Jaw displacement system that affects growth of lower jaw

Abstract

A jaw displacement system for moving a lower jaw (5) relative to an upper jaw (6), comprising:-at least one bone anchor (7),-an elongate jaw shifter (8),-a frame (9) wherein the jaw displacement system permits the application of pressure between the frame (9) and the bone anchor (7) in order to displace the jaw (5) when the frame (9) is fixed to a molar (19) and when the bone anchor (7) is fixed to the bone of the lower jaw (5) on the buccal-labial side. The lower jaw (5) is moved to the ventral side with respect to the upper jaw (6).

Description

TECHNICAL FIELD

[0001] The present invention relates to a jaw displacement system for moving the mandible relative to the maxilla. The system is provided with at least one bone anchor comprising a fixation plate for fixation of the bone anchor to the bone of the mandible. The fixation plate is connected to a connection element leading to a mounting member. When the bone anchor is attached to the bone, the connection element should protrude through the gum so that the mounting member is located in the oral cavity.

[0002] Furthermore, the jaw displacement system comprises an elongated jaw displacer having two opposite ends. The jaw displacer allows for exertion of a pressure between its two ends, and it can be attached to the mounting member with one of the ends. The jaw displacer is thus arranged to be attached to the mounting member in the oral cavity with one end.

[0003] The jaw displacement system according to the invention is particularly suitable as a medical device for influencing the growth and occlusion of the mandible in patients suffering from Class II malocclusion, also known as disto-occlusion. In such patients, the teeth of the maxilla are positioned too far forward compared to the teeth of the mandible. In most cases, this is due to underdevelopment of the mandible and / or overgrowth of the maxilla, resulting in a convex profile of the face. BACKGROUND

[0004] The mandible of patients suffering from Class II malocclusion is often underdeveloped, resulting in the dental arch of the mandible being positioned too far back relative to the dental arch of the maxilla. This increases the distance between the upper and lower incisors. This can result in one or more of the following complications:

[0005] - palatal bite of the lower incisors,

[0006] - overgrowth of the lower and upper incisors,

[0007] - functional problems, such as bruxism and disorders of the temporomandibular joint, and

[0008] - impaired facial aesthetics due to underdevelopment of the chin and convex profile of the soft tissue.

[0009] Furthermore, a mandible that is set back relative to the maxilla can also cause sleep apnea.

[0010] Several treatments exist for patients suffering from Class II malocclusion. In young patients, the growth of the mandible is attempted to be stimulated. Moving the mandible in an anterior position over a longer period of time can lead to a growth change of the condyle and gonial angle (mandibular angle) resulting in a permanent forward displacement of the chin. This forward displacement of the mandible can be achieved by using removable or adhesive orthodontic brackets, also known as orthopedic brackets, as they attempt to change the growth of the jaw. A disadvantage of using such brackets is that they are placed on the teeth, which leads to unwanted tooth movement. The forward movement of the lower incisors is especially undesirable. When using such brackets placed on the teeth, the unwanted tooth movement can eventually be much larger than the intended growth change of the jaw.

[0011] In patients suffering from Class II malocclusion, if the growth of the mandible cannot be sufficiently stimulated, or if the growth has stopped, the mandible can only be moved forward by performing a jaw surgery, in particular an osteotomy.

[0012] One of the orthopedic devices currently used to correct Class II malocclusion is the so-called Herbst device. The Herbst device has two telescopic joints extending along both sides of the dental arch, which are connected to a frame attached to the teeth of the upper jaw and to a frame attached to the teeth of the lower jaw. Thus, this device ensures that the teeth of the mandible and the mandible itself are pushed forward relative to the maxilla as soon as the patient closes his / her mouth. However, due to the tooth anchorage of the Herbst device, it mainly causes tooth movement and only to a limited extent changes the growth of the mandible. The lower premolars and incisors of the mandible are moved forward here, wherein these lower incisors are also tilted forward. This in turn leads to bite problems, periodontal problems and bone loss at the root of the lower incisors.

[0013] For example, the documents US 2014 / 0272759 and US 4462800 describe such a use of the Herbst device.

[0014] The telescopic joints of the Herbst device are usually attached between hinges provided on the upper first molars and hinges attached to the lower first premolars. If the longitudinal axis of the telescopic joints, more particularly the direction of the applied force, is tilted too much with respect to the bite plane and extends above the condyle, this will cause the mandible to rotate posteriorly. This increases the facial height and moves the chin posteriorly.

[0015] To remedy these drawbacks, mini-implants are sometimes used as a replacement for the tooth anchorage of the Herbst device to transmit the pressure of the Herbst device directly to the jawbone. Such systems are described, for example, in documents US 2006 / 0172251, WO 2009 / 085321 or WO 2010 / 037195. However, the use of these mini-implants causes the orientation of the Herbst device to deviate too much from the direction of the occlusal plane, since the mini-implants must be attached to the jawbone at a sufficient distance from the tooth roots to avoid damaging the roots. As already mentioned, such an orientation of the Herbst device causes the mandible to be rotated backwards and does not stimulate sufficiently the forward growth of the jaw in the ventral direction. In addition, the mini-implants are less adapted to absorb the relatively large forces associated with the use of the Herbst device and therefore often fail.

[0016] Furthermore, such a treatment often causes a so-called reverse bite, since the mandible is moved forward relative to the maxilla. As a result, the widest part of the dental arch of the mandible is positioned opposite the narrower part of the dental arch of the maxilla, which causes a reverse bite. SUMMARY

[0017] The present invention aims to remedy the aforementioned drawbacks by proposing a jaw displacement system with a jaw displacer which allows the mandible to be moved ventrally relative to the maxilla without the need to exert pressure directly on the teeth of the mandible. This ensures that the orientation of the jaw displacer, and in particular the direction in which the jaw displacer exerts pressure, is as close as possible to the orientation of the occlusal plane. In addition, the jaw displacement system allows relatively large forces to be absorbed, for example even in young patients whose maxilla and / or mandible are not yet fully grown.

[0018] To this end, the jaw displacement system comprises a frame which allows the molars of the same quadrant of the maxilla to be rigidly connected to each other, the frame comprising a connection element for one end of the jaw displacer. When the frame is fixed to the molars and the bone anchor is fixed to the mandible on the vestibular side, the jaw displacement system according to the invention will allow the ends of the jaw displacer to be connected respectively to the mounting member and the connection element in order to exert a pressure between the bone anchor and the frame to move the mandible ventrally relative to the maxilla.

[0019] The frame preferably forms a rigid whole.

[0020] Preferably, the connection element is provided to the frame at a location distal of the first molar when the frame is attached to the molars.

[0021] According to an embodiment of the jaw displacement system according to the invention, the frame is provided with a first jaw displacement device for the upper jaw and a second jaw displacement device for the lower jaw.

[0022] According to a preferred embodiment of the jaw displacement system according to the invention, the jaw displacement system comprises a rod and a rod guide, wherein the rod is connected to one of the end portions of the jaw displacement device, and wherein the rod guide is connected to the opposite end portion of the jaw displacement device, such that the rod can be moved relative to the rod guide in the longitudinal direction of the rod guide.

[0023] According to an embodiment of the jaw displacement system according to the invention, the rod guide comprises a spring element, which allows a pressure to be exerted along the longitudinal direction of the rod guide, such that the rod guide can be deformed in its longitudinal direction between a compressed state and an extended state.

[0024] In an interesting aspect, the jaw displacement device is at least partially made of a super-elastic material, such as a nickel-titanium alloy. More specifically, the rod is preferably made of a super-elastic material.

[0025] The invention is therefore advantageously applied to influence the growth of the lower jaw of a patient suffering from a Class II malocclusion before the lower jaw is fully grown. BRIEF DESCRIPTION OF DRAWINGS

[0026] Further details and advantages of the invention will become apparent from the following description of some specific embodiments of a jaw displacement system according to the invention. This description is given by way of example only and without limitation of the claimed scope; the reference signs used in the following description relate to the attached drawings.

[0027] Figure 1 Schematic side view of a lower jaw and a jaw joint, illustrating the effect of a treatment with a jaw displacement system according to the invention.

[0028] Figure 2 Schematic side view of a lower jaw and an upper jaw, on which a jaw displacement system according to an interesting embodiment of the invention is installed.

[0029] Figure 3 is a schematic front view of a lower jaw and an upper jaw with a jaw displacement system. Figure 2 is a schematic front view of a lower jaw and an upper jaw with a jaw displacement system.

[0030] Figure 4 is a schematic perspective view of a frame of a jaw displacement system according to the invention, comprising a jaw displacement device and a bone anchor.

[0031] Figure 5 is a schematic side view of an interesting embodiment of a jaw displacement device used in a jaw displacement system according to the invention.

[0032] Figure 6 Fig. 1 is a schematic side view of a jaw displacer according to the present invention. Figure 5 Fig. 2 is a schematic side view of a variant of the jaw displacer in Fig. 1, which variant additionally comprises a compression spring.

[0033] Figure 7 Fig. 3 is a schematic perspective view of an end piece of the jaw displacer, which end piece forms a first end of the jaw displacer.

[0034] Figure 8 Fig. 4 is a schematic front view of the end piece in Fig. 3. Figure 7

[0035] Figure 9 Fig. 5 is a schematic perspective view of a rod for a jaw displacer according to the present invention.

[0036] Figure 10 Fig. 6 is a schematic perspective view of a rod guide for a jaw displacer according to the present invention.

[0037] Figure 11 Fig. 7 is a schematic view of the palate of an upper jaw provided with a frame of an advantageous embodiment of a jaw displacement system according to the present invention.

[0038] Figure 12 Fig. 8 is a schematic view of the palate of an upper jaw provided with a frame of a preferred embodiment of a jaw displacement system according to the present invention.

[0039] Figure 13 Fig. 9 is a schematic side view of an upper jaw with frame and rod guide in Fig. 8, wherein the rod guide is in an installed position. Figure 2

[0040] Fig. 10 is a schematic side view of an upper jaw with frame and rod guide in Fig. 8, when the rod guide is freely hanging in the oral cavity. Figure 14 Figure 2 DETAILED DESCRIPTION

[0041] The jaw displacement system according to the present invention allows the mandible of a patient to be moved forward. When a patient is treated with the system according to the present invention, a number of very advantageous changes are observed in the patient's jaw, which do not occur simultaneously when using existing systems. In fact, existing systems appear to mainly ensure that the teeth of the mandible are displaced relative to the jaw. However, when the jaw displacement system according to the present invention is used, a number of significant changes are achieved in the mandible and the maxilla. Figure 1 The shape of the jaw before treatment with the jaw displacement system according to the present invention is schematically represented by a solid line, while the shape of the jaw after treatment is schematically represented by a dashed line.

[0042] ​​​Thus, the application of the jaw displacement system according to the invention ensures that the mandible 5 is lengthened in a ventral direction, as indicated by reference numeral 1. In addition, it is observed that the shape of the mandible 5 changes, because the gonial angle of the mandible 5 increases, as indicated by reference numeral 2. Furthermore, in the maxilla 6, the shape and position of the glenoid fossa, also called the mandibular fossa, also surprisingly change. As indicated schematically by reference numeral 3, by the treatment performed, the glenoid fossa is slightly moved downward and forward. Another advantage obtained by the application of the invention is the retro-inclination of the incisors of the mandible 5, as indicated by reference numeral 4.

[0043] By the application of the invention, therefore, a combination of these beneficial effects is achieved, which are used to correct, for example, a class II malocclusion of a patient. With the existing non-surgical treatment methods for class II malocclusions, such results have not been achieved.

[0044] Figure 2 、 Figure 3 and Figure 4 A first embodiment of a jaw displacement system according to the invention is shown schematically. This jaw displacement system allows the mandible 5 to be moved ventrally relative to the maxilla 6.

[0045] To this end, the jaw displacement system comprises at least a bone anchor 7, a jaw displacer 8 and a frame 9.

[0046] The bone anchor 7 has a fixation plate 10 which has to be fitted to the bone of the mandible 5 in order to fix the bone anchor 7 to the mandible 5. By means of a drill hole 11 in the fixation plate 10, the bone anchor is thus firmly fixed to the bone of the mandible 5 with a screw. The fixation plate 10 is fitted to a connection element 12 which leads to a mounting member 13. Here, the fixation plate 10 has to extend against the bone of the jaw 5 and under the gums, while the connection element 12 has to protrude through these gums, so that the mounting member 13 extends into the oral cavity. The connection element 12 preferably has a circular cross-section in order to ensure a good fit of the gums to this connection element 12.

[0047] The jaw displacer 8 has an elongated shape and therefore has two opposite ends 14 and 15. The first end 14 is provided with a fastening member for fastening the jaw displacer 8 directly to the mounting member 13 of the bone anchor 7. In the proposed embodiment, the mounting member 13 for this has a hook 16, while the fastening member is formed by a loop eye 17. When the bone anchor 7 is attached to the lower jaw 5, as shown in the figures, the opening 18 of the hook 16 is preferably directed away from the occlusal plane and is located mainly on the ventral side of the hook 16. This allows the jaw displacer 8 to be attached to the bone anchor 7 by sliding the loop eye 17 along the opening 18 on the hook 16 from the bottom to the top, thereby connecting them directly. The description from the bottom to the top means that the eye 17 is moved in a direction extending from the lower jaw 5 towards the upper jaw 6, which is almost transverse to the plane defined by the dental arch of the lower jaw 5.

[0048] The frame 9 of the jaw displacement system is arranged to rigidly connect the molars of the same quadrant of the upper jaw 6. Such a frame 9 is custom-made for each patient. To this end, at least the molars of the upper jaw of the patient are intraorally scanned, after which the frame is designed and manufactured digitally for the two quadrants of the upper jaw 6 on the basis of the data obtained from the scan, for example by means of the so-called rapid prototyping technique, such as selective laser melting (SLM).

[0049] Of course, it is also possible to start from a physical model of the upper jaw to manufacture such a frame 9 in a known manner.

[0050] The frame 9 consists of a rigid structure which should be connected laterally to the molars 19 of the upper jaw. It is generally preferred that via this structure the first premolar, the second premolar and the first molar of the same quadrant of the upper jaw 6 are rigidly connected. The second molar is not generally surrounded by the frame 9 on the distal side, because there is a risk that the frame on this side is covered by excessive growth of the gums during the treatment.

[0051] However, in order to avoid a height difference in the mastication surfaces of the first and second molar as a result of the forces exerted by the jaw displacers 8 on the frame 9 during the treatment, in some cases it can be concerned to provide an occlusal support 20 on the frame 9. This occlusal support 20 extends over the mastication surface of the second molar, but does not necessarily have to rest on it, so that the growth of the second molar is not hindered as long as it does not come into contact with the occlusal support 20.

[0052] The frame 9 has a fastening element for the second end 15 of the jaw displacer 8. This fastening element therefore allows the second end 15 of the jaw displacer 8 to be connected directly to the frame 9.

[0053] This fastening element of the frame 9 is formed by a loop 21 and cooperates with a corresponding hook 22 provided at the second end 15 of the jaw shifter 8 for this purpose. The hook 22 is attached to the loop 21 by hooking it into the loop 21, the jaw shifter 8 thus being detachably connected to the frame 9.

[0054] The jaw shifter 8 generally comprises a rod 25 and a rod guide 26. In this case, the first end 14 forms a part of the rod 25, while an end of the rod guide 26 forms the second end 15 of the jaw shifter 8 and is provided with the hook 22. The rod 25 can be moved in the longitudinal direction of the rod guide 26. By moving the rod 25 relative to the rod guide 26 in this way, the length of the jaw shifter 8 can be changed.

[0055] In the embodiment of the rod guide 26 shown in the figures, it is made hollow. More specifically, the rod guide 26 has a central cylindrical hole which is open on both sides, and the rod 25 can be moved through this cylindrical hole in the longitudinal direction of the rod guide. In this case, the rod 25 preferably comprises a cylindrical rod 27 which can be guided through the rod guide 26 in a fitting manner.

[0056] The rod 25 is provided with an end piece 28 as shown in Figure 7 and Figure 8 . This end piece 28 is partly cylindrical and contains the loop eye 17 on one side and has an axial hole 29 on the opposite side in which the cylindrical rod 27 is clamped or fixed. The diameter of the cylindrical rod 27 is thus slightly smaller than the diameter of the end piece 28. As a result, the end piece 28 forms a stop or buffer for the rod guide 26 when the rod guide 26 slides over the cylindrical rod 27 of the rod 25.

[0057] As shown in Figure 3 , when the jaw shifting system is thus installed so that in the mouth of the patient, on both sides of the jaw, there are the bone anchors 7, the jaw shifter 8 and the frame 9, the jaw shifting system ensures that when the mouth is closed, the lower jaw 5 is pushed forward relative to the upper jaw 6. More specifically, the dimensions of the rod guide 26 and the dimensions of the end piece 28 of the rod 25 are chosen so that when the mouth is closed, the rod guide 26 will press against the end piece 28. In this position, therefore, a pressure is exerted between the bone anchors 7 and the frame 9 so that the lower jaw 5 is displaced ventrally relative to the upper jaw 6.

[0058] Furthermore, the length of the rod 25, more specifically the length of the cylindrical rod 27, is chosen so that when the jaws 5 and 6 are moved into the normal open position of the mouth, the rod 27 will always extend partly into the rod guide 26 so that the jaw shifter 8 extends as a whole between the frame 9 and the mounting member 13 of the bone anchors 7.

[0059] The rods 25 and rod guides 26 of the jaw displacer 8 are non-flexible, preferably, in their longitudinal direction, virtually incompressible. Thus, when the jaw displacer 8 is installed in the mouth of a patient, the jaw displacer 8 can exert a pressure between the bone anchors 7 and the frame 9. When the patient closes his / her mouth, as a result of the pressure exerted by the jaw displacer 8, the lower jaw is thus moved forward relative to the upper jaw. The rods 25 and rod guides 26 can be made of, for example, titanium, a memory alloy or a relatively rigid plastic. Thus, in order to allow the jaw displacer 8 to exert a pressure between the bone anchors 7 and the frame 9 in its longitudinal direction, it is essential that the rods 25 and rod guides 26 are not flexible. In general, a jaw displacer is not flexible and allows a pressure to be exerted between its two ends. A flexible material or object is defined as a material or object that is not possible to exert a pressure between its opposite ends, for example a rope, a rubber band, a paper strip, etc.

[0060] In order to remove the jaw displacer 8 from the mouth or to fit it in the mouth, the jaws 5 and 6 are opened substantially. In this position with the mouth substantially open, the total length of the rods 25 and rod guides 26 is less than the distance between the mounting member 13 and the loop 21 of the frame 9.

[0061] Figure 13 The mounting position of the rod guide 26 is shown. In this position, the longitudinal direction of the rod guide 26 is tilted upwards and extends partly above the frame 9, while the hook 22 is held connected to the frame 9 with the loop 21. In this mounting position, the opening 30 of the hook 22 also points towards the top of the frame 9 and away from the mastication surface of the teeth of the upper jaw 6. Thus, in order to remove the rod guide 26 from the hook 22, it is only necessary to move it downwards from the mounting position. In order to attach the rod guide 26 to the loop 21 on the frame 9, the rod guide is reversed to make the same movement.

[0062] Once the rod guide 26 is thus connected to the frame 9 and the rod 25 is connected to the bone anchor 7, the jaws 5 and 6 are opened substantially and the rod 27 is inserted into the hole in the rod guide 26 in order to assemble the jaw displacer 8. When the jaws are closed again, the rod 27 slides through the rod guide 26 until it reaches the end piece 28. When this end piece 28 is reached, the lower jaw 5 is pushed forward.

[0063] Figure 6A replacement embodiment of the jaw shifter 8 according to the application is shown. Here, a compression spring 33 is arranged around the cylindrical rod 27 between the end piece 28 of the rod 25 and the rod guide 26. In the proposed embodiment, this compression spring 33 is formed by a helical spring which is coaxial to the rod 25. The presence of this compression spring 33 ensures on the one hand that the displacement of the rod guide 26 towards the end piece 28 is attenuated to some extent when the jaws 5 and 6 are closed. The forces exerted on the frame 9 and the bone anchors 7 are thus also attenuated when the jaws 5 and 6 are closed, and the impulse loads exerted on the bone anchors are very small. On the other hand, the presence of the compression spring 33 allows the pressure exerted by the jaw shifter 8 on the bone anchors 7 and thus on the lower jaw 5 to be adjusted according to the compression spring 33 chosen.

[0064] In order to avoid any plastic deformation of the jaw shifter 8 or more specifically of the rod 25 when they are manipulated, the jaw shifter 8 is preferably at least partially made of a super-elastic material, in particular of a nickel-titanium alloy for example. The jaw shifter 8 thus automatically returns to its original shape after it has been intentionally or unintentionally deformed. Preferably, the rod 25 or the cylindrical rod 27 of this rod is made of such a super-elastic metal. Super-elastic materials generally have a relatively high elasticity, but are not flexible.

[0065] Furthermore, when the rod 25 or the rod 27 is preferably made of a super-elastic material, it is possible to choose a smaller diameter for these components than when a non-super-elastic metal is used. Indeed, in the case where a non-super-elastic metal is used, it must be ensured that the diameter of the components is sufficiently large to avoid any plastic deformation, for example by folding or bending.

[0066] In order to prevent the hooks 22 of the jaw shifter 8, more specifically the hooks 22 of the rod guide 26, from being accidentally or unintentionally removed from the loop 21 on the frame 9, the loop 21 is oriented relative to the frame 9 such that the central axis 23 of the loop 21 has a maximum angle a of approximately 20°, preferably 15°, relative to the perpendicular of the plane 24 of the dental arch of the upper jaw 6, as is schematically shown in Figure 13 Preferably, it is ensured that the central axis 23 is almost parallel to this perpendicular.

[0067] When the rod 25 is unintentionally or accidentally removed from the rod guide 26, the rod guide 26 will automatically assume a position as is exemplarily illustrated in Figure 14 Here, the rod guide 26 extends mainly under the mastication surface of the upper jaw 6, or under the frame 9, and is directed towards the lower jaw 5. This ensures that the opening 30 of the hook 22 also faces the lower jaw, so that the hook 22 cannot be removed from the loop 21. Indeed, in order to remove the hook 22, it is necessary to manually put the rod guide 26 in the mounting position, as described above and as shown in Figure 13

[0068] ​Figure 11 A variant of the embodiment of the frame 9 of the jaw displacement system according to the application is shown. Here, a respective frame 9 is placed on the molar tooth in each quadrant of the upper jaw 6, which frames 9 are connected by means of a rigid connecting bar 31.

[0069] Figure 12 A particularly interesting embodiment of the frame 9 of the jaw displacement system according to the application is shown. Here, a frame 9 is provided on the molar tooth in each quadrant of the upper jaw 6. These frames 9 are rigidly connected to each other by means of a palatal expansion module 32 opposite the palate. Such modules are known to the expert and are often used to widen the upper jaw 6 of a patient.

[0070] In the jaw displacement system according to the application, it is particularly interesting to provide such an expansion module 32 between the frames 9 of the upper jaw 6. In fact, when the lower jaw 5 is moved forward relative to the upper jaw 6, the dental arch of the lower jaw will gradually move forward relative to the dental arch of the upper jaw as a result of the lower jaw 5 being stimulated to grow and change shape, with the result that during the treatment of the patient, a reverse bite will gradually occur.

[0071] By applying the said palatal expansion module 32 during the treatment with the jaw displacer 8, it is also possible to gradually adjust the width of the upper jaw 6 during the gradual forward displacement and growth of the lower jaw 5 in accordance with the displacement of the lower jaw 5, so that a reverse bite is avoided.

[0072] It is also important to note that at the connection of the end portions 14 and 15 of the jaw displacer 8, lateral displacement of the lower jaw 5 and the upper jaw 6 relative to each other is allowed by using a hole eye 17 or a ring 21 that cooperates with a respective hook 16 or 22. Despite the presence of the jaw displacement system in the oral cavity, the jaws 5 and 6 are still allowed to move relative to each other in a comfortable manner during, for example, a mastication action.

[0073] In certain cases, it is interesting to provide a fastening device on the lateral side of the frame 9 to, for example, fix an orthodontic wire and thus perform orthodontic treatment together with the displacement of the lower jaw 5. More particularly, for example, orthodontic treatment of the incisors of the upper jaw can thus be performed in this way. Figure 2 and Figure 4 Such a fastening device is shown in the form of a cylinder 34 with a hole with a rectangular cross section for an orthodontic wire.

Claims

1. A jaw displacement system for moving a lower jaw (5) relative to an upper jaw (6), comprising: - at least one bone anchor (7) comprising a fixation plate (10) arranged for fixing the bone anchor (7) to a bone of the lower jaw (5), wherein the fixation plate (10) is connected to a connecting element (12) leading to a mounting member (13), and wherein the connecting element (12) shall protrude through the gum when the bone anchor (7) is fixed to the bone so that the mounting member (13) is located in the oral cavity, - an elongated jaw displacer (8) having two opposite ends (14, 15), wherein a first one (14) of these ends has a fastening member (17) allowing the jaw displacer (8) to be attached to the mounting member (13), characterized in that the jaw displacement system comprises a frame (9) arranged for rigidly connecting molar teeth (19) of the same quadrant of the upper jaw (6), wherein the frame (9) comprises a fastening element (21) for a second end (15) of the jaw displacer (8) so as to connect the ends (14, 15) of the jaw displacer (8) to the mounting member (13) and the fastening element (21), respectively, to allow a pressure to be exerted between the frame (9) and the bone anchor (7), in particular the mounting member (13), so as to move the lower jaw (5) ventrally relative to the upper jaw (6) when the frame (9) is fixed to the molar teeth (19) and the bone anchor (7) is fixed to the bone of the lower jaw (5) on the labial-buccal side.

2. The jaw displacement system of claim 1, wherein, The jaw displacer (8) is not flexible and allows a pressure to be exerted between its two ends (14, 15) in its longitudinal direction.

3. The jaw displacement system of claim 1 or 2, wherein, The fastening element forms a loop (21) and cooperates with a corresponding hook (22) arranged on the second end (15) of the jaw displacer (8) for this purpose.

4. The jaw displacement system of claim 3, wherein, The loop (21) is oriented relative to the frame (9) to which it is connected so that a central axis (23) of the loop (21) has a deviation of at most 20° from a perpendicular to a plane (24) defined by the dental arch of the upper jaw (6), wherein this central axis (23) is preferably almost parallel to this perpendicular.

5. The jaw displacement system of any one of claims 1 to 4, wherein, The jaw displacer (8) comprises a rod (25) and a rod guide (26), wherein the rod (25) is connected to one of the ends (14) of the jaw displacer (8) and the rod guide (26) is connected to the opposite end (15) of the jaw displacer (8), wherein the rod (25) is movable relative to the rod guide (26) in the longitudinal direction of the rod guide (26).

6. The jaw displacement system of claim 5, wherein, The rod guide (26) is made hollow, wherein the first end is open to allow the rod (25) to be moved and guided in its longitudinal direction in the rod guide (26).

7. The jaw displacement system of claim 5 or 6, wherein, The jaw displacer (8) is at least partially made of a super-elastic material, in particular of a nickel-titanium alloy.

8. The jaw displacement system of any one of claims 5-7, wherein, The rod (25) is at least partially made of a super-elastic material, in particular of a nickel-titanium alloy.

9. The jaw displacement system of any of claims 5-8, wherein, The rod (25) comprises an end piece (28) forming the first end (24) and a bar (27) connected to the end piece (28).

10. The jaw displacement system of claim 9, wherein, The bar (27) is made of a super-elastic material.

11. The jaw displacement system of any one of claims 1 to 10, wherein, The frame (9) forms a rigid whole.

12. The jaw displacement system of any one of claims 1 to 11, wherein, The fastening element (21) is arranged on the frame (9) in a position opposite and distal to the first molar when the frame (9) is fixed to the molars (19).

13. The jaw displacement system of any one of claims 1 to 11, wherein, The fastening element (21) is arranged on the frame (9) in a position between the first and second molar when the frame (9) is fixed to the molars (19).

14. The jaw displacement system of any one of claims 1 to 13, wherein, The frame (9) has a bite support (20) which should extend at least partially opposite the mastication surface of the second molar when the frame (9) is fixed to the molars.

15. The jaw displacement system of any one of claims 1 to 14, wherein, The fastening element (21) extends opposite and buccally to the frame (9) from the molars (19) when the frame (9) is fixed to the molars (19).

16. The jaw displacement system of any one of claims 1 to 14, wherein, The frame (9) is provided for each of the two quadrants of the upper jaw (6), wherein the two frames (9) are rigidly connected to each other.

17. The jaw displacement system of any one of claims 1 to 15, wherein, The frame (9) is provided for each of the two quadrants of the upper jaw (6), wherein the frames (9) are connected by a palatal expansion module (32) which extends opposite the palate.

18. The jaw displacement system of any one of claims 1 to 17, wherein, The frame (9) is arranged to be attached to the molars (19), wherein the frame at least partially encloses each of the molars (19).

19. The jaw displacement system of any one of claims 1 to 18, wherein, The jaw displacer (8) comprises a spring element (33) which allows to exert a pressure between the ends (14, 15).

20. The jaw displacement system according to any one of claims 1 to 19 for influencing the growth of a lower jaw (5) of a patient suffering from a Class II malocclusion before the lower jaw (5) is fully grown.

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