Adjustable mandibular advancement device and strap for an adjustable mandibular advancement device

Abstract

The invention describes an adjustable mandibular advancement device (1) comprising a strap (2) and a mouth guard (3) formed by an upper portion (31) and a lower portion (32). The strap (2) comprises two ends equipped with respective holes (221) connected in an articulated manner to the attachments (321) of the lower portion (32) and a central section that passes through the guiding means (311) of the upper portion (31), such that the strap acts by traction between the two lugs (321) of the lower portion (32) of the guard (3) to prevent the free return movement of said lower portion (32) with respect to the upper portion (31). The device is characterised in that the length of the strap (2) can be selectively adjusted to a specific desired value.

Description

[0001] DESCRIPTION

[0002] Adjustable mandibular advancement device and brace for an adjustable mandibular advancement device

[0003] OBJECT OF THE INVENTION

[0004] The present invention belongs in general to the field of dentistry, and more particularly to mandibular advancement devices for the treatment of sleep apnea.

[0005] The object of the invention is a mandibular advancement device comprising a strap whose length is selectively adjustable.

[0006] BACKGROUND OF THE INVENTION

[0007] During sleep, the muscles relax, causing the airways to close and vibrate as air passes through. This vibration produces the sound known as snoring. However, snoring is not the only problem resulting from the closure of the airways, as this closure also causes impaired lung ventilation, reducing the effectiveness of sleep and sometimes causing the person to experience brief periods of breathlessness (a phenomenon known as sleep apnea).

[0008] Currently, there are several techniques for treating this problem, one of which involves the patient using a mandibular advancement device while sleeping. The mandibular advancement device essentially consists of a dental splint made up of an upper and a lower portion connected by a mandibular advancement mechanism. While there are various types of mandibular advancement mechanisms, their main function is to keep the lower portion of the mandible forward relative to the upper portion compared to a resting position, or to prevent its retrusion in cases where advancement is not necessary. This causes the patient's lower jaw to remain forward relative to the upper jaw during sleep, thus opening the airways.

[0009] European patent EP3103420B1, in the name of the applicant of the present invention, describes a mandibular advancement device in which the mandibular advancement mechanism is a tie rod with holes at its ends. Thanks to this configuration, the ends of the tie rod are inserted into projections extending from the lateral areas of the lower portion of the splint, while a central section of the tie rod passes through a hook located in the front center of the upper portion of the splint.

[0010] The length of this brace is chosen during a pre-treatment planning process to ensure a forward position of the patient's lower jaw. This length may vary throughout the treatment period for the same patient, starting with a specific length that is then gradually reduced. The shorter the brace, the greater the advancement of the lower jaw, and therefore the greater the opening of the airways. Typically, the patient begins with a brace whose length is gradually reduced over several weeks, allowing time for the patient to become accustomed to the progressively more forward position forced by the device.

[0011] Sometimes, the dental clinic gradually reduces the length of the brace as the patient becomes accustomed to it. However, it is now also common practice to provide the patient with several braces of varying lengths along with the splint. This allows the patient to begin using the device with an initial brace of a specific length and, once comfortable, replace it with a slightly shorter one. This process can continue for several weeks until the user feels comfortable with a significantly shorter brace than the initial one. It is important to remember that the shorter the brace, the more the lower jaw is positioned relative to the upper jaw, resulting in a wider airway.

[0012] One drawback of this system is the waste of time and materials, since the patient often does not need to use every single strap of different lengths. Furthermore, because the patient only has straps available in a set of fixed lengths, intermediate lengths are not available.

[0013] DESCRIPTION OF THE INVENTION

[0014] The inventors of the present invention have solved the aforementioned problems by means of an adjustable-length strap and an adjustable mandibular advancement device that employs said strap. Specifically, the strap has a configuration suitable for adjusting its length according to the patient's needs. First aspect: adjustable mandibular advancement device with adjustable-length strap

[0015] A first aspect of the invention is directed to an adjustable mandibular advancement device comprising fundamentally a brace and a dental splint formed by an upper portion and a lower portion.

[0016] The upper portion of the splint is configured to fit the patient's upper jaw dentition, and the lower portion is configured to fit the patient's lower jaw dentition. Each portion comprises a front area configured to fit the patient's incisors and canines and two side areas configured to fit the patient's premolars and molars. Outer faces of the side areas of the lower portion comprise respective anchorages, which may be projecting (pins) or recessed (channels) from the outer surface, and an outer face of the front area of ​​the upper portion comprises at least one guide means.

[0017] For its part, the tie rod comprises two ends equipped with respective holes connected in an articulated manner to the anchors of the lower portion and a central section that passes through the guide means of the upper portion.

[0018] In this way, the tie rod acts in tension between the anchors of the lower portion of the splint to prevent the free recoil of said lower portion with respect to the upper portion, from the position chosen with the length of the tensioner.

[0019] Up to this point, a mandibular advancement device similar to that described in document EP3103420B1 has been described. However, the mandibular advancement device of the present invention differs from that one in that the tie rod comprises means for selectively adjusting its length to a specific desired value.

[0020] Adjusting the length of the brace eliminates the need for the clinic to fabricate a custom-made brace each time the patient needs to modify, typically shorten, its length. It also eliminates the need to provide the patient with multiple braces of different lengths. Instead, when the patient needs to shorten the brace, they simply bring it to the dental clinic for adjustment.

[0021] In principle, there are different options for rigging configurations that allow for adjusting its length. Three preferred embodiments are described here.

[0022] First implementation: strips that can be attached to each other

[0023] In this first embodiment, the tie rod comprises two physically separate portions that can be coupled together in different positions corresponding to different lengths.

[0024] In principle, this can be achieved in various ways, although in a particularly preferred embodiment, each portion of the tie rod comprises a strip and a retaining element. The strip comprises an end element containing the hole to which the pins of the lower portion are hinged, and a patterned face. Thus, when the two strips are inserted through a hole in the retaining element with their opposing faces compressed against each other, the pattern on the face of one strip engages with the pattern on the face of the other strip, thereby fixing the length of the tie rod. In other words, the hole in the retaining element forces both faces to be compressed against each other, so that both patterns fit together, preventing their relative slippage, at least in the direction of reducing the strip's length.

[0025] In principle, the pattern mentioned can be of any type, provided it is complementary to a similar pattern, so that they fit together when the faces of the two strips are compressed against each other, preventing slippage, at least in the direction of reducing the strip's length. For example, in a particularly preferred embodiment of the invention, the face pattern is a toothed pattern with one inclined flank and another flank perpendicular to the face itself. Thus, when the two strips are inserted through the hole of the retaining element with their faces compressed against each other, they slide against each other as they move in the direction of the inclined flank of the toothed pattern, thereby allowing the length of the tie rod to be reduced. However, movement in the opposite direction is blocked, preventing an increase in its length.

[0026] The retaining element is typically cylindrical, with the hole having a cross-sectional shape complementary to that of the tie rod strips when their faces are compressed against each other. For example, the hole's cross-section may be elongated, rectangular, or square. In either case, the corners of the hole may be rounded.

[0027] However, in a particularly preferred embodiment of the invention, the hole in the retaining element is wedge-shaped or conical with a wide end and a narrow end, such that the wide end facilitates the insertion of the strips and the narrow end ensures the compression of the two toothed faces of the strips against each other.

[0028] In principle, a single retaining element could be used, although in preferred embodiments of the invention the tie rod comprises two or more retaining elements.

[0029] Second embodiment: end elements with double hole

[0030] In a preferred embodiment of the invention, an alternative to the foregoing, the tie rod comprises a first cord connected to two end pieces. Each end piece, in turn, comprises the hole to which the anchors of the lower portion are articulated, and one or more adjacent additional holes configured for attaching one end of the cord.

[0031] More preferably, the first cord has one end fixed to the additional holes of one end piece, passes through the additional hole of the other end piece, and has the opposite end fixed to the additional hole of the first end piece, making one or more turns.

[0032] Even more preferably, the first cord comprises several braided strands to reduce its length. This configuration provides a particularly simple and quick way to adjust the length of the suspender, as it is not necessary to cut or unravel the cord, but simply twist an existing cord.

[0033] Third realization: ties

[0034] According to another preferred embodiment, an alternative to the preceding ones, the tie rod comprises a second cord in which the hole to which the anchors of the lower portion are hinged is implemented by means of loops of the second cord itself. To fix the loops, the tie rod preferably further comprises clamps fixed to the base of each loop. This fixing can be carried out in any suitable manner. For example, the clamps can be made of a deformable material such as metal, so that, when squeezed, they compress around the base of each loop. However, in a particularly preferred embodiment, the clamps are fixed to the base of the loops by means of an adhesive.

[0035] Furthermore, the guiding means for the upper portion of the splint can be implemented in various ways, provided they adequately guide the brace. For example, in a preferred embodiment, the guiding means are hooks projecting from the outer surface of the front area of ​​the upper portion. In an alternative preferred embodiment, however, the guiding means are channels machined into the outer surface of the front area of ​​the upper portion. That is, in this second case, they do not project from the outer surface of the upper portion.

[0036] Second aspect: adjustable length strap for a mandibular advancement device

[0037] A second aspect of the present invention relates to a strap for an adjustable mandibular advancement device. The strap comprises two physically separate portions that can be coupled together at different positions corresponding to different lengths, where each portion of the strap comprises a strip and a retaining element. The strip comprises an end element containing the hole to which the studs of the lower portion are articulated, and a face provided with a pattern. Thus, when the two strips are inserted through a hole in the retaining element with their facing faces compressed against each other, the pattern on the face of one strip engages with the pattern on the face of the other strip, thereby fixing the length of the strap.

[0038] In principle, the pattern mentioned can be of any type, provided it is complementary to a similar pattern, so that they fit together when the faces of the two strips are compressed against each other, preventing slippage, at least in the direction of reducing the strip's length. For example, in a particularly preferred embodiment of the invention, the face pattern is a toothed pattern with one inclined flank and another flank perpendicular to the face itself. Thus, when the two strips are inserted through the hole of the retaining element with their faces compressed against each other, they slide against each other as they move in the direction of the inclined flank of the toothed pattern, thereby allowing the length of the tie rod to be reduced. However, movement in the opposite direction is blocked, preventing an increase in its length.

[0039] The retaining element is typically essentially cylindrical, with the hole having a cross-sectional shape complementary to that adopted by the tie rod strips when their faces are compressed against each other. For example, the cross-section of the hole may be elongated, such as rectangular or square. In either case, the corners of the hole may be rounded. However, in a particularly preferred embodiment of the invention, the hole in the retaining element is wedge-shaped or conical with a wide end and a narrow end, such that the wide end facilitates the insertion of the strips and the narrow end ensures the compression of the two toothed faces of the strips against each other.

[0040] In principle, a single retaining element could be used, although in preferred embodiments of the invention the tie rod comprises two or more retaining elements.

[0041] BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figures 1A-1C show perspective views of an adjustable mandibular advancement device according to an embodiment of the present invention.

[0043] Figures 2A-2C show perspective views of an adjustable mandibular advancement device according to another embodiment of the present invention.

[0044] Fig. 3 shows a first example of an adjustable tie-back portion for a mandibular advancement device according to the present invention.

[0045] Fig. 4 shows a cross-section of two tie rod portions according to the first example rigidly coupled together by means of the toothing.

[0046] Fig. 5 shows a detail of the coupling between the toothed faces of the two tie rod portions according to the first example shown in Fig. 4.

[0047] Figs. 6A-6C show a tie rod according to the invention with tie rod portions according to the first example fixed in various positions corresponding to different lengths.

[0048] Fig. 7 shows a second example of a tie rod for a mandibular advancement device according to the present invention.

[0049] Figures 8A and 8B show in greater detail the ends of the first second adjustable strap shown in Figure 7.

[0050] Fig. 9 shows a third example of an adjustable strap for a mandibular advancement device according to the present invention.

[0051] PREFERRED EMBODIMENT OF THE INVENTION

[0052] Examples of the invention are described below with reference to the accompanying figures.

[0053] Figures 1 and 2 show different views of two embodiments of the device (1) of the present invention, illustrating its component parts. Specifically, the device comprises a brace (2) and a splint (3), the splint (3) consisting of an upper portion (31) and a lower portion (32). The upper portion (31) is designed to fit against the teeth of the patient's upper jaw, while the lower portion (32) is designed to fit against the teeth of the patient's lower jaw. The splint (3) is custom-made for each patient based on medical images of their anatomy, for example, using 3D scanning, radiography, CT scans, or other methods.

[0054] As can be seen, the upper (31) and lower (32) portions of the splint (3) are connected by means of the tie rod (2). For this purpose, the tie rod (2) has end elements (25) with a hole through which an anchor, in this specific example a pin (321), is inserted. This pin is located on the side of the lower portion (32) of the splint (2). In its central section, the tie rod (2) passes through guide means (311) located on the outer surface of the upper portion (31) of the splint (3). The guide means (311) can be hooks or similar protrusions extending from the upper portion (31) of the splint (3), as shown in Figs. 1 A-1C. Alternatively, the guide means (311) can be channels machined into the upper portion (31) of the splint (3).These conduits have an inlet and an outlet, eliminating the need for elements protruding from the natural outer surface of the upper portion (31) of the splint (3). Although not visible in these figures, the tie rod (2) has an adjustable length. Furthermore, the splint (3) may have, for example, vertical lines on its upper portion (31) that can serve as a reference for the relative position of the upper splint with respect to the lower one, achieved by adjusting the length of the tie rod (2). These vertical lines are visible in the example illustrated in Fig. 2.

[0055] The three adjustable strap configurations (2) described in this document are described in more detail below.

[0056] First example: Figs. 3-6

[0057] In this first example, the adjustable tie rod (2) is formed by two physically separate portions (21, 22) as shown in Fig. 3. As can be seen, this tie rod portion (21) is formed by a strip (24) with a square or rectangular cross-section, at the end of which is an end element (25) with a hole (221). The end element (25) could be a separate piece fixed to the strip (24), although preferably both form a single piece manufactured, for example, by plastic injection molding, 3D printing, or similar means.

[0058] The hole (221) in the end element (25) is, in this example, elongated to provide the user with a certain amount of clearance, as described in the aforementioned patent EP3103420B1 belonging to the present applicant. Note, however, that the principle underlying the adjustable tie rod (2) described herein is equally applicable when the hole (221) in the end element (25) has any other shape, such as circular.

[0059] The adjustable tie rod (2) in this example has a toothed face (241), which is the upper face in Fig. 3. The teeth on this toothed face (241) are straight and perpendicular to the longitudinal direction of the strip (24), with an essentially triangular cross-section. One side of the teeth is inclined relative to the upper surface of the strip (24), while the other side is essentially perpendicular to that upper surface. This configuration is similar to that of a conventional flange.

[0060] The tie rod (2) also comprises a retaining element (23), which is not shown in Fig.

[0061] 3. The retaining element (23) is essentially cylindrical with a hole of complementary cross-section, the shape of two strips (24) of respective tie rods (2) when they rest against each other by their respective toothed faces (241). This shape may be elongated, for example, rectangular or rectangular with rounded edges. Alternatively, the shape may be square or square with rounded edges. Furthermore, the cross-section of the hole may vary along the length of the retaining element (23), thus giving it a wide end (EA) and a narrow end (EE). This is shown in more detail in Fig. 5.

[0062] Thus, Fig. 4 shows how two portions (21, 22) of the tie rod are coupled. First, the free end, i.e., the end opposite the end element, of the strip (24) of one tie rod portion (21) is inserted through the narrow end (EE) of the retaining element (23). Next, the free end of the strip (24) of the other tie rod portion (22) is inserted through the wide end (EA), so that both toothed faces (241) are facing each other. The dimensions of the hole in the retaining element (23) are configured to compress one strip (24) against the other, so that their respective teeth interact. In the direction of insertion of both strips (24), i.e., in the direction that corresponds to reducing the overall length of the tie rod (2), the inclined flanks of both teeth shift towards each other, so that the strips (24) slide over one another.However, if an attempt is made to move the strips (24) in the opposite direction, that is, trying to increase the total length of the strip, it is the flanks perpendicular to the surface of the strip (24), in this example vertical, that interact, becoming locked together and preventing any reduction in length. This is a mechanism equivalent to that which occurs in a conventional flange.

[0063] This configuration allows the length of a strap (2) to be adjusted according to the needs of each patient. To do this, it is also useful to cut off the excess length of the strip (24) from one or both strap portions (21, 22). Figures 6A-6D show strips (2) of different lengths. All of them were obtained from the two strip portions (21, 22) shown in Figure 6A, although the length inserted through the corresponding end elements (23) varied. Thus, in Figures 6B-6D, the strips (24) were inserted to a successively greater length through the corresponding end elements (23), and the excess pieces at the ends of the strips (24), which were successively longer, were trimmed.

[0064] Figures 6A-6C show tie rods (2) in which two end elements (23) are used. Using two end elements (23) is advantageous because each one fixes the free end of the strip (24) of each of the two tie rod portions (21, 22).

[0065] Second example: Figs. 7-8 In the second example, the tie (2) is formed by a cord (26) attached to two end pieces (25). Each end piece (25) is figure-eight shaped and comprises two distinct holes. One hole (221), which in this case is an elongated slot, is for attachment to the stud (321) of the lower portion (32) of the splint (3). The other hole (222), called the additional hole, is for attaching the cord (21).

[0066] This configuration allows the cord (26) to be fixed at a specific desired length. For example, it can be fixed by knotting one end of the cord (26) to the additional hole (222) of one of the end pieces (25), passing the opposite end through the additional hole (222) of the other end piece (25), and finally securing, for example by knotting it, this opposite end of the cord (26) back to the additional hole (222) of the end piece (25) where the first end was tied. Depending on the point on the cord (26) where the knot is made, the maximum length between the two end pieces (25) will vary.

[0067] In the specific example shown in Figs. 7-8, the way the cord (26) is attached to the end pieces (25) results in it having two fibers. This configuration is particularly advantageous because it allows the length to be adjusted without removing the tie rod (2), but simply by twisting the existing cord (26). Alternatively, this tie rod (2) can be easily removed, for example, by simply cutting the cord (26) and replacing it with one of the desired length.

[0068] Third example: Fig. 9

[0069] Figure 9 shows an alternative configuration of the tie (2) of the device (1) of the present invention, in which it is formed primarily by a cord (26) arranged to form two loops at its ends. Each of these loops contains the hole (221) that serves as a fastener to the stud (321) of the lower portion (32) of the splint (3). To properly secure the loops, the tie (2) of this second configuration further comprises two clamps (27) that are placed at the base of the loops and pressed together, firmly gripping the two lines of cord (21) that form each loop. Again, this configuration is advantageous because it allows the length of the tie (2) to be easily selected as desired.

Claims

AMENDED CLAIMS received by the International Bureau on February 24, 2026 (24.02.2026)

1. Adjustable mandibular advancement device (1), comprising a brace (2) and a dental splint (3) formed by an upper portion (31) and a lower portion (32), wherein the upper portion (31) of the splint (3) is configured to fit the upper jaw dentition of a patient and the lower portion (32) of the splint (3) is configured to fit the lower jaw dentition of the patient, each portion (31, 32) comprising a front zone configured to fit the patient's incisors and canines and two side zones configured to fit the patient's premolars and molars, wherein outer faces of the side zones of the lower portion (32) comprise respective anchorages (321) and an outer face of the front zone of the upper portion (31) comprises at least one guide means (311), where the tie rod (2) comprises two ends provided with respective holes (221) articulated to the anchors (321) of the lower portion (32) and a central section that passes through the guide means (311) of the upper portion (31), such that the tie rod (2) acts in tension between the two anchors (321) of the lower portion (32) of the splint (3) to prevent the free recoil of said lower portion (32) with respect to the upper portion (31), wherein the tie rod (2) comprises means for selectively adjusting its length to a specific desired value, characterized in that the guide means (311) are channels made in the outer face of the front area of ​​the upper portion (31) that do not protrude from said outer face of the upper portion (31).

2. Adjustable mandibular advancement device (1) according to claim 1, wherein the tie rod (2) comprises two physically separate portions (21, 22) that are attachable to each other in different positions corresponding to different lengths.

3. Adjustable mandibular advancement device (1) according to claim 2, wherein each portion (21, 22) of the brace (2) comprises a strip (24) and a retention element (23), the strip (24) comprising an end element (25) having the hole (221) to which the anchors (321) of the lower portion (32) are articulatedly connected and a face (241) provided with a pattern such that, when the two strips (24) are inserted through a hole of the retention element (23) with their faces (241) facing each other and compressed against one another, the pattern of the face (241) of one strip (24) engages with the pattern of the face (241) of the other strip (24), thereby fixing the length of the brace (2).

4. Adjustable mandibular advancement device (1) according to claim 3, wherein the face pattern (241) is a toothed pattern having an inclined flank and another flank perpendicular to the face (241) itself, such that when the two strips (24) are inserted through the hole of the retention element (23) with their faces (241) compressed against each other, they slide against each other as they move to reduce the length of the tie (2) in the direction in which the inclined flank of the toothed pattern is located, the movement being blocked in the opposite direction of increasing the length of the tie (2).

5. Adjustable mandibular advancement device (1) according to claim 4, wherein the hole of the retention element (23) is wedge-shaped or conical with a wide end (EA) and a narrow end (EE), such that the wide end facilitates the insertion of the strips (24) and the narrow end ensures the compression of the two toothed faces of the strips (24) against each other.

6. Adjustable mandibular advancement device (1) according to claim 1, wherein the strap (2) comprises a single cord (26) connected between the end elements (25), each end element (25) comprising the hole (221) to which the anchors (321) of the lower portion (32) are articulated and one or more additional adjacent holes (222) configured for fixing one end of the cord (26).

7. Adjustable mandibular advancement device (1) according to claim 6, wherein the cord (26) has one end fixed to the additional hole (222) of an end element (25), passes through the additional holes (222) of the other end element (25), and has the opposite end fixed to the additional holes (222) of the first end element (25), making one or more turns.

8. Adjustable mandibular advancement device (1) according to any of claims 6-7, wherein the cord (26) comprises several braided strands for adjusting its length.

9. Adjustable mandibular advancement device (1) according to claim 1, wherein the strap (2) comprises a cord (26) in which the hole (221) to which the anchors (321) of the lower portion (32) are articulated is implemented by loops of the cord (26) itself.

10. Adjustable mandibular advancement device (1) in accordance with claim 9, wherein the tie rod (2) further comprises clamps (27) attached to a base of each loop for securing it.

11. Adjustable mandibular advancement device (1) according to claim 10, wherein the clamps (27) are fixed to the base of each loop by means of an adhesive.

12. Adjustable mandibular advancement device (1) according to claim 10, wherein the clamps (27) are made of a deformable material such that, when tightened, they compress around the base of each loop [0001]DECLARATION ACCORDING TO ARTICLE 19 (1) [0002]RESPONSE TO INTERNATIONAL SEARCH REPORT FOR APPLICATION PCT / ES2025 / 070215 ADJUSTABLE MANDIBULAR ADVANCE DEVICE AND TENSIONER FOR AN ADJUSTABLE MANDIBULAR ADVANCE DEVICE [0003]An answer to the IBI and a written opinion are provided, modifying the claims as detailed in the accompanying letter. [0004]In general, all the instructions given in the IBI have been followed.

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