WO2015132406A1

WO2015132406A1 - Removable device for mandibular advancement

Info

Publication number: WO2015132406A1
Application number: PCT/EP2015/054781
Authority: WO
Inventors: Simon Ash
Original assignee: Somnowell Ltd
Priority date: 2014-03-07
Filing date: 2015-03-06
Publication date: 2015-09-11

Abstract

A removable device (100, 200) for advancing a lower jaw (20) relative to an upper jaw (10) in a mouth. An upper member (110, 210) is configured to be retained on an upper jaw buccal segment (15), positioned to the rear of the mouth, extending back towards the upper molars (14) of the upper jaw buccal segment, the upper member comprising one or more retaining members (114, 214) for securing the upper member removably on the upper jaw by engaging with one or more upper teeth (12, 13, 14) of the upper jaw buccal segment. A lower member (120, 220) is arranged to be retained on a lower jaw buccal segment (25) and inner lingual surface of the mandible (300), positioned to the rear of the mouth, extending back towards the lower molars (24) of the lower jaw buccal segment. The lower member comprises one or more retaining members (224) for securing the lower member removably on the lower jaw by engaging with one or more lower teeth (22, 23, 24) of the lower jaw buccal segment and a plate configured to lie on a portion of the lingual surface of the mandible, extending from the buccal teeth over the gingival margin onto the attached gingivae and attached oral mucosa. The upper and lower members are configured to be retained entirely within a first half of the mouth and a linking member (130, 230) is configured to connect the upper member to the lower member such that the lower jaw is advanced to and retained at a predetermined minimum distance relative to the upper jaw when the upper member is secured on the upper jaw and the lower member is secured on the lower jaw.

Description

Removable Device for Mandibular Advancement

Field of the Invention The present invention relates to a device and method for mandibular advancement, and more specifically, to a removable, compact, discrete device for advancing a lower jaw relative to an upper jaw and maintaining it there at a predetermined distance without obstructing front teeth or significantly encroaching on a hard palate, soft tissues, or a tongue space.

Background of the Invention

The relaxation of muscles during sleep or anaesthesia may cause the tongue and/or soft tissues (soft palate) of the mouth to move backwards and/or collapse against the back of the throat, thus restricting or even blocking patient's airways. The partial airflow restriction results in snoring (i.e., vibration of the soft tissue). The more complete airflow obstruction stops patient's breathing for short periods of time - the condition known as obstructive sleep apnea, which is also often accompanied by snoring. Both conditions disrupt patient's sleep, reduce patient's blood oxygenation, and cause fatigue-induced problems. The suffering patients may experience morning headaches, daytime sleepiness, high blood pressure, and even more severe complications, such as a heart attack or a stroke. The patients' bed partners may suffer as well, such as from sleeplessness and fatigue caused by the noise produced by snoring.

Mandibular advancement, i.e., advancing of the lower jaw into a forward (protruded) position in relation to a natural rest position, is one of the approaches commonly employed to control sleep related breathing disorders. Advancing of the lower jaw into the protruded position usually brings the tongue and soft tissue forward, thus preventing or minimising their collapse against the back of the throat. In this manner, the patient's airway enjoys an increased airflow and the soft tissue is prevented from vibrating. To secure and maintain the lower jaw in the protruded position, without a surgical intervention, a specially designed intraoral device, known as a mandibular advancement device or appliance, is typically secured in the patient's mouth for the duration of the sleep. The majority of mandibular advancement devices include an upper arch and a lower arch that securely fit (snap, or otherwise secured) over and extend along the upper jaw and the lower jaw respectively. The arches are typically connected using linking members (e.g., Herbst appliance) or coupled in some other manner such that securing of the device in the patient's mouth causes the patient's lower jaw to move into a protruded position, in which it remains whilst the patient continues wearing the device. Mandibular advancement devices are generally viewed as being effective in managing sleep related breathing disorders. However, for a mandibular advancement device to be effective, the patient is required to wear the device regularly and indefinitely. That is, the effectiveness of the mandibular device largely depends on whether the patient follows a routine of securing the device in his or her mouth prior to going to sleep for the duration of the sleep. The most significant factors affecting patient's compliance are the appearance of the device and the level of comfort or discomfort experienced by the patient whilst wearing the device. The earlier mandibular advancement devices were made from acrylic or similar plastic materials. However, these devices suffered from a number of shortcomings. They tended to have low robustness, degrade with use and time, and be bulky and not particularly visually appealing. Although evolved, the existing acrylic mandibular advancement devices generally require a considerable jaw opening, encroach upon the tongue space, lead to lip incompetence, a dry mouth, and otherwise adversely affect the patient. Indeed, any device that occupies the tongue space and, in particular, the area between the tongue and the lower front teeth is likely to cause the tongue to rest further back in the mouth. This is the opposite of the forward placement effect that the mandibular advancement devices strive to achieve. The anterior third of the tongue is particularly sensitive to foreign bodies in the anterior part of the mouth, which is often an area used to connect left and right hand sides of such devices. Any such devices utilising this area of the mouth are likely to cause significant irritation to the user and therefore have an associated effect on the patient's compliance in using the device.

To overcome these and other disadvantages associated with the existing mandibular advancement devices, EP2269543B1 proposes a mandibular advancement device that is formed from cast metal and has an upper member and a lower member configured respectively to rest on the upper and lower molar teeth and generally extend along the upper and lower jaws' arches. The upper and lower members are connected by the Herbst telescope or other similar appliance on both sides of the mouth such as to secure the advancement of the lower jaw in relation to the upper jaw at a predetermined distance. EP2269543B1 discloses that to decrease encroachment of the mandibular device on the tongue space, without losing the stability of the device, the lower member of the mandibular device is configured to be positioned in the labial sulcus (an area between the outer surface of the lower front teeth and the inner surface of the lower lip), extending across substantially the width of the lower front teeth, before extending up and backwards so as to cover some of the lower cuspid and molar teeth on both sides of the lower front teeth towards the rear of the lower jaw. The upper member of the mandibular device is formed as a base plate that fits behind the teeth in the upper jaw. It extends backwards covering part of the hard palate to form a horse shoe type shape.

Whilst the mandibular device of EP2269543B1 addresses some of the above- identified problems with the existing acrylic mandibular devices, such as the encroachment on the tongue space, bulkiness, and low robustness, such a device may still be perceived by some patients as being too large, obtrusive, and/or not particularly appealing. Furthermore, there is no easy way to insert or remove the mandibular device and it hard to position the device properly in the mouth, thus making it more difficult for the patients to use the device on their own regularly. Additionally, the mandibular device of EP2269543B1 is susceptible to certain imbalance caused by discrepancies between the left and right sides, which are only amplified by the rigid metal work. As noted above, the appearance of the mandibular device and the level of comfort or discomfort experienced by the patient whilst wearing the device are the most important factors affecting the patient's compliance concerning the regular use of the device, and thus the device efficiency in managing the sleep related breathing disorders. Accordingly, it is desirable to even further reduce the bulkiness of the mandibular advancement device, without sacrificing its benefits such as the degree of retention on the jaws. Such a mandibular advancement device must be unobtrusive, comfortable, and well tolerated by a patient. The mandibular advancement device should also be robust and distribute the occlusal and functional loads and forces generated by the jaw protrusion evenly over the teeth and jaws.

Considering the high costs associated with mandibular advancement devices made from cast metals, it is also desirable to provide a mandibular advancement device that can be adjusted and/or repaired, without having to rebuild the device as a whole anew. It is further desirable to provide a mandibular advancement device that is easier to insert and position correctly, and subsequently remove.

The present invention seeks to address these and other needs associated with the existing mandibular advancement devices.

According to the present invention there is provided a removable device (100, 200) for advancing a lower jaw (20) relative to an upper jaw (10) in a mouth, the device comprising an upper member (1 10, 210) configured to be retained on an upper jaw buccal segment (15), positioned to the rear of the mouth extending back towards upper molars (14) of the upper jaw buccal segment, the upper member comprising one or more retaining members (114, 214) for securing the upper member removably on the upper jaw by engaging with one or more upper teeth (12, 13, 14) of the upper jaw buccal segment; a lower member (120, 220) arranged to be retained on a lower jaw buccal segment (25) and inner lingual surface of the mandible (300), positioned to the rear of the mouth extending back towards the lower molars (24) of the lower jaw buccal segment, the lower member comprising one or more retaining members ( 224) for securing the lower member removably on the lower jaw by engaging with one or more lower teeth (22, 23, 24) of the lower jaw buccal segment, and a plate configured to lie on a portion of the lingual surface of the mandible, extending from the buccal teeth over the gingival margin onto the attached gingivae and attached oral mucosa; wherein the upper and lower members are configured to be retained entirely within a first half of the mouth; and a linking member (130, 230) configured to connect the upper member to the lower member such that the lower jaw is advanced to and retained at a predetermined minimum distance relative to the upper jaw when the upper member is secured on the upper jaw and the lower member is secured on the lower jaw.

Accordingly, embodiments of the present invention provide for a compact mandibular advancement device that is secured to and rests upon the upper and lower buccal teeth. The device is positioned towards the back of the mouth and therefore does not obstruct the upper front teeth, lower front teeth, labial sulcus, or most of the hard palate, and only minimally encroaches on the tongue space. The tip of the tongue, being particularly sensitive to foreign bodies in the anterior part of the mouth, is left clear by the device and allowed to rest in its natural position behind the upper and lower front teeth. As the device spreads the occlusal loads and forces generated by the jaw protrusion across the teeth and jaw on both sides of the mouth and does not introduce any pressure on the front teeth, it is comfortable to wear and the possibility of teeth damage, untoward tooth movements, or soft tissue damage is limited.

Further, the mandibular advancement device consists of separate components configured to be inserted and removed separately, thus making it easier for the patient to insert and properly position the device, and subsequently remove it, than a conventional mandibular advancement device. Further, if the device requires adjustments and/or repairs, only the respective component(s), and not the device as a whole, may need to be replaced. In other words, the disclosed device is easier to manufacture, repair, and use as compared to the conventional devices.

The use of separate components also helps to overcome certain problems of retention in the lower jaw common to one piece oral devices. Oral devices generally utilise the "undercuts" of the teeth, the areas around the base of the teeth providing natural retention due to the angled shape of the tooth above. However, in many cases the crowns of the teeth are conical or have perfect alignment such that there is minimal undercut area available for retention. The present device overcomes this problem by employing lingual plates, utilising the inner surface of the body of the mandible to provide the required retention.

The "attached gingivae and attached oral mucosa", the area between the gingival margins (the margin between the tooth and gum) and soft tissues forming the floor of the mouth beneath the tongue, may support a rigid surface and therefore be utilised for this purpose. This area of the mouth is not usually available for device retention since the diverging undercut jaw bone profile on one side relative to the other means there is no common insertion direction which would allow for a one piece device to be inserted into this area. Since the current device allows for each piece to be inserted independently, the lingual plates may be inserted into this area separately, allowing for the additional device retention to be utilised. Once both left and right mandibular sections are in place, the patient's own mandible bone acts indirectly as a connector between the components, thereby providing a sturdy connection and fit. This avoids the need for a major connector to be included in the device which lies in front or behind of the front teeth and therefore this sensitive area is kept clear.

A further common problem to prior art oral devices is that the tongue, being active and muscular, can act to lift the lower component of the device out of position. The provision of the lingual plates of the current invention solves this problem since the tongue naturally spreads anteriorly and laterally, partially resting on the lingual plates which lie on the neighbouring attached gingivae and oral mucosa, to provide additional retention. The described mandibular advancement device is also physically and chemically stable and, thus, is well tolerated in the mouth. It is lightweight and discrete in appearance. The overall bulk of the device is on average two-thirds of that of prior mandibular advancement devices. The disclosed device is almost invisible from outside of the mouth and, thus, is more appealing than conventional mandibular advancement devices. Consequently, it is easier for the patient to accept wearing of the device on regular basis, thereby increasing patient's compliance. Embodiments of the present invention will be described, by way of example only, with reference to the accompanying drawings, in which embodiments of a device for mandibular advancement, as it would be fitted within a patient's mouth, are illustrated, wherein: Figure 1 depicts a lateral view of a device for mandibular advancement, according to an embodiment of the present invention;

Figure 2 depicts an anterior view of a device for mandibular advancement, according to an embodiment of the present invention;

Figure 3 depicts the separate left and right frameworks of a device for mandibular advancement device, according to an embodiment of the present invention. Figure 4 depicts an occlusal view of two variants of the upper members of a device for mandibular advancement, according to embodiments of the present invention.

Figure 5 shows a partial occlusal view of a lower member of a device according to the present invention.

Figure 6A shows a laterial view of the constructed alternative linking member according to the present invention. Figure 6B shows a top view of the constructed alternative linking member according to the present invention, indicating a plane normal to the viewing direction in 6A. Figure 7A and 7B respectively show an end and side view of the female threaded tube of the alternative linking member according to the present invention. Figure 7C and 7D respectively show a lateral and top view of the claw members of the alternative linking member according to the present invention.

Figure 1 depicts a lateral view of an exemplary mandibular advancement device 100 positioned in a patient's mouth, according to an embodiment of the present invention. The device 100 has two main members, an upper member 1 10 and a lower member 120, configured to be fitted respectively onto the upper jaw 10 and lower jaw 20 of the patient's mouth. The upper member 1 10 is constructed to conform to and supported by an upper buccal segment 15, formed of upper cuspid, bicuspid, and molar teeth 12, 13, and 14 in the upper jaw 10. Similarly, the lower member 120 is constructed to conform to and be supported by a lower buccal segment 25, formed of cuspid, bicuspid, and molar teeth 22, 23, and 24, in the lower jaw 20 and a portion of the inner surface of the body of the mandible. The entire device therefore is positioned towards the rear of the mouth, that is, it leaves the front portion of the mouth (the front teeth and the area immediately behind the front teeth and in front of the tongue) clear. As discussed in greater detail with respect to Figures 3 and 4, in some embodiments, the upper member 1 10 and/or lower member 120 include an occlusal bar disposed over the occlusal (biting) surface of the upper and/or lower teeth respectively.

To retain the upper and lower members 1 10 and 120 on their respective buccal segments 15 and 25, the upper and lower members 1 10 and 120 include one or more retaining members, such as one or more clasps 1 14 and 124. The clasps 1 14 and 124 are configured to be positioned buccally, palatally, and/or lingually over and around the surfaces of one or more teeth in the buccal segments 15 and 25. The positioning and shaping of each of the clasps 1 14 and 124 is generally determined in accordance with the oral anatomy of a particular patient to rest in its natural position being the upper and lower front teeth. The lower member further includes an extended plate configured to be positioned on a portion of the lingual surface of the mandible, on the attached gingiva and attached oral mucosa between the gingival margins of the teeth and the soft tissue forming the floor of the mouth beneath the tongue, discussed in greater detail with reference to Figure 5. In some embodiments, to increase retention of the mandibular advancement device, the upper member further includes a palatal extension(s)(flanges) covering a portion of the ascending lateral palatal surface of the hard palate 17 (discussed in greater detail with respect to Figure 4). The upper and lower members 1 10 and 120 of the device 100 are positioned on the same side of the mouth (right or left) and connected by a linking member (connecting member, linkage, arrangement, component, or the like) 130 such that the lower jaw 20 can move relative to the upper jaw 10 when the device 100 is fitted in the patient's mouth, but in a limited manner. In particular, the movement of the lower jaw 20 is restricted such that the lower jaw 20 is always in an advanced position at a predetermined distance relative to the upper jaw 10.

The linking member 130 may be a piston-rod arrangement, including a telescopic arm 132 and sleeve 134, as shown in Figure 1 , each having an end 136 for engaging with mounting members (e.g., studs) 122 and 1 12 respectively. The mounting member 112 generally extends from the upper member 1 10 at a position roughly corresponding to the rear molars 14. The mounting member 122 generally extends from the lower member 120 at a position roughly corresponding to the cuspid 22 and/or the neighbouring bicuspid 23. However the linking member may equally attach at a rearward position, for example the lower molar area buccal, on the lower member and a forward position, for example near the upper cuspid or bicuspid, on the upper member. Preferably, although not necessarily, the mounting member 122 and the mounting member 1 12 are integrally formed with the respective lower and upper members 120 and 1 10. For example, the mounting members 1 12 and 122 may be embedded within the upper and lower members 1 10 and 120 respectively at the time of moulding of the device 100. The linking member 130, shown in Figure 1 , is a variation of an appliance known as a "Herbst telescope" or "Herbst appliance." Multiple variations of the "Herbst appliance" can be used as the linking member 130. For example, the telescopic arm 132 may include, at the end opposite to the end 136, a key (not shown) shaped for insertion into an opening (not shown) at the corresponding end of the sleeve 134 such that the subsequent rotation of the arm 132 causes the arm 132 to remain secured within the sleeve 134. The ends 136 may, for example, be C- shaped and configured to engage with the body of the studs 1 12 and 122. Another example of the linking member may employ a female threaded tube with an opposite thread direction in each opposing end and two claw members configured to screw into the opposing ends of the tube, allowing for adjustment of the device within the mouth. This will be discussed in more detail with reference to Figures 6 and 7. The skilled person would appreciate that other variations and types of linking members may be employed as well.

In this example the device 100 is formed of a metal, such as a gold alloy, chrome cobalt, stainless steel or a combination thereof. Of course, an alternative material with similar strength to cross-sectional thickness, such as certain plastics, would be a possible alternative. By using metal to manufacture the mandibular advancement device 100, the device 100 can be made compact and strong at the same time. The metal may be cast or sintered.

In Figure 1 , the device 100 comprises only of a single pair of the lower and upper members 1 10 and 120 and is configured to conform to and be positioned within either right or left side of the mouth, but not both. If the upper member includes a palatal extension covering a portion of the ascending lateral palatal surface of the hard palate 17, the extension does not cross the palatal midline. In other words, the device 100 solely resides within the respective half of the mouth.

Figure 2 shows an anterior view of an exemplary mandibular advancement device 200, as it would be fitted in a patient's mouth, according to an embodiment of the present invention. Whilst the device 100 depicted in Figure 1 resides solely within one half of the mouth (right or left), the device 200 consists of two separate parts, a right framework 250R and a left framework 250L, each of the frameworks being similar to the mandibular advancement device 100 and each residing within the respective half of the mouth, right or left.

In particular, the right framework 250R includes an upper right member 21 OR and a lower right member 220R connected by a linking member 230R, whilst the left framework 250L includes an upper left member 210L and a left lower member 220L connected by a linking member 230L. The right and left frameworks 250R and 250L are constructed and supported respectively by the right and left buccal segments. In the device 200 depicted in Figure 2, the right framework 250R has no direct connection with the left framework 250L. Rather, they are separate. In particular, the right upper member 21 OR has no connection with the upper left member 210L, whilst the lower right member 220R has no connection with the lower left member 220L. In some embodiments, however, where due to the oral anatomy of the patient the retention of the mandibular advancement device is a challenge, a labially placed connecting bar may be used to connect the lower right and left members 220R and 220L to provide additional retention. In such a case the connecting bar may be foldable via a central hinge to produce a device which is compact when not in use.

The right and left frameworks 250R and 250L are constructed on the standing teeth and the inner surface of the body of the mandible and are shaped to the specific oral anatomy of the patient. Figure 3 shows the differing structure of the right and left hand frameworks outside of the mouth related to the differing oral anatomy of the right and left side of the patient's mouth. This solves the problem of a non-uniform distribution of loads due to a differing oral anatomy of the left and right hand sides of a patient's mouth associated with a one piece device. As part of the design process, each model has to be surveyed. A survey line is drawn on the stone casting or equivalent if constructed on a CAD system. This survey line will determine the path of insertion of the rigid metal device. Areas below the survey line are the "undercuts". When deciding where to place the clasps the technician or designer places the origins of the clasp (where these meet the ribs or occlusal bar 226) above the survey line and then depending on the oral anatomy and degree of retention required, passes the clasp body into the insertion of the undercut (i.e. into the undercut). The clasps in general have to be kept clear of the occlusal/biting surface of the device.

In some embodiments, the upper and/or lower members have an occlusal bar 226 placed over the occlusal biting surface of the teeth. In particular embodiments occlusal bars may be placed on both upper and lower members such that the bars on the upper members oppose those on the lower members at a common occlusal plane. By utilising such opposing occlusal bars on the upper and lower members, device stability may be improved by spreading the occlusal biting loads over the teeth covered by the device, thus giving additional strength to the respective devices. Further, in some embodiments, the right framework 250R and/or the left framework 250L include palatal extensions 218 covering a portion of the ascending lateral palatal surface of the hard palate. However, the palatal extensions 218 do not cross or extend beyond the palatal midline. In other words, the right and left frameworks 250R and 250L are constructed such as to remain fully within the respective right and left halves of the patient's mouth.

The upper and lower members 21 OR and 220R and 210L and 220L of the device 200 are connected respectively by the linking members 230R and 230L such that the movements of the lower jaw 20, although allowed, are restricted - the lower jaw is always in an advanced position at a predetermined distance relative to the upper jaw 10. In Figure 3, each of the linking members 230R and 230L is similar to the linking member 130 described above with respect to Figure 1.

As shown in Figures 2 and 3, the lower members 220R and 220L are not connected, i.e., separate. However, in some embodiments, to increase retention of the device, the lower members 230R and 230L are configured to be connected by a labial bar, or the like (not shown), placed it in the labial sulcus. Figure 4 depicts an occlusal view of the upper right and left members 21 OR and 21 OL of the mandibular advancement device 200. As shown, the right upper member 21 OR is positioned to rest upon the upper right cuspid, bicuspid, and molar teeth 12, 13, and 14 of the upper right buccal segment 15R, whilst the left upper member 21 OL is positioned to rest upon the upper left cuspid, bicuspid, and molar teeth 12, 13, and 14 of the upper left buccal segment 15L. Each of the upper right and left members 21 OR and 21 OL is configured to extend backwards to the rearward upper molars 14, when fitted to the upper jaw 10. The upper right and left member 21 OR and 210L are secured to the teeth of the upper buccal segments 15R and 15L using retaining members such as clasps 214 that secure over and around the buccal (outer) and lingual (inner) surfaces of one or more teeth in the segments. Once fitted to the upper jaw 10, the upper member 210 should have very little, or no, lateral or anterior-posterior movement relative to the upper jaw 10.

In some embodiments the upper member 21 OR or 210L extends backwards so as to cover at least a portion of the occlusal biting surface of the respective buccal segment, forming a protective occlusal bar 216 for protecting the respective portion of the occlusal biting surface, minimising unwanted tooth movements, and/or increasing retention of the upper members 21 OR and 210L on the upper jaw 10. Further, in some embodiments, the upper right member 21 OR and/or the upper left member 210L include a palatal extension 218 covering a portion of the ascending lateral palatal surface of the hard palate 17. The palatal extension 218 does not cross the palatal midline.

Figure 5 shows an exemplary right lower member 220R of the current invention. As shown, the right lower member 220R is positioned to rest upon the lower right cuspid, bicuspid, and molar teeth 22, 23, and 24 of the lower right buccal segment 25R and a portion of the inner surface of the body of the mandible.

The lower member includes a lingual plate 300 extending over the attached gingivae and attached oral mucosa between the necks of the teeth and the free mobile gum or soft tissues of the under-surface of the tongue. The lingual plate extends such that the tongue may naturally rest against and over the plate, providing additional retention to the lower member of the device and preventing the movement of the tongue lifting the device out of place. The inner surface of the mandible slopes down and outwards in a direction under teeth so the lingual plate 330 placed in this region provides an opposing force to that of the occlusal retention members 226 providing enhanced retention. As previously described, this area of the mouth can only be reached due to the separate right and left hand components of the device allowing them to be individually inserted in the required directions. It may be appropriate to use an occlusal bar 226 running mesio distally (front to back) over the bicuspid and molar teeth in one or both arches. Or to use ribs 228 passing bucco palatal or bucco lingual crossing the occlusal surface on one or both jaws as in Figure 5. Each of the lower right and left members 220R and 220L is configured to extend backwards to the rearward lower molars 24, when fitted to the lower jaw 20. The lower right and left member 220R and 220L are secured/anchored to the teeth of the lower buccal segments 25 using retaining members, such as clasps 224 that secure over and around the buccal (outer) and lingual (inner) surfaces of one or more teeth in the segments. Once fitted to the lower jaw 20, the lower member 220 should have very little, or no, lateral or anterior-posterior movement relative to the lower jaw 20. In some embodiments the lower member 220R or 220L extends backwards so as to cover at least a portion of the occlusal biting surface of the respective buccal segment, forming a protective occlusal bar 226 for protecting the respective portion of the occlusal biting surface, minimising unwanted tooth movements, and/or increasing retention of the lower members 220R and 220L on the lower jaw 20.

As shown in Figures 2 to 5, the upper and lower members 210 and 220 also include mounting members 212 and 220 respectively for pivotably engaging the linking members 230R and 230L. The mounting members 212 are provided on the upper members 21 OR and 210L, at the points roughly corresponding to the positions of the terminal molars 14, whilst the mounting members 222 are provided on the lower members 220R and 220L at the points roughly corresponding to the positions of the right and left lower cuspids 22 and/or the neighbouring lower bicuspids 23. Preferably, although not necessarily, the mounting members 212 and 222 are formed integrally with and extend from the respective upper and lower members 210 and 220. In this manner, the strength of the upper and lower members 210 and 220, and consequently of the device as a whole, is increased and the possibility of the mounting members inadvertently detaching or breaking off is significantly decreased. In some embodiments, the mounting members 212 and 222 are studs having a flange or shaft embedded within the upper and lower members 210 and 220 respectively. Other suitable mounting means, however, could be used as well. Further, in some embodiments, the mounting members 212 and 222 are configured to detachably engage with the linking members 230, whilst in some other embodiments, the engagement between the mounting members 222 and linking members 230 is of a more permanent nature.

To position and secure the device 200 in the patient's mouth, it is preferable to first assemble each of the right and left frameworks 250R and 250L (or a single framework if the mandibular advancement device includes a single framework, such as the device 100 shown in Figure 1 ). The assembly process may include engaging the linking members 230 with the respective mounting members 212 and 222 of the upper and lower members 210 and 220 (e.g., if the mounting members are configured for detachable engagement) and/or engaging the arm(s) 232 with the corresponding sleeve(s) 234 to assemble the linking member(s) 230).

Once the framework(s) have been assembled, each of the frameworks can now be inserted into the patient's mouth as a complete unit. The upper member 210L or 21 OR is positioned over the upper buccal segment 15L or 15R respectively and secured to some or all teeth of the segment using the clasps 214. After the upper member 210 is secured, the lower jaw 20 is advanced to allow the corresponding lower member 220L or 220R respectively to be positioned over the lower buccal segment and secured to some or all teeth of the segment using the clasps 224. The same procedure is performed with respect to the second framework. After the framework(s) is(are) secured on the upper and lower jaws 10 and 20, the lower jaw 20 will be maintained at a predetermined advanced distance in relation to the upper jaw 10, until the device 200 is removed.

As described, the right and left frameworks 250R and 250L are secured sequentially. However, the user of the device 200 may find it more convenient to first secure the upper members 21 OR and 210L, then advance the jaw, and then secure the lower members 220R and 220L. Regardless of how the user/patient chooses to proceed, it is easier for the patient to insert, properly position, and secure the device 200 than a conventional mandibular advance device because the device 200 includes separate members, which the user can insert and secure separately and independently. The insertion path for each of the upper and lower members may be chosen to best accommodate the anatomical structure of each separate buccal jaw quadrant of the patient's teeth. This is particularly advantageous for patients with restricted mouth openings and/or small oral apertures.

To remove the device 200, the lower jaw 20 is advanced to allow the lower members 220R and 220L to be lifted out and away from the respective lower right and left buccal teeth. Then, the upper members 21 OR and 210L are detached from the upper jaw 10. Each of the right and left frameworks 230R and 230L can be removed from the patient's mouth as a complete unit.

Although the Figures depict the telescopic arm 132, 232 as being connected to the lower member 120, 220, whilst the sleeve 134, 234 being connected to the upper member 1 10, 210, in some embodiments, a reversed arrangement is employed, i.e., the arm is connected to the upper member, whilst the sleeve is connected to the lower member. The arrangement depicted in Figures 1 -4 is, however, preferred. In either of the arrangements, the length of the telescopic arm 132, 232 is such that when the lower member 120, 220 is connected to the upper member 1 10, 210 by the linking member 130, 230, although allowed to move relative to the upper member 1 10, 210, it is advanced by a predetermined minimum distance and maintained in such a position. Another example of a linking member 330 of the current invention is shown in figures 6 and 7. This linking member includes a female threaded tube 334 in which the thread direction is opposite in each half. It further includes a straight claw member 320 and a hook claw member 340, each of which having a screw end 323, 343 at the opposite end to the claw, as shown in Figures 7C and 7D. Each screw end is configured to screw into an end 311 , 312 of the female threaded tube to assemble the linking member as shown in Figures 7A and 7B. The straight claw member comprises a substantially U-shaped claw aligned along the axis of the screw end 323 which is configured to pivotally engage with the mounting member 222 of the lower member. The hook claw member comprises a C-shaped hook offset at an angle from the axis of the screw end 343 and configured to pivotally engage with the mounting member 212 of the upper member. The female threaded tube 334 includes a centrally positioned adjustment hole 310 in the wall of the tube. Unlike the Herbst device, this linking member allows for adjustment of both ends while the device is positioned within the patient's mouth, since the opposing threads allow for both screw ends to be simultaneously tightened or loosened by rotating the tube in one direction. The hole further allows for air balance when the device is adjusted and lubrication of the inner workings of the device. This arrangement also improves the ease with which the user may insert the device. The straight claw ends may firstly be fixed to the mounting member 222 of the lower member after which the patient inserts the upper framework followed by the lower framework. Once these are fully seated on the teeth and jaws, the hook claw member may be lifted and hooked onto the mounting members 212 of the upper member. Each male threaded claw member further has a small fixing hole 322, 342 which can be used to maintain the adjusted position by fixing the position of the female threaded tube 334 on the male screws 323, 343.

The clasps 214 and 224 are described herein as the preferable example of the retaining members for securing the upper and lower members 210 and 220 of the mandibular advancement device to the upper and lower jaws 10 and 20 respectively. However, the skilled person would appreciate that other arrangements are possible. The retaining members of the mandibular advancement device must secure the upper and lower members of the device respectively to the upper and lower buccal teeth, whilst preventing any lateral movement of either the upper or lower members 210 and 220 relative to the teeth. In accordance with the embodiments of the present invention, the contrary displacing forces that are applied to the mandibular advancement device whilst in use do not follow the designated path of insertion used in the design and construction of the device. Additionally, although the linking members 230, 330 were described as a sleeve- rod type arrangement, other arrangements for connecting the upper members 210L and 21 OR respectively to the lower members 210L and 21 OR may be used. The linking members 230 can be either fixed (non-detachable) or non-fixed (detachable). Further, they must be positioned in the buccal sulcus portion of the mouth (i.e., outside the teeth), and configured such that, when fitted, they advance the lower member 220 by a predetermined distance in relation to the upper member 210, whilst allowing the lower jaw 20 to retain some lateral movement relative to the upper jaw 10. By maximising the forward placement of lower jaw 20, whilst minimising adverse jaw opening, embodiments of the present invention enable the patient (wearer of the device) to maintain lip competence and reduce the untoward effects of jaw opening and lip incompetence.

Accordingly, the disclosed embodiments of the present invention provide for a mandibular device that is significantly smaller and less obtrusive than existing, conventional mandibular advancement devices. It is portable, lightweight, and discrete in appearance. The overall bulk of the described device is on average two-thirds of that of prior mandibular advancement devices. Use of the cast metal to make the device assures that the device is strong and robust, whilst is also compact. It will be appreciated though that non-cast metal and forming through such techniques as printing and sintering may be employed. Furthermore, such materials are well tolerated by patients and are inert in the oral environment. Additionally, as described, the mandibular advancement device includes separate components that may be inserted and secured separately and independently, making it easier for the patient to insert and properly position and secure the device, and subsequently remove. The device is secured to and rests upon the upper and lower buccal teeth and inner lingual surface of the mandible and does not obstruct or put pressure on the upper front teeth or lower front teeth, encroach labial sulcus, or most of the hard palate, and only minimally encroaches on the tongue space. The tip of the tongue is allowed to rest in its natural position behind the lower front teeth. The yawing displacing forces secondary to the presence of major jaw connectors of the conventional mandibular advancement devices are eliminated. Thus, patients with a shallow labial or lingual sulcus, high frenum, and/or periodontal issues, who are not able to wear conventional mandibular advancement devices due to such problems, are able to wear and will benefit from wearing the described mandibular advancement device.

Furthermore, since the mandible advancement device includes separate components, the inner lingual surface of the mandible may be utilised to provide additional retention, which is impossible in conventional one-piece devices, due to the lack of a common insertion direction. By placing lingual plates in this area of the mouth, a high retention is achieved, without the need for major connectors between the side components, which may detrimentally affect the user's perceived appearance and comfort, thus encouraging continued use of the device. The use of lingual plates on which the tongue may rest avoids the problem of the tongue lifting the device out of position, common to prior art devices.

Furthermore, as the device is positioned at the sides and back of the patient's mouth, it is almost unnoticeable from the outside of the mouth. The device also allows the patient to open his or her mouth without removing the device, thus enabling the patient to drink and talk whilst wearing the device. Therefore, the described embodiments provide for a mandibular device that is comfortable and unobtrusive, is easy to use and use properly, and promotes patient's compliance, and thus, efficiency of the device. Another advantage of the described device is that, since it includes separate components, it may be adjusted within the mouth to improve fit and retention. Furthermore repairing the device does not require remaking of the device as a whole. Rather, only respective components may need to be adjusted, repaired, or replaced.

Claims

1. A removable device (100, 200) for advancing a lower jaw (20) relative to an upper jaw (10) in a mouth, the device comprising:

an upper member (1 10, 210) configured to be retained on an upper jaw buccal segment (15), positioned to the rear of the mouth, extending back towards the upper molars (14) of the upper jaw buccal segment, the upper member comprising one or more retaining members (114, 214) for securing the upper member removably on the upper jaw by engaging with one or more upper teeth (12, 13, 14) of the upper jaw buccal segment;

a lower member (120, 220) arranged to be retained on a lower jaw buccal segment (25) and inner lingual surface of the mandible (300), positioned to the rear of the mouth, extending back towards the lower molars (24) of the lower jaw buccal segment, the lower member comprising

one or more retaining members (224) for securing the lower member removably on the lower jaw by engaging with one or more lower teeth (22, 23, 24) of the lower jaw buccal segment, and

a plate configured to lie on a portion of the lingual surface of the mandible, extending from the buccal teeth over the gingival margin onto the attached gingivae and attached oral mucosa; wherein

the upper and lower members are configured to be retained entirely within a first half of the mouth; and

a linking member (130, 230) configured to connect the upper member to the lower member such that the lower jaw is advanced to and retained at a predetermined minimum distance relative to the upper jaw when the upper member is secured on the upper jaw and the lower member is secured on the lower jaw.

2. The device according to claim 1 , wherein the upper member, the lower member, and the linking member form a first framework (250), the device further comprising:

a second framework (250) configured to be positioned entirely within a second half of the mouth, wherein the upper members of the first and second frameworks are separate when the device is secured within the mouth.

3. The device according to claim 2, wherein the first framework is separate from the second framework when the device is secured within the mouth.

4. The device according to claim 2, further comprising:

a labial bar for connecting the lower member of the first framework and the lower member of the second framework, the labial bar configured to be positioned in the labial sulcus (28) and keep the lower front teeth free, thereby increasing retention of the device after the device is secured within the mouth.

5. The removable device according to any of the preceding claims, wherein: each of the upper and lower members further comprising a mounting member (1 12, 122, 212, 222) for pivotably engaging the linking member; and the linking member is configured to connect the upper and lower members detachably.

6. The removable device according to any of the preceding claims, wherein the linking member comprises a telescopic arm (132, 232) and sleeve (134,

234), wherein one of the arm or sleeve is pivotally attached at one of its ends (136) to a rearward portion of the upper member and the other of the arm or sleeve is pivotally attached at one of its ends (136) to a forward portion of the lower member, the unattached end of the arm configured to secure removably inside the unattached end of the sleeve.

7. The removable device according to any of claims 1 to 5, wherein the linking member (330) comprises

a female-threaded tube (334), the opposing ends of the tube (311 312) each having opposite thread directions, with an adjustment hole (310) on a side wall of the tube between the two ends;

a straight claw member (320) having a male threaded screw end (323) and an opposing claw end (321 ), wherein the claw end is axially aligned with the screw end (323); a hook claw member (340) having a male threaded screw end (343) and an opposing hook end (341 ), wherein the hook end is angularly offset from the axis of the screw end (343); wherein

the screw ends (323, 343) of the claw members (320, 340) are configured to screw into the opposing ends of the tube (311 , 312) such that, in use, rotation of the tube via the adjustment hole (310) simultaneously tightens or loosens both screw ends; and

the claw end (321 ) is configured to pivotally engage the mounting member (222) of the lower member and the hook end (321 ) is configured to pivotally engage the mounting member (212) of the upper member.

8. The device according to any preceding claims, wherein at least one of the upper and lower members comprises an occlusal bar (216) configured to cover at least a portion of the biting surface of the respective jaw buccal segment.

9. The device according to any of preceding claims, wherein the one or more retaining members are configured to engage with the one or more teeth of the respective buccal segment buccally, palatally, lingually, or combination thereof.

10. The device according to any preceding claim, wherein the one or more retaining members comprise one or more clasps configured to secure the respective upper or lower member to at least one of the lingual and buccal sides of the one or more upper or lower buccal segment teeth respectively.

1 1. The device according to any preceding claim that has been moulded in accordance with an oral anatomy of the mouth of a particular patient.

12. The device according to any preceding claim, wherein the device is formed from metal, preferably from stainless steel, a gold alloy, a chrome cobalt, or a combination thereof.

13. The device according to any of the preceding claims, wherein the retaining member of the upper member comprises a palatal extension (218) for covering a portion of the ascending lateral palatal surface of the hard palate (17).

14. The device according to any of the preceding claims, wherein one or more of the upper front teeth, the lower front teeth and the anterior and middle portions of the hard palate are free from the device encroachment when the device is secured in the mouth.

15. A method of retaining a lower jaw at an advanced position relation to an upper jaw in a mouth, the method comprising:

providing an upper member configured to fit entirely within a first half of the mouth in the upper jaw, positioned to the rear of the mouth and extending back towards the upper molars of the upper jaw, and be secured removably to one or more of the upper molars;

providing a lower member configured to fit entirely within the first half of the mouth in the lower jaw, positioned to the rear of the mouth and extending back towards the lower molars of the lower jaw, and be secured removably to one or more of the lower molars and an inner lingual surface of the mandible; connecting removably the upper member with the lower member using a linking member configured to allow the lower member to move relative to the upper member while advancing and retaining the lower jaw at a predetermined minimum distance relative to the upper jaw when the upper member is secured on the upper jaw and the lower member is secured on the lower jaw;

securing removably the upper member to the one or more upper molars of the upper jaw;

advancing the lower jaw; and

securing removably the lower member to the one or more molars of the lower jaw.

16. The method according to claim 15, further comprising:

providing a second upper member configured to fit entirely within a second half of the mouth; providing a second lower member configured to fit entirely within the second half of the mouth;

connecting removably the second upper member with the second lower member using a second linking member;

securing removably the upper member to one or more upper molars of the upper jaw in the second half of the mouth; and

securing removably the lower member to one or more molars of the lower jaw and an inner lingual surface of the mandible in the second half of the mouth.