NL2019724B1

NL2019724B1 - Three-dimensionally printed removable basis element for an orthodontic appliance and an orthodontic appliance

Info

Publication number: NL2019724B1
Application number: NL2019724A
Authority: NL
Inventors: Gerrit Ipenburg Alexander
Original assignee: Aptus Bv
Priority date: 2017-10-13
Filing date: 2017-10-13
Publication date: 2019-04-23

Abstract

The invention relates to a basis element for an orthodontic appliance, configured to apply a force onto one or more teeth in order to change a teeth pattern of a patient. The basis element comprises a first contact block and a second contact block. The first and second contact blocks are respectively configured to interlock with a first and a second set of teeth. The basis element further comprises a bridge element, which extends between the contact blocks and which is configured to secure a relative position between the contact blocks. The first contact block, the second contact block and the bridge element have been manufactured by means of a three-dimensional printing process as an integral unit. The invention further relates to an orthodontic appliance, manufactured using a basis element as described above. The bridge element is at least partly removed and the appliance comprises at least one active element, which is secured to the first contact block and to the second contact block. The active element is configured to set a relative displacement between the contact blocks in order to induce a pre-tensioning force between the first and the second set of teeth.

Description

Title: Three-dimensionally printed removable basis element for an orthodontic appliance and an orthodontic appliance.

The present invention relates to a three-dimensionally printed basis element for an orthodontic appliance and an orthodontic appliance. The invention further relates to a method for manufacturing a basis element by means of three-dimensional printing, and method for manufacturing an orthodontic appliance.

In orthodontics, appliances, and in particular removable appliances have been known for time to be suitable in comprehensive orthodontic treatments as a pre-treatment step to correct the position of teeth or jaw bones of a patient and in particular to correct problems with bite, and the alignment between an upper jaw and a lower jaw.

These appliances may for example comprise active elements, such as screws or springs. An example of an active removable appliance is an activator, which is configured to change a relative position between an upper and a lower jaw, or an expansion appliance which is configured to change a dimension of a jaw arch, for example to widen a jaw arch.

Furthermore (clear) aligners are known in limited orthodontic treatments, during which individual teeth are aligned, instead of a dimension of a jaw. These aligners, which are for example manufactured by Invisalign, are in the form of series of mouth guards that are placed over the teeth and are configured to incrementally correct a position of one or more teeth with respect to other teeth.

The present invention however relates to orthodontic appliances for the use in comprehensive orthodontic treatments.

For manufacturing of these appliances, generally, a positive mould of the teeth is obtained on which a technician constructs the appliance with appropriate dimensions, wherein the mould serves as a reference. Until recently, these moulds were generally gypsum moulds, which have been cast from a negative silicone mould. These negative moulds, having a shape that complements the shape of the patient’s teeth, are made by means of a casting procedure in the mouth of the patient.

Nowadays, three-dimensional scanning and printing techniques have become available and are being used in orthodontics as well. For obtaining a positive mould of the patient’s teeth, a three-dimensional scan is made of the teeth, after which the scanned three-dimensional image of the teeth is three-dimensionally printed, in order to form the positive teeth mould on which the technician constructs the appliance.

The known techniques that make use of a positive mould have, however, been found to be complex. The step of obtaining the positive mould requires time, but also requires materials that are discarded after the appliance has been manufactured.

However, the known appliances still require the usage of a mould, since its shape must accurately match with the shape of the teeth. In particular when the appliance comprises a plurality of elements, for example one or more screws, the relative position between the elements must be maintained precisely. The mould thereby forms a reference for the appliance to ensure a correct position.

It is an object of the present invention to provide a basis element for an orthodontic appliance, and to provide an appliance for the use in comprehensive orthodontic treatments, that lacks the above disadvantages, or at least to provide an alternative.

The present invention provides a basis element for an orthodontic appliance. The basis element comprises: a first contact block and a second contact block, wherein the first contact block is configured to interlock with a first set of teeth and wherein the second contact block is configured to interlock with a second set of teeth, and a bridge element, which extends between the first contact block and the second contact block,

The first contact block, the second contact block and the bridge element of the basis element have been manufactured by means of a three-dimensional printing process as an integral unit.

This basis element forms a negative mould of the first set of teeth and the second set of teeth, and is thereby configured to form part of an orthodontic appliance. In itself, the basis element may form a retainer-type of orthodontic appliance, which is configured to maintain a relative position between both sets of teeth. Such a retainer-type of appliance is used after an orthodontic treatment has taken place, during which a position of the teeth has been changed. The retainer serves the purpose to prevent a reversion of the teeth towards their initial positions.

When the basis element were to be combined with an active element to form the appliance, a relative position between both contact blocks may be adaptable by means of the active element. If, for example, the relative position between the contact blocks were to be changed while the appliance is installed in the mouth of a patient, a pretensioning force will be applied between the contact blocks, onto both sets of teeth. The relative position between the sets of teeth will change over a period of time, under the influence of the pretensioning force. As such, a teeth pattern of a patient may be changed towards a desired teeth pattern.

The first contact block and the second contact block comprise contact portions, which are adapted to contact the respective sets of teeth. Such a set of teeth may comprise a single tooth, but preferably comprises a plurality of teeth, for example three teeth, in order to provide for a more rigid connection between the teeth and the contact block. In the present application, the set of teeth may comprise incisors, canines, premolars and molars.

The contact portions of the contact blocks are shaped complementary to the set of teeth. An inner contour of the contact portion thereby for example corresponds to the facial surface, the lingual surface, the incisal surface and the occlusal surface of the set of teeth.

The first set of teeth and the second set of teeth may be arranged on the same jaw, wherein, for example, the first set of teeth is arranged on a left portion of the jaw, whereas the second set of teeth is arranged on a right portion of the jaw. The first set of the teeth thereby opposes the second set of teeth in a transverse direction. In an installed state of the basis element onto the sets of teeth, the first contact block opposes the second contact block in the transverse direction.

The bridge element is connected to the first contact block and to the second contact block and extends between the contact blocks. The bridge element does not contact or cover any teeth that are arranged in between the teeth of the first set of teeth and the teeth of the second set of teeth. For example, the bridge element may have an upwardly-curved shape, such that the tongue of the patient may not be hindered by the bridge element.

The basis element according to the present invention provides the advantage that it is directly manufactured using three-dimensional printing, without the need for a positive mould to be formed on. After three-dimensionally printing the basis element, the bridge element forms an integral part with the contact blocks. This means that the contact blocks and bridge element are fixedly connected to each other and that no additional securing elements, such as screws, are needed to form the connection.

Since the first contact block forms an integral part with the second contact block, through the bridge element, a relative position between the first contact block and the second block can be accurately maintained. For orthodontic appliances, this relative position is of great importance, since it will form a starting point for changing a relative position between the first set of teeth and the second set of teeth.

Since the first contact block and the second contact block remain connected to each other through the bridge element, a negative mould of the teeth is no longer required as a reference for maintaining this relative position between the first contact block and the second contact block. This will result in less (manual) labour, not having to form the moulds, and therefore in shorter manufacturing times and in reduced costs.

In an embodiment, the bridge element comprises a plate, which is connected to both of the contact blocks. The plate may be configured to contact palate tissue in the mouth of the patient.

The plate is relatively thin and extends between the first contact block and the second contact block. An outer contour of the plate may thereby substantially correspond to a contour of palate tissue in the mouth of the patient. The plate thereby has an arc-like shape, following the contour of the palate or the roof of the mouth.

By following and contacting the palate tissue, the basis element may, besides interlocking with the sets of teeth, also gain additional support from the palate tissue. Furthermore does the bridge element occupy the least amount of space when it extends along the palate, providing the largest room to move the tongue in the mouth of the patient.

In a further embodiment, the bridge element comprises at least one strengthening portion. The at least one strengthening portion is arranged next to the plate and is connected to the first contact block and to the second contact block. The at least one strengthening portion is configured to contribute in securing the relative position between the contact blocks. Therefore, the at least one strengthening portion has a thickness that is substantially larger than that of the plate, resulting in less deformation when a similar mechanical load is applied onto it.

The at least one strengthening portion is integrally formed with the first contact block, the second contact block and the plate of the bridge element and may be manufactured by means of three-dimensional printing as well.

In an embodiment, the bridge element comprises two strengthening portions that both extend between the first contact block and the second contact block. At each edge of the plate, extending between the first contact block and the second contact block, a strengthening portion is provided over the length of the edge.

One of the two strengthening portions may for example be disposed between frontal ends of the first contact block and the second contact block, whereas the other of the two strengthening portions may be disposed between rear ends of the contact blocks In between the strengthening portions, the plate extends between both contact blocks.

The invention further relates to an orthodontic appliance, which is manufactured using a basis element as claimed in claim 1, wherein the bridge element is at least partly removed and wherein the appliance comprises at least one active element. The active element is secured to the first contact block and to the second contact block and is configured to set a relative displacement between the first contact block and the second contact block in order to induce a pre-tensioning force between the first set of teeth and the second set of teeth.

With the active element, the relative position between the first contact block and the second contact block becomes adaptable. Such an active element is configured to change at least one of its dimensions, for example by means of actuation, which results in a relative displacement between the contact blocks, since those are connected to the active element. The bridge element is thereby removed at least partially, such that the bridge element does no longer fixedly connect the first contact block with respect to the second contact block. As a result, the bridge element does no longer prevent relative displacement of the first contact block with respect to the second contact block.

When the appliance is arranged on the sets of teeth of the patient, a position of the sets of teeth may be adaptable. The teeth in a distorted teeth pattern, which are to be corrected by means of the orthodontic appliance, are thereby subjected to a pretensioning force of the appliance. The appliance is designed such, that the pretensioning force onto the teeth will force the teeth towards a desired, corrected position.

In a particular embodiment of the appliance, the appliance is configured to change the dimensions of an entire jaw. Such an appliance may be an expansion plate, which is configured to apply a compressive transverse force, seen from the patient’s perspective, between two sets of teeth that are arranged opposite to each other in the same jaw. Under the influence of the transverse force, a set of teeth that is arranged on the left of the jaw may be forced towards the left, whereas a set of teeth that is arranged on the right of the jaw may be forced towards the right. As such, the jaw will be widened in the transverse direction.

It is remarked that the above type of appliance is not just configured to change a position of teeth, but that it is also configured to change the shape and/or dimensions of the jaw, into which the teeth are arranged. The driving force for achieving this, however, is applied onto the teeth and not just on the jaw itself.

The active element of the appliance may be a separate part that is mounted to the basis element after the three-dimensional printing thereof. In another embodiment, however, the active element may be incorporated with the basis element and may be shaped as an integral unit as well, together with the first contact block, the second contact block and the bridge element.

An example of such an incorporated basis element could be a spring, which is configured to apply a spring load between two or more teeth and/or between two rows of teeth, in order to pre-tension the teeth and to force them to a desired relative position.

In an embodiment, the at least one active element comprises a screw device. The screw device comprises a screw and at least two bodies, which are, upon actuation of the screw, movable with respect to each other. Onto each of the bodies, anchoring rods may be provided, which are configured to be connected to a contact block or to a bridge element part connected to the respective contact block, such that a first one of the bodies is connected to the first contact block and that a second one of the bodies is connected to the second contact block.

The screw device may be configured to only allow a relative displacement between the bodies along a single direction. Relative displacements in other directions, not parallel to the single displacement direction, are thus prevented from occurring. The relative displacement between the first contact block and the second contact block is only allowed along the single displacement direction.

The screw device is, upon actuation of it, configured to pretension the sets of teeth by applying a relative force that acts between the first contact block and the second contact block. When the screw device has just been actuated, the pretensioning force is the highest. After a certain period of time, however, the teeth begin to settle and displace under the influence of the pretensioning force. After settling of the teeth, however, the pretensioning force will be lost and needs to be applied again. Screw devices thus require a repeated actuation of the screw for keeping a continuously-applied pretensioning force.

During manufacturing of the appliance, each of the anchoring rods may be arranged on a contact block, after which the rod is embedded in the basis element by sprinkling droplets of molten plastic onto the rods. The sprinkled droplets will attach to the rest of the basis element, forming an integral part, whereas the anchoring rods are embedded and secured underneath the sprinkled droplets.

In an embodiment, the at least one active element comprises a spring device. The spring device is connected to the first contact block and the second contact block as well. The spring device is, upon a change-in-length of it, configured to apply a force between the contact blocks, which is transmitted towards the sets of teeth as the pretensioning force for changing the relative position between the sets of teeth.

With respect to the screw device, the spring device provides an additional advantage that the force is applied continuously and will not become lost when the teeth settle. Upon settling of the teeth towards their desired position, the appliance may reach an end position in which end stops of the appliance interact with each other, such that the relative position between the contact blocks cannot be increased any further. An advantage of the spring device is provided since the force of the spring is no longer applied onto the sets of teeth but onto the end stop, preventing the teeth to settle any further and preventing over-correction from occurring.

When the teeth return to their initial position, the end stop no longer interact and the force of the spring device is applied onto the sets of teeth again, forcing the teeth to settle towards their desired position.

In an embodiment, the first contact block and the second contact block comprise a spring cavity, which are, together, configured to receive the spring device. In an operative position of the appliance, the spring cavities of the first contact block and the second contact block are arranged opposite to each other.

Preferably, the spring device comprises a compression spring, which is configured to apply a compressive force in order to move the contact blocks away from each other. The compression spring may, with a first end thereof, be inserted in the cavity in the first contact block and may, with a second end thereof, be inserted in the cavity in the second contact block.

In an initial position of the appliance on the sets of teeth of the patient, the compression spring is in a pretensioned condition. The sets of teeth will settle under the influence of the pretensioning force until the spring is no longer pretensioned. In case the position of the sets of teeth is not sufficient yet, the compression spring may be replaced with a different, longer compression spring, which is configured to apply a further pretensioning force onto the sets of teeth.

By providing spring cavities in the contact blocks, different types of springs may be used in the same appliance, which may result in a wider application of the appliance. Furthermore, springs with various lengths may be used, as well as springs with various spring constants.

In an embodiment, at least one of the first contact block or the second contact block comprises a retentive element. Together with the interlocking of the first contact block on the first set of teeth and of the second contact block on the second set of teeth, the retentive elements on the contact block are configured to secure a relative position of the contact block onto its respective set of teeth.

The retentive elements may for example be clasps that are connected to the contact block and that are configured to be hooked around one or more teeth in order to secure the position of the contact blocks on the respective set of teeth. The retentive elements may be secured to the contact blocks by means of embedding as well, like the anchoring rods of the screw device.

The invention further provides a method for manufacturing a basis element for an orthodontic appliance as is described above. The method comprises the steps of: providing, in a computer, a three-dimensional computer model of an oral cavity on the basis of data obtained by scanning the oral cavity of a patient with a three-dimensional scanning apparatus, extracting, in the computer, a model of a teeth pattern of the patient from the computer model, designing, in the computer, the basis element for the appliance, such that the appliance is configured to apply a force onto the teeth in order to change the teeth pattern of the patient towards a desired teeth pattern for the patient, and printing, using a three-dimensional printer, the first contact block, the second contact block and the bridge element as an integral unit.

The method for manufacturing the basis element according to the invention provides the advantage over the known method in that the basis element is directly printed, using a three-dimensional printer, whereas the known methods relate to the three-dimensional printing of a negative mould of the appliance. The basis element is printed as an integral unit, with which it is provided that a relative orientation between the first contact block and the second contact block is maintained.

First, a three-dimensional computer model of the oral cavity is provided in a computer. The computer model comprises information on a spatial position and orientation of the teeth of the patient, such that the positions of the teeth are known and that relative orientations, between the teeth, are known as well.

The three-dimensional computer model may be obtained directly during before carrying out this method. However, the data on the positions of the teeth may also be obtained earlier, by a dentist, orthodontic, or the like, and may be supplied towards a technician, who will manufacture the basis element afterwards. This last option provides the advantage that the scanning of the oral cavity of the patient may be done with their own specialist, after which the three-dimensional data may be forwarded to a central location where the basis element will be manufactured, in a specialized environment with specialized technicians.

The computer model of the oral cavity may comprise information that is irrelevant for the manufacturing of the basis element. With the step of extracting the model of the teeth pattern of the patient, the irrelevant information is discarded, after which a three-dimensional model of the teeth in their uncorrected positions, is obtained. The model of the teeth pattern can therefore be seen as a virtual positive mould of the teeth.

Based on the model of the teeth in their uncorrected positions, the basis element for the appliance may be designed in the computer. Based on the uncorrected positions of the teeth, it may be determined which teeth, or sets of teeth may need to be displaced in order to bring the teeth towards their position in the desired pattern.

During the designing of the basis element, the first contact block and the second contact block are designed such that they are configured to interlock with their respective set of teeth. The bridge element is designed to interconnect the contact blocks and, in an embodiment of the basis element, designed to follow a contour of the palate tissue of the patient.

In case an active element needs to be arranged between the contact blocks, to form the orthodontic appliance, a position of the active element may be determined as well. In determining this position, the amount and direction of the desired displacement of the sets of teeth is taken into account. The position of the active element is thereby chosen such that, in the orthodontic appliance that may be formed with the basis element, the active element is configured to apply its pretensioning force along this direction of displacement.

The bridge element may be designed to comprise a seat in which the active element may be arranged during manufacturing of the appliance, such that its position, relative to the first contact block and the second contact block, may be assured.

This step of designing the basis element may be done by the computer itself, based on an algorithm that is configured to calculate the required displacement of the teeth when the uncorrected positions of the teeth and a model for the desired pattern are known. However, a skilled technician may be able to design the basis element faster, since he may image the desired pattern in his head, so that programming of the model for the desired pattern will not be required.

After the step of designing the basis element, the basis element is printed by means of a three-dimensional printer. The printer is configured to shape a physical three-dimensional representation of the basis element that was designed in the computer.

The basis element is printed as an integral unit, which implies that the first contact block, the second contact block and the bridge element are integrally connected to each other. The basis element is thus formed as a whole, not having any connection, in particular any releasable connection, in between the contact blocks and the bridge element.

In an embodiment, the method comprises the step of comparing the model of the teeth pattern with the desired teeth pattern. During this comparing, a difference in position may be calculated for each tooth. This difference in position will, in essence, be the displacement vector for the teeth when the teeth pattern is corrected.

The step of comparing may be done by means of an algorithm in the computer, such that the entire method of manufacturing the basis element may be automated. In addition, the basis element that is designed by the computer may be checked by a technician before printing, in order to assure that the basis element is designed correctly.

In an embodiment, bridge element of the basis element comprises at least one strengthening portion. The strengthening portion may be connected to the first contact block and to the second contact block and may extend along the contour of the palate tissue of the patient.

During the step of designing the basis element, a suitable position for the at least one strengthening portion may be chosen. Thereby, it may be kept in mind that the at least one strengthening portion may not hinder the placement of the active element, when manufacturing the orthodontic appliance, and that it is preferably arranged such, that it provides for the largest possible amount of strengthening.

In an embodiment, the step of printing comprises defining a spring cavity in the first contact block and the second contact block. During the designing of the basis element, a suitable location for the spring cavities has been assigned such, that, when a spring device were to be arranged in the spring cavities, the force applied by the spring device is directed along the displacement direction of the teeth.

The invention further provides a method for manufacturing an orthodontic appliance, which is configured to apply a force onto one or more teeth, in order to change a teeth pattern of a patient. The method comprises the steps of: providing a basis element as described above, arranging an active element between the first contact block and the second contact block, securing the active element to the first contact block and to the second contact block, and at least partly removing the bridge element between the first contact block and the second contact block.

This method allows for the manufacturing of the orthodontic device, wherein a relative position between the first contact block and the second contact block is maintained, even though the bridge element is at least partially removed.

First, the basis element is provided, which is used as a component for forming the orthodontic appliance. The basis element may, in an embodiment, be manufactured by the method for manufacturing a basis element that has been described above.

After providing the basis element, an active element is arranged on the basis element. The basis element may comprise a seat, in which the active element may be arranged, in order to assure accurate placement thereof with respect to the contact block.

The active element is arranged between the first contact block and the second contact block, and may comprise anchoring rods that lay against a contact block or against a bridge element part that is connected to the respective contact block. In an embodiment, the active element is arranged on the bridge element that extends in between the first contact block and the second contact block.

After arranging the active element in between the contact blocks, the active element is secured to the first contact block and to the second contact block or secured to the bridge element part that is connected to the respective contact block. The active element, or at least part thereof, may be integrated with the contact blocks, such that a rigid connection may be obtained between the active element and the contact blocks.

For integrating the active element, molten droplets of plastic may for example be poured on the active element and onto the contact block. Upon solidifying on the contact blocks, the droplets become integrated with the contact blocks. The active elements are submerged underneath the solidified plastic and are thereby integrated within the contact blocks.

After the active element has been secured to the first contact block and the second contact block, the relative position between the first contact block and the second contact block is assured through both the bridge element and the active element.

However, the working of the active element is prevented by the bridge element. At least one of the dimensions of the active element is adaptable, such that a distance between the first contact block and the second contact block is adaptable as well. With the bridge element extending between the contact blocks, a relative displacement between them is prevented as a result of the integral connection.

For allowing the distance between the contact blocks to become adaptable, the method comprises the step of at least partially removing the bridge element between the contact blocks. With the bridge element removed at least partially, the rigid connection between the contact blocks is removed and the first contact block is no longer directly and integrally connected to the second contact block. However, the active element remains present between the first contact block and the second contact block, so the contact blocks remain connected to each other.

The method according to the invention provides that the active element becomes connected to the first contact block and to the second contact block while the contact blocks are still interconnected through the bridge element. Opposed to previous methods, during which loose contact blocks were arranged on a positive mould of the teeth, the method according to the invention does not require a positive mould to be used as a reference, since the relative position between the contact blocks remains assured through the bridge element, during the arranging and securing of the active element.

It is remarked that not just any part of the bridge element may be removed to achieve the advantage that is provided by the method. The bridge element does at least need to be separated through its entire cross-section, since otherwise, the integral connection between the contact blocks would remain.

For example, a portion of the bridge element is removed that is, in an installed position of the appliance, arranged above the tongue. It may thereby be further prevented that movement of the tongue is hindered by the bridge element.

After removing at least the part of the bridge element, other parts of the bridge element may remain connected to the contact blocks. These remaining parts of the bridge element may function as support elements which lay against the palate tissue and the gums of the patient.

In an embodiment, the method further comprises the step of at least partially removing the at least one strengthening portion. After the active element has been arranged between the contact blocks and/or after the bridge element has been removed, the at least one strengthening portion may be removed, if present, to allow the distance between the contact blocks to become adaptable.

Further characteristics of the three-dimensionally printed basis element according to the invention and of the orthodontic application according to the invention will be explained below, with reference to embodiments thereof, which are displayed in the appended drawings, in which:

Figure 1 schematically depicts an embodiment of the basis element according to the invention, seen in perspective view,

Figure 2 schematically depicts an embodiment of the orthodontic appliance according to the invention, seen in perspective view,

Figures 3a and 3b schematically depict a side view on the basis element, during the method for manufacturing the basis element, and

Figures 3c - 3e schematically depict a side view on the orthodontic appliance, during the method for manufacturing the orthodontic appliance.

Throughout the figures, the same reference numerals are used to refer to corresponding components or to components, which have a corresponding function.

Figure 1 schematically depicts an embodiment of the basis element according to the present invention, generally referred to with reference numeral 1. The basis element 1 is configured to be arranged in the oral cavity of a patient and is configured to apply a force onto one or more teeth to change and/or to maintain a position of the one or more teeth and to change and/or to maintain a teeth pattern of the patient.

The basis element 1 comprises a first contact block 2 and a second contact block 3. The first contact block 2 is configured to interlock with a first set of teeth and the second contact block 3 is configured to interlock with a second set of teeth. In the present embodiment, the first contact block 2 is arranged opposite to the second contact block 3.

The first contact block 2 is thereby configured to interlock with a number of teeth of the right portion of the upper jaw of the patient, whereas the second contact block 3 is configured to interlock with a number of teeth of the left portion of the upper jaw of the patient.

In an alternative embodiment, the basis element may as well be configured to interlock with teeth of a lower jaw of the patient.

The basis element 1 comprises a bridge element 4 that extends between the first contact block 2 and the second contact block 3. The bridge element 4 is integrally connected to the first contact block 2 and to the second contact block 3 and is configured to secure a relative position between the first contact block 2 and the second contact block 3.

The basis element 1 is manufactured as an integral unit, comprising the integrally interconnected first contact block 2, second contact block 3 and bridge element 4, by means of a three-dimensional printing process. The basis element 1 is designed in a virtual computer environment, wherein its dimensions are selected to correspond to a teeth pattern of the patient and/or correspond to a desired teeth pattern of the patient. On the basis of the virtually designed computer model, the basis element 1 is three-dimensionally printed. The three-dimensional printing provides that the shape of the actual basis element 1 accurately corresponds to the intended shape that was designed in the computer model.

The basis element 1 according to the present invention thereby provides the advantage that it does not need to be manufactured on a physical positive mould of the teeth of the patient, but that it can be designed virtually, after which it is printed.

The bridge element 4 is configured to interconnect the first contact block 2 and the second contact block 3 to assure that their relative position is maintained in the intended relative position that was designed in the virtual computer environment. The bridge element 4 thereby prevents distortions, in particular between the first contact block 2 and the second contact block 3, which may cause the basis element 1 to no longer correspond to a pattern of the teeth of the patient.

In the present embodiment, the bridge element 4 comprises a plate 5, which extends between the first contact block 2 and the second contact block 3. The plate 5 is configured to contact palate tissue of the patient, when the basis element 1 is arranged in the oral cavity of the patient. Thereto, the plate 5 follows the palate of the patient and has a shape that substantially corresponds to the shape of the palate.

The first contact block 2 comprises, at its side that is connected to the plate 5, a first jaw portion 2’, which forms a connection between the first contact block 2 and the plate 5. The first jaw portion 2’ has an inner contour, which faces, when the basis element 1 is arranged in the oral cavity of the person, the jaw of the patient and which follows the contour of the jaw in order to contribute to a rigid interlocking between the first set of teeth and the first contact block 2.

Similarly, the second contact block 3 comprises, at its side that is connected to the plate 5, a second jaw portion 3’, which forms a connection between the second contact block 3 and the plate 5. The second jaw portion 3’ has an inner contour, which faces, when the basis element 1 is arranged in the oral cavity of the person, the jaw of the patient and which follows the contour of the jaw in order to contribute to a rigid interlocking between the second set of teeth and the second contact block 3.

The plate 5 is, in a further embodiment, provided as a relatively thin element. The surface of the plate 5 is, in the virtual computer environment, thereby designed to correspond with a scanned image of the palate of the patient. As such, the plate 5 will hinder the patient as little as possible, since it is configured to follow the palate closely.

In the present embodiment, the bridge element 4 further comprises two strengthening portions 6. The strengthening portions 6 extend, just like the plate 5, between the first contact block 2 and the second contact block 3. The strengthening portions 6 thereby extend along edges of the plate 5. A first one of the strengthening portions 6 extends along a frontal side of the plate 5, whereas a second one of the strengthening portions 6 extends along a rear side of the plate 5. As such, the plate 5 is, in the present embodiment, surrounded by the first jaw portion 2’, a first one of the strengthening portions 6, the second jaw portion 3’ and a second one of the strengthening portions 6.

The strengthening portions 6 have a thickness, in particular a diameter of a cross-section, that is substantially larger than the thickness of the plate 5. The strengthening portions 6 are therefore substantially stiffer than the plate 5.

The strengthening portions 6 are integrally connected to the first contact block 2, the second contact block 3 and the plate 5, since they are three-dimensionally printed as well. Accordingly, as a result of their higher stiffness and integral connection, the strengthening portions 6 contribute in maintaining the relative position between the first contact block 2 and the second contact block 3.

In figure 2, an embodiment of the orthodontic appliance according to the present invention is displayed, which is generally referred to with reference numeral 10. The orthodontic appliance 10 is configured to be arranged in the oral cavity of the patient as well and to change a relative position between teeth of the patient.

The orthodontic appliance 10 comprises the basis element 1 that was described above, comprising the first contact block 2 and its second contact block 3, with which the orthodontic appliance 10 is configured to be arranged on the teeth of the patient.

The present embodiment of the orthodontic appliance 10 further comprises a screw device 11 as an active element, which screw device 11 extends between the first contact block 2 and the second contact block 3. In alternative embodiments of the orthodontic appliance, other types of active elements may be provided, such as for example a spring device.

The screw device 11 comprises a first screw block 12 and a second screw block 13. A screw 14 is rotatably arranged in the screw blocks 12, 13. The screw 14 is, upon rotation of it around its longitudinal axis, configured to move the first screw block 12 with respect to the second screw block 13, or vice versa. The screw 14 is thereby configured to set a relative position and/or to induce a relative displacement between the first screw block 12 and the second screw block 13. As such, a dimension of the screw device 11 is adaptable upon rotation of the screw 14.

The first screw block 12 comprises a first anchoring rod 15, with which the screw device 11 is connected to the first jaw portion 2’ of the first contact block 2 of the basis element 1. The second screw block 13 comprises a second anchoring rod 16, with which the screw device 11 is connected to the second jaw portion 3’ of the second contact block 3 of the basis element 1.

The anchoring rods 15, 16 are rigidly connected to the respective jaw portions 2’, 3’ of the contact blocks 2, 3. As such, it is achieved that upon rotation of the screw 14 of the screw device 11, the relative position between the contact blocks 2, 3 is adapted accordingly.

In the present embodiment, each of the anchoring rods 15, 16 is connected to a respective one of the contact blocks 2, 3 by means of an embedded connection. The anchoring rods 15, 16 are thereby embedded in the jaw portions 2’, 3’ of the contact blocks 2, 3. The surrounding embedding material thereby prevents movement of the anchoring rods 15, 16 within the contact blocks 2, 3.

The embedded connection is, in the present embodiment of the orthodontic appliance 10, manufactured by applying molten material, preferably the same material as from which the basis element 1 is manufactured, over the respective one of the anchoring rods 15, 16 that is arranged adjacent a respective one of the jaw portions 2’, 3’. The molten material is configured to cover the anchoring rods 15, 16 and to solidify and join with the jaw portions 2’, 3’ afterwards. As such, the anchoring rods 15, 16 become embedded within the jaw portions 2’, 3’, underneath the applied material.

In the orthodontic appliance 10, the bridge element 4 of the basis element 1, which extends between the first contact block 2 and the second contact block 3, is removed. Opposed to the basis element 1, the first contact block 2 is no longer integrally connected to the second contact block 3. However, in the orthodontic appliance 10, the first contact block 2 is now connected to the second contact block 3 through the screw device 11.

The orthodontic appliance 10 further comprises anchoring portions 17, which are arranged on the contact blocks 2, 3. The anchoring portions 17 are, for example, configured to receive an anchoring wire, with which the contact blocks 2, 3 may be secured to a respective row of teeth.

In figures 3a and 3b, a side view on the basis element 1 is displayed, during two respective steps in the method for manufacturing a basis element as described above.

Figure 3a depicts the basis element 1, being the integral unit that has been three-dimensionally printed. The basis element 1 comprises the first contact block 2, the second block 3 and the bridge element 4. The bridge element 4 is provided as the plate 5 and extends between both contact blocks 2, 3.

The plate 5 is integrally connected to the first jaw portion 2’ of the first contact block 2 and integrally connected to the second jaw portion 3’ of the second contact block 3.

In the first contact block 2, a first cavity 7 is provided with which the first contact block 2 is configured to be arranged over the first set of teeth of the patient. The first cavity 7 is displayed in the figures by a dashed line through the first contact block 2.

In the second contact block 3, a second cavity 8 is provided with which the second contact block 3 is configured to be arranged over the second set of teeth of the patient. The second cavity 8 is displayed in the figures by a dashed line through the second contact block 3.

In the present embodiment, the basis element 1 comprises a plastic material, preferably a thermoset or thermoplastic, from which the basis element is manufactured. During the three-dimensional printing of the basis element 1, the plastic material is molten, after which it is printed in the desired shape. After printing, the plastic material solidifies and remains in the same shape as in it was printed.

In figure 3b, the basis element 1 of figure 3a is displayed, wherein the bridge element 4 comprises both the plate 5 and two strengthening portions 6, which are respectively arranged along edges of the plate 5 and which extend between the first contact block 2 and the second contact block 3, in order to provide for a stiff and rigid connection between both contact blocks 2, 3.

The strengthening portions 6 are, during manufacturing of the basis element 1, three-dimensionally printed as well and are integrally connected to the first contact block 2, the second contact block 3 and the plate 5 of the basis element 1. Seen from the side, as in figure 3b, it is furthermore apparent that the strengthening portions 6 have a contour that substantially corresponds to the contour of the plate 5 and to the palate of the patient.

The basis element 1 comprises a seat 9, which is configured to receive an active element during the manufacturing of the orthodontic appliance. The seat 9 is provided on the plate 5, in between both contact blocks 2, 3, and has a shape that corresponds to a shape of the active element. In the present embodiment, the seat 9 therefore has a shape that corresponds to a shape of a screw device 11, such that position of the screw device 11 in the seat 9 is accurately maintained.

In figures 3c - 3e, side views on the orthodontic appliance 10 are displayed, during three respective and subsequent steps in the method for manufacturing an orthodontic appliance as described above.

In figure 3c, the orthodontic appliance 10 comprises the basis element 1 and a screw device 11. The screw device 11 comprises a first screw block 12, which faces the first contact block 2 of the basis element 1 and a second screw block 13, which faces the second contact block 3 of the basis element 1. In a central portion of the screw device 11, a screw 14 is provided, which interconnects the first screw block 12 and the second screw block 13.

The first screw block 12 comprises a first anchoring rod 15, which extends away from the screw 14, along a contour of the plate 5 and of the first jaw portion 2’ of the first contact block 2. The second screw block 13 comprises a second anchoring rod 16, which extends away from the screw 14, along a contour of the plate 5 and of the second jaw portion 3’ of the second contact block 3.

In the manufacturing step that is displayed in figure 3c, the screw device 11 has been arranged in the seat 9 of the basis element 1. During this step, the plate 5 and the strengthening portions 6 in between the first contact block 2 and the second contact block 3 remain intact, in order to secure the relative position between the contact blocks 2, 3.

In figure 3d, the orthodontic appliance 10 is displayed during a subsequent step in its manufacturing, following the step that is displayed in figure 3c. In figure 3d, the anchoring rods 15, 16 have been embedded, such that the first anchoring rod 15 is connected to the first contact block 2 and that the second anchoring rod 16 is connected to the second contact block 3. The screw device 11 is therewith secured to the first contact block 2 and to the second contact block 3.

In the present embodiment, the anchoring rods 15, 16 are embedded in a layer of plastic material, preferably the same type of plastic material as of which the basis element 1 has been manufactured. The layer of plastic material may, for example, be molten and may be disposed over the anchoring rods 15, 16 and the contact blocks 2, 3. After solidifying, the anchoring rods 15, 16 become covered underneath the plastic material.

Preferably, the plastic material is disposed in small droplets. These small droplets will solidify faster than larger droplets, which reduces the risk of local melting of the contact blocks 2,3 and, as a result of the local melting, the risk of unwanted deformations in the contact blocks 2,3.

After the manufacturing step of figure 3d, the anchoring rods 15, 16 have been embedded. The first contact block 2 is thereby connected to the second contact block 3 via both the bridge element 4, comprising the plate 5 and the strengthening portions 6, and the screw device 11. However, this configuration does not allow the screw device 11 to change a dimension of the orthodontic appliance 10. Accordingly, it does, when it has been installed on the teeth in the oral cavity of the patient, not allow the screw device 11 to apply a force between the rows of teeth. A subsequent step of the method therefore comprises the removing of the bridge element 4. The result of this step is displayed in figure 3e. By removing the bridge element 4, the first contact block 2 is no longer integrally connected to the second contact block 3, but only connected through the screw device 11.

The removing of the of bridge element 4 may, for example, be performed by physically cutting the plate 5 and the strengthening portions 6, such that they are no longer connected to the contact blocks 2, 3. Alternatively, the plate 5 and the strengthening portions 6 may be dissolved with an appropriate solvent to prevent the orthodontic appliance 10 from being damaged under the influence of forces that may act thereon during the cutting.

In the configuration of figure 3e, the screw device 11 is configured to adapt a relative distance between the first contact block 2 and the second block 3, and/or to apply a pretensioning force between the contact blocks 2, 3 and between respective sets of teeth of the patient, on which the contact blocks 2, 3 are configured to be arranged.

It is remarked that the above-mentioned embodiments of the basis element and of the orthodontic appliance, as well as the embodiments of the methods for manufacturing a basis element and for manufacturing an orthodontic appliance are examples of possible embodiments within the scope of the invention. It is noted that other embodiment exist, within the scope of the invention, which may, for example, be configured to correct other aspects of, or misalignments between teeth of the patient. An example thereof could be the correction of a so-called overbite, the expansion of an upper or lower jaw arch or to correct an open bite of a patient.

Claims

A basic element for an orthodontic device adapted to exert a force on one or more teeth to change a patient's tooth pattern, the basic element comprising: - a first contact block and a second contact block, the first contact block being adapted to be connected to a first set of teeth and wherein the second contact block is adapted to be connected to a second set of teeth, and - a bridge element extending between the first contact block and the second contact block, characterized in that the first contact block, the second contact block and the bridge element as an integral unit are manufactured by means of a three-dimensional printing process.

2. Basic element as claimed in claim 1, wherein the bridge element comprises a plate which is connected to each of the two or more contact blocks and is adapted to lie against the patient's palate.

3. Basic element as claimed in claim 2, wherein the bridge element comprises at least one reinforcement part which is arranged next to the plate and is connected to the first contact block and to the second contact block.

4. Basic element as claimed in claim 3, wherein the bridge element comprises two reinforcement parts and wherein on each edge of the plate which extends between the first contact block and the second contact block, a reinforcement part is provided over the length of the edge.

Orthodontic device, manufactured by using a base element according to any of claims 1-4, wherein the bridge element is at least partially removed and wherein the device comprises at least one active element, which is fixedly connected to the first contact block and with the second contact block and which is arranged to set a relative displacement between the first contact block and the second contact block to cause a biasing force between the first set of teeth and the second set of teeth.

The orthodontic device of claim 5, wherein the at least one active element comprises a screw device.

Orthodontic device according to claim 5 or 6, wherein the at least one active element comprises a spring device.

The orthodontic device according to claim 7, wherein the first contact block and the second contact block comprise a spring cavity which, in an operative position of the device, are arranged opposite each other and which, together, are adapted to receive the spring device.

The orthodontic device of any one of claims 5-8, wherein at least one of the first contact block or the second contact block comprises a retaining element adapted to secure the contact block to its respective set of teeth.

Method for manufacturing a basic element for an orthodontic device according to one of the claims 1-4, comprising the steps of: - providing, in a computer, a three-dimensional model of an oral cavity based on values obtained by scanning the oral cavity with a three-dimensional scanning device, - extracting, in the computer, a model of a patient's tooth pattern from the computer model, - designing, in the computer, the basic element for the device such that the device is adapted to exert a force on the teeth to change a patient's tooth pattern to a desired tooth pattern for the patient, and - printing, using a three-dimensional printer, of the first contact block, the second contact block and the bridge element as an integral unit.

The method of claim 10, including the step of comparing the model of the tooth pattern with the desired tooth pattern.

A method according to claim 10 or 11, wherein the bridge element comprises at least one reinforcement portion connected to the first contact block and to the second contact block.

A method according to any of claims 10-12 wherein the step of printing comprises defining a spring cavity in the first contact block and the second contact block.

A method for manufacturing an orthodontic device adapted to exert a force on one or more teeth to change a patient's tooth pattern, comprising the steps of: - providing a basic element as claimed in any one of claims 1- 4, - arranging an active element between the first contact block and the second contact block, - attaching the active element to the first contact block and the second contact block, and - at least partially removing the bridge element between the first contact block and the second contact block.

The method of claim 14, wherein the base element is manufactured by the method of any of claims 10-13.