An umbrella scanning method and system for edentulous jaws or dentition defects

Abstract

The present invention relates to the field of intraoral scanning for implant restoration, and particularly to an umbrella-shaped scanning method and system for tooth agenesis or dentition defect, including providing a plurality of positioning bodies, each positioning body being provided with an identification body at least including a top feature, a cutting surface geometry and curve feature, and an auxiliary rod recognition body; presetting a CAD model corresponding to each identification body; obtaining the design of the teeth this time, and obtaining the point cloud data of the plurality of positioning bodies through an intraoral scanner; preprocessing the point cloud data to remove background noise and non-target point cloud, and automatically identifying and segmenting to extract the feature point cloud of each identification body; processing the feature point cloud with the CAD model to output a registration result. In the scanning process of the present invention, the feature point cloud is accurately extracted through automatic recognition and segmentation technology, an initial transformation matrix is constructed using four coplanar key points, and the transformation matrix is optimized through iterative least squares method, so as to improve the accuracy of scanning data and the quality of model reconstruction.

Description

Technical Field

[0001] The present invention relates to the field of intraoral scanning for implant restoration, and particularly to an umbrella-shaped scanning method and system for dentition defect or dentition loss. Background Art

[0002] Digital intraoral scanning is a key technology for digital impression taking in oral implant restoration. Based on the principle of optical scanning, this technology projects light sources such as lasers into the mouth, performs depth reconstruction in real time, obtains local point cloud data, fuses the point cloud data using point cloud registration algorithms, and then generates three-dimensional mesh data using reconstruction algorithms to scan the morphology of intraoral tissues in real time. In the digital design stage of implant restoration, a scanning rod is used to connect to an implant or an implant abutment during scanning to obtain the three-dimensional morphology of the scanning rod, the surrounding dentition, and soft tissues. And the exact three-dimensional position of the implant is calculated through these data.

[0003] In the prior art, since the scanning rod is usually cylindrical and mainly positioned on the side, the scanning area at the top is small and lacks sufficient geometric morphological features, making it impossible to quickly and accurately obtain the three-dimensional morphology of the scanning rod with this conventional strategy. The scanning strategy directly affects the scanning accuracy. Previous studies on natural teeth have shown that the method starting from the occlusal surface to the palatal side and then to the buccal side has relatively high accuracy.

[0004] The method starting from the occlusal surface to the palatal side and then to the buccal side further includes scanning of the occlusal surface of the tooth, the side near the palate on the inner side of the tooth (palatal side), and the side near the cheek on the outer side of the tooth (buccal side):

[0005] Scanning the occlusal surface: First, scan the occlusal surface of the tooth, which is the upper or lower surface where the teeth contact each other. The scanner moves over the tooth to capture a detailed image of the occlusal surface.

[0006] Scanning the palatal (lingual) side: Next, the scanner moves to the inner side of the tooth, i.e., the part near the palate (lingual side) of the oral cavity. The dentist or technician carefully inserts the scanner into the mouth while capturing an image of the palatal side.

[0007] Scanning the buccal side: Then, the scanner moves to the outer side of the tooth, i.e., the part near the buccal side.

[0008] During the scanning process, the dentist or technician ensures that every corner of the tooth is scanned, including the contact points between the teeth and the junction between the teeth and the gums. After the scanning is completed, the device integrates the captured data into a complete three-dimensional model. This model can be used for diagnosis, treatment planning, or fabricating restorations.

[0009] However, the occlusal surface area of the conventional scanning rod is small and has no obvious characteristic morphology, so the above scanning strategy cannot be realized. Therefore, the present invention needs a new scanning strategy for dentition defect or dentition loss. Summary of the Invention

[0010] The object of the present invention is to address the above technical problems and propose an umbrella scanning method and system for edentulous or dentition defect. The object of the present invention can be achieved by the following technical solutions:

[0011] The present invention provides an umbrella scanning method for edentulous or dentition defect, comprising the following steps:

[0012] Provide a plurality of positioning bodies, each positioning body comprising a scanning rod body and an auxiliary rod disposed on the side of the scanning rod body, and each positioning body is provided with an identification body including at least a top feature, a cutting surface geometry and curve feature, and an auxiliary rod identification body;

[0013] Preset a CAD model corresponding to each identification body in advance;

[0014] Obtain the design of the teeth this time: select an appropriate length of the auxiliary rod according to the distance between two adjacent implant composite abutments, and the scanning rod body is configured to be installed on each implant composite abutment,

[0015] Obtain the point cloud data of a plurality of positioning bodies through an intraoral scanner;

[0016] Preprocess the point cloud data to remove background noise and non-target point clouds, and automatically identify and segment to extract the feature point clouds of each identification body;

[0017] Process the feature point clouds with the CAD model to output a registration result; until the termination condition of registration is met, output the corresponding point cloud model.

[0018] Further, processing the feature point clouds with the CAD model to output a registration result including:

[0019] Select four coplanar key points through the feature point clouds, and calculate a preliminary transformation matrix based on the four coplanar key points for preliminary alignment with the CAD model of the scanning rod body;

[0020] Use the preliminary transformation matrix as input for iterative optimization, and in each iteration process, perform corresponding update selection and translation according to the minimum distance error between the position of the feature point clouds and the CAD model.

[0021] Further, it also includes, in each iteration process, calculating the overlap degree of two majority feature point clouds under the current transformation, where the overlap degree is the ratio of the number of overlapping points to the total number of points, for quantifying the alignment accuracy; when the overlap degree is lower than a preset threshold, adjust the I CP algorithm parameters, and the parameters include the number of iterations, adjusting the search range or optimizing the distance metric standard.

[0022] Further, the termination conditions include whether the threshold of the number of iterations is reached, whether the error reaches a predetermined upper threshold, or a combination of the number of iterations and the error threshold.

[0023] Further, obtaining the point cloud data of multiple positioning bodies by an intraoral scanner includes:

[0024] Using the intraoral scanner to scan the implant from the top preferentially to obtain the three-dimensional position data of multiple positioning bodies, providing accurate reference points for subsequent scans;

[0025] Start scanning from the occlusal surface of the oral cavity at the top of the scanning rod installed on the implant, and perform locked scanning based on the top features of the scanning rod;

[0026] Scan the scanning rod from the buccal and lingual sides of the oral cavity, identify the geometric and curve features of the cutting surface, and obtain the point cloud data of the points where the scanning rod contacts adjacent teeth, the scanning rod or soft tissues;

[0027] Scan the gingival soft tissue with less impact on the accuracy to complete the scanning of the soft tissue.

[0028] Based on the same inventive concept, the present invention also provides an umbrella-type scanning system for edentulous or dentition defect, including multiple positioning bodies, a scanner scanning head and a scanning control device:

[0029] Multiple positioning bodies, each positioning body includes a scanning rod body and an auxiliary rod arranged on the side of the scanning body, and each positioning body is provided with identification bodies including at least top features, cutting surface geometric and curve features, and auxiliary rod identification bodies; select the appropriate length of the auxiliary rod according to the distance between two adjacent implant composite abutments, and the scanning rod body is configured to be installed on the composite abutment of each implant,

[0030] The scanner scanning head, obtaining the point cloud data of multiple positioning bodies through an intraoral scanner;

[0031] The scanning control device is configured to: preset the CAD model corresponding to each identification body;

[0032] Preprocess the point cloud data to remove background noise and non-target point clouds, and automatically identify and segment and extract the feature point clouds of each identification body;

[0033] Process the feature point clouds with the CAD model to output the registration result; until the termination condition of registration is met, output the corresponding point cloud model.

[0034] Compared with the prior art, the present invention has at least one of the following technical effects:

[0035] The present invention provides a digital umbrella scanning method for edentulous or dentition defect, which scans a plurality of positioning bodies with specific geometric and curve features installed on implants. Each positioning body includes a scanning rod body equipped with a side auxiliary rod. These positioning bodies correspond to a preset CAD model, allowing the length of the auxiliary rod to be adjusted according to the distance between implants, thereby ensuring precise installation. During the scanning process, the point cloud data collected by the intraoral scanner is preprocessed to remove background noise and non-target point clouds, and the feature point clouds are accurately extracted through automatic recognition and segmentation techniques. An initial transformation matrix is constructed using four coplanar key points to achieve a preliminary alignment of the point cloud data with the CAD model. The transformation matrix is optimized through iterative least squares method for further fine adjustment of the alignment, effectively reducing the error between the point cloud and the model. Thereby improving the accuracy of the scanned data and the quality of model reconstruction, significantly enhancing the accuracy of oral implant restoration design and the reliability of implementation, and solving the problem that the current traditional intraoral scanning technology often has a simple geometric shape (such as cylindrical) of the scanning rod and a small area in the occlusal surface region, lacking sufficient geometric features, resulting in difficulty in accurately capturing complex internal details. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments:

[0037] Figure 1 It is a flowchart of the steps of the umbrella scanning method in the embodiment of the present invention;

[0038] Figure 2 It is a schematic installation diagram of the positioning body under edentulous in the embodiment of the present invention;

[0039] Figure 3 It is a data processing flowchart of the intraoral scanner scanning the positioning body in the embodiment of the present invention;

[0040] Figure 4 It is a point cloud matching calculation diagram of the intraoral scanner scanning the positioning body in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] The present invention will be described below with reference to specific embodiments and certain drawings, but the present invention is not limited thereto. Any of the described drawings is illustrative and non-limiting. In the drawings, for the purpose of illustration, the dimensions of some elements may be enlarged and not drawn to scale. The dimensions and relative dimensions do not necessarily correspond to the actual examples of implementing the present invention.

[0042] Furthermore, the terms first, second, third, etc. in the description and claims are used to distinguish similar elements and are not necessarily used to describe an order or temporal sequence. The terms are interchangeable where appropriate, and embodiments of the present invention may operate in other sequences than those described or shown herein.

[0043] In addition, the terms "top", "bottom", "upper", "lower", "side", "lateral", etc. in the description and claims are used for descriptive purposes and are not necessarily used to describe relative position. The terms so used are interchangeable where appropriate, and embodiments of the present invention described herein may operate in other orientations than those described or shown herein.

[0044] The term "comprising" used in the claims should not be construed as limited to the means listed thereafter; it does not exclude other elements or steps. It is to be interpreted as specifying the presence of the stated features, integers, steps or components but does not exclude the presence or addition of one or more other features, integers, steps or components or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B, which means that the only relevant components of the device with respect to the present invention are A and B.

[0045] In the context of the present invention, a marker is understood to include any 2D or 3D geometric object capable of defining a predefined reference point, the coordinates of which can be determined. The types of suitable markers are essentially not limited. Preferred markers have regular geometric shapes because the predefined reference point of the marker can be easily defined or even be intuitive. Suitable markers can be, for example, an equilateral triangle, a square, a rectangle, a circle or a regular polygon, where, for example, the center point can be considered as the predefined reference point. Suitable markers can also be line segments, where the midpoint can be considered as the predefined reference point. Suitable 3D markers can be, for example, a sphere, a hemisphere or a cube, the center point of which can then be considered as the predefined reference point. The applicant has found that the size and shape of the markers can vary within a very wide range, and markers of different shapes and / or sizes can be used as part of the same pattern. The applicant has found that the contrast between the marker and its surroundings can be further enhanced by adding a strongly contrasting edge around the marker.

[0046] In the context of the present invention, pre - calibration is understood to mean an identification process, including its result, in which identification techniques are applied to identify in a clinical situation in connection with a given type of implant or various implants, in order to obtain all the information necessary to retrieve the implant position and orientation from the pattern formed by the markers that are part of the scan positioning. The information thus collected forms reference information in the process of correlating the implant type or equivalent in the clinical situation presented inter - orally in a visualization mode.

[0047] In the context of the present invention, the "vector" of a dental implant or implant root is defined as spatial information that first defines the orientation axis of the dental implant root. The carrier further includes the position of the top of the dental implant root along the orientation axis. Thus, the top is defined as the surface corresponding to the height of the implant root.

[0048] An explanation of the creative process of the present invention will be given.

[0049] The inventor's clinical research found that: the current intraoral scanning technology faces the problem of insufficient accuracy in the application of edentulous jaw scanning. Since the lack of teeth in edentulous patients results in the lack of obvious geometric features in soft tissues, which limits the availability of necessary geometric features during the scanning process. Secondly, mucosal soft tissues such as the buccal and lingual sides in the mouth may introduce data noise during the scanning process. As the amount of scanned data increases, the cumulative error will gradually increase, further reducing the scanning accuracy. Although some studies have tried to enhance the geometric features in the soft tissue transition stage by adding auxiliary devices to the scanning rod, this method has achieved certain results in improving the accuracy of edentulous jaw implant scanning, but it still has not reached the accuracy level comparable to that of single-tooth or multi-tooth implant restorations. In addition, the conventional implant scanning strategy usually first scans the occlusal surface of the dental arch and then scans the buccal or lingual side of the dental arch. This method has been proven to provide high scanning accuracy in single-tooth or multi-tooth implants. In natural teeth and dental crown restorations, the soft tissue transition area is part of the dental crown contour. For edentulous jaw implant restorations, this transition area is mainly soft tissue.

[0050] In modern oral implant and restoration procedures, obtaining accurate intraoral three-dimensional images is crucial for successful edentulous jaw implant restoration. Currently, most intraoral scanners rely on optical technology to scan inside the mouth through lasers or other light sources to obtain detailed images of implants and their surrounding soft tissues. However, for edentulous patients, since the implants are usually buried under the bone and there are no reliable geometric feature points in the mouth, traditional cylindrical scanning rods often have difficulty providing sufficient accuracy to guide the precise positioning of implants. This is mainly because the shape and size of traditional scanning rods limit their scanning range and feature point capture ability inside the mouth.

[0051] In view of these limitations of the prior art, the present invention provides an umbrella scanning method and system for edentulous or dentition defect, the system being composed of a plurality of positioning bodies, each positioning body including a scanning rod body and an auxiliary rod disposed on the side surface of the scanning rod body. The positioning body not only includes top features, cutting surface geometric forms, and auxiliary rods on the side surface of the scanning rod body, which are used to enhance the recognition of geometric features in the soft tissue transition stage, cooperate with automatic feature point cloud matching and iterative optimization of the ICP algorithm to improve the alignment accuracy between the point cloud data and the model. By selecting four coplanar key points to construct a transformation matrix and performing continuous iteration, the optimization process takes into account the overlap degree and minimum distance error of the point cloud, further finely adjusts the alignment, and ensures that the finally output model meets the high-precision standard by setting termination conditions. This umbrella scanning method is not only applicable to conventional edentulous restoration, but also particularly suitable for complex implant restoration of edentulous jaws.

[0052] The First Embodiment

[0053] In this embodiment, for the situation of edentulous or severely defective dentition, conventional scanning methods often have difficulty in capturing accurate three-dimensional data due to the lack of stable reference points. This embodiment introduces a positioning rod with a plurality of identification bodies including at least top features, cutting surface geometry and curve features, and auxiliary rod identification bodies, which improves the feature recognition ability during intraoral scanning to ensure the accuracy of data. At the same time, an automated feature point cloud registration and alignment algorithm is adopted to improve the automation degree of data processing and the accuracy of the final result. The specific implementation is as follows:

[0054] As Figures 1 to 4 shown, the present invention provides an umbrella scanning method for edentulous or dentition defect. This method uses a plurality of positioning bodies, each positioning body including a scanning rod body and an auxiliary rod disposed on the side surface of the scanning rod body. Each positioning body is provided with an identification body including at least top features, cutting surface geometry and curve features, and auxiliary rod identification bodies; each identification body is relative to a pre-set CAD model to ensure the accuracy and reproducibility of scanning. During the scanning process, first, the length of the auxiliary rod is selected according to the distance between two adjacent implant composite abutments. The scanning rod body is configured to be installed on each implant composite abutment, and an intraoral scanner is used to collect the point cloud data of the positioning body. Then, the point cloud data is pre-processed to remove background noise and non-target point clouds. Through edge detection and curve fitting, the feature point clouds of each identification body are automatically identified and segmented and extracted; the registration result is output by processing these feature point clouds with the CAD model; until the termination condition of registration is met, the corresponding point cloud model is output.

[0055] Among them, these feature point clouds are processed with the CAD model, and the output registration results include: First, four coplanar key points are selected through the feature point clouds, and a preliminary transformation matrix is calculated based on the four coplanar key points for preliminary alignment with the CAD model of the scanning rod body; Subsequently, the preliminary transformation matrix is used as the input for iterative optimization, and in each iteration process, corresponding update selection and translation are performed according to the minimum distance error between the position of the feature point cloud and the CAD model. In each iteration process, the overlap degree of the two majority feature point clouds under the current transformation is calculated, and the overlap degree is the ratio of the number of overlapping points to the total number of points, which is used to quantify the alignment accuracy; When the overlap degree is lower than the preset threshold, the ICP algorithm parameters are adjusted, and the parameters include the number of iterations, the adjusted search range, or the optimized distance metric standard. The termination conditions include whether the threshold of the number of iterations is reached, whether the error reaches the upper limit of the predetermined threshold, or a combination of the number of iterations and the error threshold.

[0056] The specific registration process is as Figure 4 shown. Four coplanar key points are determined. First, the vector ac and the vector ab are calculated, and the corresponding normal vector is calculated using the vector cross product formula The normal vector is perpendicular to the plane formed by points a, b, and c. The fourth point d is verified for coplanarity through the normal vector. The dot product of the vector ad and the normal vector is calculated. Considering the numerical accuracy, if the dot product is close to zero, then point d is also on this plane. Then, the preliminary transformation matrix is estimated through the four coplanar points. Specifically, the geometric center e of the four points and the center e' of the corresponding points in the target point cloud are found. The optimal rotation matrix R and translation vector t are calculated using the positions of the four points in the original and target clouds. Specifically, the least squares method is used in point cloud registration to determine the rotation matrix R and translation vector t to minimize the total registration error, that is, by minimizing ∑||(R*p +t)-p' i +t)-p' i || 2 to complete, where pi and p' i are the corresponding points in the original and target point clouds.

[0057] When there is a preliminary transformation matrix, it is optimized iteratively. In each iteration, the nearest corresponding points are found for the points after the current transformation, and the transformation matrix is recalculated based on the newly found corresponding point pairs to further reduce the average distance between points. When the update amount of the transformation matrix is less than a certain threshold, or the preset number of iterations is reached, or the error between the point clouds is small enough, the algorithm terminates.

[0058] As Figure 2 and Figure 4As shown, multiple scanning rod bodies are designed with an umbrella-shaped scanning part and its corresponding connecting part. The top of the umbrella-shaped scanning part is equipped with a first top surface, on both sides of which are symmetrically arranged a first cutting surface and a second cutting surface with unique geometric shapes. These cutting surfaces extend outward from the first top surface, forming distinct intersection lines with each other and with the first top surface. This constitutes a structure with anisotropy at the top, greatly enhancing the recognition and positioning ability of the scanning rod in an intraoral scanning device, especially from the perspective of the top of the rod body. In addition, the auxiliary rod in this design has a unique function to eliminate noise and unnecessary data generated during scanning. Through its specially designed structure and materials, the auxiliary rod can reduce reflection and scattering in the scanned data, optimizing the quality of the data. During the data processing stage, the configuration of the auxiliary rod allows the algorithm to more effectively separate and eliminate non-target point clouds, improving the clarity and usability of the final image. This integrated elimination function not only simplifies the subsequent data processing steps but also provides more accurate and reliable scanning results.

[0059] Therefore, by integrating the registration algorithm and optimizing for the complex geometric features at the top of the umbrella-shaped scanning part, it is possible to quickly and accurately identify and position, effectively processing the unique data points generated by the umbrella-shaped structure. This not only enhances the automation level of the scanning process but also ensures high reproducibility and precise alignment of the data, greatly supporting complex dental restoration and implant operations.

[0060] Meanwhile, obtaining the point cloud data of multiple positioning bodies through an intraoral scanner includes: as Figure 2 shown, using the intraoral scanner to first scan the implant from the top to obtain the three-dimensional position data of multiple positioning bodies, providing accurate reference points for subsequent scanning; then, starting from the occlusal surface of the oral cavity, scan the top of the scanning rod installed on the implant and perform locked scanning based on the top features of the scanning rod; that is, accurately position through the top features of the scanning rod, and at the same time ensure the horizontal alignment of the scanning rod with the bottom of the oral cavity through locked scanning, then turn to scan the scanning rod on the buccal and lingual sides of the oral cavity, identify the cutting geometry and curve features of the scanning rod, obtain the point cloud data of the contact between the scanning rod and adjacent teeth, scanning rod or soft tissue, improving the overall scanning accuracy, and finally also includes scanning the gingival soft tissue with less impact on accuracy to complete the scanning of the soft tissue and ensure the comprehensiveness of the data.

[0061] Second Embodiment

[0062] An umbrella-type scanning system for edentulous or dentate defects, comprising multiple positioning bodies, a scanner scanning head, and a scanning control device:

[0063] Multiple positioning bodies, each positioning body includes a scanning rod body and an auxiliary rod arranged on the side of the scanning body, and each positioning body is provided with identification bodies including at least top features, cutting surface geometry and curve features, and auxiliary rod identification bodies; select an appropriate auxiliary rod length according to the distance between two adjacent implant composite abutments, and the scanning rod body is configured to be installed on the composite abutment of each implant.

[0064] A scanner scanning head, obtaining point cloud data of multiple positioning bodies through an intraoral scanner.

[0065] A scanning control device, configured to: preset a CAD model corresponding to each identification body.

[0066] Preprocess the point cloud data to remove background noise and non-target point clouds, and automatically identify and segment to extract the feature point clouds of each identification body.

[0067] Process the feature point clouds with the CAD model to output a registration result; until the termination condition of registration is met, output the corresponding point cloud model.

[0068] Although the present invention has been disclosed above with preferred embodiments, it is not used to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and decorations made to the above embodiments according to the technical essence of the present invention without departing from the technical solution of the present invention all belong to the protection scope of the technical solution of the present invention.

Claims

1. An umbrella scanning method for edentulous or dentition defect, characterized in that, Including the following steps: Providing a plurality of positioning bodies, each of the positioning bodies including a scanning rod body and an auxiliary rod disposed on the side surface of the scanning rod body, and each of the positioning bodies being provided with identification bodies including at least a top feature, a cutting surface geometry and curve feature, and an auxiliary rod identifier; Presetting a CAD model corresponding to each of the identification bodies in advance; Obtaining the current tooth design: Selecting an appropriate auxiliary rod length according to the distance between two adjacent implant composite abutments, and the scanning rod body being configured to be installed on each of the implant composite abutments, Obtaining point cloud data of the plurality of positioning bodies by an intraoral scanner; Preprocessing the point cloud data to remove background noise and non-target point clouds, and automatically identifying and segmenting to extract feature point clouds of each of the identification bodies; Processing the feature point clouds with the CAD model to output a registration result; until a termination condition for registration is met, outputting a corresponding point cloud model, wherein, Processing the feature point clouds with the CAD model to output a registration result further including: Selecting four coplanar key points through the feature point clouds, and calculating a preliminary transformation matrix based on the four coplanar key points for preliminary alignment with the CAD model of the scanning rod body; Taking the preliminary transformation matrix as an input for iterative optimization, and in each iteration process, performing corresponding update selection and translation according to the minimum distance error between the position of the feature point cloud and the CAD model.

2. The umbrella scanning method according to claim 1, wherein Further included is calculating, in each iteration process, the overlap degree of two majority feature point clouds under the current transformation, the overlap degree being the ratio of the number of overlapping points to the total number of points for quantifying the alignment accuracy; when the overlap degree is lower than a preset threshold, adjusting ICP algorithm parameters, the parameters including the number of iterations, adjusting the search range, or optimizing the distance metric standard.

3. The umbrella scanning method according to claim 2, wherein The termination conditions include whether the threshold of the number of iterations is reached, whether the error reaches a predetermined threshold upper limit, or a combination of the number of iterations and the error threshold.

4. The umbrella scanning method according to claim 1, wherein Obtaining point cloud data of the plurality of positioning bodies by an intraoral scanner includes: Using the intraoral scanner to first scan the implant from the top to obtain three-dimensional position data of the plurality of positioning bodies, providing accurate reference points for subsequent scanning; Starting from the occlusal surface of the oral cavity, scanning the top of the scanning rod installed on the implant, and performing locked scanning based on the top feature of the scanning rod; Scanning the scanning rod from the buccal and lingual sides of the oral cavity, identifying the cutting surface geometry and the curve feature, and obtaining the point cloud data of the contact between the scanning rod and adjacent teeth, the scanning rod, or soft tissue; Scanning the gingival soft tissue with less impact on accuracy to complete the scanning of the soft tissue.

5. An umbrella scanning system for tooth loss or tooth defect, including a plurality of positioning bodies, a scanner scanning head, and a scanning control device: Multiple positioning bodies, each positioning body includes a scanning rod body and an auxiliary rod arranged on the side surface of the scanning rod body, and each positioning body is provided with an identification body including at least a top feature, a cutting surface geometry and a curve feature, and an auxiliary rod identifier; an appropriate auxiliary rod length is selected according to the distance between two adjacent implant composite abutments, and the scanning rod body is configured to be mounted on the composite abutment of each implant. A scanner scanning head, obtaining point cloud data of multiple positioning bodies through an intraoral scanner. A scanning control device, configured to: preset a CAD model corresponding to each identification body. Preprocess the point cloud data to remove background noise and non-target point clouds, and automatically identify and segment to extract the feature point clouds of each identification body. Process the feature point clouds with the CAD model to output a registration result; until the termination condition of registration is met, output the corresponding point cloud model.

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