A method for measuring the distance from the root apex to the buccal and palatal bone plate of the alveolar process based on three-dimensional reconstruction

Abstract

The present invention discloses a method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction, which specifically relates to the technical field of medical image measurement. The technical key points are: taking the root apex as the origin and the distance between the root apex and the first reference point as the radius to construct a first sphere, obtaining a first intersection point where the first sphere intersects with the outer surface of the mandible and has the smallest distance with the root apex, and the distance from the first intersection point to the root apex is the shortest distance from the root apex to the buccal bone plate; constructing a connecting line between the first intersection point and the root apex, and extending the connecting line toward the root apex to obtain an intersection point between the connecting line and the outer surface of the palatal alveolar bone, that is, obtaining a second reference point on the outer surface of the palatal alveolar bone corresponding to the root apex; taking the root apex as the origin and the distance between the root apex and the second reference point as the radius to construct a second sphere, obtaining a second intersection point where the second sphere intersects with the outer surface of the palatal alveolar bone and has the smallest distance with the root apex, and the distance from the second intersection point to the root apex is the shortest distance from the root apex to the palatal bone plate.

Description

Technical Field

[0001] The present invention relates to the technical field of medical image measurement, and in particular to a method for measuring the distance from a root apex to a buccal and palatal bone plate of an alveolar process based on three-dimensional reconstruction. Background Art

[0002] In the human oral cavity, the teeth in the posterior maxillary region are closely associated with the maxillary sinus, the largest sinus in the jaw. Tooth roots vary greatly in number and shape, and are located at a distance from the buccal and palatal bone plates, presenting numerous challenges for dental procedures such as tooth extraction, implant placement, and apical surgery. The buccal and palatal alveolar bone plates comprise the buccal and palatal alveolar ridge plates. The distance between the root apex / implant site and the buccal and palatal bone plates is an important clinical indicator for assessing surgical difficulty and complication risk. Cone beam CT (CBCT) is currently the preferred imaging method for evaluating the anatomy of the posterior maxillary region due to its low radiation dose and excellent three-dimensional imaging capabilities.

[0003] Many literatures have used apical surgical guides to guide the surgeon to accurately locate the root apex of maxillary posterior teeth. However, the selection of surgical path under guide guidance mainly depends on clinical experience, without considering the shortest path from the root apex to the buccal and palatal bone plate.

[0004] At present, more mature computer-aided systems such as 3-Matic 12.0 developed by Materialise can measure the shortest distance from a point to the surface of an object, but they have the following defects: (1) the coordinates of the nearest point on the surface of an object cannot be given; (2) the shortest distance from the root apex to the buccal or palatal bone plate cannot be calculated. For the above reasons, the application of 3-matic in clinical indicator measurement is subject to many restrictions.

[0005] Based on this, the present invention provides a method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction to solve the above-mentioned related problems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that the existing technology is unable to calculate the shortest distance from the root apex to the buccal or palatal bone plate. The purpose is to provide a distance measurement method from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction. By narrowing the scope of the target area layer by layer, the calculation of the shortest distance from the root apex to the buccal and palatal sides is converted into the calculation of the distance from the root apex to all points of the bone plate in the corresponding part, which narrows the traversal range, improves the calculation efficiency, and accurately calculates the shortest distance from the root apex to important structures, solving the related problem that the existing technology is unable to calculate the shortest distance from the root apex to the buccal or palatal bone plates. The method can be widely used in treatment plan evaluation, minimally invasive surgery guide design, complication risk assessment, and promotes the clinical transformation of dental precision medicine.

[0007] The present invention is achieved through the following technical solutions:

[0008] A method for measuring the distance from the root apex to the buccal and palatal bone plate of the alveolar process based on three-dimensional reconstruction, the method comprising:

[0009] Constructing a three-dimensional coordinate system in a CBCT image of the patient's head, dividing the CBCT image into a plurality of xy-axis coordinate plane images along the z-axis direction, and performing region division on each xy-axis coordinate plane image according to a pre-established partitioning rule, wherein each xy-axis coordinate plane image is divided into a plurality of image regions;

[0010] Determine the image area where the root apex point to be measured is located, and obtain the first reference point on the outer surface of the mandible corresponding to the root apex point based on the pre-established reference point matching rule of the outer surface of the mandible;

[0011] A first sphere is constructed with the root apex as the origin and the distance between the root apex and the first reference point as the radius. The first intersection point where the first sphere intersects with the outer surface of the mandible and has the smallest distance to the root apex is obtained. The distance from the first intersection point to the root apex is the shortest distance from the root apex to the buccal bone plate.

[0012] Constructing a connecting line between the first intersection point and the root apex point, and extending the connecting line toward the root apex point to obtain an intersection point between the connecting line and the outer surface of the palatal alveolar bone, that is, obtaining a second reference point on the outer surface of the palatal alveolar bone corresponding to the root apex point;

[0013] A second sphere was constructed with the root apex as the origin and the distance between the root apex and the second reference point as the radius. The second intersection point where the second sphere intersected with the outer surface of the palatal alveolar bone and had the smallest distance to the root apex was obtained. The distance from the second intersection point to the root apex was the shortest distance from the root apex to the palatal bone plate.

[0014] Furthermore, a three-dimensional coordinate system is constructed in the CBCT image of the patient's head, specifically:

[0015] Obtain a CBCT image of the patient's head, and construct an xyz three-dimensional coordinate system with the x-axis perpendicular to the right side of the patient's head, the y-axis perpendicular to the back of the patient's head, and the z-axis perpendicular to the top of the patient's head.

[0016] Furthermore, each xy-axis coordinate plane image is divided into regions according to a pre-built partitioning rule. Each xy-axis coordinate plane image is divided into multiple image regions, specifically:

[0017] Obtain the most anterior first position point on the outer surface of the mandible in the xy-axis coordinate plane image. If the number of first position points is 1, the axis passing through the first position point and parallel to the y-axis is defined as the first region. If the number of first position points is greater than 1, the region parallel to the y-axis and included in the projection range of all first position points on the x-axis is defined as the first region.

[0018] Obtain the leftmost second position point on the outer surface of the mandible in the xy-axis coordinate plane image. If the number of second position points is 1, the axis passing through the second position point and parallel to the x-axis is defined as the second region. If the number of second position points is greater than 1, the region parallel to the x-axis and encompassed by the projections of all second position points on the y-axis is defined as the second region. The second region is located to the left of the first region.

[0019] Obtain the third rightmost position point on the outer surface of the mandible in the xy coordinate plane image. If the number of third position points is 1, the axis passing through the third position point and parallel to the x-axis is defined as the second region. If the number of third position points is greater than 1, the region parallel to the x-axis and encompassed by the projections of all third position points on the y-axis is defined as the third region. The third region is located to the right of the first region.

[0020] The area between the front side of the second area and the left side of the first area is the fourth area, the area between the front side of the third area and the right side of the first area is the fifth area, the area between the back side of the second area and the left side of the first area is the sixth area, and the area between the back side of the third area and the right side of the first area is the seventh area.

[0021] Furthermore, based on the pre-established reference point matching rule of the outer surface of the mandible, the first reference point on the outer surface of the mandible corresponding to the apex point is obtained, specifically:

[0022] If the root apex is located in the first area, the intersection point of the y-axis of the root apex and the most anterior side of the outer surface of the mandible is obtained as the first reference point;

[0023] If the root apex is located in the second area or the sixth area, the intersection point of the x-axis of the root apex and the leftmost side of the outer surface of the mandible is obtained as the first reference point;

[0024] If the root apex is located in the third area or the seventh area, the intersection point of the x-axis of the root apex and the rightmost side of the outer surface of the mandible is obtained as the first reference point;

[0025] If the apex point is located in the fourth area or the fifth area, obtain the perpendicular points of the apex point with the x-axis and the y-axis respectively and connect the two perpendicular points to obtain a reference oblique line. Draw a perpendicular line between the apex point and the reference oblique line, and the intersection point of the perpendicular line with the outer surface of the mandible is used as the first reference point.

[0026] Furthermore, a first sphere is constructed with the root apex as the origin and the distance between the root apex and the first reference point as the radius, and a first intersection point where the first sphere intersects with the outer surface of the mandible and has the smallest distance with the root apex is obtained, specifically:

[0027] On the xy-axis coordinate plane image, a first sphere is constructed with the root apex as the origin and the distance between the root apex and the first reference point as the radius;

[0028] Obtain multiple intersection points where the first sphere intersects the outer surface of the mandible, calculate the distance values ​​between the multiple intersection points and the root apex point respectively, and select the intersection point with the smallest distance value from the root apex point as the first intersection point.

[0029] Furthermore, a second sphere is constructed with the root apex as the origin and the distance between the root apex and the second reference point as the radius, and a second intersection point where the second sphere intersects with the outer surface of the palatal alveolar bone and has the smallest distance from the root apex is obtained, specifically:

[0030] On the xy-axis coordinate plane image, a second sphere is constructed with the root apex as the origin and the distance between the root apex and the second reference point as the radius;

[0031] Obtain multiple intersection points where the second sphere intersects the outer surface of the palatal alveolar bone, calculate the distance values ​​between the multiple intersection points and the root apex point respectively, and select the intersection point with the smallest distance value from the root apex point as the second intersection point.

[0032] The present invention also provides a system for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction. The system is used in any of the above-mentioned methods for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction. The system comprises:

[0033] a region partitioning module, configured to construct a three-dimensional coordinate system in the CBCT image of the patient's head, divide the CBCT image into a plurality of xy-axis coordinate plane images along the z-axis direction, and perform region partitioning on each xy-axis coordinate plane image according to a pre-established partitioning rule, wherein each xy-axis coordinate plane image is divided into a plurality of image regions;

[0034] A first reference point acquisition module is used to determine the image area where the root apex point to be measured is located, and obtain a first reference point on the outer surface of the mandible corresponding to the root apex point based on a pre-established reference point matching rule on the outer surface of the mandible;

[0035] The buccal bone plate spacing calculation module is used to construct a first sphere with the root apex as the origin and the distance between the root apex and the first reference point as the radius, and obtain the first intersection point where the first sphere intersects with the outer surface of the mandible and has the smallest distance with the root apex. The distance from the first intersection point to the root apex is the shortest distance from the root apex to the buccal bone plate;

[0036] A second reference point acquisition module is used to construct a connecting line between the first intersection point and the root apex point, and extend the connecting line toward the root apex point to obtain an intersection point between the connecting line and the outer surface of the palatal alveolar bone, that is, to obtain a second reference point on the outer surface of the palatal alveolar bone corresponding to the root apex point;

[0037] The palatal bone plate spacing calculation module is used to construct a second sphere with the root apex as the origin and the distance between the root apex and the second reference point as the radius, and obtain the second intersection point where the second sphere intersects with the outer surface of the palatal alveolar bone and has the smallest distance from the root apex. The distance from the second intersection point to the root apex is the shortest distance from the root apex to the palatal bone plate.

[0038] The present invention also provides a computer device, comprising a system memory and a processor, wherein the system memory stores a computer program, and the processor implements the steps of any one of the above-mentioned methods when executing the computer program.

[0039] The present invention also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of any one of the methods described above are implemented.

[0040] The present invention also provides a computer program product comprising instructions, which, when executed by a computer device cluster, enables the computer device cluster to perform any of the above methods.

[0041] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0042] In the present invention, by narrowing the scope of the target area layer by layer, the calculation of the shortest distance from the root apex to the buccal and palatal sides is converted into the calculation of the distance from the root apex to all points of the bone plate of the corresponding part, which reduces the traversal range, improves the calculation efficiency, and accurately calculates the shortest distance from the root apex to important structures. This solves the related problem that the existing technology cannot calculate the shortest distance from the root apex to the buccal or palatal bone plate. It can be widely used in treatment plan evaluation, minimally invasive surgical guide design, complication risk assessment, and promotes the clinical transformation of dental precision medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the examples. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort. In the drawings:

[0044] Figure 1 Flowchart of the method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction in this embodiment;

[0045] Figure 2Schematic diagram of the image area in the method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction in this embodiment, wherein Figure a is an xy-axis coordinate plane image of the right side of the oral cavity, and Figure b is an xy-axis coordinate plane image of the left side of the oral cavity;

[0046] Figure 3 Schematic diagram of the first reference point in the method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction in this embodiment, wherein Figure a is an xy-axis coordinate plane image of the right side of the oral cavity, and Figure b is an xy-axis coordinate plane image of the left side of the oral cavity;

[0047] Figure 4 Schematic diagram of the first sphere scan in the method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction in this embodiment;

[0048] Figure 5 Schematic diagram of the second reference point in the method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction in this embodiment;

[0049] Figure 6 Schematic diagram of the second sphere scan of the method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction in this embodiment;

[0050] Figure 7 Schematic diagram of a mandibular mask layer illustrating an example of a method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction in this embodiment;

[0051] Figure 8 Schematic diagram of the automatic distance measurement selection interface of an example of a method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction in this embodiment;

[0052] Figure 9 、 Figure 10 All of them are schematic diagrams of the shortest distance interfaces of the buccal and palatal bone plates corresponding to the examples of the distance measurement method from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction in this embodiment;

[0053] Figure 11 3D distance diagram of an example of a method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on 3D reconstruction in this embodiment;

[0054] Figure 12 Schematic diagram of the modules of the system for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction in this embodiment;

[0055] Figure 13 This is a structural diagram of a computer device in this embodiment. DETAILED DESCRIPTION

[0056] The following description of exemplary embodiments of the present disclosure is made in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be appreciated by those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope of the present disclosure. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0057] In this disclosure, unless otherwise specified, the use of terms such as "first," "second," etc. to describe various elements is not intended to limit the positional relationship, temporal relationship, or importance relationship of these elements. Such terms are simply used to distinguish one element from another. In some examples, the first element and the second element may refer to the same instance of the element, while in some cases, based on the context of the description, they may also refer to different instances.

[0058] The terms used in the descriptions of various examples in this disclosure are for the purpose of describing specific examples only and are not intended to be limiting. Unless the context clearly indicates otherwise, if the number of elements is not specifically limited, the element may be one or more. In addition, the term "and / or" used in this disclosure encompasses any one and all possible combinations of the listed items.

[0059] At the same time, it needs to be explained that in the accompanying drawings, "x axis" means x-axis, "y axis" means y-axis, "z axis" means z-axis, "x axis scanning" means x-axis scanning direction, "y axis scanning" means y-axis scanning direction, and "zaxis scanning" means z-axis scanning direction.

[0060] Example 1

[0061] See also Figure 1 As shown, this embodiment also provides a method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction, the method comprising:

[0062] S1: Construct a three-dimensional coordinate system in the CBCT image of the patient's head, divide the CBCT image into multiple xy-axis coordinate plane images along the z-axis direction, and divide each xy-axis coordinate plane image into multiple image regions according to a pre-established partitioning rule;

[0063] It should be noted that the CBCT image is in a mirror image relationship with the actual patient's oral position. The left side of the image is the right side of the patient's oral cavity, and the right side of the image is the left side of the patient's oral cavity. In this embodiment, the front, back, left, and right directions are described based on the image position relationship. The front side refers to the upper end of the image, the back side refers to the lower end of the image, the left side refers to the left end of the image, and the right side refers to the right end of the image. An xyz space three-dimensional coordinate system is constructed in the CBCT image of the patient's head. According to the PatientPosition attribute labeled (0x0018, 0x5100) in the DICOM file, the scanning direction of the CBCT image and the position relationship of the patient's head can be determined, thereby assisting in constructing the xyz space three-dimensional coordinate system. At the same time, it should be noted that the xy axis coordinate plane image refers to an image parallel to the xOy axis plane. At the same time, see Figure 2 As shown, an xy-axis coordinate plane image can also only include the oral structure of one side. For example, Figure a shows the xy-axis coordinate plane image of the right side of the oral cavity, and Figure b shows the xy-axis coordinate plane image of the left side of the oral cavity.

[0064] Specifically, in this embodiment, a CBCT image of the patient's head is first acquired, and then an xyz three-dimensional coordinate system is constructed with the x-axis perpendicular to the right side of the patient's head, the y-axis perpendicular to the back side of the patient's head, and the z-axis perpendicular to the top of the patient's head. It should be further explained that the x-axis extends toward the right end of the image, and the y-axis extends toward the bottom end of the image.

[0065] Then, see Figure 2 As shown, each xy-axis coordinate plane image is divided into seven image regions according to the pre-constructed partitioning rules. Specifically, the most anterior first position point on the outer surface of the mandible in the xy-axis coordinate plane image is obtained. If the number of first position points is 1, the axis passing through the first position point and parallel to the y-axis is the first region; if the number of first position points is greater than 1, the region parallel to the y-axis and included in the projection range of all first position points on the x-axis is the first region;

[0066] Obtain the leftmost second position point on the outer surface of the mandible in the xy-axis coordinate plane image. If the number of second position points is 1, the axis passing through the second position point and parallel to the x-axis is defined as the second region. If the number of second position points is greater than 1, the region parallel to the x-axis and encompassed by the projections of all second position points on the y-axis is defined as the second region. The second region is located to the left of the first region.

[0067] Obtain the third rightmost position point on the outer surface of the mandible in the xy coordinate plane image. If the number of third position points is 1, the axis passing through the third position point and parallel to the x-axis is defined as the second region. If the number of third position points is greater than 1, the region parallel to the x-axis and encompassed by the projections of all third position points on the y-axis is defined as the third region. The third region is located to the right of the first region.

[0068] The area between the front side of the second area and the left side of the first area is the fourth area, the area between the front side of the third area and the right side of the first area is the fifth area, the area between the back side of the second area and the left side of the first area is the sixth area, and the area between the back side of the third area and the right side of the first area is the seventh area.

[0069] S2: determining the image region where the root apex point to be measured is located, and obtaining a first reference point on the outer surface of the mandible corresponding to the root apex point based on a pre-established reference point matching rule on the outer surface of the mandible;

[0070] It should be noted that, in this embodiment, the apex point to be measured can be determined in the acquired image, or in the acquired CBCT image, or on the xy-axis coordinate plane image, depending on the actual needs, and no excessive restrictions are imposed here.

[0071] Specifically, refer to Figure 3 As shown, in this embodiment, if the apex point is located in the first area, the intersection point (B1) of the y-axis line of the apex point (A1) and the anteriormost side of the outer surface of the mandible is obtained as the first reference point; if the apex point is located in the second area or the sixth area, the intersection point (B2 or B6) of the x-axis line of the apex point (A2 or A6) and the leftmost side of the outer surface of the mandible is obtained as the first reference point; if the apex point is located in the third area or the seventh area, the intersection point (B3 or B7) of the x-axis line of the apex point (A3 or A7) and the rightmost side of the outer surface of the mandible is obtained as the first reference point; if the apex point is located in the fourth area or the fifth area, the perpendicular points of the apex point (A4 or A5) with the x-axis and y-axis are obtained respectively and the two perpendicular points are connected to obtain a reference oblique line, a perpendicular line (A4P4 or A5P5) between the apex point and the reference oblique line is drawn, and the intersection point (B4 or B5) of the perpendicular line with the outer surface of the mandible is taken as the first reference point.

[0072] S3: Construct a first sphere with the root apex as the origin and the distance between the root apex and the first reference point as the radius. Obtain the first intersection point where the first sphere intersects with the outer surface of the mandible and has the smallest distance to the root apex. The distance from the first intersection point to the root apex is the shortest distance from the root apex to the buccal bone plate.

[0073] For details, see Figure 4As shown, in this embodiment, a first sphere is constructed on the xy-axis coordinate plane image with the root apex as the origin and the distance between the root apex and the first reference point as the radius; scanning is performed downward along the z-axis direction from the top of the first sphere, and scanning is performed in each xy-axis coordinate plane image according to the corresponding scanning direction according to the image area, with the scanning starting point being the surface of the first sphere and the scanning end point being the outer surface of the mandible, thereby obtaining multiple intersection points P where the first sphere intersects with the outer surface of the mandible n , calculate the distance values ​​between multiple intersection points and the root apex point respectively, select the intersection point with the smallest distance value with the root apex point as the first intersection point, and the distance from the first intersection point to the root apex point is the shortest distance from the root apex point to the buccal bone plate.

[0074] It should be noted that, in the present embodiment, scanning is performed in each xy-axis coordinate plane image according to the corresponding scanning direction based on the image area, specifically: the first area is the front protrusion, which is scanned from a position closer to the z-axis to a position farther away in the y-axis direction, and first scanned from a position closer to the z-axis to a position farther away in the x-axis direction, and then scanned from a position farther away to a closer position; the third area, the fifth area and the seventh area are the right part or the right rear part, which are scanned from a position closer to the z-axis to a position farther away in the y-axis direction, and scanned from a position farther away from the z-axis to a position closer in the x-axis direction; the second area, the fourth area and the sixth area are the left part or the left rear part, which are scanned from a position closer to the z-axis to a position farther away in the y-axis direction, and scanned from a position closer to the z-axis to a position farther away in the x-axis direction.

[0075] S4: constructing a connecting line between the first intersection point and the root apex point, and extending the connecting line toward the root apex point to obtain an intersection point between the connecting line and the outer surface of the palatal alveolar bone, that is, obtaining a second reference point on the outer surface of the palatal alveolar bone corresponding to the root apex point;

[0076] Specifically, in the examples, see Figure 5 As shown in the figure, point M is the first intersection point, point A is the root node, and the connecting line MA is constructed, and then extended in a straight line toward the root apex point A to obtain the second reference point N.

[0077] S5: Construct a second sphere with the root apex as the origin and the distance from the root apex to the second reference point as the radius. Obtain the second intersection point where the second sphere intersects with the outer surface of the palatal alveolar bone and has the smallest distance to the root apex. The distance from the second intersection point to the root apex is the shortest distance from the root apex to the palatal bone plate.

[0078] For details, see Figure 6As shown, in this embodiment, a second sphere is constructed on the xy-axis coordinate plane image with the root apex as the origin and the distance between the root apex and the second reference point as the radius; scanning is performed downward along the z-axis direction from the top of the second sphere, and scanning is performed in each xy-axis coordinate plane image according to the image area in the corresponding scanning direction, with the scanning starting point being the surface of the first sphere and the scanning end point being the outer surface of the mandible, to obtain multiple intersection points P where the second sphere intersects with the outer surface of the palatal alveolar bone. n , calculate the distance values ​​between multiple intersection points and the root apex point respectively, select the intersection point with the smallest distance value with the root apex point as the second intersection point, and the distance from the second intersection point to the root apex point is the shortest distance from the root apex point to the palatal bone plate.

[0079] It should be noted that, in the present embodiment, scanning is performed in each xy-axis coordinate plane image according to the corresponding scanning direction based on the image area, specifically: the first area is scanned from a position farther from the z-axis to a position closer to the z-axis in the y-axis direction, and is scanned from a position closer to the z-axis to a position farther away in the x-axis direction; the third area, the fifth area, and the seventh area are scanned from a position closer to the z-axis to a position farther away in the y-axis direction, and are scanned from a position closer to the z-axis to a position farther away in the x-axis direction; the second area, the fourth area, and the sixth area are scanned from a position closer to the z-axis to a position farther away in the y-axis direction, and are scanned from a position farther away from the z-axis to a position closer to the x-axis direction.

[0080] Specifically, in this embodiment, by narrowing the scope of the target area layer by layer, the calculation of the shortest distance from the root apex to the buccal and palatal sides is converted into the calculation of the distance from the root apex to all points of the corresponding bone plate, which reduces the traversal range, improves the calculation efficiency, and accurately calculates the shortest distance from the root apex to important structures. It can be widely used in treatment plan evaluation, minimally invasive surgical guide design, complication risk assessment, and promotes the clinical transformation of dental precision medicine.

[0081] At the same time, this embodiment also gives an example of the distance from the root apex to the buccal and palatal bone plates of the alveolar ridge, see Figure 7-11 As shown, select the mandibular mask layer in sequence; select the apex point A, right-click and select "Distance to External Mandible" to obtain the shortest distance to the corresponding buccal and palatal bone plates.

[0082] Example 2

[0083] See also Figure 12 As shown, the present invention also provides a system for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction, which is used in any of the above-mentioned methods for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction, and the system includes:

[0084] A region division module 100 is configured to construct a three-dimensional coordinate system in a CBCT image of a patient's head, divide the CBCT image into a plurality of xy-axis coordinate plane images along the z-axis direction, and perform region division on each xy-axis coordinate plane image according to a pre-established partitioning rule, where each xy-axis coordinate plane image is divided into a plurality of image regions;

[0085] A first reference point acquisition module 200 is used to determine the image region where the root apex point to be measured is located, and obtain a first reference point on the outer surface of the mandible corresponding to the root apex point based on a pre-established reference point matching rule on the outer surface of the mandible;

[0086] The buccal bone plate spacing calculation module 300 is configured to construct a first sphere with the root apex as the origin and the distance between the root apex and the first reference point as the radius, and obtain a first intersection point where the first sphere intersects with the outer surface of the mandible and has the smallest distance to the root apex. The distance from the first intersection point to the root apex is the shortest distance from the root apex to the buccal bone plate.

[0087] The second reference point acquisition module 400 is used to construct a connecting line between the first intersection point and the root apex point, and extend the connecting line toward the root apex point to obtain an intersection point between the connecting line and the outer surface of the palatal alveolar bone, that is, to obtain a second reference point on the outer surface of the palatal alveolar bone corresponding to the root apex point;

[0088] The palatal bone plate spacing calculation module 500 is used to construct a second sphere with the root apex as the origin and the distance between the root apex and the second reference point as the radius, and obtain the second intersection point where the second sphere intersects with the outer surface of the palatal alveolar bone and has the smallest distance from the root apex. The distance from the second intersection point to the root apex is the shortest distance from the root apex to the palatal bone plate.

[0089] It should be noted that the modules in the system of Example 2 correspond to the steps in the method of Example 1. The steps in the method of Example 1 have been described in detail in Example 1. The contents of the modules in the system will not be described in detail in this Example 2.

[0090] Example 3

[0091] See also Figure 13 As shown, this embodiment further provides a computer device, including a system memory 1005 and a processor 1001, wherein the system memory 1005 stores a computer program, and the processor 1001 implements the steps of any of the above methods when executing the computer program.

[0092] It should be noted that the processor 1001 is configured to execute the steps of the above method embodiments according to the instructions in the program code. Alternatively, the processor 1001 implements the functions of the modules / units in the above system / device embodiments when executing the computer program.

[0093] Specifically, in this embodiment, the computer program may be divided into one or more modules / units, one or more modules / units being stored in the system memory 1005 and executed by the processor 1001 to complete the present application. One or more modules / units may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device.

[0094] The terminal device may be a computing device such as a desktop computer, laptop, PDA, or cloud server. The terminal device may include, but is not limited to, a processor 1001 and a system memory 1005. Those skilled in the art will appreciate that this does not constitute a limitation on the terminal device and may include more or fewer components than shown, or a combination of certain components, or different components. For example, the terminal device may also include input / output devices 1003, a network access device 1002, a bus 1006, and the like.

[0095] The processor 1001 may be a central processing unit (CPU), or other general-purpose processors 1001, digital signal processors 1001 (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor 1001 may be a microprocessor or any conventional processor.

[0096] The system memory 1005 can be an internal storage unit of the terminal device, such as a hard disk or memory of the terminal device. The system memory 1005 can also be the storage device 1004 of the terminal device, such as a plug-in hard disk, a SmartMedia Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped on the terminal device. Furthermore, the system memory 1005 can also include both the internal storage unit of the terminal device and the storage device 1004. The system memory 1005 is used to store computer programs and other programs and data required by the terminal device. The system memory 1005 can also be used to temporarily store data that has been output or is about to be output.

[0097] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems, systems and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0098] Example 4

[0099] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of any one of the above methods are implemented.

[0100] Among them, the computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared or semiconductor system, system or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection with one or more wires, a portable computer disk, a hard disk. Random Access Memory (RAM), Read-Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM), a register, a hard disk, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above, or any other form of computer-readable storage medium known in the art.

[0101] An exemplary storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an application-specific integrated circuit (ASIC). In an embodiment of the present invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device.

[0102] Example 5

[0103] This embodiment further provides a computer program product comprising instructions. When the instructions are executed by a computer device cluster, the computer device cluster executes the method described in Embodiment 1.

[0104] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for measuring the distance from the root apex to the buccal and palatal bone plate of the alveolar process based on three-dimensional reconstruction, characterized in that the method include: Acquire a CBCT image of the patient's head, construct an xyz three-dimensional coordinate system with the x-axis perpendicular to the right side of the patient's head, the y-axis perpendicular to the back side of the patient's head, and the z-axis perpendicular to the top of the patient's head, divide the CBCT image into multiple xy-axis coordinate plane images along the z-axis direction, and divide each xy-axis coordinate plane image into multiple image regions according to a pre-established partitioning rule; Determine the image area where the root apex point to be measured is located, and obtain the first reference point on the outer surface of the mandible corresponding to the root apex point based on the pre-established reference point matching rule of the outer surface of the mandible; A first sphere is constructed with the root apex as the origin and the distance between the root apex and the first reference point as the radius. The first intersection point where the first sphere intersects with the outer surface of the mandible and has the smallest distance to the root apex is obtained. The distance from the first intersection point to the root apex is the shortest distance from the root apex to the buccal bone plate. Constructing a connecting line between the first intersection point and the root apex point, and extending the connecting line toward the root apex point to obtain an intersection point between the connecting line and the outer surface of the palatal alveolar bone, that is, obtaining a second reference point on the outer surface of the palatal alveolar bone corresponding to the root apex point; A second sphere was constructed with the root apex as the origin and the distance between the root apex and the second reference point as the radius. The second intersection point where the second sphere intersected with the outer surface of the palatal alveolar bone and had the smallest distance to the root apex was obtained. The distance from the second intersection point to the root apex was the shortest distance from the root apex to the palatal bone plate.

2. The method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction according to claim 1, characterized in that: Each xy-axis coordinate plane image is divided into regions according to the pre-built partitioning rules. Each xy-axis coordinate plane image is divided into multiple image regions, specifically: Obtain the most anterior first position point on the outer surface of the mandible in the xy-axis coordinate plane image. If the number of first position points is 1, the axis passing through the first position point and parallel to the y-axis is defined as the first region. If the number of first position points is greater than 1, the region parallel to the y-axis and included in the projection range of all first position points on the x-axis is defined as the first region. Obtain the leftmost second position point on the outer surface of the mandible in the xy-axis coordinate plane image. If the number of second position points is 1, the axis passing through the second position point and parallel to the x-axis is defined as the second region. If the number of second position points is greater than 1, the region parallel to the x-axis and encompassed by the projections of all second position points on the y-axis is defined as the second region. The second region is located to the left of the first region. Obtain the third rightmost position point on the outer surface of the mandible in the xy coordinate plane image. If the number of third position points is 1, the axis passing through the third position point and parallel to the x-axis is defined as the second region. If the number of third position points is greater than 1, the region parallel to the x-axis and encompassed by the projections of all third position points on the y-axis is defined as the third region. The third region is located to the right of the first region. The area between the front side of the second area and the left side of the first area is the fourth area, the area between the front side of the third area and the right side of the first area is the fifth area, the area between the back side of the second area and the left side of the first area is the sixth area, and the area between the back side of the third area and the right side of the first area is the seventh area.

3. The method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction according to claim 1, characterized in that: Based on the pre-established reference point matching rules for the outer surface of the mandible, the first reference point on the outer surface of the mandible corresponding to the root apex is obtained, specifically: If the root apex is located in the first area, the intersection point of the y-axis of the root apex and the most anterior side of the outer surface of the mandible is obtained as the first reference point; If the root apex is located in the second area or the sixth area, the intersection point of the x-axis of the root apex and the leftmost side of the outer surface of the mandible is obtained as the first reference point; If the root apex is located in the third area or the seventh area, the intersection point of the x-axis of the root apex and the rightmost side of the outer surface of the mandible is obtained as the first reference point; If the apex point is located in the fourth area or the fifth area, obtain the perpendicular points of the apex point with the x-axis and the y-axis respectively and connect the two perpendicular points to obtain a reference oblique line. Draw a perpendicular line between the apex point and the reference oblique line, and the intersection point of the perpendicular line with the outer surface of the mandible is used as the first reference point.

4. The method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction according to claim 1, characterized in that: The first sphere is constructed with the root apex as the origin and the distance between the root apex and the first reference point as the radius. The first intersection point where the first sphere intersects with the outer surface of the mandible and has the smallest distance with the root apex is obtained. Specifically, On the xy-axis coordinate plane image, a first sphere is constructed with the root apex as the origin and the distance between the root apex and the first reference point as the radius; Obtain multiple intersection points where the first sphere intersects the outer surface of the mandible, calculate the distance values ​​between the multiple intersection points and the root apex point respectively, and select the intersection point with the smallest distance value to the root apex point as the first intersection point.

5. The method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction according to claim 1, characterized in that: A second sphere is constructed with the root apex as the origin and the distance from the root apex to the second reference point as the radius. The second intersection point where the second sphere intersects with the outer surface of the palatal alveolar bone and has the smallest distance from the root apex is obtained. Specifically, On the xy-axis coordinate plane image, a second sphere is constructed with the root apex as the origin and the distance between the root apex and the second reference point as the radius; Obtain multiple intersection points where the second sphere intersects the outer surface of the palatal alveolar bone, calculate the distance values ​​between the multiple intersection points and the root apex point respectively, and select the intersection point with the smallest distance value from the root apex point as the second intersection point.

6. A system for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction, characterized in that: The system is used in a method for measuring the distance from the root apex to the buccal and palatal bone plates of the alveolar process based on three-dimensional reconstruction as described in any one of claims 1 to 5, and the system comprises: a region partitioning module, configured to construct a three-dimensional coordinate system in the CBCT image of the patient's head, divide the CBCT image into a plurality of xy-axis coordinate plane images along the z-axis direction, and perform region partitioning on each xy-axis coordinate plane image according to a pre-established partitioning rule, wherein each xy-axis coordinate plane image is divided into a plurality of image regions; A first reference point acquisition module is used to determine the image area where the root apex point to be measured is located, and obtain a first reference point on the outer surface of the mandible corresponding to the root apex point based on a pre-established reference point matching rule on the outer surface of the mandible; The buccal bone plate spacing calculation module is used to construct a first sphere with the root apex as the origin and the distance between the root apex and the first reference point as the radius, and obtain the first intersection point where the first sphere intersects with the outer surface of the mandible and has the smallest distance with the root apex. The distance from the first intersection point to the root apex is the shortest distance from the root apex to the buccal bone plate; A second reference point acquisition module is used to construct a connecting line between the first intersection point and the root apex point, and extend the connecting line toward the root apex point to obtain an intersection point between the connecting line and the outer surface of the palatal alveolar bone, that is, to obtain a second reference point on the outer surface of the palatal alveolar bone corresponding to the root apex point; The palatal bone plate spacing calculation module is used to construct a second sphere with the root apex as the origin and the distance between the root apex and the second reference point as the radius, and obtain the second intersection point where the second sphere intersects with the outer surface of the palatal alveolar bone and has the smallest distance from the root apex. The distance from the second intersection point to the root apex is the shortest distance from the root apex to the palatal bone plate.

7. A computer device comprising a system memory and a processor, wherein the system memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

9. A computer program product comprising instructions, characterized in that When the instructions are executed by a computer device cluster, the computer device cluster is caused to perform the method according to any one of claims 1 to 5.

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