JP7701587B2 - Retainer and method for manufacturing the same - Google Patents

Description

The present invention relates to a retainer for maintaining the alignment of teeth after orthodontic treatment and a method for manufacturing this retainer.

First, before explaining retainers, let's briefly explain the underlying orthodontic treatment.

Conventional orthodontic treatment involves wire orthodontics, which uses wires to gradually move the teeth to straighten them, but this method has drawbacks such as a lack of aesthetics and the difficulty of cleaning the mouth because the wires cannot be removed during orthodontic treatment.

As a result, in recent years, there has been an increase in aligner orthodontics, which uses aesthetically pleasing, removable, transparent mouthpieces to straighten teeth.

After completing this type of orthodontic treatment, if left untreated, the teeth will tend to revert to their original alignment, so it is necessary to use a retainer to keep the teeth in place.

Existing retainers include a mouthpiece type known as a press retainer. This type is made entirely from transparent resin and has the advantage of being aesthetically pleasing, but has the disadvantage that it covers the biting surfaces of the teeth, making it impossible to adjust the bite after orthodontic treatment.

As will be obvious to those skilled in the art, it is extremely important to adjust the occlusion after orthodontic treatment. This is because, as is also said in occlusion, poor bite alignment (malocclusion) causes uneven forces on the teeth, which can lead to various problems such as cracks in the teeth, cavities caused by bacteria entering the cracks, and tooth bending. For this reason, if occlusion cannot be properly adjusted even after orthodontic treatment, and the occlusal forces applied to each tooth are uneven, large occlusal forces can be applied at night due to physiological phenomena such as bruxism and teeth grinding, which can cause problems such as the teeth reversing their alignment.

Therefore, there are retainers that can adjust the bite after orthodontic treatment and are worn with the biting surfaces of the teeth exposed; specifically, there are retainers called wraparound retainers and QCM retainers.

As shown in Figure 7, the former type of wraparound retainer mainly uses a metal wire to maintain the alignment of teeth, and the wire runs from the front teeth to the back teeth on the labial and buccal sides (Patent Document 1).

However, as mentioned above, while aligner orthodontics that emphasizes aesthetics is on the rise, using wire retention after aligner orthodontics does not follow this trend, and wraparound retainers are unlikely to be actively accepted in the first place.

Furthermore, although wraparound retainers are durable, they have the problem that the wire is bent frequently, which requires the technician to be highly skilled. Furthermore, compared to the press retainers mentioned above, wraparound retainers have the problem that they have a smaller contact area with the teeth and therefore less holding power to firmly hold the teeth in place after orthodontic treatment.

In contrast, the latter QCM retainer, as shown in Figure 8, has a transparent resin belt instead of a wire around at least the labial and buccal sides of the anterior teeth, which is more aesthetically pleasing than a wraparound retainer and reduces bending of the wire.

However, they are much less durable than wraparound retainers, and have the problem of needing to be replaced if they break. Moreover, like wraparound retainers, they have a smaller contact area with the teeth compared to press retainers, and so they also have a weaker holding power in firmly holding the teeth in place after orthodontic treatment.

As you can see, each type of retainer has its drawbacks.
In order to compensate for these disadvantages, it has been proposed to use different types of retainers in combination, for example, using a mouthpiece-type press retainer during the day and a wraparound retainer while sleeping.

However, in this case, the teeth alignment, which is maintained by exposing the biting surfaces of the teeth with a wraparound retainer while sleeping, tends to return to its original alignment somewhat when it is replaced with a press retainer that covers the biting surfaces of the teeth during the day. In other words, when different types of retainers are used together, the way in which retention is achieved changes when each retainer is worn, and the intended retention function is not achieved.

JP 2005-270618 A

The present invention was developed to solve all of the various disadvantages associated with existing retainers, and its main objective is to provide a retainer that can adjust the bite, is aesthetically pleasing and durable, and can firmly maintain the alignment of the teeth after orthodontic treatment.

In other words, the retainer of the present invention maintains the alignment of teeth after orthodontic treatment and is worn with the occlusal surfaces of the teeth exposed. It has a front fitting part that is attached to the surface of the teeth from the labial and buccal sides, and a back fitting part that is attached to the back of the teeth from the palate or tongue side, and is characterized in that the front fitting part is transparent and covers the surface of the gums as well.

A retainer constructed in this manner is worn with the occlusal surfaces of the teeth exposed, making it possible to adjust the bite after orthodontic treatment, and since the front fitting portion is transparent, it is aesthetically pleasing.
In addition, since the front fitting portion is attached to the surface of the teeth from the labial and cheek sides and also covers the surface of the gums, it is highly durable, and since the contact area with the teeth is significantly increased compared to existing wraparound retainers and QCM retainers, it can firmly maintain the alignment of the teeth after orthodontic treatment, and also has the secondary effect of providing an unprecedented fit and being less likely to fall off.
In this manner, the retainer according to the present invention combines various advantages of existing retainers.

It is preferable that the front fit portion and the back fit portion are made of a thermoplastic resin.
This has superior durability compared to QCM retainers using resin belts, and can be used continuously for at least two years.

However, the connecting part between the rear side of the front fitting part and the rear side fitting part passes through a narrow clearance area behind the innermost tooth. Therefore, this connecting part has to be made thin by design, and if it is made of resin like the fitting part, it is not possible to ensure mechanical strength.
Therefore, it is preferable to further include a connector that is provided between the rear side of the front fitting portion and the rear side of the back fitting portion and has strength greater than these fitting portions.
This ensures the strength of the connecting portion between the rear side of the front fitting portion and the rear side of the back fitting portion.

It is preferable that the joint between the connector and the front fitting portion is located on the surface of a back tooth.
This allows the connector to be hidden even when the mouth is opened, maintaining excellent aesthetics.

In addition, the retainer manufacturing method of the present invention is a method for manufacturing a retainer that maintains the alignment of teeth after orthodontic treatment, which involves creating a dental mold having a plurality of simulated teeth and simulated gums to support them, creating a molding die that fits into the dental mold while leaving a gap between it and the dental mold, and pouring resin into the gap formed by fitting the dental mold and the molding die together and allowing it to harden, thereby creating a front side fitting portion that is attached to the surfaces of the teeth from the labial and cheek sides, and a back side fitting portion that is attached to the back sides of the teeth from the palate or tongue side, wherein the front side fitting portion is transparent and also covers the surface of the gums.
According to this method for producing a retainer, it is possible to obtain the above-mentioned effects of the retainer, that is, it is possible to provide a retainer that can adjust the bite, has excellent aesthetics and durability, and can firmly maintain the alignment of the teeth after orthodontic treatment.

The present invention, configured in this way, can provide a retainer that combines the various advantages of existing retainers, such as the ability to adjust the bite, excellent aesthetics and durability, and the ability to firmly maintain the alignment of teeth after orthodontic treatment.

FIG. 2 is a schematic diagram showing a state in which the retainer of the embodiment is used; FIG. 4 is a schematic diagram showing a state before the retainer of the embodiment is attached. 5A to 5C are schematic diagrams illustrating a method for manufacturing the retainer according to the embodiment. 5A to 5C are schematic diagrams illustrating a method for manufacturing the retainer according to the embodiment. 5A to 5C are schematic diagrams illustrating a method for manufacturing the retainer according to the embodiment. 5A to 5C are schematic diagrams illustrating a method for manufacturing the retainer according to the embodiment. FIG. 1 is a schematic diagram showing a conventional wraparound retainer. FIG. 1 is a schematic diagram showing a conventional QCM retainer.

Below, one embodiment of the retainer according to the present invention will be described with reference to the drawings.

<Configuration>
The retainer 100 according to this embodiment is for maintaining the alignment of teeth after orthodontic treatment, and is attached to the teeth T with the occlusal surfaces T1 of the teeth T exposed, as shown in Fig. 1. For ease of explanation, the teeth and gums of a model prepared in advance will be described below as the actual teeth T and gums A after orthodontic treatment.

Specifically, as shown in FIG. 1, the retainer 100 has a front fit portion 10, a back fit portion 20, and a pair of connectors 30 interposed between these fit portions.

The front fitting portion 10 is attached to the surface of the teeth T from the labial and cheek sides, as shown in Figures 1 and 2.

This front fitting portion 10 is shaped to fit the labial and buccal surfaces (labial and buccal surfaces) of the teeth T after orthodontic treatment, and in this embodiment, it is molded to fit the surface of the teeth alignment after orthodontic treatment.

To explain more specifically, the front fitting portion 10 is made of a transparent resin and is provided continuously from the backmost tooth T on one side, through the front teeth, to the backmost tooth T on the other side. In this embodiment, it is made of a thermoplastic resin that can be used for denture bases, and is a colorless and transparent resin whose main component is, for example, an acrylic resin, a polyamide resin, or a polyester resin.

The front fitting portion 10 is characterized by covering the surface of the gums A as well as the surface of the teeth T, as shown in Figure 1.

In other words, the front fitting portion 10 is shaped to fit not only the surface of the teeth T, but also the surface of the gums A, and in this embodiment, it is molded to fit both the surface of the teeth T and the surface of the gums A.

More specifically, this front fitting portion 10 is provided continuously from the surface of the gum A at the point where the backmost tooth T on one side is supported, through the surface of the point where the front teeth are supported, and over to the surface of the point where the backmost tooth T on the opposite side is supported.

As shown in Figures 1 and 2, the back-side fitting portion 20 is attached to the back surface of the tooth T from the palate or tongue side, and is separate from the front-side fitting portion 10 described above.

This back-side fitting portion 20 is shaped to fit the palatal surface (palatal surface) or lingual surface (lingual surface) of the teeth T after orthodontic treatment, and in this embodiment, it is molded after the back of the teeth alignment after orthodontic treatment.

To explain more specifically, the back side fitting portion 20 is made of a transparent resin, and is provided continuously from the backmost tooth T on one side, through the front teeth, to the backmost tooth T on the other side. In this embodiment, it is made of a thermoplastic resin that can be used for denture bases, and is colorless and transparent, with acrylic resin, polyamide resin, or polyester resin as the main component, for example, and is made of the same material as the front side fitting portion 10 described above.

And, as shown in Figure 1, this back fitting portion 20 covers not only the back surface of the teeth T but also the back surface of the gums A.

In other words, the rear fitting portion 20 is shaped to fit not only the rear surface of the tooth T, but also the rear surface of the gum A, and in this embodiment, it is molded to fit not only the rear surface of the tooth T, but also the rear surface of the gum A.

More specifically, this back-side fitting portion 20 is provided continuously from the back side of the portion of the gum A that supports the backmost tooth T on one side, through the back side of the portion that supports the front teeth, and over to the back side of the portion that supports the backmost tooth T on the opposite side.

The connector 30 is placed between the rear side of the front fitting part 10 and the rear side of the back fitting part 20 to connect these fitting parts 10, 20, and in this embodiment, it is passed through the rear side of the rearmost tooth T.

The connector 30 is made of a material that is stronger than the front fitting part 10 and the back fitting part 20, and specifically, is made of a metal wire.

One end of the connector 30 is a front joint 31 that is joined to the rear side of the front fitting portion 10, and the other end of the connector 30 is a rear joint 32 that is joined to the rear side of the rear fitting portion 20.

The front joint 31 is located on the surface of the molars, more specifically on the surface of the backmost tooth T, or on the surface of the tooth T one or two teeth before that, and is located in a position that is not visible even when the mouth is opened.

The back joint 32 is located on the back surface of the molar, more specifically, on the front surface of the backmost tooth T, or on the back surface of the tooth T one or two teeth before that.

<Production method>
Next, an example of a method for manufacturing the above-mentioned retainer 100 will be described.

First, as shown in the upper part of Figure 3, a dental mold 40 is created in advance, which includes multiple simulated teeth 41 that mimic teeth T after orthodontic treatment and simulated gums 42 that support the teeth 41. The dental mold 40 is then waxed up and embedded in a flask 50.

Next, as shown in the lower part of Figure 3, wax is used to sprue onto the dental mold 40 to create a mold 60 that is slightly larger than the above-mentioned dental mold 40.

Then, as shown in the upper part of Figure 4, the surface of this sprued dental mold 40 is molded with plaster or the like to create the above-mentioned mold 60, as shown in the lower part of Figure 4.

This molding die 60 is fitted into the dental mold 40 that has been dewaxed and the wax removed. As described above, since it is slightly larger than the dental mold 40, when it is fitted into the dental mold 40, gaps are created between the front surface of the simulated tooth 41, the back surface of the simulated tooth 41, the front surface of the simulated gum 42, and the back surface of the simulated gum 42 that constitute the dental mold 40.

As shown in the upper part of Figure 5, a connector 30 is attached to the back side of the innermost simulated tooth 41 of the dental mold 40 in advance, and the molding die 60 shown in the lower part of Figure 5 is fitted to this dental mold 40, and resin is poured into the resulting gap and allowed to harden.

This creates a prototype 70 of the front fitting portion 10 and the back fitting portion 20 connected by the connector 30, as shown in Figure 6.

Then, the prototype 70 of the front fit portion 10 and the back fit portion 20 is polished, etc., to produce the front fit portion 10 and the back fit portion 20 into the desired shape.

<Action and effect>
According to the retainer 100 thus configured, since it is worn with the occlusal surfaces T1 of the teeth T exposed, it is possible to adjust the occlusion after orthodontic treatment, and since the front fitting part 10 is transparent, it is excellent in aesthetics.
Furthermore, since the front fitting portion 10 is attached to the surface of the teeth T from the labial and cheek sides and also covers the surface of the gums A, it is highly durable, and since the contact area with the teeth T is significantly increased compared to existing wrap-around retainers and QCM retainers, it can firmly maintain the alignment of the teeth after orthodontic treatment, and furthermore, it has the secondary effect of providing an unprecedented fit and being less likely to come off.
In this manner, the retainer 100 of this embodiment combines various advantages of existing retainers.

In addition, because the front fit portion 10 and the back fit portion 20 are made of thermoplastic resin, they are more durable than QCM retainers that use resin belts, and can be used continuously for at least two years.

Here, in this embodiment, the connector 30 connecting the rear side of the front fitting portion 10 and the rear side of the back fitting portion 20 is a part that passes through an area with narrow clearance even further back than the rearmost tooth T, and from a design perspective, it has to be made thin; if it is made from resin like the fitting portion, the mechanical strength cannot be guaranteed.
In contrast, in this embodiment, a metal wire is used as the connector 30, so that the strength of the connecting portion between the rear side of the front fitting portion 10 and the rear side of the back fitting portion 20 can be ensured.

In addition, the front joint portion 31 that is joined to the front fitting portion 10 of the connector 30 is located on the surface of the molars, so the connector 30 is hidden even when the mouth is open, maintaining excellent aesthetics.

<Other embodiments>
The present invention is not limited to the above-described embodiment.

For example, in the above embodiment, the front fit portion 10 and the back fit portion 20 are made of the same material, but they may be made of different materials.

In addition, one or both of the front fitting portion 10 and the back fitting portion 20 are not limited to being colorless and transparent as described in the above embodiment, but may be, for example, colored and transparent.

In the above embodiment, the connector 30 is passed through the innermost tooth T, but it may be passed through between the innermost tooth T and the tooth T immediately before it.

The connector 30 is not limited to a metal wire, but may be made of a reinforcing material such as glass fiber or carbon fiber.

The method for producing the front fitting portion 10 and the back fitting portion 20 is not limited to the method described in the above embodiment, and they may also be produced using a 3D printer.

The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the invention.

T...tooth T1...occlusal surface A...gums 100...retainer 10...front fitting portion 20...rear fitting portion 30...connector 31...front joint portion 32...rear joint portion 40...tooth mold 41...simulated tooth 42...simulated gums 50...flask 60...mold 70...master mold

Claims (5)

A retainer is used to maintain the alignment of teeth after orthodontic treatment and is worn with the occlusal surfaces of the teeth exposed.
a front fitting part that is attached to the surface of the teeth from the lip and cheek side;
and a back-side fitting portion that is attached to the back surface of the tooth from the palate side or the tongue side,
The front fitting portion is transparent and covers the surface of the gums,
Further, a connector is provided only between the rear side of the front fitting portion and the rear side of the back fitting portion ,
This retainer is characterized in that the connecting device is positioned so as to extend from the rear side of the front fitting portion through the rear side of the rearmost tooth to reach the rear side of the front fitting portion, and is formed from a wire having greater strength than the fitting portion . The retainer according to claim 1, characterized in that the front fit portion and the back fit portion are made of thermoplastic resin. 3. The retainer according to claim 1 , wherein the connector has a strength greater than that of each of the fitting portions. 4. The retainer according to claim 3, wherein a joint portion of the connector with the front fitting portion is positioned on a surface of a back tooth. 10. A method of making the retainer of claim 1, comprising the steps of :
A dental mold is made having a plurality of simulated teeth and simulated gums supporting the teeth,
A molding die is prepared to be fitted onto the toothed die with a gap therebetween;
A method for manufacturing a retainer, characterized in that the front side fitting portion and the back side fitting portion are created by pouring resin into the gap formed by fitting the tooth mold and the molding die together and allowing it to harden.