Temporomandibular joint coordinate system establishing method

Abstract

The invention discloses a temporomandibular joint coordinate system establishment method, which comprises the following steps: step (1), taking a straight line of a condylar process inner pole and a condylar process outer pole as a condylar process long axis, and enabling an X axis of a TMJ coordinate system to pass through the condylar process long axis; (2) a straight line, perpendicular to the X axis of the TMJ coordinate system, of the vertex of the transcondylar process is the Z axis of the TMJ coordinate system, and the intersection point is the original point O of the TMJ coordinate system; and (3) passing through the original point O, drawing a straight line vertical to the X axis and the Z axis of the TMJ coordinate system, and forming the Y axis of the TMJ coordinate system. According to the temporal-mandibular joint coordinate system establishing method, the TMJ morphological position can be accurately reflected.

Description

Technical Field

[0001] The present application relates to the field of medical technology, and in particular to a method for establishing a temporomandibular joint coordinate system. Background Art

[0002] TMD is a general term for a group of common musculoskeletal diseases in clinical practice: temporomandibular disorder (TMD); TMD is a general term for musculoskeletal diseases with the same or similar symptoms but with unclear etiology. The main features are pain in the affected temporomandibular joint area and masticatory muscles, abnormal joint clicking, and mandibular movement disorders, with an incidence rate of up to 20-50%. TMD can cause significant discomfort, affecting the patient's quality of life and work efficiency. It is estimated that TMD causes 17.8 million days of work loss per year for every 100 million adult workers, bringing an economic burden to society. The occurrence and development of TMD is closely related to the morphology of TMJ: the temporomandibular joint (TMJ) is composed of the temporal bone fossa, articular tubercle, articular disc, condyle, joint capsule, and intracapsular and extracapsular ligaments. The left and right condyles are connected as a whole through the mandible and work in tandem. When the condylar volume decreases, the inclination of the articular tubercle and the depth of the fossa increase, the articular disc is more likely to shift during the condylar movement, leading to the occurrence of TMD. People with asymmetrical condyles are more likely to develop TMD. The occurrence and development of TMD is closely related to the position of the TMJ: compared with normal people, the position of the mandibular condyle in TMD patients is posterior relative to the fossa, the anterior space of the TMJ joint becomes larger, the posterior space decreases, and the superior space decreases. People with posterior condylar position are more likely to have internal TMJ disorder, causing TMD. Clinical studies have confirmed that after the sagittal TMJ position is reconstructed to a coordinated and stable state, the symptoms of TMD patients are effectively improved. In summary, the study of the morphological position of the TMJ has great clinical significance and economic value.

[0003] However, the TMJ coordinate system establishment method currently widely used in clinical practice is to use the cross section of the skull coordinate system as the initial measurement plane, select the maximum cross section of the condyle in parallel layer by layer, and use the line connecting the inner and outer poles of the condyle cross section as the long axis of the condyle. The plane perpendicular to the cross section is established through the long axis of the condyle as the sagittal plane of the coordinate system, and the plane perpendicular to the long axis of the condyle and the cross section through the center of the long axis of the condyle is the coronal plane of the coordinate system. The TMJ is measured on the established coronal and sagittal planes. Since the condyle has its own morphology, its maximum cross section is not parallel to the cross section of the skull coordinate system, and the condyle long axis obtained in this way is not true, and it is difficult to reflect the true morphological position of the TMJ.

[0004] Therefore, how to provide a method for establishing a temporomandibular joint coordinate system that can accurately reflect the morphological position of the TMJ has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present application is to propose a method for establishing a temporomandibular joint coordinate system that can accurately reflect the morphological position of the TMJ.

[0006] A method for establishing a temporomandibular joint coordinate system disclosed in the present application includes the following steps:

[0007] Step (1): The straight line passing through the inner pole and the outer pole of the condyle is taken as the long axis of the condyle, so that the X axis of the TMJ coordinate system passes through the long axis of the condyle;

[0008] Step (2): A straight line perpendicular to the X-axis of the TMJ coordinate system is drawn through the condylar apex as the Z-axis of the TMJ coordinate system, and the intersection point is the origin O of the TMJ coordinate system;

[0009] Step (3): Draw a straight line through the origin O that is perpendicular to both the X-axis and the Z-axis of the TMJ coordinate system to form the Y-axis of the TMJ coordinate system.

[0010] Furthermore, the TMJ coordinate system includes the coronal plane, sagittal plane, and horizontal plane of the condyle; the TMJ is projected onto the coronal plane, sagittal plane, and horizontal plane respectively to obtain the TMJ coordinate system.

[0011] Furthermore, the coronal plane of the condyle passes through the X-axis and Z-axis of the TMJ coordinate system;

[0012] and / or, the Y-axis and Z-axis of the TMJ coordinate system in the sagittal plane;

[0013] And / or, the horizontal plane passes through the X-axis and Y-axis of the TMJ coordinate system.

[0014] Furthermore, before step (1), the method for establishing the temporomandibular joint coordinate system further includes the following steps:

[0015] The cone beam CT (CBCT) data were imported into the software to reconstruct the TMJ three-dimensional model, and the inner and outer poles and the condylar apex of the condyle were calculated using python.

[0016] Furthermore, the cone beam CT (CBCT) data were imported into the software to reconstruct the TMJ three-dimensional model, and the inner and outer poles and the condylar vertex of the condyle were calculated using Python, including the following steps:

[0017] Step S1: selecting the inner pole of the condyle, the outer pole of the condyle and the vertex of the condyle on the reconstructed TMJ three-dimensional model, and converting them into a point set;

[0018] Step S2: Use Python function to automatically calculate the condylar inner pole, condylar outer pole and condylar apex.

[0019] Furthermore, the functional programming principle of Python: calculate the point with the farthest distance between the point set in the inner pole area of ​​the condyle and the point set in the outer pole area, which are defined as the inner pole of the condyle and the outer pole of the condyle respectively; calculate the point in the condyle vertex area that is farthest from the line connecting the inner pole and the outer pole of the condyle, which is defined as the condyle vertex.

[0020] The method for establishing the temporomandibular joint coordinate system of the present application can accurately reflect the morphological position of the TMJ. The method for establishing the temporomandibular joint coordinate system of the present application can accurately reflect the morphological position of the TMJ.

[0021] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 It is a schematic diagram of a TMJ three-dimensional reconstruction model of the method for establishing a temporomandibular joint coordinate system of the present application;

[0024] Figure 2 It is a schematic diagram of anatomical landmarks of the method for establishing a temporomandibular joint coordinate system of the present application;

[0025] Figure 3 It is a schematic diagram of region selection of the method for establishing the temporomandibular joint coordinate system of the present application;

[0026] Figure 4 It is a schematic diagram of a regional point set of the method for establishing a temporomandibular joint coordinate system of the present application;

[0027] Figure 5 is a schematic diagram of the long axis of the condyle of the present application;

[0028] Figure 6 is a schematic diagram of the coordinate system axes of this application;

[0029] Figure 7 is a schematic diagram of the temporomandibular joint coordinate system of the present application;

[0030] Figure 8 It is a sagittal projection schematic diagram of this application. DETAILED DESCRIPTION

[0031] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0032] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "multiple" means two or more.

[0033] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] Reference below Figure 1-Figure 8 A method for establishing a temporomandibular joint coordinate system according to an embodiment of the present application is described.

[0035] like Figure 1-Figure 8 As shown, the present application discloses a method for establishing a temporomandibular joint coordinate system, comprising the following steps:

[0036] Step (1): The straight line passing through the inner pole and the outer pole of the condyle is taken as the long axis of the condyle, so that the X axis of the TMJ coordinate system passes through the long axis of the condyle;

[0037] Step (2): A straight line perpendicular to the X-axis of the TMJ coordinate system is drawn through the condylar apex as the Z-axis of the TMJ coordinate system, and the intersection point is the origin O of the TMJ coordinate system;

[0038] Step (3): Draw a straight line through the origin O that is perpendicular to both the X-axis and the Z-axis of the TMJ coordinate system to form the Y-axis of the TMJ coordinate system.

[0039] The present application also discloses some embodiments, wherein the TMJ coordinate system includes the coronal plane, sagittal plane, and horizontal plane of the condyle; the TMJ is projected onto the coronal plane, sagittal plane, and horizontal plane respectively to obtain the TMJ coordinate system.

[0040] The present application also discloses some embodiments, wherein the coronal plane of the condyle passes through the X-axis and the Z-axis of the TMJ coordinate system;

[0041] The present application also discloses some embodiments in which the sagittal plane passes through the Y-axis and the Z-axis of the TMJ coordinate system;

[0042] The present application also discloses some embodiments in which the horizontal plane passes through the X-axis and the Y-axis of the TMJ coordinate system.

[0043] The present application also discloses some embodiments. Before step (1), the method for establishing the temporomandibular joint coordinate system further includes the following steps:

[0044] The cone beam CT (CBCT) data were imported into the software to reconstruct the TMJ three-dimensional model, and the inner and outer poles and the condylar apex of the condyle were calculated using python.

[0045] This method simply reflects the TMJ coordinate system of the true morphological position of the condyle and automatically calculates the condylar landmarks within the defined range.

[0046] Compared with some condylar landmark calibration methods in the prior art: the existing three-dimensional calibration of condylar landmarks is mostly manual, which may be affected by various factors (including subjective ideas, experience, emotions, etc.), resulting in inconsistency and unpredictability of the results, and reduced accuracy. At the same time, manual punctuation is slow and time-consuming. In summary, manual punctuation is not only inefficient, but also prone to errors.

[0047] This application can reflect the TMJ coordinate system of the real condylar structure. This measurement method is based on the real three-dimensional structure of the condyle, automatically calculates the anatomical landmarks of the condyle, effectively eliminates the influence of the skull coordinate system on the long axis of the condyle in the traditional measurement method, and improves the accuracy of calibration; at the same time, this measurement method is simple, low-cost, easy to operate, and conducive to promotion.

[0048] The present application also discloses some embodiments, wherein the cone beam CT (CBCT) data is imported into the software to reconstruct the TMJ three-dimensional model, and the inner and outer poles and the condyle vertex are calculated by using Python, including the following steps:

[0049] Step S1: selecting the inner pole of the condyle, the outer pole of the condyle and the vertex of the condyle on the reconstructed TMJ three-dimensional model, and converting them into a point set;

[0050] Step S2: Use Python function to automatically calculate the condylar inner pole, condylar outer pole and condylar apex.

[0051] Compared with the traditional coordinate system establishment method: this method is based on the real anatomical structure of the condyle, eliminating the influence of the large coordinate system of CBCT shooting, and is more accurate; experiments have shown that the TMJ indicators measured based on this method are more in line with clinical reality and can better guide clinical diagnosis and treatment; the operation steps of this method are simple, easy to use, and highly reproducible. The above three points are very conducive to the large-scale promotion and popularization of this method.

[0052] Compared with the traditional punctuation method: the present invention adopts computer programming learning, and can automatically find the condylar anatomical landmarks within the range of manual calibration. Compared with the traditional punctuation method, it avoids human errors, has high accuracy and strong reproducibility.

[0053] The present application also discloses some embodiments, the functional programming principle of Python: calculating the point with the farthest distance between the point set of the inner pole region of the condyle and the point set of the outer pole region, defining them as the inner pole of the condyle and the outer pole of the condyle respectively; calculating the point in the condyle vertex region that is farthest from the line connecting the inner pole and the outer pole of the condyle, defining it as the condyle vertex.

[0054] The anatomical landmarks consist of the condylar medial pole, condylar lateral pole, and condylar apex.

[0055] The specific steps of this application include:

[0056] Step 1: Region selection: Select the region (red part) of the condylar landmarks (the inner pole of the condyle, the outer pole of the condyle, and the condylar apex) on the condylar reconstruction model ( Figure 3 ), and transform it into a point set ( Figure 4 )

[0057] Step 2: Use Python function to automatically calculate the condylar landmarks (the inner pole of the condyle, the outer pole of the condyle, and the condylar vertex) ( Figure 5 ). Python functional programming principle: Calculate the point with the farthest distance between the point set in the condylar inner pole area and the point set in the outer pole area, and define them as the condylar inner pole and the condylar outer pole respectively; calculate the point in the condylar vertex area that is farthest from the condylar inner pole-outer pole line, and define it as the condylar vertex. Using this method to punctuate can improve punctuation efficiency and avoid human punctuation errors.

[0058] Terminology explanation:

[0059] TMJ (Temporomandibular joint): Temporomandibular joint, composed of the temporal bone fossa, articular tubercle, articular disc, condyle, joint capsule and intracapsular and extracapsular ligaments. The left and right condyles are connected as a whole through the mandible and move in coordination with each other.

[0060] TMD (Temporomandibular disease): Temporomandibular joint disorder is a general term for musculoskeletal system diseases with the same or similar symptoms but with unknown etiology. The main symptoms are pain in the temporomandibular joint area and masticatory muscles, abnormal joint clicking, and mandibular movement disorders on the affected side, with an incidence rate of up to 20-50%.

[0061] CBCT (Cone Beam Computed Tomography): Cone beam computed tomography. It is an advanced X-ray imaging technology that collects data through cone beam X-ray scanning and two-dimensional surface detectors, and then obtains three-dimensional images after computer reconstruction algorithm processing. CBCT is widely used in the field of oral medical diagnosis. It can clearly display structures such as jaws, teeth, lower alveolar, neural tube, etc., helping doctors to comprehensively diagnose the lesions in the tooth area, determine the degree of oral lesions, and choose appropriate treatment methods according to the lesions.

[0062] Python: is a high-level programming language used in a variety of applications, including website development, data analysis, artificial intelligence, automation, scientific computing, etc. Python's design philosophy emphasizes code readability and concise syntax (especially the use of spaces to delimit code blocks instead of braces or keywords). Compared to C++ or Java, Python allows developers to express ideas with less code. Python supports multiple programming paradigms, including procedural, object-oriented, and functional programming. In addition, Python also has a powerful standard library and rich third-party libraries that can help developers easily complete various complex tasks.

[0063] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "multiple" means two or more.

[0064] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0065] The other components and operations of the method for establishing the temporomandibular joint coordinate system according to the embodiment of the present application are known to those of ordinary skill in the art and will not be described in detail here. In the description of the present application, "first feature" and "second feature" may include one or more of the features. Among them, the up-down direction, left-right direction and front-back direction are based on the up-down direction, left-right direction and front-back direction shown in the figure.

[0066] In the description of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature.

[0067] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0068] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A method for establishing a temporomandibular joint coordinate system, characterized in that: The steps include: Step (1): a straight line passing through the inner pole and the outer pole of the condyle is taken as the long axis of the condyle, so that the X axis of the TMJ coordinate system passes through the long axis of the condyle; Step (2): a straight line perpendicular to the X-axis of the TMJ coordinate system is drawn through the condylar apex as the Z-axis of the TMJ coordinate system, and the intersection point is the origin O of the TMJ coordinate system; Step (3): Draw a straight line through the origin O that is perpendicular to both the X-axis and the Z-axis of the TMJ coordinate system. Form the Y-axis of the TMJ coordinate system.

2. The method for establishing a temporomandibular joint coordinate system according to claim 1, characterized in that: The TMJ coordinate system includes the condylar coronal plane, sagittal plane, and horizontal plane; the TMJ is projected onto the coronal plane, the sagittal plane, and the horizontal plane respectively to obtain the TMJ coordinate system.

3. The method for establishing a temporomandibular joint coordinate system according to claim 2, characterized in that: The condylar coronal plane passes through the X-axis and the Z-axis of the TMJ coordinate system; and / or, the sagittal plane passes through the Y axis and the Z axis of the TMJ coordinate system; And / or, the horizontal plane passes through the X-axis and Y-axis of the TMJ coordinate system.

4. The method for establishing a temporomandibular joint coordinate system according to any one of claims 1 to 3, characterized in that: Before step (1), the method for establishing the temporomandibular joint coordinate system further includes the following steps: The cone beam CT (CBCT) data were imported into the software to reconstruct the TMJ three-dimensional model, and the inner and outer poles of the condyle and the condyle vertex were calculated using python.

5. The method for establishing a temporomandibular joint coordinate system according to claim 4, characterized in that: The step of importing cone beam CT (CBCT) data into software to reconstruct the TMJ three-dimensional model and using Python to calculate the inner and outer poles of the condyle and the condyle vertex comprises the following steps: Step S1: selecting the condylar inner pole, the condylar outer pole and the condylar vertex on the reconstructed TMJ three-dimensional model, and converting them into a point set; Step S2: Use Python function to automatically calculate the condylar inner pole, the condylar outer pole and the condylar apex.

6. The method for establishing a temporomandibular joint coordinate system according to claim 4, characterized in that: The functional programming principle of Python is as follows: the point with the farthest distance between the point set in the inner pole area of ​​the condyle and the point set in the outer pole area are calculated, which are defined as the inner pole of the condyle and the outer pole of the condyle respectively; the point in the condyle vertex area that is farthest from the line connecting the inner pole and the outer pole of the condyle is calculated, which is defined as the condyle vertex.

Images