Method and system for generating a model for use in intraoral navigation in a patient

Abstract

A computer-implemented method (100) for generating, by one or more computer processors, a 3-dimensional model (100) for use in assisted navigation in the oral cavity of a patient, wherein the method is based on at least one initial scan of an anatomical region of the patient's oral cavity, comprising: receiving an initial data set comprising surface boundary information from the initial scan, and generating a 3-dimensional digital patient model from at least a portion of the initial data set, performing a 3-dimensional surface scan of a portion of the oral cavity using a 3-dimensional surface scanner and thereby acquiring a 3-dimensional surface scan, wherein the 3-dimensional surface scan comprises a region of interest, aligning the acquired 3-dimensional surface scan with at least a portion of the 3-dimensional digital patient model, and definingusing the acquired 3D surface scan and the digital patient model, a spatial transformation designed to align the acquired 3D surface scan and the 3D digital patient model or to bring them to a predetermined degree of overlap, determining position and orientation information of the 3D surface scanner relative to a 3D digital patient model using at least the transformation, and generating a second dataset comprising the position and orientation information of the 3D surface scanner relative to the 3D digital patient model.

Description

Field of invention

[0001] The present invention relates to a method and a system for generating a model for use in navigation in the oral cavity of a patient for specific, but by no means exclusive, application in the planning of a dental procedure. Background of the invention

[0002] Digital software tools for dental procedures and planning utilize precise scan data of the oral cavity, which can include anatomical objects of interest (e.g., teeth) and anatomical structures such as bone and gum tissue, as well as artificial structures like dental prostheses, abutments, and retention systems. Accurate scan data of the oral cavity facilitates the design and positioning of dental prostheses and retention systems in particular.

[0003] In the field of digital dental technology, scan data of anatomical structures are generally acquired optically or radiologically. Optical scanners (i.e., those using visible wavelengths and, in some cases, infrared and / or UV wavelengths) for three-dimensional measurement directly from intraoral surface structures or from extraoral impressions of oral surface structures are widespread and economical. Typically, the surface data is represented by a surface mesh comprising triangular elements, which is routinely stored and exchanged between systems in STL or similar digital surface definition formats.

[0004] Radiological scanners such as digital volume tomography (DVT) or computed tomography (CT) scanners use X-rays to generate volumetric datasets of anatomical structures. Surface representations can also be derived from these datasets by applying thresholding techniques. These techniques analyze the intensity values ​​(measured, for example, in Hounsfield units) of individual scan elements (voxels) to determine whether they exceed or fall below certain thresholds. Radiologically dense structures (hereinafter referred to as "volumetric density" structures and objects), such as teeth, can be identified in this way. The interface of the identified volumetric density scan structures can then be modeled as triangulated surface data (e.g., a triangular surface mesh) and subsequently stored and exchanged between systems in STL or similar digital surface definition formats.

[0005] Calculations using scan data from MRI (magnetic resonance imaging) are more complex, with contour analysis methods based on the gradients of neighboring scan elements being preferred. Even in these cases, however, volumetric structures or objects, such as gums, gingiva, and other tissues, especially soft tissue, can be identified, and their interfaces can be modeled as triangulated surface data for further processing.

[0006] For the aforementioned scanning methods, such as surface scanning using infrared, visible, or UV radiation, as well as volumetric methods like radiological methods such as CBCT or CT scans and, similarly, MRI, so-called marker elements exist. These marker elements are designed to be clearly visible in the three-dimensional measurement data of one or more of the corresponding surface or volumetric scanning procedures—and sometimes even possess features that help to determine their position and orientation with greater precision. Consequently, they can be used to define exact reference points within the dataset when placed and fixed in a position relative to the dentition or jawbone of a patient before scanning. In this way, marker elements can enable the definition of a reference frame within the corresponding scan data with high accuracy.

[0007] In the context of this disclosure, the term "dental restoration" includes any type of partial or complete replacement of a single tooth or multiple teeth. The term "virtual dental restoration" (hereinafter also referred to simply as "dental restoration") is to be understood as including suitable electronic representations of dental restorations, i.e., digital, three-dimensional representations, preferably surface representations, of the jawbone, gingival tissue, marker elements, retention systems, and the like, with sufficient accuracy.

[0008] Custom-designed prostheses are often intended to replace an anatomical feature removed from the existing oral cavity. Besides the importance of precision in the fabrication of dental prostheses (e.g., crowns), preparatory steps (e.g., drilling a receptacle for retention systems) must be performed with very high precision, and proper prosthesis planning requires an accurate model of the patient's anatomy. Similarly, the positioning of all elements, such as retention systems, placed in the model of the patient's anatomy must be reproduced with very high accuracy in the planning phase, in the corresponding position of the patient's actual anatomy, both in terms of position and orientation.

[0009] To achieve the latter, existing techniques involve placing and attaching marker elements in dental templates and / or relative to the patient's dentition or jawbone, thereby creating a reference frame in the digital model of the patient's dental status. This reference frame forms the basis for digital implant planning and subsequently for the fabrication of a drill guide, such as a 3D-printed, cast, or thermoformed template. This template can be placed over the patient's remaining teeth, screwed into the jawbone, or otherwise anchored in position and features one or more guide openings to control the correct alignment and position of a drill and, subsequently, a dental post to anchor a dental prosthesis.This process is very complex and consequently expensive, usually requires several visits by the patient to the doctor's office, and despite the successes achieved in terms of accuracy, still involves a large number of potential sources of error.

[0010] There is a growing need for greater immediacy and lower costs in dental treatments. Particularly in connection with procedures that can be completed in one or at least fewer appointments than in the past, novel approaches are being sought to shorten the planning and execution of dental treatments. Consequently, it is an object of the present invention to mitigate at least some of the disadvantages of known dental restoration methods.

[0011] DE 10 2023 106 238 B3 relates to the creation of a virtual three-dimensional model of an alveolus in which an object is placed, and a method for creating such an alveolus model.

[0012] US 2024 / 0 144 600 A1 concerns the 3D modeling of tooth structures, in particular the creation of textured 3D models of tooth structures.

[0013] US 2023 / 0218375A1 relates to a data processing device, a data processing method and a data processing system that processes three-dimensional data, including the position of each point of a group of points that represents at least the surface of an object, wherein the three-dimensional data is acquired by a three-dimensional scanner.

[0014] US 2020 / 0 306 010 A1 refers generally to the planning of orthodontic treatments.

[0015] WO 2016 / 010 737 A2 generally concerns a computer-assisted surgical system and in particular a system for determining the reference position based on medical data collected before the operation.

[0016] WO 2014 / 122 301 A1 concerns a method and a system for tracking an object in relation to a body for image-guided surgery.

[0017] The present invention is defined by independent claims 1, 16 and 17. Embodiments are the subject of the respective dependent claims. Brief description

[0018] The problem is at least partially solved by a computer-implemented method for generating a 3-dimensional model for use in navigation within a patient's oral cavity. One embodiment comprises a method for generating such a 3-dimensional model according to independent claim 1. Another embodiment provides a system for generating a 3-dimensional model according to independent claim 16.

[0019] Dependent claims 2 to 15 represent different embodiments of the invention.

[0020] According to one aspect of the invention, a computer-implemented method for generating, by one or more computer processors, a 3-dimensional model for use in assisted navigation in a patient's oral cavity is provided, wherein the method is based on at least one first scan of an anatomical region of the patient's oral cavity. The method comprises: Receiving an initial data set, which may include surface boundary information from the initial scan (which, it should be noted, may include surface scan data obtained from a surface scan or generated from volumetric density scan data); Generating a 3-dimensional digital patient model from at least part of the first data set; Performing a 3-dimensional surface scan of a part of the oral cavity using a 3-dimensional surface scanner, thereby capturing a 3-dimensional surface scan, wherein the 3-dimensional surface scan includes a region of interest; Aligning the captured 3-dimensional surface scan with at least a part of the 3-dimensional digital patient model; Specify, using the captured 3-dimensional surface scan and the digital patient model, a spatial transformation designed to align the captured 3-dimensional surface scan and the 3-dimensional digital patient model or to bring them into a predetermined degree of overlap; Establishing positional or orientation information of the 3-dimensional surface scanner relative to a 3-dimensional digital patient model using at least the transformation; and Generating a second data set, encompassing the position and orientation information of the 3-dimensional surface scanner relative to the 3-dimensional digital patient model.

[0021] The anatomical region typically includes at least one type of patient tissue. Tissue types within the patient's anatomical region may include bone and / or dental tissue (i.e., enamel, dentin, and / or cementum), as well as soft tissue (e.g., gingival tissue). Similarly, the 3D digital patient model may include one or more portions of jawbone, gingival tissue, and one or more teeth.

[0022] The invention recognizes that a patient's dental surfaces represent a highly unique and detailed topology that can be used to precisely position an object relative to them with very high accuracy. Accordingly, once a detailed 3D digital model of the patient's anatomy has been created, a navigation support system can very precisely inform a user or a robotic dental treatment system about the position and orientation of the field of view of a 3D surface scanner (and consequently the device itself) relative to the patient's dentition (or an impression thereof), based on the surface scan of the patient's anatomy or dental impression captured by the 3D surface scanner.

[0023] Since the first data set includes surface boundary information for the patient's jawbone and consequently the digital patient model can also represent the jawbone relative to the patient's dentition in an exact manner, the method according to the invention also serves to provide information about the position and orientation of the field of view of a 3-dimensional surface scanner relative to such a jawbone of a patient, even if there is no visibility of the bone structure in the field of view of the 3-dimensional surface scanner.

[0024] Accordingly, the invention allows the use of marker elements to be avoided or at least significantly reduced. Marker elements are no longer required to support the digital treatment planning process of a dental procedure or to manufacture drill guides for placing dental anchorage systems. Instead, more immediate feedback and support during treatment can be provided, allowing a user or, alternatively, a robotic navigation and treatment system to determine its exact position relative to the dentition or oral anatomy of a patient. Under certain circumstances, the use of the system according to the invention can even minimize exposure to X-rays.

[0025] In one embodiment, the second data set further comprises at least a part of the 3-dimensional digital patient model.

[0026] In one embodiment, the surface boundary information of the first data set includes surface segments, wherein the surface segments have identifiers assigned to them that identify the type of tissue that each surface segment represents, the tissue type being selected from a group that includes gingival tissue, bone tissue, and dental tissue.

[0027] In the context of carrying out the method according to the invention, this can include identifying elements of the anatomical region of the patient's oral cavity in the 3-dimensional digital patient model, i.e., by a user or a suitably trained artificial neural network, but can also include storing identifiers in association with surface segments that indicate the tissue type in the process of generating the 3-dimensional digital patient model, that is, storing previously assigned identifiers in association with such a surface segment, for example, when the first data set is based on a previously obtained volumetric density scan and is subsequently processed.

[0028] The surface boundary information of the first data set was generated from a group of density scan segments from the second data set, which is merged in a conventional 3D coordinate system with a set of corresponding surface scan segments from a surface scan, wherein the merging can be carried out using appropriately marked surface scan segments and their alignment, preferably geometrically, to segments of volumetric density scans, for example by identifying surface scan segments and segments of volumetric density scans that are similar to each other in terms of shape and volume.This means that in situations where, according to the prior art, such merging might depend on the position and orientation information of one or more marker elements within the three-dimensional measurement data, the use of such marker elements can be avoided when implementing the present invention.

[0029] The present invention may include scaling and applying translational and rotational transformations to the surface scan segments and / or segments from volumetric density scans to achieve the best possible alignment of the surface scan segments and the segments from volumetric density scans in the general 3D coordinate system; in the process of merging the surface scan segments and the segments from volumetric density scans, i.e., when aligning the segments of both scans, for example when a geometric overlap exists, elements from both the surface scan and the volumetric scan that represent the dental surface of the person's dentition may be used.

[0030] The second dataset can include a digital representation of the 3D surface scanner within a general reference frame, where the digital representation of the 3D surface scanner is positioned and oriented according to its location and orientation. The digital representation of the 3D reference scanner can be schematic, i.e., created by integrating a 3D surface model of the geometry of the 3D surface scanner, where the 3D surface model of the surface scanner is positioned and oriented according to the location and orientation of the 3D surface scanner at the time the 3D surface scan of the region of interest was acquired.

[0031] In one embodiment, the second data set can be transferred to a visualization system configured to display at least a portion of the second data set to a user in a 2-dimensional, pseudo-3-dimensional, or 3-dimensional image. The visualization system can further be configured to enhance or overlay the display of the portion of the second data set with a view of the patient's oral cavity.

[0032] These embodiments allow a user to obtain a very fluid and natural view of the patient's oral cavity (either through an image display or a live view) while simultaneously providing the user with visual feedback on the position and orientation of the 3-dimensional surface scanner in the patient's oral cavity and relative to the technique and the patient's jaw.

[0033] In one embodiment, the second data set can be generated as a 3-dimensional output model, which allows simplified post-processing of the information contained in the second data set, for example in the process of designing dental prostheses or in developing a plan for dental treatment or control that includes the placement of a dental anchorage system.

[0034] In one embodiment, a region of interest in the 3-dimensional output model can be defined based on the dental treatment or control plan, and the region of interest can be identified in the 3-dimensional output model, for example by applying a specific label to sections of the 3-dimensional output model that lie within the region of interest, thus allowing, for example, easier highlighting of such areas in the output of the visualization system or the definition of a "no-go area" when the 3-dimensional output model is loaded into a robotic navigation and treatment system to perform a dental procedure via a robotic (assistive) system.

[0035] In one example, the procedure involves generating the second dataset as a 3D output model. For instance, the procedure might include transferring the second dataset to a navigation system designed to display the 3D output model. In addition to the 3D patient model, the navigation system could receive a treatment or check-up plan, identify one or more deviations of the 3D output model from the treatment or check-up plan, and flag the deviations in the 3D output model.

[0036] In one embodiment, the method comprises acquiring and updating the 3D surface scan, continuously or in real time. This ensures an immediate or near-immediate update of the second data set generation and thus contributes to making the use of, for example, a (robotic) visualization and navigation system together with such an embodiment a near-real experience for the user. The barriers to using such a system can be reduced, making the advantages for the patient particularly clear due to the higher precision of navigation achieved with the system according to the invention.

[0037] In one embodiment, the 3D surface scanner can include a dental instrument, such as a dental drill, a dental probe, or another dental instrument suitable for determining a patient's dental status or for acting on their teeth, gums, or jawbone, either integrally formed with it or mounted on it. Such an embodiment is particularly useful when the invention is used as a navigation support system for a user during a dental examination or treatment procedure, as it ensures that the field of view of the 3D surface scanner always precisely "sees" the area on which the dental instrument would act.

[0038] In a further embodiment, as described above, the invention comprises transmitting the second data set to a robotic navigation system designed to control or assist the navigation of a dental instrument, for example a dental drill or dental probe or another type of dental instrument, based on the position and orientation information contained in the second data set.

[0039] In one embodiment, aligning at least one area of ​​the 3D digital patient model with the acquired 3D surface scan comprises exclusively dental surfaces of the 3D digital patient model. Such alignment could, for example, be performed by applying a least squares method to determine the best possible match between the surface structures (topology) encoded in the 3D digital patient model and those from the 3D surface scan. Alternative known methods for determining the best possible matches of topologies are known in the art and are therefore not described in detail.

[0040] In a further embodiment, when aligning at least a portion of the 3D digital patient model with the acquired 3D surface scan, only surface boundary information from the first data set containing segments labeled as dental tissue is used. This can facilitate the determination of the best possible match between the 3D digital patient model and the acquired 3D surface scan, since a patient's dental surfaces represent a unique, extremely detailed, and static topology that can serve as a basis for the highly precise alignment of the acquired 3D surface scan with the 3D digital patient model.

[0041] In one embodiment, the first data set comprises labeled surface scan segments that form a 3-dimensional surface model of a corresponding object recognized and segmented from the surface scan data, each surface scan segment having a corresponding label that identifies the surface scan segment. In such embodiments, the method comprises: Receiving a third dataset with labeled segments of a volumetric density scan, wherein each labeled segment of a volumetric density scan comprises a 3-dimensional volumetric density model of an interface of a corresponding object, which was detected and segmented from data of a volumetric density scan of the anatomical region, and each segment of a volumetric density scan has a corresponding label that identifies the segment of the volumetric density scan; Merging labeled surface scan segments from the first dataset with labeled segments of a volumetric density scan from the third dataset into a common 3D coordinate system; and

[0042] Generating the 3-dimensional digital patient model from at least the part of the first data set that was merged with the labeled segments of a volumetric density scan.

[0043] In accordance with this aspect, a computer-implemented procedure for planning a dental procedure is also provided, including: the method for generating, by one or more computer processors, the 3-dimensional model for use in navigation within a patient's oral cavity, as described above; and Generating an overlay dataset comprising an overlay of at least a portion of the digital patient model and at least a portion of the 3-dimensional surface scan.

[0044] In one embodiment, the dental procedure includes the implantation of a dental prosthesis or a dental prosthesis support structure, for example, dental anchoring systems.

[0045] According to a further aspect, the invention provides a system for generating a 3-dimensional model for use in assisted navigation in a patient's oral cavity. The system comprises: at least one computer processor; a storage unit; a 3-dimensional surface scanner for performing a 3-dimensional surface scan of a portion of a patient's oral cavity to acquire a 3-dimensional surface scan encompassing a region of interest; and, optionally, at least one visualization device and / or a robotic navigation (assistance) system, wherein the storage unit stores instructions which, when executed by the computer processor, implement the inventive method according to one of the aspects or embodiments described above.

[0046] In particular, such a system comprises a generator for a 3-dimensional digital patient model, designed to generate a 3-dimensional digital patient model from at least a part of an initial dataset of surface boundary model data from an intraoral scan of an anatomical region of the patient's oral cavity; a surface scan alignment unit designed to align the captured 3-dimensional surface scan with at least a part of the 3-dimensional digital patient model; a device for determining the spatial transformation in order to determine a spatial transformation using the captured 3-dimensional surface scan and the digital patient model, which is designed to align or match the captured 3-dimensional surface scan and the 3-dimensional digital patient model; a scanner position and orientation determination unit, designed to determine a position and orientation of the 3-dimensional surface scanner relative to the 3-dimensional digital patient model using at least the transformation; and an output generator designed to output a second data set comprising at least a part of the 3-dimensional digital patient model and the position and orientation information of the 3-dimensional surface scanner relative to the 3-dimensional digital patient model.

[0047] In one embodiment, the output generator system is configured to generate the second data set in such a way that the parts of the 3-dimensional digital patient model and the digital representation of the 3-dimensional surface scanner are transformed into a common reference frame in which the digital representation of the 3-dimensional surface scanner can be positioned and oriented according to the position and orientation specified by the scanner position and orientation determination unit.

[0048] In one embodiment, the system is designed to continuously or in real time read further 3-dimensional surface scan information from the 3-dimensional surface scanner and to continuously or in real time update the 3-dimensional surface scan and thus the second data set.

[0049] In one embodiment, the 3-dimensional surface scanner comprises a dental instrument, for example a dental drill, a dental probe or another dental instrument suitable for determining the dental status of a patient or for acting on his teeth, gums and jawbone, or it is formed integrally with or mounted on it.

[0050] The present invention utilizes the understanding that the geometry and specific position of a person's tooth surface are unique and can therefore be considered a highly precise three-dimensional topology, which itself can be regarded as a defining reference frame. Consequently, the use of marker elements in the process of acquiring the three-dimensional measurement data and generating the datasets based thereon can be avoided. Accordingly, in one embodiment, the digital patient model of the present invention does not include a digital representation of a marker element.

[0051] In yet another aspect, the invention comprises a computer program code which, when loaded into a storage device and executed by a computer processor in communicative connection with a 3-dimensional surface scanner to perform a 3-dimensional surface scan of a part of a patient's oral cavity, implements the inventive method according to one of the aspects and / or one of the embodiments as described above in a suitably configured computer in order to create a system for generating a 3-dimensional model for use in assisted navigation in a patient's oral cavity. Brief description of the drawings

[0052] The invention is explained in more detail by the following detailed description together with the drawings. In the following detailed description, the same reference numerals denote the same elements unless otherwise specified.

[0053] While the following detailed description describes certain embodiments of the invention in more detail, it should be noted that features described in the context of only one of the embodiments should nevertheless also be available in the context of any other embodiment of the invention or in combination with it, whether they are described in the detailed description or not, unless such a combination of features would lead to meaningless results.

[0054] The following detailed description is in no way intended to limit the invention to the specific embodiments or combinations of features therein; instead, the invention is limited and defined exclusively by the appended claims. Fig. 1A is an overview representation of the system for generating a model for use in intraoral navigation in a patient according to an embodiment of the present disclosure; Fig. Figure 1B is an overview of the processor and memory of the system. Fig. 1A according to an embodiment of the present disclosure; The Fig. 2A and Fig. 2B illustrate exemplary flowcharts of procedures for generating a model for use in intraoral navigation in a patient according to embodiments of the present disclosure; The Fig. Figures 3A to 3O illustrate an exemplary embodiment of a method for generating a model for use in intraoral navigation in a patient according to embodiments of the present disclosure; The Fig. 4A, Fig. 4B, Fig. 5A and Fig. Figure 5B shows the implementation of various aspects of the present disclosure in the form of a first exemplary graphical user interface; The Fig. Figures 6A to 6J show the implementation of various aspects of the present disclosure in the form of a second exemplary graphical user interface; The Fig. Figures 7A to 7T show the implementation of various aspects of the present disclosure in the form of a third exemplary graphical user interface. Detailed description

[0055] One aspect of the invention is the generation of a 3-dimensional model for use in navigation within a patient's oral cavity. One embodiment comprises a method for generating such a 3-dimensional model.

[0056] Fig. 1A is an overview representation of a computer-activated system 100 for generating a model for use in intraoral navigation in a patient according to an embodiment of the present disclosure, shown with external or remote services 102. Fig. 1B is an overview of the processor 104 and the memory 106 of the system 100. Fig. 1A according to an embodiment of the present disclosure.

[0057] Referring to the Fig. 1A and Fig. 1B, the system 100 comprises at least one processor 104, a memory 106 (comprising local memory 108 and mass storage 110), one or more input devices 112 (including an intraoral scanner in the form of a 3-dimensional surface scanner 114), one or more output devices 116 (including at least one display 118 on which a graphical user interface (GUI) 120 is generated), and one or more network adapters 122. The system 100 also comprises a bus 124 to facilitate communication between the processor 104, the memory 106, input devices 112, output devices 116, and network adapters 122.It should be noted that the 3-dimensional surface scanner 114 is in data exchange with the bus 124 and that this data exchange can be wired or wireless; in the latter case, the data exchange is facilitated by a wireless protocol (not shown) such as Bluetooth (brand) or Wi-Fi (brand).

[0058] Remote services 102 include a surface scanning service 130, a volumetric density scanning service 132, a segmentation service 134, and a dental planning service 136.

[0059] The processor 104 implements programs and applications read from memory 106, which implement various functions of the system 100, as described below. Consequently, the processor 104 comprises a scan segment merging device 230, a generator 232 for generating a 3-dimensional digital patient model, an update device 234 for a 3-dimensional surface scan, a surface scan alignment unit 236 (which includes, for example, an object detection device 238 that implements object detection), a spatial transformation setting device 240, a scanner position and orientation setting device 242, a navigation system 244 (which includes a display processing device 246 and a deviation detection device 248), a display generator 250, and an output generator 252.

[0060] Memory 106 comprises program and application code 260, designed to be read and executed by processor 104, enabling processor 104 to perform the various functions described above. Memory 106 also comprises surface boundary models 262 (which may include labeled surface scan segments), received from surface scan service 130 or scan service 132 for determining volumetric density from remote services 102; data 264 from volumetric density scans (which may include labeled segments of a volumetric density scan), received from scan service 132 for determining volumetric density (from remote services 102); merged segments 266 from surface scans and volumetric density scans (generated and output by the scan segment merger device 230); and captured 3D surface scans 268 (received from the 3D surface scanner 114).the position and orientation of the 3-dimensional scanner 270 (generated and output by the scanner position and orientation determination device 242), plans 272 for dental treatment or control (received by the external dental planning service 136) and displays 274 (generated and output by display generator 250).

[0061] Network adapters 122 facilitate communication between the system 100 and remote services 102.

[0062] The Fig. 2A and Fig. Figure 2B illustrates exemplary flowcharts of methods 300 and 320 for generating a model for use in intraoral navigation in a patient according to embodiments of the present disclosure. Method 300 of Fig. 2A can be considered a simple method for generating such a model, whereas method 320 of Fig. 2B may be considered a complex procedure for generating such a model, but it is understood that procedures 300 and 320 have some common steps and embody the same core techniques.

[0063] Referring to Fig. 2A, Procedure 300 is a method for automatically generating, by Processor 104, a 3-dimensional model for use in navigation within a patient's oral cavity. For this purpose, Procedure 300 uses at least one intraoral surface scan of an anatomical region of the patient's oral cavity. The anatomical region comprises at least one tissue of the patient.

[0064] In step 302, system 100 receives an initial dataset of surface boundary model data from an intraoral scan. This initial dataset may include surface scan data obtained from a first surface scan and received by remote surface scanning service 130 of remote services 102. Alternatively, the initial dataset may be generated from volumetric density scan data received by scanning service 132 for determining volumetric density from remote services 102.

[0065] Step 302 may include saving the first data set in surface boundary models 262.

[0066] In this embodiment, the first data set comprises one or more identified surface scan segments, each of which comprises a single segment corresponding to objects and / or features detected by image recognition and segmentation processing (for example, by the segmentation service 134) in a surface scan of the oral cavity and, in particular, the anatomical region of interest.In this embodiment, the surface scan data is generated by the remote surface scanning service 130, which can perform one or any combination of the following operations: acquiring surface scan data acquired by a surface scanner (for example, an optical scanner or a camera), converting the surface scan data into a 3-dimensional model accessible to the processor(s) 104 of the system 100, processing or converting it into another format, if necessary, to prepare it for display on the display 118, and storing it in a computer-readable file as surface boundary models 262 of memory 106. In an alternative embodiment, the system 100 comprises the surface scanning service 130; in such embodiments, the method 300 comprises the steps performed by the surface scanning service 130.

[0067] The remote services 102 can also access the segmentation service 134, which is trained to receive scan data (whether surface (IOS) or volumetric density (CBCT or CT) scan data) and use image processing, extraction, and classification to segment received scan images containing an anatomical area of ​​interest into different identified objects and assign a classification identifier to each segment. The segmentation service 134 can provide the segments in the form of individual virtual 3D segment models, each of which is a digital 3D representation of the respective anatomical part or feature of the patient's anatomy.In one embodiment, the segmentation service 134 provides each segment as a single digital 3D model, preferably (but not exclusively) in STL format as a triangular mesh or a point cloud.

[0068] In an alternative embodiment, the system 100 comprises the segmentation service 134. In such an embodiment, the method 300 comprises the steps performed by the segmentation service 134.

[0069] In step 304, generator 232 generates a 3-dimensional digital patient model from at least a part of the first data set.

[0070] The GUI 120 can include a 3D model display field for showing the 3-dimensional digital patient model (in this embodiment, based on the surface scan of the area of ​​interest). The GUI 120 includes various user controls that allow the user to instruct the display generator 250 to perform various operations, such as, but not limited to: selecting and loading patient scan data sets; selecting and editing display views; selecting content to display on the GUI 120; selecting objects of interest and / or identifiers of objects of interest that may be contained in a patient's scan data; and selecting and displaying identifiers, descriptions, and images of implants, prostheses, materials, etc., in connection with planning a patient's dental treatment.

[0071] In step 306, a 3D surface scan of a portion of the patient's oral cavity is performed using the 3D surface scanner 114, capturing a 3D surface scan that encompasses a region of interest. This region of interest could be, for example, a diseased tooth or the proposed position of a dental implant or prosthesis.

[0072] In step 308, the surface scan alignment unit 236 aligns the 3D surface scan acquired in step 306 with at least a portion of the 3D digital patient model generated in step 304, for example, by identifying features common to both using object or feature recognition (implemented by the object recognition unit 238). The surface scan alignment unit 236 outputs the results of this process, for example, in the form of data mapping pixels or voxels of the 3D surface scan acquired in step 306 that have been determined to correspond to pixels or voxels of the 3D digital patient model.

[0073] In step 310, the spatial transformation device 240, which uses as inputs the 3-dimensional surface scan acquired in step 306, the 3-dimensional digital patient model generated in step 304 and the output of the surface scan alignment unit 236, defines a spatial transformation designed to align or fit the acquired 3-dimensional surface scan and the 3-dimensional digital patient model to each other.

[0074] In step 312, the scanner position and orientation determination device 242 determines the position and orientation of the 3-dimensional surface scanner 114 relative to the 3-dimensional digital patient model using at least the transformation. In step 314, the generator 252 generates a second data set comprising the position and orientation of the 3-dimensional surface scanner 114 relative to the 3-dimensional digital patient model. The second digital data set can be output to a storage device, such as memory or non-volatile storage. The storage device can be located remotely from the system 100 or consist of graphics memory of the system 100 (or a remote system) so that the position and orientation can be used when generating a display.

[0075] It should be noted that procedure 300 uses only patient-specific surface scan data (captured by surface scanning service 130) when generating the 3-dimensional digital patient model. Procedure 320 of Fig. Method 2B is also a method for automatically generating, by processor 104, a 3-dimensional model for use in navigating a patient's oral cavity using an intraoral surface scan of the patient's oral cavity anatomical region. However, method 320 also uses volumetric density scan data (e.g., from CT or CBCT scans) from scan service 132 to determine the volumetric density when generating the 3-dimensional digital patient model.

[0076] Referring to Fig. In step 322, system 100 receives an initial data set of surface scan data (in the form of labeled surface scan segments) of the intraoral surface from surface scan service 130 of remote services 102. Each segment comprises a 3-dimensional surface model of a corresponding object that was detected and segmented within the surface scan data. This step may include storing the initial data set in surface boundary models 262. The initial data set is as described above in the context of procedure 300.

[0077] In step 324, system 100 receives a data set of labeled segments from an intraoral surface volumetric density scan from volumetric density scanning service 132, which belongs to remote services 102. Each volumetric density scan segment comprises a 3-dimensional volumetric density model of an interface surface of a corresponding object, detected and segmented from volumetric density scan data from a volumetric density scan of the patient's oral cavity. This step may include saving the data set to volumetric density scan data 264.

[0078] The dataset of labeled segments of a volumetric density scan comprises individual segments corresponding to objects and / or features identified via image recognition and segmentation processing (for example, by the Segmentation Service 134) in one or more volumetric density CT or CBCT scans of the oral cavity and surrounding tissue, typically including the region of interest. The labeled segments of a volumetric density scan are generated and received by the Volumetric Density Scanning Service 132.The volumetric density scanning service 132 can perform one or any combination of the following operations: acquiring data from volumetric density scans acquired by a volumetric density scanner (using volumetric scanning equipment, for example, a cone-beam computed tomography (CBCT) scanner); converting the volumetric density scan data into a 3-dimensional model that can be accessed and read by a processor 104 of the system 100, editing or converting it to another format if necessary to prepare it for display on the display 118, and storing it in a computer-readable file that can be received by the system 100 and stored as volumetric density scan data 264 in memory 106.

[0079] In certain alternative embodiments, the system 100 comprises the scanning service 132 for determining the volumetric density; in such embodiments, the method 320 comprises the steps performed by the scanning service 132 for determining the volumetric density. Similarly, in embodiments in which the system 100 comprises the segmentation service 134, the method 320 comprises the steps performed by the segmentation service 134.

[0080] In step 326, the scan segment merging device 230 combines the labeled surface scan segments and the labeled segments of a volumetric density scan into a common 3-dimensional coordinate system. The received surface scan segments and volumetric density scan segments are generally acquired using different modalities (and thus using different and typically independent scanning devices / equipment), so that the scan data generated by each scanning modality are captured and stored according to a 3D coordinate system specific to the scanning device / equipment by which the data were acquired.Consequently, it becomes important to fit the resulting scan data from each scanner into a common 3-dimensional coordinate system so that similar objects from each scan can be aligned and displayed as occupying the same spatial volume - as they should, since they each represent the same object or feature.

[0081] The result of merging into a common 3D coordinate system is that for each pair of segments from a surface scan and a volumetric density scan corresponding to the same patient object or feature from the scanned anatomical area of ​​interest, there should be one or more corresponding points that "match" in the 3D space of the common 3D coordinate system (i.e., the points from each segment in the segment pair should essentially or exactly coincide). These matching points correspond to a corresponding point on the patient anatomy object / feature in question. Matching points are presented only for those areas of the patient anatomy that the respective scan modality was able to capture.

[0082] Since surface scan data only includes image data visible at the surface, and volumetric scan data includes image data from both the surface and below the surface, only a merging of points from the segment(s) of volumetric density scans that correspond to surface-visible points of the scanned object can be performed (since the segment(s) of surface scans do not contain any data points from below the surface).Ideally, the points of each corresponding (or jointly represented) pair of a surface scan segment and its associated volumetric density scan should align exactly in the common 3-dimensional coordinate system. However, it is possible that the points will only align substantially (that is, coincide within a margin of error) due to differences in accuracy between the scan modalities, as well as differences in the resolution and generation accuracy of the 3-dimensional scan segment models generated for each scan modality. Nevertheless, merge step 326 should result in surface scan segments corresponding to (or also represented in) scanned objects that occupy approximately the same space in the 3-dimensional coordinate system as similar regions of the associated object represented by corresponding volumetric density scan segments.

[0083] Consequently, step 326 yields the two sets of segments (surface segments and volumetric segments) that are to be visible, superimposed, or otherwise combined as desired, for example, in the common 3-dimensional coordinate system.

[0084] In step 328, generator 232 generates a 3-dimensional digital patient model from at least a portion of the first data set, combined with the labeled segments of a volumetric density scan. In step 330, a 3-dimensional surface scan of a portion of the patient's oral cavity is performed using the 3-dimensional surface scanner 114, capturing a 3-dimensional surface scan that includes a region of interest. The region of interest can be, for example, a diseased tooth or the proposed position of a dental implant or prosthesis.Optionally, in step 332, the 3-dimensional surface scan is repeatedly or continuously or in real time updated with the 3-dimensional surface scanner 114, so that the surface scan that develops as the 3-dimensional surface scanner 114 is moved in its position or orientation is captured.

[0085] The 3D model display field of the GUI 120 can be used to display the 3-dimensional digital patient model (in this embodiment based on the surface scan and the data from scans of the volumetric density of the area of ​​interest).

[0086] In step 334, the surface scan alignment unit 236 aligns the 3D surface scan acquired in step 330 (or updated in step 332) with at least a portion of the 3D digital patient model generated in step 328, for example, by identifying features common to both using object or feature recognition. The surface scan alignment unit 236 outputs the results of this process, for example, in the form of data mapping pixels or voxels of the 3D surface scan acquired in step 330 or 332 that have been determined to correspond to pixels or voxels of the 3D digital patient model.

[0087] In step 336, the spatial transformation device 240, which uses as inputs the 3-dimensional surface scan acquired in step 330 / 332, the 3-dimensional digital patient model generated in step 328 and the output of the surface scan alignment unit 236, defines a spatial transformation designed to align or fit the acquired 3-dimensional surface scan and the 3-dimensional digital patient model to each other.

[0088] In step 338, the scanner position and orientation determination device 242 determines the position and orientation of the 3-dimensional surface scanner 114 relative to the 3-dimensional digital patient model using at least the transformation.

[0089] In step 340, the generator 250 generates the second data set, comprising at least a part of the digital patient model and a digital representation of the 3-dimensional surface scanner 114 in a common reference frame, wherein the digital representation of the 3-dimensional surface scanner is positioned and oriented according to the position and orientation determined in step 338.

[0090] The second data set can be stored or output to display 274 of memory 106 (for example, by the output generator 252) and is suitable for display on the screen of a computer or other computing device (for example, with the 3D model display field of the GUI 120 on display 118), so that a user can check whether the 3D digital patient model and the digital representation of the 3D surface scanner 114 are correctly positioned and aligned relative to each other. The display generator 250 can optionally generate the second data set as an editable 3D model.

[0091] The second data set is particularly useful in embodiments in which the 3-dimensional surface scanner 114 includes, is formed integrally with, or is mounted on a dental drill, dental probe, or other dental instrument, as this allows the user to determine whether the 3-dimensional surface scanner 114 (and consequently the dental instrument) is positioned and oriented as desired relative to the intraoral region of interest.

[0092] In step 342, the display generator 250 outputs the second data set (for example, in the form of an editable 3D model) to the navigation system 244. The navigation system 244 is configured to convert the second data set into a display for viewing and editing using the 3D model display field of the GUI 120. The display editing unit 246 of the navigation system 244 provides the GUI 120 with user controls that allow the user to control the GUI 120 to perform various operations, for example, but not limited to: selecting and loading scan data sets of a patient, selecting and editing display views (e.g.,(rotating, zooming in or out of the display), selecting content to display on the GUI 120, selecting objects of interest and / or identifiers of objects of interest that may be contained in a patient's scan data, selecting and displaying identifiers, descriptions, and images of implants, prostheses, materials, etc., in connection with planning a patient's dental treatment, etc. Consequently, the user can navigate through the 3D digital patient model while viewing the model of the 3D surface scanner 114 in the correct position and orientation relative to the 3D digital patient model, including as position and orientation evolve in response to operation of the 3D surface scanner 114 and / or the patient moving their head or jaw.

[0093] Dental treatment or check-up plans are received by System 100 from the remote dental planning service 136 and stored by System 100 in Dental Treatment or Check-up Plans 272 in memory 106. The deviation detection unit 248 of the navigation system 244 is configured to retrieve a dental treatment or check-up plan from the Dental Treatment or Check-up Plans 272 or from the Dental Planning Service 136 in order to identify one or more deviations of the second data set from the Dental Treatment or Check-up Plan and to modify the display so that these deviations become apparent. The deviations can be recognized as inputs by the surface scan alignment unit 236 using the corresponding dental treatment or check-up plan and the 3-dimensional digital patient model.Changing the display to detect deviations can be achieved by overlaying the deviations – for example, by marking or coloring areas with deviations – on the editable 3-dimensional model.

[0094] The Fig. Figures 3A to 3O illustrate an exemplary embodiment of an aspect of the present invention, according to which the method 320 of Fig. 2B is applied when generating a 3-dimensional alveolar model from 3-dimensional surface scan segments (the 3D surface model of a corresponding object, recognized and segmented from surface scan data) and volumetric density scan segments (the 3D volumetric density model of an interface of a corresponding object, recognized and segmented from volumetric density scan data) in conjunction with an object. In the illustrated embodiment, the object is a tooth, and the generated alveolar model is a dental alveolus equivalent to that part of the outer shape of the portion of the tooth that lies below the gingival line, i.e., the tooth root.

[0095] Fig. Figure 3A shows an example of a 3D surface boundary model 1a, generated from a volumetric density scan. Individual structures in model 1a correspond to actual structures in the patient's oral cavity. As shown, the 3D surface boundary model 1a embodies representations of the anatomical structure of the patient's actual gingival tissue 2, bone 3, and teeth (labeled 11, 12, 13, 14, 15, 16, and 17 according to the notation of the Federation Dentair Internationale (FDI), a tooth numbering system commonly used in the dental industry), alongside other individual teeth (which are not labeled).In one embodiment, the surface boundary model 1a is generated from the volumetric 3D structures represented in the volumetric density scan and extracted by image recognition and segmentation techniques, for example, by thresholding the intensity values ​​(measured in Hounsfield units) of individual scan elements in the X-ray images. In one embodiment, the surface boundary model 1a comprises a point cloud, a triangular or other polygonal mesh, or another digital 3D model.

[0096] Fig. Figure 3B shows an example of a 3D surface model 1b, generated based on a surface scan of the same anatomical area as in Fig. 3A. Individual structures in model 1b correspond to actual structures in the patient's oral cavity. As shown, the 3D surface model 1b represents the anatomical structure of the patient's actual gingival tissue 2 and teeth (labeled 11, 12, 13, 14, 15, 16, and 17 according to the FDI notation). Since bone lies beneath the surfaces of the gums and teeth in a patient's oral cavity, bone information is typically not found in surface scan model 1b.

[0097] The surface scan and the volumetric density scan are obtained by scanning the same oral areas of interest, so that models 1a and 1b comprise corresponding model anatomical structures representing a specific anatomical structure(s) of the patient (e.g., teeth 11, 12, 13, 14, 15, 16, and 17, and gingiva 2). Model 1b comprises a point cloud, a triangular or other polygonal tissue, or other digital 3D model generated from the 3D surface structures depicted in the surface scan.

[0098] As in the Fig. 3A and Fig. As indicated in 3B, model 1a, a volumetric density scan, and surface scan model 1b are surface models of the (generally identical) anatomical area. The 3D surface models 1a and 1b do not include representations of the internal anatomy. This means that neither model contains information about the alveoli or any other structure beneath the visible outer surface of the objects in the model. In the illustrated example, where the object is a tooth, this means that there is no certainty regarding the anatomy of the tooth socket in which the tooth sits, as the alveolus is not represented in the 3D model with the volumetric density scan ( Fig. 3A) still in the 3D surface scan model ( Fig. 3B) is visible.

[0099] Both in model 1a in Fig. 3A as well as in model 1b in Fig. In 3B, only the crown portions of the teeth are modeled; neither of the scan models includes the anatomy of the root or the alveolus in which the tooth sits. While surface detail is helpful for planning a patient's dental or surgical treatment, as well as for designing prostheses, the lack of information about subsurface areas in models 1a and 1b, which pertain to the patient's anatomy below the visible surfaces of the oral cavity, can hinder accurate planning and design.

[0100] To facilitate the generation of an accurate 3D alveolar model, in one embodiment the respective volumetric density scan data and the surface scan data, from which the corresponding 3D surface models 1a and 1b are generated, are transferred to a segmentation application. The segmentation application can be a remote service 244 or a local application (stored in local memory 204 and executed by one or more processors 201). A segmentation processor processes all received surface scan data and volumetric density scan data to automatically detect and extract objects (via an image recognition function) and categorize individual detected objects into labeled categories or classes (via a segmentation function).

[0101] For example, in one embodiment where the object is a tooth in a patient's oral cavity, the segmentation processor receives intraoral surface scan data, CBCT data, or other volumetric density scan data and processes each of these scan datasets to detect objects and label detected objects as the individually identified teeth, gums, bone, and possibly other objects such as fillings, implants, etc., detected in the received scan data. The segmentation processor labels detected objects with appropriate object type tags that are associated with the object type (or classification) of the detected object.

[0102] For example, the segmentation processor may detect an object in the 3D model or scan data that corresponds to tooth type 16 and assign the object type label "16" (or another unique label that classifies the detected object as belonging to the unique object type corresponding to the patient's actual tooth 16). The segmentation processor detects and classifies (i.e., "labels") detected data segments in the scan data into a multitude of individual segments, as well as belonging to different detected object types.

[0103] Preferably, the individual data segments comprise a 3D surface model representing the scanned actual object (e.g., a scanned tooth, parts of the gums, bone, implant, etc.). In one embodiment, each segment corresponds to a single object in the patient's oral cavity and is labeled as such. Each segment comprises a self-contained 3D model represented as a 3-dimensional triangular (or other polygonal) mesh.

[0104] Referring to Fig. 3C, a segmentation processor can detect representations of individual teeth 11, 12, 13, 14, 15, 16, and 17 in the patient's volumetric density scan and segment each detected representation of each tooth 11, 12, 13, 14, 15, 16, and 17, of the gingiva 2, and of the bone 3 into corresponding independent segments 11a, 12a, 13a, 14a, 15a, 16a, 17a, 2a, and 3a, which together form a segmented model 10a of the volumetric density scan. Each segment is converted into an independent surface mesh, for example, a 3D triangular mesh, and each segment can be selected independently (for example, when presenting the segmented model on a graphical user interface (GUI)), as explained below.

[0105] Since segments 11a-17a, 2a, and 3a were extracted from volumetric scan data, each segment contains all available information from the volumetric density scan. This means that objects (such as nerve canals) and parts of objects (such as tooth roots) that cannot be captured in a surface scan because they lie beneath the visible surfaces inside and outside the patient's mouth are nevertheless modeled in the volumetric density scan segments. Each segment from a volumetric density scan includes all object information (based on what is captured in the volumetric scan data), even from below the surfaces of the scanned anatomical area of ​​the patient. That is, each of teeth 11a-17a includes the root information that is clearly visible in the segmented model.

[0106] Similarly, a segmentation processor, referring to Fig. 3D representations of individual teeth 11, 12, 13, 14, 15, 16, and 17 in the patient's surface scan are recognized, and each recognized representation of each tooth 11, 12, 13, 14, 15, 16, and 17, as well as of the gingiva 2, is segmented into a corresponding independently selectable segment 11b, 12b, 13b, 14b, 15b, 16b, 17b, and 2b, which together form a segmented surface scan model 10b. Each segment is converted into an independent surface mesh, for example, a 3D triangular mesh.

[0107] While segmented model 10b encompasses all segments of the patient's scanned anatomical area, each segment is an independently selectable 3D model of the corresponding scanned object. Accordingly, each segment 11b-17b and 2b can be viewed individually, as shown, for example, in Fig. Figure 3I is shown (which alone shows tooth segment 16b corresponding to patient tooth 16). Tooth segment 16b comprises only that part of tooth 16 that is present in the surface scan. Consequently, tooth segment 16b represents only the crown of tooth 16, since only the crown (the part of tooth 16 located above the gingival line) is visible during the surface scan.

[0108] Fig. Figure 3E shows the segmented surface model 10a of the volumetric density scan and the segmented surface model 10b of the surface scan, merged into a common 3-dimensional coordinate system. Typically, independent imaging systems are used to acquire the surface scan data and the volumetric density scan data. For example, an intraoral scanner (IOS) can be used to acquire the surface scan of the patient's oral cavity, while a CBCT scanner can be used to acquire the patient's volumetric density scan. Both scans are valuable in that they provide important information and complement each other by giving a more complete picture of the patient's actual oral situation.Surface scanners (for example, optical scanners) can provide details of the visible topography of a patient's dentition in very high resolution, but can only capture surface details and not internal details.

[0109] In contrast, volumetric density scans (such as CT or CBCT scans) can capture internal volumetric and density details of the patient's dentition, such as jaw dimensions and density, complete teeth (including roots), and nerve pathways. Surface scans and volumetric density scans together can form the basis for planning dental treatment and the prosthetic fabrication process.

[0110] Since independent imaging systems acquire image data relative to the specific 3D coordinate system of the imaging system capturing the scan, merging the scans within a single display field with its own 3D coordinate system requires aligning both scans. This process is often referred to as scan alignment or aligning. Methods exist for aligning 3D meshes to a single 3D coordinate system.

[0111] In one embodiment, the surface scan data and the volumetric density scan data are segmented into 3D triangular mesh segments corresponding to individual teeth and jaws. This is followed by the determination of key points for the corresponding tooth segments from the surface scan and the volumetric density scan for each tooth, and then the alignment of these key points in a common 3D coordinate system. This process can be performed, for example, using the CoDiagnostix™ dental implant planning software offered by Dental Wings, Inc. (a Straumann Group company).

[0112] In Fig. In 3E, the positions of segments (11a, 12a, 13a, 14a, 15a, 16a, 17a, 2a, and 11b, 12b, 13b, 14b, 15b, 16b, 17b, and 2b) of the respective segmented models 10a and 10b correspond to the same actual anatomical structures (11, 12, 13, 14, 15, 16, 17, and 2) in the patient's mouth. As can be seen, it is very important that the segments corresponding to parts of the same anatomical structure from each scan type (e.g., internal or surface) are merged in the same 3-dimensional coordinate system. When properly merged, segments representing the same anatomical structure essentially coincide, as shown.

[0113] In one embodiment, a segmentation processor processes the scan data to identify portions of the scan data and classify them into individual segments, which are in turn classified into anatomical structure types based on a set of labeled training data comprising multiple instances of each anatomical structure type. In one embodiment, the segmentation processor is a trained convolutional neural network (CNN) developed from a large dataset of scan images obtained from a large number of diverse individuals with varying structural anatomical features, including the presence (or absence) of different teeth, gums, bone, and other natural and artificial structures (e.g., implants, prostheses, etc.).

[0114] Fig. Figure 3F illustrates the problem that occurs when a dental scan segment 16b (see Fig. 3D) is removed from the surface scan. As illustrated, removing the crown segment 16b results in a hole 16c in model 10b where the crown 16b should actually be. This is to be expected, since the segmented 3D surface scan model 10b is generated solely based on the surface scan data, which contains no information about the bone or other features below the surface, such as the root of the tooth. Consequently, when tooth segment 16b is removed from the segmented surface scan model 10b (see Fig. 3D) is selected and removed, no information about the alveolus is available, and the surface scan model 10b shows only a hole 16c where tooth segment 16b was located before removal.

[0115] Fig. 3G shows the segmented 3D surface scan model after tooth segment 16b was removed and tooth segment 16a was extracted from the segmented 3D model of the volumetric density scan (from Fig. 3C) was integrated into the same 3D coordinate system. Fig. 3H shows tooth segment 16a, separated and removed from the other segments of model 10b of the volumetric density scan. Tooth segment 16a comprises a crown portion 16a. c and a root section 16a r The root section 16a r The tooth 16 comprises a stem 16a t and three individual roots (one lingual root 16a r_l , a mesiobuccal root 16a r_mbs (in Fig. 3H not visible) and a distobuccal root 16a r_dbrWhile tooth 16 can have three individual roots, other teeth may have only one root or two or more. For simplicity, the stem and individual roots of a given tooth are referred to collectively as "the root" of the tooth. Above the gum line, only the crown of tooth 16a is visible in a surface scan. c visible. The root section 16a r It is not visible above the gum line to the naked eye or to the cameras in an intraoral scanner.

[0116] Fig. 3I shows the single tooth segment 16b (from the segmented 3D surface scan model 10b of Fig. 3G). As noted, tooth segment 16b represents only the crown of tooth 16, since only the crowns of the teeth are visible to the surface scanning cameras (because they are located above the gum line and are visible to both the naked eye and the camera lens(es)).

[0117] Since the surface scan and the volumetric density scan depict the same area of ​​interest, both scans include surface information belonging to the same, corresponding anatomical structures (assuming that the same areas were scanned in each scan). This means that for visible areas such as the crowns of the teeth, both the surface scan and the volumetric density scan include surface information or surface boundary information belonging to the crowns of the teeth.

[0118] Surface scans performed with optical sensors tend to produce images with significantly higher resolution, resulting in highly detailed 3D surface models. Volumetric density scans, on the other hand, typically employ modalities that are either not as accurate or where it is medically unsafe to guarantee the images are as precise as those obtained from optical scans. For example, volumetric density scans generated using X-ray technologies such as CT or CBCT modalities rely on X-ray radiation, and while highly accurate images could be obtained with a high dose of X-rays, such an approach would be medically unsafe for the patient. Consequently, when used on patients, CT and CBCT modalities must be set to very low levels of X-ray radiation to ensure their safety.A disadvantage here is the lower accuracy of the images. Accordingly, crown surface data from a surface scan will generally exhibit a higher level of detail than crown surface data from a volumetric density scan.

[0119] In order to generate a 3D model of the patient's oral situation after tooth removal, the application retains the root area of ​​tooth 16a. r of tooth segment 16a from the volumetric density scan and removes the crown portion of 16a c For this purpose, the application determines the gingival line around tooth segment 16b from the volumetric density scan based on the points along the lower edge of tooth segment 16b from the surface scan.

[0120] Fig. Figure 3J shows tooth segment 16a from the surface scan and tooth segment 16b from the volumetric density scan merged (with both shown within the same 3D coordinate system). As shown, gingival line 16b gl that set of points which corresponds to the lower edge of tooth segment 16b from the surface scan. Since the application determines the position of gingival line 16b gl Knowing this, she calculates the crown section 16a c , since all points are on the same side of the gum line (also called the intersection line) on which tooth segment 16b from the surface scan lies, within the respective 3D coordinate system of the application.

[0121] Simply put, the application removes all points from tooth segment 16a in the volumetric density scan that coincide with or are substantially contained within the same volume of the 3D coordinate system area as tooth segment 16b from the surface scan (such as the crown 16b). This means that the corresponding sections of the tooth segment from the volumetric density scan and the tooth segment from the surface scan are displayed together. Put even more simply, the root portion of 16a is... r obtained by subtracting 16b from 16a (and removing points further out, if necessary).

[0122] Fig. 3K illustrates the square root of 16a r after the removal of the crown portion 16a cfrom tooth segment 16a from the volumetric density scan. Since this is a surface model, only the outer points of the segment are present in the 3D model; consequently, if the crown area of ​​16a c is removed from segment 16a, the inside 16a r_interior empty. The shape of the root part 16a r is exclusively through points on the outer surface of the tooth root 16a r defined as defined by the surface model of the individual segments, obtained from the volumetric density scan.

[0123] Accordingly, the contours of the inner surface of the root follow the contours of the outer surface of the tooth root itself. The remaining root 16a r can therefore be combined with surface model 10a (with crown segment 16a removed) from Fig. 3F is shown to generate a 3D surface model 10d representing the oral situation of the patient with extracted tooth 16. This is in the Fig. 3L, Fig. 3M and Fig. 3N shown. Fig. 3L shows the 3D model 10d essentially along the horizontal plane with a view of the lingual side to show the hole 16c and the alveolar contour 16s. Fig. 3M shows the Model 10d from a different orientation, along the same horizontal plane as in Fig. 3I, viewed from the posterior side of the model. From this perspective, the alveolar contour is more clearly visible. Fig. 3N shows another view of model 10d, looking into the alveolus from which tooth 16 was virtually extracted. The contours of alveolus 16s are visible and show where the three individual root tips were located before the virtual extraction of tooth 16.

[0124] Alveolus 16h encompasses the contours in which the stem and each of the individual roots were situated prior to the virtual extraction of the tooth. As illustrated, alveolus 16h follows the contours of the root of the extracted tooth, including a stem alveolus segment 16a. t and three individual root alveoli, including the lingual root alveolus 16s r_l , the mesiobuccal root alveolus 16s r_mbr and the distobuccal root alveolus 16s r_dbr , which of the lingual root 16a r_l , the mesiobuccal root 168 r_mbr or the distobuccal root 16a r_dbr , are equivalent to.

[0125] The segmented tooth model from the volumetric density scan only includes the outer (boundary) surfaces of the tooth object and therefore contains no information about the interior of the tooth itself. Consequently, the segmentation processor produces a 3D mesh of the tooth's outer surfaces without any modeling of the tooth's interior. For closed objects like a tooth, the 3D mesh model is also a closed triangular mesh (the number of edges and triangular facets assigned to each given vertex is the same). Since the interior of the detached root segment 16a r (i.e., segment 16 with removed crown portion 16a) c ) is empty, the inner surfaces of the root segment 16a follow. r the same contours as the outer surfaces of the root segment 16a r That is, the inner surfaces are simply the same outer walls of the root segment 16a. r, however, viewed from the inside of the walls.

[0126] By removing the crown portion 16a c From segment 16a of the volumetric density scan, an open mesh is generated (i.e., there is at least one vertex in the mesh where the number of edges associated with the vertex is greater than the number of triangular facets associated with that vertex). For the purposes of this text, an edge facet is a facet where the number of adjacent facets (sharing an edge) is different from the number of edges of the facet. In the context of removing crown portion 16a c The remaining part of segment 16a from the volumetric density scan, i.e., the detached root segment 16a, is comprised of segment 16a. r, a set of marginal facets along the marginal line (where the crown meets the gingiva), creating an open network. Since in the detached root segment 16a r Since no information is available, the inner surface of the open network is the outer surface of the detached root segment 16a. r identical.

[0127] At each point after merging the segmented surface model 10a of the volumetric density scan and the segmented surface model 10b of the surface scan in the common 3-dimensional coordinate system (see Fig. 3E) The user can examine the patient's oral cavity or perform a procedure there (for example, removing dental tissue with a dental drill). For this, the user inserts the head of the appropriate dental instrument into the oral cavity. The surface scanner 114 of System 100 scans the oral cavity and System 100, as described above with reference to Fig. As described in 2B, a display environment is generated on the GUI 120 from the second data set (i.e., at least a part of the digital patient model) as well as a digital representation of the surface scanner 114, wherein the surface scanner 114 is positioned and oriented according to its real position and orientation relative to the digital patient model.

[0128] Fig. Figure 3O is a schematic view of a display environment 400 of the GUI 120, which includes a representation of the digital patient model 402 and a digital representation 404 of the surface scanner 114. In this example, the surface scanner 114 is integrated into or includes a dental drill (shown without the drill tip for clarity). The surface scanner 114 includes a pair of lateral extrusions to each side of the head of the dental drill, so these are also depicted in the digital representation 404 of the surface scanner 114 (at 406a, 406b). (This arrangement maximizes the 3-dimensional sensitivity of the optical elements (i.e., the light source(s) and the light detector(s) of the surface scanner 114.)

[0129] When the user is working inside the oral cavity with the surface scanner 114, the system 100 updates the view shown in the display environment 400 of the GUI 120 based on the scan data that the system 100 continuously receives from the surface scanner 114. As a result, the user can see exactly where the surface scanner 114 is located inside the oral cavity, including the position and orientation of the drill tip.

[0130] The Fig. 4A, Fig. 4B, Fig. 5A and Fig. Figure 5B illustrates an exemplary embodiment of a display environment 500 of the GUI 120 during various steps within the workflow of planning a dental treatment. The GUI display environment 500 can be displayed on an electronic display 118 of the system 100, on which a dental treatment planning application is running. The GUI display environment 500 includes a control element 501 (not shown individually) that allows a user to select scan data of a patient and load it into the memory 106 of the system 100 or an external storage device (not shown) accessible via the system 100 or accessible from a remote service 102 via a network adapter 122.

[0131] In the context of the described aspects of the invention, scan data includes surface scan data and volumetric density scan data of an anatomical area of ​​interest in a patient. In another embodiment, both the surface scan and the volumetric density scan are acquired before planning the dental treatment; in other embodiments, the surface scan data and / or the volumetric density scan data are acquired during the use of the application for planning the dental treatment.

[0132] For example, the remote surface scanning service 130 can include an application for an optical scanner communicating with another optical scanner that transmits optical scan data to the system 100 during or after completion of an intraoral scan of the areas of interest in a patient's oral cavity. Similarly, the volumetric density scanning service 132 can include an application for a volumetric density scanner communicating with another volumetric density scanner that transmits volumetric density scan data to the system 100 during or after completion of an intraoral scan of the areas of interest in a patient's oral cavity.

[0133] As described above, the system 100 controls the display of graphical content in the GUI display environment 500 of the GUI 120, including monitoring user input for controlling the graphical controls via user input device(s) 112 such as a mouse, keyboard, joystick, speech recognition, etc. The user input can correspond to actions to be performed, for example, to activate various application functions specific to the essential features of the application or GUI functions for changing the appearance or content of the features displayed.

[0134] More specifically, the frontend GUI displays controls for user input and monitors user input that is assigned to the corresponding functional controls. Upon receiving user input in conjunction with a corresponding control, the GUI activates a function according to the relevant control, as well as the type and content of the user input. The GUI also responds to backend processes that communicate with the backend GUI, which in turn communicates with the frontend GUI to display, modify, remove, and / or clear information from the electronic display.

[0135] Such selected functions may result in the unrestricted display, removal, and / or modification of models, views, segments, and / or annotations on the display; the display, removal, and updating of various user controls and information in the GUI display environment 500; and the receipt and return of information that supports essential functional features of the system 100, including, but not limited to, assessments of essential treatments, planning of essential treatments, and virtual execution of treatments or operations (such as tooth extraction, implant placement, prosthesis design and insertion, etc.).

[0136] Referring to Fig. 4A comprises the GUI display environment 500 global controls 501, such as those for file management, typical display controls, and other controls typical of the GUI display environment. Controls 501 may include, for example, controls for file selection, controls for saving / exporting files, controls for the display field format, etc. In addition, the GUI display environment 500 comprises patient data-specific controls 502, such as those for modeling the arch and individual teeth.

[0137] The GUI display environment 500 includes functional controls 503, among them a control 512 for tooth extraction. The tooth extraction control 512 is generally shown as a single control, but may include a variety of controls, such as a guided dialog of pop-up display fields and other well-known interactive GUI techniques for displaying and responding to information requests and receiving user input. The GUI 500 also includes and presents at least one display field 503 for displaying a 3-dimensional anatomical model of the oral situation (or selected parts thereof) of a selected patient, obtained from the patient's scan data and selected via selection controls among the controls 502.

[0138] The controls 501 comprise one or more controls (not shown) which, when selected, allow the selection of surface data and volumetric density scan data of a patient from the memory 106 of the system 100. In one embodiment, when patient scan data is first loaded, the GUI display environment 500 can display one or a plurality of display fields 503 (only one is shown) to provide a visual overview of the patient's oral situation on the display. Fig. Figure 4A shows display field 503 displaying a 3D model of a volumetric density scan. Environment 500 can also include various additional views of the patient's oral situation based on data from volumetric density scans. For example, environment 500 can include a panoramic display field, an axial display field, cross-sectional display fields, and a tangential display field (not shown).

[0139] An important function of the virtual tooth extraction tool, accessible via control 512, is to virtually display the patient's oral situation after the virtual removal of one or more teeth or other objects selected for extraction. For example, if a tooth has been virtually removed and is displayed within the GUI display environment 500, the resulting 3D model should include a representation of the tooth socket as it would be visible to the naked eye after the removal of the tooth intended for extraction. This ensures that the system 100 generates a realistic digital patient model for display in the display environment 500, which incorporates a digital representation from the surface scanner 114. This model can also be modified, for example, by a virtual tooth extraction that reflects a planned tooth extraction.

[0140] As in Fig. As shown in Figure 4A, a user can activate a virtual tooth extraction tool by selecting the tooth extraction control 512 by moving a graphical cursor 520 over the control 512 using a mouse (not shown) and clicking on the control 512 with the mouse. Fig. Figure 4B shows an embodiment of a popup dialog 513 that is displayed in the GUI environment 500 when the tooth extraction control 512 is activated. As illustrated, the dialog can include a tooth selection overview that allows a user of the system 100 to select one or more individual teeth for virtual tooth extraction.

[0141] In one embodiment, the user can click on an individual tooth in the overview to select that tooth for extraction. The user can then select a corresponding checkbox or option button to save the alveolar model generated by the tool during alveolus generation and / or to extract the tooth extraction model (this model contains the model from display 503, excluding the tooth(s) selected for extraction, and augmented by the generated alveolar models for the selected tooth(s)). Once the user has completed selecting the tooth(s) for extraction, they can click the "Select" button 517 to activate the tooth extraction tool.

[0142] Fig. Figure 5A presents a posterior view (a view of the maxillary arch from behind, looking towards the patient's face) of the 3D tooth extraction model 10D, from which the 3D alveolus model 16a, corresponding to the alveolus from which tooth 16 is extracted, is more clearly visible. The alveolus model 16a is shown together with the 3D surface scan model from which tooth 16 has been extracted. Fig. Figure 5B shows the same model 10D from the inferior perspective (view from bottom to top towards the maxilla). As illustrated, tooth 16 is missing, but the interior 16c of the alveolus 16a is visible and follows the contours of the root(s) of the extracted tooth 16.

[0143] Fig. 6A illustrates a GUI display environment 700, generated by the system 100 (for example, by the display generator 250 from Fig. 1B), in which surface scans and volumetric density scans of a patient were imported and loaded into memory 106 of system 100. Fig. Figure 6A illustrates the patient's dental situation after a dental professional has selected and virtually placed an implant. Techniques for virtually placing the implant in a virtual model of a patient's dentition are already established in practice, for example, through the use of the dental implant planning software CoDiagnostix. ® In Fig. In 6A, a virtual implant post 710 was placed and is shown in corresponding display fields of the graphics environment 700 in various types of views. In the example shown, the implant post 710 is virtually placed in a cross-sectional view (display field 703d), an axial view (display field 703c), a panoramic view (display field 703b), a tangential view (display field 703e), and a 3D view (display field 703a).

[0144] As shown in the various views in fields 703a to 703e, the placement of the implant is demonstrated by the placement of an implant post or screw 710, which is the base component of the complete implant. A complete implant comprises an implant post 710, an abutment attached to the implant post 710 (not shown), and an abutment for a prosthesis or dental restoration (also not shown), which may be a crown, bridge, or denture.

[0145] In the initial planning phase, only the implant post 710 needs to be virtually positioned. The implant planning software provides virtual guide(s) 711 for positioning the virtual implant. These guides do not correspond to any physical component but are purely optical indicators that assist the dental professional in placing the implant at the correct angle. Fig. 6A The virtual guides 711 appear in the 3D display field 703a as a long cylindrical rod whose central axis coincides with the central axis of the implant post 710 and whose diameter corresponds to the diameter of the abutment receptacle inside the implant post. Preferably, the cylinder of the virtual guide 711 extends along the central axis above the occlusal plane of the tooth for implant placement, such that the length of the cylinder is much greater than its diameter. Preferably, the guide 711 is displayed in a color that contrasts with the colors used in the 3D model and other display fields, so that the user of the application can immediately see the guide in relation to the content in each display field.

[0146] The GUI display environment 700 includes a control element 712 for tooth extraction, which in the example environment is accessed by selecting a control element from the controls 702 of the display field that corresponds to the part of the patient's dentition in which the intended implant will be placed. In the illustrated embodiment, the dental professional selects the control element for the lower arch, right-clicks it to open a context menu, and selects a control element 712 for tooth extraction from the context menu. The tooth extraction control element can be selected to instruct the dental treatment planning application to automatically perform a virtual tooth extraction (using the principles described above).There are various ways to implement the control element used to call up the automated virtual tooth extraction tool - the crucial point is that one or more controls are provided that allow the user to activate the tooth extraction workflow.

[0147] Fig. Figure 6B illustrates a popup window 713 that appears in the GUI display environment 700 when the user selects the tooth extraction control 712. The popup window presents various options and controls for user input to obtain the inputs requested by the virtual tooth extraction tool, including a tooth selection control 713 and a mode selection option 714. In the Fig. In the embodiment shown in 6B, the control element 713 for tooth selection displays a set of selectable tooth symbols that correspond to the teeth in the selection area of ​​the patient's dentition, selected by the user. Fig. 6A. The user (i.e., the healthcare professional) can select the tooth corresponding to the tooth for which the virtual implant post 710 is to be placed. In the example, the user selects tooth 35 corresponding to the tooth on the left side of the lower arch where the virtual implant post 710 is placed. To select the mode, the user selects "Mode: Cut out alveolus" from the drop-down menu 714, activates the checkbox 716 to indicate that the extracted tooth should be saved as a separate file for future planning, and activates the virtual tooth extraction tool by clicking "Extract" 717.

[0148] Fig. 6C displays a 3D surface model of the patient's dentition in display field 703a. Finally, the virtual tooth extraction tool adds two 3D model files to the list of available model scans and 3D models in section 702 using the controls of the GUI display environment 700. The user can select these files to display them in the field. One file is a model of the extracted tooth (indicated by 721 in the file list). The model of the extracted tooth is processed by the virtual tooth extraction tool according to the parameters associated with the Fig. 1 and Fig. Four described techniques were used to create a model of the extracted tooth, where the extracted tooth model is a 3D surface model of the patient's dentition (including the previously placed implant abutment 310), with the selected tooth 35 removed from the model and an alveolus created in the model and inserted in its place. The second file is a model of the extracted tooth (designated 722) and is a model of tooth 35 with the crown removed from the root.

[0149] Once these files have been created, the user can click on the planning menu 723 in the GUI display environment 700, as shown in Fig. 6D is shown, and the option "Virtual Planning Export" (724) is selected. In the next step, shown in Fig. 6E, the user can select the export file format in a format selection field 727 of a popup window 726. In the example, the user selects an STL format option 728 and clicks "Next" 729 to proceed to the next menu. In the next step, shown in Fig. 6F, the user activates an option button 732 and thus selects an option to export the selected model scans or segmentations without further processing.

[0150] After clicking the "Next" button, 733 will be displayed. Fig. 6G from popup window 730 for selecting the export file, the tooth extraction file 731 was selected. After clicking "Next" 732, the popup window 735 for implant selection is displayed, shown in Fig. 6H, where control 736 can be selected to choose a scan body. Control 736 for selecting a scan body includes a scan selection control 737, where a suitable scan body can be selected from a collection of possible scan body types. The user can select a scan body from the scan body menu to add the selected scan body to the model for export. The scan body allows verification of the correct postoperative placement of the implant (or other anchoring element) relative to the dental surfaces of the patient's dentition after implantation and, if applicable, a healing period. This can be achieved by merging the three-dimensional measurement data of the surface scan, obtained from the person's postoperative oral cavity, with the 3D digital patient model, including the selected scan body.

[0151] Then the user clicks the "Next" button. 738. In Fig. On screen 6I, the user can select further options, such as the 3D coordinate system to which the model should be exported, and whether the objects should be exported as individual files with a common coordinate system. Clicking "Export Planning" on screen 741 selects the export function based on the options and parameters chosen by the user in the previous screens. The exported files are saved in a known location in the computer's readable memory.

[0152] In Fig. The same process can be used to export the crown segment from the surface scan of the virtually extracted tooth (and optionally the crown segment of the antagonist, i.e., the crown segment of the tooth in the opposite jaw that, when the jaws are closed, meets the tooth intended for extraction). It is important to ensure that the surface scan tooth segments are exported to the same coordinate system as the exported model of the virtual tooth extraction.

[0153] The resulting files include a 3D model of the patient's dentition with a virtual extraction of the tooth at the site where the planned replacement implant is to be placed. A virtual socket is located at the site of the extracted tooth. The model also includes the virtual implant abutment, placed in the socket where the dental professional had inserted it during the implant planning process.

[0154] The Fig. Figures 7A to 7T illustrate a GUI display environment 900 of a prosthesis design application, for example, a computer-aided design (CAD) or computer-aided manufacturing (CAM) tool. In one embodiment, the prosthesis design tool is an application that operates in the system 100, which refers to the Fig. 1A and Fig. 1B has already been described.

[0155] Fig. 7A is a GUI display environment 900, displayed on a GUI 120 of the electronic display 118, which has controls for user inputs and display areas, as explained below. To construct a prosthesis, the user creates a new case by clicking on the control 901 ( Fig. 7A) clicks, enters case information (for example, in the text fields "Case ID", "Patient ID", and "Dentist ID" to be assigned to the new case), and selects 3D models generated from the patient's scan data and loads them into memory for use by System 100. In this example, a dental crown is to be designed. The user enters the file names for the virtual tooth extraction files (in this case, by entering a model of a lower tooth) and the name of the extracted tooth file (the lower wax model), and loads the files into the system (for example, by clicking "Save"). Fig. 7B). System 100 displays the 3D model for the selected file(s) for virtual tooth extraction in display field 903 ( Fig. 7C). If necessary, the system provides 100 controls in the environment 900 for cleaning up the scan (for example, to fill holes in incomplete scan data, to smooth scan lines, to remove noise, etc.). Subsequently, the system can provide 100 tools for adjusting the orientation of the model(s) to the occlusal plane, if required ( Fig. 7D).

[0156] Before proceeding with the design, the user marks the tooth positions in the displayed model to indicate to System 100 the position(s) of the tooth(s) for which a prosthesis is to be designed, and to indicate which teeth are adjacent to the tooth(s) for which a prosthesis is to be designed (see Fig. 7E). Following, in Fig. In step 7F, the user selects the platform (implant manufacturer, implant type, and connection) as well as the scan body. These selections should match the implant and scan bodies chosen in the application for planning the dental implant or treatment, and on which the virtual tooth extraction files were based.

[0157] Once this step is complete, the user can proceed with constructing the prosthesis. Fig. In step 6J, the surface scan crown segment from the 3D model was exported as a single segment into a suitable 3D coordinate system as the virtual tooth extraction model. Since the surface scan crown model was generated from an optical scan of the patient's original tooth (before the actual extraction of the real tooth), the surface scan crown segment can be used as a digital wax model without having to rescan the patient's mouth. Because the surface scan crown segment was exported as a single segment, matching the same 3D coordinate system as the virtual tooth extraction model, the surface scan crown segment of the virtually extracted tooth can be mounted into the display field with the virtual tooth extraction model and can be used by System 100 as the upper part of the crown of the prosthesis. By importing the surface scan crown segment file as the wax model file ( Fig. 7B) the designer can select that a clone of the wax model should be created ( Fig. 7G), to instruct a prosthesis design application included in System 100 to use the wax model contained in the wax model file as the crown surface of the prosthesis. Once the wax model cloning tool clones the wax model as the prosthesis, the user can fine-tune the prosthesis shape using the adjust, shape, and design controls available in the GUI display environment 900. Environment 900 also includes controls for rotating and changing the view of the model displayed in the display field 903, allowing the user to view the prosthesis 904 from all angles. For example, the model 905 is in Fig. 7H is rotated so that the prosthesis 904 can be viewed from the buccal side. This allows the designer to make adjustments to the prosthesis by viewing it in situ within the model 905 for virtual tooth extraction.

[0158] Once the visible surfaces of the crown have been designed based on the extracted surface scan crown segment obtained during the tooth extraction process, the user can design the lower portion of the prosthesis. The System 100 can provide the designer with controls for entering restoration specifications (see Fig. 7I), for example, for the material type, color, and output type (e.g., output of an STL file, output of an order confirmation, which may be done via direct communication to a remote manufacturing facility).

[0159] In Fig. 7J displays model 905 of the virtual tooth extraction in display field 903. Since the example case is in the Fig. 7A to 7T is a new case of constructing a prosthesis for an implant, and model 905 of the virtual tooth extraction with the implant placed in the model was exported (for example, using the one in conjunction with the Fig. (Process described in sections 6A to 6J), model 905 of virtual tooth extraction includes a virtual implant abutment. In this example, a temporary abutment is selected, automatically virtually connected to the implant abutment, and displayed as shown. The user can then select the thickness of the cement gap ( Fig. 7K), determine the thickness of the material ( Fig. 7L) and display the prosthesis 904 within the model 905, which also includes the contours of the alveolus (or the “emergency profile”) ( Fig. 7M). The user can then turn off the display of model 905, so that only the prosthesis is displayed ( Fig. 7N).

[0160] Fig. 7O shows the model 905, which has been reactivated for display (see the on / off buttons for displaying different models in Fig. 70), rotated to provide a good lateral view of the alveolus 910 from the outside. When a low level of anatomical transparency is set (to show the implant post and abutment in the socket 910), it becomes clear that an anatomically correct prosthesis 904 can be designed to match the patient's oral anatomy by using the socket contours to guide the design of the lower crown portion of the prosthesis so that it fits the contours of the inside of the socket 910. In this regard, the prosthesis design application provides controls for adjusting the shape and fit of the lower part of the crown.

[0161] Once the lower part of the crown prosthesis is shaped to match the contours of alveolus 910, the designer can proceed with specifying the prosthesis shell. The application may then retrieve information on the proximal distance between the prosthesis surfaces and the teeth on both sides of the prosthesis (when virtually attached to the virtual implant post 906). Fig. 7P) automatically calculated and a shell surface generated (viewed from the buccal side in Fig. 7Q and downwards to the occlusal plane in Fig. 7R looking). Fig. 7S displays the final prosthesis design within the model, with the anatomical model adjusted to show both the upper and lower jaw transparently, allowing partial visibility of the implant post 906, the abutment, and the crown of the prosthesis. The user can easily check the placement and shape of the prosthesis by visually inspecting the model. Fig. 7S. Fig. 7T shows the same model and orientation as in Fig. 7S, but with the anatomy in full opacity. The workflow continues with the usual steps before the crown is sent to production.

[0162] Once the prosthesis design is complete, the design files can be exported and used to manufacture the prosthesis. In one embodiment, the exported design files can be sent to a production facility or a remote manufacturing service. In another embodiment, the exported prosthesis design files can be used to generate 3D printer instructions for transmission to a 3D printer, which then triggers the 3D printing of the prosthesis in response to such instructions.

[0163] The aspects and embodiments of the invention described above offer several advantages with regard to the visualization of virtual bases, anatomically based treatment planning, and anatomically based prosthesis design. According to one advantage, specialists in anatomically based treatment and prosthesis designers can plan treatment and design anatomically accurate prostheses based on an exact 3-dimensional model of the dental socket, which is the site of treatment planning and prosthesis design, and which reflects the patient-specific dental socket anatomy.

[0164] The model can be generated before the anatomical object is extracted from the patient, allowing for precise treatment planning and prosthesis design before or simultaneously (i.e., in parallel) with the actual surgical extraction. This means that the patient may only need to visit the healthcare professional performing the treatment once. During these one or two visits, the patient's relevant anatomical area, including the anatomical object to be extracted, can be scanned.The scan data can be imported into a digital treatment planning tool, which includes a tool for generating a virtual alveolar model and / or a tool for virtual extraction of the object, each of which generates a virtual alveolar model that is contained in the display of a virtual anatomical model of the patient's anatomical area of ​​interest (i.e., the area that includes the intended extraction object and adjacent anatomical objects or features).

[0165] Using the virtual alveolar model included in the displayed virtual anatomical model, the healthcare professional can precisely position an implant or other treatment body within the virtual alveolar model, design and print 3D-printable surgical templates, and export the virtual alveolus model for use in a separate prosthesis design tool to create the anatomically accurate prosthesis. If the healthcare professional has access to technology for immediate prosthesis fabrication, the prosthesis can be fabricated while the patient is still in the office. Otherwise, the prosthesis can be sent to a laboratory for fabrication, and the patient can return to the office once the implant-related anatomical environment has healed sufficiently to allow for prosthesis placement.

Claims

[1] Computer-implemented method for generating, by one or more computer processors (104), a 3-dimensional model for use in assisted navigation in the oral cavity of a patient, wherein the method is based on at least one initial scan of an anatomical region of the oral cavity of the patient, comprising: Receiving an initial data set comprising surface boundary information from the initial scan, and generating a 3-dimensional digital patient model (402) from at least a part of the initial data set; Performing a 3-dimensional surface scan of a part of the oral cavity using a 3-dimensional surface scanner (114) and thereby acquiring a 3-dimensional surface scan, wherein the 3-dimensional surface scan includes a region of interest; Aligning the captured 3-dimensional surface scan with at least a part of the 3-dimensional digital patient model (402); Specify, using the acquired 3-dimensional surface scan and the digital patient model (402), a spatial transformation designed to align the acquired 3-dimensional surface scan and the 3-dimensional digital patient model (402) with each other or to bring them into a predetermined degree of overlap; Establishing position and orientation information of the 3-dimensional surface scanner relative to the 3-dimensional digital patient model (402) using at least the transformation; and Generating a second data set comprising the position and orientation information of the 3-dimensional surface scanner (114) relative to the 3-dimensional digital patient model (402). [2] Method according to claim 1, wherein the second data set further comprises at least a part of the 3-dimensional digital patient model (402). [3] Method according to claim 1 or claim 2, wherein the surface boundary information of the first data set comprises surface segments, the surface segments having identifiers assigned to them that identify the type of tissue that each surface segment represents, the tissue type being selected from a group comprising gingival tissue, bone tissue and dental tissue. [4] Method according to claim 3, comprising identifying elements of the anatomical region of the patient's oral cavity in the 3-dimensional digital patient model (402) comprising storing surface segments associated identifiers that identify the tissue type, in the process of generating the 3-dimensional digital patient model (402) [5] Method according to one of the preceding claims, wherein the second data set further comprises a digital representation (404) of the 3-dimensional surface scanner (114) in a general reference frame, wherein the digital representation of the 3-dimensional surface scanner (114) is positioned and oriented according to the position and orientation information. [6] Method according to any of the preceding claims, comprising generating the second data set as a 3-dimensional output model. [7] Method according to claim 6, comprising that the navigation system receives a plan for dental treatment or control, determines a region of interest in the 3-dimensional output model based on the plan for dental treatment or control and identifies the region of interest in the 3-dimensional output model. [8] Method according to any of the preceding claims, comprising transferring the second data set to a visualization system configured to visualize at least part of the second data set using a 3-dimensional or a pseudo-3-dimensional display device. [9] Method according to claim 8, comprising that the visualization system enhances or overlays the display of part of the second data set with a view of the patient's oral cavity. [10] Method according to any of the preceding claims, comprising capturing and updating the 3-dimensional surface scan, continuously or in real time. [11] Method according to any of the preceding claims, comprising transferring the second data set to a robotic navigation system designed to control the navigation of a dental instrument, for example a dental drill, a dental probe or another type of dental instrument, based on the position and orientation information contained in the second data set. [12] Method according to any of the preceding claims, wherein the 3-dimensional surface scanner (114) comprises a dental drill, a dental probe or another type of dental instrument, formed integrally with it or mounted on it. [13] Method according to one of the preceding claims, wherein when aligning at least one part of the 3-dimensional digital patient model (402) onto the acquired 3-dimensional surface scan, only surface boundary information of the first data set with segments labelled as dental tissue is used. [14] Method according to any of the preceding claims, wherein the surface boundary information from the first scan is determined from a surface scan and / or a scan of the volumetric density of the anatomical region of the patient's oral cavity. [15] Method according to any of the preceding claims, wherein the digital patient model (402) does not include a digital representation of a marker element. [16] System (100) for generating a 3-dimensional model for use in assisted navigation in the oral cavity of a patient, the system (100) comprising: at least one computer processor (104); a storage unit (106); a 3-dimensional surface scanner (114) for performing a 3-dimensional surface scan of a portion of the patient's oral cavity; and, optionally, a display device (118) and / or a robotic navigation (support) system, wherein the storage unit (106) stores instructions which, when executed by the computer processor (104), implement a method according to any one of claims 1 to 15. [17] Computer program code which, when executed by a computer processor (104) in communicative connection with a 3-dimensional surface scanner (114) to perform a 3-dimensional surface scan of a part of a patient's oral cavity, performs the method according to any one of claims 1 to 15.

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