AU2003227280A1 - Clenching inhibitor mini-splint - Google Patents

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant: MYOHEALTH PTY LTD A.C.N. 101 099 692 Invention Title: CLENCHING INHIBITOR MINI-SPLINT The following statement is a full description of this invention, including the best method of performing it known to us: 2 CLENCHING INHIBITOR MINI-SPLINT The present invention relates generally to intra-oral devices, and in particular to improvements in or to new forms of intra-oral devices. In particular, the present invention relates to intra-oral devices that are designed to be worn by patients suffering from conditions which occur during sleep, such as for example, conditions associated with sleep disorders, sleep apnoea, snoring, bruxism or the like. Even more particularly, the present invention relates to an improved intra-oral device and to a method of using such intra-oral device which is of the type intended to be worn by a person whilst asleep, in which the device functions to inhibit the forces of bruxism, and hence reduce or eliminate potential damage to teeth caused as a result of voluntary or involuntary jaw clenching and grinding which occur whilst the person is asleep. The present invention finds particular application as an intra-oral device and a method of using such a device, in which the device is provided with a contact portion, such as for example, a protrusion, an inclined plane, platform, ramp or similar which is arranged for contact with opposed forwardly located teeth (anterior teeth) so as to prevent opposing more rearwardly located teeth (posterior teeth) from contacting each other during sleep. A particularly preferred form of the device has a generally arcuate body portion which cooperates with at least three or more forwardly located teeth, such as incisor teeth and/or canine teeth, to retain the device in place during use so that the contact portion is centrally located for contact with opposing forward teeth.

Although the present invention will be described with particular reference to one form of an intra-oral device having a contact portion in the form of a ramp or similar arrangement for keeping opposed rearwardly located teeth in spaced apart relationship from each other so as to prevent them from contacting one another to minimise the H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 3 chances of grinding them together, it is to be noted that the scope of the present invention is not restricted to the described embodiment, but rather the scope of the present invention is more extensive so as to include other forms of the intra-oral device, other arrangements of the contact portion, and the use of the various forms of the devices in a wide variety of situations for numerous purposes.

The habit of clenching the jaw and jaw muscles to bring the upper and lower teeth together and moving the teeth against each other in a grinding movement, known as bruxism, can present a serious dental health problem.

Such grinding and clenching of the teeth is often associated with stress, and it usually occurs at night whilst the patient is asleep. Often the patient is unaware of this condition or of the harm that it is causing until the damage is manifest. It is often only when the harm or damage becomes observable that the condition is diagnosed, which is often too late to remediate the damage. Grinding of the teeth results from a patient tightly clenching his or her jaw muscles, thereby forcing together the occlusal surfaces of the opposed upper and lower teeth, sometimes with considerable force. As well as the actual clenching action itself in which the opposed teeth are brought into contact with each other, the jaw muscles cause the upper and lower teeth to move laterally with respect to each other simultaneously while being forced into contact with each other, hence producing a grinding action in the teeth. Such grinding can, if unchecked, result in serious damage to the teeth of the patient, as well as compounding the harm caused by the clenching action. As an example, in the short term, constant grinding can wear enamel from tooth surfaces, particularly the crown or cusp of the tooth. In the long term, grinding can eventually wear through the enamel of the tooth and into the tooth pulp itself and/or through any previous restorations of the teeth, such as fillings, H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 4 crowns and the like, leading to irreparable damage and harm to the tooth and nerves as well as requiring further restorations. Furthermore, the clenched muscles, when chronic, can lead to the development of conditions such as temporo-mandibular joint disorder, myofacial pain, headaches, migraine and the like, resulting in permanent and/or temporary harm to the patient.

In the past, there have been known and used, a variety of different appliances or devices intended to be worn inside the mouth, such appliances or devices being referred to within the dental profession as "splints", or more correctly "occlusal splints". One commonly employed splint is, and has been, what is termed a flat plane full mouth occlusal splint. Such an appliance is intended to cover all of the teeth on either the upper or lower arch or jaw of the patient, hence the name full mouth, so that when in place, each and every tooth on the opposing arch to which the device is fitted comes into contact with the surface of the splint more or less simultaneously with all the other teeth as the jaws close, hence the term flat plane. Wearing such a flat plane full mouth splint has certainly resulted in benefits. However, the splints are only partially effective since there have also been shown to be certain problems and disadvantages associated with the use of such full mouth splints. By way of example only, whilst a full width splint serves to protect all of the teeth of the patient, in reality it is possible for the patient to continue to clench and grind on the splint, which gives rise to the onset of muscle pain and, in some scenarios, headaches of varying degrees of severity, caused by the clenching action and not by the grinding action. Although this type of splint to some extent protects teeth from grinding against each other, the full mouth type of splint still allows the patient to clench his or her teeth as hard and as intensely as they could when not wearing the splint, and accordingly such splints do not entirely inhibit the adverse effects of bruxism.

H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 5 Thus, whilst such full mouth splints minimise the adverse effects of grinding, they are poor at reducing the harm caused by clenching. Therefore, there is a need for a more effective splint that addresses the problems of both clenching and grinding.

Another problem associated with existing splints relates to the very size and bulk of such splints which are often intrusive for the patient by being uncomfortable and in some ways disfiguring to wear and to use. The end result of which is that many patients choose to discontinue use of such splints because to some extent the disadvantages of using the splints outweigh the advantages. Thus, there is a need for a less intrusive splint.

Another problem associated with existing splints relates to the clinical steps that a patient is required to undergo before a satisfactory splint can be obtained.

The successful fitting of previously available splints within the mouth of a patient is by the very nature of the fitting method time-consuming and necessitates the utilisation of a high level of skill on the part of the person fitting the splint, typically a dentist, which contributes to the high cost of such splints. Thus, there is a need for a splint that can be made more quickly, fitted more easily and is less expensive to produce and fit.

Experience has shown that, when opposing back teeth of a patient, as for example cuspids, bicuspids and molars, are able to make contact with the surface of a full mouth flat plane splint of the aforementioned type, intense maximal clenching forces can and do occur. It has been known for some time that there exists in the gum surrounding the incisor teeth receptors which function to open the mouth when any of the incisor teeth are subjected to clenching, or to any other forces for that matter, without the back teeth touching. Such a movement is termed a jaw opening reflex which when initiated results H:\mbourke\Keep\Speci\Myohe,1th Clenching Inhibitor Mini Spiint.doc 25/07/03 6 in an inhibitory effect on the clenching muscles themselves. Scientific studies have revealed that an intra-oral appliance which allows for contact with opposing incisors only can inhibit the forces of bruxism, and hence the deleterious effects associated therewith, by as much as This discovery gave rise to yet a further form of splint, which was designed to take advantage of this jaw opening reflex. This form of the splint covered the two front teeth of either the upper or lower arch only. Such a splint also included a projection which was so designed that only the opposing incisor teeth of the arch not fitted with the splint could come into contact with the projection with any movement of the jaws of the patient, the rear teeth being prevented from contacting each other.

Accordingly, a splint of this type having the projection was found to have an acceptable effect in reducing the forces of bruxism. However, traditionally such splints have been available to the dentist or like practitioner only in the form of a pre-fabricated multi-purpose onesize-fits-all shell which is intended for use with all patients, regardless of age, size of teeth or jaws, curvature of the mouth, teeth or jaws, and the like. In practice, the dentist or practitioner fitted the prefabricated splint around the patient's front teeth by adding a mix of a suitable cold-cure acrylic resin and allowing it to set hard. Trimming, contouring, polishing and adjustment together with final finishing to satisfy the particular requirements of any patient was then done by the dentist in the dentist's own surgery with the splint in place.

This form of splint has also been found to suffer from problems and disadvantages. Firstly, since the appliance is only intended to cover two of the front teeth of the patient, retention of the splint in place on the teeth can become a problem, with there being a real possibility of the splint becoming loose after a period of H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 -7use, particularly if there has been any wear of the splint where it contacts the teeth. Should the device or appliance becomes loose owing to its small size there is a chance that the patient could inadvertently or accidentally swallow or inhale the device, with the obvious dire consequences to the patient. Thus, there is a need for a splint that is more securely held in place against the teeth during use.

There is furthermore a concern in the dental profession that the use of a splint covering only two teeth is insufficient to adequately carry the load of the forces on the projection, particularly if the two teeth involved are heavily filled or restored, as can often be the case in people suffering from bruxism owing to previous damage caused by this condition. In a practical sense, over-loading of teeth in such a manner can damage the teeth themselves as well as surrounding support structures, such as gum and bone. Thus, there is a chance that when using such splints damaged teeth are susceptible to further damage.

Another problem of using such mass produced prefabricated multi-purpose one-size-fits-all shells to produce splints relates to the creation of such splints in a dental surgery by the dentist. In such circumstances, there is no guarantee that the relevant dentist or fitter has the necessary time or expertise to produce a completed splint of suitable quality and durability with the required degree of accuracy, especially when compared to equivalent splints which could be manufactured by a dental technician working in the improved conditions of a dental laboratory or similar.

Also, when the dentist is making the splint, there also exists the possibility of the cold-cure material from which the splint and optionally the projection is made, setting too hard during the creation of the splint, thereby preventing ready removal of the splint from the mouth. This is very distressing for patient and dentist H:\mbourke\Keep\Speci\Myohealth -Clenching Inhibitor Mini Splint.doc 25/07/03 8 alike, since such an appliance would then need to be carefully cut out from around the tooth, a time-consuming and potentially painful exercise, which could result in injury to the patient and which also results in destruction of the appliance itself, for which it is unlikely that the dentist could recover costs. Thus, there is a need for an improved intra-oral device and method of making the device that can be made more efficiently and effectively in a dental laboratory or similar.

The present invention seeks to overcome the problems and disadvantages associated with prior art splints by providing an improved form of intra-oral splint which provides improved protection to the teeth of the wearer/patient against bruxism, is of a sufficient size to avoid the possibility of swallowing and aspiration, which is more securely retained in place in contact with the teeth in use, which can be made more inexpensively, and which can be more or less custom manufactured in a dental laboratory or the like, as distinct from being created insitu on a patient, with far less clinical time involved, and a resultant better finish.

In accordance with one aspect of the present invention, there is provided an intra-oral device for the prevention of grinding and/or clenching of the teeth of a person in order to reduce the forces and effects of bruxism, said device including: a main body portion which is adapted, in use, to have disposed therewithin at least three of the more forwardly located teeth of the upper or lower arch of the patient; and an anterior contact portion disposed substantially centrally of said main body and constructed and arranged so that at least one of the opposing more forwardly located teeth of the patient contacts the contact portion during any movement of the jaws of the patient.

H:\mbourke\Keep\Speci\yohealth Clenching Inhibitor Mini Splint.doc 25/07/03 9 In accordance with a further aspect of the invention, there is provided a method of manufacture of an intra-oral device of the type referred to in the preceding paragraph, such method including: forming an impression of the teeth or jaw of a patient; creating in a laboratory or the like the said intra-oral device using different non-toxic materials to form a hard outer shell thereof, a malleable yet settable internal liner or layer to be in contact with the teeth of the user in use of the device, and an anterior contact portion associated therewith, wherein the anterior contact portion is arranged so that only one or more opposing incisor teeth of the patient can come into contact therewith during any movement of the jaw of the patient to inhibit the forces and effects of bruxism.

According to one aspect of the present invention, there is provided a custom made intra-oral discluder device for the treatment of a person suffering from a condition requiring amelioration by wearing the device, said device comprising: a body of a first material generally conformed to a shape including the device to be worn within the mouth of the person being treated; a layer of a second material located on one side of the body for closely conforming to the shape of the teeth of the person so as to facilitate retention of the device in the mouth of the person when located in place within the mouth during use of the device, said first material being different from said second material; and a contact portion attached to the body on the side opposite to the side having the layer of relatively hard material, wherein the size and/or shape and/or position of the contact portion is determined by the shape of the mouth and/or teeth of the person, taking into account the H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 10 relationship between the opposing upper and lower teeth, in order to prevent contact between opposing upper and lower teeth, thereby ameliorating the condition.

According to another aspect of the present invention, there is provided a custom made intra-oral device for the treatment of a person suffering from a condition requiring amelioration by wearing the device, said device comprising: a generally arcuate tray made from a relatively harder material forming a body of the device, said arcuate tray being generally conformed to the general arrangement of the teeth of the person; a layer of relatively softer material located within the arcuate tray closely conformed to the arrangement of the teeth so as to retain the device in the mouth during use; and a selectively adjustable contact portion made from the relatively harder material, attached to the outside surface of the tray, wherein the size, shape and position of the contact portion is determined by the relationship between the upper and lower teeth so as in use to prevent contact between opposing upper and lower teeth, thereby ameliorating the condition.

Typically, the contact portion has a contact surface.

More typically, the contact surface is linear, planar, smooth, continuous, tapered or the like, being located within a single plane. Even more typically, the plane is an oblique plane, an inclined plane, a tapered plane.

Typically, the end or ends, preferably both ends, of the contact portion are rounded, smooth, curved, dome-like or the like. More typically, the side or sides, preferably both sides, are rounded, smooth, curved, domelike or the like. Even more typically, the sides and/or ends of the contact portion smoothly merge or transit into the contact surface.

H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 11 Typically, the contact portion is a boss, bump, protrusion, platform, ramp, wedge, pyramidal prism, bulge or similar. More typically, the surface of the protrusion etc, is inclined to the front and/or rear of the device.

More typically, the ramp is angularly inclined. Even more typically, the surface of the ramp is tapered from one end to the other. Even more typically, the front end of the ramp is located at a lower level to the rear end of ramp, and the ramp slopes downwardly from the rear to the front end. Even more typically, the ramp is shaped so that the incisor teeth contact the ramp before the rear teeth contact opposing rear teeth. Even more typically, one, two, three, four, five, six or more incisor/canine teeth contact the ramp or ramp surface, preferably, three or more incisor/canine teeth.

Typically, the forwardly located teeth are anterior teeth. More typically, the anterior teeth are incisor and/or canine teeth. Even more typically, the splint is fitted over at least three anterior teeth, preferably at least four teeth, more preferably at least five teeth and most preferably, at least six teeth, being all of the incisor teeth the first pair of canine teeth.

In order that the invention may be more clearly understood and put into practical effect, reference will now be made to one preferred embodiment of an intra-oral device or appliance in accordance with the present invention. The ensuing description is given by way of non-limiting example only and is with reference to the accompanying drawings, wherein: Figure 1 is a top perspective view of one form of the intra-oral device in accordance with the invention; Figure 2 is a vertical section of the device of Figure 1, taken along the line 2 to 2 of Figure 1; Figure 3 is an in-situ side view of the mouth (jaw) of a patient having an intra-oral device of the type shown in Figure 1 in position on the upper teeth (jaw) of the H: \mbourke\KeepNSpeci\Myoheah Clenching Inhibitor Mini Splint.doc 25/07/03 12 patient with the lower incisor teeth in contact with the inclined ramp surface; and Figure 4 is a frontal view of the arrangement of Figure 3.

Turning now to the drawings, a device in accordance with the present invention, generally denoted as includes an arcuate main body, generally denoted as 1, which is adapted in use to be disposed over a number of incisor teeth 2 of either the upper arch or lower arch of the mouth of a patient. In one embodiment, the device contacts at least 3 upper incisor/canine teeth 2 or at least three lower incisor/canine teeth. In another embodiment, the device cooperates with at least six of the front or incisor/canine teeth 2 of a patient, as is illustrated in Figure 4. It is to be noted that the device 2 can receive any number of forwardly located teeth from three to six, such as the incisor teeth and/or canine teeth. Preferably, the device is configured to contact the upper incisor and/or canine teeth of the mouth, ie., the six most forwardly located upper teeth or anterior teeth. The main body 1 is preferably made from a plastics material or a combination of plastics material having different properties. Main body 1 is provided with a hard outer shell 3, in the form of a tray or similar, and an internal liner or layer 4, made of different material from each other, in which the inner layer 4 is located with the tray-like shape of outer shell 3. The hard outer shell 3 may be formed from any suitable non-toxic plastics material, as for example a polymeric material, typically an acrylate or methacrylate, homopolymer or copolymer.

The internal layer or lining 4, on the other hand, is preferably formed from any suitable thermoplastics material, and in an especially preferred embodiment, is formed from a material known as thermacryl, which is a polyester resin of any suitable type, typically in combination with an acrylic material. It is to be noted that the inner layer 4 is readily mouldable to the shape H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 13 of the teeth, particularly when warmed or heated. Such material, whilst still relatively hard and hence load and impact resistance, softens in hot water or the like. The utilisation of such thermoplastics material means that, when softened and the overall intra-oral device is first positioned in the mouth of the patient, it in effect adapts itself to or molds itself to the form of the teeth, thereby ensuring proper fit of the overall device. After immersion in hot water and initial softening and placement of the device in the mouth, the thermoplastics material re-hardens or sets on cooling. Such allows the dentist, and the patient, to have total control over both the degree of retention of the overall device and the actual stability thereof when in place. As no cold-cure material is used, there is very little if any chance of the material of inner layer 4 permanently adhering to the teeth on setting.

The main body 1 has associated therewith, in effect molded thereto, a contact portion having a contact surface, such as for example, in the form of an anterior ramp 5. The ramp 5 is preferably formed from a suitable high impact acrylic material, thereby exhibiting resistance to the onset of fracture due to loading and other stresses. In an especially preferred embodiment, the ramp 5 is formed from a methyl methacrylate containing monomer/homopolymer/copolymer combination or the like.

Ramp 5 may be integrally formed with shell 2 or may be attached to shell 2 by any suitable fastening means, such as an adhesive, a glue or the like. If integrally formed, ramp 5 will require modification to some extent to form a customised shape. Typically, customising takes place in a dental laboratory or similar.

In one form, ramp 5 extends from beyond the front of body 1 so as to protrude from the front of body 1 and extends beyond the rear of body 1 to protrude from the rear of body 1 in order to provide an enlarged contact surface or area for the opposed incisor teeth. The H: \mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 14 surface of ramp 5 is planar, being substantially smooth and inclined so as to form a single surface inclined plane or a surface with a single profile or shape that extends continuously in the one plane from one end to the other end.

In operation of the device of the present invention, the device is fitted against the teeth centrally within the mouth and securely retained in place by receiving more than two incisor or forwardly located teeth therein. The device 10 is typically fitted to the upper front incisor and/or canine teeth, preferably the central six anterior teeth. As a person clenches their jaws, the lower front incisor teeth contact the ramp 5 before the opposing rear teeth contact each other, thus promoting the jaw-opening reflex which inhibits the clenching of the jaws and prevents the posterior teeth from grinding against each other since the jaw involuntarily opens before the rear teeth have a chance to contact each other.

It is to be noted that the intra-oral device in accordance with the present invention can adopt many different forms and be used in a variety of different contexts, such as for example: To protect the teeth of the user and any restorations thereof, such as for example, fillings, crowns or the like, from wear and fracture during sleep or at other times; To assist in recovery from temporo-mandibular joint disorders and facial pain of the type often related to or with muscular dysfunction; and/or' To minimise and even prevent headaches, migraines and like conditions.

The intra-oral device in accordance with the present invention exhibits a number of significant advantages over known and presently in use splints.

Firstly, such device is manufactured, in effect custom made, in a laboratory by a qualified skilled dental H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 15 technician, using models or molds of the individual patient's teeth as taken by the dentist. When compared with prior art arrangements, which required creation or formation in the dental surgery, by the dentist, directly in the mouth of the patient, the practical and economic advantages of the device of the present invention are self-evident since the splint can be made more inexpensively than splints made by the dentist or in the dental surgery, and with less pain and discomfort to the patient as well as almost completely overcoming the possibility of the splint adhering to the teeth when curing during manufacture.

The materials and methods able to be employed in a laboratory give rise to an improved product, exhibiting a superior finish in terms of contours, such as conforming to the teeth/jaw of the patient, polish, ease of operation, fit or the like, ultimately being responsible for enhanced patient comfort. The better fitting, more comfortable and less obtrusive inta-oral device encourages the patient to persist in wearing thereof which reduces the adverse effects of bruxism.

Furthermore, the laboratory processes employed in manufacture afford improved durability and longevity to the end product, an important consideration bearing in mind the high costs of dental treatment and providing splints.

Secondly, and by reason of the fact that the main body of the intra-oral device covers at least six, and not just two, of the incisors/canines of the patient, then over-loading of the teeth covered thereby cannot occur.

This is in marked contrast to the prior art devices. The size of the device, and mode of creation thereof, also enhances retention and stability, as well as minimising the possibility of unwanted dislodgement, swallowing or aspiration.

H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 16 Thirdly, and by being custom made in a laboratory environment, all sizes and shapes of teeth and jaws of patients can be readily accommodated.

Furthermore, the very nature of the intra-oral device means that, again when compared with the prior art, minimal clinical time will be required for patient delivery. In a typical situation, a patient will attend a dental surgery to allow the dentist to take or make the necessary impression (for delivery to the laboratory).

Such can take perhaps about 5 minutes. Once the device is custom made by the laboratory and delivered to the dentist, a further visit by the patient for preliminary fitting and any subsequent adjustment will again occupy perhaps from 5 to 10 minutes.

Another advantage of the present invention is that the device is of a relatively larger size when compared to some of the small prior art devices so that there is little or no chance that the splint of the present invention can be swallowed or inhaled involuntarily or accidentally when the patient is asleep. This is a major advance over previously available similar devices.

It will be clearly understood that, although a number of prior art devices are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art, in Australia or in any other country.

For the purposes of this specification it will be clearly understood that the word "comprising" means "including but not limited to", and that the words "comprise" and "comprises" have a corresponding meaning.

H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03

Claims (23)

1. An intra-oral device for the prevention of grinding and/or clenching of teeth of a person to reduce the forces and/or effects of bruxism, said device comprising: a main body portion which is adapted, in use, to have disposed therewithin at least 3 of the more forwardly located teeth of either the upper or lower arch of the person; and a contact portion disposed substantially centrally of said main body and arranged so that at least one of the opposing more forwardly located teeth of the person contacts the contact portion during movement of the jaws of the patient.

2. A method of manufacture of an intra-oral device including: forming an impression of the teeth or jaw of a patient; creating in a laboratory or similar the intra- oral device using different non-toxic materials to form a hard outer shell, a malleable internal layer for contact with the teeth of the user in the use of the device, and a contact portion associated therewith, wherein the contact portion is arranged so that at least one of the opposing more forwardly located teeth of the patient contacts the contact portion during movement of the jaw of the patient to inhibit the forces and/or effects of bruxism.

3. A method or device according to any preceding claim, in which the contact portion is a protrusion having a contact surface.

4. A method or device according to any preceding claim, in which the protrusion is a ramp, platform, wedge, bulge, pyramidal prism or the like.

A method or device according to any preceding claim, in which the protrusion is an anterior ramp located H:\mbourke\Kee\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/0?/0 18 on the device to face towards the opposing teeth.

6. A method or device according to any preceding claim, in which the anterior ramp extends beyond the front face or end of the body portion.

7. A method or device according to any preceding claim, in which the anterior ramp extends beyond the rear face or end of the main body portion.

8. A method or device according to any preceding claim, in which the anterior ramp extends both beyond the front and beyond the rear of the main body portion.

9. A method or device according to any preceding claim, in which the surface of the ramp is linear, planar, smooth or continuous.

A method or device according to any preceding claim, in which the surface of the ramp is located within a single plane.

11. A method or device according to any preceding claim, in which the plane is an oblique plane, an inclined plane, a tapered plane or the like.

12. A method or device according to any preceding claim, in which the surface of the ramp is inclined to the front or to the rear of the device.

.13. A method or device according to any preceding claim, in which the surface of the ramp is tapered from one end to the other, or inclined from one side to the other, or both.

14. A method or device according to any preceding claim, in which the front end of the ramp is located at a lower level to the rear end of the ramp, and the ramp slopes downwardly from the rear to the front end.

A method or device according to any preceding claim, in which the ramp is shaped so that the incisor/canine teeth contact the ramp before the rear teeth contact the opposing rear teeth.

16. A method or device according to any preceding claim, in which the more forwardly located teeth are anterior teeth. H;\mbourke\Keep\Spci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03 19

17. A method or device according to any preceding claim, in which the anterior teeth are incisors and/or canine teeth.

18. A method or device according to any preceding claim, in which the teeth are the two pairs of incisor teeth and the first pair of canine teeth.

19. A method or device according to any preceding claim, in which the device is adapted to receive therein or be cooperatively associated with at least four anterior teeth, preferably at least five anterior teeth, more preferably at least six anterior teeth.

A custom made intra-oral discluder device for the treatment of a person suffering from a condition requiring amelioration by wearing the device, said device comprising: a body of a first material generally conformed to a shape including the device to be worn within the mouth of the person being treated; a layer of a second material located on one side of the body for closely conforming to the shape of the teeth of the person so as to facilitate retention of the device in the mouth of the person when located in place within the mouth during use of the device, said first material being different from said second material; and a contact portion attached to the body on the side opposite to the side having the layer of relatively hard material, wherein the size and/or shape and/or position of the contact portion is determined by the shape of the mouth and/or teeth of the person, taking into account the relationship between the opposing upper and lower teeth, in order to prevent contact between opposing upper and lower teeth, thereby ameliorating the condition.

21. A custom made intra-oral device for the treatment of a person suffering from a condition requiring amelioration by wearing the device, said device comprising: H;\mbourke\Keep\Speci\Myohea1th C1enching Inhibitor Mini Splint.doc 25/07/03 20 a generally arcuate tray made from a relatively harder material forming a body of the device, said arcuate tray being generally conformed to the general arrangement of the teeth of the person; a layer of relatively softer material located within the arcuate tray closely conformed to the arrangement of the teeth so as to retain the device in the mouth during use; and a selectively adjustable contact portion made from the relatively harder material, attached to the outside surface of the tray, wherein the size, shape and position of the contact portion is determined by the relationship between the upper and lower teeth so as in use to prevent contact between opposing upper and lower teeth, thereby ameliorating the condition.

22. A method substantially as hereinbefore described with reference to the accompanying drawings.

23. An intra-oral device substantially as hereinbefore described with reference to the accompanying drawings. Dated this 25th day of July 2003 MYOHEALTH PTY LTD By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia H:\mbourke\Keep\Speci\Myohealth Clenching Inhibitor Mini Splint.doc 25/07/03