Dental correction system and design method thereof

Abstract

The invention discloses a dental orthodontic system which comprises N shell-shaped orthodontic appliance groups, the first shell-shaped orthodontic appliance group in the N shell-shaped orthodontic appliance groups comprises a plurality of shell-shaped orthodontic appliances corresponding to a plurality of orthodontic steps with the previous orthodontic sequence in a series of orthodontic steps designed based on gradually moving a first dentition layout to a second dentition layout, the ith shell-shaped appliance group comprises a plurality of shell-shaped appliances corresponding to a plurality of correction steps with the previous correction sequence in a series of correction steps designed by gradually moving the actual tooth layout to the second dentition layout when the (i-1) th shell-shaped appliance is worn, and i is greater than or equal to 2 and less than or equal to N; according to the dental correction system, the problem of wearing discomfort caused by insufficient expression rate in the correction process can be solved in time, and correspondingly, the invention further discloses a design method of the dental correction system.

Description

Technical Field

[0001] The present invention relates to the technical field of dental orthodontics, and in particular to a dental correction system and a design method thereof. Background Art

[0002] In recent years, in the field of dental orthodontics, shell-shaped dental appliances using bracketless invisible orthodontic technology have become increasingly popular due to their advantages of beauty and convenience when worn. Bracketless invisible orthodontic technology is that patients wear a series of transparent shell orthodontic appliances to move their teeth from the initial position to the target position.

[0003] In existing correction schemes, the patient's teeth are first scanned to obtain the patient's initial tooth state; then, based on the initial tooth state, a series of digital jaw models representing the corrected tooth state are generated through virtual correction design; and based on the digital jaw model, a series of tooth models representing the corrected tooth state are first manufactured using a rapid prototyping method, and finally a corresponding series of shell-shaped appliances are manufactured based on the series of tooth models. Generally speaking, each correction step can correspond to a pair of shell-shaped appliances, and a pair of shell-shaped appliances can be used to wear for about two weeks.

[0004] However, the correction ability of the dental appliance in each correction step is often weakened after the patient wears it for a certain period of time due to the influence of its structure and material, or the force generated by the interaction with the teeth. For example, the elastic stress of a shell-shaped appliance may weaken after one week of use. Therefore, in the later stage of each correction step of the patient wearing the shell-shaped appliance, the tooth movement often cannot achieve the pre-designed result. In addition, based on the accumulation of deviations in the correction process, the deviation of the correction result will gradually increase. This increase in deviation is bound to gradually cause discomfort when wearing subsequent appliances, and may even cause pain to the patient and make the subsequent appliances incapable of being worn, so that the original design has to be readjusted, resulting in a huge waste of manpower and materials caused by appliances that cannot be worn. Summary of the invention

[0005] The main purpose of the present invention is to propose a dental correction system and a design method thereof, aiming to avoid the problem that the correction schemes in the prior art are directly based on the first dentition layout and the second dentition layout to obtain a series of shell-shaped orthodontic appliances for correction. During the correction process, the subsequent shell-shaped orthodontic appliances may be uncomfortable to wear or even cannot be worn due to the accumulation of deviations between the actual layout and the target layout of each correction step, resulting in a waste of manpower and materials.

[0006] To achieve the above object, an embodiment of the present invention provides a dental orthodontic system, which includes N groups of shell-shaped orthodontic appliances. The first group of shell-shaped orthodontic appliances in the N groups of shell-shaped orthodontic appliances includes a plurality of shell-shaped orthodontic appliances corresponding to several orthodontic steps with earlier orthodontic sequences in a series of orthodontic steps designed for gradually moving the first dental arch layout to the second dental arch layout. The i-th group of shell-shaped orthodontic appliances includes a plurality of shell-shaped orthodontic appliances corresponding to several orthodontic steps with earlier orthodontic sequences in a series of orthodontic steps designed for gradually moving the actual tooth layout at the end of wearing the (i - 1)-th shell-shaped orthodontic appliance to the second dental arch layout, where 2 ≤ i ≤ N.

[0007] Optionally, the N groups of shell-shaped orthodontic appliances are used to gradually move the patient's dental arch from the first dental arch layout to the second dental arch layout, and adjacent groups of shell-shaped orthodontic appliances correspond to consecutive orthodontic stages.

[0008] Optionally, the number of orthodontic appliances included in each group of shell-shaped orthodontic appliances in the N groups of shell-shaped orthodontic appliances is 5 to 15.

[0009] Optionally, the number of orthodontic appliances in each group of shell-shaped orthodontic appliances is the same.

[0010] Optionally, the number of orthodontic appliances in each group of shell-shaped orthodontic appliances is determined based on the tooth movement methods designed for each tooth to be moved in the corresponding orthodontic stage.

[0011] Optionally, the number of orthodontic appliances in different groups of shell-shaped orthodontic appliances with the same tooth movement method for each tooth to be moved is the same.

[0012] Optionally, the number of orthodontic appliances in different groups of shell-shaped orthodontic appliances with the same key tooth movement method for each tooth to be moved is the same.

[0013] Optionally, the number of orthodontic appliances in different groups of shell-shaped orthodontic appliances with the same tooth movement method for each characteristic tooth is the same.

[0014] Optionally, the number of orthodontic appliances in different groups of shell-shaped orthodontic appliances with the same key tooth movement method for each characteristic tooth is the same.

[0015] Optionally, the number of orthodontic appliances in the i-th group of shell-shaped orthodontic appliances changes according to the wearing result of the (i - 1)-th group of shell-shaped orthodontic appliances.

[0016] Optionally, the number of orthodontic appliances in the i-th group of shell-shaped orthodontic appliances decreases as the deviation between the actual tooth layout and the target tooth layout at the end of wearing the (i - 1)-th group of shell-shaped orthodontic appliances increases.

[0017] Optionally, when the deviation between the actual layout and the target layout at the end of wearing the (i - 1)-th group of shell-shaped orthodontic appliances is greater than a second set threshold, the number of orthodontic appliances in the i-th group of shell-shaped orthodontic appliances is reduced by a first preset amount, and the first preset amount is 1 to 3.

[0018] Optionally, when the deviation between the actual tooth layout at the end of wearing the (i - 1)-th shell orthodontic appliance group and the target tooth layout is less than a second set threshold, the number of orthodontic appliances in the i-th shell orthodontic appliance group is increased by a second preset amount, and the second preset amount is 1 to 3.

[0019] Optionally, the difference in the number of orthodontic appliances included in adjacent shell orthodontic appliance groups is less than or equal to 3.

[0020] Optionally, the number of orthodontic appliances in each shell orthodontic appliance group is determined based on the ideal orthodontic steps for achieving a preset achievement rate for different tooth movement methods of each tooth to be moved, and the ideal orthodontic steps are obtained by statistically analyzing the expression rates of different tooth movement methods of different teeth.

[0021] Optionally, the expression rate is statistically obtained from one or a combination of the following information: clinical data, literature research data, and simulation result data of finite element model simulation of long-term tooth movement.

[0022] Optionally, the number of orthodontic appliances in each shell orthodontic appliance group is determined based on the evaluation result of the intermaxillary occlusion condition of the target dental arch digital model corresponding to each orthodontic step, and / or based on the evaluation result of the simulation of wearing the corresponding digital orthodontic appliance for the target dental arch digital model corresponding to each orthodontic step.

[0023] Optionally, the elasticity of the shell orthodontic appliances within each shell orthodontic appliance group is consistent.

[0024] Optionally, the elasticity of the shell orthodontic appliances between each shell orthodontic appliance group gradually decreases with the order of the orthodontic stages.

[0025] Optionally, the elasticity of the shell orthodontic appliances between each shell orthodontic appliance group gradually increases with the order of the orthodontic stages.

[0026] To achieve the above object, the present invention also provides a design method for a dental orthodontic system, including the following steps:

[0027] Step S1, obtaining a first dental arch digital model and a second tooth alignment, and forming a series of target dental arch digital models based on the first dental arch digital model and the second tooth alignment, where the series of target dental arch digital models correspond to a series of tooth orthodontic states that gradually progress the patient's teeth from the tooth alignment corresponding to the first dental arch digital model to the second tooth alignment;

[0028] Step S2, selecting the target dental arch digital models corresponding to several consecutive orthodontic steps with a previous orthodontic order in the series of target dental arch digital models as a first series of dental arch digital models, and obtaining a shell orthodontic appliance group including several shell orthodontic appliances based on the first series of dental arch digital models;

[0029] Step S3: Obtain a digital dental model representing the actual dental arch layout at the end of wearing the shell orthodontic appliance group as the first dental arch digital model, and return to Step S1 until the actual dental arch layout at the end of wearing the shell orthodontic appliance group is the same as the second dental arch layout.

[0030] Optionally, selecting the target dental arch digital models corresponding to several consecutive orthodontic steps with a prior orthodontic sequence in the series of target dental arch digital models as the first series of dental arch digital models includes:

[0031] Obtain the expression rates of different tooth movement modes of each tooth at different orthodontic steps through statistics;

[0032] Based on the expression rates, determine the ideal orthodontic steps for various tooth movement modes of each tooth to reach a preset achievement rate;

[0033] Based on the ideal orthodontic steps of each tooth, select several target dental arch digital models with a prior orthodontic sequence according to each tooth to be moved in the series of target dental arch digital models as the first series of dental arch digital models.

[0034] Optionally, the step of selecting several target dental arch digital models with a prior orthodontic sequence according to each tooth to be moved in the series of target dental arch digital models as the first series of dental arch digital models based on the ideal orthodontic steps of each tooth includes:

[0035] Determine the ideal orthodontic steps of different tooth movement modes of each tooth to be moved;

[0036] Select the minimum ideal orthodontic step among the ideal orthodontic steps of different tooth movement modes of each tooth to be moved as the ideal orthodontic step of the current tooth to be moved;

[0037] Based on the ideal orthodontic steps of each tooth to be moved, determine the number of appliances in the current shell orthodontic appliance group, and thus select several target dental arch digital models with a prior orthodontic sequence as the first series of dental arch digital models.

[0038] Optionally, in the step of determining the number of appliances in the current shell orthodontic appliance group based on the ideal orthodontic steps of each tooth to be moved, select the minimum ideal orthodontic step among the ideal orthodontic steps of each tooth to be moved as the number of appliances in the current shell orthodontic appliance group.

[0039] Optionally, in the step of determining the number of appliances in the current shell orthodontic appliance group based on the ideal orthodontic steps of each tooth to be moved, determine the characteristic teeth among each tooth to be moved, determine the ideal orthodontic steps of the characteristic teeth, and use the ideal orthodontic steps of the characteristic teeth as the number of appliances in the current shell orthodontic appliance group.

[0040] Optionally, based on the ideal orthodontic treatment steps for each tooth, several target dental arch digital models with earlier treatment sequences are selected from the series of target dental arch digital models according to each tooth to be moved as the first series of dental arch digital models, including:

[0041] Determine the ideal orthodontic treatment steps for different movement modes of each tooth to be moved;

[0042] Calculate the mean or weighted average of the ideal orthodontic treatment steps for different movement modes of each tooth to be moved to obtain the average ideal orthodontic treatment steps, and based on the average ideal orthodontic treatment steps, select several target dental arch digital models with earlier treatment sequences from the series of target dental arch digital models as the first series of dental arch digital models.

[0043] Optionally, selecting several target dental arch digital models corresponding to consecutive treatment steps with earlier treatment sequences from the series of target dental arch digital models as the first series of dental arch digital models, including:

[0044] Evaluate the treatment status and / or treatment effect of each target dental arch digital model in the series of target dental arch digital models in sequence, and obtain the evaluation results of the treatment status and / or treatment effect of each target dental arch digital model;

[0045] If the evaluation result of the current target dental arch digital model does not meet the preset requirements, all target dental arch digital models corresponding to the treatment steps before the current target dental arch digital model are used as the first series of dental arch digital models.

[0046] Optionally, selecting several target dental arch digital models corresponding to consecutive treatment steps with earlier treatment sequences from the series of target dental arch digital models as the first series of dental arch digital models, including:

[0047] For the first orthodontic treatment stage, select several target dental arch digital models with earlier treatment sequences from the series of target dental arch digital models formed by the first dental arch digital model corresponding to the first dental arch layout and the second dental arch layout based on a preset value;

[0048] For the i-th orthodontic treatment stage, calculate the deviation between the actual tooth layout at the end of wearing the (i - 1)-th shell orthodontic appliance group and the target tooth layout;

[0049] Based on the comparison results of the deviation with the first set threshold and the second set threshold, adjust the preset number of orthodontic appliances in the i-th shell orthodontic appliance group;

[0050] Based on the adjustment result, select the corresponding number of target dental arch digital models with earlier treatment sequences from the series of target dental arch digital models as the first series of dental arch digital models.

[0051] Optionally, in the step of adjusting the preset number of appliances in the i-th shell-shaped appliance group based on the comparison results of the deviation with the first set threshold and the second set threshold, when the deviation between the actual tooth layout at the end of wearing the (i - 1)-th shell-shaped appliance group and the target tooth layout is greater than the second set threshold, the number of appliances in the i-th shell-shaped appliance group is reduced according to the first adjustment parameter.

[0052] Optionally, the first adjustment parameter is determined based on the relationship between the difference between the deviation between the actual tooth layout at the end of wearing the (i - 1)-th shell-shaped appliance group and the target tooth layout and the first set threshold and the reference threshold.

[0053] Optionally, in the step of adjusting the preset number of appliances in the i-th shell-shaped appliance group based on the comparison results of the deviation with the first set threshold and the second set threshold, when the deviation between the actual tooth layout at the end of wearing the (i - 1)-th shell-shaped appliance group and the target tooth layout is less than the second set threshold, the number of appliances in the i-th shell-shaped appliance group is increased according to the second adjustment parameter.

[0054] Optionally, the second adjustment parameter is determined based on the relationship between the difference between the deviation between the actual tooth layout at the end of wearing the (i - 1)-th shell-shaped appliance group and the target tooth layout and the second set threshold and the reference threshold.

[0055] Compared with the prior art, a dental orthodontic system and its design method of the present invention have the following beneficial effects:

[0056] 1. After each orthodontic treatment plan is designed, the present invention only selects several appliances with earlier orthodontic order in the orthodontic treatment plan as the current orthodontic stage. After the end of the current orthodontic stage, the orthodontic treatment plan is restarted with the actual tooth state in the current orthodontic stage and the second dentition layout, and several shell-shaped appliances corresponding to several orthodontic steps are designed and obtained according to the new orthodontic treatment plan to continue the orthodontic treatment, so as to avoid the problem in the prior art that a series of shell-shaped appliances for gradually moving the patient's teeth from the first dentition layout to the second dentition layout are directly manufactured, and during the orthodontic treatment process, due to the accumulation of deviations, the subsequent shell-shaped appliances may be uncomfortable to wear or even unable to be worn, resulting in waste of manpower and materials.

[0057] 2. For each orthodontic stage, the present invention obtains the ideal orthodontic steps for different tooth movement methods of each tooth to be moved to reach the preset achievement rate based on the expression rate obtained by statistics, and determines the number of appliances in the current orthodontic stage accordingly, making the design of the number of appliances in each shell-shaped appliance group more reasonable, making the expression rate of each orthodontic stage more in line with the design requirements, and improving the orthodontic efficiency of each orthodontic stage.

[0058] 3. Based on the evaluation of the orthodontic status and / or orthodontic effect of each target dental and maxillofacial digital model in a series of target dental and maxillofacial digital models corresponding to each orthodontic plan, the number of appliances in the shell-shaped appliance group corresponding to each orthodontic stage is determined according to the evaluation results, so that the shell-shaped appliances in each orthodontic stage better meet the design requirements, thereby improving the patient's comfort and orthodontic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] One or more embodiments are illustrated by way of example in the pictures in the corresponding drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0060] Figure 1 It is a system architecture diagram of a dental orthodontic system in an embodiment of the present application;

[0061] Figure 2 It is a schematic diagram corresponding to the i-th shell-shaped appliance group and the i-th target dental and maxillofacial digital model in an embodiment of the present application;

[0062] Figure 3 It is a step flowchart of a design method of a dental orthodontic system in another embodiment of the present application;

[0063] Figure 4a AND Figure 4b It is a schematic diagram for detecting intermaxillary collision in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0064] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present application, many technical details are presented for the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can still be implemented. The following division of each embodiment is for convenient description and should not constitute any limitation on the specific implementation manner of the present application. The various embodiments can be combined and cross-referenced with each other without contradiction.

[0065] To simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent their actual structures as products. Additionally, to simplify the drawings for better understanding, in some figures, components with the same structure or function are only schematically shown for one of them, or only one of them is labeled. In this document, "one" not only means "only this one" but also means "more than one" situation.

[0066] In each embodiment of the present application, the "anterior tooth area" and "posterior tooth area" are defined according to the classification of teeth on pages 36 - 38 of the second edition of Introduction to Stomatology published by Peking University Medical Press. The posterior tooth area includes premolars and molars, which are teeth numbered 4 - 8 in the FDI notation. The teeth in the anterior tooth area are those numbered 1 - 3 in the FDI notation, and the teeth in the anterior tooth area include central incisors, lateral incisors, and canines. Additionally, for teeth in the deciduous dentition stage, the "anterior tooth area" and "posterior tooth area" are defined according to the classification of deciduous teeth on pages 40 - 41 of the second edition of Introduction to Stomatology published by Peking University Medical Press, including three categories: deciduous incisors, deciduous canines, and deciduous molars. The anterior tooth area includes deciduous incisors and deciduous canines, among which the deciduous incisors include deciduous central incisors and deciduous lateral incisors, and the posterior tooth area includes deciduous molars, among which the deciduous molars include the first deciduous molar and the second deciduous molar.

[0067] In each embodiment of the present application, the "occlusal plane" is obtained according to the definition and confirmation method on page 83 of the sixth edition of Orthodontics. One way is the line connecting the occlusal midpoint of the first permanent molar and the midpoint between the upper and lower central incisors (at the 1 / 2 of overbite or open bite); another way is obtained by equally dividing the occlusal contact points of the posterior teeth, and usually the occlusal contact points of the first permanent molar and the first deciduous molar or the first premolar are used.

[0068] As can be seen from the background technology, current orthodontic treatment plans are to directly manufacture a series of shell - shaped orthodontic appliances for gradually moving the patient's teeth from the first dentition layout to the second dentition layout. Each shell - shaped orthodontic appliance corresponds to one orthodontic step and is usually worn for about two weeks. However, due to the influence of its structure and material, or the influence of the forces generated by the interaction with the teeth, the orthodontic ability of the orthodontic appliance for each orthodontic step often shows a phenomenon of orthodontic force attenuation after the patient wears it for a certain period. For example, after a shell - shaped orthodontic appliance is used for one week, its elastic stress may weaken. Therefore, in the later stage of each orthodontic step of wearing the shell - shaped orthodontic appliance, the tooth movement often cannot reach the pre - designed result. Moreover, due to the accumulation of deviations during the orthodontic process, the deviation of the orthodontic result gradually increases. This increase in deviation is bound to gradually cause discomfort during the wearing of subsequent orthodontic appliances, and may even cause pain to the patient and the inability to wear subsequent orthodontic appliances, thus having to readjust the original design, resulting in a great waste of manpower and materials caused by the unusable orthodontic appliances.

[0069] Based on this, the present invention provides a dental orthodontic system, comprising: N sets of shell-shaped orthodontic appliances, the N sets of shell-shaped orthodontic appliances being used to gradually move the patient's teeth from a first dentition layout to a second dentition layout. Among them, the first set of shell-shaped orthodontic appliances in the N sets of shell-shaped orthodontic appliances comprises a plurality of shell-shaped orthodontic appliances corresponding to several orthodontic steps with earlier orthodontic sequences in a series of orthodontic steps designed for gradually moving the first dentition layout to the second dentition layout. The i-th set of shell-shaped orthodontic appliances comprises a plurality of shell-shaped orthodontic appliances corresponding to several orthodontic steps with earlier orthodontic sequences in a series of orthodontic steps designed for gradually moving the actual tooth layout at the end of wearing the (i - 1)-th set of shell-shaped orthodontic appliances to the second dentition layout, where 2 ≤ i ≤ N. The present invention only selects several orthodontic steps with earlier orthodontic sequences in the orthodontic plan designed for gradually moving the first dentition layout to the second dentition layout to obtain the corresponding plurality of shell-shaped orthodontic appliances as the first set of shell-shaped orthodontic appliances, and then for each subsequent set of shell-shaped orthodontic appliances, a plurality of shell-shaped orthodontic appliances are obtained by selecting several orthodontic steps with earlier orthodontic sequences in each orthodontic plan designed based on the actual dentition layout of the previous set of shell-shaped orthodontic appliances and the second dentition layout as the current set of shell-shaped orthodontic appliances. That is to say, for each orthodontic plan, only several orthodontic steps with earlier orthodontic sequences are selected to obtain several orthodontic appliances for orthodontic treatment in the current orthodontic stage, so as to avoid excessive cumulative deviation during the orthodontic process. After the completion of the current orthodontic stage, a new orthodontic plan is restarted with the actual tooth state in the current orthodontic stage and the second dentition layout, and several shell-shaped orthodontic appliances corresponding to several orthodontic steps are designed and obtained according to the new orthodontic plan to continue the orthodontic treatment, thereby avoiding the problem in the prior art that due to directly manufacturing a series of shell-shaped orthodontic appliances for gradually moving the patient's teeth from the first dentition layout to the second dentition layout, the subsequent shell-shaped orthodontic appliances may be uncomfortable to wear or even unable to be worn during the orthodontic process due to deviation accumulation, resulting in waste of manpower and materials.

[0070] Next, specific implementation details of the dental orthodontic system described in this application will be specifically described in combination with specific embodiments. The following content is only implementation details provided for convenient understanding and is not necessary for implementing this solution.

[0071] An exemplary embodiment of the present application provides a dental orthodontic system, as Figure 1As shown, the dental orthodontic system includes N sets of shell-shaped orthodontic appliances 11 to 1N, and the N sets of shell-shaped orthodontic appliances 11 to 1N are used to gradually reposition the patient's teeth from the first dentition layout to the second dentition layout. The first dentition layout can be the initial dentition layout when the patient starts orthodontic treatment, or the dentition layout after orthodontic treatment for a period of time. The second dentition layout can be the final dentition layout of the patient's orthodontic treatment, or the stage dentition layout for a certain stage target of orthodontic treatment. In various embodiments of the present invention, each set of shell-shaped orthodontic appliances 11 to 1N corresponds to an orthodontic stage, and adjacent sets of shell-shaped orthodontic appliances 1i and 1(i + 1) correspond to consecutive orthodontic stages. For the first set of shell-shaped orthodontic appliances 11, it includes a plurality of shell-shaped orthodontic appliances corresponding to the plurality of orthodontic steps with earlier orthodontic sequences in a series of orthodontic steps designed based on gradually moving the first dentition layout to the second dentition layout. For each set of shell-shaped orthodontic appliances subsequent to the first set of shell-shaped orthodontic appliances 11, it includes a plurality of shell-shaped orthodontic appliances corresponding to the plurality of orthodontic steps with earlier orthodontic sequences in a series of orthodontic steps designed based on gradually moving the actual tooth layout at the end of wearing the previous adjacent orthodontic stage to the second dentition layout. For example, the i-th set of shell-shaped orthodontic appliances includes a plurality of shell-shaped orthodontic appliances corresponding to a number of orthodontic steps with earlier orthodontic sequences in a series of orthodontic steps designed based on gradually moving the actual tooth layout at the end of wearing the (i - 1)-th shell-shaped orthodontic appliance to the second dentition layout, where 2 ≤ i ≤ N. Specifically, each set of shell-shaped orthodontic appliances corresponds to an orthodontic plan (or orthodontic program), and each orthodontic plan corresponds to a type of target dental model group, such as Figure 2As shown, that is, the N shell-shaped appliance groups 11 to 1N correspond to the N target dental arch digital model groups 21 to 2N. Each target dental arch digital model group is designed to gradually reposition the patient's teeth from the actual dentition layout at the end of wearing the previous shell-shaped appliance group adjacent to the shell-shaped appliance group corresponding to the current target dental arch digital model group to the second dentition layout. That is, for the first type of target dental arch digital model group, since it is the initial stage of orthodontics and there is no adjacent previous shell-shaped appliance group for the corresponding shell-shaped appliance group, the first type of target dental arch digital model group is designed to gradually reposition the patient's teeth from the first dentition layout to the second dentition layout. That is to say, the first type of target dental arch digital model group 21 in the N target dental arch digital model groups 21 to 2N is designed to include a series of target dental arch digital models for gradually repositioning the patient's teeth from the first dentition layout to the second dentition layout. The jth type of target dental arch digital model group 2j in the N target dental arch digital model groups 21 to 2N is designed to include a series of target dental arch digital models for gradually repositioning the patient's teeth from the actual dentition layout at the end of wearing the (j - 1)th shell-shaped appliance group 1(j - 1) to the second dentition layout, where 2 ≤ j ≤ N. That is to say, the series of target dental arch digital models refer to computer digital data models for guiding the manufacture of tooth models. The obtained tooth models are three-dimensional models of tooth states (which can also be called tooth arrangements). The tooth orthodontic states include a series of corrected tooth states. Each tooth state corresponds to a tooth digital data model. Each tooth state includes the geometries of several teeth corresponding to one orthodontic step and the positional relationships between the teeth.

[0072] The ith shell-shaped appliance group 1i in the N shell-shaped appliance groups 11 to 1N includes several shell-shaped appliances obtained based on the m target dental arch digital models with earlier corresponding orthodontic sequences in the corresponding ith type of target dental arch digital model group 2i. Among them, 1 ≤ i ≤ N. The adjacent shell-shaped appliances in each shell-shaped appliance group correspond to consecutive orthodontic steps. The adjacent shell-shaped appliance groups in the N shell-shaped appliance groups 11 to 1N correspond to consecutive orthodontic stages. For example, the shell-shaped appliance group 1i and the shell-shaped appliance group 1(i + 1) are adjacent shell-shaped appliance groups and correspond to consecutive orthodontic stages. That is, the actual tooth layout at the end of wearing the shell-shaped appliance group 1i is the initial tooth layout for designing the shell-shaped appliance group 1(i + 1).

[0073] It can be seen that after wearing several shell-shaped appliances in each shell-shaped appliance group in the present application, the orthodontic treatment plan is restarted with the current actual dentition state and the second dentition layout, and the next shell-shaped appliance group including shell-shaped appliances corresponding to several treatment steps is designed and obtained according to the new orthodontic treatment plan to continue the orthodontic treatment, avoiding the problems of waste of manpower and materials caused by the discomfort or even inability to wear the subsequent shell-shaped appliances due to the accumulation of deviations during the orthodontic treatment process in the prior art, where a series of shell-shaped appliances are directly manufactured to gradually move the patient's teeth from the first dentition layout to the second dentition layout.

[0074] In some embodiments, the number m of shell-shaped appliances included in each shell-shaped appliance group 11-1N is determined by a doctor or a designer based on experience. Generally speaking, if the number of shell-shaped appliances included in each shell-shaped appliance group is too large, the accumulated deviation during the orthodontic treatment process may still be too large, causing discomfort to the patient and the inability to wear the subsequent orthodontic appliances. If the number of shell-shaped appliances included in each shell-shaped appliance group is too small, the restart of the orthodontic treatment plan is too frequent, and the patient needs to visit the doctor frequently and wait for the preparation of new orthodontic appliances, prolonging the orthodontic treatment cycle. Therefore, based on the experience of the doctor or the designer, the number m of shell-shaped appliances included in each shell-shaped appliance group is 5 to 15. For example, in some specific embodiments, the number of orthodontic appliances included in each shell-shaped appliance group is designed to be 10.

[0075] In some embodiments, for ease of design, each shell-shaped appliance group contains the same number of appliances. The number of appliances in each shell-shaped appliance group is preset based on the experience of doctors or designers. The term "same" means that the number of appliances in each shell-shaped appliance group is the same or substantially the same. "Substantially the same" means that the number of shell-shaped appliances in the first N - 1 shell-shaped appliance groups in the wearing order is the same, while the number of shell-shaped appliances in the Nth shell-shaped appliance group may be different from the number of shell-shaped appliances in each of the first N - 1 shell-shaped appliance groups. For example, in the Nth shell-shaped appliance group, since the actual tooth layout at the end of wearing the (N - 1)th shell-shaped appliance group is already close to the second dentition layout, only a smaller number of shell-shaped appliances may be required to gradually move the patient's teeth from the actual tooth layout at the end of wearing the (N - 1)th shell-shaped appliance group to the second dentition layout. Therefore, the number of appliances in the Nth shell-shaped appliance group is less than the number of appliances in the first N - 1 shell-shaped appliance groups. For example, the number of shell-shaped appliances in each of the first N - 1 shell-shaped appliance groups is 10, and the number of shell-shaped appliances in the last shell-shaped appliance group is 5. Or, it is determined that the number of shell-shaped appliances in the last shell-shaped appliance group is a few more than the number of appliances in each of the other shell-shaped appliance groups. For example, the number of shell-shaped appliances in each of the first N - 1 shell-shaped appliance groups is 10, and the number of shell-shaped appliances in the last shell-shaped appliance group is 13, that is, the number of appliances in the Nth shell-shaped appliance group is more than the number of appliances in the first N - 1 shell-shaped appliance groups.

[0076] Of course, in some other embodiments, in addition to the case where the number of appliances in the Nth shell-shaped appliance group is different from that in the first N - 1 shell-shaped appliance groups, the number of appliances in each of the first N - 1 shell-shaped appliance groups may not be exactly the same, that is, the number of appliances in at least two adjacent shell-shaped appliance groups among the first N - 1 shell-shaped appliance groups is different. For example, doctors or designers can design the number of appliances in the current shell-shaped appliance group according to needs. For example, if the number of appliances in the current shell-shaped appliance group is the same as that in the previous shell-shaped appliance group and it is not convenient to design the next shell-shaped appliance group when the patient finishes wearing the current shell-shaped appliance group, the number of appliances in the current shell-shaped appliance group can be adjusted according to the patient's time. In this way, doctors or designers can flexibly adjust the number of appliances in each shell-shaped appliance group according to the actual situation of the patient, which is more convenient for promoting the orthodontic process.

[0077] In some preferred embodiments, doctors or designers can also adjust the number of appliances in subsequent shell-shaped appliance groups according to the wearing results of the previous shell-shaped appliance group. For example, the number of appliances included in each shell-shaped appliance group can be initially set based on the experience of doctors or designers. The initial settings of the number of appliances included in each shell-shaped appliance group can be the same or different. For example, if each shell-shaped appliance group is initially set to include 10 appliances, then the first shell-shaped appliance group is designed to include 10 shell-shaped appliances, and the number of appliances in subsequent shell-shaped appliance groups can be determined according to the treatment results of the previous shell-shaped appliance group. For example, the number of appliances in the i-th shell-shaped appliance group changes with the treatment results of the (i - 1)-th shell-shaped appliance group. The treatment results mainly refer to the deviation between the actual layout of the patient's teeth at the end of wearing the (i - 1)-th shell-shaped appliance group and the designed target layout. Generally speaking, the greater the deviation, the less satisfactory the treatment result of the current shell-shaped appliance group and the lower the expression rate. This may be due to the excessive number of shell-shaped appliances included in the current shell-shaped appliance group, resulting in an excessive accumulated deviation. At this time, the number of appliances in the i-th shell-shaped appliance group can be considered to be reduced. If the deviation between the actual layout of the patient's teeth and the designed target layout at the end of wearing the (i - 1)-th shell-shaped appliance group is very small, it means that the expression rate of the current shell-shaped appliance is high. At this time, the number of appliances in the i-th shell-shaped appliance group can be considered to be increased to minimize the number of restarts of the treatment plan and improve the treatment efficiency. Among them, the increase or decrease in the number of appliances in the i-th shell-shaped appliance group can be determined by doctors or designers based on experience. For example, when the deviation between the actual layout of the patient's teeth and the designed target layout at the end of wearing the (i - 1)-th shell-shaped appliance group exceeds the expectation (which can be based on the experience of doctors or designers), the number of appliances in the i-th shell-shaped appliance group is reduced by a first preset amount. The first preset amount is 1 to 3. For example, the number of appliances in the i-th shell-shaped appliance group is reduced by 1. If the deviation between the actual layout of the patient's teeth and the designed target layout at the end of wearing the (i - 1)-th shell-shaped appliance group is very small and there is basically no deviation, the number of appliances in the i-th shell-shaped appliance group is increased by a second preset amount. The second preset amount is 1 to 3. For example, the number of appliances in the i-th shell-shaped appliance group is increased by 1.

[0078] Of course, generally speaking, the difference in the number of shell-shaped appliances included in adjacent shell-shaped appliance groups should preferably be less than or equal to 3, and the difference in the number of shell-shaped appliances included in all different shell-shaped appliance groups should also preferably be less than or equal to 5, so as to prevent the number of appliances in the adjusted shell-shaped appliance group from being too many or too few. If there are too many, the accumulated deviation during the treatment process may still be too large, causing discomfort to the patient and the inability to wear subsequent appliances. If there are too few, it will lead to too frequent restarts of the treatment plan.

[0079] In some other embodiments, in order to better achieve the predetermined target for the expression rate of each group of shell orthodontic appliances, the number of orthodontic appliances included in each group of shell orthodontic appliances can also be designed individually according to the experience of doctors or designers. For example, doctors or designers can design the number of orthodontic appliances included in each group of shell orthodontic appliances based on experience for the different movement modes of the teeth to be moved by each shell orthodontic appliance in each group of shell orthodontic appliances. Among them, the different movement modes of the teeth include: overall movement, rotation, torque, uprighting, extrusion and intrusion movement modes. In some embodiments, the shell orthodontic appliances in each group of shell orthodontic appliances are designed with a single movement mode. For example, for each tooth to be moved, there are three tooth movement modes: overall movement, rotation and extrusion. Each shell orthodontic appliance can be designed with a single movement mode. For example, first design the overall movement of the tooth. After the overall movement is completed, then design the rotation of the tooth. Finally, design the extrusion movement of the tooth. Generally, the tooth movement modes of the shell orthodontic appliances in the same group of shell orthodontic appliances are preferably the same. Of course, when designing the orthodontic treatment plan, if there are too few orthodontic treatment steps with the same movement mode in the current orthodontic treatment stage, the shell orthodontic appliances in the same group of shell orthodontic appliances can also have different movement modes. Since the expression rates of different tooth movement modes often vary, for the shell orthodontic appliances with a single tooth movement mode, the number of orthodontic appliances in different groups of shell orthodontic appliances with the same tooth movement mode is the same. For example, if the shell orthodontic appliances in the first group of shell orthodontic appliances and the second group of shell orthodontic appliances all have the same tooth movement mode, then the number of orthodontic appliances in the first group of shell orthodontic appliances and the second group of shell orthodontic appliances is the same. Another example is that assuming that the movement mode of the teeth to be moved by the shell orthodontic appliances in the first group of shell orthodontic appliances is the overall buccolingual movement, and the movement type of the teeth to be moved by the shell orthodontic appliances in the second group of shell orthodontic appliances is rotation, then based on the experience of doctors or designers, the number of orthodontic appliances in the first group of shell orthodontic appliances and the second group of shell orthodontic appliances is designed differently. For example, according to experience, the number of shell orthodontic appliances in the first group of shell orthodontic appliances is designed to be greater than the number of shell orthodontic appliances in the second group of shell orthodontic appliances. Of course, the achievement of the expression rate may also be related to the designed single-step movement amount. Therefore, in some preferred embodiments, it can be selected to make the number of orthodontic appliances in different groups of shell orthodontic appliances with the same tooth movement mode and the corresponding single-step movement amount the same.

[0080] In some other embodiments, the shell orthodontic appliances of each shell orthodontic appliance group can be designed to include a composite movement that combines multiple movement methods. The composite movement is designed to simultaneously perform multiple tooth movement methods on the teeth to be moved. For example, three tooth movement methods, namely overall movement, rotation, and elongation, are performed simultaneously. In this case, the number of orthodontic appliances in each shell orthodontic appliance group can be customized based on the movement methods included in the composite movement of each shell orthodontic appliance. In some examples, similarly, the number of orthodontic appliances in different shell orthodontic appliance groups with the same composite movement method for each tooth to be moved is the same. For example, if each shell orthodontic appliance in adjacent shell orthodontic appliance groups has the same composite movement method for each tooth to be moved, then the number of orthodontic appliances in these adjacent shell orthodontic appliance groups is the same. In some other examples, since each tooth to be moved has multiple different tooth movement methods and the expression rates of these multiple tooth movement methods vary in different orthodontic steps, key tooth movement methods can be determined among the multiple tooth movement methods. The number of orthodontic appliances in different shell orthodontic appliance groups with the same key tooth movement method for each tooth to be moved is the same. The key tooth movement method can be determined by a doctor or a designer based on experience, or it can be determined based on the statistical results of the expression rates of different tooth movement methods for the teeth in each tooth position, and the tooth movement method with a lower expression rate for each tooth to be moved is determined as its key tooth movement method. The present invention is not limited thereto.

[0081] During the orthodontic treatment process, there may also be some characteristic teeth. The expression rate of these characteristic teeth plays a crucial role in the comfort of wearing subsequent orthodontic appliances. Therefore, the number of orthodontic appliances in adjacent shell orthodontic appliance groups can be determined based on the tooth movement methods of the characteristic teeth. In some examples, a doctor or a designer can pre-determine the characteristic teeth. For example, for the mandibular dentition, the mandibular canine teeth (i.e., the teeth in the 33 or 43 tooth positions) and the mandibular first molar teeth (i.e., the teeth in the 36 or 46 tooth positions) are selected as characteristic teeth. The number of orthodontic appliances in different shell orthodontic appliance groups with the same tooth movement method for each key tooth is the same. Similarly, the number of orthodontic appliances in adjacent shell orthodontic appliance groups with the same key tooth movement method for each key tooth can also be designed to be the same.

[0082] Similarly, the achievement of the expression rate may also be related to the designed single-step movement amount. For the composite movement method, it can also be that the number of orthodontic appliances in adjacent shell orthodontic appliance groups with the same tooth movement method and the corresponding single-step movement amount is the same.

[0083] It can be seen that the present invention can customize the number of orthodontic appliances included in each shell orthodontic appliance group based on the different movement methods of each tooth to be moved or the different movement methods of each tooth to be moved and the corresponding single-step movement amounts, so that each shell orthodontic appliance group can better achieve its set expression rate and improve the orthodontic efficiency.

[0084] In some other embodiments, the number of appliances in each set of shell-shaped appliances can be determined not only by a doctor or a designer presetting it based on experience in advance, but also based on the ideal number of orthodontic steps to reach a preset achievement rate for different tooth movement modes of each tooth to be moved.

[0085] The preset achievement rate refers to the expected expression rate that a doctor or a designer hopes to achieve for each tooth movement mode, which can be a set value. The ideal number of orthodontic steps for different tooth movement modes of each tooth to be moved to reach the preset achievement rate can be obtained by statistically analyzing the expression rates of different movement modes of different teeth, that is, determining the ideal number of orthodontic steps for various movement modes of each tooth to reach the ideal expression rate based on the average value of the expression rates of different movement modes of each tooth at each orthodontic step obtained through statistics. Determining the number of appliances in each set of shell-shaped appliances based on the ideal number of orthodontic steps for various movement modes of each tooth to reach the ideal expression rate can make the number of appliances in each set of shell-shaped appliances more reasonable and improve the expression rate of each set of shell-shaped appliances.

[0086] In the present invention, the expression rate can be statistically obtained through one or a combination of the following information: clinical data, literature research data, and simulation result data of finite element model simulating long-term tooth movement.

[0087] Among them, clinical data can more widely reflect the actual situation of tooth orthodontics, and the obtained expression rate can better fit the clinical treatment of patients; literature research data can more prominently reflect orthodontic characteristics, making the expression rate more scientific and reasonable; simulation result data of finite element model simulating long-term tooth movement does not require data collection and is more convenient to implement.

[0088] In this way, statistically analyzing the expression rate through multiple methods is beneficial to providing accurate and objective data, and then determining an accurate and objective expression rate result.

[0089] In some examples, through clinical data research, data of male patients aged 18 to 35 with good periodontal conditions were collected as the statistical research objects. The average value of the expression rates (the percentage of the actual achieved orthodontic amount to the designed orthodontic amount) of the teeth of patients in each orthodontic step in 12 movement modes in 6 degrees of freedom (the positive direction of the tooth long axis, the negative direction of the tooth long axis, the positive direction of the labiolingual direction, the negative direction of the labiolingual direction, the positive direction of the mesiodistal direction, the negative direction of the mesiodistal direction, the rotational direction towards the mesial around the tooth long axis, the rotational direction towards the distal around the tooth long axis, the rotational direction towards the mesial around the labiolingual direction, the rotational direction towards the distal around the labiolingual direction, the rotational direction towards the labial around the mesiodistal direction, the rotational direction towards the lingual around the mesiodistal direction) was statistically analyzed. Based on the average value of the expression rates of different movement modes of each tooth in each orthodontic step, the ideal orthodontic steps for each tooth to achieve the preset achievement rate in various movement modes were determined. According to the ideal orthodontic steps for each tooth to achieve the preset achievement rate in various movement modes, the number of orthodontic appliances in each shell-shaped orthodontic appliance group was determined. For each tooth, the ideal orthodontic steps to achieve the preset achievement rate in various movement modes may not be the same. In this regard, in some preferred embodiments, the number of orthodontic appliances in the current shell-shaped orthodontic appliance group can be determined according to the smallest ideal orthodontic steps among the ideal orthodontic steps of different movement modes of all teeth. Generally speaking, the movement mode corresponding to the smallest ideal orthodontic steps means that the orthodontic difficulty of this movement mode is relatively large, and this movement mode can also be used as the key movement mode of the current tooth. If the smallest ideal orthodontic steps of different teeth are different, the minimum value of multiple smallest ideal orthodontic steps can be determined as the number of orthodontic appliances in the current shell-shaped orthodontic appliance group; in some other preferred embodiments, the average value or weighted average value of the ideal orthodontic steps of different movement modes of each tooth can also be calculated respectively to obtain the average ideal orthodontic steps, and the number of orthodontic appliances in the current shell-shaped orthodontic appliance group is determined based on this average ideal orthodontic steps.

[0090] In some other examples, the long-term movement of teeth can also be obtained through finite element simulation calculation, and the expression rates of different movement modes of a single tooth in each orthodontic step are obtained. Based on the expression rates of different movement modes of each tooth in each orthodontic step, the ideal orthodontic steps for each tooth to achieve the preset achievement rate in various movement modes are determined, so as to determine the number of orthodontic appliances in each shell-shaped orthodontic appliance group according to the ideal orthodontic steps for each tooth to achieve the preset achievement rate in various movement modes. Similarly, for the specific method of determining the number of orthodontic appliances in each shell-shaped orthodontic appliance group according to the ideal orthodontic steps for each tooth to achieve the preset achievement rate in various movement modes, reference can be made to the foregoing scheme, and details are not described herein again.

[0091] In some examples, through literature research, the expression rate of each orthodontic step can also be obtained for the situation where the patient mainly has a certain movement mode and the correction degree of other movement modes is relatively small. The ideal orthodontic steps for the key movement mode to reach the preset achievement rate are determined according to the corresponding expression rate, and then the number of orthodontic appliances in each shell-shaped orthodontic appliance group is determined according to the ideal orthodontic steps for each tooth to reach the preset achievement rate for various movement modes.

[0092] The orthodontic force applied by the orthodontic appliance to the patient's teeth is related to the elasticity of the shell-shaped orthodontic appliance. Generally speaking, during the orthodontic stage, the orthodontic force generated by the shell-shaped orthodontic appliance should not change. A change in the orthodontic force will make the patient feel uncomfortable and require readjustment to the new orthodontic force. Additionally, if the elasticity of the shell-shaped orthodontic appliance needs to be changed, it is necessary to replace the diaphragm used to prepare the shell-shaped orthodontic appliance, which also increases the complexity of orthodontic appliance preparation. Therefore, in some embodiments, for the convenience of orthodontic appliance preparation and the comfort of the patient during wearing, the elasticity of the shell-shaped orthodontic appliances in each shell-shaped orthodontic appliance group is the same. It should be noted that when preparing different shell-shaped orthodontic appliances, even if the same diaphragm is used, due to the influence of tooth morphology and preparation technology in different dental arch models, the elasticity of different shell-shaped orthodontic appliances cannot be exactly the same. Even for the same shell-shaped orthodontic appliance, the elasticity of different parts cannot be exactly the same. Therefore, when the present invention states that the elasticity of the shell-shaped orthodontic appliance is the same, it means that the elasticity of the diaphragm used to prepare the shell-shaped orthodontic appliance is the same.

[0093] Generally speaking, the orthodontic force generated by a shell orthodontic appliance with greater elasticity is weaker, and the patient feels more comfortable wearing it, but it may result in a lower expression rate. On the contrary, a shell orthodontic appliance with less elasticity generates a greater orthodontic force, reducing the comfort of the patient wearing it, but it may lead to a higher expression rate of the orthodontic result. Therefore, in some embodiments, considering that patients may not be able to adapt to a large orthodontic force at the beginning of orthodontics, the elasticity of the shell orthodontic appliances between each shell orthodontic appliance group gradually decreases with the orthodontic steps. That is, the orthodontic appliance worn by the patient in the initial orthodontic stage has greater elasticity and generates a smaller orthodontic force, making the patient feel more comfortable wearing it, easily adapting to the wearing of the orthodontic appliance, and facilitating the continuous progress of orthodontics. As the patient gradually adapts to the wearing of the orthodontic appliance, the elasticity of the shell orthodontic appliances in subsequent orthodontic stages gradually becomes smaller, and the generated orthodontic force gradually increases, thereby improving the comfort of the patient on the basis of ensuring the orthodontic efficiency. Of course, in some other embodiments, the elasticity of the shell orthodontic appliances between each shell orthodontic appliance group can also gradually increase with the orthodontic steps. That is, when the dental oral condition is good, a relatively large orthodontic force is applied to the patient's teeth at the initial wearing to ensure the orthodontic efficiency and increase the patient's confidence in orthodontics. In subsequent orthodontic stages, the elasticity of each shell orthodontic appliance can be gradually increased, that is, the orthodontic force is reduced, making the patient feel more comfortable wearing it. However, it should be noted that generally, the difference in the number of shell orthodontic appliances included in adjacent shell orthodontic appliance groups is less than or equal to 3, and the difference in the number of shell orthodontic appliances included in different shell orthodontic appliance groups is less than or equal to 5, so as to prevent the number of orthodontic appliances in the adjusted shell orthodontic appliance group from being too many or too few. If there are too many, the accumulated deviation during the orthodontic process may still be too large, causing discomfort to the patient and the inability to wear subsequent orthodontic appliances. If there are too few, it will lead to too frequent restart of the orthodontic plan.

[0094] It is worth mentioning that in order to ensure the convenience of preparation and the comfort of the patient wearing, although the elasticity between the shell orthodontic appliance groups is different, the elasticity of the orthodontic appliances within each shell orthodontic appliance group is preferably the same, so that the patient does not need to constantly adapt to the different orthodontic forces brought about by the different elasticity of the shell orthodontic appliances.

[0095] As Figure 3 shown, in some other embodiments of the present invention, a design method for a dental orthodontic system is further provided, including:

[0096] Step S1, obtaining a first dental arch digital model and a second dental arch layout, and forming a series of target dental arch digital models based on the first dental arch digital model and the second dental arch layout. The series of target dental arch digital models correspond to a series of orthodontic states in which the patient's teeth gradually progress from the dental arch layout corresponding to the first dental arch digital model to the second dental arch layout.

[0097] A dental digital model generally refers to a computer - processable data model used to guide the manufacture of a physical tooth model (i.e., a positive mold), which is usually a virtual three - dimensional model of the tooth state (which can also be called tooth arrangement, including the geometric shapes of several teeth corresponding to a treatment step and the positional relationships between the teeth). These virtual three - dimensional models can be observed, modified, or otherwise processed using a computer with a graphical interface, a workstation, or other data - processing devices. A dental digital model can include models of teeth and their surrounding tissues. For example, teeth can include the crown part, the neck part, and the root part; and the surrounding tissues can include the gingiva and the alveolar bone, etc.

[0098] In various embodiments of the present invention, the first dental digital model can be a data model corresponding to the first dental arch layout or a data model corresponding to the actual tooth layout at the end of wearing the previous set of shell - shaped orthodontic appliances. The first dental arch layout can be the initial dental arch layout when the patient starts orthodontic treatment or the dental arch layout after a period of orthodontic treatment. The second dental arch layout can be the final dental arch layout as the ultimate goal of the patient's orthodontic treatment or the stage dental arch layout as a stage goal of the orthodontic treatment. In some embodiments, for the acquisition of the first dental digital model, first, a physical tooth model is manufactured according to the patient's current tooth state or the state of the teeth and their surrounding tissues (such as the gingiva, facial soft tissues) (for example, a plaster tooth model is manufactured by taking an impression), and then the physical tooth model is scanned to generate a first dental digital model representing the patient's current tooth state. Of course, it is also possible to directly obtain images of teeth or teeth and their surrounding tissues through optical scanning, three - dimensional photography, three - dimensional videography, or medical CT scanning, and then generate a first dental digital model of the patient's current tooth state through computer processing. For example, a cone - beam CT can be used to scan the patient's teeth to obtain a first dental digital model including tooth regions such as the crown, neck, and root. It should be noted that the virtual first dental digital model can be digitally processed and displayed, for example, it can be displayed in the graphical interface of a computer.

[0099] After that, based on the first dental digital model and the second dental arch layout reflecting the current orthodontic goal, a series of target dental digital models are automatically formed by a computing and processing device. The series of target dental digital models correspond to a series of tooth orthodontic states that gradually progress the patient's teeth from the first dental arch layout or the actual tooth layout at the end of wearing the previous set of shell - shaped orthodontic appliances to the second dental arch layout. Generally speaking, this process includes several orthodontic steps (for example, including 40 - 80 orthodontic steps). Each orthodontic step corresponds to a tooth orthodontic state, and each tooth orthodontic state corresponds to a target dental digital model. Therefore, a series of target dental digital models can be obtained and stored by the computing and processing device.

[0100] Step S2: Select the target dental digital models corresponding to several consecutive orthodontic steps with earlier orthodontic sequences in the series of target dental digital models as the first series of dental digital models, and obtain a set of shell orthodontic appliances containing several shell orthodontic appliances based on the first series of dental digital models.

[0101] During the orthodontic process, the orthodontic results of each orthodontic step are affected by many factors. For example, the wearing time of the patient, and in addition, each shell orthodontic appliance may have a phenomenon of orthodontic force attenuation after the patient wears it for a certain period of time. Therefore, the result of each orthodontic step may deviate from the expected orthodontic goal. That is to say, it is difficult to achieve a 100% expression rate for each orthodontic step. The accumulated deviation of multiple orthodontic steps will increase the discomfort of wearing subsequent orthodontic appliances, and even make it difficult to wear. Therefore, for each series of target dental digital models formed based on the first dental digital model and the second dental arch layout, only select several target dental digital models with earlier orthodontic sequences in the series of target dental digital models and use them as an orthodontic stage.

[0102] In some embodiments, in the step of selecting the target dental digital models corresponding to several consecutive orthodontic steps with earlier orthodontic sequences in the series of target dental digital models as the first series of dental digital models, the number of orthodontic appliances in the current orthodontic stage can be determined based on the experience of the doctor or designer. Select the target dental digital models with the corresponding number of orthodontic appliances in the series of target dental digital models according to the orthodontic sequence, and then obtain several shell orthodontic appliances based on the several target dental digital models. Preferably, the number of shell orthodontic appliances included in each orthodontic stage is 5 to 15. As described in the foregoing embodiments, the number of orthodontic appliances included in each orthodontic stage can be basically the same, or can be individually designed by the doctor or designer for the number of orthodontic appliances in each orthodontic stage and vary. However, the difference in the number of orthodontic appliances included in different orthodontic stages should be less than or equal to 5, and the difference in the number of orthodontic appliances between adjacent orthodontic stages is preferably less than or equal to 3, so as to prevent the number of orthodontic appliances in the adjusted set of shell orthodontic appliances from being too many or too few. Too many may still cause too large a deviation accumulated during the orthodontic process, resulting in discomfort for the patient and the inability to wear subsequent orthodontic appliances, while too few will lead to too frequent restart of the orthodontic plan.

[0103] Specifically, a physical model of the shell-shaped orthodontic appliance can be manufactured according to the selected target dental digital model. In this embodiment, the physical model of the shell-shaped orthodontic appliance can be manufactured based on rapid prototyping. The rapid prototyping technology can be divided into the following typical forming processes: Stereo lithography Apparatus (SLA), Laminated Object Manufacturing (LOM), Selected Laser Sintering (SLS), Fused Deposition Modeling (FDM), Three Dimensional Printing (3DP), etc. The specific rapid prototyping technology will not be elaborated here.

[0104] Next, a shell-shaped orthodontic appliance can be manufactured based on the above physical model. In some embodiments, by means of a hot pressing forming device, through positive pressure or negative pressure film pressing technology, an appliance diaphragm made of a transparent polymer material (an elastic polymer, such as polycarbonate) can be pressed on the above physical model to form a shell, thereby obtaining a shell-shaped orthodontic appliance. However, the method for manufacturing a shell-shaped orthodontic appliance based on a physical model in this application is not limited to hot pressing, and other suitable methods such as 3D printing can also be used to manufacture the shell-shaped orthodontic appliance.

[0105] In some other embodiments, selecting several consecutive orthodontic steps with a previous orthodontic sequence in the series of target dental digital models as the first series of dental digital models includes:

[0106] Obtaining the expression rate of different tooth movement modes of each tooth at different orthodontic steps according to statistics;

[0107] Determining the ideal orthodontic steps for each tooth movement mode to reach a preset achievement rate based on the expression rate;

[0108] Selecting several target dental digital models with a previous orthodontic sequence in the series of target dental digital models as the first series of dental digital models based on the ideal orthodontic steps of each tooth.

[0109] The preset achievement rate refers to the expected expression rate that doctors or designers hope each tooth movement mode can reach. It can be a set value. The ideal orthodontic steps for different tooth movement modes of each tooth to reach the preset achievement rate can be obtained by statistically analyzing the expression rate of different tooth movement modes of different teeth, that is, determining the ideal orthodontic steps for each tooth movement mode to reach the ideal expression rate based on the average value of the expression rate of different tooth movement modes of each tooth at each orthodontic step obtained through statistics.

[0110] In the present invention, the expression rate can be statistically obtained through one or a combination of the following information: clinical data, literature research data, and simulation result data of finite element model for simulating long-term tooth movement.

[0111] Among them, clinical data can more widely reflect the actual situation of tooth correction, and the obtained expression rate can better fit the clinical treatment of patients; literature research data can more prominently reflect the correction characteristics, making the expression rate more scientific and reasonable; the simulation result data of finite element model for simulating long-term tooth movement does not require data collection and is more convenient to implement.

[0112] In this way, statistically obtaining the expression rate through various methods is beneficial to providing accurate and objective data, and then determining an accurate and objective expression rate result.

[0113] In some examples, through clinical data research, data of male patients aged 18 to 35 with good periodontal conditions are collected as the statistical research object, and the average value of the expression rate (the percentage of the actual achieved correction amount to the designed correction amount) of the teeth of patients in each correction step in 12 movement modes in 6 degrees of freedom (positive in the long axis direction of the tooth, negative in the long axis direction of the tooth, positive in the labiolingual direction, negative in the labiolingual direction, positive in the mesiodistal direction, negative in the mesiodistal direction, rotational direction towards the mesial around the long axis of the tooth, rotational direction towards the distal around the long axis of the tooth, rotational direction towards the mesial around the labiolingual direction, rotational direction towards the distal around the labiolingual direction, rotational direction towards the labial around the mesiodistal direction, rotational direction towards the lingual around the mesiodistal direction) is statistically obtained. Based on the average value of the expression rate of different movement modes of each tooth in each correction step, the ideal correction steps for each tooth to reach the preset achievement rate are determined, and the number of appliances in each shell-shaped appliance group is determined according to the ideal correction steps for each tooth to reach the preset achievement rate for various movement modes. The ideal correction steps for each tooth to reach the preset achievement rate for various movement modes may not be the same. In this regard, in some preferred embodiments, the number of appliances in the current shell-shaped appliance group can be determined according to the smallest ideal correction step among the ideal correction steps of different movement modes of all teeth. Generally speaking, the movement mode corresponding to the smallest ideal correction step means that the correction difficulty of this movement mode is relatively large, and this movement mode can also be used as the key movement mode of the current tooth. If the smallest ideal correction steps of different teeth are different, the minimum value of multiple smallest ideal correction steps can be determined as the number of appliances in the current shell-shaped appliance group; in other preferred embodiments, the average value or weighted average of the ideal correction steps of different movement modes of each tooth can also be calculated respectively to obtain the average ideal correction step, and the number of appliances in the current shell-shaped appliance group is determined based on this average ideal correction step.

[0114] In other examples, finite element simulations can also be used to calculate the long-term movement of teeth to obtain the expression rates of different movement modes of a single tooth at each orthodontic treatment step, and based on the expression rates of different movement modes of each tooth at each orthodontic treatment step, determine the ideal number of orthodontic treatment steps for each movement mode of each tooth to reach a preset achievement rate, so as to determine the number of appliances in each shell-shaped appliance group according to the ideal number of orthodontic treatment steps for each movement mode of each tooth to reach the preset achievement rate. Similarly, for the specific method of determining the number of appliances in each shell-shaped appliance group according to the ideal number of orthodontic treatment steps for each movement mode of each tooth to reach the preset achievement rate, reference can be made to the foregoing solution and will not be elaborated here.

[0115] In some examples, through literature research, it is also possible to obtain the expression rates of each orthodontic treatment step in the case where the patient mainly has a certain movement mode and the correction degree of other movement modes is relatively small, determine the ideal number of orthodontic treatment steps for the key movement mode to reach the preset achievement rate according to the corresponding expression rates, and then determine the number of appliances in each shell-shaped appliance group according to the ideal number of orthodontic treatment steps for each movement mode of each tooth to reach the preset achievement rate.

[0116] In still other embodiments, selecting several consecutive orthodontic treatment step-corresponding target dentomaxillary digital models in the series of target dentomaxillary digital models as the first series of dentomaxillary digital models includes:

[0117] Successively evaluate the orthodontic treatment status and / or orthodontic treatment effect of each target dentomaxillary digital model in the series of target dentomaxillary digital models to obtain the evaluation results of the orthodontic treatment status and / or orthodontic treatment effect of each target dentomaxillary digital model;

[0118] If the evaluation result of the current target dentomaxillary digital model does not meet the preset requirements, use the target dentomaxillary digital model corresponding to the previous orthodontic treatment step of the current target dentomaxillary digital model as the first series of dentomaxillary digital models.

[0119] That is to say, the number of appliances in each shell-shaped appliance group can also be determined based on the evaluation of the orthodontic treatment status and / or orthodontic treatment effect of each target dentomaxillary digital model in the target dentomaxillary digital model group corresponding to the current shell-shaped appliance group.

[0120] The target dentomaxillary digital model represents a tooth orthodontic plan for correcting the patient's dental arch from the first dental arch layout or the actual tooth layout at the end of wearing the previous shell-shaped appliance group to the second dental arch layout, and each target dentomaxillary digital model corresponds to the tooth orthodontic status at one stage (or step) in this tooth orthodontic plan. The number of appliances in each shell-shaped appliance group can be determined based on the evaluation result of the intermaxillary occlusion condition of each target dentomaxillary digital model, and / or based on the evaluation result of the simulated wearing of each target dentomaxillary digital model and the corresponding digital appliance.

[0121] In some preferred embodiments, the evaluation of the intermaxillary occlusion relationship of each target dental digital model is mainly achieved by obtaining the intermaxillary occlusion relationship of the upper and lower dental arches when each target dental digital model is in a preset occlusion state, and / or the intermaxillary occlusion relationship of the upper and lower dental arches during the movement of the target dental digital model along a preset trajectory towards a predetermined occlusion state. The preset occlusion state includes static occlusion, protrusive occlusion and / or lateral occlusion. The intermaxillary occlusion relationship mainly includes intermaxillary collision, where the intermaxillary collision includes the collision location and depth of the teeth. After obtaining the intermaxillary occlusion relationship, the evaluation result of the current target dental digital model can be obtained according to a preset occlusion evaluation criterion. If the evaluation result of the current target dental digital model does not meet the requirements, each shell-shaped orthodontic appliance of the current shell-shaped orthodontic appliance set is obtained based on the target dental digital models corresponding to the previous and previous orthodontic steps.

[0122] A three-dimensional coordinate system is established for the target dental digital model. The shape, boundary, position, etc. of each tooth model in the target dental digital model can be determined by the coordinates in this coordinate system. At the same time, the relative position of the upper dental arch and the lower dental arch can also be defined by the parameters of this coordinate system (such as vectors representing relative distance and orientation). Based on the occlusion indication parameters, the upper dental arch and the lower dental arch can occlude with each other according to a predetermined tooth occlusion state. The occlusion indication parameters include occlusion parameters indicating static occlusion and / or dynamic occlusion of the teeth. Dynamic occlusion can include protrusive occlusion and / or lateral occlusion.

[0123] Specifically, for each target dental digital model, based on the parameters of its upper and lower dental arches and the parameters of the tooth occlusion state, the intermaxillary collision of the upper and lower dental arches in the tooth occlusion state can be calculated, including the collision position and depth. The intermaxillary collision can simulate the situation where the upper and lower dental arches of the solid teeth come into contact with each other, including the distribution of the contact parts and the contact area, etc.

[0124] Among them, for the calculation of the intermaxillary collision, in some embodiments, after the upper and lower dental arches can occlude with each other according to a predetermined tooth occlusion state, multiple reference points are selected on the upper or lower jaw, and multiple rays are emitted along the normal direction of the occlusal plane M to obtain the intersection position information of each ray and the opposite jaw teeth. According to the relative position of the intersections, it is judged whether an intermaxillary collision occurs between the upper and lower jaw teeth and the collision depth is calculated. For example, when the position order of the intersections of a certain ray and the upper and lower jaw teeth along its emission direction changes in two consecutive steps, it is judged that an intermaxillary collision occurs between the upper and lower jaw teeth, and the maximum value of the distances between the two intersections of all the rays judged to have an intermaxillary collision is used as the collision depth of the opposite jaw teeth. For example, tooth 12 and tooth 42 are opposite jaw teeth. Suppose a ray a is emitted from the lower jaw to the upper jaw along the normal direction of the occlusal plane. If the intersection A' of all rays a and tooth 42 is below the intersection A of ray a and tooth 12, as Figure 4a, it indicates that there is no intermaxillary collision between the upper and lower jaw teeth. When the intersection point A' of ray a and tooth No. 42 intersects with the intersection point A of ray a and tooth No. 12 or the intersection point A' of ray a and tooth No. 42 is above the intersection point A of ray a and tooth No. 12, it indicates that there is a collision between tooth No. 12 and tooth No. 42, such as Figure 4b , then for all the detected rays with collisions, the distance between the two intersection points can be obtained, and the maximum value of the distances is selected as the collision depth between tooth No. 12 and tooth No. 42.

[0125] After obtaining the collision positions and collision depths of each pair of opposing teeth, the current target dental arch digital model can be evaluated based on the collision positions and collision depths of each pair of opposing teeth. In this embodiment, different rules can be adopted to evaluate the intermaxillary collision for different tooth occlusion states. For example, for static occlusion, the evaluation rule can be: whether the difference in the collision depths at different collision positions of the corresponding posterior teeth in the upper and lower dental arches is less than a set value, such as 0.5 mm, and whether the collision depth of the corresponding anterior teeth in the upper and lower dental arches is less than 0.2 mm. For the protrusive occlusion state, whether the corresponding anterior teeth in the upper and lower dental arches and the corresponding anterior teeth in the lower dental arch are less than 0.2 mm, and whether there is no occlusal contact between the corresponding posterior teeth in the upper and lower dental arches. For the lateral occlusion state, the evaluation rule can be: whether the corresponding anterior teeth in the upper and lower dental arches are in contact, and whether the corresponding posterior teeth in the upper and lower dental arches are not in contact.

[0126] In some preferred embodiments, in addition to the data representing the tooth geometry and the positional arrangement between teeth, mechanical parameters can also be added to each target dental arch digital model. The mechanical parameters include elastic modulus, strain, etc. By adding mechanical parameters to the target dental arch digital model in the present invention, the mechanical relationship between the appliance and the target dental arch digital model can be expressed, so as to utilize this mechanical relationship to determine the influence of the appliance on the positions of each tooth in the target dental arch digital model; obtaining the corresponding appliance digital model based on each target dental arch digital model, and the appliance digital model includes the mechanical parameters and morphological parameters of the appliance; combining the target dental arch digital model and the appliance digital model to simulate the wearing of the appliance on the patient's dental arch, and obtaining the tooth orthodontic changes after the patient's dental arch wears the appliance according to the mechanical parameters and morphological parameters of the appliance model and the target dental arch digital model, so as to evaluate the orthodontic effect of the shell-shaped appliance corresponding to the current target dental arch digital model. When the orthodontic effect does not meet the requirements, each shell-shaped appliance of the current shell-shaped appliance set is obtained based on the target dental arch digital models corresponding to the previous and previous orthodontic steps.

[0127] The following description will explain the process of combining the target dental arch digital model with the orthodontic appliance digital model: First, apply force to the anterior tooth region of both models so that the orthodontic appliance digital model and the target dental arch digital model are combined with each other in this region. Then, gradually apply force to the posterior tooth region of both models so that the orthodontic appliance model and the target dental arch digital model are combined with each other in this region. During this period, the force originally applied to the anterior tooth region can be maintained or removed. Finally, after the wearing operation is completed, the previously applied pressure can be removed, and the orthodontic appliance model generates an orthodontic force on the dental arch model. Then, analyze the contact between the target dental arch digital model and the orthodontic appliance digital model.

[0128] After combining the target dental arch digital model with the orthodontic appliance digital model, the shapes of both models will change, thereby generating interaction forces between them, namely the orthodontic force exerted by the orthodontic appliance digital model on the target dental arch digital model and the resistance force reversely exerted by the target dental arch digital model on the orthodontic appliance digital model. These two forces cause changes in the shapes and / or positions of different regions of the two models, so that mechanical equilibrium is achieved in different regions. Generally, due to the high hardness of teeth, it can be considered that the shape basically does not change during orthodontic treatment; while the periodontal tissues (such as the periodontal ligament and alveolar bone) have lower hardness and are prone to deformation during orthodontic treatment, and the deformation of the periodontal tissues is also an important factor leading to tooth movement. Therefore, the wearing effect of the orthodontic appliance can be evaluated by the deformation of the periodontal tissues. In a specific embodiment, the mechanical equilibrium between the target dental arch digital model and the orthodontic appliance digital model can be calculated by finite element simulation. When in the state of mechanical equilibrium, the tooth movement in the patient's dental arch represented by the target dental arch digital model can be used as the change in the orthodontic treatment state, and then the evaluation result of the orthodontic treatment effect of the current target dental arch digital model can be based on whether the change in the orthodontic treatment state reaches the preset target.

[0129] To further improve the expression rate of each orthodontic stage, the selection of the number of target dental arch digital models in the subsequent orthodontic stage can also be adjusted according to the wearing result of the previous shell-shaped orthodontic appliance group. Thus, in some other embodiments, selecting the target dental arch digital models corresponding to several consecutive orthodontic steps with earlier orthodontic order in the series of target dental arch digital models as the first series of dental arch digital models further includes:

[0130] For the first orthodontic stage, select several target dental arch digital models with earlier orthodontic order from the series of target dental arch digital models formed by the first dental arch digital model corresponding to the first dental arch layout and the second dental arch layout based on the preset number of orthodontic appliances;

[0131] For the i-th orthodontic stage, calculate the deviation between the actual layout and the target layout at the end of wearing the (i - 1)-th shell-shaped orthodontic appliance group;

[0132] Based on the comparison results of the deviation with the first set threshold and the second set threshold, determine whether to reduce or increase the preset number of orthodontic appliances in the i-th shell orthodontic appliance group.

[0133] Specifically, for obtaining the deviation between the actual layout of the patient's teeth at the end of wearing the (i - 1)-th shell orthodontic appliance group and the designed target layout, first, it is necessary to obtain the actual digital dental model of the patient's teeth at the end of wearing the (i - 1)-th shell orthodontic appliance group. This actual digital dental model represents the actual tooth layout of the patient at the end of wearing the current shell orthodontic appliance group. Among them, the actual digital dental model can be obtained by scanning the positive mold converted from the intraoral negative mold taken with silicone rubber or by intraoral scanning, which will not be elaborated here. Based on this actual digital dental model, the actual coordinates of each tooth at the end of wearing the (i - 1)-th shell orthodontic appliance group can be obtained. At the same time, according to the target layout obtained by designing the (i - 1)-th shell orthodontic appliance group, the set coordinates of each tooth can be obtained. Taking tooth No. 15 as an example, assume that the actual coordinates of tooth No. 15 at the end of wearing the (i - 1)-th shell orthodontic appliance group are (x15’, y15’, z15’, θ15’), where x15’, y15’, z15’, θ15’ are the X-axis, Y-axis, Z-axis coordinates and the angular coordinate in the local coordinate system of the tooth respectively; the set coordinates of tooth No. 15 are (x15, y15, z15, θ15), and x15, y15, z15, θ15 are the X-axis, Y-axis, Z-axis coordinates and the angular coordinate in the local coordinate system of the tooth respectively. According to the current actual coordinates (x15’, y15’, z15’, θ15’) and the set coordinates (x15, y15, z15, θ15) of this tooth, calculate the offset of tooth No. 15 at the end of wearing the (i - 1)-th shell orthodontic appliance group. The offset includes the first to third offset components of the X-axis, Y-axis, and Z-axis and the fourth offset component of the angle θ.

[0134] For a patient's dentition, there are generally multiple teeth designed to move, i.e., teeth to be moved. During the orthodontic treatment process, there will be corresponding offsets between the actual tooth layout and the designed stage design target layout of each tooth to be moved, and the offsets of each tooth to be moved are often different. In some embodiments, the offsets of each tooth to be moved can be obtained separately, and the maximum value among the offsets of each tooth to be moved can be selected, or after weighted synthesis of the offsets of each tooth to be moved, it is used as the deviation between the actual tooth layout and the target tooth layout at the end of wearing the (i - 1)-th shell orthodontic appliance group. Among them, for the offsets of each tooth to be moved, the offset of the corresponding tooth to be moved can be determined according to each offset component of each tooth to be moved. In some examples, the offset can be determined according to the maximum value of each offset component of the tooth to be moved, or after weighted synthesis of each offset component of the tooth to be moved, it is used as the offset of the tooth to be moved. However, it should be noted that since different offset components have different dimensions. For example, for tooth No. 15, the first - third offset components on the X - axis, Y - axis, and Z - axis and the fourth offset component of the angle θ are 0.1 mm, 0.2 mm, 0.25 mm, and 0.5°, respectively. The distance component and the angle component cannot be directly compared or weighted synthesized. Therefore, each offset component needs to be normalized before comparison. The normalization can be achieved by designing corresponding normalization parameters for each offset component. For example, the normalization parameter for different offset components can be selected as the target offset under its corresponding movement mode. For example, the following expression can be used to normalize the difference between each offset component and the corresponding first offset threshold:

[0135] Pi = Δi / Ni,

[0136] where Pi is the result of normalizing the i - th offset component of the tooth to be moved, Δi is the i - th offset component of the tooth to be moved, and Ni is the normalization parameter corresponding to the i - th offset component.

[0137] In some other embodiments, it is also possible to first determine the key offset components of each tooth to be moved, use the key offset components of each tooth to be moved as the offsets of each tooth to be moved, select the maximum value among the offsets of each tooth to be moved, or after weighted synthesis of the offsets of each tooth to be moved, use it as the deviation between the actual tooth layout and the target tooth layout at the end of wearing the (i - 1)-th shell orthodontic appliance group; or it is also possible to determine the characteristic teeth among each tooth to be moved, determine the offset of the characteristic teeth based on the above method, and use the offset of the characteristic teeth as the deviation between the actual tooth layout and the target tooth layout at the end of wearing the (i - 1)-th shell orthodontic appliance group.

[0138] After obtaining the deviation between the actual tooth layout and the target tooth layout at the end of wearing the (i - 1)-th shell orthodontic appliance group, the deviation can be compared with the first set threshold and the second set threshold respectively to determine whether to reduce or increase the number of orthodontic appliances in the i-th shell orthodontic appliance group. The first set threshold is the maximum tolerance value of the deviation between the actual layout and the target layout at the end of wearing the (i - 1)-th shell orthodontic appliance group. When the deviation is greater than the first set threshold, it means that the number of orthodontic appliances in the i-th shell orthodontic appliance group needs to be reduced. When the deviation is less than the second set threshold, it means that the expression rate of the (i - 1)-th shell orthodontic appliance group is very high, and an increase in the number of orthodontic appliances in the i-th shell orthodontic appliance group can be considered. In some embodiments, when the deviation is greater than the first set threshold, the reduction amount of the orthodontic appliances in the i-th shell orthodontic appliance group is determined based on a first adjustment parameter, and the first adjustment parameter is determined based on the relative relationship between the difference between the deviation and the first set threshold and a set reference threshold. Assuming that the deviation between the actual layout and the target layout at the end of wearing the (i - 1)-th shell orthodontic appliance group is M1 and the first set threshold is T1, then the difference D1 = M1 - T1 between the deviation and the corresponding first set threshold is calculated, and the ratio of the difference D1 to the set reference threshold Δ1 is calculated. The reduction amount of the shell orthodontic appliances in the i-th shell orthodontic appliance group is determined according to this ratio. In this example, the reduction amount m1 of the shell orthodontic appliances in the i-th shell orthodontic appliance group, that is, the first adjustment parameter is:

[0139]

[0140] For example, when the obtained is 1.2, then m1 = 1, and it is determined that the number of shell orthodontic appliances in the i-th shell orthodontic appliance group can be reduced by one.

[0141] In some embodiments, when the deviation is less than the second set threshold, the increase amount of the orthodontic appliances in the i-th shell orthodontic appliance group is determined based on a second adjustment parameter, and the second adjustment parameter is determined based on the relationship between the difference between the set second set threshold and the deviation and the reference threshold. Assuming that the deviation between the actual layout and the target layout at the end of wearing the (i - 1)-th shell orthodontic appliance group is M1 and the second set threshold is T2, then the difference D2 = T2 - M1 between the second set threshold and the deviation is calculated, and the ratio of the difference D2 to the set reference threshold Δ1 is calculated. The increase amount of the shell orthodontic appliances in the i-th shell orthodontic appliance group is determined according to this ratio. In this example, the increase amount m2 of the shell orthodontic appliances in the i-th shell orthodontic appliance group is:

[0142]

[0143] For example, when the obtained is 0.5, then m2 = 1, and it is determined that the number of shell orthodontic appliances in the i-th shell orthodontic appliance group can be increased by one.

[0144] Of course, the number of appliances in the i-th shell-shaped appliance group cannot be increased or decreased infinitely. Its increase or decrease should at least ensure that the number of shell-shaped appliances in the i-th shell-shaped appliance group is greater than or equal to 5, and the difference in the number of appliances included in the adjacent shell-shaped appliance groups does not exceed 3, and the difference in the number of appliances between any shell-shaped appliance groups among all different shell-shaped appliance groups does not exceed 5.

[0145] Step S3: Obtain a digital dental model representing the actual dental arch layout at the end of wearing the shell-shaped appliance group as the first dental arch digital model, and return to step S1 until the actual dental arch layout at the end of wearing the shell-shaped appliance group is the same as the second dental arch layout.

[0146] That is to say, if the dental appliance treatment state corresponding to the last target dental arch digital model selected in the current treatment stage is the second dental arch layout, then the end of wearing all the shell-shaped appliances in the shell-shaped appliance group corresponding to the current treatment stage means the end of the treatment process; otherwise, after the end of each treatment stage, it is necessary to obtain the digital dental model at the end of wearing the shell-shaped appliance group corresponding to this treatment stage. This digital dental model represents the actual dental arch layout at the end of the previous treatment stage, and use this digital dental model as the first dental arch digital model to return to step S1 to continue execution, that is, continue to form a series of target dental arch digital models based on this digital dental model and the second dental arch layout for the design of the shell-shaped appliance group in the next treatment stage. It should be noted that the "same" in "until the actual dental arch layout at the end of wearing the shell-shaped appliance group is the same as the second dental arch layout" here can be exactly the same or basically the same. The "basically the same" means that the deviation between the actual dental arch layout at the end of wearing the shell-shaped appliance group and the second dental arch layout is within a set range.

[0147] Those of ordinary skill in the art can understand that the above embodiments are specific embodiments for implementing the present application, and in practical applications, various changes can be made in form and details without departing from the spirit and scope of the present application.

Claims

1. A dental orthodontic system, characterized in that, It includes N sets of shell orthodontic appliances. Among them, the first set of shell orthodontic appliances in the N sets of shell orthodontic appliances includes several shell orthodontic appliances corresponding to several orthodontic steps with earlier orthodontic sequences in a series of orthodontic steps designed for gradually moving the first dental arch layout to the second dental arch layout; the i-th set of shell orthodontic appliances includes several shell orthodontic appliances corresponding to several orthodontic steps with earlier orthodontic sequences in a series of orthodontic steps designed for gradually moving the actual tooth layout at the end of wearing the (i - 1)-th set of shell orthodontic appliances to the second dental arch layout, where 2 ≤ i ≤ N.

2. The dental orthodontic system according to claim 1, wherein The N sets of shell orthodontic appliances are used to gradually move the patient's dental arch from the first dental arch layout to the second dental arch layout, where adjacent sets of shell orthodontic appliances correspond to consecutive orthodontic stages.

3. The dental orthodontic system according to claim 2, characterized in that, The number of orthodontic appliances included in each of the N sets of shell orthodontic appliances is 5 to 15.

4. The dental orthodontic system according to claim 3, wherein The number of orthodontic appliances in each set of shell orthodontic appliances is the same.

5. The dental orthodontic system according to claim 3, wherein The number of orthodontic appliances in each set of shell orthodontic appliances is determined based on the tooth movement methods designed for each tooth to be moved in the corresponding orthodontic stage.

6. The dental orthodontic system according to claim 5, characterized in that, The number of orthodontic appliances in different sets of shell orthodontic appliances with the same tooth movement method for each tooth to be moved is the same.

7. The dental treatment system according to claim 6, wherein The number of orthodontic appliances in different sets of shell orthodontic appliances with the same key tooth movement method for each tooth to be moved is the same.

8. The dental orthodontic system according to claim 5, characterized in that, The number of orthodontic appliances in different sets of shell orthodontic appliances with the same tooth movement method for each characteristic tooth is the same.

9. The dental orthodontic system according to claim 8, wherein, The number of orthodontic appliances in different sets of shell orthodontic appliances with the same key tooth movement method for each characteristic tooth is the same.

10. The dental orthodontic system according to claim 5, wherein, The number of orthodontic appliances in the i-th set of shell orthodontic appliances changes with the wearing result of the (i - 1)-th set of shell orthodontic appliances.

11. The dental orthodontic system according to claim 10, wherein, The number of orthodontic appliances in the i-th set of shell orthodontic appliances decreases as the deviation between the actual tooth layout at the end of wearing the (i - 1)-th set of shell orthodontic appliances and the target tooth layout increases.

12. The dental orthodontic system according to claim 11, wherein, When the deviation between the actual layout and the target layout at the end of wearing the (i - 1)-th set of shell orthodontic appliances is greater than the second set threshold, the number of orthodontic appliances in the i-th set of shell orthodontic appliances decreases by the first preset amount, and the first preset amount is 1 to 3.

13. The dental orthodontic system according to claim 10, characterized in that, When the deviation between the actual tooth layout and the target tooth layout at the end of wearing the (i - 1)-th set of shell orthodontic appliances is less than the second set threshold, the number of orthodontic appliances in the i-th set of shell orthodontic appliances increases by the second preset amount, and the second preset amount is 1 to 3.

14. The dental correction system according to any one of claims 5 to 13, characterized in that: The difference in the number of orthodontic appliances between adjacent sets of shell orthodontic appliances is less than or equal to 3.

15. The dental orthodontic system according to claim 3, wherein The number of orthodontic appliances in each set of shell orthodontic appliances is determined based on the ideal orthodontic steps for each tooth to be moved to reach a preset achievement rate with different tooth movement methods, and the ideal orthodontic steps are obtained by statistically analyzing the expression rates of different movement methods of different teeth.

16. The dental orthodontic system according to claim 15, characterized in that, The expression rate is statistically obtained through one or a combination of the following information: clinical data, literature research data, and simulation result data of finite element model simulating long-term tooth movement.

17. The dental orthodontic system according to claim 3, wherein, The number of orthodontic appliances in each set of shell orthodontic appliances is determined based on the evaluation result of the intermaxillary occlusion condition of the target dental arch digital model corresponding to each orthodontic step, and / or based on the evaluation result of the simulation wearing of the target dental arch digital model corresponding to each orthodontic step and the corresponding digital orthodontic appliance.

18. The dental orthodontic system according to any one of claims 1-13 and 15-17, characterized in that, The elasticity of the shell orthodontic appliances within each set of shell orthodontic appliances is consistent.

19. The dental correction system according to any one of claims 1 to 13 and 15 to 17, characterized in that: The elasticity of the shell orthodontic appliances among the respective shell orthodontic appliance groups gradually decreases as the order of the orthodontic stages progresses.

20. The dental orthodontic system according to any one of claims 1-13 and 15-17, characterized in that: The elasticity of the shell orthodontic appliances among the respective shell orthodontic appliance groups gradually increases as the order of the orthodontic stages progresses.

21. A design method of a dental orthodontic system, characterized in that, Comprising the following steps: Step S1, obtaining a first dental digital model and a second dental arch layout, and forming a series of target dental digital models based on the first dental digital model and the second dental arch layout, the series of target dental digital models corresponding to a series of tooth orthodontic states that gradually and progressively move the patient's teeth from the dental arch layout corresponding to the first dental digital model to the second dental arch layout; Step S2, selecting the target dental digital models corresponding to several consecutive orthodontic steps with a prior orthodontic order in the series of target dental digital models as the first series of dental digital models, and obtaining a shell orthodontic appliance group comprising several shell orthodontic appliances based on the first series of dental digital models; Step S3, obtaining a digital dental model representing the actual dental arch layout at the end of wearing the shell orthodontic appliance group as the first dental digital model, and returning to Step S1 until the actual dental arch layout at the end of wearing the shell orthodontic appliance group is the same as the second dental arch layout.

22. The design method of the dental orthodontic system according to claim 21, wherein, The selection of the target dental digital models corresponding to several consecutive orthodontic steps with a prior orthodontic order in the series of target dental digital models as the first series of dental digital models includes: Obtaining the expression rates of different tooth movement modes of each tooth at different orthodontic steps based on statistics; Determining the ideal orthodontic steps for various tooth movement modes of each tooth to reach a preset achievement rate based on the expression rates; Based on the ideal orthodontic steps of each tooth, selecting several target dental digital models with a prior orthodontic order according to each tooth to be moved in the series of target dental digital models as the first series of dental digital models.

23. The design method of the dental orthodontic system according to claim 22, characterized in that, The selection of several target dental digital models with a prior orthodontic order according to each tooth to be moved in the series of target dental digital models as the first series of dental digital models based on the ideal orthodontic steps of each tooth includes: Determining the ideal orthodontic steps of different tooth movement modes of each tooth to be moved; Selecting the smallest ideal orthodontic step among the ideal orthodontic steps of different tooth movement modes of each tooth to be moved as the ideal orthodontic step of the current tooth to be moved; Based on the ideal orthodontic steps of each tooth to be moved, determining the number of orthodontic appliances in the current shell orthodontic appliance group, and thereby selecting several target dental digital models with a prior orthodontic order as the first series of dental digital models.

24. The design method of the dental orthodontic system according to claim 22, characterized in that, Among the determination of the number of orthodontic appliances in the current shell orthodontic appliance group based on the ideal orthodontic steps of each tooth to be moved, selecting the smallest ideal orthodontic step among the ideal orthodontic steps of each tooth to be moved as the number of orthodontic appliances in the current shell orthodontic appliance group.

25. The design method of the dental orthodontic system according to claim 22, characterized in that, Among the determination of the number of orthodontic appliances in the current shell orthodontic appliance group based on the ideal orthodontic steps of each tooth to be moved, determining characteristic teeth among each tooth to be moved, determining the ideal orthodontic steps of the characteristic teeth, and taking the ideal orthodontic steps of the characteristic teeth as the number of orthodontic appliances in the current shell orthodontic appliance group.

26. The design method of the dental orthodontic system according to claim 22, wherein Based on the ideal orthodontic steps for each tooth, several target dental arch digital models with earlier orthodontic sequences are selected from the series of target dental arch digital models according to each tooth to be moved as the first series of dental arch digital models, including: Determine the ideal orthodontic steps for different movement modes of each tooth to be moved; Calculate the mean or weighted average of the ideal orthodontic steps for different movement modes of each tooth to be moved to obtain the average ideal orthodontic steps, and select several target dental arch digital models with earlier orthodontic sequences from the series of target dental arch digital models based on the average ideal orthodontic steps as the first series of dental arch digital models.

27. The design method of the dental orthodontic system according to claim 21, characterized in that, The selection of several consecutive orthodontic step-corresponding target dental arch digital models with earlier orthodontic sequences from the series of target dental arch digital models as the first series of dental arch digital models includes: Evaluate the orthodontic status and / or orthodontic effect of each target dental arch digital model in the series of target dental arch digital models in turn, and obtain the evaluation results of the orthodontic status and / or orthodontic effect of each target dental arch digital model; If the evaluation result of the current target dental arch digital model does not meet the preset requirements, all target dental arch digital models corresponding to the previous orthodontic steps of the current target dental arch digital model are used as the first series of dental arch digital models.

28. The design method of the dental orthodontic system according to claim 21, characterized in that, The selection of several consecutive orthodontic step-corresponding target dental arch digital models with earlier orthodontic sequences from the series of target dental arch digital models as the first series of dental arch digital models includes: For the first orthodontic stage, select several target dental arch digital models with earlier orthodontic sequences from the series of target dental arch digital models formed by the first dental arch digital model corresponding to the first dental arch layout and the second dental arch layout based on a preset value; For the i-th orthodontic stage, calculate the deviation between the actual tooth layout at the end of wearing the (i - 1)-th shell orthodontic appliance group and the target tooth layout; Based on the comparison results of the deviation with the first set threshold and the second set threshold, adjust the preset number of orthodontic appliances in the i-th shell orthodontic appliance group; Based on the adjustment result, select the corresponding number of target dental arch digital models with earlier orthodontic sequences from the series of target dental arch digital models as the first series of dental arch digital models.

29. The design method of the dental orthodontic system according to claim 28, characterized in that, In the step of adjusting the preset number of orthodontic appliances in the i-th shell orthodontic appliance group based on the comparison results of the deviation with the first set threshold and the second set threshold, when the deviation between the actual tooth layout and the target tooth layout at the end of wearing the (i - 1)-th shell orthodontic appliance group is greater than the second set threshold, the number of orthodontic appliances in the i-th shell orthodontic appliance group is reduced according to the first adjustment parameter.

30. The design method of the dental orthodontic system according to claim 29, characterized in that, The first adjustment parameter is determined based on the relationship between the difference between the deviation between the actual tooth layout and the target tooth layout at the end of wearing the (i - 1)-th shell orthodontic appliance group and the first set threshold and the reference threshold.

31. The method for designing a dental correction system according to claim 28, wherein: In the step of adjusting the preset number of orthodontic appliances in the i-th shell orthodontic appliance group based on the comparison results of the deviation with the first set threshold and the second set threshold, when the deviation between the actual tooth layout and the target tooth layout at the end of wearing the (i - 1)-th shell orthodontic appliance group is less than the second set threshold, the number of orthodontic appliances in the i-th shell orthodontic appliance group is increased according to the second adjustment parameter.

32. The design method of the dental orthodontic system according to claim 31, characterized in that, The second adjustment parameter is determined based on the relationship between the difference between the deviation of the actual tooth layout at the end of wearing the (i-1)-th shell orthodontic appliance group and the target tooth layout and the second set threshold and the reference threshold.

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