is shown in FIG. 4.

[0081] In step 401, the computing device obtains oral scan data of a target object.

[0082] First, the computing device determines the information in the oral cavity of the target object by scanning the oral cavity of the target object in an X-ray, nuclear magnetic resonance or the like. Then, the corresponding oral scan data and digital oral model are generated according to the information in the oral cavity. The digital tooth model is presented by a facet modeling method, wherein each tooth surface is composed of a plurality of triangular facets.

[0083] In step 402, the computing device determines tooth representation data of the target object based on the oral scan data. The tooth representation data indicates the concave-convex degree of each tooth at different positions. The value of the tooth representation data is positively correlated with the convex degree of the position.

[0084] Specifically, after obtaining the digital oral model, the computing device calculates the SDF value of the digital oral model, determines the tooth representation data of each digital tooth model, and obtains the different concave-convex degrees of each tooth according to the tooth representation data, to determine whether there is a defect on the tooth surface.

[0085] In step 403, the computing device determines the defect region of the tooth of the target object according to the tooth representation data, fills the undercut of the defect region, and determines the digital tooth model.

[0086] Specifically, the computing device further determines, according to the tooth representation data and the first region, whether the candidate region of the target object tooth belongs to a defect region, and if not, the candidate region is not processed; otherwise, if the candidate region belongs to the defect region, the defect region is expanded, and a defect region containing the entire undercut to be filled is obtained, and the expanded defect region is filled.

[0087] At step 404, the computing device presses the dental appliance based on the digitized dental model.

[0088] The method further includes the following steps: taking a region of an ith tooth located in the first region as a candidate region, the first region indicating a labial side and / or a gum line, the ith tooth being any tooth of the target object tooth, and i being a positive integer; and determining a defect region of the ith tooth according to the candidate region and tooth representation data corresponding to the ith tooth, the defect region being used to fill the undercut.

[0089] In one embodiment, the SLA method is used to manufacture the solid dental model. Specifically, based on the polymerization reaction of photosensitive resin, a laser under computer control is used to perform point-by-point scanning on the liquid resin along the profile of each layer of the dental model, so that the scanned thin layer of resin undergoes polymerization reaction, gradually forming a line from a point, and finally forming a solidified cross section of a thin layer of the solid dental model, while the resin that is not scanned remains in the original liquid state. When the solidification of a layer is completed, the lifting platform moves a layer thickness distance, and a new layer of liquid resin is covered on the surface of the resin that has been solidified in the previous layer, for re-scanning and solidification. The newly solidified layer is firmly bonded to the previous layer, and the cycle is repeated until the entire solid dental model is manufactured. Subsequently, the part is placed under high-intensity ultraviolet light for curing, so as to obtain the solid dental model, i.e., the positive model or male mold used to manufacture the dental appliance.

[0090] Further, the method of manufacturing the dental appliance can include: using a hot-pressing device to press a dental appliance film made of transparent polymer material (a polymer with elasticity, such as polycarbonate) on the solid dental model by the positive pressure film pressing technology, to form a shell, thereby manufacturing the dental appliance. However, the method of manufacturing the dental appliance based on the dental model is not limited to the hot-pressing method, and other methods can also be used to manufacture the dental appliance based on the solid dental model.

[0091] In this way, the embodiments of the present application realize rapid positioning and filling of the tooth defect part, so as to ensure that manual positioning and filling of the undercut are no longer needed in subsequent undercut filling operations, and at the same time, it can be ensured that problems such as difficulty in demolding of the dental appliance and discomfort in wearing the dental appliance due to unfilled undercut will not occur.

[0092] Based on the same technical concept, FIG. 5 exemplarily shows a tooth defect determination apparatus provided by an embodiment of the present application, which can execute the flow of the tooth defect determination method. The apparatus comprises an acquisition module 501, a processing module 502, and a determination module 503.

[0093] The acquisition module 501 is configured to acquire tooth representation data of a target object, the tooth representation data indicating the concave-convex degree of each tooth at different position regions, and the value of the tooth representation data being positively correlated with the convex degree of the position region.

[0094] The processing module 502 is configured to take the region of the ith tooth located in the first region as a candidate region, the first region indicating the labial side and / or the gum line, the ith tooth being any tooth of the target object, and i being a positive integer.

[0095] The determination module 503 is configured to determine a defect region of the ith tooth according to the candidate region and the tooth representation data corresponding to the ith tooth, the defect region being used to fill the undercut.

[0096] In a possible implementation, the candidate region further comprises a region of the ith tooth whose tooth representation data is less than a first threshold value.

[0097] In a possible implementation, the determination module 503 is specifically configured to: determine a region to be filled according to the tooth representation data corresponding to the ith tooth; and determine the defect region according to the region to be filled and the candidate region.

[0098] In a possible implementation, the determination module 503 is specifically configured to determine the defect region according to the region to be filled and the candidate region.

[0099] In a possible implementation, the candidate region is the region intersection of the region of the ith tooth whose tooth representation data is less than the first threshold value and the region of the ith tooth located in the first region.

[0100] In a possible implementation, the determination module 503 is specifically configured to expand the candidate region by a first preset value along the tooth contour to obtain the defect region.

[0101] In a possible implementation, the determination module 503 is specifically configured to expand the candidate region by a first preset value, and stop expanding at a tooth hole line to obtain an expanded region, the tooth hole line being the boundary line between the tooth and the gum; and take the merged region of the expanded region and the candidate region as the defect region.

[0102] In a possible implementation, if a preset condition is met, it is determined that the ith tooth does not have a defect region; wherein the preset condition includes at least one of the following: an area of the candidate region is less than a first area threshold, the candidate region is not in the region to be filled, a number of triangular facets in the candidate region is less than a first number threshold, or an area sum of the triangular facets in the candidate region is less than a second area threshold.

[0103] The application provides a computing device or system of another exemplary embodiment. Those skilled in the art can understand that various aspects of the application can be implemented as a system, a method or a program product. Therefore, various aspects of the application can be implemented in the form of a complete hardware embodiment, a complete software embodiment (including firmware, microcode, etc.), or an embodiment combining hardware and software aspects, which can be collectively referred to as "circuitry", "module" or "system" herein.

[0104] In some possible implementations, the computing device according to the application can at least include at least one processor and at least one memory, taking the computing device as an example. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps in the library capacity configuration method according to various exemplary embodiments of the application described in the specification.

[0105] The computing device 130 according to this embodiment of the application is described below with reference to FIG. 6. FIG. 6 shows the computing device 130 as an example only, and should not be taken as any limitation to the functions and uses of the embodiments of the application. As shown in FIG. 6, the computing device 130 is in the form of a general smart terminal (or Bluetooth headset). The components of the computing device 130 can include but are not limited to the at least one processor 131, the at least one memory 132, and the bus 133 connecting different system components including the memory 132 and the processor 131.

[0106] The bus 133 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a processor or a local bus using any of a variety of bus structures. The memory 132 can include a readable medium in the form of volatile memory, such as a random access memory (RAM) 1321 and / or a cache memory 1322, and can further include a read-only memory (ROM) 1323. The memory 132 can also include a program / utility 1325 having a set of (at least one) program modules 1324, including but not limited to an operating system, one or more application programs, other program modules, and program data, each of which can include or be a component of a network environment, or some combination thereof.

[0107] The computing device 130 can also communicate with one or more external devices 134 such as a keyboard or pointing device, through an input / output (I / O) interface 135. And, the computing device 130 can communicate with one or more networks, such as a local area network (LAN), a wide area network (WAN), and / or the Internet, through a network adapter 136. It will be appreciated that the network adapter 136 can

[0108] In some possible embodiments, various aspects of the tooth defect determination method provided in the present application can also be implemented in the form of a program product, which includes a computer program for causing a computer device to execute the steps of the library capacity configuration method according to various exemplary embodiments of the present application described above in the specification when the program product is run on the computer device.

[0109] The program product can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium may, for example, be but is not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or apparatus, or any combination thereof. More specific examples (a non-exhaustive list) of the readable storage medium include an electrical connection having one or more wires, a portable disc, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or a flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0110] The program product for determining a tooth defect of the embodiments of the present application can adopt a portable compact disc read-only memory (CD-ROM) and include a computer program, and can be run on a smart terminal. However, the program product of the present application is not limited thereto, and in the present document, the readable storage medium can be any tangible medium containing or storing a program, which can be used by or in conjunction with an instruction execution system, device, or apparatus.

[0111] It should be noted that, although several units or sub-units of the apparatus are mentioned in the above detailed description, such division is merely exemplary and not mandatory. Indeed, according to an embodiment of the application, the features and functionalities of two or more units described above can be embodied in one unit. Conversely, the features and functionalities of one unit described above can be further divided into units embodied by several units.

[0112] Moreover, although the operations of the method(s) herein can be described in a particular, sequential order, this is not meant to be a restriction on the order in which such operations are performed, nor that all described operations are necessarily performed. Additionally or alternatively, certain of the described operations can be performed in parallel, been executed at different times, or in a different order. All such modifications and variations are within the scope of the present application.

[0113] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks and / or flowchart flow or flows and / or block or blocks of the block diagram.

[0114] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks and / or flowchart flow or flows and / or block or blocks of the block diagram.

[0115] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A method of tooth defect determination, characterized by, The method comprises: obtaining tooth characteristic data of a target object, the tooth characteristic data indicating the degree of concave-convex of different position regions of each tooth, and the value of the tooth characteristic data being positively correlated with the degree of convexity of the position region; regarding a region of an i-th tooth located in a first region as a candidate region, the first region indicating a labial side and / or a gum line, the i-th tooth being any tooth of the target object, and i being a positive integer; determining a defect region of the i-th tooth according to the candidate region and tooth characteristic data corresponding to the i-th tooth, the defect region being used to fill the undercut.

2. The method of claim 1, wherein, The candidate region further comprises a region of the i-th tooth, in which the tooth characteristic data is less than a first threshold value.

3. The method according to claim 1 or 2, characterized in that, The determining of the defect region of the i-th tooth according to the candidate region and tooth characteristic data corresponding to the i-th tooth comprises: determining a region to be filled according to the tooth characteristic data corresponding to the i-th tooth; determining the defect region according to the region to be filled and the candidate region.

4. The method of claim 3, wherein, The determining of the defect region according to the region to be filled and the candidate region comprises: reducing the candidate region according to the region to be filled to determine the defect region.

5. The method of claim 1, wherein, The candidate region is a region intersection of the region of the i-th tooth located in the first region and the region of the i-th tooth, in which the tooth characteristic data is less than the first threshold value.

6. The method of claim 5, wherein, The determining of the defect region of the i-th tooth according to the candidate region and tooth characteristic data corresponding to the i-th tooth comprises: extending the candidate region by a first preset value along a tooth contour to obtain the defect region.

7. The method of claim 6, wherein, The extending of the candidate region by the first preset value along the tooth contour to obtain the defect region comprises: extending the candidate region by the first preset value and stopping the extension at a tooth hole line to obtain an extended region, the tooth hole line being a boundary line between a tooth and a gum; combining the extended region and the candidate region to obtain the defect region.

8. The method of any one of claims 1-2, 4-7, wherein, The method further comprises: if a preset condition is met, determining that the i-th tooth does not have the defect region. The preset condition comprises at least one of the following: the area of the candidate region is less than a first area threshold value, the candidate region is not in the region to be filled, the number of triangular facets in the candidate region is less than a first number threshold value, or the area sum of the triangular facets in the candidate region is less than a second area threshold value.

9. A method of manufacturing a dental appliance, the method comprising: The method comprises: obtaining oral scanning data of a target object; determining tooth characteristic data of the target object based on the oral scanning data, the tooth characteristic data indicating the degree of concave-convex of different position regions of each tooth, and the value of the tooth characteristic data being positively correlated with the degree of convexity of the position region; determining a defect region of a tooth of the target object according to the tooth characteristic data; filling the defect region with an undercut to determine a digital tooth model; pressing a dental appliance based on the digital tooth model; The determining of the defect region of the tooth of the target object according to the tooth characteristic data comprises the following steps: A region of an ith tooth located in a first region is taken as a candidate region, the first region indicating a labial side and / or a gum line, the ith tooth being any tooth of the teeth of the target object, and i being a positive integer; A defect region of the ith tooth is determined according to the candidate region and tooth representation data corresponding to the ith tooth, the defect region being used to fill the undercut.

10. A computing device, comprising: comprise a processor and a memory; The memory is configured to store computer instructions. The processor is connected with the memory and is configured to execute the computer instructions in the memory, so as to implement the method in any one of claims 1 to 9.

11. A computer readable storage medium, characterized in that, The computer program or instructions are stored in the computer readable storage medium, and when the computer program or instructions are executed by the user equipment, the method in any one of claims 1 to 9 is implemented.

12. A computer program product comprising computer programs / instructions, characterized in that, The computer program / instructions are executed by the processor, and the method in any one of claims 1 to 9 is implemented.

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