Abstract:
A comfortable mouth guard for upper teeth of a wearer which does not interfere with ability to speak or breath is described wherein at least 70% of the lingual side of the anterior teeth are uncovered. In some embodiments soft inserts increase the thickness of the posterior portions, and in some embodiments a hard insert provides increased protection of the anterior teeth. The hard insert can be used in mouth guards whether or not they include the comfort feature.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to the field of mouth guards, especially mouth guards suited for athletic and other activities where protection of teeth is important. 
         [0002]    Conventional mouth guards are designed to fully cover a wearer&#39;s teeth with as much thickness as can be tolerated by the wearer. Some types of conventional mouth guards are designed to be worn on the upper teeth and to redistribute the impact associated with blows to the jaw, mouth, or chin. Such mouth guards are substantially U-shaped and are molded from a moldable plastic precursor, either by molding the precursor to an impression or by softening the precursor by preheating it and allowing the wearer to bite into the precursor to configure the mouth guard to the upper teeth. Such mouth guards include a channel defined by an interior side wall, an exterior side wall, and a bottom wall. 
         [0003]    Such conventional mouth guards are often uncomfortable and often interfere with speech of the wearer, thereby causing some wearers to remove the mouth guard often during use, for example at an athletic event. 
         [0004]    It is an object of the present invention to provide an improved, more comfortable mouth guard wherein the wearer&#39;s teeth are adequately protected but where interference with speech and breathing are minimized. 
         [0005]    Others have attempted to meet this objective but have failed in one way or another. For example, U.S. Pat. No. 6,092,524 to Brown, Sr., discloses a mouth guard which includes a front, or labial, wall having a bottom edge spaced a predetermined distance from the lower, or incisal edge of the anterior teeth whereby the lower, or incisal edge is free to engage a wearer&#39;s tongue during speech. 
         [0006]    The permanent teeth of most humans consist of 16 upper teeth in the upper jaw and 16 lower teeth in the lower jaw. In the Universal Numbering System as illustrated in  FIG. 8 , the upper teeth are numbered from 1 to 16 starting on the right side and the lower teeth are numbered 17 to 32 starting on the left side. The right and left central incisors are numbered 8 and 9, and the right and left lateral incisors are numbered 7 and 10. The bicuspids are numbered 6 and 11. The upper right set of posterior teeth, called 1 st  and 2 nd  bicuspids, and 1 st , 2 nd and 3 rd  molars, is numbered 1 to 5 and the upper left set of posterior teeth is numbered 12 to 16. The central and lateral incisors and cuspids are considered the anterior teeth. The anterior teeth each have an incisal edge, a labial side, and a lingual side, a labial gum line, and a lingual gum line. The posterior teeth each have a crown portion which terminates at a gum line. 
         [0007]    Mouth guards are conventionally formed by first obtaining an impression of the prospective wearer&#39;s dentition, i.e., a negative, and then making a cast or positive model of the dentition from the impression. Then a sheet of plastic such as ethylene vinyl acetate (EVA) is heated to soften it and is placed on the dentition of the model, after which a cylinder is applied over the plastic and compressed air is blown onto the plastic to “press” it and cool it. The resulting molded plastic is known as the first press, and this process is usually repeated with at least one subsequent sheet being pressed, the second sheet being known as the second press. The second press fuses with the first press and does not separate on cooling. 
       SUMMARY OF THE INVENTION 
       [0008]    The mouth guard of the invention is configured to fit on and protect the upper teeth of a wearer and comprises a left posterior portion and a right posterior portion, the left and right posterior portions molded to conform to and surround the left set and right set of posterior teeth, respectively, and a central portion shaped to overlay the anterior teeth. It has been discovered that it is crucial to wrap the bottom of the mouth guard around the incisal edge of the upper central and lateral incisors in order to protect that edge as well as to maintain comfort and hold the mouth guard in place so that the mouth guard covers between about 5% and 30% of the lingual side of the upper central and lateral incisors, leaving at least about 70% to 95% of the length of the upper central and lateral incisors between the incisal edge and the gum line uncovered. The cuspids are also partially exposed between the gum line and the incisal edge, but not necessarily be at least 70% as are the central and lateral incisors. 
         [0009]    In some embodiments the covered section of the central and lateral incisors does not exceed 20% if the distance from the incisal edge to the gum line and at least 80% of the distance from the gum line to the incisal edge of the central and lateral incisors is uncovered. 
         [0010]    In most cases the upper anterior teeth which are partially uncovered on the lingual side include both central incisors, and preferably also include the lateral incisors and canines. In some cases one or more incisors or canines are missing, in which case the mouth guard can be configured to fill in the gaps where teeth are missing. 
         [0011]    The mouth guard of the invention includes a portion which overlaps the incisal edge of the anterior teeth for protection from front impact as well as from impact from lower teeth which is of minimal thickness on the incisal edge. In some embodiments the thickness on the incisal edge is 3 to 8 mm before pressing or molding, and 30 to 50% less after pressing or molding. 
         [0012]    The exposure of the uncovered portion of the lingual side of the anterior teeth between the gum line and the mouth guard allows the wearer to speak without interference and also improves the comfort of the mouth guard. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a front view of a mouth guard according to the invention showing a model in phantom with the teeth indicated by their Universal Tooth Numbering System numbering. 
           [0014]      FIG. 2  is an underside view of a mouth guard according to the invention mounted on the model, showing the covered portion of the teeth in phantom. 
           [0015]      FIG. 3  is a cross-sectional view through III-III of  FIG. 2 . 
           [0016]      FIG. 4  is a cross-sectional view through IV-IV of  FIG. 2 . 
           [0017]      FIG. 5  is a perspective view of a mouth guard of the invention exploded from the model. 
           [0018]      FIG. 6  is a perspective view of a first press of a mouth guard with soft inserts placed on the posterior portions of the first press. 
           [0019]      FIG. 7  is a perspective view of the components of an embodiment of a mouth guard according to the invention being exploded from a model. 
           [0020]      FIG. 8  is a diagram of the Universal tooth numbering system entitled “Diagram of the Tooth Numbering System.” 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    Referring now to the drawings, and, more particularly, to  FIG. 1  thereof, a preferred embodiment of the present invention provides an improved mouth guard  17  illustrated on a upper jaw model  24  which includes teeth numbered 1 to 16, following the Universal Teeth Numbering System numbering scheme which is described in  FIG. 8 .  FIG. 1  is a view from the labial, or front, side of the mouth guard  17 , showing the teeth and model in phantom. The six anterior teeth, numbers 6 to 11, have incisal edges  19  which are covered by a portion  18  of the mouth guard. The labial sides of all of the teeth are covered by the mouth guard, from the top  20  to the incisal edge  19 . 
         [0022]    Referring to  FIG. 2  which illustrates an underside view of a mouth guard  17  according to the invention mounted on the model  24 , showing the covered portion of the teeth in phantom, posterior teeth, numbers 1-5 and 12-16, are completely covered by the mouth guard  17  in this embodiment. Anterior teeth  6 - 11  are covered  18  on the labial side and 70% uncovered on the lingual side, from the incisal edge up to cut line  40 . Portion  18  covers the incisal edge  19 . The posterior section of the lingual side  42  covers the posterior teeth 12-16 and 1-5. The labial side  48  of the posterior teeth is fully covered by the mouthguard. 
         [0023]      FIG. 3  illustrates a cross-sectional view through III-III of  FIG. 2 , wherein left central incisor  9  having incisal edge  19  is illustrated within the labial side  54  of the gum and lingual side  56  of the gum. The mouth guard  17  has a top  20  labial side, bottom  50  labial side, and bottom lingual side  52  which covers 30%, A, of the distance, B, between the gum line and the incisal edge of tooth  9  as well as teeth  7 ,  8 , and  10  (not shown in  FIG. 3 ). According to the invention, no more than 30% of distance B is covered by portion A, and preferably only 20% is covered. At a minimum, 5% of distance B must be covered. The lingual side of the mouth guard terminates at cut line  40 . The incisal edge  19  is covered by a portion  18  of the mouth guard  17 . 
         [0024]      FIG. 4  illustrates a cross-sectional view through IV-IV of  FIG. 2  showing left 1 st  molar  14  covered by mouth guard  17  with the labial side from top  20  to bottom  50  covering a portion of the labial side  54  of the gum and the entire lingual side  58  of the tooth and part of the lingual side  56  of the gum from the bottom  52  of the lingual side of the mouth guard  17  to the gum line  58 . The occlusal surface  30  of tooth  14  is also fully covered  18  by mouth guard  17 . 
         [0025]      FIG. 5  is a perspective view of a mouth guard  17  of the invention exploded from the model  24 , with portion  18  covering the incisal edge of the incisors terminating at a line  40  which is 30% of the distance between the incisal edge and the gum line. This embodiment was constructed by placing a molten sheet of EVA on the model  24  of a wearer&#39;s teeth and gums, applying compressed air to press and cool the molten sheet of EVA, cutting and trimming the pressed and cooled first sheet, illustrated as having fingers  31  (in phantom), placing a second molten sheet of EVA on the pressed and cooled first sheet, applying compressed air to the second sheet to press and cool the second sheet, and cutting and trimming the second sheet into the illustrated embodiment. 
         [0026]      FIG. 6  is a perspective view of a first press  32  illustrating the fingers  31  which are located between the posterior teeth of the model  24 . In the embodiment illustrated in this drawing, soft inserts  62  and  60  are placed on the posterior portions of the first press  32 . These soft inserts can be EVA and are placed before placing a molten second sheet of EVA over the entire mouth guard. 
         [0027]      FIG. 7  is a perspective view of the components of an embodiment of a mouth guard according to the invention being exploded from a model  24  to illustrate how this particular embodiment is constructed. First EVA sheet  24 , also known as the “first press, is placed on the model in molten state and is then pressed and cooled with compressed air, and then soft EVA inserts  62  and  60  are placed on the first sheet after it is pressed and cooled. Fingers  31  are formed on this first press. In this embodiment, hard insert  66 , which is a co-polyester material having a higher Tg than EVA approved for dental use and sold under the trademark Essix Ace plastic by Raintree Essix, Inc. 4001 Division St, Metairie, La. 70002, is placed on the anterior portion of the first press  32  and then the second sheet  64 , also known as the “second press,” is heated and placed on top of the hard insert  66 , soft inserts  62  and  60 , and first sheet  32 . Other higher Tg plastics than Essix Ace brand can be used in other embodiments. 
         [0028]    The resultant mouth guard has greater thickness above the posterior portions and has greater impact resistance for the anterior teeth than prior mouth guards, while at the same time providing improved comfort, improved protection, and less interference with speaking and breathing than prior mouth guards. 
         [0029]    In some embodiments, the hard insert  66  can be used in conventional mouth guards which do not include the comfort feature of the invention. 
         [0030]      FIG. 8  is a diagram of the Universal tooth numbering system entitled “Diagram of the Tooth Numbering System.” This numbering system is widely used and does not form part of the invention. 
         [0031]    The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While the invention has been depicted and described and is defined by reference to particular preferred embodiments of the invention, such references do not imply a limitation on the invention, and no such limitation is to be inferred. The invention is capable of considerable modification, alteration and equivalents in form and function, as will occur to those ordinarily skilled in the pertinent arts. The depicted and described preferred embodiments of the invention are exemplary only and are not exhaustive of the scope of the invention. Consequently, the invention is intended to be limited only by the spirit and scope of the appended claims, giving full cognizance to equivalents in all respects.