Orthodontic working anatomic arch, and orthodontic treatment system including anatomic wire

The invention relates to an orthodontic working arch wire (2) for moving at least one tooth of a dental arch of patient to be treated from a first spatial configuration toward a second spatial configuration, including an element for connecting (42) to the tooth to be treated, which is intended to be attached onto the tooth being treated by snap-fining onto a bracket glued onto one of the surfaces of said tooth, the working arch wire being rigid, the connecting element being movable relative to the orthodontic working arch wire and connected to the orthodontic working arch wire by elastically deformable connecting means (43, 43a).

This is a non-provisional application claiming the benefit of International Application Number PCT/EP2010/064141 filed Sep. 24, 2010.

The invention relates to a working arch wire designed for orthodontic correction and anatomically made to measure. The invention also relates to an orthodontic treatment system including a series of these orthodontic working arch wires.

Orthodontic treatment systems allow the correction of the position of a certain number of teeth located on the dental arches of the maxilla and/or the mandible of a patient. To this end, orthodontic treatment systems comprise collapsible metal arches, force generators attached onto the connectors, which are themselves attached onto the teeth to be moved or to be used as abutments. These applied forces are tension/compression and/or torsion forces. The metal arches are placed on the dental arches either vestibularly or lingually. The forces are transmitted to the teeth to be moved through connectors glued to them. In current devices, the metal arches which rest on other teeth, involved or not in the treatment, consequently generate parasitic forces on the latter teeth in reaction to the forces thus generated. One of the difficulties in orthodontic practice is how best to control, during the patient's treatment, these parasitic reaction forces which reduce the effectiveness of the treatment, in order to attain an optimal treatment.

For example, document US 2004/0048223 describes an orthodontic treatment system consisting of transmitting forces on the teeth to be treated by maxillary and/or mandibular caps made of semirigid material, covering the occlusal faces of all the teeth of the dental arch. The forces exerted on the teeth to be treated are obtained by an offset between the shape of the caps and stops attached onto the teeth to be treated. However, in this system the forces are not completely individualized and parasitic reaction forces are exerted on the teeth adjacent to the teeth to be treated.

In document US 2006/0099544, the orthodontic treatment system described includes an elastomer arch having recesses for receiving specific hooks or brackets glued to the teeth. However, in this second system, the resilience of this arch, though allowing the movement of the teeth to be treated, does not make it possible to decouple movements and, consequently, to individualize the forces to only the teeth to be treated. Once again parasitic reaction forces are exerted on the teeth adjacent to the teeth to be treated.

Also, these two methods alter interdental relationships by emplacing non-conformal, harmful and uncomfortable occlusal contacts.

One goal of the invention is to provide an orthodontic treatment system including orthodontic working wire arches which minimize parasitic reaction forces due to the forces needed for treating a tooth to be moved.

To this end there is provided, according to the invention, an orthodontic working wire arch designed to move at least one tooth to be treated in the dental arch of a patient from a first spatial configuration toward a second spatial configuration, the arch including an element for connecting to the tooth to be treated, attached onto said tooth to be treated, the working wire arch being rigid, the connecting element being movable with respect to the orthodontic working wire arch by elastically deformable connecting means.

Thus, the use of a connecting element that is movable with respect to the working wire arch makes it possible to optimally individualize the forces designed to move the tooth to be treated between two spatial configurations, the parasitic reaction forces being absorbed by the rigid orthodontic working wire arch by being distributed over the totality of this working wire arch.

Advantageously, but optionally, the orthodontic working wire arch has at least one of the following additional features:the connecting element includes a connector designed to be attached onto the tooth to be treated;the connecting element includes a connecting base connected to the orthodontic working wire arch by elastically deformable connecting means;The connecting base includes a recess designed to receive the connector;

The connector is inserted into the recess by clip action or by a vertical forked tenon;the recess has a shape complementary to a shape of the connector;the connector has the general shape of a truncated pyramid, particularly individualized in its shape and dimensions;the connector has, ringing it, a sunken groove or a bead in relief;the connector consists of three portions arranged so as to form a stress breaker of the silentbloc type;the orthodontic working arch wire also has a cavity designed to receive all or part of the connecting element;the elastically deformable connecting means are of the same material as the orthodontic working wire arch and part of the connecting element, so that there is no discontinuity of material between the orthodontic working wire arch and the part of the connecting element;the connecting means include at least one tab and/or an alveolar structure and/or a pontic connection;the orthodontic working wire arch includes a metal web designed to generate a force tending to open and/or to close the orthodontic working wire arch by spring effect;the orthodontic working wire arch includes a channel designed to receive a metal web;the working wire arch includes one or more extensions covering the gum allowing remote anchorage, particularly by clipping, onto a screw threaded into the bone;the working wire arch is so arranged as not to disturb the inter-arch relationships by not covering the occlusal surfaces of the teeth; andthe working wire arch is made of plastic, such as PA12 or PA6-6 polyamide.

There is also provided, according to the invention, an orthodontic treatment system designed to carry out a displacement of at least one tooth to be treated in a dental arch of a patient from an initial spatial configuration toward a desired final spatial configuration, comprising a series of orthodontic working wire arches having at least one of the foregoing features, so as to carry out the displacement by successive steps, each orthodontic working wire arch carrying out one step.

With reference toFIGS. 1 and 2, an orthodontic working wire arch2according to the invention is made to measure and anatomically to be positioned on the lingual or vestibular faces of the teeth of a dental arch1. Here, inFIGS. 1 and 2, the orthodontic working wire arch is positioned on the lingual faces of the teeth of the dental arch1. The lingual or vestibular faces of the teeth1are totally or partially covered by the orthodontic working wire arch2. This arrangement makes it possible to not cover the occlusal grinding surfaces of the teeth of the dental arch whereon is placed the orthodontic working wire arch2according to the invention.

With reference toFIG. 3, we will describe generally the attachment to a tooth1of an orthodontic working wire arch2according to the invention. On the surface, here the lingual surface, of the tooth1is glued a connecting element4, or even a connector, to which is connected the orthodontic working wire arch2, by clipping for example. In section, the orthodontic working wire arch2according to the invention has a section shape one profile whereof substantially follows the surface of the tooth whereon the orthodontic working wire arch2according to the invention is designed to be positioned. In the implementation variation illustrated here inFIG. 3, the orthodontic working wire arch2according to the invention includes a reinforcing web3. This reinforcing web3makes it possible to increase the corrective actions of the orthodontic working wire arch2according to the invention in remodeling the overall shape of the dental arch whereon is installed the orthodontic working wire arch according to the invention.

Generally, the orthodontic wire arch2is made of plastic compatible with use in the mouth. Considering the stresses required to exert the correction forces on the teeth, on the one hand, and on the other hand to carry out the remodeling of the dental arch whereon the orthodontic working wire arch2is installed, the material must have specific compressive, tensile and flexural strength characteristics. In particular, the material used is a PA 12 polyamide or possibly a PA6-6 polyamide. For its part, the reinforcing web3is generally a metal wire making it possible, by spring effect, to open or to close the orthodontic working wire arch2wherein it is installed. As is known per se, the metal wire forming the reinforcing web3is made of titanium.

Now, with reference toFIG. 4, we will describe the connectors41,41′,41″ making it possible to attach an orthodontic working wire arch2according to the invention. To each of the surfaces, lingual surfaces here, of the teeth1of the dental arch to be corrected is bonded a connector41,41′,41″. These connectors41,41′,41″ are generally of truncated pyramidal shape, with a substantially rectangular or substantially triangular base, or of a conical paralellopipedal shape each having a base411whereon is applied an suitable adhesive in order to glue the connector onto one of the vestibular and lingual surfaces of the tooth1. Each of the connectors41,41′,41″ has an upper face410spaced substantially parallel to the base411. The base411and the upper face410are of generally rectangular shape, the upper face410being homothetically smaller with respect to the base411. Connecting on each of the sides the base411with the upper face410, each of the connectors41,41′,41″ has lateral faces412sloping toward each other. The faces412have a sunken groove413which forms here a continuous or discontinuous ring on the connectors41,41′,41″. As a variation of implementation, the faces412have a bead in relief instead and in the place of the foregoing groove413. The dimensions of the base411, and consequently of the upper face410, are matched to the lingual or vestibular surface of the tooth1whereon said base411is designed to be bonded. This makes it possible to optimize and to ensure, on the one hand, the adhesion of the connector on the tooth throughout the entire treatment of the patient and, on the other hand, the transmission of forces which are likely to be necessary for a desired displacement of the tooth to be treated.

With reference toFIG. 4bis, the connector51has a base411to which is applied a suitable adhesive in order to glue the connector to one of the vestibular and lingual faces of the tooth. Here, this base is of substantially rectangular shape. It is topped with a narrowed neck511on which is laid a head512. The head512includes an upper face410and a bead510in relief extending belt-wise along a lateral boundary of said head512. The head has a substantially triangular shape, the corners whereof are rounded. This rounded shape makes it possible to avoid causing injuries.

As a variation of implementation, connectors of the silentbloc type can be made up of three irreversibly assembled portions comprising: a base whereon is applied an appropriate adhesive in order to glue the connector onto one of the vestibular and lingual surfaces of the tooth1, this base being topped with a force transmitting structure, capped with an elastic polymer of the rubbery or polyurethane, or even silicone type, and the assembly finally being wrapped in a carcase, the development of an outer face whereof is similar to an outer face of the connectors previously described.

With reference toFIG. 5, will describe in detail a connecting element4between the tooth1and the orthodontic working wire arch2according to the invention, which makes it possible to individually straighten or move said tooth between a first spatial configuration and a second spatial configuration, once the orthodontic working wire arch is positioned in the patient's mouth. To that end, the connecting element4has, in addition to a connector41attached onto the lingual or vestibular surface of the tooth1to be treated, a connecting base42connected to the orthodontic working wire arch2according to the invention by elastically deformable connecting means43. The connecting base42is of generally paralellopipedal shape and includes a cavity421extending as a hollow into one face of the connecting base42designed to be facing the connector41when the orthodontic working wire arch2according to the invention is mounted to the tooth1. The shape of the cavity421is the complement of the shape of the connector41so that the cavity421receives, during said assembly, the connector41clip action or clipping.

As a variation of implementation illustrated inFIG. 5bis, a lug425located on the face423opposite the connecting base makes it possible to limit the movement of the tab by cooperation with a hollow receptacle426located facing it in the working wire arch1.

When the connector41is clipped into the cavity421, the cavity421has a protuberance424(alternately a depression) extending in relief (alternately in depression) from at least one lateral face of the cavity421toward the inside thereof and designed to be received in the groove413(alternately, to receive the bead in relief) of the connector41. As a variation in implementation the protuberance (424) extends belt-wise over all or part of a periphery of the cavity421.

In another variation of implementation, the connecting base42includes, from an upper lateral face423, a groove422opening into the cavity421. Such a vertical groove422makes it possible to assemble the connecting base42by a forked tenon joint to the connector41attached onto the tooth1upon upward or downward vertical motion, depending on whether the orthodontic working wire arch2is mounted on the maxilla or on the mandible of the patient. One or two boss retainers427make it possible to hold the connecting base firmly to the connector41by resisting tearout or unclipping forces, by constituting an undercut in the engagement direction.

With reference toFIG. 6andFIG. 7, we will describe in greater detail the interaction between the connecting base42and the orthodontic working wire arch2according to the invention. Facing the working base42, the orthodontic working wire arch2has a cavity22as well as an opening21running through a thickness of the orthodontic working wire arch2from the bottom of the cavity22to one opposite face of the orthodontic working wire arch2. This opening21has two advantages:it makes it possible to press on the connecting base using an instrument capable of passing through it, in order to correctly clip the working wire arch onto the connectors in difficult locations, andit allows movement of fluids, saliva among others, to and out of the cavity22during a displacement of the connecting base42within this cavity22of the orthodontic working wire arch2according to the invention.

Here, illustrated inFIG. 6, the connecting base42is connected to the working wire arch2by elastically deformable connecting means43,43awhich are shown here as tabs. The shapes of the tabs constituting the elastically deformable connecting means43,43aare diverse and varied and especially suited by their shape to the spatial displacement of the tooth1to be treated to move from a first spatial configuration to a second spatial configuration by a translation movement and/or a rotation movement. In addition to their varied shapes, the number of tabs constituting the elastically deformable connecting means43,43acan vary between one and four (each lateral face of the connecting base42has one or no tab), which makes it possible to increase the possible displacements that can be performed on the tooth to which the connecting base42will be bonded. As a variation of implementation, the elastically deformable connecting means43,43ahave a narrow pontic connection spread over all or part of a periphery of the connecting base42as illustrated inFIG. 7a. In another variation of implementation, the elastically deformable connecting means include a sponge type alveolar structure distributed over all or part of a periphery of the connecting base42as illustrated inFIG. 7c. Other structures of elastically deformable connecting means43are possible.

Whatever the structure of the elastically deformable connecting means43, the orthodontic working wire arch2according to the invention, the elastically deformable connecting means43and the connecting base42are made of the same material. This prevents discontinuities of material between the orthodontic wire arch and the connecting base, which would weaken and complicate the orthodontic working wire arch2according to the invention.

Such an assembly of the different connecting bases42and the orthodontic working wire arch2according to the invention allows each of the connecting bases42to be able to move within the corresponding cavity22of the orthodontic working wire arch2. The elastically deformable connecting means43connecting the connecting base42with the orthodontic working wire arch2according to the invention make it possible to generate forces transmitted to the tooth to be treated in order to achieve the desired displacement between a first spatial configuration of this tooth and a second desired spatial configuration of this same tooth. Indeed, any movement of the connecting base42in the associated cavity22of the orthodontic working wire arch2gives rise to a force due to the elasticity of the material making up the elastically deformable connecting means. The intensity of this force transmitted by the connecting base42to the tooth1to be treated therefore depends on the size and on the shape of the structure of the elastically deformable connecting means used on said base42connecting to the orthodontic working wire arch2according to the invention, a structure that can be modulated as described previously in its manufacture according to the forces to be produced while respecting the physiology of living tissues. This makes it possible to personalize the forces to be produced on each tooth to be treated both in direction, in intensity, and in the movement boundary. Due to its stiffness, the working wire arch allows the parasitic reaction force to the force exerted on the tooth to be treated to be “diluted” in order not to transmit this parasitic force to the teeth adjacent to the teeth to be treated, but to spread it over the entire orthodontic working wire arch, making the parasitic force resulting from this spreading negligible and thus resolving the disadvantage of the current conventional systems. This stiffness of the orthodontic working wire arch allows the latter, once in place on the dental arch to be treated, to retain its shape in reaction to the force exerted on the tooth to be treated. Thus, by not deforming as a result of this reaction, the orthodontic working wire arch allows a spreading of the parasitic reaction force over the entirety of said orthodontic working wire arch.

However, the design of an orthodontic working wire arch2according to the invention does not allow transmission of substantially constant forces during dental displacement over distances greater than a few tenths of a millimeter. That is why the orthodontic working wire arches according to the invention must change during the progression of the treatment that allows the displacement of the teeth to be treated between an initial spatial configuration toward a desired final spatial configuration. The successive orthodontic working wire arches comprised in an orthodontic treatment system according to the invention are different from one another and each corresponds to a step in the progression of the desired orthodontic correction of the patient.

We will now briefly describe a method for making an orthodontic working wire arch according to the invention. To this end, an initial step of three-dimensional entry of the configuration of the teeth as well as of their roots of a patient to be treated is carried out by means of an X-ray scanner or a three-dimensional photo scanner (or other frequency spectrum usable for this purpose). Then, based on this data entry, a representation of the arches is integrated and processed in order to allow repositioning of the teeth according to the treatment objectives demanded and desired by the practitioner. A gradual repositioning of the teeth allows the corrected arches to be visualized. This repositioning takes into account the consistency of occlusal relationships during the course of the treatment. A segmentation of this progressive repositioning is then defined, each segment representing a step with which will be associated an orthodontic working wire arch according to the invention. From there, the orthodontic working wire arches according to the invention will be defined, then manufactured on a machine using a so-called laser fusion or stereolithography technique based on data representing the segmentation of the gradual repositioning defined previously. The series of orthodontic working wire arches thus obtained is incorporated into the orthodontic treatment system.

Of course, it is possible to apply numerous modifications to the invention without departing from its scope.