Abstract:
The oral appliance engages over the mandibular incisors and presents a flat raised upper contact surface which is sufficiently wide to contact at least part of one of the two upper center incisors and preferably both of them. This prevents tooth contact between the upper and lower dental arches to prevent grinding of the teeth. It prevents contact of the upper canine teeth with any teeth or the appliance so as to decrease the facial muscular tension which is sometimes associated with headaches and migraines. Application of the appliance to the lower dental arch is phonetically and aesthetically superior to other configurations and arrangements.

Description:
FIELD OF THE INVENTION 
     This oral appliance is a body, having a curved trough sized to fit over the lower anterior teeth, to protect the user&#39;s teeth in the event of the user&#39;s clenching and/or grinding of his teeth and to reduce facial muscle tension and tooth wear. 
     BACKGROUND OF THE INVENTION 
     Grinding and clenching of the teeth have been shown to increase under stress and by anticipation of stressful events. The increased pressure and lateral movement against tooth surfaces produce fractures and/or wearing down of teeth surfaces. 
     Grinding and clenching also cause increased tension and contraction of facial musculature. This can cause facial pain and can contribute to muscle tension headaches and migraines. Increased muscle tension and contraction cause fatigue, spasming and cramping of the facial muscles resulting in pain and limitation of motion of the mandible. Patients suffering from these symptoms are typically treated with a mouth appliance such as described by Norton in U.S. Pat. No. 4,671,766 and Sullivan in U.S. Pat. No. 4,519,386. 
     The appliances generally used are custom made by the dentist for covering the user&#39;s full upper or lower arches. Unfortunately, in most cases, full arch appliances still allow the grinding and clenching to exist on the appliance, without long lasting marked reduction in facial muscular tension and contractions. Other appliances as described by Hays in U.S. Pat. No. 5,277,203 and by Boyd, Sr., in U.S. Pat. No. 5,513,656 are used on the upper teeth. These upper appliances can allow for the opposing mandibular canine teeth to come in contact with the appliance. The contact of the opposing canine teeth with the appliance initiates increased facial muscular tension. 
     Most appliances are custom fabricated and fitted by a In dentist for the individual, usually at a prohibitive cost of hundreds to thousands of dollars. Other appliances can be ingested, inhaled or lost, thereby causing danger and cost to the user. 
     Therefore, there is a continuing need for simplifying and improving means and methods for the prevention of damage to teeth and in the reduction of facial muscular tension and contraction as it relates to facial pain, headaches, migraines and temporomandibular disorders. 
     SUMMARY OF THE INVENTION 
     In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to an oral appliance which is comprised of a body having a curved trough on the under side thereof for the placement therein of thermoplastic material for fitting onto the lower anterior teeth, i.e., the mandibular incisors. The body includes a flattened raised ramp extending anteriorly and posteriorly on the top of the appliance when the appliance is set over the lower incisors to prevent contact between the upper and lower posterior teeth and to prevent the opposing upper canine teeth from coming into contact with the lower teeth or with the appliance. The ramp is sufficiently wide to contact at least part of one of the two upper center incisors and preferably both of them. 
     It is thus a purpose and advantage of this invention to provide the user with a self-fitting, customized appliance for placement on the lower incisors without the need of seeing a dentist for fabrication, fitting and adjustments of the appliance. The placement of the oral appliance on the lower incisors is very much superior to placement on the upper arch. A phonetic advantage is achieved because placement of an appliance on the upper arch interferes with the tongue position during speaking while placement on the mandible incisors permits the user to speak more clearly. Similarly, the placement of the oral appliance on the mandible is aesthetically superior because it is less visible, being largely hidden behind the upper incisors and the lips. 
     It is another purpose and advantage of this invention to provide a prefabricated curved trough to correspond to the general curvature of the lower central and/or lateral incisors which is retained by a thermoplastic material within the trough. After heating and molding of the thermoplastic material, the appliance is placed over the lower incisor teeth. 
     It is a further purpose and advantage of this invention to provide a self-fitting customized appliance which has a flat, raised ramp parallel to the horizontal line of the bite which in allows the upper central incisor teeth to rest on this ramp, discluding the remaining posterior and canine teeth even when the mandible is moved in all excursions. 
     It is a further purpose and advantage of this invention to provide an oral appliance which has a hollow channel for a necklace line to be inserted to help prevent ingestion, inhalation and/or loss of the appliance. 
     It is a further purpose and advantage of this invention to provide an oral appliance which has a reservoir in its posterior extension which allows for a radio-opaque material to be placed within. This provides a radiographic means of location if ingested or inhaled. 
    
    
     The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description, taken in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the oral appliance of this invention as seen from an upper posterior position. 
     FIG. 2 is a perspective view of the oral appliance of this invention from a lower anterior view. 
     FIG. 3 is a side elevational view thereof. 
     FIG. 4 is a view from the posterior side. 
     FIG. 5 is a bottom view. 
     FIG. 6 is an elevational view from the anterior. 
     FIG. 7 is a central section through the appliance, enlarged as compared to FIG.  3 . 
     FIG. 8 is a section taken generally along line  8 — 8  of FIG.  7 . 
     FIG. 9 is a view similar to FIG. 7, showing thermoplastic material installed in the appliance and the lower anterior teeth about to make an impression therein. 
     FIG. 10 is a view similar to FIG. 9, showing the lower anterior teeth making the impression. 
     FIG. 11 is a view of the appliance similar to FIGS. 9 and 10, after the appliance is removed from the anterior teeth. 
     FIG. 12 is a bottom view of the appliance of FIG. 11, enlarged with respect to FIG.  5  and showing the dental impression of the lower incisors therein. 
     FIG. 13 is a section similar to FIG. 8, but showing the dental impression of the lower incisors in the thermoplastic material in the oral appliance. 
     FIG. 14 is a view of the anterior end thereof. 
     FIG. 15 is a plan view of the oral appliance as shown installed on the center mandibular incisors. 
     FIG. 16 is an anterior view thereof. 
     FIG. 17 is a lateral view thereof, showing engagement of the oral appliance on the mandibular incisors and the upper incisors in contact with the top surface ramp of the oral appliance. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The oral appliance of this invention is generally indicated at  10  in FIGS. 1-17. The oral appliance  10  protects the user&#39;s teeth from being fractured and from being worn down, because of clenching and grinding of the teeth. The oral appliance  10  also acts to decrease the facial muscular tension which can be partial causation for headaches and migraines. The oral appliance  10  is configured to prevent full closure of the mandible, thereby reducing pressure within the temporomandibular joints. The oral appliance  10  comprises anterior and posterior surfaces  12  and  14  which, together with top surface  16 , form a trough which is numerically identified at  18  in FIGS. 1,  3  and  7 . The trough  18  is formed in the body  20  of the oral appliance. The trough has a length which, when viewed posteriorly, is formed by the right end  22  and left end  24  of the body. As seen in FIG. 16, the length between the left and right ends is sufficient to substantially cover the four lower incisors, and not reach the lower canines  26  and  28 . The trough  18  is curved, especially the anterior surface  12 , see FIG. 5, to accommodate for the forward arch of the lower incisors, see FIG.  12 . The body can be made of synthetic polymer composition material. 
     The body  20  also carries an upper incisor contact surface  30  which is a flat ramp. The ramp lies generally in the tooth plane. The width of the anterior end of the ramp, “W” in FIG. 15, is illustrated as being substantially as wide as the two center upper incisors  32  and  34 , see FIG.  16 . However, the width W may be narrower so that only one of the upper incisors, and even only a part of one of the upper incisors, contacts the ramp  30 . The narrower ramp  30 ′ is indicated in broken lines and as having a width W′. The narrower contact may be particularly useful when the location, shape and/or size of the upper incisors are not uniform or symmetrical. However, contact with the two central upper incisors is preferred for optimally minimized stress concentration. 
     The body  20  is cut down to lower surfaces  36  and  38  beside the ramp  30 , see FIGS. 6,  8 ,  13 ,  14 ,  15 ,  16  and  17 , so that the upper canines  40  and  42  do not come into contact with the ramp  30  or other parts of the appliance  10 , upon lateral mandibular motion. Placement of the oral appliance  10  on the lower incisors prevents the upper canines from coming into contact with the appliance or other teeth. This freedom of the canines from contact tends to reduce facial muscular tension. Furthermore, as seen in FIG. 3, the height of the oral appliance, that is, the distance from the top  16  of the trough  18  to the upper contact surface  30 , is small compared to previous practice so that this decrease in opening between the upper and lower teeth does not initiate the increase of muscular tension associated with other appliances. The placement of the oral appliance on the lower incisors is very much superior to placement on the upper arch. A phonetic advantage is achieved because placement on the lower mandible creates less interference with tongue position during speaking so that the user can speak more clearly. Similarly, the placement of the oral appliance on the mandible is aesthetically superior because of its reduced visibility. 
     The oral appliance  10  is personally fitted to the user by the installation of a thermoplastic material  44  in the trough  18 , see FIGS. 9,  10 ,  11  and  12 . Before installation of the thermoplastic material, a radio-opaque member  46  is installed in the corresponding recess in the wall  14  which defines the posterior surface, see FIGS. 7,  9 ,  10  and  11 . The thermoplastic material  44  keeps the radio-opaque member  46  in place. The radio-opaque member can be a small steel ball, or the like. After the thermoplastic material  44  is installed, as seen in FIG. 9, the dental impression is made therein by means of the lower incisors  48 , see FIG.  10 . When the thermoplastic material is sufficiently hardened, the oral appliance with the molded thermoplastic material is removed from the teeth to leave a tooth impression  50 , see FIGS. 11,  12  and  13 . The oral appliance thus is fitted over the user&#39;s lower anterior incisors and is held in place by means of the personalized fit between the incisors and the tooth impression material. As also is apparent from FIGS. 10,  11  and  17 , the lower incisors extend only part way into the dental material so that they do not contact the bottom  16  of the trough  18  (see FIG.  7 ), thus assuring that the lower incisors do not contact the body  20  of the appliance. Once in place, the flat ramp surface  30 , which extends both anteriorly and posteriorly of the tooth arch, comes in contact with one or both of the center two upper incisors. This prevents the upper and lower back teeth from contacting the opposing back teeth when the mouth is closed. The oral appliance  10  prevents the upper canine teeth  40  and  42  from contacting any other teeth. 
     In addition, due to the width of the ramp  30  at the dental arch line being narrower then the body  20 , the appliance  10  prevents the upper canines  40  and  42  from contacting the appliance  10  even when the mandible moves from side to side. The appliance not only protects the teeth from contacting and damaging each other, but also reduces the tension and contraction of the facial muscles used in mastication. The flat ramp also allows the user to perform mandibular exercises, using the ramp as a guide. The ramp allows the mandible to be moved forward and backward and side to side without any inter-dentular interference. 
     The upper contact surface  30  extends both anteriorly and posteriorly with respect to the trough  18  so as to permit forward and backward mandibular motion. The anterior portion  52  and posterior portion  54  of the body  20 , as best seen in FIG. 3, respectively extend forwardly and rearwardly of the walls which define the trough  18 , to permit this motion. The anterior portion contains a hole  56  therethrough, through which can be positioned a necklace  58 , see FIG.  1 . The necklace can retain the oral appliance in convenient position when not in use, and can prevent swallowing of the oral appliance when it is in use. The radios-opaque member  46  permits determination of the location of the oral appliance by X-ray, should it be ingested or inhaled. The oral appliance  10  is to be removed by the user when eating or drinking. The appliance is to be used while sleeping. It is to be used during stressful and/or painful occasions during the day. It is also to be used throughout the day as a guide for therapeutic motion exercises that can be performed using the horizontal flat ramp  30  as a guide for these exercise movements of the mandible as the mandible moves anteriorly and posteriorly and side-to-side. 
     This invention has been described in its presently contemplated best modes and it is clear that it is susceptible to numerous modifications, modes and embodiments within the ability of those skilled in the art and without the exercise of the inventive faculty. Accordingly, the scope of this invention is defined by the scope of the following claims.