CN106137414B - Method and system for determining target dentition layout - Google Patents

Abstract

The invention provides a method and a system for determining a target dentition layout, the method comprising the steps of: receiving a raw data set representing a raw dentition layout, the raw data set comprising a data set representing a raw position of at least one key tooth; obtaining a set of parameters representing a header structure; determining a data set representing a target position of at least one key tooth based on the data set representing an original position of the at least one key tooth using the set of parameters; and generating a target data set representing a target dentition layout from the data set representing the target position of the at least one key tooth. The method and the system not only allow the target dentition layout to be determined quickly, conveniently, automatically or semi-automatically, but also integrate the biological integral correction concept into the tooth fixed correction and invisible correction computer tooth arrangement design, so that the biological safety, the rationality and the effectiveness of the tooth correction design are improved.

Description

Method and system for determining target dentition layout

Technical Field

The present invention relates generally to the field of orthodontic technology and, more particularly, to a method and system for determining a target dentition layout based on target positions of a plurality of key teeth.

Background

The malformation of the jaw is one of three diseases of the oral cavity, and has high prevalence rate. The traditional orthodontic method for dentognathic deformity mostly adopts a fixed bracket appliance adhered to teeth. Compared with the traditional fixed bracket correction technology, the novel invisible correction technology does not need brackets and steel wires, but adopts a series of invisible correction devices which are made of safe elastic transparent high polymer materials, so that the correction process is almost finished without the awareness of other people, and the daily life and social contact are not influenced; moreover, as the patient can take off and wear the mask by himself, the oral hygiene can be maintained normally; meanwhile, because the complicated steps of bonding the bracket and adjusting the arch wire are not needed, the clinical operation is greatly simplified, and the whole correcting process is time-saving and labor-saving.

Whether conventional fixed or recently developed invisible correction, involves the design or prediction of the target position of dentition after dental correction. In particular, in some invisible appliance designs, a current dentition layout image of a patient is first acquired and a final dentition layout is manually determined by a physician from the original dentition layout, i.e., the final target position of the dentition (which may also be referred to as the dentition target position) is determined solely by the physician's experience. The doctor or designer then makes a series of invisible appliances by performing linear or non-linear interpolation calculations between the original dentition layout and the final dentition layout by computer-aided design means to obtain a plurality of intermediate dentition layouts.

Although it is an intuitive practice to set a target position based on an initial position and then produce an intermediate position, as for how to determine the target position, a method is currently adopted in which a designer mechanically simulates the target position of tooth arrangement according to the requirements of a clinician, and the designer mainly considers the problems of mechanical movement and mathematics of teeth in tooth arrangement design, and hardly considers the biological integral structure problems of root and alveolar bone angle/position relationship, oral soft and hard tissue health and joint health, and facial aesthetics. The level of the clinician is different, and the control degree of the tooth arrangement result is different; therefore, the appliance worn by the patient is likely to fail to achieve good correction effect or prolong the correction period due to insufficient control capability of medical technology and aesthetic principles of the clinician.

Further, the predetermined target position is not necessarily a medically reachable or reasonably reachable target position, resulting in a medically impossible or difficult to achieve such a manually determined target position.

Therefore, there is a need for a method and system for determining a target dentition layout that is both medically and aesthetically pleasing, and yet is practically operable.

Disclosure of Invention

Accordingly, the invention provides a method and a system for digitally determining a target dentition layout, which are based on a plurality of key teeth, determine the positions of the key teeth firstly by utilizing parameters representing a head structure, and then determine the positions of the whole upper jaw dentition and/or lower jaw dentition based on the determined positions of the key teeth, so that the concept of biological integral correction is possibly integrated into the design of tooth fixing correction and invisible correction computer dentition.

Accordingly, according to one aspect of the present invention, there is provided a method for determining a target dentition layout, comprising the steps of: receiving a raw data set representing a raw dentition layout, the raw data set comprising a data set representing a raw position of at least one key tooth; obtaining a set of parameters representing a header structure; determining a data set representing a target position of at least one key tooth based on the data set representing an original position of the at least one key tooth using the set of parameters; and generating a target data set representing a target dentition layout from the data set representing the target position of the at least one key tooth.

According to a particular embodiment of the invention, the raw data set comprises data representative of at least one of a maxillary raw dentition layout and a mandibular raw dentition layout. And the set of parameters representing the header structure includes: at least one of a cephalogram parameter measurement data set, a dental image measurement data set, and a dental parameter standard value set.

Further in accordance with a specific embodiment of the present invention, the at least one key tooth comprises a maxillary first molar and the data set representing the target position of the at least one key tooth comprises a vertical target position of the maxillary first molar.

And, when the maxillary first molar is pathologically elongated, the at least one key tooth comprises a maxillary first premolar or a maxillary second premolar, and the data set representing the target position of the at least one key tooth comprises a vertical target position of the maxillary first premolar or the maxillary second premolar.

According to an embodiment of the present invention, the parameter set representing the head structure includes a head shadow parameter measurement data set and a standard value set of a corresponding head shadow parameter, and the method further includes: and determining the vertical target position of the first maxillary molar by comparing the measured data of the head shadow parameters with the standard values of the corresponding head shadow parameters.

Preferably, the head shadow parameters include at least one of an angle of intersection of an auricle plane and a mandible plane (FMA), an angle of intersection of an anterior basis cranium plane and a mandible plane (SN-MP), and a posterior-anterior aspect ratio (S-Go/N-Me).

And the target data set includes data representing a vertical target position of the maxillary dentition, the method further comprising: and determining the data representing the vertical target position of the maxillary dentition by using a combined plane composed of the maxillary first molars and the maxillary central incisors according to the data representing the vertical target position of the maxillary first molars.

And, the target data set further comprises data representing a vertical target position of the mandibular dentition, the method further comprising: and determining the data representing the vertical target position of the mandibular dentition by utilizing the overlay coverage or occlusal relationship of the maxillary teeth and the corresponding mandibular teeth according to the data representing the vertical target position of the maxillary dentition.

According to a further embodiment of the invention, the at least one key tooth comprises a mandibular cuspid tooth and a mandibular first molar tooth and the data set representing the target position of the at least one key tooth comprises lateral target positions of the mandibular cuspid tooth and the mandibular first molar tooth.

Wherein, according to an embodiment of the invention, the set of parameters representative of the head structure comprises a set of lateral position measurement data and a set of reference data of the mandibular canine and mandibular first molar teeth, the method further comprising: determining lateral target positions of the mandibular canine and mandibular first molars based on the lateral position measurement dataset and the reference dataset for the mandibular canine and mandibular first molars.

Preferably, the lateral position measurement dataset and the reference dataset for the mandibular canine and mandibular first molar comprise any one of the following datasets: a data set representing the relationship of the lateral positions of the mandibular canine and mandibular first molars and the alveolar bone position, a data set representing the positional relationship of the WALA ridge of the mandibular dentition to the FA points of the mandibular canine and mandibular first molars, and a data set and standard value set representing the lateral position measurements of the mandibular canine and mandibular first molars, determined from the alveolar bone CT image.

And the target data set comprises data representing a lateral target position of the mandibular dentition, the method further comprising: determining the data representative of the lateral target positions of the mandibular dentition from the data representative of the lateral target positions of the mandibular canine and mandibular first molars using a mandibular occlusion curve fitted to the mandibular canine and mandibular first molars and incisors in the mandible.

Moreover, the target data set further comprises data representing a lateral target position of the maxillary dentition, the method further comprising: and obtaining a mirror image maxillary occlusion curve according to the mandibular occlusion curve, and determining the data representing the transverse target position of the maxillary dentition.

According to a further embodiment of the invention, the at least one key tooth comprises a mandibular central incisor and the data set representing the target position of the at least one key tooth comprises an anteroposterior target position of the mandibular central incisor.

Wherein, according to an embodiment of the invention, the set of parameters representative of the head structure comprises an anteroposterior position measurement dataset and a reference dataset of incisors in the lower jaw, the method further comprising: determining an anterior-posterior target position of the incisors in the lower jaw based on the anterior-posterior position measurement dataset and the reference dataset of the incisors in the lower jaw.

Preferably, the anterior-posterior position measurement dataset and the reference dataset of the incisors in the lower jaw comprise any one of the following datasets: and the data set represents the relation between the front and back positions of incisors in the lower jaw and the position of the alveolar bone, the data set represents the position relation between the WALA ridge of the mandibular dentition and the FA point of the incisors in the lower jaw, and the head shadow parameter measurement data set and the standard value set of the corresponding head shadow parameters.

For example, the head shadow parameters include at least one of a lower middle incisor-mandibular plane angle (IMPA), an angle between the long axes of the upper and lower middle incisors (U1-L1), an angle between the long axis of the lower middle incisor and the line NB (L1-NB angle), a perpendicular distance between the incisal margin of the lower middle incisor and the line NB (L1-NB line distance), an upper middle incisor convex distance (AP-L1), and a lower middle incisor convex distance (NP-L1), wherein the line NB is the line connecting the nasal root point and the lower alveolar seat point.

And the target data set includes data representing an anteroposterior target position of the mandibular dentition, the method further comprising: determining the data representative of the anteroposterior target positions of the mandibular dentition from the data representative of the anteroposterior target positions of the incisors in the mandible using a mandibular occlusion curve fitted to the mandibular cuspid teeth and the mandibular first molars and incisors in the mandible.

And, the target data set further comprises data representing anteroposterior target positions of the maxillary dentition, the method further comprising: and obtaining a mirrored maxillary occlusion curve according to the mandibular occlusion curve, and determining the data representing the anteroposterior target positions of the maxillary dentition.

Finally, according to a further embodiment of the invention, the at least one key tooth comprises a maxillary first molar, a mandibular cuspid and mandibular first molar, and a mandibular central incisor, and the data set representing the target position of the at least one key tooth comprises a vertical target position of the maxillary first molar, a lateral target position of the mandibular cuspid and mandibular first molar, and a anteroposterior target position of the mandibular central incisor, and the target data set comprises data representing the vertical, lateral and anteroposterior target positions of the maxillary and mandibular dentitions.

Wherein the method further comprises: fitting the mandible cuspid, the first mandibular molar and the mandibular central incisor to obtain a mandibular occlusion curve; determining the front-back direction and the transverse target position of each tooth of the maxillary dentition according to the mandibular occlusion curve; generating a mirrored maxillary occlusion curve based on the mandibular occlusion curve; and determining a front-to-back and a lateral target position for each tooth of the maxillary dentition.

Preferably, the method further comprises: the target position of each tooth of the mandibular dentition is adjusted so that the torque, the axis inclination angle of each tooth of the mandibular dentition is equal to or substantially equal to a standard value and the twist angle of each tooth is not greater than a specified threshold value.

Moreover, the method may further comprise: and adjusting the target position of each tooth of the maxillary dentition so that the torque and the axial inclination angle of each tooth of the maxillary dentition are equal to or basically equal to the standard values, and the torsion angle of each tooth is based on that the overlapping coverage of the tooth and the corresponding mandibular tooth is uniform and the apical fossa is well embedded.

Additionally, the method further comprises: and integrally moving the positions of the upper and lower jaw dentitions according to the joint parameters to obtain a target data set reflecting the joint parameters.

Preferably, the integral movement comprises: adjusting the vertical, lateral and anteroposterior target positions of the upper and lower jaw dentitions such that the measured data of the positions of the mandibular condyloid processes in the glenoid fossa equals or approximates to standard values when the upper and lower jaw dentitions are in the maximum cusp contact relationship.

Furthermore, the method further comprises: and adjusting the central incisors, the cuspids and the first molars of the upper and lower jaws based on the aesthetic indexes of the labial and facial parts to obtain a target data set reflecting the aesthetic indexes.

Moreover, the method may further include: and adjusting the target data set according to the correction means and the correction limit corresponding to the correction tool.

Preferably, the method is computer-implemented.

Accordingly, there is also provided, in accordance with another aspect of the present invention, a system for determining a target dentition layout, comprising: an input unit for receiving an original data set representing an original dentition layout and obtaining a parameter set representing a head structure, the original data set comprising a data set representing an original position of at least one key tooth; a controller for determining a data set representing a target position of at least one key tooth based on a data set representing an original position of at least one key tooth using the set of parameters; and generating a target data set representing a target dentition layout from the data set representing the target position of the at least one key tooth.

Accordingly, by applying the method and system of the present invention, the target position of the entire maxillary and/or mandibular dentition is determined by using several key teeth, thereby allowing the target dentition layout to be determined quickly, conveniently, automatically or semi-automatically, improving the tooth arrangement efficiency.

Furthermore, the invention can quickly and accurately determine the position of the target dentition which is expected to be obtained and can be obtained after correction according to factors of biological integrity such as the original tooth arrangement, alveolar bone, facial structure and the like of a patient.

Finally, the method of the invention makes it possible to integrate the concept of biological integrity correction into the design of fixed teeth correction and invisible teeth correction of computer tooth arrangement, and improves the biological safety, rationality and effectiveness of tooth correction design.

Drawings

The above and other features of the present invention will be further explained by the following detailed description thereof taken in conjunction with the accompanying drawings. It is appreciated that these drawings depict only several exemplary embodiments in accordance with the invention and are therefore not to be considered limiting of its scope. The drawings are not necessarily to scale and wherein like reference numerals refer to like parts, unless otherwise specified.

FIG. 1 illustrates a flow chart of a method for determining a target dentition layout according to an embodiment of the present invention;

FIGS. 2A-2D are schematic diagrams illustrating a head shadow parameter according to an embodiment of the present invention;

FIG. 3 is a dental position diagram according to an embodiment of the present invention;

FIGS. 4A-4C are schematic diagrams illustrating the head shadow angles FMA, SN-MP, and the head shadow ratio S-Go/N-Me, respectively, according to an embodiment of the present invention;

FIG. 5 is a diagram illustrating the relationship of WALA ridges to FA points, according to an embodiment of the present invention;

FIG. 6 illustrates a graph of bite curves according to an embodiment of the present invention;

FIGS. 7A-7B are schematic diagrams illustrating tooth torque and normalized values thereof, according to an embodiment of the present invention;

FIGS. 8A-8B are schematic views for explaining the inclination of the tooth axis and its standard value according to an embodiment of the present invention;

FIGS. 9A-9B are schematic diagrams illustrating the positional relationship of a joint and dentition according to one embodiment of the present invention;

FIG. 10 shows a schematic diagram of a computer system in accordance with one embodiment of the present invention.

Detailed Description

The following detailed description refers to the accompanying drawings, which form a part of this specification. The exemplary embodiments mentioned in the description and the drawings are only for illustrative purposes and are not intended to limit the scope of the present invention. It will be understood by those skilled in the art that many other embodiments may be employed and that various changes may be made to the described embodiments without departing from the spirit and scope of the invention. It will be understood that the aspects of the present invention described and illustrated herein are capable of being arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are encompassed by the present invention.

The invention provides a method and a system for determining target dentition layout, and by applying the method and the system, the target dentition layout expected to be obtained after correction and available can be quickly and accurately determined according to the biological integrity factors of the original tooth arrangement, alveolar bone, facial structure and the like of a patient, so that the biological integrity correction concept can be possibly integrated into the fixed correction and tooth correction computer dentition design, and the effect which can be achieved after the tooth correction can be fully known by the patient before the correction starts, so that the biological safety, the reasonability and the effectiveness of the tooth correction design are improved.

For dental correction, it is very important to determine the target dentition layout after correction, especially the target positions of the individual teeth on the dentition. Particularly, for some tooth arrangement methods, it is necessary to determine target positions of teeth after correction, then determine corresponding tooth positions of each tooth arrangement stage, and then design a tooth corrector applicable to each corresponding tooth arrangement stage, so that it is very important to determine target positions of teeth of a reasonable dentition according to medical rules. However, currently, the clinician determines the target position of the teeth according to personal experience, and the teeth alignment operator manually moves each tooth according to the doctor's instruction to determine the target position of each tooth on the tooth row, because the clinician level is not uniform, the degree of control of the tooth alignment result is uneven, and the determined target position of the teeth cannot be optimized.

The present invention therefore proposes a method and a system for determining a target dentition layout on the basis of "key teeth", and which, according to one embodiment of the present invention, allows a fast, convenient, automated or semi-automated determination of a target dentition layout, particularly suitable for determining a target dentition layout by means of a computer system. Hereinafter, the present invention will be exemplarily described with reference to fig. 1.

FIG. 1 shows a flow chart of a method for determining a target dentition layout according to an embodiment of the present invention. In the method shown in fig. 1, an original data set representing an original dentition layout is first received in step S100, wherein the original data set includes morphology and position data of an original dentition (at least one tooth of the upper and lower jaw, preferably all teeth of the upper and lower jaw), so that the original data set includes a data set representing an original position of at least one key tooth. Which will be described separately below.

For example, the data of the original dentition is, for example, data of the original dentition of a patient. Wherein the original dentition layout (which may also be referred to as original dentition, current dentition, or current dentition layout) of the patient represents an original morphology and position of each tooth included on the patient's pre-corrected dentition.

The data representing the original dentition layout, such as a digital model representing the original dentition layout, may be generated by a variety of methods. For example, the dentition alignment state may be obtained by taking an impression, thereby creating a physical dental model. The image of the tooth or the tooth and the surrounding tissues can also be directly obtained by optical scanning, X-ray imaging, ultrasonic imaging, three-dimensional photography, three-dimensional camera shooting, medical CT scanning or nuclear magnetic resonance and other methods. Further, the acquired dentition layout, or the state of the teeth and their surrounding tissue, may be converted into a dentition layout dataset by scanning of a physical dental model, or computer processing of an oral tissue image, whereby X, Y, Z coordinates of the teeth in three-dimensional space are obtained, which may be visualized and manipulated (e.g. translated or rotated) on a graphical interface of a computer system. Here, the digital model representing the original dentition layout may be a maxillary dentition of the original dentition layout and/or a mandibular dentition of the original dentition layout.

Generally speaking, a plaster model of the patient's dentition may be obtained by means of an impression using generally known techniques, and then scanned by a scanner to generate a dentition layout data set. Which may include, for example, a non-contact type laser scanner, a contact type laser scanner, and the like. And the data set produced by the scanner may be in any of a variety of digital formats to ensure compatibility with the software.

It should be noted that the present invention is not limited to the method used to obtain the original dentition layout. Data of the original dentition layout may also be obtained, for example, by an intra-oral imaging system. An intra-oral imaging system is a diagnostic device that allows a dental practitioner to see within a patient's mouth and display the surface shape characteristics of the teeth on a display monitor. Some three-dimensional (3D) intraoral imagers may include an intraoral camera with a light source. The three-dimensional intraoral imager may be inserted into the patient's mouth by a dental practitioner. After the intraoral imager is inserted into the oral cavity, the dental practitioner can capture images of the visible portions of the teeth and gums. And the images captured by the intraoral camera may be displayed on a display monitor and may be transmitted to a computing device to obtain data of the original dentition layout.

Furthermore, the dentition layout may include not only the state of the crown but also the state of the root of the tooth. For example, data of the root and the peripheral tissues can be acquired by a two-dimensional or three-dimensional X-ray system, a CT scanner, a nuclear magnetic resonance apparatus, and the like.

Since the digital model representing the original dentition layout may be the maxillary dentition of the original dentition layout and/or the mandibular dentition of the original dentition layout, if the digital model representing the original dentition layout is the maxillary dentition and the mandibular dentition of the original dentition layout, then paraffin bites in the patient may be used to derive the relative positions of the maxillary and mandibular dentitions in the mid-bite state. For example, for laser scanning, a laser scan may be performed by placing a paraffin bite on a plaster model of the patient's current mandibular dentition, then performing a paraffin bite, and then placing the mandibular dentition on the patient's current mandibular dentition such that the relative positions of the maxillary and mandibular dentitions are determined according to the paraffin bite, thereby obtaining a model of the maxillary and mandibular dentitions that represents the same relative position as the patient's oral cavity. Of course, it is also possible to scan the wax bite separately and combine the data from the scanned wax bite with the data from the scanned plaster model to produce a digital model of the maxillary and mandibular dentition representing the patient's original dentition layout.

Also, in this step, a digital model of each tooth may be further obtained based on the obtained digital model of the dentition. That is, the digital model of the maxillary dentition and/or the mandibular dentition obtained by the scanning may be segmented into a digital model of each tooth by automatic computer segmentation, manual segmentation, or a combination of automatic and manual segmentation, and the coordinates of each tooth may be determined.

Of course, in step S100, as described above, according to one embodiment, a digital model of the entire maxillary dentition and/or mandibular dentition may be obtained and then segmented into a digital model of each tooth. According to another embodiment, the plaster model of the dentition obtained by impression can be divided to obtain a plaster model of a single tooth, the position of each tooth in the dentition or the mutual position relationship between teeth can be recorded, then each tooth can be scanned to obtain a digital model of each tooth, and then the whole dentition, i.e. the digital model representing the original dentition layout of the patient can be obtained in the computer according to the recorded position of each tooth in the dentition or the mutual position relationship between teeth. The above embodiments are exemplary and not limiting, and thus, it is within the scope of the present invention to obtain a digital model representing the original dentition layout of a patient.

And, in step S110, a parameter set representing the structure of the header is acquired. It should be noted that the execution order of step 100 and step 110 may be interchanged, and the two steps may be performed simultaneously or combined. The present invention does not limit the execution order or manner of the above two steps.

The parameter set representing the structure of the header may comprise a header shadow data set. Further, it may preferably further include a dental statistical parameter set, parameters obtained based on CT images of the tooth and the head structure, and the like.

The head shadow data set will be explained first below. In general, there are two main types of measurements, contact measurement and noncontact measurement, for dental and skull models. The contact measurement mainly includes direct contact measurement of the tooth jaw model by various measuring instruments, and is divided into manual contact measurement and needle contact mechanical measurement. The manual measurement is a traditional measurement method, which is still widely used at present, and the main tools are as follows: the ruler, divider, vernier caliper and universal angle ruler are two-dimensional measuring methods, have the advantages of low cost and suitability for clinical individual model measurement, but have the defects that the use tools are hard, therefore, anhydrite must be poured, and a large amount of space is needed for storing models, so that the time and the labor are wasted, and the precision is not high.

The non-contact measurement is to reconstruct a three-dimensional image of the model of the teething jaw through an optical instrument and computer software, the fine structure of the model is clear and identifiable, the model not only can be rotated or translated freely to observe and measure each part of the surface of the model, but also can finish the three-dimensional coordinate extraction of any point, and the measurement and analysis of the distance between any two points, any angle, arc length, curved surface area and other items in space can be completed, so that the index which cannot be related to the manual measurement can be possible, and the measurement is convenient and visual. An X-ray skull positioning measurement method is established by Broadbent and Hofranth in Germany in 1931, and X-ray positive lateral slice analysis becomes an important method for researching tooth jaw and skull models. With the development of computer technology, the head shadow measurement is developed from the initial manual point tracing measurement to the current exploration of full-automatic image measurement and analysis, and the precision and the efficiency are improved. At present, computer head shadow measurement and analysis methods and corresponding software are generated in succession at home and abroad, such as digitized head shadow measurement software of WinCeph, OnyxCeph and the like.

However, it should be noted that the present invention is not limited to the method of obtaining the head shadow data by X-ray. With the development of imaging techniques such as CT, magnetic resonance, etc., more accurate head shadow data can be obtained. Images of the teeth and surrounding bone structures, soft tissue, muscles, blood vessels, etc. can be obtained, for example, by combining cone beam tomography (CBCT) with a digital computer. During a CBCT scan, the CBCT scanner rotates around the patient's head and several hundred different CBCT images are available, which may be referred to as CBCT images. The CBCT image may be transmitted to a computing device so that three-dimensional anatomical data may be generated. Special software can then be used to manipulate and visualize the three-dimensional anatomical data for cephalometric analysis of CBCT images.

Hereinafter, a process of obtaining the head shadow data by the X-ray will be described as an example. As shown in fig. 2A-2B, first, a cranial lateral head image as shown in fig. 2A is acquired by an X-ray imaging technique under strict positioning of a head positioner and input into a computer, thereby obtaining an original data set of a head structure.

Then, for example, after acquiring a digital cranial position head image, a head shadow map as shown in fig. 2C can be obtained using digital head shadow measurement software, such as WinCeph software (obtaining head shadow lines from an X-ray head image as shown in fig. 2B). It should be noted that although the present invention will be described in the present application by way of example in terms of digitizing software, the present invention does not exclude the way in which contact measurements are made manually or in terms of manually tracing a head-shadow.

Medically, various scholars propose different cephalometric measurement methods and corresponding cephalometric marker points, marker planes and marker angles. For example, commonly used landmark points for cephalometric measurements include: cranial marker points (e.g., including sphenoid saddle points (s.sela) and ear points (p.poison), etc.), maxillary marker points (e.g., including superior alveolar ridge points (spr. superior rosthon) and superior incisor points (ui. superior incisor), etc.), mandibular marker points (e.g., including condylar apex (co. dylon) and inferior incisor points (li. lower incisor), etc.), soft tissue lateral marker points (e.g., including eye points (e.eye), soft tissue nasal root points (NS nasal of tissue), and lip edge points (superior tires), etc.).

Also, the commonly used marker planes include a reference plane and a measurement plane, wherein the reference plane is a plane that is relatively stable in the cephalometric measurement. The most commonly used current reference planes are the anterior skull base plane (SN), the eye-ear plane (FH), and the aesthetic plane (EP). The measuring planes include a palatal plane (ANS-PNS), a total cranial base plane (Ba-N), a synthetic plane (OP), a Mandibular Plane (MP), etc. Thus, the reference plane, each measurement mark point, and the other measurement planes constitute 8 measurement items such as an angle, a line pitch, and a ratio.

For example, as shown in fig. 2D, 1 represents the anterior cranial base plane; 2 represents the eye-ear plane; 3 represents the occlusal plane; 4 represents the mandible plane; and 5 represents an aesthetic plane.

Further, a head shadow angle may be determined. Commonly used cephalometric angles include: SNA angle (angle formed by the center of the sphenoid saddle, the nasion point and the upper alveolar seat point), NP-FH (also called face angle, i.e. the lower angle after the intersection of the face plane NP and the auricle plane FH), SN-MP (the intersection angle of the anterior cranial base plane and the mandible plane), MP-FH (also called mandible plane angle, which is the intersection angle of the Mandible Plane (MP) and the auricle plane (FH)), 1 [ (TXX-) -SN angle (the lower inner angle at which the upper central incisor tooth major axis intersects the SN plane), 1 [ (TX-) -MP angle (the upper inner angle at which the lower central incisor tooth major axis intersects the mandible plane), FMA (the intersection angle of the auricle plane and the mandible plane), and the like.

And the usual line distances for cephalometric measurements include: ANS-Me (lower front height); S-Go (high back); N-Me (front height), and commonly used ratios include S-Go/N-Me (back-front height ratio), ANS-Me/N-Me (bottom-front height ratio), and the like.

It should be noted that each of the above measurement items has a specific meaning, which indicates the characteristic or growth variation trend of the corresponding structure. However, evaluating an index in isolation often leads to erroneous conclusions. Because the skull is a complex formed by the structures of the parts of the jaw and the craniofacial area. Whether it is normal or not is not completely dependent on a certain index: but depends on the cooperation between the parts and therefore needs to be considered comprehensively. The malformation of the jaw and the jaw is caused by the disorder of the jaw and the craniofacial parts.

Therefore, the method for designing the corrected dentition positions by measuring various head shadow parameters, mainly utilizing the head shadow parameters and combining other parameters can comprehensively consider the angle/position relation between the tooth roots and the alveolar bones, the biological integral structural problems of oral soft and hard tissue health and joint health and the facial aesthetic problems so as to design the dentition target positions according with the in-situ medicine and the aesthetics.

Further, in step S120, a data set representing a target position of the at least one key tooth is determined, which represents a target position of the at least one key tooth, based on the data set representing an original position of the at least one key tooth, using the set of parameters. And further, in step S130, a target data set representing a target dentition layout representing a target position of the original dentition is determined from the data set representing a target position of at least one key tooth.

Here, first, the present invention proposes a concept of "key teeth", which refer to a certain tooth or teeth included in the dentition and play an important role in determining the position of the entire dentition. And the determination of the target position after the original dentition correction comprises the determination of the target position on three-dimensional space coordinates in the vertical direction, the transverse direction and the front-back direction. And therefore will be described in detail below with respect to how the target position for each direction is determined.

1. Determining vertical positioning of tooth arrangement

First, according to an embodiment of the present invention, the target positions include a vertical target position, and in order to determine the vertical target position of the entire dentition, maxillary first molars are selected as the key teeth. Therefore, in the first embodiment, in step S120, it is necessary to determine a data set representing the target position of at least one key tooth representing the desired vertical target position after the first molar correction of the upper jaw using the obtained parameter set.

As mentioned above, there are many parameters that can be obtained by cephalometric measurements, and in one embodiment of the present invention, the desired vertical target position after first molar correction of the maxilla is determined by selecting the cephalometric angles FMA and SN-MP, and the cephalometric ratio S-Go/N-Me as the primary parameters.

Fig. 3 shows a dentition diagram of the entire dentition of a normal person, with specific numbers marked for each tooth. It should be noted, however, that the dentition of some patients or adolescents does not include all of the teeth shown in fig. 3, and fig. 3 is only intended to illustrate the positions of the individual teeth and is not intended to limit the present invention.

Wherein the maxillary first molars include molars with a dental position number of 16 or 26 (i.e., left or right maxillary first molars). Here, it is preferable that the vertical positions of the left and right maxillary first molars are adjusted to be substantially uniform, and then the vertical position of the entire dentition is determined based on the vertical position of the left or right maxillary first molars. However, the vertical position of the entire dentition may be determined using only the left maxillary first molars or the right maxillary first molars, which is not limited by the present invention.

First, FMA is the angle of intersection of the eye-ear plane and the mandibular plane, as shown in fig. 4A. The normal congener FMA angles are substantially close, for example, normal chinese FMA measurements mean 31.3 degrees (standard deviation 5.0 degrees) as determined by the two analysis.

And SN-MP is the intersection angle of the anterior skull base plane and the mandible plane, as shown in FIG. 4B. Similarly, the SN-MP angle of a normal congener is substantially close, for example, the measurement mean of SN-MP of a normal Chinese in the dental replacement stage is 35.8 degrees (standard deviation is 3.6 degrees), and the measurement mean of SN-MP in the permanent stage is 32.5 degrees (standard deviation is 5.2 degrees).

High angle if FMA and SN-MP angles are above the average range; whereas, when the FMA and SN-MP angles are below the average range, the angles are low; on the other hand, when the FMA and SN-MP angles fall within the average range, the average angle is obtained.

And the head shadow ratio S-Go/N-Me (posterior-anterior height ratio), as shown in FIG. 4C, the S-Go/N-Me (posterior-anterior height ratio) normal ratio is about 62%, which is an important index, and an excessively large ratio indicates that the face grows in a horizontal sagittal direction, whereas the face grows in a vertical direction.

Thus, based on the measured parameters of the head shadow in combination with the dental statistics, the vertical position of the maxillary first molar may be determined. For example, if the patient is judged to belong to high angle or mean angle cases collectively by their FMA and SN-MP angles, the maxillary first molars cannot be designed to elongate; in the case of low angle cases, the maxillary first molars cannot be designed to be impacted. Meanwhile, the range of S-Go/N-Me was maintained around the normal ratio by adjusting the vertical position of the maxillary first molar.

It should be noted that: the above design is for the case of a pathologically elongated maxillary first molars, which if replaced by the vertical height of the maxillary first premolars (i.e. teeth in the 14 or 24 tooth position) or maxillary second premolars (i.e. teeth in the 15 or 25 tooth position), i.e. in this case the key tooth determining the vertical height may be the maxillary first premolars or maxillary second premolars.

Moreover, comprehensive consideration is also needed according to the specific case, for example, the correction target is correspondingly adjusted according to the correction means and the correction limit included in the used tool; the principle is as follows: the correction means and the tool support tooth movement are realized, and the design can be close to the standard; the tooth movement is not supported, the limit supported by the correction means and the tool is taken as the design limit, the tooth is drawn close to the ideal correction target as far as possible, and the tooth is kept in place at the minimum limit.

Once the vertical height of the maxillary first molar is determined, in step S130, the desired vertical height of the current maxillary and mandibular dentition after correction, that is, the target height of the remaining teeth in the vertical direction, may be determined based on the vertical height of the maxillary first molar, that is, the target data set representing the target dentition layout is obtained.

In one embodiment of the present invention, the vertical height of the other teeth of the upper jaw is determined by using an Occlusal Plane (OP) as a reference mark. In stomatology, the occlusal plane is an imaginary plane that is the average plane of the incisal and occlusal surfaces of the teeth and, strictly speaking, is not a plane, which represents the two-dimensional average of these surfaces. The proper joint plane is one of the factors for ensuring the physiological coordination state of the organs and tissues of the jaw face.

The coplanar plane is determined by the following three points: two of the points are determined by the first molars on both sides of the upper jaw (i.e. teeth at positions 16 and 26), and the third point is determined by one tooth positioned relatively to the normal middle incisors on the upper jaw (i.e. teeth at positions 11 or 21) (the position of the middle incisors needs to be determined by referring to the relationship between labial teeth), which is as follows:

A. selection of maxillary bilateral first molar points: landmark points for easy identification-optional nests; mesial/distal marginal ridges; a mesial/distal abutment; a dental tip; bracket anchor points, etc. Different landmark points may be selected according to different planes.

B. Selection of maxillary central incisor points: landmark points for easy identification-optional nests; mesial/distal marginal ridges; a mesial/distal abutment; cutting corners; cutting ends; bracket anchor points, etc. Different landmark points may be selected according to different planes.

Accordingly, the vertical height of the remaining maxillary teeth is determined as follows: if an imaginary plane formed by the mesio-incisal angle of the maxillary central incisors at the ideal position to the mesio-buccal cusp of the bilateral first molars at the ideal position is taken as a fitting plane (there are also those using the mesio-lingual cusp or the distal buccal cusp of the bilateral second molars as an anchor point), the positional relationship of each maxillary tooth to the plane is: the maxillary central incisor, cuspid and premolar cheek tips are contacted with the plane, and according to the definition of different maxillary occlusion planes, the near-middle cheek tip, the near-middle tongue tip or the maxillary second molar cheek tip of the maxillary first molar is contacted with the plane; the lateral incisors do not contact the plane; the distance between the tooth tips of the molars and the plane is increased from the front to the back.

The method for determining the vertical height of the teeth of the lower jaw comprises the following steps: the anterior teeth (generally, the upper and lower sides 3-3 are called anterior teeth) are in good overlying relation with the upper jaw. When the occlusal finger cusps are combined in a staggered manner, the vertical distance of the upper teeth covering the lower teeth lip (buccal) surface is 2-4mm, and for the anterior teeth, the vertical distance between the incisal edges of the upper incisors and the lower incisors is normally 2-4 mm; when the covering finger cusps are crossed, the horizontal distance of the upper teeth covering the lower teeth is normally about 2-4mm, and for the anterior teeth, the horizontal distance between the incisal margins of the upper incisor and the lower incisor is in the fore-and-aft direction. The posterior teeth (other teeth than the anterior teeth) are arranged in the most widely contacting occlusal relationship with the posterior teeth of the upper jaw.

And, finally, it is also necessary to adjust according to the case specific: for example, the vertical height of the anterior teeth can be correspondingly adjusted by referring to aesthetic analysis such as smile lines of a case and the like, and correspondingly adjusted by referring to the correction means and the correction limit contained by the used tool; and the vertical height of the posterior teeth is correspondingly adjusted according to the correction means, the used correction means and the correction limit contained by the used tool.

The overall principle is as follows: the correction means and the tool support tooth movement are realized, and the design can be close to the standard; the realization that tooth movement is not supported, the limit supported by the tool is taken as the design limit, the tooth is drawn close to the ideal correcting target as much as possible, and the tooth is kept in place at the minimum limit.

2. Determining transverse positioning of tooth arrangement:

also, according to another embodiment of the present invention, the target position includes a lateral target position, and in order to determine the lateral target position of the entire dentition, the lateral width of the entire dentition is located by selecting as the key teeth the lower cuspid tooth (i.e., the tooth at 33 or 43 dentition) and the lower first molar tooth (i.e., the tooth at 36 or 46 dentition).

Therefore, in the second embodiment, in step S120, it is necessary to determine a data set representing the target position of at least one key tooth representing the lateral target position desired after correction of the mandibular cuspid and mandibular first molar using the obtained set of parameters.

Similar to the first embodiment described above, the mandibular first molars include molars with a dental position number of 36 or 46 (i.e., left or right mandibular first molars), and the mandibular cuspids include cuspids with a dental position number of 33 or 43 (i.e., left or right mandibular cuspids). Here, it is preferable that the lateral positions of the left and right mandibular first molars are adjusted to be substantially symmetrical and the lateral positions of the left and right mandibular cuspids are also adjusted to be substantially symmetrical, and then the lateral position of the entire dentition is determined based on the lateral positions of the left or right mandibular first molars and the left or right mandibular cuspids.

The general principle is to determine the ideal width position of the mandibular canine and mandibular first molar with reference to the width of the basal bone. Specifically, the ideal width position of the mandibular cuspid and mandibular first molar may be determined by any one or a combination of three methods.

The method comprises the following steps: alveolar bone CT sagittal section method. The corresponding rule is as follows: the root of the long axis of the mandibular canine tooth and the mandibular first molar tooth is determined to be located in the center of the alveolar bone by the CT sagittal sectional view. Since the CT image is a slice image, there are slice images of a cross section, a coronal section, and a sagittal section. Here, the ideal width position is determined by using the CT sagittal section when the root of the long axis of the lower maxillary canine and the first mandibular molar is located at the center of the alveolar bone.

The second method comprises the following steps: WALA Ridge (WALA Ridge, wherein WALA is abbreviated by human name) Ridge.

As shown in fig. 5, WALA Ridge is a line connecting WALA points (i.e., the most prominent Point at the membrane-gingival junction), and clinically refers to a soft tissue band immediately above the mandible-membrane-gingival junction, substantially at the level of the center of rotation of the tooth, which represents the extent of the basal arch. The clinical research finds that: the distance between the FA point (the most prominent point on the crown surface of each tooth) and the WALA Ridge represents the relative relationship between the tooth and the alveolar bone. Therefore, by referencing the WALA Ridge to determine the position of the tooth, the root can be positioned in the middle of the alveolar bone.

The invention proposes: the distance between the FA point of the lower jaw cuspid and the WALA Ridge is set to be 0-1mm, and preferably 0.6 mm; the distance from the FA point of the first molar to the WALA Ridge is set to 1-3mm, preferably 2 mm.

The third method comprises the following steps: statistical width of mandibular canine and mandibular first molar. Wherein the statistical width: reference is made to the statistics of the width between the mandibular cuspid and the mandibular first molar reported in each document.

For the statistical width, reference may be made to the statistics of the width between the mandibular cuspid and the mandibular first molar reported in each document. For example, reference may be made to "the national merged teeth and arch measurement study in Jiangsu, Guyan et al, dentistry, 3 months 2010, Vol.30, phase 3" or "the normal merged youth crown, arch width and Bolton index measurements, Guo et al, university of Tianjin, 2004, phase 2", and so on.

In summary, the lateral position of the mandibular cuspids and mandibular first molars may be determined based on any one or a combination of the three above approaches.

And, it needs to be adjusted according to the case specific situation. For example, the correction target is adjusted according to the correction means and the correction limit contained in the used tool. Wherein the principle is as follows: for the cuspid teeth without obvious dislocation before correction, keeping the width of the cuspid teeth consistent before and after correction as much as possible; for cuspids with obvious malposition before correction, the design can be closed to the standard if the correction means and the tool support tooth movement are realized; the tooth movement is not supported, the limit supported by the correction means and the tool is taken as the design limit, the tooth is drawn close to the ideal correction target as far as possible, and the tooth is kept in place at the minimum limit.

And, once the lateral positions of the mandibular canine and mandibular first molar are determined, in step S130, the desired lateral arrangement of the current upper and lower mandibular dentition after correction, i.e. the positions of the remaining teeth in the lateral direction, may be determined based on the lateral positions of the mandibular canine and mandibular first molar, i.e. a target data set representing the target dentition layout is obtained. Regarding this step, the following will be described together with the front-rear direction tooth arrangement method.

3. Determining the front-to-back positioning of tooth arrangement

Furthermore, according to an embodiment of the present invention, the target positions include forward and backward target positions, and in order to determine the forward and backward target positions of the entire dentition, an incisor (dentition number 31 or 41) in the lower jaw is selected as a key tooth to locate the forward and backward depth of the entire dentition. Therefore, in the third embodiment, in step S120, it is necessary to determine a data set representing the target position of at least one key tooth representing the desired anteroposterior target position of the incisors in the lower jaw after correction using the obtained parameter set.

Among them, the mandibular central incisors include mandibular central incisors with a dental position number of 31 or 41 (i.e., left or right mandibular central incisors). Here, it is preferable that the anteroposterior positions of the incisors in the left and right mandibles are adjusted to be substantially uniform, and then the anteroposterior position of the entire dentition is determined based on the anteroposterior positions of the incisors in the left or right mandible. However, it is also possible to determine the anteroposterior position of the entire dentition using only the left mandibular incisors or to determine the anteroposterior position of the entire dentition using the right mandibular incisors, which is not a limitation of the present invention.

The general principle is as follows: and determining the ideal front-back position and angle of the incisors in the lower jaw by referring to the angle/position relation between the incisors in the lower jaw in the lateral skull slice and the alveolar bone.

Specifically, the ideal width position of the incisors in the lower jaw can be determined by any one of the following three methods or a combination of several methods.

The method comprises the following steps: the alveolar bone CT sagittal section.

The corresponding rule is as follows: the root of the incisor long axis in the lower jaw is determined to be an ideal position when the root is positioned in the center of the basal bone by the CT sagittal sectional view.

The second method comprises the following steps: WALA Ridge method.

The invention proposes: the distance from the FA point of the incisors in the lower jaw to the WALA Ridge is set to be 0-0.5mm, and preferably 0.1 mm.

The third method comprises the following steps: the head shadow measures various angles and line distances.

For example, the cephalometric angles include: IMPA, L1-NB, AP-L1, NP-L1, U1-L1 and the like, and the line distances include L1-NB (mm), AP-L1, NP-L1 and the like

For example, the mean value of measurements of IMPA (lower central incisor-mandibular plane angle) for normal Chinese can be determined to be 93.9 degrees (standard deviation 6.2 degrees) according to the Tweed analysis.

The average value of U1-L1 (the included angle between the major axes of the upper and lower middle incisors) of a normal Chinese person in the tooth replacing period is 122.0 degrees (the standard deviation is 6.0 degrees), and the average value of U1-L1 in the permanent tooth period is 125.4 degrees (the standard deviation is 7.9 degrees)

For example, the average of measurements of the angle (angle between the long axis of the lower central incisor and the line joining the NB) and the line distance (perpendicular distance between the incisor margin of the lower central incisor and the line joining the NB) of normal Chinese L1-NB is 27 degrees and 6mm, where the line joining the nasion point and the lower alveolar ridge point.

Of these, AP-L1 (upper middle incisor pitch), NP-L1 (lower middle incisor pitch) pitch parameters are preferably used. For these two parameters, there are two methods of measurement: 1) is the vertical distance from the incisor ends of the upper and lower incisors to the nasion point to the anterior point of the chin (plane), 2) is the vertical distance from the incisor ends of the upper and lower incisors to the upper socket point to the anterior point of the chin (AP plane).

Therefore, according to method three, the anterior-posterior position of the incisors in the lower jaw can be determined based on the measured head shadow parameters in combination with the dental statistics.

In summary, the anterior-posterior position of the incisors in the lower jaw may be determined according to any one of the above three ways or a combination of the three ways.

Finally, the method also comprises the following steps: the adjustment is carried out according to the specific situation of a case: the position and the angle of the lower incisor are correspondingly adjusted according to the convex shrinkage degree of the lower jaw and the relative position relationship (I type/II type/III type) of the lower jaw and the upper jaw in facial aesthetics; and correspondingly adjusting according to the correction means and the used tools. The principle is as follows: the correction means and the tool support tooth movement are realized, and the design can be close to the standard; the tooth movement is not supported, the limit supported by the correction means and the tool is taken as the design limit, the tooth is drawn close to the ideal correction target as far as possible, and the tooth is kept in place at the minimum limit.

And, once the front-rear height of the incisors in the lower jaw is determined, the remaining teeth are arranged correspondingly in the front-rear direction in step S130. In addition, with reference to the second specific embodiment, in step S130, the desired lateral arrangement of the current upper and lower dentition after the correction may be determined based on the lateral positions of the lower molar teeth and the lower molar teeth, that is, the lateral positions of the remaining teeth are determined, so as to obtain the target data set representing the target dentition layout.

Wherein the reference mark is a bite curve (line of occlusion) shown in fig. 6. The standard occlusion curve is a connecting line formed by contact points of the upper and lower teeth when the upper and lower teeth are occluded. In order to determine the target positions of the remaining teeth, except for the above-mentioned critical teeth, it is necessary to fit a target bite curve based on several critical teeth, as follows:

A. first, the occlusion curve of the mandible is determined: fitting a curve according to the positions of incisors, mandibular canine teeth and mandibular first molar teeth in the mandible; wherein, the lower jaw arrangement should satisfy the condition that the incisal margin of the lower jaw incisor, the cuspid cusp, the premolar and the molar buccal cusp need to be positioned on the occlusion curve. Further, it is also required to satisfy the requirement that neither the space nor the crowding is present in the dentition (or the space and the crowding amount satisfy the setting requirements).

Finally, after the incisal margins or cusps of the teeth meet the condition of lying on the occlusion curve, the following requirements also need to be satisfied for the specific position of each mandibular tooth: the torque, the shaft inclination angle of each tooth satisfy the standard values (as shown in fig. 7B and 8B), and the tooth torsion angle is small.

B. After the bite curve of the mandible is determined, the positions for the maxillary teeth should satisfy: the upper dental arch uses the mirror occlusion curve of the lower dental arch; the arrangement of the upper teeth is to meet the condition that the upper incisors and the cuspids cover the corresponding lingual occlusal belts on the occlusion curve, and the central fossa walking shapes of the premolars and the molars are consistent with the occlusion curve; no clearance or crowding exists in dentition (or the clearance and the crowding amount meet the set requirement);

finally, after the incisal edges or cusps of the teeth meet the condition of being on the occlusal curve, the following requirements also need to be met for the specific position of each maxillary tooth: the torque and the axial inclination angle of each tooth satisfy the standard values (as shown in fig. 7B and 8B), and the tooth torsion angle is subject to uniform covering with mandibular teeth and good apical fossa fitting.

For the occlusion relation, the vertical relation between the upper and lower jaw tooth arrays and the occlusion plane determines the occlusion relation of the upper and lower jaws in the vertical direction; the position relation between the upper and lower jaw dentition and the dental arch curve determines the front-back and transverse occlusion relation of the upper and lower jaws.

Hereinafter, concepts of the torque, the inclination angle, and the torsion angle of the teeth will be briefly described.

Tooth torque: the angle formed by the tangent to the clinical crown of the tooth and the perpendicular to the occlusal plane is called torque. Fig. 7A shows a diagram of tooth torque values. As shown, A represents that the clinical coronal tangent gingival end is positive behind the vertical of the occlusal plane, whereas the tooth torque in B is negative.

For each tooth, the tooth torque has a normal value or normal range value that can be referenced. For example: fig. 7B shows an example of normal values of tooth torque for some teeth of the upper and lower jaws (where the numerical values contained in fig. 7B are in degrees). Thus, the tooth torque can be set within a normal range according to the reference value to determine the specific position of each tooth.

Tooth axis inclination: the angle formed by the long axis of the clinical crown of the tooth and the vertical line of the combined plane is an axial inclination angle. The inclination of the axis is positive when the gum end of the long axis of the clinical crown inclines to the far middle, and the inclination of the axis is negative when the gum end inclines to the near middle. Normal resultant shaft inclination is mostly positive.

Fig. 8A shows a schematic diagram of tooth axis inclination values. As shown, the inclination of the tooth axis in A represents a positive value, whereas the inclination of the tooth axis in B represents a negative value.

For each tooth, there is a normal value or normal range of values for tooth axis inclination that can be referenced. For example: FIG. 8B shows an example of normal values for tooth axis inclination for certain teeth of the upper and lower jaws (where the numerical values contained in FIG. 8B are in degrees). Thus, the tooth axis inclination can be set within a normal range in accordance with the reference value to determine the specific position of each tooth.

Tooth torsion degree: generally, the angle formed by the tangent line of the clinical dental arch of the tooth and the tooth axis is the torsion angle. If the teeth are severely twisted, the appearance is affected and the chewing function is not good, so that the twisting angle of the teeth should be small in general.

And, adjusting according to the case specific situation: correspondingly adjusting the correction target according to the correction means and the correction limit contained in the used tool; the principle is as follows: the correction means and the tool support tooth movement are realized, and the design can be close to the standard; the tooth movement is not supported, the limit supported by the correction means and the tool is taken as the design limit, the tooth is drawn close to the ideal correction target as far as possible, and the tooth is kept in place at the minimum limit.

4. Also, it should be noted that although in the above description, embodiments of how to determine the vertical direction, the lateral direction, and the front-back direction of the dentition are described separately, the present invention also includes a fourth embodiment in which these three embodiments are combined to determine the position of the dentition in three dimensions.

In the fourth embodiment, in step S120, it is necessary to determine a data set representing the desired vertical target position after the first molar correction of the upper jaw, the desired lateral target position after the first molar correction of the lower cuspid and lower jaw, and the desired anteroposterior target position after the correction of the incisors in the lower jaw, which data set represents the target position of at least one key tooth, using the obtained parameter sets.

Also, in step S130, a target data set representing a target dentition layout may be determined which represents the vertical, lateral and forward-backward positions desired after the current upper and lower mandibular dentition correction, based on the vertical height of the upper maxillary first molar, the desired lateral target positions after the mandibular cuspid and mandibular first molar correction, and the desired forward-backward target positions after the mandibular central incisor correction.

5. Further, the present invention includes fifth, sixth and 7 embodiments for determining the position of the dentition in two dimensions by combining any two of the three embodiments for determining the vertical, lateral or anteroposterior position, respectively.

For example, in the fifth embodiment, in step S120, it is necessary to determine a data set representing the desired vertical target position after the first molar correction of the upper jaw and the desired anteroposterior target position after the incisor correction of the lower jaw, which represents the target position of at least one key tooth, using the obtained parameter set.

Also, in step S130, a target data set representing a target dentition layout may be determined which represents the desired vertical and forward and backward positions of the current upper and lower jaw dentition after correction, based on the vertical height of the upper jaw first molar and the data set representing the target position of at least one key tooth of the desired forward and backward target positions of the lower jaw after correction of the incisors.

The sixth and seventh embodiments are also similar and will not be repeated here.

In addition, in determining the position of the entire dentition, it is preferable to also take into account the position of the joint. As shown in fig. 9A, the condyles are located at the terminal end of the mandible, which determines the position of the mandible. Therefore, the following requirements should be considered in determining the dentition position: when the upper and lower mandibular teeth are in the maximum cusp contact relationship, the mandibular condyle should be in the correct position within the glenoid fossa.

Specifically, the condyles are located at the uppermost and foremost positions of the glenoid fossa (which the scholars refer to as being located at the uppermost and rearmost positions of the glenoid fossa) and are opposite to the posterior slope of the articular tubercle; and anatomical studies of the location of the condyles yield: for example, the mesial ridge should be located at the apex of the glenoid fossa, which is the uppermost position of the glenoid fossa, with the antero-posterior direction at the medial position and the horizontal direction at the medial position. Also, the position of the mandible is adjusted so that the measurement data of the joint space satisfies the standard value (as shown in fig. 9B), or approximates to the standard value.

Finally, aesthetics is an important reference index for dental correction and also an important factor in determining tooth position. Therefore, after the position of the tooth is basically determined according to the above rule, the central incisors, the cuspids and the first molars can be appropriately adjusted in the vertical direction, the lateral direction and the front-back direction according to the lip and face aesthetics.

Moreover, the application also provides a system for realizing the method. FIG. 10 illustrates a system 200 of the present application in accordance with an exemplary embodiment. The system 200 may be any form of digital platform including a desktop computer, a notebook, a portable palm top computer, a digital platform, a cluster of computers, a network workstation, and the like.

The system 200 shown in fig. 10 includes: one or more input components 210 internally connected by a bus 250; one or more output components 220; one or more Central Processing Units (CPUs) 230; and one or more storage components 240, the storage components 240 storing therein one or more computer programs 244, one or more operating systems 246, and optionally one or more databases 248.

Wherein the input component 210 enables data input to be provided to the system 200. Common input components 210 include a data input interface, a network transmission interface, or other type of input component. In the present application, the input component 210 is used to acquire a set of raw data representing the raw dentition layout and a set of parameters representing the head structure, i.e. to receive an electronic image of the patient's teeth at an initial position, for example acquired with an intra-oral scanner or a CT scanner based on an impression or partial impression of the patient's teeth, and X-ray head shadow raw data or data processed by specific head shadow software.

And, the output component 220 is used for providing the calculation result to the user, and the common output component 220 includes a user graphic interface (GUI), a three-dimensional display interface, an output data interface, a network transmission interface, or other types of output components. For example, the computer system is programmed to provide a Graphical User Interface (GUI) and a three-dimensional display interface to facilitate the user in setting parameters and determining the optimal target dentition position via the computer system.

A Central Processing Unit (CPU)230 generally controls overall operation of the system 280, such as operations associated with display, data processing, data storage, data communication, and recording operations. The Central Processing Unit (CPU)230 may include one or more processors to execute instructions to perform all or a portion of the steps of the methods described above. Further, Central Processing Unit (CPU)230 may include one or more modules that facilitate handling interactions between Central Processing Unit (CPU)230 and other components. For example, Central Processing Unit (CPU)230 may include an input/output module to facilitate interaction between input component 210, output component 220, and Central Processing Unit (CPU) 230.

The memory 240 may be implemented by any type or combination of random access memory device RAM 241 or read only memory device ROM 242, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Read Only Memory (PROM), Read Only Memory (ROM), CD-ROM, magnetic tape, floppy disk, and optical data storage device. The memory 240 may be configured to store various types of data to support operations at the system 200. Examples of such data include any operating system 246, computer programs 244, databases 248, etc. for operating on system 200. Wherein the computer program 244 is executable in the system 200, the computer program 244 instructs the respective modules of the central processor 230 by instructions to perform the methods described in the present application. Also, in the present invention, the memory 240 is further configured to store a raw data set representing a raw dentition layout and a parameter set representing a head structure.

Where the method shown in fig. 1 may be implemented in a computer readable medium, e.g., in computer software, hardware, or a combination thereof. For a hardware implementation, the embodiments described herein may be implemented by one or more of an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Digital Signal Processing Device (DSPD), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), a processor, a controller, a microcontroller, a microprocessor, other electronic units designed to perform the functions described herein, or a selective combination thereof.

For a software implementation, the embodiments described herein may be implemented with separate software modules, such as a process module and a function module, each of which performs one or more of the functions and operations described herein. The software code may be implemented as a software application written in any suitable programming language and may be stored in a memory or other computer-readable medium of a dedicated computer system and executed by a processor of the computer system, or may be installed in other electronic devices with data storage and processing capabilities, such as a tablet, server, and the like.

Accordingly, system 200 may be configured to perform any of the steps and any combination of the steps of the methods described and incorporated herein and will not be repeated here.

Also, for the sake of brevity, conventional data networking, application development, and other functional aspects of the systems (of the individual operating components within the systems) may not be described in detail herein. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent typical functional relationships and/or physical couplings between the various elements. It should be noted that many variations and/or additional functional relationships or physical connections may be present in a practical system.

Further, those skilled in the art will appreciate that any computing device used by a user may include not only the various conventional support software and drivers normally associated with a computer, but also an operating system (e.g., Windows, OS2, UNIX, Linux, Solaris, MacOS, etc.). It will be appreciated by those of ordinary skill in the art that each computing device may be embodied as a custom existing system, add-on product, upgrade software, stand-alone system, distributed system, method, data processing system, device for data processing, and/or computer program product. Thus, any program stored herein can take the form of an entirely software embodiment, an entirely hardware embodiment, or an embodiment combining software and hardware aspects. Further, any program may take the form of a computer program product on a computer-readable storage medium having computer-readable program code means (computer-readable program code means) embodied in the storage medium. Any suitable computer readable storage medium may be utilized including: hard disks, CD-ROMs, optical storage devices, magnetic storage devices, and the like.

While various aspects and embodiments of the invention are disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration only and are not intended to be limiting. The scope and spirit of the present invention are to be determined only by the appended claims.

Likewise, the various diagrams may illustrate an exemplary architecture or other configuration of the disclosed methods and systems that is useful for understanding the features and functionality that may be included in the disclosed methods and systems. The claimed invention is not limited to the exemplary architectures or configurations shown, but rather, the desired features can be implemented in various alternative architectures and configurations. In addition, to the extent that flow diagrams, functional descriptions, and method claims do not follow, the order in which the blocks are presented should not be limited to the various embodiments which perform the recited functions in the same order, unless the context clearly dictates otherwise.

Unless otherwise expressly stated, the terms and phrases used herein, and variations thereof, are to be construed as open-ended as opposed to limiting. In some instances, the presence of an extensible term or phrases such as "one or more," "at least," "but not limited to," or other similar terms should not be construed as intended or required to imply a narrowing in instances where such extensible terms may not be present.

Claims (23)

1. A method for determining a target dentition layout, comprising the steps of:

receiving an original data set representing an original dentition layout, the original data set comprising data sets representing original positions of a plurality of key teeth, the plurality of key teeth comprising cuspids of the lower jaw, first molars, middle incisors, and first molars and middle incisors of the upper jaw;

obtaining a set of parameters representing a header structure;

determining a data set representing target positions of the plurality of keywords based on the data set representing original positions of the plurality of keywords using the parameter set of the head structure; and

generating a target data set representing a target dentition layout from the data set representing target positions of the plurality of incisors;

wherein said generating a target data set representing a target dentition layout from a data set representing target positions of said plurality of incisors comprises:

determining data representing vertical target positions of maxillary dentition using a combined plane composed of the maxillary first molars and the maxillary middle incisors, according to the data representing the vertical target positions of the maxillary first molars and the maxillary middle incisors;

determining the data representative of the lateral target positions of the mandibular dentition from the data representative of the lateral target positions of the mandibular canine and mandibular first molars using a mandibular occlusion curve fitted to the mandibular canine and mandibular first molars and incisors in the mandible;

determining the data representative of the anteroposterior target positions of the mandibular dentition from the data representative of the anteroposterior target positions of the incisors in the mandible using a mandibular occlusion curve fitted to the mandibular cuspid teeth and the mandibular first molars and incisors in the mandible.

2. The method of claim 1 wherein the raw data set includes data representative of a maxillary raw dentition layout and a mandibular raw dentition layout.

3. The method of claim 1, wherein the set of parameters representing a header structure comprises: at least one of a cephalogram parameter measurement data set, a dental image measurement data set, and a dental parameter standard value set.

4. The method of claim 1, wherein the plurality of key teeth comprise maxillary first premolars or maxillary second premolars when the maxillary first molars are pathologically elongated, and the data set representing target positions of the plurality of key teeth comprises vertical target positions of the maxillary first premolars or maxillary second premolars.

5. The method of claim 1, wherein the set of parameters representative of the head structure includes a set of head shadow parameter measurement data and a set of standard values for respective head shadow parameters, the method further comprising: and determining the vertical target position of the first maxillary molar by comparing the measured data of the head shadow parameters with the standard values of the corresponding head shadow parameters.

6. The method of claim 5, wherein the head shadow parameters include at least one of an angle of intersection of an auricle plane and a mandible plane (FMA), an angle of intersection of an anterior basis cranium plane and a mandible plane (SN-MP), and a posterior-anterior aspect ratio (S-Go/N-Me).

7. The method of claim 1, wherein the target data set further includes data representing a vertical target position of mandibular dentition, the method further comprising: and determining the data representing the vertical target position of the mandibular dentition by utilizing the overlay coverage or occlusal relationship of the maxillary teeth and the corresponding mandibular teeth according to the data representing the vertical target position of the maxillary dentition.

8. The method of claim 1, wherein the set of parameters representative of head structure includes a lateral position measurement dataset and a reference dataset for the mandibular canine and mandibular first molar, the method further comprising: determining lateral target positions of the mandibular canine and mandibular first molars based on the lateral position measurement dataset and the reference dataset for the mandibular canine and mandibular first molars.

9. A method according to claim 8, wherein the lateral position measurement dataset and the reference dataset for the mandibular canine and mandibular first molar comprise any one of the following datasets: a data set representing the relationship of the lateral positions of the mandibular canine and mandibular first molars and the alveolar bone position, a data set representing the positional relationship of the WALA ridge of the mandibular dentition to the FA points of the mandibular canine and mandibular first molars, and a data set and standard value set representing the lateral position measurements of the mandibular canine and mandibular first molars, determined from the alveolar bone CT image.

10. The method of claim 1, wherein the target data set further comprises data representing a lateral target position of maxillary dentition, the method further comprising: and obtaining a mirror image maxillary occlusion curve according to the mandibular occlusion curve, and determining the data representing the transverse target position of the maxillary dentition.

11. The method of claim 1, wherein the set of parameters representative of head structure includes an anteroposterior position measurement dataset and a reference dataset of incisors in the mandible, the method further comprising: determining an anterior-posterior target position of the incisors in the lower jaw based on the anterior-posterior position measurement dataset and the reference dataset of the incisors in the lower jaw.

12. The method of claim 11, wherein the anterior-posterior position measurement dataset and the reference dataset for the incisors in the lower jaw comprise any one of the following datasets: and the data set represents the relation between the front and back positions of incisors in the lower jaw and the position of the alveolar bone, the data set represents the position relation between the WALA ridge of the mandibular dentition and the FA point of the incisors in the lower jaw, and the head shadow parameter measurement data set and the standard value set of the corresponding head shadow parameters.

13. The method of claim 12, wherein the head shadow parameters comprise at least one of an inferior medial incisor-mandibular plane angle (IMPA), an angle between a long axis of the inferior and superior medial incisors (U1-L1), an angle between a long axis of the inferior medial incisor and a line NB (L1-NB angle), a perpendicular distance between an incisal edge of the inferior medial incisor and a line NB (L1-NB pitch), an upper medial incisor pitch (AP-L1), and a lower medial incisor pitch (NP-L1), wherein the line between a nasal root point and a lower seating point is the line between a nasal root point and a lower seating point.

14. The method of claim 1, wherein the target data set further comprises data representing anteroposterior target positions of maxillary dentition, the method further comprising: and obtaining a mirrored maxillary occlusion curve according to the mandibular occlusion curve, and determining the data representing the anteroposterior target positions of the maxillary dentition.

15. The method of claim 1, wherein the method further comprises:

determining the front-back direction and the transverse target position of each tooth of the maxillary dentition according to the mandibular occlusion curve;

generating a mirrored maxillary occlusion curve based on the mandibular occlusion curve; and

determining a front-to-back and a lateral target position for each tooth of the maxillary dentition.

16. The method of claim 15, wherein the method further comprises: the target position of each tooth of the mandibular dentition is adjusted so that the torque, the axis inclination angle of each tooth of the mandibular dentition is equal to or substantially equal to a standard value and the twist angle of each tooth is not greater than a specified threshold value.

17. The method of claim 16, wherein the method further comprises: and adjusting the target position of each tooth of the maxillary dentition so that the torque and the axial inclination angle of each tooth of the maxillary dentition are equal to or basically equal to the standard values, and the torsion angle of each tooth is based on that the overlapping coverage of the tooth and the corresponding mandibular tooth is uniform and the apical fossa is well embedded.

18. The method of any one of claims 1 to 17, wherein the method further comprises: and integrally moving the positions of the upper and lower jaw dentitions according to the joint parameters to obtain a target data set reflecting the joint parameters.

19. The method of claim 18, wherein the bodily movement comprises: adjusting the vertical, lateral and anteroposterior target positions of the upper and lower jaw dentitions such that the measured data of the positions of the mandibular condyloid processes in the glenoid fossa equals or approximates to standard values when the upper and lower jaw dentitions are in the maximum cusp contact relationship.

20. The method of any one of claims 1 to 17, wherein the method further comprises: and adjusting the central incisors, the cuspids and the first molars of the upper and lower jaws based on the aesthetic indexes of the labial and facial parts to obtain a target data set reflecting the aesthetic indexes.

21. The method of any one of claims 1 to 17, wherein the method further comprises: and adjusting the target data set according to the correction means and the correction limit corresponding to the correction tool.

22. The method of any one of claims 1 to 17, wherein the method is computer-implemented.

23. A system for determining a target dentition layout, comprising:

an input unit for receiving an original data set representing an original dentition layout and acquiring a parameter set representing a head structure, the original data set comprising a data set representing original positions of a plurality of key teeth including cuspids of the lower jaw, first molars, middle incisors, and first molars and middle incisors of the upper jaw;

a controller for performing the steps of:

determining a data set representing target positions of a plurality of key teeth based on the data set representing original positions of the plurality of key teeth using the set of parameters of the head structure; and

generating a target data set representing a target dentition layout from the data set representing target positions of a plurality of incisors;

wherein said generating a target data set representing a target dentition layout from a data set representing target positions of said plurality of incisors comprises:

determining data representing vertical target positions of maxillary dentition using a combined plane composed of the maxillary first molars and the maxillary middle incisors, according to the data representing the vertical target positions of the maxillary first molars and the maxillary middle incisors;

determining the data representative of the lateral target positions of the mandibular dentition from the data representative of the lateral target positions of the mandibular canine and mandibular first molars using a mandibular occlusion curve fitted to the mandibular canine and mandibular first molars and incisors in the mandible;

determining the data representative of the anteroposterior target positions of the mandibular dentition from the data representative of the anteroposterior target positions of the incisors in the mandible using a mandibular occlusion curve fitted to the mandibular cuspid teeth and the mandibular first molars and incisors in the mandible.

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