Apparatus for use in an oral cavity of a subject

Abstract

There is provided a system for determining locations of one or more teeth of a subject and / or locations of one or more oral features in an oral cavity of a subject. The system comprises an apparatus for use in an oral cavity of a subject, and a processor. The apparatus comprises a body. The apparatus further comprises a pressure sensor arranged on the body, configured to detect pressure applied to the pressure sensor by a first tooth of the subject. The apparatus further comprises a camera system arranged on the body, configured to generate intra-oral images in response to a detection of pressure by the pressure sensor. The processor is configured to determine, based on the generated images, locations of one or more teeth of the subject and / or locations of one or more oral features.

Description

[0001] 2025PF00026

[0002] 1

[0003] APPARATUS FOR USE IN AN ORAL CAVITY OF A SUBJECT

[0004] FIELD OF THE INVENTION

[0005] The disclosure relates to methods and apparatus for determining locations of one or more teeth of the subject and / or locations of one or more oral features.

[0006] BACKGROUND OF THE INVENTION

[0007] An oral scanner may be used to signal regular missed spots on a subject’s teeth, by measuring old plaque with a QLF technique. To have a meaningful action following detection of old plaque, information about location (for example, what tooth, on what side, and which area) where the plaque is detected is important.

[0008] This may be achieved through the use of a tooth location classifier. The tooth location classifier may take the tooth images as input, and based on distinct teeth morphology and the predictive order of teeth (e.g. a canine always being between front teeth and a premolar, molars being next to each other, etc.) the model is able, with a certain accuracy, to predict the teeth number of a tooth in the image, or a number of images forming (at least a part ol) a video stream . Following this, the region on the tooth where the plaque is located can be established.

[0009] There currently exist certain challenges. Image analysis techniques often face accuracy problems, especially when the angles of the obtained images are shallow. It is not always clear how the teeth are spaced relative to each other in these images with sufficient accuracy, in order for the aforementioned location information to then be accurately determined.

[0010] SUMMARY OF THE INVENTION

[0011] As noted above, there currently exist certain challenges. Embodiments of the present disclosure address these and other challenges.

[0012] According to a first aspect, there is provided a system for determining locations of one or more teeth of a subject and / or locations of one or more oral features in an oral cavity of a subject. The system comprises an apparatus for use in an oral cavity of a subject, and a processor. The apparatus comprises a body. The apparatus further comprises a pressure sensor arranged on the body, configured to detect pressure applied to the pressure sensor by a first tooth of the subject. The apparatus further comprises a camera system arranged on the body, configured to generate intra-oral images in response to a detection of pressure by the pressure sensor. The processor is configured to determine, based on the generated images, locations of one or more teeth of the subject and / or locations of one or more oral features in the generated images.2025PF00026

[0013] 2

[0014] An advantage of the first aspect is that when pressure is applied to the pressure sensor (for example, by a tooth of the subject, when the subject bites down on the pressure sensor), image acquisition by the camera system is triggered. Images may only be generated if the apparatus is positioned in an oral cavity.

[0015] Another advantage of the first aspect is the comfort and / or ease of the operation of the apparatus for the user (which may be the subject themselves, or a dentist, for example), in comparison to other intra-oral scanners.

[0016] The apparatus may comprise the processor.

[0017] The pressure sensor may be arranged on the body, such that the pressure sensor faces an occlusal and / or an incisal tooth surface of the subject when in use.

[0018] The camera system may comprises one or more of a first camera, a second camera, and a third camera. The first camera may be arranged to capture images of the occlusal side of the teeth of the subject when in use, the second camera may be arranged to face the lingual side of the teeth of the subject when in use, and the third camera may be arranged to face the buccal side of the teeth of the subject when in use. In these embodiments, images of three different regions of one or more teeth of the subject will be acquired, when image acquisition is triggered.

[0019] The pressure sensor may be further configured to generate a pressure map when pressure is applied to the pressure sensor by the first tooth. This may enable a profile of the first tooth to be determined, along with the generated intra-oral images. This profile may enable, for example, a chewing surface of the first tooth of the subject to be generated accurately, for example, when generating a model of the subject’s teeth.

[0020] The processor may be further configured to determine, based on the pressure map, a location and / or an index of the first tooth of the subject. This information may be used to determine the location of the apparatus within the oral cavity of the subject, and used in combination with the generated intra-oral images, to more accurately determine the locations of one or more teeth of the subject and / or locations of one or more oral features when the images are analysed.

[0021] The processor may be further configured to determine, based on the generated images and the location and / or the index of the first tooth of the subject, the locations of the one or more teeth and / or the locations of the one or more oral features in the generated images. This may enable the locations of the one or more teeth and / or the locations of the one or more oral features to be determined more accurately.

[0022] The processor may be further configured to determine the locations of the one or more teeth and / or the locations of the one or more oral features in the generated images using one or more of: a computer vision method, a machine learning method, and a neural network. For example, where the machine learning method configured to index one or more teeth present in the intra-oral images, the aforementioned location information (determined from the pressure map) may also be used by the machine learning method, in order to more accurately index the one or more teeth.2025PF00026

[0023] 3

[0024] The processor may be further configured to, based on the arrangement of the camera system on the body, the pressure map, and the generated images, determine, for one or more teeth captured in the generated images, a distance between each respective captured tooth and the first tooth, and determine, based on the determined distances, the locations of the one or more teeth and / or the locations of the one or more oral features in the generated images. This may enable the locations of the one or more teeth and / or the locations of the one or more oral features to be determined more accurately, and / or enable a more accurate mouth map and / or a model of the subject’s teeth to be generated.

[0025] The processor may be further configured to, based on the determined distances, determine a jaw length of the subject. The determined jaw length may be used to generate a more accurate mouth map and / or a model of the subject’s teeth, and / or enable the locations of the one or more teeth and / or the locations of the one or more oral features to be determined more accurately.

[0026] The processor may be further configured to determine, based on the locations of the one or more teeth, a mouth map of the subject.

[0027] The one or more oral features may comprise one or more of: plaque, tartar, a stained spot, a carious lesion, a crack, a filling, a retracted gum, a crown, food debris, and sealant.

[0028] The camera system may be configured to generate light induced fluorescence images. This may enable the apparatus to detect plaque and / or tartar and / or caries in the generated intra-oral images, which may then be located more accurately.

[0029] According to a second aspect, there is provided a method of determining locations of one or more teeth of a subject and / or locations of one or more oral features in an oral cavity of a subject. The method comprises detecting pressure applied to a pressure sensor of an apparatus for use in an oral cavity of a subject by a first tooth of the subject. The method further comprises, in response to detecting the pressure, causing a camera system of the apparatus to generate intra-oral images. The method further comprises determining, based on the generated images in the generated images, locations of one or more teeth of the subject and / or locations of one or more oral features.

[0030] According to a third aspect, there is provided a computer program product comprising a computer readable medium. The computer readable medium has a computer readable code embodied therein. The computer readable code is configured such that, on execution by a suitable computer or processor, the computer or processor is caused to perform the method described earlier.

[0031] These and other aspects will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Exemplary embodiments will now be described, by way of example only, with reference to the following drawings, in which:

[0034] Fig. 1 is a diagram illustrating an example apparatus according to embodiments of the disclosure;2025PF00026

[0035] 4

[0036] Fig. 2 is a flow chart illustrating a method according to an embodiment; and Fig. 3 is a block diagram illustrating an example processor according to embodiments of the disclosure.

[0037] DETAILED DESCRIPTION OF EMBODIMENTS

[0038] There are provided herein techniques for determining locations of one or more teeth of the subject and / or locations of one or more oral features.

[0039] Embodiments of the present disclosure provide a system and method for determining locations of one or more teeth of a subject and / or locations of one or more oral features in an oral cavity of a subject.

[0040] The system comprises an apparatus for use in an oral cavity of a subject, and a processor. The apparatus comprises a body, a pressure sensor arranged on the body, configured to detect pressure applied to the pressure sensor by a first tooth of the subject, and a camera system arranged on the body, configured to generate intra-oral images in response to a detection of pressure by the pressure sensor. The processor is configured to determine, based on the generated images, locations of one or more teeth of the subject and / or locations of one or more oral features in the generated images.

[0041] The camera system, arranged on the body of the apparatus, generates intra-oral images of a subject in response to a detection of pressure by a pressure sensor arranged on the body of the apparatus. Based on the generated images, locations of one or more teeth of the subject and / or locations of one or more oral features in the oral cavity are determined by a processor of the system.

[0042] In some embodiments, the apparatus comprises the processor. An example of such a system (wherein the apparatus comprises the processor) is now described with reference to Fig. 1.

[0043] Fig. 1 is a schematic diagram illustrating a system 100 for determining locations of one or more teeth of a subject and / or locations of one or more oral features in an oral cavity of a subject. The system 100 comprises an apparatus 100a (for example, an intraoral scanner, or an oral scanner) for use in an oral cavity of a subject, according to an embodiment.

[0044] As illustrated in Fig. 1, the apparatus 100a comprises one or more processors 102. The one or more processors 102 can be implemented in numerous ways, with software and / or hardware, to perform the various functions described herein. The one or more processors 102 can comprise a plurality of software and / or hardware modules, each configured to perform, or that are for performing, individual or multiple steps of the method described herein.

[0045] The one or more processors 102 may comprise, for example, one or more microprocessors, one or more multi-core processors and / or one or more digital signal processors (DSPs), one or more processing units, and / or one or more controllers (e.g. one or more microcontrollers) that may be configured or programmed (e.g. using software or computer program code) to perform the various functions described herein. The one or more processors 102 may be implemented as a combination of dedicated hardware (e.g. amplifiers, pre-amplifiers, analog-to-digital convertors (ADCs) and / or digital-to-2025PF00026

[0046] 5

[0047] analog convertors (DACs)) to perform some functions and one or more processors (e.g. one or more programmed microprocessors, DSPs and associated circuitry) to perform other functions.

[0048] The one or more processors 102 can be configured to perform the method described herein, such as the embodiments of the method described with reference to Fig. 2. For example, the one or more processors 102 may be configured to cause the system 100 to perform the embodiments of the method described herein, such as the embodiments of the method described with reference to Fig. 2.

[0049] As illustrated in Fig. 1, the apparatus 100a may comprise at least one memory.

[0050] Alternatively or in addition, at least one memory may be external to (e.g. separate to or remote from) the apparatus 100a. For example, another apparatus may comprise at least one memory according to some embodiments. A hospital database may comprise at least one memory, at least one memory may be a cloud computing resource, or similar. The one or more processors 102 of the apparatus 100a may be configured to communicate with and / or connect to at least one memory. The at least one memory may comprise any type of non-transitory machine-readable medium, such as cache or system memory including volatile and non-volatile computer memory such as random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), and electrically erasable PROM (EEPROM). At least one memory can be configured to store program code that can be executed by the one or more processors 102 of the apparatus 100a to cause the apparatus 100a to operate in the manner described herein.

[0051] Alternatively or in addition, at least one memory can be configmed to store information required by or resulting from the method described herein. For example, at least one memory may be configmed to store generated intra-oral images, or any other information, or any combination of information, required by or resulting from the method described herein. The one or more processors 102 of the apparatus 100a can be configmed to control at least one memory to store information required by or resulting from the method described herein.

[0052] As illustrated in Fig. 1, the apparatus 100a may comprise at least one user interface. Alternatively or in addition, at least one user interface may be external to (e.g. separate to or remote from) the apparatus 100a. The one or more processors 102 of the apparatus 100a may be configured to communicate with and / or connect to at least one user interface. One or more processors 102 of the apparatus 100a can be configured to control at least one user interface to operate in the manner described herein.

[0053] A user interface can be configured to render (or output, display, or provide) information required by or resulting from the method described herein. For example, one or more user interfaces may be configured to render (or output, display, or provide) any information, or any combination of information, required by or resulting from the method described herein. Alternatively or in addition, one or more user interfaces can be configured to receive a user input. For example, one or more user interfaces may allow a user to manually enter information or instructions, interact with and / or control the apparatus 100a. Thus, one or more user interfaces may be any one or more user interfaces that enable the2025PF00026

[0054] 6

[0055] rendering (or outputting, displaying, or providing) of information and / or enables a user to provide a user input.

[0056] The user interface may comprise one or more components for this. For example, one or more user interfaces may comprise one or more switches, one or more buttons, a keypad, a keyboard, a mouse, a display or display screen, a graphical user interface (GUI) such as a touch screen, an application (e.g. on a smart device such as a tablet, a smart phone, or any other smart device), or any other visual component, one or more speakers, one or more microphones or any other audio component, one or more lights (e.g. one or more light emitting diodes, LEDs), a component for providing tactile or haptic feedback (e.g. a vibration function, or any other tactile feedback component), a smart device (e.g. a smart mirror, a tablet, a smart phone, a smart watch, or any other smart device), or any other user interface, or combination of user interfaces. One or more user interfaces that are controlled to render information may be the same as one or more user interfaces that enable the user to provide a user input.

[0057] As illustrated in Fig. 1, the apparatus 100a may comprise at least one communications interface (or communications circuitry). Alternatively or in addition, at least one communications interface may be external to (e.g. separate to or remote from) the apparatus 100a. A communications interface can be for enabling the apparatus 100a, or components of the apparatus 100a (e.g. one or more processors 102, one or more sensors, one or more memories, one or more user interfaces and / or any other components of the apparatus 100a), to communicate with and / or connect to each other and / or one or more other components. For example, one or more communications interfaces can be for enabling one or more processors 102 of the apparatus 100a to communicate with and / or connect to one or more sensors, one or more memories, one or more user interfaces and / or any other components of the apparatus 100a.

[0058] A communications interface may enable the apparatus 100a, or components of the apparatus 100a, to communicate and / or connect in any suitable way. For example, one or more communications interfaces may enable the apparatus 100a, or components of the apparatus 100a, to communicate and / or connect wirelessly, via a wired connection, or via any other communication (or data transfer) mechanism. In some wireless embodiments, for example, one or more communications interfaces may enable the apparatus 100a, or components of the apparatus 100a, to use radio frequency (RF), Bluetooth, or any other wireless communication technology to communicate and / or connect.

[0059] As illustrated in Fig. 1, the apparatus 100a comprises a body 104, a pressure sensor 106 arranged on the body 104, and a camera system 108a, 108b, 108c arranged on the body 104. Although the camera system 108a, 108b, 108c illustrated in Fig. 1 comprises a plurality of cameras (in this example, three), in other embodiments, the camera system of the apparatus 100a may comprise a single camera.

[0060] The pressure sensor 106 is configured to detect pressure applied thereto (for example, by a first tooth of the subject). The camera system 108a, 108b, 108c is configured to generate intra-oral images in response to a detection of pressure by the pressure sensor 106. The images would record, for example, oral features (for example, the presence of any plaque on the surface of one or more teeth), and one or more teeth of the subject.2025PF00026

[0061] 7

[0062] The camera system 108a, 108b, 108c may comprise one or more cameras and / or image sensors that are sensitive to visible light. An example camera is an “RGB camera”, which is a camera that uses a Color Array Filter (CFA) with a standard Bayer pattern. The CFA is sensitive to the primary colors of visible light: red, green, and blue. However, the camera system 108a, 108b, 108c may be any suitable system that can be embedded in an apparatus 100a and can capture images of an oral cavity.

[0063] The camera system 108a, 108b, 108c may alternatively or additionally comprise one or more near infra red (NIR) light emitting diodes (LEDs). In these embodiments, the one or more cameras and / or image sensors may also be sensitive to near infra-red light. Alternatively, the camera system 108a, 108b, 108c may additionally comprise one or more cameras and / or image sensors that are sensitive to NIR light. Where the camera system 108a, 108b, 108c is configured to generate light induced fluorescence images, the camera system 108a, 108b, 108c may also then, in these embodiments, be further configured to generate NIR images, and to detect NIR light in the generated NIR images. The QLF light images and the NIR images may be used and / or analysed in conjunction with each other to detect and / or distinguish between plaque and tartar in the oral cavity. The generated NIR images may also be analysed in order to detect caries and / or demineralization properties in the oral cavity (for example, through the analysis of different scattering patterns in the NIR images).

[0064] The processor 102 is configured to determine, based on the images generated by the camera system 108a, 108b, 108c, locations of one or more teeth of the subject and / or locations of one or more oral features. For example, analysis of the images may be performed to determine the location of plaque in the oral cavity. This analysis may be performed for the purpose of determining a brushing configuration for an electric toothbrush based on the location of the plaque.

[0065] The images may be acquired over an extended time period. For example, the images may form (at least a part of a) video stream. One of the images may be acquired and / or analyzed before another of the images is acquired and / or analyzed. In this way, the apparatus 100a may enable real-time processing of a video stream obtained using the camera system 108a, 108b, 108c of the apparatus 100a.

[0066] The one or more oral features may comprise one or more of plaque, tartar, a stained spot, a carious lesion, a crack, a fdling, a retracted gum, a crown, food debris, and sealant.

[0067] The locations may comprise one or more of a dentition segment (for example, “inner right upper molars”), an index of a tooth (for example, “upper right 2ndmolar”, or a tooth number), or a region of the tooth (for example, “close to the gumline”).

[0068] A dentition segment may signify a particular region within the jaw as well as the relevant tooth surface e.g., the inner (lingual) surface or outer (facial). A specific tooth location may signify a single full tooth surface, and a tooth region location may signify a specific part of the full tooth surface, e.g., at the gum line, interdentally, halfway up the tooth etc. For example, the "Rustogi modification of the Navy plaque index" divides a single tooth surface (facial or lingual) into 9 regions, and this may be used. Of course, other ways of dividing an individual tooth surface into sub-regions may be considered.2025PF00026

[0069] 8

[0070] The apparatus 100a is therefore configured such that, when pressure is applied to the pressure sensor 106 (for example, by a tooth of the subject, when the subject bites down on the pressure sensor 106), image acquisition by the camera system 108a, 108b, 108c is triggered. The camera system 108a, 108b, 108c is configured to generate intra-oral images in response to an application of pressure to the pressure sensor 106 by a tooth of the subject (for example, when the subject bites down on the pressure sensor 106).

[0071] In the embodiment illustrated in Fig. 1, the pressure sensor 106 is arranged on a first surface 110a of a first member 112 of the body of the apparatus 100a. In the embodiment shown in Fig. 1, the pressure sensor 106 and the first surface 110a are arranged so as to face an occlusal and / or an incisal tooth surface of the subject when in use. In this embodiment, the pressure sensor 106 is arranged to face an occlusal and / or an incisal tooth surface of a tooth of the upper jaw of the subject. In this embodiment, it will be appreciated that, in use, a tooth of the upper jaw of the subject will apply pressure to the pressure sensor 106 when the subject bites down on the pressure sensor 106.

[0072] In other embodiments, the pressure sensor 106 may be arranged to face an occlusal and / or an incisal tooth surface of a tooth of the lower jaw of the subject. In these embodiments, it will be appreciated that, in use, a tooth of the lower jaw of the subject will apply pressure to the pressure sensor 106 when the subject bites up on the pressure sensor 106.

[0073] In other embodiments, the apparatus 100a may comprise a first pressure sensor and a second pressure sensor, wherein the first pressure sensor 106 is arranged to face an occlusal and / or an incisal tooth surface of a tooth of the upper jaw of the subject, and wherein the second pressure sensor is arranged to face an occlusal and / or an incisal tooth surface of a tooth of the lower jaw of the subject. In these embodiments, it will be appreciated that, in use, a first tooth of the upper jaw of the subject will apply pressure to the first pressure sensor 106, and a second tooth of the lower jaw of the subject will apply pressure to the second pressure sensor 106, when the subject bites the pressure sensors.

[0074] In the embodiment illustrated in Fig. 1, the camera system 108a, 108b, 108c comprises a first camera 108a, a second camera 108b, and a third camera 108c, wherein the first camera 108a is arranged on a second surface 110b of the first member 112, the second camera 108b is arranged on a second member 114 of the body, and the third camera 108c is arranged on a third member 116 of the body, wherein the first member 112 extends between the second member 114 and the third member 116. The third member 116 may be configured such that a distal end of the third member 116 acts as a lip retractor when the apparatus 100a is in use. This may enable the apparatus 100a to be operated more easily and / or accurately during a scan of the subject’s mouth, and enable improved acquisition of intra-oral images by the apparatus 100a.

[0075] As shown in Fig. 1, the first camera 108a, a second camera 108b, and a third camera 108c are arranged on a surface of the apparatus 100a that generally forms a U-shape / C-shape / semicircle that surrounds a particular tooth of the subject when in use, allowing that tooth to be imaged from multiple sides.2025PF00026

[0076] 9

[0077] The first camera 108a is arranged to capture images of the occlusal side of the teeth of the subject when in use. In some embodiments, the first camera 108a may be configured such that, when the apparatus 100a is in use, the first camera 108a is tilted 10 degrees towards the distal molars. The second camera 108b is arranged to face the lingual side of the teeth of the subject when in use. The third camera 108c is arranged to face the buccal side of the teeth of the subject when in use.

[0078] In the embodiment illustrated in Fig. 1, it will be appreciated that, when a first tooth of the subject applies pressure to the pressure sensor 106 (for example, when the subject bites down on the pressure sensor 106), image acquisition by each of the first, second and third cameras will be triggered respectively. Thus, three intra-oral images will be obtained, of the occlusal side of the teeth, the lingual side of the teeth, and the buccal side of the teeth, respectively, when the subject bites down on the pressure sensor 106. Thus, the different regions of one or more teeth of the subject will appear in three different intraoral images, from three different angles.

[0079] In use, a scan of the oral cavity of the subject may be performed using the apparatus 100a. During the scan, the apparatus 100a may be moved throughout a number of the different positions in the mouth of the subject. In each of these different positions, the subject may bite down on the pressure sensor 106 to trigger image acquisition. This will result in a number of sets of intraoral images (where each set is generated at each of the different positions of the apparatus 100a) being generated. These intraoral images, imaging different entities in the oral cavity of the subject (for example, one or more teeth of the subject and / or one or more oral features), may be correlated and combined in order to generate a mouth map of the subject (for example, a 3D model). The mouth map, or model, may include information about one or more oral features (for example, lesions, decay, cracks), as well as the teeth structure of the subject. In order to accurately assemble the intraoral images into a mouth map, the relative position of the intraoral images (for example, relative to the jaw of the subject) may need to be determined, in order to accurately determine the locations of the imaged entities.

[0080] It will be appreciated that, by virtue of their arrangement on the body of the apparatus 100a, the relative positions of the pressure sensor 106 and each camera of the camera system 108a, 108b, 108c are therefore known.

[0081] In some embodiments, the pressure sensor 106 is further configured to generate a pressure map of an occlusal surface or an incisal surface of the first tooth, when pressure is applied to the pressure sensor 106 by the first tooth. By biting down to trigger an image, a profile of a tooth (upper and lower jaw) may be captured. This process may be similar to acquiring a profile of a foot using a pressure sensitive foot bed scanner, where the profile of the foot is generated in response to a subject’s foot applying pressure to the scanner (i.e. when the subject stands on the scanner).

[0082] For example, the pressure sensor 106 may comprise a plurality of pressure zones (e.g., a pressure zone array), each of which senses pressure applied to them. When pressure is applied to this pressure sensor 106 (for example, by a tooth of a subject), the pressure sensor 106 creates a signal indicating the pressure zone (s) in which pressure is being applied. It will be appreciated that different2025PF00026

[0083] 10

[0084] types of teeth (for example, canines, incisors, molars, etc.), when applying pressure to the pressure sensor 106, will in the generation of different, recognisable, pressure patterns (or pressure maps). The processor 102 may then recognize a generated pressure pattern using any suitable method. The recognised pressure pattern may be used to identify which tooth is applying pressure to the pressure sensor 106 when the subject bites down on the apparatus 100a.

[0085] As the pressure map generated by the first tooth (which is applying pressure to the pressure sensor 106) enables identification and / or indexing of the first tooth (for example, the determination of the tooth number of the first tooth), the generated pressure map may then be used to determine the location of the first tooth of the subject.

[0086] Therefore, in some embodiments, the processor 102 may further be configured to determine, based on the pressure map, a location and / or an index of the first tooth of the subject.

[0087] As the location of the first tooth is able to be determined, by virtue of the pressure map, the location of the pressure sensor 106 (and therefore the apparatus 100a) in the oral cavity of the subject is also able to be determined, at the time the intraoral images are generated.

[0088] As the location of the pressure sensor 106 in the oral cavity is able to be determined, and the relative positions of the pressure sensor 106 and each camera of the camera system 108a, 108b, 108c are known (as described above), the position of the camera(s) in the oral cavity may also be determined. This position information of the camera(s) may be used to more accurately determine the position of the entities in the generated intra-oral image(s) (for example, teeth and / or oral features) when processing the intraoral images. For example, the position information of the camera(s) may be used to more accurately assemble the intraoral images to form a mouth map of the subject. In some embodiments, the processor 102 may be further configured to determine, based on the locations of the one or more teeth, a mouth map of the subject.

[0089] That is, as the generated pressure map is indicative of the location of the first tooth (by virtue of different teeth generating different, recognizable pressure maps), the generated pressure map is informative of the position of the pressure sensor 106 relative to the subject’s teeth. Utilising this position information (for example, the location and / or an index of the first tooth of the subject) and the known relative positions of the pressure sensor 106 and each camera of the camera system 108a, 108b, 108c, the processor 102 may more accurately determine the locations of the one or more teeth and / or the locations of the one or more oral features in the generated intraoral images. It will be appreciated that, utilizing the pressure map enables one part of the first tooth (the occlusal or the incisal surface) to effectively be accurately “pinned” when generating a model of the subject’s teeth. This then enables the rest of the tooth (for example, the lingual and buccal surfaces, as captured in generated intraoral images) to be mapped in the model with greater accuracy, as they can be mapped with respect to the known position of the occlusal surface.2025PF00026

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[0091] Therefore, in some embodiments, the processor 102 may further be configured to determine, based on the generated images and the location and / or the index of the first tooth of the subject, the locations of the one or more teeth and / or the locations of the one or more oral features.

[0092] For example, in some embodiments, the processor 102 may be further configured to, based on the arrangement of the camera system 108a, 108b, 108c on the body, the pressure map, and the generated images, determine, for one or more teeth captured in the generated images, a distance between each respective captured tooth and the first tooth. The processor 102 may then be further configured to determine, based on the determined distances, the locations of the one or more teeth and / or the locations of the one or more oral features.

[0093] In some embodiments, pressure information obtained by the pressure sensor 106 may be used to determine a jaw length of the subject. For example, in some embodiments, the processor 102 may be further configured to, based on the determined distances described above, determine a jaw length of the subject.

[0094] It will be appreciated that, as the generated pressure map is indicative of the location of the first tooth (as described above), and the relative of positions of the pressure sensor 106 and the camera(s) enable the relative distances between each respective captured tooth and the first tooth to then be determined, this information may also be used to determine the jaw length of the subject.

[0095] As noted above, the determined jaw length of the subject, in combination with the location information of the one or more teeth of the subject, and the generated intraoral images, may be used to more accurately determine a model of the subject’s teeth, or a mouth map of the subject.

[0096] In some embodiments, the processor 102 is further configured to determine the locations of the one or more teeth and / or the locations of the one or more oral features using one or more of: a computer vision method, a machine learning method, and a neural network.

[0097] For the purposes of the present disclosure, the term “machine learning method” encompasses within its scope the following concepts: ML algorithms, comprising processes or instructions through which data may be used in a training process to generate a model artefact for performing a given task, or for representing a real world process or system; the model artefact that is created by such a training process, and which comprises the computational architecture that performs the task; and the process performed by the model artefact in order to complete the task. The terms ML model, Artificial Intelligence (Al) model, AI / ML (AIML) model, ML algorithm, and Al algorithm may be used interchangeably herein.

[0098] For example, the processor 102 may be further configured to determine the locations of the one or more teeth and / or the locations of the one or more oral features by applying an ML algorithm to the images. The ML algorithm may be trained to predict the presence of teeth in the images input into the algorithm. For example, the ML algorithm may have been trained using deep learning techniques.

[0099] An example of the ML algorithm is an AIML model operable to implement instance segmentation and / or image classification. The AIML model may be a neural network. The AIML model2025PF00026

[0100] 12

[0101] may be trained on collected and, optionally, annotated data of teeth. The annotation may be performed using any suitable framework, such as Amazon Sagemaker, Roboflow or Labelbox. The model by be trained in any suitable framework, such as PyTorch or TensorFlow. The AIML model may be trained on around 1000 images per image modality, or any other suitable number of images to train the AIML model to implement instance segmentation and / or image classification.

[0102] For example, an image analysis algorithm (e.g. a deep learning algorithm, use of standard image processing tools that leverage colour characteristics, or image segmentation techniques) may be used to determine the locations of the one or more teeth and / or the locations of the one or more oral features. In some embodiments, generated intraoral images from multiple separate image acquisitions, may be aligned, and / or generated intraoral images may be segmented to identify, for example, particular tooth indexes / numbers. Segmentation of the intraoral images may allow for the identification of the location and / or morphology of the teeth, as well as the identification and location of cracks, lesions, and / or caries in the teeth, and / or other oral features.

[0103] The image analysis algorithm may apply morphological operations to the images. The morphological operations may determine structural elements of the teeth as captured in the images. The structural elements may be one or more of a size, a shape, an area, etc. of the teeth as captured in the images. The determined structural elements may be compared to known, typical, and / or default structural elements of teeth of a generic user (e.g., a typical tooth size, shape, area, etc).

[0104] The morphological operations may also enable one or more of advantageous features of the system 100. For example, a detected tooth within the images may be analysed in conjunction with the relative location of the apparatus 100a at the time the image was generated (where the location of the apparatus 100a may be determined based on a generated pressure map). The location of the detected tooth may then be determined based on the relative location of the apparatus 100a. Any structural element of the detected tooth (e.g., the size, shape, area, etc.) may be analysed in conjunction with the location of the apparatus 100a, to identify and / or located the detected tooth.

[0105] In some embodiments, the obtained pressure maps may further be used in the construction of a model of the subject’s teeth, or a mouth map. A pressure map of a first tooth may be analysed to determine a surface structure of the occlusal or incisal surface of the first tooth. This surface structure may then be included in the mouth map / model of the subject’s teeth. It will be appreciated that multiple pressure maps, obtained for each tooth of the subject with an occlusal or incisal surface, may be used to obtain a detailed model of the chewing surfaces of the subject’s teeth, and / or enable the chewing surfaces to be formed in high resolution. In some embodiments, the pressure sensor 106 may be configured to span an area effective in capturing the profile of multiple teeth, which may enable an improved mouth profile map to be generated.

[0106] In some embodiments, the camera system 108a, 108b, 108c may be configured to generate light induced fluorescence images and / or NIR images. For example, the camera system 108a, 108b, 108c may comprise an illumination source(s) (e.g. blue light source(s)) and sensor(s) for recording2025PF00026

[0107] 13

[0108] light-induced fluorescence (QLF) images for QLF detection of plaque. In such a case, the oral features will be detected by red fluorescence in the intraoral images.

[0109] As noted above, the system 100 may utilise the QLF images to measure plaque and / or tartar on a subject’s teeth. As noted above, the system 100, in some embodiments, may be configured to enable the relative position of the intraoral images to be more accurately determined (for example, through utilising a generated pressure map to determine the relative location of the apparatus 100a in the subject’s mouth at the time a particular intraoral image was generated). This information, on the relative position of the intraoral images, may be used by, for example, a tooth location classifier, to more accurately predict the teeth number of a tooth in an intraoral image. Where the QLF images also indicate that plaque and / or tartar is present on this identified tooth, it will be appreciated that the system 100 is thus able to more accurately identify the location of the plague and / or tartar in the subject’s mouth. This improved determination of locations of one or more teeth of the subject and / or locations of one or more oral features may enable improved oral care feedback to be generated and / or provided to the subject and / or a user of the apparatus 100a. For example, where plaque and / or tartar is located in the subject’s mouth with greater accuracy, improved oral care feedback may be provided that allows this plaque and / or tartar to be removed (for example, oral care routine advice that is directed specifically to the location at which the plaque and / or tartar was detected).

[0110] The apparatus 100a therefore may be suitable for determining a location of plaque within a subject mouth. The apparatus 100a may be a plaque-detection device comprising: a multi-camera oral scanner, and a 2D pressure sensor array arranged so that when a subject bites down on the sensor, it captures the profile of the teeth, as described above.

[0111] As noted above, in the system 100 illustrated in Fig. 1, the apparatus 100a comprises the processor 102. However, in alternative embodiments of the system 100, the processor 102 may be a remote processor, and the apparatus 100a may instead comprise a local processor that is configured to store and / or transmit the generated intraoral images and / or the pressure signal (for example, the pressure map) to the remote processor. The remote processor may then be configured to perform the operations of the processor 102 described above. For example, the remote processor may be one or more of a cloud computing network, a wireless device, and any other suitable communication device.

[0112] Fig. 2 illustrates a method 200 performed by an apparatus for use in an oral cavity of a subject according to an embodiment. More specifically, Fig. 2 illustrates a method 200 of determining locations of one or more teeth of a subject and / or locations of one or more oral features in an oral cavity of a subject. The method 200 illustrated in Fig. 2 is a computer-implemented method. For example, the method 200 may be implemented by an application or software installed on the apparatus 100a. As described with reference to Fig. 1, the apparatus 100a comprises one or more processors 102. The method 200 illustrated in Fig. 2 can generally be performed by or under the control of the one or more processors 102 of the apparatus 100a described with reference to Fig. 1, and / or a remote processor (as described above), such as a processor 300 described later with reference to Fig. 3.2025PF00026

[0113] 14

[0114] With reference to Fig. 2, at block 202, the method 200 comprises detecting pressure applied to a pressure sensor 106 of an apparatus 100a for use in an oral cavity of a subject by a first tooth of the subject. For example, a processor 102 of the apparatus 100a may receive a signal that has been generated by the pressure sensor 106 of the apparatus 100a, in response to pressure being applied to the pressure sensor 106.

[0115] At block 204 of Fig. 2, the method 200 comprises, in response to detecting the pressure, causing a camera system 108a, 108b, 108c of the apparatus 100a to generate intra-oral images. For example, in response to a processor 102 of the apparatus 100a receiving a signal that has been generated by the pressure sensor 106 of the apparatus 100a, in response to pressure being applied to the pressure sensor 106, the processor may cause a camera system 108a, 108b, 108c of the apparatus 100a to generate intra-oral images.

[0116] At block 206 of Fig. 2, the method 200 comprises determining, based on the generated images, locations of one or more teeth of the subject and / or locations of one or more oral features. For example, a processor 102 of the apparatus 100a, or a remote processor (as described above) may determine, based on the generated images, locations of one or more teeth of the subject and / or locations of one or more oral features in the generated images.

[0117] In some embodiments (as described above), the pressure sensor 106 of the apparatus 100a may be further configured to generate a pressure map of an occlusal surface or an incisal surface of the first tooth, when pressure is applied to the pressure sensor 106 by the first tooth. In these embodiments, the method 200 may further comprise, determining, based on the pressure map, a location and / or an index of the first tooth of the subject. For example, the processor 102 of the apparatus 100a, or a remote processor (as described above), may determine based on the pressure map, a location and / or an index of the first tooth of the subject.

[0118] In some embodiments, the method 200 may further comprise determining, determine, based on the generated images and the location and / or the index of the first tooth of the subject, the locations of the one or more teeth and / or the locations of the one or more oral features. This step may be performed by the processor 102 of the apparatus 100a, or a remote processor (as described above).

[0119] In some embodiments, the method 200 may further comprise determining the locations of the one or more teeth and / or the locations of the one or more oral features using one or more of: a computer vision method, a machine learning method, and a neural network. This step may be performed by the processor 102 of the apparatus 100a, or a remote processor (as described above).

[0120] In some embodiments, the method 200 may further comprise, based on the arrangement of the camera system 108a, 108b, 108c on the body, the pressure map, and the generated images, determine, for one or more teeth captured in the generated images, a distance between each respective captured tooth and the first tooth, and determining, based on the determined distances, the locations of the one or more teeth and / or the locations of the one or more oral features. These steps may be performed by the processor 102 of the apparatus 100a, or a remote processor (as described above).2025PF00026

[0121] 15

[0122] In some embodiments, the method 200 may further comprise, based on the determined distances, determining a jaw length of the subject. This step may be performed by the processor 102 of the apparatus 100a, or a remote processor (as described above).

[0123] In some embodiments, the method 200 may further comprise, based on the locations of the one or more teeth, determining a mouth map of the subject. This step may be performed by the processor 102 of the apparatus 100a, or a remote processor (as described above).

[0124] Fig. 3 is a block diagram illustrating an example processor 300 according to embodiments of the disclosure. Processor 300 may be used to implement one or more processors described herein, for example, processor 102 shown in Fig. 1. Processor 300 may be any suitable processor type including, but not limited to, a microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable array (FPGA) where the FPGA has been programmed to form a processor, a graphical processing unit (GPU), an application specific circuit (ASIC) where the ASIC has been designed to form a processor, or a combination thereof.

[0125] The processor 300 may include one or more cores 302. The core 302 may include one or more arithmetic logic units (ALU) 304. In some embodiments, the core 302 may include a floating point logic unit (FPLU) 306 and / or a digital signal processing unit (DSPU) 308 in addition to or instead of the ALU 304.

[0126] The processor 300 may include one or more registers 312 communicatively coupled to the core 302. The registers 312 may be implemented using dedicated logic gate circuits (e.g., flip-flops) and / or any memory technology. In some embodiments the registers 312 may be implemented using static memory. The register may provide data, instructions and addresses to the core 302. In some embodiments, processor 300 may include one or more levels of cache memory 310 communicatively coupled to the core 302. The cache memory 310 may provide computer-readable instructions to the core 302 for execution. The cache memory 310 may provide data for processing by the core 302. In some embodiments, the computer-readable instructions may have been provided to the cache memory 310 by a local memory, for example, local memory attached to the external bus 316. The cache memory 310 may be implemented with any suitable cache memory type, for example, metal-oxide semiconductor (MOS) memory such as static random access memory (SRAM), dynamic random access memory (DRAM), and / or any other suitable memory technology.

[0127] The processor 300 may include a controller 314, which may control input to the processor 300 from other processors and / or components included in a system (e.g., the pressure sensor 106 shown in FIG. 1) and / or outputs from the processor 300 to other processors and / or components included in the apparatus (e.g., the camera system 108a, 108b, 108c shown in FIG. 1). Controller 314 may control the data paths in the ALU 304, FPLU 306 and / or DSPU 308. Controller 314 may be implemented as one or more state machines, data paths and / or dedicated control logic. The gates of controller 314 may be implemented as standalone gates, FPGA, ASIC or any other suitable technology. The registers 312 and the cache 310 may communicate with controller 314 and core 302 via internal connections 320A, 320B,2025PF00026

[0128] 16

[0129] 320C and 320D. Internal connections may implemented as a bus, multiplexor, crossbar switch, and / or any other suitable connection technology.

[0130] Inputs and outputs for the processor 300 may be provided via a bus 316, which may include one or more conductive lines. The bus 316 may be communicatively coupled to one or more components of processor 300, for example the controller 314, cache 310, and / or register 312. The bus 316 may be coupled to one or more components of the apparatus, such as the pressure sensor 106 and the camera system 108a, 108b, 108c mentioned previously.

[0131] The bus 316 may be coupled to one or more external memories. The external memories may include Read Only Memory (ROM) 332. ROM 332 may be a masked ROM, Electronically Programmable Read Only Memory (EPROM) or any other suitable technology. The external memory may include Random Access Memory (RAM) 333. RAM 333 may be a static RAM, battery backed up static RAM, Dynamic RAM (DRAM) or any other suitable technology. The external memory may include Electrically Erasable Programmable Read Only Memory (EEPROM) 335. The external memory may include Flash memory 334. The External memory may include a magnetic storage device such as disc 336. In some embodiments, the external memories may be included in an apparatus, such as the example apparatus 100a in Fig. 1.

[0132] There is provided a computer program comprising instructions which, when executed by a processor (such as one or more processors 102 of the apparatus 100a, a remote processor, or the processor 302), cause the processor to perform at least part of, or all of, the method described herein.

[0133] There is provided a computer program product comprising a computer readable medium. The computer readable medium has a computer readable code embodied therein. The computer readable code is configured such that, on execution by a suitable computer or processor (such as one or more processors 102 of the apparatus 100a, a remote processor, or the processor 302), the computer or processor is caused to perform the method described herein. The computer readable medium may be, for example, any entity or device capable of carrying the computer program product. For example, the computer readable medium may include a data storage, such as a ROM (such as a CD-ROM or a semiconductor ROM) or a magnetic recording medium (such as a hard disk). Furthermore, the computer readable medium may be a transmissible carrier, such as an electric or optical signal, which may be conveyed via electric or optical cable or by radio or other means. When the computer program product is embodied in such a signal, the computer readable medium may be constituted by such a cable or other device or means. Alternatively, the computer readable medium may be an integrated circuit in which the computer program product is embedded, the integrated circuit being adapted to perform, or used in the performance of, the method described herein.

[0134] There is thus provided herein an apparatus, method, and computer program product for determining locations of one or more teeth of the subject and / or locations of one or more oral features, which address the limitations associated with the existing techniques.2025PF00026

[0135] 17

[0136] It will be understood that at least some or all of the method steps described herein can be automated. That is, at least some or all of the method steps described herein can be performed automatically. The method described herein can be a computer-implemented method.

[0137] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

[0138] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the principles and techniques described herein, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored or distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.

Claims

2025PF0002618CLAIMS:

1. A system for determining locations of one or more teeth of a subject and / or locations of one or more oral features in an oral cavity of a subject, the system comprising:an apparatus for use in an oral cavity of a subject, the apparatus comprising:a body;a pressure sensor arranged on the body, configured to detect pressure applied to the pressure sensor by a first tooth of the subject; anda camera system arranged on the body, configured to generate intra-oral images in response to a detection of pressure by the pressure sensor, anda processor configured to determine, based on the generated images, locations of one or more teeth of the subject and / or locations of one or more oral features in the generated images.

2. The system of claim 1, wherein the apparatus comprises the processor.

3. The system of claim 1 or 2, wherein the pressure sensor is arranged the body, such that the pressure sensor faces an occlusal and / or an incisal tooth surface of the subject when in use.

4. The system of claim 3, wherein the camera system comprises one or more of a first camera, a second camera, and a third camera, wherein:the first camera is arranged to capture images of the occlusal side of the teeth of the subject when in use;the second camera is arranged to face the lingual side of the teeth of the subject when in use; andthe third camera is arranged to face the buccal side of the teeth of the subject when in use.

5. The system of any preceding claim, wherein the pressure sensor is further configured to generate a pressure map when pressure is applied to the pressure sensor by the first tooth.

6. The system of claim 4, wherein the processor is further configured to determine, based on the pressure map, a location and / or an index of the first tooth of the subject.2025PF00026197. The system of claim 6, wherein the processor is further configured to determine, based on the generated images and the location and / or the index of the first tooth of the subject, the locations of the one or more teeth and / or the locations of the one or more oral features in the generated images.

8. The system of claim 7, wherein the processor is further configured to determine the locations of the one or more teeth and / or the locations of the one or more oral features in the generated images using one or more of: a computer vision method, a machine learning method, and a neural network.

9. The system of any of claims 5-8, wherein the processor is further configured to:based on the arrangement of the camera system on the body, the pressure map, and the generated images, determine, for one or more teeth captured in the generated images, a distance between each respective captured tooth and the first tooth; anddetermine, based on the determined distances, the locations of the one or more teeth and / or the locations of the one or more oral features in the generated images.

10. The system of claim 9, wherein the processor is further configured to:based on the determined distances, determine a jaw length of the subject.

11. The system of any preceding claim, wherein the processor is further configured to determine, based on the locations of the one or more teeth, a mouth map of the subject.

12. The system of any preceding claim, wherein the one or more oral features comprise one or more of:plaque;tartar;a stained spot;a carious lesion;a crack;a filling;a retracted gum;a crown;food debris; andsealant.

13. The system of any preceding claim, wherein the camera system is configured to generate light induced fluorescence images.2025PF000262014. A method of determining locations of one or more teeth of a subject and / or locations of one or more oral features in an oral cavity of a subject, the method comprising:detecting pressure applied to a pressure sensor of an apparatus for use in an oral cavity of a subject by a first tooth of the subject;in response to detecting the pressure, causing a camera system of the apparatus to generate intra-oral images; anddetermining, based on the generated images, locations of one or more teeth of the subject and / or locations of one or more oral features in the generated images.

15. A computer program product comprising a computer readable medium, the computer readable medium having a computer readable code embodied therein, the computer readable code being configured such that, on execution by a suitable computer or processor:the computer or processor performs the method as claimed in claim 14.

Images