EP4665265A1

EP4665265A1 - Orthodontic device for correcting the position of teeth

Info

Publication number: EP4665265A1
Application number: EP24710831.9A
Authority: EP
Inventors: Gabriella GALLUCCIO; Adriana Assunta DE STEFANO; Gaetano IERARDO; Claudio Guerra; Denise CORRIDORE; Rosanna GUARNIERI
Original assignee: Universita degli Studi di Roma La Sapienza
Current assignee: Universita degli Studi di Roma La Sapienza
Priority date: 2023-02-14
Filing date: 2024-02-14
Publication date: 2025-12-24
Also published as: WO2024171070A1

Abstract

Orthodontic device (100) comprising a body (3), a constraining surface (30) for the constraint to a tooth, preferably to a molar tooth, a first housing (6), a second housing (7), a first closing element (1) for the first housing (6), a second closing element (2) for the second housing (7); said first closing element (1) and second closing element (2) being able to be moved independently of each other so as to define a first open condition and a first closed condition of the first housing (6) and a second open condition and a second closed condition of the second housing (7), wherein said first condition of the first housing (6) is independent of said second condition of the second housing (7) and vice versa.

Description

“ORTHODONTIC DEVICE FOR CORRECTING THE POSITION OF TEETH”

FIELD OF THE INVENTION

The present invention concerns an orthodontic device for molar teeth, comprising at least two buccal tubes that are independent of each other and ensure versatility of use during orthodontic treatments for the correction of the teeth position.

STATE OF THE PRIOR ART

As known, in the field of orthodontics, there are various therapeutic techniques that allow to treat pathologies or anatomical malformations of the dental arch, whether it is the superior or inferior arch.

These techniques make it possible to re-establish the correct positioning of the teeth in a physiological realignment condition or, in cases where it is necessary, these techniques make it possible to apply forces to individual teeth that allow a gradual displacement in order to ensure the complete realignment of the dental arch teeth.

Generally, these treatments are therefore able to re-establish the aesthetic and correct masticatory function exerted by the crown of the teeth, but also to re-establish the correct mechanical stability of the tooth which, at the end of the treatment, is once again in a condition of correct physiological function.

Orthodontic treatments can be carried out by means of systems of brackets fastened to the tooth surface. The fastening can take place either on the outer surface (vestibular surface) or on the inner tooth surface (lingual surface) depending on the clinical need or the same nature of the same brackets, i.e. geometry, volumetric encumbrance, type of treatment for which the brackets are used.

There are also orthodontic treatments made by means of transparent aligners that are individually designed and packaged for each patient, are removable and are made of plastic material.

Among the various orthodontic devices that can be applied to the vestibular surface of teeth, there are orthodontic devices specific to the molar teeth. Molar teeth are positioned in the end portions of the superior and inferior dental arches. Orthodontic devices for molar teeth allow the distal ends of the orthodontic arches to be anchored. The function of these fastening elements for molar teeth is therefore to constrain the orthodontic arch in a desired position in such a way that forces or torques can be transferred to the teeth in the other fastening elements positioned in each of the teeth of the inferior and/or superior dental arch, such as e.g. premolars, incisors and canine teeth.

Many of the devices for molar teeth known in the art allow the positioning of the orthodontic arches in the housings of the orthodontic devices from a side position, i.e. an insertion of the orthodontic wires in a direction parallel to the surface of the molar tooth, which direction is known in the art as insertion from a “mesial” to “distal” position, where the term “mesial” means the area of the dental arch close to the midline of the dental arch (centre of the arch) and the term “distal” means the area of the dental arch facing the rear ends of the dental arch. This is due to the fact that orthodontic devices for molar teeth generally have substantially through-hole shaped housings for orthodontic arches, whereby the insertion of the arch into the molar tube hole takes place in a direction parallel to the occlusal surface of the teeth and in a direction from front (mesial) to rear.

The insertion of the orthodontic arch in the front-rear direction has several disadvantages. A first disadvantage is related to the difficulty of accessing the through holes of the orthodontic device because the spaces and shape of the mouth near the molar teeth force the clinician to difficult movements or, in any case, to movements that require a long time to position the orthodontic arches.

Some of the orthodontic devices for molar teeth may have a configuration such that the through hole can be obtained by means of opening elements which can be in an open configuration or in a closed configuration. In the open configuration, the use of closing systems is necessary to keep the arch in the housing. Some systems involve the presence of elements outside the device, such as e.g. constraining elements of a metallic nature (metal ligatures) or constraining elements of an elastic nature (elastic ligatures) that are positioned by the clinician.

Other systems (self-ligating systems) involve self-ligating systems in the same device. In the case of self-ligating systems, the closing system is usually an embedded door that can have two different operating modes. A first mode provides that the door in a closed configuration substantially transforms the housing into a tube, but leaves some freedom of movement (sliding) of the arch in the tube. The freedom of movement of the arch depends on the section of the arch being housed (passive self-ligating systems).

The second mode provides a self-ligating system in which the door in the closed configuration pushes the arch into contact with the housing surface (active self-ligating systems).

In the open configuration, the opening elements allow the orthodontic wires to be inserted into the housings in a direction substantially perpendicular to the vestibular surface of the tooth and in a direction parallel to the occlusal surface of the teeth.

Currently, orthodontic devices with embedded closing/opening systems (self-ligating) are typically characterised by a single housing. In these cases, however, the size of the single slot (housing) does not allow two arches to be inserted simultaneously and the door to be respectively closed correctly.

Orthodontic devices for molar teeth in which there are two housings are known, but typically these devices have the disadvantage that only one of the two housings can be opened (or closed) with a closing element. In addition to this limit, these devices further inhibit the ability to independently insert one or more orthodontic arches into the housings at different steps of orthodontic treatments.

In other words, the “multi-brackets” orthodontic treatment involves the use of orthodontic arches of progressively increasing diameter (and with various alloys offering various degrees of arch flexibility) to facilitate progressive dental movements with contained and continuous forces applied.

In most cases of orthodontic treatment, a single arch is used, however, there are treatment cases in which therapy may involve the use of two orthodontic arches, which therefore requires a second housing distinct from the first housing.

It is known, e.g. from WO 2018/135569 Al or EP 3922208 Al, to make devices for correcting the position of teeth, comprising a “bracket” for orthodontic wires (orthodontic arches) which is equipped with two housings, each of which has an open inlet section for a respective orthodontic wire, which section is removably obstructed by a covering element that can be translated from an open position to a closed position and vice versa.

The covering elements described in these patents can be sequentially moved, i.e. when one of them is in the open position, the other must necessarily be in its own closed position. This makes the installation operation of the respective orthodontic implant rather inefficient, when it is necessary to use two orthodontic wires (arches).

The orthodontic devices currently available therefore have the disadvantage of inhibiting or making it difficult to simultaneously house a plurality of orthodontic arches, typically two orthodontic wires, thereby limiting the versatility of choice the clinician can take when planning the orthodontic treatment therapy.

Object of the present invention is to solve the problems mentioned above and to provide an orthodontic device for vestibular orthodontic therapies that allows to increase the versatility of orthodontic treatment for correcting the position of teeth in a simple way.

Another object of the present invention is to provide an apparatus comprising at least one orthodontic device according to the present invention.

These and other objects are achieved by the present invention through a procedure and a system according to the accompanying independent claims. Preferred aspects are set forth in the dependent claims.

BRIEF SUMMARY OF THE INVENTION

According to an aspect of the present invention, this relates to an orthodontic device for correcting the positioning of teeth, which comprises a body, a constraining surface for constraining to a tooth, a first housing, a second housing, a first closing element for the first housing, a second closing element for the second housing, said first closing element and second closing element being able to be moved independently of each other so as to define a first open condition and a first closed condition of the first housing and a second open condition and a second closed condition of the second housing, wherein the first open or closed condition of the first housing is independent of the open or closed condition of the second housing and vice versa.

It is hereby intended that in the text below, the ordinal adjectives “first” and “second” do not refer to a relevance order or relation. These adjectives are used for the sole purpose of indicating terms referring to the first housing and the second housing. In other words, the terms “first closing element”, “first open condition” and “first closed condition” refer to the “first housing”. Similarly, the terms “second closing element”, “second open condition” and “second closed condition” refer to the “second housing”. Furthermore, in the text hereinafter, “first housing in the first closed condition” and “second housing in the second closed condition” are housings which, in the closed configuration, substantially both define a “buccal tube”, as known in the field of orthodontic treatments. In other words, the term “first housing in the first closed condition” defines “a first buccal tube” and the term “second housing in the second closed condition” defines “a second buccal tube”.

The constraining surface allows to constrain the orthodontic device to the outer surface of a tooth by means of known techniques, such as welding the orthodontic device to a metal band having an inner surface adhering to the tooth crown, alternatively, the orthodontic device may have a constraining surface that can be constrained to the tooth by gluing with adhesive materials.

The orthodontic device may be constrained to the outer surface of one of the molar teeth being in the inferior dental arch or the superior dental arch.

The first housing and the second housing may be substantially grooves in the body of the orthodontic device, which extend in a direction parallel to the constraining surface and perpendicular to the central axis of the grooves.

In particular, the housings specified herein are tubular housings, each of which has a side wall with an opening section for the entry of an orthodontic wire (arch), which section may be occluded by the respective movable closing element and two open bases for the possible sliding of the orthodontic wire (arch).

The opening section of each housing is preferably substantially opposite the constraining surface and, according to a preferred aspect of the invention, defines a direction of insertion of the orthodontic wire that is substantially orthogonal to such constraining surface, i.e. orthogonal to the outer tooth surface to which the body (“bracket”) is constrained.

However, embodiments in which there are further housings in the body of the orthodontic device and further closing elements similar to the housings and closing elements described above are not excluded. Advantageously, the first closing element and the second closing element can be moved independently of each other so as to define an open condition and a closed condition of the first housing and the second housing.

Advantageously, the movement of the first closing element and the second closing element is such that it allows the operator to easily have either the first housing or the second housing independently of each other in an open configuration in such a way as to be able to easily identify the best treatment configurations for correcting the teeth position at any time during the treatment, between the step of starting the treatment and ending the treatment.

In other words, according to the present invention, the fact that the “condition of the first housing is independent of the condition of the second housing, and vice versa” means that the first housing can be arranged, thanks to the suitable movement of the respective closing element, in a closed configuration or an open configuration regardless of whether the second housing is in a closed configuration or an open configuration, and vice versa. This characteristic implies that the two closing elements of the aforesaid housings are movable along trajectories that do not interfere with or hinder each other, i.e. they can be moved independently of each other.

The movement of the first closing element, as well as that of the second closing element, may take place along a direction substantially parallel to the constraining surface and parallel to the central axis of the tooth.

Embodiments in which the movement of both closing elements takes place along a direction substantially parallel to the constraining surface of the orthodontic device and perpendicular to the central axis of the tooth are not excluded.

According to a possible aspect of the invention, the orthodontic device comprises a protrusion for anchoring elastic bands known in the art. This protrusion may comprise a shank extending substantially parallel to the constraining surface and a head at the end of the shank.

Advantageously, the protrusion for anchoring elastic bands has a head at the end of the shank in such a way that the movement of the elastic bands can be limited in a direction substantially perpendicular to the constraining surface. These elastic bands, in use, allow to apply a force perpendicular to the plane passing through the first closing element and/or the second closing element or allow to apply a force in a direction depending on the point of application of the other end of the elastic band. Said end point is determined by the type of force that is intended to be exerted, depending on the specific clinical treatment chosen.

According to a possible aspect, the first closing element and the first housing in the first closed condition and, similarly, the second closing element and the second housing in the second closed condition have a section between 0.20 mm² and 0.52 mm², preferably 0.40 mm².

According to a preferred aspect, the section is substantially rectangular. For example, the rectangular section of the housing may have a greater dimension in the range between 0.01 inch (0.25 mm) and 0.03 inch (0.76 mm), preferably 0.022 inch (0.56 mm) and a smaller dimension in the range between 0.02 inch (0.51 mm) and 0.04 inch (1.02 mm), preferably 0.028 inch (0.71 mm).

The first closed condition defined by the first housing and the first closing element substantially defines a channel in the body of the orthodontic device.

Taking a plane substantially perpendicular to the constraining surface and perpendicular to the channel, it is possible to identify on such plane a closed section defined by a profile with a first section portion defined by the intersection of the plane with the first housing and a second section portion defined by the intersection of the plane with the first closing element.

Similarly, this also applies to the section defined by the second closing element and the second housing.

Advantageously, this section is between 0.20 mm² and 0.52 mm² in such a way as to be able to have sections that are functional to the specific orthodontic treatment for correcting the teeth position, i.e. in such a way as to have sections which allow freedom of movement (sliding) of the arch, also depending on the diameter of the arch in the housing.

According to a possible aspect, the first housing comprises a first recess and the second housing comprises a second recess, said first recess and second recess form a first opening and a second opening for the insertion of an opening instrument to be able to move the first closing element to a first open condition or a first closed condition or to move the second closing element to a second open condition or a second closed condition.

Advantageously, the first opening of the first housing and the second opening of the second housing allow the operator to move the first closing element or the second closing element in conditions where it would be difficult to operate manually. For example, in conditions where the position of teeth to be treated is such that the movement of the first element or second element is inaccessible at the beginning of treatment or at an intermediate step between the beginning of treatment and the end of treatment. Under these conditions, the insertion of an opening instrument allows to easily move the first closing element or the second closing element independently of each other. An opening instrument may be equipped with an end which can be inserted into the first opening or the second opening and act in such a way as to move the first closing element or the second closing element. A typical opening instrument may be, e.g., a fine-tipped conical instrument that can be inserted into the recess and in which, through the rotation of the instrument, it is possible to impart a vertical force to move the closing elements.

According to a possible further aspect of the invention, the first housing and the first closing element in a first open condition are configured so as to allow the insertion of a portion of a first orthodontic wire into the first housing in a direction substantially perpendicular to the constraining surface and wherein the second housing and the second closing element in a second open condition are configured so as to allow the insertion of a portion of a second orthodontic wire into the second housing in a direction substantially perpendicular to the constraining surface.

In other words, the opening section of each housing, preferably opposite the constraining surface of the body of the orthodontic device to the tooth surface, it is shaped in such a way as to define an entry direction for the respective orthodontic wire (arch) that is substantially perpendicular to this constraining surface and, therefore, is substantially perpendicular to the side wall of the tooth to which the orthodontic device of the invention is constrained.

Advantageously, the insertion of a first orthodontic wire and/or a second orthodontic wire into the first and second housings in a direction that is substantially perpendicular to the constraining surface allows to minimise the time for inserting the orthodontic wires into the orthodontic device in the clinic or outpatient setting. This may also be advantageous in the case where a portion of the first orthodontic wire has been inserted at an initial step of the treatment but, following clinical evaluations, it is necessary to insert a second orthodontic wire at an intermediate step of the treatment, without changing the positioning of the first orthodontic wire previously positioned in the first housing. In other words, it is possible to correct the strategy of correcting the teeth position by means of a further tractive force acting on the dental arch to speed up the physiological repositioning of the teeth or to change the orthodontic treatment mode. Another object of the present invention consists of an apparatus (or implant) comprising a plurality of constraining elements comprising housings for a first orthodontic wire and a second orthodontic wire, in which at least one of the constraining elements is one of the orthodontic devices described above.

The plurality of constraining elements comprises housings for a first orthodontic wire and a second orthodontic wire, typically, the plurality of constraining elements allows to constrain the orthodontic wires in such a way that the contact between the orthodontic wires and the respective housings can exert twisting forces and/or tractive forces that allow gradual realignment of the teeth during the orthodontic treatment period. Typically, the constraining elements which exert a twisting force and/or tractive forces are constrained to the teeth at the position close to the midpoint of the dental arch, such as e.g. premolar teeth, or incisors or canine teeth.

The constraining elements positioned in the distal area of the dental arch may be orthodontic devices according to the present invention, wherein the orthodontic arch, e.g. at an initial step of treatment, is positioned in one of the housings so as to minimise the dynamic friction between the first closing element and the first housing with the orthodontic wire or so as to minimise the dynamic friction between the second closing element and the second housing with the second orthodontic wire. In other words, at an initial step, it is intended to minimise friction between the closing elements and the housings with the orthodontic wires in such a way as to ensure a gradual realignment of the teeth that is exerted by the interaction with the constraining elements and the orthodontic wires. With the gradual realignment of the teeth, it is possible, by moving the first closing element or the second closing element, to insert one or more orthodontic wires with gradually larger sections so as to gradually ensure static friction between the orthodontic wires and the respective housings and closing elements at a step of the consolidation and stabilisation treatment of the realignment achieved.

According to a possible aspect, one or more orthodontic devices are positioned at the end of the orthodontic wires.

Advantageously, the positioning of one or more orthodontic devices at the end of the orthodontic wires, i.e. in the maximum distal position of the dental arch, allows to regulate the teeth realignment strategy depending on the clinical need. In other words, in the case where a first orthodontic wire was initially inserted into a first housing but this orthodontic wire is not capable of ensuring an adequate mechanical action on the teeth, it is possible to insert a second orthodontic wire into the second housing in order to correct the realignment of the teeth according to a new clinical strategy. This is possible thanks to the possibility that the first orthodontic wire or the second orthodontic wire can be inserted into the respective housings in a direction perpendicular to the supporting surface of the orthodontic device.

According to a possible aspect, the first orthodontic wire has a length greater than the length of the second orthodontic wire.

Advantageously, the difference in length between the first orthodontic wire and the second orthodontic wire allows to regulate the teeth realignment depending on the clinical needs. Typically, in the case where the first orthodontic wire has a length greater than the length of the second orthodontic wire, the first orthodontic wire is defined, as known in the art, as “continuous arch”, i.e. the orthodontic wire is positioned in such a way as to be constrained and have a length substantially equal to the length of the dental arch. In this case, the first orthodontic wire constrained that is misaligned to the two ends of the dental arch can carry out a primary realignment function. The second orthodontic wire is defined as “segmented arch”, i.e. a second orthodontic wire that is shorter than the first orthodontic wire. In this case, the second orthodontic wire (segmented arch) can be constrained to a first end of the orthodontic device and, at the second end, it can be constrained to a portion of the constraining elements in order to increase, e.g., the tractive force or the twisting force only in a portion of the dental arch.

According to a possible aspect, the section of the first orthodontic wire and the second orthodontic wire is between 0.20 mm² and 0.52 mm², preferably 0.40 mm².

Preferably, the section of the first orthodontic wire and the second orthodontic wire are substantially rectangular.

Advantageously, depending on the degree of realignment achieved or depending on possible clinical treatment corrections, it is possible to insert portions of orthodontic wires with different sections into the first housing or the second housing, in order to regulate the level of friction between the inner surfaces of the first housing and the first closing element or between the inner surfaces of the second housing and the second closing element.

Advantageously, a rectangular section is capable of reducing the friction between orthodontic wire and the inner surface of the housings when using wires of smaller section in the first treatment steps, i.e. wires with section smaller than the section of the housings in the closed configuration. In the final treatment steps, instead, arches with rectangular section are usually used, the interaction between the arch and the housing allows the arch to impart forces to achieve the correct final position of the tooth. According to a possible aspect, the first orthodontic wire or the second orthodontic wire has at least one folded portion.

Considering two points A and B lying on the central axis of the first orthodontic wire when in a substantially straight condition, said points A and B both lie on a plane passing through the central axis of the first orthodontic wire and it is possible to define a minimum distance X between said points A and B. In the case where at least one portion of the first orthodontic wire has a folded portion and at least one of said points A or B lies on a plane different from the substantially straight condition, the minimum distance is therefore increased by at least 0.1X. In other words, the distance between A and B is at least X+0. IX.

Advantageously, the presence of a folded portion allows to locally regulate the teeth positioning by inserting a first orthodontic wire with a folded portion and/or a second orthodontic wire with a folded portion. This is advantageous compared to the known art because the side insertion, i.e. placement from the mesial point toward the distal point of an orthodontic wire with a folded portion, would not be possible according to the orthodontic devices known in the art, because it would not be possible to slide the orthodontic wire both through the plurality of constraining elements and the orthodontic device. This is particularly advantageous whenever the orthodontic device is positioned on the first molar teeth, as the presence of a folded portion in one of the orthodontic wires would not allow the wire to slide into the housing if the folded portion is intended to be positioned distally to the first molar tooth.

According to a possible aspect, the first orthodontic wire and/or the second orthodontic wire are made of metal material, preferably stainless steel or a nickel-titanium-copper (CuNiTi) alloy or a Titanium-Molybdenum-Steel (TMA) alloy.

Advantageously, the first orthodontic wire and/or the second orthodontic wire made of metal material allows to ensure adequate mechanical strength both in terms of tractive forces and/or twisting forces of the orthodontic wires in the respective housings and allow a good degree of biocompatibility with the oral cavity.

According to a possible aspect, the body of the orthodontic device is formed by milling technique or by metal injection moulding.

In use, a method for the teeth realignment by means of an apparatus comprising constraining elements for a first orthodontic wire and a second orthodontic wire, wherein at least one of the constraining elements is an orthodontic device of the type specified above, comprising a body (“bracket”) equipped with a surface constraining to a tooth, a first housing and a second housing, and with a first closing element and a second closing element of such first housing and second housing, respectively, wherein these closing elements can be moved independently, comprises the steps of:

(a) constraining at least one orthodontic device to a molar tooth and constraining at least one other constraining element to a premolar tooth or a canine tooth or an incisor tooth;

(b) moving at least one first closing element and/or at least one second closing element of said at least one orthodontic device so as to define a first open condition of the first housing and/or a second open condition of the second housing,

(c) inserting at least one portion of the first orthodontic wire into the first housing in the first open condition and/or inserting at least one portion of the second orthodontic wire into the second housing in the second open condition,

(d) constraining at least the first orthodontic wire and/or at least the second orthodontic wire to at least one constraining element,

(e) moving at least one first closing element or at least one second closing element so as to define a first closed condition of the first housing containing the first orthodontic wire and/or a second closed condition of the second housing containing the second orthodontic wire.

Advantageously, in at least one of the steps b) or c) or e) depending on the patient's tooth misalignment condition, the operator may decide whether a first orthodontic wire should be inserted at the beginning of the treatment, or whether a first orthodontic wire and a second orthodontic wire should be inserted depending on the necessary degree of dental realignment.

Advantageously, at any time between the beginning of the orthodontic treatment and the end of the orthodontic treatment, thanks to the first closing element and the second closing element which can be moved independently of each other, the operator may decide to regulate the realignment by easily removing the first orthodontic wire or the second orthodontic wire or in case, e.g., in a first treatment step the operator had inserted only one orthodontic wire, the operator may insert a second orthodontic wire in a subsequent treatment step without changing the position or affecting the contribution of the first orthodontic wire in the teeth realignment treatment.

BRIEF DESCRIPTION OF THE FIGURES

With reference to the accompanying figures, exemplary and non-limiting embodiments of the present invention are now described, wherein:

- Figure 1 is a schematic and perspective view of an orthodontic device according to an embodiment of the present invention;

- Figure 2a is a schematic side view of the orthodontic device of figure 1 with a first housing in a first open configuration and a second housing in a second open configuration;

- Figure 2b is a schematic side view of the orthodontic device of figure 1 with a first housing in a first closed configuration and a second housing in a second closed configuration; - Figure 3 is a schematic and perspective view of an apparatus comprising the orthodontic device of figure 1 in a closed configuration and comprising a portion of orthodontic wires in the housings of the orthodontic device;

- Figure 4a is a schematic side view of an apparatus comprising the orthodontic device of figure 1 in an open configuration, in order to be able to house orthodontic wires in the housings of the orthodontic device;

- Figure 4b is a side view of an apparatus comprising the orthodontic device of figure 1 in a closed configuration, in which the orthodontic wires are housed in the orthodontic device;

- Figure 5a is a schematic view of a teeth realignment apparatus comprising the device of figure 1 at the beginning of treatment;

- Figure 5b is a schematic top view of the tooth realignment apparatus of figure 5a, comprising the device of figure 1 at the end of treatment;

- Figure 6a, 6b, 6c is a front view of a portion of the tooth realignment apparatus in which there is an orthodontic device of figure 1 and in which at least one first orthodontic wire or one second orthodontic wire has at least one portion folded in three possible configurations;

- Figure 7a is a schematic view of the device of figure 1 comprising an orthodontic wire without a folded portion;

- Figure 7b is a schematic view of the device of figure 1 comprising an orthodontic wire with a folded portion.

DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION

An orthodontic device 100 for correcting the teeth position comprises a body 3, a constraining surface 30 for constraining to a tooth.

Advantageously, the constraining surface 30 of the orthodontic device 100 is such as to ensure a small surface encumbrance with respect to the outer tooth surface but, at the same time, it is such as to ensure stiffness of a mechanical constraint for coupling the device 100 to the tooth.

The orthodontic device 100 further comprises a first housing 6 and a second housing 7, as shown e.g. in figure 1. The first housing 6 and the second housing 7 may be grooves with an opening section preferably facing the end opposite the constraining surface 30, as shown e.g. in figure 1.

In other words, the first and second housings 6, 7 may have tubular configuration, each of which has a side surface with an opening section preferably opposite the constraining surface 30 of the body 3 with respect to the axis of the tubular housing and the respective bases orthogonal to the axis of the tubular housing, which are open for the possible sliding of an orthodontic wire (arch).

The orthodontic device 100 further comprises a first closing element 1 for the first housing 6, a second closing element 2 for the second housing 7.

The first closing element 1 is movable so as to define a first closed condition and a first open condition of the first housing 6 independently of the second closing element 2 also movable so as to define a second closed condition and a second open condition of the second housing 7, as shown e.g. in figure 2a and figure 2b.

In other words, the trajectory followed by the first closing element 1 during its movement and the trajectory followed by the second closing element 2 during its movement do not intersect or hinder each other, so that it is possible to arrange the first housing 6 in a closed configuration/condition or in an open configuration/condition, regardless of whether the second housing 7 is arranged in a closed configuration/condition or in an open configuration/condition, and vice versa.

The first closing element 1 in the first closed condition and the second closing element 2 in the second closed condition substantially define channels in the body 3. An example of the first open condition and the second open condition is shown in figure 2a, while an example of the first closed condition and the second closed condition is shown in figure 2b.

The first closing element 1 and the second closing element 2 may be movable, in particular preferably translatable, in a direction substantially parallel to the constraining surface 30.

According to a possible aspect of the invention, the first closing element 1 and the first housing 6 in the first closed condition and the second closing element 2 and the second housing 7 in the second closed condition have a section (orthogonal to the extent axis of the respective tubular housing 6, 7) between 0.20 mm² and 0.52 mm², preferably 0.40 mm².

Preferably, the section of the first housing 6 in the first closed condition and/or the section of the second housing 7 in the second closed condition are substantially rectangular.

In other words, the first housing 6 and the first closing element 1 in the first closed condition substantially define a channel in the body 3.

Taking a plane perpendicular to the constraining surface 30 and perpendicular to the central axis of the channel in the body 3, a section on said plane may be defined for at least one portion of profile from the first closing element 1 and the remaining portion of profile from the first housing 6.

Similarly, the second housing 7 and the second closing element 2 in the second closed condition substantially define a channel in the body 3 with section defined as described above.

The rectangular section dimensions, as defined above, of the first housing 7 in the first closed condition and the second housing 7 in the second closed condition may have a greater dimension in the range between 0.01 inch (0.25 mm) and 0.03 inch (0.76 mm), preferably 0.022 inch (0.56 mm) and a smaller dimension between 0.02 inch (0.51 mm) and 0.04 inch (1.02 mm), preferably 0.028 inch (0.71 mm).

Embodiments in which the channels can have a polygonal or circular shaped section are not excluded.

According to a possible aspect, the first housing 6 comprises a first recess 50 and the second housing 7 comprises a second recess 51.

The first recess 50 and the second recess 51 form a first opening 50a and a second opening 51a, respectively, for the insertion of an opening instrument 52 to be able to move the first closing element 1 to a first open condition or a first closed condition and/or to move the second closing element 2 to a second open condition or a second closed condition.

The opening instrument 52 can be a device, not shown in the figures, such as e.g. a fine-tipped conical instrument that can be inserted into the first recess 50 or the second recess 51, wherein a vertical force can be imparted through the rotation of the instrument to move either the first closing element 1 or the second closing element 2, respectively.

Typically, the opening instrument 52 comprises an end that can be inserted either into the first recess 50 in order to be able to move the first closing element 6 or can be inserted into the second recess 51 in order to be able to move the second closing element 7. This allows the operator to be able to move the first closing element 6 or the second closing element 7 in cases where it is not possible to manually move the first closing element 6 and/or the second closing element 7. In other words, the end of the opening instrument 52 allows, therefore, to move the first closing element 6 or the second closing element 7 under conditions of difficult access to the inside of the oral cavity.

According to a possible aspect of the invention, the first housing 6 and the first closing element 1 in a first open condition is configured so as to allow the insertion of a portion 101 of a first orthodontic wire 10 into the first housing 6 in a direction D substantially perpendicular to the constraining surface 30, and the second housing 7 and the second closing element 2 in a second open condition are configured so as to allow the insertion of a portion 110 of a second orthodontic wire 11 into the second housing 7 in a direction D substantially perpendicular to the constraining surface 30. An example of inserting orthodontic wires into the respective housings is shown in figure 3 and figure 4a.

In other words, both the first housing 6, when it is in its open condition thanks to the suitable displacement of the respective first closing element 1, and the second housing 7, when it is in its open condition thanks to the suitable displacement of the respective second closing element 2, define a direction D for inserting a respective first and second orthodontic wire (arch) 10, 11 which, preferably, is substantially orthogonal to the constraining surface 30 of the body 3, i.e. it is preferably substantially orthogonal to the tooth surface to which the body 3 is constrained.

As shown in the figures, the opening section of each housing 6, 7, when not obstructed by the respective closing element 1, 2, is shaped to allow the insertion of a respective orthodontic wire 10, 11 in a direction D orthogonal to the constraining surface 30, i.e. orthogonal to the tooth surface to which the body 3 of the orthodontic device 100 is constrained. It is noted that these opening sections of the housings 6, 7, according to a preferred aspect of the invention, are substantially coplanar and the travel followed by the respective closing elements 1, 2, i.e. their trajectory, also lies substantially on the same plane.

According to a preferred aspect of the invention, this plane is substantially parallel to the constraining surface 30 and can be substantially parallel to the side tooth surface to which the constraining surface 30 is applied.

According to a preferred aspect of the invention, the directions D of insertion of the first and second orthodontic wires 10, 11 within the first and second housings 6, 7 may be substantially parallel.

The movement of the first closing element 1 and the second closing element 2 to the respective first open condition and second open condition allows to insert portion 101 of the first orthodontic wire 10 and the portion 110 of the second orthodontic wire 11 in a direction D substantially perpendicular to the constraining surface 30, so that the first portion 101 of the first orthodontic wire 10 and the portion 110 of the second orthodontic wire cannot substantially move in a direction perpendicular to the constraining surface 30, whereas they can move in a direction substantially parallel to the constraining surface 30, as shown e.g. in figure 3.

The tubular shape of the housings 6, 7, which is transformed into a channel-like shape with a longitudinal extent axis and the two respective bases opened when the respective closing element 1, 2 obstructs the respective opening section for the entry of the orthodontic wire 10, 11, prevents indeed each orthodontic wire 10, 11 from exiting its own housing 6, 7 in a direction perpendicular to the axis of this tubular housing 6, 7, but at the same time it allows a possible sliding of each orthodontic wire 10, 11 in a direction substantially parallel to or coincident with such axis of the respective tubular housing 6, 7,

This is especially advantageous during the first orthodontic treatment steps where teeth can be necessarily subjected to tractive forces and can move in functional directions for correcting the position of the teeth, as will be better described hereinafter.

Preferably, the first orthodontic wire 10 and/or the second orthodontic wire 11 are made of metal material, preferably stainless steel or a nickel-titanium-copper (CuNiTi) alloy or A Titanium-Molybdenum-Steel (TMA) alloy.

According to a possible aspect, the orthodontic device 100 comprises a protrusion 4 for anchoring elastic bands, which comprises a shank 41 which extends substantially parallel to the constraining surface 30 and a head 42 at the end of the shank 41.

The protrusion 4 allows to anchor elastic bands known in art, which can serve as a further stabilising element of the orthodontic device 100. Advantageously, the shank 41 and the head 42 can be configured so as to limit the movement of the elastic bands in a direction substantially perpendicular to the central axis of the shank 41 or in other directions desired by the clinician, in order to optimise the orthodontic treatment.

The invention further comprises an apparatus 200 comprising a plurality of constraining elements 20 which comprise housings for a first orthodontic wire 10 and a second orthodontic wire 11, wherein at least one of the constraining elements 20 is one of the constraining devices 100 as described above.

The plurality of the constraining elements 20 allows a first orthodontic wire 10 and/or a second orthodontic wire 11 to be housed and allows to apply tractive forces or torsional moments, which allow a gradual realignment of the dental arch, to the first orthodontic wire 10 and the second orthodontic wire 11, as shown e.g. in figures 5a and 5b.

Thus, the following method is provided, in use, for the realignment of teeth by means of an apparatus (implant) 200 comprising constraining elements 20 for a first orthodontic wire 10 and a second orthodontic wire 11, wherein at least one of the constraining elements 20 is an orthodontic device 100, of the type specified above, comprising a body 3 (“bracket”) equipped with a constraining surface 30 to a tooth, a first housing 6 and a second housing 7, and a first closing element 1 and a second closing element 2 for such first housing 6 and second housing 7, respectively, wherein such first and second closing elements 1, 2 can be moved independently of each other so as to define first and second opening and closing conditions, also independent of each other, of the respective housings 6, 7, which comprises the steps of:

(a) constraining at least one orthodontic device 100 to a molar tooth and constraining at least one other constraining element 20 to a premolar tooth or a canine tooth or an incisor tooth; (b) moving at least one first closing element 1 and/or at least one second closing element 2 of said at least one orthodontic device 100 so as to define a first open condition of the first housing 6 and/or a second open condition of the second housing 7;

(c) inserting at least one portion 101 of the first orthodontic wire 10 into the first housing 6 in the first open condition and/or inserting at least one portion 110 of the second orthodontic wire 11 into the second housing 7 in the second open condition;

(d) constraining at least the first orthodontic wire 10 and/or at least the second orthodontic wire 11 to at least one other constraining element 20;

(e) moving at least one first closing element 1 and/or at least one second closing element 2 so as to define a first closed condition of the first housing 6 containing the first orthodontic wire 10 and/or a second closed condition of the second housing 7 containing the second orthodontic wire 11.

It should be noted that, through the use of the apparatus 200 comprising at least one orthodontic device 100 according to the present invention, advantageously, in at least one of the steps b) or c) or e), depending on the patient's tooth misalignment condition, the operator may decide whether a first orthodontic wire 10 should be inserted at the beginning of the treatment, or whether a first orthodontic wire 10 and a second orthodontic wire 11 should be inserted, depending on the necessary degree of dental realignment.

During the initial treatment step, the portion 101 of the first orthodontic wire 10, which portion is positioned in the first housing 6 in a first closed configuration, and/or the portion 110 of the second orthodontic wire 11, which portion is positioned in the second housing 7 in a second closed configuration, may be subjected to displacements in a direction parallel to the constraining surface 30, as a result of the tractive forces or torsional moments applied by the plurality of constraining elements 20 to the first orthodontic wire 10 and/or the second orthodontic wire 11.

In other words, the first housing 6 in the first closed configuration, which houses the portion 101 of the first orthodontic wire 10, ensures a sliding of the first orthodontic wire 10 as a result of the tractive forces or torsional moments applied at the points where said wires are constrained to the plurality of constraining elements 20. The same applies to the second housing 7 in the second closed configuration, which houses the portion 110 of the second orthodontic wire.

Preferably, the first orthodontic wire 10 has a length greater than the length of the second orthodontic wire 11.

Advantageously, at any time during the tooth realignment treatment in which it is necessary to regulate the tractive force or torsional moments acting on the orthodontic wires 10, 11, it is possible to insert the first orthodontic wire 10 into the first housing 6 and to insert the second orthodontic wire 11 into the second housing 7, given the fact that the first orthodontic wire 10 has also a length greater than the length of the second orthodontic wire 11.

As a result of the different length of the first orthodontic wire 10 compared to the second orthodontic wire 11, the plurality of constraining elements 20 which constrains the first orthodontic wire 10 is greater than the plurality of constraining elements 20 which constrains the second orthodontic wire 11. Therefore, this allows to regulate at any time the intensity of tractive forces or torsional moments in specific areas of the dental arch.

According to a possible aspect of the invention, the section of the first orthodontic wire 10 and the second orthodontic wire 11 is between 0.20 mm² and 0.52 mm², preferably 0.40 mm².

According to another preferred aspect, the section of the first orthodontic wire 10 and second orthodontic wire 11 is substantially rectangular.

This allows to insert the first orthodontic wire 10 into the first housing 6 in the first open condition and to insert the second orthodontic wire 11 into the second housing 7 in the second open condition, wherein the section of the first orthodontic wire and the section of the first orthodontic wire 10 and the second orthodontic wire 11 is between 0.20 mm² and 0.52 mm². During the initial step of the tooth realignment treatment, the section of the first orthodontic wire 10 and the second orthodontic wire 11 may be chosen in such a way as to minimise friction between the first orthodontic wire 10 and the first housing 6 in the first closed configuration and in such a way as to minimise friction between the second orthodontic wire 11 and the second housing 7 in the second closed configuration, i.e. in such a way as to maximise sliding in a direction parallel to the constraining surface 30 of the portion 101 of the first orthodontic wire 10 in the first housing 6 in the first closed condition and of the portion 110 of the second orthodontic wire 11 in the second housing 7 in the second closed condition.

Maximising said sliding therefore allows to facilitate the realignment of the teeth during the initial and intermediate steps of the treatment.

During the final step of the tooth realignment treatment, the section of the first orthodontic wire 10 and the second orthodontic wire 11 may be chosen in such a way as to maximise friction between the first portion 101 of the first orthodontic wire 10 and the first housing 6 in the first closed condition and in such a way as to maximise friction between the portion 110 of the second orthodontic wire 11 and the second housing 7 in the second closed configuration, i.e. in such a way as to minimise sliding in a direction parallel to the constraining surface 30 of the portion 101 of the first orthodontic wire 10 in the first housing 6 in the first closed condition and of the portion 110 of the second orthodontic wire 11 in the second housing 7 in the second closed configuration. Minimising said sliding therefore allows to consolidate the realignment of teeth, typically at the end of the treatment.

According to a possible aspect, the first orthodontic wire 10 or the second orthodontic wire 11 has at least one folded portion 60.

Taking two points A and B lying on the central axis of the first orthodontic wire 10 or the second orthodontic wire 11 in a substantially straight condition, such as e.g. shown in figure 7b, said points A and B both lie on a plane passing through the central axis of the first orthodontic wire 10 or the second orthodontic wire 11 and it is possible to define a minimum distance X between said points A and B.

In the case where the first orthodontic wire 10 or the second orthodontic wire 11 has at least one folded portion 60, said points A and B lie on two different planes, such as e.g. shown in figure 7a, and the minimum distance X is then increased by at least 0. IX. In other words, the distance between A and B is equal to at least X+0. IX.

In other words, the first closing element 1 and the second closing element 2, which can be moved independently of each other, allow to locally regulate the realignment of teeth by inserting a portion 101 of the first orthodontic wire 10 comprising a folded portion 60 into the housing 6 in a first open configuration and/or allow the insertion of a portion 110 of the first orthodontic wire 11 comprising a folded portion 60 in a second open configuration.

This is advantageous compared to the known art in which the insertion of the orthodontic wires takes place laterally, that is by placing the orthodontic wires from the mesial point to the distal point of the dental arch. Examples of at least one orthodontic wire comprising a folded portion are shown in figures 6a, 6b, 6c.

The folded portions 60 of the first orthodontic wire 10 or the second orthodontic wire 11 allow to regulate the local stiffness level at certain points of the apparatus 100, during the tooth realignment treatment step. For example, during the treatment step, it is possible to replace the second orthodontic wire 11 with a second orthodontic wire 11 comprising at least one folded portion 60, in order to have an orthodontic wire 11 with a higher level of stiffness which may, e.g., induce greater tractive forces or torsional moments at the plurality of constraining elements 20, compared to the tractive forces or torsional moments produced by the second orthodontic wire 11 in the absence of at least one folded portion.

According to a possible aspect, one or more devices 100 of the apparatus 200 are positioned at the end of the orthodontic wires 10, 11.

Typically, one or more devices 100 of the apparatus 200 are constrained to the molar teeth, preferably to the first permanent molar.

One or more orthodontic devices 100 may be constrained at the extreme points at the end of the orthodontic wires 10, 11. Typically, the orthodontic wires 10, 11 are positioned in such a way that the main direction of extent of the orthodontic wires 10, 11 are substantially parallel to the dental arch, thus substantially defining arches. The positioning of one or more orthodontic devices 100 at the end of the orthodontic wires allows to ensure a displacement of the orthodontic wires 10, 11 inside the first and second housings 6, 7 of the orthodontic device 100 substantially in the proximity of the ends of the dental arch, i.e. in the proximity of the molar teeth, while ensuring that tractive forces or torsional moments are applied to the orthodontic wires 10, 11 at the plurality of the constraining elements 20 in such a way as to ensure complete realignment of the dental arch, i.e. in such a way that even at the plurality of the constraining elements 20, the twisting forces or the moments are substantially null at the time when the desired dental realignment is achieved.

Claims

1. An orthodontic device (100) for correcting the position of teeth, which comprises a body (3), a constraining surface (30) for constraining to a tooth, a first housing (6), a second housing (7), a first closing element (1) for the first housing (6), a second closing element (2) for the second housing (7), said first closing element (1) and second closing element (2) being able to be moved independently of each other so as to define a first open condition and a first closed condition of the first housing (6) and a second open condition and a second closed condition of the second housing (7), wherein said first condition of the first housing (6) is independent of said second condition of the second housing (7) and vice versa.

2. The device according to claim 1, comprising a protrusion (4) for anchoring elastic bands (43), comprising a shank (41) which extends substantially parallel to the constraining surface (30) and a head (42) at the end of the shank (41).

3. The device according to one of the preceding claims, wherein the first closing element (1) and the first housing (6) in the first closed condition and the second closing element (2) and the second housing (7) in the second closed condition have a section between 0.20 mm² e 0.52 mm², preferably said section being substantially rectangular.

4. The device according to one of the preceding claims, wherein the first housing (6) comprises a first recess (50) and the second housing (7) comprises a second recess (51), said first recess (50) and second recess (51) forming a first opening (50a) and a second opening (51a) for the insertion of an opening instrument (52) to be able to move the first closing element (1) to a first open condition or a first closed condition or to move the second closing element (2) to a second open condition or a second closed condition.

5. The device according to one of the preceding claims, wherein the first housing (6) and the first closing element (1) in a first open condition are configured so as to allow the insertion of a portion (101) of a first orthodontic wire (10) into the first housing (6) in a direction (D) substantially perpendicular to the constraining surface (30) and wherein the second housing (7) and the second closing element (2) in a second open condition are configured so as to allow the insertion of a portion (110) of a second orthodontic wire (11) into the second housing (7) in a direction (D) substantially perpendicular to the constraining surface (30).

6. An apparatus (200) comprising a plurality of constraining elements (20) comprising housings for a first orthodontic wire (10) and a second orthodontic wire (11), wherein at least one of the constraining elements (20) is one of the constraining devices (100) according to one of the preceding claims.

7. The apparatus according to claim 6, wherein one or more devices (100) are positioned at the end of the orthodontic wires (10,11).

8. The apparatus according to claim 6 or 7, wherein the first orthodontic wire (10) has a length greater than the length of the second orthodontic wire (11).

9. The apparatus according to one of claims 6-8, wherein the section of the first orthodontic wire (10) and the second orthodontic wire (11) is between 0.20 mm² and 0.52 mm², preferably said section being substantially rectangular.

10. The apparatus according to one of claims 6-9, wherein the first orthodontic wire (10) or the second orthodontic wire (11) has at least one folded portion (60).