A method, system, equipment, and medium for reconstructing the mandibular osteotomy plane.

Abstract

This invention relates to the field of oral implant technology, and discloses a method, system, device, and medium for reconstructing the mandibular osteotomy plane. This invention utilizes preoperative CBCT image data and immediate postoperative CBCT image data of the mandibular bone harvesting procedure to reconstruct the preoperative and immediate postoperative cortical bone models of the mandibular bone. The immediate postoperative cortical bone model and multiple first actual osteotomy planes are registered with the preoperative cortical bone model. The mandible in the preoperative cortical bone model is then trimmed, and the portion containing the harvested bone area is preserved. Finally, the actual bone fragments harvested after the mandibular bone harvesting procedure and multiple clearly defined second actual osteotomy planes are obtained. This invention overcomes the limitation that the boundaries of the cancellous bone within the mandible are difficult to discern on CBCT, reconstructing a precise, actual, and bounded osteotomy plane containing the cancellous bone portion. This facilitates the evaluation of surgical safety and the accuracy of the bone harvesting guide.

Description

Technical Field

[0001] This invention relates to the field of oral implant technology, and in particular to a method, system, device and medium for reconstructing the osteotomy plane of the mandible. Background Technology

[0002] Tooth loss is accompanied by alveolar bone remodeling. The proposed implantation site often has bone defects, requiring bone grafting before implantation. Autologous bone is the gold standard for alveolar bone reconstruction. Autologous bone can be obtained from intraoral or extraoral sources. Intraoral bone harvesting is less invasive, less expensive, and more acceptable to patients than extraoral bone harvesting. The most commonly used intraoral bone donor site is the external oblique line of the mandible, but there is a risk of damage to the mandibular canal. Bone harvesting guides can reduce this risk. How to evaluate the osteotomy accuracy of bone harvesting guides is very important, which is especially important for setting the safety distance that must be considered when designing different types of guides.

[0003] Previous studies evaluating the accuracy of intraoral bone harvesting of mandibular blocks have generally utilized CBCT (cone beam computed tomography) immediately after the procedure to reconstruct the actual osteotomy plane using threshold segmentation. However, because the boundaries of the cancellous bone within the mandible are difficult to discern on CBCT, the aforementioned threshold segmentation method struggles to accurately reconstruct the actual osteotomy plane. Furthermore, the high precision required for the bone harvesting guide is primarily to avoid damage to the mandibular canal and adjacent tooth roots within the cancellous bone of the mandible. Therefore, accurately reconstructing the actual osteotomy plane, including the cancellous bone portion, is of paramount importance.

[0004] Therefore, there is an urgent need for a new method to reconstruct the mandibular osteotomy plane in order to accurately reconstruct the actual bounded osteotomy plane that includes the cancellous bone portion. Summary of the Invention

[0005] This invention provides a method, system, device, and medium for reconstructing the osteotomy plane of the mandible, thereby overcoming the shortcomings of existing technologies that cannot accurately reconstruct the actual osteotomy plane including the cancellous bone portion.

[0006] This invention provides a method for reconstructing the osteotomy plane of the mandible, comprising:

[0007] Obtain preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting. The preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting are CBCT image data containing cortical bone and cancellous bone in a preset area. The preset area includes the preset mandibular bone harvesting area and the preset surrounding area of ​​the preset mandibular bone harvesting area.

[0008] Based on the CBCT image data immediately after mandibular bone harvesting, a cortical bone model immediately after mandibular bone harvesting was reconstructed. The cortical bone model immediately after mandibular bone harvesting includes the cortical bone portion of the mandible in the non-bone harvesting area and the osteotomy surfaces of cortical bone in multiple bone harvesting areas.

[0009] Based on the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, multiple first actual osteotomy planes were obtained using the least squares method. Among them, multiple first actual osteotomy planes are all boundless planes.

[0010] Based on the preoperative CBCT image data of mandibular bone harvesting, a preoperative cortical bone model of the mandibular bone was reconstructed.

[0011] The immediate cortical bone model after mandibular bone harvesting is linked with multiple first actual osteotomy planes. Based on the non-harvested cortical bone portion of the mandibular bone in the immediate cortical bone model after mandibular bone harvesting, the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes are registered with the pre-mandibular bone model.

[0012] Based on the registered mandibular bone harvesting immediate postoperative cortical bone model, multiple first actual osteotomy planes, and the preoperative mandibular bone harvesting cortical bone model, the mandible in the preoperative mandibular bone harvesting cortical bone model is trimmed sequentially according to the multiple first actual osteotomy planes, and the part containing the bone harvesting area is preserved, to obtain the actual bone block harvested after mandibular bone harvesting and multiple second actual osteotomy planes, wherein the multiple second actual osteotomy planes are all bounded planes.

[0013] In one embodiment, reconstructing the immediate cortical bone model after mandibular bone harvesting based on immediate CBCT image data includes:

[0014] Based on the CBCT image data immediately after mandibular bone harvesting, the first effective area of ​​cortical bone in the mandible was determined, and a cortical bone mask was obtained immediately after mandibular bone harvesting.

[0015] Based on the immediate cortical bone mask after mandibular bone harvesting, a model of the immediate cortical bone after mandibular bone harvesting was reconstructed.

[0016] In one implementation, the step of obtaining multiple first actual osteotomy planes using the least squares method based on the cortical bone osteotomy surfaces of multiple bone harvesting areas in a cortical bone model immediately after mandibular bone harvesting, including:

[0017] Based on each of the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, the first fitting plane that best fits the cortical bone osteotomy surface of each bone harvesting area is obtained using the least squares method. This first fitting plane is used as the first actual osteotomy plane corresponding to the bone harvesting area where the cortical bone osteotomy surface of each bone harvesting area is located, thus obtaining multiple first actual osteotomy planes.

[0018] In one embodiment, reconstructing a pre-operative cortical bone model of the mandible based on pre-operative CBCT image data includes:

[0019] Based on the CBCT image data before mandibular bone harvesting, the second effective area of ​​cortical bone in the mandible was determined, and a cortical bone mask was obtained before mandibular bone harvesting.

[0020] Based on the preoperative cortical bone mask for mandibular bone harvesting, a preoperative cortical bone model for mandibular bone harvesting was reconstructed.

[0021] In one embodiment, the step of linking the immediate post-mandibular bone harvesting cortical bone model and multiple first actual osteotomy planes, and registering the immediate post-mandibular bone harvesting cortical bone model and multiple first actual osteotomy planes with the pre-mandibular bone harvesting cortical bone model based on the unharvested cortical bone portion of the mandibular bone in the immediate post-mandibular bone harvesting cortical bone model, includes:

[0022] Based on the spatial relationship between the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes, a linkage relationship between the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes is constructed. Taking the unharvested cortical bone portion of the mandibular bone in the immediate cortical bone model after mandibular bone harvesting as a reference, the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes are simultaneously superimposed on the pre-mandibular cortical bone model.

[0023] In one implementation, based on the registered mandibular bone harvesting immediate postoperative cortical bone model, multiple first actual osteotomy planes, and the preoperative mandibular bone harvesting preoperative cortical bone model, the mandible in the preoperative mandibular bone harvesting preoperative cortical bone model is sequentially trimmed according to the multiple first actual osteotomy planes, and the portion containing the bone harvesting area is retained, to obtain the actual bone fragments harvested after mandibular bone harvesting and multiple second actual osteotomy planes, including:

[0024] Select the first actual osteotomy plane from among multiple first actual osteotomy planes;

[0025] Based on the first actual osteotomy plane, the mandible in the preoperative cortical bone model of the mandibular bone harvesting is trimmed to obtain the first trimmed sub-model and the second trimmed sub-model.

[0026] The parts of the first and second trimming models that contain the bone harvesting area are retained, while the parts that do not contain the bone harvesting area are deleted.

[0027] Select the next first actual osteotomy plane among multiple first actual osteotomy planes, and repeat the above steps until the jawbone in the preoperative cortical bone model of the mandibular bone harvesting is cut according to all the first actual osteotomy planes of the multiple first actual osteotomy planes, to obtain the actual bone block after the mandibular bone harvesting, and use multiple surfaces of the actual bone block after the mandibular bone harvesting, except for one curved surface of the jawbone surface, as multiple second actual osteotomy planes.

[0028] This invention also provides a method for evaluating mandibular bone harvesting, comprising:

[0029] The system receives preoperative CBCT images and immediate postoperative CBCT images of the subjects undergoing mandibular bone harvesting. The subjects are those who have undergone mandibular bone harvesting. The preoperative and immediate postoperative CBCT images of the subjects are CBCT images of a pre-defined area containing cortical and cancellous bone. The pre-defined area includes a pre-defined mandibular bone harvesting area and a pre-defined peripheral area of ​​the pre-defined mandibular bone harvesting area.

[0030] Based on the preoperative CBCT image data and immediate postoperative CBCT image data of the mandibular bone harvesting procedure of the subject to be evaluated, the actual bone fragments and multiple second actual osteotomy planes of the subject to be evaluated after mandibular bone harvesting are obtained by the method of reconstructing the mandibular osteotomy plane described above.

[0031] Based on the actual bone fragments obtained after mandibular osteotomy and multiple second actual osteotomy planes, the intraoperative bone harvesting parameters and postoperative bone fragment parameters of the patient under evaluation were obtained to evaluate the operative safety and bone harvesting effect of the mandibular osteotomy performed on the patient.

[0032] In a preferred embodiment, the mandibular bone harvesting evaluation method provided by the present invention further includes:

[0033] Based on the bone harvesting guide plate pre-selected for the patient to be evaluated, multiple preoperative osteotomy planes for first mandibular bone harvesting are obtained, wherein the multiple preoperative osteotomy planes for first mandibular bone harvesting are all boundless planes.

[0034] According to any of the above methods for reconstructing mandibular osteotomy planes, multiple first mandibular osteotomy planes are replaced with multiple first mandibular osteotomy planes designed before osteotomy. The mandible in the preoperative cortical bone model of mandibular osteotomy is trimmed and the part containing the planned osteotomy area is retained to obtain the planned bone block to be removed before mandibular osteotomy and multiple second mandibular osteotomy planes designed before osteotomy. The multiple second mandibular osteotomy planes designed before osteotomy are all bounded planes.

[0035] Multiple preoperative planned osteotomy planes for second mandibular bone harvesting were compared with multiple actual second osteotomy planes of the patient to obtain osteotomy displacement errors and osteotomy angle errors between the multiple preoperative planned osteotomy planes for second mandibular bone harvesting and the multiple actual second osteotomy planes of the patient to evaluate the accuracy of the bone harvesting guide plate pre-selected for the patient.

[0036] The present invention also provides a system for reconstructing the osteotomy plane of the mandible, comprising:

[0037] The data acquisition module is used to acquire CBCT image data before mandibular bone harvesting and CBCT image data immediately after mandibular bone harvesting. The CBCT image data before mandibular bone harvesting and CBCT image data immediately after mandibular bone harvesting are CBCT image data containing cortical bone and cancellous bone in a preset area. The preset area includes a preset mandibular bone harvesting area and a preset surrounding area of ​​the preset mandibular bone harvesting area.

[0038] The first reconstruction module is used to: reconstruct the immediate cortical bone model after mandibular bone harvesting based on the immediate CBCT image data after mandibular bone harvesting. The immediate cortical bone model after mandibular bone harvesting includes the cortical bone portion of the mandible in the non-bone harvesting area and the osteotomy surfaces of the cortical bone in multiple bone harvesting areas.

[0039] The fitting module is used to: obtain multiple first actual osteotomy planes based on the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, using the least squares method. Among them, the multiple first actual osteotomy planes are all boundaryless planes.

[0040] The second reconstruction module is used to: reconstruct the preoperative cortical bone model of the mandible based on the preoperative CBCT image data of the mandibular bone harvesting procedure;

[0041] The registration module is used to link the immediate cortical bone model after mandibular bone harvesting with multiple first actual osteotomy planes, and to register the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes with the pre-mandibular bone harvesting cortical bone model based on the non-bone harvesting area of ​​the mandibular cortical bone in the immediate cortical bone model after mandibular bone harvesting.

[0042] The first trimming module is used to: based on the registered mandibular bone immediate postoperative cortical bone model, multiple first actual osteotomy planes, and the preoperative mandibular bone model, trim the mandible in the preoperative mandibular bone model according to the multiple first actual osteotomy planes and retain the part containing the bone harvesting area, to obtain the actual bone block after mandibular bone harvesting and multiple second actual osteotomy planes, wherein the multiple second actual osteotomy planes are all bounded planes.

[0043] The present invention also provides an electronic device, including a processor and a memory storing a computer program, wherein the processor executes the computer program to implement any of the above-described methods for reconstructing the mandibular osteotomy plane and / or for evaluating mandibular osteotomy.

[0044] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for reconstructing the mandibular osteotomy plane and / or the method for evaluating mandibular osteotomy as described above.

[0045] The present invention also provides a computer program product, the computer program product comprising a computer program that can be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer is capable of performing any of the above-described methods for reconstructing the mandibular osteotomy plane and / or the mandibular osteotomy evaluation method.

[0046] This invention provides a method, system, device, and medium for reconstructing mandibular osteotomy planes. Utilizing preoperative CBCT image data and immediate postoperative CBCT image data from mandibular osteotomy, a preoperative cortical bone model and an immediate postoperative cortical bone model are reconstructed. Multiple unbounded first actual osteotomy planes are obtained based on the immediate postoperative cortical bone model using the least squares method. The immediate postoperative cortical bone model and the multiple first actual osteotomy planes are registered with the preoperative cortical bone model. Based on the multiple first actual osteotomy planes… The osteotomy planes sequentially trim the mandible in the preoperative cortical bone model and preserve the portion containing the bone harvesting area, ultimately obtaining the actual bone fragments harvested after mandibular bone harvesting and multiple clearly defined second actual osteotomy planes. This addresses the limitation of the mandible's internal cancellous bone having indistinguishable boundaries on CBCT, reconstructing precise actual bounded osteotomy planes containing the cancellous bone portion. This aids in evaluating surgical safety and the accuracy of the bone harvesting guide, effectively promoting the improvement of bone harvesting guides, and providing important data references for selecting bone harvesting guides and evaluating patient prognosis. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0048] Figure 1 This is a flowchart illustrating a method for reconstructing the mandibular osteotomy plane provided by the present invention.

[0049] Figure 2 This is an example image of a cortical bone model reconstructed immediately after mandibular bone harvesting based on CBCT image data.

[0050] Figure 3 Examples of cortical bone osteotomy surfaces and multiple first actual osteotomy planes are shown in Figure a. Figure a shows the cortical bone portion (red) of the actual top vertical osteotomy surface, and the fitted actual top vertical osteotomy surface (semi-transparent green); Figure b shows the cortical bone portion (red) of the actual bottom horizontal osteotomy surface, and the fitted actual bottom horizontal osteotomy surface (semi-transparent green); Figure c shows the cortical bone portion (red) of the actual mesial osteotomy surface, and the fitted actual mesial osteotomy surface (semi-transparent green); Figure d shows the cortical bone portion (red) of the actual distal osteotomy surface, and the fitted actual distal vertical osteotomy surface (semi-transparent green). The fitted actual top vertical osteotomy surface, actual bottom horizontal osteotomy surface, actual mesial osteotomy surface, and actual distal vertical osteotomy surface are all first actual osteotomy planes.

[0051] Figure 4 This is an example image of a preoperative cortical bone model of the mandible reconstructed from preoperative CBCT images.

[0052] Figure 5 This diagram illustrates the process of registering the immediate post-mandibular osteotomy model and multiple first actual osteotomy planes with the pre-mandibular osteotomy model. Figure a shows the registration of the immediate post-mandibular osteotomy model (green) to the pre-mandibular osteotomy model (yellow); Figure b shows the overlay of multiple first actual osteotomy planes (semi-transparent green) onto the pre-mandibular osteotomy model; Figure c shows the sequential trimming of the mandible in the pre-mandibular osteotomy model according to the multiple first actual osteotomy planes, deleting the portion outside the harvested bone (red) and retaining the portion containing the harvested bone area; Figure d shows the actual bone fragments harvested after the mandibular osteotomy; Figure e shows multiple second actual osteotomy planes (yellow for the actual top vertical osteotomy plane, black for the actual bottom horizontal osteotomy plane, blue for the actual mesial osteotomy plane, and red for the actual distal osteotomy plane).

[0053] Figure 6This diagram illustrates the process of obtaining the planned bone fragments and multiple planned osteotomy planes for the second mandibular bone harvesting procedure. Figure a shows the planned bone harvesting guide (blue) and multiple pre-operatively designed osteotomy planes for the first mandibular bone harvesting (semi-transparent green). Figure b shows the multiple pre-operative osteotomy planes (i.e., multiple pre-operatively designed osteotomy planes for the first mandibular bone harvesting, semi-transparent green) superimposed on the pre-operative cortical bone model of the mandibular bone harvesting procedure. Figure c shows the process of trimming the pre-operative cortical bone model of the mandibular bone harvesting procedure using multiple pre-operatively designed osteotomy planes for the first mandibular bone harvesting procedure, deleting the portion outside the bone fragments (red), and retaining the portion containing the planned harvesting area. Figure d shows the obtained planned bone fragments for the mandibular bone harvesting procedure. Figure e shows the obtained multiple pre-operatively designed osteotomy planes for the second mandibular bone harvesting procedure (yellow is the planned top vertical osteotomy plane, black is the planned bottom horizontal osteotomy plane, blue is the planned mesial osteotomy plane, and red is the planned distal osteotomy plane).

[0054] Figure 7 This is one of the schematic diagrams comparing multiple planned osteotomy planes for second mandibular bone harvesting with multiple actual osteotomy planes in the patient being evaluated. Figure a shows the planned distal osteotomy plane (green) and the actual distal osteotomy plane (red); Figure b shows the planned apical vertical osteotomy plane (green) and the actual apical vertical osteotomy plane (red); Figure c shows the planned mesial osteotomy plane (green) and the actual mesial osteotomy plane (red); Figure d shows the planned basal horizontal osteotomy plane (green) and the actual basal horizontal osteotomy plane (red).

[0055] Figure 8 This is the second schematic diagram comparing multiple planned osteotomy planes for second mandibular bone harvesting with multiple actual second osteotomy planes in the patient being evaluated. Figure a shows a chromatogram of displacement deviation analysis between the planned distal osteotomy plane and the actual distal osteotomy plane; Figure b shows a chromatogram of displacement deviation analysis between the planned top vertical osteotomy plane and the actual top vertical osteotomy plane; Figure c shows a chromatogram of displacement deviation analysis between the planned mesial osteotomy plane and the actual mesial osteotomy plane; Figure d shows a chromatogram of displacement deviation analysis between the planned bottom horizontal osteotomy plane and the actual bottom horizontal osteotomy plane.

[0056] Figure 9 This is a schematic diagram of a system for reconstructing the osteotomy plane of the mandible, provided by the present invention.

[0057] Figure 10 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, embodiments of this invention, and should not be construed as limiting the invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. In the description of this invention, it should be understood that the terminology used is for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] The following is combined with Figures 1-10 This invention describes the method, system, device, and medium for reconstructing the mandibular osteotomy plane.

[0060] Figure 1 This is a schematic flowchart of the method for reconstructing the mandibular osteotomy plane provided by the present invention. (Refer to...) Figure 1 The present invention provides a method for reconstructing the mandibular osteotomy plane, which may include:

[0061] Step S110: Obtain preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting. The preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting are CBCT image data of a preset area containing cortical bone and cancellous bone. The preset area includes a preset mandibular bone harvesting area and a preset surrounding area of ​​the preset mandibular bone harvesting area (e.g., an area of ​​at least 1-2 cm around the preset mandibular bone harvesting area).

[0062] Step S120: Based on the CBCT image data immediately after mandibular bone harvesting, reconstruct the immediate cortical bone model immediately after mandibular bone harvesting. The immediate cortical bone model immediately after mandibular bone harvesting includes the cortical bone portion of the mandible in the non-bone harvesting area and the osteotomy surfaces of the cortical bone in multiple bone harvesting areas.

[0063] Step S130: Based on the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, multiple first actual osteotomy planes are obtained using the least squares method, wherein the multiple first actual osteotomy planes are all boundaryless planes.

[0064] Step S140: Reconstruct the preoperative cortical bone model of the mandible based on the preoperative CBCT image data of the mandibular bone harvesting.

[0065] Step S150: Link the immediate cortical bone model after mandibular bone harvesting with multiple first actual osteotomy planes, and register the immediate cortical bone model after mandibular bone harvesting with multiple first actual osteotomy planes and the pre-mandibular bone harvesting cortical bone model according to the unharvested cortical bone portion of the mandibular bone in the immediate cortical bone model after mandibular bone harvesting.

[0066] Step S160: Based on the registered mandibular bone harvesting immediate postoperative cortical bone model, multiple first actual osteotomy planes, and the preoperative mandibular bone harvesting preoperative cortical bone model, the mandible in the preoperative mandibular bone harvesting preoperative cortical bone model is cut sequentially according to the multiple first actual osteotomy planes, and the part containing the bone harvesting area is retained, to obtain the actual bone block harvested after mandibular bone harvesting and multiple second actual osteotomy planes, wherein the multiple second actual osteotomy planes are all bounded planes.

[0067] In one embodiment, mandibular bone harvesting can be external oblique mandibular bone harvesting, chin bone harvesting, etc. Furthermore, preoperative and postoperative CBCT scans can be performed on patients requiring mandibular bone harvesting. The tool used can be a Siemens Celestar 3D CBCT system, and the scanning parameters can be set as follows: voltage 80kV, current 5mA, slice thickness 0.5mm, scanning time 10 minutes, etc., to obtain preoperative and immediate postoperative CBCT image data of mandibular bone harvesting. Alternatively, preoperative and immediate postoperative CBCT image data of the same individual can be obtained from a dental hospital's system or other platforms. The osteotomy surfaces shown in the obtained preoperative and immediate postoperative CBCT image data of mandibular bone harvesting need to include both cortical bone and cancellous bone, and multiple osteotomy surfaces can intersect.

[0068] In one embodiment, step S120 may include:

[0069] Based on the CBCT image data immediately after mandibular bone harvesting, the first effective area of ​​cortical bone in the mandible was determined, and a cortical bone mask was obtained immediately after mandibular bone harvesting. The "effective area" refers to all cortical bone in the area where the osteotomy plane of the bone harvesting area is located and the surrounding cortical bone area of ​​at least 1-2 cm that can be clearly reconstructed.

[0070] Based on the immediate cortical bone mask after mandibular bone harvesting, a model of the immediate cortical bone after mandibular bone harvesting was reconstructed.

[0071] Specifically, medical image processing software, such as Mimics (which can automatically identify and segment cortical and cancellous bone for 3D reconstruction), can be used to set a first threshold range. This allows for the identification of clearly visible cortical bone in immediate CBCT images following mandibular osteotomy, generating a cortical bone mask for immediate post-operative reconstruction of a 3D model. See also... Figure 2The green part represents cortical bone, and the inner side of it represents cancellous bone. As can be seen, in the immediate cortical bone model of the mandible reconstructed using CBCT image data immediately after mandibular bone harvesting, the mandible is incomplete and has osteotomy lines. The osteotomy lines of the cortical bone part are clearly distinguishable, while the osteotomy lines of the cancellous bone part are not distinguishable.

[0072] Cone-beam computed tomography (CBCT) is a medical imaging technique used to generate three-dimensional images in dentistry, oral and maxillofacial surgery, and other medical fields. In CBCT images, tissue structures of different densities, such as cortical bone and trabecular bone (also known as spongy bone), can be visually distinguished or differentiated using specific software. In CBCT imaging, the density of different tissues is measured in Hertz (HU) units or similar values, which are related to the tissue's ability to block X-rays. Higher-density materials, such as cortical bone, will have a higher HU value, while lower-density materials, such as trabecular bone, will have a lower HU value. The specific threshold values ​​for cortical and trabecular bone in CBCT scans can differ because different CBCT machines and different imaging settings (such as resolution and grayscale range) can affect the threshold settings. Generally, the first threshold range for cortical bone can be set above approximately 300 HU, with a common range of 400-3000 HU, while the first threshold range for trabecular bone is likely lower, typically between 100-400 HU. The specific value of the first threshold range can be determined based on local settings and clinical standards.

[0073] In one embodiment, step S130 may include:

[0074] Based on each of the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, the first fitting plane that best fits the cortical bone osteotomy surface of each bone harvesting area is obtained using the least squares method. This first fitting plane is used as the first actual osteotomy plane corresponding to the bone harvesting area where the cortical bone osteotomy surface of each bone harvesting area is located, thus obtaining multiple first actual osteotomy planes.

[0075] Specifically, 3D reverse modeling software, such as Geomagic (Geomagic Studio 2015; 3DSystems, Rock Hill, SC, USA) (which can automatically identify and extract the actual osteotomy plane), can be used to achieve step S130. See also Figure 3First, select one cortical bone osteotomy surface from multiple bone harvesting areas. Then, use the least squares method to fit the first fitting plane that best fits the cortical bone osteotomy surface of the bone harvesting area. This first fitting plane represents the actual osteotomy plane at the position corresponding to the cortical bone osteotomy surface of the bone harvesting area. Then, repeat the above steps for other cortical bone osteotomy surfaces of bone harvesting areas to obtain the first actual osteotomy plane at multiple positions corresponding to multiple cortical bone osteotomy surfaces of multiple bone harvesting areas.

[0076] The principle of the least squares method is to find a plane such that the sum of the squares of the perpendicular distances (residuals) from all selected points to this plane is minimized. The least squares method can ensure that the generated first fitting plane can be as close as possible to or fit the given set of data points (i.e., the cortical bone osteotomy surface of the bone harvesting area), thus providing a more accurate and stable plane fitting result.

[0077] In one embodiment, step S140 may include:

[0078] Based on the CBCT image data before mandibular bone harvesting, the second effective area of ​​cortical bone in the mandible was determined, and a cortical bone mask was obtained before mandibular bone harvesting.

[0079] Based on the preoperative cortical bone mask for mandibular bone harvesting, a preoperative cortical bone model for mandibular bone harvesting was reconstructed.

[0080] Specifically, medical image processing software, such as Mimics, can be used to set a second threshold range to locate clearly visible cortical bone in preoperative CBCT images of the mandible. This allows for the generation of a preoperative cortical bone mask, which is then used to reconstruct a three-dimensional preoperative cortical bone model of the mandible. See also Figure 4 In the pre-operative cortical bone model of the mandible reconstructed from the CBCT image data before the mandibular bone harvesting surgery, the entire mandible is a complete mandible, the yellow part is the cortical bone that can be completely reconstructed, and the interior surrounded by the yellow part is cancellous bone.

[0081] In one embodiment, step S150 may include:

[0082] Based on the spatial relationship between the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes, a linkage relationship between the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes is constructed. Taking the unharvested cortical bone portion of the mandibular bone in the immediate cortical bone model after mandibular bone harvesting as a reference, the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes are simultaneously superimposed on the pre-mandibular cortical bone model.

[0083] Specifically, the linkage relationship refers to the simultaneous movement of multiple first actual osteotomy planes and their identical (including the same direction, angle, distance, etc.) movements when the cortical bone model is moved immediately after mandibular bone harvesting. Preferably, see [reference needed]. Figure 5 Three-dimensional reverse modeling software, such as Geomagic (Geomagic Studio 2015; 3DSystems, Rock Hill, SC, USA) or 3-Matic Medical 12.0 (which can automatically complete the model registration), can be used to simultaneously overlay the immediate cortical bone model after mandibular osteotomy and multiple first actual osteotomy planes onto the pre-mandibular osteotomy cortical bone model.

[0084] In one embodiment, see Figure 5 Step S160 may include:

[0085] Select the first actual osteotomy plane from among multiple first actual osteotomy planes;

[0086] Based on the first actual osteotomy plane, the mandible in the preoperative cortical bone model of the mandibular bone harvesting is trimmed to obtain the first trimmed sub-model and the second trimmed sub-model.

[0087] The parts of the first and second trimming models that contain the bone harvesting area are retained, while the parts that do not contain the bone harvesting area are deleted.

[0088] Select the next first actual osteotomy plane among multiple first actual osteotomy planes, and repeat the above steps until the jawbone in the preoperative cortical bone model of the mandibular bone harvesting is cut according to all the first actual osteotomy planes of the multiple first actual osteotomy planes, to obtain the actual bone block after the mandibular bone harvesting, and use multiple surfaces of the actual bone block after the mandibular bone harvesting, except for one curved surface of the jawbone surface, as multiple second actual osteotomy planes.

[0089] Specifically, step S160 can be achieved using 3D reverse modeling software, such as Geomagic (Geomagic Studio 2015; 3DSystems, Rock Hill, SC, USA).

[0090] "With boundaries" means that the plane is not an infinitely extending plane, but has boundaries. In this embodiment, the boundaries include the osteotomy range of cortical bone and cancellous bone. The actual bone block obtained after mandibular bone harvesting is composed of the outer surface of the cortical bone in the bone harvesting area and various bounded planes. The bounded planes include the osteotomy planes of cortical bone and cancellous bone. The bounded planes have certain boundaries and ranges, which are the positions cut by the working tip of the osteotomy instrument during osteotomy.

[0091] This invention can obtain the actual bounded osteotomy plane containing cancellous bone, which is difficult to reconstruct directly using CBCT image data. Furthermore, it can determine the depth to which the osteotomy instruments enter the jawbone during jawbone harvesting, and can be used to evaluate the surgical safety and accuracy of jawbone harvesting.

[0092] This invention provides a method for reconstructing mandibular osteotomy planes. Using preoperative CBCT image data and immediate postoperative CBCT image data from mandibular osteotomy, a preoperative cortical bone model and an immediate postoperative cortical bone model are reconstructed. Multiple unbounded first actual osteotomy planes are obtained based on the immediate postoperative cortical bone model using the least squares method. The immediate postoperative cortical bone model and the multiple first actual osteotomy planes are registered with the preoperative cortical bone model. Based on the multiple first actual osteotomy planes... The mandible in the preoperative cortical bone model is trimmed sequentially, and the portion containing the bone harvesting area is preserved. This results in the actual bone fragments harvested after mandibular bone harvesting and multiple clearly defined second actual osteotomy planes. This method can solve the problem that the boundaries of the cancellous bone inside the mandible are not easily distinguishable on CBCT, and reconstructs accurate actual bounded osteotomy planes containing the cancellous bone portion. This helps in evaluating surgical safety and the accuracy of bone harvesting guides, effectively promotes the improvement of bone harvesting guides, and provides important data references for selecting bone harvesting guides and evaluating patient prognosis.

[0093] Based on the method for reconstructing the mandibular osteotomy plane provided by this invention, this invention can also provide a method for evaluating mandibular osteotomy, including:

[0094] The system receives preoperative CBCT images and immediate postoperative CBCT images of the subjects undergoing mandibular bone harvesting. The subjects are those who have undergone mandibular bone harvesting. The preoperative and immediate postoperative CBCT images of the subjects are CBCT images of a pre-defined area containing cortical and cancellous bone. The pre-defined area includes a pre-defined mandibular bone harvesting area and a pre-defined peripheral area of ​​the pre-defined mandibular bone harvesting area.

[0095] Based on the preoperative CBCT image data and immediate postoperative CBCT image data of the mandibular bone harvesting procedure of the subject to be evaluated, the actual bone fragments and multiple second actual osteotomy planes after the mandibular bone harvesting procedure of the subject to be evaluated are obtained by the above-described method of reconstructing the mandibular osteotomy plane.

[0096] Based on the actual bone fragments obtained after mandibular osteotomy and multiple second actual osteotomy planes, the intraoperative bone harvesting parameters and postoperative bone fragment parameters of the patient under evaluation are obtained, such as the actual depth of bone harvesting and the actual size of the postoperative bone fragments. These parameters are used to evaluate the operational safety and bone harvesting effect of the mandibular osteotomy performed on the patient. The evaluation method can be to compare various data with preset thresholds, etc.

[0097] In a preferred embodiment, see Figure 6-8 It may also include the following steps:

[0098] Based on the bone harvesting guide plate pre-selected for the patient to be evaluated, multiple preoperative osteotomy planes for first mandibular bone harvesting are obtained, wherein the multiple preoperative osteotomy planes for first mandibular bone harvesting are all boundless planes.

[0099] According to any of the above methods for reconstructing mandibular osteotomy planes, multiple first mandibular osteotomy planes are replaced with multiple first mandibular osteotomy planes designed before osteotomy. The mandible in the preoperative cortical bone model of mandibular osteotomy is trimmed and the part containing the planned osteotomy area is retained to obtain the planned bone block to be removed before mandibular osteotomy and multiple second mandibular osteotomy planes designed before osteotomy. The multiple second mandibular osteotomy planes designed before osteotomy are all bounded planes.

[0100] Multiple preoperative planned osteotomy planes for second mandibular bone harvesting were compared with multiple actual second osteotomy planes of the patient to obtain osteotomy displacement errors and osteotomy angle errors between the multiple preoperative planned osteotomy planes for second mandibular bone harvesting and the multiple actual second osteotomy planes of the patient to evaluate the accuracy of the bone harvesting guide plate pre-selected for the patient.

[0101] Specifically, 3D reverse modeling software, such as Geomagic (Geomagic Studio 2015; 3D Systems, Rock Hill, SC, USA), can be used to generate multiple preoperative osteotomy planes for the first mandibular bone harvesting based on the pre-selected bone harvesting guide for the patient. Furthermore, 3D reverse modeling software, such as Geomagic (Geomagic Studio 2015; 3D Systems, Rock Hill, SC, USA), can be used to compare multiple preoperative planned osteotomy planes for the second mandibular bone harvesting with multiple actual second osteotomy planes for the patient. Alternatively, Solidworks 2019 can be used, which can generate virtual osteotomy planes based on the designer's design. Finally, ANSYS Workbench 19.0 can be used, which can automatically calculate the displacement error between the two planes.

[0102] The system for reconstructing the mandibular osteotomy plane provided by the present invention is described below. The system for reconstructing the mandibular osteotomy plane described below can be referred to in correspondence with the method for reconstructing the mandibular osteotomy plane described above.

[0103] Reference Figure 9 The present invention provides a system for reconstructing the mandibular osteotomy plane, which may include:

[0104] The data acquisition module is used to acquire CBCT image data before mandibular bone harvesting and CBCT image data immediately after mandibular bone harvesting. The CBCT image data before mandibular bone harvesting and CBCT image data immediately after mandibular bone harvesting are CBCT image data containing cortical bone and cancellous bone in a preset area. The preset area includes a preset mandibular bone harvesting area and a preset surrounding area of ​​the preset mandibular bone harvesting area.

[0105] The first reconstruction module is used to: reconstruct the immediate cortical bone model after mandibular bone harvesting based on the immediate CBCT image data after mandibular bone harvesting. The immediate cortical bone model after mandibular bone harvesting includes the cortical bone portion of the mandible in the non-bone harvesting area and the osteotomy surfaces of the cortical bone in multiple bone harvesting areas.

[0106] The fitting module is used to: obtain multiple first actual osteotomy planes based on the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, using the least squares method. Among them, the multiple first actual osteotomy planes are all boundaryless planes.

[0107] The second reconstruction module is used to: reconstruct the preoperative cortical bone model of the mandible based on the preoperative CBCT image data of the mandibular bone harvesting procedure;

[0108] The registration module is used to link the immediate cortical bone model after mandibular bone harvesting with multiple first actual osteotomy planes, and to register the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes with the pre-mandibular bone harvesting cortical bone model based on the non-bone harvesting area of ​​the mandibular cortical bone in the immediate cortical bone model after mandibular bone harvesting.

[0109] The trimming module is used to: based on the registered mandibular bone immediate postoperative cortical bone model, multiple first actual osteotomy planes, and the preoperative mandibular bone model, trim the mandible in the preoperative cortical bone model according to the multiple first actual osteotomy planes and retain the part containing the bone harvesting area, to obtain the actual bone block after mandibular bone harvesting and multiple second actual osteotomy planes, wherein the multiple second actual osteotomy planes are all bounded planes.

[0110] In one implementation, the first reconstruction module may include:

[0111] The first mask generation submodule is used to: determine the first effective area of ​​cortical bone in the mandible based on the CBCT image data immediately after mandibular bone harvesting, and obtain the cortical bone mask immediately after mandibular bone harvesting.

[0112] The first reconstruction submodule is used to reconstruct the immediate cortical bone model after mandibular bone harvesting based on the immediate cortical bone mask after mandibular bone harvesting.

[0113] In one implementation, the fitting module may include:

[0114] The fitting submodule is used to: based on each of the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, use the least squares method to obtain the first fitting plane that best fits the cortical bone osteotomy surface of each bone harvesting area, and use it as the first actual osteotomy plane corresponding to the bone harvesting area where the cortical bone osteotomy surface of each bone harvesting area is located, so as to obtain multiple first actual osteotomy planes.

[0115] In one implementation, the second reconstruction module may include:

[0116] The second mask generation submodule is used to: determine the second effective area of ​​cortical bone in the mandible based on the preoperative CBCT image data of mandibular bone harvesting, and obtain the preoperative cortical bone mask of mandibular bone harvesting.

[0117] The second reconstruction submodule is used to reconstruct the pre-operative cortical bone model of the mandible based on the pre-operative cortical bone mask.

[0118] In one implementation, the registration module may include:

[0119] The registration submodule is used to: construct the linkage relationship between the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes based on the spatial positional relationship between the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes; and, using the non-harvested cortical bone portion of the mandibular bone in the immediate cortical bone model after mandibular bone harvesting as a reference, simultaneously superimpose the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes onto the pre-mandibular bone harvesting cortical bone model.

[0120] In one implementation, the first trimming module may include:

[0121] The selection submodule is used to: select the first first actual osteotomy plane among multiple first actual osteotomy planes;

[0122] The trimming submodule is used to trim the mandible in the preoperative cortical bone model of the mandibular bone harvesting based on the first actual osteotomy plane, to obtain the first trimming submodel and the second trimming submodel.

[0123] The filtering submodule is used to: retain the portions of the first and second trimming sub-models that contain the bone harvesting area, and delete the portions that do not contain the bone harvesting area;

[0124] The repeating submodule is used to: select the next first actual osteotomy plane among multiple first actual osteotomy planes, repeat the above steps, until the jawbone in the preoperative cortical bone model of the mandibular bone harvesting is cut according to all the first actual osteotomy planes of the multiple first actual osteotomy planes, to obtain the actual bone block after the mandibular bone harvesting, and use multiple surfaces of the actual bone block after the mandibular bone harvesting, except for one curved surface of the jawbone surface, as multiple second actual osteotomy planes.

[0125] The present invention also provides a mandibular bone harvesting evaluation system, which may include:

[0126] The data receiving module is used to receive CBCT image data before mandibular bone harvesting and CBCT image data immediately after mandibular bone harvesting of the subject to be evaluated, wherein the subject to be evaluated is a subject who has undergone mandibular bone harvesting.

[0127] The third reconstruction module is used to: obtain the actual bone fragments and multiple second actual osteotomy planes of the patient after mandibular osteotomy based on the preoperative CBCT image data and the immediate postoperative CBCT image data of the patient after mandibular osteotomy using the method described above for reconstructing the mandibular osteotomy plane.

[0128] The first evaluation module is used to obtain the intraoperative bone harvesting parameters and postoperative bone fragment parameters of the patient based on the actual bone fragments obtained after mandibular bone harvesting and multiple second actual osteotomy planes, so as to evaluate the operational safety and bone harvesting effect of the mandibular bone harvesting procedure performed on the patient.

[0129] In one implementation, it may further include:

[0130] The preoperative design module is used to: generate multiple preoperative osteotomy planes for first mandibular bone harvesting based on the bone harvesting guide plate pre-selected for the patient to be evaluated.

[0131] The second trimming module is used to: according to the method of reconstructing the mandibular osteotomy plane described above, replace multiple first actual osteotomy planes with multiple first mandibular osteotomy preoperative design osteotomy planes, trim the mandible in the preoperative cortical bone model of the mandibular osteotomy and retain the part containing the planned osteotomy area, to obtain the planned bone block of the mandibular osteotomy and multiple second mandibular osteotomy preoperative plan osteotomy planes, wherein the multiple second mandibular osteotomy preoperative plan osteotomy planes are all bounded planes;

[0132] The second comparison module is used to compare multiple preoperative planned osteotomy planes for second mandibular bone harvesting with multiple actual second osteotomy planes of the patient to obtain osteotomy displacement errors and osteotomy angle errors between the multiple preoperative planned osteotomy planes for second mandibular bone harvesting and the multiple actual second osteotomy planes of the patient to evaluate the accuracy of the bone harvesting guide plate pre-selected for the patient.

[0133] Figure 10 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 10 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other via the communication bus 840. The processor 810 can call logical instructions in the memory 830 to execute a method for reconstructing the mandibular osteotomy plane, the method including:

[0134] Obtain preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting. The preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting are CBCT image data containing cortical bone and cancellous bone in a preset area. The preset area includes the preset mandibular bone harvesting area and the preset surrounding area of ​​the preset mandibular bone harvesting area.

[0135] Based on the CBCT image data immediately after mandibular bone harvesting, a cortical bone model immediately after mandibular bone harvesting was reconstructed. The cortical bone model immediately after mandibular bone harvesting includes the cortical bone portion of the mandible in the non-bone harvesting area and the osteotomy surfaces of cortical bone in multiple bone harvesting areas.

[0136] Based on the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, multiple first actual osteotomy planes were obtained using the least squares method. Among them, multiple first actual osteotomy planes are all boundless planes.

[0137] Based on the preoperative CBCT image data of mandibular bone harvesting, a preoperative cortical bone model of the mandibular bone was reconstructed.

[0138] The immediate cortical bone model after mandibular bone harvesting is linked with multiple first actual osteotomy planes. Based on the non-harvested cortical bone portion of the mandibular bone in the immediate cortical bone model after mandibular bone harvesting, the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes are registered with the pre-mandibular bone model.

[0139] Based on the registered mandibular bone harvesting immediate postoperative cortical bone model, multiple first actual osteotomy planes, and the preoperative mandibular bone harvesting cortical bone model, the mandible in the preoperative mandibular bone harvesting cortical bone model is trimmed sequentially according to the multiple first actual osteotomy planes, and the part containing the bone harvesting area is preserved, to obtain the actual bone block harvested after mandibular bone harvesting and multiple second actual osteotomy planes, wherein the multiple second actual osteotomy planes are all bounded planes.

[0140] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part 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, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0141] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program that can be stored on a non-transitory computer-readable storage medium, wherein when the computer program is executed by a processor, the computer is capable of performing the methods for reconstructing the mandibular osteotomy plane provided by the above methods, the method comprising:

[0142] Obtain preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting. The preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting are CBCT image data containing cortical bone and cancellous bone in a preset area. The preset area includes the preset mandibular bone harvesting area and the preset surrounding area of ​​the preset mandibular bone harvesting area.

[0143] Based on the CBCT image data immediately after mandibular bone harvesting, a cortical bone model immediately after mandibular bone harvesting was reconstructed. The cortical bone model immediately after mandibular bone harvesting includes the cortical bone portion of the mandible in the non-bone harvesting area and the osteotomy surfaces of cortical bone in multiple bone harvesting areas.

[0144] Based on the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, multiple first actual osteotomy planes were obtained using the least squares method. Among them, multiple first actual osteotomy planes are all boundless planes.

[0145] Based on the preoperative CBCT image data of mandibular bone harvesting, a preoperative cortical bone model of the mandibular bone was reconstructed.

[0146] The immediate cortical bone model after mandibular bone harvesting is linked with multiple first actual osteotomy planes. Based on the non-harvested cortical bone portion of the mandibular bone in the immediate cortical bone model after mandibular bone harvesting, the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes are registered with the pre-mandibular bone model.

[0147] Based on the registered mandibular bone harvesting immediate postoperative cortical bone model, multiple first actual osteotomy planes, and the preoperative mandibular bone harvesting cortical bone model, the mandible in the preoperative mandibular bone harvesting cortical bone model is trimmed sequentially according to the multiple first actual osteotomy planes, and the part containing the bone harvesting area is preserved, to obtain the actual bone block harvested after mandibular bone harvesting and multiple second actual osteotomy planes, wherein the multiple second actual osteotomy planes are all bounded planes.

[0148] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a method for reconstructing the mandibular osteotomy plane provided by the methods described above, the method comprising:

[0149] Obtain preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting. The preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting are CBCT image data containing cortical bone and cancellous bone in a preset area. The preset area includes the preset mandibular bone harvesting area and the preset surrounding area of ​​the preset mandibular bone harvesting area.

[0150] Based on the CBCT image data immediately after mandibular bone harvesting, a cortical bone model immediately after mandibular bone harvesting was reconstructed. The cortical bone model immediately after mandibular bone harvesting includes the cortical bone portion of the mandible in the non-bone harvesting area and the osteotomy surfaces of cortical bone in multiple bone harvesting areas.

[0151] Based on the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, multiple first actual osteotomy planes were obtained using the least squares method. Among them, multiple first actual osteotomy planes are all boundless planes.

[0152] Based on the preoperative CBCT image data of mandibular bone harvesting, a preoperative cortical bone model of the mandibular bone was reconstructed.

[0153] The immediate cortical bone model after mandibular bone harvesting is linked with multiple first actual osteotomy planes. Based on the non-harvested cortical bone portion of the mandibular bone in the immediate cortical bone model after mandibular bone harvesting, the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes are registered with the pre-mandibular bone model.

[0154] Based on the registered mandibular bone harvesting immediate postoperative cortical bone model, multiple first actual osteotomy planes, and the preoperative mandibular bone harvesting cortical bone model, the mandible in the preoperative mandibular bone harvesting cortical bone model is trimmed sequentially according to the multiple first actual osteotomy planes, and the part containing the bone harvesting area is preserved, to obtain the actual bone block harvested after mandibular bone harvesting and multiple second actual osteotomy planes, wherein the multiple second actual osteotomy planes are all bounded planes.

[0155] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units 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 modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0156] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0157] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for reconstructing the osteotomy plane of the mandible, characterized in that, include: Obtain preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting. The preoperative CBCT image data and immediate postoperative CBCT image data of mandibular bone harvesting are CBCT image data containing cortical bone and cancellous bone in a preset area. The preset area includes the preset mandibular bone harvesting area and the preset surrounding area of ​​the preset mandibular bone harvesting area. Based on the CBCT image data immediately after mandibular bone harvesting, a cortical bone model immediately after mandibular bone harvesting was reconstructed. The cortical bone model immediately after mandibular bone harvesting includes the cortical bone portion of the mandible in the non-bone harvesting area and the osteotomy surfaces of cortical bone in multiple bone harvesting areas. Based on the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, multiple first actual osteotomy planes were obtained using the least squares method. Among them, multiple first actual osteotomy planes are all boundless planes. Based on the preoperative CBCT image data of mandibular bone harvesting, a preoperative cortical bone model of the mandibular bone was reconstructed. The immediate cortical bone model after mandibular bone harvesting is linked with multiple first actual osteotomy planes. Based on the non-harvested cortical bone portion of the mandibular bone in the immediate cortical bone model after mandibular bone harvesting, the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes are registered with the pre-mandibular bone model. Based on the registered mandibular bone harvesting immediate postoperative cortical bone model, multiple first actual osteotomy planes, and the preoperative mandibular bone harvesting cortical bone model, the mandible in the preoperative mandibular bone harvesting cortical bone model is trimmed sequentially according to the multiple first actual osteotomy planes, and the part containing the bone harvesting area is preserved, to obtain the actual bone block harvested after mandibular bone harvesting and multiple second actual osteotomy planes, wherein the multiple second actual osteotomy planes are all bounded planes.

2. The method for reconstructing the mandibular osteotomy plane according to claim 1, characterized in that, The process of reconstructing an immediate cortical bone model after mandibular bone harvesting based on immediate CBCT image data includes: Based on the CBCT image data immediately after mandibular bone harvesting, the first effective area of ​​cortical bone in the mandible was determined, and a cortical bone mask was obtained immediately after mandibular bone harvesting. Based on the immediate cortical bone mask after mandibular bone harvesting, a model of the immediate cortical bone after mandibular bone harvesting was reconstructed. Preferably, the step of reconstructing the preoperative cortical bone model of the mandible based on preoperative CBCT image data includes: Based on the CBCT image data before mandibular bone harvesting, the second effective area of ​​cortical bone in the mandible was determined, and a cortical bone mask was obtained before mandibular bone harvesting. Based on the preoperative cortical bone mask for mandibular bone harvesting, a preoperative cortical bone model for mandibular bone harvesting was reconstructed.

3. The method for reconstructing the mandibular osteotomy plane according to claim 2, characterized in that, Based on the cortical bone resection surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, multiple first actual osteotomy planes are obtained using the least squares method, including: Based on each of the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, the first fitting plane that best fits the cortical bone osteotomy surface of each bone harvesting area is obtained using the least squares method. This first fitting plane is used as the first actual osteotomy plane corresponding to the bone harvesting area where the cortical bone osteotomy surface of each bone harvesting area is located, thus obtaining multiple first actual osteotomy planes.

4. The method for reconstructing the mandibular osteotomy plane according to claim 3, characterized in that, The process involves linking the immediate post-mandibular bone harvesting cortical bone model with multiple first actual osteotomy planes, and registering the immediate post-mandibular bone harvesting cortical bone model and multiple first actual osteotomy planes with the pre-mandibular bone harvesting cortical bone model based on the unharvested cortical bone portion of the mandibular bone in the immediate post-mandibular bone harvesting cortical bone model, including: Based on the spatial relationship between the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes, a linkage relationship between the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes is constructed. Taking the unharvested cortical bone portion of the mandibular bone in the immediate cortical bone model after mandibular bone harvesting as a reference, the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes are simultaneously superimposed on the pre-mandibular cortical bone model.

5. The method for reconstructing the mandibular osteotomy plane according to claim 4, characterized in that, The method involves using a registered mandibular bone harvesting model immediately after the procedure, multiple first actual osteotomy planes, and a pre-operative mandibular bone harvesting model. Based on these first actual osteotomy planes, the mandible in the pre-operative mandibular bone harvesting model is sequentially trimmed, retaining the portion containing the harvesting area, to obtain the actual bone fragments harvested after the mandibular bone harvesting procedure and multiple second actual osteotomy planes, including: Select the first actual osteotomy plane from among multiple first actual osteotomy planes; Based on the first actual osteotomy plane, the mandible in the preoperative cortical bone model of the mandibular bone harvesting is trimmed to obtain the first trimmed sub-model and the second trimmed sub-model. The parts of the first and second trimming models that contain the bone harvesting area are retained, while the parts that do not contain the bone harvesting area are deleted. Select the next first actual osteotomy plane among multiple first actual osteotomy planes, and repeat the above steps until the jawbone in the preoperative cortical bone model of the mandibular bone harvesting is cut according to all the first actual osteotomy planes of the multiple first actual osteotomy planes, to obtain the actual bone block after the mandibular bone harvesting, and use multiple surfaces of the actual bone block after the mandibular bone harvesting, except for one curved surface of the jawbone surface, as multiple second actual osteotomy planes.

6. A method for evaluating mandibular bone harvesting, characterized in that, include: The system receives preoperative CBCT images and immediate postoperative CBCT images of the subjects undergoing mandibular bone harvesting. The subjects are those who have undergone mandibular bone harvesting. The preoperative and immediate postoperative CBCT images of the subjects are CBCT images of a pre-defined area containing cortical and cancellous bone. The pre-defined area includes a pre-defined mandibular bone harvesting area and a pre-defined peripheral area of ​​the pre-defined mandibular bone harvesting area. Based on the preoperative CBCT image data and immediate postoperative CBCT image data of the mandibular bone harvesting procedure of the subject to be evaluated, the actual bone fragments and multiple second actual osteotomy planes of the subject to be evaluated after mandibular bone harvesting are obtained by the method of reconstructing the mandibular osteotomy plane as described in any one of claims 1-5. Based on the actual bone fragments obtained after mandibular osteotomy and multiple second actual osteotomy planes, the intraoperative bone harvesting parameters and postoperative bone fragment parameters of the patient under evaluation were obtained to evaluate the operative safety and bone harvesting effect of the mandibular osteotomy performed on the patient.

7. The method for evaluating mandibular bone harvesting according to claim 6, characterized in that, Also includes: Based on the bone harvesting guide plate pre-selected for the patient to be evaluated, multiple preoperative osteotomy planes for first mandibular bone harvesting are obtained, wherein the multiple preoperative osteotomy planes for first mandibular bone harvesting are all boundless planes. According to any of the above methods for reconstructing mandibular osteotomy planes, multiple first mandibular osteotomy planes are replaced with multiple first mandibular osteotomy planes designed before osteotomy. The mandible in the preoperative cortical bone model of mandibular osteotomy is trimmed and the part containing the planned osteotomy area is retained to obtain the planned bone block to be removed before mandibular osteotomy and multiple second mandibular osteotomy planes designed before osteotomy. The multiple second mandibular osteotomy planes designed before osteotomy are all bounded planes. Multiple preoperative planned osteotomy planes for second mandibular bone harvesting were compared with multiple actual second osteotomy planes of the patient to obtain osteotomy displacement errors and osteotomy angle errors between the multiple preoperative planned osteotomy planes for second mandibular bone harvesting and the multiple actual second osteotomy planes of the patient to evaluate the accuracy of the bone harvesting guide plate pre-selected for the patient.

8. A system for reconstructing the osteotomy plane of the mandible, characterized in that, include: The data acquisition module is used to acquire CBCT image data before mandibular bone harvesting and CBCT image data immediately after mandibular bone harvesting. The CBCT image data before mandibular bone harvesting and CBCT image data immediately after mandibular bone harvesting are CBCT image data containing cortical bone and cancellous bone in a preset area. The preset area includes a preset mandibular bone harvesting area and a preset surrounding area of ​​the preset mandibular bone harvesting area. The first reconstruction module is used to: reconstruct the immediate cortical bone model after mandibular bone harvesting based on the immediate CBCT image data after mandibular bone harvesting. The immediate cortical bone model after mandibular bone harvesting includes the cortical bone portion of the mandible in the non-bone harvesting area and the osteotomy surfaces of the cortical bone in multiple bone harvesting areas. The fitting module is used to: obtain multiple first actual osteotomy planes based on the cortical bone osteotomy surfaces of multiple bone harvesting areas in the immediate cortical bone model after mandibular bone harvesting, using the least squares method. Among them, the multiple first actual osteotomy planes are all boundaryless planes. The second reconstruction module is used to: reconstruct the preoperative cortical bone model of the mandible based on the preoperative CBCT image data of the mandibular bone harvesting procedure; The registration module is used to link the immediate cortical bone model after mandibular bone harvesting with multiple first actual osteotomy planes, and to register the immediate cortical bone model after mandibular bone harvesting and multiple first actual osteotomy planes with the pre-mandibular bone harvesting cortical bone model based on the non-bone harvesting area of ​​the mandibular cortical bone in the immediate cortical bone model after mandibular bone harvesting. The first trimming module is used to: based on the registered mandibular bone immediate postoperative cortical bone model, multiple first actual osteotomy planes, and the preoperative mandibular bone model, trim the mandible in the preoperative mandibular bone model according to the multiple first actual osteotomy planes and retain the part containing the bone harvesting area, to obtain the actual bone block after mandibular bone harvesting and multiple second actual osteotomy planes, wherein the multiple second actual osteotomy planes are all bounded planes.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method for reconstructing the mandibular osteotomy plane as described in any one of claims 1 to 5 and / or the method for evaluating mandibular osteotomy as described in any one of claims 6 or 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for reconstructing the mandibular osteotomy plane as described in any one of claims 1 to 7 and / or the method for evaluating mandibular osteotomy as described in any one of claims 6 or 7.

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