Shell-shaped dental instruments, their manufacturing methods, and the design methods of digital dental models
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG YINCHILI MEDICAL TECH CO LTD
- Filing Date
- 2024-12-30
- Publication Date
- 2026-06-30
Smart Images
Figure CN122297133A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of orthodontic technology, and in particular to a shell-shaped dental instrument, a method for generating the same, and a method for designing digital dental models. Background Technology
[0002] In clinical orthodontic treatment, functional attachments are sometimes used to enhance the orthodontic effect when using shell-type orthodontic appliances. Common functional attachments include traction structures, which suspend traction components so that traction force is applied to the corresponding areas. In many cases, such as anterior tooth intrusion, tooth elongation, gap adjustment, eruption traction, and tooth rotation, traction structures are needed for auxiliary treatment.
[0003] In existing technologies, one approach involves using additional devices in conjunction with the clear aligner, such as lingual clips or anchorage screws, commonly used in fixed orthodontic treatments, to simultaneously complete the correction. However, this method significantly reduces treatment comfort and aesthetics. Another approach is to directly create a traction structure within the clear aligner. For example, one method involves creating a small notch (i.e., a traction hook) at the edge of the tooth cavity corresponding to the tooth requiring traction within the clear aligner. When wearing the aligner, the traction element is hooked onto the traction hook for retention, while the other side is hooked onto another traction hook or lingual clip to achieve inter-tooth traction. However, when the traction force is too great, this method can cause the edge of the aligner to curl outwards, forming a raised edge. This not only causes the traction element to slip off, but the raised edge can also easily scratch the oral mucosa. Another scenario involves a protruding structure extending outward from the surface of the clear aligner's shell. The side surface of this protruding structure has openings for attaching traction components. Existing protruding structures are typically cylindrical or prismatic in shape. While this structure can withstand greater orthodontic force compared to openings directly at the edge of the clear aligner, the traction force it can withstand is also limited. When the orthodontic plan requires greater traction (such as retraction of the upper anterior teeth or extraoral traction), the cylindrical or prismatic protruding structure may deform, resulting in an inability to provide accurate and stable traction force.
[0004] Therefore, it is necessary to provide a more comfortable invisible orthodontic appliance that can provide more stable traction. Summary of the Invention
[0005] The purpose of this application is to provide a shell-shaped dental instrument and its generation method, as well as a design method for a digital dental model, which effectively solves the above-mentioned problems. Based on the principle of mechanical analysis, the protruding structure used for traction in the prior art is improved so that it can be applied to different orthodontic needs and can continuously provide more stable traction force.
[0006] To achieve the above objectives, embodiments of this application provide a shell-shaped dental instrument, comprising a shell-shaped body having multiple tooth receiving cavities. A portion of the surface of the shell-shaped body is provided with a traction portion for suspending traction members. The traction portion is integrally formed with the shell-shaped body and has a hollow structure. A receiving groove for accommodating the traction member is provided on the side surface of the traction portion. The receiving groove is used for detachable connection with the traction member. The maximum length of any first cross-section of the traction portion in a first direction is greater than the maximum length in a second direction. The first direction is the direction of the long axis of the traction member. The first direction and the second direction are perpendicular to each other, and the first direction and the second direction are located on the first cross-section. The receiving groove is arranged facing the first direction or the opposite direction of the first direction.
[0007] Preferably, the maximum length of the traction part in the first direction is at least twice the maximum length of the traction part in the second direction.
[0008] Preferably, the width of the first cross section in the second direction increases and then decreases from the first end of the traction portion to the second end of the traction portion, and the first cross section is closer to the first end at the point where its width is greatest in the second direction, wherein the first end and the second end are the two ends of the first cross section along the first direction.
[0009] Preferably, the side surface of the first end on the traction part is a first side surface, and the side surface of the second end on the traction part is a second side surface. The first side surface and the second side surface are arranged opposite to each other, wherein the receiving groove is located on the second side surface.
[0010] Preferably, the length of the traction portion in the first direction gradually decreases from the end adjacent to the shell-shaped body to the end away from the shell-shaped body.
[0011] Preferably, the longitudinal section of the traction part is semi-circular, semi-elliptical, or shark fin shaped.
[0012] Preferably, the length of the traction portion in the second direction gradually decreases from the end adjacent to the shell-shaped body to the end away from the shell-shaped body.
[0013] Preferably, the area of the first cross-section gradually decreases from the end adjacent to the shell-like body to the end away from the shell-like body.
[0014] Preferably, the receiving groove is formed by a portion of the side surface of the traction part being recessed into the traction part, or the receiving groove is an opening structure that connects the interior of the traction part with the exterior.
[0015] Preferably, the traction part is located on the labial or buccal side or the lingual side of the tooth receiving cavity.
[0016] Preferably, when the tooth receiving cavity extends to cover the gums, the traction part is provided at the gums.
[0017] Preferably, when the shell-shaped body is used to be worn on the maxillary dentition, the shell-shaped body further includes a palatal support portion spanning the palate, the palatal support portion being connected to the tooth receiving cavities on the left and right sides, wherein the traction portion is located on the palatal support portion.
[0018] Preferably, the length of the traction part in the second direction is greater than or equal to 1 mm and less than or equal to 10 mm.
[0019] Preferably, the plurality of tooth receiving cavities are used to enclose the plurality of teeth in the anterior tooth region, and the palatal bearing portion is connected to the lingual edge of the plurality of tooth receiving cavities respectively.
[0020] Preferably, the traction portion extends beyond the incisal edge of the anterior teeth to the lingual side.
[0021] Preferably, the plurality of tooth receiving cavities include a first tooth receiving portion for receiving a plurality of teeth in the left posterior tooth region and a second tooth receiving portion for receiving a plurality of teeth in the right posterior tooth region, wherein the palatal bearing portion is connected to the lingual edge of the first tooth receiving portion and the lingual edge of the second tooth receiving portion, respectively.
[0022] Preferably, the plurality of tooth receiving cavities further include a third tooth receiving portion for enclosing the plurality of teeth in the anterior tooth region, the third tooth receiving portion being connected to the first tooth receiving portion and the second tooth receiving portion respectively.
[0023] Preferably, the palatal support portion is connected to the lingual edge of the third tooth receiving portion.
[0024] Preferably, the palatal support portion is provided with a plurality of traction portions, which are arranged sequentially along the sagittal direction; or, the palatal support portion is provided with a single traction portion, the long axis of which is arranged along the sagittal direction.
[0025] Another embodiment of this application provides a method for designing a digital dental model to obtain a basic digital dental model and a treatment plan;
[0026] The placement position of the digital traction device is obtained according to the treatment plan, and the morphological data of the digital traction device is determined according to the placement position; the determined digital traction device and the basic digital dental model are merged to generate a digital dental model with the traction device.
[0027] Preferably, determining the morphological data of the digital traction unit based on the placement position includes: selecting a corresponding basic digital traction unit from the model library based on the placement position, and adjusting the morphological data of the basic digital traction unit based on one or more of the placement surface size, adjacent tooth spacing, and occlusal engagement at the placement position.
[0028] Preferably, the maximum length of the first cross section of the basic digital traction unit in the first direction is greater than the maximum length in the second direction. The first direction is the direction of the long axis of the basic digital traction unit. The first direction and the second direction are perpendicular to each other. Furthermore, the first direction and the second direction are located on the first cross section.
[0029] Preferably, the basic digital traction unit also has a digital receiving slot, and the digital receiving slot is arranged facing the first direction or the opposite direction of the first direction.
[0030] Preferably, the placement location includes the labial and buccal sides of the tooth model, the lingual side of the tooth model, and the palatal region.
[0031] Preferably, the morphological data includes the scaling ratio and orientation of the digital traction unit.
[0032] Preferably, a virtual weak connection structure is generated at the connection between the digital traction part and the basic digital dental model.
[0033] Another embodiment of this application provides a method for generating a shell-shaped dental instrument. The method involves manufacturing a physical model of the digital dental model obtained by the design method of any one of the above-described digital dental models using additive manufacturing, and then manufacturing the shell-shaped dental instrument using a hot-pressing method based on the physical model. Alternatively, the method involves generating a digital model of the shell-shaped dental instrument from the digital dental model obtained by the design method of any one of the above-described digital dental models, and then manufacturing the shell-shaped dental instrument using additive manufacturing based on the digital model of the shell-shaped dental instrument.
[0034] This invention provides a shell-shaped dental instrument, a method for generating the same, and a method for designing digital dental models, which, compared with existing technologies:
[0035] The traction unit on the shell-shaped dental instrument in this application has a special structural design. Specifically, the length of any first cross-section of the traction unit in a first direction is greater than its length in a second direction. The first direction is the direction of the long axis of the traction unit. The receiving groove is set towards the first direction or the opposite direction. That is to say, the length of the traction unit in the traction direction is greater than its length in other directions. This design can more effectively increase the bending resistance of the structure. In addition, the area of the first cross-section gradually decreases from the end adjacent to the shell-shaped body to the end away from the shell-shaped body. The traction unit adopts a structure that is smaller at the top and larger at the bottom, which can effectively utilize the bending resistance of the bottom while saving material and space in the upper part. This not only ensures the comfort of the traction unit in the patient's mouth, but also effectively improves the deformation resistance of the traction unit, adapting to different orthodontic needs during the treatment process and continuously and stably providing traction force.
[0036] This application also includes a design method for a digital dental model, which can pre-add a digital traction unit according to the treatment plan, and adjust the position and shape data of the traction unit in a timely manner according to the needs of different treatment steps, taking into account the patient's intraoral condition and the changes in the designed tooth position during the treatment process.
[0037] The method for preparing the shell-shaped dental instrument of the present invention involves designing the shell-shaped dental instrument using the above-mentioned design method and then preparing the corresponding shell-shaped dental instrument. The method involves first 3D printing, then thermoforming and cutting, which allows for the production of corresponding dental instruments according to the patient's personalized orthodontic needs. Alternatively, the shell-shaped dental instrument can be prepared by direct 3D printing. For structures that are more complex or difficult to form, they can be directly printed, resulting in higher preparation efficiency and better control over the preparation accuracy. Attached Figure Description
[0038] 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.
[0039] Figure 1 This is a schematic diagram of the structure of a shell-shaped dental instrument according to Embodiment 1 of this application;
[0040] Figure 2 This is a force analysis diagram of a traction unit in Embodiment 1 of this application;
[0041] Figure 3 yes Figure 2 A schematic diagram of the first cross-section corresponding to the central traction section;
[0042] Figure 4 This is a schematic diagram of the first cross-section corresponding to another traction part in Embodiment 1 of this application;
[0043] Figure 5 These are force diagrams of two different structural forms of traction components;
[0044] Figure 6 yes Figure 5 Finite element analysis diagram of the traction unit corresponding to the middle morphology P1;
[0045] Figure 7 yes Figure 5 Finite element analysis diagram of the traction unit corresponding to the middle morphology P2;
[0046] Figure 8 This is a schematic diagram of another shell-shaped dental instrument in Embodiment 1 of this application;
[0047] Figure 9 yes Figure 8 A magnified view of region A in the image;
[0048] Figure 10 This is a force diagram of two different structural forms of the traction part in Embodiment 1 of this application;
[0049] Figure 11 yes Figure 10 Finite element analysis diagram of the traction unit corresponding to the middle morphology P3;
[0050] Figure 12 yes Figure 10 Finite element analysis diagram of the traction unit corresponding to the middle morphology P4;
[0051] Figure 13 A schematic diagram of the longitudinal section of a traction unit in Embodiment 1;
[0052] Figure 14 Another cross-sectional schematic diagram of a traction unit in Embodiment 1;
[0053] Figure 15 This is a schematic diagram of another shell-shaped dental instrument in Embodiment 1 of this application;
[0054] Figure 16 This is a schematic diagram of another shell-shaped dental instrument in Embodiment 1 of this application;
[0055] Figure 17 This is a schematic diagram of another shell-shaped dental instrument in Embodiment 1 of this application;
[0056] Figure 18 This is a schematic diagram of another shell-shaped dental instrument in Embodiment 1 of this application;
[0057] Figure 19 This is a schematic diagram of another shell-shaped dental instrument in Embodiment 1 of this application;
[0058] Figure 20 This is a flowchart of the design method for the digital dental model in Embodiment 2 of this application;
[0059] Figure 21 This is a virtual model corresponding to the basic digital traction unit in Embodiment 2 of this application;
[0060] Figure 22 It is the virtual model corresponding to the digital dental model in Embodiment 2 of this application;
[0061] Figure 23 These are schematic diagrams of the electronic devices provided in Embodiments 2 and 3 of this application. Detailed Implementation
[0062] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application 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 presented in the various embodiments of this application to enable readers to better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.
[0063] The term "posterior region" mentioned in the various embodiments of this application is defined according to the classification of teeth in the 2nd edition of *Introduction to Stomatology*, published by Peking University Medical Press, pages 36-38. It includes 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 central incisors, lateral incisors, and canines.
[0064] The shell-like body contains several cavities to accommodate multiple teeth and is divided into lingual and labial surfaces, as well as mesial and distal surfaces. The term "lingual surface" is based on the nomenclature of the crown surfaces in the 2nd edition of *Introduction to Stomatology*, published by Peking University Medical Press, on pages 35-36. The labial and buccal surfaces are the surfaces of the crowns of anterior teeth that are closest to the lips, called the labial surface; the buccal surfaces are the surfaces of the crowns of posterior teeth that are closest to the buccal surface. The lingual surface is the surface of the crowns of both anterior and posterior teeth that is closest to the tongue. The mesial and distal surfaces are the two surfaces of the crown that meet adjacent teeth, collectively called the proximal surfaces. The surface closer to the facial midline is called the mesial surface, and the surface farther from the facial midline is called the distal surface.
[0065] Shell-shaped orthodontic appliances (corresponding to the shell-shaped dental instruments in the various embodiments of this application) are invisible and aesthetically pleasing orthodontic devices manufactured through computer-aided three-dimensional design. They are typically worn on the teeth and are composed of polymer materials, such as TPU, PETG, or a combination of both. These appliances generate forces that cause changes in the deformed jawbone, misaligned teeth, and periodontal tissues, promoting normal growth and development of the dentofacial region. Shell-shaped orthodontic appliances utilize biomechanical principles to correct deformed teeth. Through an orthodontic system comprising a series of shell-shaped appliances, gentle and sustained bio-force is applied to gradually move the teeth, restoring them to their normal positions and aligning them properly. During the treatment process, additional attachments or unique structures are typically used on the shell-shaped appliances to apply extra corrective force to the teeth.
[0066] In some cases, existing invisible aligners employ a protruding structure on the surface of the aligner housing. The side surface of the protruding structure has openings for attaching traction components. The protruding structure is usually in a relatively regular geometric shape, such as a cylinder or prism. Although this structure can withstand greater orthodontic force than openings directly at the edge of the invisible aligner, the traction force it can withstand is also limited. When the orthodontic plan requires greater traction (such as retraction of the upper anterior teeth or extraoral traction), the protruding structure may deform, resulting in an inability to provide accurate and stable traction force.
[0067] This application provides an improvement to the above-mentioned situation. In some embodiments of this application, a shell-shaped dental instrument includes a shell-shaped body with multiple tooth-receiving cavities. A traction portion for suspending traction elements protrudes outward from a portion of the surface of the shell-shaped body. The traction portion is integrally formed with the shell-shaped body and has a hollow structure. A receiving groove for accommodating the traction element is provided on the side surface of the traction portion. The receiving groove is used for detachable connection with the traction element. The length of any first cross-section of the traction portion in a first direction is greater than its length in a second direction. The first direction is the direction of the long axis of the traction element. The first direction and the second direction are perpendicular to each other, and the first direction and the second direction are located on the first cross-section. The receiving groove is oriented towards the first direction or the opposite direction. The inventors of this application have optimized the structural morphology of the traction portion on existing invisible aligners through theoretical mechanical analysis and verified the optimization results through finite element analysis. The special structural features of the traction portion in this application can improve its bending resistance during use. Therefore, the traction portion can be placed at different positions as needed to meet the traction force under different orthodontic requirements. Furthermore, the special features of the traction portion mean that it is not easily deformed during use and can continuously and stably provide traction force.
[0068] The various embodiments of this application will now be described with reference to the accompanying drawings.
[0069] Example 1
[0070] refer to Figure 1 As shown, the embodiment of the application provides a shell-shaped dental instrument 1, including a shell-shaped body with multiple tooth receiving cavities 11, the multiple tooth receiving cavities 11 having orthodontic function. A traction part 12 for suspending traction elements is provided on a portion of the surface of the shell-shaped body. The traction part 12 is integrally formed with the shell-shaped body and is arranged in a hollow structure. The side surface of the traction part 12 has a receiving groove 13 for accommodating the traction element. The receiving groove 13 is used for detachable connection with the traction element. The maximum length of any first cross section 121 of the traction part 12 in the first direction X is greater than the maximum length in the second direction Z. The first direction X is the direction of the long axis of the traction part 12. The first direction X and the second direction Z are perpendicular to each other, and the first direction X and the second direction Z are located on the first cross section 121. The receiving groove 13 is arranged facing the first direction X or the opposite direction of the first direction X. That is to say, the first direction X or the opposite direction of the first direction X is the direction that mainly bears the traction force. In this direction, the length of the traction part 12 needs to be greater than the length in other directions to more effectively increase the bending resistance of the structure. The specific analysis is as follows:
[0071] refer to Figure 2 and Figure 3 As shown, with Figure 2 The traction method of the traction unit 12 is illustrated by example. The bending moment of the traction unit 12 in the first direction X is caused by... Figure 2 It can be seen that the bending moment is the largest at the root. The bending moment in the first direction X can be expressed as Mx = Fd, where d is the vertical distance from the position where the traction force F is applied to the root of the bending device. Figure 2 The Y direction in the figure is the protruding direction of the traction unit 12 (third direction Y). i The cross section corresponding to the height is as follows Figure 3 As shown, the centroid of this cross-section is (x... ci y i , z ci The centroid calculation can be approximated as follows: Where δ Z To determine the width of the region after dividing the cross section into n equal parts along the second direction Z, x cij Let x be the centroid coordinate of the equally divided region. Where z cij Let z be the centroid coordinates corresponding to this equally divided region. Due to the symmetry of the cross section, z ci =0,d i <c i .
[0072] The moment of inertia of the cross section in this embodiment Where δX The width of the region after dividing the cross section into n equal parts along the first direction X is z k The width of the elongated, equally divided region in the second direction Z is given.
[0073] For section i, the normal stress at any point on the section is... If the maximum normal stress occurs at A i point d i For A i The distance of a point from the Z-axis, if the maximum normal stress occurs at point B. i point c i For B i The distance d from the point to the Z-axis can be determined from the centroid property. i <c i .
[0074] Therefore, increasing the length of the first direction X is equivalent to increasing a. k and d i If the length of the first direction X increases by a factor of s, the increased length... Increasing the width in the second direction Z is equivalent to increasing z. k If the length of the second direction Z increases by a factor of s, the increased length... Therefore, it can be seen that increasing the length in the first direction X can provide an exponentially greater bending resistance to the traction section 12. In other words, increasing the length of the traction section 12 in the first direction X can more effectively increase the bending resistance of the structure. In a preferred design, the length of the traction section 12 in the first direction X is at least twice the length in the second direction Z.
[0075] Further preferred options, refer to Figure 4 As shown, the inventors of this application, through extensive research, discovered that the maximum length X1 of the traction part 12 in the first direction X is at least twice the maximum length Z1 of the traction part 12 in the second direction Z. Furthermore, the maximum length X1 of the traction part 12 in the first direction X is no greater than five times the maximum length Z1 of the traction part 12 in the second direction Z. Since the traction part 12 is not only subjected to traction force in the first direction X during use, but also to certain component forces in other directions, this design not only effectively improves the bending resistance of the traction part 12 in the traction direction, but also ensures the stability of the traction part 12 after it is subjected to certain component forces in other directions during traction.
[0076] In some implementations, reference continues. Figure 4As shown, the width of the first cross-section 121 in the second direction Z first increases and then decreases from the first end 121a of the traction part 12 to the second end 121b of the traction part 12, and the maximum width E in the second direction Z is closer to the first end 121a. In this embodiment, the first cross-section 121 is approximately teardrop-shaped, and this design can further improve the bending strength of the traction part 12. Figure 5 The diagram illustrates two different structures, with the traction force F representing the position and direction of the traction force on the traction unit 12 in different structures. Figure 5 The intermediate shape P1 is the traction part 12 shape where the width of the first cross-section 121 in the second direction Z first increases and then decreases from the first end 121a to the second end 121b of the traction part 12. The intermediate shape P2 is the traction part 12 shape where the width of the first cross-section 121 in the second direction Z is equal from the first end 121a to the second end 121b of the traction part 12. Further reference Figure 6 and Figure 7 Finite element analysis shows that, under the same load, the stress level of the traction part 12 structure corresponding to shape P1 is the lowest, indicating that its bending strength is higher under the same load.
[0077] Further selection, participate Figure 8 and Figure 9 As shown, the side surface of the first end portion 121a on the traction part 12 is the first side surface 123, and the side surface of the second end portion 121b on the traction part 12 is the second side surface 122. The first side surface 123 and the second side surface 122 are arranged opposite to each other, that is, the first side surface 123 and the second side surface 122 are discontinuous. The receiving groove 13 is located on the second side surface 122. Compared to the case where the receiving groove 13 is located on the first side surface 123, since the traction part 12 is a hollow structure, the space at the second side surface 122 is smaller. Therefore, when the receiving groove 13 is located on the second side surface 122, the overall bending strength of the traction part 12 is higher than when the receiving groove 13 is located on the first side surface 123. (Reference) Figure 10 As shown in the figure, configuration P3 is a simplified force diagram when the receiving groove 13 is located on the first side surface 123, and configuration P4 is a simplified force diagram when the receiving groove 13 is located on the second side surface 122. In the figure, F represents the direction of the traction force and the force position of the traction part 12, and is simultaneously referenced. Figure 11 and Figure 12 As shown, Figure 11 and Figure 12Based on the finite element analysis results of forms P3 and P4 under the same load, the stress level of the traction part 12 structure corresponding to form P4 is the lowest, indicating that it has higher bending strength under the same load. Therefore, the bending strength of the receiving groove 13 located on the second side surface 122 is higher.
[0078] In one implementation, reference Figure 13 As shown, the length H1 of the traction part 12 in the first direction X gradually decreases from the end adjacent to the shell-shaped body to the end away from the shell-shaped body. Since the end of the traction part 12 away from the shell-shaped body will come into contact with the patient's oral cavity during the wearing of the shell-shaped dental instrument 1, this design improves the bending resistance of the traction part 12 in the first direction X, and the smaller volume of the end of the traction part 12 away from the shell-shaped body also ensures the comfort of the traction part 12 in the patient's mouth. Optionally, refer to... Figure 13 As shown, the longitudinal section of the traction part 12 is semi-circular, semi-elliptical, or shark fin-shaped. This longitudinal section is the section containing the first direction X and the third direction Y (the protruding direction of the traction part 12), with the third direction Y perpendicular to both the first direction X and the second direction Z. This further ensures that the end of the traction part 12 furthest from the shell-like body has a more rounded shape, improving patient comfort during wear.
[0079] Similarly, refer to Figure 14 As shown in the figure, the figure represents any cross-section obtained after the plane containing the third direction Y and the second direction Z intersects the traction part 12. The third direction Y is perpendicular to both the first direction X and the second direction Z. The length H2 of the traction part 12 in the second direction Z gradually decreases from the end adjacent to the shell-like body to the end farther from the shell-like body. This design improves the bending resistance of the traction part 12 in the second direction Z, and the smaller volume at the end of the traction part 12 away from the shell-like body also ensures comfort of the traction part 12 within the patient's mouth. Optionally, the longitudinal section of the traction part 12 is semi-circular or semi-elliptical. This further ensures that the end of the traction part 12 away from the shell-like body has a more rounded shape, which can improve patient comfort during wear.
[0080] In other embodiments, reference is made to Figure 4 As shown, the area of the first cross-section 121 gradually decreases from the end adjacent to the shell-like body to the end away from the shell-like body. The larger the moment of inertia of the cross-section relative to an axis, the stronger the bending resistance of the device about that axis. For the above device, when the cross-section remains constant, the bending section modulus W = I. Zi / d i (or W = I) Zi / c iGiven a fixed value, the bending resistance of any section of the above structure is the same, while the bending moment Fy... i As the traction part 12 increases in size closer to the shell-like body, the risk of failure is higher at the end of the traction part 12 closer to the shell-like body than at the end farther away from the shell-like body. Therefore, a structural design in which the area of the first cross-section 121 gradually decreases from the end adjacent to the shell-like body to the end farther away from the shell-like body can increase the value of W. Since W is a term related to a high power of the width and length, increasing the length and width dimensions can effectively increase the bending section modulus. In other words, a structural form in which the area of the first cross-section 121 gradually decreases from the end adjacent to the shell-like body to the end farther away from the shell-like body can effectively enhance the bending resistance of the bottom while saving material and space in the upper part.
[0081] In some embodiments, the receiving groove 13 is formed by a portion of the side surface of the traction part 12 being recessed into the traction part 12, or the receiving groove 13 is an opening structure that connects the interior of the traction part 12 with the exterior.
[0082] Specifically, in one scenario, the receiving groove 13 in this application is a recessed structure formed by a portion of its side surface being recessed into the traction part 12. During use, traction components such as rubber bands are fixed at the recessed structure. The advantage of this design is that, during wear, the traction part 12 can be considered as a closed structure, with the internal cavity structure not connected to the outside. The gas or gas-liquid mixture inside the traction part 12 can improve its resistance to deformation.
[0083] In another scenario, the receiving slot 13 serves as an opening structure connecting the interior and exterior of the traction unit 12. This opening structure on the traction unit 12 can be achieved by importing patient dental model data into the system during the orthodontic appliance manufacturing process to generate a tooth model for each step. The system then places a virtual traction unit on the corresponding tooth model at each step according to the medical treatment plan. During placement, the bottom surface of the traction unit 12 contacts and fuses with the tooth surface or gingiva, and the opening direction is set towards the first direction X or the opposite direction of the first direction X. After obtaining the orthodontic appliance shape by 3D printing a tooth model and pressing a diaphragm onto a solid tooth model, the opening structure is obtained through a cutting process. Preferably, the opening structure is an arc-shaped opening to reduce stress concentration during traction, which can lead to deformation of the traction unit 12. Alternatively, during the orthodontic appliance manufacturing process, patient dental model data can be imported into the system to generate a tooth model for each step. The system then places the traction unit 12 on the tooth model at each step according to the medical treatment plan. The placement position and orientation of the traction unit 12 can differ in each step. During placement, the base of the traction unit 12 contacts the center of the tooth surface, with the opening facing either the first direction X or the opposite direction of the first direction X. After obtaining the shape of the orthodontic appliance through 3D printing and molding, the opening structure is obtained through a cutting process. Preferably, the opening structure is an arc-shaped opening to reduce the problem of stress concentration during traction that could lead to deformation of the traction unit 12.
[0084] In some embodiments, the traction unit 12 is located on the labial / buccal or lingual side of the tooth receiving cavity 11. The tooth receiving cavity 11 encloses the crown portion of the tooth, and the location of the traction unit 12 on the labial / buccal or lingual side of the tooth receiving cavity 11 can adapt to different orthodontic needs, such as Class II traction, Class III traction, or vertical traction. (Reference) Figure 15 As shown, Figure 15 The image shows one embodiment where the traction unit 12 is located on the labial side of the tooth receiving cavity 11. Alternatively, the traction unit 12 can also be used for tooth intrusion, in which case a greater extension length is required. The labial / buccal or lingual side of the tooth receiving cavity 11 can extend to cover the gingiva. The traction unit 12 is positioned corresponding to the gingiva, and the receiving groove 13 is positioned away from the tooth. The advantage of this configuration is that it does not affect the crown's containment force on the tooth, especially when the crown cavity requiring the tooth receiving cavity needs to apply force to the tooth for alignment. Furthermore, positioning the traction unit 12 corresponding to the gingiva in cases requiring anchorage can effectively improve the anchorage effect without affecting the orthodontic effect of the shell-shaped dental instrument itself.
[0085] In other embodiments, reference is made to Figure 1As shown, when the shell-shaped body is worn on the maxillary dentition, the shell-shaped body also includes a palatal support portion 14 spanning the palate. The palatal support portion 14 is connected to the tooth receiving cavities 11 on the left and right sides, wherein the traction portion 12 is located on the palatal support portion 14. Furthermore, through extensive research, the inventors of this application have discovered that when the traction portion 12 is positioned on the palatal support portion 14, in order to meet the traction force requirements and facilitate manufacturing, the length of the traction portion 12 in the second direction Z is greater than or equal to 1 mm and less than or equal to 10 mm. Also, the length of the traction portion 12 in the first direction X is at least twice the length in the second direction Z. The need to place the traction portion 12 on the palatal side generally arises when the orthodontic force or anchorage requirement is relatively high. A larger traction portion 12 can further provide stronger traction force, meeting different traction force requirements and situations.
[0086] Further reference Figure 16 As shown, multiple tooth receiving cavities 11 are used to enclose multiple teeth in the anterior region. The palatal bearing portion 14 is connected to the lingual edge of each of the multiple tooth receiving cavities 11. This implementation can bind the teeth in the anterior region as a whole through multiple tooth receiving cavities 11. It can be used to apply force to all the enclosed teeth in the anterior region as a whole through the traction portion 12, or sometimes the enclosed teeth in the anterior region as a whole serve as anchorage, with the traction portion 12 serving as the anchorage point. For example, this implementation can replace the need for anchorage screws in the palate. The traction portion 12 replaces the anchorage screws for maxillary anterior tooth retraction, which is a common clinical technique in orthodontics, especially in cases involving tooth extraction. In this case, the traction portion 12 can be connected to the traction device on the teeth in the posterior region through a traction element to apply a force to move the maxillary anterior teeth distally. To make the anterior teeth retraction more stable, refer to... Figure 17 As shown, the palatal support portion 14 can be provided with multiple traction portions 12, which are symmetrically arranged about the dental midline. The traction portions 12 on both sides of the dental midline are respectively connected to the traction devices on the corresponding posterior teeth, providing a stable and reliable traction force for anterior tooth retraction. More preferably, in order to provide sufficient accommodating space for the traction member on the traction portion 12, the protrusion height of the traction portion 12 towards the lingual side exceeds the incisal edge of the anterior teeth, but the protrusion height of the traction portion 12 towards the lingual side should not affect the occlusal relationship of the maxilla and mandible when it is set.
[0087] In another implementation, refer to Figure 18As shown, the multiple tooth receiving cavities 11 in the shell-shaped dental instrument 1 include a first tooth receiving portion 111 for wrapping multiple teeth in the left posterior region and a second tooth receiving portion 112 for wrapping multiple teeth in the right posterior region. The palatal support portion 14 is connected to the lingual edge of the first tooth receiving portion 111 and the lingual edge of the second tooth receiving portion 112, respectively. In this case, the first tooth receiving portion 111 and the second tooth receiving portion 112 are only used to wrap the teeth in the patient's maxillary posterior region, and the support portion is also correspondingly located in the posterior region. This embodiment can bind the teeth in the posterior region as a whole through the first tooth receiving portion 111 and the second tooth receiving portion 112. It can be used to apply force to all the wrapped teeth in the posterior region as a whole through the traction portion 12, or to use the wrapped teeth in the posterior region as a support, with the traction portion 12 being the support point.
[0088] Further, refer to Figure 19 As shown, the multiple tooth receiving cavities 11 in the shell-shaped dental instrument 1 also include a third tooth receiving portion 113 for enclosing multiple teeth in the anterior region. The third tooth receiving portion 113 is respectively connected to the first tooth receiving portion 111 and the second tooth receiving portion 112. In this case, the shell-shaped dental instrument 1 can enclose all or part of the teeth in the maxilla. The multiple tooth receiving cavities 11 can apply orthodontic force to the teeth through elastic deformation. Furthermore, the palatal support portion 14 can be set in different positions according to different orthodontic needs. It can be connected only to the lingual edge of the first tooth receiving portion 111 and the second tooth receiving portion 112, or it can be connected to the lingual edge of the first tooth receiving portion 111, the second tooth receiving portion 112 and the third tooth receiving portion 113, or it can be connected only to the lingual edge of the third tooth receiving portion 113. Further details are omitted here.
[0089] In other embodiments, continue to refer to Figure 19 As shown, the palatal support portion 14 is provided with multiple traction portions 12, which are arranged sequentially along the sagittal direction. Alternatively, the palatal support portion 14 may have only one traction portion 12, with its long axis arranged along the sagittal direction. This configuration is primarily for orthodontic treatments requiring sagittal traction force. When multiple traction portions 12 are arranged sequentially along the sagittal direction, the physician can attach traction devices to different traction portions 12 according to different treatment needs. Alternatively, to achieve greater traction, traction devices can be attached to multiple traction portions 12 simultaneously.
[0090] Example 2
[0091] This embodiment provides a method for designing digital dental models, referring to... Figure 20 As shown, the specific steps are as follows:
[0092] Step 101: Obtain the basic digital dental model and treatment plan;
[0093] Generally, a 3D model of the patient's current tooth layout is obtained from intraoral scan data or a plaster cast. This 3D model is then adjusted according to the orthodontic plan to obtain a basic digital dental model. In other words, the basic digital dental model corresponds to the tooth layout at the stage of the treatment plan. Of course, in some cases, tooth alignment is not required using shell-type dental instruments, and the basic digital dental model can still correspond to the patient's current tooth layout.
[0094] Step 102: Obtain the placement position of the digital traction unit according to the treatment plan, and determine the morphological data of the digital traction unit according to the placement position.
[0095] The placement of the digital traction device is determined according to the treatment plan. The digital traction device can be placed on the labial or buccal side or lingual side of the teeth on the basic digital dental model, or at the gingiva on the labial or buccal side of the basic digital dental model. In some cases, the digital traction device can be placed on the palate of the basic digital dental model according to the treatment plan. In this case, palate data of the patient's mouth needs to be obtained in the early model acquisition process. If the basic digital dental model corresponds to the tooth layout under the stage goal, the palate model on the basic digital dental model needs to be obtained by performing deformation equations based on the initially obtained palate model. Only in this way can the palate model on the basic digital dental model better fit the patient's intraoral condition.
[0096] In addition, determining the morphological data of the digital traction unit based on the placement location includes: selecting a corresponding basic digital traction unit from the model library based on the placement location, and adjusting the morphological data of the basic digital traction unit according to one or more of the placement surface size, adjacent tooth spacing, and occlusal alignment at the placement location. In one embodiment, the model library contains two different basic digital traction units: one for placement on the tooth surface or gum line, and the other for placement on the palate. Furthermore, the two different basic digital traction units have different sizes; the basic digital traction unit for palate placement is larger to accommodate the palate's need for greater traction or support. Figure 21As shown in the figure, the virtual model 100 of the basic digital traction unit is shown. Different types of basic digital traction units have the same structural form, only differing in size. Specifically, the length of the first cross-section of the basic digital traction unit in the first direction is greater than its length in the second direction. The first direction is the direction of the long axis of the basic digital traction unit. The first direction and the second direction are perpendicular to each other, and the first direction and the second direction are located on the first cross-section.
[0097] After determining the corresponding basic digital traction unit based on its placement location, the morphological data of the basic digital traction unit is adjusted according to one or more of the following: the size of the placement surface at the placement location, the distance between adjacent teeth, and the occlusal alignment. This mainly includes scaling the basic digital traction unit according to one or more of the above conditions to ensure that it does not collide with adjacent or opposing teeth at the placement location. After determining the scaling ratio, the digital traction unit is generated. It is conceivable that adjusting the morphological data of the basic digital traction unit can be done not only by adjusting the ratio but also by adjusting the overall shape of the basic digital traction unit. However, the adjusted digital traction unit needs to satisfy the requirement that the maximum length of its first cross-section in the first direction is greater than its maximum length in the second direction. Furthermore, adjusting the morphological data also includes adjusting the orientation of the digital traction unit so that its first direction is consistent with the traction direction.
[0098] Furthermore, the design of the receiving slot can be adjusted based on its shape. Specifically, when the receiving slot of the traction unit on a shell-shaped dental instrument is formed by a partial recess of the traction unit's side surface into the traction unit, a basic digital traction unit with a digital receiving slot should be selected. The digital receiving slot should be positioned on the basic digital traction unit facing either the first direction or the opposite direction. Conversely, when the receiving slot of the traction unit on a shell-shaped dental instrument is an opening structure connecting the interior and exterior of the traction unit, a basic digital traction unit without a digital receiving slot can be selected. The receiving slot can be obtained through cutting during subsequent shell-shaped dental instrument manufacturing.
[0099] Step 103: Merge the determined digital traction unit and the basic digital dental model to generate a digital dental model with the traction unit. This is done by merging the basic digital dental model and the digital traction unit using Boolean operations, referring to... Figure 22 As shown in the figure, the virtual model 200 is a digital dental model with a traction device. The acquisition process is simple and direct, and a composite model of the digital dental model and the digital traction device can be obtained quickly.
[0100] Furthermore, to facilitate better demolding during the subsequent hot-press molding process when producing shell-shaped dental instruments, a virtual weak connection structure is generated at the junction of the digital traction unit and the basic digital dental model. When printing the digital dental model with the traction unit using additive manufacturing, the weak connection structure is printed simultaneously. After the hot-press molding and cutting processes are completed, the weak connection structure breaks during the mold-opening process, separating the solid structure of the traction unit from the solid structure of the dental model, thus avoiding the problem of difficult demolding.
[0101] Example 3
[0102] This embodiment provides a method for generating a shell-shaped dental instrument. In some embodiments, a physical model of the digital dental model obtained by the design method of the digital dental model described in Embodiment 2 is manufactured using additive manufacturing. Additive manufacturing, also known as 3D printing, integrates computer-aided design, material processing and forming technology, and uses a digital model file as a basis. Through software and a numerical control system, specialized metallic materials, non-metallic materials, and medical biomaterials are layered and deposited using methods such as extrusion, sintering, melting, light curing, and spraying to create a physical object. Then, a shell-shaped dental instrument is manufactured using a thermoforming method based on the physical model.
[0103] In other embodiments, the digital dental model obtained according to the digital dental model design method described in Example 2 generates a digital model of a shell-shaped dental instrument. The digital model of the shell-shaped dental instrument is a negative mold of the digital dental model and has a certain thickness, generally between 0.5mm and 1.5mm. Then, the shell-shaped dental instrument is manufactured using additive manufacturing based on the digital model of the shell-shaped dental instrument.
[0104] It is worth mentioning that all modules involved in this embodiment are logical modules. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this invention, this embodiment does not introduce units that are not closely related to solving the technical problem proposed by this invention; however, this does not mean that other units are absent from this embodiment.
[0105] One embodiment of the present invention relates to an electronic device, such as... Figure 23 As shown, it includes at least one processor 1101; and,
[0106] A memory 1102 is communicatively connected to the at least one processor 1101; wherein,
[0107] The memory 1102 stores instructions that can be executed by the at least one processor 1101, which enable the at least one processor 1101 to execute a design method for a digital dental model or a method for generating a shell-shaped dental instrument.
[0108] 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.
[0109] 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.
[0110] One embodiment of the present invention relates to a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the method embodiments described above.
[0111] 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 the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.
[0112] It should be noted that the above embodiments can be freely combined as needed to form different new implementation schemes without causing contradictions. All implementation schemes formed by such combinations are within the protection scope of this invention. In order to save space in the application text, they will not be described in detail here.
[0113] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
[0114] Similarly, the above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A shell-shaped dental instrument, characterized in that, The device includes a shell-shaped body with multiple tooth-receiving cavities. A portion of the shell-shaped body has a traction part that suspends a traction member protruding outward. The traction part is integrally formed with the shell-shaped body and has a hollow structure. The side surface of the traction part has a receiving groove for accommodating the traction member. The receiving groove is used for detachable connection with the traction member. The maximum length of any first cross-section of the traction part in a first direction is greater than the maximum length in a second direction. The first direction is the direction of the long axis of the traction part. The first direction and the second direction are perpendicular to each other. Furthermore, the first direction and the second direction are located on the first cross-section. The receiving groove is oriented towards the first direction or the opposite direction of the first direction.
2. The shell-shaped dental instrument according to claim 1, characterized in that, The maximum length of the traction part in the first direction is at least twice the maximum length of the traction part in the second direction.
3. The shell-shaped dental instrument according to claim 1, characterized in that, The width of the first cross section in the second direction increases and then decreases from the first end of the traction portion to the second end of the traction portion, and the first cross section is closer to the first end at the point where its width is greatest in the second direction, wherein the first end and the second end are the two ends of the first cross section along the first direction.
4. The shell-shaped dental instrument according to claim 3, characterized in that, The side surface of the first end on the traction part is a first side surface, and the side surface of the second end on the traction part is a second side surface. The first side surface and the second side surface are arranged opposite to each other, wherein the receiving groove is located on the second side surface.
5. The shell-shaped dental instrument according to claim 1, characterized in that, The length of the traction part in the first direction gradually decreases from the end adjacent to the shell-shaped body to the end away from the shell-shaped body.
6. The shell-shaped dental instrument according to claim 5, characterized in that, The longitudinal section of the traction part is semi-circular, semi-elliptical, or shark fin shaped.
7. The shell-shaped dental instrument according to claim 1 or 5, characterized in that, The length of the traction part in the second direction gradually decreases from the end adjacent to the shell-shaped body to the end away from the shell-shaped body.
8. The shell-shaped dental instrument according to claim 1, characterized in that, The area of the first cross section gradually decreases from the end adjacent to the shell-like body to the end away from the shell-like body.
9. The shell-shaped dental instrument according to claim 1, characterized in that, The receiving groove is formed by a portion of the side surface of the traction part being recessed into the traction part, or the receiving groove is an opening structure that connects the interior of the traction part with the exterior.
10. The shell-shaped dental instrument according to claim 1, characterized in that, The traction unit is located on the labial or buccal side or lingual side of the tooth receiving cavity.
11. The shell-shaped dental instrument according to claim 10, characterized in that, When the tooth receiving cavity extends to cover the gums, the traction part is provided at the gums.
12. The shell-shaped dental instrument according to any one of claims 1-6, characterized in that, When the shell-shaped body is used to be worn on the maxillary dentition, the shell-shaped body also includes a palatal support portion that spans the palatal palate and is connected to the tooth receiving cavities on the left and right sides, wherein the traction portion is located on the palatal support portion.
13. The shell-shaped dental instrument according to claim 12, characterized in that, The length of the traction part in the second direction is greater than or equal to 1 mm and less than or equal to 10 mm.
14. The shell-shaped dental instrument according to claim 12, characterized in that, The plurality of said tooth receiving cavities are used to enclose the plurality of teeth in the anterior tooth region, and the palatal bearing portion is connected to the lingual edge of the plurality of said tooth receiving cavities respectively.
15. The shell-shaped dental instrument according to claim 14, characterized in that, The traction part extends beyond the lingual side of the anterior teeth.
16. The shell-shaped dental instrument according to claim 12, characterized in that, The plurality of tooth receiving cavities include a first tooth receiving portion for receiving a plurality of teeth in the left posterior region and a second tooth receiving portion for receiving a plurality of teeth in the right posterior region, wherein the palatal bearing portion is connected to the lingual edge of the first tooth receiving portion and the lingual edge of the second tooth receiving portion, respectively.
17. The shell-shaped dental instrument according to claim 16, characterized in that, The plurality of tooth receiving cavities also include a third tooth receiving portion for enclosing the plurality of teeth in the anterior region, the third tooth receiving portion being connected to the first tooth receiving portion and the second tooth receiving portion respectively.
18. The shell-shaped dental instrument according to claim 17, characterized in that, The palatal support portion is connected to the lingual edge of the third tooth receiving portion.
19. The shell-shaped dental instrument according to claim 12, characterized in that, The palatal support portion is provided with a plurality of traction portions, which are arranged sequentially along the sagittal direction; or, the palatal support portion is provided with a single traction portion, the long axis of which is arranged along the sagittal direction.
20. A method for designing a digital dental model, characterized in that: Obtain a basic digital dental and jaw model and a treatment plan; The placement position of the digital traction unit is obtained according to the treatment plan, and the morphological data of the digital traction unit is determined according to the placement position; The merged digital traction unit and the basic digital dental model are used to generate a digital dental model with the traction unit.
21. The method for designing a digital dental model according to claim 20, characterized in that, Determining the morphological data of the digital traction unit based on the placement position includes: Based on the placement location, select the corresponding basic digital traction unit from the model library, and adjust the morphological data of the basic digital traction unit according to one or more of the placement surface size, adjacent tooth spacing, and occlusal connection status at the placement location.
22. The method for designing a digital dental model according to claim 21, characterized in that, The maximum length of the first cross section of the basic digital traction unit in the first direction is greater than the maximum length in the second direction. The first direction is the direction of the long axis of the basic digital traction unit. The first direction and the second direction are perpendicular to each other. Furthermore, the first direction and the second direction are located on the first cross section.
23. The method for designing a digital dental model according to claim 22, characterized in that, The basic digital traction unit also has a digital receiving slot, and the digital receiving slot is arranged facing the first direction or the opposite direction of the first direction.
24. The method for designing a digital dental model according to claim 20, characterized in that, The placement locations include the labial and buccal sides of the dental model, the lingual side of the dental model, and the palatal region.
25. The method for designing a digital dental model according to claim 21, characterized in that, The morphological data includes the scaling ratio and orientation of the digital traction unit.
26. The method for designing a digital dental model according to claim 20, characterized in that, A virtual weak connection structure is generated at the connection point between the digital traction unit and the basic digital dental model.
27. A method for manufacturing a shell-shaped dental instrument, characterized in that, A physical model of the digital dental model obtained by the design method of the digital dental model according to any one of claims 20-26 is manufactured using additive manufacturing. The shell-shaped dental instrument is then manufactured using a hot-pressing method based on the physical model. Alternatively, a digital model of the shell-shaped dental instrument is generated from the digital dental model obtained by the design method of the digital dental model according to any one of claims 20-25. The shell-shaped dental instrument is then manufactured using additive manufacturing based on the digital model of the shell-shaped dental instrument.