Method and device for determining the path of fenestration in apical surgery under navigation

Abstract

The present invention provides a method and device for determining a fenestration path for apical surgery under navigation, wherein the method comprises the following steps: S1, obtaining CT image data of a patient's affected tooth and jaw data, calculating the CT image data of the affected tooth to obtain calculation parameters of the surgical path; S2, obtaining the starting point and end point of the surgical path according to the calculation parameters of the surgical path combined with the jaw data of the affected tooth, and then generating the surgical path. The present invention improves the efficiency of preoperative design, reduces the learning cost of doctors, and has a standardized design of the scheme with high accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical navigation, and in particular relates to a method and a device for determining a fenestration path for apical surgery under navigation. Background Art

[0002] When conventional root canal treatment or root canal retreatment cannot control the infection of periapical tissues, microapical surgery can be used as an effective treatment method. The basic principle is to resect the root apex 3mm perpendicular to the long axis of the tooth, with a success rate of up to 95%. However, accurate positioning of the root apex and achieving precise minimally invasive bone window opening and apical resection have always been a major difficulty in the field of microapical surgery. In recent years, the application of dynamic navigation technology in apical surgery has been widely recognized. The current dynamic navigation preoperative design requires the patient's preoperative CT image data to be imported into a special design software to achieve three-dimensional reconstruction of the patient's surgical area. Subsequently, the physician can use the three-dimensional image information in the design software to make detailed preoperative planning of the surgical path and complete the design of the surgical plan. However, the design of the plan depends to a certain extent on the doctor's professional skills and experience. It requires a professional software environment and relatively complex operations using CT images. The learning curve is long and it relies heavily on individual experience. In order to improve the design accuracy, repeated manual adjustments and verifications are often required, which is a cumbersome and time-consuming process. Therefore, although dynamic navigation technology provides important assistance for microapical surgery, there is still room for further optimization and improvement in the accuracy and efficiency of surgical plan design. Summary of the invention

[0003] The purpose of the present invention is to address the deficiencies of the prior art and provide a method for determining the path of fenestration in apical surgery under navigation, which improves the efficiency of preoperative design, reduces the learning cost of doctors, and makes the plan standardized with high accuracy.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A method for determining a fenestration path for apical surgery under navigation comprises the following steps:

[0006] S1, obtaining CT image data of the patient's affected teeth and jaw data, and calculating the CT image data of the affected teeth to obtain calculation parameters of the surgical path;

[0007] S2. The starting point and the end point of the surgical path are obtained according to the calculation parameters of the surgical path and the jaw bone data of the affected tooth, and the surgical path is generated according to the starting point and the end point.

[0008] Furthermore, the calculation parameters in step S1 include the tip point root_tip of the tooth root and the long axis direction root_vec of the tooth root.

[0009] Furthermore, the method for obtaining the calculation parameters includes:

[0010] S101: acquiring the 3D model data of the affected tooth through the CT image data thereof, obtaining the 3D model of the affected tooth, and obtaining the center root_center of the polydata of the root part in the 3D model of the affected tooth by using a computer graphics algorithm, wherein the polydata is the 3D model data of the root;

[0011] S102: Taking the tooth root center root_center as the origin and the direction of the tooth long axis as the normal, a root cutting plane plane_cut is drawn, wherein the direction of the tooth long axis is from the crown side of the tooth to the root side of the tooth;

[0012] S103: using the root cutting plane plane_cut to cut the three-dimensional model of the affected tooth into two parts, namely, the first part part1 and the second part part2, taking the first part part1 to calculate the connected domain, obtaining n connected domains region, extracting root_polydata of a single connected domain region, wherein root_polydata is the three-dimensional data of the tooth root in the single connected domain, and calculating the tip point root_tip of the tooth root for the three-dimensional data root_polydata of the tooth root in the single connected domain;

[0013] Wherein, the part1 is the positive direction part of the root cut plane plane_cut, and the second part part2 is the negative direction part of the root cut plane plane_cut; the root tip point root_tip is the corner point closest to the origin of the long axis when all the corner points on the root_polydata are projected onto the long axis of the tooth;

[0014] S104: Calculate the distance left_length between the origin orgin_cut on the root cutting plane plane_cut and the root tip point root_tip, and determine whether the length of the connection distance left_length exceeds a threshold; when the length of the connection distance left_length exceeds the threshold, execute S105; when the length of left_length does not exceed the threshold, execute S106;

[0015] S105: The origin orgin_cut is translated a certain distance along the long axis of the tooth as the new origin, and the root cutting plane is re-made with the direction of the long axis of the tooth as the normal. S103-104 are repeated for multiple iterations of a single connected domain to extract the most connected domains until the length of left_length does not exceed the threshold;

[0016] S106: translating the root truncation plane along the normal direction by a certain distance to obtain a second root truncation plane, and using the second root truncation plane to re-cut root_polydata into two parts, namely, a first part part1' and a second part part2', wherein the first part part1' is a positive direction part of the second root truncation plane, and the second part part2' is a negative direction part of the second root truncation plane;

[0017] S107: Take the center of the second part part2' as the top surface center root_top of the root, take the line connecting the root tip point root_tip and the top surface center root_top as the root long axis direction root_vec, and use the root tip point root_tip and the root long axis direction root_vec as calculation parameters of the window opening path.

[0018] Furthermore, the method of obtaining the center root_center of the polydata of the root part by using a computer graphics algorithm includes: using a computer graphics algorithm to divide the three-dimensional model of the affected tooth into a three-dimensional model of the crown and a three-dimensional model of the root, and calculating the centroid of the three-dimensional model of the root, that is, obtaining the center root_cente of the polydata of the root part.

[0019] Furthermore, the implementation method of step S2 includes:

[0020] S201: moving the root tip point root_tip along the root long axis direction root_vec by the apical resection distance to obtain the first calibration point Point1;

[0021] S202: Draw a first line segment Line1 along the negative direction of the buccal-lingual direction Vec_coronal of the tooth, passing through the first calibration point Point1, and divide the intersection of the first line segment Line1 and the three-dimensional model data polydata of the tooth root into an entry point and an exit point;

[0022] The entry point and the exit point are obtained by sorting the intersection points of the first line segment Line1 and the three-dimensional model data polydata of the tooth root, with odd-numbered points as entry points and even-numbered points as exit points;

[0023] S203: Find the entry point Point_tmp and the exit point Point_end closest to the tooth root tip point root_tip;

[0024] S204: The first line segment Line1 and the jaw data form an intersection. If there is an intersection, the point closest to the starting point of the first line segment is taken as the starting point Point_start of the path. Otherwise, the penetration point Point_tmp is taken as the starting point Point_start of the path.

[0025] Another object of the present invention is to provide a device for determining the path of the fenestration in the above-mentioned navigation-based apical surgery, comprising:

[0026] A data acquisition module is used to acquire CT image data of the patient's affected teeth and jaw data;

[0027] A parameter calculation module, used to calculate and obtain the calculation parameters of the surgical path according to the CT image data of the affected tooth obtained by the data acquisition module;

[0028] The path generation module is used to obtain the starting point and end point of the surgical path based on the calculation parameters of the surgical path combined with the jaw data, and then generate the surgical path.

[0029] An electronic device comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0030] A computer-readable storage medium stores a computer program, which implements the steps of the above method when executed by a processor.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention obtains three-dimensional model data of a single tooth by performing three-dimensional patchwork on the dental CT data in computer software, processes the three-dimensional model data based on a computer graphics algorithm, and gives the best window path recommendation on the three-dimensional model in combination with the requirements of clinical medicine for apical surgery. The present invention improves the efficiency of preoperative design, reduces the learning cost of doctors, turns the design plan into a standardized process, avoids the problem that the design accuracy of the existing plan depends on the influence of human factors, and improves the accuracy of the plan. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a flowchart of a method for determining a fenestration path during guided apical surgery according to an embodiment of the present invention.

[0033] Figure 2 A flowchart of obtaining window path calculation parameters according to an embodiment of the present invention;

[0034] Figure 3 The present invention provides a flowchart for obtaining the start and end points of a designed window opening path according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be described clearly and completely below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0037] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0038] like Figure 1 As shown, an embodiment of the present invention discloses a method for determining a fenestration path for apical surgery under navigation, comprising the following steps:

[0039] S1, obtaining CT image data of the affected tooth and the jaw, and calculating the CT image data of the affected tooth to obtain calculation parameters of the surgical path;

[0040] See also Figure 2 , the specific method of this step is:

[0041] S101: In the software, the CT medical image data of the affected tooth is 3D sliced ​​to obtain the 3D model data of the affected tooth, and the 3D model of the affected tooth is obtained according to the 3D model data of the single tooth. The 3D model of the affected tooth is then segmented into a 3D model of the crown and a 3D model of the root using a computer graphics algorithm, and the centroid of the 3D model of the root is calculated to obtain the center of the polydata of the root part, i.e., root_center, where polydata is the 3D model data of the root;

[0042] S102: Take the root center root_center as the origin and the direction of the long axis of the tooth as the normal to make a root cutting plane plane_cut;

[0043] Wherein, the long axis of the tooth refers to an imaginary line passing through the center of the tooth, and the direction of the long axis of the tooth refers to the direction from the crown of the tooth to the root of the tooth;

[0044] S103: Use the root cutting plane plane_cut to cut the three-dimensional model of the affected tooth into two parts, namely the first part part1 and the second part part2, and take the first part part1 to calculate the connected domain. When there are multiple tooth roots, each tooth root in the first part part1 may form an independent three-dimensional body (single tooth root three-dimensional model connected domain) after being cut, and the multiple tooth roots may merge into a large independent three-dimensional body (multiple tooth root three-dimensional model connected domain). Extract each three-dimensional body to obtain n connected domains region, extract root_polydata of a single connected domain region, and calculate the tip point root_tip of the root, wherein root_polydata is the three-dimensional model data of the tooth root in the single connected domain;

[0045] Among them, the first part part1 is the positive direction part of the root cutting plane plane_cut, and the second part part2 is the negative direction part of the root cutting plane plane_cut; the tip point of the tooth root root_tip is the corner point closest to the origin of the long axis when all the corner points on the root_polydata are projected onto the long axis of the tooth;

[0046] S104: Calculate the distance left_length between the origin orgin_cut of the root cutting plane plane_cut and the tip point root_tip of the tooth root, and determine whether the length of left_length exceeds a threshold; when the length of left_length exceeds the threshold, execute S105; when the length of left_length does not exceed the threshold, execute S106;

[0047] In this embodiment, the threshold is set to the standard length of apical resection, 3 mm, and in other embodiments, it is set according to the actual situation of the affected tooth;

[0048] S105: With the origin orgin_cut shifted 0.3 mm along the long axis of the tooth as the new origin, the root cutting plane is re-made with the direction of the long axis of the tooth as the normal, and S103-S104 are repeated until the length of left_length does not exceed the threshold, so as to iterate multiple times for a single connected domain, extract the most connected domains, and then segment the multiple roots that are fused together as much as possible;

[0049] S106: The root section plane is translated along the normal direction by a certain distance to obtain a second root section plane, which is 0.1 mm in this embodiment and can also be determined according to the tooth size, and the long axis direction of the tooth root is corrected to make it closer to the state of the tooth root three-dimensional model. The second root section plane is used to re-cut the tooth root three-dimensional model data root_polydata of a single connected domain into a first part part1' and a second part part2';

[0050] The first part part1' is the positive direction part of the second root truncation plane, and the second part part2' is the negative direction part of the second root truncation plane;

[0051] S107: Take the center of the second part part2' obtained in step S106 as the top surface center root_top of the root, take the tip point root_tip of the root and the line connecting the top surface center root_top of the root as the long axis direction root_vec of the root, and use the tip point root_tip of the root and the long axis direction root_vec of the root as the calculation parameters of the window opening path.

[0052] S2. The starting point and end point of the surgical path are obtained based on the calculation parameters of the surgical path and the data of the affected tooth and jaw, and then the surgical path is generated. Figure 3 ; The specific implementation of this step is:

[0053] S201: The tip point root_tip of the tooth root is moved along the root long axis direction root_vec by the apical resection distance to obtain the first calibration point Point1. In this embodiment, the apical resection distance is 3 mm, which can also be determined according to the tooth size.

[0054] S202: Draw a first line segment Line1 along the negative direction of the buccal-lingual direction Vec_coronal of the tooth, passing through the first calibration point Point1, and divide the intersection of the first line segment Line1 and the tooth root three-dimensional model data polydata into an entry point and an exit point;

[0055] The entry point and the exit point are obtained by sorting the intersection points of the first line segment Line1 and the tooth root three-dimensional model data polydata, with odd-numbered points as entry points and even-numbered points as exit points.

[0056] S203: Find the entry point Point_tmp and the exit point Point_end closest to the tip point root_tip of the tooth root;

[0057] S204: If the first line segment Line1 and the jaw data have an intersection, the point of the intersection closest to the starting point of the first line segment is taken as the starting point Point_start of the path; otherwise, the entry point Point_tmp is taken as the starting point Point_start of the path, and the surgical path is generated by combining the starting point Point_start and the exit point Point_end of the path.

[0058] In one embodiment, a device for determining a path for opening a window in an apical surgery under navigation is provided, comprising:

[0059] A data acquisition module is used to acquire CT image data of the patient's affected teeth and jaw data;

[0060] A parameter calculation module, used to calculate and obtain the calculation parameters of the surgical path according to the CT image data of the affected tooth obtained by the data acquisition module;

[0061] The path generation module is used to obtain the starting point and end point of the surgical path based on the calculation parameters of the surgical path combined with the jaw data, and then generate the surgical path.

[0062] In one embodiment, an electronic device is provided, which can be, but is not limited to, various personal computers, laptops, smart phones, tablet computers, etc. The electronic device includes a processor, a memory, a network interface, a display screen, an input device, and a database connected via a system bus. Among them, the processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the electronic device is used to store the CT data of the affected tooth and the jaw data required for apical surgery. The network interface of the electronic device is used to communicate with an external terminal through a network connection. The display screen of the electronic device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the electronic device can be a touch layer covered on the display screen, or a button set on the housing of the electronic device, or an external keyboard, touchpad, or mouse, etc. When the computer program is executed by the processor, a method for navigating the apical surgery window path is implemented.

[0063] A computer-readable storage medium stores a computer program, which implements the steps of the above method when executed by a processor.

[0064] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of the specification of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining a fenestration path for apical surgery under navigation, characterized in that: The steps include: S1, obtaining CT image data of the patient's affected teeth and jaw bone data, and calculating the CT image data of the affected teeth to obtain calculation parameters of the surgical path; S2, according to the calculation parameters of the surgical path combined with the affected tooth and jaw bone data, the starting point and the end point of the surgical path are obtained, and the surgical path is generated according to the starting point and the end point; The calculation parameters in step S1 include the tip point root_tip of the tooth root and the long axis direction root_vec of the tooth root; Methods for obtaining calculation parameters include: S101: acquiring the 3D model data of the affected tooth through the CT image data thereof, obtaining the 3D model of the affected tooth, and obtaining the center root_center of the polydata of the root part in the 3D model of the affected tooth by using a computer graphics algorithm, wherein the polydata is the 3D model data of the root; S102: Taking the root center root_center as the origin and the direction of the long axis of the tooth as the normal, a root cutting plane plane_cut is drawn, wherein the direction of the long axis of the tooth is from the crown side of the tooth to the root side of the tooth; S103: using the root cutting plane plane_cut to cut the three-dimensional model of the affected tooth into two parts, namely, the first part part1 and the second part part2, taking the first part part1 to calculate the connected domain, obtaining n connected domains region, extracting root_polydata of a single connected domain region, wherein root_polydata is the three-dimensional data of the tooth root in the single connected domain, and calculating the tip point root_tip of the tooth root for the three-dimensional data root_polydata of the tooth root in the single connected domain; Wherein, the part1 is the positive direction part of the root cut plane plane_cut, and the second part part2 is the negative direction part of the root cut plane plane_cut; the root tip point root_tip is the corner point closest to the origin of the long axis when all the corner points on the root_polydata are projected onto the long axis of the tooth; S104: Calculate the distance left_length between the origin orgin_cut on the root cutting plane plane_cut and the root tip point root_tip, and determine whether the length of the connection distance left_length exceeds a threshold; when the length of the connection distance left_length exceeds the threshold, execute S105; when the length of left_length does not exceed the threshold, execute S106; S105: The origin orgin_cut is translated a certain distance along the long axis of the tooth as the new origin, and the root cutting plane is re-made with the direction of the long axis of the tooth as the normal. S103-104 are repeated for multiple iterations of a single connected domain to extract the most connected domains until the length of left_length does not exceed the threshold; S106: translating the root truncation plane along the normal direction by a certain distance to obtain a second root truncation plane, and using the second root truncation plane to re-cut root_polydata into two parts, namely, a first part part1' and a second part part2', wherein the first part part1' is a positive direction part of the second root truncation plane, and the second part part2' is a negative direction part of the second root truncation plane; S107: taking the center of the second part part2' as the top surface center root_top of the tooth root, taking the line connecting the root tip point root_tip and the top surface center root_top as the root long axis direction root_vec, and using the root tip point root_tip and the root long axis direction root_vec as calculation parameters of the window opening path; The implementation method of step S2 includes: S201: moving the root tip point root_tip along the root long axis direction root_vec by the apical resection distance to obtain the first calibration point Point1; S202: Draw a first line segment Line1 along the negative direction of the buccal-lingual direction Vec_coronal of the tooth, passing through the first calibration point Point1, and divide the intersection of the first line segment Line1 and the three-dimensional model data polydata of the tooth root into an entry point and an exit point; The entry point and the exit point are obtained by sorting the intersection points of the first line segment Line1 and the three-dimensional model data polydata of the tooth root, with odd-numbered points as entry points and even-numbered points as exit points; S203: Find the entry point Point_tmp and the exit point Point_end closest to the tooth root tip point root_tip; S204: The first line segment Line1 and the jaw data form an intersection. If there is an intersection, the point closest to the starting point of the first line segment is taken as the starting point Point_start of the path. Otherwise, the penetration point Point_tmp is taken as the starting point Point_start of the path.

2. The method for determining the fenestration path for apical surgery under navigation according to claim 1, characterized in that: The method of obtaining the center root_center of the polydata of the root part by using a computer graphics algorithm includes: using a computer graphics algorithm to divide the three-dimensional model of the affected tooth into a three-dimensional model of the crown and a three-dimensional model of the root, and calculating the centroid of the three-dimensional model of the root, that is, obtaining the center root_cente of the polydata of the root part.

3. A device for determining the path of fenestration in apical surgery under navigation according to any one of claims 1 to 2, characterized in that: include: A data acquisition module, used to acquire CT image data of the patient's affected teeth and jaw data; A parameter calculation module, used to calculate and obtain the calculation parameters of the surgical path according to the CT image data of the affected tooth obtained by the data acquisition module; The path generation module is used to obtain the starting point and end point of the surgical path based on the calculation parameters of the surgical path combined with the jaw data, and then generate the surgical path.

4. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 2 are implemented.

5. 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 2 are implemented.

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