DE102015017301B3 - Orthodontic treatment apparatus and method of making same - Google Patents

Abstract

Described and illustrated is a method for producing an orthodontic arch (10) having arch segments (15) and fastening elements (14). of the one-piece cohesive orthodontic arch (10) in a generative manufacturing process, with joint cohesive formation of the fastening elements (14) with the arch segments (15).

Description

The present application relates to an orthodontic treatment apparatus for correcting misaligned teeth and a corresponding method.

Orthodontics as a treatment method in orthodontics deals with moving teeth to compensate for misalignments.

In the prior art, the applicant is aware of a number of orthodontic treatment appliances that cannot be documented in writing and are basically divided into removable and fixed appliances, colloquially also called “brackets” or “dental braces”.

From the U.S. 2016/0302884 A1 it is known to form brackets in one piece with a material connection together with holding webs. However, the holding webs are broken away after processing.

the WO 2013/052691 A1 discloses self-ligating brackets which are produced in an additive manufacturing process.

Finally revealed the EP 1 959 858 B1 an orthodontic archwire, which is fixed to teeth in a conventional manner, ie with brackets, the special feature being that the wire itself has regions of different cross-sectional thickness.

The aim of all appliances is the targeted movement of the teeth through the application of forces with at least approximately constant vectors of as constant strength as possible over a sufficiently long period of time. Such forces are transmitted from the tooth via the periodontium to the bone and ultimately result in a remodeling of the periodontal structures and bone remodeling (in the manner of attachment and depletion), which ultimately causes movement of the teeth in the bone.

As the closest state of the art, the very common so-called multi-bracket appliance (abbreviated: MB appliance), which is not documented in print, should be mentioned, which is a "fixed brace". This appliance has a large number of separate holding elements, also called brackets, which are attached to each tooth. For this purpose, the tooth surface is usually roughened or etched and a bracket is bonded to each tooth.

Such a bracket usually has a slot (so-called “slot”) to provide a holding property. The MB appliance also includes what is known as an orthodontic arch, which consists, for example, of a wire (made of a shape-memory alloy). This bow is inserted into the slots of the brackets under deformation and attached to the bracket, for example, by means of a wire ligature, rubber ligature or a small lock. Due to the shape memory properties and/or the elastic deformation properties of the material, the arch exerts the force described above on the teeth due to its restoring forces.

However, these MB apparatuses have various disadvantages: it is necessary to use a large number of arches of ever larger diameter in succession, with the arches used initially (with a small diameter) typically still having a round cross-section. Later arches with a larger cross-sectional diameter usually have a rectangular cross-section. This shape is used to transfer torque from the archwire to the bracket (in conjunction with the slot, which is also rectangular). However, archwires with a rectangular cross-section and a smaller diameter have a relatively large amount of play in the bracket slot, which is associated with a considerable loss of torque (when the torque is transmitted).

In addition, the arch of an MB appliance when used lingually (i.e. in the area of the inside of the tooth) proves to be relatively complex in terms of shaping, since the contour of the arch can only be created with a separate special appliance, due to the relatively complicated imaging of the inside of the dentition (so-called "mushroom "-Shape).

The so-called alloying of the archwire is relatively complicated with this prior art, since the archwire has to be painstakingly fixed to the bracket with a rubber band, a wire ligature, a lock or the like, which is even more difficult on the lingual side because of the tongue play that is present on the outside. The clinical time required for attaching the arch thus extends to several minutes, which can certainly be associated with a certain inconvenience for the patient.

The so-called aligner splint, which typically consists of a thermoelastic plastic (e.g. PET or polycarbonate), should be mentioned as further prior art. These plastic splints are so-called loose or non-fixed braces.

For this purpose, after taking an impression of the teeth and determining a target state (treatment goal), computer-aided meh intermediate steps are calculated and a corresponding number of plastic splints (aligners) are manufactured, for example in a compression molding or deep-drawing process. These splints cover more or less the entire tooth, in contrast to an orthodontic archwire, which significantly contacts a tooth via a support element fixed on only one side of the tooth.

However, the aligners described have some disadvantages, in particular that they are loose braces, which means that successful treatment (also) depends on the reliability of the wearer. In addition, there is rather insufficient power and torque transmission due to the relatively smooth aligner material and the smooth tooth surface, especially in the case of teeth with a rather rounded shape. The aligners are naturally not made of shape memory material.

In addition, it can happen during the course of the treatment that the actual tooth position deviates from the desired intermediate target position in such a way that the aligners that have already been manufactured can no longer be used at all. In this case, a new measurement must be carried out and a new set of aligners must be manufactured, which entails additional costs.

It is therefore the object of the present invention to provide a manufacturing method for an orthodontic treatment apparatus which can be manufactured in a simple and flexible manner and allows the greatest possible flexibility with secure attachment.

• • Berechnen der Bogensegmente hinsichtlich der Querschnitte und der Geometrie am Computer,
• • Herstellung des einstückig-stoffschlüssig ausgebildeten orthodontischen Bogens in einem generativen Fertigungsverfahren, unter gemeinsamer einstückig-stoffschlüssiger Ausbildung der Befestigungselemente mit den Bogensegmenten.

The invention solves the problem initially with the features of claim 1, in particular through the following steps:

• • Calculation of the arc segments with regard to the cross-sections and the geometry on the computer,
• • Production of the one-piece, materially bonded orthodontic arch in a generative manufacturing process, with a joint, one-piece, materially bonded formation of the fastening elements with the arch segments.

In this sense, an orthodontic arch consists of arch segments and fastening elements arranged between them. The orthodontic arch is completely integrally formed.

The fasteners are non-slidably secured to the arch framework.

In all cases, however, the orthodontic archwire has one or more attachment elements which can cooperate with tooth-side support elements to provide a closure. According to the invention, the cross section of the fastening elements deviates from the cross section of the arc segments (or at least one arc segment). In other words, the fastening element is not only provided by a specially shaped or aligned section of an archwire, but it has a locking structure with means which are suitable in terms of their shape to cooperate with corresponding counter-means of a tooth-side retaining element. The mounting elements thus have a certain stability. In particular, the fastening elements can be female in relation to the means, e.g. have constricted areas which can be pushed through by pin-like or projection-like areas of the mounting element to produce an engagement. Advantageously, these can therefore be matrices or patrices.

The clips or the fastening elements can be made from any material suitable for intra-oral use, for example steel, NiTi, polymer or the like. In any case, the material used should be suitable for supporting the positive button or snap mechanism, for which it should usually have a certain degree of spring hardness or the like.

The fastening elements can have connection sections for the arc segments surrounding them.

Another advantage of the arch-end fastener/tooth-side retainer closure system is that the two elements can be attached to a tooth in any configuration, i.e., at any angle. This is not readily possible with the devices of the prior art.

The individual arch segments of the orthodontic arch according to the invention can have identical cross sections or also different cross sections or cross sections with different thicknesses. As already described, all arch segments can be produced in one piece with a material connection.

The finished orthodontic archwire is thus generally U-shaped and is not consistent in cross-section along its longitudinal or axial extent, but rather has a varying transverse dimension cutting geometry, in particular due to the fasteners interposed between the arches. Together, arch segments and fasteners form the orthodontic arch.

In contrast to the known MB appliances, in which the arch is bent out of a wire with a constant cross-section, in the present invention an arch is created with a changing cross-section, which is why the orthodontic arch in one embodiment is not made of arch wire.

Rather, the orthodontic arch according to the invention is produced in a generative or additive manufacturing process, so that it can be created or printed out directly in the desired form.

• So bietet ein variierender Querschnitt den Vorteil, einzelne Bogenabschnitte mit einer unterschiedlichen Materialstärke, also einem unterschiedlichen Querschnittsdurchmesser, zu versehen, so dass die einzelnen Abschnitte (auch Segmente genannt) unterschiedliche Kräfte auf die zu beaufschlagenden Zähne ausüben. Da z.B. die Molaren größere Wurzeloberflächen als die Schneidezähne haben, und daher größere Kräfte für die Ausübung eines gleich starken Druckes benötigen, weisen die den Molaren zugeordneten Segmente in der Regel einen größeren Querschnitt auf als die Segmente, welche im Frontzahnbereich angeordnet sind.

Because the arch provided has a varying cross-section, several advantages can be achieved at the same time:

• A varying cross section offers the advantage of providing individual arcuate sections with a different material thickness, ie a different cross-sectional diameter, so that the individual sections (also called segments) exert different forces on the teeth to be acted upon. Since, for example, the molars have larger root surfaces than the incisors and therefore require greater forces to exert the same pressure, the segments assigned to the molars generally have a larger cross section than the segments arranged in the front tooth area.

Thus, by varying the cross-sectional configuration of an orthodontic archwire, greater stiffness can be achieved in specific segments or areas of the archwire, resulting in a much more variable and advantageously usable orthodontic archwire.

On the other hand, due to the varying cross-section (even in the case of segments with the same cross-sectional diameter), a (only in particular integral) formation of fastening elements cooperating with tooth-side retaining elements (as an integral part of the orthodontic arch) can be achieved. Due to the change in cross section of the orthodontic arch in the region of the associated tooth-side holding elements, fastening elements that cooperate with the holding elements on the arch side (in particular integrally bonded to the arch) can be formed. This facilitates the attachment of the bow to the teeth or to the tooth-side mounting elements, since a wire does not first have to be laboriously inserted into the corresponding bracket slots, as is the case in the prior art, but rather a simple button or snap mechanism is made possible.

All these advantages can be realized with a varying cross-section.

In contrast to non-fixed braces, such as aligners or plastic splints, which usually enclose several sides of the tooth, the present invention advantageously relates to fixed braces, i.e. fixed orthodontic treatment appliances and is therefore basically more comparable to MB appliances than to aligners, especially since the present sheet according to the invention can consist of a shape memory material (eg NiTi), but does not have to. A (particularly spring-hard) wire can also be used.

A shape memory material within the meaning of the present patent application is preferably a nickel-titanium material (NiTi) or another shape memory alloy. Alternatively, a shape-memory polymer can also be used, or as mentioned also a non-shape-memory substance.

Despite subsequent deformation, the materials can usually seem to "remember" their earlier shape and at least strive for this earlier shape. By striving for the previous shape, in particular the required forces are exerted on the teeth in such orthodontic treatment apparatuses.

In this sense, the orthodontic arch according to the invention is first produced directly in a form which corresponds to the final desired state or an intermediate desired state of the teeth. When the bow is inserted into the bite, there is a deformation from the original shape to the actual state of the teeth. Finally, the desired force is applied to the teeth by the restoring forces.

An orthodontic arch within the meaning of the invention usually only cooperates with one side of the teeth (thus, for example, the inside of the tooth or the outside of the tooth), while, for example, an aligner surrounds the teeth on several sides.

The contour of the arch is essentially U-shaped, with the area between the legs of the U being basically left free (with the exception of auxiliary arches, which will be described later).

According to the invention, the orthodontic arch is arranged in the teeth (preferably lingually, i.e. on the inside of the tooth) with the aid of holding elements fixed on the tooth side, either in the upper jaw or in the lower jaw, depending on the treatment required (or usually both).

For this purpose, a holding element is attached to at least one, in particular to each, tooth of the jaw, comparable to the brackets in the MB method described. These mounting elements are firmly connected to the respective tooth and are also called attachments. For this purpose, the tooth can in particular be cleaned and etched (to enlarge the surface). Drying or bonding or other measures can also be carried out. The respective mounting element is then attached to the tooth, e.g. by means of a bonding process. The holding element can consist, for example, of one or more dental composite(s) and can harden on the tooth, with such a method being able to be based on conventional methods for directly attaching brackets or attachments.

However, within the meaning of the present patent application, mounting elements fixed on the tooth side also include mounting elements which are attached to a so-called mini-implant (TAD=Transitoric Anchoring Device). In this case, the holding element is not attached directly to the crown of the tooth, but rather is assigned to the teeth on the jaw. The fastening element can be attached to the implant in a similar way to that on the tooth itself, and the method for producing an orthodontic arch is also essentially comparable.

Advantageously, the holding elements for attaching the orthodontic arch in the oral cavity cooperate with specially designed sections or with special fastening elements of the orthodontic arch.

For this purpose, the orthodontic arch is subdivided into fastening elements that interact with the tooth-side fastening elements and arch segments arranged between the fastening elements.

The orthodontic arch can in particular have loops or other shaped elements in the individual arch segments. Typically, the arc segment cross-section has a diameter of between 0.2mm and 3mm. The (typically round) arc segment cross section can vary not only between the segments, but also within an individual arc segment.

According to the invention, the fastening elements and the arcuate segments are formed together in one piece with a material connection, i.e. in particular manufactured in one piece. In other words, the orthodontic arch including arch segments and fastening elements consists of one piece or of one part. For this purpose, a generative manufacturing process can be used to produce the orthodontic arch.

Such a process, which can also be described as additive manufacturing, is a primary forming process in which a specific product does not require a special tool that has stored the respective geometry of the piece to be finished (e.g. casting mold). Rather, a corresponding orthodontic arch is produced on the basis of computer-internal data models from formless material (e.g. powder or liquids or the like) using a free-form fabrication method. In particular, a so-called selective laser melting method (SLM) can be used. Therefore, in this case, no archwire or archwire in the conventional sense is necessary.

In particular, a 3D printing method is used and a corresponding 3D printer can be used for this purpose. This has the advantage that the conditions in a patient's oral cavity can be addressed very individually, production is inexpensive and, in particular, the cross-section of the orthodontic arches can also be ideally adapted and varied. Auxiliary archwires which are still to be described are preferably also produced directly in one piece with the orthodontic archwire in the manner described.

Preferably, the holding elements and the fastening elements or at least one pair of holding, fastening elements can be brought into engagement in a form-fitting manner. In this way, the orthodontic arch can be attached to the holding elements in a particularly elegant manner.

According to an advantageous embodiment, tooth-side retaining elements and bow-side fastening elements can be brought into engagement in a form-fitting manner, in the manner of a button or snap-in mechanism.

In other words, the idea of the advantageous embodiment is to provide a novel locking mechanism for attaching an orthodontic arch on the jaw side. For this purpose, the bow has specially shaped clips or fastening elements, each of which is attached to a bracket or a tooth Attachment can be fastened in a form-fitting manner, using buttons, clips, snaps or latches.

In this way, the time for attaching (so-called alloying) the bow can be significantly reduced, since the bow is no longer attached with separate elements (such as locks or elastics), but can simply be pressed open with the help of the snap fasteners provided. The clinical time requirement can therefore be reduced from a few minutes to just a few seconds.

The holding elements, which are fixed on the tooth side and which can be, for example, so-called attachments (but also brackets), are brought into positive engagement with the arch-side fastening elements, also called clips. Both a fastening element and a holding element can form or provide part of a button or snap mechanism for this purpose.

For example, a section of the holding element can snap or click into a region of the fastening element, in particular in the manner of a button. For this purpose, the fastening element has a specially provided (in particular female) shape, which accordingly differs from the cross-sectional shape of the rest of the orthodontic arch or the arch segments (or the arch segments surrounding them).

According to a particularly advantageous embodiment of the invention, the retaining elements and fastening elements can be designed in the manner of a male-female closure or the retaining elements and the fastening elements can be brought into engagement in the manner of a male-female closure. In this way, a button-like fastening of the orthodontic arch to the teeth or to the holding elements is made possible. In this case, the matrix is advantageously arranged on the arch side and the patrix on the tooth side (which enables the orthodontic arch to be designed flat). In principle, however, the matrix and the patrix can also be arranged the other way around according to the core of the invention.

In particular, wing or bar elements of the matrix can overlap or engage behind corresponding holding surfaces of the patrix.

As an alternative, however, a mushroom head mount or another type of snap-in mechanism can also be selected. For example, a grip can be provided between the mounting elements and the fastening elements. The mushroom head can, for example, reach through a constriction and behind it can reach behind surfaces assigned to the mushroom head, in particular a matrix.

The arrangement of the matrix on the arch side also offers advantages in terms of printing technology, since the jaw is not penetrated by a matrix.

In terms of this advantageous embodiment, holding elements or fastening elements can therefore provide or form a female part or male part.

According to a further, particularly advantageous embodiment of the invention, the fastening elements can each have a fastening surface which is formed essentially inversely to a fastening surface of the tooth-side fastening elements. Fastening surface and mounting surface can here, for example, engage behind one another or rest against one another. They can be used particularly advantageously in the case of a matrix closure. The surfaces can cooperate and support or form the button or snap mechanism.

According to a further, particularly advantageous embodiment of the invention, the treatment apparatus has an opening mechanism in the region of a pair of holding element and fastening element. The opening mechanism can be activated manually in order to disengage the support element and fastening element from one another in the event that the orthodontic archwire is to be removed from the support elements or from the dentition and to be replaced by another orthodontic archwire, for example.

A corresponding opening mechanism ensures, in particular, that a form-fitting engagement between the holding element and the fastening element is canceled. For example, the opening mechanism can be provided in the manner of a tab that can be gripped from behind, which is designed here in particular on the sheet side and/or on the matrix side. The tab can be designed in the manner of a bar or in the manner of an eye and can be gripped behind by a dental probe or a similar instrument, whereby an opening process can be initiated (in particular by bending the sheet material).

The lug can either be an element (e.g. a bar) which is in any case firmly arranged on the holding element or the fastening element for effecting the button or snap mechanism (which, for example, provides a surface that engages behind). In an alternative embodiment, the tab but also a separate Train element, which protrudes from the conventional webs and in this way forms a separate eye or a separate eyelet.

The opening mechanism is preferably arranged on the bend side, that is to say on the fastening element, and is in particular designed as a one-piece material connection with the fastening element (for example as a tab).

According to the invention, the fastening elements are formed in one piece with the arch segments in a materially bonded manner, so that the entire orthodontic arch is formed in one piece with material bonding. It can therefore be produced in a generative manufacturing process, for example in 3D printing, and in particular also together with one or more auxiliary sheets.

According to a further advantageous embodiment of the invention, the treatment apparatus has at least one auxiliary arch between non-adjacent teeth, which can be formed at least partially in one piece with the orthodontic arch in a cohesive manner. In other words, a corresponding auxiliary arch is produced in one piece or in one piece with the orthodontic arch, in particular together in a generative process described above.

An auxiliary archwire typically provides additional support or force between different areas of the orthodontic archwire. The ends of the auxiliary arch can be arranged in the area of the fastening elements, for example, or alternatively in the area of the arch segments. The auxiliary arches are usually designed as transpalatal arches in the upper jaw or as lingual arches in the lower jaw.

The invention also solves the problem with an orthodontic arch, in particular produced in a method according to one of claims 1 to 7.

• • Erstellen eines Modells des Gebisses in einem Soll-Zustand,
• • Herstellen eines Bogensegmente und Befestigungselemente aufweisenden orthodontischen Bogens auf Basis des Modells, wobei die Befestigungselemente einen von den Bogensegmenten abweichenden, eine Befestigungsfunktion bereitstellenden Querschnitt aufweisen,
• • Befestigen des orthodontischen Bogens an dem Gebiss durch ein formschlüssiges, knopf- oder schnappmechanismusartiges Ineingriffbringen der Befestigungslemente und vorher gebissseitig festgelegter Halterungselemente.

A method in which such a sheet can be used is characterized in particular by the following steps:

• • Creation of a model of the dentition in a target state,
• • Production of an orthodontic arch having arch segments and fastening elements on the basis of the model, the fastening elements having a cross-section which differs from the arch segments and provides a fastening function,
• Securing the orthodontic archwire to the denture by positive, button or snap-type engagement of the fasteners and previously fixed denture-side retaining members.

In this sense, it is therefore possible to work with a model, which can in particular be a physical or a virtual model. The model can already have support elements (physical or virtual) or already take their positioning into account.

The fastening elements can thus be connected to mounting elements in multiple ways, namely in particular first to mounting elements of the model and then to mounting elements of the human jaw.

In this sense, a physical model can be modeled on a set of teeth in the conventional way. Methods for producing a corresponding model are also already sufficiently known for virtual models. The model represents the target state, i.e. the ultimately desired, healed state. Alternatively, an intermediate state can also be referred to as a target state, which is to be reached first, as an intermediate step in a sequence of intermediate steps.

In a further step, an orthodontic arch can then be created based on the model. In this case, the fastening elements have a special shape which differs in particular from the cross section of the arcuate segments in order to enable subsequent closure between fastening elements and holding elements. In this sense, the fastening elements then provide part of the closure between the fastening element and the mounting element, with the other part being provided by the mounting element. This can in particular be a button-like or snap-type or latch-type closure.

Alternatively, the fastening elements can also first be fastened to the arch segments, the orthodontic arch then being inserted in its entirety into the model and the orthodontic arch being attached to the model by attaching the fastening elements to the holding elements. After this or as a result of this, the orthodontic arch can then be modeled. In this case, too, the orthodontic arch can then be removed and inserted into a human set of teeth. The healing effect can then set in as a result of the restoring forces of the orthodontic archwire described above.

The main advantage of this process is that in the last process step the fastening to the human dentition due to the button or snap mechanism, a large time saving is achieved, the treatment being designed much more comfortably for the patient to be treated.

All the features and descriptions were not repeated again with regard to device claim 8 solely for reasons of process economy. However, all features and descriptions relating to patent claims 1 to 7 shall be deemed to be disclosed in connection with patent claim 8, insofar as they are transferrable.

The same applies, of course, the other way around, i.e. all device features described and to be described in the description of the figures should also be transferrable to patent claims 1 to 7.

• 1 eine sehr schematische, perspektivische Überblicksaufsicht eines orthodontischen Bogens einer erfindungsgemäßen orthodontischen Behandlungsapparatur unter Fortlassung eines Hilfsbogens, geltend für alle Ausführungsbeispiele
• 2a eine Teilansicht eines ersten Ausführungsbeispiels eines orthodontischen Bogens, etwa in dem in 1 mit IIa gekennzeichneten Bereich,
• 2b eine Rückansicht des Bogenteils gemäß 2a, etwa entlang des Ansichtspfeiles Ilb in 2a,
• 3 der orthodontische Bogen gemäß 1 in einem in ein Gebiss eingesetztem Zustand, geltend für alle Ausführungsbeispiele unter Darstellung eines Transpalatinalbogens,
• 4a in einer sehr schematischen Querschnittsansicht eine Darstellung eines Paares aus bogenseitigem Befestigungselement sowie zahnseitigem Halterungselement in geöffnetem Zustand, gemäß dem Ausführungsbeispiel nach 2,
• 4b das in 4a dargestellte Paar in eingerastetem oder geschlossenem Zustand,
• 5a eine perspektivische, schematische Ansicht des Paares gemäß 4a und
• 5b eine perspektivische, schematische Ansicht des Paares gemäß 4b.

Further special features result from the non-cited subclaims and from the description that now follows. In the figures show:

• 1 a very schematic, perspective overview view of an orthodontic arch of an orthodontic treatment apparatus according to the invention with the omission of an auxiliary arch, valid for all exemplary embodiments
• 2a a partial view of a first embodiment of an orthodontic arch, such as in 1 area marked IIa,
• 2 B a rear view of the bow part according to FIG 2a , approximately along the view arrow Ilb in 2a ,
• 3 the orthodontic arch according to 1 in a state inserted into a dentition, valid for all exemplary embodiments showing a transpalatal arch,
• 4a in a very schematic cross-sectional view, a representation of a pair of arch-side fastening element and tooth-side mounting element in the open state, according to the embodiment 2 ,
• 4b this in 4a pair shown in latched or closed condition,
• 5a a perspective, schematic view of the pair according to 4a and
• 5b a perspective, schematic view of the pair according to 4b .

The description of the figures should be preceded by the fact that, for the sake of clarity, parts or elements that are the same or comparable to one another are denoted by the same reference numbers, sometimes with the addition of apostrophes or lower-case letters.

1 shows an orthodontic arch 11 of a first treatment apparatus according to the invention in a schematic, slightly perspective top view. The orthodontic arch (or arch for short) 11 is designed as a device on the lingual side, ie for attachment to the inside of the teeth (not shown).

The orthodontic arch 11 according to 1 is substantially U-shaped, with a base 12 in the mesial region and legs 13 of the U-shape extending towards the distal region.

The sheet 11 is produced in a generative manufacturing process, in one piece, as a workpiece and consists of a shape memory material, for example a nickel-titanium material.

As shown, the arch 11 is manufactured directly in its desired position and does not require any special preparation (in contrast to MB wires, which must first be brought into a desired position).

The target position represents either the desired end position of the teeth to be loaded or, as a rule, an intermediate position.

Already in 1 indicates the basic subdivision of the orthodontic arch, alternating between fastening elements 14 and arch segments 15 arranged in between (wherein in 1 only some of the fastening elements or arc segments shown are provided with corresponding reference numerals as an example).

2a and 2 B , which is an enlarged representation of a 1 roughly marked with a circle and labeled IIa, illustrate this structure: As an example, two fastening elements 14a and 14b are shown in 2a to recognize between which an arc segment 15a is arranged. Furthermore, a further arcuate segment 15b adjoins the fastening element 14a, and a further arcuate segment (not shown) would adjoin the fastening element 14b.

Already at first glance you can 2a unequivocally a variation of the cross section of the illustrated orthodontic arch 11 along its longitudinal extent I: The cross section in the area of the arch segments 15a and 15b is essentially circular and deviates significantly from this circular shape in the area of the fastening elements 14 (in the manner of a more complex cross section).

The fastening elements 14a and 14b are designed according to their cross-section in such a way that they form fastening surfaces to be described later in more detail, which are connected to corresponding fastening surfaces in FIGS 1 and 2 not shown, tooth-side support elements (engaging) can cooperate. The fastening elements 14 are also designed in such a way that they have opening or actuating tabs 16a and 16b, which enable the fastening elements 14 to be detached from the holding elements, which are not shown, in a manner that will also be described in detail later.

Furthermore, the 2a and 2 B It can be seen that the fastening elements 14 each have lateral connecting flanges 17, which on the one hand laterally delimit a cavity 18 formed in the fastening elements and also provide the connection to the adjoining arc segments 15.

In this sense, the arc segment 15a can be identified 2 B connected via a flange 17b' to the fastening element 14b and via a flange 17a to the fastening element 14a.

As in the 2a and 2 B is also already indicated, the connections between the arcuate segments 15 and the fastening elements 14 (via their flanges 17) are integrally formed integrally. In this sense, the arch segments 15 are not manufactured separately from the fastening elements 14, but they are formed directly in one piece together with them, in particular from the same material (for example NiTi).

This one-piece production is advantageously carried out in an additive manufacturing process, for example in an SLM process using powdered or liquid starting material, in particular by a 3D printer.

In this way, an orthodontist can independently print out or produce such an orthodontic sheet 11 on a suitable printer without having to rely on special tools or third parties.

Typically, the arcuate segments 15 have a substantially round cross-section, which is advantageous since in this way a contact with the surrounding teeth that is as smooth and painless as possible is made possible. Like the 2a and 2 B As can be seen, the arcuate segments 15, such as the arcuate segment 15a, can form what are known as loops 19, in order in this way to increase the length of the corresponding arcuate segment 15a. This serves in particular to regulate the transmission of force to the adjacent teeth, since arch segments of greater length generally apply lower forces than arch segments of shorter length. The loops 19 are produced directly as part of the generative manufacturing process.

Another way of regulating the forces to be applied is to vary the cross section of the orthodontic arch 11 in the area of the respective arch segments 15 (this applies in particular to all of the exemplary embodiments). Thus, in an area in which greater forces are required to be applied, a larger arched cross-section (in particular with the same cross-sectional shape) can be used. For example, a larger arch cross-section is used in the molar area than in the anterior area. Alternatively, a smaller arch segment cross-section can also be provided where teeth only have to be moved less due to a smaller misalignment.

According to 2a in this regard, for example, the arcuate segment 15b has a larger cross-sectional diameter than the arcuate segment 15a. However, both arcuate segments 15a and 15b have a round cross-section in terms of their shape. In addition, both arcuate segments 15a and 15b are provided with a homogeneous cross section (ie with a constant cross-sectional diameter) which does not vary within the segment.

Of course, embodiments can also be realized in which the diameter of the cross section varies within a segment 15, e.g. becomes larger in the longitudinal direction I towards the distal region. Also, of course, within the scope of the present invention are orthodontic archwires or archwire segments 15 which vary not necessarily in diameter but rather in cross-sectional shape within a segment 15 or from segment 15a to segment 15b.

3 shows the in 1 and 2 illustrated orthodontic bow 11 as part of a complete orthodontic treatment apparatus 10 for correcting misaligned teeth, in one fixed state on an exemplary upper jaw 20 .

The orthodontic arch 11 is arranged in particular on the inside 21 (i.e. on the lingual side) of the teeth 22 shown (wherein 3 only some of the teeth are provided with the reference number 22 as an example).

The illustrated orthodontic treatment apparatus 11 is shown to have 3 a transpalatal arch 23 (which is also called the palatal arch). This transpalatal arch 23 is made in one piece with the orthodontic arch 11 and is thus created with it in one piece and from the same material using the same additive manufacturing process. It serves in particular to maintain the width between opposite molars and can thereby prevent these teeth from moving forward, but also pull these molars into a necessary orthopedic position.

When used in a lower jaw, a corresponding orthodontic treatment apparatus can, of course, alternatively provide a lingual auxiliary arch.

ID 3 For example, the transpalatal arch 23 is located on two (non-adjacent) fasteners 14x and 14y. In principle, however, it is also conceivable that the two ends of the transpalatal arch 23 connect to arch segments 15 .

The slightly perspective view according to 3 makes it clear that the fastening elements 14 can lie not only at different angles with respect to the xy plane spanned by the teeth, but also at a tilted attachment with respect to the height vector z, ie in the figure plane of FIG 3 in, enable.

• Während Befestigungselemente 14 und Halterungselemente 24 in 3 im zusammenwirkenden Zustand dargestellt und kaum zu differenzieren sind, zeigt 5a in einer sehr schematischen perspektivischen Ansicht ein an ein zahnseitiges Halterungselement 24 angenähertes beispielhaftes Befestigungselement 14, wobei auf Grund der Übersichtlichkeit an dem Flansch 17 des Befestigungselementes 14 kein anschließendes Bogensegment 15 dargestellt ist.

For this purpose, the fastening elements 14 interact in the manner to be described below with the retaining elements 24 fixedly arranged on the tooth side:

• While fasteners 14 and support members 24 in 3 are shown in the interacting state and can hardly be differentiated 5a in a very schematic perspective view, an example of a fastening element 14 approximated to a tooth-side retaining element 24, wherein no adjoining arcuate segment 15 is shown on the flange 17 of the fastening element 14 for the sake of clarity.

5b then puts in a view accordingly 5a the fastening element 14 and the holding element 24 in a mounted or fastened state, this fastening process being based on the schematic cross-sectional views of FIG 4a and 4b will subsequently be described in more detail.

First of all, however, it should be noted that the mounting element 24 essentially has two areas: firstly a male area 25 interacting with the fastening element 14 and a base area 26 on the tooth side. This base area 26 is attached to a tooth in the manner of an attachment or a bracket, in particular on the inside 21 of a tooth 22, firmly arranged. The mounting element 24 is therefore preferably produced in the manner of an attachment from dental composite, which uses only one adhesive connection surface, as a result of which the bond between the tooth and the attachment or mounting element 24 is better than when a conventional bracket is attached using an MB method (since there usually several layers of different materials are bonded together: tooth, composite, cement, bracket base).

Dental composite only has mediocre abrasion resistance. However, this is counteracted by the fact that the holding element is surrounded by the arch-side fastening element (in a manner that will be described below) for almost the entire treatment time. Depending on the shape of the tooth and the patient's individual circumstances, the tooth-side retaining element has a variable size with a mesio-distal length of around 1.5 to 3 mm, a height measured perpendicularly from the tooth surface of 0.7 to 1.6 mm and a gingival coronal height of 2 to 3 mm. Due to this low overall height, shearing forces are generally considered to be very low and the wearing comfort with a lingual attachment is improved.

The mounting elements 24 are transferred from a virtual, computer-generated form into the patient's mouth in the following manner: First, a sample workpiece of the actual dentition is created in the current state with the mounting elements attached, for example in a rapid prototyping process. A transfer template is then produced, for example made of silicone or in a deep-drawing process over the printed model. The fastening elements are present as cavities in the transfer template and are then not completely filled with a dental composite (light-dual or chemically curing). After curing, the surface of the composite is still reactive due to the oxygen inhibition layers. After preparatory measures on the tooth surface (e.g. cleaning, Surface enlargement by etching, drying, bonding, other measures if necessary), the cavities in the transfer template that remain after the filling described above are filled with a preferably dual-curing composite and the template is then placed in the patient's mouth without delay, where the composite hardens and so connects the support member with the tooth surface.

Regarding the 5a and 5b (but also 4a and 4b) it should first be noted that the base 26 in the figures is only to be understood as an exemplary embodiment and is in particular shown enlarged. The base is preferably made much smaller or flatter and conformed to the surface to be attached and attached using the methods described above.

If the attachment elements are attached to the teeth (preferably one attachment element to each tooth), attachment of the orthodontic arch 11 to the teeth, as in 4a illustrated, take place: Thus, a male part area 25, which in particular is in the form of a double hump, of the holding element 24 is overlapped by the fastening element 14 providing a female part. Here, the patrix area 25 can enter or engage in a cavity 18 of the fastening element 14 and deflect lateral webs 27 of the fastening element 14 in order to fully enter the cavity 18 . The webs 27a and 27b are deflected to such an extent that they can get past the head of the male area 25 and then snap in behind the head of the male area 25, whereby the head of the male area 25 is gripped from behind, as is shown in 4b is shown.

In the illustrated embodiment after 4 the matrix or the fastening element 14 has a wedge-shaped central web 28 which comes to lie in a corresponding indentation in the patrix 25 . The webs 27a and 27b are in one 4b shown, mounted or behind-gripping state with mounting surfaces 29 on corresponding inverse mounting surfaces 30 on the mounting element 24. In this way, the surfaces form a form fit.

An actuating tab 16 already described as part of the fastening element 14 adjoins the side of the matrix. Together with the base 26, this tab 16 forms a guide channel or a guide eye 31 which is accessible, for example, for a dental probe or for a similar instrument. As a result, the holding element 24 or the female part can be bent up so far that the web 27a associated with the tab 16 detaches from the undercut of the male part 25 and passes the male part head, so that the female part or the fastening element 14 is released. If this is done for each fastening element 14 of the orthodontic archwire 11, the orthodontic archwire 11 can be easily removed from the oral cavity of the patient and, in particular, an alternative orthodontic archwire with a different treatment geometry can be used.

• Zunächst werden anhand eines Computermodells Sollpositionen jedes zu bewegenden Zahnes definiert. Es wird zudem eine Sequenzierung der Ist- zu den Sollpositionen festgelegt (Festlegung der Schrittweite und der Stellungsunterschiede der Zähne zwischen den einzelnen Schritten). Insbesondere werden außerdem virtuelle Abbildungen der Halterungselemente am Computer den einzelnen Zähnen zugeordnet und es werden die Bogensegmente hinsichtlich der Querschnitte und der Geometrie (Loops oder ähnlichem) am Computer anhand der klinischen Erfordernisse berechnet.

A treatment method with the orthodontic treatment apparatus according to the invention of the first embodiment, which is also to be disclosed in this application, can be carried out in particular as follows:

• First, target positions of each tooth to be moved are defined using a computer model. In addition, a sequencing of the actual to the target positions is determined (determination of the increment and the position differences of the teeth between the individual steps). In particular, virtual images of the mounting elements are also assigned to the individual teeth on the computer and the arch segments are calculated on the computer with regard to the cross sections and the geometry (loops or the like) on the basis of the clinical requirements.

In particular, a calculation is carried out in such a way that the relative position of the fastening elements to the respective tooth always remains the same and that the relative position of the respective fastening element in the fastening element on the tooth always remains the same, i.e. in the different sequencing stages fastening elements in the orthodontic arch change their position or position. Can change position, but advantageously remain unchanged compared to the support elements. In this way, the target positions of the teeth in the respective treatment step are transferred exactly to the position of the fastening element on the arch.

Sheets assigned to the individual intermediate steps are printed, which differ in particular with regard to the cross sections.

The proposed method has the combined advantages of the MB method and the aligner method of the prior art, without adopting their disadvantages. As with aligners, several inserts for several intermediate steps can be produced with the aid of a computer, with the problem of insufficient power transmission being avoided in the present case. The variable arch cross-sections also make it possible to reduce the number of therapy steps.

In principle, the invention also includes the use of what are known as brackets instead of attachments, that is to say holding elements which are typically made of metal and are fixed to the tooth with a separate composite or similar binding agent. The only decisive factor here is the design of the holding element and its suitability for form-fitting engagement (like a button or snap mechanism) with a corresponding fastening element.

In all of the exemplary embodiments, an advantage can be seen in the fact that the orthodontic arch already has a specially designed (in particular female) fastening element arranged on it, which can provide a form fit with the brackets or attachments attached to the tooth for simple clipping of the orthodontic arch to the dentition .

Claims (8)

Method for the production of an orthodontic arch (10) having arch segments (15) and fastening elements (14), comprising the following steps: • Calculation of the arc segments (15) with regard to the cross sections and the geometry on the computer, • Production of the orthodontic arch (10) designed as a one-piece material bond in an additive manufacturing process, with the fastening elements (14) being jointly formed as a one-piece material bond with the arch segments (15). procedure after claim 1 , characterized in that the fastening elements (14) have a cross-section which differs from the arcuate segments (15) and provides a fastening function. procedure after claim 1 or 2 , characterized in that the calculation is carried out in such a way that the relative position of a fastening element (14) in a holding element (24) on a tooth always remains the same. Method according to one of the preceding claims, characterized in that loops (19) are also produced directly as part of the additive manufacturing process. Method according to one of the preceding claims, characterized in that the one-piece production takes place in an additive manufacturing process in an SLM process using powdered or liquid starting material, in particular by a 3D printer. Method according to one of the preceding claims, characterized in that an auxiliary arch (23) is produced in one piece or in one piece with the orthodontic arch (10). Method according to one of the preceding claims, characterized in that arcuate segments (15) have different or different thickness cross-sections. An orthodontic arch (10) made by a method according to any one of the preceding claims.

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