Method and electronic device for generating tooth arrangement reference curve and target tooth layout

Abstract

The invention relates to the technical field of orthodontic digital design, and discloses a method and electronic equipment for generating a tooth arrangement reference curve and a target tooth layout, and the method comprises the following steps: obtaining a target three-dimensional first jaw digital model and a three-dimensional second jaw digital model having an occlusion corresponding relation with the target three-dimensional first jaw digital model, the three-dimensional second jaw digital model is generated by a second jaw initial tooth layout without tooth arrangement; based on the target three-dimensional first jaw digital model, obtaining an edge cutting point of each tooth of a first jaw; gathering the cutting edge points of all teeth of the first jaw to form a first jaw cutting edge reference curve; and adjusting the first jaw cutting edge reference curve to obtain a second jaw cutting edge reference curve for the second jaw row teeth. According to the embodiment of the invention, manual steps in tooth arrangement can be reduced as much as possible, the accuracy of obtaining the target tooth layout can be improved, and the speed and the automation degree of the whole tooth arrangement process are improved.

Description

Technical Field

[0001] This invention relates to the field of orthodontic digital design technology, and in particular to a method and electronic device for generating tooth alignment reference curves and target tooth layouts. Background Technology

[0002] Shell-shaped orthodontic appliances are a type of orthodontic device made of safe, elastic, transparent polymer material. They have the advantages of being completely invisible during the orthodontic process, aesthetically pleasing, easy to operate, and convenient for oral cleaning. Moreover, due to their transparent and aesthetically pleasing characteristics, the orthodontic process is completed almost imperceptibly to others, and they have gradually become the first choice for orthodontic patients.

[0003] With the rapid development of computer technology, dental treatment increasingly relies on it. For example, in the design of orthodontic target positions, an initial dental arch curve is typically generated based on a 3D digital model representing the initial tooth layout. This initial arch curve is then adjusted to an ideal state, and the initial tooth layout is further adjusted based on this ideal arch curve to obtain a 3D digital model representing the target tooth layout. However, in practical applications, it has been found that the accuracy of the target tooth layout generated in this way depends primarily on the accuracy of the arch curve, and the accuracy of the ideal arch curve, in turn, depends on the accuracy of the initial arch curve. If the initial tooth layout is disorganized, the resulting arch curve will deviate significantly from the ideal state. Furthermore, considering only the tooth layout without considering other oral physiological characteristics may result in an unattainable target tooth layout. A current approach involves automatically generating the arch curve, which is then adjusted by a dentist or professional designer based on oral physiological characteristics. This ensures that the resulting arch curve better matches the patient's oral physiological features, making the target tooth layout easier to achieve. This method, on the one hand, increases the need for manual adjustments, resulting in lower efficiency; on the other hand, the quality of the adjusted dental arch curve is also affected by the adjuster's experience, thus impacting the quality of the target tooth layout. Furthermore, when a case requires simultaneous tooth arrangement for both the upper and lower jaws, separate tooth arrangement designs are needed for the maxilla and mandible. This necessitates obtaining dental arch curves for the maxilla and mandible separately, not only increasing the number of steps but also further increasing the possibility of intermediate errors. Summary of the Invention

[0004] The purpose of this invention is to provide a method and electronic device for generating a tooth alignment reference curve and a target tooth layout, which minimizes manual steps in tooth alignment, improves the accuracy of obtaining the target tooth layout, and increases the speed and automation of the overall tooth alignment process.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a method for generating a tooth arrangement reference curve, comprising: acquiring a target three-dimensional digital model of a first jaw and a three-dimensional digital model of a second jaw that has an occlusal correspondence with the target three-dimensional digital model of the first jaw, wherein the three-dimensional digital model of the second jaw is generated from the initial tooth layout of the second jaw before tooth arrangement; acquiring the incisal edge points of each tooth of the first jaw based on the target three-dimensional digital model of the first jaw; aggregating the incisal edge points of all teeth of the first jaw to form a first jaw incisal edge reference curve; and adjusting the first jaw incisal edge reference curve to obtain a second jaw incisal edge reference curve for tooth arrangement in the second jaw.

[0006] Compared with the prior art, the embodiments of the present invention, when arranging teeth in the second jaw, refer to the tooth layout of the target position of the first jaw to obtain the position of the incisal edge of the teeth in the target position of the first jaw. Utilizing the physiological characteristic relationship between the incisal edge of the first jaw and the incisal edge of the second jaw, a reference curve for arranging teeth in the second jaw is obtained. This eliminates the need to obtain a traditional dental arch curve for arranging teeth separately for the second jaw and to perform the manual adjustment process of the traditional dental arch curve. Therefore, it can reduce the influence of the initial dentition layout of the second jaw on the design result of the tooth arrangement target, and also reduce the intermediate error caused by manual adjustment in the traditional tooth arrangement target reference curve. This improves the automation level of the tooth arrangement process, speeds up the automatic tooth arrangement, and makes the automatic tooth arrangement result more accurate and reliable.

[0007] Optionally, adjusting the first jaw incisal edge reference curve to obtain a second jaw incisal edge reference curve for arranging teeth in the second jaw includes: adjusting the first jaw incisal edge reference curve in a reference plane and in a direction perpendicular to the reference plane to obtain a second jaw incisal edge reference curve corresponding to the second jaw; wherein, the reference plane is a jaw plane or a horizontal plane. Since the first jaw incisal edge reference line and the second jaw incisal edge reference line have a physiological correspondence, this application limits the use of the jaw incisal edge reference curve obtained after tooth arrangement in the first jaw to obtain the second jaw incisal edge reference curve, so that the second jaw can be directly arranged according to the second jaw incisal edge reference curve without needing to obtain a separate dental arch curve, and is not affected by the initial tooth arrangement regularity of the second jaw.

[0008] Optionally, if the first jaw is a mandible and the second jaw is a maxilla, adjusting the first jaw incisal reference curve in a direction perpendicular to the reference plane includes: moving the anterior tooth segment of the first jaw incisal reference curve downwards by a first preset distance. This application defines an adjustment method for transforming the first jaw incisal reference curve into a second jaw incisal reference curve, so as to obtain the second jaw incisal reference curve more accurately.

[0009] Optionally, the first preset distance is the vertical distance between the midpoints of the incisal edges of the upper and lower central incisors when the upper and lower central incisors are at the standard torque angle, the lower central incisors and the upper central incisors are in light contact on the lingual side, and the sagittal distance between the upper and lower central incisors is within the range of 2-4 mm; or, the first preset distance is within the range of 1.7-2.2 mm.

[0010] Optionally, adjusting the first incisal reference curve in a direction perpendicular to the reference plane further includes: vertically shifting each tooth in the posterior segment of the first incisal reference curve by a second preset distance, wherein: the second preset distance corresponding to the second maxillary tooth 6 segment is the long-axis projection distance V6 from the buccal apex of maxillary tooth 6 to the central fossa; the second preset distances corresponding to the second maxillary tooth 4 segment and the second preset distances corresponding to the second maxillary tooth 5 segment are obtained based on V6 using direct assignment, linear interpolation, or nonlinear interpolation; or, it further includes: vertically shifting the posterior segment of the first incisal reference curve by a third preset distance, wherein the third preset distance includes the set of long-axis projection distances from the buccal apex to the central fossa of each single maxillary tooth in each posterior segment. This application defines another vertical adjustment method when transforming from the first incisal reference curve to the second incisal reference curve, so as to accurately and practically obtain the second incisal reference curve.

[0011] Optionally, if the first jaw is a mandible and the second jaw is a maxilla, adjusting the first jaw incisal reference curve in the direction of the reference plane includes: uniformly expanding the first jaw incisal reference curve along the labial and buccal sides by a fourth preset distance; or, expanding the first jaw incisal reference curve along the labial sides by a fourth preset distance in the anterior tooth segment and along the buccal sides by a fifth preset distance in each tooth of the posterior tooth segment, wherein the fifth preset distance corresponding to the second jaw's 6th tooth segment is the buccal-lingual projection distance K6 from the buccal apex of the maxillary 6th tooth to the central fossa; the fifth preset distances corresponding to the second jaw's 4th tooth segment and the fifth preset distances corresponding to the second jaw's 5th tooth segment are obtained based on K6 using direct assignment, linear interpolation, or nonlinear interpolation; or, expanding the first jaw incisal reference curve along the labial sides by a fourth preset distance in the anterior tooth segment and along the buccal sides by a sixth preset distance in each tooth of the posterior tooth segment, wherein the sixth preset distance is the buccal-lingual projection distance from the buccal apex of a single maxillary tooth to the central fossa. This application specifies the horizontal adjustment method when transforming from the first jaw incision reference curve to the second jaw incision reference curve, so as to obtain the second jaw incision reference curve more accurately.

[0012] Optionally, the fourth preset distance is the sagittal distance between the midpoints of the incisal edges of the upper and lower central incisors when the upper and lower central incisors are at the standard torque angle, the lower central incisors and upper central incisors are in light lingual contact, and the sagittal distance between the upper and lower central incisors is within the range of 2-4 mm; or, the fourth preset distance is within the range of 1.7-2.2 mm. Optionally, adjusting the incisal edge feature position of the three-dimensional second jaw digital model based on the first jaw incisal edge reference curve includes: adjusting the occlusal feature position of the three-dimensional second jaw digital model based on the first jaw incisal edge reference curve until the posterior tooth regions of the three-dimensional second jaw digital model and the three-dimensional first jaw digital model conform to the cusp-fossa alignment relationship; wherein, the occlusal feature position includes the lingual incisal edge point of the anterior tooth region and the central groove point of the posterior tooth region. Since accurate matching of the occlusal feature position can make the occlusal relationship after tooth arrangement more stable, this application limits the adjustment of the occlusal feature position during the adjustment of the second jaw tooth layout so that the occlusal relationship of the target tooth layout is more stable.

[0013] Optionally, the target three-dimensional first jaw digital model is generated by processing the initial three-dimensional first jaw digital model based on an automatic tooth arrangement method, wherein the automatic tooth arrangement method includes: calculating the initial dental arch curve of the three-dimensional first jaw digital model; adjusting the initial dental arch curve to obtain the target dental arch curve; and adjusting the three-dimensional first jaw digital model based on the target dental arch curve to generate the target three-dimensional first jaw digital model.

[0014] Optionally, calculating the initial dental arch curve of the three-dimensional first jaw digital model includes: constructing an initial dental arch curve based on the same feature point of several teeth in the three-dimensional first jaw digital model; or, constructing an initial dental arch curve in the dental coordinate system based on the tooth features of the three-dimensional first jaw digital model using a preset dental arch curve representation model.

[0015] Optionally, the preset dental arch curve representation model is a deformed elliptical equation representation model; or, it is a representation model combining a first function equation for the anterior teeth region and a second function equation for the posterior teeth region; wherein, the first function equation is an elliptic curve function, a beta function, or a power function, and the second function equation is a parabolic function or a cubic curve function.

[0016] Optionally, adjusting the initial dental arch curve to obtain the target dental arch curve includes: adjusting the initial dental arch curve according to the orthodontic plan or orthodontic goal to obtain the target dental arch curve; wherein, the sum of the distances from each tooth in the three-dimensional first jaw digital model to the target dental arch curve converges to the first preset condition.

[0017] An embodiment of the present invention provides a method for generating a target tooth layout, comprising: processing a second jaw incisal edge reference curve for tooth arrangement in the second jaw based on the above-described method for generating a tooth arrangement reference curve; adjusting a three-dimensional digital model of the second jaw corresponding to the initial tooth layout of the second jaw based on the second jaw incisal edge reference curve, so that the incisal edge feature positions of each tooth in the second jaw conform to the second jaw incisal edge reference curve, thereby generating a target three-dimensional digital model of the second jaw.

[0018] Compared with the prior art, the embodiments of the present invention, when performing joint tooth arrangement of the second and first jaws, first arrange the teeth of the first jaw, and then use the physiological characteristic relationship between the incisal edge points of the first and second jaws to arrange the teeth of the second jaw. There is no need to obtain the traditional dental arch curve for tooth arrangement separately for the second jaw, nor to adjust the dental arch curve. Therefore, it can reduce the impact of the initial dentition layout of the second jaw on the tooth arrangement target design result, and also reduce the intermediate error caused by manual adjustment of the tooth arrangement reference curve, improve the automation of the tooth arrangement process, speed up the overall speed of automatic tooth arrangement, and make the automatic tooth arrangement result more accurate and reliable.

[0019] Furthermore, embodiments of the present invention also provide an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the above-described method for generating a tooth alignment reference curve, or the above-described method for generating a target tooth layout. Attached Figure Description

[0020] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0021] Figure 1 This is a flowchart of a method for generating a tooth alignment reference curve provided in the first embodiment of this application;

[0022] Figure 2 This is a flowchart of the automatic tooth alignment method in the method for generating a tooth alignment reference curve provided in the first embodiment of this application;

[0023] Figure 3 This is a schematic diagram illustrating the method for generating a tooth alignment reference curve provided in the first embodiment of this application, showing the acquisition of the incisal edge points of teeth in the anterior region.

[0024] Figure 4This is a schematic diagram illustrating the long axial projection distance from the buccal apex to the central fossa of a tooth in the posterior region, as exemplified in the method for generating a tooth arrangement reference curve provided in the second embodiment of this application.

[0025] Figure 5 This is a schematic diagram illustrating the buccal-lingual projection distance from the buccal apex to the central fossa of a tooth in the posterior region, as exemplified in the method for generating a tooth alignment reference curve provided in the third embodiment of this application.

[0026] Figure 6 This is a flowchart of the automatic tooth alignment method in the method for generating a tooth alignment reference curve provided in the fourth embodiment of this application;

[0027] Figure 7 This is a flowchart of the method for generating the WALA crest in the method for generating a tooth alignment reference curve provided in the fourth embodiment of this application;

[0028] Figure 8 This is a schematic diagram of the intersection of the cross section formed by the labial-lingual axis and the root-coronal axis with the three-dimensional digital model of the jaw, as exemplified in the method for generating a tooth arrangement reference curve provided in the fourth embodiment of this application.

[0029] Figure 9 This is a schematic diagram of the WALA ridge protrusion position in the method for generating a tooth alignment reference curve provided in the fourth embodiment of this application;

[0030] Figure 10 This is a schematic diagram illustrating the positional relationship between the FA point and the WALA ridge in an example of the method for generating a tooth alignment reference curve provided in the fourth embodiment of this application.

[0031] Figure 11 This is a schematic diagram illustrating the angular relationship between point FA and the WALA ridge in an example of the method for generating a tooth alignment reference curve provided in the fourth embodiment of this application.

[0032] Figure 12 This is a flowchart of a method for generating a target tooth layout provided in the fifth embodiment of this application;

[0033] Figure 13 This is a schematic diagram of an electronic device provided in the sixth embodiment of this application. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the various embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this invention to facilitate a better understanding of this application. However, the technical solutions claimed in the claims of this application can be implemented even without these technical details and with various variations and modifications based on the following embodiments.

[0035] In embodiments of the present invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing the present invention and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the present invention according to the specific circumstances.

[0036] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0037] The terms "anterior region" and "posterior region" mentioned in the various embodiments of this application are defined according to the classification of teeth in the 2nd edition of *Introduction to Stomatology*, published by Peking University Medical Press, pages 36-38. These include premolars and molars, teeth marked as 4-8 using the FDI notation, and teeth marked as 1-3 using the FDI notation for the anterior region. Teeth in the anterior region include the central incisors, lateral incisors, and canines.

[0038] The terms "horizontal plane," "coronal plane," and "sagittal plane" mentioned in the various embodiments of this application refer to terms in biomedical anatomy: a horizontal plane (also called a "transverse plane") is a cross-section perpendicular to the vertical axis that divides the human body into upper and lower parts; a coronal plane is a cross-section that longitudinally cuts the human body into anterior and posterior parts along the left and right directions; a sagittal plane is a cross-section that divides the human body into left and right parts, and the left and right cross-sections are called sagittal planes, while cross-sections that are equal on the left and right are called median sagittal planes.

[0039] The inventors of this application discovered in their research on digital design for orthodontic treatment that, in order to use computer technology for automatic tooth alignment, dental arch curves are often used as reference curves during tooth alignment. However, in practice, this method is not very accurate and often requires additional manual adjustments. The reasons for this are twofold: firstly, the confirmation of the dental arch curve is based on the initial dentition layout, and when the initial dentition layout is relatively disordered, the accuracy of the obtained dental arch curve is low; secondly, the accuracy of the dental arch curve during manual adjustment is affected by human experience, thus impacting the quality of the obtained target tooth layout. To address the aforementioned technical problems, this invention provides a method for generating a tooth arrangement reference curve. When arranging teeth in the second jaw, the method first refers to the tooth layout of the target position in the first jaw to obtain the position of the incisal edge of the teeth in the target position. Then, utilizing the physiological relationship between the incisal edges of the first and second jaws, a reference curve for tooth arrangement in the second jaw is obtained. This eliminates the need for obtaining a separate traditional dental arch curve for the second jaw and the manual adjustment process required for the traditional dental arch curve. Therefore, it reduces the impact of the initial dentition layout of the second jaw on the tooth arrangement target design result, reduces intermediate errors caused by manual adjustment of the tooth arrangement reference curve, improves the automation level of the tooth arrangement process, accelerates the automatic tooth arrangement speed, and makes the automatic tooth arrangement results more accurate and reliable.

[0040] The following details the implementation of the method for generating tooth alignment reference curves in this application. The following implementation details are provided for ease of understanding and are not necessary for implementing this solution.

[0041] First, it should be noted that the method for generating the tooth alignment reference curve in this embodiment can be implemented by hardware or a combination of computer software and hardware. For hardware implementation, the method for generating the tooth alignment reference curve can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic devices for implementing the function of generating the target tooth layout, or a selection of combinations of the above devices.

[0042] The method for generating a tooth alignment reference curve provided in the first embodiment of the present invention is illustrated using the mandible as the first jaw and the maxilla as the second jaw as an example. The specific process is as follows: Figure 1 As shown, it specifically includes:

[0043] Step 101: Obtain the initial layout of the maxillary and mandibular teeth to be treated, thereby generating the corresponding three-dimensional digital model of the maxilla and the three-dimensional digital model of the mandible.

[0044] Specifically, the initial tooth layout can be processed into a digital model of the jaw through automatic modeling, or a three-dimensional digital model representing the tooth layout can be directly obtained when acquiring the tooth layout. These methods will not be listed individually here. In some embodiments, "initial" can refer to the tooth layout before orthodontic treatment, that is, the tooth layout before tooth arrangement, or it can refer to the current tooth layout when the target tooth layout needs to be reconfirmed during orthodontic treatment.

[0045] In some embodiments, the acquired three-dimensional digital model can be a dental mesh model after tissue segmentation, where each tooth in the jaw is an independent mesh model. In some embodiments, the generated corresponding three-dimensional maxillary and three-dimensional mandibular digital models can be three-dimensional maxillary and three-dimensional mandibular digital models that have undergone occlusal registration.

[0046] Step 102: Process the three-dimensional mandibular digital model based on the automatic tooth alignment method to generate the target three-dimensional mandibular digital model.

[0047] It should be noted that steps 101-102 above involve first obtaining the initial mandibular digital model, and then obtaining the target mandibular digital model through tooth arrangement. In practical applications, the target mandibular digital model can be obtained directly. For example, in some embodiments, if the patient only needs to design the maxilla and not the mandible, the obtained mandibular digital model can be directly used as the "target three-dimensional mandibular digital model" in the target state. In some embodiments, the target three-dimensional mandibular digital model can also be designed using other tooth arrangement design devices and pre-stored in the hardware. When implementing the method for generating tooth arrangement reference curves in this embodiment, it can be directly called.

[0048] The automatic tooth alignment method in this embodiment is as follows: Figure 2 As shown, it may include:

[0049] Step 201: Calculate the initial dental arch curve of the three-dimensional mandibular digital model.

[0050] In one embodiment, this step constructs an initial dental arch curve based on the same feature point of several teeth in the three-dimensional mandibular digital model. The same feature point refers to a feature point of the same type, specifically the center point (or centroid) of each tooth. The constructed initial dental arch curve can be a two-dimensional or three-dimensional curve. In constructing a two-dimensional dental arch curve, the projection points of all feature points onto the occlusal plane or horizontal plane can be taken, and a two-dimensional curve can be fitted within the corresponding plane. In constructing a three-dimensional dental arch curve, each feature point can be fitted using spline interpolation smoothing or Gaussian smoothing methods. The dental arch curve obtained by feature point fitting encompasses the positional information of each tooth, making the resulting dental arch curve more consistent with the tooth layout of the dentition. Furthermore, the aforementioned methods for obtaining feature points of several teeth can acquire all teeth in the jaw or only a portion of them. When acquiring only a portion of teeth, 3-6 teeth can be selected to reduce the amount of tooth information collected and accelerate the acquisition of the dental arch curve. Specifically, feature points of teeth 1, 3, and 6 can be acquired. Since teeth 1, 3, and 6 occupy distinct characteristic positions in the entire dentition—for example, tooth 1 is generally the most anterior tooth in the sagittal direction, tooth 6 is near the distal end and at the widest point of the dental arch, and tooth 3 is located at the turning point of the dental arch curve—fitting the dental arch curve based on the feature points of teeth 1, 3, and 6 increases the accuracy of the calculated dental arch curve while reducing the amount of data.

[0051] In another embodiment, an initial dental arch curve can be constructed on the dental coordinate system based on the tooth features of the three-dimensional mandibular digital model using a preset dental arch curve representation model. In one embodiment, the preset dental arch curve representation model can be a deformed elliptical equation representation model, and the deformation method can be specifically adjusted based on the dental arch width, dental arch width compensation information, etc.

[0052] In another embodiment, the dental arch curve can be pre-defined as a combination of a first function equation for the anterior teeth and a second function equation for the posterior teeth; wherein the first function equation is an elliptic curve function, a beta function, or a power function, and the second function equation is a parabolic function or a cubic curve function. This embodiment uses known curve functions to generate the dental arch curve, greatly accelerating the generation speed of the dental arch curve. Furthermore, it can combine multiple curve types and deformation methods to make the obtained dental arch curve more suitable for describing the patient's actual dental arch morphology.

[0053] Step 202: Adjust the initial dental arch curve to obtain the target dental arch curve.

[0054] Specifically, the initial dental arch curve can be adjusted according to the treatment plan or treatment goal to obtain the target dental arch curve. For example, if the treatment goal is arch expansion, the posterior segment of the initial dental arch curve is adjusted, especially increasing the width of the arch curve in the segment of teeth 5-7. Furthermore, other treatment plans or goals can be further adjusted in other ways, such as further limiting the sum of distances from each tooth in the three-dimensional mandibular digital model to the target dental arch curve to converge to the first preset condition. The first preset condition can be a minimum sum, or a smaller threshold set by a professional designer based on experience. Therefore, in this embodiment, while meeting the basic adjustment goal of the dental arch curve, the sum of distances from the target dental arch curve to each tooth is further limited to a minimum, reducing the total movement of each tooth in the dentition during orthodontic treatment.

[0055] Step 203: Based on the target dental arch curve, adjust the three-dimensional mandibular digital model to generate the target three-dimensional mandibular digital model.

[0056] As can be seen, steps 201 to 203 above illustrate some ways to achieve automatic tooth alignment. In practical applications, other existing automatic tooth alignment methods can also be used, which will not be elaborated here.

[0057] Step 103: Obtain the incisal edge points of each tooth in the mandible based on the target three-dimensional digital model of the mandible.

[0058] Specifically, when the tooth is a molar, the incisal point is the buccal apex. Two buccal apexes can be taken simultaneously, or the higher of the two buccal apexes can be taken, or the midpoint between the two buccal apexes can be taken. When the tooth is a premolar, the incisal point is the buccal apex or buccal groove. When the tooth is an incisor or canine, the incisal point is the upper incisal point.

[0059] In some embodiments, the cutting edges can be automatically calculated in the following way:

[0060] When the tooth is in the anterior region, Figure 3 For example, take the point v where the tooth has the highest projection on the long axis, and calculate the projection distances val1 and val2 of point v relative to the tooth's centroid O on the long axis vec1 and buccal-lingual axis vec2, respectively. Then, calculate the spatial coordinates of the tangent point Q according to the following formula: Q = O + val1*vec1 + val2*vec2.

[0061] When the tooth is a posterior tooth, the buccal cusp is used as the incisal edge point. The calculation method can include: taking the portion of the tooth point set whose projection relative to the tooth's centroid in the buccal-lingual direction is positive, and performing the same calculation as for anterior teeth to obtain the posterior incisal edge point. It is worth noting that, when using the above method for posterior molars, the higher of the two buccal cusps is obtained. It is understood that other methods can also be used to obtain or calculate the other buccal cusp point; these will not be listed here.

[0062] In addition, in other embodiments, each cutting edge point can be identified by manual annotation or by a machine learning model that identifies feature points, which will not be listed here.

[0063] Step 104: Collect the incisal edge points of all mandibular teeth to form a mandibular incisal edge reference curve.

[0064] Specifically, in one embodiment, all cutting edge points can be connected sequentially with lines, and the resulting lines can be smoothed using a smoothing algorithm. In another embodiment, curves can be fitted to each cutting edge point. Other methods can also be used in practical applications, which will not be listed here.

[0065] Step 105: Adjust the mandibular incisal edge reference curve to obtain the maxillary incisal edge reference curve for maxillary tooth arrangement.

[0066] In some embodiments, this step specifically includes: adjusting the mandibular incision reference curve in both the reference plane and the direction perpendicular to the reference plane to obtain the corresponding maxillary incision reference curve. The reference plane is either the jaw plane or a horizontal plane.

[0067] In some embodiments, adjusting the mandibular incisal reference curve in a direction perpendicular to the reference plane includes: moving the anterior tooth portion of the mandibular incisal reference curve downwards by a first preset distance to obtain the corresponding maxillary incisal reference curve. In one embodiment, the first preset distance can be in the range of 1.7-2.2 mm, and the specific value can be determined by a technician based on experience, such as based on the crown size, for example, 1.7 mm, 2 mm, or 2.2 mm. This application defines the adjustment method for transforming the mandibular incisal reference curve to the maxillary incisal reference curve in order to obtain the maxillary incisal reference curve more accurately.

[0068] In another embodiment, the first preset distance is the vertical distance between the midpoints of the incisal edges of the upper and lower central incisors when the upper and lower central incisors are at the standard torque angle, the lower central incisors and the upper central incisors are in light contact on the lingual side, and the sagittal distance between the upper and lower central incisors is within the range of 2-4 mm.

[0069] In some embodiments, adjusting the mandibular incisal reference curve in the direction of the reference plane includes: expanding the mandibular incisal reference curve along the buccal side to obtain a corresponding maxillary incisal reference curve. Specifically, the mandibular incisal reference curve is uniformly expanded along the labial-buccal side by a fourth preset distance. Optionally, the fourth preset distance is the sagittal distance between the midpoints of the incisal edges of the upper and lower central incisors when the upper and lower central incisors are at the standard torque angle, the lower central incisors and upper central incisors are in light lingual contact, and the sagittal distance between the upper and lower central incisors is within the range of 2-4 mm. Optionally, the fourth preset distance can be in the range of 1.7-2.2 mm. The specific value can be determined by a technician based on experience, such as based on the crown size, such as 1.7 mm, 2 mm, or 2.2 mm.

[0070] As can be seen, in this embodiment, when arranging maxillary teeth, the position of the incisal edge of the mandibular target tooth is obtained by referring to the tooth layout of the mandibular target position. By utilizing the physiological relationship between the mandibular and maxillary incisal edges, a reference curve for maxillary tooth arrangement is obtained. This eliminates the need to obtain a traditional dental arch curve for maxillary tooth arrangement separately and to perform manual adjustment of the traditional dental arch curve. Therefore, it can reduce the influence of the initial maxillary dentition layout on the design result of tooth arrangement target, and also reduce the intermediate error caused by manual adjustment in the traditional tooth arrangement target reference curve. This improves the automation level of the tooth arrangement process, speeds up the automatic tooth arrangement, and makes the automatic tooth arrangement result more accurate and reliable.

[0071] The second embodiment of this application provides a method for generating a tooth alignment reference curve. The main difference between this embodiment and the first embodiment is that, in the first embodiment, when adjusting the reference curve based on the mandibular incisal edge in a direction perpendicular to the reference plane, only the reference curve of the anterior tooth segment is adjusted. In this embodiment, when adjusting the reference curve in a direction perpendicular to the reference plane, the reference curve of the posterior tooth segment is also adjusted.

[0072] In one embodiment, adjusting the mandibular incisal reference curve in a direction perpendicular to the reference plane further includes: vertically moving each tooth in the posterior segment of the mandibular incisal reference curve by a second preset distance, wherein, as... Figure 4 As shown, the second preset distance corresponding to the maxillary tooth 6 segment is the long-axis projection distance V6 from the buccal apex v1 to the central fossa v2; the second preset distances corresponding to the maxillary tooth 4 segment and the maxillary tooth 5 segment are obtained based on V6 using direct assignment, linear interpolation, or nonlinear interpolation. That is, when the anterior tooth segment is adjusted vertically at the height of the first preset distance, the long-axis projection distance V6 from the buccal apex to the central fossa is calculated for the posterior tooth segment corresponding to tooth 6. Then, the difference between the first preset distance and V6 is directly calculated to set the movement amount for tooth 4 and tooth 5 segments, respectively.

[0073] In another embodiment, adjusting the mandibular incisal reference curve in a direction perpendicular to the reference plane further includes: vertically moving the posterior segment of the mandibular incisal reference curve by a third preset distance, wherein the third preset distance includes the set of long-axis projection distances from the buccal apex to the central fossa of each individual tooth in the posterior segment. That is, when the anterior segment is adjusted vertically by a first preset distance, the adjustment amount for each individual tooth in the posterior segment is calculated using a uniform calculation rule, including the long-axis projection distance from the buccal apex to the central fossa.

[0074] It should be noted that the long axis in this embodiment can be the direction from the root crown to the root apex, the z-axis in the local coordinate system of the tooth, the anatomical vertical direction, or the occlusal direction. The specific direction can be selected as needed, and will not be elaborated here.

[0075] This application defines other vertical adjustment methods when transforming from the mandibular incisor reference curve to the maxillary incisor reference curve. While providing an accurate and feasible method for obtaining the maxillary incisor reference curve, this embodiment provides a variety of adjustment methods, and different adjustment methods can be selected as needed to better meet the requirements of the application scenario.

[0076] The third embodiment of this application provides a method for generating a tooth alignment reference curve. The main difference between this embodiment and the first embodiment is that, in the process of adjusting the corresponding maxillary incisal edge reference curve based on the mandibular incisal edge reference curve in the first embodiment, the reference curve is adjusted by uniform expansion in the direction of the reference plane. In this embodiment, the adjustment amount is calculated individually in the direction of the reference plane, making the adjustment result more accurate.

[0077] In one embodiment, the expansion amounts of the anterior and posterior segments of the mandibular incisal reference curve are different. Specifically, the mandibular incisal reference curve is expanded labially in the anterior segment by a fourth preset distance, and each tooth in the posterior segment is expanded buccally by a fifth preset distance. The fifth preset distance for each tooth in the posterior segment is interpolated based on the buccal-lingual projection distance from the buccal apex of the maxillary sixth tooth to the central fossa. That is, as... Figure 5 As shown, the fifth preset distance corresponding to the maxillary tooth segment 6 is the buccal-lingual projection distance K6 from the buccal apex v1 to the central fossa v2; the fifth preset distances corresponding to the maxillary tooth segment 4 and the maxillary tooth segment 5 are obtained based on K6 using direct assignment, linear interpolation, or nonlinear interpolation. Specifically, the setting method for the fourth preset distance is similar to that in the first embodiment, and will not be repeated here. It can be seen that this embodiment utilizes the physiological characteristics of the gradual change in the cutting edge reference curve, requiring only the calculation of expansion at a small number of locations, while other locations are determined using direct assignment or interpolation, thus accelerating the calculation speed of the movement at each location on the reference curve.

[0078] In another embodiment, the mandibular incisal reference curve is expanded along the labial side of the anterior tooth segment by a fourth preset distance, and along the buccal side of the posterior tooth segment by a sixth preset distance, where the sixth preset distance is the buccal-lingual projection distance from the buccal apex of a single tooth to the central fossa. This application defines the horizontal adjustment method when transforming from the mandibular incisal reference curve to the maxillary incisal reference curve. Specifically, for different tooth positions, the adjustment amount is calculated using the positional parameters of different teeth to obtain the maxillary incisal reference curve more accurately.

[0079] As can be seen, in the process of adjusting the corresponding maxillary incisal edge reference curve in this embodiment, different methods are used to adjust the anterior and posterior tooth segments according to the patient's oral physiological characteristics. A variety of adjustment methods are provided, and different adjustment methods can be selected as needed to better meet the requirements of the application scenario.

[0080] The fourth embodiment of this application provides a method for generating a tooth arrangement reference curve. The main difference between this embodiment and the previous embodiment is that the method for automatically arranging teeth on a three-dimensional mandibular digital model in the first embodiment is mainly based on the target dental arch curve. In this embodiment, the WALA ridge protrusion of the teeth is used to fit and form the WALA ridge as a reference curve for tooth arrangement. Since the obtained WALA ridge curve can be directly used as the target tooth arrangement curve, the intermediate adjustment process of the tooth arrangement curve is reduced, the intermediate error is reduced, and it is more in line with the oral physiological characteristics of the patient.

[0081] like Figure 6 As shown, the method for automatically arranging teeth in a three-dimensional digital model of the mandible includes:

[0082] Step 601: Obtain the initial mandibular tooth layout and gingival tissue status to be corrected, thereby generating a three-dimensional mandibular digital model corresponding to the initial mandibular tooth layout.

[0083] In some embodiments, the tooth layout can be the tooth layout before orthodontic treatment, or the current tooth layout when the target tooth layout needs to be reconfirmed during orthodontic treatment. In some embodiments, the obtained initial mandibular tooth layout can be a dentition mesh model after incisor classification, in which each tooth is an independent model.

[0084] In some embodiments, the state of the gingival tissue can be obtained using a digital gingival model obtained by oral scanning. Specifically, it can be a virtual digital gingival model generated by a computer or an actual digital gingival model obtained by oral scanning, and no limitation is made here.

[0085] Step 602: Based on the three-dimensional digital model of the mandible, determine the spatial correction reference curve based on the WALA ridge.

[0086] Specifically, such as Figure 7 As shown, the methods for generating WALA crests include:

[0087] Step 701: Preset the local coordinate system for each tooth, including the labial-lingual axis and the root-coronal axis.

[0088] Specifically, the local coordinate system for a single tooth is generally constructed during the creation of the dental model, and the data can be used directly. The three axes can be root-coronal, mesiodistal, and labiolingual. The origin of the local coordinate system can be the center point of the tooth (such as the geometric center point, centroid point, etc., which will not be listed here). Regarding the labiolingual direction, for example, the anterior teeth use the labiolingual direction, and the posterior teeth can use the buccal-lingual direction. The labiolingual direction is the labiolingual direction that passes through the center point of the tooth, and the buccal-lingual direction is the buccal-lingual direction that passes through the center point of the tooth.

[0089] Step 702: The cross section formed by the labial-lingual axis and the root-coronal axis of a tooth intersects with the gingival portion of the three-dimensional mandibular digital model to obtain the intersection line.

[0090] Specifically, with Figure 8 Taking this as an example, it can be seen that the outline of the digital model can be obtained after the cross section intersects with the three-dimensional mandibular digital model. The buccal gingival part a is selected.

[0091] Step 703: Select the most prominent point on the labial side of the intersection line as the WALA ridge protrusion of the tooth.

[0092] In some embodiments, the method for identifying the WALA ridge protrusion includes: finding a vertex on this intersection line that has a labial direction value greater than its two adjacent vertices. Regarding the labial direction, for anterior teeth, the labial direction is taken as the labial-lateral direction; for posterior teeth, the labial direction is taken as the buccal-lateral direction. It should be noted that the intersection line can be a curved segment, with its endpoint near the crown located on the gingival line and its endpoint near the bottom located on the bottom boundary of the gingival model. Since the number of vertices on a curved segment is finite, the labial direction value of each vertex can be obtained through traversal calculation. If the number of vertices is large, it can also be calculated by sampling a subset of points. Figure 8 Taking the intersection line a as an example, with the direction from the root to the crown and the direction from the lingual side to the labial side as the positive directions of the two axes of the coordinate system, a series of vertices P on the intersection line a are defined. Figure 9 To explain, the lip direction value of point P (Pj, Pg) is calculated. The lip direction value is the value of the point on the lip direction axis Pj. A series of vertices P are selected, and point Px is selected. Px satisfies the condition that the lip direction value is greater than the lip direction value of Px-1 (the point above Px) and Px+1 (the point below Px). In other words, Px is the WALA ridge protrusion point at the confirmed location.

[0093] In another embodiment, the method for identifying WALA ridge protrusions includes: on the gingival surface, selecting a series of points as intersection points of the gingival surface along the shortest geodesic line between each target buccal gingival line point and its corresponding boundary point, forming the set of curve points; selecting the most convex point among the intersection points of the gingival surface as the WALA point corresponding to the corresponding tooth. In this embodiment, the shortest geodesic line refers to the shortest distance between the target buccal gingival line point and its corresponding boundary point on the gingival surface, which can be directly obtained through existing program libraries and will not be elaborated here; after obtaining the shortest geodesic line between the target buccal gingival line point and its corresponding boundary point on the gingival surface, a series of points are uniformly selected along this shortest geodesic line as intersection points of the gingival surface.

[0094] As can be seen, the above-described embodiments are used to select vertices based on the buccal point of the gingival line of a tooth and the corresponding bottom surface boundary point, to obtain a set of curve points, and to select the most convex point in the set of curve points as the WALA ridge protrusion. In practical applications, other methods can also be used to select the most convex point, which will not be listed here.

[0095] Step 704: Assemble the WALA ridge protrusions of the teeth and connect them to form the WALA ridge.

[0096] In some embodiments, the WALA ridge protrusions corresponding to each tooth can be connected sequentially to obtain the initial shape of the WALA ridge. In other embodiments, the WALA ridge protrusions can be fitted into the dental arch WALA ridge using beta curves, parabolas, or ellipses, etc.

[0097] In one embodiment, after obtaining the initial morphology of the WALA ridge, the initial morphology of the WALA ridge can be mapped onto the buccal surface of the gingiva to obtain the WALA ridge located on the buccal surface of the gingiva, and then the WALA ridge is used as a spatial orthodontic reference curve.

[0098] In some embodiments, after obtaining the WALA ridge, the process may further include smoothing the WALA ridge. Methods such as spline interpolation smoothing and Gaussian smoothing can be used, and other smoothing algorithms can also be employed in practice, which will not be listed here. It is understood that in this embodiment, the smoothed WALA ridge is used as the spatial correction reference curve.

[0099] As can be seen, through steps 701 to 704 above, a WALA ridge curve can be obtained on the buccal surface of the gingival model. This curve is a three-dimensional curve, which not only expresses the position of the patient's alveolar bone boundary but also the vertical height of the teeth. Furthermore, this application specifies that the WALA ridge is obtained from the most convex point on the labial side corresponding to each tooth position on the gingival portion. Based on a series of these vertices, the WALA ridge is confirmed, achieving both feasibility and accuracy in WALA ridge confirmation.

[0100] Step 603: Adjust the pose of each tooth in the three-dimensional mandibular digital model in three-dimensional space based on the spatial orthodontic reference curve to generate the target three-dimensional mandibular digital model.

[0101] Specifically, when adjusting the position of teeth in three-dimensional space, adjustments can be made in two dimensions: (A) adjusting the impedance center of the teeth to be at the same height as the corresponding position of the spatial orthodontic reference curve, and (B) adjusting the horizontal distance between the FA point of the teeth and the corresponding position of the spatial orthodontic reference curve to be within a preset range.

[0102] Regarding (A) vertical adjustment of teeth:

[0103] The impedance center of the tooth can be calculated first. The calculation process includes: in some embodiments, the three-dimensional mandibular digital model includes a root portion, and the initial position of the impedance center of the tooth is calculated based on the total height of the tooth. Specifically, half the height of the root portion is used as the impedance center.

[0104] In some embodiments, the three-dimensional mandibular digital model includes a root portion and an alveolar bone portion. The intersection of the alveolar bone portion and the root portion is mapped onto the long axis of the tooth. An initial point is obtained based on each vertex at the intersection, such as taking the average value of the vertices at the intersection as the initial point. The initial point is then shifted down by a predetermined distance to obtain the initial position of the impedance center of the tooth. The predetermined distance is half the height of the root. Specifically, in this embodiment, the distance between the point where the apex of the single digital tooth model is mapped onto the long axis and the point where the intersection of the digital alveolar bone model and the digital tooth model mesh is mapped onto the long axis is used as the starting point. The position halfway along the digital root model is the location of the impedance center. Regarding the calculation of the apex, when there is only one root, the lowest point of that root can be directly selected. When there are multiple roots, the average value of the lowest points of multiple roots can be selected.

[0105] The above calculation process exemplifies various methods for identifying the impedance center, enabling accurate prediction of the impedance center in both rootless and non-rooted cases, facilitating accurate determination of the impedance center in different application scenarios. It is understood that in other embodiments, besides the calculation methods described above, other methods can be used to calculate the impedance center of the tooth, which will not be listed here.

[0106] Specifically, after identifying the impedance center of a tooth, the position and posture of the tooth can be adjusted based on the impedance center. Furthermore, the corresponding position of the tooth's impedance center and the spatial orthodontic reference curve can be confirmed by the projection height value in the root-coronal direction. For example, the initial position of the tooth's impedance center and the closest point on the orthodontic reference curve to the tooth can be projected onto the root-coronal axis of the tooth to obtain their respective projection points. Based on the deviation in the height of the projection points, the vertical height of the tooth can be adjusted.

[0107] Regarding (B) horizontal adjustment of teeth:

[0108] The initial position of the FA point for each tooth can be calculated first. In some embodiments, the calculation process includes: pre-setting a local coordinate system for each tooth, including a labial-lingual axis and a root-coronal axis; intersecting the cross-section formed by the labial-lingual axis and the root-coronal axis of a tooth with the tooth portion of the three-dimensional mandibular digital model to obtain an intersection line; selecting a segment on this intersection line from the gingival line on the labial surface to the crown height as the FACC axis of that tooth; and selecting the midpoint of the FACC axis as the initial position of the FA point for that tooth. The midpoint of the FACC axis is the center point of the curve segment. This embodiment limits the method of confirming the FA point, achieving more accurate FA point extraction and facilitating the accuracy of the reference data during adjustment.

[0109] In some embodiments, after confirming the initial position of the FA point, the horizontal distance between the FA point of the tooth and the corresponding position on the spatial orthodontic reference curve is adjusted to ensure that the horizontal distance between the FA points of the adjusted teeth is within a preset range. Specifically, this includes: calculating the initial position of the FA point for each tooth; finding the nearest point of the FA point on the spatial orthodontic reference curve; and moving the tooth based on its FA point until the horizontal distance to the nearest point on the spatial orthodontic reference curve is within the preset range. This application defines the FA point adjustment method to ensure accurate tooth adjustment based on the FA point. The aforementioned preset range can be set differently for different teeth; for example, a fixed value can be used as the range. Figure 10 and Figure 11 As shown, the distance between the FA point of the moved tooth and the nearest point on the spatial orthodontic reference curve in the horizontal direction is fixed as follows: 0.1mm for the central incisor, 0.3mm for the lateral incisor, 0.6mm for the canine, 0.8mm for the first premolar, 1.3mm for the second premolar, 2.0mm for the first molar, and 2.2mm for the second molar. Alternatively, an upper and lower error range can be set based on these fixed values. For example, if the upper and lower error is set to 10%, the preset range can be set accordingly. Taking the central incisor as an example, with a fixed value of 0.1mm and an upper and lower error of 10%, the corresponding preset range is 0.09mm-0.11mm. The same principle applies to other tooth positions, and they will not be listed individually here.

[0110] By adjusting (A) and (B) above, a target three-dimensional mandibular digital model corresponding to the target tooth layout can be obtained. In some embodiments, the adjustment dimension also includes (C) mesiodistal adjustment:

[0111] The mesiodistal adjustment process specifically includes: gap detection and collision detection. Specifically, based on the three-dimensional mandibular digital model, the arch length is obtained on the occlusal plane; based on the three-dimensional mandibular digital model, the sum of the widths of all teeth is obtained; the mesiodistal positions of the teeth are adjusted according to the relationship between the arch length and the sum of the widths until the gap standard is met. The arch length obtained on the occlusal plane is compared with the sum of the widths of all teeth. If the arch length is too large, the gap is determined to be too large; if the sum of the widths of all teeth is too large, crowding or even collision may exist, and the mesiodistal positions of teeth that are too close together need to be adjusted. In practical applications, the gap standard can be set to 0.05mm.

[0112] It is understood that after automatic tooth alignment, in order to verify the rationality of the tooth alignment, it is necessary to check whether the target positions of the excluded teeth collide with each other, or whether the gap between two adjacent teeth is too large. In order to fine-tune the position of the teeth in the mesiodistal direction when an unreasonable situation is found, so that the obtained target tooth layout is more reasonable in three-dimensional space.

[0113] As can be seen, compared with the prior art, this implementation method utilizes the physiological characteristics of the WALA ridge in the oral cavity corresponding to the patient's alveolar bone position as a reference for spatial tooth alignment. This not only facilitates obtaining a more accurate tooth alignment target that better matches the patient's actual situation, but also has a higher achievability rate. Furthermore, since the WALA ridge is not affected by tooth alignment before and after tooth alignment, it not only reduces the impact of the initial dentition layout on the tooth alignment target, but also reduces intermediate errors caused by manual adjustments to the tooth alignment reference line, improving the automation level of the tooth alignment process and making the automatic tooth alignment results more accurate.

[0114] The fifth embodiment of this application provides a method for generating a target tooth layout, the process of which is as follows: Figure 12 As shown, it specifically includes:

[0115] Step 1201: Obtain the maxillary incisal edge reference curve for maxillary tooth arrangement based on a method for generating a tooth arrangement reference curve.

[0116] Specifically, the method for generating the tooth alignment reference curve can be any one of the methods described in the first to fourth embodiments above, and will not be repeated here.

[0117] Step 1202: Adjust the three-dimensional maxillary digital model corresponding to the initial tooth layout of the maxilla based on the maxillary incisal edge reference curve, so that the incisal edge feature position of each maxillary tooth conforms to the maxillary incisal edge reference curve, and generate the target three-dimensional maxillary digital model.

[0118] In some embodiments, this step of adjusting the incisal feature position of the three-dimensional maxillary digital model based on the maxillary incisal reference curve specifically includes: adjusting the occlusal feature position of the three-dimensional maxillary digital model until the posterior tooth regions of the three-dimensional maxillary digital model and the three-dimensional mandibular digital model conform to the cusp-fossa alignment relationship. Specifically, the occlusal feature position includes the lingual incisal point of the anterior tooth region and the central groove point of the posterior tooth region. Since accurate matching of the occlusal feature position can make the occlusal relationship after tooth arrangement more stable, this application limits the adjustment of the occlusal feature position during the adjustment of the maxillary tooth layout so that the occlusal relationship of the obtained target tooth layout is more stable.

[0119] It is worth mentioning that, although the first to fifth embodiments described above use the first jaw as the mandible and the second jaw as the maxilla as an example, those skilled in the art will understand that in actual applications, the first jaw can also be the maxilla and the second jaw as the mandible. For example, if it is only used to generate a reference curve for maxillary tooth arrangement, since the maxilla and mandible are relative jaws with an occlusal relationship, the distance value setting method in the calculation steps of each parameter involved in tooth arrangement is similar, but the reference direction is opposite. The specific implementation process will not be listed one by one here.

[0120] It is worth mentioning that the examples above in this application are merely illustrative for ease of understanding and do not constitute a limitation on the technical solutions of this invention.

[0121] The steps of the various methods described above are only for clarity. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of the algorithm and process, are also within the scope of protection of this patent.

[0122] The sixth embodiment of this application relates to an electronic device, such as... Figure 13 As shown, it includes: at least one processor 1301; and a memory 1302 communicatively connected to the at least one processor 1301; wherein the memory 1302 stores instructions executable by the at least one processor 1301, the instructions being executed by the at least one processor 1301 to enable the at least one processor 1301 to perform the method for generating a tooth arrangement reference curve in the first to fourth embodiments described above, or the method for generating a target tooth layout in the fifth embodiment described above.

[0123] The memory and processor are connected via a bus, which can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors and memories. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.

[0124] The processor manages the bus and general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory is used to store data used by the processor during operation.

[0125] Another embodiment of this application relates to a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the method for generating a tooth alignment reference curve as described in some of the above embodiments.

[0126] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0127] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A method for generating a tooth alignment reference curve, characterized in that, include: Obtain a target three-dimensional first jaw digital model and a three-dimensional second jaw digital model that has an occlusal correspondence with the target three-dimensional first jaw digital model, wherein the three-dimensional second jaw digital model corresponds to the initial tooth layout of the second jaw. Based on the target three-dimensional digital model of the first jaw, the incisal edge points of each tooth in the first jaw are obtained; The incisal edge points of all teeth in the first jaw are collected to form a reference curve for the incisal edge of the first jaw; Adjust the first jaw incisal edge reference curve to obtain the second jaw incisal edge reference curve for the second jaw teeth arrangement.

2. The method for generating a tooth alignment reference curve according to claim 1, characterized in that, The step of adjusting the first jaw incisal edge reference curve to obtain a second jaw incisal edge reference curve for the second jaw tooth arrangement includes: The first jaw incision reference curve is adjusted in the reference plane and in the direction perpendicular to the reference plane to obtain the second jaw incision reference curve corresponding to the second jaw; wherein, the reference plane is the jaw plane or the horizontal plane.

3. The method for generating a tooth alignment reference curve according to claim 2, characterized in that, If the first jaw is the mandible and the second jaw is the maxilla, then adjusting the first jaw incisal edge reference curve in a direction perpendicular to the reference plane includes: moving the anterior tooth segment of the first jaw incisal edge reference curve downward by a first preset distance.

4. The method for generating a tooth alignment reference curve according to claim 3, characterized in that, The first preset distance is the vertical distance between the midpoints of the incisal edges of the upper and lower central incisors when the upper and lower central incisors are at the standard torque angle, the lower central incisors and the upper central incisors are in light contact on the lingual side, and the sagittal distance between the upper and lower central incisors is within the range of 2-4 mm; or, the first preset distance is within the range of 1.7-2.2 mm.

5. The method for generating a tooth alignment reference curve according to claim 3, characterized in that, Adjusting the first occlusal incisal reference curve in a direction perpendicular to the reference plane further includes: vertically moving each tooth in the posterior segment of the first occlusal incisal reference curve by a second preset distance, wherein: the second preset distance corresponding to the second maxillary tooth 6 segment is the long-axis projection distance V6 from the buccal cusp of the maxillary tooth 6 to the central fossa; the second preset distances corresponding to the second maxillary tooth 4 segment and the second preset distances corresponding to the second maxillary tooth 5 segment are obtained based on V6 using direct assignment, linear interpolation, or nonlinear interpolation; or... It also includes: vertically moving the posterior tooth segment of the first occlusal incisal reference curve by a third preset distance, wherein the third preset distance includes the set of long axial projection distances from the buccal apex to the central fossa of each single maxillary tooth in each posterior tooth region.

6. The method for generating a tooth alignment reference curve according to claim 2, characterized in that, If the first jaw is a mandible and the second jaw is a maxilla, then adjusting the reference curve of the first jaw's incision edge in the direction of the reference plane includes: uniformly expanding the reference curve of the first jaw's incision edge along the labial / buccal side by a fourth preset distance; or... The first jaw incisal reference curve is expanded along the labial side of the anterior tooth segment by a fourth preset distance, and along the buccal side of each tooth in the posterior tooth segment by a fifth preset distance. The fifth preset distance corresponding to the second jaw tooth 6 segment is the buccal-lingual projection distance K6 from the buccal cusp of the maxillary tooth 6 to the central fossa. The fifth preset distances corresponding to the second jaw tooth 4 segment and the second jaw tooth 5 segment are obtained based on K6 using direct assignment, linear interpolation, or nonlinear interpolation. Alternatively... The first jaw incisal reference curve is extended along the labial side to expand the anterior tooth segment by a fourth preset distance, and each tooth in the posterior tooth segment is extended along the buccal side by a sixth preset distance. The sixth preset distance is the buccal-lingual projection distance from the buccal apex of a single maxillary tooth to the central fossa.

7. The method for generating a tooth alignment reference curve according to claim 6, characterized in that, The fourth preset distance is the sagittal distance between the midpoints of the incisal edges of the upper and lower central incisors when the upper and lower central incisors are at the standard torque angle, the lower central incisors and the upper central incisors are in light contact on the lingual side, and the sagittal distance between the upper and lower central incisors is in the range of 2-4 mm; or, the fourth preset distance is in the range of 1.7-2.2 mm.

8. The method for generating a tooth alignment reference curve according to any one of claims 1-7, characterized in that, The adjustment of the three-dimensional second jaw digital model based on the first jaw incision reference curve includes: The occlusal feature positions of the three-dimensional second jaw digital model are adjusted based on the first jaw incisal edge reference curve until the posterior tooth regions of the three-dimensional second jaw digital model and the three-dimensional first jaw digital model conform to the cusp-fossa alignment relationship; wherein, the occlusal feature positions include the lingual incisal edge point of the anterior tooth region and the central groove point of the posterior tooth region.

9. The method for generating a tooth alignment reference curve according to claim 1, characterized in that, The target three-dimensional first jaw digital model is generated by processing the initial three-dimensional first jaw digital model based on an automatic tooth arrangement method, wherein the automatic tooth arrangement method includes: Calculate the initial dental arch curve of the three-dimensional first jaw digital model; Adjust the initial dental arch curve to obtain the target dental arch curve; Based on the target dental arch curve, adjust the three-dimensional first jaw digital model to generate the target three-dimensional first jaw digital model.

10. The method for generating a tooth alignment reference curve according to claim 9, characterized in that, The calculation of the initial dental arch curve of the three-dimensional first jaw digital model includes: An initial dental arch curve is constructed based on the same feature point of several teeth in the three-dimensional first jaw digital model; or, Based on the tooth features of the three-dimensional first jaw digital model, an initial dental arch curve is constructed on the jaw coordinate system using a preset dental arch curve representation model.

11. The method for generating a tooth alignment reference curve according to claim 10, characterized in that, The preset dental arch curve representation model is represented by the equation of a deformed ellipse; or, The model represents the anterior region using a combination of a first functional equation and the posterior region using a second functional equation; wherein the first functional equation is an elliptic curve function, a beta function, or a power function, and the second functional equation is a parabolic function or a cubic curve function.

12. The method for generating a tooth alignment reference curve according to claim 9, characterized in that, The adjustment of the initial dental arch curve to obtain the target dental arch curve includes: Adjust the initial dental arch curve according to the treatment plan or treatment goal to obtain the target dental arch curve; Wherein, the sum of the distances from each tooth in the three-dimensional first jaw digital model to the target dental arch curve converges to the first preset condition.

13. A method for generating a target tooth layout, characterized in that, include: The method for generating a tooth arrangement reference curve according to any one of claims 1-12 is used to obtain a second jaw incisor reference curve for tooth arrangement in the second jaw; The three-dimensional digital model of the second jaw is adjusted based on the incisal edge reference curve of the second jaw to make the incisal edge feature position of each tooth of the second jaw conform to the incisal edge reference curve of the second jaw, thereby generating the target three-dimensional digital model of the second jaw.

14. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform a method for generating a tooth alignment reference curve as described in any one of claims 1 to 12, or a method for generating a target tooth layout as described in claim 13.

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