RU2730969C1 - Method of orthodontic treatment by direct arc method using 3d modeling and individual elements of bracket system for its implementation - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: group of inventions refers to medicine, namely to orthodontic treatment. Disclosed is a method for orthodontic treatment by a direct arc technique using 3D modeling, in which arches and individual orthodontic elements of a bracket system are used for treatment, made for each specific clinical case, for which 3D model of the patient's jaw is obtained and the initial shape of the orthodontic arch is selected, then using 3D modeling, determining the desired curve specifying the shape and location of the still strained orthodontic arch at the end of the treatment, wherein proceeding from the fact that the desired curve is located symmetrically relative to the sagittal plane, and the shape of the desired curve corresponds to a curve averaged to accuracy of 1 mm between the initial shape of the selected orthodontic arch established at the beginning of the treatment and the shape of the non-tensioned arc used at the end of the treatment, and, based on the shape of the desired curve obtained as result of 3D modeling, determining the shape of individual dental bracket orthodontic elements for each tooth. Invention also discloses individual elements of a bracket system for orthodontic treatment by a direct arc method using 3D modeling, in which an orthodontic arch having the shape of a desired curve completely enters the slots and holes of the individual elements of the bracket system, sites of the individual elements of the bracket system repeat the shape of the corresponding teeth, wherein between the area of the individual element of the bracket system and the tooth surface a gap is set for uniform distribution of the adhesive in order to further fix the individual element of the bracket system on the tooth, wherein the desired curve at the end of treatment is arranged symmetrically relative to the sagittal plane, and its shape corresponds to averaged within 1 mm of the curve between the initial shape of the still tense orthodontic arc set at the beginning of the treatment, and the shape of the non-tensioned arc used at the end of the treatment.EFFECT: group of inventions provides shorter time for achieving the result of patient's orthodontic treatment.10 cl, 17 dwg

Description

The invention relates to the field of dentistry, namely to orthodontics, proposes a method of orthodontic treatment by the method of a straight arc using 3D modeling and individual elements of the bracket system for its implementation, and allows you to achieve a pre-planned using 3D modeling and implemented using a manufactured individual bracket systems for moving teeth.

To give the patient's dentition the correct shape, orthodontic appliances are used, consisting of a wire arch with the ability to restore shape, which, for example, can be made for an individual patient, and a set of individual elements of the bracket system, each of which includes a body with a platform for attachment to the tooth and a groove or hole for installing the arc.

In this case, the shape-recovery wire used can be both planar, i.e. located in one plane, and curved as a result of the calculation individually for the patient.

For example, US patent (US Patent No. 6,648,640) "Interactive Orthodontic Treatment System Based on Intra-Oral Dental Scanning" describes an approach using pre-made braces and a custom-made wire arch. Such an archwire may have complex twists and bends to compensate for the position of slots or holes in standard orthodontic fixed structures, and thus is not necessarily a flat planar wire. Given the complexity of the shape of the orthodontic arch, the process of shaping it must be fully automated using materials that have certain characteristics so that they can take and maintain this shape. But, the emergence at the beginning or during treatment of the need to change the shape of the arc, entails a complete replacement of the entire complex arc. Finally, the curvature of the arch, as a rule, is directed along three dimensions in space, which significantly narrows the possibilities of its movement with sliding inside the grooves or holes of the elements of the bracket system, although such sliding would contribute to successful treatment, since it would accompany the movement of the teeth to their corrected position ...

Currently, the most common treatment for the normalization of the position of the teeth is a method called the "straight arch technique".

In this method, orthodontic arcs are used, which have both circular and rectangular cross-sections with a predetermined curvature in the plane. Orthodontic bows also have the effect of reshaping. These arcs are installed in the holes or grooves with which the elements of the bracket system are equipped. In this case, each element of the bracket system is glued with a mounting pad to the corresponding tooth. After installation, the archwires tend to return to their original shape, and thus move the teeth into the desired position.

A known method of manufacturing an individual orthodontic apparatus for treating a patient, described in RF patent No. 2495642 (conv. Prior. 31.10.2007 FR 0707686, publ. 20.10.2013), selected as a prototype.

The patent for the invention describes a method of manufacturing an individual orthodontic apparatus for treating a patient, containing at least one therapeutic orthodontic arch and a plurality of elements, each of which contains a bracket with at least one groove adapted to receive the specified orthodontic arch. In this case, each bracket is made with the possibility of installation on an intermediate piece, which, in turn, is made with the possibility of installation on a base intended for installation on the front or back side of the tooth. The specified method includes individual computer modeling of the specified brackets, intermediate parts and bases after image formation in the corrected position of the dental arch and the sides of the teeth, on which it is necessary to fix these bases. According to the invention, in said image, the project bow is positioned relative to the indicated sides of the teeth, while the geometry of the said project bow is similar to the geometry of the orthodontic bow. Computer modeling of these elements is carried out to give them an envelope corresponding to the geometry of the gap, which, upon completion of orthodontic treatment, will separate the tooth and the treatment bow when the tooth takes its corrected position and the bow restores its original shape.

The main disadvantage of the solution proposed in the prototype is that the last orthodontic arch at the end of the treatment of a real patient does not take its nominal shape in a free state due to restrictions on the part of the teeth and other individual characteristics of the patient. Accordingly, the formed image in the corrected position of the dental arch and the surfaces of the teeth, on which it is necessary to fix the indicated bases of the elements of the bracket system, can be used only as a first approximation, since in reality the arch will not be able to finally restore its original shape, and the tooth will not take its corrected position.

The objective of the invention is to develop a method of orthodontic treatment by the method of a straight arc using 3D modeling, which makes it possible to carry out a pre-planned movement of the patient's teeth and to implement the movement using a manufactured individual bracket system.

The technical result is to reduce the time to achieve the result of the patient's orthodontic treatment.

The problem is solved, and the technical result is achieved by the fact that in the method of orthodontic treatment proposed in the invention by the method of a straight arc using 3D modeling, standard arcs and individual elements of the bracket system are used, manufactured for each specific clinical case. For this, a 3D model of the patient's jaw is obtained and the initial shape of the standard orthodontic arch is selected. Then, using 3D modeling, the desired curve is determined, defining the shape and position of the still strained standard orthodontic arch at the end of the treatment. In this case, it is assumed that the desired curve is located symmetrically relative to the sagittal plane. Moreover, the shape of the desired curve corresponds to the averaged one with an accuracy of 1 mm. curve between the original shape of the selected standard orthodontic arch, set at the start of treatment, and the shape of the unstressed standard arch used at the end of treatment. Based on the shape of the desired curve obtained as a result of 3D modeling, the shapes of the elements of the bracket system for each tooth are determined.

In a particular case, the method of orthodontic treatment is used for the upper jaw.

In a particular case, the method of orthodontic treatment is used for the lower jaw.

The method of orthodontic treatment proposed according to the invention can be performed from the side of the lingual surface of the teeth.

In a particular case, the orthodontic treatment method proposed according to the invention can be performed from the side of the vestibular surface of the teeth.

The problem is also solved, and the technical result is achieved by the fact that the individual elements of the bracket system for orthodontic treatment by the method of a straight arc using 3D modeling are made in such a way that the standard orthodontic arch, having the shape of the desired curve, completely enters the grooves and holes of the individual elements of the bracket system ... The pads of the individual elements of the bracket system follow the shape of the corresponding teeth. In this case, a gap is set between the platform and the surface of the tooth for uniform distribution of the glue for further fixation of the individual elements of the bracket system on the tooth. Moreover, the desired curve at the end of the treatment is located symmetrically relative to the sagittal plane, and its shape corresponds to the average one with an accuracy of 1 mm. the curve between the original shape of the selected standard still strained orthodontic arch, set at the beginning of treatment, and the shape of the unstressed standard arch used at the end of treatment.

Some of the elements of the bracket system can be made in the form of braces. Also, some of the elements of the bracket system can be made in the form of buccal or lingual tubes or locks. It is also possible to make some of the elements of the bracket system in the form of buttons or bite pads.

The proposed method of treating a patient avoids the negative effect of the fact that the last orthodontic arch at the end of the treatment of a real patient does not take its nominal shape in a free state due to restrictions on the part of the teeth and other individual characteristics of the patient.

Modeling the shape and position of the last orthodontic arch at the end of treatment in such a way that the desired curve defining the shape and location of the still strained standard orthodontic arch at the end of treatment is symmetrically positioned relative to the sagittal plane, and its shape corresponds to the average one with an accuracy of 1 mm. the curve between the initial shape of the still strained standard orthodontic arch, set at the beginning of the treatment, and the shape of the unstressed standard arch used at the end of the treatment, allows for the correct planning and implementation of a pre-planned movement of the patient's teeth. This makes it possible to use a standard orthodontic arch in a still tense state at the end of the treatment, while the patient's teeth already occupy their design position, calculated previously using 3D modeling.

In the future, the invention is illustrated by a detailed description of an example of its implementation and illustrated by the accompanying drawings, in which:

Fig. 1 is a 3D model of the patient's jaws in the occlusal relationship;

Fig. 2 - plane of the orthodontic arch for the upper jaw at the end of treatment;

Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 are figures explaining the process of 3D modeling of the desired curve of a deformed standard orthodontic arch at the end of treatment;

Fig. 11, Fig. 12 - 3D model of the upper jaw with the desired curve shown;

Fig. 13 is a 3D model of the patient's jaws in the occlusal relationship with the desired curves in the occlusal relationship;

Fig. 14 is a 3D model of the patient's jaws in an occlusal relationship with a standard orthodontic arch and elements of an individual bracket system placed on it at the end of treatment;

Fig. 15 is an example of a 3D model of the patient's upper jaw with elements of the individual bracket system placed at the beginning of treatment.

FIG. 16 - an example of the location of the desired curve for the case of treatment with lingual elements of an individual bracket system

FIG. 17 is an example of a 3D model of a patient's jaw with lingual elements of an individual bracket system placed.

The proposed method of orthodontic treatment by the method of a straight arc using 3D-modeling can be implemented both for the occlusal relationship of the patient's teeth, and separately for the upper and lower jaws.

Below is a detailed description of the method of orthodontic treatment for the upper jaw. It should be clarified that the example is given for the vestibular arrangement of the orthodontic elements of the bracket system. An example of an orthodontic treatment method for a lingual location is illustrated in FIG. 16 and FIG. 17. A description is also given of the method of orthodontic treatment for the lower jaw, depending on the occlusal relationship of the patient's teeth.

In the method according to the invention, a standard orthodontic arch 1 is used, which is still in tension at the end of the treatment (Fig. 14). To determine its position and shape using 3D modeling, it is necessary to have 3D models of the patient's jaws in the occlusal relationship. These jaw models can be obtained from, for example, an intraoral scan of a patient, a scan of a plaster cast from a patient's jaw impression, or a scan of a patient's dental impression.

Based on the fact that the treatment takes place using the straight arch technique, it is assumed that at the end of the treatment the arch lies in the same plane without any bends. In the proposed invention, standard orthodontic bows are used, therefore the shape of the last arch at the end of treatment is close to its standard shape in a free state.

Treatment is carried out using elements of an individual bracket system 2, which are fixed orthodontic structures (braces, buccal tubes, buccal locks, orthodontic buttons, etc.), modeled and manufactured individually for each specific clinical case.

To set the position of the orthodontic arch 1 for the upper jaw at the end of treatment, first set the plane 3, in which the orthodontic arch 1 for the upper jaw lies at the end of treatment (Fig. 1). The position of plane 3 is selected based on the current position of the upper jaw teeth and their shape, as well as their desired position at the end of the treatment. If necessary, in some cases, prior to this, a preliminary movement of teeth on a 3D model by intrusion / extrusion is carried out for the correct position of the centers of the clinical crown of teeth relative to the specified plane. The centers of the clinical crown of all teeth in the upper jaw should be approximately in line.

Section 4 of the 3D model of the upper jaw is created with plane 3 (Fig. 2).

Select the standard size of standard orthodontic bows. Based on the shape of the dentition in section 4 of the 3D model, the most suitable standard size of standard orthodontic archwires for the upper and, if necessary, for the lower jaw, which will be used to treat the patient, is selected.

Modeling of the shape of a standard orthodontic arch 1 for the upper jaw at the end of treatment takes place in section 4 of the 3D model in several stages.

At the first stage (Fig. 2), the location of curve 5 is determined, which has the shape of a standard orthodontic arch in an unstressed, that is, a free state relative to the dentition, for which a sagittal plane 6 is set in section 4 of the 3D model, dividing the jaw symmetrically into left and right parts ... Curve 5 of the standard orthodontic arch is located symmetrically relative to it.

It should be understood that a standard orthodontic arch, the shape of which corresponds to curve 5 and which is set initially, cannot take its nominal shape in a free state at the end of treatment due to restrictions on the part of the patient's teeth and other individual characteristics of the patient.

At the next stage, curve 7 is created, in the first approximation repeating the shape of the first orthodontic arch installed in the elements of the bracket system at the very beginning of treatment. For this, point 8 is determined for each tooth in section 4 of the 3D model, which lies in the center of the crown of the tooth on the axis 9, which describes the vestibulo-oral position of the tooth (Fig. 3). Axis 9 passes through point 8 of the center of the crown contour, in the specific example shown, from the vestibular side, i.e. where the center of the platform of the bracket-system element will be located later. Axis 9 is directed along the normal to the contour of the crown at the point where it intersects it.

Then, for the tooth along its axis 9 from the point of its intersection with the contour of the tooth, in a specific example, in the vestibular direction, a distance is set aside corresponding to the standard indentation of the bottom of the groove, for example, the bracket of the bracket system 2 from the center of its platform for this tooth, and point 10 is set (Fig. 4). In the specific example given, for the vestibular position of the bracket system 2, for the buccal locks and tubes that are elements of the bracket system 2, this is the distance from the inner edge of the hole. These actions are performed for the teeth in the area of which the orthodontic arch 1 will be deformed freely during the treatment. Taking into account these points 10, a curve 7 is set (Fig. 5).

Creation of a curve 11, the shape of which is intermediate between the shape of a standard orthodontic arch defined by the location of curve 5 and curve 7 (Fig. 6).

To obtain the control points 12 of the curve 11, first, the points 13 of intersection of the axes 9 of the teeth with the curve 5 of the standard orthodontic arch are plotted (Fig. 6). Then, the segments are built connecting the obtained points 13 with the corresponding control points 10 of the curve 7 located on the axis of one tooth. Within each such segment, point 12 is set, which is a control point for curve 11. The range of location of point 12 is possible up to 1 mm in both directions from the middle of the segment, but within it. Then, according to the obtained control points 12, the curve 11 itself is plotted (Fig. 7).

Curve 11, in fact, sets the tension of the standard orthodontic arch at the end of the treatment, since this arch will tend to occupy the position of curve 5 of the standard orthodontic arch, that is, it will be under load at the end of the treatment, which guarantees the effect of the elements of the braces 2 on the corrected teeth until the end of treatment.

Creation of curve 14 (Figs. 8-10), which is an approximated curve of the standard arch at the end of treatment, that is, the desired curve, is necessary to simulate the shape of the standard orthodontic arch 1 for the upper jaw symmetrical about the sagittal plane 6 at the end of treatment. For this, through each point 12, along which the curve 11 was set, a segment is drawn up to the line of symmetry denoting the sagittal plane 6. The segment is drawn perpendicular to the sagittal plane 6 (Fig. 8).

Then, for each pair of symmetrical teeth of the same name, on the line of symmetry denoting the sagittal plane 6, point 15 is set equidistant from the ends of the segments constructed for them (Fig. 9).

From this point 15, points 16 are laid symmetrically on both sides at a distance of 17, which is found as the arithmetic mean of the lengths of the constructed segments for a given pair of teeth (Fig. 10). Based on these points 16, an approximated desired curve 14 is constructed.

The sought curve 14 is the desired shape of the orthodontic arch 1 for the upper jaw at the end of the treatment, it defines its contact lateral face (Fig. 11 and 12).

On the basis of the modeled position and shape of the orthodontic arch 1 for the upper jaw, at the end of the treatment, its 3D model is created in the corresponding ratio with the models of the jaws. In the future, it is used to set the position of the teeth and to model the elements of the bracket system.

In a similar way, it is possible to make 3D modeling for using a standard arch and individual elements of the bracket system, which have a lingual location. Illustrative drawings are shown in FIG. 16 and 17. In this case, in FIG. 16 shows the curve 18 of a standard lingual orthodontic arch and the obtained desired curve 19 for the case of treatment with the lingual elements 19 of the bracket system. 3D-modeling of elements of 19 lingual braces is performed in the same way as for vestibular elements.

Obtained from the results of 3D modeling of the desired curve 14 in Fig. 11 and 12 (19 in Fig. 16 for lingual treatment), defining the position and shape, for example, of the orthodontic arch 1 for the upper jaw at the end of treatment, allows the use at the end of treatment of a standard orthodontic arch that is still strained, while the patient's teeth already occupy their design position. This makes it possible to successfully use the method of orthodontic treatment proposed in the invention by the method of a straight arc using 3D modeling and using standard arches.

In this case, it is not necessary to strictly correspond to the indentations of the teeth from the arch, their angulation, rotation and inclination to the standard values, since they are compensated by the individual prescription of the bracket system 2 in the position determined by the desired curve 14 (Fig. 14).

The alignment of the teeth of the lower jaw is carried out taking into account the aligned position of the teeth of the upper jaw. If necessary, the position of the teeth on both jaws is corrected to obtain the correct occlusal relationship and the desired aesthetics (Figs. 13 and 14).

During the alignment process, a virtual articulator can be used to simulate the movement of the patient's lower jaw.

The modeling of the position and shape of the arch for the lower jaw at the end of treatment is performed after modeling the position of the teeth, since in any case the treatment will be performed with a standard set of arches, and the position of the teeth of the lower jaw for them will correspond to the movements of the teeth of the upper jaw, performed according to the modeled position and shape on the basis of the standard arch for the upper jaw. Inaccuracies will be compensated for by the individual prescription of the bracket system and restrictions on the side of the teeth of the upper jaw.

To determine the position of the orthodontic arch for the lower jaw during 3D modeling, a technique is used that is similar to the technique for determining the desired curve 14 for the upper jaw. In this case, a plane is set in which the desired curve 17 of the standard orthodontic arch for the lower jaw lies at the end of the treatment. Its position is chosen based on the aligned position of the lower jaw teeth. The position of the teeth of the upper jaw is also taken into account so that the elements of the bracket system installed on the lower jaw do not interfere with the teeth of the upper jaw. To do this, create a section of the model of the lower jaw with a plane in which the desired curve 17 of the standard orthodontic arch for the lower jaw lies. In this section, 3D-modeling of the shape of a standard orthodontic arch for the lower jaw is performed.

An axis describing the vestibulo-oral position of the tooth is set for each tooth in section. Then, for each tooth along its axis from the point of its intersection with the tooth contour in the vestibular or lingual direction for lingual braces, the distance corresponding to the standard indentation of the bottom of the bracket groove from the center of its platform for this tooth is set and a point is set. For buccal tubes and locks, this is the distance from the inner edge of the opening. Then, from these points, an approximated curve is set. This curve is the desired curve defining the shape of the standard orthodontic arch for the lower jaw at the end of the treatment. The desired curve defines the inner contact surface of a standard orthodontic arch. Thus, 3D modeling of the shape of a standard orthodontic arch for the lower jaw is, in fact, similar to 3D modeling of the shape of a standard orthodontic arch for the upper jaw.

Also, if there is a computed tomogram of the patient's jaws, it is combined with 3D models of the jaws, which makes it possible to take into account the position and size of the tooth roots when aligning the teeth.

For 3D modeling of the elements of an individual bracket system 2, data from a 3D model of the patient's jaws at the end of treatment in the occlusal relationship and a 3D model of orthodontic arches at the end of treatment are required. This data is obtained in accordance with the method of 3D modeling proposed in the invention.

3D models of the bodies of the elements of the bracket system 2 are created taking into account the position of the modeled orthodontic standard arches at the end of treatment relative to aligned teeth (Fig. 14), while the contact lateral faces of the orthodontic standard arches are on the desired curves defining the shape and location of the deformed standard orthodontic arch at the end of treatment. Thus, the modeled arcs completely enter the grooves and holes of the elements of the bracket system 2, and the platforms of the elements of the bracket system 2 repeat the shape of the corresponding teeth. In this case, a gap is set between the platform and the surface of the tooth for uniform distribution of the glue for further fixing the elements of the bracket system 2 on the patient's teeth.

On the obtained 3D-models of the elements of the bracket system 2, the required marking is performed and a relief is applied to the inner surface of the platforms.

After that, 3D models of the elements of the bracket system 2 are ready for manufacturing.

Since the modeled elements of the bracket system 2 are individual, additive technologies should be used for their manufacture, such as 3D-printing with metal, or, for example, casting using wax-based models, also obtained using additive technologies.

To install the elements of the bracket system 2 obtained by the method of the invention, the method of indirect fixation should be used. It allows you to accurately reproduce the desired modeled position of the elements of the bracket system 2 relative to the corresponding teeth in the patient's mouth, as shown in FIG. 15 (in Fig. 16 for lingual treatment). Various types and technologies of positioners for indirect fixation can be used: thermoformed transfer mouth guards, mouth guards with indicating and guiding elements for placement, individual positioners for each tooth.

Thus, the problem solved by the present invention, namely the development of a method for orthodontic treatment using a straight arc method using 3D modeling, allows to guarantee the pre-calculated position of the patient's teeth at the end of the treatment. At the same time, the absence of the need to adjust the location of the elements of the bracket system during treatment can significantly reduce the time to achieve a guaranteed result of the patient's orthodontic treatment.

Claims (10)

1. A method of orthodontic treatment by the method of a straight arc using 3D modeling, characterized in that arches and individual orthodontic elements of a bracket system are used for treatment, manufactured for each specific clinical case, for which a 3D model of the patient's jaw is obtained and the initial shape of the orthodontic arcs, then, using 3D modeling, determine the desired curve defining the shape and location of the still strained orthodontic arch at the end of treatment, while proceeding from the fact that the desired curve is located symmetrically relative to the sagittal plane, and the shape of the desired curve corresponds to the average one with an accuracy of 1 mm of the curve between the initial shape of the selected orthodontic arch established at the beginning of treatment and the shape of the unstressed arch used at the end of treatment, and, based on the shape of the desired curve obtained as a result of 3D modeling, the shapes of individual orthodontic elements of the bracket system for each tooth are determined ... 2. A method of orthodontic treatment according to claim 1, characterized in that the treatment is applied to the upper jaw. 3. The method of orthodontic treatment according to claim 1, characterized in that the treatment is applied to the lower jaw. 4. The method of orthodontic treatment according to claim 2 or 3, characterized in that the treatment is performed from the side of the lingual surface of the teeth. 5. The method of orthodontic treatment according to claim 2 or 3, characterized in that the treatment is performed from the side of the vestibular surface of the teeth. 6. Individual elements of a bracket system for orthodontic treatment by the method of a straight arc using 3D modeling, characterized in that the orthodontic arch, having the shape of the desired curve, completely enters the grooves and holes of the individual elements of the bracket system, the platforms of the individual elements of the bracket system are repeated the shape of the corresponding teeth, while between the platform of the individual element of the bracket system and the surface of the tooth, a gap is set for uniform distribution of the glue in order to further fix the individual element of the bracket system on the tooth, and the desired curve at the end of the treatment is located symmetrically relative to the sagittal plane, and its shape corresponds to a curve averaged with an accuracy of 1 mm between the initial shape of the still strained orthodontic arch, set at the beginning of treatment, and the shape of the unstressed arch used at the end of treatment. 7. Individual elements of a bracket system according to claim 6, characterized in that they are made in the form of braces. 8. Individual elements of the bracket system according to claim 6, characterized in that they are made in the form of buccal or lingual tubes or locks. 9. Individual elements of the bracket system according to claim 6, characterized in that they are made in the form of buttons. 10. Individual elements of the bracket system according to claim 6, characterized in that they are made in the form of bite pads.

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