Navigation method and device for maxillary embedded tooth windowing

Abstract

The invention discloses a navigation method and device for maxillary embedded tooth windowing, and is applied to the technical field of dynamic navigation of alveolar surgery. Comprising the following steps: a patient wears a U-shaped tube for navigation system registration for CBCT scanning to obtain a CBCT image for navigation path design; determining the approach of the windowing operation according to the form and position of the diseased tooth of the patient in the CBCT image; selecting a reference plane from the 3D view of the navigation system as a navigation path plane; generating a navigation path of the windowing operation on the reference plane; and repeating the above method to complete the preliminary design of the navigation path, and finely adjusting the navigation path according to requirements. According to the method, the optimal navigation path is determined by dynamically analyzing the three-dimensional data of the oral cavity of the patient before the operation.

Description

Technical Field

[0001] This invention relates to the field of dynamic navigation technology in alveolar surgery, and more specifically to a navigation method and device for opening windows in maxillary impacted teeth. Background Technology

[0002] The Dynamic Navigation System (DNS) is a navigation system that integrates digital 3D design and spatial motion tracking technology with CBCT 3D imaging technology. It provides real-time, visualized guidance and verification throughout the surgical procedure. The 3D scanning module acquires 3D data of the patient's oral cavity using equipment such as CBCT; the image processing and planning module reconstructs and analyzes the data to provide pre-operative planning; the real-time tracking module uses optical locators and other equipment to capture real-time positional changes of surgical instruments and the patient's oral cavity; and the display module presents real-time information to the surgeon in a 3D visualized format, achieving dynamic guidance during the surgical process. As part of digital healthcare, it has wide applications in dental implantation, maxillofacial surgery, and endodontic treatment.

[0003] Dynamic navigation systems offer advantages such as independence from guide plates, intraoperative guidance throughout the procedure, and high flexibility in intraoperative manipulation. DNS-guided extraction of supernumerary teeth improves the accuracy of positioning maxillary supernumerary and impacted teeth, reduces positioning time, and minimizes bone trauma, proving invaluable for these procedures. However, in practical applications, most navigation systems only provide simple position tracking and lack personalized preoperative path dynamic design capabilities for impacted and complex tooth extractions, failing to fully meet the high precision and safety requirements of such surgeries. Existing dynamic navigation systems for impacted tooth extraction lack personalized preoperative path dynamic design capabilities, focusing primarily on real-time intraoperative tracking while neglecting dynamic preoperative path design. Path planning is often simplistic and lacks detailed consideration of complex anatomical structures. Therefore, providing a navigation method and device for fenestration of maxillary impacted teeth is a problem urgently needing to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a navigation method and device for opening windows in maxillary impacted teeth, which plans the optimal path by dynamically analyzing the three-dimensional data of the patient's oral cavity before the operation.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A navigation method for opening windows in maxillary impacted teeth includes the following steps:

[0007] S1. Before navigation path design, the patient wears a U-shaped tube for navigation system registration and undergoes a CBCT scan to obtain CBCT images for navigation path design.

[0008] S2. Determine the approach for fenestration surgery based on the morphology and location of the patient's affected teeth in CBCT images;

[0009] S3. Select a reference plane in the 3D view of the navigation system as the navigation path plane;

[0010] S4. Generate a navigation path for the fenestration surgery on the reference plane;

[0011] S5. Repeat S3-S4 to complete the initial design of the navigation path, and fine-tune the navigation path according to the requirements.

[0012] S6. Before the operation, complete the registration of the navigation system, instruments, and surgical area, and register the ultrasonic bone scalpel used in the operation. The dynamic navigation system determines the angle and position of the ultrasonic bone scalpel head by identifying the markers on the ultrasonic bone scalpel handle and the reference plate.

[0013] Optionally, S3 specifically involves selecting two positioning points in the 3D view of the navigation system and generating a reference plane that passes through the line connecting the positioning points and is perpendicular to the current viewpoint.

[0014] Optionally, S4 specifically involves: combining the shape and location of the affected tooth, selecting two high points on the line where the reference plane and the bone surface intersect to form the starting path on the bone surface; combining the depth of the affected tooth and the thickness of the bone surface, selecting two points on the reference plane to form the ending path within the bone, determining the path cutting depth, and the polygon formed by the four points on the reference plane is the navigation path on the reference plane.

[0015] Optionally, fine-tuning the navigation path in S5 involves adjusting point coordinates and rotating or translating the reference plane.

[0016] Optionally, in S6, the angle and position of the ultrasonic bone scalpel tip relative to the patient's teeth are determined as follows:

[0017] Images of the ultrasonic bone scalpel are captured, and the reference plate markers of the ultrasonic bone scalpel in the images are decoded and identified. Three-dimensional reconstruction is performed based on the principle of triangulation to obtain the three-dimensional data of the markers. The three-dimensional data of the markers is aligned with the theoretical coordinate data to achieve the positioning of the ultrasonic bone scalpel, thus obtaining the instrument positioning coordinates T of the ultrasonic bone scalpel handle. h and reference plate instrument positioning coordinates T r Combined with the calibration information of the ultrasonic bone scalpel T clb Obtain the current ultrasonic bone scalpel tip pose T p Combined with registration information T reg Obtain the current tooth pose Tt Calculate the position of the cutter head relative to the teeth

[0018] T p =T h ·T clb ;

[0019] T t =T r ·T reg ;

[0020]

[0021] Optionally, the navigation process of the navigation system is as follows:

[0022] The navigation system simultaneously observes the ultrasonic bone scalpel handle and reference plate to obtain the current pose of the ultrasonic bone scalpel tip relative to the teeth, and determines the plane normal and tip coordinates of the ultrasonic bone scalpel tip. Based on the pre-designed navigation path, the surgical path plane and target point are determined separately. By comparing the current ultrasonic bone scalpel tip pose with the target expected path, the angle difference, position difference, and offset difference can be obtained. The angle difference is the angle between the plane normal of the ultrasonic bone scalpel tip and the plane normal of the surgical path; the position difference is the projection distance of the tip of the ultrasonic bone scalpel tip on the surgical path plane; and the offset is the distance from the projection point of the tip of the ultrasonic bone scalpel tip on the surgical path plane to the target point.

[0023] A navigation device for fenestration of maxillary impacted teeth, performing the above-described navigation method for fenestration of maxillary impacted teeth, includes: an ultrasonic bone scalpel, a CBCT scanning module, a path planning module, and a dynamic navigation module. The ultrasonic bone scalpel is used to perform bone fenestration, the CBCT scanning module is used to acquire CBCT image data of the patient's oral cavity, the path planning module is used to plan the bone fenestration path, and the dynamic navigation module is used for real-time navigation during the operation.

[0024] Optionally, the ultrasonic bone scalpel is equipped with a dedicated reference plate.

[0025] As can be seen from the above technical solution, compared with the prior art, the present invention provides a navigation method and device for opening windows in maxillary impacted teeth, which has the following beneficial effects: The present invention generates the optimal path by dynamically analyzing the three-dimensional data of the patient's oral cavity before surgery, so as to give full play to the value of dynamic navigation technology; In clinical application, doctors can quickly plan a surgical path that avoids important nerves and blood vessels, and combined with real-time navigation during surgery, the accuracy of surgery is significantly improved and the probability of complications is reduced. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 This is a flowchart of the navigation method for opening windows in maxillary impacted teeth according to the present invention.

[0028] Figure 2 This is a flowchart illustrating the positioning of the ultrasonic bone scalpel handle of the present invention.

[0029] Figure 3 This is a flowchart illustrating the calculation of the angle and position of the ultrasonic bone scalpel tip of the present invention;

[0030] Figure 4 This is a schematic diagram of the reference plate registration of the present invention;

[0031] Figure 5 This is a schematic diagram of the calibration of the ultrasonic bone scalpel instrument of the present invention;

[0032] Figure 6 This is a schematic diagram of the ultrasonic bone scalpel handle of the present invention;

[0033] Figure 7 This is a schematic diagram of the ultrasonic bone scalpel reference plate of the present invention. Detailed Implementation

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0035] This invention discloses a navigation method for opening windows in maxillary impacted teeth, such as... Figure 1 As shown, it includes the following steps:

[0036] S1. Before navigation path design, the patient wears a U-shaped tube for navigation system registration and undergoes a CBCT scan to obtain CBCT images for navigation path design.

[0037] S2. Determine the approach for fenestration surgery based on the morphology and location of the patient's affected teeth in CBCT images;

[0038] S3. Select a reference plane in the 3D view of the navigation system as the navigation path plane;

[0039] S4. Generate a navigation path for the fenestration surgery on the reference plane;

[0040] S5. Repeat S3-S4 to complete the initial design of the navigation path, and fine-tune the navigation path according to the requirements.

[0041] S6. Before the operation, complete the registration of the navigation system, instruments, and surgical area, and register the ultrasonic bone scalpel used in the operation. The dynamic navigation system determines the angle and position of the ultrasonic bone scalpel head by identifying the markers on the ultrasonic bone scalpel handle and the reference plate.

[0042] Furthermore, S3 specifically involves selecting two positioning points in the 3D view of the navigation system and generating a reference plane that passes through the line connecting the positioning points and is perpendicular to the current viewpoint.

[0043] Furthermore, S4 specifically involves: combining the shape and location of the affected tooth, selecting two high points on the line where the reference plane and the bone surface intersect to form the starting path on the bone surface; combining the depth of the affected tooth and the thickness of the bone surface, selecting two points on the reference plane to form the ending path within the bone, determining the path cutting depth, and the polygon formed by the four points on the reference plane is the navigation path on the reference plane.

[0044] Furthermore, in S5, fine-tuning of the navigation path specifically involves adjusting point coordinates and rotating or translating the reference plane.

[0045] Furthermore, in S6, the angle and position of the ultrasonic bone scalpel tip relative to the patient's teeth are specifically determined as follows:

[0046] like Figure 2 As shown, images of the ultrasonic bone scalpel are captured, and the reference plate markers of the ultrasonic bone scalpel in the images are decoded and identified. Each marker on the ultrasonic bone scalpel handle and the reference plate has a unique code. Since the markers on both the ultrasonic bone scalpel handle and the reference plate have unique codes, they can be directly matched using binocular vision. Three-dimensional reconstruction is performed based on the principle of triangulation to obtain the three-dimensional data of the markers. The three-dimensional data of the markers is then aligned with the theoretical coordinate data. Because the markers have unique codes, they can be directly mapped to the theoretical coordinates of the instrument. The coordinate transformation relationship between the two is then calculated using ICP, thus achieving alignment and positioning of the ultrasonic bone scalpel. The positioning coordinates T of the ultrasonic bone scalpel handle are obtained. h and reference plate instrument positioning coordinates T r ;like Figure 3 As shown, combined with the calibration information T of the ultrasonic bone scalpel clb Obtain the current ultrasonic bone scalpel tip pose T p Combined with registration information T reg Obtain the current tooth pose T t Calculate the position of the cutter head relative to the teeth

[0047] Tp =T h ·T clb ;

[0048] T t =T r ·T reg ;

[0049]

[0050] In this embodiment of the invention, the ultrasonic bone scalpel model in the navigation system is abstracted into a three-point model (the three points are the starting point, the tip, and the ending point of the ultrasonic bone scalpel, approximating a parabola). On the reference plate, multiple ultrasonic bone scalpel tip recesses are preset. Correspondingly, the coordinates of the ultrasonic bone scalpel abstract model on the reference plate are fixed values. In the actual calibration process, the ultrasonic bone scalpel instrument and the reference plate are placed in the field of view of the navigator at the same time. The ultrasonic bone scalpel is aligned with the recess of the reference plate and secured to obtain the relative coordinates of the ultrasonic bone scalpel tip model relative to the instrument itself. At the same time, it is registered with the known coordinates of the recess of the bone scalpel model on the reference plate. The registration matrix is ​​the mathematical expression of its mapping relationship.

[0051] Assuming the ultrasonic bone scalpel model is abstracted into three points A, B, and C, the calibration process places the ultrasonic bone scalpel handle and the reference plate in the same coordinate system, thus obtaining the coordinates of points A, B, and C relative to the handle. Through calculation, the coordinates A', B', and C' of the scalpel head relative to the handle are obtained. If the scalpel head is replaced during use, the calibration process needs to be repeated.

[0052] like Figure 4 As shown, the reference plate registration process is achieved through U-tube registration (the U-tube has small balls and pits that can be visualized in CT, and the relative positions of the pits and the visualized balls are known). The registration process is as follows: the patient wears the U-tube and takes a CT scan. Since it is a single procedure, the visualized balls and the CT coordinate system are consistent at this time. During the procedure, the patient wears the U-tube, and the pits on the U-tube are selected sequentially using an instrument with a known spherical tip. At this time, the reference plate needs to be observed simultaneously to determine the relative positional relationship between the pits on the U-tube and the reference plate. Since the relative positions of the pits and the visualized balls are known, the relative positional relationship between the reference plate and the dental CT data can be determined by integrating the data.

[0053] like Figure 5As shown, the instrument calibration process of the ultrasonic bone scalpel is achieved through an instrument calibration plate (containing uniquely coded marker points). The calibration plate has a molded slot that allows the scalpel head to be inserted in a unique orientation. The relative orientations of all points / normals on the molded slot relative to the calibration plate are known. When the scalpel head is inserted into the molded slot, both the calibration plate and the ultrasonic bone scalpel handle can be observed simultaneously, achieving simultaneous positioning of both. Since the molded slot and the scalpel head are completely aligned, the points / normals on the molded slot can directly determine the points / normals on the scalpel head. Therefore, the coordinates of the points / normals on the scalpel head in the ultrasonic bone scalpel handle coordinate system can be integrated to determine the relative positional transformation relationship between the handle data and the scalpel head data.

[0054] Furthermore, the navigation process of the navigation system is as follows:

[0055] The navigation system simultaneously observes the ultrasonic bone scalpel handle and reference plate to obtain the current pose of the ultrasonic bone scalpel tip relative to the teeth, and determines the plane normal and tip coordinates of the ultrasonic bone scalpel tip. Based on the pre-designed navigation path, the surgical path plane and target point are determined separately. By comparing the current ultrasonic bone scalpel tip pose with the target expected path, the angle difference, position difference, and offset difference can be obtained. The angle difference is the angle between the plane normal of the ultrasonic bone scalpel tip and the plane normal of the surgical path; the position difference is the projection distance of the tip of the ultrasonic bone scalpel tip on the surgical path plane; and the offset is the distance from the projection point of the tip of the ultrasonic bone scalpel tip on the surgical path plane to the target point.

[0056] and Figure 1 Corresponding to the method described above, this invention also discloses a navigation device for fenestration of maxillary impacted teeth. The navigation method for fenestration of maxillary impacted teeth includes: an ultrasonic bone scalpel, a CBCT scanning module, a path planning module, and a dynamic navigation module. The ultrasonic bone scalpel is used to perform bone fenestration; the CBCT scanning module is used to acquire CBCT image data of the patient's oral cavity; the path planning module is used to plan the bone fenestration path; and the dynamic navigation module is used for real-time navigation during the procedure. The ultrasonic bone scalpel... Figure 6 As shown.

[0057] Furthermore, such as Figure 7 As shown, the ultrasonic bone scalpel is equipped with a dedicated reference plate.

[0058] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0059] Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A navigation method for opening windows in maxillary impacted teeth, characterized in that, Includes the following steps: S1. Before navigation path design, the patient wears a U-shaped tube for navigation system registration and undergoes a CBCT scan to obtain CBCT images for navigation path design. S2. Determine the approach for fenestration surgery based on the morphology and location of the patient's affected teeth in CBCT images; S3. Select a reference plane in the 3D view of the navigation system as the navigation path plane; S4. Generate a navigation path for the fenestration surgery on the reference plane; S5. Repeat S3-S4 to complete the initial design of the navigation path, and fine-tune the navigation path according to the requirements. S6. Before the operation, complete the registration of the navigation system, instruments, and surgical area, and register the ultrasonic bone scalpel used in the operation. The dynamic navigation system determines the angle and position of the ultrasonic bone scalpel tip relative to the patient's teeth by identifying the landmarks on the ultrasonic bone scalpel handle and reference plate.

2. The navigation method for opening windows in maxillary impacted teeth according to claim 1, characterized in that, S3 specifically involves selecting two positioning points in the 3D view of the navigation system and generating a reference plane that passes through the line connecting the positioning points and is perpendicular to the current viewpoint.

3. The navigation method for opening windows in maxillary impacted teeth according to claim 1, characterized in that, S4 specifically involves: combining the shape and location of the affected tooth, selecting two high points on the line where the reference plane and the bone surface intersect to form the starting path on the bone surface; combining the depth of the affected tooth and the thickness of the bone surface, selecting two points on the reference plane to form the ending path within the bone, determining the path cutting depth, and the polygon formed by the four points on the reference plane is the navigation path on the reference plane.

4. The navigation method for opening windows in maxillary impacted teeth according to claim 1, characterized in that, In S5, fine-tuning the navigation path involves adjusting point coordinates and rotating or translating the reference plane.

5. The navigation method for opening windows in maxillary impacted teeth according to claim 1, characterized in that, S6 specifies the angle and position of the ultrasonic bone scalpel tip relative to the patient's teeth as follows: Images of the ultrasonic bone scalpel are captured, and the reference plate markers of the ultrasonic bone scalpel in the images are decoded and identified. Three-dimensional reconstruction is performed based on the principle of triangulation to obtain the three-dimensional data of the markers. The three-dimensional data of the markers is aligned with the theoretical coordinate data to achieve the positioning of the ultrasonic bone scalpel, thus obtaining the instrument positioning coordinates T of the ultrasonic bone scalpel handle. h and reference plate instrument positioning coordinates T r Combined with the calibration information of the ultrasonic bone scalpel T clb Obtain the current ultrasonic bone scalpel tip pose T p Combined with registration information T reg Obtain the current tooth pose T t Calculate the position of the cutter head relative to the teeth T p =T h ·T clb ; T t =T r ·T reg ; 6. The navigation method for opening windows in maxillary impacted teeth according to claim 1, characterized in that, The navigation process of the navigation system is as follows: The navigation system simultaneously observes the ultrasonic bone scalpel handle and reference plate to obtain the current pose of the ultrasonic bone scalpel tip relative to the teeth, and determines the plane normal and tip coordinates of the ultrasonic bone scalpel tip. Based on the pre-designed navigation path, the surgical path plane and target point are determined separately. By comparing the current ultrasonic bone scalpel tip pose with the target expected path, the angle difference, position difference, and offset difference can be obtained. The angle difference is the angle between the plane normal of the ultrasonic bone scalpel tip and the plane normal of the surgical path; the position difference is the projection distance of the tip of the ultrasonic bone scalpel tip on the surgical path plane; and the offset is the distance from the projection point of the tip of the ultrasonic bone scalpel tip on the surgical path plane to the target point.

7. A navigation device for opening windows in maxillary impacted teeth, characterized in that, A navigation method for fenestration of maxillary impacted teeth according to any one of claims 1-6 includes: an ultrasonic bone scalpel, a CBCT scanning module, a path planning module, and a dynamic navigation module. The ultrasonic bone scalpel is used to perform bone fenestration, the CBCT scanning module is used to acquire CBCT image data of the patient's oral cavity, the path planning module is used to plan the bone fenestration path, and the dynamic navigation module is used for real-time navigation during the operation.

8. A navigation device for opening windows in maxillary impacted teeth according to claim 7, characterized in that, The ultrasonic bone scalpel is equipped with a special reference plate.

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