Patent Publication Number: US-2020281701-A1

Title: Three-dimensional intraoral scanner

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and the benefit of U.S. Provisional Application Ser. No. 62/814,588, filed on Mar. 6, 2019, the entire content of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Field 
     Aspects of example embodiments of the present disclosure relate to a three-dimensional intraoral scanner. 
     2. Related Art 
     Previously, traditional x-ray machines have been used to take images of a patient&#39;s tooth and tooth root structure and condition. The method, however, has drawbacks, including a cumbersome, uncomfortable, and labor-intensive process to take x-rays, many of which are necessary to image all parts of a patient&#39;s oral cavity (or mouth). Further, the resulting images are merely two-dimensional representations of the patient&#39;s mouth and the only available angle from which to view the patient&#39;s teeth is from the outside of the patient&#39;s mouth toward the inside. 
     To overcome some of these deficiencies, intraoral scanners have been developed. These related-art intraoral scanners, however, must be manually moved around a patient&#39;s mouth to get a sufficient number of images or data points to create a three-dimensional representation of the patient&#39;s mouth. This process is cumbersome, labor-intensive, and may take from about 10 to about 15 minutes to complete. Further, these related-art intraoral scanners may only include optical sensors configured to sense visible light, meaning the resulting three-dimensional representation only shows the patient&#39;s visible teeth and gum condition, not the underlying root condition. 
     SUMMARY 
     The present disclosure is directed toward various embodiments of a three-dimensional intraoral scanner that uses both optical and ultrasonic images to rapidly provide a three-dimensional representation of a patient&#39;s oral cavity, including the visible teeth and gum condition along with the underlying root condition. 
     This summary is provided to introduce a selection of features and concepts of example embodiments of the present disclosure that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter nor is it intended to be used in limiting the scope of the claimed subject matter. One or more of the described features according to one or more example embodiments may be combined with one or more other described features according to one or more example embodiments to provide a workable method or device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a representation of a patient&#39;s mouth with a cutaway showing a tooth&#39;s underlying root structure; 
         FIG. 2  is a perspective view of a three-dimensional intraoral scanner according to an embodiment of the present disclosure; 
         FIGS. 3 and 4  show a process of using the three-dimensional intraoral scanner shown in  FIG. 2  according to an embodiment of the present disclosure; 
         FIG. 5  is a perspective view of a three-dimensional intraoral scanner according to another embodiment of the present disclosure; 
         FIGS. 6-8  show aspects of a three-dimensional intraoral scanner according to another embodiment of the present disclosure; and 
         FIG. 9  shows a three-dimensional intraoral scanner according to another embodiment of the present disclosure; 
         FIG. 10  shows a three-dimensional intraoral scanner according to another embodiment being moved along a patient&#39;s mouth; 
         FIGS. 11 and 12  show interchangeability between a wireless module and a corded connection; 
         FIGS. 13-15  show covers for the three-dimensional intraoral scanners; and 
         FIGS. 16 and 17  show a three-dimensional intraoral scanner according to another embodiment of the present disclosure; and 
         FIG. 18  shows examples of a point cloud of a patient&#39;s mouth, a dense point cloud of the patient&#39;s mouth, a three-dimensional representation of the patient&#39;s mouth, and a three-dimensional representation of the patient&#39;s mouth with texturing and shading. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of example embodiments of the present disclosure and is not intended to represent the only forms in which the present disclosure may be embodied. The description sets forth aspects and features of the present disclosure in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent aspects and features may be accomplished by different embodiments, and such other embodiments are encompassed within the spirit and scope of the present disclosure. As noted elsewhere herein, like element numbers in the description and the drawings are intended to indicate like elements. Further, descriptions of features, configurations, and/or other aspects within each embodiment should typically be considered as available for other similar features, configurations, and/or aspects in other embodiments. 
     Referring to  FIG. 1 , a mouth is shown with a plurality of teeth  10 . One of the teeth  10  has a “cut-away” view showing the underlying root structure  15  of the tooth  10 , such as what could be viewed by using, for example, an x-ray. To accurately diagnose a patient, the condition of both the tooth  10  and the underlying root structure  15  should be examined. Traditionally, diagnosing a patient included both a direct physical examination of the patient&#39;s mouth to inspect the visible teeth and gums along with a number of x-ray images to inspect the inner portions of the tooth and the underlying root structures. This multi-step process is tedious, costly, and labor-intensive. 
     Recently, intraoral scanners have been developed. However, these related-art intraoral scanners must be moved (or swept) along a patient&#39;s mouth to take a sufficient number of images to produce a three-dimensional representation (or model) of a patient&#39;s mouth and may only include optical sensors such that only the visible aspects of a patient&#39;s teeth and gums can be represented. A technician must be trained to use these related-art scanners, as they generally cannot be moved too quickly or the resulting images will be distorted and three-dimensional representations (or models) will be inaccurate with flaws and missing information, and they must be maintained at a proper orientation to ensure all relevant aspects of a patient&#39;s mouth are captured. Further, x-rays may still be used to diagnose the condition of underlying roots, which is otherwise not visible when using only optical sensors. Although these related-art intraoral scanners may be less cumbersome than the previous physical examination and x-rays, they are still labor intensive and time consuming and still require a multi-step process for diagnosing a patient. 
     According to embodiments of the present disclosure, a three-dimensional intraoral scanner is provided that concurrently (or simultaneously) takes both optical images and ultrasonic images of all relevant aspects of a patient&#39;s oral cavity (or mouth) within about one to two seconds. For example, the three-dimensional intraoral scanner may have a mouth guard or mouth tray form (or shape) that sits between a patient&#39;s upper and lower teeth and extends along all of (or substantially all of) the patient&#39;s teeth. Because the three-dimensional intraoral scanner is embodied as a mouth guard or mouth tray, there is no need for a technician to move (or sweep) the three-dimensional intraoral scanner along a patient&#39;s mouth, thereby allowing an untrained or lesser trained technician to use the three-dimensional intraoral scanner and allowing the scanning to occur much faster. Further, because the three-dimensional intraoral scanner includes both optical and ultrasonic sensors, the resulting three-dimensional representation may overlay both the visible tooth and gum condition with the underlying root condition. 
     Referring to  FIG. 2 , a three-dimensional intraoral scanner  100  is shown. The three-dimensional intraoral scanner  100  may include an outer U-shaped portion  110  and an inner portion  120  connected to the outer U-shaped portion  110 . In use in a patient&#39;s mouth, the outer U-shaped portion  110  may sit outside of (e.g., may sit along an outer surface of) the patient&#39;s teeth and gums and the inner portion  120  may sit inside of (e.g., may sit along an inner surface of) the patient&#39;s teeth and gums. The patient may hold the three-dimensional intraoral scanner  100  in his or her mouth by clamping down on the inner portion  120  of the three-dimensional intraoral scanner  100 . 
     In different embodiments, the size of the three-dimensional intraoral scanner  100  may be suitably varied for use with adult patients and child patients. That is, the three-dimensional intraoral scanner  100  may be formed in different sizes to fit adult patients and child patients. 
     Referring to  FIGS. 2-4 , the three-dimensional intraoral scanner  100  includes a plurality of optical and ultrasonic sensors (e.g., optical and ultrasonic cameras)  130 / 135 . The sensors  130 / 135  may be arranged on an inner surface of the outer U-shaped portion  110  and on an outer surface of the inner portion  120 . In some embodiments, additional sensors  130 / 135  may be formed on upper and lower surfaces of the inner portion  120  to capture images of the hard palate (e.g., the roof), the floor of a patient&#39;s mouth, and the patient&#39;s tongue. 
     The placement of the sensors  130 / 135  in  FIGS. 2-4  is schematically illustrated for ease of description and understanding. The sensors  130 / 135  may be suitably arranged on the three-dimensional intraoral scanner  100  to capture images of the entire oral cavity (or mouth). Accordingly, the position of the sensors  130 / 135  is merely shown for reference, and the positions of the sensors  130 / 135  may be suitably adjusted. 
     In some embodiments, the optical cameras  130  may be structured light cameras, Time-of-Flight (ToF) depth sensors, and/or other depth sensors, and may use polarization to prevent or substantially reduce instances of specular reflection. For example, the optical cameras  130  may have polarization filters (e.g., polarizers) arranged over the lens to prevent or substantially reduce specular reflections, which may occur when imaging teeth because they are often wet with saliva. 
     The ultrasonic sensors  135  may be configured to image a patient&#39;s tooth root structure. Because tooth roots are generally covered by gum tissue, except when a patient is suffering periodontitis (gum disease), the optical sensors  130  are generally unable to image the teeth root structures. The ultrasonic sensors  135 , however, are able to penetrate gum tissue by using ultrasonic waves, which reflect from the relatively hard or dense root structures but pass through the relatively soft gum tissue. Thus, by using the combination of optical and ultrasonic sensors  130 / 135 , a composite three-dimensional representation of a patient&#39;s visible tooth structure and non-visible tooth root structure may be generated. 
     In some embodiments, a computer vision system (or computer vision algorithm) may use the received optical and ultrasonic images to create a three-dimensional representation (or model) of a patient&#39;s mouth. For example, the computer vision system may utilize a machine learning algorithm to colorize the received ultrasonic images for consistency with the received optical images, to accurately orient the received optical information with the received ultrasonic information, to create a point cloud (e.g., a set of data points in a three-dimensional space), and/or to create triangulated three-dimensional mesh with color textures.  FIG. 18  shows examples of a point cloud of a patient&#39;s mouth, a dense point cloud of the patient&#39;s mouth, a three-dimensional representation (or model) of the patient&#39;s mouth, and a three-dimensional representation of the patient&#39;s mouth with texturing and shading. 
     For example, rather than calibrating each three-dimensional intraoral scanner  100  to compensate for differences in manufacturing (e.g., manufacturing tolerances, optical and ultrasonic sensor alignment, etc.), the computer vision system may be used to interpret the received information and to generate an accurate three-dimensional representation of a patient&#39;s mouth. 
     In some embodiments, the three-dimensional intraoral scanner  100  may include a battery (e.g., a rechargeable battery) inside the outer U-shaped portion  110  and/or inside the inner portion  120 , and the three-dimensional intraoral scanner  100  may include a wireless transceiver to wirelessly receive and transmit data to a nearby computer system. That is, for ease of use and patient comfort, the three-dimensional intraoral scanner  100 , according to some embodiments, may be wireless. 
     The wireless transceiver may operate by using the Bluetooth® standard (Bluetooth is a registered trademark of BLUETOOTH SIG, INC., a Delaware Corporation). The battery may be charged by, for example, wireless charging, such as by induction charging or the like, such that a charging port may be omitted from the three-dimensional intraoral scanner  100 . However, in some embodiments, a charging port, with or without a cover, may be included for charging the battery. 
     In some embodiments, a wire may be provided for powering the three-dimensional intraoral scanner  100  and for data transfer with a nearby computer system. 
       FIG. 5  is a perspective view of a three-dimensional intraoral scanner  200  according to another embodiment of the present disclosure. The three-dimensional intraoral scanner  200  may be a one-piece (e.g., integral) design that extends under and around a patient&#39;s teeth, different from the three-dimensional intraoral scanner  100  which was positioned on opposite sides of a patient&#39;s teeth but not under a patient&#39;s teeth. 
     A plurality of optical and ultrasonic sensors  230 / 235  may be arranged on the surface (e.g., on both surfaces) of the three-dimensional intraoral scanner  200 . For example, some of the illustrated silver dots may be optical sensors  230  and other ones may be ultrasonic sensors  235 , or in other embodiments, each of the silver dots may be both optical and ultrasonic sensors  230 / 235 . The optical and ultrasonic sensors  230 / 235  are substantially similar to the optical and ultrasonic sensors  130 / 135  described above, and accordingly, a repeated description thereof will be omitted. Also, the position of the sensors  230 / 235  may be suitably varied from what is shown in  FIG. 5  to capture images of a patient&#39;s oral cavity (or mouth). 
     In the three-dimensional intraoral scanner  200 , sensors  230 / 235  may be arranged at a base of a trough  210  to capture images of tooth enamel. For example, because the three-dimensional intraoral scanner  100  shown in  FIG. 2  does not extend under a patient&#39;s teeth, it may not be able to capture images of a patient&#39;s tooth enamel where cavities often form. The three-dimensional intraoral scanner  200 , however, has a mouthpiece shape with the trough  210  that extends under the patient&#39;s teeth, thereby providing images (e.g., optical images) of the enamel of a patient&#39;s teeth to better assist with diagnosing cavities and the like. 
     The three-dimensional intraoral scanner  200  may also include a soft protrusion  220  that extends from an inner portion of the scanner  200 . The protrusion  220  may contact a patient&#39;s hard palate (the roof of the mouth) to ensure proper spacing between the three-dimensional intraoral scanner  200  and the hard palate for better imaging and the like. In some embodiments, however, the protrusion  220  may be omitted. 
     Similar to the three-dimensional intraoral scanner  100 , the three-dimensional intraoral scanner  200  may include a battery and a wireless transceiver for wireless operation. In other embodiments, however, a wired connection may be provided to power the three-dimensional intraoral scanner  200  and for data transfer between the three-dimensional intraoral scanner  200  and a nearby computer system. 
       FIGS. 6-8  show aspects of a three-dimensional intraoral scanner  300  according to another embodiment of the present disclosure. The three-dimensional intraoral scanner  300  may have a single-trough shape  310  to fit around one row of a patient&#39;s teeth or a double-trough shape to fit around both upper and lower rows of a patient&#39;s teeth (see, e.g.,  FIGS. 16 and 17 ). 
     Referring to  FIGS. 7 and 8 , the three-dimensional intraoral scanner  300  may include a sled  320  that is configured to move along the trough  310 . The sled  320  may include a circuit board  321 , and a plurality of optical and ultrasonic sensors  330 / 335  may be arranged on the circuit board  321 . By including the sled  320 , the number of sensors  330 / 335  in the three-dimensional intraoral scanner  300  may be reduced when compared to the three-dimensional intraoral scanners  100 / 200  described above. 
     The sled  320  may move along the trough  310  by, for example, magnetic attraction and repulsion. In other embodiments, the sled  320  may move along the trough  310  by using a motor. The sled  320  may move along the entire length of the trough  310  in about one to about two seconds to image a patient&#39;s entire mouth. 
     In some embodiments, a plurality of sleds  320  may be provided in the three-dimensional intraoral scanner  300 . For example, one sled  320  may be provided at one end of the trough  310  to move toward a patient&#39;s front teeth and another sled  320  may be provided at another end of the trough  310  to move toward the patient&#39;s front teeth. In such an embodiment, the scanning time may be reduced. For example, the scanning time may be half of the scanning time of an embodiment in which only one sled  320  is present. 
     In some other embodiments, when the three-dimensional intraoral scanner  300  has the double-trough shape, one or more sleds  320  may be provided in each of the upper trough to image a patient&#39;s upper teeth and corresponding root structure and the lower trough to image the patient&#39;s lower teeth and corresponding root structure. 
     The trough  310  may be made from (or may include) a glass or crystal material that is transparent or translucent to both visible light and ultrasonic waves. This way, as the sled  320  moves along the trough, the optical and ultrasonic sensors  330 / 335  may image the patient&#39;s teeth and underlying root structure while maintaining a barrier (e.g., a glass or crystal barrier) between the sled  320  and the patient&#39;s mouth. An outer body of the three-dimensional intraoral scanner  300  (e.g., the outer surfaces of the three-dimensional intraoral scanner  300 )  305  may be, for example, a plastic or the like for increased durability and comfort. 
     The three-dimensional intraoral scanner  300  may include a cable  340  for powering the sensors  330 / 335  and for transmitting data to from the sensors  330 / 335  to a nearby computer system. However, in some embodiments, the three-dimensional intraoral scanner  300  may include a battery and a wireless transceiver. 
       FIG. 9  shows a three-dimensional intraoral scanner according to another embodiment of the present disclosure. For example, the three-dimensional intraoral scanner shown in  FIG. 9  may include a wireless transceiver for wireless connection to a computer vision system. 
       FIG. 10  shows a three-dimensional intraoral scanner  500  according to another embodiment being moved along a patient&#39;s mouth. The three-dimensional intraoral scanner  500  may be relatively small compared to the other embodiments described herein and may be used to scan only portions of a patient&#39;s mouth. For example, the three-dimensional intraoral scanner  500  may be about the size of one tooth. The three-dimensional intraoral scanner  500  may be manually used to scan a patient&#39;s wisdom teeth or only a painful area of the patient&#39;s mouth without scanning the patient&#39;s entire mouth. 
     The three-dimensional intraoral scanner  500  may include the optical and/or ultrasonic sensors  330 / 335  as described above. In some instances, the three-dimensional intraoral scanner  500  may be manually moved along a patient&#39;s entire mouth to scan the patient&#39;s entire mouth. Although more time consuming than the other embodiments described herein, the smaller size of the three-dimensional intraoral scanner  500  may be useful for children and infants, for example. 
       FIGS. 11 and 12  show interchangeability between a wireless module  350  and a wired connection  360 . Here, the three-dimensional intraoral scanner  300  is shown as an example, but interoperability between the wireless module  350  and the wired connection  360  may be applied to any of the embodiments of the three-dimensional intraoral scanners described herein. For example, the three-dimensional intraoral scanner  300  may include a connection port, and the wireless module  350  and the wired connection  360  may both be able to connect to the connection port. In this way, the three-dimensional intraoral scanner  300  may be used with either the wireless module  350  for a wireless connection to a computer vision system or the wired connection  360  for a wired connection to the computer vision system, giving the user more flexibility. 
       FIGS. 13-15  show covers  370 / 375  for the three-dimensional intraoral scanners. To protect the three-dimensional intraoral scanner  300  and for patient safety and sanitation, the covers  370 / 375  may be provided on the three-dimensional intraoral scanner  300 . For example, an upper cover  370  may be molded to have the same shape as the trough  310  and may be press-fit onto the three-dimensional intraoral scanner  300 , and a lower cover  375  may be flat to match the flat bottom of the three-dimensional intraoral scanner  300 . In some embodiments, the upper cover  370  and the lower cover  375  may snap-fit together around (e.g., entirely around) the three-dimensional intraoral scanner  300  to provide a clean exterior surface for the patient. After use, the covers  370 / 375  may be cleaned and sterilized in an autoclave. 
     The covers  370 / 375  may be sized and shaped to fit any of the three-dimensional intraoral scanner described herein. In some embodiments, the upper cover  370  may have an opening therein to allow the wireless module  350  or the wired connection  360  to pass therethrough. 
       FIGS. 16 and 17  show a three-dimensional intraoral scanner  400  according to another embodiment of the present disclosure. The three-dimensional intraoral scanner  400  is similar to the three-dimensional intraoral scanner  300  shown in, for example,  FIGS. 6-8  but includes both a first (or upper) trough  410  and a second (or lower) trough  420 . The three-dimensional intraoral scanner  400  may include, for example, two or four sleds  320 , with either one or two sleds  320  being arranged under and facing the first trough  410  and either one or two sleds  320  being arranged over and facing the second trough  420 . 
     In some embodiments, the sled  320  may be modified to have a first group of sensors  330 / 335  that face into the first trough  410  and a second group of sensors  330 / 335  that face into the second trough  420 . In such an embodiment, only one or two sleds  320  may be included in the three-dimensional intraoral scanner  400  because one sled  320  can image the patient&#39;s upper and lower teeth and oral cavity. 
       FIG. 18  shows examples of a point cloud of a patient&#39;s mouth, a dense point cloud of the patient&#39;s mouth, a three-dimensional representation of the patient&#39;s mouth, and a three-dimensional representation of the patient&#39;s mouth with texturing and shading. 
     It will be understood that, although the terms “first”, “second”, “third”, etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section, without departing from the spirit and scope of the inventive concept. 
     Spatially relative terms, such as “beneath”, “below”, “lower”, “under”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that such spatially relative terms are intended to encompass different orientations of the device in use or in operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” or “under” other elements or features would then be oriented “above” the other elements or features. Thus, the example terms “below” and “under” can encompass both an orientation of above and below. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly. In addition, it will also be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the inventive concept. As used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. As used herein, the term “major component” means a component constituting at least half, by weight, of a composition, and the term “major portion”, when applied to a plurality of items, means at least half of the items. 
     As used herein, the singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. Further, the use of “may” when describing embodiments of the inventive concept refers to “one or more embodiments of the present disclosure”. Also, the terms “exemplary” and “example” are intended to refer to an example or illustration. As used herein, the terms “use,” “using,” and “used” may be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively. 
     It will be understood that when an element or layer is referred to as being “on”, “connected to”, “coupled to”, or “adjacent to” another element or layer, it may be directly on, connected to, coupled to, or adjacent to the other element or layer, or one or more intervening elements or layers may be present. In contrast, when an element or layer is referred to as being “directly on”, “directly connected to”, “directly coupled to”, or “immediately adjacent to” another element or layer, there are no intervening elements or layers present. 
     Any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed within the recited range. For example, a range of “1.0 to 10.0” is intended to include all subranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. 
     Although example embodiments of a three-dimensional intraoral scanner have been described and illustrated herein, many modifications and variations within those embodiments will be apparent to those skilled in the art. Accordingly, it is to be understood that a three-dimensional intraoral scanner according to the present disclosure may be embodied in forms other than as described herein without departing from the spirit and scope of the present disclosure.