BACKGROUND

Field of the Invention

[0001] The present invention generally relates to orthodontic brackets. More particularly, the present invention relates to an ultra-thin, self-ligating orthodontic bracket and its locking and unlocking mechanism.

Description of the Related Art

[0002] Generally, misalignment of teeth is corrected by wearing dental attachments like aligners and braces. The dental aligners are used to treat minor misalignment. Whereas major misalignment of the teeth needs to be fixed with orthodontic bracket braces. These fixed orthodontic brackets are used to correct the major teeth misalignment by the application of forces selectively by interconnected arch wires held together by brackets attached to a user’s teeth using elastic ligatures or thin Stainless-Steel ligatures. But the major drawback of using such brackets is that they need to be ligated to bracket and to the teeth. More over the ligation is a time-consuming process and many times the thin ligature wire deforms and cause irritation to the soft tissues in the mouth. Furthermore, the elastic chains are quickly degradable in the mouth and can accumulate debris. This creates an unhygienic situation and an unsightly appearance of the teeth.

[0003] Hence, a mechanical self-ligation bracket has been developed and these brackets can be used both labial and lingual side to the teeth. For example, [0004] United States Patent Number 10,555,793 to Falcone Matthew

Jameset. al., entitled "Self-ligating orthodontic brackets" deals with a self-ligating orthodontic bracket that comprises a controlled-locking or automatic pivoting dip to place and remove the arch wire.

[0005] United States Patent Application Number 20110086323 to Wessinger

Michael entitled “Self-Ligating Bracket for Orthodontics" deals with a self- ligating orthodontic bracket for securing and releasing arch wire in the channel comprises a sliding element that is displaceable back and forth along the channel to open and dose position for securing arch wire.

[0006] Moreover, the labial brackets can be easily attached and cleaned frequently whereas the lingual bracket attachment has some challenges. In some way, the dentist finds it very difficult to see the bracket placed in the lingual side and it requires more time to ligate arch wires on the Lingual Side of the teeth. Also, the dentist could not easily access the lingual side because of the poor lighting as well as the limited mouth opening of the patient. Further, there will be difficulty in incorporating auxiliaries like “torqueing auxiliary” to the lingual appliance. Another disadvantage is that the ends of ligature wire may pock the patient’s tongue and other soft tissues.

[0007] In addition to the bracket design and slot position, the self-ligation lock is a major difference with traditional cad cam brackets and traditional self-ligation systems. Traditional brackets add about 1 mm thickness for the sliding self- ligation lock and for its housing. Any increase in thickness of the bracket is a limitation and might interfere with the patients activities.

[0008] Hence, there is a need for a novel, ultra-thin, self-ligating orthodontic brackets that Open the lock automatically upon unlocking by the labio-lingual programmed deformation of the lock.

SUMMARY

[0009] The prirnary object of the present invention is to provide an effective and ultra-thin self-ligating orthodontic bracket that do not interfere with the patient's regular activities.

[0010] Another object of the present invention is to provide a novel design of the orthodontic bracket that reduces the bracket profile to the minimum.

[0011] Yet another object of the present invention is to provide a method of locking and unlocking mechanism of the self-ligating orthodontic bracket.

[0012] Still another object of the present invention is to provide a simple method for automatic opening during unlocking of the lock from lock slot.

[0013] To achieve the aforementioned objectives, the present invention discloses a simple, comfortable, novel, ultra-thin self-ligation orthodontic bracket with variety of locking and unlocking mechanism that allows the user to perform regular activities.

[00141 According to the present invention, a self-ligating orthodontic bracket for coupling an arch wire to a tooth comprising, a bracket base for attaching bracket to the tooth, a bracket slot positioned inside the bracket base to hold the arch wire in position, a bracket stem that extends incisal to the bracket base to join the slot with the base, incisal tie wings that also acts as a locking undercut and helps in locking and unlocking of the arch wire slot, a lock slot positioned in the middle of the bracket, cervical to the bracket slot and incisal to the cervical tie wing that provides housing to the self-ligating lock, a slot cover to cover the lock slot and a self-ligating lock to lock and unlock the arch wire.

[0015] The present invention also provides a method for coupling an arch wire to a tooth comprising the steps of: attaching bracket base to the teeth, placing the arch wire in the edge wise or ribbon wise bracket slot, pressing the lock towards the bracket to engage with incisal tie wing and/or further pressing it cervically to lock the arch wire and performing an action in reverse on the lock to unlock the arch wire. [0016] In one embodiment, the lock slot is funnel shaped and lock is zigma shaped. [0017] In another embodiment, the lock slot is plain rectangular in shape and lock is Z shaped.

[0018] In another embodiment, the lock slot has rectangular depression and lock is shaped as elliptical ring attached with rectangular block.

[0019] In yet another embodiment, the lock slot at its incisal aspect has a cylindrical hole horizontally that opens into the lock slot thus allowing a rectangular lock to rotate within it. Here, the lock slot allows the sliding of the lock that is square or round in cross section, cervico-incisaly and the cylindrical hole allows the lock to rotate within it.

[0020] In the present invention, the lock is made up of any of flexible materials like NiTi, spring metal, plastics and other flexible materials.

[0021] The orthodontic device and method of the present invention helps in automatic opening during unlocking of the lock and preferably it is used to correct the major misalignments of teeth without causing any discomfort to the user while wearing. :

[0022] The objective and advantages of the present invention will become more evident from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The objective of the present invention will now be described in more detail with reference to the accompanying drawings, in which:

[0024] FIG. 1 shows the overall design of the ultra-thin orthodontic bracket having reduced bracket profile;

[0025] FIG. 2A shows the bracket profile having lock slot;

[0026] FIG. 2B shows the view of slot cover removed showing the space for lock slot block hole;

[0027] FIG.2C shows the mesial and distal extensions of the slot cover to prevent the lock from sliding out from the lock slot;

[0028] FIG. 2D shows the slot cover on its mesial and distal aspect that can extend mesialy and distally to form a mesial and distal cervical tie wing to lock the lock within the lock slot; In the absence of the lock it can be used to ligate the regular ligature tie and hence it is called mesial and distal cervical tie wings

[0029] FIG. 3 shows orthodontic bracket with vertical slide lock in accordance with the first embodiment;

[0030] FIG. 4 shows the different lock designs of the present invention to increase the range of action of these locks;

[0031] FIGS. 5A and 5B show the funnel shaped lock actuator for lingual bracket; [0032] FIG. 6A shows the inciso cervical opening and closing of the lock slot in accordance with the first embodiment;

[0033] FIG. 6B shows the labio lingual rotation of the lock after bracket unlocking in accordance with the first embodiment; [0034] FIG. 7 shows the increase in length of the lock by vertical pulling to disengage the incisal tie wing in accordance with the first embodiment;

[0035] FIG. B shows the Zigma Shaped Lock used in the funnel shaped lock slot in accordance with the first embodiment;

[0036] FIG. 9 shows the image of the bracket with vertical slide lock in accordance with the second embodiment; [0037] FIG. 10 shows the image of the cervical activation of locking and unlocking of vertical sliding bracket in accordance with the second embodiment;

[0038] FIG. 11A shows the image of the inciso-cervical opening of the slot in accordance with the second embodiment;

[0039] FIG.11B shows the image of the Labio Lingual rotation of the lock after bracket unlocking in accordance with the second embodiment;

[0040] FIGS. 12A and 12B show the image of the lock and lock slot in accordance with the third embodiment;

[0041] FIG. 13 shows the image of the rectangular lock with elliptical ring in accordance with the third embodiment; and [0042] FIG.14 shows the image of square or round shaped lock with the lock slot having a cylindrical hole at the incisal part in accordance with the fourth embodiment

REFERENCE NUMERALS

100 - Self-ligating orthodontic device

10 - Bracket base

20 - Bracket stem

30 - Bracket slot

40 - Lock Slot block hole

50 - Incisal tie wing

60 - Cervical tie wing

60a - Mesial and distal extensions on slot cover

70 - Lock slot

80 - Lock

80a - Zigma shaped lock

80b - Rectangular lock with elliptical ring

DETAILED DESCRIPTION OF THE INVENTION

[0043] The present invention provides a simple, novel, ultra-thin and self- ligating orthodontic bracket that has minimum bracket profile which improves the comfortableness of the user. Also, the present invention provides with an automatic opening during unlocking the lock.

[0044] Generally, orthodontic bracket can be used in both labial and lingual brackets. Likewise, the orthodontic bracket of the present invention can also be used in Stock Lingual Brackets, CAD CAM Lingual brackets, customized Labial Brackets and in stock Labial Brackets. More particularly, the orthodontic device of the present invention is described as Ultra-thin self-ligation CAD CAM lingual brackets which is an extensive development of normal lingual orthodontics.

[0045] The parts of the ultra-thin self-ligating orthodontic bracket is explained in detail below and the overall design of the reduced bracket profile is shown in

FIG- 1 -

[0046] According to the present invention, a self-ligating orthodontic bracket

100 for coupling an arch wire to a tooth, wherien the bracket comprises a bracket base 10 for attaching bracket to the tooth, a bracket slot 30 positioned inside the bracket base to hold the arch wire(not shown) in position, a bracket stem 20 that extends incisal to the bracket base to join the slot with the base, incisal tie wings 50 that also acts as a locking undercut and help in locking and unlocking of the arch wire slot, a lock slot 70 positioned in the middle of the bracket, cervical to the bracket slot and above the cervical tie wing 60 that provides housing to the self-ligating lock, a slot cover (not shown) to cover the lock slot and a self-ligating lock 80 to lock and unlock the arch wire. Bracket Base 10:

[0047] In normal lingual cad cam brackets, the lingual surface is selected in its normal circumferential shape. The Upper Incisors on the lingual side possess a saucer like depression and that shape is selected for the bracket base. All other teeth have a convex surface.

Bracket Stem 20:

[0048] The bracket stem 20 extends from the bracket baselO till the area occupied by the arch wires (i.e. base of the bracket slot). Normally, the bracket stem is thicker than the bracket base. But in the present invention, the bracket stem 20 extends incisal to the bracket base 10 and hence can have a very low bracket profile. In this new design, the bracket base extends only up to the cervical plane of the lingual arch wire, so the slot can extend into the bracket where the base normally occupies. This design can reduce the bracket profile to the minimum.

Bracket Slot 30:

[0049] Traditionally in orthodontics, horizontal slots for arch wires are used. The slots other than the horizontal slots which house other wires are also sometimes incorporated in the bracket design. But in the present invention, the bracket slot is placed at a position where it is partly inside the bracket base itself. To further reduce the bracket profile, the bracket slot stem assembly can be taken towards the bracket base 10. This is shown by the arrow. The slot will then be placed within the base, thereby reducing the bracket profile, as shown in FIG. 1. Tie Wings:

[0050] Similar to the traditional brackets, the present invention is also incorporated with a pair of tie wing which are presented incisal 50 and cervical position 60. But the major difference is that the tie wings can be moved modified in shape, size, length and orientation in the design phase of CAD.

Lock Slot 70 and Lock Slot Cover

[0051] The lock slot is the one that houses the self-ligation lock in and is located within the thickness of the bracket. In the present invention, the lock slot 70 is located in the middle portion of the bracket, cervical to the arch wire slot and above the cervical tie wing 60 as shown in FIGS. 2A and 2B. This slot is covered by the slot cover (not shown). This slot provides space for self-ligation lock to operate. After housing the self-ligation lock, the lock slot is covered by the lock cover. This allows the lock to function easily.

[0052] The lock slot 70 at its cervical end has a hole40 passing through the slot cover and the bracket base. This will house a small pole that will limit the cervical movement of the self-ligation slot.

[0053] The lock slot differs in shape with respect to the various lock designs.

[0054] In one embodiment, the lock slot is funnel shaped and lock is zigma shaped80a.

[0055] In another embodiment, the lock slot is plain rectangular in shape and lock is Z shaped.

[0056] In another embodiment, the lock slot has rectangular depression and lock is shaped as an elliptical ring attached with rectangular block80b. [0057] In yet another embodiment the lock slot at its incisal aspect has a cylindrical hole horizontally that opens into the lock slot, thus allowing a rectangular lock to rotate within it. Here the lock slot allows the sliding of the lode that is square or round in cross section, cervico-incisaly and the cylindrical hole allows the lock to rotate within it.

[0058] FIG. 2C shows the mesial and distal extensions of the slot cover. These extensions will prevent the lock from sliding out from the lock slot. The slot cover on its mesial and distal aspect can extend mesialy and distally to form a mesial and distal cervical tie wing to lock the lock within the lock slot as shown in FIG. 2D. In the absence of the lock it can be used to ligate the regular ligature tie and hence it is called mesial and distal cervical tie wings

[0059] In the present invention, the lock is made up of any of the flexible materials like NiTi, spring metal, plastics and other flexible materials.

[0060] According to the present invention, a method for coupling an arch wire to a tooth, comprising the steps of, attaching bracket base to the teeth, placing the arch wire in the edge wise or ribbon wise bracket slot, pressing the lock towards the bracket to engage with incisal tie wing and/or further pressing it cervically to lock the arch wire and performing the reverse action in the lock or lock slot to unlock the arch wire slot.

[0061] The action is selected from vertical pulling or pushing, twisting, bending and other means to4he lock or lock slot to enable either secure or release of the arch wire. [0062] In the first embodiment, ultra-thin self-ligation cad cam brackets with funnel shape self-ligation is explained. Here, the lock slot is placed about 0.3-

0.5 mm from its surface of the bracket. The lock slot is funnel shaped and it can be increased in length. The funnel starts from the mesial and distal surface of the brackets with the apex of the funnel at the centre of the bracket. The 0.3 mm location within the bracket surface makes it possible to have a cover for the lock slot. Moreover, the lock for this funnel shaped lock slot is in zigma shape and is shown in FIG. 8.

[0063] The vertical slide lock of orthodontic bracket is shown in FIG. 3. Also, there are different lock designs which are possible to increase the range of action of the lock as shown in FIG. 4.

[0064] In accordance with the first embodiment, the method of locking an arch wire to the tooth comprises the steps of engaging the arch wire in the edge wise or ribbon wise slot, pressing the lock towards the bracket so that it engages the incisal tiewing, after engaging the incisal tiewing, the lock is pressed cervically to lock behind the incisal tiewing whereas the unlocking is done in reverse direction. The unlocking is done by pulling the lock from the incisal aspect which will deform the lock at its cervical aspect temporarily, thus increasing its inciso-cervical length as shown in FIGS. 5 and 7. Thus, the process follows the steps of unlocking the lock followed by labio-lingual deformation of the lock that automatically opens the lock. [0065] Referring to FIG. 6A, the half funnel shape allows the flexible lock to deform in the inciso-cervical direction to release or engage the incisal tiewing and thus affecting the unlocking and locking. The lock deforms labio-lingually at the apex of the funnel, thus opening the lock after disengaging the 'incisal tiewing as shown in FIG. 6B.

[0066] In the second embodiment, ultra-thin self-ligation bracket with automatic opening during unlocking is explained. Here, the lock slot is placed about 0.3 -

0.5 mm from the bracket surface. The lock slot is plain rectangular in shape. The 0.3-0.5 mm location within the bracket surface makes it possible to have a cover for the lock slot. Moreover, the lock is Z shaped when viewed from the proximal aspect.

[0067] The lock deforms labio-lingually above the cervical bar of the self-ligation lock and deforms to allow the arch wire to be engaged into the arch wire slot.

Once the arch wire is locked within the arch wire slot then the lock is pulled cervical with the incisal locking arm engaged into the incisal tiewings.

[0068] FIG. 9 shows the image of the bracket with vertical slide lock of the second embodiment . [0069] In accordance with the second embodiment, the method of locking an arch wire to the tooth comprises the steps of: engaging the arch wire in the edge wise or ribbon wise slot, pressing the lock towards the bracket so that it engages the incisal tie wing, after engaging the incisal tie wing, the lock is pressed cervically to lock behind the incisal tie wing.

[0070] FIG. 10 shows the lock opening automatically because of bending the area above the cervical bar away from the tooth so that the moment the lock is disengaged from the incisal tiewing, thus, the lock automatically opens to receive or to remove the arch wire. Pulling the lock from the incisal aspect will bring the entire lock incisaly thus disengaging it from the incisal tiewing. Once unlocked, the labio-lingual deformation of the lock will automatically open the lock. Thus, the lock is in its passive position is not engaged in the incisal tie wing.

[0071] FIG. 11A shows the inciso-cervical opening and closing of the slot and

FIG. 11B shows the Labio Lingual rotation of the lock after bracket unlocking.

[0072] In the third embodiment, ultra-thin self-ligation cad cam bracket with ring ligation is explained. Here, the lock slot bears a rectangular depression and lock is having a rectangular block with an elliptical ring 80battached to it as shown in FIG. 13. The rectangular depression of the lock slot will house the rectangular portion of the ring ligation as shown in FIGS. 12A and 12B.

[0073] An action that automatically opens the lock upon unlocking and at the same time requires only pressing the locking ring incisaly and towards the bracket to lock the arch wire. This makes the fabrication of the lock easy and makes it very efficient.

[0074] In accordance with the third embodiment, the unlocking effect is achieved by sharply bending the elliptical ring at the incisal level of the arch wire to create the missing wall for the slot. The rectangular block is bend in an opposite direction to the bend portion of the elliptical ring which makes the ligation to automatically open during unlocking.

[0075] In the fourth embodiment, ultra-thin selMigation cad cam bracket with lock slot in its insical aspect is explained. As shown in FIG. 14 the lock slot (70) is at incisal aspect has a cylindrical hole horizontally opens into the lock slot

(70) thus allowing a rectangular lock to rotate within it. Here the lock slot (70) allows the sliding of the lock that is square or round in cross section (80), cervico-incisaly and the cylindrical hole allows the lock (80) to rotate within it.

This rotation allows the slot opening as the lock reaches the cylindrical hole, whereas rectangular portion of the slot allows the sliding of the lock to reach the cylindrical part of the lock slot.

[0076] Thus, the advantages of the present invention, including but not limited to, are: a novel, simple self-ligating orthodontic bracket having minimum bracket profile that improves the user’s comfort level to perform various activities without having any pain. [0077] While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of foe specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within foe scope of foe invention as claimed.