Abstract:
An expansible ear canal insert for treating TMJ disorders and headaches which acts directly on the TMJ and associated ligament and muscle structures to reduce stress and loads placed on the articulator disc located between the temporal bone and the mandible, as well as supportive muscles and ligaments near the TMJ. The insert is adapted to expand by application of body heat. In the expanded condition, the insert provides support to the TMJ and associated ligament and muscle structures.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates generally to medical devices, and more particularly, to medical devices for alleviation of jaw discomfort and/or headaches. 
       BACKGROUND 
       [0002]    Many people suffer from pain in the joint located between the skull and the jaw. The joint is formed between the temporal bone of the skull and the mandible or jaw bone, and is commonly known as the temporo-mandibular joint or “TMJ”. The human body has two temporo-mandibular joints, one located on each side of the jaw in front of each ear. The TMJs move every time a person chews, talks, or swallows. 
         [0003]    In greater detail, the TMJ is a paired joint articulating the mandibular condyle, articulator disc, and squamous portion of the temporal bone. The TMJ is capable of both glide and hinge movements. Specifically, the TMJ is formed by the mandibular condyle fitting into the mandibular fossa of the temporal bone. A separation of these two bones is accomplished by the articulator disc which is composed of dense fibrous connective tissue. Ligaments attach the articulator disc to the condyle, permitting rotational movement of the articulator disc during mouth opening and closure. 
         [0004]    Displacement of the articulator disc introduces strain to the jaw muscles and causes muscle pain or fatigue around the jaw. In addition, articulator disc displacement often causes a painful clicking in the TMJ during certain jaw movements as the disc moves between normal and displaced positions. A number of other symptoms may occur as a result of a strained disc, including TMJ lock, shoulder, neck, and back pain, and headaches. 
         [0005]    Conventional methods of treating temporo-mandibular joint disorders can be costly, physically cumbersome, involve invasive and irreversible treatment or be time consuming. Some conservative methods for treating TMJ discomfort include the use of an intra-oral splint, medication, and life style changes. One type of intra-oral splint is a stabilization apparatus which is used to help alter the posture of the mandible to a more open, relaxed, resting position. Another type of intra-oral splint is an anterior positioning apparatus. The anterior positioning apparatus attempts to decrease the compression load on the joint and alter the structural condyle disc relation. Both types of splints, however, cannot be used full time without risking displacement of teeth. Treatment by medication often involves the use of addictive drugs and/or anti-depressants and therefore can lead to misuse and abuse. In addition, medications often produce adverse side effects in the patient. Other conservative methods include chiropractic or physical therapy. Unfortunately, these methods require extensive time commitments and physical exertion by the patient. 
         [0006]    More aggressive treatment of TMJ discomfort includes orthodontic treatment such as grinding down of teeth and various types of surgery. Orthodontic treatments, however, merely indirectly address TMJ pain by adjusting the dental articulation and overall bite of the patient. Furthermore, orthodontic approaches are invasive, irreversible, and expensive. 
         [0007]    An alternative procedure and related apparatus for treatment of TMJ discomfort are disclosed in U.S. Pat. No. 5,769,891, the contents of which are incorporated by reference herein in their entirety. According to the disclosure in U.S. Pat. No. 5,769,891, a prosthesis is provided for insertion into the ear canal. The prosthesis has a rigid structural portion of a shape conforming to the ear canal when the jaw is in an open position. The prosthesis provides added support to the TMJ and associated secondary musculature to reduce strain in the TMJ area. In practice, this prosthesis is inserted into the ear canal with the jaw in either the open or closed position. Support is provided when the jaw is closed as the internal diameter of the ear canal is reduced. Another apparatus for treatment of TMJ discomfort is disclosed in U.S. patent application Ser. No. 12/075,046 (incorporated by reference). This apparatus likewise uses a substantially rigid structure providing support to the TMJ and associated secondary musculature. 
         [0008]    Many people also suffer from severe headaches. In some instances, such headaches are related to defined TMJ disorders. In other cases, the headaches are not related to any discernable TMJ disorder. It has been found that the insertion of a substantially rigid prosthesis as disclosed in U.S. Pat. No. 5,769,891 and U.S. patent application Ser. No. 12/075,046 may provide relief for a sizeable percentage of people who suffer from headaches even where there is no discernable TMJ disorder. Without being limited to a specific theory, the present inventors believe that that support within the ear canal may reduce tension in surrounding muscles and ligaments, thereby relieving stress that may cause a tension headache. 
         [0009]    While the prior rigid devices are believed to provide substantial benefits, they have to be sized for individual users or classes of users. Thus, a structure that is substantially self-adjusting for users of different sizes would be desirable. 
       SUMMARY OF THE DISCLOSURE 
       [0010]    According to one aspect, the present disclosure provides an ear canal insert for treating TMJ disorders and/or headaches which acts directly on the TMJ and associated ligament and muscle structures to reduce stress and loads placed on the articulator disc located between the temporal bone and the mandible, as well as supportive muscles and ligaments near the TMJ. The insert includes an internal support and a deformable covering adapted to conform to the contours of the ear canal when the internal support and/or the deformable covering is expanded. In the expanded condition, the insert provides support to the TMJ and associated ligament and muscle structures. This support maintains the ear canal in an expanded circumferential condition generally approximating the ear canal when the jaw is open. 
         [0011]    According to another aspect, the present invention provides an ear canal insert for treating TMJ disorders. The insert includes a deformable, covering of heat expansible material. The covering expands when exposed to body heat to conform to the contours of the ear canal. In the expanded condition, the insert provides support to the TMJ and associated ligament and muscle structures. 
         [0012]    These and other aspects of the disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a cut-away view illustrating an exemplary insert for insertion into an ear canal for treatment of TMJ discomfort incorporating an expansible endoskeleton frame disposed in embedded relation within a deformable cover; 
           [0014]      FIG. 2  is a view illustrating insertion of the exemplary insert of  FIG. 1  into the ear canal of a user; 
           [0015]      FIG. 3  is a view similar to  FIG. 2  showing the exemplary insert in the ear canal with the endoskeleton frame in expanded condition; 
           [0016]      FIG. 4  is a side view of a TMJ in an unoccluded condition with the disc in the normal position; 
           [0017]      FIG. 5  is a side view of a TMJ showing the disc in a displaced orientation; 
           [0018]      FIG. 6  is a cut-away view illustrating another embodiment of an insert for insertion into an ear canal for treatment of TMJ discomfort incorporating an expansible endoskeleton frame disposed within a deformable cover with a solid wall hollow sound bore at the interior of the endoskeleton frame; and 
           [0019]      FIG. 7  is a view similar to  FIG. 6  illustrating another embodiment of an insert for insertion into an ear canal for treatment of TMJ discomfort incorporating an expansible cover with a solid wall hollow sound bore at the interior. 
       
    
    
       [0020]    While the concepts of the instant disclosure are susceptible to various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the disclosure as defined by the appended claims and all equivalents thereto. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0021]    Exemplary constructions and practices will now be described through reference to the drawings, wherein like elements are designated by like reference numerals in the various views. For purposes of illustration,  FIG. 1  illustrates a prosthesis  10  adapted for insertion into an ear canal  12  as shown generally at  FIGS. 2 and 3 . According to a contemplated practice, the prosthesis  10  includes a hollow deformable body  14  incorporating an interior sound transmission channel  16  extending in tunnel-like relation along the length of the prosthesis. 
         [0022]    In the illustrated exemplary construction the deformable body  14  has a generally sleeve-like configuration surrounding the sound transmission channel  16 . According to one contemplated arrangement, the deformable body  14  is formed from silicone rubber or the like although other shape-conforming materials may likewise be used if desired. As shown, in the exemplary construction an endoskeleton frame  20  is disposed in embedded relation within the deformable body  14 . The endoskeleton frame defines a support member within the deformable body  14 . By way of example only, and not limitation, such a structure may be achieved by positioning the endoskeleton frame  20  about a mandrel corresponding generally to the size and shape of the desired sound transmission channel  16  and then casting the silicone rubber or other material forming the deformable body  14  around the mandrel and the endoskeleton frame  20 . Once the silicone rubber or other material forming the deformable body  14  has cured, the formed sleeve structure with the embedded endoskeleton frame  20  can be pulled off of the shaping mandrel. This results in a hollow sleeve structure in which the endoskeleton frame  20  is embedded in the deformable body in surrounding relation to the open sound transmission channel  16 . 
         [0023]    According to one contemplated practice, the endoskeleton frame  20  is formed with an initial diameter which is compressible to assume a reduced size facilitating insertion into the ear canal  12 . As will be described further hereinafter, it may be desirable to carry out the insertion into the ear canal with the user&#39;s mouth open due to the expanded condition of the ear canal. However, insertion may also take place with the user&#39;s mouth in a closed condition if desired. As illustrated, the endoskeleton frame  20  may utilize a generally serpentine ring structure disposed in surrounding relation to the sound transmission channel  16 . As will be appreciated, such a structure may undergo substantial radial adjustment. However, it is likewise contemplated that any number of other configurations may be used if desired. By way of example only, and not limitation, various constructions for expansible endoskeletons are disclosed in US Patent Application 2007/0183613 in the name of Juneau et al. the teachings of which are incorporated herein by reference in their entirety. 
         [0024]    In accordance with one contemplated practice, the endoskeleton frame  20  may be formed from a so called “shape memory alloy” such as a nickel titanium alloy or the like. Such materials may have a relatively malleable character at typical room temperatures and take on a substantially more rigid state upon being subjected to elevated temperature conditions such as exist in the human body. Accordingly, in practice the endoskeleton frame  20  may be compressed by a user prior to insertion into an ear canal and thereafter be allowed to expand back to a pre-deformed shape after insertion into the ear canal as it is exposed to body heat. Moreover, in the elevated temperature state, the endoskeleton frame of shape memory alloy is characterized by enhanced rigidity due to a martensitic solid phase transformation at such temperatures. As will be described further hereinafter, such enhanced rigidity provides a desirable level of support to the prosthesis  10  within the ear canal  12 . 
         [0025]    While the use of a shape memory alloy may be desirable in some circumstances, it is likewise contemplated that other materials may be used which remain rigid at room temperature, but which nonetheless exhibit expansion at body temperature conditions. By way of example only, and not limitation, it is contemplated that one material that may be used in forming the endoskeleton frame  20  is a manganese/copper/nickel alloy or the like characterized by a relatively high coefficient of thermal expansion. By way of example only, one such material that may be used is a 72% manganese, 18% copper, 10% nickel alloy sold under the trade designation High Expansion 72 by Carpenter Technology having a place of business in Reading Pa. However, other alloys with relatively high coefficients of thermal expansion at body temperature conditions may also be used. 
         [0026]    It is also contemplated that naturally resilient materials which are readily compressible but which bias outwardly in a spring-like manner following compression may be used in forming the endoskeleton frame  20 . By way of example only, and not limitation, resilient polymers such as nylon and the like which are suitable for machining or other formation practices to provide a serpentine ring structure or other structure as may be desired may be particularly desirable. 
         [0027]    While the use of an expandable endoskeleton frame  20  with a resilient covering may be desirable for many applications, it is likewise contemplated that the covering itself may be substantially expandable upon application to body heat. This expansion may be in conjunction with corresponding expansion of an internal endoskeleton. Alternatively, expansion of the resilient covering may be substantially independent of any internal endoskeleton. In fact, it is contemplated that the internal endoskeleton may be eliminated entirely in some instances. 
         [0028]    By way of example only, and not limitation, it is contemplated that in one exemplary practice the deformable body  14  may be formed from an open cell foam such as a polyurethane foam or the like which has been loaded with plastic microspheres or other expansible fillers adapted to expand and contract in a substantially reversible manner upon application and removal of heat. When such an insert is inserted into the ear canal  12 , the expansible fillers expand thereby causing the foam to expand and take on a more rigid character. Upon removal from the ear canal  12 , the microspheres then contract back to the original state. As will be described further hereinafter, in the expanded state, the prosthesis will hold the ear canal in an open condition thereby providing support to the adjacent muscles and ligaments associated with the proximate temporo-mandibular joint 
         [0029]    It is also contemplated that the deformable body  14  may be formed from a foam material or the like characterized by a relatively high coefficient of thermal expansion at body temperatures such that the use of expansible fillers is not required. In this regard, body temperature sensitive foams or other materials which expand and take on enhanced rigidity may be particularly useful. 
         [0030]    Regardless of the specific configuration of the prosthesis that may be used, the prosthesis operates by expanding within the ear canal so as to hold the ear canal in an open condition similar to the condition the ear canal has with the mouth in an open condition prior to insertion. This support within the ear canal provides corresponding support to the proximately positioned TMJ.  FIG. 2  illustrates the insertion of a compressed prosthesis  10  into the ear canal  12  by a user.  FIG. 3  illustrates the prosthesis  10  within the ear canal after insertion with the deformable body  14  expanded at least partially back to its pre-deformed state as a result of exposure to body heat and/or due to natural resiliency. As will be appreciated, the expansion of the deformable body  14  causes the deformable body  14  to press outwardly into generally conforming relation relative to the walls of the ear canal  12 . In this state, the prosthesis  10  acts to hold the ear canal open. 
         [0031]    According to a potentially desirable practice, the length of the deformable body  14  is selected such that a distal end portion extends slightly past the bend in the ear canal known as the isthmus  22 . The isthmus  22  is in close proximity to the temporo-mandibular joint and is located approximately 20-22 millimeters from the outside of an adult ear. However, this distance may vary in different individuals. It is contemplated that using a deformable body having a length such that it extends substantially from the entrance to the ear canal into engagement with the isthmus facilitates providing desired support to the proximately positioned temporo-mandibular joint. 
         [0032]    As illustrated, it is contemplated that at least one anterior projecting retraction element  40  may extend away from the deformable body  14  so as to project towards the exterior of the ear. Following insertion, at least a portion of the retraction element  40  may reside outside of the ear canal  12 . In this position, a wearer may grasp the retraction element  40  to facilitate removal of the prosthesis  10 . 
         [0033]    The retraction element  40  is preferably substantially pliable to facilitate insertion and aid in removability while avoiding discomfort to the wearer. At the same time, the retraction element  40  should be characterized by sufficient strength to avoid breakage. By way of example only, and not limitation, it is contemplated that a suitable retraction element  40  may be formed from thermoplastic monofilament nylon adhesively bonded onto a surface of the endoskeleton frame  20  or a surface of the deformable body  14 . However, other suitable polymeric or non-polymeric materials may likewise be utilized if desired. The retraction element  40  may include a bulbous head portion  41 . Such a bulbous head portion  41  may enhance the ability of a wearer to grasp the retraction element  40  during removal of the prosthesis  10  from the ear canal  12 . In the event that the retraction element  40  is formed from nylon or other thermoplastic material, a suitable bulbous head portion  41  may be formed by selectively melting the terminal end of the retraction element  40  to form a melted polymer bead which is thereafter permitted to resolidify. The surface of the resolidified bead may thereafter be smoothed by sanding or other suitable treatment to remove irregularities so as to enhance comfort during use. 
         [0034]    Referring now to  FIGS. 4 and 5 , in the expanded condition the prosthesis  10  influences the relationship between the temporal bone  44  and the mandible  46  in each temporo-mandibular joint  48 , thereby relieving pain inducing stress in the temporo-mandibular joint  48  and related muscles, ligaments, and nerves. In this regard, it will be appreciated that one source of temporo-mandibular joint discomfort is a dislocated articulator disc  50 . As shown in  FIG. 4 , when the jaw or mandible  46  is in an open or unoccluded position corresponding to the mouth being open, the articulator disc  50  is usually in a normal, unstrained position between the temporal bone  44  and a condyle surface of the mandible  46 . As is often the case with a person experiencing temporo-mandibular joint discomfort, the articulator disc  50  slips to a displaced position when the mandible  46  is subsequently closed, as illustrated in  FIG. 5 . The displacement of the articulator disc  50  is often indicated by a clicking or popping noise as the mandible  46  moves between open and closed positions. In the displaced position, the articulator disc  50  is no longer between the condyle surface and the temporal bone  44 , and the articulator disc  50  and attached ligaments become strained. Strain on these members stresses the surrounding muscles, which may ultimately result in face, neck, and back pain. 
         [0035]    To treat temporo-mandibular joint discomfort arising from a displaced articulator disc  50 , the prosthesis  10  is provided for reducing stresses and loads on the articulator disc  50 . The prosthesis  10  reshapes and holds the ear canal in a condition substantially corresponding to the condition when the mouth is open thereby providing a support structure which helps align the temporo-mandibular joint  48  and associated muscles and ligament structures so that the temporo-mandibular joint  48  has a normal rotational movement. Strain or compression on the articulator disc  50  is therefore reduced, thereby alleviating pain in the temporo-mandibular joint and associated structures. It may be desirable for the user&#39;s mouth to be held in an open condition during insertion of the prosthesis  10  such that the expandable prosthesis naturally conforms with the naturally occurring expanded condition the ear canal has when the mouth is open. However, the prosthesis  10  may also be inserted with the mouth in a closed position followed by expansion of the prosthesis causing the ear canal to open more fully. 
         [0036]    It is to be understood a dislocated disc is only one cause of temporo-mandibular joint discomfort and that there are many other sources of such pain. Nerves, ligaments, and muscle groups (such as the masticatory musculature) are located proximal to the temporo-mandibular joint, and improper loading, strain, or alignment of these members provide potential sources of temporo-mandibular joint pain. Rather than being limited to disc dislocation situations, as outlined above, the prosthesis  10  addresses misalignment and stress in the temporo-mandibular joint and related structures by supporting these structures for normal rotational movement. 
         [0037]    The prosthesis  10  alleviates temporo-mandibular joint discomfort by supporting the temporo-mandibular joint  48  and associated muscles, nerves, and ligaments for proper rotation of the mandible between open and closed positions. By inserting the prosthesis  10  into the ear canal, the prosthesis will thereafter expand to urge the walls of the ear canal outwardly to take on the shape when the mandible  46  is open and disc  50  is in the normal position. That is, the ear canal  12  is expanded and held open as if the mandible  46  is open. In the expanded condition the sound transmission channel  16  is also held in an open condition such that hearing is not impaired. Thus, a natural body orifice is used to reposition the mandible  46  without requiring surgery or other painful and invasive techniques. 
         [0038]    As noted above, the example of a dislocated disc is merely illustrative of a temporo-mandibular joint condition addressed by the present device and is in no means meant to limit the scope of the present invention. Accordingly, it will be appreciated that the present device addresses stresses and misalignments in not only the disc but also any muscles, ligaments, and nerves associated with the temporo-mandibular joint. As noted previously, the reduction in strain to the muscles and ligament structures is also believed to be beneficial in reducing headaches. 
         [0039]    As will be appreciated, in the embodiment of  FIG. 1 , the expansion of the endoskeleton  20  acts to hold the sound transmission channel  16  in an open condition by virtue of spreading radially outwardly. The endoskeleton  20  also provides resistance against compression within the ear canal.  FIG. 6  illustrates an alternative embodiment wherein elements corresponding to those described previously are designated by like reference numerals within a  100  series. Specifically, in the embodiment of  FIG. 6 , the prosthesis  110  includes a substantially rigid hollow tube or sound bore  160  of a material such as acrylic or the like that extends along the length of the deformable body  114  at the interior of the endoskeleton frame  120 . In this construction, the interior of the hollow sound bore  160  defines the sound transmission channel  116 . The hollow sound bore  160  also provides an interior support for the endoskeleton frame to limit compression during insertion. The sound bore  160  may be contoured to conform generally with the curvatures of the ear canal. In this regard, shapes such as illustrated in U.S. Pat. No. 5,769,891 and U.S. patent application Ser. No. 12/075,046 may be particularly useful. 
         [0040]    In use, the rigid hollow sound bore  160  may aid in inserting the prosthesis  110  into the ear canal. Specifically, the rigid hollow sound bore  160  defines an additional support member providing a degree of axial rigidity even when the deformable body is in a substantially flexible state. Further, the solid wall construction of the sound bore aids in maintaining the sound transmission channel  116  in an open condition at all times. Thus, there is no interference with hearing during the period prior to expansion. 
         [0041]    The exemplary prosthesis  110  illustrated in  FIG. 6  also includes at least one anterior projecting retraction element  140  including a bulbous head portion  141  extending away from the deformable body  114  so as to project towards the exterior of the ear as previously described. The retraction element  140  may be adhesively bonded onto a surface of the endoskeleton frame  120 , a surface of the sound bore  160  or a surface of the deformable body  114 . 
         [0042]      FIG. 7  illustrates still another exemplary embodiment wherein elements corresponding to those described previously are designated by like reference numerals within a  200  series. In the embodiment of  FIG. 7 , the prosthesis  210  is devoid of an expanding endoskeleton frame. Rather, expansion is provided by the material forming the deformable body  214 . As noted previously, such material may include shape conforming temperature sensitive foams and the like which expand upon exposure to body heat. Such expansion causes the deformable body  214  to press outwardly on the walls of the ear canal thereby holding the ear canal open in a condition corresponding to the condition of the ear canal when the jaw is open. As shown, the exemplary prosthesis  210  includes a support member in the form of a substantially tubular sound bore  260  of solid wall construction formed from a material such as acrylic or the like that extends along the length of the deformable body  214 . In this construction, the interior of the hollow sound bore  260  defines the sound transmission channel  216 . 
         [0043]    In use, the rigid hollow sound bore  260  may aid in inserting the prosthesis  210  into the ear canal by providing a degree of axial rigidity even when the deformable body is in a substantially flexible state. Further, due to the solid wall construction of the sound bore, the sound transmission channel  216  remains open at all times. Thus, there is no interference with hearing once the deformable body  214  has expanded. The sound bore  260  may be contoured to conform generally with the curvatures of the ear canal. In this regard, shapes such as illustrated in U.S. Pat. No. 5,769,891 and U.S. patent application Ser. No. 12/075,046 may be particularly useful. 
         [0044]    The exemplary prosthesis  210  also includes at least one anterior projecting retraction element  240  including a bulbous head portion  241  extending away from the deformable body  214  so as to project towards the exterior of the ear as previously described. The retraction element  240  may be adhesively bonded onto a surface of the sound bore  260  or a surface of the deformable body  214 . 
         [0045]    It will be appreciated that the foregoing description provides examples of the disclosed apparatus and method of use. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to examples herein are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure or claims more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the claims entirely unless otherwise indicated. 
         [0046]    Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by the context. 
         [0047]    Accordingly, this disclosure contemplates the inclusion of all modifications and equivalents of the subject matter recited in the appended claims as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is contemplated unless otherwise indicated herein or otherwise clearly contradicted by the context.