AU2775302A - A dental appliance for reducing snoring and/or obstructive sleep apnea - Google Patents

Description

P/00/011 Regulation 3.2 1

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT oo. *O ooo o o o* oo Invention Title: A DENTAL APPLIANCE FOR REDUCING SNORING AND/OR OBSTRUCTIVE SLEEP APNEA Applicant: JOHN GUY ANGOVE The following statement is a full description of this invention, including the best method of performing it known to me: A DENTAL APPLIANCE FOR REDUCING SNORING AND/OR OBSTRUCTIVE SLEEP APNEA Field Of the Invention The present invention relates to a dental appliance of the type used to reduce snoring and/or obstructive sleep apnea.

Background of the Invention Snoring and obstructive sleep apnea are often the result of the complete or partial obstruction of an individual's pharyngeal airway during sleep. Typically, °""such airway obstruction is caused by the rear portion of the tongue or the soft palate contacting with the posterior pharyngeal wall.

It has been well documented that movement of the lower jaw forward relative to Sthe upper jaw can reduce and sometimes eliminate snoring and sleep apnea by causing the pharyngeal airway to remain open. In order to maintain the lower jaw in this anterior protruded position, dental appliances have been developed for use by a patient at night. However, such dental appliances suffer from a number of disadvantages, such as a lack of comfort, poor hygiene and undesirable movement of the teeth and supporting structures.

The present invention seeks to provide an improved dental appliance for reducing snoring and/or obstructive sleep apnea.

Summary of the Invention According to the present invention there is provided a dental appliance for reducing snoring and/or obstructive sleep apnea, said appliance including an upper dental plate and a lower dental plate, said upper and lower dental plates including a retaining portion and means for maintaining the lower jaw of a -3wearer in an anterior protruded position, and wherein the retaining portion of each of said upper and lower dental plates is of a composite construction including an inner layer arranged to be in contact with the wearer's teeth and an outer layer.

Preferably, the composite construction of the retaining portion of each of the upper and lower dental plates is such that it is sufficiently flexible to enable them to be fitted over the wearer's teeth and to be retained on the respective teeth due to engagement therewith or to engagement with soft tissue adjacent the wearer's teeth.

Preferably, the composite construction is also such that the upper and lower dental plates are of sufficient strength to adequately support the maintaining So...o means.

S S. The inner layer of the composite construction is preferably made of a soft material. The term "soft material" refers to a material which is suitable for use in the construction of a dental plate, is comfortable against the teeth and/or the soft tissue of the wearer, exhibits a degree of elasticity and is also preferably one that is considered safe to be in contact with the soft tissue. An example of a preferred material for the inner layer is a dental grade EVA (ethylene vinyl acetate) or polyurethane.

The outer layer is preferably made of a material which is harder than the material of the inner layer. An example of a preferred material for the outer layer is a dental grade polycarbonate material or copolymer.

The maintaining means preferably includes at least an upper bite block mounted on the upper dental plate and a lower bite block mounted on the lower dental plate. The bite blocks being configured during use of the appliance to hold the lower jaw in an anterior protruded position. Each of said bite blocks includes a ramp face, a release edge and an engaging surface. The ramp face -4of the bite block of the upper dental plate being arranged in use to engage against the ramp face of the bite block of the lower dental plate so as to retain said lower jaw in said anterior protruded position. The engaging surface of the bite block of the upper dental plate is located in use in contact with or substantially adjacent to the teeth of the lower jaw. The engaging surface of the bite block of the lower dental plate is located in use in contact with or substantially adjacent to the outer layer of the upper dental plate.

Preferably, the upper dental plate includes a pair of upper bite blocks and the lower dental plate includes a pair of lower bite blocks.

Each of the bite blocks are preferably made form a dental grade acrylic which can be chemically attached to the outer layer of the composite construction of the respective upper or lower dental plate.

:Preferably, the ramp face of each bite block is located in use substantially within the lingual space of the wearer's mouth. The ramp face of the lower bite block is located on the distal side of the bite block and preferably has its release edge located superior to the engaging surface of the lower bite block. The release edge of the upper bite block is preferably arranged in use to contact the teeth of the lower jaw.

Preferably, the ramp face of the upper bite block extends into the lingual aspect of the mouth in a superior direction approximately as far as the junction between the teeth of upper jaw and the soft tissue.

The substantially vertical distance between the release edges of the respective bite blocks in use the closed position) is substantially equivalent to the increased opening required between the upper and lower jaws to release the engagement between the ramp faces of the bite blocks so as to enable the lower jaw to return to its intended posterior position.

The dental appliance is preferably arranged so that once the dental plates are engaged limited vertical opening of the upper and lower jaws can occur whilst holding the lower jaw in the anterior protruded position. This limited vertical opening reduces the stress placed on the lower jaw and it associated structures (muscles, tendons, etc) and thus improves the comfort of the appliance. A preferred amount of vertical opening is about 2 5 mm.

The thickness of a spacing portion of each dental plate can be varied to change the spacing between the teeth of the upper and lower jaws when the appliance is in use.

The inner and outer layers of the composite construction of the upper and lower !'"'"dental plates preferably each have a thickness of about 1.5 mm.

S" 15 The spacing portion preferably has a thickness of about 5 mm.

:::The upper and lower dental plates preferably are formed so as to provide a high degree of occlusal coverage sufficient to evenly distribute pressure on the teeth.

Brief Description of the Drawings An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings.

Figure 1 is a side view of a dental appliance in accordance with an embodiment of the invention located within a wearer's mouth.

Figure 2 illustrates in partial cross-section the engagement of one of the bite blocks of the lower dental plate with the outer layer of the upper dental plate along the line A-A in Figure 1.

-6- Figure 3 illustrates in partial cross-section the engagement of one of the bite blocks of the upper dental plate with the teeth of the lower jaw along the line B- B in Figure 2.

Figure 4 is a cross-sectional view schematically illustrating the engagement of the ramp face of the bite block on the lower dental plate with the ramp face of the bite block on the upper dental plate.

Detailed Description of the Preferred Embodiment Figure 1 illustrates schematically a wearer's upper jaw 10 and lower jaw 12 as positioned when properly fitted with an appliance 20 in accordance with an :'"'"embodiment of the invention. The appliance 20 includes an upper dental plate 22 and a lower dental plate 24. The upper and lower dental plates 22, 24 are configured to fit over the wearer's teeth in a manner similar to a conventional mouth guard. Each of the upper and lower dental plates 22, 24 are configured so that there is sufficient occlusal coverage to minimize any pressure on the wearer's teeth or wearer's gum tissue during use.

As illustrated in Figure 1, the dental appliance 20 when properly positioned within a wearer's mouth locates the lower jaw 12 of the wearer in an anterior protruded position.

Each of the upper and lower dental plates 22, 24 includes a retaining portion 26 of the general form of a mouth guard on which is mounted a pair of bite blocks 28, 29. The bite blocks 28, 29 of each of the upper and lower dental plates 22, 24 are located at substantially opposite sides of the respective upper and lower dental plates 22, 24 in an area adjacent to the wearer's molars. ,Each of the upper and lower dental plates 22, 24 therefore has a left and a right side bite block 28, 29.

-7- To facilitate retention of the upper and lower dental plates 22, 24 about the wearer's teeth and to improve the wearer's degree of comfort, the retaining portion 26 is made of a composite construction. The composite construction includes an inner layer 30 which is arranged to be in contact with or substantially adjacent to the wearer's teeth and/or soft gum tissue and an outer layer 32.

The inner layer 30 of the composite construction is preferably made from a "soft" material. A "soft" material is a material which is suitable for use in the construction of dental plates, is comfortable against the teeth and/or the gum tissue of the wearer, exhibits a degree of elasticity, and is also preferably one that is considered safe to be in contact with the gum tissue. An example of i such a material is a dental grade EVA (ethylene vinyl acetate) or polyurethane.

S0 15 The outer layer 32 is preferably made of a material which is harder than the :material of the inner layer 30. An example of such a material is dental grade polycarbonate material or copolymer.

A retaining portion 26 having a composite construction of a soft inner layer and a hard outer layer 32 can be achieved using conventional dental appliance manufacturing techniques. Such techniques enable each of the upper and lower dental plates 22, 24 to be constructed specifically for a particular wearer so that they can be readily retained on the teeth of the wearer during use.

Once the retaining portion 26 of each of the upper and lower dental plates 22, 24 is constructed, the bite blocks 28, 29 can be attached. As is apparent from Figures 2 and 3, the bite blocks 28, 29 are attached to the outer layer 32 of the respective retaining portion 26 of the upper and lower dental plates 22, 24. The bite blocks 28, 29 are made from a dental grade acrylic which is chemically attached to the outer layer 32 of the respective upper and lower dental plates 22, 24.

-8- The pair of bite blocks 28 on the upper dental plate 22 have a different configuration to the pair of bite blocks 29 on the lower dental plate 24.

However, as illustrated in Figure 1, the bite blocks 28, 29 of the upper and lower dental plates 22, 24 are configured so that when the dental appliance 20 is in use, they engage together so as to maintain the lower jaw 12 of the wearer in an anterior protruded position. More particularly, the left and right side bite blocks 28 on the upper dental plate 22 engage with the corresponding left and right side bite blocks 29 on the lower dental plate 24, so as to force the lower jaw 12 forward to the anterior protruded position.

In order to locate the lower jaw 12 in the required anterior protruded position, o the wearer must first open their mouth a sufficient distance so that each of the upper and lower dental plates 22, 24 can be secured about the respective teeth.

0000° This opening distance is relatively large because of the size of the bite blocks 15 28, 29 and their initial engagement. When the wearer subsequently moves their :lower jaw 12 forward a predetermined distance, a clearance between the bite blocks 28, 29 on the upper and lower dental plates 22, 24 is achieved. This clearance is sufficient to allow the upper and lower jaws to move together loll.

thereby decreasing the opening distance. This position of the jaws is the in-use position. In the in-use position, as shown in Figure 1, there is a pre-determined spacing 40 between the outer layers 32 of the retaining portions 26 of the upper and lower dental plates 22, 24. This spacing 40 is sufficient to enable air to flow into the mouth and to prevent discomfort to the wearer because of an unnatural opening space between the upper and lower jaws 10, 12. As will be explained in more detail subsequently, the upper and lower jaws 10, 12 will be retained in the position shown in Figure 1 during sleep.

Figure 2 illustrates the configuration of the right side bite block 29 of the lower dental plate 24 of the appliance 20. This Figure also illustrates in more detail the nature of the engagement between the retaining portion 26 of the lower dental plate 24 against the teeth of the lower jaw 12 and the adjacent gum tissue. As explained previously, the retaining portion 26 has a composite -9construction that includes the inner layer 30 and the outer layer 32. The bite block 29 is chemically attached to the outer layer 32 so that in the area of the lower dental plate 24 where the bite block 29 is secured, the lower dental plate 24 has a three component construction the inner layer 30, outer layer 32 and bite block 29). In other areas of the lower dental plate 24 the construction is two components the inner layer 30 and outer layer 32).

The lower dental plate 24 has an inner side lower edge 50 and an outer side lower edge 52. As illustrated in Figure 2, the inner side lower edge 50 is located inferior to the junction between the teeth of the lower jaw 12 and the soft tissue. The outer side lower edge 52 of the lower dental plate 24 finishes substantially adjacent to the junction between the teeth and the soft tissue. The relative positionings of the lower edges 50, 52 of the lower dental plate 24 is such as to ensure proper retention of the retaining portion 26 of the dental plate S 15 on the wearer's teeth. It is advantageous to finish the inner side lower edge of the lower plate 24 inferior to below the junction between the teeth and the soft tissue because it allows the inner edge of bite block 29 to be constructed more smoothly and thus the bite block 29 does not need to have any sharp angled edges which might irritate the tongue. It is advantageous to finish the outer side lower edge 52 of the lower dental plate 24 adjacent the junction between the teeth and the soft tissue to avoid contact with the soft tissue, 9.

thereby decreasing the risk of irritation to the mucosa.

The bite block 29 shown in Figure 2 includes a ramp face 29a, a release edge 29b and a spacing portion 29c. The portion of the bite block 29 on which the ramp face 29a is positioned extends into the lingual space 200. The ramp face 29a, as shown in Figure 1, is located on the distal side of the bite block 29.

The release edge 29b is located at the upper most or superior edge of the ramp face 29a. The release edge 29b is the edge of the bite block 29 which must be cleared in order to disengage the bite block 29 on the lower dental plate 24 from the bite block 28 on the upper dental plate 22. Adjoining the release edge 29b is a bite block top surface 29d. The function of the top surface 29d will be described subsequently. The bite block 29 also includes an engaging surface 29e, which is the surface of the bite block 29 which is in contact with the retaining portion 26 of the upper dental plate 22 when the appliance 20 is in use.

Figure 3 illustrates the right side bite block 28 of the upper dental plate 22. As with the lower dental plate 24, in the area at which the bite block 28 is attached, the upper dental plate 22 has a three component construction the inner layer 30, outer layer 32 and bite block 28). In other areas of the upper dental plate 22 the construction is two layers the inner layer 30 and outer layer 32).

The upper dental plate 22 has an inner side upper or superior edge 60 and an outer side upper or superior edge 62. The inner side upper edge 60 is superior :to the junction between the teeth and the soft tissue of the upper jaw 10 in a ::*direction towards the palate. The outer side upper edge 62 finishes substantially adjacent to the junction between the teeth and the soft tissue. The Sinner side upper edge 60 is positioned so as to control the vertical opening distance of the jaws 10, 12 required to locate the appliance 20 properly within a wearer's mouth and to subsequently release the appliance 20. This opening of S the wearer's mouth will be described in more detail subsequently.

The bite block 28 on the upper dental plate 24, includes a ramp face 28a, a release edge 28b, a spacing portion 28c and a bite block surface 28d. As best illustrated in Figure 1, the ramp face 28a on the bite block 28 is located on the mesial side of the bite block 28. In use of the appliance 20, the ramp face 29a on the distal side of the lower bite block 29 engages with the ramp face 28a on the mesial side of the upper bite block 28. It should be noted that both the upper and lower dental plates 22, 24 each include two bite blocks 28, 29 which are arranged to engage with correspondingly positioned bite blocks on the opposing dental plate 22, 24.

-11 The release edge 28b of the upper bite block 28 is located at the lower most inferior portion of the ramp face 28a. The release edge 28b is the edge of the bite block 28 which must be cleared in order to disengage the bite block 28 from the bite block 29 on the lower dental plate 24. The release edge 28b adjoins the bite block bottom surface 28d.

The engaging surface 29e of the lower dental block 29 is located during use of the appliance 20 substantially adjacent to or in contact with the outer layer 32 of the retaining portion 26 of the upper dental plate 22.

The spacing portions 28c, 29c of the dental blocks 28, 29 would be of *°*substantially identical thickness so that an even spacing between the upper and "lower jaws 10, 12 is ensured.

gigol 15 To locate the appliance 20 in a wearer's mouth, the wearer must first position :each of the upper and lower dental plates 22, 24 individually in position. In order to achieve this, given the size of the bite blocks 28, 29, the wearer must open their jaws so that there is a very large and unnatural spacing between the S* upper and lower jaws 10, 12. In this position, the release edges 28b, 29b of the respective upper and lower bite blocks 28, 29 would typically be in contact. In order to reduce the large opening between the upper and lower jaws 10, 12, the wearer must open their jaws 10, 12 a fraction more and then force their lower jaw 12 forward to an anterior protruded position. As the jaws 10, 12 are opened the release edges 28b 29b clear one another. When the lower jaw 12 is then moved forward the top surface 29d of bite block 29 and the bottom surface 28d of the bite block 28 move over one another until the ramp faces 28a, 29a engage. As the ramp faces 28a, 29a of the respective upper and lower bite blocks 28, 29 come into sliding engagement with each other it is possible for the wearer to close their jaws together a sufficient distance so that they achieve a more comfortable position which is called the in-use position.

-12- In the in-use position, the lower jaw 12 is maintained in the anterior protruded position but the spacing 40 between the retaining portions 26 of the upper and lower plates 22, 24 is such as to prevent discomfort to the wearer because of an unnaturally large space between the teeth of the upper and lower jaws 10, 12.

However, it will be appreciated that because of the engagement between the ramp faces 28a, 29a of the upper and lower bite blocks 28, 29, the lower jaw 12 will be maintained in the required forward position. To return the lower jaw 12 to its normal position it is necessary for the wearer to consciously open their mouth a sufficient distance so as to bring the release edges 28b, 29b of the respective bite blocks 28, 29 into substantial horizontal alignment so that the top surface 28d of the upper bite block 28 can move over the bottom surface 29d of the lower bite block 29a and thereby disengage the bite blocks 28, 29. At this point, the upper and lower dental plates 22, 24 are free to be removed.

I S 15 Figure 4 shows schematically the engagement between the ramp surfaces 28a, S° 29a of the bite blocks 28, 29 when the appliance 20 is in use. As is apparent from this Figure, the ramp surfaces 28a, 29a of the bite blocks 28, 29 contact OllS together during use of the appliance 20. (The portions of the ramp faces 28a, 29a which contact are shown cross-hatched). In order to release the lower jaw 12 from the anterior protruded position, any contact between the upper and lower bite blocks 28, 29 must be removed. It will also be appreciated that the wearer must open their jaws a distance S in order to provide a clearance between bite blocks 28, 29 to enable release of the upper and lower dental plates 22, 24.

Accordingly, by increasing the spacing S between the release edge 28b and the release edge 29b the degree of opening required to release the lower jaw 12 from the anterior protruded position can be varied.

It will be appreciated that the appliance 20 as described herein is arranged to maintain the lower jaw 12 of the wearer in the anterior protruded position. The lower jaw 12 is maintained in this position while still ensuring that the spacing -13between the jaws 10, 12 ensures comfort to the wearer. At the same time, inadvertent release of the lower jaw 12 is prevented due to the configuration of the bite block 28, 29. Due to the shape of the surface 29e of the lower bite block 29, when the wearer open their jaw the spacing between the engaging surface 29e and the inner side of the retaining portion 26 increases. This increased spacing enables limited side to side movement of the jaws. This features greatly increases the comfort of the appliance.

The use of a retaining portion 26 of a composite construction improves the wearer's comfort because the inner layer 30 which contacts the teeth or the surrounding soft tissue is "soft" and is less likely to cause discomfort to the wearer. By adopting this composite construction the dental plates offer comfort to the wearer, the necessary degree of strength to enable the dental plates to be maneuvered on and off the wearer's teeth, and to enable strong engagement between the bite blocks 28, 29 of the upper and lower dental plates 22, 24.

The retaining portions 26 of the upper and lower dental plates 22, 24 are shaped so that they can be secured to the wearer's teeth in a manner similar to that of a conventional mouth guard and consequently there are no wires or 20 other attachment mechanisms necessary to secure the plates to their respective teeth. The appliance is therefore more readily cleaned and less likely to become smelly because of build up of contamination on retaining wires or the like.

It is envisaged that for some wearer's it may be desirable to increase the structural rigidity of the appliance by including a metal strengthener in either or both of the upper or lower dental plates. The metal strengthener would preferably be located within the inner side of the retaining portion and extend along the length of the retaining portion. Alternatively, the metal strengthener may be embedded in the inner layer of the retaining portion and covered by the outer layer.

14- The embodiment has been described by way of example only and modifications within the spirit and scope of the invention are envisaged.

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Claims (22)

1. A dental appliance for reducing snoring and/or obstructive sleep apnea, said appliance including an upper dental plate and a lower dental plate, said upper and lower dental plates including a retaining portion and means for maintaining the lower jaw of a wearer in an anterior protruded position, and wherein the retaining portion of each of said upper and lower dental plates is of a composite construction including an inner layer arranged to be in contact with the wearer's teeth and an outer layer.

2. A dental appliance according to claim 1 wherein the composite construction of the retaining portion of each of the upper and lower dental plates is such that it is sufficiently flexible to enable the upper and lower dental plates to be fitted over the wearer's teeth and to be retained on the respective teeth 15 due to engagement therewith or to engagement with soft tissue adjacent the wearer's teeth. S•3. A dental appliance according to claim 1 or claim 2 wherein the composite construction is such that the upper and lower dental plates are of 20 sufficient strength to adequately support the maintaining means.

4. A dental appliance according to any one of the preceding claims wherein the inner layer of the composite construction is made of a soft material.

5. A dental appliance according to claim 4 wherein the soft material is a dental grade EVA (ethylene vinyl acetate) or a polyurethane.

6. A dental appliance according to any one of the preceding claims wherein the outer layer is made of a material which is harder than the material of the inner layer. -16-

7. A dental appliance according to claim 6 wherein the outer layer is made from a dental grade polycarbonate material or copolymer.

8. A dental appliance according to any one of the preceding claims wherein the maintaining means includes at least an upper bite block mounted on the upper dental plate and a lower bite block mounted on the lower dental plate.

9. A dental appliance according to claim 8 wherein the upper and lower bite blocks are configured during use of the appliance to hold the lower jaw in an anterior protruded position. A dental appliance according to claim 8 or claim 9 wherein each of said bite blocks includes a ramp face, a release edge and an engaging surface.

11. A dental appliance according to claim 10 wherein the ramp face of the bite block of the upper dental plate is arranged in use to engage against the ramp face of the bite block of the lower dental plate so as to retain said lower jaw in said anterior protruded position.

12. A dental appliance according to claim 10 wherein the engaging surface of the bite block of the upper dental plate is located in use in contact with or substantially adjacent to the teeth of the lower jaw and the engaging surface of the bite block of the lower dental plate is located in use in contact with or substantially adjacent to the outer layer of the upper dental plate.

13. A dental appliance according to any one of claims 8 to 12 wherein the upper dental plate includes a pair of upper bite blocks and the lower dental plate includes a pair of lower bite blocks.

14. A dental appliance according to any one of claims 8 to 13 wherein each of the bite blocks is made from a dental grade acrylic which is attached to

17- the outer layer of the composite construction of the respective upper or lower dental plate. A dental appliance according to any one of claims 10 to 14 wherein the ramp face of each bite block is located in use substantially within the lingual space of the wearer's mouth. 16. A dental appliance according to any one of claims 10 to 15 wherein the ramp face of the lower bite block is located on the distal side of the lower bite block and has its release edge located superior to the engaging surface of the lower bite block. 17. A dental appliance according to claim 16 wherein the release edge of the upper bite block is arranged in use to contact the teeth of the lower jaw. S18. A dental appliance according to any one of claims 10 to 17 wherein the ramp face of the upper bite block extends into the lingual aspect of the mouth in a superior direction approximately as far as the junction between the teeth of upper jaw and the soft tissue.

19. A dental appliance according to any one of claims 10 to 18 wherein the substantially vertical distance between the release edges of the respective bite blocks in use is substantially equivalent to the increased opening required between the upper and lower jaws to release the engagement between the ramp faces of the bite blocks so as to enable the lower jaw to return to its intended posterior position. A dental appliance according to any one of the preceding claims wherein once the dental plates are engaged limited vertical opening of the upper and lower jaws can occur whilst holding the lower jaw in an anterior protruded position. -18-

21. A dental appliance according to claim 20 wherein the limited vertical opening is about 2 5 mm.

22. A dental appliance according to any one of claims 10 to 21 wherein the spacing between the teeth of the upper and lower jaw is determined by the thickness of a spacing portion of each dental plate.

23. A dental appliance according to claim 22 wherein the spacing portion has a thickness of about 5 mm.

24. A dental appliance according to any one of claims 1 to 23 wherein the inner and outer layers of the composite construction of the upper and lower dental plates each have a thickness of about 1.5 mm. 15 25. A dental appliance according to any one of the preceding claims wherein the upper and lower dental plates are formed so as to provide a degree of occlusal coverage sufficient to evenly distribute pressure on the teeth.

26. A dental appliance according to any one of claims 10 to 25 wherein the lower bite block is configured so that when a wearer opens their jaw a spacing between the engaging surface of the lower bite lock and the retaining portion of the upper bite block increases so as to allow limited side to side movement of the jaws.

27. A dental appliance according to any one of the preceding claims further including strengthening means located in either or both of said upper and lower dental plates, said strengthening means being arranged to increase the structural rigidity of the appliance.

28. A dental appliance according to claim 27 wherein the strengthening means is in the form of a metal strengthener. -19-

29. A dental appliance substantially as hereinbefore described with reference to the accompanying drawings. DATED: 28 March 2002 PHILLIPS ORMONDE FITZPATRICK Attorneys for: JOHN GUY ANGOVE o.. C