Personalized craniofacial growth guide and method of designing the same, craniofacial growth guide system

Abstract

The application provides a personalized craniofacial growth guide and a design method thereof and a craniofacial growth guide system, and the design method comprises the following steps: obtaining an initial value of a craniofacial parameter combination of a guide object; determining a target value of the craniofacial parameter combination of the guide object; determining a design parameter of a basic structural unit of the personalized craniofacial growth guide based on the target value; opening a bite of the guide object based on the target value on a articulator, and designing the personalized craniofacial growth guide based on the design parameter. The technical scheme of the application conforms to physiological characteristics of different periods of growth and development of the craniofacial part of a human being, and designs a structure of the personalized growth guide according to the personalized dental and facial deformity characteristics of the guide object, so that the best balance of the individualized shape and function of each part of the craniofacial part of the guide object is realized.

Description

Technical Field

[0001] This application belongs to the field of craniofacial orthodontics technology, specifically providing a personalized craniofacial growth guide and its design method, as well as a craniofacial growth guidance system. Background Technology

[0002] The craniofacial region can be broadly divided into three parts: teeth and their occlusion, bones, and soft tissues. During growth and development, each part follows its own distinct growth and developmental pattern, interacting and influencing the others. Throughout the long process of human growth and development, influenced by genetic or environmental factors, various problems may arise in the development of teeth and their occlusion, bones, and soft tissues, resulting in malocclusion, jawbone developmental abnormalities, and soft tissue developmental abnormalities, collectively known as dentofacial deformities. These deformities threaten a person's appearance, function, and health. Therefore, correcting existing dentofacial deformities and preventing potential problems during subsequent development through therapeutic devices is a common method in orthodontics for preventative and interceptive treatment of dentofacial deformities.

[0003] Utilizing growth potential to guide the growth of teeth, jawbones, and soft tissues in an ideal direction is a crucial concept for early intervention in dentofacial deformities. Currently, various devices made of different materials and in different styles have emerged, such as bite guides, functional appliances, muscle trainers, and jaw position adjusters, made of materials like metal, resin, plastic, and silicone, and available in fixed / removable, integrated / separate, prefabricated / customized styles. The basic commonality of these devices is to set and maintain the target position of teeth or jawbones, altering the spatial layout and biomechanical environment of the oral and maxillofacial tissue structures (the magnitude, direction, and site of force generated by oral function), and utilizing growth potential to help teeth or jawbones grow to the target position. Therefore, they can be collectively referred to as craniofacial growth guiding devices.

[0004] The aforementioned existing craniofacial growth guidance devices are generally designed to address specific problems in a particular tissue structure. Their design philosophy does not comprehensively consider the different needs of various facial tissue structures in terms of morphology and function. Therefore, they have some limitations in terms of indication selection and efficacy. At the same time, the lack of a design philosophy in growth guidance devices results in a relatively coarse and unpersonalized target location, which cannot meet the specific treatment needs of different patients, affecting efficacy, prolonging treatment course, affecting comfort, and increasing the difficulty of patient cooperation. Summary of the Invention

[0005] The purpose of this application is to solve the problems existing in the prior art, and based on reasonable medical concepts and in accordance with the physiological characteristics of various craniofacial tissues at different stages of growth and development, to provide a personalized craniofacial growth guide and its design method, as well as a craniofacial growth guidance system composed of the personalized craniofacial growth guide.

[0006] The first aspect of this application provides a method for designing a personalized craniofacial growth guide, the method comprising the following steps:

[0007] Obtain the initial values ​​of the craniofacial parameter combination of the guiding object;

[0008] Determine the target values ​​for the craniofacial parameter combination of the guided object;

[0009] Based on the target value, determine the design parameters of the basic structural unit of the personalized craniofacial growth guide;

[0010] The occlusion of the guided object is opened on the occluder based on the target value, and a personalized craniofacial growth guide is designed based on the design parameters.

[0011] Furthermore, the craniofacial parameter combination includes: a set of tooth surface feature parameters of the guiding object and / or dental arch morphology.

[0012] Furthermore, the set of tooth surface feature parameters includes: the facial features of the guiding object in the vertical and sagittal directions, and the tooth features of the guiding object in the sagittal direction.

[0013] Preferably, the set of tooth surface feature parameters further includes: bone and tooth features of the guiding object in the vertical direction, bone features of the guiding object in the sagittal direction, and facial, bone, and tooth features of the guiding object in the horizontal direction.

[0014] Furthermore, the initial value of the dental arch morphology is characterized by the initial dental arch curve, and the target value of the dental arch morphology is characterized by the target dental arch curve.

[0015] Further, the target dental arch curve is generated through the following steps:

[0016] Annotate the tooth feature points of the guided object;

[0017] The first characteristic parameter C1 and the second characteristic parameter C2 of the guided object were measured respectively.

[0018] Based on the first characteristic parameter C1, the first ideal dental arch characteristic parameter R1 is determined, and a first curve of the following form is determined according to R1:

[0019] Y = AX 4 +BX 2 ,

[0020] Where X and Y are the coordinates of each point on the curve, and both X and Y are located on the jaw plane. Their X-axis and Y-axis are orthogonal, and the Y-axis corresponds to the projection of the midsagittal plane onto the jaw plane. A and B are the coefficients of the fourth and second terms of the first curve, respectively, and are coupled and related to R1.

[0021] Based on the second characteristic parameter C2, the second ideal dental arch characteristic parameter R2 is determined, and the second curve of the following form is determined according to R2:

[0022]

[0023] The portion of the first curve located in the first dentition interval and the portion of the second curve located in the second dentition interval are spliced ​​together to obtain the target dental arch curve of the guided object in one craniofacial growth guidance cycle.

[0024] Preferably, C1 and C2 remain unchanged in the same craniofacial growth guidance cycle of the guided object, and C1 and C2 are defined in different craniofacial growth guidance cycles of the guided object;

[0025] R1 and R2 are used to characterize the ideal arch shape of the dentition of the guided object, and R1 and R2 are statistically strongly correlated with C1 and C2, respectively.

[0026] Preferably, the first dentition interval is the left and right posterior tooth region; and the second dentition interval is the anterior tooth region.

[0027] Preferably, the intersection of the first dentition interval and the second dentition interval is located within the projection area of ​​the canine in the occlusal plane.

[0028] Furthermore, the basic structural unit includes: an upper guide groove, a lower guide groove, and a composite plate connecting the upper and lower guide grooves.

[0029] Preferably, the design parameters include the shape, style, angle, and depth of the upper and lower guide grooves.

[0030] Preferably, the craniofacial parameter combination also includes the morphology of each tooth of the guiding object.

[0031] Preferably, the design method further includes the following steps: adding at least one retention attachment to the personalized craniofacial growth guide, wherein the retention attachment is designed to retain the craniofacial growth guide on an erupted deciduous permanent tooth whose root development is basically complete or a deciduous tooth whose root resorption does not exceed 1 / 2 of the root length.

[0032] Preferably, the design method further includes the following step: adding at least one guiding attachment to the personalized craniofacial growth guide, the guiding attachment causing the erupting or soon-to-erupt teeth to erupt in an ideal direction and position.

[0033] Preferably, the craniofacial parameter combination also includes the functional status of the masticatory organs of the guiding object.

[0034] Preferably, the design method further includes the following step: adding at least one of a lip block, a tongue block, a cheek shield, and a tongue position guide to the personalized craniofacial growth guide.

[0035] The second aspect of this application provides a personalized craniofacial growth guide, which is composed of multiple basic structural units, including an upper budding groove, a lower budding groove, and a composite plate connecting the upper and lower budding grooves;

[0036] This personalized craniofacial growth guide was designed and generated using the aforementioned personalized craniofacial growth guide design method.

[0037] A third aspect of this application provides a craniofacial growth guidance system, comprising at least two of the aforementioned personalized craniofacial growth guides, each used to guide the craniofacial growth process of the subject in at least two non-overlapping craniofacial growth guidance cycles.

[0038] The technical solutions provided in this application, through the embodiments, conform to the physiological characteristics of different stages of human craniofacial growth and development. Based on the individualized dental deformities of the guided subjects, the spatial positional relationships and biomechanical environment between different craniofacial tissue structures are changed in stages. At the same time, based on reasonable medical concepts, the masticatory organs are considered as a complete functional unit, respecting the functional and aesthetic principles of the masticatory organs, and achieving the best balance between the individualized morphology and function of the masticatory organs for each guided subject. Attached Figure Description

[0039] Figure 1a This is a schematic diagram of the structure of a personalized craniofacial growth guide provided according to an embodiment of this application;

[0040] Figure 1b This is a top view of a personalized craniofacial growth guide provided according to an embodiment of this application;

[0041] Figure 1c A side view of a personalized craniofacial growth guide provided according to an embodiment of this application;

[0042] Figure 1d This is a rear view of a personalized craniofacial growth guide provided according to an embodiment of this application;

[0043] Figure 2 This is a flowchart illustrating the design method of a personalized craniofacial growth guide provided according to an embodiment of this application;

[0044] Figure 3a In one specific embodiment, images of the craniofacial region at various angles before the start of a craniofacial growth guidance cycle are shown.

[0045] Figure 3bIn one specific embodiment, photographs of the inside of the oral cavity of the guided object from various angles before the start of a craniofacial growth guidance cycle;

[0046] Figure 3c In one specific embodiment, the guided object is an oral X-ray fluoroscopy taken before the start of a craniofacial growth guidance cycle;

[0047] Figure 3d In one specific embodiment, the guided object is a lateral cephalometric X-ray of the skull before the start of a craniofacial growth guidance cycle;

[0048] Figure 3e In one specific embodiment, the guiding object is a frontal X-ray of the skull before the start of a craniofacial growth guidance cycle;

[0049] Figure 4 This is a flowchart illustrating the process of determining the set of tooth surface feature parameters according to an embodiment of this application;

[0050] Figure 5 The relative positional relationships of the three-dimensional solid models of the jaws in the target state on the mechanical articulator according to the embodiments of this application;

[0051] Figure 6 This is a flowchart illustrating the determination of the target dental arch curve of the guided object during a craniofacial growth guidance cycle according to an embodiment of this application.

[0052] Figure 7 For a specific tooth position diagram;

[0053] Figure 8 The result is the fit of a real dental arch to an ideal dental arch morphology standard using a quartic function;

[0054] Figure 9 The dental occlusion of the subject after using the craniofacial growth guide system provided in the embodiments of this application. Detailed Implementation

[0055] The present application will now be further described based on preferred embodiments and with reference to the accompanying drawings.

[0056] Figure 1a A schematic diagram of the structure of the personalized craniofacial growth guide 8 provided for some preferred embodiments of this application. Figures 1b to 1d These are the top view, side view, and rear view of the personalized craniofacial growth guide 8, respectively.

[0057] The personalized craniofacial growth guide 8 is used to guide the growth of the craniofacial region of the subject during a craniofacial growth guidance cycle. In the embodiments of this application, without loss of generality, the subject refers to an adolescent or child who is in the growth and development stage of at least one of the following three parts: teeth and their occlusion, skull and jawbone, and facial soft tissue.

[0058] Furthermore, guiding the craniofacial growth of the target can refer to, based on the natural growth potential, combining external interventions applied by instruments (including altering the spatial relationship and biomechanical environment between different craniofacial tissue structures) to block and correct dental and facial deformities that exist in the growth and development of the aforementioned parts, such as malocclusion, jawbone developmental abnormalities, and soft tissue developmental abnormalities; it can also refer to the process of purposefully intervening in the growth of one or all of the aforementioned parts for preventive or purely aesthetic purposes, in the absence of dental and facial deformities in the medical sense.

[0059] Furthermore, because human craniofacial growth and development have different physiological characteristics at different stages—for example, during the growth and development of the jawbone, the development of the upper and lower jaws is not synchronous, generally manifested as the lower jaw developing later—as permanent teeth erupt, the occlusion of the upper and lower teeth, driven by the need for function, guides the lower jaw to adapt to the position of the upper jaw and upper dentition in three-dimensional space, causing changes in the position of the lower jaw, secondary growth and remodeling of the temporomandibular joint, thereby coordinating the growth between different craniofacial tissues. Therefore, the above-mentioned guidance of craniofacial growth generally needs to be carried out in stages: within one craniofacial growth guidance cycle, a personalized craniofacial growth guide is used; in another craniofacial growth guidance cycle that does not overlap in time, another or a personalized craniofacial growth guide is used. The number of guidance cycles is generally determined by factors such as the age of the guided subject, the growth and development of various craniofacial tissues, the severity of dental deformities, or the gap between the desired effect and the initial state. The aforementioned at least two personalized craniofacial growth guides used in at least two non-overlapping craniofacial growth guidance cycles constitute a craniofacial growth guidance system for guiding the craniofacial growth process of the guided subject.

[0060] Back Figures 1a to 1d As shown in the figure, in an embodiment of this application, the personalized craniofacial growth guide 8 includes an upper budding groove 81, a lower budding groove 82, and a composite plate 83. The composite plate 83 is located between the upper and lower budding grooves, connecting them into a whole. In an embodiment of this application, the aforementioned upper budding groove 81, lower budding groove 82, and composite plate 83 are referred to as the basic structural units of the personalized craniofacial growth guide 8.

[0061] Furthermore, such as Figures 1a to 1dAs shown, the upper eruption guide groove 81 is formed by the upper eruption guide groove outer wall 811, the upper eruption guide groove inner wall 812, and the cladding plate 83. Its groove is arched and is used to accommodate the upper dentition, part of the maxilla, and part of the soft tissue such as the upper gingiva of the guided object and guide its growth process. The lower eruption guide groove 82 is formed by the lower eruption guide groove outer wall 821, the lower eruption guide groove inner wall 822, and the cladding plate 83. Its groove is arched and is used to accommodate the lower dentition, part of the mandible, and part of the soft tissue such as the lower gingiva of the guided object and guide its growth process. At the same time, through the connection of the cladding plate 83, it can further guide the secondary growth and remodeling of the temporomandibular joint of the guided object, thereby adjusting the occlusal relationship of the upper and lower jaws.

[0062] In some preferred embodiments, the personalized craniofacial growth guide 8 can be made of medical silicone or other similar soft and elastic materials by molding or other techniques known to those skilled in the art. During the manufacturing process, the outer walls of the upper and lower growth guide grooves, the inner walls of the upper and lower growth guide grooves and the composite plate can be made integrally, or they can be made separately and then assembled by bonding or other similar methods.

[0063] Furthermore, in some preferred embodiments, the upper budding groove 81 and / or the lower budding groove 82, as well as the inner and outer walls of the upper budding groove 81 and / or the lower budding groove 82, also include various attachments. For example, in some preferred embodiments, the upper budding groove 81 and / or the lower budding groove 82 includes at least one retention attachment. The retention attachment uses the erupted teeth in the correct position to retain the growth guide, thereby helping the softer personalized craniofacial growth guide 8 to stabilize in the correct wearing position, and using the teeth already retained in the correct position to strengthen the intervention force applied to the various tissue structures of the craniofacial region of the guided object; as another example, in some preferred embodiments... In the embodiments, the upper eruption guide groove 81 and / or the lower eruption guide groove 82 include at least one guiding accessory. The guiding accessory is used to guide the erupting or about-to-erupt teeth to erupt in the ideal direction and position. It can be a spatial structure that extends along the guiding path or an obstacle avoidance structure that blocks incorrect paths. Furthermore, in some preferred embodiments, the inner and outer walls of the upper eruption guide groove 81 and / or the lower eruption guide groove 82 may also include at least one of the following: lip guard, tongue guard, buccal shield, and tongue position guide. As guiding accessories for the masticatory organs, the above accessories can guide or adjust the position and shape of tissue structures in different parts of the oral cavity, thereby guiding the functional state of the masticatory organs as a whole.

[0064] In the embodiments of this application, the morphology of each of the above basic structural units, such as the groove shape, style, angle and depth of the upper guide groove and / or lower guide groove, as well as the position, shape and size of various accessories set on each basic structural unit, are referred to as the design parameters of each basic structural unit. Table 1 below lists the design parameters of the basic structural units that can be set in some embodiments.

[0065] Table 1

[0066]

[0067] Clearly, the core step in designing a personalized craniofacial growth guide is correctly determining the aforementioned design parameters. By wearing a personalized craniofacial growth guide designed and manufactured according to these parameters, the recipient can gradually guide the tissue structures of various parts of the craniofacial region to the target location during their corresponding craniofacial growth guidance cycle. To improve the growth guidance effect of the personalized craniofacial growth guide, the determination process of the aforementioned design parameters should follow these principles:

[0068] a) The design of craniofacial growth guides should be based on reasonable medical concepts, taking the masticatory organs as a complete functional unit, respecting the functional and aesthetic principles of the masticatory organs, and achieving the best balance between the personalized morphology and function of each patient's masticatory organs.

[0069] b) The design of craniofacial growth guides also needs to conform to the physiological characteristics of different stages of human craniofacial growth and development, and to change the spatial positional relationship and biomechanical environment between different craniofacial tissue structures in stages according to the individualized dental deformity characteristics of patients.

[0070] c) The design of craniofacial growth guides should also conform to the principle of functional synergy. During the growth and development of the craniofacial region, the development of the maxilla and mandible is asynchronous, with the mandible developing later. As permanent teeth erupt, the occlusion of the maxilla and mandible guides the mandible to adapt to the position of the maxilla and maxillary arch in three-dimensional space due to the need to perform functions, causing changes in the position of the mandible, secondary growth and remodeling of the temporomandibular joint, thereby coordinating the growth between different craniofacial tissue structures.

[0071] d) Furthermore, based on the physiological laws of occlusal development and jawbone development, it is necessary to achieve the goals of guiding tooth eruption and guiding jawbone growth in stages. The teeth that play a supporting and fixing role are different in each stage, and the teeth that need to be guided to erupt are different. The adjustment of the relative positional relationship of a large number of jaw bones in the same stage and the guidance of growth can also be achieved step by step. Therefore, a corresponding personalized craniofacial growth guide should be designed for each craniofacial growth guidance cycle, and finally a craniofacial growth guidance system suitable for the entire craniofacial growth stage should be formed.

[0072] Therefore, this application also provides a design method for the aforementioned personalized craniofacial growth guide. Figure 2 A flowchart illustrating the design method of the personalized craniofacial growth guide described above is shown in some preferred embodiments, such as... Figure 2 As shown, this design method includes the following steps:

[0073] Step S100: Obtain the initial values ​​of the craniofacial parameter combination of the guiding object;

[0074] Step S200: Determine the target value of the craniofacial parameter combination of the guided object;

[0075] Step S300: Determine the design parameters of the basic structural units of the personalized craniofacial growth guide based on the target value;

[0076] Step S400: Open the occlusion of the guiding object on the occluder based on the target value, and design a personalized craniofacial growth guide based on the design parameters.

[0077] The above steps will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0078] <Step S100>

[0079] Step S100 is used to obtain the initial state of parameters such as the position, shape, and relative relationship of various parts of the craniofacial region of the guided object at the beginning stage of a craniofacial growth guidance cycle. In the embodiments of this application, the position, shape, and relationship of the teeth and occlusion, skull and jawbone, facial soft tissue, and other parts of the craniofacial region of the guided object can be characterized by a combination of craniofacial parameters.

[0080] In some specific embodiments, the craniofacial parameter combination includes a set of dental surface feature parameters and / or dental arch morphology.

[0081] 1) Set of tooth surface feature parameters

[0082] Table 2 below shows an optional set of tooth surface feature parameters and the indices used. As shown in Table 2, the set of tooth surface feature parameters can be composed of a two-dimensional matrix. This two-dimensional matrix represents the tooth surface features of the guiding object from two dimensions. One dimension is tooth shape, bone shape, and facial shape, and the other dimension is vertical, sagittal, and horizontal. In the two-dimensional matrix that constitutes the set of tooth surface feature parameters shown in Table 2, each element in the matrix can be selected from indices known to those skilled in the art. For example, when it is necessary to represent the vertical bone shape features of the guiding object, the FMA index can be used. When it is necessary to represent the sagittal facial shape features of the guiding object, the lateral convexity index can be used.

[0083] Table 2

[0084]

[0085]

[0086] The importance of each indicator in the above set of tooth surface feature parameters varies. Among them, the facial features of the guiding object in the vertical and sagittal directions (i.e., subfacial height and lateral convexity) and the tooth features of the guiding object in the sagittal direction (i.e., molar relationship) can effectively reflect the tooth surface features of the guiding object. Therefore, in some embodiments, the set of tooth surface feature parameters can be composed of the above three indicators. In addition, in order to more comprehensively evaluate the tooth surface features of the guiding object, in other embodiments, all nine indicators of the above 3×3 matrix can be selected to construct the set of tooth surface feature parameters.

[0087] In addition to the two-dimensional set of tooth surface feature parameters mentioned above, in some preferred embodiments of this application, the set of tooth surface feature parameters also includes the following occlusal performance parameters, such as: tooth development stage, reverse occlusion, tooth position and occlusal plane angle, etc.

[0088] 2) Dental arch curve

[0089] The maxillary dentition, composed of the teeth in the upper jaw, and the mandibular dentition, composed of the teeth in the lower jaw, are arranged in a roughly arch-shaped pattern. In the field of oral science, this arch-shaped pattern can be represented by curves of various functional forms, which are called dental arch curves.

[0090] Specifically, by marking the characteristic points on each tooth of the maxilla and mandible (such as the midpoint of the crown, the cusp, or the buccal cusp of each tooth), and then fitting each marked point, the initial dental arch curve of the guided object can be obtained. This curve represents the initial value of the dental arch morphology before the start of a craniofacial growth guidance cycle.

[0091] Figure 3a , Figure 3b , Figure 3c , Figure 3d and Figure 3e The following are examples of a specific embodiment: the morphology of the craniofacial region at various angles, intraoral photographs at various angles, lateral cephalometric radiographs, and anteroposterior cephalometric radiographs of the guided object before the start of a craniofacial growth guidance cycle. In addition, a three-dimensional solid model of the guided object's teeth and jaws can be generated based on the above data, and the occlusal plane angle can be measured on a mechanical articulator. By measuring and evaluating the tissue structure information contained in the above data and model, the initial values ​​of the above set of tooth surface feature parameters can be obtained. Table 3 below lists the initial values ​​of the set of tooth surface feature parameters of the guided object in this embodiment.

[0092] Table 3

[0093]

[0094]

[0095] Furthermore, after marking and fitting the feature points on each tooth, the initial maxillary / mandibular dental arch curve of the guided object can be obtained. In addition, the fitted initial dental arch curve can be further measured and analyzed, for example, by... Figures 3a to 3e The initial dental arch curve of the guided object was measured and analyzed, which determined that there was mild narrowing and deformation of the upper and lower dental arches before the start of the craniofacial growth guidance cycle. Among them, the upper and lower anterior dental arches were crowded by 2 mm.

[0096] <Step S200>

[0097] For a subject requiring craniofacial growth guidance (e.g.) Figures 3a to 3e (and the embodiments shown in Table 3) Generally, before the start of a craniofacial growth guidance cycle, the initial state of the parameters in its craniofacial parameter combination, such as at least one of the indicators in the set of dental surface feature parameters, and / or at least one of its maxillary and mandibular dental arch curves, and / or at least one of its occlusal performance set, will deviate from its ideal state. The ideal state of each parameter in the above-mentioned craniofacial parameter combination is its target value at the end of the craniofacial growth guidance cycle.

[0098] In the embodiments of this application, step S200 is used to determine the target value of the above-mentioned craniofacial parameter combination of the guiding object. Obviously, in the embodiments of this application, the target value of the craniofacial parameter combination includes at least the target value of the set of dental surface feature parameters and the target value of the dental arch morphology. Preferably, it also includes the target value of the above-mentioned occlusal performance set.

[0099] In some preferred embodiments, such as Figure 4 As shown, the target values ​​for the set of tooth surface feature parameters and the dental arch morphology can be determined through the following steps:

[0100] Step A100: Clarify the adjustment direction of each parameter in the craniofacial parameter combination.

[0101] The direction of adjustment for each parameter should be determined based on the occlusal development stage of the target individual, the tooth eruption sequence, the jawbone growth trend and growth pattern, and the oral functional characteristics. For example, in some preferred embodiments, it can be adjusted according to... Figure 4 The steps shown first determine the causes and degree of influence of dental surface deformities by analyzing the set of tooth surface feature parameters and the morphology of the dental arch. Then, based on the analysis results, strategies for mandibular bone movement, tooth movement, and facial soft tissue adjustment are formulated in sequence.

[0102] Specifically, the analysis of the causes and degree of influence of dental facial deformities can be carried out along the vertical, sagittal, and horizontal directions of the guided object, with the following steps performed sequentially in each direction:

[0103] The first step is to extract the facial and bone parameters in this direction;

[0104] The second step is to determine whether there are any jawbone morphological abnormalities in the target subject in that direction based on the bone type parameters in that direction.

[0105] The third step is to determine whether there are any soft tissue morphological abnormalities in this direction based on the relative relationship between the bone type parameters and the facial type parameters in this direction.

[0106] The fourth step is to extract the tooth shape parameters in this direction and use these parameters to determine whether there are any abnormalities in the jawbone positional relationship or the tooth / bone positional relationship in this direction.

[0107] The fifth step is to determine the degree of influence of each type of tooth surface deformity in that direction.

[0108] In the above steps, the mechanism of facial morphology of the guided object is first analyzed by deconstructing the relative relationship between facial and bone types. Based on the relative relationship between bone and facial parameters, the soft tissue morphological characteristics, i.e., the coverage characteristics of soft tissue relative to the jawbone, can be determined. This allows us to determine whether different facial morphological abnormalities are caused by bone abnormalities, craniofacial soft tissue morphological abnormalities (i.e., normal bone and dental types), or both. For example, when the guided object has dental deformities in the sagittal direction, and its facial parameters (lateral convexity value) are relatively consistent with its bone parameters (ANB value), it can be considered that the soft tissue coverage is not the cause of the dental deformity in the sagittal direction. When the lateral convexity value of the guided object deviates more from the normal range than the ANB value, it can be considered that the cause of the dental deformity in the sagittal direction includes not only bone abnormalities but also soft tissue morphological abnormalities.

[0109] Next, the tooth profile parameters of the guided object are extracted. For example, based on the sagittal tooth profile parameters, it can be determined whether there is an abnormal tooth / bone positional relationship in the sagittal direction (such as mesial movement of molars due to premature loss of deciduous teeth). Furthermore, based on the molar relationship, the sagittal positional relationship of the mandible is classified into Class I (normal), Class II (mandibular retrusion), and Class III (mandibular anterior displacement). Among them, the above-mentioned abnormal tooth / bone positional relationship, mandibular retrusion, and mandibular anterior displacement (i.e., abnormal jawbone positional relationship) are all causes of sagittal tooth surface deformities.

[0110] Finally, by synthesizing the various causes of dental deformities in this direction obtained above, and by evaluating the degree of influence of each cause based on craniofacial morphology, the analysis of the causes and degree of influence of dental deformities in this direction is completed.

[0111] Step A200: Determine the target position of the mandible relative to the maxilla.

[0112] Specifically, the target position of the mandible relative to the maxilla can be determined through at least one of the following methods: clinical diagnosis, facebow transfer, mechanical articulation adjustment on a three-dimensional solid model of the jaw, or virtual articulation adjustment on a digital three-dimensional model of the jaw. Figure 3a Taking the guided object shown as an example, based on the analysis of its basic dental facial deformity characteristics, its mandible needs to be rotated and repositioned to the right to correct left mandibular deviation, left-sided crossbite, and left mandibular deviation; at the same time, the mandible should be moved back as much as possible to correct anterior crossbite and improve the concave facial profile. To this end, the relative positional relationship of the upper and lower dental arches and jawbones is first recorded using occlusal recording materials. Then, the mechanical articulator is transferred through an anatomical facebow. The parameters of the mechanical articulator are then adjusted so that the mandible of the three-dimensional solid model of the teeth and jaws on the mechanical articulator can achieve ideal occlusion relative to the maxilla (i.e., determine the target occlusal relationship). Alternatively, the parameters of the virtual articulator can be adjusted in the virtual articulator operation software so that the mandible of the three-dimensional digital model of the teeth and jaws on the virtual articulator can achieve ideal occlusion relative to the maxilla. Figure 5 The relative positional relationships of the three-dimensional model of the jaw in the target state on the articulator are shown.

[0113] Step A300: Determine and design the target values ​​of each parameter in the craniofacial parameter combination of the guided object.

[0114] In this step, the target values ​​of each parameter in the craniofacial parameter combination can be determined according to the functional and aesthetic principles of occlusion. For example, the target values ​​of parameters such as the target dental arch curve, occlusal plane angle and position, upper and lower anterior tooth angle and inclination, and upper and lower molar position.

[0115] It should be noted that, as described in the preceding steps, determining the initial and target values ​​of the craniofacial parameter combination for the guided object requires following different steps. When determining the target value for the guided object, the basic approach is to first analyze the external characteristics of the facial soft tissues, and then analyze the characteristics of the bones and teeth and their mutual influences, thereby gradually and deeply determining the various causes of facial deformities and their degree of influence. For determining the target value of the craniofacial parameter combination, the desired alignment relationship of the upper and lower jaws in three-dimensional space is first set. Then, using aesthetic and functional occlusion principles, personalized dental arch morphology, occlusion between the upper and lower dental arches, the position of the dental arch on the jawbone, the angle and position of the upper and lower anterior teeth, and the angle and position of the occlusal plane are designed. The reason for adopting the above steps is that the morphology and development of the bones are the basis for the various craniofacial tissues to grow in the ideal direction. Guiding their growth to achieve the target state as soon as possible helps to use this as a framework for further adjustment of the teeth and facial tissues.

[0116] <Determining the target dental arch curve>

[0117] The following, with reference to the accompanying diagrams, details the method for determining the target dental arch curve. Adjusting the arch shape to address the arch morphology issues of the patient is a crucial step in guiding cranial growth towards the ideal direction, as this provides the necessary foundation for ideal dentition alignment. Currently, various methods exist for generating or determining the ideal arch shape; however, these often rely on the experience of the dentist or technician, performed manually, or selecting the closest pre-established ideal arch shape from several. These methods cannot guarantee that the generated arch shape meets the functional requirements of dentofacial development and dentition alignment, nor do they consider the differences in dentofacial development stages and rates across different regions. Therefore, they often fail to provide the most suitable target dental arch curve for the patient. Thus, a more rational method for determining the target dental arch curve is needed.

[0118] Figure 6 A flowchart illustrating the determination of the target dental arch curve of the guide object in a craniofacial growth guidance cycle in some preferred embodiments of this application is shown, such as Figure 6 As shown, the target dental arch curve is generated through the following steps:

[0119] Step B100: Annotate the tooth feature points of the guided object.

[0120] Specifically, tooth feature points can be marked on the three-dimensional digital model of the teeth and jaws of the target object, or on images such as cross-sectional radiographs, for subsequent measurement and generation of the target dental arch curve. Statistical analysis shows that shifting the target dental arch curve of the mandible outward by 2.5 mm can obtain the target dental arch curve of the maxilla that meets aesthetic and functional requirements. Therefore, in the embodiments of this application, the target dental arch curve of the mandible can be generated first, and then the target dental arch curve of the maxilla can be generated based on the target dental arch curve of the mandible.

[0121] The marking of tooth feature points can be done manually or automatically. Tooth feature points can be specific locations on each jaw known to those skilled in the art, such as the cusp, mesobalvular cusp, or distobuccal cusp on the crown of a specific tooth. For example, 18 feature points can be marked on the jaw: the midpoint of the incisal edge of the left and right No. 1 teeth, the midpoint of the incisal edge of the left and right No. 2 teeth, the cusp of the left and right No. 3 teeth, the buccal cusp of the left and right No. 4 teeth, the buccal cusp of the left and right No. 5 teeth, the mesobalvular and distobuccal cusps of the left and right No. 6 teeth, and the mesobalvular and distobuccal cusps of the left and right No. 7 teeth.

[0122] In step B200, the first feature parameter C1 and the second feature parameter C2 of the guided object are measured respectively.

[0123] In the embodiments of this application, the first characteristic parameter C1 and the second characteristic parameter C2 refer to quantities with the following properties: On the one hand, C1 and C2 both characterize the inherent characteristics of a jaw in a craniofacial growth guidance cycle. These characteristics are independent of the changes in the dental arch morphology during the guidance cycle. That is, in a craniofacial growth guidance cycle, regardless of whether the jaw is in the ideal arch shape that the guidance cycle should be in, the values ​​of C1 and C2 remain unchanged. On the other hand, C1 and C2 have different definitions in the complete process of craniofacial growth. That is, when the complete process of craniofacial growth is divided into guidance cycles that do not overlap in time, the values ​​of C1 and C2 may be determined according to the characteristics of different tooth combinations in different guidance cycles.

[0124] In some preferred embodiments, C1 is determined by the geometric features of a first set of teeth, wherein the first set of teeth includes a plurality of specific teeth of the maxilla or mandible of a particular jaw; C2 is determined by the geometric features of a second set of teeth, wherein the second set of teeth is a proper subset of the first set of teeth, i.e., the first set of teeth contains and is greater than all the teeth in the second set of teeth.

[0125] by Figure 7 Taking the tooth position diagram shown as an example, in some embodiments, the first tooth set may include 10 teeth from L5 to R5. Correspondingly, the first feature parameter C1 is the sum of the crown widths of teeth 5-5 in the mandible, i.e. Figure 7The sum of the crown widths of teeth L5 to R5 in the middle jaw (it should be noted that, in this application, the sum of the crown widths of n1-n2 refers to the sum of the crown widths of each tooth measured from the leftmost tooth Ln1 to the rightmost tooth Rn2 in the maxilla or mandible), the second set of teeth is a proper subset of the first set of teeth, containing four teeth from L2 to R2, and correspondingly, the second feature parameter C2 is the sum of the crown widths of the mandible's teeth 2-2, i.e. Figure 7 The first tooth set is the sum of the crown widths of teeth L2 to R2. Additionally, the second tooth set may also include 6 teeth (L3 to R3) or 8 teeth (L4 to R4). Correspondingly, the second characteristic parameter C2 is the sum of the crown widths of teeth 3-3 and 4-4 of the mandible. In other embodiments, when teeth L5 or R5 have not yet erupted or are in a stable state, the first tooth set may only include 8 teeth (L4 to R4) of the mandible, and the second tooth set may be 6 teeth (L3 to R3) or 4 teeth (L2 to R2) of the mandible. In this case, the first characteristic parameter C1 is the sum of the crown widths of teeth 4-4 of the mandible, and the second characteristic parameter C2 is the sum of the crown widths of teeth 3-3 and 2-2 of the mandible.

[0126] Step B300: Determine the first ideal dental arch feature parameter R1 based on the first feature parameter C1, and determine the first curve of the following form according to R1:

[0127] Y = AX 4 +BX 2 ,

[0128] Wherein, X and Y are the coordinates of each point on the curve, and both X and Y are located on the jaw plane. Their X-axis and Y-axis are orthogonal, and the Y-axis corresponds to the projection of the midsagittal plane onto the jaw plane. A and B are the coefficients of the fourth and second terms of the first curve, respectively, and are coupled and related to R1.

[0129] Step B400: Determine the second ideal dental arch characteristic parameter R2 based on the second characteristic parameter C2, and determine the second curve in the following form based on R2:

[0130]

[0131] Step B500: The portion of the first curve located in the first dentition interval and the portion of the second curve located in the second dentition interval are spliced ​​together to obtain the target dental arch curve of the guided object in one craniofacial growth guidance cycle.

[0132] Steps B300 and B400 obtain the first ideal dental arch feature parameter R_1 and the second ideal dental arch feature parameter R2 from the first feature parameter C1 and the second feature parameter C2, respectively. Then, based on R1 and R2, the first curve and the second curve are determined. Then, in step B500, the two curves are truncated and spliced ​​to obtain the final target dental arch curve.

[0133] Unlike C1 and C2, in the embodiments of this application, the first ideal dental arch characteristic parameter R1 and the second ideal dental arch characteristic parameter R2 characterize the features that can be found on a dentition when it is in the ideal dental arch shape of a certain craniofacial growth guidance cycle, which are only related to the ideal dental arch curve. That is, if the specific values ​​of R1 and R2 are determined, the target dental arch curve used to describe the ideal arch shape can also be determined. In some preferred embodiments, the first ideal dental arch characteristic parameter R1 is the 5 / 6 proximal point size of the mandible when the dentition of the guided object is in the ideal arch shape (in this application, the m1 / m2 proximal point size refers to the distance between the proximal points of the m1 and m2 teeth on both sides of the maxilla or mandible, and so on). Figure 4 For example, its 5 / 6 adjacency point size refers to the distance between the adjacency points of teeth L5 and L6 on the left and the adjacency points of teeth R5 and R6 on the right.

[0134] The applicant, through statistical analysis of a large amount of normal dental data that meets both aesthetic and functional evaluation standards, discovered that C1 and R1, as well as C2 and R2, are statistically correlated. Therefore, by statistically analyzing multiple normal dental data, C1 / R1 and C2 / R2 can be obtained in advance. After measuring the C1 and C2 of the target patient, the aforementioned statistical relationships are used to determine the R1 and R2 corresponding to the ideal arch shape. Furthermore, since R1 and R2 are derived from statistics on normal dental data of individuals who simultaneously meet normal aesthetic and functional standards, they do not rely on the experience of physicians or technicians. The process of determining R1 and R2 from C1 and C2 undoubtedly eliminates the influence of subjective factors, making the generation of the target dental arch curve more consistent with the physiological characteristics of the target patient's own growth and development.

[0135] Furthermore, the reason for using two different types of curves to splice together the target dental arch curve is that, firstly, using only one type of function curve, such as a beta function curve or a quartic curve, to describe the dental arch morphology can mathematically find the fitting parameters that minimize the overall cost function. However, in some dentition regions, such as the anterior region, the morphology may differ from the optimal morphology that conforms to functional and developmental characteristics.

[0136] Figure 8 The results of fitting a real dentition to an ideal dental arch morphology standard using a quartic function are shown, such as... Figure 8As shown, although the fitted dental arch curve can satisfy the requirement of minimizing the overall cost function of each landmark point on the dentition, the curve shape in its anterior region is closer to a rounded trapezoid. However, based on the analysis of the geometric characteristics of each anterior tooth of this jaw (e.g., the crown width of its left No. 3 to right No. 3 teeth), it is found that the arrangement of its anterior teeth should be closer to a circle. Obviously, by using curves with different function forms to describe different dentition regions, although it may be possible to obtain a dental arch curve with a non-minimized cost function mathematically, it is more in line with the functional requirements of the dental arch shape.

[0137] Secondly, for individuals in the craniofacial growth stage, the dentition not only exhibits different dental arch morphologies in different regions, but also shows significant differences in the development speed and status of each region during dentition development. The relationship between the ideal dental arch morphologies in each region is constantly changing, forming the characteristic of the ideal dental arch curve changing in stages and regions as a whole. Therefore, it is necessary to establish a combination of personalized target dental arch curves for specific dentitions in stages and dentition regions to better fit the developmental characteristics of the dentition.

[0138] For the reasons mentioned above, in the embodiments of this application, the first curve is in the form of a quartic function curve, which is mainly used to characterize the ideal dental arch shape in the posterior region, and the second curve is in the form of a perfect circle, which is mainly used to characterize the ideal dental arch shape in the anterior region. The target dental arch curve can be obtained by splicing the two curves together.

[0139] Furthermore, analysis of measurement data from multiple normal dentitions revealed that, since the first curve includes at least two polynomial coefficients A and B, these two coefficients jointly influence the curve shape, and their influences are mutually coupled. This results in A, B, and R1 being correlated as a whole. Therefore, it is necessary to construct an intermediate dental arch curve to establish the relationship between R1 and A and B. To this end, in some preferred embodiments, the relationship between R1 and A and B is determined through the following steps:

[0140] Step B310: Obtain the optimal dental arch curves of multiple normal dentitions that meet functional and aesthetic standards. The optimal dental arch curves have the same functional form as the first curve, and their two coefficients A... best B best The determination is based on the fitting of measurement data for each normal jaw.

[0141] Specifically, the optimal dental arch curve can be fitted based on the measurement data of each reference jaw using methods known to those skilled in the art.

[0142] Step B320: Obtain the intermediate dental arch curve for each normal dentition, wherein the intermediate dental arch curve has the same functional form as the first curve, and its two coefficients include a fixed coefficient A.mean And a variable coefficient B adjust Where, the fixed coefficient A mean Based on the corresponding coefficient A in each optimal dental arch curve best The statistical value is determined, and the variable coefficient B is... adjust The determination was based on the fitting of measurement data from the normal jaw.

[0143] Specifically, firstly, the coefficient A in multiple optimal dental arch curves... best Perform statistical analysis to obtain statistical values, such as the mean, and use them as a fixed coefficient A. mean Then, with the coefficients fixed, the intermediate dental arch curves of each normal dentition are fitted. Obviously, the coefficients B (i.e., variable coefficients) of these intermediate dental arch curves are different for different reference dentitions, denoted as B0. adjust In this way, an intermediate dental arch curve with a sufficiently small error relative to the optimal dental arch curve for each normal jaw can be obtained, but which contains only one variable coefficient.

[0144] Step B330, statistically determine B adjust With A best B best And the relationship between R1.

[0145] Correlation statistics revealed that the variable coefficient B adjust The coefficients A and B, which are respectively strongly correlated with the optimal dental arch curve and the first ideal dental arch characteristic parameter R1, can be used as a "bridge" to establish the relationship between R1 and A and B. Therefore, in step B330, the relationship between the first ideal dental arch characteristic parameter R1 and the variable coefficient B can be established based on the first ideal dental arch characteristic parameter R1 of each normal jaw. adjust The statistical relationship, and the variable coefficient B for each normal jaw. adjust The relationship between the coefficients A and B of the optimal dental arch curve is used to determine the coefficients A and B of the first curve of the guided object, represented by R1. Then, the coefficients A and B of the first curve of the guided object, represented by C1, are obtained according to the relationship between C1 and R1. Since the first characteristic parameter C1 is a quantity that remains unchanged in the dental jaw of the guided object during a craniofacial growth guidance cycle, this method can automatically generate the first curve using the measurable data of the dental jaw of the guided object before the guidance cycle.

[0146] Based on a similar implementation, in step B400, a second curve can be automatically generated using measurable data of the subject's jaws prior to the guidance cycle, which will not be elaborated further here.

[0147] After obtaining the first curve and the second curve through the above steps, in step B500, the portion of the first curve in the first dentition interval and the portion of the second curve in the second dentition interval are spliced ​​together to obtain the target dental arch curve corresponding to a craniofacial growth guidance cycle of the guided object's dentition. In some preferred embodiments, the first dentition interval is the left and right posterior tooth region, and the second dentition interval is the anterior tooth region. Further, the intersection of the first dentition interval and the second dentition interval is located in the projection area of ​​the canines in the occlusal plane.

[0148] Since the first curve and the second curve may be misaligned at the junction of the first and second dental arch intervals, in some preferred embodiments, a transition curve can be used to connect the truncated first curve and the second curve. This transition curve can be generated through the following steps:

[0149] First, a specific length is cut off from the portion of the first curve in the first dentition area and extended towards the posterior dentition area;

[0150] Then, a transition curve is generated by fitting the remaining part of the first curve with the part of the second curve in the second dental arch interval.

[0151] In particular, special attention should be paid to the specific length of the cut. It should not be too small to avoid a sharp turn when the first curve and the second curve are spliced ​​together, nor should it be too large to avoid excessive cutting and excessive deviation in the shape of the target curve after fitting. In some preferred embodiments, the specific length of the cut is greater than or equal to the crown length of the first premolar and less than or equal to 10 mm.

[0152] <Steps S300 and S400>

[0153] After obtaining the target value of the craniofacial parameter combination in step S200, the design parameters of the basic structural unit of the personalized craniofacial growth guide can be determined in step S300 according to the above target value.

[0154] In some specific embodiments, the basic structural units of a personalized craniofacial growth guide can be constructed first. Each structural unit corresponds to the design parameters of the target position. The range of adjustment allowed for each parameter is set according to the characteristics of the pre-selected guide material (elasticity, hardness, ductility, etc.). The growth guidance process is decomposed to obtain the treatment target position corresponding to the craniofacial growth guidance cycle.

[0155] Next, in step S400, the occlusion of the guide object is opened on the mechanical or virtual frame according to the target occlusal relationship between the mandible and the maxilla, thereby opening space for accommodating the various basic structural units of the personalized craniofacial growth guide. Then, each basic structural unit is designed according to the design parameters obtained in step S300. Finally, a physical model of the personalized craniofacial growth guide or a three-dimensional digital model of the virtual personalized craniofacial growth guide is obtained through integrated or combined methods.

[0156] Furthermore, in some preferred embodiments, as described above, in addition to the basic structural unit, the personalized craniofacial growth guide also includes various attachments in the grooves of the upper and / or lower eruption guide grooves, as well as on the inner and outer walls of the upper and / or lower eruption guide grooves. Obviously, the design parameters of various attachments should be selected based on the functions they perform, and designed according to whether they are in the target position. Therefore, in some preferred embodiments, the craniofacial parameter combination also includes the morphology of each tooth of the guided object (including eruption stage, position, etc.) and the functional state of the masticatory organs of the guided object (including the functional state of each part such as the tongue, lips, and cheeks).

[0157] Based on the target values ​​for tooth morphology and masticatory organ function, various attachment structures can be added to the basic structural unit. For example, a primary permanent tooth with a basically completed root development or a primary tooth with root resorption not exceeding 1 / 2 of its root length can be used as a retention tooth. A retention attachment corresponding to the retention tooth can be added to the corresponding position of the basic structural unit. This retention attachment can stabilize the position of the craniofacial growth guide in the mouth. Alternatively, at least one guiding attachment can be added to guide teeth that are erupting or about to erupt to erupt in the ideal direction and position, and to correct misaligned erupted teeth. Furthermore, according to the ideal functional state that the masticatory organ wants to achieve, at least one of the following can be added to the personalized craniofacial growth guide: a lip guard, a tongue guard, a buccal shield, and a tongue position guide.

[0158] Furthermore, during the complete craniofacial growth guidance process for a subject, since the developmental stages and speeds of different parts vary, it is often necessary to divide the growth guidance process into two, three, or even more craniofacial growth guidance cycles, and design a corresponding personalized craniofacial growth guide for each cycle. The aforementioned at least two personalized craniofacial growth guides corresponding to different cycles can constitute a complete craniofacial growth guidance system, thereby continuously providing growth guidance for the subject during the craniofacial growth and development process.

[0159] Still with Figures 3a to 3eTaking the guided subject as an example, the permanent teeth 6, 1, and 2 (i.e., the 6th, 1st, and 2nd permanent teeth on the left and right sides) will begin to erupt approximately 12 months later. When designing the personalized craniofacial growth guide used in the current guidance cycle, deciduous teeth III, IV, and V can be used as retaining teeth to stabilize the relative position of the upper and lower jaws. This ensures that the jawbone can be maintained in the treatment target position when the subject wears the growth guide at night, thus guaranteeing normal jawbone growth. Therefore, retaining attachments can be designed on deciduous teeth III, IV, and V to increase the stability of the growth guide and maintain the jaw position.

[0160] At the same time, the target positions for permanent teeth 6, 1, and 2 can be reserved on the craniofacial growth guide so that these permanent teeth can erupt as naturally as possible to achieve the ideal permanent tooth arrangement and dental arch shape according to the eruption path and eruption space reserved on the growth guide: the positions of 1 and 2 should be more labial than the current deciduous teeth I and II, and normal anterior overbite should be established to achieve the required aesthetics and function; the upper left 6 should erupt a little more than the upper right 6 to correct the inconsistency between the left and right lateral occlusal planes.

[0161] To ensure sufficient material space between the upper and lower jaws to accommodate the growth guide, and to ensure the retention, resistance, and tolerance of the growth guide, the occlusal space between the upper and lower dental arches can be appropriately opened on the articulator according to the desired material properties.

[0162] After these teeth have developed, the patient enters the next craniofacial growth guidance cycle. At this time, the newly erupted 6, 1, and 2 teeth can support the jaw position. Then, new clinical data can be submitted to design the next personalized craniofacial growth guide, using the permanent 6, 1, and 2 teeth as retaining teeth to help the growth guide stabilize the jaw position relationship and reserve the necessary eruption path and target position for the next permanent 3, 4, and 5 teeth to erupt.

[0163] Figure 9 It shows Figures 3a to 3e The illustrated guide object shows the tooth occlusion after approximately 3 years of craniofacial growth guidance using the craniofacial growth guide system provided in this application embodiment. Figure 9 It can be seen that the deformities of various parts of the craniofacial region of the guided subjects have been significantly improved and are growing in the desired direction.

[0164] The specific embodiments of this application have been described in detail above. For those skilled in the art, several improvements and modifications can be made to this application without departing from the principle of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A method for designing a personalized craniofacial growth guide, characterized in that, Includes the following steps: Obtain the initial values ​​of the craniofacial parameter combination of the guiding object; Determine the target values ​​for the craniofacial parameter combination of the guided object; Based on the target value, determine the design parameters of the basic structural unit of the personalized craniofacial growth guide; Based on the target value, the occlusion of the guided object is opened on the scaffold, and a personalized craniofacial growth guide is designed based on the design parameters; The craniofacial parameter combination includes the dental arch morphology of the guiding object; The initial value of the dental arch morphology is characterized by the initial dental arch curve, and the target value of the dental arch morphology is characterized by the target dental arch curve. The target dental arch curve is generated through the following steps: Annotate the tooth feature points of the guided object; The first characteristic parameter of the guided object was measured separately. Second characteristic parameter ; Based on the first feature parameter Determine the characteristic parameters of the first ideal dental arch ,according to Determine the first curve in the following form: ， in, X , Y The coordinates of each point on the curve are respectively, and X , Y All are located on the jaw plane, and their X axis, Y The axes are orthogonal, and Y The axis corresponds to the projection of the midsagittal plane onto the jaw plane. A , B These are the coefficients of the fourth and second terms of the first curve, respectively, and are related to the... Coupling-related; Based on the second feature parameter Determine the characteristic parameters of the second ideal dental arch ,according to Determine the second curve in the following form: The portion of the first curve located in the first dentition interval and the portion of the second curve located in the second dentition interval are spliced ​​together to obtain the target dental arch curve of the guided object in one craniofacial growth guidance cycle; The first dentition interval is the left and right posterior tooth region; and the second dentition interval is the anterior tooth region.

2. The personalized craniofacial growth guide design method according to claim 1, characterized in that, The craniofacial parameter combination also includes: The set of tooth surface feature parameters of the guided object.

3. The personalized craniofacial growth guide design method according to claim 2, characterized in that, The set of tooth surface feature parameters includes: The surface features of the guided object in the vertical and sagittal directions, and the tooth features of the guided object in the sagittal direction.

4. The personalized craniofacial growth guide design method according to claim 3, characterized in that, The set of tooth surface feature parameters also includes: The guiding object's skeletal and dental features in the vertical direction, the guiding object's skeletal features in the sagittal direction, and the guiding object's facial, skeletal, and dental features in the horizontal direction.

5. The personalized craniofacial growth guide design method according to claim 1, characterized in that: The , The same craniofacial growth guidance cycle for the guided object remains unchanged, and the above... , Different craniofacial growth guidance cycles are defined in different ways for different guided objects; The , The ideal arch shape used to characterize the dentition of the guided object, and the , Each with the above , Strong statistical correlation.

6. The personalized craniofacial growth guide design method according to claim 1, characterized in that: The intersection of the first dentition interval and the second dentition interval is located within the projection area of ​​the canine in the occlusal plane.

7. The personalized craniofacial growth guide design method according to claim 1, characterized in that, The basic structural unit includes: Upper guide groove, lower guide groove, and the connecting plate between the upper and lower guide grooves.

8. The personalized craniofacial growth guide design method according to claim 7, characterized in that, The design parameters include: The shape, style, angle, and depth of the upper and lower guide grooves.

9. The personalized craniofacial growth guide design method according to claim 2, characterized in that, The craniofacial parameter combination also includes the morphology of each tooth of the guiding object.

10. The personalized craniofacial growth guide design method according to claim 9, characterized in that, It also includes the following steps: At least one retention attachment is added to the personalized craniofacial growth guide. The retention attachment is designed to retain the craniofacial growth guide on a mature deciduous permanent tooth with basically completed root development or a deciduous tooth with root resorption not exceeding 1 / 2 of the root length.

11. The personalized craniofacial growth guide design method according to claim 9, characterized in that, It also includes the following steps: At least one guiding attachment is added to the personalized craniofacial growth guide, which guides the erupting or soon-to-erupt teeth to erupt in an ideal direction and position.

12. The personalized craniofacial growth guide design method according to claim 2, characterized in that, The craniofacial parameter combination also includes the functional status of the masticatory organs of the guided object.

13. The personalized craniofacial growth guide design method according to claim 12, characterized in that, It also includes the following steps: At least one of the following is added to the personalized craniofacial growth guide: lip block, tongue block, cheek shield, and tongue position guide.

14. A personalized craniofacial growth guide, composed of multiple basic structural units, characterized in that: The basic structural unit includes an upper guide groove, a lower guide groove, and a composite plate connecting the upper and lower guide grooves; The personalized craniofacial growth guide is designed and generated using the design method of the personalized craniofacial growth guide described in claim 1.

15. A craniofacial growth guidance system, characterized in that: It includes at least two personalized craniofacial growth guides as described in claim 14, each used to guide the craniofacial growth process of the subject in at least two non-overlapping craniofacial growth guidance cycles.

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