ORTHODONTIC BRACKET
An orthodontic bracket that includes a body having a lingual surface for attachment to a tooth and an archwire slot. At least two tie wings extend from the body and define a space directly therebetween. The orthodontic bracket further includes a locking shutter having a stem. A portion of the stem is positioned in the space directly between the tie wings. The locking shutter is movable between an open position, in which access to the archwire slot is permitted and a closed position where access to the archwire slot is inhibited.
The present application is a continuation of U.S. application Ser. No. 09/847,505, filed May 2, 2001 which is a continuation of U.S. application Ser. No. 09/327,732, filed Jun. 8, 1999 now issued and granted under U.S. Pat. No. 6,257,883 which is a continuation of U.S. application Ser. No. 08/745,512, filed Nov. 12, 1996 now issued and granted under U.S. Pat. No. 5,913,680 which is a continuation-in-part of U.S. application Ser. No. 08/625,944, filed on Apr. 1, 1996 now issued and granted under U.S. Pat. No. 5,857,850 which is a continuation-in-part of U.S. application Ser. No. 08/412,338 filed on Mar. 31, 1995 now abandoned which is a continuation-in-part of U.S. application Ser. No. 08/206,724 filed on Mar. 7, 1994 now issued and granted under U.S. Pat. No. 5,474,445, the entire contents of all of which are hereby incorporated by reference.
FIELD OF THE INVENTIONThe present invention relates in general to pre-engaging orthodontic brackets and in particular to a pre-engaging twin orthodontic bracket and to a plurality of orthodontic brackets forming a set of braces.
BACKGROUNDAccording to established orthodontic techniques, it is well known that one is able to ligate an archwire to a bracket utilizing an elastic, elastomeric or metal ligature. In a twin edgewise orthodontic bracket, the elastic ligature is stretched around respective undercuts of gingival and occlusal tie wings so as to overlay the archwire at mesial and distal ends of the bracket.
The ligating procedure involves carefully stretching the elastic or elastomeric ligature (or wrapping and twisting a metal ligature) around the tie wings utilizing appropriate orthodontic instruments. It has been found that the time-consuming ligation procedure contributes to lengthy chair time. Furthermore, the elastic ligatures are known to lose their elasticity with time and are subject to degradation. Also, the elastic and metal ligatures have been known to trap food particles in areas of the bracket which are difficult for the patient to clean, and to increase the level of friction against the archwire. Finally, the use of sharp metal ligatures around the bracket can subject the clinician to unnecessary exposure to infectious bacteria, or viruses such as hepatitis B, or possibly the HIV virus particularly in blood.
In an effort to overcome these disadvantages of elastic ligatures, certain advances have been made in the area of pre-engaging orthodontic brackets. Each of U.S. Pat. Nos. 4,144,642; 4,248,588; 4,698,017; 3,772,787; 4,786,242; 4,559,012; 4,561,844; 4,655,708; 4,077,126; 4,419,078; 4,634,661; 4,197,642; and 4,712,999 illustrate one or more designs of pre-engaging brackets. These prior art devices overcome some of the disadvantages associated with elastic ligatures. For example, pre-engaging orthodontic brackets eliminate, or at least reduce, exposure of the clinician to sharp ligatures, thereby alleviating the problem of contracting harmful bacteria or viruses. In addition, pre-engaging orthodontic brackets permit continuous low deflection differential archwire contact separately for both round and rectangular archwires at at least two different levels of contact, which is not possible with degrading elastic, elastomeric or rigid, high deflection metal ligatures. However, most of the known prior art pre-engaging orthodontic brackets lack the reliability and the accessible ease of operability that most clinicians require. In addition, the majority of prior art pre-engaging orthodontic brackets are of a single design that have three or fewer tie wings.
It is therefore an object of the present invention to provide a novel twin pre-engaging orthodontic bracket which obviates or mitigates at least one of the above-identified disadvantages associated with prior art orthodontic brackets.
SUMMARYIn one embodiment, the invention provides an orthodontic bracket that includes a body having a lingual surface for attachment to a tooth and an archwire slot. At least two tie wings extend from the body and define a space directly therebetween. The orthodontic bracket further includes a locking shutter having a stem. A portion of the stem is positioned in the space directly between the tie wings. The locking shutter is movable between an open position, in which access to the archwire slot is permitted and a closed position where access to the archwire slot is inhibited.
In another embodiment the shutter includes an end that is positioned in the archwire slot when the shutter is in the closed position. The end of the shutter includes a labial surface that is concave about an axis parallel to a mesio-distal axis.
In yet another embodiment the archwire slot includes a sidewall. The orthodontic bracket further includes a notch formed into the sidewall of the archwire slot that extends mesio-distally across the body substantially the same length as the archwire slot. The shutter further includes an end that is positioned in the notch when the shutter is in the closed position.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGSPreferred embodiments of the present invention will now be described more fully with reference to the accompanying drawings, in which:
Referring now to
A shutter 30 formed of resilient stainless steel is pivotally mounted on the occlusal tie wings 18 and is movable between a closed position where access to the archwire slot 20 is inhibited and an open position where access to the archwire slot is permitted (see
The shutter 30 curves labially and gingivally around the occlusal tie wings 18 and then curves lingually towards the archwire slot 20. When the shutter 30 is in the closed position and the archwire applies a labially directed force to the shutter 30, the gingival end 36 of the shutter 30 contacts the deflection surfaces 24 to inhibit the shutter from being accidentally removed from the archwire slot 20. At the same time, the lingual surface 38 of the shutter 30 contacts the archwire 22 to urge it continuously into the archwire slot 20. When the shutter 30 is pivoted and translated to remove it from the archwire slot 20, the gingival end 36 can be accommodated by the resting grooves 26 to hold the shutter in the open position although this is not necessary as shown by the dotted line in
The design of the shutter 30 is such that a rectangular archwire 22 is seated to apply torque to the archwire slot 20 depending on the rectangular cross-sectional shape of the archwire 22. The continuous active seating or biasing of the archwire 22 by the shutter 30 provides for accurate tooth movement. Referring now to
Referring now to
Referring now to
Referring now to FIGS. 6 to 10, yet another embodiment of a pre-engaging twin orthodontic bracket is shown and is generally indicated to by reference numeral 110. As can be seen, orthodontic bracket 110 includes a body 112 and a lingual mounting pad 114 attached to the body. The mounting pad 114 has a lingual surface to be attached to a tooth. A pair of laterally spaced gingival tie wings 116 and a pair of laterally spaced occlusal tie wings 118 extend from a labial surface of the body 112. The gingival tie wings 116 and the occlusal tie wings 118 curve lingually. A horizontal crossbar 117 extends across the interwing region 112′ of the body 112 and interconnects the occlusal tie wings 118. A ball hook 119 extends from one of the gingival tie wings 116.
The gingival surface 115 of the body in the interwing region 112′ between the gingival tie wings 116 is convex and is generally semi-elliptical. The labial surface of the body in the interwing region 112 has a notch 150 formed in it. The gingival tie wings 116 are bevelled as indicated by reference numeral 121. An archwire slot 120 extends mesiodistally across the body 112 and between the gingival and occlusal tie wings located at opposed mesial and distal sides of the body and opens labially to receive an archwire 122. The occlusal wall of the archwire slot 120 is continuous and is constituted by the occlusal tie wings 118 and the crossbar 117. The occlusal wall of the archwire slot 120 has a notch formed in it to define two deflection surfaces 124 and 126 respectively. Deflection surface 124 is constituted by a labial bevel while deflection surface 126 is constituted by a lingual bevel.
Looking at
Referring now to
The archwire slot 120 is designed to accommodate circular cross-section or rectangular cross-section archwires 122. When the archwire 122 is positioned in the archwire slot and the shutter is closed, the lingual surface of the shutter 132 contacts the archwire to urge it continuously against the body 112 (see
During this pivotal movement of the shutter 132, the convex interwing gingival surface 115 of the body 112 and the flexing of the initially compressed shutter over the convex surface 115 as the shutter 132 pivots around the pivot pin 130 with the end of the shutter in the notch as shown in
Although the shutter 132 has been described as having a D-shaped cup 138 to surround the pivot pin 130, the shutter can curl back around itself to surround substantially the pivot pin 130 between the gingival tie wings. Also, although the pivot pin has been described as being accommodated in curved slots and bonded to the orthodontic bracket, it should be apparent to those of skill in the art that the pivot pin may be integrally formed with and extend between the gingival tie wings.
Although the gingival surface of the body in the interwing region has been described as being semi-elliptical, it should be appreciated that other surface configurations are suitable. Also, although the pivot pin has been described as being accommodated in a groove extending across the gingival tie wings and the body, the pivot pin may only extend between the gingival tie wings in the interwing region 112′ making the gingival tie wings more accessible. Also, although the shutter has been shown as pivoting about a pivot pin extending between the gingival tie wings, the pivot pin may extend between the occlusal tie wings.
Referring now to FIGS. 12 to 15, yet another embodiment of an orthodontic bracket is shown and is generally indicated to by reference numeral 220. As can be seen, orthodontic bracket 220 includes a body 222 and a locking shutter 224. For illustrative purposes, the orthodontic bracket 220 is configured for a maxillary tooth but it can be appreciated that the orthodontic bracket 220 could be used on a mandibular tooth.
Body 222 includes a lingual mounting pad 226 having a lingual tooth attaching surface 228 adapted for direct attachment to a tooth or to a pad that may be attached to a tooth. A pair of laterally spaced occlusal tie wings 234 and a pair of laterally spaced gingival tie wings 236 project from a labial surface of the body 222. Each tie wing 234,236 curves lingually to define an undercut 238 for receiving a ligature. An archwire slot 240 extends mesiodistally across the body 222 and between the occlusal and gingival tie wings at opposed mesial and distal sides of the body. The archwire slot 240 accommodates an archwire 242. The archwire slot 240 has a pair of opposed surfaces 244,246 at its mesial and distal ends. Inverted V-shaped deflection notches 248 are provided in the gingival tie wings 236 above the archwire slot. The deflection notches 248 are provided to receive a gingival edge 250 of the locking shutter 224 in the closed position.
The locking shutter 224 extends between the occlusal and gingival tie wings at opposed mesial and distal sides of the body 222 and across the archwire slot 240. The locking shutter 224 has a body 252 which is cranked as indicated at 254 to provide a pair of relatively inclined portions 256,258. Occlusal edge 260 of the shutter body 252 is provided with a recess 262 (as seen in
The locking shutter 224 is retained on the orthodontic bracket 220 by means of an off-center pivot pin 268 that passes through an aperture (not shown) formed in the arm 264 and is secured to the occlusal tie wing 234. The shutter 224 is thus able to slide in a generally occlusal-gingival plane about the pin 268 as indicated by arrow 269 in
An indentation 272 is formed in the arm 266 and a corresponding dimple 274 formed in the underlying occlusal tie wing 234. Arm 266 includes a buccally-extending return 276 that passes around the distal side of the occlusal tie wing 234 and has a retaining plate 278 that is received within a slot 280 formed in the side of the occlusal tie wing 234.
The indentation 272 cooperates with the dimple 274 to form a detent which inhibits pivotal movement of the shutter 224 about the pivot pin 268 and retains the locking shutter 224 in the closed position. The retaining plate 278 cooperates with the slot 280 and the shutter cooperates with the deflection notches 248 to inhibit labial movement of the locking shutter when in the closed position and an archwire applies a labially directed force to the shutter so that the locking shutter 224 retains the archwire 242 within the archwire slot 240.
To open the locking shutter 224, it is simply necessary to overcome the detent provided by the indentation 272 and dimple 274 and rotate the locking shutter 224 about the pivot pin 268. Access to the archwire slot 240 is thus obtained. Similarly, to close the locking shutter 224, it is simply necessary to pivot the locking shutter about the pivot pin 268 so that the gingival edge 250 engages the deflection notches 248 and the indentation 272 engages the dimple 274. The locking shutter 224 is thus held securely and cooperates with the archwire 242 to apply the requisite forces to the archwire within the archwire slot.
An alternative embodiment of an orthodontic bracket is shown in
As can be seen, the locking shutter 224a is pivotally secured to a boss 290 that extends between the gingival tie wings 236a by way of centrally positioned pivot pin 268a. One edge 292 of the locking shutter 224a is arcuate giving the shutter 224a a generally semi-circular appearance. Deflection notches 248a are formed in the occlusal tie wings 234a adjacent the archwire slot 240a. It will be noted that the labial surfaces of the occlusal tie wings 234a are labially protrusive so that the arcuate edge 292 of the locking shutter 224a is aligned with the deflection notches 248a.
Dimples (not shown) are formed on each of the gingival tie wings 236a and corresponding indentations 272a are formed on the locking shutter 224a. The dimples and indentations 272a cooperate when the locking shutter 224a is either in the open or closed positions to retain the locking shutter in that position. An aperture 267a is provided in the shutter to receive a tool and facilitate movement of the shutter 224a. The locking shutter 224a can be pivoted about pivot pin 268a so as to bring the arcuate edge 292 into engagement with the notches 248a as shown in
Another alternative arrangement of an orthodontic bracket 220′ is shown in FIGS. 18 to 20. In this embodiment, like reference numerals will be used to indicate like components of the embodiment of FIGS. 12 to 15 with the suffix “′” added for clarity. In this embodiment, the locking shutter 224′ is relieved and is generally C-shaped to provide a pair of arms 264′ and 266′. Similar to the previous embodiment, the locking shutter 224′ is pivotally secured to a boss 290′ extending between the gingival tie wings 236′ by way of a pivot pin 268′. A dimple 274′ is provided on both gingival tie wings 236′. Indentations 272′ on the arms 264′ and 266′ co-operate with the dimples 274′ with the detent formed between the indentations and dimples maintaining the locking shutter 224′ in the open position. The notches 248′ define deflection surfaces to inhibit labial movement of the shutter 224′ and its removal from the archwire slot 240′ when the shutter 224′ is in the closed position and an archwire applies a labially directed force to the shutter. In order to move the shutter from the open to closed position, it is necessary to overcome the detent provided by the indentations 272′ and the dimples 274′ and pivot the shutter 224′ about the pivot pin 268′.
In embodiments of the orthodontic brackets illustrated in FIGS. 12 to 20, it will be observed that movement of the locking shutter between open and closed positions is obtained by simple rotation of the locking shutter about the pivot pin so that the locking shutter remains captive to the body but at the same time is securely held in the closed and/or open positions by the action of the detent formed between the indentations and dimples.
A further embodiment of an orthodontic bracket is shown in FIGS. 21 to 24, in which like reference numerals will be used to denote like components of the embodiment of FIGS. 12 to 15 with a suffix ‘c’ added for clarity. As can be seen, a circular track 500 is formed on the mesial, distal, occlusal and gingival sides of the orthodontic bracket 220c. The circular track 500 passes through the occlusal and gingival tie wings 234c and 236c respectively to intersect the archwire slot 240c. Bores 501 are formed in the circular tracks 500 in the mesial and distal sides of the gingival tie wings 236c slightly above the archwire slot 240c. The archwire slot 240c is offset occlusally so that the gingival tie wings 236c are longer than the occlusal tie wings 234c .
The track 500 receives a shutter in the form of a part circular clip 502 having a circular protrusion 504 at one end. The clip 502 is slidable in the track 500 but provides a friction grip against the track to inhibit unintentional movement. The circular protrusion 504 is accommodated by one of the bores 501 to hold the clip 502 in either the closed or open positions.
The clip 502 may be rotated in the track 500 between an open position in which access to the archwire slot 240c is available (see
A still further embodiment of an orthodontic bracket 220b is shown in FIGS. 25 to 27 in which like reference numerals will be used to denote like components of the embodiment of FIGS. 12 to 15, with a suffix “b” added for clarity. As can be seen, the shutter 224b is slidable within a slot 510 formed in each of the occlusal wings 234b. A U-shaped strap 512 is secured to the labial face of shutter 224b and extends through a guide slot 514 and a washer 515 in the base of each of the slots 510. A coil spring 516 is positioned in each slot beneath the shutter 224b and surrounds each arm 512a of the strap 512. The arms 512a are cranked slightly above the coil springs 516 toward the archwire slot 240b as indicated to by reference numeral 518. The springs 516 bias the shutter 224b to a closed position in which the gingival edge 250b of the shutter 224b engages the notches 248b.
The labial surface of the shutter 224b carries a wedge 520 that cooperates with a complementary recess 522 formed in the slots. The wedge 520 retains the shutter 224b in the open position and may be released by application of a force to the bight 512b of the strap 512 to release the shutter 224b under the action of the springs 516. The shutter 224b is thus retained in the closed position to resist labial movement of an archwire 242b in the archwire slot 240b. The spring loaded shutter 224b may also be applied in a similar manner to two single orthodontic brackets or a 3 wing orthodontic bracket.
A still further embodiment of an orthodontic bracket 220d is shown in FIGS. 28 to 31 where like reference numerals will be used to indicate like components of the embodiment illustrated in FIGS. 12 to 15 with the suffix “d” added for clarity. In this embodiment, grooves 530 are formed in the mesial and distal sides of the body 222d. Each groove 530 extends through the gingival and occlusal tie wings 236d and 234d. The grooves 530 terminate in blind bores 532 in the gingival tie wings 236d. Blind bores 534 are also formed in the grooves 530 in the occlusal tie wings 236d adjacent the archwire slot 240d (see
A shutter 224d in the form of a generally U-shaped clip 538 is formed with a pair of outer arms 540 interconnected by a lateral bight 542. The ends of the arms 540 are formed with inwardly-directed projections 544 for receipt within the bores 532 or 534.
A support arm 546 is secured to the lateral bight 542 and is jogged to provide a horizontal arm 546a between a pair of vertical arms 546b and 546c respectively. One of the vertical arms 546c is received within a vertical slot 548 in the body 220d and maintains alignment of the clip 538 as it is moved between the open and closed positions. The slot 548 is located in the interwing region of the body 222d to provide uniform support.
The clip 538 is assembled on the orthodontic bracket 220d so that the arms 540 are received within the respective grooves 530. The projections 544 are received within the blind bores 534 so that the archwire slot 240d is open for receipt of an archwire as shown in
A further embodiment of an orthodontic bracket 220e is shown in FIGS. 32 to 36. In this embodiment like reference numerals will be used to denote like components of the embodiment of FIGS. 12 to 15 with a suffix “e” added for clarity. In the embodiment of FIGS. 32 to 36, grooves 560 are formed in the occlusal tie wings 234e only. The shutter 224e includes side flanges 562 that have inwardly directed protrusions 564 to engage the grooves 560. The shutter 224e has a pair of lingually angulated occlusal arms 264e and 266e and a centrally positioned gingival arm 566 defined partly by a pair of slits 568 in the shutter 224e (best seen in
In a further embodiment shown in
Referring now to FIGS. 38 to 41, still yet another embodiment of an orthodontic bracket is shown. In this embodiment, like reference numerals will be used to denote like components of the embodiment of FIGS. 12 to 15 with a “1000” added for clarity. As can be seen, the orthodontic bracket 1220 is similar to one of the orthodontic brackets disclosed in Applicant's U.S. Pat. No. 5,474,445 issued on Dec. 12, 1995, the contents of which are incorporated herein by reference. In this embodiment, a projection 1001 is formed on the gingival surface 1003 of the body 1222 in the interwing region. The shutter 1224 generally resembles a cruciform and has a gingival arm 1005 with an inverted doghouse shaped aperture 1267 in it to accommodate the projection 1001 and retain the shutter 1224 in the closed position. The shape of the aperture 1267 also permits a tool to enter the aperture so that a labially directed force can be applied to the shutter 1224 using the tool to release the shutter 1224 from the projection 1001. The mesial and distal arms 1007 and 1009 respectively of the shutter 1224 curve lingually into the archwire slot 1240. The arms 1007 and 1009 are resilient and are somewhat flattened when contacting a full dimension rectangular archwire 1242 accommodated in the archwire slot 1240 to apply a bias to move the archwire 1242 into the base of the archwire slot. In this way, a continuous rotation action and torque is applied to the archwire whether round or rectangular (even where that archwire is of relatively small cross-sectional dimension) to apply a continuous force to the tooth through the orthodontic bracket 1220. The occlusal arm 1011 of the shutter 1224 curves labially to define a single loop which surrounds a pivot pin 1013 to secure the shutter 1224 to the orthodontic bracket 1220 and to provide a shutter with a continuous smooth lingual surface.
A similar arrangement of an orthodontic bracket 2220 to that described above is shown in FIGS. 42 to 45. In this embodiment, like reference numerals will be used to denote like components of the embodiment of FIGS. 12 to 15 with a “2000” added for clarity. As can be seen, the orthodontic bracket 2220 also has a shutter 2224 generally resembling a cruciform. The gingival arm 2005 of the shutter 2224 has a doghouse shaped aperture 2267 in it to accommodate a projection 2001 and retain the shutter 2224 in the closed position. Unlike the previous embodiment, the mesial and distal arms 2007 and 2009 on the shutter 2224 are relatively rigid. A spring member in the form of a ribbon 700 is located on the lingual surface of the shutter 2224 and extends mesiodistally. The ribbon 700 is configured to provide a pair of convex lingually extending formations 702 that are aligned with the occlusal and gingival tie wings at opposed mesial and distal sides of the body 2222 and thus bear against an archwire 2242 located in the archwire slot 2240. The central portion 704 of the ribbon 700 is secured to the shutter 2224 with the lateral extremities 706 of the ribbon being free to slide horizontally over the lingual surface of the shutter 2224 and thereby allow flexure of the formations 702. In this manner, different thicknesses of archwires 2242 can be accommodated by the orthodontic bracket 2220 while still ensuring that a continuous force is applied to the tooth through the orthodontic bracket.
Referring now to FIGS. 48 to 52, still yet another embodiment of an orthodontic bracket 3220d is shown similar to that shown in FIGS. 28 to 31. In this embodiment, like reference numerals will be used to denote like components of the embodiment of FIGS. 28 to 31 with a “3000” added for clarity. As can be seen, the orthodontic bracket 3220d can be modified to provide a continuous seating action bias to an archwire accommodated in the archwire slot. In this arrangement, a spring member in the form of a resilient shim 720 is attached to the vertical arm 3546b of the support arm 3546. The shim 720 thus projects gingivally from the labial edge of the horizontal arm 3546a so as to be spaced from the lingual vertical arm 3546c. The shim 720 has a jog directed lingually toward the archwire slot 3240d and presents a generally convex surface 722 towards the archwire slot 3240d. The gingival edge 724 of the shim 720 recurves labially.
As the arms 3540 slide within the slots 3530 to the move the clip 3538 to a closed position as shown in
Referring now to FIGS. 53 to 55, still yet another embodiment of an orthodontic bracket 4220 is shown similar to that shown in FIGS. 12 to 15. In this embodiment, like reference numerals will be used to denote like components of the embodiment of FIGS. 12 to 15 with a “4000” added for clarity. As can be seen, the orthodontic bracket 4220 can be modified to provide a continuous bias to an archwire accommodated in the archwire slot. In this embodiment, a spring member in the form of a resilient shim 730 is secured to the lingual surface of the shutter 4224 adjacent the interwing region of the body 4220. The shim 730 is integrally formed with the shutter 4224 and is folded lingually about the occlusal edge 4260 of the shutter between the arms 4264 and 4266 respectively. The shim 730 is curved lingually to present a generally convex surface 732 spaced from the shutter 4224 and its end 734 recurved to form a smooth lip engaged with the lingual face of the shutter 4224. The end 734 of the shim 730 is free to slide relative to the shutter 4224 when the convex surface 731 is flattened due to contact with an archwire 4242 in the archwire slot 4240. The shim 730 is thus able to continuously exert a corrective force upon different configurations of archwires 4242 within the archwire slot 4240 when the shutter 4224 is in the closed position.
Referring now to FIGS. 56 to 58, still yet another embodiment of an orthodontic bracket 5220b is shown similar to that shown in FIGS. 25 to 27. In this embodiment, like reference numerals will be used to denote like components of the embodiment of FIGS. 25 to 27 with a “5000” added for clarity. As can be seen, the orthodontic bracket 5220b can be modified to provide a continuous bias to an archwire accommodated in the archwire slot. In the arrangement shown, a spring member in the form of a resilient shim 740 is formed on the lingual face of the shutter 5224b in the archwire slot 5240b. The shim 740 is formed with a convex lingual surface 742 that engages an archwire 5242b when the shutter 5224b is in the closed position. The shim 740 is secured to the shutter 5224b adjacent its occlusal end only and therefore, the gingival end 744 of the shim 740 is free to slide relative to the shutter 5224b. In this manner, the shim 740 may flex to accommodate different sizes and shapes of archwires 5242b accommodated in the archwire slot 5240b to provide a continuous action on the archwire wire.
Referring now to FIGS. 59 to 62, still yet another embodiment of an orthodontic bracket 6220e is shown similar to that shown in FIGS. 32 to 36. In this embodiment, like reference numerals will be used to denote like components of the embodiment of FIGS. 32 to 36 with a “6000” added for clarity. As can be seen, the orthodontic bracket 6220e can be modified to provide a continuous bias to an archwire accommodated in the archwire slot. In the arrangement shown, a spring member in the form of a shim 750 is secured to the lingual surface of the shutter 6224e and presents a convex surface 752 toward the archwire slot 6240e to engage an archwire 6242b in the same manner as described above to provide a continuous action on the archwire wire. The gingival edge 754 of the shim is free to slide relative to the lingual surface of the shutter 6224e.
A continuously acting orthodontic bracket may also be provided with self-locking labial brackets such as those shown in U.S. Pat. No. 5,094,614 to Wildman, the contents of which are incorporated herein by reference. As shown in FIGS. 63 to 71, the orthodontic bracket 7220 has a pair of wings 7242 with an archwire slot 7240 to receive an archwire 7242.
A shutter 7224 is located between the gingival and occlusal tie wings located at opposed mesial and distal sides of the body 7222 and includes a central body portion 7322 encompassed by a locking spring 7324. The mesial and distal edges of the shutter body 7322 are received within grooves 7326 so that the shutter 7224 may slide between open and closed positions. The grooves 7326 have undercuts 7328 that terminate at steps 7330 in the occlusal and gingival tie wings 7234 and 7236 respectively. The steps 7330 receive one end of a spring 7324. The opposite ends are formed as an occlusal tail. A spring member in the form of a resilient shim 760 is secured to the tail 7332 so as to be spaced from the retaining spring 7324. A lingual step 7235 accommodates the shim 760 from a lingual aspect. The shim 760 thus engages an archwire 7242 in the archwire slot 7240 when the shutter 7224 is in the closed position in a resilient manner to provide a continuous biasing action against the archwire as shown in
Similarly, as shown in
An alternative arrangement for the shim 760 is shown in
A further modification of an existing orthodontic bracket 7220′ is shown in FIGS. 74 to 78 in which the orthodontic bracket known as the Damon bracket and shown in U.S. Pat. No. 5,439,378, the contents of which are incorporated herein by reference, is modified to provide a spring member in the form of a resilient shim 770 on the lingual surface of the shutter 7224′. Shutter 7224′ may be extended occlusally to accommodate the shim 770 which in this embodiment is formed by folding a continuous extension of the shutter 7224′ back upon itself. The shim 770 presents a convex surface 772 which enters the archwire slot 7240′ when the shutter 7224′ is in a closed position. One end 744 of shim 770 is free to slide relative to the shutter 7224′. In this manner, the shim 770 may flex to accommodate different sizes and shapes of archwires 7242′ accommodated in the archwire slot 7240′ to provide a continuous action on the archwire.
As those of skill in the art will appreciate, in the embodiments illustrated in FIGS. 38 to 78, the spring member may be formed as a separate member and attached to the shutter adjacent either its gingival or occlusal ends in a manner so that it extends into the archwire slot to bias the archwire. Alternatively, the spring member may be integrally formed with the shutter by a folding portion of the shutter about an edge. If the spring member is to be integrally formed with the shutter, a continuous extension of the shutter is typically folded about either a gingival or occlusal edge of the shutter and is configured so that it extends into the archwire slot to bias the archwire.
Referring now to FIGS. 79 to 82, still yet another embodiment of an orthodontic bracket 8220 is shown similar to that shown in
Dimples (not shown) are formed on each of the gingival tie wings 8236a and corresponding indentations 8272a are formed on the locking shutter 8224a. The dimples and indentations 8272a cooperate when the locking shutter 8224a is either in the open or closed positions to retain the locking shutter in that position. An aperture 8267a is provided in the shutter 8224a to receive a tool and facilitate movement of the shutter 8224a. The locking shutter 8224a can be pivoted about pivot pin 8268a so as to bring the shutter 8224a into engagement with the archwire 8242a in the archwire slot 8240a as shown in
Another embodiment of an orthodontic bracket 9220 utilizing an alternative shutter structure is shown in FIGS. 83 to 87. In this embodiment, like reference numerals will be used to denote like components of the embodiment of FIGS. 12 to 15 with a suffix ‘9000’ added for clarity. As shown in FIGS. 83 to 87, the shutter 9224 is pivotal and is formed from a wire 9001 bent into a generally cruciform outline. The wire 9001 has opposite ends that are turned over to provide oppositely-directed tails 9003 and 9005. The tails 9003, 9005 extend parallel to a common axis but are offset from one another.
Each of the tails 9003, 9005 is received in a respective bore 9007 formed in each of the occlusal tie wings 9234. The tails 9003, 9005 are free to rotate within the respective bores to permit pivotal movement of the shutter 9224.
The wire 9001 defines a pair of oppositely-directed arms 9009, 9011 which extend across the archwire slot 9240. A horizontal recess 9013 is formed in each of the gingival tie wings 9236 adjacent the archwire slot 9240 to provide an abutment surface to limit pivotal movement of the shutter 9224 towards the archwire slot 9240.
The wire 9001 between the arms 9009, 9011 is formed into a rearwardly-projecting hook 9015 as can best be seen in
As shown in
A further embodiment of an orthodontic bracket 9220′ utilizing a wire for a shutter 9224′ is shown in
The wire 9001′ between the arms 9009′, 9011′ is formed as an elongate U-shaped projection 9020 and is received within a locking clip 9022. As can best be seen in
Referring now to
Referring now to
Within the archwire slot 10020 is a slot activator in the form of a generally rectangular, resilient spring member 10032 formed of suitable material such as for example Nickel-Titanium or spring stainless steel. The spring member 10032 extends mesiodistally along the archwire slot. The spring member 10032 has a central portion 10034 secured to the lingual wall of the archwire slot 10020 such as for example by way of a weld 10036 or a sleeve (not shown). Opposed ends of the spring member 10032 curve labially towards the locking shutter 10024 to define protrusive mesial and distal wings 10038 and 10040. The mesial and distal wings 10038 and 10040 of the spring member 10032 extend into the archwire slot 10020 starting from the lingual wall of the archwire slot a distance equal to approximately one third to one half of the depth of the archwire slot. The archwire slot 10020 formed in the body 10012 is mildly deeper than in conventional orthodontic brackets to accommodate the thickness of the central portion 10034 of the spring member 10034.
In use, when an archwire 10022 is placed into the archwire slot 10020 and the locking shutter 10024 is closed, the mesial and distal wings 10038 and 10040 of the spring member 10032 contact the archwire 10022 to bias it towards the locking shutter 10024. As shown in
Referring now to
Although the distal end of the spring member 10132 is shown attached to the body, it should be apparent to those of skill in the art that the mesial end of the spring member 10132 may be secured to the body with the distal end of the spring member 10132 being free. The length of the spring member 10132 is less than the length of the archwire slot 10120 so that the free end of the spring member remains in the archwire slot when the spring member 10132 is partially flattened by a large rectangular archwire accommodated by the archwire slot.
The orthodontic bracket 10110 functions in a similar manner to the previous embodiment. When a small round archwire is placed in the archwire slot 10120 and the locking shutter (not shown) is closed, the convex spring member 10132 biases the archwire 10122 towards the locking shutter. When a large rectangular archwire 10122 is placed in the archwire slot 10120, the spring member is only partially flattened and biases the archwire towards the locking shutter.
Referring now to
Referring now to
Referring now to
In this embodiment, the locking shutter 10524 includes a single loop adjacent one end to surround a pivot pin 10580 extending between the occlusal tie wings 10518. A hole 10582 is provided in the locking shutter 10524 and co-operates with a pair of spaced projections 10584 extending upwardly from the gingival surface of the body in the interwing region of the orthodontic bracket. Each projection 10584 includes a head 10586 and an undercut stem 10588 supporting the head above the gingival surface of the body. The projections 10584 are spaced a distance slightly greater than the diameter of the hole 10582 so that the heads 10586 must be compressed towards one another to fit into the hole. The undercut stems 10588 allow the projections 10584 to snap back to their original positions once the heads have passed through the hole 10582 thereby to lock the shutter 10524 in place in a closed position.
Referring now to
Referring now to
The slot activator in the embodiment is in the form of a pair of spring members 10832. The spring members extend labially along the mesial and distal sides of the body 10812 and contact an archwire 10822 accommodated by the archwire slot 10820 exterior to the archwire slot but near the mesial and distal sides of the body 10812. The spring members 10832 are secured to the body by welds and contact the archwire at a lateral angle greater than 90 degree to facilitate flattening of the spring members 10832 when a large rectangular archwire is accommodated by the archwire slot.
In the embodiment illustrated in
Referring now to
In the closed condition, the locking shutter 10924 is biased by the spring 10985, which acts on the pivot pin 10980, into notches 10987 formed in the occlusal surfaces of the gingival tie wings 10916. When it is desired to release the locking shutter 10924 and move it to an open condition, it is necessary to apply an occlusally directed force on the locking shutter to compress the spring 10985 and move the locking shutter occlusally allowing the gingival end of the locking shutter to clear the notches 10987 and pivot to the open condition. Closing the locking shutter is achieved by performing the above steps in reverse.
Referring now to
Referring now to
Referring now to
If desired, a lubricating or sealing agent can be applied to the body, locking shutter and/or archwire of the previously described orthodontic brackets.
The orthodontic brackets described above can be formed of any suitable material such as ceramic, plastic or other cosmetic material. If appropriate, the archwire slot may be constituted by a metallic insert accommodated by the body of the orthodontic bracket. Likewise in the case of the embodiment shown in
When the orthodontic brackets are to be used to form braces, it is preferred that pre-engaging twin orthodontic brackets of one of the types illustrated herein be used and attached to the central and lateral teeth and first and second molars and that single orthodontic brackets without wings (not shown) be used and applied to the cuspid and premolar teeth. This system of orthodontic brackets provides advantages in that the nature of the single orthodontic brackets are easier to bond to the posterior crowns of the cuspid and premolar teeth. Also, the single orthodontic brackets provide greater interbracket distances allowing for greater archwire flexibility in the posterior middle regions, cuspids and premolars. Better rotational control is however maintained with the use of the twin preengaging orthodontic brackets on the central and lateral teeth and first and second molars.
Although a number of embodiments of orthodontic brackets have been disclosed, those of skill in the art will appreciate that other variations and/or modifications may be made to the present invention without departing from the scope thereof as defined by the appended claims.
Claims
1. An orthodontic bracket comprising:
- a body including a lingual surface for attachment to a tooth and having an archwire slot;
- at least two tie wings extending from the body and defining a space directly therebetween; and
- a locking shutter having a stem, a portion of the stem being positioned in the space directly between the tie wings, the locking shutter being movable between an open position, in which access to the archwire slot is permitted, and a closed position, in which access to the archwire slot is inhibited.
2. An orthodontic bracket as claimed in claim 1, wherein the tie wings are gingival tie wings.
3. An orthodontic bracket as claimed in claim 3, further comprising at least two occlusal tie wings.
4. An orthodontic bracket as claimed in claim 1, wherein the shutter further includes an arm coupled to the stem, wherein the arm is wider than the stem to form a T-shaped locking shutter, and wherein the arm is positioned in the archwire slot when the locking shutter is in the closed position.
5. An orthodontic bracket as claimed in claim 4, wherein the arm includes an end having a labial surface that is concave.
6. An orthodontic bracket as claimed in claim 1, wherein the archwire slot includes a notch, and wherein the shutter includes an end that is positioned in the notch when the shutter is in the closed position.
7. An orthodontic bracket as claimed in claim 6, wherein the notch is a first notch, and wherein the body and the tie wings collectively form a second notch in the labial surface that extends mesio-distally across the body substantially the same length as the archwire slot.
8. An orthodontic bracket as claimed in claim 1, wherein the locking shutter is pivotally coupled to the body.
9. An orthodontic bracket comprising:
- a body including a lingual surface for attachment to a tooth and having an archwire slot;
- at least two tie wings extending from the body and defining a space directly therebetween; and
- a locking shutter having a stem, a portion of the stem being positioned in the space directly between the tie wings, the stem being movable between an open position, in which access to the archwire slot is permitted, and a closed position, in which access to the archwire slot is inhibited, wherein the shutter includes an end that is positioned in the archwire slot when the shutter is in the closed position, the end including a labial surface that is concave about an axis that is parallel to a mesio-distal axis.
10. An orthodontic bracket as claimed in claim 9, wherein the tie wings are gingival tie wings.
11. An orthodontic bracket as claimed in claim 10, further comprising at least two occlusal tie wings.
12. An orthodontic bracket as claimed in claim 9, wherein the shutter further includes an arm coupled to the stem, wherein the arm is wider than the stem to form a T-shaped locking shutter, and wherein the arm is positioned in the archwire slot when the locking shutter is in the closed position.
13. An orthodontic bracket as claimed in claim 9, wherein the archwire slot includes a notch, and wherein the end of the shutter is positioned in the notch when the shutter is in the closed position.
14. An orthodontic bracket as claimed in claim 13, wherein the notch is a first notch, and wherein the body and the tie wings collectively form a second notch in the labial surface that extends mesio-distally across the body substantially the same length as the archwire slot.
15. An orthodontic bracket as claimed in claim 9, wherein the locking shutter is pivotally coupled to the body.
16. An orthodontic bracket comprising:
- a body including a lingual surface for attachment to a tooth and having an archwire slot having a sidewall;
- a notch formed into the sidewall of the archwire slot and extending mesio-distally across the body substantially the same length as the archwire slot;
- at least two tie wings extending from the body and defining a space directly therebetween; and
- a locking shutter having a stem, a portion of the stem being positioned in the space directly between the tie wings, the stem being movable between an open position, in which access to the archwire slot is permitted, and a closed position, in which access to the archwire slot is inhibited, wherein the shutter includes an end that is positioned in the notch when the shutter is in the closed position.
17. An orthodontic bracket as claimed in claim 16, wherein the tie wings are gingival tie wings.
18. An orthodontic bracket as claimed in claim 17, further comprising at least two occlusal tie wings.
19. An orthodontic bracket as claimed in claim 16, wherein the shutter further includes an arm coupled to the stem, wherein the arm is wider than the stem to form a T-shaped locking shutter, and wherein the arm is positioned in the archwire slot when the locking shutter is in the closed position.
20. An orthodontic bracket as claimed in claim 16, wherein the locking shutter is pivotally coupled to the body.
Type: Application
Filed: Aug 4, 2006
Publication Date: Nov 30, 2006
Inventor: John Voudouris (Toronto)
Application Number: 11/462,412
International Classification: A61C 1/00 (20060101); A61C 13/38 (20060101);