Computer implementation method for digitally designing the geometric shape of adjacent teeth

Abstract

Disclosed are systems and techniques for designing a digital dental matrix with improved interproximal contacts, including generating a digital three-dimensional model of a patient's desired future dental structure, where the future dental structure represents the intended shape of at least one tooth of the patient; selecting one or more pairs of adjacent teeth within the 3D model; for each selected pair of teeth, determining a position and orientation within the interproximal space of the adjacent teeth to insert a digital 3D geometric shape having one or more initial parameters; and inserting the digital 3D geometric shape at the determined position and orientation.

Description

Technical Field

[0001] The present disclosure relates to a dental restoration device for reshaping teeth.

Background Art

[0002] Dental practitioners often utilize various dental devices to reshape or restore a patient's dental structure. The dental device can be either a stock design that the dentist adapts to an individual patient or a custom device constructed from a model of the patient's dental structure and extended to the desired dental structure. The model can be either a physical model or a digital model. Historically, it has been found difficult to construct a model that forms a tight but flossable contact in one step. Instead, dentists employ a process that is time-consuming and can be uncomfortable for the patient to separate the formed contacts using blades, saws, and other tools.

Summary of the Invention

[0003] This disclosure relates to a technique for designing dental restoratives having improved and customized interproximal contacts to reduce or eliminate the need to separate interproximal contacts. In a first aspect, the first method includes generating a digital three-dimensional (3D) model of a patient's future desired dental structure, the future dental structure representing the intended shape of at least one of the patient's teeth; selecting one or more pairs of adjacent teeth in the 3D model; determining the position and orientation of the adjacent teeth in the interproximal space to insert a digital 3D geometric shape having one or more initial parameters for each selected pair of teeth; and inserting the digital 3D geometric shape at the determined position and orientation. The one or more initial parameters of the digital 3D geometric shape may include at least one thickness greater than 100 microns and less than 500 microns. Furthermore, determining the position and orientation in the interproximal space may include offsetting adjacent teeth to intersect the respective geometric shapes of adjacent teeth; determining the Boolean intersection result of the adjacent teeth; and determining the best-fitting plane based on the Boolean intersection result. In addition, determining the position and orientation within the interdental space between adjacent teeth may include determining the contact points between adjacent teeth, determining a landmark coordinate system for each adjacent tooth, determining the average of the landmark coordinate systems for each adjacent tooth, determining the orientation based on the determined average of the landmark coordinate systems, and determining the position based on the contact points between adjacent teeth. The method may further include refining the digital 3D geometric shape. Refining the digital 3D geometric shape may include subdividing the 3D geometric shape into one or more parts between the lingual and facial ends of the 3D geometric shape, and translating one or more parts of the 3D geometric shape relative to the digital 3D model to adjust the resulting 3D geometric shape in the digital 3D model.Refining a 3D digital geometric shape may also include positioning a predefined 3D geometric shape in terms of position and orientation relative to a 3D model, and scaling a predefined 3D geometric shape based on one or more parameters of the 3D model. Refining a digital 3D geometric shape may also include orienting the 3D geometric shape perpendicular to at least a first and a second part, and adjusting one or more parameters of each individual part to adjust the resulting 3D geometric shape in the digital 3D model. The parameters may include at least one of a first thickness along the mesial-distal axis, a distance along the gingival-occlusal axis, and an offset of each individual part. The parameters of each individual part may differ for each part. The method may further include generating a file representing a 3D dimensional physical matrix containing the 3D model and the refined 3D geometric shape, and generating a physical matrix from that representation. Generating a physical matrix from that representation may include constructing the physical matrix from that representation using a 3D printer. In addition, the refinement of the 3D geometric shape may include adding an oval cylinder to each instance of the digital 3D geometric shape, such that the oval cylinder is divided by an individual digital 3D geometric shape; for each added oval, aligning the central plane of the individual oval cylinder with the individual digital 3D geometric shape; for each digital 3D geometric shape, determining the angle between the individual dividing plane and the individual 3D digital geometric shape; and for each digital 3D geometric shape, rotating the individual digital 3D geometric shape based on the individually determined angle to match the individual oval to the tooth inclination of each tooth.

[0004] In a second aspect, the second method may include generating a digital three-dimensional (3D) model of a patient's future desired dental structure, the future dental structure representing the intended shape of at least one of the patient's teeth; selecting one or more pairs of teeth in the 3D model, where the teeth in the pair are adjacent; determining the position and orientation of the adjacent teeth in the interproximal space in order to insert a digital 3D geometric shape having one or more initial parameters for each selected pair of teeth; inserting the digital 3D geometric shape at the determined position and orientation; refining the digital 3D geometric shape; generating a file representing a 3D physical matrix including the 3D model and the refined 3D geometric shape; and generating the physical matrix from the representation.

[0005] Details of one or more examples are shown in the attached drawings and the following description. Other features, purposes, and advantages will become apparent from the description and drawings, as well as from the claims. [Brief explanation of the drawing]

[0006] [Figure 1] This block diagram illustrates an exemplary system for designing and manufacturing dental appliances having improved and customized interproximal contacts for restoring a patient's dental structure, according to various aspects of the present disclosure.

[0007] [Figure 2] This flowchart illustrates exemplary techniques for generating digital models of dental appliances having improved and customized interproximal contact areas, according to various aspects of the present disclosure.

[0008] [Figure 3A] This is a conceptual diagram illustrating exemplary techniques for determining the position and orientation of an inserted interproximal geometric shape using Boolean cross results, according to various aspects of the present disclosure. [Figure 3B]This is a conceptual diagram illustrating exemplary techniques for determining the position and orientation of an inserted interproximal geometric shape using Boolean cross results, according to various aspects of the present disclosure.

[0009] [Figure 4] This is a conceptual diagram illustrating exemplary techniques for optimizing the contact geometric shape according to various aspects of the present disclosure.

[0010] [Figure 5] This is a conceptual diagram illustrating how a landmarking coordinate system can be used to calculate the orientation and position of the interproximal tooth geometric shape according to various aspects of this disclosure.

[0011] [Figure 6A] This is a conceptual diagram illustrating the arrangement of interdental geometric shapes with options for offsetting features along the mesial-distal axis, according to various aspects of the present disclosure. [Figure 6B] This is a conceptual diagram illustrating the arrangement of interdental geometric shapes with options for offsetting features along the mesial-distal axis, according to various aspects of the present disclosure.

[0012] [Figure 7] This is a conceptual diagram illustrating exemplary techniques for arranging an egg-shaped cylinder within a 3D model according to various aspects of the present disclosure.

[0013] [Figure 8A] This is a conceptual diagram illustrating exemplary techniques for orienting an oval cylinder according to various aspects of the present disclosure. [Figure 8B] This is a conceptual diagram illustrating exemplary techniques for orienting an oval cylinder according to various aspects of the present disclosure. [Figure 9A] This is a conceptual diagram illustrating exemplary techniques for orienting an oval cylinder according to various aspects of the present disclosure. [Figure 9B] This is a conceptual diagram illustrating exemplary techniques for orienting an oval cylinder according to various aspects of the present disclosure.

[0014] [Figure 10A] A flowchart showing exemplary techniques for determining the position and orientation of interproximal geometries according to various aspects of the present disclosure. [Figure 10B] A flowchart showing exemplary techniques for determining the position and orientation of interproximal geometries according to various aspects of the present disclosure.

[0015] [Figure 11A] A flowchart showing exemplary techniques for refining a digital 3D geometry to customize an interproximal geometry according to various aspects of the present disclosure. [Figure 11B] A flowchart showing exemplary techniques for refining a digital 3D geometry to customize an interproximal geometry according to various aspects of the present disclosure. [Figure 11C] A flowchart showing exemplary techniques for refining a digital 3D geometry to customize an interproximal geometry according to various aspects of the present disclosure. [Figure 11D] A flowchart showing exemplary techniques for refining a digital 3D geometry to customize an interproximal geometry according to various aspects of the present disclosure.

Mode for Carrying Out the Invention

[0016] FIG. 1 is a block diagram showing an exemplary system 100 for designing and manufacturing a dental appliance for restoring a patient's dental structure according to various aspects of the present disclosure. In the example of FIG. 1, system 100 includes a clinic 104, an appliance design facility 108, and a manufacturing facility 110.

[0017] Physician 106 can treat patient 102 at clinic 104. For example, physician 106 can create a digital model of patient 102's current dental structure. Dental structures include the crowns or roots of one or more teeth in a dental arch, gingiva, periodontal ligaments, alveolar bone, cortical bone, implants, artificial crowns, bridges, veneers, dentures, orthodontic appliances, or any part of any structure that can be considered part of the dentition before, during, or after treatment. In one example, the digital model of the current dental structure includes a three-dimensional (3D) model of the patient's current dental structure. The 3D model may be generated using an intraoral scanner, cone-beam computed tomography (CBCT) scanning (i.e., 3DX lines), optical coherence tomography (OCT), magnetic resonance imaging (MRI), or any other 3D imaging system. In some examples, the computing device 190 stores a digital model of the patient's 102 current dental structure.

[0018] The computing device 190 in the clinic 104 can store a digital model of the patient's future dental structure. The future dental structure represents the intended shape of the dental structure obtained by applying dental appliances such as dental prostheses 101. In one example, physician 106 may create a physical model of the future dental structure, or may use an imaging system (e.g., as described above) to create a digital model of the future dental structure. In another example, physician 106 may modify the digital model of the patient's current structure (e.g., by adding material to the surface of one or more teeth of the dental structure) to generate a digital model of the future dental structure. In yet another example, the computing device 190 may modify the digital model of the current dental structure to generate a model of the future dental structure. In yet another example, the modification of the patient's dental structure may be performed off-site by a third-party provider. Such modifications may be defined, considered, and modified by physician 106 or under his / her direction. Dental structures may be designed in a digital environment, or alternatively, the physical rendering of the initial dentition may be physically modified using conventional dental laboratory techniques (e.g., wax application). This physical model of the tooth may be digitized via a 3D scanner.

[0019] In one scenario, computing device 190 outputs a digital model representing the (e.g., current and / or future) dental structure of patient 102 to another computing device, such as computing device 150 and / or computing device 192. As shown in Figure 1, in some examples, computing device 150 in design facility 108, computing device 190 in clinic 104, and computing device 192 in manufacturing facility 110 may be connected to communicate with each other via network 114. Network 114 may include wired or wireless networks such as WIFI®, BLUETOOTH®, 3G, 4G LTE, 5G, etc.

[0020] In the example shown in Figure 1, the design facility 108 includes a computing device 150 configured to automatically design dental appliances for reshaping the dental structure of patient 102. In one example, the computing device 150 includes one or more processors 172, one or more user interface (UI) devices 174, one or more communication units 176, and one or more storage devices 178.

[0021] The UI device 174 may be configured to receive user input and / or output information, also called data, to the user of the computing device 150. One or more input components of the UI device 174 may receive input. Just a few examples of inputs include haptic input, voice input, dynamic input, and optical input. For example, the UI device 174 may be a mouse, keyboard, voice response system, video camera, button, control pad, microphone, or any other type of device for detecting input from a human or machine. In some examples, the UI device 174 may also be a presence-aware input component, which may include a presence-aware screen, a touch-sensitive screen, and so on.

[0022] One or more output components of the UI device 174 can generate an output. Examples of outputs include data output, tactile output, audio output, and video output. In some examples, the output components of the UI device 174 include display devices (e.g., presence screens, touchscreens, liquid crystal display (LCD) displays, light-emitting diode (LED) displays, optical head-mounted displays (HMDs), light-emitting diodes, speakers, or any other type of device for generating an output to a human or machine).

[0023] The processor 172 corresponds to one or more processors, such as a general-purpose microprocessor, a specially designed processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a collection of discrete logic circuits, or any type of processing device capable of performing the techniques described herein. In one example, the storage device 178 may store program instructions (e.g., software instructions or modules) executed by the processor 172 to perform the techniques described herein. In another example, the techniques may be performed by specially programmed circuits of the processor 172. In these or other methods, the processor 172 may be configured to perform the techniques described herein.

[0024] In some examples, the storage device 178 may include one or more computer-readable storage media. The storage device 178 may be configured to store more data than volatile memory. The storage device 178 may also be configured as a non-volatile memory space for long-term storage of data, and can retain data after activation / off cycles. Examples of non-volatile memory include solid-state drives (SSDs), hard disk drives (HDDs), flash memory, or electrically programmable memories (EPROMs) or electrically erasable and programmable memories (EEPROMs). The storage device 178 can store program instructions and / or data associated with software components 182-189 and / or the operating system 180.

[0025] In the example in Figure 1, the storage device 178 includes an orthotic feature library 164, a model library 166, and a physician preference library 168. Libraries 164, 166, and 168 may include relational databases, multidimensional databases, maps, hash tables, or any data structure for storing data. In one example, the model library 166 includes a 3D model of the patient's current and / or future dental structure. As will be described in more detail below, libraries 164, 166, and 168 may also include representations of interproximal 3D geometric shapes. In some cases, libraries 164, 166, and 168 may be stored locally on the computing device 150, or they may be accessed via a networked file share, cloud storage, or other remote data store.

[0026] The computing device 150 can execute software components 182-189 using one or more processors 172. The computing device 150 can execute any of the components 182-189 as a virtual machine running on the underlying hardware or within a virtual machine. For example, any of the components 182-189 can be implemented as part of the operating system 180.

[0027] According to the techniques of this disclosure, a computing device 150 automatically or semi-automatically generates a digital model of a dental appliance 101 for restoring the dental structure of patient 102, based on a digital model of the patient's future dental structure. A preprocessor 181 can preprocess the digital model of the patient's future dental structure. In one example, the preprocessor 181 performs preprocessing to identify one or more teeth in the patient's future dental structure. In some cases, the preprocessor 181 can identify the local coordinate system of each individual tooth and the global coordinate system containing each tooth of the future dental structure. In another example, the preprocessor 181 can preprocess the digital model of the future dental structure to identify the root structure of the dental structure. In yet another example, the preprocessor 181 can identify the gingiva. In this way, the preprocessor 181 can determine the portion of the future dental structure that includes the gingiva and the portion that includes the teeth. In yet another example, the preprocessor 181 can preprocess the digital model of the future dental structure by extending the roots and identifying the apical surface of the root of each individual tooth.

[0028] The landmark identification unit 182 can determine one or more landmarks of a future dental structure. Example landmarks include slices, midpoints, gingival boundaries, nearest neighbors between two adjacent teeth (e.g., contact points or nearest points (or nearest points of contact) between adjacent teeth), convex hulls, centers of mass, or other landmarks. A slice refers to a cross-section of a dental structure. A tooth midpoint refers to the geometric center (also called the geometric midpoint) of a tooth within a given slice. A gingival boundary refers to the boundary between the gingiva of a dental structure and one or more teeth. A convex hull refers to a polygon whose vertices include a subset of vertices within a given set of vertices, and whose boundary circumscribes the entire set of vertices. A tooth center of mass refers to the midpoint, center point, centroid, or geometric center of a tooth. In some cases, the landmark identification unit 182 determines landmarks within the local coordinate system of each tooth.

[0029] In some examples, the landmark identification unit 182 determines multiple slices of the patient's future dental structure. In one example, each slice has the same thickness. In other examples, one or more slices have a different thickness than the others. The thickness of a given slice may be predefined. In one example, the landmark identification unit 182 automatically determines the thickness of each slice. In another example, the thickness of each slice may be user-defined.

[0030] In some examples, the landmark identification unit 182 determines the midpoint of each tooth. In one example, the landmark identification unit 182 determines the midpoint of a particular tooth by calculating the extreme values ​​of the geometric shape of that particular tooth based on the entire tooth (for example, without dividing the dental structure into slices), and then determining the midpoint of that particular tooth based on the extreme values ​​of the geometric shape of the tooth.

[0031] In some examples, the landmark identification unit 182 determines the midpoint of each tooth in each slice. The landmark identification unit 182 may determine the midpoint of a particular tooth in a particular slice by calculating the center of mass of the arrangement of vertices around the edge of that particular tooth in that particular slice. In some cases, the midpoint of a particular tooth in a particular slice may be biased toward one edge of the tooth (for example, if one edge has more points than the other).

[0032] In another example, the landmark identification unit 182 may determine the midpoint of a particular tooth in a particular slice based on the convex hull of the particular tooth in the particular slice. For example, the landmark identification unit 182 may determine the convex hull of the set of edge points of the teeth in a given slice. In some cases, the landmark identification unit 182 determines the geometric center from the convex hull by performing a fill operation on the region circumscribing the convex hull and calculating the center of mass of the filled convex hull.

[0033] In some examples, the landmark identification module 182 determines the nearest neighbor between two adjacent teeth. The nearest neighbor between two adjacent teeth may be a contact point or the closest point. In one example, the landmark identification module 182 determines the nearest neighbor between two adjacent teeth in each slice. In another example, the landmark identification module 182 determines the nearest neighbor between two adjacent teeth based on the entire adjacent tooth (for example, without dividing the dental structure into slices).

[0034] A spline refers to a curve that passes through multiple points or vertices, such as a piecewise polynomial parametric curve. A mold splitting surface refers to a 3D mesh that bisects two sides of one or more teeth (for example, separating the facial side of one or more teeth from the lingual side of one or more teeth). A gingival trim surface refers to a 3D mesh that trims the surrounding shell along the gingival margin. A shell refers to an object with nominal thickness. In some examples, the inner surface of the shell coincides with the surface of the dental arch, and the outer surface of the shell is a nominal offset of the inner surface. A facial ribbon refers to a reinforcing rib with nominal thickness offset facially from the shell. A window refers to an aperture that provides access to the tooth surface so that a dental composite can be placed on top of the tooth. A door refers to a structure that covers the window. An incisal ridge reinforces the incisal edge of the dental appliance 101 and can be derived from the dental arch shape. Case frame sparering refers to connectable material used to join components of dental appliance 101 (e.g., the lingual portion of dental appliance 101, the facial portion of dental appliance 101, and its dependent components) to a manufacturing case frame. In this way, case frame sparering can be used to join components of dental appliance 101 to the case frame during manufacturing, protecting various components from damage or loss and / or reducing the risk of component mix-ups.

[0035] In some examples, the custom feature generator 184 generates one or more splines based on landmarks. The custom feature generator 184 may generate splines based on the midpoints of multiple teeth and / or the nearest neighbors between adjacent teeth (e.g., the contact points or nearest junctions between adjacent teeth). In some cases, the custom feature generator 184 generates one spline for each slice. In one example, the custom feature generator 184 generates multiple splines for a given slice. For example, the custom feature generator 184 may generate a first spline for a first subset of teeth (e.g., right molars), a second spline for a second subset of teeth (e.g., left molars), and a third spline for a third subset of teeth (e.g., anterior teeth).

[0036] The orthotic feature library 164 includes a set of predefined orthotic features that may be included in the dental orthosis 101. The orthotic feature library 164 may also include a set of predefined orthotic features that define one or more functional characteristics of the dental orthosis 101. Examples of predefined orthotic features include, among others, vents, rear snap clamps, door hinges, door snaps, incisal edge alignment features, center clips, custom labels, manufacturing case frames, and space matrix handles. Each vent is configured to allow excess dental composite to drain from the dental orthosis 101. The rear snap clamp is configured to connect the facial portion of the dental orthosis 101 to the lingual portion of the dental orthosis 101. Each door hinge is configured to pivotably connect individual doors to the dental orthosis 101. Each door snap is configured to fix individual doors in the closed position. In some examples, the incisal edge alignment feature comprises a pair of male and female tabs on the incisal edge of the dental orthosis 101 (e.g., along the median sagittal plane). In one example, an edge alignment feature is used to maintain vertical alignment between the facial portion and the lingual portion of the dental appliance 101. Each central clip is configured to provide vertical alignment between the lingual portion and the facial portion of the dental appliance 101. Each custom label contains data identifying the component of the dental appliance 101. A manufacturing case frame is configured to support one or more components of the dental appliance 101. For example, the manufacturing case frame can detachably connect the lingual portion and the facial portion of the dental appliance 101 to each other for safe handling and transport of the dental appliance 101 from the manufacturing facility 110 to the clinic 104.

[0037] In other implementations, the orthotic feature library 164 can be configured to include one or more interproximal geometric shapes that are inserted between adjacent teeth. These predefined geometric shapes may include, to name a few, library portions, scaled geometric shapes, and / or parametric shapes. For example, the orthotic feature library 164 may include 3D fins of uniform thickness. In another example, the orthotic feature library 164 may include 3D fins subdivided such that each subdivided portion has an individual thickness, which can be modified to better conform to the spacing and orientation of adjacent teeth. Generally, the fins may have an initial thickness of 100 to 500 microns, depending on the particular implementation. For example, in one implementation, a fin with a uniform thickness of 150 microns is stored in the orthotic feature library 164. In yet another example, the orthotic feature library 164 may include an oval cylinder that can be placed in the interproximal space between adjacent teeth. Techniques for arranging and refining interproximal geometric shapes are described in more detail below.

[0038] The feature manager 186 determines the parameters of one or more predefined orthotic features included in the predefined orthotic feature library 164. In one example, the predefined orthotic feature is configured to perform the function of a dental appliance 101. The parameters of the predefined orthotic feature may include the size, shape, scale, position, and / or orientation of the predefined orthotic feature. The feature manager 186 may determine the parameters of the predefined orthotic feature based on one or more rules. The rules may be pre-programmed or machine-generated, for example, by machine learning.

[0039] In some cases, Feature Manager 186 determines the placement of the posterior snap clamps based on rules. In one example, Feature Manager 186 places two posterior snap clamps along the dental arch at opposite ends of the dental arch (for example, placing the first snap clamp at one end and the second snap clamp at the other). In some examples, Feature Manager 186 places the posterior snap clamps one tooth past the outermost tooth to be repaired. In some examples, Feature Manager 186 places the female end of the posterior snap clamp on the lingual side of the splitting surface and the male end of the posterior snap clamp on the facial side.

[0040] In some cases, the feature manager 186 determines the placement of vents based on rules. In one example, the feature manager 186 places the vents on the centerline of the corresponding door on the incisal edge side of the dental appliance 101.

[0041] In some scenarios, Feature Manager 186 determines the placement of door hinges based on rules. In one scenario, Feature Manager 186 places each door hinge on the centerline of the corresponding door. In another scenario, Feature Manager 186 places the female part of the door hinge to secure to the facial side of the dental appliance 101 (for example, towards the incisal edge of a tooth) and the male part of the door hinge to secure to the outer surface of the door.

[0042] In one example, Feature Manager 186 determines the placement of door snaps based on a rule by positioning them along the centerline of the corresponding door. In another example, Feature Manager 186 positions the female part of the door snap to be fixed to the outer surface of the door and extend downward toward the gums. In yet another example, Feature Manager 186 positions the male part of the door snap to be fixed to the gum side of the facial ribbon. For example, the door snap can be fixed in the closed position by fastening the male part of the door snap to the facial ribbon.

[0043] In other examples, the feature manager 186 may determine the initial placement, orientation, and thickness of one or more interproximal tooth geometric shapes according to this disclosure.

[0044] The feature manager 186 may determine the parameters of predefined ostomy features based on the preferences of the physician 102. The physician preference library 168 may contain data indicating various physician 102 preferences. In one example, physician preferences directly influence the parameters of one or more ostomy features. For example, the physician preference library 168 may contain data indicating preferred sizes for various ostomy features, such as vent size. In such an example, a larger vent allows the dental composite or resin pressure to reach equilibrium more quickly during the door seating process, but may result in larger ridges that need to be finished after curing. In another example, the physician preference library 168 may contain data indicating preferred initial sizes or shapes of interproximal geometric shapes.

[0045] As another example, physician preferences indirectly influence the parameters of orthotic features. For instance, the physician preference library 168 may include data indicating preferred stiffness of the orthosis or preferred clamping of self-clamping features. Such preference choices may also influence more complex design changes to the degree of activation of the matrix cross-sectional thickness and / or clamp geometry. The feature manager 186 may determine the parameters of orthotic features by applying physician preferences to one or more rules, simulations (e.g., Monte Carlo), or finite element analyses. Feature parameters can also be derived from the properties of the material used in the matrix, such as the type of composite that dentists prefer to use in orthotics.

[0046] The model assembler 188 generates a digital 3D model of the dental appliance 101 used to reshape the dental structure (for example, into a future dental structure) in response to the determination of parameters for custom and predefined appliance features. The digital model of the dental appliance 101 may include a point cloud, a 3D mesh, a NURBS, or other digital representation of the dental appliance 101. In some cases, the model assembler 188 stores the digital model of the dental appliance 101 in the model library 166.

[0047] The model assembler 188 can output a digital model of the dental appliance 101. For example, the model assembler 188 can output the digital model of the dental appliance 101 to a computing device 192 in a manufacturing facility 110 that manufactures the dental appliance 101 (e.g., via a network 114). In another example, the computing device 150 sends the digital model of the dental appliance 101 to a computing device 190 in the clinic 104 for manufacturing at the clinic 104. In some implementations, the model assembler 188 generates a computer-readable file containing data describing the digital model of the dental appliance 101. This file may be stored in a storage device 164, and the file may be referenced in the future by the system 100 to refine previous digital models, or by the manufacturing system 194 to produce a physical matrix of the digital model.

[0048] The refinement module 189 can be used to refine a digital model of the dental appliance 101. For example, the refinement module 189 can be used to modify one or more parameters of the digital model. In some implementations, modifications to the digital model include modifying one or more parameters of the geometric shape of the inserted adjacent teeth. The refinement module 189 can be configured to incrementally modify the digital model in response to user input received (e.g., from a physician 106), or it can be configured to automatically refine the digital geometric shape using predefined rules or based on machine learning techniques.

[0049] In some implementations, the refinement module 189 can also graphically display incremental refinements in real time when the parameters of the digital model are changed. For example, when the thickness or position of an adjacent interdental fin is modified according to received user input, the refinement module 189 can update the parameters of the modified adjacent interdental fin and display any changes to the adjacent interdental fin relative to the digital model in real time via the UI device 174. In other implementations, the refinement module 189 can graphically display the final refinement, which is automatically calculated using predefined rules or machine learning.

[0050] The advantage of presenting the refinement graphically (either incrementally or upon completion of refinement) is that a user of system 100 (e.g., a physician 106) can visually inspect the digital model of the dental appliance 101 before the model is provided to the manufacturing system 194. In some implementations, one or more aspects of the digital model of the dental appliance 101 can be provided to the refinement module 189 before system 100 provides the digital model to the model assembler 188.

[0051] The computing device 192 may transmit a digital model of the dental appliance 101 to the manufacturing system 194. The manufacturing system 194 manufactures the dental appliance 101 according to the digital model of the dental appliance 101. The manufacturing system 194 may form the dental appliance 101 using any number of manufacturing techniques, including, among others, 3D printing, chemical vapor deposition (CVD), thermoforming, injection molding, lost wax casting, milling, machining, and laser cutting.

[0052] A dentist 106 can receive a dental appliance 101 and use it to reshape one or more teeth of patient 102. For example, the dentist 106 can apply dental composite to the surface of one or more teeth of patient 102 through one or more doors of the dental appliance 101. Excess dental composite can be removed through one or more vents. In some situations, the presence of interproximal geometric shapes in the dental appliance 101 allows the dentist 106 to better control the amount of dental composite or bonding material used during the filling procedure on patient 102. Generally, the advantages of using the techniques described herein include a significant reduction in the need for the dentist 106 to remove excess dental composite. As a result, the time spent treating patient 102 using the dental appliance 101 can be reduced, and the dentist 106 can be limited in using saws, blades, and other tools to separate interproximal dental composite after it has hardened.

[0053] In some examples, the model assembler 188 generates a digital model of the dental appliance 101 based on an existing digital model (for example, stored in the model library 166). In one example, the model library 166 may include data indicating appliance success criteria associated with each completed dental appliance 101, such as manufacturing and printing yield, physician and / or customer feedback or evaluation, or a combination thereof. For example, the model assembler 188 can use an existing digital model to generate a new or up-to-date digital model of the dental appliance 101 in response to a determination that the appliance success criteria of a previous dental appliance 101 meet a threshold criterion (e.g., a manufacturing yield threshold or a physician evaluation threshold). In one example, the existing digital model is a template or reference digital model. In such an example, the model assembler 188 can generate the digital model 101 of the dental appliance based on a template digital model. For example, the template digital model may be associated with different characteristics of the patient's original dental structure, such as a patient with small teeth or who cannot open their mouth wide.

[0054] In one example, the model assembler 188 generates a digital model 101 of a dental appliance based on an existing digital model by utilizing one or more morphing algorithms. For example, the model assembler 188 can use a morphing algorithm to interpolate the geometric shape of the appliance features. In one example, the model assembler 188 can generate a new digital model of the dental appliance 101 based on the design of an existing digital model. In one example, the design features of the existing digital model may include windows inset from the periphery so that the model assembler 188 can morph the geometric shape of the existing digital model based on landmarks of different dental structures.

[0055] The techniques of this disclosure may enable a computing device to automatically determine the shape of the dental appliance 101 and the placement of various appliance features. In this way, the computing device can generate a digital model 101 of the dental appliance more accurately and quickly. More accurate determination of the shape of the dental appliance 101 and the placement of appliance features can improve the effectiveness of the dental appliance 101 and tooth restoration. Faster determination of the shape of the dental appliance 101 and the placement of appliance features allows dentists to orthodontic treatment of patients' teeth earlier, thereby improving the appearance and / or function of the patient's teeth, and potentially improving the patient's experience. Furthermore, reducing the time required to generate a digital model of the dental appliance 101 can reduce manufacturing costs and make treatment more affordable for a wider range of patients.

[0056] Although it is stated that the computing device 150 automatically generates a digital model of the dental appliance 101 based on a digital model of the patient's future dental structure, in some examples the computing device 150 may use a digital model of the patient's current, unrestored dental structure to generate all or part of the digital model of the dental appliance 101. For example, the computing device 150 may use a digital model of the current dental structure to determine the position of a snap clamp (which may be placed on an unrestored tooth) or to generate a facial ribbon (for example, because the gingival margin may not change during restoration).

[0057] Figure 2 is a flowchart illustrating exemplary techniques 200 for generating digital models of dental appliances according to various aspects of this disclosure. Figure 2 will be described in the context of the system 100 shown in Figure 1.

[0058] In step 202, the computing device 150 receives a digital 3D model of the patient's 102 future (i.e., desired) dental structure. In one example, the computing device 150 receives the digital model of the future dental structure from another computing device, such as the computing device 190 in the clinic 104. The digital model of the patient's future dental structure may include a point cloud or a 3D mesh of the future dental structure. A point cloud includes a set of points that represent or define an object in three-dimensional space. A 3D mesh includes multiple vertices (also called points) and geometric faces (e.g., triangles) defined by vertices. In one example, the physician 106 creates a physical model of the future dental structure and uses an imaging system to create a digital model of the future dental structure. In another example, the physician 106 modifies the digital model of the patient's 102 current structure (e.g., by adding material to the surface of one or more teeth of the dental structure) to generate a digital model of the future dental structure. In some cases, selective removal of tooth structures may be planned. In other embodiments, the designed future structure may take into account, for example, a dentist's preference for subsequent treatment steps in which tooth voids may be overcontoured in the digital model, because the dentist prefers to be able to adjust them by hand during subsequent finishing. In yet another example, the computing device 190 may modify a digital model of a current dental structure to generate a model of a future dental structure. Instead of the physician, computer, or prosthesis manufacturer creating the future dental structure, a third-party laboratory and technician may be engaged in all or part of the dentition design work.

[0059] In step 204, the computing device 150 selects one or more pairs of teeth in the 3D model. For example, the computing device 150 performs a search on the digital model to identify the portion of the 3D mesh that represents the teeth present in the 3D model. The 3D mesh portion corresponding to adjacent tooth pairs can be automatically selected. In other implementations, teeth can be selected in response to user input. For example, the user can draw bounding boxes around the mesh portion representing teeth, and the computing device 150 can select those teeth in response to user input. In other words, one or more teeth can be selected by the computing device 150 using manual techniques (e.g., in response to user input highlighting specific elements of the 3D mesh belonging to adjacent tooth pairs) or automatic techniques (e.g., detecting curvature changes between adjacent mesh elements representing tooth boundaries, or applying a tooth template to a 3D mesh and determining tooth segmentation based on the applied template). In addition, various combinations of automatic tooth segmentation, landmark identification, and / or tooth identification algorithms may be used. Further deep learning algorithms may be used to assess the confidence in automatically selected and flagged tooth pairs for further consideration.

[0060] In step 206, for each selected pair of teeth, the computing device 150 determines the position and orientation within the interdental space between the selected adjacent teeth in order to insert a digital 3D geometric shape. There are several techniques that the computing device 150 can use to determine the position and orientation. In one example, the computing device 150 uses a Boolean intersection of the offsets between adjacent teeth to determine the best-fitting plane. The use of Boolean intersection will be described in more detail elsewhere, for example, with reference to Figures 3A and 3B. In another example, the computing device 150 uses a landmark coordinate system to determine the position and orientation. The use of landmark coordinate systems will be described in more detail elsewhere, for example, with reference to Figures 4 and 5.

[0061] In step 208, the computing device 150 inserts digital 3D geometric shapes into the determined positions and orientations. For example, based on the determined positions and orientations, 3D fins can be inserted between 3D meshes representing adjacent teeth.

[0062] In step 210, the computing device 150 refines the digital 3D geometric shape using the refinement module 189. For example, the refinement module 189 can receive user input and, in response to the received user input, modify the thickness parameter of one or more parts of the 3D fin. As another example, in response to user input, the refinement module 189 can translate one or more parts of the 3D fin to reposition each part within the interdental space between adjacent teeth. Such a refinement module may also refine the shape and cross-section of the 3D fin to generate slopes or curves to improve, for example, the local strength, flexibility, alignment with adjacent tooth structures, or the fin's ability to produce a desired geometric shape in restoration while maintaining mechanical integrity through the molding, hardening, and removal processes.

[0063] In step 212, the computing device 150 generates a file representing a 3D dimensional dental appliance (such as dental appliance 101) that includes a 3D model and refined 3D geometric shapes. For example, the computing device 150 can generate a file that specifies the 3D model using any number of conventional techniques.

[0064] In step 214, the computing device 150 generates the dental appliance 101 from its representation. For example, the computing device 150 can send the file to a manufacturing system 194 which can produce the dental appliance 101 using any number of techniques, including, among others, 3D printing, CVD, thermoforming, injection molding, lost wax casting, milling, machining, and laser cutting.

[0065] Figures 3A and 3B are conceptual diagrams illustrating exemplary techniques for determining the position and orientation of inserted interproximal geometric shapes using Boolean cross results, according to various aspects of the present disclosure. The conceptual diagrams are described in the context of system 100. For example, Figures 3A and 3B are described in the context of computing device 150.

[0066] In a particular implementation, the computing device 150 offsets or translates the 3D meshes representing adjacent teeth 302a and 302b to cause the 3D meshes to intersect. The intersection 304 of adjacent teeth 302a and 302b can be of varying widths. For example, in one implementation, the 3D meshes are offset so that their intersection 304 is only 100 microns. Specifically, in this example, each 3D mesh representing adjacent teeth 302a and 302b is individually offset by 50 microns, resulting in an intersection of 100 microns. Next, the computing device 150 determines the Boolean intersection result of the overlapping meshes. For example, using a Boolean intersection technique, the computing device 150 identifies and retains the overlapping portions of the 3D mesh and discards the non-overlapping portions.

[0067] After the computing device 150 performs a Boolean intersection, it can also determine the best-fitting plane 306 of the remaining 3D mesh corresponding to adjacent teeth 302a and 302b. There are various techniques for determining the best-fitting plane 306. For example, an iterative process can be used, thereby refining the plane's position until a plane is generated and the average distance between each vertex of the intersection mesh and the generated plane is minimized. Once the best-fitting plane 306 is determined, the computing device 150 can thicken the plane. For example, as shown in Figure 3A, the plane 308 has a uniform thickness such as 150 microns. To complete the refinement of the model, the computing device 150 can perform a Boolean subtraction to generate a modal refinement that includes an adjacent intertooth space 310 into which a 3D geometric shape can be inserted. This separates the 3D mesh corresponding to adjacent teeth 302a and 302b by a selected thickness within the model.

[0068] Figure 3B shows a technique similar to that shown in Figure 3A. The main difference is that, as shown in Figure 3B, the plane is subdivided into regions (or zones) 508a, 508b, and 508c, allowing the computing device 150 to specify different parameters for each of the subdivided areas. For example, the computing device 150 can specify a first thickness of region 508a for a first distance along the mesial-distal axis and the gingival-occlusal axis. This allows the computing device 150 to generate a better fit for the interproximal geometric shape to be inserted into the interproximal spaces 310a-310c. However, while Figure 3B shows the best-fit plane subdivided into three regions, it should be understood that the best-fit plane can be subdivided into any number of regions to refine the model according to the needs of patient 102. Also, it should be understood that the thickness may be 0 and / or may include values ​​below the resolution limit of the fabrication device. In another example, the geometric shape can be controlled to be greater than the proven minimum resolution of the fabricated device, ensuring that all features of the device can be repeatedly fabricated, tested, and deployed for clinical use, regardless of daily process variations in the fabricated device.

[0069] Figure 4 is a block diagram illustrating exemplary techniques for optimizing contact geometric shapes according to various aspects of the present disclosure. In some situations, the intersections or contact areas between teeth may not occur in a convenient position for the digital representation of the dental appliance 101. Figure 4 shows an example of an exemplary method of how the initially determined position can be mapped to a more ideal position. In the disclosed techniques, other optimization techniques are also possible, but the initial position is modified to align more closely with the mold parting surface. As shown in Figure 4, for a particular tooth represented by the 3D mesh 402, the computing device 150 can calculate the CG point 404 of the “contact body”. Referring back to Figure 3, 304 represents an exemplary contact body. That is, as used herein, the “contact body” is defined as the volume generated by the intersection of offset teeth. As used herein, the “CG point” refers to the centroid of the contact body (here, adjacent teeth). For example, the CG point can be represented by the mathematical center of the contact body and can be determined using conventional techniques.

[0070] The computing device 150 can also introduce molded splitting surfaces 406 that point to a 3D mesh that bisects two sides of one or more teeth (for example, separating the facial side of one or more teeth from the lingual side of one or more teeth), as described above. For example, the molded splitting surfaces 406 can be generated using anatomical landmarks from within the patient's dentition. In one embodiment, the geometric shape of the molded splitting surfaces 406 may be created to pass through the midpoint of each of a series of slices or other subdivisions of the tooth. Other embodiments and formulations are possible.

[0071] For example, the mold partition surface 406 may be generated using one or more neural networks in other implementations. A generative adversarial neural network (GAN) may be used. Alternatively, a graph convolutional neural network (GraphCNN) may be used. Furthermore, combinations of these and other networks may be used.

[0072] Next, the computing device 150 maps the CG point 404 to the intersection line of the mold division surface 406 and the contact plane, which is the best-fitting plane for the intersecting teeth. For example, referring back to Figure 3, the computing device 150 can determine the position where the contact plane intersects the mold division surface, which designates the best-fitting plane 306. After the computing device has mapped the CG point 404, it can generate a parametric oval at the new point 408. For example, in some implementations, the position of the new point 408 can be determined by translating the CG point 404 in the XY plane. The computing device 150 can also determine the size of the parametric oval based on one or more parameters of the adjacent teeth. For example, the size of the parametric oval may be determined based on some combination of the average anatomical contact size of the adjacent teeth and which particular teeth are adjacent. As a result, for example, incisors, canines, and molars may all have different shapes and different sizes of contact areas, depending on the particular implementation.

[0073] Figure 5 is a conceptual diagram illustrating how a landmarking coordinate system can be used to calculate the orientation and position of adjacent intertooth geometric shapes in various embodiments of this disclosure. In the illustrated example, the computing device 150 identifies, or otherwise determines, a first set of landmark coordinate systems 502a for a first 3D mesh representing tooth 302a. For example, the first landmark coordinate system can be represented by the X, Y, and Z axes defined for the 3D mesh representing the first tooth 302a. Similarly, the computing device 150 identifies, or otherwise determines, a second set of landmark coordinate systems 502b for a second 3D mesh representing tooth 302b. According to a particular implementation, the landmark coordinate systems 502a and 502b can be automatically determined based on their form in the digital 3D model. In other implementations, the user can manually adjust the landmark coordinate system 502b, based on the user's expertise, until the landmark coordinates visually reflect the desired result of the adjustment. However, please understand that landmark coordinates 502a and 502b can be determined similarly by other methods.

[0074] Next, the computing device 150 can calculate the average landmark coordinate system 512 by averaging the first landmark coordinate systems 502a and 502b. For example, the computing device 150 can calculate the average of the X origin, Y origin, and Z origin of the first landmark coordinate system 502a and the second landmark coordinate system 502b, respectively, such that the distance 508 between the first landmark coordinate system 502a and the average landmark coordinate system 512 is the same as or substantially the same as the distance 510 between the second landmark coordinate system 502b and the average landmark coordinate system 512.

[0075] The computing device 150 can also calculate the orientation angle of the landmark coordinate system. According to a particular implementation, the first landmark coordinate system axis 502a and the second landmark coordinate system axis 502b are surface normals. That is, the landmark coordinate system axes 502a and 502b form imaginary lines oriented at a 90-degree angle to the surfaces of teeth 302a and 302b, respectively. In other words, the landmark coordinate system axis 502a forms an imaginary line perpendicular to the 3D mesh representing tooth 302a, and the landmark coordinate system axis 502b forms an imaginary line perpendicular to the 3D mesh representing tooth 302b. By using the surface normals, the computing device 150 can calculate the orientation angle of the average landmark coordinate system axis 512. For example, according to a particular implementation, the orientation angle of the average landmark coordinate system axis 512 can be determined by the computing device 150 such that the angle 504 with the first landmark coordinate system axis 502a is the same as the angle 506 with the second landmark coordinate system axis 502b. In other words, the computing device 150 can determine the orientation angle of the mean landmark coordinate system axis 512 by determining the angle 504 between the surface normal represented by the landmark coordinate system axis 502a and the mean landmark coordinate system axis 512, which is the same as the angle 506 between the surface normal represented by the second landmark coordinate system axis 502b and the mean landmark coordinate system axis 512.

[0076] After the computing device 150 calculates the orientation angle of the average landmark coordinate system axis 512, the computing device 150 can translate the average landmark coordinate system to point 514. In some implementations, point 514 represents the point where the 3D meshes representing teeth 302a and 302b intersect. For example, in one implementation, point 514 can be determined by generating a pair of points with the minimum distance (one from each tooth mesh 302a and 302b) and calculating the midpoint between them. In other implementations, point 514 can represent a point in the inter-tooth space between adjacent teeth, thereby the teeth being at their nearest neighbor point without intersecting.

[0077] Figures 6A and 6B are conceptual diagrams illustrating exemplary techniques for refining interproximal geometric shapes according to various aspects of the present disclosure. Generally, the concepts shown in Figures 6A and 6B represent refinement of a 3D model. For example, Figures 6A and 6B show a 3D model after one or more 3D geometric shapes (e.g., 3D fins 602a-602g) have been inserted into their respective interproximal spaces. Thus, Figures 6A and 6B are described in the context of a computing device 150 capable of performing the operations described herein using a refinement module 189.

[0078] As shown in Figures 6A and 6B, it may be advantageous to subdivide the interdental 3D geometric shape 602a-602g into a facial portion 604a-604g and a lingual portion 606a-606g by bisecting the interdental 3D geometric shape using a calculated mold division surface, such as mold division surface 406. This makes it possible to refine the arrangement of the 3D interdental geometric shape by independently moving the facial portion represented by the subdivided portions 604d and 604e, and the lingual portion represented by the subdivided portions 606d and 606e. For example, as shown in Figure 6B, the facial subdivided portions 604d and 604e and the lower subdivided portions 606d and 606e can be displaced in response to input received by the refinement module 189 to reposition each subdivided portion to improve the fit of the interdental 3D geometric shape to the 3D mesh representing the adjacent teeth. In other words, the refinement module 189 can adjust the profile of the interproximal 3D geometric shape by translating one of the subdivisions 604d, 604e, 606d, and 606e relative to each adjacent tooth, thereby refining the amount of contact between adjacent teeth or the level of tightness during flossing.

[0079] Figures 7, 8A, 8B, 9A, and 9B are conceptual diagrams illustrating an exemplary technique for refining the interproximal tooth geometry using an oval cylinder. According to a particular implementation, the oval cylinder is initially positioned as shown in Figure 7. The orientation of the oval cylinder is then modified as shown in Figures 8A, 8B, 9A, and 9B. As a result, Figures 7, 8A, 8B, 9A, and 9B are illustrated in the context of a computing device 150 capable of performing the operations described herein using a refinement module 189.

[0080] Figure 7 is a conceptual diagram illustrating exemplary techniques for positioning an oval cylinder within a 3D model according to various embodiments of this disclosure. The refinement module 189 can position contact planes 704a to 704k between 3D meshes representing teeth 702a to 702l using the techniques described herein. For example, according to a particular implementation, the refinement module 189 can determine the positions of the contact planes 704a to 704k by calculating the best-fit plane 306, as described in relation to Figures 3A and 3B.

[0081] The refinement module 189 can then generate one or more oval cylinders, such as an exemplary oval cylinder depicted as an oval cylinder 710. For example, according to a particular implementation, the oval cylinder may be a stock oval cylinder stored in the orthotic feature library 164. In other implementations, the oval cylinder may be a scaled version of a stock oval cylinder stored in the orthotic feature library 164. In other implementations, the oval cylinder can be generated. For example, the oval cylinder can be generated by scaling the cylinder along the Z and / or Y axes to modify the cylinder into an oval shape. In another example, the oval cylinder can be generated based on a parametric equation according to the dimensions of the interdental space between adjacent teeth. In another example, the oval cylinder may be based on a shape measured in a study of contact structures. In such a situation, the cross-section of the cylinder may technically differ from an oval where, for example, the anatomical contact is known to be kidney-shaped. In another example, the rules for generating the structural contact may differ for each pair of teeth. For example, the oval shape in a pair of teeth with existing contacts between untreated teeth may be treated differently from the gap or pair of teeth where only occlusal lengthening is performed during treatment. One or more oval cylinders, such as one or more of the oval cylinders 710, can be used to insert a contact window, such as a contact window 706, into the 3D model. For example, according to a particular implementation, the refinement module 189 can define one or more contact planes 704a to 704k such that the centers of the contact planes 704a to 704k bisect each oval cylinder, such as one of the oval cylinders shown as oval cylinder 710. In other words, the refinement module 189 can use interplane alignment to position the oval cylinders at their respective interproximal tooth contacts. For example, the oval cylinders can be positioned at interproximal tooth contacts such that the central plane of the cylinder conforms to the contact planes 704a to 704k. An example of using interplane alignment is shown for the orientation of the contact window 706, but other positions and orientations are also possible.

[0082] As described, by arranging the oval cylinders, the oval geometric shape defines contact windows, such as contact windows 706, passing through individual contact planes. For example, each of the oval cylinders can be subtracted from its respective interdental fin (e.g., using the Boolean subtraction technique) to generate contact windows. This makes it possible for the 3D model to include contact windows of configurable size and shape. Furthermore, configurable contact windows can enable the creation of dental appliances that create precise and tight interdental contacts with minimal bonding between teeth, allowing for quicker separation of adjacent teeth after the restorative material has hardened, and providing a filling procedure that is less reliant on saws, blades, and other tools.

[0083] Figures 8A, 8B, 9A, and 9B are conceptual diagrams illustrating exemplary techniques for oriented oval cylinders according to various embodiments of the present disclosure. As shown in Figures 8A and 8B, the refinement module 189 can orient oval cylinders 802a to 802g to take into account the varying tooth tip angles of teeth 804a to 804j. For example, according to a particular embodiment, the angle between the mold division surfaces in each of the contact planes 704a to 704k can be calculated by determining the intersection curve where the mold division surface and the contact plane intersect. According to a particular implementation, a line can be best fitted to this intersection curve, and the angle between the best-fit line and the Z-axis (i.e., the vertical axis) can be determined.

[0084] Next, using the resulting angles for each of the contact planes 704a to 704k, one or more oval geometric shapes, such as one or more oval cylinders shown as oval cylinders 710, can be rotated so that the resulting contact window matches the orientation of each tooth. For example, an oval cylinder positioned relative to contact plane 704g can be rotated by an amount equal to the calculated angle between the mold splitting plane measured at contact plane 704g and the Z-axis (i.e., the vertical axis). The oval cylinder is then subtracted (e.g., using Boolean subtraction techniques) from the interproximal fins inserted between teeth 702g and 702h to generate a contact window with an orientation angle that reflects the tooth inclination of teeth 702g and 702h.

[0085] Once the orientation of cylinders 802a-802g is corrected, the refinement module 189 can position the reoriented cylinders 802a-802g at their respective positions relative to the contact planes 704a-704k. As shown in Figure 8B, after rotation, the contact windows defined by the oval cylinders 802a-802g present a natural, aligned, and parameterized contact definition for the 3D mesh representing the teeth 804a-804j.

[0086] Figures 9A and 9B show different conceptual diagrams of the oval cylinder 802c relative to the 3D mesh representing the tooth 804c. As illustrated and described, the orientation angle of the oval cylinder 802c is, here, the inclination of the 3D mesh representing the tooth 804c. According to certain implementations, as described above, each oval cylinder can be subtracted from its respective adjacent interdental fin to generate contact windows. It may also be advantageous to further refine one or more oval cylinders before generating individual contact windows. For example, according to some implementations, as shown by Figure 9B, before subtraction, the oval cylinder 802c can be subdivided into a lingual component 902a and a facial component 902b, respectively. For example, the refinement module 189 can subdivide the oval cylinder 802c using the mold division surfaces of the tooth 804c (such as mold division surfaces like mold division surface 406). In one implementation configuration, the refinement module 189 can position the dividing surface such that it divides the oval cylinder 802c into two parts, generating a lingual component 902a and a facial component 902b. This allows for greater design control of the contact window. For example, instead of only modifying the position and orientation of the entire oval cylinder 802c, the refinement module 189 can modify the position and orientation of either the lingual component 902a or the facial component 902b.

[0087] Figures 10A and 10B are flowcharts illustrating exemplary techniques for determining the position and orientation of the interproximal geometric shape in step 206 of technique 200. For clarity, the exemplary techniques in Figures 10A and 10B will be described individually, but it should be understood and acknowledged that the disclosed techniques can be used in combination.

[0088] Referring to Figure 10A, in step 1002, the computing device 150 offsets or translates the 3D meshes representing adjacent teeth to intersect them. For example, as shown and described in relation to Figures 3A and 3B, the computing device 150 can translate the 3D meshes representing teeth 302a and 302b. In one implementation, the 3D meshes are offset so that they intersect by only 50 microns. In step 1004, the computing device 150 determines the Boolean intersection result of the overlapping meshes. For example, the computing device 150 can determine the intersection 304 shown and described in relation to Figures 3A and 3B. Step 1004 is generally performed using conventional techniques. For example, using a Boolean intersection technique, the computing device 150 identifies and retains the overlapping portions of the 3D mesh and discards the non-overlapping portions.

[0089] In step 1006, the computing device 150 determines the best-fitting plane based on the Boolean cross-section results. For example, the computing device 150 can use conventional techniques to calculate the best-fitting plane 306 shown and described in relation to Figures 3A and 3B based on the Boolean cross-section results.

[0090] Referring here to Figure 10B, a technique for determining the position and orientation using the landmark coordinate system of adjacent teeth is described. In step 1012, the computing device 150 determines the contact point between adjacent teeth. For example, as shown and described in Figure 5, the computing device 150 can determine point 514 by determining the intersection of the 3D mesh representing teeth 304a and 304b.

[0091] In step 1014, the computing device 150 determines a landmark coordinate system for each adjacent tooth. For example, as shown and explained in Figure 5, the computing device 150 may determine the landmark coordinate system based on the morphology present in the digital 3D model, based on received user input, and using other techniques.

[0092] In step 1016, the computing device 150 determines the average of the landmark coordinate systems for each adjacent tooth. For example, as shown and explained with reference to Figure 5, the computing device 150 can calculate the average of the X, Y, and Z coordinate systems of the first landmark coordinate system 502a and the second landmark coordinate system 502b, respectively, such that the distance 508 between the first landmark coordinate system 502a and the average landmark coordinate system 512 is the same as or substantially the same as the distance 510 between the second landmark coordinate system 502b and the average landmark coordinate system 512.

[0093] In step 1018, the computing device 150 determines the orientation based on the determined mean of the landmark coordinate system. For example, as shown and explained in Figure 5, the orientation angle with respect to the mean landmark coordinate system 512 can be determined by the computing device 150 such that the angle 504 with the first landmark coordinate system axis 502a is the same as the angle 506 with the second landmark coordinate system axis 502b.

[0094] In step 1020, the computing device 150 determines its position based on the contact points between adjacent teeth. For example, as illustrated with reference to Figure 5, the computing device 150 can translate the mean landmark coordinate system to point 514. In other words, according to a particular implementation, the calculated mean landmark coordinate system 512 is modified by the value of point 514 to determine its position.

[0095] Figures 11A to 11D are flowcharts illustrating exemplary techniques for refining digital 3D geometric shapes in step 210 of technique 200, according to various embodiments of this disclosure. In certain implementations, this includes customizing the interproximal geometric shapes, according to various embodiments of this disclosure. For clarity, the exemplary techniques in Figures 11A to 11D will be described independently, but it should be understood and recognized that one or more of the techniques shown in Figures 11A to 11D can be used in combination to refine a digital 3D model, such as a digital 3D model representing a dental appliance 101.

[0096] Referring to Figure 11A, in step 1102, the refinement module 189 subdivides the 3D geometric shape into one or more parts between the lingual end and the facial end of the 3D geometric shape. For example, as shown and described in Figures 6A and 6B, the refinement module 189 can use the mold division surface to subdivide the 3D fins 602a-602g into lingual ends 606a-606g and facial ends 604a-604g.

[0097] In step 1104, the refinement module 189 translates one or more parts of the 3D geometric shape relative to the digital 3D model to adjust the resulting 3D geometric shape in the digital 3D model. For example, as shown and illustrated in Figure 6B, the refinement module 189 can translate the facial portion 604d and / or 604e and the tongue portion 606d and / or 606e to adjust the fit of the 3D fins 602d and / or 602e, respectively.

[0098] Referring to Figure 11B, in step 1112, the refinement module 189 subdivides the 3D geometric shape perpendicularly into at least a first part and section parts. For example, as shown and explained with reference to Figure 3B, the refinement module 189 can subdivide the 3D fin into multiple zones 308a to 308c.

[0099] In step 1114, the refinement module 189 adjusts one or more parameters of each individual part to adjust the resulting 3D geometric shape in the digital 3D model. The parameters may include the relative position of each part, the thickness of each part, and other parameters. For example, as shown and explained with reference to Figure 3B, the refinement module 189 can modify the thickness of zone 308a so that it has a different thickness from zones 308b and 308c. Similarly, the refinement module 189 can modify the thickness of zones 308b and / or 308c.

[0100] In Figure 11C, in step 1122, the refinement module 189 positions a predefined 3D geometric shape in terms of position and orientation relative to the digital 3D model. For example, as shown and described with reference to Figure 3A, the refinement module 189 can position a predefined plane 306 at the intersection of a 3D mesh representing adjacent teeth 302a and 302b. As another example, as shown and described with reference to Figures 5 and 6A, the refinement module 189 can insert a 3D fin at point 514 having an orientation equal to the landmark axis 512.

[0101] In step 1124, the refinement module 189 scales a predefined 3D geometric shape based on one or more parameters of the 3D model. For example, as shown and explained with reference to Figure 3A, the refinement module 189 can increase the thickness of the best-fit plane 306 to generate a 3D fin 308. As another example, the refinement module 189 can scale any of the 3D fins 602a to 602g to promote improved interproximal fit between 3D meshes representing adjacent teeth.

[0102] Referring to Figure 11D, in step 1132, the refinement module 189 adds an oval cylinder to each instance of the digital 3D geometric shape. For example, as shown and described in relation to Figure 7, the refinement module 189 can insert one or more oval cylinders into the contact planes 704a-704k in the adjacent interdental space of the 3D mesh representing teeth 702a-702l. Furthermore, according to a particular implementation, the inserted 3D geometric shape is bisected by individual digital 3D geometric shapes. For example, as shown and described in relation to Figure 7, the refinement module 189 positions the oval cylinder (e.g., oval cylinder 710) such that it bisects the contact plane that generates a contact window 706.

[0103] In step 1134, the refinement module 189 aligns the individual oval cylinder central planes to individual digital 3D geometric shapes. For example, as shown and described in relation to Figures 8A and 8B, the individual oval cylinder central planes can be aligned to any inclination present in each tooth of the 3D model.

[0104] In step 1136, the refinement module 189 determines the angles between individual division planes and individual digital 3D geometric shapes. For example, the angles between each of the contact planes 704a to 704k and the mold division planes can be calculated, as shown and explained with reference to Figures 8A to 9B. In other words, determining the angles between individual division planes may include determining the angles between the occlusal-gingival axis of the tooth and the individual 3D digital geometric shapes. The resulting values ​​can then be used to rotate one or more oval geometric shapes, such as one or more oval cylinders represented by the oval cylinder 710, so that the resulting contact window matches the orientation of the tooth.

[0105] In step 1138, the refinement module 189 rotates individual digital 3D geometric shapes based on individually determined angles to match individual oval shapes to the tooth inclinations of their respective adjacent teeth. For example, as shown and illustrated in Figure 9A, the orientation of the oval cylinder 802c matches the orientation of the 3D mesh representing the teeth 804c. In some implementations, the refinement module 189 can further refine the arrangement and orientation of the geometric shapes by subdividing the individual digital 3D geometric shapes. For example, as shown and illustrated in Figure 9B, a mold division surface can be applied to the oval cylinder 802c to divide the cylinder 802c into a lingual portion 1002a and a facial portion 1002b. In addition to the embodiments described above, the following embodiments are also noted. (Note 1) A computer implementation method for digitally designing the geometric shape of adjacent teeth, To generate a digital three-dimensional (3D) model of a patient's future dental structure, wherein the future dental structure represents the intended shape of at least one tooth of the patient. Selecting one or more pairs of teeth in the 3D model, wherein the teeth in the pair are adjacent, For each selected pair of teeth, the position and orientation of the adjacent teeth within the interdental space are determined in order to insert a digital 3D geometric shape having one or more initial parameters. Insert the digital 3D geometric shape into the determined position and orientation, Computer implementation methods, including those mentioned above. (Note 2) The computer mounting method according to Appendix 1, wherein one or more initial parameters of the digital 3D geometric shape include at least one thickness that is greater than 100 microns and less than 500 microns. (Note 3) Determining the position and orientation within the adjacent interdental space is, By offsetting the adjacent teeth and causing their respective geometric shapes to intersect, Determining the Boolean crossing result of the adjacent teeth, The best-fitting plane is determined based on the Boolean intersection result, The computer implementation method described in Appendix 1, including the method described in Appendix 1. (Note 4) Determining the position and orientation within the adjacent interdental space is, Determining the contact point between adjacent teeth, For each of the adjacent teeth, determine the landmark coordinate system, For each of the adjacent teeth, the mean of the landmark coordinate system is determined based on the landmark coordinates, The orientation is determined based on the determined average of the landmark coordinate system, The position is determined based on the contact point between the adjacent teeth, The computer implementation method described in Appendix 1, including the method described in Appendix 1. (Note 5) To refine the aforementioned digital 3D geometric shape. The computer implementation method described in Appendix 1, further including the above. (Note 6) The aforementioned refinement is, The 3D geometric shape is subdivided into one or more parts between the lingual end and the facial end of the 3D geometric shape, The process involves translating one or more parts of the 3D geometric shape relative to the digital 3D model to adjust the resulting 3D geometric shape within the digital 3D model. The computer implementation method described in Appendix 5, including the method described in Appendix 5. (Note 7) The aforementioned refinement is, The 3D geometric shape is subdivided vertically into at least a first part and a second part, Adjusting one or more parameters of each of the individual parts to adjust the resulting 3D geometric shape in the digital 3D model, The computer implementation method described in Appendix 5, including the method described in Appendix 5. (Note 8) The computer implementation method according to Appendix 7, wherein the parameters include at least one of a first thickness along the mesial-distal axis, a distance along the gingival-occlusal axis, and an offset of each of the individual portions. (Note 9) The computer implementation method described in Appendix 8, wherein the parameters of each individual part are different for each of the respective parts. (Note 10) The aforementioned refinement is, Positioning a predefined 3D geometric shape in relation to the aforementioned 3D model, The predefined 3D geometric shape is scaled based on one or more parameters of the 3D model, The computer implementation method described in Appendix 5, including the method described in Appendix 5. (Note 11) To generate a file that represents a 3D dimensional physical matrix including the 3D model and the refined 3D geometric shape, To generate the physical matrix from the aforementioned representation, The method described in Appendix 10, further including the method described in Appendix 10. (Note 12) The computer implementation method according to Appendix 11, wherein generating the physical matrix from the representation includes constructing the physical matrix from the representation using a 3D printer. (Note 13) The aforementioned refinement is, Adding an egg-shaped cylinder to each instance of the digital 3D geometric shape, wherein the egg-shaped cylinder is divided by the individual digital 3D geometric shape, For each added oval cylinder, the central plane of the individual oval cylinder is aligned to the individual digital 3D geometric shape, For each digital 3D geometric shape, the angle between the individual dividing surface and the individual digital 3D geometric shape is determined. For each digital 3D geometric shape, the individual digital 3D geometric shape is rotated based on the individually determined angle to make the individual egg shape match the tooth inclination of each adjacent tooth. The computer implementation method described in Appendix 5, including the method described in Appendix 5. (Note 14) A computer implementation method for digitally designing the geometric shape of adjacent teeth, To generate a digital three-dimensional (3D) model of a patient's future dental structure, wherein the future dental structure represents the intended shape of at least one tooth of the patient. Selecting one or more pairs of teeth in the 3D model, wherein the teeth in the pair are adjacent, For each selected pair of teeth, the position and orientation of the adjacent teeth within the interdental space are determined in order to insert a digital 3D geometric shape having one or more initial parameters. Insert the digital 3D geometric shape into the determined position and orientation, The aforementioned digital 3D geometric shape is refined, To generate a file that represents a 3D dimensional physical matrix including the 3D model and the refined 3D geometric shape, To generate the physical matrix from the aforementioned representation, Computer implementation methods, including those mentioned above.

Claims

1. A computer implementation method for digitally designing the geometric shape of adjacent teeth, The computing device generates a digital three-dimensional (3D) model of the patient's desired dental structure, wherein the desired dental structure represents the intended shape of at least one of the patient's teeth. The computing device selects one or more pairs of teeth in the 3D model, wherein the teeth in the pair are adjacent, and the selection is performed. The computing device determines the position and orientation of adjacent teeth within the interdental space in order to insert a digital 3D geometric shape having one or more initial parameters for each selected pair of teeth. The computing device inserts the digital 3D geometric shape into the determined position and orientation, Computer implementation methods, including those mentioned above.

2. The computer mounting method according to claim 1, wherein one or more initial parameters of the digital 3D geometric shape include at least one thickness that is greater than 100 microns and less than 500 microns.

3. Determining the position and orientation within the adjacent interdental space is, By offsetting the adjacent teeth and causing their respective geometric shapes to intersect, Identifying the overlapping portion of the geometric shapes of the intersecting adjacent teeth, The best-fitting plane is determined based on the identified overlapping portion, The computer implementation method according to claim 1, including the method described in claim 1.

4. Determining the position and orientation within the adjacent interdental space is, Determining the contact point between adjacent teeth, For each of the adjacent teeth, determine the landmark coordinate system, For each of the adjacent teeth, the mean of the landmark coordinate system is determined based on the determined landmark coordinate system, The orientation is determined based on the determined average of the landmark coordinate system, The position is determined based on the contact point between the adjacent teeth, The computer implementation method according to claim 1, including the method described in claim 1.

5. To refine the aforementioned digital 3D geometric shape. The computer implementation method according to claim 1, further comprising:

6. The aforementioned refinement is, The 3D geometric shape is subdivided into one or more parts between the lingual end and the facial end of the 3D geometric shape, The process involves translating one or more parts of the 3D geometric shape relative to the digital 3D model to adjust the 3D geometric shape within the digital 3D model. The computer implementation method according to claim 5, including the method described in claim 5.

7. The aforementioned refinement is, The 3D geometric shape is subdivided perpendicularly into at least a first portion and a second portion, Adjusting one or more parameters of each of the individual parts to adjust the 3D geometric shape within the digital 3D model, The computer implementation method according to claim 5, including the method described in claim 5.

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