Patent Publication Number: US-2023135385-A1

Title: Orthodontic aligner with built-in hook or traction device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application claims priority to U.S. Provisional Patent Application No. 63/275,797 filed on Nov. 4, 2021, entitled “Orthodontic Aligner with Built-In Hook or Traction Device,” the contents of which are hereby incorporated herein by reference. 
    
    
     BACKGROUND 
     Field of the Art 
     This disclosure relates to removable orthodontic aligners that include additional built-in traction devices. For example, a removable orthodontic aligner in accordance with the present invention includes built-in hooks that are integrally formed simultaneously with the rest of the aligner. 
     Discussion of the State of the Art 
     Removable orthodontic aligners are gaining in popularity due to the convenience of these aligners. The aligners are typically clear and thus are more aesthetically pleasing than conventional metal braces. Further, the aligners can be removed from the patient&#39;s teeth for eating, drinking, brushing, flossing, etc. 
     One problem with removable aligners is that the corrective force provided by the aligners is less than that of conventional metal hardware, such as braces. As such, orthodontic treatment may be prolonged using the aligners. In some cases, the tooth arrangement is too irregular, and aligners are not an option because they do not provide enough corrective force. 
     SUMMARY 
     An orthodontic aligner in accordance with the present invention includes a built-in hook for use with elastic bands. In this manner, the present aligner provides more corrective force than a conventional aligner. Because the aligner body and the built-in hooks are made simultaneously, the aligner is easier to manufacture than an aligner to which hooks are later applied. 
     Using interactive software, an orthodontic practitioner is able to select a location for a built-in hook before the aligner is made. Then, the aligner, or a series of aligners, is fabricated with the hook built in. As such, the hook location is accurate and reproducible. 
     In one example, the orthodontic aligner in accordance with the present invention includes an aligner body configured for receiving upper teeth or lower teeth. The aligner body has a facial surface, a lingual surface, a gingival edge, and an incisal edge. The orthodontic aligner further includes a hook integrally formed on the facial surface or the lingual surface of the aligner body. The hook is configured for removably attaching an elastic band thereto. The hook is positioned between the gingival edge and the incisal edge of the aligner body. The hook may protrude at an angle relative to the facial surface or the lingual surface of the aligner body. The angle may be less than 60 degrees and may be greater than 20 degrees. A distance between the hook and the gingival edge of the aligner body may be at least 1 mm. The hook and the aligner body may be formed simultaneously. 
     In another example, a method of making an orthodontic aligner in accordance with the present invention includes uploading a scan of a patient&#39;s teeth to an interactive software program to create a virtual model of the patient&#39;s teeth; selecting a position for an aligner hook on the virtual model of the patient&#39;s teeth using the interactive software; creating a physical 3D model of the patient&#39;s teeth corresponding to the virtual model, wherein the 3D model includes a protrusion corresponding to the selected position for the aligner hook; and thermoforming a plastic sheet over the 3D model, thereby creating an orthodontic aligner having a built in aligner hook. Selecting the position for the aligner hook may include selecting a location and an angle of the aligner hook relative to the patient&#39;s teeth. 
     In yet another example, a method of making an orthodontic aligner in accordance with the present invention includes uploading a scan of a patient&#39;s teeth to an interactive software program to create a virtual model of the patient&#39;s teeth; selecting a position for an aligner hook on the virtual model of the patient&#39;s teeth using the interactive software; and 3D printing the orthodontic aligner based on the virtual model, wherein the 3D printed orthodontic aligner comprises a built in aligner hook in the selected position. Selecting the position for the aligner hook may include selecting a location and an angle of the aligner hook relative to the patient&#39;s teeth. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       The accompanying drawings illustrate several embodiments and, together with the description, serve to explain the principles of the invention according to the embodiments. It will be appreciated by one skilled in the art that the particular arrangements illustrated in the drawings are merely exemplary and are not to be considered as limiting of the scope of the invention or the claims herein in any way. 
         FIGS.  1 A and  1 B  illustrate a conventional approach for adding elastic bands to orthodontic aligners. 
         FIGS.  2 A and  2 B  illustrate an aligner with a built-in hook in accordance with one embodiment of the present invention. 
         FIGS.  3 A- 3 C  illustrate models of a set of teeth to be used in manufacturing an aligner with a plurality of built-in hooks in accordance with another embodiment of the present invention. 
         FIGS.  4 A and  4 B  illustrate an aligner having reinforced, built in hooks in accordance with the present invention. 
         FIG.  5    is a flow chart illustrating a method for making an aligner with a built-in hook in accordance with the present invention. 
         FIG.  6 A  is a plan view of an aligner having built in hooks configured to engage with a face mask, in accordance with one embodiment of the present invention. 
         FIG.  6 B  illustrates a patient wearing a face mask coupled to the aligner from  FIG.  6 A , in accordance with one embodiment of the present invention. 
         FIG.  6 C  is a plan view of a palate expander aligner having built in hooks configured to engage with a face mask, in accordance with one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     An orthodontic aligner in accordance with the present invention includes an aligner body and a built-in hook. The aligner body is configured for receiving upper teeth or lower teeth and includes a facial surface, a lingual surface, a gingival edge, and an incisal edge. The hook is integrally formed on either the facial surface or the lingual surface of the aligner body. The hook is configured so that an elastic band can be attached thereto. The hook is positioned between the gingival edge and the incisal edge of the aligner body. The hook and the aligner body are made at the same time by creating a physical 3D model of the patient&#39;s teeth that includes protrusions in pre-selected hook locations. A polymer is then thermoformed over the physical 3D model, thereby creating the aligner having built-in hooks. 
     The invention is described by reference to various elements herein. It should be noted, however, that although the various elements of the inventive apparatus are described separately below, the elements need not necessarily be separate. The various embodiments may be interconnected and may be cut out of a singular block or mold. The variety of different ways of forming an inventive apparatus, in accordance with the disclosure herein, may be varied without departing from the scope of the invention. 
     Generally, one or more different embodiments may be described in the present application. Further, for one or more of the embodiments described herein, numerous alternative arrangements may be described; it should be appreciated that these are presented for illustrative purposes only and are not limiting of the embodiments contained herein or the claims presented herein in any way. One or more of the arrangements may be widely applicable to numerous embodiments, as may be readily apparent from the disclosure. In general, arrangements are described in sufficient detail to enable those skilled in the art to practice one or more of the embodiments, and it should be appreciated that other arrangements may be utilized and that structural changes may be made without departing from the scope of the embodiments. Particular features of one or more of the embodiments described herein may be described with reference to one or more particular embodiments or figures that form a part of the present disclosure, and in which are shown, by way of illustration, specific arrangements of one or more of the aspects. It should be appreciated, however, that such features are not limited to usage in the one or more particular embodiments or figures with reference to which they are described. The present disclosure is neither a literal description of all arrangements of one or more of the embodiments nor a listing of features of one or more of the embodiments that must be present in all arrangements. 
     Headings of sections provided in this patent application and the title of this patent application are for convenience only and are not to be taken as limiting the disclosure in any way. 
     Devices and parts that are connected to each other need not be in continuous connection with each other, unless expressly specified otherwise. In addition, devices and parts that are connected with each other may be connected directly or indirectly through one or more connection means or intermediaries. 
     A description of an aspect with several components in connection with each other does not imply that all such components are required. To the contrary, a variety of optional components may be described to illustrate a wide variety of possible embodiments and in order to more fully illustrate one or more embodiments. Similarly, although process steps, method steps, or the like may be described in a sequential order, such processes and methods may generally be configured to work in alternate orders, unless specifically stated to the contrary. In other words, any sequence or order of steps that may be described in this patent application does not, in and of itself, indicate a requirement that the steps be performed in that order. The steps of described processes may be performed in any order practical. Further, some steps may be performed simultaneously despite being described or implied as occurring non-simultaneously (e.g., because one step is described after the other step). Moreover, the illustration of a process by its depiction in a drawing does not imply that the illustrated process is exclusive of other variations and modifications thereto, does not imply that the illustrated process or any of its steps are necessary to one or more of the embodiments, and does not imply that the illustrated process is preferred. Also, steps are generally described once per aspect, but this does not mean they must occur once, or that they may only occur once each time a process, or method is carried out or executed. Some steps may be omitted in some embodiments or some occurrences, or some steps may be executed more than once in a given aspect or occurrence. 
     When a single device or article is described herein, it will be readily apparent that more than one device or article may be used in place of a single device or article. Similarly, where more than one device or article is described herein, it will be readily apparent that a single device or article may be used in place of the more than one device or article. 
     The functionality or the features of a device may be alternatively embodied by one or more other devices that are not explicitly described as having such functionality or features. Thus, other embodiments need not include the device itself. 
     Techniques and mechanisms described or referenced herein will sometimes be described in singular form for clarity. However, it should be appreciated that particular embodiments may include multiple iterations of a technique or multiple instantiations of a mechanism unless noted otherwise. Alternate implementations are included within the scope of various embodiments in which, for example, functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those having ordinary skill in the art. 
     Overview 
     The apparatus of the present invention is an orthodontic aligner having built-in hooks for attaching elastic bands thereto. The built-in hooks are formed and positioned to be more effective, comfortable, and aesthetically pleasing than hooks formed by conventional methods. 
     Apparatus 
       FIGS.  1 A and  1 B  depict a set of aligners  102 ,  104  that are configured for being used with elastic bands  106 . In this approach, the upper aligner  102  includes a precision cut hook  108  that is formed by cutting notches in the aligner  102  from the gingival (top) edge of the aligner towards the incisal or occlusal (lower) edge of the aligner  102 . The lower aligner  104  includes a notch  110  cut therein for accommodating a button  112  that is attached directly to one of the patient&#39;s lower teeth  114 . 
     One disadvantage of the approach shown in  FIGS.  1 A and  1 B  is that the precision cut hook  108  has sharp edges that may poke the inner surfaces of the patient&#39;s mouth. The location of the hook  108  being along the gingival edge of the aligner  102  may be problematic since the plastic of the aligner  102  is relatively thin along the gingival edge and the hook  108  is susceptible to breaking or bending due to the reduced thickness. Indeed, the aligner  102  is limited to one hook  108  per tooth surface due to the reduced thickness of the plastic at the hook location. The pulling force applied to the gingival edge of the aligner  102  by the elastic band  106  is mostly in the vertical direction, which may cause the aligner  102  to become dislodged and fall out of place. Another disadvantage is that it may be uncomfortable or unsightly for the patient to have a button  112  semi-permanently attached directly to a tooth. Yet another disadvantage is that the elastic band  106  may be difficult for the patient to attach to the hook  108  and the button  112  due to the close proximity of the hook  108  and the button  112  to the gingival edge of the aligners  102 ,  104 . 
     The aligners of the present invention are formed with built in hooks, rather than cutting notches in the aligner to form hooks.  FIGS.  2 A and  2 B  illustrate an aligner  200  having an aligner body  202  and a hook  204  protruding therefrom. The aligner body  202  is configured for being positioned over either the upper teeth or the lower teeth. The aligner body  202  has a facial surface  206  that faces the patient&#39;s inner lip and inner cheek. The aligner body  202  further has a lingual surface  208  that faces the patient&#39;s tongue. Still further, the aligner body  202  has a gingival edge  210  that is positioned along the patient&#39;s gum line and an incisal edge  212  that is positioned along the biting surfaces of the teeth. 
     The hook  204  is integrally formed with the aligner body  202 . That is, the aligner body  202  and the hook  204  are formed at the same time. In the embodiment shown in  FIGS.  2 A and  2 B , the hook  204  is formed on the facial surface  206  of the aligner body  202 . However, the hook  204  may alternatively or additionally be formed on the lingual surface  208  of the aligner body  202 . For example, as shown in  FIGS.  3 A and  3 B , multiple hooks  204  may be formed on the aligner body  202  and may be positioned on the facial surface  206 , the lingual surface  208 , or both. The hook  204  is angled and configured for removably attaching an elastic band thereto. 
     One advantage of the built-in hook  204  is that the hook  204  is positioned adjacent to the middle of the tooth rather than near the gingival edge  210  of the aligner body  202 , which helps to keep the aligner  200  in place in the patient&#39;s mouth. Another advantage of the hook  204  in accordance with the present invention is that attachments applied directly to the teeth (such as the button  112  shown in  FIG.  1 B ) are not required. The hooks  204  can be angled in such a way that they don&#39;t poke into the inner surfaces of the mouth. For example, as shown in  FIGS.  3 A and  3 B , the hooks  204  are not perpendicular to the tooth surface. Rather, the hooks  204  are at an angle  214  relative to the tooth surface. The angle  214  is preferably less than 45 degrees. The angle may be greater than about 15 degrees to accommodate placement of the elastic bands around the hook  204 . The angle of the hooks  204  may be customized depending on the tooth anatomy and orthodontic needs of the patient. For example, the hooks  204  may be angled forwards, backwards, up, or down. The hooks  204  can additionally or alternatively be angled and positioned in a more discreet location so that the hooks  204  are less noticeable. In one example, the angle  214  is between 20 and 60 degrees. Anterior hooks generally have an angle  214  that is less than that of posterior hooks so that the hooks can be as comfortable as possible for the patient while still being accessible for attaching elastics thereto. In addition, the greater the angle  214 , the higher the number of elastics that can be attached to the hook  204 . 
     The angle of the hook  204  helps to hold the aligner  200  in position in the patient&#39;s mouth. That is, the corrective force supplied by an elastic band coupled to the hook  204  has a more horizontal orientation compared to that provided by using the approach depicted in  FIGS.  1 A and  1 B . Using the hooks  204  of the present invention makes attaching elastic bands easier compared to conventional precision cut hooks. 
     The hook  204  is spaced from the gingival edge  210  of the aligner body  202  by a distance  216  (see  FIG.  2 B ). In this manner, the hook  204  is more sturdy because it is formed in a thicker portion of the aligner body  202  rather than the relatively thin portion of the aligner body  202  along the gingival edge  210 . The distance  216  between the gingival edge  210  of the aligner body  202  and the hook  204  allows the bands coupled to the hook  204  to exert more horizontal force, which is advantageous for antro-posterior correction of the malocclusion. In one example, the distance  216  is at least 1 mm. This distance  216  facilitates the patient being able to attach elastic bands to the hook  204 . That is, elastic bands are easier to attach to the hooks  204  of the present invention compared to the conventional precision cut hooks due to the distance  216  between the patient&#39;s gum line and the hook  204 . Ideally, the distance  216  is as great as possible. For example, the hook  204  is preferably positioned as occlusal as occlusion permits. 
       FIGS.  3 A- 3 C  depict virtual 3D models of a set of teeth having a plurality of pre-selected hook positions to add strength for heavy rubber bands usage. These virtual 3D models may be used to make the aligners  200  having hooks  204  built in at the pre-selected positions. As shown in  FIGS.  3 A and  3 B , the hooks  204  of the present invention are formed in such a way that allows for two hooks  204  to be applied to one tooth surface. In contrast, it would not be possible to add two conventional precision cut hooks to a single tooth surface without weakening, damaging, or breaking the aligner.  FIG.  3 C  depicts an exemplary embodiment of built in hooks  220  that align with each other. Hooks  220  on the upper teeth align with hooks  220  on the bottom teeth so that, when the upper teeth come into contact with the bottom teeth, the upper hooks  220  are positioned between the lower hooks  220 . These hooks  220  may be used for holding anterior-posterior correction or crossbite correction in treatment and during retention. These hooks  220  may also be used to guide the arches together correctly in planned orthognathic surgeries. 
     The aligners  200  of the present invention are formed with the hooks  204 . That is, the hooks  204  are formed simultaneously with the rest of the aligner  200 . As such, the aligner  200  with the built in hook  204  is easier to manufacture than conventional manufacturing procedures, which require the hook to be cut into the aligner or require the hook to be added after the aligner is made. Another advantage of the aligner  200  with the built in hook  204  is that the location of the hook  204  is more accurate and more reproducible when a series of aligners is required for orthodontic treatment. 
       FIGS.  4 A and  4 B  depict aligners  200  in accordance with the present invention having built in hooks  204 . The hooks  204  shown in  FIGS.  4 A and  4 B  are reinforced with hard resin  222  or a similarly strong, rigid material that is made within the model fabrication. These hooks  204  having reinforcement elements  222  may be used, for example, in situations where heavy elastics or surgical wires used for orthognathic surgeries are required. 
     One exemplary method  500  for forming the aligners  200  is depicted in  FIG.  5   . First, in step  502 , a scan of a patient&#39;s teeth is uploaded to an interactive software program configured for generating a virtual model of the patient&#39;s teeth. Next, in step  504 , the orthodontic practitioner using the interactive software selects one or more locations for adding hooks  204  to the aligner  200 . The locations for the hooks  204  are selected on the virtual model of the patient&#39;s teeth. For example,  FIGS.  3 A- 3 C  depict virtual models of the patient&#39;s teeth with hook locations and angles added thereto. In step  504 , the practitioner is able to select a location and an angle of the desired hooks relative to the patient&#39;s teeth. The location and angle of the desired hooks is based on the orthodontic needs of the patient. Next, in step  506 , a physical 3D model of the patient&#39;s teeth is generated corresponding to the virtual model. The physical 3D model includes protrusions in the pre-selected hook locations. Finally, in step  508 , a polymer is thermoformed over the physical 3D model in order to form the aligner  200  having built in hooks  204 . 
     In accordance with an embodiment of the invention, the method of making an orthodontic aligner may be embodied in software (herein also referred to as interactive software program). The software may execute on a computing device, wherein it obtains digital data comprising a scan of a patient&#39;s teeth. The software generates a virtual model of the patient&#39;s teeth. Additionally, the software receives a user input selecting a position for an aligner hook on the virtual model of the patient&#39;s teeth. A variety of input methods may be used, as would be understood by a person of ordinary skill in the art, without departing from the scope of the invention, including, but not limited to input via a keyboard, mouse, touch, etc. In one embodiment, the a virtual model and the user input selecting a position for an aligner may be sent to a production system to create a physical 3D model of the patient&#39;s teeth corresponding to the virtual model, wherein the 3D model includes a protrusion corresponding to the selected position for the aligner hook. 
     In one embodiment, the computing device that the software is executing on may be any computing device that would be used by a person of ordinary skill in the art, without departing from the scope of the invention, including, but not limited to a personal computer, a mobile computing device, a server (on-premise or cloud computing server), etc. In one embodiment, the software may be a stand-alone software or may be a plug-in that interacts with a virtual modeling software. The software plug-in may interface with a virtual modeling software via application programming interface (API), via a screen-scraping technique, etc. In one embodiment, the software may run on a remote or a cloud server and may interface with a virtual modeling software that is running on a local computing device via an electronic communication, such as the internet, local area network, etc. 
     In one embodiment, the software generates a composite model comprising the virtual model as well as protrusions based on user input. In another embodiment, the software separately sends virtual model data as well as the user input data and associated location data to the 3D model generation system. 
     Alternatively, the aligner  200  having built in hooks  204  may be 3D printed based directly on the virtual model of the patient&#39;s teeth. Direct printed aligners may allow more variation of the auxiliaries used and in the hook designs. As such, the step  506  of making a physical 3D model of the patient&#39;s teeth can be eliminated, thereby saving time and expense, and minimizing the number of steps and errors in the process of manufacturing the aligners  200 . For example, Graphy, a specialized materials company based in Korea, has developed a process for direct 3D printing aligners. These aligners can be 3D printed with the hooks built in, in accordance with the present invention. 
     Forming the aligner  200  simultaneously with the hooks  204  is advantageous in that another step of adding hooks to the aligner is avoided. In conventional procedures, hooks are added to the aligner after the aligner is formed. For example, after the aligner is made, notches are cut into the gingival edge of the aligner to form precision cut hooks. 
     One example of an aligner  300  having built in hooks  304 ,  306  is depicted in  FIG.  6 A . The aligner  300  includes hooks  304  in the canine position that may be used with a facemask. The angle  314  of the hooks  304  relative to the aligner body  302  is configured for preventing the force of the elastics from allowing the aligner  300  to be dislodged from its desired position when the aligner  300  is coupled to a face mask.  FIG.  6 B  depicts a patient  308  wearing a face mask  310  that is attached to the aligner  300  with elastic members  312 . 
     In a similar example, shown in  FIG.  6 C , an aligner  320  is configured to be used as a palate expander and may be used in conjunction with a face mask, such as the face mask  310  shown in  FIG.  6 B . Similar to the previous example, the aligner  320  includes built in hooks  324 ,  326 . The hooks  324  are located adjacent to the canine teeth and the angle  334  between the hooks  324  and the body of the aligner  320  is configured for preventing the force of the elastics  312  from allowing the aligner  320  to become dislodged from its desired position when the aligner  320  is removably coupled to the face mask  310 . The aligner  320  further includes an empty space  322  for accommodating the front teeth. As such, the aligner  320  does not engage with the front teeth, but rather, is used as a palate expander. In contrast, the aligner  300  shown in  FIG.  6 A  engages with the front teeth to facilitate alignment of the front teeth. 
     Additional Considerations 
     As used herein any reference to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. 
     Some embodiments may be described using the expression “coupled” and “connected” along with their derivatives. For example, some embodiments may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled,” however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments are not limited in this context. 
     As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and Bis false (or not present), A is false (or not present) and Bis true (or present), and both A and B are true (or present). 
     In addition, use of the “a” or “an” are employed to describe elements and components of the embodiments herein. This is done merely for convenience and to give a general sense of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise. 
     Upon reading this disclosure, those of skill in the art will appreciate still additional alternative structural and functional designs for a system and a process for creating an interactive message through the disclosed principles herein. Thus, while particular embodiments and applications have been illustrated and described, it is to be understood that the disclosed embodiments are not limited to the precise construction and components disclosed herein. Various apparent modifications, changes and variations may be made in the arrangement, operation and details of the method and apparatus disclosed herein without departing from the spirit and scope defined in the appended claims.