GB2267439A - Orthodontic device - Google Patents

Abstract

An orthodontic device for controlling the movement of teeth is disclosed. The device comprises a main body portion which can provide a lingual or transpalatal arch 16, and the device includes a "U"-shaped portion 17, 18 extending from each opposed extreme of the body portion arch. Each "U"-shaped portion is constructed and arranged to extend in use via one side of the "U"-shape along a mouth towards its rear. The U-shape portion then crosses a biting surface in a retromolar area via the base of the "U"-shape and returns along the buccal sulcus by the side of a tooth to be controlled. Each "U"-shaped portion includes means to attach the device to an adjacent tooth. The device enables the advantage of the lingual or transpalatal arch to be retained while at the same time dispensing with the need to weld or solder. <IMAGE>

Description

ORTHODONTIC DEVICE The present invention relates to an orthodontic device, in particular to a device including a lingual or transpalatal arch and for use in anchoring and adjusting the position of opposed molar teeth fitted with elements of an orthodontic appliance.

Typically, first molars are used for anchorage control etc.

in orthodontic treatment. Such treatment uses devices and appliances constructed and arranged to enhance the cosmetic appearance, to adjust the functional aspects of the bite etc. of teeth by maintaining or adjusting spacing, angulation, inclination, alignment and such other factors as may contribute to a correct functioning and pleasing appearance in a set of teeth for any particular individual.

An orthodontic device or appliance may typically be fitted to the teeth of a child during the early permanent dentition, although many older or indeed younger patients can be and are so treated. Typically in such children first molars are present, but not necessarily second or third molars which may not have erupted. Thus, anchorage via first molars is more often than not usual, when they are present.

In order to maintain the opposed molars in a suitable anchoring condition their forward and rotational as well as tipping movement must be controlled. Thus, there are a variety of known devices for attachment to molars either via a head gear tube or other means which secures the particular device employed in a supportive relationship with a metal band surrounding each molar. Such bands are known as "molar bands" and are typically of stainless steel.

Probably, the device of the above kind most familiar to many families is the head gear. That device includes a wire face bow the ends of which extend into the mouth and push backwards on the molar bands via head gear tubes incorporated in the bands. Furthermore, there is an arrangement of elastic bands or springs outside the mouth and around the head to give the necessary backward push to the bow. As will be appreciated, such devices are somewhat clumsy and not easy or comfortable to wear. Also, there have been recent reports of face bows becoming disconnected and leading, inter alia, to penetrating eye injuries.

In addition, molars may be controlled by a device comprising a lingual or transpalatal arch, the ends of which are welded/or soldered to the lingual aspect of a molar band. Such devices are much less clumsy, but suffer from the disadvantage of requiring a welding or soldering operation either separately in the surgery or in an outside laboratory.

Basically, it is usually undesirable to permit the first molar to move forward, which it may do if there is space available e.g. after an extraction. When the molar moves forward it tends to tip and rotate around its large palatal root. Joining the molars via an arch helps to prevent this movement. Also, because the dental arch is narrower further forward, the teeth become restricted by the thick outer bone, limiting forward movement.

If a molar has already rotated, the transpalatal arch can be adjusted to de-rotate it. Furthermore, a spring across the palate known commonly as the "quadhelix" can be used to contract or expand the arch.

I have now found surprisingly that the advantages of the lingual or transpalatal arch can be retained while at the same time dispensing with the need to weld or solder by extending a device including such an arch across the patient's biting surface via a retromolar area and thence to an end piece constructed and arranged to locate in a conventional head gear tube.

Accordingly, the present invention provides an orthodontic device for use in controlling the movement of teeth, which device comprises a main body portion which can provide a lingual or transpalatal arch, and the device including a "U"-shaped portion extending from each opposed extreme of the body portion arch, each "U"-shaped portion being constructed and arranged to extend in use via one side of the "U"-shape along a mouth towards its rear, to cross a biting surface in a retromolar area via the base of the "U" -shape and to return along the buccal sulcus by the side of a tooth to be controlled, each "U"-shaped portion including means at its extremity remote from the body portion arch to attach the device to an adjacent tooth.

An orthodontic device according the invention may be made of any suitable material, but is preferably made of metal.

Preferred materials are stainless steel, nickel/titanium alloy, or another alloy with a shape memory.

The device can be individually constructed by a dentist or a technician to suit an individual patient. Alternatively, it may be manufactured in a range of shapes and sizes which may be adjusted later to personalise the fit.

Preferably the device comprises a shaped wire arrangement and the main body portion arch may be passive or active.

Thus, in a passive device the main body portion arch can in use extend upwardly from each "U"-shaped portion into and across the patient's mouth arch. Alternatively, in an active device the main body portion arch may be shaped as a quadhelix.

In a preferred orthodontic device according to the invention the attachment means of each "U"-shaped portion comprises an arm portion which can extend into and locate within a head gear tube of a molar band. More preferably, the attachment means extends from each "U"-shaped portion itself as a "U"-shaped extension opposed to and lying in a plane perpendicular to the plane of the "U" -shaped portion and providing said arm portion as a lower side in use of its opposed "U"-shape extending towards the "U"-shaped portion. In such an arrangement the base of the "U"shaped extension preferably includes an arrangement for securing the arm portion to a tooth band.

In addition to the device of the invention, the invention includes a method of improving the function and cosmetic appearance of a set of teeth using an orthodontic appliance, which method includes the step of anchoring opposed teeth at each end of a set of teeth to be treated by attaching to each tooth a band providing a head gear tube on an outer surface thereof and attaching to each band via its head gear tube an end of a device according to the invention to effect anchoring thereof.

Preferably, in the above method the anchored teeth are first molars. However, second molars may also be used for anchorage when desired and if present.

Specific preferred embodiments of the device and method of the invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 shows a schematic plan view from below of an upper set of human teeth and a transpalatal arch; Figure 2 shows a plan view from below of an upper set of human teeth including molar bands and a device according to the invention extending between the bands; Figure 3 shows a view from the right hand side of the set of teeth of Figure 2; Figures 4 shows details of a molar band; and Figure 5 shows a plan view from below of an upper set of human teeth including molar bands and an alternative device according to the invention extending between the bands.

Referring to Figure 1, that shows a convention transpalatal arch 11 extending between first molars 12 and 13. The effect of the arch 11 is outwardly to space the molars 12 and 13 and effectively to anchor them against the thick outer jaw bone 14. Also, because the arch 11 is welded (not shown) to molar bands (not shown) molar tipping and rotation is reduced or minimised.

Referring now to Figure 2, the device 15 of the invention there shown comprises a main body portion 16 shaped to provide a transpalatal arch. The body portion 16 includes "U"-shaped portions 17,18 extending from each extreme thereof and along mouth 19 via one side 21,22 of the "U"shape and towards the rear of the mouth 19. The "U"shaped portion 17,18 then crosses a biting surface 23,24 in a retromolar area 25,26 via the base 27,28 of the "U"shape and then returns along the buccal sulcus of the mouth 19 by the side of a tooth 29,31 to be controlled. The teeth 29,31 shown are first molars and each includes a molar band 32,33 having a head gear tube 34,35 and a palatal cleat 36,37.

As can be seen more clearly from Figure 3, the "U"-shaped portion 17,18 extends into a "U"-shaped extension 41 (only one shown) which includes an arm 42 which can extend into and locate within the head gear tube 34 of molar band 32.

Furthermore, the base of the "U"-shaped extension may include a recessed portion 43 and the molar band 32 may include a hook 44 between and around both of which an elastic or steel ligature may be looped to fix the arm 42 secure in the tube 34.

Finally, referring to Figure 5, that shows a device similar to the device of Figure 2 except that the main body portion 16' providing transpalatal arch is active and can readily be adjusted to provide expansion, contracting and rotation of molars. Thus, the body portion 16' shown comprises a quadhelix arrangement as known Per se in conventional transpalatal arches. Here, however, the conventional arch is again combined with a transretromolar area extension to effect intermolar linkage via head gear tubes 34,35 on the outside of conventional molar bands 32,33.

As will be clear from the above description, the orthodontic device of the invention has a number of advantages, namely amongst others: 1. It is readily removable and adjustable.

2. It requires no laboratory procedures such as soldering or welding.

3. It avoids the need to weld extra attachments to receive preformed arches.

4. It can embody various configurations of transpalatal arch e.g. plain arch/quadhelix etc.

5. The palatal cleat remains free.

6. It can be secured to a molar band for safety with elastic or steel ligature.

7. It is relatively inexpensive.

As will be appreciated the invention is not limited to the details of the embodiments described specifically above and numerous variations and modifications may be made within the spirit and scope of the claims which follow. For example, the device combined with suitable attachments to lower molar bands could be used in the lower arch for a similar purpose.

Claims (17)

1. An orthodontic device for use in controlling the movement of teeth, which device comprises a main body portion which can provide a lingual or transpalatal arch, and the device including a "U"-shaped portion extending from each opposed extreme of the body portion arch, each "U" -shaped portion being constructed and arranged to extend in use via one side of the "U"-shape along a mouth towards its rear, to cross a biting surface in a retromolar area via the base of the "U"-shape and to return along the buccal sulcus by the side of a tooth to be controlled, each "U"-shaped portion including means at its extremity remote from the body portion arch to attach the device to an adjacent tooth.

2. An orthodontic device according to claim 1, which is made of metal.

3. An orthodontic device according to claim 1 or claim 2, which is made of stainless steel, nickel/titanium alloy, or another alloy with a shape memory.

4. An orthodontic device according to any one of the preceding claims, wherein the device comprises a shaped wire arrangement.

5. An orthodontic device according to any one of the preceding claims, wherein the main body portion arch is passive.

6. An orthodontic device according to any one of the preceding claims, wherein the main body portion arch can in use extend upwardly from each "U"-shaped portion into and across the patient's mouth arch.

7. An orthodontic device according to any one of claims 1 to 4, wherein main body portion arch is active.

8. An orthodontic device according to claim 7, wherein the main body portion arch is shaped as a quadhelix.

9. An orthodontic device according to any one of the preceding claims, wherein the attachment means of each "U"shaped portion comprises an arm portion which can extend into and locate within a head gear tube of a molar band.

10. An orthodontic device according to claim 9, wherein the attachment means extends from each "U"-shaped portion itself as a "U"-shaped extension opposed to and lying in a plane perpendicular to the plane of the "U"-shaped portion and providing said arm portion as a lower side in use of its opposed "U"-shape extending towards the "U"-shaped portion.

11. An orthodontic device according to claim 10, wherein the base of the "U"-shaped extension includes an arrangement for securing the arm portion to a tooth band.

12. An orthodontic device according to claim 1, substantially as hereinbefore described.

13. An orthodontic device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

14. A method of improving the function and cosmetic appearance of a set of teeth using an orthodontic appliance, which method includes the step of anchoring opposed teeth at each end of a set of teeth to be treated by attaching to each tooth a band providing a head gear tube on an outer surface thereof and attaching to each band via its head gear tube an end of a device according to any one of the preceding claims to effect anchoring thereof.

15. A method according to claim 14, wherein the anchored teeth are first molars.

16. A method according to claim 14, substantially as hereinbefore described.

17. A method of improving the function and cosmetic appearance of a set of teeth using an orthodontic appliance substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.