WO2003037206A1

WO2003037206A1 - Orthodontic device and assembly procedure

Info

Publication number: WO2003037206A1
Application number: PCT/EP2002/012071
Authority: WO
Inventors: Antonio Costa
Original assignee: Antonio Costa
Priority date: 2001-10-31
Filing date: 2002-10-29
Publication date: 2003-05-08
Also published as: ITMI20012290A1

Abstract

The orthodontic device comprises a screw connected to the bone structure of a patient's mouth, and means for connection to a tooth exerting a force on the tooth to make it move. The device also comprises an intermediary element placed between the screw and the connection means extending from the mucosa covering the bone structure of the mouth. The assembly procedure for an orthodontic device consists of bending a bar-shaped intermediary element having at its opposite ends a first seat where a screw can be housed and a second seat where an element for connection to a tooth can be housed, so that, when the device is applied, the intermediary element extends from the mucosa of the mouth.

Description

ORTHODONTIC DEVICE AND ASSEMBLY PROCEDURE

DESCRIPTION The present finding refers to an orthodontic device of the implanted type and to a procedure for assembling the aforementioned orthodontic device.

As is known, orthodontic apparatuses are used to move the teeth inside the mouth, applying one or more forces of a suitable strength upon them.

In particular, there are two main types of orthodentic device.

Amongst these for the first type it is necessary to apply a support body which must be introduced in the hole through a full surgical intervention which is made in the bone after having created a flap of a few centimetres in the mucosa. Once the support body has been introduced in the hole through a full surgical intervention, it is necessary to wait for a time of a few weeks for the bone to heal and then a second period of time for for osseointegration between support body and the walls of the hole in the bone which lasts about 12 weeks at the least .

Only after such a period of time is it possible to make a further incision of the mucosa, to realise the connection system with the orthodontic apparatus and/or with a t'ooth. Therefore, according to- the above, this type of operation involves extremely long times and the execution of a substantially invasive surgical intervention. Moreover, once the support body has osseointegrated it is necessary to apply a rigid arm to it, for example through a screw or another connection system, which allows association with the orthodontic apparatus and/or with a tooth.

Such a solution is also extremely expensive and difficult to carry out from the structural point of view.

One only has to think that, besides having to substantially increase the size of the head of the support element, it is necessary to carry out mechanical operations in it, such a rather costly threadings .

Once the orthodontic therapy has ended it is also necessary to remove the support body through the use of a trephine consequently with a further invasive surgical intervention on the patient .

Implanted orthodontic devices of the second known type, to which we shall refer hereafter, comprise a screw of substantial size (in terms of length and diameter) equipped with a head on which one or more cuts and/or seats are formed for the connection of wires to the orthodontic apparatus.

The wire applies a force on the tooth which causes it to move .

Nevertheless, devices of the conventional type have numerous drawbacks, mainly due to the fact that due to the substantial size, in particular of the screw, the device is very invasive and, therefore, it is very uncomfortable for the patient and also both of the aforementioned solutions involve work by the dental surgeon and not just the dentist. In particular, the device is very uncomfortable for the patient when the screw is positioned in areas where there is a marked and continuous muscular action like, for example on the fornices .

Moreover, the zone where the screw is inserted is often subject to inflammation since the patient, who finds it hard to tolerate a screw of a substantial size, usually applies a continuous rubbing action around the proximity of the screw for which reason the head of the screw, in which the wire passes, must be protected with covering material.

The technical task proposed of the present invention is, therefore, to realise an orthodontic device and an assembly procedure for the aforementioned orthodontic device which allows the aforementioned drawbacks of the prior art to be eliminated.

In this technical task a purpose of the invention is that of realising a device which is small in size and which, therefore, is not very invasive when it is applied in the mouth of a patient. In fact, with self-threading screws it is possible to avoid making a surgical flap in the mucosa and making a hole in the bone.

Another purpose of the invention is that of realising a device which reduces or completely eliminates the problems of tolerability for the patient.

Advantageously, this is also obtained when the screw is positioned in areas where there is a marked and continuous muscular action like, for example on the fornices. A further purpose of the invention is that of realising a device which does not cause the risk of inflammation in the area where the screw is applied, since the patient to which the device is applied does not apply a continuous rubbing action in the area where the screw is applied, and which does not require intervention by a surgeon but only that by a dentist .

The last but not least purpose of the invention is that of realising a device which allows the application of forces aligned with the desired displacement, so as to avoid undesired inclinations of the tooth which is treated.

The technical task, as well as these and other purposes, according to the present invention are achieved by realising an orthodontic device, characterised in that it comprises a screw, suitable for being connected to the bone structure of a patient's mouth, means for connecting to a tooth, suitable for applying a force upon said tooth to cause it to move, and an intermediary element placed between said screw and said connection means, suitable for extending from the mucosa covering the bone structure of the mouth when the device is applied to a patient.

Advantageously, the device according to the finding is assembled, before use, through an assembly procedure for an orthodontic device, ^' characterised in that it comprises a screw with a head having a small thickness to as to be able to be arranged under connecting tissues when the screw is directly connected to the bone structure of a patient's mouth, means for connecting to a tooth or an orthodontic apparatus suitable for applying a force upon said tooth to cause it to move, and an intermediary element placed between said screw and said connection means, suitable for extending from the mucosa covering the bone structure of the mouth when the device is applied to a patient.

Other characteristics ^' of the present invention are, moreover, defined in the other claims.

Further characteristics and advantages of the invention shall become clearer from the description of a preferred but not exclusive embodiment of the orthodontic device and assembly procedure for the aforementioned orthodontic device according to the finding, illustrated for indicating and not limiting purposes in the attached drawings, in which: figure 1 shows an exploded perspective view of the orthodontic device according to the present finding;

- figure 2 shows a perspective view of the intermediary element of the device according to the finding not refolded. figure 3 shows a perspective view of a different embodiment of the intermediary apparatus of the device according to the finding not refolded.

- figures 4 and 4a show the device according to the finding applied to the mouth of a patient at the beginning and at the end of the treatment, respectively.

With reference to the aforementioned figures an orthodontic device is shown, wholly indicated with reference numeral 1. The device 1 comprises a screw 2 with a small sized head suitable for allowing it to be arranged under connecting tissues avoiding inflammation of the overlying part be it gum, adherent mucosa-tissue, or mobile mucosa. This is not possible with the solutions brought to the prior art.

Moreover, the device 1 also comprises an intermediary element 4 placed between the screw 2 and the connection means 3, suitable for extending from the mucosa covering the bone structure of the mouth when the device is applied to a patient .

The intermediary element 4 comprises a bar that has a first seat 5 for housing the screw 2, and second seats 6 for housing the connection means 3.

Preferably the first seat 5 comprises an eyelet and the bar 4 has an enlarged portion 7 at least at the second seats 6.

The second seats 6 comprises two parallel holes, as shown in the attached figures.

In a preferred embodiment, the bar 4 is made from a malleable plastic material, usually an alloy of stainless steel or titanium, so that when the bar is bent before being inserted into the patients mouth it keeps its shape and, moreover, has its edges rounded at the area in contact with the mucosa.

In a different embodiment, on the other hand, the bar 4 is bent by the manufacturer in the production process.

The connection means 3 comprises an elastic spring 8 capable of being activated in traction made from an alloy without shape memory, so that the force exerted by the device on to the tooth that needs to be shifted is always the same even some time after the application of the device.

The connection means also comprises an element for attachment to the tooth 9, for example consisting of a stainless steel wire, that is connected to an end of the spring 8.

Preferably, between the spring 8 and the attachment element 9 a plate 10 is interposed which has two housings in which the end of the spring 8 and a central portion of the wire 9 are inserted and locked.

Suitably, the screw 2 is substantially small in size and, in particular, -the screw has a length of less than 6 mm and preferably a length of between 4-5 mm) , and a diameter of less than 2mm and preferably a diameter of between 1-1.5 mm) . Figure 3 shows a different embodiment of the bar 4 according to the finding.

In particular, the bar 4 shown in figure 3 has a plurality of eyelets 5, all aligned along the axis 11.

The screw can be applied in any eyelet (possibly, many screws can be applied) and the eyelets which are not necessary can be cut and left out.

The device according to the finding can be applied to both the maxillary and the mandibulea.

For example, in the maxillary one can use the lower surface of the anterior nasal spine, which proves useful for the movement of the incisors, the zygomatic ridge and the retro molar tuber and the edentulus alveolar process.

On the other hand, in the mandibulea there are two zones for the insertion, a front one in the synphysis, in the area between canines, and a rear one, near to the external oblique line until the retromolar triangle.

Thanks to the minimal invasiveness of the device, in particularly favourable clinical cases (good thickness and density of the bone tissue) other portions of the maxillary bone can also advantageously be used.

The device according to the finding is inserted using local anaesthetic directly through the mucosa by piercing it without having to create a flap.

The only examinations required are panoramic radiography of the arch and sometimes lateral cranial teleradiography.

The gum and the bone are pierced by a low velocity drill having a 1mm drill bit using lots of irrigation and, then, the screw is inserted with a screw driver.

Then, the end of the bar that extends out from the mucosa which covers the bone structure so that the spring is always outside of the mucosa and can expand freely, the wire 9 is connected to the tooth to be moved to which a small plate of the known type has previously been fitted equipped with seats to which the wires are to be connected.

The present finding also refers to an assembly procedure of the orthodontic device.

The procedure consists of the bending of the intermediary element 4 in the shape of a bar that has at the two opposite ends the first seat 5 where a screw 2 can be housed and the second seats 6 where the element 9 for connection to a tooth is housed, so that when the device 1 is applied the intermediary element 4 extends from the mucosa of the mouth.

Therefore the screw 2 is connected to the first seat 5 and the device is implanted.

Preferably the bar 4 is bent at the first seat 5.

In the case in which the bar 4 has the structure shown in figure 3, the bar 4 is cut at one of the first seat 5, so as to get rid of the eyelets which are not necessary for the connection.

In practice it has been noted how the orthodontic device and the assembly procedure of the aforementioned orthodontic device according to the invention are particularly advantageous because thanks to the small size, in particular of the screw, the risk of complications related to the contact with the tooth roots or nerve structures is drastically.

Advantageously, the forces applied to the tooth are aligned with the desired movements, so as to avoid undesired inclinations of the tooth.

Moreover, the device is not very and, therefore, causes few problems of tolerability for the patient and, therefore, few problems associated with rubbing in the zone where the screw has been applied.

The orthodontic device and the assembly procedure of the aforementioned orthodontic device thus conceived are susceptible to numerous modifications and variants, all covered by the inventive concept. Moreover, all of the details can be replaced with technically equivalent elements. In practice the materials, as well as the sizes, can be whatever according to requirements and the state of the art .

Claims

1. Orthodontic device, characterised in that it comprises a screw with a head having a small thickness to as to be able to be arranged under connecting tissues when the screw is directly connected to the bone structure of a patient's mouth, means for connecting to a tooth or an orthodontic apparatus suitable for applying a force upon said tooth to cause it to move, and an intermediary element placed between said screw and said connection means, suitable for extending from the mucosa covering the bone structure of the mouth when the device is applied to a patient.

2. Device according to claim 1, characterised in that said intermediary element comprises a bar with at least one first seat for housing said screw, and at least one second seat for housing said connection means.

3. Device according to one or more of the previous claims, characterised in that said first seat comprises at least one eyelet .

4. Device according to one or more of the previous claims, characterised in that said first seat comprises a plurality of eyelets .

5. Device according to one or more of the previous claims, characterised in that said bar has an enlarged portion at least at said second seats.

6. Device according to one or more of the previous claims, characterised in that said second seats comprise two parallel slots.

7. Device according to one or more of the previous claims, characterised in that said bar is made from malleable plastic material .

8. Device according to one or more of the previous claims, characterised in that said connection means comprises an elastic spring.

9. Device according to one or more of the previous claims, characterised in that said connection means comprises at least one element for attachment to a tooth, said attachment element being connected to an end of said spring.

10. Device according to one or more of the previous claims, characterised in that between said spring and said attachment element is placed at least one plate with at least two housings in which at least one end of said spring is inserted and locked.

11. Device according to one or more of the previous claims, characterised in that said screw is a self-threading screw and has a length of less than 6 millimetres and preferably between 4-5_. millimetres and a diameter of less than 2 millimetres and preferably between 1-1.5 millimetres.

12.. Assembly procedure for an orthodontic device, characterised in that it consists of bending a bar-shaped intermediary element having at its opposite ends at least one first seat where a screw can be housed and at least one second seat where an element for connection to a tooth can be housed, so that when the device is applied to the patient the intermediary element extends from the mucosa of the mouth whilst the head of the screw remains completely under the connecting tissues.

13. Procedure according to the previous claim, characterised in that said bar is bent at said first seat.

14. Procedure according to claim 12 or 13, characterised in that said bar is cut at said first seat, so as to get rid of the eyelets which are not necessary for the connection.

15. Orthodontic device and application procedure of the aforementioned orthodontic device as described and claimed.