Surgical navigation registration method based on intraoral scanning registration and marker relay

Abstract

The invention provides a surgical navigation registration method based on intraoral scanning registration and marker relay. The method comprises the following steps: acquiring dentition data of a patient before an operation, making a removable personalized biteplate marker with a registration point, exporting a same-coordinate system dentition and marker model, performing 3D printing on the marker, and calibrating to generate a configuration file; preoperative CT data without markers and the model are imported, a three-dimensional skull model is segmented and reconstructed, a dentition and skull model is registered and fused, and a marker model is transferred; selecting a marker model registration point to obtain a CT coordinate, obtaining a camera coordinate by combining a configuration file and a feature point coordinate recognized by the camera, and performing registration and alignment to establish a coordinate system corresponding relation to complete registration. In the operation, coordinate system transfer between two markers can be completed according to the requirements of different operation modes or operation areas, a marker configuration file is automatically updated, and relay registration is completed. According to the invention, secondary ray exposure can be avoided, registration precision and surgical applicability are improved, and navigation reliability is guaranteed.

Description

Technical Field

[0001] This application relates to the field of surgical navigation technology, and in particular to a surgical navigation registration method based on intraoral scan registration and marker relay. Background Technology

[0002] In maxillofacial surgery, surgical navigation systems are crucial tools for achieving precise procedures. Patient registration, as the first step in navigation surgery, aims to establish a coordinate system transformation relationship between the navigation camera space and the preoperative CT image space, ensuring a precise correspondence between the actual anatomical location during surgery and the preoperative planned CT image location. Currently, among the commonly used optical navigation systems in clinical practice, visible light-based dynamic navigation systems are widely used due to their advantages such as fast response speed and ease of operation. The routine registration process requires the patient to first fix a marker to their teeth (maxillary or mandibular, depending on the surgical site) using resin bonding. The patient then wears this marker during preoperative CT imaging (the marker must be worn continuously until the end of the surgery). The CT data is then imported into the navigation system for virtual planning. Before surgery, the navigation camera identifies the corner points of the marker's black and white blocks to determine its actual spatial coordinates. The marker registration point is then selected in the CT image, and the ICP algorithm is used to complete the registration, alignment, and coordinate system transformation, ultimately achieving patient registration.

[0003] However, existing registration methods have significant limitations in clinical application: Firstly, due to the mobility of the mandible, markers can only be fixed to the maxilla or mandible alone, resulting in a single registration covering only a single jaw area, which cannot meet the global positioning requirements of mandibular-maxillary joint surgeries (such as orthognathic surgery and complex fracture reduction surgery); secondly, markers fixed to the dentition will obscure the occlusal surface, seriously affecting the intraoperative assessment of the patient's occlusal relationship, which is a key step in maxillofacial surgery to determine the effect of bone repositioning and ensure postoperative functional recovery; at the same time, if osteotomy or tooth extraction is involved in the operation, the markers are prone to loosening and displacement, directly causing navigation failure and increasing surgical risks; in addition, patients have already had a CT scan taken at the initial diagnosis, and the current method still requires patients to wear additional markers for CT scans before surgery, resulting in unnecessary secondary radiation exposure, which is not in line with the clinical concept of minimally invasive diagnosis and treatment. Summary of the Invention

[0004] In view of this, the embodiments of this application provide a surgical navigation registration method based on intraoral scanning registration and marker relay, which can avoid secondary radiation exposure, improve registration accuracy and surgical applicability, and ensure navigation reliability.

[0005] The technical solution of this application embodiment is implemented as follows: In a first aspect, embodiments of this application provide a surgical navigation registration method based on intraoral scan registration and marker relay, the method comprising: Before the operation, the patient's dentition data is obtained. Based on the dentition data and the patient's occlusal relationship, a removable personalized occlusal plate marker with registration points is made. At the same time, the dentition model with the same coordinate system and the occlusal plate marker model are exported. The occlusal plate marker is 3D printed and calibrated in the navigation software to generate a marker configuration file that records the spatial position information of the registration points relative to the marker feature points. Import the preoperative CT data of patients who did not wear markers, the dental arch model, and the occlusal plate marker model into the surgical navigation software; The preoperative CT data is segmented and reconstructed to generate a three-dimensional skull model. The dental arch model is registered and fused with the three-dimensional skull model. Based on the same coordinate system, the occlusal plate marker model is transferred to the dental arch of the three-dimensional skull model. Select a point on the transferred occlusal plate marker model to obtain the coordinates of the registration point in the CT image coordinate system. Combine the marker configuration file and the coordinates of the marker feature points identified by the navigation camera to obtain the coordinates of the registration point in the navigation camera coordinate system. Register and align the two sets of coordinates to establish the correspondence between the navigation camera and the CT image coordinate system, and complete the patient registration.

[0006] Secondly, embodiments of this application also provide a surgical navigation registration device based on intraoral scan registration and marker relay, the device comprising: The acquisition module is used to acquire the patient's dentition data before surgery, and to create a removable personalized occlusal plate marker with registration points based on the dentition data and the patient's occlusal relationship. At the same time, it exports the dentition model and the occlusal plate marker model with the same coordinate system. The occlusal plate marker is 3D printed and calibrated in the navigation software to generate a marker configuration file that records the spatial position information of the registration points relative to the marker feature points. The import module is used to import the preoperative CT data of patients who are not wearing markers, the dental arch model, and the occlusal plate marker model into the surgical navigation software. The registration module is used to segment and reconstruct the preoperative CT data to generate a three-dimensional skull model, register and fuse the dental arch model with the three-dimensional skull model, and transfer the occlusal plate marker model to the dental arch of the three-dimensional skull model based on the same coordinate system of the two. The registration module is used to select points on the transferred occlusal plate marker model to obtain the coordinates of the registration points in the CT image coordinate system, combine the marker configuration file and the coordinates of the marker feature points identified by the navigation camera to obtain the coordinates of the registration points in the navigation camera coordinate system, and align the two sets of coordinates to establish the correspondence between the navigation camera and the CT image coordinate system, thereby completing patient registration.

[0007] Thirdly, embodiments of this application also provide an electronic device, including: a processor, a storage medium, and a bus, wherein the storage medium stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor communicates with the storage medium via the bus, and the processor executes the machine-readable instructions to perform the surgical navigation registration method based on intraoral scan registration and marker relay as described in any of the first aspects.

[0008] Fourthly, embodiments of this application also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the surgical navigation registration method based on intraoral scan registration and marker relay as described in any one of the first aspects.

[0009] The embodiments of this application have the following beneficial effects: By acquiring the patient's dentition data preoperatively and creating removable, personalized occlusal splints with registration points, and simultaneously exporting dentition and occlusal splint models in the same coordinate system, the procedure eliminates the need for patients to wear additional splints during preoperative CT scans, fundamentally avoiding the potential risks of secondary radiation exposure associated with existing techniques. Preoperative CT data without splints, along with the dentition and occlusal splint models, are imported into navigation software. This software combines the registration and fusion of the CT-reconstructed 3D head model with the dentition model, and the transfer of the occlusal splint model based on the same coordinate system, leveraging the stable anatomy of the dentition. The structure ensures the reliability of the registration basis and achieves precise positioning of the occlusal plate markers in CT space through coordinate system association. Finally, by aligning the coordinates of the registration points in the CT image coordinate system and the navigation camera coordinate system, the correspondence between the navigation camera and the CT image coordinate system is established, completing patient registration. This not only solves the problem of obstructed occlusal assessment caused by the fixed and non-removable markers in existing technologies (the detachable design allows for temporary removal during surgery to check occlusion), but also overcomes the limitation of single-jaw registration. Relying on the adaptability of the personalized occlusal plate to the upper and lower jaws, it lays the foundation for subsequent global registration of the upper and lower jaws. Furthermore, the marker relay registration method overcomes the limitation of markers not being movable or repositioned during surgery, meeting the requirements of performing multiple surgical procedures and surgeries on different sites in a single navigation surgery. At the same time, the entire process requires no complex operations, significantly improving the safety, convenience, and applicability of surgical navigation registration while ensuring registration accuracy, providing a superior basic technical framework for maxillofacial surgical navigation. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a flowchart illustrating steps S101-S104 provided in the embodiments of this application; Figure 2 This is a flowchart illustrating steps S201-S203 provided in the embodiments of this application; Figure 3 This is a flowchart illustrating steps S301-S304 provided in the embodiments of this application; Figure 4 This is a flowchart illustrating steps S401-S402 provided in the embodiments of this application; Figure 5 This is a flowchart illustrating steps S501-S503 provided in the embodiments of this application; Figure 6 This is one of the schematic diagrams of surgical navigation registration based on intraoral scan registration and marker relay provided in the embodiments of this application; Figure 7 This is the second schematic diagram of surgical navigation registration based on intraoral scan registration and marker relay provided in the embodiments of this application; Figure 8 This is a graph showing the experimental results of the non-inferiority model provided in the embodiments of this application; Figure 9 This is a schematic diagram of the surgical navigation registration device based on intraoral scan registration and marker relay provided in the embodiments of this application; Figure 10 This is a schematic diagram of the composition structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0013] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0014] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0015] In the following description, the terms "first, second, third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0016] It should be noted that the term "comprising" will be used in the embodiments of this application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application and is not intended to limit this application.

[0018] See Figure 1 , Figure 1This is a flowchart illustrating steps S101-S104 of the surgical navigation registration method based on intraoral scan registration and marker relay provided in this application embodiment. Figure 1 Steps S101-S104 are explained below.

[0019] In step S101, the patient's dentition data is acquired preoperatively. Based on the dentition data and the patient's occlusal relationship, a removable personalized occlusal plate marker with registration points is made. At the same time, a dentition model with the same coordinate system and the occlusal plate marker model are exported. The occlusal plate marker is 3D printed and calibrated in navigation software to generate a marker configuration file that records the spatial position information of the registration points relative to the marker feature points.

[0020] Acquiring patient dentition data can be done using an intraoral scanner (such as chairside intraoral scanners commonly used in current technology). Compared to traditional impression methods, intraoral scanning can directly acquire high-precision three-dimensional dentition data and avoid errors in impression materials, providing an accurate data foundation for subsequent personalized occlusal plate design. When fabricating the occlusal plate based on the dentition data and occlusal relationship, the occlusal plate body is designed in digital design software (such as CAD design software) using the patient's three-dimensional dentition shape as a reference, perfectly fitting the inner surface of the dentition. Simultaneously, registration points are set on the inner and outer surfaces of the occlusal plate for registration. The placement of the markers must adhere to the principle of "uniform staggered arrangement" to ensure coverage of different areas of the occlusal plate during subsequent registration, thereby improving registration accuracy. The removable design addresses the issue of non-removable markers affecting occlusal assessment in existing technologies. The occlusal plate can be temporarily removed during surgery to check the occlusal relationship, and then reinserted (as the occlusal plate is individually adapted to the dentition, positional accuracy is still guaranteed after reinsertion). Exporting a dentition model and an occlusal plate marker model with the same coordinate system is a core prerequisite for subsequent model transfer, especially in digital design. In the software, the occlusal plate marker model is designed and generated based on the dental arch model. The coordinate systems of the two are unified during the design phase, requiring no additional calibration. This provides a coordinate reference for the subsequent transfer of the occlusal plate marker model from the dental arch model to the CT head model. The 3D printing uses biocompatible resin materials (such as light-cured resin commonly used in dentistry) to ensure that there is no safety risk when the occlusal plate marker comes into contact with oral tissues during surgery. Through the calibration process of the navigation system, the "marker feature points" on the occlusal plate marker are first identified by the navigation camera (usually black and white corner points on the marker, which have high contrast and are easy for the camera to accurately identify), and the coordinate system of the marker itself is established. Then, the probe accompanying the navigation system is used to click on the registration points on the occlusal plate one by one, and the coordinates of the registration points are recorded in the above marker coordinate system. Finally, a "marker configuration file" in TXT format is generated. This file is essentially a "spatial position relationship table of registration points relative to marker feature points". During subsequent registration, as long as the navigation camera identifies the marker feature points, the spatial coordinates of the registration points can be calculated from this file without repeated calibration.

[0021] In step S102, the preoperative CT data of the patient who did not wear the marker, the dental arch model, and the occlusal plate marker model are imported into the surgical navigation software.

[0022] In existing technologies, patients need to wear markers and have CT scans before surgery, resulting in secondary radiation exposure. In this solution, the preoperative CT data of patients who do not wear markers refers to the CT data taken during the patient's initial diagnosis (no additional scans are required). The data preparation can be completed simply by importing the CT data, the dental arch model obtained from the intraoral scan, and the designed occlusal plate marker model into the navigation software, thus avoiding secondary radiation exposure from the source.

[0023] In step S103, the preoperative CT data is segmented and reconstructed to generate a three-dimensional skull model. The dental arch model is registered and fused with the three-dimensional skull model. Based on the same coordinate system, the occlusal plate marker model is transferred to the dental arch of the three-dimensional skull model.

[0024] When generating a 3D skull model from preoperative CT data segmentation and reconstruction, the CT processing module of the navigation software segments the CT tomographic data (separating the skull bones, soft tissues, and other structures) and reconstructs it into an STL format 3D skull model. This transforms the CT data from a "two-dimensional tomographic model" into a "three-dimensional operable model," facilitating subsequent registration with the dental arch model. The purpose of registration and fusion is to find a "common reference" between the dental arch model and the 3D skull model. Since the dental arch is part of the skull skeleton, the two have a fixed anatomical relationship. The registration algorithm can accurately locate the dental arch model to the corresponding dental arch position in the 3D skull model. Because the dental arch model and the occlusal plate marker model already have the same coordinate system during the design phase, after the dental arch model and the 3D skull model are registered and fused, the occlusal plate marker model will be "synchronously transferred" to the dental arch of the 3D skull model. At this time, the position of the occlusal plate marker model in CT space completely corresponds to the actual position of the occlusal plate marker worn by the patient during surgery, providing a CT space coordinate reference for subsequent registration.

[0025] In step S104, a point is selected on the transferred occlusal plate marker model to obtain the coordinates of the registration point in the CT image coordinate system. The coordinates of the registration point in the navigation camera coordinate system are obtained by combining the marker configuration file and the coordinates of the marker feature points identified by the navigation camera. The two sets of coordinates are registered and aligned to establish the correspondence between the navigation camera and the CT image coordinate system, and the patient registration is completed.

[0026] In the navigation software, the doctor selects preset registration points (corresponding one-to-one with the physical registration points on the occlusal plate marker model transferred to the CT head model) by clicking the mouse. The navigation software automatically reads the coordinates of these registration points in the CT image coordinate system (denoted as SCT). After the patient wears the occlusal plate marker during the operation, the navigation camera identifies the black and white corner points (i.e., marker feature points) on the marker in real time and obtains the coordinates of the feature points in the navigation camera coordinate system. Then, the marker configuration file generated by the preoperative calibration is loaded, and the coordinates of the registration points in the navigation camera coordinate system (denoted as Scam) are calculated according to the "positional relationship between the registration points and the feature points" in the configuration file. The SCT and Scam are aligned by the registration algorithm (such as the ICP algorithm), and the transformation matrix between the navigation camera coordinate system and the CT image coordinate system is calculated. Once the transformation matrix is ​​determined, the navigation system can convert the "actual position of the patient" captured by the camera during the operation into coordinates in CT space in real time, realizing "precise correspondence between intraoperative operation and preoperative CT planning", thus completing the patient registration.

[0027] In some embodiments, an intraoral scanner is used to acquire the patient's dentition data, which is exported in STL format; the registration points of the occlusal plate markers are evenly and alternately arranged on the inner and outer surfaces of the occlusal plate; during calibration in the navigation software, the marker coordinate system is established by identifying the black and white corner points on the markers using a navigation camera, and the coordinates of the registration points on the occlusal plate are marked onto the marker coordinate system using a probe, and the marker configuration file is output in TXT format.

[0028] Here, the intraoral scanner is a commonly used high-precision data acquisition device in the field of dentistry. Its scanning accuracy can reach the level of 0.01mm, which can completely capture the morphological features of the dental arch (including cusps, pits and fissures, and adjacent relationships) to meet the accuracy requirements of subsequent personalized occlusal plate design. The STL format is a universal format for 3D models. It has the characteristics of small file size and strong compatibility. It can be recognized by most digital design software and navigation software, avoiding errors caused by data format incompatibility.

[0029] In the embodiments of this application, the specific meaning of "uniformly staggered" is: the registration points are distributed on both the inner surface (the side in contact with the dentition) and the outer surface (the side exposed in the oral cavity) of the occlusal plate, and the spacing between the registration points on the same side is uniform (e.g., 10-15mm), while the positions of the registration points on different sides are staggered (to avoid overlapping in the same vertical direction). The advantages of this setting are: on the one hand, setting registration points on both the inner and outer surfaces can increase the number and distribution range of registration points, thereby improving the registration accuracy; on the other hand, the staggered setting can avoid the problem of "some registration points not being recognized" caused by the obstruction of registration points (e.g., instruments obstructing registration points on the outer surface during surgery), ensuring that at least a sufficient number of registration points participate in the calculation.

[0030] The black and white corner points on the markers have the characteristics of "high contrast" and "clear geometric features." The image recognition algorithm of the navigation camera can quickly and accurately locate the corner point coordinates, avoiding coordinate system establishment errors caused by blurred feature points. Typically, at least four black and white corner points are set on the markers, and the corner points are not coplanar to ensure that a unique three-dimensional coordinate system can be established. The probe pen that comes with the navigation system has a high-precision positioning function (usually with a built-in positioning sensor). When the probe pen clicks on the physical registration point on the interlocking plate, the probe pen transmits the coordinates of the registration point to the navigation software in real time. The software then associates the coordinates with the established marker coordinate system to complete the position binding of "registration point-marker coordinate system". The TXT format is a plain text format, which not only occupies little storage space, but can also be opened and edited directly with tools such as Notepad (such as correcting coordinate errors of individual registration points). At the same time, it is convenient for the navigation software to quickly read the data, avoiding reading delays or errors caused by complex formats.

[0031] In some embodiments, see Figure 2 , Figure 2 This is a flowchart illustrating steps S201-S203 provided in the embodiments of this application. The dental arch model and the three-dimensional skull model are registered and fused. Based on the same coordinate system, the occlusal plate marker model is transferred to the dental arch of the three-dimensional skull model. This can be achieved through steps S201-S203, which will be explained in conjunction with each step.

[0032] In step S201, the ICP algorithm is used to register and fuse the dental arch model with the three-dimensional skull model.

[0033] The ICP algorithm (Iterative Closest Point Algorithm) is a classic algorithm in the field of 3D model registration. Its core principle is to iteratively find the closest point pair between two models and calculate the optimal transformation matrix to maximize the overlap between the two models. Compared with other registration algorithms (such as feature-based registration algorithms), the ICP algorithm has the advantages of "high accuracy and strong robustness". It is especially suitable for the registration of models with "high correlation of anatomical structures" such as dental arch models and 3D head models. The cusp and crown morphology of the dental arch model is completely matched with the corresponding parts of the 3D head model. The ICP algorithm can achieve sub-millimeter-level registration accuracy by capturing these subtle morphological features, which meets the accuracy requirements of maxillofacial surgery (usually requiring a registration error of <0.5mm).

[0034] In step S202, during registration and fusion, the tooth arch model and the corresponding identical tooth cusps on the three-dimensional skull model are selected for coarse registration.

[0035] The purpose of coarse registration is to "preliminarily align" the positions of the dental arch model and the 3D head model, providing a good initial position for subsequent fine registration. If fine registration is performed directly, and the initial position deviation between the two models is too large, the ICP algorithm may get stuck in a "local optimum," leading to registration failure. During operation, in the navigation software, first select 1-3 obvious cusps on the dental arch model (such as the cusps of the maxillary central incisors and the cusps of the mandibular first molars), and then find the corresponding cusps on the 3D head model (identified by the morphological features of the cusps reconstructed from CT). Align the two sets of cusps by manually clicking. Since the cusps are significant anatomical landmarks of the dental arch, with fixed positions and easy identification, coarse registration based on these cusps can quickly control the positional deviation between the two models to a small range (usually <5mm), ensuring that subsequent fine registration can successfully converge to the "global optimum."

[0036] In step S203, after coarse registration is completed, the tooth surface is selected for fine registration.

[0037] The purpose of fine registration is to further reduce the positional error between the two models based on coarse registration. In the navigation software, a large area of ​​tooth surface on the dental arch model (such as the buccal and occlusal surfaces of the entire maxillary dentition) is selected, and the corresponding tooth surface area is selected on the 3D head model. The ICP algorithm iteratively calculates all 3D points in these two areas, continuously adjusting the position of the dental arch model until the point cloud overlap of the two areas is the highest (usually requiring an average error of <0.2mm). Compared to coarse registration based only on cusps, fine registration based on tooth surfaces utilizes more positional information (the number of point clouds on tooth surfaces is much greater than that of cusps), which can effectively offset the minor errors in coarse registration and ensure that the registration accuracy between the dental arch model and the 3D head model meets the requirements of subsequent "occlusal plate marker model transfer". If the registration accuracy is insufficient, the position of the transferred occlusal plate marker model in CT space will deviate too much from the actual position, ultimately affecting the accuracy of patient registration.

[0038] In some embodiments, see Figure 3 , Figure 3 This is a flowchart illustrating steps S301-S304 provided in the embodiments of this application. The method also includes marker relay steps S301-S304, which will be explained in conjunction with each step.

[0039] In step S301, when the surgery requires osteotomy or involves multiple procedures or regions, new markers are installed in areas not involved in the surgery.

[0040] In maxillofacial surgery, osteotomy procedures (such as Le Fort I osteotomy and mandibular body osteotomy) can lead to the separation of bone structures. If the original markers are installed on the bone in the osteotomy area (such as markers fixed to the maxilla in existing technology), the markers will shift with the separated bone fragments after the osteotomy, causing the navigation system to be unable to obtain accurate spatial coordinates from the markers, thus rendering the navigation system ineffective. In addition, in multi-operative and multi-regional surgeries such as full-face fracture repair, the operations in different surgical areas may obscure the original markers, making the markers unrecognizable by the camera. Areas not involved in the surgery refer to anatomical areas that will not undergo osteotomy, incision, or other operations (such as the area within the hairline at the top of the skull and the non-surgical area of ​​the mandible). The bone structures in these areas are stable, and the installation of new markers will not cause displacement due to surgical operations, so they can serve as stable benchmarks for subsequent navigation.

[0041] In step S302, the new marker and the currently used marker are simultaneously placed in the navigation camera's field of view. Simultaneous placement in the field of view is a prerequisite for "coordinate system transfer." The navigation system needs to simultaneously identify the feature points of both markers to establish the positional relationship between the "original marker coordinate system" and the "new marker coordinate system." If the two markers cannot be identified simultaneously, the system cannot determine their relative positions, and errors will occur during coordinate system transfer. In actual operation, the angle and position of the navigation camera are adjusted to ensure that the black and white corner points of both markers are clearly displayed within the camera's viewfinder, while avoiding obstruction of the markers by surgical instruments or the patient's head.

[0042] In step S303, the registration operation is re-executed to transfer the navigation system's marker coordinate system to the new marker.

[0043] Here, using the original marker as a reference (whose coordinate system has been linked to the CT coordinate system), the registration point on the new marker is selected in the navigation software, and the coordinates of the registration point in the original marker's coordinate system are obtained (calculated by the camera simultaneously recognizing two markers). Then, combined with the calibration file of the new marker, the correspondence between the new marker's coordinate system and the CT coordinate system is established. At this time, the navigation system's "reference coordinate system" is switched from the original marker to the new marker, and subsequent navigation will use the new marker as a reference to calculate spatial coordinates.

[0044] In step S304, an osteotomy is performed or the original marker is removed. If it is necessary to further expand the surgical area, the marker transfer operation is repeated.

[0045] Here, after the coordinate system transfer is completed, the original marker is no longer used as a navigation reference. Even if the original marker is displaced due to the osteotomy, it will not affect the normal operation of the navigation system. If the original marker obstructs the surgical field of view, the doctor can directly remove the original marker without worrying about navigation failure. For multi-area surgeries (such as full-face fracture repair, involving multiple surgical areas of the maxilla, mandible, and zygomatic bone), the marker relay can be repeated according to the process of "first install the original marker in area A → install the new marker in area B and transfer the coordinate system → osteotomy in area A → install the new marker in area C and transfer the coordinate system → osteotomy in area B". This ensures that the navigation system always has a stable reference marker throughout the entire surgical process, completes the relay registration, and achieves "full surgical coverage".

[0046] In some embodiments, see Figure 4 , Figure 4 This is a flowchart illustrating steps S401-S402 provided in the embodiments of this application. The method further includes steps S401-S402, which will be explained in conjunction with each step.

[0047] In step S401, when fabricating a removable personalized occlusal plate marker before surgery, a fitting structure adapted to the morphology of the occlusal plate is set on the inner surface of the occlusal plate that contacts the patient's dentition.

[0048] In step S402, when the occlusal plate marker is worn during the operation, the occlusal plate is made to fit tightly against the dentition through the fitting structure to prevent the occlusal plate marker from shifting during the operation.

[0049] The fitting structure refers to a "concave-convex matching structure" designed on the inner surface of the occlusal plate according to the specific morphology of the patient's dentition. For example, if there are raised cusps on the dentition, a corresponding groove is designed on the inner surface of the occlusal plate; if there are recessed pits and fissures on the dentition, a corresponding raised ridge is designed on the inner surface of the occlusal plate. In existing technologies, some removable markers are prone to displacement during surgery due to poor fit with the dentition, caused by the patient swallowing, head movement, or collision with surgical instruments, thus affecting the registration accuracy. However, the fitting structure in this solution, through "morphological locking," establishes a stable connection between the occlusal plate and the dentition, preventing the occlusal plate from translating or rotating due to slight external forces. In practical applications, even if the occlusal plate needs to be temporarily removed to check the occlusal relationship, the fitting structure can guide the occlusal plate back to its original position when it is put back on (because of the morphological adaptation, there is only one correct wearing position), ensuring that the positional accuracy after re-wearing is consistent with the initial wearing, and avoiding positional deviations caused by repeated wearing.

[0050] In some embodiments, see Figure 5 , Figure 5This is a flowchart illustrating steps S501-S503 provided in the embodiments of this application. A point is selected on the transferred occlusal plate marker model to obtain the coordinates of the registration point in the CT image coordinate system. The coordinates of the registration point in the navigation camera coordinate system are obtained by combining the marker configuration file and the coordinates of the marker feature points identified by the navigation camera. This can be achieved through steps S501-S503, which will be explained in conjunction with each step.

[0051] In step S501, after obtaining the coordinates of the registration point in the CT image coordinate system, the configuration file of the occlusal plate marker generated by calibration is loaded.

[0052] The marker configuration file records the spatial positional relationship between the registration point and the marker feature point. After loading this file, the navigation software can directly call these positional relationship data without having to remeasure parameters such as the distance and angle between the registration point and the feature point during the operation, which saves operation time and avoids measurement errors during the operation. Each occlusal plate marker corresponds to a unique configuration file (because the size of the occlusal plate marker and the position of the registration point are different for different patients), the navigation software will match the corresponding configuration file through information such as file name and patient ID to avoid coordinate calculation errors caused by loading the wrong file.

[0053] In step S502, the coordinates of the black and white corner points on the bite plate markers are identified by the navigation camera.

[0054] During the procedure, after the patient wears the occlusal marker, the navigation camera captures images of the marker in real time and automatically identifies the pixel coordinates of the black and white corner points using a corner detection algorithm (such as the Harris corner detection algorithm). Then, by combining the camera's intrinsic parameters (such as focal length and pixel size) and extrinsic parameters (such as the camera's position relative to the patient), the pixel coordinates are converted into three-dimensional coordinates in the navigation camera coordinate system. To ensure recognition accuracy, the navigation system can use multi-frame image fusion, continuously capturing multiple frames of marker images and averaging the corner coordinates in each frame to offset instantaneous errors caused by camera shake and changes in lighting, ultimately outputting stable and accurate three-dimensional corner coordinates.

[0055] In step S503, the spatial coordinates of the registration point under the navigation camera are calculated based on the configuration file.

[0056] Let the coordinates of the marker feature points (black and white corner points) in the camera coordinate system be P1, P2, P3..., and the position vector of the registration point relative to the feature point recorded in the configuration file be V (e.g., the vector of registration point A relative to feature point P1 is X-axis +5mm, Y-axis -3mm, Z-axis +2mm). The navigation software will calculate the camera coordinates of the registration point by vector addition based on the camera coordinates of the feature point and the position vector V: Registration point coordinates = Feature point coordinates + Position vector V. Even if the marker rotates slightly during the operation (e.g., a slight change in the angle of the marker due to a small change in the patient's head), as long as the camera can recognize the change in the coordinates of the feature point, the position vector V remains unchanged (it is fixed in the configuration file). The software can recalculate the registration point coordinates using the updated feature point coordinates to ensure that the registration point coordinates are always synchronized with the actual position of the marker.

[0057] In some embodiments, the removable personalized occlusal plate marker is also used to assist in intraoperative intermaxillary ligation to fix the position of the mandible, form a stable occlusal relationship, and simultaneously support global registration of the maxilla and mandible.

[0058] Here, intermaxillary ligation is a common procedure in maxillofacial surgery. Its purpose is to fix the maxilla and mandible together using tools such as ligatures and rubber bands to ensure stable occlusion during surgery (especially in fracture reduction and orthognathic surgery, where stable occlusion is the benchmark for bone repositioning). The occlusal plate marker in this embodiment fits both the upper and lower dentition (designed based on occlusal relationship) and can serve as an auxiliary support for intermaxillary ligation. Compared to traditional intermaxillary ligation (ligation directly on the teeth), the auxiliary effect of the occlusal plate can avoid damage to the teeth caused by the ligatures, while providing a more stable fixation effect (the occlusal plate has a larger coverage area and more even force distribution).

[0059] In existing technologies, markers are only fixed to the maxilla or mandible, establishing a connection between a single jaw and the CT coordinate system, but failing to achieve precise registration of both the maxilla and mandible simultaneously. In contrast, the occlusal plate markers in this solution fit the upper and lower jaw dentition, and the relative positional relationship between the maxilla and mandible remains unchanged after the position is fixed by intermaxillary ligation. Once the occlusal plate markers are registered (established with the CT coordinate system), the maxilla and mandible will also establish a connection with the CT coordinate system along with the occlusal plate markers. The navigation system can simultaneously obtain the coordinates of the maxilla and mandible in CT space, achieving global registration of the maxilla and mandible. The advantage of this global registration is that the surgeon can simultaneously observe the positional changes of the maxilla and mandible during surgery (e.g., when the fracture fragments are reduced, the occlusal relationship of the maxilla and mandible can be compared in real time to see if it is consistent with the preoperative plan), improving surgical precision and efficiency.

[0060] The embodiments of this application will be described in detail below with reference to practical applications. Please refer to [link / reference]. Figure 6 , Figure 6This is one of the schematic diagrams of surgical navigation registration based on intraoral scan registration and marker relay provided in the embodiments of this application, such as... Figure 6 As shown, it includes five subgraphs, 6 (AE).

[0061] 6A shows the dental arch model obtained through intraoral scanning and the dental arch and occlusal plate marker model exported from the digital design software. It demonstrates the process of obtaining a dental arch model through intraoral scanning before surgery, designing occlusal plate markers based on the dental arch model in digital software, and maintaining the same coordinate system when exporting both models. This corresponds to the steps of obtaining dental arch data before surgery, creating occlusal plate markers, and exporting models with the same coordinate system.

[0062] 6B is a physical object of the personalized bite plate marker, which is pre-calibrated in the navigation software. The top image shows the physical bite plate marker made by 3D printing, and the bottom image shows the calibration interface in the navigation software. The camera identifies the corner points of the black and white blocks of the marker, and the probe marks the coordinates of the registration points.

[0063] 6C shows the skull model with an occlusal splint marker, demonstrating the state of the occlusal splint marker on the skull model, and how the occlusal splint can assist in intermaxillary ligation.

[0064] 6D is a navigation software that registers the oral scan dental arch model with the CT-reconstructed 3D model. The navigation software has an interface for selecting coarse registration of cusps and fine registration of tooth surfaces. The ICP algorithm can be used to perform coarse registration first and then fine registration.

[0065] 6E is the process of transferring the occlusal plate marker model to the dentition of the CT 3D model, performing registration point registration, and completing the registration process. The dentition model and the occlusal plate model are in the same coordinate system. After the dentition model and the CT model are registered, the occlusal plate model is synchronously transferred to the dentition of the CT model. Then, the registration is completed by aligning the registration points. This corresponds to the core steps of model transfer, registration point coordinate acquisition, and coordinate system establishment.

[0066] Please see Figure 7 , Figure 7 This is a second schematic diagram of surgical navigation registration based on intraoral scan registration and marker relay provided in the embodiments of this application, such as... Figure 7 As shown, it includes two subgraphs, 7 (AB).

[0067] "7A Skull Model with Second Marker" demonstrates the installation of a new marker (second marker) in an area not involved in the surgery (such as the non-surgical area of ​​the top of the skull). The second marker and the original occlusal plate marker (first marker) are located in different areas of the skull to avoid mutual obstruction.

[0068] 7B Two markers are simultaneously recognized by the camera, and secondary registration is completed in the navigation software to complete the marker coordinate system transfer. The upper image shows the real-time image of the navigation camera capturing two markers at the same time (displaying "Camera normal"). The lower image shows the navigation software registration interface, which displays successful registration and registration point error value. Through secondary registration, the navigation coordinate system is transferred from the first marker to the second marker to ensure that the navigation can still work normally after subsequent osteotomy or removal of the first marker.

[0069] Please see Figure 8 , Figure 8 This is a graph showing the experimental results of the non-inferiority model provided in the embodiments of this application, such as... Figure 8 As shown, the horizontal axis "ΔTRE" represents the difference in target registration error (TRE) between the new registration method and the existing fixed marker registration method (registration error is a non-inferiority index), with a value ranging from -0.20 to 0.20. A value greater than 0 indicates that the new registration method has higher registration accuracy, and a value less than 0 indicates that the traditional fixed marker registration method has higher accuracy. The "NIMTRE (TRE non-inferiority threshold)" value is 0.16. When the 95% confidence interval of the difference between the new registration method and the traditional method falls entirely to the right of the horizontal axis -0.16, it indicates that the registration accuracy of the new registration method is no worse than that of the traditional method. The vertical axis represents different registration methods, including the "marker relay registration" and "removable marker registration, i.e., the occlusal plate marker of this application" in this application, and the comparative methods "simple oral scan registration" and "fixed marker registration". Experimental results show that the "marker relay registration" and "removable marker registration" in the embodiments of this application are more accurate than the traditional methods. The 95% confidence intervals of ΔTRE for both the "simple oral scan registration" and "removable marker registration" methods are greater than -0.16, indicating that the accuracy is no worse than that of the traditional method compared with "fixed marker registration". This proves that the embodiments of this application are no worse than the prior art in terms of registration accuracy, while having their own functional advantages (such as removable and relay).

[0070] In summary, the embodiments of this application have the following beneficial effects: By acquiring dentition data through preoperative intraoral scanning and designing and fabricating removable, personalized occlusal markers, patients are no longer required to wear additional markers for CT scans before surgery, thus avoiding secondary radiation exposure. Furthermore, the occlusal markers are personalized based on the patient's dentition morphology and occlusal relationship, and can be temporarily removed during surgery without affecting occlusal assessment. They also assist in intermaxillary ligation to fix the mandibular position, forming a stable occlusal relationship. This overcomes the limitation of existing technologies that can only register a single jaw, achieving global registration of the maxilla and mandible, aiding in fracture reduction or precise bone fragment positioning and fixation during orthognathic surgery. High-precision registration and fusion of the dentition model and the CT-reconstructed 3D skull model are achieved through the ICP algorithm, relying on the dentition model and the occlusal marker model... The method uses the same coordinate system to transfer the marker model, ensuring registration accuracy. It innovatively introduces marker relay technology, allowing the marker coordinate system to be transferred to a new marker installed in a non-surgical area when surgery requires osteotomy or involves multiple procedures or regions. This effectively solves the problem of navigation failure caused by marker displacement after osteotomy in existing technologies, adapting to complex surgical scenarios such as full-face fracture repair and achieving full procedure coverage. Furthermore, non-inferiority model experiments have verified that this method shows no statistical difference compared to simple intraoral scanning registration, and its accuracy is not inferior to traditional methods compared to conventional fixed marker registration. While ensuring navigation registration accuracy, it significantly improves surgical safety, convenience, and applicability, providing a superior technical solution for maxillofacial surgical navigation.

[0071] Based on the same inventive concept, this application also provides a surgical navigation registration device based on intraoral scan registration and marker relay, which corresponds to the surgical navigation registration method based on intraoral scan registration and marker relay in the first embodiment. Since the principle of the device in this application is similar to the above-mentioned surgical navigation registration method based on intraoral scan registration and marker relay, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0072] like Figure 9 As shown, Figure 9 This is a schematic diagram of the structure of a surgical navigation registration device 900 based on intraoral scan registration and marker relay provided in this application embodiment. The surgical navigation registration device 900 based on intraoral scan registration and marker relay includes: The acquisition module 901 is used to acquire the patient's dentition data before surgery, and to create a removable personalized occlusal plate marker with registration points based on the dentition data and the patient's occlusal relationship. At the same time, it exports the dentition model and the occlusal plate marker model with the same coordinate system. The occlusal plate marker is 3D printed and calibrated in the navigation software to generate a marker configuration file that records the spatial position information of the registration points relative to the marker feature points. Import module 902 is used to import preoperative CT data of patients who are not wearing markers, the dental arch model and the occlusal plate marker model into the surgical navigation software; The registration module 903 is used to segment and reconstruct the preoperative CT data to generate a three-dimensional skull model, register and fuse the dental arch model with the three-dimensional skull model, and transfer the occlusal plate marker model to the dental arch of the three-dimensional skull model based on the same coordinate system of the two. The registration module 904 is used to select points on the transferred occlusal plate marker model to obtain the coordinates of the registration points in the CT image coordinate system, combine the marker configuration file and the coordinates of the marker feature points identified by the navigation camera to obtain the coordinates of the registration points in the navigation camera coordinate system, and align the two sets of coordinates to establish the correspondence between the navigation camera and the CT image coordinate system, thereby completing the patient registration.

[0073] Those skilled in the art should understand that Figure 9 The functions of each unit in the surgical navigation registration device 900 based on intraoral scan registration and marker relay can be understood with reference to the relevant description of the surgical navigation registration method based on intraoral scan registration and marker relay. Figure 9 The functions of each unit in the surgical navigation registration device 900 based on intraoral scan registration and marker relay shown can be implemented by a program running on a processor or by specific logic circuits.

[0074] In one possible implementation, the acquisition module 901 uses an intraoral scanner to acquire the patient's dentition data, which is exported in STL format; the registration points of the occlusal plate markers are evenly and alternately arranged on the inner and outer surfaces of the occlusal plate; during calibration in the navigation software, the marker coordinate system is established by identifying the black and white corner points on the markers using a navigation camera, and the coordinates of the registration points on the occlusal plate are marked under the marker coordinate system using a probe, and the marker configuration file is output in TXT format.

[0075] In one possible implementation, the registration module 903 registers and fuses the dental arch model with the three-dimensional skull model, transferring the occlusal plate marker model onto the dental arch of the three-dimensional skull model based on the same coordinate system of the two, including: The dental arch model and the three-dimensional skull model are registered and fused using the ICP algorithm. During registration and fusion, coarse registration is performed by selecting the same cusps on the dental arch model and the corresponding three-dimensional skull model; After coarse registration is completed, fine registration is performed on the selected tooth surface.

[0076] In one possible implementation, the registration module 904 further includes the following marker relay step: When surgery requires osteotomy or involves multiple procedures or areas, new markers are installed in areas not involved in the surgery. Make the new marker and the currently used marker both appear in the navigation camera's field of view simultaneously; Re-execute the registration operation to transfer the navigation system's marker coordinate system to the new marker; Perform osteotomy or remove the original markers. If it is necessary to further expand the surgical area, repeat the marker transfer procedure.

[0077] In one possible implementation, it also includes: When fabricating a removable, personalized occlusal plate marker before surgery, a fitting structure adapted to the morphology of the occlusal plate is set on the inner surface of the occlusal plate that contacts the patient's dentition. When the occlusal plate marker is worn during the procedure, the fitting structure ensures that the occlusal plate fits tightly against the dentition, thus preventing the occlusal plate marker from shifting during the procedure.

[0078] In one possible implementation, the registration module 904 selects a point on the transferred occlusal plate marker model to obtain the coordinates of the registration point in the CT image coordinate system, and obtains the coordinates of the registration point in the navigation camera coordinate system by combining the marker configuration file and the coordinates of the marker feature points identified by the navigation camera, including: After obtaining the coordinates of the registration points in the CT image coordinate system, load the occlusal plate marker configuration file generated during calibration; The navigation camera identifies the coordinates of the black and white corner points on the bite plate markers. The spatial coordinates of the registration point under the navigation camera are calculated based on the configuration file.

[0079] In one possible implementation, the removable personalized occlusal plate marker is also used to assist in intraoperative intermaxillary ligation to fix the position of the mandible, form a stable occlusal relationship, and simultaneously support global registration of the maxilla and mandible.

[0080] The aforementioned surgical navigation registration device, based on intraoral scan registration and marker relay, acquires dentition data through preoperative intraoral scanning and designs and manufactures removable, personalized occlusal plate markers. This eliminates the need for patients to wear additional markers for preoperative CT scans, thus avoiding secondary radiation exposure. Furthermore, the occlusal plate markers are personalized based on the patient's dentition morphology and occlusal relationship, and can be temporarily removed during surgery without affecting occlusal assessment. It also assists in intermaxillary ligation to fix the mandibular position, forming a stable occlusal relationship. This overcomes the limitation of existing technologies that can only register a single jaw, achieving global registration of the maxilla and mandible, and aiding in precise bone positioning and fixation during fracture reduction or orthognathic surgery. The device utilizes the ICP algorithm to achieve high-precision registration and fusion of the dentition model and the CT-reconstructed 3D skull model, and relies on… The transfer of marker models is completed using the same coordinate system for the dental arch model and the occlusal plate marker model, ensuring registration accuracy. An innovative marker relay technology is introduced, allowing the marker coordinate system to be transferred to a new marker installed in a non-surgical area when osteotomy is required or when multiple procedures or regions are involved. This effectively solves the problem of navigation failure caused by marker displacement after osteotomy in existing technologies, adapting to complex surgical scenarios such as full-face fracture repair and achieving full procedure coverage. Furthermore, non-inferiority model experiments have verified that this method shows no statistical difference compared to simple intraoral scanning registration, and its accuracy is not inferior to traditional methods compared to conventional fixed marker registration. While ensuring navigation registration accuracy, it significantly improves surgical safety, convenience, and applicability, providing a superior technical solution for maxillofacial surgical navigation.

[0081] like Figure 10 As shown, Figure 10 This is a schematic diagram of the composition structure of the electronic device 1000 provided in the embodiments of this application. The electronic device 1000 includes: The device 1000 includes a processor 1001, a storage medium 1002, and a bus 1003. The storage medium 1002 stores machine-readable instructions executable by the processor 1001. When the electronic device 1000 is running, the processor 1001 communicates with the storage medium 1002 via the bus 1003. The processor 1001 executes the machine-readable instructions to perform the steps of the surgical navigation registration method based on intraoral scan registration and marker relay as described in the embodiments of this application.

[0082] In practical applications, the various components in the electronic device 1000 are coupled together via a bus 1003. It is understood that the bus 1003 is used to achieve communication between these components. In addition to a data bus, the bus 1003 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 10 The general labeled all buses as Bus 1003.

[0083] The aforementioned electronic device acquires dentition data through preoperative intraoral scanning and designs and manufactures removable, personalized occlusal plate markers. This eliminates the need for patients to wear additional markers for preoperative CT scans, thus avoiding secondary radiation exposure. Furthermore, the occlusal plate markers are personalized based on the patient's dentition morphology and occlusal relationship, and can be temporarily removed during surgery without affecting occlusal assessment. They also assist in intermaxillary ligation to fix the mandibular position, forming a stable occlusal relationship. This overcomes the limitation of existing technologies that can only register a single jaw, achieving global registration of the maxilla and mandible, aiding in fracture reduction or precise bone fragment positioning and fixation during orthognathic surgery. The device utilizes the ICP algorithm to achieve high-precision registration and fusion of the dentition model and the CT-reconstructed 3D skull model, relying on the dentition model and occlusal plate markers... The method uses the same coordinate system of the object model to complete the transfer of the marker model, ensuring registration accuracy. It innovatively introduces marker relay technology, which can transfer the coordinate system of the marker to a new marker installed in a non-surgical area when the surgery requires osteotomy or involves multiple procedures and regions. This effectively solves the problem of navigation failure caused by marker displacement after osteotomy in existing technologies, and is suitable for complex surgical scenarios such as full facial fracture repair, achieving full procedure coverage. Moreover, the non-inferiority model experiment verified that this method has no statistical difference compared with simple intraoral scanning registration, and its accuracy is not inferior to traditional methods compared with existing conventional fixed marker registration. While ensuring navigation registration accuracy, it significantly improves surgical safety, convenience and applicability, providing a better technical solution for maxillofacial surgery navigation.

[0084] This application also provides a computer-readable storage medium storing executable instructions. When the executable instructions are executed by at least one processor 1001, the surgical navigation registration method based on intraoral scan registration and marker relay described in this application is implemented.

[0085] In some embodiments, the storage medium may be a magnetic random access memory (FRAM), a read-only memory (ROM), or a programmable read-only memory (PROM). Erasable Programmable Read-Only Memory (EPROM) Electrically Erasable Programmable Read-Only Memory (EEPROM) Read-only memory, flash memory, magnetic surface storage, optical disc, or CD-ROM ROM, Compact Disc Read It can be a memory such as a memory only; or it can be a device that includes one or any combination of the above-mentioned memories.

[0086] In some embodiments, executable instructions may take the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0087] As an example, executable instructions may, but do not necessarily, correspond to files in the file system. They may be stored as part of a file that holds other programs or data, for example, in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple collaborating files (e.g., a file that stores one or more modules, subroutines, or code sections).

[0088] As an example, executable instructions can be deployed to execute on a single computing device, or on multiple computing devices located in one location, or on multiple computing devices distributed across multiple locations and interconnected via a communication network.

[0089] The aforementioned computer-readable storage medium acquires dentition data through preoperative intraoral scanning and designs and manufactures removable, personalized occlusal markers. This eliminates the need for patients to wear additional markers and undergo CT scans before surgery, thus avoiding secondary radiation exposure. Furthermore, the occlusal markers are personalized based on the patient's dentition morphology and occlusal relationship, and can be temporarily removed during surgery without affecting occlusal assessment. They also assist in intermaxillary ligation to fix the mandibular position, forming a stable occlusal relationship. This overcomes the limitation of existing technologies that can only register a single jaw, achieving global registration of the maxilla and mandible, aiding in precise bone fragment positioning and fixation during fracture reduction or orthognathic surgery. The ICP algorithm enables high-precision registration and fusion of the dentition model and the CT-reconstructed 3D skull model, and relies on the dentition model and occlusion... The same coordinate system of the plate marker model completes the marker model transfer, ensuring registration accuracy. An innovative marker relay technology is introduced, allowing the marker coordinate system to be transferred to a new marker installed in a non-surgical area when surgery requires osteotomy or involves multiple procedures or regions. This effectively solves the problem of navigation failure caused by marker displacement after osteotomy in existing technologies, adapting to complex surgical scenarios such as full-face fracture repair and achieving full procedure coverage. Furthermore, non-inferiority model experiments have verified that this method shows no statistical difference compared to simple intraoral scanning registration, and its accuracy is not inferior to traditional methods compared to conventional fixed marker registration. While ensuring navigation registration accuracy, it significantly improves surgical safety, convenience, and applicability, providing a superior technical solution for maxillofacial surgical navigation.

[0090] In the several embodiments provided in this application, it should be understood that the disclosed methods and electronic devices can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0091] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0092] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0093] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a platform server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0094] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A surgical navigation registration method based on intraoral scan registration and marker relay, characterized in that, The method includes: Before the operation, the patient's dentition data is obtained. Based on the dentition data and the patient's occlusal relationship, a removable personalized occlusal plate marker with registration points is made. At the same time, the dentition model with the same coordinate system and the occlusal plate marker model are exported. The occlusal plate marker is 3D printed and calibrated in the navigation software to generate a marker configuration file that records the spatial position information of the registration points relative to the marker feature points. Import the preoperative CT data of patients who did not wear markers, the dental arch model, and the occlusal plate marker model into the surgical navigation software; The preoperative CT data is segmented and reconstructed to generate a three-dimensional skull model. The dental arch model is registered and fused with the three-dimensional skull model. Based on the same coordinate system, the occlusal plate marker model is transferred to the dental arch of the three-dimensional skull model. Select a point on the transferred occlusal plate marker model to obtain the coordinates of the registration point in the CT image coordinate system. Combine the marker configuration file and the coordinates of the marker feature points identified by the navigation camera to obtain the coordinates of the registration point in the navigation camera coordinate system. Register and align the two sets of coordinates to establish the correspondence between the navigation camera and the CT image coordinate system, and complete the patient registration.

2. The surgical navigation registration method based on intraoral scan registration and marker relay according to claim 1, characterized in that, The patient's dentition data is acquired using an intraoral scanner and exported in STL format. The registration points of the occlusal plate markers are evenly and alternately set on the inner and outer surfaces of the occlusal plate. During calibration in the navigation software, the black and white corner points on the markers are identified by the navigation camera to establish a marker coordinate system. The coordinates of the registration points on the occlusal plate are marked onto the marker coordinate system using a probe. The marker configuration file is output in TXT format.

3. The surgical navigation registration method based on intraoral scan registration and marker relay according to claim 1, characterized in that, The dental arch model is registered and fused with the three-dimensional skull model. Based on the same coordinate system, the occlusal plate marker model is transferred to the dental arch of the three-dimensional skull model, including: The dental arch model and the three-dimensional skull model are registered and fused using the ICP algorithm. During registration and fusion, coarse registration is performed by selecting the same cusps on the dental arch model and the corresponding three-dimensional skull model; After coarse registration is completed, fine registration is performed on the selected tooth surface.

4. The surgical navigation registration method based on intraoral scan registration and marker relay according to claim 1, characterized in that, This also includes the following marker relay steps: When surgery requires osteotomy or involves multiple procedures or areas, new markers are installed in areas not involved in the surgery. Make the new marker and the currently used marker both appear in the navigation camera's field of view simultaneously; Re-execute the registration operation, transfer the navigation system's marker coordinate system to the new marker, and update the marker configuration file in the system; Perform osteotomy or remove the original markers. If it is necessary to further expand the surgical area, repeat the marker transfer procedure.

5. The surgical navigation registration method based on intraoral scan registration and marker relay according to claim 1, characterized in that, The method further includes: When fabricating a removable, personalized occlusal plate marker before surgery, a fitting structure adapted to the morphology of the occlusal plate is set on the inner surface of the occlusal plate that contacts the patient's dentition. When the occlusal plate marker is worn during the procedure, the fitting structure ensures that the occlusal plate fits tightly against the dentition, thus preventing the occlusal plate marker from shifting during the procedure.

6. The surgical navigation registration method based on intraoral scan registration and marker relay according to claim 1, characterized in that, Selecting points on the transferred occlusal plate marker model to obtain the coordinates of the registration points in the CT image coordinate system, and combining the marker configuration file and the coordinates of the marker feature points identified by the navigation camera to obtain the coordinates of the registration points in the navigation camera coordinate system, including: After obtaining the coordinates of the registration points in the CT image coordinate system, load the occlusal plate marker configuration file generated during calibration; The navigation camera identifies the coordinates of the black and white corner points on the bite plate markers. The spatial coordinates of the registration point under the navigation camera are calculated based on the configuration file.

7. The surgical navigation registration method based on intraoral scan registration and marker relay according to claim 1, characterized in that, The removable personalized occlusal plate marker is also used to assist in intermaxillary ligation during surgery to fix the position of the mandible and form a stable occlusal relationship, while simultaneously supporting global registration of the maxilla and mandible.

8. A surgical navigation registration device based on intraoral scan registration and marker relay, characterized in that, The device includes: The acquisition module is used to acquire the patient's dentition data before surgery, and to create a removable personalized occlusal plate marker with registration points based on the dentition data and the patient's occlusal relationship. At the same time, it exports the dentition model and the occlusal plate marker model with the same coordinate system. The occlusal plate marker is 3D printed and calibrated in the navigation software to generate a marker configuration file that records the spatial position information of the registration points relative to the marker feature points. The import module is used to import the preoperative CT data of patients who are not wearing markers, the dental arch model, and the occlusal plate marker model into the surgical navigation software. The registration module is used to segment and reconstruct the preoperative CT data to generate a three-dimensional skull model, register and fuse the dental arch model with the three-dimensional skull model, and transfer the occlusal plate marker model to the dental arch of the three-dimensional skull model based on the same coordinate system of the two. The registration module is used to select points on the transferred occlusal plate marker model to obtain the coordinates of the registration points in the CT image coordinate system, combine the marker configuration file and the coordinates of the marker feature points identified by the navigation camera to obtain the coordinates of the registration points in the navigation camera coordinate system, and align the two sets of coordinates to establish the correspondence between the navigation camera and the CT image coordinate system, thereby completing patient registration.

9. An electronic device, characterized in that, include: The device includes a processor, a storage medium, and a bus, wherein the storage medium stores machine-readable instructions executable by the processor, and when the electronic device is in operation, the processor communicates with the storage medium via the bus, and the processor executes the machine-readable instructions to perform the surgical navigation registration method based on intraoral scan registration and marker relay as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the surgical navigation registration method based on intraoral scan registration and marker relay as described in any one of claims 1 to 7.

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