Prosthesis for alleviating TMJ discomfort

A prosthesis for insertion in an ear to reduce pain resulting from TMJ disorders. The ear insert conforms to the shape of the ear canal when the jaw is in an open position. The ear insert supports the TMJ and associated secondary musculature to reduce strain in the TMJ area, including the muscles, ligaments, nerves, and the temporo-mandibular joint itself. The insert is hollow on the inside to permit hearing and is made of a rigid material which retains the shape of the ear canal. A method for forming the ear insert includes forming a mold of the ear canal when the jaw is in the open position. The mold is then used to form the ear insert.

FIELD OF THE INVENTION 
The present invention generally relates to medical devices and, more 
particularly relates to devices for relieving temporo-mandibular joint 
discomfort. 
BACKGROUND OF THE INVENTION 
Many people suffer from pain in a joint located between the skull and the 
jaw. The joint is formed between the temporal bone of the skull and the 
mandible, and is commonly known as the temporo-mandibular joint or "TMJ". 
The human body actually 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 even swallows. 
In greater detail, the TMJ is a paired joint articulating the mandibular 
condyle, articulator disc, and squamous portion of the temporal bone, and 
is capable of 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 disc to the condyle, permitting rotational movement 
of the disc during mouth opening and closure. Each TMJ has an articulator 
disc of primarily cartilage material located between the condyle area and 
the temporal bone. The disc moves within the joint during opening and 
closure of the jaw and, when displaced, strains the jaw muscles and causes 
muscle pain or fatigue around the jaw. In addition, 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. 
Unfortunately, conventional methods of treating temporo-mandibular joint 
disorders can be costly, physically cumbersome, or involve invasive and 
irreversible treatment. 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. 
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. 
SUMMARY OF THE INVENTION 
In view of the foregoing, it is a general aim of the present invention to 
provide a device for alleviating TMJ discomfort which is easy to use, 
inexpensive, and relatively non-invasive. 
In that regard, an object of the present invention is to provide a device 
for treating TMJ disorders 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 the temporal bone and the mandible, 
as well as supportive muscles and ligaments near the TMJ. 
More specifically, it is an object of the present invention to provide an 
ear insert which supports the TMJ structure to reduce loads and stresses 
associated with the masticatory musculature, the temporo-mandibular joint, 
and associated structures, thereby reducing TMJ discomfort. 
It is also an object of the present invention to provide a method for 
forming a prosthesis so that the prosthesis fits in an ear canal and 
relieves TMJ discomfort. 
It is, therefore, a feature of the present invention to provide an ear 
insert made of relatively rigid material shaped for insertion in the ear 
canal of a patient to a certain depth. The ear insert is formed to closely 
conform to the shape of the ear canal when the jaw is in an unoccluded or 
open position. When the device is placed in each ear and the jaw is 
subsequently closed, the ear insert influences the positioning of the jaw 
in relation to the temporal bone to thereby relieve strain on the TMJ. 
It is also a feature of the present invention to provide a method for 
forming an ear insert having the proper anatomical shape. Mold material is 
injected into an ear canal when the TMJ is in an unoccluded position. An 
ear insert formed from the impression, when inserted in the ear canal, 
reshapes the ear canal to correspond to the ear canal contour associated 
with the unoccluded TMJ position. 
These and other objects and advantages of the invention will become more 
apparent from the following detailed description when taken in conjunction 
with the accompanying drawings.

While the invention is susceptible of 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 invention as defined by the appended 
claims. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
For purpose of illustration, the invention is shown in FIG. 1 as embodied 
in a prosthesis 10 adapted for insertion into, and to generally correspond 
to the shape of, an ear canal 12. In practicing the invention, the ear 
insert 10 influences the relationship between the temporal bone 14 and the 
mandible 16 in each temporo-mandibular joint 18, thereby relieving pain 
inducing stress in the TMJ and related muscles, ligaments, and nerves, as 
will be described with further detail herein. 
One source of TMJ discomfort is a dislocated disc 20. As shown in FIG. 3, 
when the jaw or mandible 16 is in an open or unoccluded position, the disc 
20 is usually in a normal, unstrained position between the temporal bone 
14 and a condyle surface 17 of the mandible. As is often the case with a 
person experiencing TMJ discomfort, the disc 20 slips to a displaced 
position when the mandible 16 is subsequently closed, as illustrated in 
FIG. 4. The displacement of the disc 20 is often indicated by a clicking 
or popping noise as the jaw 16 moves between open and closed positions. In 
the displaced position, the disc is no longer between the condyle surface 
17 and the temporal bone 14, and the disc 20 and ligaments attached to the 
disc become strained. Strain on these members stresses the surrounding 
muscles, which may ultimately result in face, neck, and back pain. 
To treat TMJ discomfort arising from a displaced disc 20, and in accordance 
with the present invention, the intra-aural prosthesis 10 is provided for 
reducing stresses and loads on the disc 20. The ear insert 10 reshapes the 
ear canal and provides a rigid structure which helps align the TMJ 18 and 
associated muscle and ligament structures so that the TMJ has normal 
rotational movement between the condyle surface 17 and inferior surface of 
the articulator disc 20. Strain or compression on the disc 20 is therefore 
reduced, thereby alleviating pain in the TMJ and associated structures. 
It should be noted that a dislocated disc is only one cause of TMJ 
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 TMJ, and improper loading, strain, or alignment of 
these members provide potential sources of TMJ pain. Rather than being 
limited to disc dislocation situations, as outlined above, the present 
invention addresses misalignment and stress in the TMJ and related 
structures by supporting these structures for normal rotational movement 
between the condyle 17 and disc 20. 
Turning to the structure of the ear insert 10, it will be appreciated that 
the insert conforms to the contours of an ear canal 12 (FIG. 2). The ear 
canal 12 forms a generally cylindrical path leading to the tympanic 
membrane 21. A bend in the ear canal known as the isthmus 22 is located 
approximately 20-23 millimeters from the outside of an adult ear, and is 
located in close proximity to the TMJ 18. As shown in FIG. 1, the ear 
insert 10 has an outside surface 28 molded to conform to the ear canal 12. 
The ear insert 10 has a generally cylindrical inner core 29. The outside 
surface 28 is shaped to engage the surface of the ear canal 12. The 
specific diameter of the ear insert 10 depends on the precise size of the 
patient's ear canal, but is generally ranges around 7-9 millimeters. The 
insert 10 is preferably 20-22 millimeters long so that it engages the 
isthmus 22 of the ear canal. 
As best shown in FIGS. 1 and 2, the ear insert 10 preferably has a hollow 
center 32 which allows the patient to hear while wearing the ear inserts 
10. In an alternative embodiment, ear insert 10 need not be completely 
hollow, but could be formed from a sufficiently acoustically conductive 
material which enables the patient to hear. In still another embodiment, 
for example an ear insert for use at night while sleeping, it is desirable 
to reduce the amount of noise which the patient can hear. In this 
embodiment, the ear insert 10 has a solid construction formed of material 
which absorbs or otherwise reduces audible noise levels. 
The ear insert 10 is made from moldable material which cures to form a 
rigid structure. In the preferred embodiment, the ear insert 10 is made of 
two layers. The first or interior surface 40 is made of hard material such 
as clear acrylic, while the second or exterior surface 42 is made of 
relatively soft material such as PVC or silicone, as shown in FIG. 1. It 
will be appreciated that in the two-layer ear insert 10, the interior 
surface 40 maintains the shape of the ear canal 12 while the exterior 
surface 42 improves the comfort of the insert. In an alternative 
embodiment, the ear insert 10 comprises a single layer of rigid yet 
comfortable material such as hard acrylic. 
In accordance with a significant aspect of the present invention, the ear 
insert 10 conforms to the shape of the ear canal 12 when the mandible 16 
is in the unoccluded position. In order to accomplish this, the present 
invention further provides a novel method for fabricating the ear insert 
10. The method includes the step of forming a mold of the ear canal 12 
using one of two methods. The first method uses a powder and oil catalyst 
and the second method uses a silicone mixture to form a mold of the ear 
canal 12. Significantly, the ear canal impression is formed with the 
mandible 16 in an unoccluded position. The impression is then used to form 
the ear insert 10. It will therefore be appreciated that when placed 
inside the ear canal 12, the ear insert 10 manipulates the shape of the 
ear canal so that it corresponds to the ear canal shape associated with an 
open jaw. 
The required positioning of the jaw 16 for the above method can be carried 
out by simply placing an object between the teeth of a patient to space 
the jaw during the molding step. It has been found that a gap of about 
15-17 millimeters between upper and lower teeth of the patient is 
adequate. A simple tool for maintaining this gap is tongue depressor 
placed between the patient's teeth so that the width of the depressor is 
aligned vertically. It is to be understood, however, that a tongue 
depressor is but one example of such a span tool, and that a variety of 
other objects can be employed with similar efficacy. 
In an alternative embodiment, the ear insert 10 may be formed in standard 
sizes adapted for universal fit. In this embodiment, the ear insert 10 is 
generally cylindrical and has pre-determined contour, shape, and length 
for insertion into a typical ear. The ear insert 10 is pre-formed using 
conventional fabrication techniques rather than being formed from an ear 
mold. Accordingly, the ear insert 10 is sized to have a diameter in a 
typical range, such as 6-9 millimeters. The ear insert 10 also has a 
length adapted to reach the isthmus 22 of a typical ear, such as between 
20-22 millimeters. In addition, the ear insert 10 is shaped to match the 
typical contour of an ear canal 12. By forming the ear insert 10 according 
to the criteria listed above, the ear insert 10 is pre-fabricated, and 
does not require the formation and use of an ear mold to form the insert. 
This embodiment further contemplates providing a set of differently sized 
standard ear inserts, such as small, medium, and large. Each size is 
formed having a length, diameter, and shape which is adapted to engage the 
isthmus 22 of a typical ear of corresponding small, medium, or large size. 
Under this embodiment, the ear inserts 10 may be provided in 
pre-determined standard sizes. 
It will therefore be appreciated that the ear insert 10 of the present 
invention alleviates TMJ discomfort by supporting the TMJ 18 and 
associated muscles, nerves, and ligaments for proper rotation of the 
mandible between open and closed positions. Returning to the specific 
example of a dislocated disc, the normal and displaced positions of the 
disc 20 are illustrated in FIGS. 4 and 5, respectively. The ear insert 10 
is formed to correspond to the shape of the ear canal 12 when the jaw 16 
is unoccluded and the disc 20 is in the normal position. When the jaw 16 
is subsequently closed, the ear insert 10 maintains the positioning of the 
jaw so that the disc 20 is not displaced. Accordingly, the present 
invention advantageously utilizes a natural body orifice to reposition the 
mandible 16 without requiring surgery or other painful and invasive 
techniques. As noted above, the example of a dislocated disc is merely 
illustrative of a TMJ 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 TMJ. 
From the foregoing it will be appreciated that the present invention 
provides a prosthesis for treating TMJ discomfort. The prosthesis is in 
the form of an ear insert which is shaped to conform to the surface of an 
ear canal when the mandible is open. The ear insert is sufficiently long 
to engage the isthmus of the ear canal. The ear insert supports the TMJ 
for normal rotation between the mandible and the temporal bone to reduce 
strain (and discomfort caused by strain) in the TMJ and associated 
muscles, ligaments, and nerves.