CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to U.S. Provisional Patent Application Serial No. 61/350,330, filed June 1, 2010, which is hereby incorporated by reference in its entirety. BACKGROUND

A number of mouthguards currently exist in the art for protecting the teeth and for reducing the chance of shock, concussions, and other injuries as a result of high impact collisions and blows during athletic competition. Mouthguards generally are

characterized as being non-personalized, universal and stock model type, or are formed to have direct upper jaw tooth-formed contact. These are customizable mouthguards.

Additionally, the mouthguards may be tethered or untethered. Mouthguards may be tethered to a fastening point, such as a helmet or face guard, to prevent the chance of the mouthguard from being lost as well as to prevent swallowing of the mouthguard or choking on the mouthguard by the user.

The lack of a mouthguard or the use of an improperly fitted mouthguard have been found to be responsible for illnesses and/or injuries resulting from impacts, collisions, or blows that occur to the jaw structure of an athlete. Such injured athletes are susceptible to headaches, presence of earaches, ringing in the ears, clogged ears, vertigo, concussions and dizziness. The cause of these types of health problems and injuries are generally not visible by inspection of the mouth or the jaw but more particularly relate to the temporomandibular joint (TMJ) and surrounded tissues where the lower jaw is connected to the skull in the proximity where the auriculo-temporalis nerves and supra- temporo arteries pass from the neck into the skull to the brain.

In addition to protection of the teeth and the TMJ, athletes clench their teeth during exertion, which can result in hundreds of pounds of compressed force exerted from the lower jaw onto the upper jaw. Such clenching can result in headaches, muscle spasms, damage to teeth, injury to the TMJ, and pain in the jaw. Furthermore, clenching of the teeth makes breathing more difficult during physical exercise.

Most importantly, many problems exist with prior mouthguards. Mouthguards with a rigid labial or buccal walls do accept wide teeth, were bulky and had sharp edges. When the custom appliances were placed in hot water to soften for fitting, the mouthguards tended to collapse and permit portions to touch and stick together upon removal from the hot water thus making fitting of such mouthguards always a problem. Delamination and chewing destruction caused short life of the mouthguards.

SUMMARY OF THE INVENTION

The present invention provides a mouthguard. Generally, the mouthguard includes a tray formed from a non-softenable material. The tray generally includes an arched wall comprising a top, a bottom, a lingual surface, and a facial surface and, in addition to the arched wall, at least one generally vertical recess in at least a portion of the lingual surface. The mouthguard further includes a generally arched trough formed from a heat-softenable material. Generally, the trough includes an arched wall comprising a lingual surface and a facial surface. Moreover, the trough includes at least one member protruding from the facial surface that is positioned and shaped to fit within the at least one recess of the tray.

In some embodiments, at least one recess extends to the top of the lingual surface. In other embodiments, at least one recess extends to the bottom of the lingual surface.

In some embodiments, a cross section of the recess can define an opening in the lingual surface having a lingual surface width, and a cavity having a cavity width that is generally parallel to the lingual surface width. In certain embodiments, the cavity width is greater than the surface width.

In some embodiments, a cross section of the recess can define an opening in the lingual surface, and a recess depth that is generally perpendicular to the lingual surface, wherein the recess depth is great enough to permit the tray to flex in a plane generally axial to the recess.

In some embodiments, fitting the trough member into the tray recess reduces delamination of the trough from the tray. The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 illustrates an exploded perspective view of an exemplary embodiment of a mouthguard.

FIG. 2 illustrates a top view of an exemplary embodiment of a mouthguard component.

FIG. 3 illustrates a rear view of an exemplary embodiment of a mouthguard component.

FIG. 4 illustrates a front view of an exemplary embodiment of a mouthguard component.

All Figures are illustrated for ease of explanation of the basic teachings of the present invention only; the extensions of the Figures with respect to number, position, relationship and dimensions of the parts to form the embodiment will be explained or will be within the skill of the art after the following description has been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following description has been read and understood.

Where a numeral is used in various Figures of the drawings, the numeral designates the same or similar parts in the various Figures in which it is used.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention provides a mouthguard that can offer improved durability compared to existing mouthguards. Multi-component mouthguards— i.e., mouthguards formed from two or more components that are affixed, adhered, or otherwise attached to one another to form the mouthguard— are susceptible to delamination of the components. Delamination affects the mouthguard's ability to provide the desired performance and/or protective function for which it is designed. Delamination decreases the useful life and, therefore, negatively affects the durability of the mouthguard.

The mouthguard described herein includes at least two connected components. One component is formed from a heat-softenable material that, in use, is fitted over and/or around the dentition of a user. A second component is formed from non- softenable material that provides, at a rriiriimum, support for the heat-softenable component. These two components are attached to one another by, at a minimum, a system of one or more members protruding from the heat-softenable material that fit vithin corresponding one or more recesses in the second component, forming a male- female fit that at least partially secures the two components to one another.

In some cases, one or more of the recesses can possess a generally vertical orientation so that the recess forms a natural flexion point in the non-softenable material. Thus, a recess can provide two distinct functions within the mouthguard. First, a recess can provide the female portion of a male-female fit as described in the immediately preceding paragraph. Additionally, by providing flexion about the z-axis, a recess can improve flexibility of the mouthguard to provide better and more comfortable fit over a wider range of user arches.

As used herein, the following terms shall have the indicated meanings:

"Arched" refers to having a form like that of an arch, particularly at least a portion of a dental arch such as, for example, the maxillary arch.

"Heat-softenable" refers to materials that soften and become moldable when heated to a temperature within a glass transition temperature range of from about 120°F to about 200°F.

"Non-softenable" refers to materials that do not soften and become moldable when heated to a temperature of 200°F or less.

The term "and/or" means one or all of the listed elements or a combination of any two or more of the listed elements.

The terms "comprises" and variations thereof do not have a limiting meaning where these terms appear in the description and claims. Unless otherwise specified, "a," "an," "the," and "at least one" are used interchangeably and mean one or more than one.

Also herein, the recitations of numerical ranges by endpoints include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

Furthermore, when the terms "top," "bottom," "right," "left," "forward,"

"rearward," "front," "rear," "first," "second," "inside," "outside," "upper," "lower," "inferior," "superior," "anterior," "posterior," "proximal," "distal," "facial," "buccal," "labial," "oral," "lingual," "palatal," "mesial," and similar positional and/or relative terms are used, the terms should be understood to reference the structures shown in the drawings as they will typically be utilized by one skilled in the art or otherwise as would be recognized by one skilled in the art.

Moreover, various embodiments are described. Unless embodiments are mutually exclusive or unless otherwise indicated, a mouthguard can include the features of any two or more embodiments described herein.

The present invention generally provides a mouthguard that may be custom fit to the dentition of a user. The mouthguard generally includes a heat-softenable material shaped to fit over the teeth of the maxillary arch. In use, the heat-softenable material may be heated sufficiently to soften the material so that the heat-softenable material is moldable around the teeth of the maxillary arch. The heat-softenable material may be placed over the teeth of the maxillary arch and then molded to the dentition of the user and then allowed to cool to produce a mouthguard custom fit to the user. The molding of the softened heat-softenable material may be performed by the user forcing the maxillary teeth into the softened heat-softenable material.

Custom fitting the mouthguard can involve immersing the mouthguard into water that has been heated to or above the glass transition temperature of the heat-softenable material. In some cases, the water may be boiling. In other cases, however, the water may be heating to a sub-boiling temperature and still be warm enough to soften the heat- softenable material.

After the heat-softenable material has been softened, the mouthguard can be inserted into the mouth and registered with the maxillary arch. The user then exerts a force pressing the maxillary teeth into the softened heat-softenable material, thereby causing the heat-softenable material to conform to the contours of at least a portion of the user's maxillary teeth and, optionally, at least a portion of the user's gums. The user may exert the force by providing a biting force to the mouthguard. Alternatively, the user may exert the force by pressing the mouthguard upwardly into the maxillary teeth with the tongue or a finger.

Referring now to the Figures, an exploded view of a mouthguard 10 is generally shown in FIG. 1. The mouthguard 10 includes at least two components: a trough 20 formed at least in part from a heat-softenable material and a tray 30 formed at least in part from a non-softenable material. Exemplary heat-softenable materials and exemplary non-softenable materials are described in more detail below. In some embodiments, the mouthguard 10 can include one or more components in addition to the trough 20 and tray 30 that are shown in FIG. 1. Such additional components may be mouthguard components such as, for example, one or more components described in detail in one or more of U.S. Pat. No. 6,505,626; 6,505,627; 6,505,628; 6,508,251; 6,510,853; 6,588,430; 6,675,806; 6,675,807; 6,691,710; and 7,299,804.

As shown in FIG. 2 and FIG. 3, the tray 30 includes a generally arched wall 32 having a top 34, a bottom 36, a facial surface 38, and a lingual surface 40. The tray 30 further includes at least one recess 42 in at least a portion of the lingual surface 40.

The tray 30 can include any number of recesses 42. In some embodiments, the tray 30 may include a single recess 42. In other embodiments, however, a tray 30 can include, for example, two, three, four, five, six, seven, eight, nine, ten, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 recesses 42. In embodiments that include multiple recesses 42, the size, shape, and/or disposition on the lingual surface 40 of each recess 42 may be independent of the size, shape, and/or disposition on the lingual surface 40 of any other recess 42.

A recess 42 can assume a variety of shapes, sizes, orientations, and dispositions along the lingual surface 42 of the tray 30. For example, a recess 42 may extend to the top 34 of the lingual surface 40, as shown in FIG. 1 and FIG. 2. Alternatively, a recess 42 may extend to the bottom 36 of the lingual surface 40, as shown in FIG. 3. In other embodiments, a recess 42 may extend to both the top 34 and bottom 36 of the lingual surface 40 or, in alternative embodiments, reach neither the top 34 nor bottom 36 of the lingual surface 40.

A recess 42 can have any suitable shape. In some embodiments, a recess 42 may be generally circular or ovoid 42', as illustrated in FIG. 2. In other embodiments, a recess 42 may be polygonal 42" such as, for example, generally rectangular, pentagonal, hexagonal, etc. as shown in FIG. 2. Polygonal recesses 42 are also illustrated in FIG. 1 and FIG. 3.

In cross section, illustrated in the top view of FIG. 2, a recess 42 can define an opening 44 at the lingual surface 40 having a lingual surface width 46. As used herein, the lingual surface width 46 is the shortest distance from one edge of the recess 42 to the other edge of the recess 42 across the recess opening 44 and generally co-planar with the lingual surface 40. In cross section, a recess 42 can further define a cavity 48 having a cavity width 50. As used herein, the cavity width 50 is the greatest diameter across the cavity 48 that is generally parallel to the lingual surface width 46. As used herein, diameter refers to a straight line passing from side to side of a cavity 48 regardless of the geometry of the cavity 48.

In some embodiments, a recess 42 may be configured so that the cavity width 50 is greater than the lingual surface width 46 of the recess 42. In such embodiments, insertion of trough member 28 into the recess 42 forms a male-female fit that can help maintain the integrity of the tray-trough assembly and, therefore, decrease the likelihood and extent to which the tray 30 and trough 20 might delaminate during use. The structural integrity provided to a tray-trough assembly generally increases as the number of recess-member fits increases, at least within the range of recess-member fits typically present in a mouthguard 10.

In some embodiments, a recess 42 can define an opening 44 and a recess depth

52. As used herein, the recess depth 52 is the greatest diameter across the cavity 48 that is generally perpendicular to the recess opening 44. In some embodiments, the recess depth is great enough so that the recess forms a natural flexion point in the tray, allowing the tray 30 to flex along the long axis of the recess. In some embodiments, a recess 42 may assume a generally vertical orientation in the lingual surface 40 so that the long axis of the recess 42 generally aligns with the z-axis of the tray 30. In such embodiments, the recess can provide the tray 30 with structural flexibility that permits the tray 30 and, therefore, the mouthguard 10 to flex to comfortably accommodate great variation in the maxillary arches among users. Such flexibility generally increases as the number of generally vertical recesses 42 increases in the lingual surface 40 of the tray 30, at least within the range of generally vertical recesses 42 typically present in a mouthguard 10 The trough 20 is generally arched so that it is able to accept at least a portion of a maxillary arch of a user and, optionally, at least a portion of the user's gums. The trough 20 includes a generally arched wall 22 that includes a lingual surface 24 and a facial surface 26. The facial surface 26 includes at least one member 28 protruding from the facial surface 26. The member 28 is positioned and shaped to fit within at least a portion of at least one recess 42 in the lingual surface 40 of the tray 30.

The trough 20 can include any number of members 28. In some embodiments, the trough 20 will have no more members 28 than the tray 30 has recesses 42. Thus, often, each recess 42 in the lingual surface 40 of the tray 30 can accept a corresponding member 28 protruding from the facial surface 26 of the trough 20, although it is not necessary that each recess 42 have a corresponding member 26. Consequently, the trough 20 can include two, three, four, five, six, seven, eight, nine, ten, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 members 28. In embodiments that include multiple members 28, the size, shape, and/or disposition on the facial surface 26 of each member 28 may be independent of the size, shape, and/or disposition on the facial surface 26 of any other member 28.

A member 28 can assume a variety of shapes, sizes, orientations, and/or dispositions along the facial surface 26 of the trough 20. Typically, the size, shape, orientation, and/or disposition along the facial surface 26 of the trough 20 will generally correspond to the size, shape, orientation, and/or disposition of recesses 42 on the lingual surface 40 of the tray 30.

Accordingly, a member 28 can have any suitable shape. In some embodiments, a member 28 may be generally circular or ovoid. In other embodiments, a member 28 may be polygonal such as, for example, generally rectangular, pentagonal, hexagonal, etc. In addition to the male-female fit of the one or more members 28 into the one or more corresponding recesses 42, the tray 30 and the trough 20 may be attached, affixed, adhered, or otherwise assembled to one another in any suitable manner. Heat-Softenable Material

The heat-softenable material may be any suitable material that softens and becomes moldable when heated to a temperature between about 120°F and 200°F.

Suitable heat-softenable materials can therefore be softenable within a glass transition temperature range of as low as 120°F to as high as about 200°F such as, for example, within a glass transition temperature range of, for example, from about 140°F to approximately 185°F or 190°F.

Suitable materials include, for example, low melt temperature ethylene vinyl acetate (EVA) thermoplastics. In some embodiments, the heat-softenable material softens sufficiently for deformation to receive the impression of teeth after being immersed in water at a temperature range of approximately 140°F to approximately 180°F for approximately two minutes.

In some embodiments, the heat-softenable material can include a

polycaprolactone such as, for example, polycaprolactone CAPA 6500 (Perstorp UK, Ltd., Cheshire, UK) or TONE (P-767, Union Carbide Corporation, Piscataway, NJ). A polycaprolactone may be used alone or, for example, in a mixture with EVA. In other embodiments, the heat-softenable material can include a mixture of polycaprolactone and a polyolefin elastomer such as, for example, a copolymer of ethylene and octene-1 (e.g., ENGAGE, Dupont Canada, Inc., Mississauga, Ontario). In other embodiments, the heat- softenable material may be a thermoplastic olefin such as, for example ADFLEX

(LyondellBasell Industries N.V., Rotterdam, Netherlands). In other embodiments, the heat-softenable material may be a thermoplastic polyurethane having a low melt point (e.g., less than 160°F) such as, for example, certain TEXTN thermoplastic polyurethanes (Bayer AG, Leverkusen, Germany). In still other embodiments, the heat-softenable material may be a thermoplastic polyolefin such as, for example, EXACT (ExxonMobil Chemical Co., Houston, TX). Non-softenable Material

The non-softenable material may be any suitable material that does not appreciably softens and remains substantially unmoldable when heated to a temperature of about 200°F. Suitable non-softenable materials include thermoplastic materials such as, for example, higher melt temperature thermoplastics including, for example, certain EVA copolymer resins such as ELVAX 250 or ELVAX 260. In some embodiments, the non-softenable material may have a Shore "A" hardness of approximately 82, which can provide a durable, rubbery material.

In some embodiments, the non-softenable material can include a mixture of styrene block copolymer and high-density polyethylene (HDPE). More specifically, the styrene block copolymer may include DYNAFLEX (part number G2780-0001 from GLS Corporation, McHenry, IL) while the HDPE may include HD-6706 ESCORENE (ExxonMobile Chemical Co., Houston, TX).

In another embodiment, the non-softenable material can include a styrene block copolymer mixed with polyolefin elastomer, which is a copolymer of ethylene and octene-1. A suitable copolymer is available as ENGAGE (Dupont Canada, Inc.,

Mississauga, Ontario).

In another embodiment, the non-softenable material can include a mixture of thermoplastic rubber and a polyolefin elastomer as described above. Suitably

thermoplastic rubbers include, for example, SANTOPRENE (ExxonMobile Chemical Co., Houston, TX) and KRATON Thermoplastic Rubber (Kraton Polymers U.S. LLC, Houston, TX)

In other embodiments, the non-softenable material can include a thermoplastic polyurethane having a relative high melt point (e.g., greater than 180°F) and a durometer at or above 90A and/or 40D. Thermoplastic polyurethanes suitable for use as the non- softenable material include, for example, certain TEXIN thermoplastic polyurethanes (Bayer AG, Leverkusen, Germany).

In still other embodiments, the non-softenable material can include a saturated elastomeric base styrenic (SEBS) such as, for example, UNISOFT (United Soft Plastics, Inc., Lawrenceville, GA). For any method disclosed herein that includes discrete steps, the steps may be conducted in any feasible order. And, as appropriate, any combination of two or more steps may be conducted simultaneously.

The complete disclosure of all patents, patent applications, and publications, and electronically available material cited herein are incorporated by reference in their entirety. In the event that any inconsistency exists between the disclosure of the present application and the disclosure(s) of any document incorporated herein by reference, the disclosure of the present application shall govern.

The foregoing detailed description, drawings, and examples have been given for clarity of understanding only and represent merely exemplary embodiments. Thus, no unnecessary limitations are to be understood from the description, drawings, and examples. The invention is not limited to the exact details shown and described, for variations obvious to one skilled in the art will be included within the invention defined by the claims.

Unless otherwise indicated, all numbers expressing quantities of components, molecular weights, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless otherwise indicated to the contrary, the numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. All numerical values, however, inherently contain a range necessarily resulting from the standard deviation found in their respective testing measurements.

All headings are for the convenience of the reader and should not be used to limit the meaning of the text that follows the heading, unless so specified.