CN111658187B - Method for simulating pose change of digital tooth model - Google Patents
Method for simulating pose change of digital tooth model Download PDFInfo
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- CN111658187B CN111658187B CN202010239922.3A CN202010239922A CN111658187B CN 111658187 B CN111658187 B CN 111658187B CN 202010239922 A CN202010239922 A CN 202010239922A CN 111658187 B CN111658187 B CN 111658187B
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
- A61C7/00—Orthodontics, i.e. obtaining or maintaining the desired position of teeth, e.g. by straightening, evening, regulating, separating, or by correcting malocclusions
- A61C7/002—Orthodontic computer assisted systems
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T17/00—Three dimensional [3D] modelling, e.g. data description of 3D objects
- G06T17/20—Finite element generation, e.g. wire-frame surface description, tesselation
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/10—Segmentation; Edge detection
- G06T7/12—Edge-based segmentation
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/10—Image acquisition modality
- G06T2207/10072—Tomographic images
- G06T2207/10081—Computed x-ray tomography [CT]
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/30—Subject of image; Context of image processing
- G06T2207/30004—Biomedical image processing
- G06T2207/30036—Dental; Teeth
Abstract
The invention discloses a method for simulating pose change of a digital tooth model, which comprises the following steps: acquiring a digital dental model, wherein the digital dental model comprises a digital dental crown model and a digital dental root model; segmenting the digitized dental model into a single digitized tooth model comprising a digitized crown model and a digitized root model; based on the initial position and the target correcting position of the single digital tooth model, the pose change design of the single digital tooth model is carried out by combining the rotation center of the single digital tooth model, so that the pose change position of the digital tooth root model is controlled. The method solves the problems of design rationality and safety caused by the fact that the pose change of the teeth cannot be simulated in advance in the tooth correction process.
Description
Technical Field
The invention belongs to the technical field of tooth correction, and particularly relates to a method for simulating pose change of a digital tooth model.
Background
The existing orthodontic treatment technology for correcting the dental deformity comprises the traditional fixed correction technology based on an arch wire and a bracket and the hidden correction technology developed in recent years.
In orthodontic treatment, the type of tooth movement includes two basic ways from a mechanical point of view: translation and rotation, and the two moving modes depend on the position relation of the impedance center and the rotation center. The impedance center is a resistance center which restrains the movement of an object when force acts on the object, and the position of the impedance center is related to the length, the shape and the periodontal tissue of a tooth root and is unrelated to the correcting force applied to the tooth; the center of rotation is a center around which the object rotates under the action of an external force, and the center of rotation varies with the magnitude of the orthodontic force applied to the teeth, the direction of the action, and the position of the point of action.
In orthodontic treatment, an appliance effects movement of teeth by applying an orthodontic force to the teeth. The expression of the torque of the correcting force is related to the position of the rotation center, and the improper control of the rotation center can greatly increase the risk that the tooth root breaks through the bone wall in the tooth moving process. In the fixed orthodontic technology, torque force is applied by different arch wires and brackets in torque control, the realization of the mode is determined according to clinical experience of a clinician, and the torque angle and the torque force are difficult to control accurately, so that the position of a rotation center is difficult to control, particularly, the labial alveolar bone of teeth in an anterior tooth area is thin, and the risk that a tooth root breaks through a bone wall is easy to occur during rotation. For the invisible orthodontic technology without brackets, an orthodontic scheme needs to be designed virtually in advance, the design has very high requirements on experience of clinicians and designers and design accuracy of design and software, so that pose change adjustment is carried out on a digital tooth model in a design stage, and the orthodontic effect of a subsequently prepared shell-shaped tooth appliance on teeth of a patient is determined. The important adjustment means in the change of the pose of the digital tooth model is to control the torque of teeth needing torque movement, control the tooth root at the safe movement position in the alveolar bone and reduce the occurrence probability of medical accidents.
Therefore, the research on how to obtain the pose change of the tooth model through a digital means has great significance for obtaining the pose change position of the tooth root in advance so as to realize the safe movement of the tooth.
Disclosure of Invention
The invention mainly aims to overcome the defects of the prior art and provide a method for simulating the pose change of a digital tooth model, and solves the problems of design rationality and safety caused by the fact that the pose change of teeth cannot be simulated in advance in the tooth correction process through the initial position and the target position of a single digital tooth model and the pose change design of a rotation center of the single digital tooth model.
The technical scheme provided by the invention is as follows:
a method of simulating pose changes of a digitized tooth model, comprising:
acquiring a digital dental model: acquiring a digital dental model, wherein the digital dental model comprises a digital dental crown model and a digital dental root model;
segmenting the digital dental model: segmenting the digitized dental model into a single digitized tooth model comprising a digitized crown model and a digitized root model;
designing the pose change of a single digital tooth model: based on the initial position and the target correcting position of the single digital tooth model, the pose change design of the single digital tooth model is carried out by combining the rotation center of the single digital tooth model, so that the pose change position of the digital tooth root model is controlled.
Preferably, the method for designing the center of rotation of the single digital tooth model comprises the following steps: designing a digital tooth appliance which enables a digital crown model to move from an initial position to a target correction position based on the pose change of the single digital tooth model, and judging the type of the pose change of the single digital tooth model, wherein the type of the pose change of the single digital tooth model comprises translation and rotation; and then controlling the position of the design rotation center based on the pose change type of the single digital tooth model and the ratio of the moment generated by the digital dental appliance applied to the digital dental crown model to the balance moment generated by the digital dental crown model applied to the digital dental appliance. Preferably, when the type of pose change of the single digital tooth model is translation, the ratio of the moment generated by applying the digital crown model to the balance moment generated by applying the digital dental appliance is 1.
Preferably, the center of rotation position is designed at infinity.
Preferably, when the type of pose change of the single digital tooth model is rotation, the ratio of the moment generated by applying the digital crown model to the balance moment generated by applying the digital dental appliance is 0, or between 0 and 1, or greater than 1.
Preferably, when the pose change type of the single digital tooth model is rotation, the rotation center position is designed to be coincident with the impedance center of the tooth when the ratio of the moment generated by applying the digital crown model to the balance moment generated by applying the digital dental appliance is 0.
Preferably, the pose of the digitized root model is changed to a tilt movement.
Preferably, when the type of pose change of the single digital tooth model is rotation, and the ratio of the moment generated by applying the digital dental crown model to the balance moment generated by applying the digital dental appliance is 0 to 1, the rotation center position is designed to be a position away from the impedance center of the tooth and the rotation center is not coincident with the impedance center.
Preferably, the pose change of the digitized root model is rotation.
Preferably, when the pose change type of the single digital tooth model is rotation, the rotation center position is designed at a position close to the cusp of the digital dental crown model when the ratio of the moment generated by applying the torque to the digital dental crown model to the balance moment generated by applying the torque to the digital dental appliance is greater than 1.
Preferably, the pose of the digital root model is changed into root control movement, and the movement amount of the digital root model is larger than that of the digital crown model.
Preferably, the digital dental appliance is a digital bracket appliance or a digital shell dental appliance.
Preferably, the single digital tooth model comprises a single digital tooth model in an anterior tooth area and a single digital tooth model in a posterior tooth area.
Preferably, the method further comprises the step of obtaining a digital alveolar bone model, wherein the pose of the digital tooth root model is adjusted in the corresponding digital alveolar bone so as to avoid the digital alveolar bone model from generating bone windowing or bone cracking.
Preferably, the digital alveolar bone model is obtained by a full jaw curve slice, an oral cavity CT slice or an oral cavity cone beam CT slice.
The method for simulating the pose change of the digital tooth model can bring at least one of the following beneficial effects:
based on the initial position and the target correcting position of the single digital tooth model, the pose change design of the single digital tooth model is carried out by combining the rotation center of the single digital tooth model, when the pose change of a single digital tooth model is designed, the digital tooth root model is controlled to move at a safe position, thereby obtaining the pose change position of the tooth root in advance, combining the relative positions between the monomandibular teeth and between the maxillary and mandibular teeth, the digital tooth arrangement design of the whole jaw teeth can be carried out, the digital tooth arrangement design scheme can be used for a patient to visually know the change of the correction process, and the digital tooth corrector for the upper jaw or the lower jaw is designed and prepared, and the prepared digital tooth corrector can enable teeth to generate expected movement and change when the patient is corrected, so that the problem that whether the tooth roots can safely move or not can not be known in advance is solved.
Drawings
The foregoing features, technical features, advantages and embodiments are further described in the following detailed description of the preferred embodiments, which is to be read in connection with the accompanying drawings.
FIG. 1 is a cross-sectional view of a partial overhead shadow including teeth in an initial position and an actual correction position.
Fig. 2 is a schematic view illustrating the movement of the maxillary anterior teeth from the initial position to the actual correction position according to one embodiment.
Fig. 3 is a schematic view illustrating the movement of maxillary anterior teeth from the initial position to the actual correction position according to another embodiment.
Fig. 4 is a schematic view illustrating a movement of maxillary anterior teeth from an initial position to an actual correction position according to still another embodiment.
Fig. 5 is a flowchart of a method for simulating pose changes of a digital tooth model according to an embodiment of the present invention.
Fig. 6 is CBCT display images of teeth at different stages of a plurality of shell-shaped dental appliances correcting different teeth of a patient with a heavily inward-inclined deep overlay, which are obtained based on the simulation method of the present invention.
Fig. 7A is a lateral craniofacial image of teeth of a plurality of shell-shaped dental appliances at an initial stage of correction of teeth of a heavily-inward-inclined deep-bite patient, which is obtained based on a simulation method of the present invention.
Fig. 7B is a lateral image of the head of a patient with a plurality of shell-shaped dental appliances having teeth with a deep combination of a heavily inward-inclined type, which are obtained based on the simulation method of the present invention, after the teeth of the patient are corrected for a certain period.
Detailed Description
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.
The terms "anterior dental zone" and "posterior dental zone" are defined according to the classification of teeth in the 2 nd edition, pages 36-38 of the introduction to oral medicine, published by the university of Beijing medical Press, the anterior dental zone including incisors, lateral incisors and cuspids, teeth shown in FDI notation as 1-3, and the posterior dental zone including premolars and molars, teeth shown in FDI notation as 4-8.
Referring to fig. 1, taking the correction of inwardly inclined deeply-overlapped teeth as an example, when teeth 10 in the maxillary anterior dental area and teeth 30 in the mandibular anterior dental area are corrected, it is necessary to move the teeth 10 from an initial position 10a to an actual correction position 10b indicated by a dotted line, move the teeth 30 from the initial position 30a to an actual correction position 30b indicated by a dotted line, and setting a rotation center 101 at different positions when a correction force is applied to the teeth 10 will cause different movement paths of the teeth 10 and different correction effects, which will be described in detail below with reference to the correction of the teeth 10 in the maxillary anterior dental area as an example.
Referring to fig. 2, when the tooth 10 is at the initial position 10a, the root of the tooth 10 is located at the safe position in the center of the alveolar bone 20, the center of rotation 101 of the tooth 10 is designed at the cusp of the tooth 10, the adduction orthodontic force is applied to the tooth 10, and the tooth 10 rotates to the actual orthodontic position 10b indicated by the dotted line with the center of rotation 101 as the center, so that it can be seen that when the tooth 10 is located at the actual orthodontic position 10b, the tooth 10 breaks through the labial bone wall of the alveolar bone 20, and if the orthodontic manner is directly applied to the inside of the oral cavity of a patient, the serious consequences of bone windowing or bone fracture may be caused, which may cause medical accidents.
Referring to fig. 3, when the tooth 10 is in the initial position 10a, the root of the tooth 10 is close to the labial bone wall of the alveolar bone 20, the center of rotation 101 of the tooth 10 is designed to coincide with the center of impedance 102 of the tooth 10, an orthodontic force extending labially is applied to the tooth 10, and the tooth 10 is rotated about the center of rotation 101 from the initial position 10a to the actual orthodontic position 10b indicated by a dotted line, and it can be seen that, in the actual orthodontic position 10b, the root apex of the tooth 10 is located at a safe position in the center of the alveolar bone 20, but a part of the root of the tooth 10 adjacent to the labial cervical line breaks through the labial bone wall of the alveolar bone 20, which presents a certain orthodontic risk.
Referring to fig. 4, when the tooth 10 is at the initial position 10a, the root of the tooth 10 is close to the labial bone wall of the alveolar bone 20, which is substantially the same as the position of the tooth 10 at the initial position 10a in fig. 3, and the center of rotation 101 of the tooth 10 is designed at the labial cervical line of the tooth 10, and at this time, the center of rotation 101 and the center of resistance 102 are not coincident, and an orthodontic force that extends labially is applied to the tooth 10, and the tooth 10 rotates about the center of rotation 101 from the initial position 10a to the actual orthodontic position 10b indicated by a dotted line, it can be seen that, at the actual orthodontic position 10b and during the movement from the initial position 10a to the actual orthodontic position 10b, the root of the tooth 10 is always located at a safe position within the alveolar bone 20, and there is no risk that the root of the tooth 10 breaks through the labial bone wall of the alveolar bone 20, which is an ideal orthodontic manner.
As can be seen from fig. 2 to 4, setting the rotation center 101 at a proper position plays an important role in safely moving teeth, and in order to solve the problem that the position of the pose change of the tooth root cannot be obtained in advance and whether the tooth root can be safely moved cannot be known in advance in the tooth correction process, referring to fig. 5, an embodiment of the present invention provides a method for simulating the pose change of a digital tooth model, where the method includes steps S11 to S13, and may further include step S14.
Step S11, acquiring a digital dental model: obtaining a digital dental model, wherein the digital dental model comprises a digital dental crown model and a digital dental root model.
The digital dental model can be a digital dental model of an upper jaw or a lower jaw, and the digital dental model can be obtained through initial dental information or intermediate dental information in a treatment process. The initial dental information or the intermediate dental information may be obtained by intraoral scanning, or obtained by scanning a dental model of a user, and the initial dental information may specifically include: tooth shape, gum position, etc., and may also include root information obtained from CBCT data (Cone beam CT, also known as Cone beam CT). The tooth shape further includes the shapes of the labial side, lingual side, occlusal surface and the like of the tooth, and further includes the cusp, crest, pit, sulcus and the like of the tooth.
The digital dental model comprises a digital dental crown model and a digital dental root model, wherein the digital dental crown model part and the digital dental root model part can be subsequently designed as an integral structure, and can also be subsequently designed as separate parts.
Step S12, segmenting the digital dental model: the digital dental model is segmented into a single digital tooth model that includes a digital crown model and a digital root model.
The digital dental model is characterized in that the digital dental model is influenced by factors such as tooth scanning precision or three-dimensional reconstruction precision of a digital dental model, scanning results of the digital dental model are integrated, the digital dental model comprises a digital gum model, a digital dental crown model and a digital dental root model, the digital dental crown models of the upper jaw and the lower jaw are connected together, in order to realize the simulation of the orthodontic process of a single tooth and obtain the pose change of the digital dental model of the single tooth, the digital dental model is divided into single digital dental models, each single digital dental model comprises a front dental area single digital dental model and a rear dental area single digital dental model, and each single digital dental model comprises a digital dental crown model and a digital dental root model. The digital dental model can be segmented by one of the following methods: (1) extracting and segmenting segmentation boundaries among tooth models in the digital tooth-jaw model by utilizing a graphic image processing technology; (2) manually marking each tooth, and then performing interactive segmentation based on a segmentation method of a watershed algorithm; (3) and (3) segmenting the single tooth based on the single tooth segmentation technology of the average curvature of the surface of the model. The digital dental model can be divided in other dividing forms, and the method for dividing the digital dental model into single digital tooth models in the prior art can be adopted.
Step S13, designing the pose change of a single digital tooth model: based on the initial position and the target correcting position of the single digital tooth model, the pose change design of the single digital tooth model is carried out by combining the rotation center of the single digital tooth model, so that the pose change position of the digital tooth root model is controlled.
Based on the initial position and the target correcting position of a single digital tooth model, when correcting and simulating the correcting case, taking the rotation of a simulated tooth as an example, adjusting the rotation center of the target tooth to the optimal position by design, doing rotary motion at the point to approach the target correcting position, controlling the digital tooth root model to move in the safe position range of the alveolar bone, generating the effect of the digital tooth model moving by taking the rotation center as the center, expressing the motion mode of the analog movement of the digital tooth model, and being capable of obtaining the position and the posture change position of the tooth root in advance, not only providing the digital tooth arrangement design scheme for a patient to visually know the change of the correcting process, but also knowing whether the tooth root can safely move in advance, designing and preparing the digital tooth corrector based on the position and the posture change of the single digital tooth model subsequently, when teeth are corrected, the teeth can be expected or expected to move, and the serious consequences that the teeth are undesirably changed in pose due to the fact that the designed digital shell-shaped dental appliance is adopted to accommodate the teeth with inaccurate pose or the digital bracket corrector is adopted, and the teeth are improperly moved to cause bone windowing and bone cracking are avoided.
Taking the inward-inclined deep occlusion for correction as an example, based on the initial position and the target correction position of a single digital tooth model of a maxillary anterior tooth zone, the rotation center is positioned at the intersection point of a labial enamel dentin boundary and an upper alveolar marginal point through design, the posture change of the single digital tooth model can be designed to extend teeth of the anterior tooth zone to the labial side and then be integrally recovered to the lingual side, when the posture change is designed, the digital tooth corrector designed based on the posture change of the single digital tooth model is designed aiming at the safe position movement of different single digital tooth models of the anterior tooth zone in an alveolar bone all the time, and when the digital tooth corrector is used for correcting teeth, the safe position movement of tooth roots of the teeth in the alveolar bone is effectively ensured, and the risk is reduced.
The design method of the rotation center of the single digital tooth model comprises the following steps: designing a digital tooth appliance which enables a digital crown model to move from an initial position to a target correction position based on the pose change of the single digital tooth model, and judging the type of the pose change of the single digital tooth model, wherein the type of the pose change of the single digital tooth model comprises translation and rotation; and then controlling the position of the design rotation center based on the pose change type of the single digital tooth model and the ratio of the moment generated by the digital dental appliance applied to the digital dental crown model to the balance moment generated by the digital dental crown model applied to the digital dental appliance. The digital dental appliance may be a digital bracket appliance or a digital shell dental appliance. The method of the present invention is described in detail below, primarily by way of example, where the digital dental appliance is a digital shell dental appliance.
The design method of the digital shell-shaped dental instrument can specifically comprise the following steps: designing a digital shell-shaped dental instrument with the digital dental crown model accommodated therein based on the pose change of the single digital tooth model, wherein the ratio of the torque generated by the digital shell-shaped dental instrument applied to the digital dental crown model to the balance torque generated by the digital dental crown model applied to the digital shell-shaped dental instrument is controlled within a preset value or range so as to adjust the pose change of the digital tooth model.
The design of the digital shell-shaped dental instrument can be the design of a digital shell-shaped dental instrument model or the design of a solid shell-shaped dental instrument, the digital shell-shaped dental instrument model can be used for specially designing a virtual digital shell-shaped dental instrument model by using a finite element analysis method, and the solid shell-shaped dental instrument can be used for designing an entity after the solid hot-press molding operation is carried out on the digital dental jaw model, namely, the solid shell-shaped dental instrument is subjected to special cutting design on the solid hot-press molded dental instrument.
Because the digital shell-shaped dental instrument wraps the digital dental crown model, the digital shell-shaped dental instrument can apply force to the digital dental crown model in multiple directions, the force application size and direction can be designed according to different requirements when the digital shell-shaped dental instrument is designed, and the force application moment is the product of the force and the distance from the force application point to the impedance center. When the digital shell-shaped dental instrument applies force to the digital dental crown model in multiple directions, the digital dental crown model generates balance force resisting the force applied by the digital shell-shaped dental instrument to the digital shell-shaped dental instrument, wherein the balance moment generated by the balance force is the product of the balance force and the distance from the force application point to the resistance center. The resulting moment applied to the digital crown model, which is different from the resulting balancing moment applied to the digital shell-like dental implement, will cause movement of the single digital tooth model in either translation or rotation. In addition, because the distance from the action point of the applied force to the impedance center is different for different patients, the ratio of the moment to the force must be adjusted according to the digital tooth root length and the application point of the patient, so the method is a targeted design for the patient, and is more suitable for the design of the digital shell-shaped dental instrument performed by the actual oral situation of the patient, so that the correction safety and the pertinence are stronger.
The ratio of the moment generated by applying the digital crown model to the balance moment generated by applying the digital shell-shaped dental instrument can be 0, or between 0 and 1, or more than 1, different ratios can be selected according to the posture change type of the single digital tooth model, the position of the rotation center of the single digital tooth model can be controlled and designed, and the movement type of the single digital tooth model can be further adjusted, when the digital shell-shaped dental instrument designed based on the posture change of the single digital tooth model is worn by a patient, the digital shell-shaped dental instrument enables a target tooth to have the designed or expected rotation center, the target tooth generates expected or expected movement according to the position relation of the impedance center and the rotation center, and the tooth root can be in the expected or expected safe position when moving.
When the pose change type of the single digital tooth model is translation, the ratio of the moment generated by being applied to the digital crown model to the balance moment generated by being applied to the digital shell-shaped dental instrument is 1. At this time, the rotation center position is preferably designed to be at infinity. When the posture change type of the single digital tooth model is translation, the digital crown model and the digital root model move simultaneously in the same direction, for example, the digital crown model and the digital root model move horizontally to a new position at equal distance with the occlusal plane as a reference in the labial or lingual, mesial or distal direction. When the digital shell-shaped dental instrument designed for translation based on the posture change type of the single digital tooth model is worn by a patient, the force applied to the target tooth by the digital shell-shaped dental instrument enables the rotation center of the target tooth to be located at infinity, and the target tooth generates expected or expected translation.
When the pose change type of the single digital tooth model is rotation, and the ratio of the moment generated by applying the digital crown model to the balance moment generated by applying the digital shell-shaped dental instrument is 0, the rotation center position is designed to be a position coinciding with the impedance center of the tooth, and the single digital tooth model rotates around the rotation center or three-dimensionally rotates approximately around the rotation center. At this time, the attitude change of the digitized root model is preferably a tilt shift, that is, the digitized root model and the digitized crown model are shifted in opposite directions around the rotation center. When the digital shell-shaped dental instrument designed for rotation based on the posture change type of the single digital tooth model is worn by a patient, the force applied to the target tooth by the digital shell-shaped dental instrument makes the rotation center of the target tooth coincide with the impedance center, and the balance moment applied to the digital shell-shaped dental instrument makes the target tooth generate the expected or expected rotation, particularly when the target tooth rotates around the rotation center, the tooth root and the tooth crown move towards opposite directions.
When the posture change type of the single digital tooth model is rotation, and the ratio of the moment generated by applying the digital dental crown model to the balance moment generated by applying the digital shell-shaped dental appliance is 0 to 1, the rotation center position is designed to be away from the impedance center of the tooth, and the rotation center is not coincident with the impedance center, and the single digital tooth model rotates around the rotation center or approximately rotates around the rotation center in three dimensions. At this time, the pose change of the digital root model is preferably rotation, specifically, the change of the tooth inclination, and the digital crown model and the digital root model move in the same direction. When the digital shell-shaped dental instrument designed for rotation based on the posture change type of the single digital tooth model is worn by a patient, the force applied to the target tooth by the digital shell-shaped dental instrument causes the rotation center of the target tooth to be far away from the impedance center of the target tooth and not to coincide, and the ratio of the moment generated by applying to the target tooth and the balance moment generated by applying to the digital shell-shaped dental instrument causes the target tooth to generate expected or expected rotation.
When the pose change type of the single digital tooth model is rotation, and the ratio of the moment generated by applying the digital crown model to the balance moment generated by applying the digital shell-shaped dental instrument is more than 1, the rotation center position is designed at the position of the digital crown model close to the cusp, and the single digital tooth model can rotate around the rotation center or rotate around the rotation center in three dimensions approximately. At this time, the pose change of the digitized tooth root model is preferably the root control movement, that is, the movement amount of the digitized tooth root model is larger than that of the digitized tooth crown model. When the digital shell-shaped dental instrument designed for rotation based on the posture change type of the single digital tooth model is worn by a patient, the force applied to the target tooth by the digital shell-shaped dental instrument enables the rotation center of the target tooth to be close to the position of the cusp, and the ratio of the moment generated by applying to the target tooth and the balance moment generated by applying to the digital shell-shaped dental instrument enables the target tooth to generate expected or expected rotation, particularly when the target tooth rotates around the rotation center, the moving amount of the tooth root is larger than that of the tooth crown, or the tooth crown of the tooth is kept basically still, so that the tooth root of the tooth is moved in the alveolar bone.
In some embodiments of the present invention, designing a digital shell-like dental instrument with a digital crown model housing based on pose changes of a single digital tooth model may include: one or more shell appliances, which may be provided with a number of tooth-receiving cavities, have a geometry that allows a single digital crown model to be gradually repositioned from an initial position to a target appliance position. The initial position is the digital model relative position that the patient gathered when seeking medical advice, and the position is rescued to the target and is embodied for the position that carries out final correction effect according to patient appeal and intraoral condition through doctor and medical designer, because individual difference, different patients' intraoral condition is all inequality, need remove the tooth to the target position from initial position gradually, and the ware is rescued to wearing to the tooth to the multiunit shell form tooth of a series of differences at this in-process needs.
For a patient needing to correct the inward-inclined deep occlusion, when the shell-shaped tooth corrector is worn, the shell-shaped tooth corrector controls the torque of an upper anterior tooth, one or more shell-shaped tooth correctors are worn to enable the tooth root of the upper anterior tooth to gradually move to the center of an alveolar bone from a position close to the labial bone wall, then one or more shell-shaped tooth correctors are worn to gradually complete the adduction of the anterior tooth, and finally the correction of the inward-inclined deep occlusion is completed.
Referring to fig. 6, 7A and 7B, wherein fig. 6 is a CBCT image of a patient obtained by cone beam computed tomography, and fig. 7A and 7B are cranial slices of the patient at different stages of correction; fig. 6 shows the correction process for four teeth, wherein each column from left to right shows the correction process for one tooth, and the numbers 12, 11, 21, and 22 are marks of the corresponding columns of teeth by using the FDI labeling method, and the teeth shown are maxillary right side incisors, maxillary right side central incisors, maxillary left side central incisors, and maxillary left side lateral incisors, respectively. The first row of images from top to bottom represents the CBCT display image of the teeth at step 0 of the correction, i.e., the image of the initial stage of the tooth correction, the cranio-lateral image of which is shown in fig. 7A; the second row of images represent the tooth CBCT display images in the step 7 of correction, namely the teeth are corrected and subjected to a certain correction stage; the third row of images represents the CBCT display image of the teeth at step 28 of the correction, i.e., the image after the dental correction is continued for a certain correction period, and the cranial image of this period is shown in fig. 7B. As can be seen from fig. 6, 7A and 7B, based on the method for simulating pose changes of the digital tooth model of the present invention, the pose change positions of the tooth roots are obtained in advance, and then when a plurality of shellliform tooth appliances prepared by using the pose change design of a single digital tooth model correct a plurality of teeth of a patient with highly inward inclined deep occlusion, the tooth roots of the upper anterior teeth are always located at the corresponding safe positions in the alveolar bone without the risk of breaking through the labial bone walls of the corresponding alveolar bone.
In some embodiments of the present invention, the method for simulating pose changes of a digital dental model further includes step S14, obtaining a digital alveolar bone model, and adjusting the pose of the digital dental root model in the corresponding digital alveolar bone to avoid bone fenestration or bone dehiscence of the digital alveolar bone model. The acquisition of the digitized alveolar bone model may be performed before step S13. The digital alveolar bone model can be obtained in a full jaw curved surface fracture slice, an oral CT (computed tomography) slice or an oral cone beam CT slice (namely a CBCT slice). When the pose change of the digital tooth model is adjusted based on the digital alveolar bone model, whether the digital tooth root model moves out of the edge of the digital alveolar bone model in the moving process can be simulated at the same time, and the actual intraoral condition of a patient can be fitted better. When the digital shell-shaped dental instrument prepared by the design method is used for correcting a patient, the tooth root of a target tooth can be adjusted in the alveolar bone corresponding to the target tooth in an expectable manner, so that the alveolar bone is prevented from being subjected to bone windowing or bone cracking, and the correction risk is reduced.
The single digital tooth model includes the single digital tooth model in preceding tooth district and the single digital tooth model in back tooth district, because the intraoral actual conditions of human body, the digital alveolar bone model of lip side that the digital tooth model in preceding tooth district corresponds is thinner for the digital alveolar bone model of lip side that the digital tooth model in back tooth district corresponds, consequently when designing the digital tooth model in preceding tooth district, the position of rotation center selects more importantly, the position of selecting sets up improperly, more easily cause the phenomenon of windowing or bone fracture. The design result is more intuitively evaluated and adjusted by combining the real digital alveolar bone model of the patient.
In some embodiments of the present invention, a shell-shaped dental appliance designed based on pose changes of a single digital tooth model can be prepared by the following method: 3D printing is carried out on the digital dental model after pose change based on a series of designs to prepare an entity dental model, then a shell-shaped dental instrument containing teeth is obtained on the entity dental model by adopting a hot press molding mode, then the shell-shaped dental instrument containing teeth is obtained by cutting along a gum line or a position close to the gum line on the shell-shaped dental instrument containing teeth, and then preparation modules such as cleaning, disinfecting and packaging are carried out on the shell-shaped dental instrument to prepare the shell-shaped dental instrument, so that a patient can directly wear the shell-shaped dental instrument for use, and the aim of correcting the teeth is achieved after the shell-shaped dental instrument is worn by a series of shell-shaped dental instruments.
More specifically, the manufacturing modules in the manufacturing method can also be 3D printing equipment, film pressing equipment, cutting equipment, polishing equipment and cleaning and disinfecting equipment, and the specific manufacturing process is that firstly, a digital finite element model of the digital dental model meeting the requirements is directly printed out through a 3D printing technology, secondly, film pressing operation is carried out on the printed 3D dental model, and finally, the shell-shaped dental instrument with the pressed film is cut, polished, cleaned, disinfected and the like, so that the shell-shaped dental instrument is finally manufactured.
In some embodiments of the present invention, the shell-shaped dental apparatus designed based on pose change of a single digital tooth model can be further prepared by the following method: the designed digital shell-shaped dental instrument is printed and prepared by a direct 3D printing method, the preparation method is based on a digital shell-shaped dental instrument model, the shell-shaped dental instrument after direct 3D printing can be directly worn and used by a patient through processes of polishing, cleaning, disinfecting, packaging and the like, and the purpose of tooth correction is achieved after the shell-shaped dental instrument is worn by a series of shell-shaped dental instruments.
In an embodiment, the manufacturing module in the manufacturing method may be an additive manufacturing machine, and the shell-shaped dental appliance is manufactured by using an additive manufacturing technology, that is, the shell-shaped dental appliance is directly printed after obtaining a finite element digital model of the shell-shaped dental appliance meeting the requirements by using a 3D printing technology, and the 3D printing technology may be SLA (stereo lithography) or DLP (digital light projection).
It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (14)
1. A method of simulating pose changes of a digitized tooth model, comprising:
acquiring a digital dental model: acquiring a digital dental model, wherein the digital dental model comprises a digital dental crown model and a digital dental root model;
segmenting the digital dental model: segmenting the digitized dental model into a single digitized tooth model comprising a digitized crown model and a digitized root model;
designing the pose change of a single digital tooth model: based on the initial position and the target correcting position of the single digital tooth model, the pose change design of the single digital tooth model is carried out by combining the rotation center of the single digital tooth model, so that the pose change position of the digital tooth root model is controlled;
the method for designing the rotation center of the single digital tooth model comprises the following steps: designing a digital tooth appliance which enables a digital crown model to move from an initial position to a target correction position based on the pose change of the single digital tooth model, and judging the type of the pose change of the single digital tooth model, wherein the type of the pose change of the single digital tooth model comprises translation and rotation; and then controlling the position of the design rotation center based on the pose change type of the single digital tooth model and the ratio of the moment generated by the digital dental appliance applied to the digital dental crown model to the balance moment generated by the digital dental crown model applied to the digital dental appliance.
2. The method for simulating pose changes of digital tooth models according to claim 1, wherein when the pose change type of the single digital tooth model is translation, the ratio of the moment generated by applying the digital tooth crown model to the balance moment generated by applying the digital tooth appliance is 1.
3. The method for simulating pose changes of a digital tooth model according to claim 2, wherein the rotation center position is designed at infinity.
4. The method for simulating pose changes of digital tooth models according to claim 1, wherein when the pose change type of the single digital tooth model is rotation, the ratio of the moment generated by applying the digital dental crown model to the balance moment generated by applying the digital dental appliance is 0, or between 0 and 1, or greater than 1.
5. The method according to claim 4, wherein when the type of the pose change of the single digital tooth model is rotation, and the ratio of the moment generated by applying the digital crown model to the balance moment generated by applying the digital dental appliance is 0, the rotation center position is designed to be coincident with the impedance center of the tooth.
6. The method of simulating pose changes of a digitized tooth model according to claim 5, wherein the pose changes of the digitized tooth root model are tilt movements.
7. The method for simulating pose changes of digital tooth models according to claim 4, wherein when the pose change type of the single digital tooth model is rotation, the ratio of the moment generated by applying the digital dental crown model to the balance moment generated by applying the digital dental appliance is 0 to 1, the rotation center position is designed to be a position away from the impedance center of the tooth and the rotation center is not coincident with the impedance center.
8. The method of simulating pose changes of a digitized tooth model according to claim 7, wherein the pose changes of the digitized tooth root model are rotations.
9. The method for simulating pose changes of digital tooth models according to claim 4, wherein when the pose change type of the single digital tooth model is rotation, the rotation center position is designed at a position adjacent to a cusp of the digital tooth crown model when a ratio of a moment generated by applying the torque to the digital tooth crown model to a balance moment generated by applying the torque to the digital tooth appliance is greater than 1.
10. The method of simulating pose changes of a digitized tooth model according to claim 9, wherein the pose changes of the digitized tooth root model are root control movements, and the amount of movement of the digitized tooth root model is greater than the amount of movement of the digitized tooth crown model.
11. The method for simulating pose changes of a digital tooth model according to claim 1, wherein the digital dental appliance is a digital bracket appliance or a digital shell-shaped dental appliance.
12. The method for simulating pose changes of a digital tooth model according to claim 1, wherein the single digital tooth model comprises a single digital tooth model in an anterior tooth area and a single digital tooth model in a posterior tooth area.
13. The method for simulating pose changes of a digital tooth model according to claim 1, further comprising obtaining a digital alveolar bone model, wherein the pose of the digital tooth root model is adjusted inside the corresponding digital alveolar bone to avoid bone fenestration or bone fracture of the digital alveolar bone model.
14. The method for simulating pose changes of a digital tooth model according to claim 13, wherein the digital alveolar bone model is obtained by a full jaw surface slice, an oral cavity CT slice or an oral cavity cone beam CT slice.
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| CN113855298B (en) * | 2021-10-19 | 2023-05-09 | 杭州美齐科技有限公司 | Tooth resistance center positioning method |
| CN114376746B (en) * | 2021-12-22 | 2024-04-02 | 上海爱乐慕健康科技有限公司 | Tooth arrangement method and device, and tooth correction appliance design and manufacturing method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1686058A (en) * | 2005-04-28 | 2005-10-26 | 上海隐齿丽医学技术有限公司 | Computer assisted hidden tooth abnormal correction system |
| CN106073913A (en) * | 2016-08-16 | 2016-11-09 | 苏州迪凯尔医疗科技有限公司 | Carry out tooth based on alveolar bone form and move integrally the invisalign method of design |
| CN106137414A (en) * | 2015-04-14 | 2016-11-23 | 上海时代天使医疗器械有限公司 | Determine the method and system of target dentition layout |
| KR20190128925A (en) * | 2018-05-09 | 2019-11-19 | 시스루테크 주식회사 | Method for determining the center of rotation of a tooth model and method for manufacturing a transparent correction device using the same |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6739870B2 (en) * | 2001-09-26 | 2004-05-25 | 3M Innovative Properties Company | Use of finite element analysis for orthodontic mechanics and appliance selection |
| US8439672B2 (en) * | 2008-01-29 | 2013-05-14 | Align Technology, Inc. | Method and system for optimizing dental aligner geometry |
| CN105380719B (en) * | 2014-08-22 | 2018-04-03 | 洪庆在 | Transparent apparatus for correcting and its manufacture method |
| EP3435911A1 (en) * | 2016-03-28 | 2019-02-06 | Align Technology, Inc. | Systems, methods, and devices for predictable orthodontic treatment |
| KR101740385B1 (en) * | 2016-07-06 | 2017-05-26 | 배기선 | 3d grid template for manufacturing digital set-up model and teeth alignment method of digital set-up model by 3d grid template |
-
2020
- 2020-03-31 CN CN202010239922.3A patent/CN111658187B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1686058A (en) * | 2005-04-28 | 2005-10-26 | 上海隐齿丽医学技术有限公司 | Computer assisted hidden tooth abnormal correction system |
| CN106137414A (en) * | 2015-04-14 | 2016-11-23 | 上海时代天使医疗器械有限公司 | Determine the method and system of target dentition layout |
| CN106073913A (en) * | 2016-08-16 | 2016-11-09 | 苏州迪凯尔医疗科技有限公司 | Carry out tooth based on alveolar bone form and move integrally the invisalign method of design |
| KR20190128925A (en) * | 2018-05-09 | 2019-11-19 | 시스루테크 주식회사 | Method for determining the center of rotation of a tooth model and method for manufacturing a transparent correction device using the same |
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