Method and electronic device for generating 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 target tooth layout, and the method comprises the following steps: obtaining a to-be-corrected initial tooth layout and a gingival tissue state, thereby generating a three-dimensional dental digital model corresponding to the initial tooth layout; based on the three-dimensional dental digital model, determining a space correction reference curve based on a WALA ridge; adjusting the pose of each tooth in the three-dimensional dental digital model in a three-dimensional space based on the space correction reference curve, and generating a target three-dimensional dental digital model; wherein the height of the impedance center of the tooth is adjusted to be equal to that of the corresponding position of the space correction reference curve, and the horizontal distance between the FA point of the tooth and the corresponding position of the space correction reference curve is adjusted to be within a preset range. The accuracy of obtaining the target tooth layout can be improved, and the target tooth layout better meeting oral physiological conditions of a patient is obtained.

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 a target tooth layout. 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 orthodontic treatment using shell-type orthodontic appliances, 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 requires additional manual adjustment, resulting in lower efficiency. Furthermore, the quality of the adjusted dental arch curve is also affected by the experience of the person making the adjustment, thus impacting the quality of the target tooth layout. Summary of the Invention

[0004] The purpose of this invention is to provide a method and electronic device for generating a target tooth layout, which can improve the accuracy of obtaining the target tooth layout and obtain a target tooth layout that is more in line with the patient's oral physiological conditions.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a method for generating a target tooth layout, comprising: acquiring an initial tooth layout to be treated and the state of the gingival tissue, thereby generating a three-dimensional digital model of the jaw corresponding to the initial tooth layout; determining a spatial orthodontic reference curve based on the WALA ridge based on the three-dimensional digital model of the jaw; adjusting the pose of each tooth in the three-dimensional digital model of the jaw in three-dimensional space based on the spatial orthodontic reference curve to generate a target three-dimensional digital model of the jaw; including: adjusting the impedance center of the tooth to be at the same height as the corresponding position of the spatial orthodontic reference curve, and adjusting the horizontal distance between the FA point of the tooth and the corresponding position of the spatial orthodontic reference curve to be within a preset range.

[0006] Compared to existing technologies, the embodiments of this invention utilize 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 and patient-appropriate tooth alignment target but also achieves a higher success rate. Furthermore, since the WALA ridge is not affected by tooth alignment before or after tooth alignment, it reduces the impact of the initial dentition layout on the tooth alignment target and minimizes intermediate errors caused by manual adjustments to the tooth alignment reference line. This enhances the automation of the tooth alignment process, resulting in more accurate automatic tooth alignment results.

[0007] Optionally, based on the three-dimensional digital model of the jaw, a spatial orthodontic reference curve based on the WALA ridge is determined, including: presetting 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 gingival portion of the three-dimensional digital model to obtain an intersection line, selecting the most convex point on the labial side of the intersection line as the WALA ridge convex point of that tooth; and connecting the WALA ridge convex points of the teeth to form the WALA ridge. This application specifies that the WALA ridge is obtained from the intersection line obtained by intersecting the labial-lingual cross section of the gingival portion, and the vertex most biased towards the labial side is obtained. The WALA ridge is confirmed based on a series of the above vertices, thus achieving accurate confirmation of the WALA ridge.

[0008] Optionally, after obtaining the WALA ridge, the process includes: smoothing the WALA ridge.

[0009] Optionally, adjusting the impedance center of the tooth to be at the same height as the corresponding position of the spatial orthodontic reference curve includes: calculating the initial position of the tooth impedance center; wherein, if the three-dimensional digital model of the jaw includes a root portion, the initial position of the tooth impedance center is calculated based on the total height of the tooth; if the three-dimensional digital model of the jaw includes a root portion and an alveolar bone portion, the initial position of the tooth impedance center is obtained by shifting it down a predetermined distance based on the point mapped from the intersection of the alveolar bone portion and the root portion to the long axis of the tooth. This application specifies the method for confirming the impedance center, providing a calculation method for cases with or without a root, facilitating the determination of the impedance center in different application scenarios.

[0010] Optionally, the predetermined distance is half the height of the tooth root.

[0011] Optionally, the horizontal distance between the FA point of the adjusted tooth and the corresponding position on the spatial orthodontic reference curve is within a preset range, including: 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 the FA point until the horizontal distance to the nearest point corresponding to the FA point on the spatial orthodontic reference curve is within the preset range. This application defines the FA point adjustment method to achieve accurate and feasible tooth adjustment based on FA points.

[0012] Optionally, calculating the initial position of the FA point for each tooth includes: presetting 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 dental digital model to obtain an intersection line; selecting a segment on the 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 on the FACC axis as the initial position of the FA point of that tooth. This application limits the confirmation method of the FA point, achieving more accurate FA point extraction and facilitating the accuracy of the reference data during adjustment.

[0013] Optionally, the horizontal distance between the FA point of the adjusted teeth and the corresponding position of the spatial orthodontic reference curve is within a preset range, including: determining the incisal edge feature points of each tooth based on the three-dimensional digital model of the jaw; adjusting the teeth until the incisal edge feature points of all adjusted teeth form a smooth curve. Because the curve formed by the incisal edge feature points is smooth, the alignment of the teeth can be confirmed vertically. Furthermore, because the alignment of the incisal edge feature points can achieve a stable occlusal relationship, this application limits the smoothness of the curve formed by the incisal edge feature points after tooth adjustment. This ensures that the teeth arranged based on the FA point can make uniform contact during occlusion, forming a good and stable occlusal relationship, and contributing to uniform force distribution on the teeth during occlusion.

[0014] Optionally, determining the incisal edge feature point of each tooth includes: when the tooth is a molar, the incisal edge feature point is the buccal cusp; when the tooth is a premolar, the incisal edge feature point is the buccal cusp or buccal groove; when the tooth is an incisor or canine, the incisal edge feature point is the superior incisal edge.

[0015] Optionally, adjusting the pose of each tooth in the three-dimensional digital model of the jaw based on the spatial orthodontic reference curve to generate the target three-dimensional digital model of the jaw includes: adjusting the tooth posture angle; wherein, the spatial position of each tooth is adjusted until the posture angle is the standard posture angle or within the allowable error range of the standard posture angle; wherein the standard posture is determined based on the standard jaw model; wherein the posture angle includes the torque angle, torsion angle and / or axial tilt angle of the tooth. Since standard teeth are not completely vertical and have a certain tilt, this application limits the adjustment of posture angles during tooth arrangement so that the tilt of the teeth after tooth arrangement is more in line with the physiological characteristics of the teeth, so that the adjusted teeth are more in line with the physiological state of standard teeth.

[0016] Optionally, adjusting the pose of each tooth in the three-dimensional digital model of the jaw based on the spatial orthodontic reference curve to generate a target three-dimensional digital model of the jaw includes: gap detection and collision detection; wherein, based on the three-dimensional digital model of the jaw, the length of the dental arch curve is obtained on the jaw plane; based on the three-dimensional digital model of the jaw, the sum of the widths of all teeth is obtained; and the position of the teeth in the mesiodistal direction is adjusted according to the relationship between the length of the dental arch curve and the sum of the widths until the gap standard is met.

[0017] Embodiments of the present invention also provide a method for generating a target tooth layout, comprising: acquiring an initial maxillary tooth layout and an initial mandibular tooth layout to be corrected, thereby generating corresponding three-dimensional maxillary digital models and three-dimensional mandibular digital models; processing the three-dimensional mandibular digital model based on the above-described method for generating a target tooth layout to generate a target three-dimensional mandibular digital model; acquiring the incisal edge points of each mandibular tooth based on the target three-dimensional mandibular digital model; aggregating the incisal edge points of all mandibular teeth to form a mandibular incisal edge reference curve; adjusting the three-dimensional maxillary digital model based on the mandibular incisal edge reference curve to generate the target three-dimensional maxillary digital model; including: adjusting the incisal edge points of each maxillary tooth to conform to the incisal edge reference curve.

[0018] Compared to existing technologies, this implementation method, after using the WALA ridge as an orthodontic reference for spatial tooth arrangement, is further applied to the joint tooth arrangement of the maxilla and mandible. First, the mandibular teeth are arranged based on the WALA ridge, and then the maxillary teeth are arranged using the characteristic relationship between the mandibular incisal edge point and the maxillary incisal edge point. There is no need to obtain the dental arch curve for tooth arrangement separately for the maxillary teeth, so it can also reduce the influence of the initial maxillary dentition layout on the tooth arrangement target, and reduce the intermediate error caused by manual adjustment of the tooth arrangement reference line, improve the automation of the tooth arrangement process, and make the automatic tooth arrangement result more accurate.

[0019] Optionally, adjusting the three-dimensional maxillary digital model based on the mandibular incisal reference curve includes: adjusting the mandibular incisal reference curve in a reference plane and in a direction perpendicular to the reference plane to obtain the corresponding maxillary incisal reference curve; wherein, the reference plane is a jaw plane or a horizontal plane; and adjusting the incisal feature position of the three-dimensional maxillary digital model based on the maxillary incisal reference curve. Since the mandibular incisal reference line and the maxillary incisal reference line have a physiological correspondence, this application limits the use of the jaw incisal reference curve obtained after mandibular tooth arrangement to obtain the maxillary incisal reference curve, so that the maxilla can directly arrange teeth according to the maxillary incisal reference curve without needing to obtain a separate dental arch curve, and is not affected by the initial neatness of the maxillary tooth layout.

[0020] Optionally, 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; adjusting the mandibular incisal reference curve in the direction of the reference plane includes: expanding the mandibular incisal reference curve along the buccal side; wherein the expansion is uniform with a second preset distance; or, the anterior tooth region is expanded with a third preset distance, and the posterior tooth region is expanded with a fourth preset distance, wherein the third preset distance is smaller than the fourth preset distance. This application defines an adjustment method for transforming the mandibular incisal reference curve into a maxillary incisal reference curve, so as to accurately and reliably obtain the maxillary incisal reference curve.

[0021] Optionally, adjusting the three-dimensional maxillary digital model based on the mandibular incisal reference curve includes: adjusting the occlusal feature positions of the three-dimensional maxillary digital model based on the mandibular incisal reference curve; wherein the occlusal feature positions include the lingual incisal point in the anterior region and the central groove point in the posterior region. Since accurate matching of occlusal feature positions can make the occlusal relationship more stable after tooth arrangement, this application limits the adjustment of occlusal feature positions during the adjustment of the maxillary tooth layout to ensure a more stable occlusal relationship for the obtained target tooth layout.

[0022] Furthermore, embodiments of the present invention also provide an electronic device, including: 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 target tooth layout.

[0023] Embodiments of the present invention also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for generating a target tooth layout. Attached Figure Description

[0024] 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.

[0025] Figure 1 This is a flowchart of a method for generating a target tooth layout provided in one embodiment of this application;

[0026] Figure 2 This is a flowchart of the method for generating the WALA ridge in a method for generating a target tooth layout provided in an embodiment of this application;

[0027] Figure 3 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 in the method for generating a target tooth layout provided in an embodiment of this application.

[0028] Figure 4 This is a schematic diagram of the WALA ridge protrusion position in a method for generating a target tooth layout provided in one embodiment of this application;

[0029] Figure 5 This is a schematic diagram illustrating the positional relationship between the FA point and the WALA ridge, as exemplified in a method for generating a target tooth layout provided in one embodiment of this application.

[0030] Figure 6 This is a schematic diagram illustrating the angular relationship between the FA point and the WALA ridge in an example of a method for generating a target tooth layout provided in one embodiment of this application.

[0031] Figure 7 This is a schematic diagram of the adjustment of tooth incisal edge feature points in a method for generating a target tooth layout provided in another embodiment of this application;

[0032] Figure 8This is a flowchart of a method for generating a target tooth layout provided in another embodiment of this application;

[0033] Figure 9 This is a schematic diagram of an electronic device provided in another 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 for tooth alignment. However, in practice, this method is not very accurate and often requires 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 messy, 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, impacting the quality of the obtained target tooth layout. To address these technical problems, this invention provides a method for generating a target tooth layout. It 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 and patient-appropriate tooth alignment target 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 influence 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.

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

[0041] First, it should be noted that the method for generating the target tooth layout in this embodiment can be implemented by hardware or a combination of computer software and hardware. For hardware implementation, the method for generating the target tooth layout 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 specific process of the method for generating a target tooth layout provided by one embodiment of the present invention can be as follows: Figure 1 As shown, it specifically includes:

[0043] Step 101: Obtain the initial tooth layout and gingival tissue status of the teeth to be treated, thereby generating a three-dimensional digital model of the jaw corresponding to the initial tooth layout.

[0044] Specifically, the initial tooth layout is represented by a digital model of the jaw, which can be a digital model of the jaw at the initial position in an actual case or a digital model of the jaw at the initial position in a test case. The source of the model is determined as needed and will not be listed here. In some embodiments, it can be the tooth layout before orthodontics or the current tooth layout when the target tooth layout needs to be reconfirmed during orthodontics.

[0045] In some embodiments, the initial tooth layout can be a dentition mesh model after incisor classification, where each tooth is an independent model. In some embodiments, the initial tooth layout is a single dentition row, such as a single mandible.

[0046] In some embodiments, the state of gingival tissue can be represented by a digital gingival model, which can be a generated virtual digital gingival model or an actual digital gingival model obtained from an oral scan, and is not limited here.

[0047] Step 102: Based on the three-dimensional digital model of the jaw, determine the spatial orthodontic reference curve based on the WALA ridge.

[0048] Specifically, such as Figure 2 As shown, the methods for generating WALA crests include:

[0049] Step 201: Preset the local coordinate system for each tooth, including the labial-lingual axis and the root-coronal axis.

[0050] 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.

[0051] Step 202: 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 dental digital model to obtain the intersection line.

[0052] Specifically, with Figure 3Taking this example to continue, it can be seen that after the cross section intersects with the three-dimensional digital model of the teeth and jaws, the outline of the digital model can be obtained. Select the buccal gingival part a.

[0053] Step 203: Select the most prominent point on the labial side of the intersection line as the WALA ridge protrusion of the tooth.

[0054] 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 3 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 4 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.

[0055] 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.

[0056] 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.

[0057] Step 204: Assemble the WALA ridge protrusions of the teeth and connect them to form the WALA ridge.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] As can be seen, through steps 201 to 204 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 of the corresponding 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.

[0062] Step 103: Adjust the pose of each tooth in the three-dimensional digital model of the dentition based on the spatial orthodontic reference curve to generate the target three-dimensional digital model of the dentition.

[0063] 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.

[0064] Regarding (A) vertical adjustment of teeth:

[0065] The impedance center of the tooth can be calculated first. The calculation process includes: in some embodiments, the three-dimensional digital model of the jaw 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.

[0066] In some embodiments, the three-dimensional digital dental 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.

[0067] 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.

[0068] 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.

[0069] Regarding (B) horizontal adjustment of teeth:

[0070] 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 digital dental 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.

[0071] 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 5 and Figure 6 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.

[0072] By adjusting (A) and (B) above, a target three-dimensional digital model of the jaw can be obtained corresponding to the target tooth layout.

[0073] In some embodiments, the adjustment dimension further includes (C) near-far-mid adjustment:

[0074] The mesiodistal adjustment process specifically includes: gap detection and collision detection. Specifically, based on the three-dimensional digital model of the jaw, the length of the dental arch curve is obtained on the occlusal plane; based on the three-dimensional digital model of the jaw, the sum of the widths of all teeth is obtained; the position of the teeth in the mesiodistal direction is adjusted according to the relationship between the length of the dental arch curve and the sum of the widths until the gap standard is met. The length of the dental arch curve obtained on the occlusal plane is compared with the sum of the widths of all teeth. If the comparison result shows that the length of the dental arch curve is too large, the gap is determined to be too large. If the comparison result shows that the sum of the widths of all teeth is too large, there may be crowding or even collision, so the position of teeth that are too close together in the mesiodistal direction needs to be adjusted. In practical applications, the gap standard can be set to 0.05mm.

[0075] 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.

[0076] 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.

[0077] Another embodiment of this application provides a method for generating a target tooth layout. The main improvement of this embodiment compared with the previous embodiment is that it increases the adjustment of the incisal edge feature points of the teeth, so that the adjusted target tooth layout has a more stable occlusal relationship.

[0078] like Figure 7 As shown, specifically, the process of adjusting the position and posture of the teeth further includes:

[0079] Step 701: Based on the three-dimensional digital model of the jaw, determine the incisal edge feature points of each tooth.

[0080] Specifically, when the tooth is a molar, the incisal edge feature point is the buccal apex; when the tooth is a premolar, the incisal edge feature point is the buccal apex or buccal groove; when the tooth is an incisor or canine, the incisal edge feature point is the superior incisal edge.

[0081] Step 702: Adjust the teeth until the incisal edge feature points of all the adjusted teeth form a smooth curve.

[0082] In this embodiment, since the curve formed by the incisal edge feature points is smooth, the alignment of the teeth can be confirmed in the vertical direction. Furthermore, since the alignment of the incisal edge feature points can achieve a stable occlusal relationship, this application limits the adjustment of the curve formed by the incisal edge feature points to be smooth, so that the result of tooth arrangement based on the FA point can better ensure that the upper and lower teeth can make uniform contact during biting, forming a good and stable occlusal relationship, which helps to ensure that the teeth are evenly stressed during biting.

[0083] Another embodiment of this application provides a method for generating a target tooth layout. This embodiment is an improvement on the previous embodiment. The main improvement is that the tooth posture angle is adjusted so that the adjusted target tooth layout is more in line with the physiological state of standard teeth.

[0084] In some embodiments, adjusting the tooth posture angle specifically includes: adjusting the spatial position of each tooth until the posture angle is the standard posture angle or within the allowable error range of the standard posture angle; wherein the standard posture is determined based on a standard jaw model. It is evident that assigning the standard posture angle of each tooth in the standard jaw model to the tooth to be adjusted is a simple and effective adjustment method to determine that each tooth has an ideal posture angle after adjustment.

[0085] In other embodiments, the posture angles of each tooth are first set to standard values, and then optimized and adjusted based on these values ​​to achieve a smoother occlusal side of the target tooth layout. It is evident that fine-tuning based on standard posture angles can take into account the rationality of other feature positions, resulting in a smoother occlusal side.

[0086] It should be noted that attitude angles include the torque angle, torsion angle, and / or axial tilt angle of the teeth.

[0087] As can be seen, since standard teeth are not completely vertical and have a certain degree of tilt, this application limits the adjustment posture angle during tooth arrangement so that the tilt of the teeth after tooth arrangement is more in line with the physiological characteristics of teeth, so that the adjusted teeth are more in line with the physiological state of standard teeth.

[0088] It is worth mentioning that the above embodiments are mainly used to generate the target tooth layout for a single jaw. In actual applications, it may be necessary to adjust the target tooth layout for the patient's maxilla or mandible at the same time. Therefore, we will continue to explain the bimaxillary tooth arrangement.

[0089] Another embodiment of this application provides a method for generating a target tooth layout, such as... Figure 8 As shown, it specifically includes:

[0090] Step 801: 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.

[0091] Specifically, the methods for obtaining each model are similar to those in the first embodiment, and will not be repeated here.

[0092] Step 802: Process the three-dimensional mandibular digital model based on the method for generating the target tooth layout in the above embodiments to generate the target three-dimensional mandibular digital model.

[0093] Specifically, in this step, the three-dimensional mandibular digital model obtained in step 801 is processed according to the processing methods in the aforementioned embodiments. That is, the three-dimensional mandibular digital model is used to arrange teeth through the WALA ridge of the mandible to obtain the target three-dimensional mandibular digital model.

[0094] Step 803: Obtain the incisal edge points of each tooth in the mandible based on the target three-dimensional digital model of the mandible.

[0095] Specifically, the identification of the incisal edge of a tooth can be obtained through the medical meaning of the feature points, or it can be identified through machine learning algorithms and feature point recognition models.

[0096] Step 804: Collect the incisal edge points of all mandibular teeth to form a mandibular incisal edge reference curve.

[0097] 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, the cutting edge points can be fitted with a three-dimensional curve. In practical applications, other methods can also be used, which will not be listed here.

[0098] Step 805: Adjust the three-dimensional maxillary digital model based on the mandibular incision reference curve to generate the target three-dimensional maxillary digital model.

[0099] Specifically, this step may include: adjusting the mandibular incisor reference curve in a reference plane and in a direction perpendicular to the reference plane to obtain the corresponding maxillary incisor reference curve; and adjusting the incisor feature position of the three-dimensional maxillary digital model based on the maxillary incisor reference curve. The reference plane is either a jaw plane or a horizontal plane.

[0100] In some embodiments, adjusting the mandibular incisal reference curve in a direction perpendicular to the reference plane includes: moving the anterior tooth region portion of the mandibular incisal reference curve downward by a first preset distance (e.g., 2 mm); adjusting the mandibular incisal reference curve in the direction of the reference plane includes: expanding the mandibular incisal reference curve along the buccal side.

[0101] Specifically, in expanding the mandibular incisal reference curve along the buccal side, in one embodiment, it is expanded uniformly at a second preset distance (e.g., 2 mm); or in another embodiment, the anterior tooth region is expanded at a third preset distance, and the posterior tooth region is expanded at a fourth preset distance, wherein the third preset distance is smaller than the fourth preset distance. The adjustment method for transforming the mandibular incisal reference curve to the maxillary incisal reference curve is defined to ensure accurate and feasible acquisition of the maxillary incisal reference curve. For example, when the preset target tooth layout is shallow overbite, different expansion amounts for the anterior and posterior tooth regions can be used, such as a third preset distance of 1 mm and a fourth preset distance of 3 mm.

[0102] In some embodiments, adjusting the three-dimensional maxillary digital model based on the mandibular incisal reference curve specifically includes: adjusting the occlusal feature positions of the three-dimensional maxillary digital model based on the mandibular incisal reference curve; wherein, the occlusal feature positions include the lingual incisal edge point in the anterior region and the central groove point in the posterior region. Since accurate matching of the occlusal feature positions can make the occlusal relationship more stable after tooth arrangement, this application limits the adjustment of the occlusal feature positions during the adjustment of the maxillary tooth layout to ensure a more stable occlusal relationship for the obtained target tooth layout.

[0103] As can be seen, since the mandibular incisal reference line and the maxillary incisal reference line have a physiological correspondence, this application limits the use of the incisal reference curve obtained after mandibular tooth arrangement to obtain the maxillary incisal reference curve. This allows the maxilla to directly arrange teeth according to the maxillary incisal reference curve without needing to obtain the dental arch curve separately, and it is not affected by the initial neatness of the maxillary tooth arrangement. It also reduces intermediate errors caused by manual adjustment of the tooth arrangement reference line, improves the automation of the tooth arrangement process, and makes the automatic tooth arrangement results more accurate.

[0104] 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.

[0105] 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.

[0106] Another embodiment of this application relates to an electronic device, such as... Figure 9 As shown, it includes: at least one processor 901; and a memory 902 communicatively connected to the at least one processor 901; wherein the memory 902 stores instructions executable by the at least one processor 901, the instructions being executed by the at least one processor 901 to enable the at least one processor 901 to perform the method for generating a target tooth layout in the above partial embodiments, or the digital modeling method for dental orthodontic jaw models in the above partial embodiments.

[0107] 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.

[0108] 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.

[0109] 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 target tooth layout as described in some of the above embodiments, or the digital modeling method for dental orthodontic models as described in some of the above embodiments.

[0110] 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.

[0111] 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 target tooth layout, characterized by, The method comprises the following steps: acquiring an initial tooth arrangement and a state of gingival tissue to be corrected, thereby generating a three-dimensional dental digital model corresponding to the initial tooth arrangement; determining a WALA ridge-based spatial correction reference curve based on the three-dimensional dental digital model; adjusting the position of each tooth in the three-dimensional space in the three-dimensional dental digital model based on the spatial correction reference curve, thereby generating a target three-dimensional dental digital model; wherein the adjusting comprises: adjusting the impedance center of the tooth to be the same height as the corresponding position of the spatial correction reference curve, and adjusting the horizontal distance between the FA point of the tooth and the corresponding position of the spatial correction reference curve to be within a preset range.

2. The method for generating a target tooth layout of claim 1, wherein, The method comprises the following steps: presetting a local coordinate system of each tooth, which comprises a labial-lingual axis and a root-crown axis; intersecting a cross section formed by the labial-lingual axis and the root-crown axis of a tooth with the gingival part of the three-dimensional dental digital model to obtain an intersection line, and selecting the most convex point on the intersection line on the labial side as the WALA ridge convex point of the tooth; collecting the WALA ridge convex points of the teeth and connecting them to form the WALA ridge.

3. The method for generating a target tooth layout of claim 2, wherein, After the WALA ridge is obtained, the method comprises the following steps:

4. The method for generating a target tooth layout according to any one of claims 1-3, wherein, adjusting the impedance center of the tooth to be the same height as the corresponding position of the spatial correction reference curve, which comprises the following steps: calculating the initial position of the impedance center of the tooth; wherein, if the three-dimensional dental digital model comprises a tooth root part, calculating the initial position of the impedance center of the tooth according to the total height of the tooth; 5. The method for generating a target tooth layout of claim 4, wherein, if the three-dimensional dental digital model comprises a tooth root part and an alveolar bone part, obtaining the initial position of the impedance center of the tooth by moving down a predetermined distance from the point on the tooth long axis mapped from the intersection of the alveolar bone part and the tooth root part.

6. The method for generating a target tooth layout of any one of claims 1-3, wherein, The predetermined distance is half the height of the tooth root. The method comprises the following steps: calculating the initial position of the FA point of each tooth; finding the nearest point of the FA point on the spatial correction reference curve; 7. The method for generating a target tooth layout of claim 6, wherein, moving the tooth based on the FA point of the tooth until the horizontal distance between the tooth and the corresponding nearest point on the spatial correction reference curve is within the preset range. The method comprises the following steps: presetting a local coordinate system of each tooth, which comprises a labial-lingual axis and a root-crown axis; intersecting a cross section formed by the labial-lingual axis and the root-crown axis of a tooth with the tooth part of the three-dimensional dental digital model to obtain an intersection line, and selecting a segment of the intersection line from the gum line to the height of the tooth crown on the labial side as the FACC axis of the tooth; 8. The method for generating a target tooth layout of claim 1, wherein, selecting the midpoint of the FACC axis as the initial position of the FA point of the tooth. The method comprises the following steps: determining the incisal edge feature point of each tooth based on the three-dimensional dental digital model; adjusting the tooth until the incisal edge feature points of all the adjusted teeth form a smooth curve.

9. The method for generating a target tooth layout of claim 8, wherein, The incisal edge feature point of each tooth includes: when the tooth is a molar, the incisal edge feature point is a buccal cusp point; when the tooth is a premolar, the incisal edge feature point is a buccal cusp or a buccal groove point; and when the tooth is an incisor or a canine, the incisal edge feature point is an upper incisal edge point.

10. The method for generating a target tooth layout of any one of claims 1-3, wherein, The adjusting of the positions of the teeth in the three-dimensional space based on the spatial orthodontic reference curve to generate a target three-dimensional dental model includes: adjusting a posture angle; wherein, The spatial positions of the teeth are adjusted until the posture angle is a standard posture angle or within an allowable error of the standard posture angle; wherein the standard posture is determined based on a standard dental model; and wherein the posture angle includes a torque angle, a torsion angle and / or an axis inclination angle of the tooth.

11. The method for generating a target tooth layout of any one of claims 1-3, wherein, The adjusting of the positions of the teeth in the three-dimensional space based on the spatial orthodontic reference curve to generate a target three-dimensional dental model includes: gap detection and collision detection; wherein, The length of an arch curve is obtained on a jaw plane based on the three-dimensional dental model; The sum of the widths of all teeth is obtained based on the three-dimensional dental model; The positions of the teeth in the mesial-distal direction are adjusted according to the relationship between the length of the arch curve and the sum of the widths until the gap standard is met.

12. A method for generating a target tooth layout, characterized by, It includes: An initial dental layout of the upper jaw and an initial dental layout of the lower jaw to be corrected are obtained, thereby generating a corresponding three-dimensional upper jaw digital model and a three-dimensional lower jaw digital model; The three-dimensional lower jaw digital model is processed based on the method for generating a target dental layout according to any one of claims 1-11 to generate a target three-dimensional lower jaw digital model; Incisal edge points of each tooth of the lower jaw are obtained based on the target three-dimensional lower jaw digital model; The incisal edge points of all teeth of the lower jaw are collected to form a lower jaw incisal edge reference curve; A target three-dimensional upper jaw digital model is generated based on the lower jaw incisal edge reference curve; It includes: adjusting the incisal edge points of each tooth of the upper jaw to meet the incisal edge reference curve.

13. The method for generating a target tooth layout of claim 12, wherein, The adjusting of the three-dimensional upper jaw digital model based on the lower jaw incisal edge reference curve includes: The lower jaw incisal edge reference curve is adjusted in a reference plane and a direction perpendicular to the reference plane to obtain an upper jaw incisal edge reference curve of the corresponding upper jaw; wherein the reference plane is a jaw plane or a horizontal plane; The incisal edge feature position of the three-dimensional upper jaw digital model is adjusted based on the upper jaw incisal edge reference curve.

14. The method for generating a target tooth layout of claim 13, wherein, The adjusting of the lower jaw incisal edge reference curve in a direction perpendicular to the reference plane includes: moving the front tooth area part of the lower jaw incisal edge reference curve downward by a first preset distance; The adjusting of the lower jaw incisal edge reference curve in the direction of the reference plane includes: expanding the lower jaw incisal edge reference curve along the buccal side; wherein the expansion is uniform at a second preset distance; or, The front tooth area is expanded by a third preset distance, and the back tooth area is expanded by a fourth preset distance; the third preset distance is smaller than the fourth preset distance.

15. The method for generating a target tooth layout of claim 12, wherein, The adjusting of the three-dimensional upper jaw digital model based on the lower jaw incisal edge reference curve includes: adjusting a position of an occlusal feature of the three-dimensional maxillary digital model based on the mandibular incisal reference curve; wherein the position of the occlusal feature comprises a lingual incisal point of an anterior region and a central groove point of a posterior region.

16. An electronic device, comprising: comprising: at least one processor; and, a memory communicatively connected to the at least one processor; wherein the memory has stored 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 method for producing a target dental arrangement of any one of claims 1 to 15.

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