Orthodontic device

Abstract

Orthodontic device (1) capable of causing a displacement of a mandible relative to a maxilla, comprising a lower part secured to said mandible and an upper part secured to said maxilla, connected in an articulated manner by two telescopic connecting rods (2), characterized in that the upper and lower parts each comprise a frame (3) produced digitally to at least partially surround a part of the teeth of the maxilla and the mandible, each frame (3) having a tongue (5) projecting laterally and towards the outside of the maxilla or the mandible, the tongue (5) comprising an orifice (9) comprising means for coupling an articulation element (7) of the connecting rod (2). Figure for the abstract: Fig. 6

Description

Title of the invention: Orthodontic device Technical field

[0001] The present invention is in the field of orthodontics. It relates more particularly to an orthodontic device capable of causing a displacement of a mandible relative to a maxilla and comprising in particular two connecting rods. Prior art

[0002] Various solutions have been proposed to cause a displacement of the mandible relative to the maxilla. The aim is to move the mandible relative to its original position by a very small distance, of the order of a few millimeters, initially, in order, in particular, to stimulate growth. This mandibular propulsion can be used as part of a class II or class III orthodontic treatment, or to increase respiratory flow, in order to resolve problems of sleep apnea syndromes.

[0003] The invention relates more particularly to an orthodontic assembly of the type perfectly known to a person skilled in the art, under the name of “Herbst orthosis” or “Herbst connecting rods”.

[0004] Essentially, this type of orthosis has gutters cooperating, respectively, with the upper row of teeth and the lower row of teeth. These gutters are generally made of a rigid material, for example thermoformed acrylic resin, and are connected to each other by a system of rods mounted with sliding capacity. More particularly, two metal rods are arranged, respectively, on each side of the upper gutter and the lower gutter. The two rods are connected with articulation capacity to the gutters usually by means of a wire frame embedded in the gutter.

[0005] The resulting disadvantage, apart from the need to use cobalt chrome wire for the framework, which is a substance classified as carcinogenic, mutagenic and reprotoxic (CMR), is the complexity of manufacturing since it is necessary to manufacture a wire metal framework and to conform it in three dimensions so that it adapts specifically to the morphology of the patient. Once conformed, it is then necessary to manufacture the gutters and to embed said metal framework in them to ensure support. One of the difficulties lies in maintaining this framework during the casting of the resin. Any movement of this framework, even minimal, would cause incompatibility or discomfort for the patient, or the device would not ensure optimal treatment.

[0006] A second difficulty lies in the fact that it is then necessary to fix the system of the articulation of the connecting rod to the wire frame, in particular by carrying out precision welding / brazing. This type of assembly therefore requires a high level of skill and dexterity for the dental technician who must very precisely adjust the position and orientation of the articulation system on the wire frame and then carry out the welding. A shift in the articulation system during this welding could also cause incompatibility or discomfort for the patient, or a risk that the device does not provide optimal treatment. Statement of the invention

[0007] The present invention aims to overcome the drawbacks of the prior art by proposing an orthodontic device perfectly adapted to the morphology of the patient and to his treatment program, the manufacture of which is simple and rapid, in particular making it possible to avoid carrying out precision welding / brazing.

[0008] Another objective is to reduce or even avoid the use of cobalt chromium.

[0009] For this purpose, the invention relates to an orthodontic device capable of causing a displacement of a mandible relative to a maxilla, comprising a lower part secured to said mandible and an upper part secured to said maxilla, connected in an articulated manner by two telescopic connecting rods.

[0010] According to the invention, the upper and lower parts each comprise a frame produced digitally, that is to say of anatomical shape and in computer-aided manufacturing design (CAD / CAM), to at least partially surround a part of the teeth of the maxilla and the mandible, each frame having a tongue projecting laterally and towards the outside of the maxilla or the mandible, the tongue comprising an orifice comprising means of coupling with an articulation element of the connecting rod.

[0011] In this way, the manufacture of the device is simplified, and does not use a wire frame, nor does it implement precision welding. The digitally produced frame adapts perfectly to the patient's morphology and allows the connecting rods to be fixed precisely and quickly. The orientation of the tabs and therefore of the articulation elements they receive is predetermined according to the patient's morphology and the extent of the mandibular displacement to be achieved. The articulation element is received and fixed in an orifice which determines its position and orientation. The fixing of the articulation element is therefore simple, quick and reproducible, and does not require any particular skill or dexterity, nor does it present any difficulty.

[0012] In this configuration, several embodiments can be envisaged.

[0013] The coupling means may be of any suitable type, for example by snap-fastening, or are preferably in the form of a thread and the element The joint includes a thread.

[0014] According to a particular embodiment, the coupling means are in the form of a metal cylinder fixed in the orifice of the tongue which itself comprises means for coupling with the articulation element. For assembly, it is then simply necessary to couple the articulation element with the cylinder and to connect the connecting rod to the articulation element.

[0015] In order to reduce the use of metal and in particular of Chrome Cobalt, the frames are made of resin, polyetheretherketone (PEEK), or even a polyaryletherketone (PAEK) or plastic, and the orifice of the tab receives the cylinder which is held in the orifice by resin or glue, and said frames thus form gutters.

[0016] In this configuration, the cylinder preferably comprises a flat on its side wall to reinforce the rotational connection with the glue or resin.

[0017] According to another embodiment, the frames are made of metal, and the orifice of the tab receives either directly the articulation element, or the cylinder held in the orifice by at least one weld point, and said frames are covered with resin to form gutters. The fixing of the cylinder involves only basic welding, without any issue of positioning precision since the cylinder is held in an orifice which determines its position and orientation.

[0018] Preferably, the cylinder has a shouldered head to rest on the tongue.

[0019] Advantageously, the connecting rods are articulated relative to the articulation element according to an amplitude of approximately 360° in a horizontal plane and of at least approximately 90° in a vertical plane.

[0020] According to a particular embodiment, the articulation element is for example a spherical head screw around which one end of the connecting rod is mounted and articulated. Brief description of the drawings

[0021] [Fig.l] is a view illustrating the frames provided with tabs implemented in the device according to the invention, and mounted respectively on a maxilla and a mandible.

[0022] [Fig.2] is a view similar to that of [Fig.l], the reinforcements having been covered of resin and connecting rods having been fixed to the tabs by the articulation element.

[0023] [Fig.3] is a schematic sectional view of a tab receiving a cylinder, itself even receiving the connecting rod articulation element.

[0024] [Fig.4] is a schematic sectional view of another embodiment illustrating a tab with a threaded hole directly receiving the articulation element of the connecting rod.

[0025] [Fig.5] is a view of the orthodontic device of the invention, jaws closed.

[0026] [Fig.6] is a view of the orthodontic device of the invention, jaws open. Detailed description of the invention

[0027] With reference to Figures 1 to 6, the invention relates to an orthodontic device (1), perfectly adapted to the morphology of the patient, and capable of causing a displacement of a mandible relative to a maxilla, the manufacture of which is simple, in particular making it possible to avoid carrying out precision welding / brazing and to avoid having recourse to a wire frame, and preferably to avoid the use of cobalt chrome.

[0028] The orthodontic device (1) comprises a lower part secured to said mandible and an upper part secured to said maxilla, connected in an articulated manner by two telescopic connecting rods (2).

[0029] A first connecting rod (2) is located on the right of the patient, for example substantially at the level of the first right molars for the top of the connecting rod (2), and for example substantially at the level of the right canine for the bottom of the connecting rod (2). The second connecting rod (2) is located on the left of the patient, for example substantially at the level of the first left molars for the top of the connecting rod (2), and for example substantially at the level of the left canine for the bottom of the connecting rod (2).

[0030] In the context of the present invention, the term "link" designates a set of two elongated elements, one sliding in the other so that the total length of the link (2) is variable. Usually in the devices according to the invention, it is the lower element which slides in the upper element, without this being limiting.

[0031] In the orthodontic device (1) according to the invention, the upper and lower parts each comprise a frame (3) produced digitally to at least partially surround a part of the teeth of the maxilla and the mandible.

[0032] In order to avoid the use of cobalt chrome, the frames (3) can be made directly from resin, PEEK, PEAK or plastic, in which case they cover a larger part of the teeth and directly form gutters, or they can be made from metal and then covered with resin (4) to form the gutters as such.

[0033] According to the invention, each frame (3) has a tab (5) projecting laterally and towards the outside of the maxilla or the mandible, the tab (5) comprises an orifice (9) comprising means for coupling an articulation element (7) of the connecting rod (2) preferably according to an amplitude of approximately 360° in a horizontal plane and of approximately 90° at least in a vertical plane. The tab (5) may have a thickness of, for example, between 0.5 and 5 mm.

[0034] According to a particular embodiment, the orifice (9) of the tab (5) receives a metal cylinder (8) held in the orifice (9) by resin or glue when the frame (3) is made of resin, PEEK, PEAK or plastic, or by at least one welding point when the frame (3) is made of metal, or it can be envisaged that the orifice (9) of the tab (5) is tapped and that the cylinder (8) is threaded. The cylinder (8) has for example a shouldered head to come to bear on the tab (5). In an embodiment not illustrated, the orifice (9) of the tab (5) is stepped so as to receive the shouldered head of the cylinder (8) so that the plane of the tab is coplanar with that of the shouldered head. For example, the length of the cylinder (8) is less than or equal to the thickness of the tab (5) to avoid the risk of injury to the patient.

[0035] In the case where the cylinder (8) is held in the orifice (9) by glue or resin, the latter preferably comprises a flat on its side wall, not shown in the figures, to prevent rotational movements.

[0036] The cylinder (8) itself receives the articulation element (7) and comprises coupling means complementary to coupling means provided on the articulation element (7). These means are for example a tapping made in the cylinder (8) and a thread made on the articulation element (7).

[0037] According to another embodiment, and in particular when the frames (3) are made of metal, the orifice (9) of the tongue (5) can directly receive the articulation element (7). As for the previous version, the coupling means of the orifice (9) are for example a tapping made in the bore (9) of the tongue (5) and a thread made on the articulation element (7).

[0038] In these configurations, the articulation element (7) is for example in the form of a spherical head screw, forming a ball joint, around which one end of the connecting rod (2) is mounted and articulated.

[0039] In particular, each end of a connecting rod (2) comprises a hemispherical cage (10) with an opening intended to receive the screw (7) in insertion, so that the cage (10) is positioned between the tab (5) and the spherical head of the screw (7) to form the ball joint in order to allow total freedom of articulation to the connecting rods (2) both in an anteroposterior plane and in a lateral plane, and this in a reduced bulk.

[0040] It is clear from the above that the invention provides an orthodontic device (1) perfectly adapted to the morphology of the patient and to his treatment program, the manufacture of which is simple, rapid and reproducible, making it possible in particular to avoid carrying out precision welds / brazing and to reduce, or even avoid, the need to use cobalt chrome.

Claims

Claims

1. Orthodontic device (1) capable of causing a displacement of a mandible relative to a maxilla, comprising a lower part secured to said mandible and an upper part secured to said maxilla, connected in an articulated manner by two telescopic connecting rods (2), characterized in that the upper and lower parts each comprise a frame (3) produced digitally to at least partially surround a part of the teeth of the maxilla and the mandible, each frame (3) having a tongue (5) projecting laterally and towards the outside of the maxilla or the mandible, the tongue (5) comprising an orifice (9) comprising means for coupling an articulation element (7) of the connecting rod (2).

2. Orthodontic device (1) according to claim 1, characterized in that the coupling means are a thread and the articulation element (7) comprises a thread.

3. Orthodontic device (1) according to claim 1, characterized in that the coupling means are in the form of a metal cylinder (8) fixed in the orifice (9) of the tongue (5), the cylinder (8) comprises means for coupling with the articulation element (7).

4. Orthodontic device (1) according to claim 3, characterized in that the frames (3) are made of resin, PEEK, PEAK or plastic, and the orifice (9) of the tab (5) receives the cylinder (8) held in the orifice (9) by resin or glue, said frames (3) form gutters.

5. Orthodontic device (1) according to claim 4, characterized in that the cylinder (8) comprises a flat on its side wall.

6. Orthodontic device (1) according to one of claims 2 or 3, characterized in that the frames (3) are made of metal, and the orifice (9) of the tab (5) receives either directly the articulation element (7), or the cylinder (8) held in the orifice by at least one welding point, said frames (3) are covered with resin (4) to form gutters.

7. Orthodontic device (1) according to claim 3, characterized in that the cylinder (8) has a shouldered head to come to bear on the tongue (5).

8. Orthodontic device (1) according to one of the preceding claims, characterized in that the connecting rods (2) are articulated relative to the articulation element (7) with an amplitude of approximately 360° in a horizontal plane and of at least approximately 90° in a vertical plane.

9. Orthodontic device (1) according to claim 8, characterized in that the articulation element (7) is a ball-head screw around which one end of the connecting rod (2) is mounted and articulated.

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