The invention relates to a connection device between a dental appliance, such as an expander, and its anchorage to dental pieces, usually to molars or premolars.

This device comprises a connector which in turn comprises an appropriate channel to accommodate in the interior thereof the clamping wire or branch of the dental appliance.

This wire, which we refer to as branch, will act as the axis on which the connector and therefore the anchorage to the dental pieces will pivot.

In this way this connector allows the articulated connection between the expanders, normally a fixed jack type, and the anchorage elements thereof in dental braces. This invention falls within the dental sector, more specifically in the field of orthodontics.

BACKGROUND

Currently, when there is a transverse bone deficiency of the upper jaw with respect to the face, the most widespread solution is to perform a skeletal expansion to widen it.

The expansion force is usually applied by means of a fixed jack mechanism anchored to some upper teeth (usually molars and premolars) by means of braces to which the fixed jack mechanism is welded.

These braces fully encircle the teeth they are fixed to.

Some of these more commonly used devices are:

-The Hyrax expander, with metal frame and jack. -The Haas-type expander with resin flanges that are in contact with the mucosa.

-The Minn expander, which includes a spring to soften the application of the force.

-The McNamara with the peculiarity that the teeth anchorage device does not involve bands but rather resin blocks.

This type of appliance is also used in the lower jaw to cause expansion. The connection between the jack system (Hyrax, Haas ...) and the teeth has commonly been carried out through metal braces to which the appliance is welded by silver or laser welding, silver welding being the most common type.

This method turns these devices into a rigid block when placed in the mouth causing serious problems when inserted to be fitted into position, especially in cases involving divergent molars.

This leads to undesirable solutions such as placing larger braces than require, for their adjustment, using filler material on the molar pieces. This solution entails disadvantages such as gingivitis, continuous debonding and breakage due to inappropriate brace adjustment.

This welded anchorage system also generates other problems and thus, for example, damages the braces because they become weakened through heating and this makes it easier for them to break again.

Although the treatments with these devices seek skeletal and not dental expansion, the fact is that in practice dental movement also occurs, the result being a combination of both skeletal and dental movement.

With the system used so far, which is a rigid connection between the branches and the anchorage braces, the unwanted tooth movement generates other drawbacks because since the teeth tip during expansion, the braces or the resin do not adapt to this new inclination, producing debonding and breakage.

Another common problem is that they become un-welded because of the forces to which the branch and braces are subjected and, since the connection is rigid, it tends to break, requiring new welds that take time to manufacture and weaken the appliance structure due to the need to heat the piece to be welded which, after several welding operations, weakens.

The defects of this current system which causes debonding and breakage of the connection elements between the expanders and the teeth (braces or resin) also entail the problem of the recurrence of the expansion performed, since, for example, when a brace breaks, the patient's record must be taken and sent to the laboratory, which means three to five days without the appliance and the consequent inconvenience of new patient appointments.

Another problem of the most common currently used welding system for this type of appliance, silver welding, is precisely this metal entering the organism. So, although there is no record of the grams of silver that may be ingested with this appliance, the presence of this metal in our mouth does not seem very convenient.

On the other hand, the presence of different metals in the mouth (silver for welding in combination with other metals and alloys present in the jack or in the bands), can lead to problems regarding the generation of magnetic fields. It is highly desirable to find a system that provides mobility to the braces so the appliances can be easily adapted even with divergent molars and in which fitting them is easy and also in which these braces progressively adapt to the changing inclination of the anchoring teeth.

More preferably, a system is preferred in which it is not necessary to heat and therefore cause the loss of properties of the expander or the anchorage braces, and in which an additional metal such as silver need not be applied.

To this end, the present invention focuses on providing a solution to all these adverse aspects of the current art. There are references to the existence of lingual cleat systems to avoid welding and therefore to prevent the wire and band from losing properties.

This lingual cleat system does not allow the free rotation of the wire inside the band and in order to insert the wire into the lingual cleat, the wire needs to be bent over itself, which often causes breakage.

The closest known document of the prior art in the patent literature is WO2010014518, which contains some matching technical elements, but applied to other types of mouth devices whose function is to hold a traction wire to produce the dental movement. That traction wire is in turn the tooth brace, which prevents any pivoting movement, this being the essential part of the invention proposed.

Patent US2002106604 discloses a connection element between an orthodontic appliance and the dental pieces, this element consisting of a laminar-shaped surface that binds to the tooth and whose opposite part presents a retaining element of the appliance with a channel in its interior and a protrusion, but in no case presents a pivoting connection to an anchorage.

On the other hand, patent US2013034822 refers to a device for the connection of an orthodontic appliance to a dental piece, said device being a laminar-shaped piece whose anchorage element is a protrusion on its outer side, also without the characteristic pivotal movement. DESCRIPTION OF THE INVENTION

To solve the problems described, the following is required:

An articulated connection between the dental appliances, such as an expander, and the anchorage elements such that:

Fitting and adjustment thereof are facilitated without a need to oversize the anchorage braces and thus avoiding the need for fillers.

The position of the anchorage brace adjusts to the position of the dental pieces in the event of a change in their inclination, avoiding dysfunctions or unwanted effects.

An easily removable connection:

Easily replaceable in case of breakage without needing laboratory repairs that not only delay treatment but can be counterproductive.

The invention relates to a connection device between a dental appliance such as an expander and its brace for anchorage to the dental pieces, this connection being mobile and, in particular, having a pivoting movement allowing a hinge like movement of the anchorage brace relative to the branch. For this purpose, the invention refers to a connection device between the dental appliance and its pivoting anchorage which comprises: Means for clamping onto and retaining the branch.

Means for attachment to the anchorage brace.

Wherein

The means for attachment to the anchorage brace comprise a suitable base to be attached to the braces. This base is connected to the braces by any means that allow permanent connection thereof.

The means for clamping onto and retaining the branch comprise:

A main channel connected to the aforementioned base, this channel being suitable to longitudinally accommodate the branch in its interior. At least one area of narrowing or full closure of the mouth of said channel. In this narrowing area, the channel opening shall be smaller than the diameter of the lodged branch, such that it is retained inside the channel.

Optionally a mooring element such as a through hole or a protrusion such as a sphere.

In order to prevent the branch from coming out of the main channel, the latter has at least one narrowing area where its mouth has an opening smaller than the diameter of the lodged branch avoiding the accidental exit thereof, or an area of full closure of the channel.

Since the implementation wherein the main channel is fully closed generates greater difficulties, the description will focus on the implementation wherein the channel presents a narrowing area without reaching full closure of the same. This narrowing acts as a clamp, allowing both the insertion and the extraction of the branch when exerting the appropriate pressure but preventing its accidental exit.

In addition the device may comprise a groove in its support that runs parallel to the main channel and facilitates the entry and exit of the branch in and out of this channel.

To favour the clamping, the end of the narrowing area may present a preferably rounded profile.

In one possible embodiment, there is only one narrowing area which allows both the pivoting movement on the axis defined by the branch and the pivoting movement on an axis defined perpendicular to the branch and perpendicular to the plane of the base of the device. To ensure attachment of the branch to the device, the device may optionally comprise mooring elements.

The possible mooring elements include protrusions, notches or holes on the outer wall of the main channel.

The device which is the object of the present invention, in addition to serving for skeletal expansion, may also collaborate in the traction of the dental pieces and to this end a secondary channel is provided, on the outer side of the wall of the main channel, which runs in parallel thereto and is suitable to accommodate the elastic elements that cause the traction.

In addition, in order to facilitate the mooring of such elastic elements, a through tunnel is provided at the connection between the main channel and the support.

With this connection device, we convert the Hyrax, Haas... expanders into removable appliances fixed to the bands or resin in the case of the McNamara expander, wherein the bands or resin are free to rotate towards vestibular, palatal and even mesial or distal directions freely, thus solving the problem of inserting these appliances inside the mouth and also that of adapting the position of the braces to the changing inclination of the teeth.

Insertion of the Hyrax branches through the lower part of the channel with a simple clamp makes laboratory manufacture very easy, as well as its insertion in the patient's mouth by the orthodontist.

Being a standard element, if there is a breakage in the brace that supports it or in itself, the repair can be performed on the spot at the dentist's clinic by replacing the broken brace with another one of the same number with the built-in connection device, thus avoiding recurrence and more appointments with the patient.

This method, also used in the all other fixed-removable appliances, also allows movement of the braces and involves less wear for the wire by preventing it from bending over itself. BRIEF DESCRIPTION OF THE FIGURES

Figures 1 and 2 show the state of the art, whereby figure 1 shows the dental appliance (1) in this case an expansion jack, branches (2) connected by welding points (3) to braces (4) which act as an anchorage and which must adjust to the dental piece (5) but which, when this dental piece is tilted outward, it is not possible to insert and accommodate the brace on the dental piece so, as shown in figure 2, the braces (4) in this case braces are made larger in size so that they can be loosely fitted onto the dental piece, then filling in the remaining gaps with filler material.

Figure 3 shows the branch (2) connected to the connection device (5) in turn connected to the brace (4) so that the branch acts as an axis on which the brace pivots due to the connection device.

Figure 4 shows three drawings of three possible positions of the brace when pivoting on the branch thanks to the connection device.

Figure 5 shows the device (5) and the brace (4) housed on a dental piece (6), the device being connected to a branch (2) and wherein the parts of the device are shown, namely the support (7), to the main channel (8), the outer wall (9) of the main channel with a gripping element (10), in this case a sphere attached to the outer wall of the main channel, and also shown is an extension (11) of the outer wall of the main channel that generates a narrowing area of the main channel. Figure 6 shows a cross-sectional view of a possible embodiment of the device which depicts the support (7), the main channel (8), the outer wall (9) of the main channel, an extension (11) of the outer wall of the main channel with a rounded edge (16) that generates a narrowing area (12) of the main channel whose opening is smaller than the diameter of the branch. Also shown in this embodiment is a secondary channel (13) suitable to accommodate the elastic elements that cause dental traction, as well as a through tunnel

(14) that facilitates the mooring of the aforementioned elastic elements, as well as a groove

(15) parallel to the main channel that facilitates the operations of insertion and removal of the branch from the device. Figure 7 shows a device with the same elements as in figure 7, but showing the branch (2) inserted in the main channel (8).

Figure 8 shows an embodiment of the device depicting the support (7), the main channel (8), the secondary channel (13), the through tunnel (14), the groove (15), the gripping elements (10) in this case notches on the outer wall (9) of the main channel, as well as an extension (11) of that outer wall that generates a narrowing area of the main channel.

Figure 9 shows the front and side of an embodiment wherein the main channel has a minimum longitudinal dimension.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

Described below is an embodiment of the invention that is not the only one and is not limiting to the scope but merely explanatory.

The invention refers to a connection device between a dental appliance and the braces which will be the anchorage thereof to the dental pieces.

The device comprises:

A support (7) that will be connected to the brace (4) on its rear side. A main channel (8) on the front side of the support, suitable for accommodating and fastening by clamping one of the branches (2) of the dental appliance.

Gripping elements (10) in this case notches on the outer wall (9) of the main channel.

The said outer wall (9) has an extension (11) coinciding with the narrowing area, such that in fact this extension is what generates such narrowing (12) of the main channel, such that the opening of this narrowing area is smaller than the diameter of the branch (2), thus preventing the accidental exit of the branch (2) from the main channel (8).

The device described in addition comprises a secondary channel (13) suitable for accommodating the elastic elements that generate traction of the dental pieces as well as a through tunnel (14) suitable to accommodate the mooring elements of such elastic elements.

The support, on its front side, has a groove (15) that facilitates the operations of inserting and extracting the branch (2) into and from the main channel (8). Since the branch (2) is inserted into the main channel (8), the device acts as a hinge between the dental appliance (1) and the brace (4) allowing the latter to pivot, facilitating the fitting operations of the braces onto the patient's dental pieces.

On the other hand, by incorporating the secondary channel the same device allows its use as an element for dental traction.

Another of the advantages of the device described is that since it is a device that allows rotation on an axis, it also allows control of the molar torque during all phases of the treatment.

A device such as the one described allows easy housing in the patient's mouth by facilitating the adjustment of the braces (4) to the dental pieces and, on the other hand, in case of breakage or if for any other reason it is necessary to replace any part of the dental appliance, separating the braces from the rest of the appliance is carried out by simply removing the branch (2) from the main channel (8).