Patent Publication Number: US-2012040302-A1

Title: Self-ligating non-metalic orthodontic bracket

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit under Title 35, United States Code §119(e) of U.S. Provisional Application No. 61/280,182 filed on Oct. 29, 2009. 
    
    
     FIELD OF THE INVENTION 
     The following invention relates to orthodontic brackets, and in particular self-ligating orthodontic brackets which hold an arch wire adjacent thereto. 
     BACKGROUND OF THE INVENTION 
     The science of orthodontics relies on a variety of different appliances for applying forces to the teeth to move them to more optimal positions. One common orthodontic appliance is known as a bracket. Multiple brackets are typically bonded temporarily to surfaces of the teeth. Wires, often including an “arch wire,” pass adjacent the multiple brackets, typically through channels in the brackets. Ends of the arch wire are anchored to some of the teeth and the arch wire can be tensioned to increase tension on the arch wire and apply forces to the teeth adjacent to the brackets and arch wire. 
     To keep the arch wire or other wire within the channel of the bracket, or otherwise adjacent the bracket, some brackets, known as self-ligating brackets, include fasteners for capturing the arch wire adjacent the brackets and within the channel of the bracket or otherwise adjacent the bracket. Such fasteners, often called clips, are known in the prior art which are coupled to the bracket and capture the arch wire to the bracket. U.S. Pat. No. 7,585,171 is directed to an orthodontic bracket with rotary ligating cover which is illustrative of one form of self-ligating bracket known in the prior art. U.S. Pat. No. 7,192,274 teaches a ceramic orthodontic appliance with arch wire slot liner which liner acts as a form of ligating cover for holding the arch wire to the bracket. Beneficially, such clips or other fasteners allow the arch wire to slide relative to the bracket but keep the arch wire from popping out of the channel or otherwise translating away from the bracket. U.S. Pat. Nos. 7,585,171 and 7,192,274 are incorporated by reference herein in their entirety. 
     Often an important consideration in the wearing of orthodontic appliances is that the appearance of the appliance wearer not be excessively negatively impacted by the wearing of the brackets or other orthodontic appliances associated with the brackets. One technique for minimizing the appearance of the brackets is to form them out of transparent or translucent materials, or out of materials which are generally a similar color as the teeth. Such brackets can be formed of plastic or can be formed of other materials. One material often utilized is sapphire (aluminum oxide), also referred to as mono-crystalline brackets. Various different forms of aluminum oxide including sapphire can beneficially be utilized. A problem with many brackets having such a desirable non-metallic appearance is that ligating techniques for self-ligating brackets are not generally effective when formed of the rigid and brittle materials such as those forming mono-crystalline brackets. While flexible metal clips can conceivably be utilized to hold the arch wire adjacent the bracket, such metallic structures undermine the purpose of utilizing the mono-crystalline bracket material in the first place, namely minimizing the appearance of metal on the teeth of the wearer. 
     U.S. Pat. No. 7,192,274 illustrates one attempt at effectively holding the arch wire to a ceramic bracket while minimizing the utilization of metallic capturing materials. However, the complexity of this prior art ceramic self-ligating bracket as well as the potential for arch wire separation would benefit from improvement. Most particularly, the self-ligating bracket is preferably configured in such a way as to minimize the appearance of metal while also providing a secure anchoring of the arch wire to the bracket, preferably in a way that allows movement of the arch wire in direction relative to the bracket, but keeping the arch wire from translating entirely away from the bracket. 
     SUMMARY OF THE INVENTION 
     With this invention a self-ligating bracket is provided which can hold an arch wire adjacent the bracket and capture the arch wire adjacent the bracket while still allowing the arch wire to slide relative to the bracket.  FIGS. 1-3  reveal a preferred embodiment with  FIGS. 1 and 2  depicting the arch wire in position adjacent the bracket (having been slid into a primary channel of the bracket along arrow A ( FIG. 2 )). In  FIG. 1  a retainer clip has bee closed to secure the arch wire to the bracket. In  FIG. 2  the retainer clip is shown during rotation (along arrow B) from an open position toward a closed position where a latch bar snaps over posts or is otherwise bent over posts to secure the retainer clip over the arch wire. 
     As best shown in  FIG. 3 , the entire retainer clip is allowed to rotate from an open position ( FIGS. 2 and 3 ) to a closed position ( FIG. 1 ). To allow such rotation, a portion of the retainer clip is in the form of an axle which passes through a tube. This tube resides within a groove at a bottom of the channel within the bracket. The tube can be formed of a metal material and will not be visible because it is directly behind the arch wire. The tube is hollow and the retainer clip has the axle preferably continuous through the tube to ensure that the retainer clip cannot be separated from the bracket and holds the arch wire to the bracket. Arms of the retainer clip extend from the axle and come together at a latch bar. This latch bar can pass over the posts, such as by snapping or by being bent around the posts, to hold the retainer clip to the bracket. 
     The retainer clip is preferably made of stainless steel and has dimensions and material properties (including an elastic limit and ultimate strength) associated with the material forming the retainer clip sufficient to hold the arch wire adjacent the bracket. In particular, either the retainer clip can be dimensioned so that forces applied thereto do not exceed the elastic limit thereof so that the stainless steel can snap resiliently with the latch bar snapping over the posts, or the elastic limit of the material forming the retainer clip can be exceeded but not the ultimate strength, so that the retainer clip does not break but is merely bent to pass over the posts and then is bent into position beneath the posts to hold the retainer clip to the bracket. With either technique, either associated with materials selected for the forming of the retainer clip, or by selection of a diameter for the material forming the retainer clip, effective attachment of the arch wire is achieved. 
     Other materials besides stainless steel could also be utilized for the retainer clip including titanium or titanium alloys, or other metals, preferably of a biocompatible nature. If generally non-biocompatible metals are utilized, the metals could conceivably be coated with a biocompatible coating. Any material currently in existence or developed in the future which has suitable strength and biocompatibility characteristics to function as the retainer clip could conceivably be utilized according to this invention. 
     While the bracket shown in  FIGS. 1-3  is most preferred, brackets of a variety of different known geometries could be utilized according to this invention. Typically, such brackets have a channel into which the arch wire is placed. For brackets with such a channel, most preferably the tube is located in a groove at the bottom of the channel. If arch wires did not include such a channel, the tube could be otherwise formed or attached on any portion of the bracket. The tube, being formed of metal, is typically bonded to the bracket utilizing known techniques for bonding metals to ceramics. For instance, when the tube is formed of stainless steel and the bracket is formed of mono-crystalline aluminum oxide known bonding materials can be painted onto the tube and bracket interface and heated to cure the bonding agent and secure the tube to the bracket. While the bracket is shown with multiple posts on each side of the bracket, brackets having other configurations could also be utilized. 
     In  FIGS. 4 and 5  two alternative bracket configurations are shown. In  FIG. 4 , a second alternative bracket is shown which differs from the embodiment of  FIGS. 1-3  in that rather than placing the slot below the channel and utilizing a tube through which the axle passes, a bore is formed in the bracket and the axle passes through this bore in the bracket. This bore could go entirely through the bracket or could be a blind bore stopping short within the bracket. Most preferably, the retainer clip forms a continuous circuit to minimize the possibility of it becoming dislodged. As an alternative, the bore could be sufficiently deep but not entirely through the bracket and the axle could extend sufficiently far into the bore that displacement of the retainer clip axle from the bore is precluded. 
     In  FIG. 5  an alternative bracket is depicted which has a bore passing entirely through the first alternative bracket. In this first alternative bracket, the bore is shown continuous through the first alternative bracket and the axle is shown continuous passing through this bore. Also, the position of the bore relative to the channel is somewhat different in  FIG. 5  relative to  FIG. 4 . Other orientations for the bore or tube could be provided relative to the bracket with either an axle of the retainer clip passing entirely through the tube or with the axle terminating at ends within the tube or within a bore. In either event a pivoting joint is provided for coupling the retainer clip to the bracket in a manner allowing the retainer clip to rotate relative to the bracket between an open position and a closed position. In the closed position the arch wire is effectively captured adjacent the bracket while allowing the arch wire to slide relative to the bracket. 
     OBJECTS OF THE INVENTION 
     Accordingly, a primary object of the present invention is to provide an orthodontic bracket which includes a retainer clip for retaining an arch wire adjacent the orthodontic bracket. 
     Another object of the present invention is to provide an orthodontic bracket of a self-ligating nature. 
     Another object of the present invention is to provide a method for holding an arch wire adjacent an orthodontic bracket. 
     Another object of the present invention is to provide a non-metallic orthodontic bracket which is self-ligating in nature. 
     Another object of the present invention is to provide a non-metallic orthodontic bracket which includes a retainer clip for holding an arch wire adjacent the non-metallic orthodontic bracket. 
     Another object of the present invention is to provide a low visibility orthodontic bracket. 
     Another object of the present invention is to provide a low visibility non-metallic orthodontic bracket with metallic portions hidden behind an arch wire path. 
     Another object of the present invention is to provide an orthodontic bracket which lends itself to ready manufacture utilizing known techniques. 
     Other further objects of the present invention will become apparent from a careful reading of the included drawing figures, the claims and detailed description of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an orthodontic bracket according to a preferred form of this invention with a retainer clip thereof in a closed position holding an arch wire along an arch wire path within a primary groove of the bracket. 
         FIG. 2  is a perspective view similar to that which is shown in  FIG. 1  but with the retainer clip in an open position. 
         FIG. 3  is a perspective view of the orthodontic bracket of  FIG. 1  shown without the arch wire and with the retainer clip in an open position. 
         FIG. 4  is a perspective view of an alternative embodiment of that which is shown in  FIG. 1  and from a reverse point of view and with a retainer clip thereof shown in a closed position. 
         FIG. 5  is a perspective view of a second alternative bracket to that which is shown in  FIG. 1  with a retainer clip shown in a closed position. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, wherein like reference numerals represent like parts throughout the various drawing figures, reference numeral  10  ( FIG. 1 ) is directed to a bracket for attachment to a tooth surface for use in orthodontic procedures including holding of an arch wire W in a desired position adjacent the tooth and adjacent teeth. The bracket  10  is of a type which is self-ligating in that it is itself configured with a retainer clip  50  for holding the arch wire W along an arch wire path adjacent to the bracket  10 . Many features of the bracket  10  are particularly configured for use when the bracket  10  is formed of a non-metallic material, such as a ceramic material, and particularly for instance aluminum oxide. 
     In essence, and with particular reference to  FIG. 3 , basic details of the bracket  10  are described according to a most preferred embodiment. The bracket  10  is a unitary mass of material extending from a base surface  12  to an outer surface opposite the base surface  12 . The bracket  10  includes at least one post  20 , and preferably a plurality of posts  20  extending from sides of the bracket  10  which are generally oriented facing vertically upward and downward when the bracket  10  is mounted on a tooth outer surface. Side surfaces of the bracket  10  are preferably defined by end walls  24 . 
     A primary channel  30  extends into the outer surface and between the pair of end walls toward the base surface  12 . This primary channel  30  is sized to receive an arch wire W therein ( FIG. 1 ). A secondary channel  40  can optionally be provided intersecting the primary channel  30  and defining a space between multiple posts  20 . 
     A retainer clip  50  is pivotably attached to the unitary mass of material forming the bracket  10 . The retainer clip  50  includes an axle  52  which interfaces with an axle support, preferably in the form of a tube  60 . The retainer clip  50  also includes arms  54  extending from the axle  52  and preferably joined together by a latch bar  56 . The tube  60  preferably resides within a lower groove  32  within a portion of the primary channel  30  spaced from the outer surface of the bracket  10 . The retainer clip  50  can thus move between an open position and a closed position to selectively secure the arch wire within the primary channel  30  and along the arch wire path. 
     More specifically, and with continuing reference to  FIG. 3 , details of the unitary mass of material forming the bracket  10  are described, according to this most preferred embodiment. The unitary mass of material can be formed of a variety of different materials and is preferably a solid mass of a single homogenous material. In a preferred form of this invention the material is ceramic and most preferably aluminum oxide in a particular composition and in a substantially mono-crystalline form which can be characterized as sapphire. In such a form, the bracket  10  can be at least partially translucent and hence less noticeable when mounted to teeth. The ceramic material could also be poly-crystalline. As an alternative, the unitary mass of material could be some other material (e.g. metal or plastic) and still function according to this invention. Material suitable for forming the bracket  10  include those materials known in the prior art and in the future developed suitable for use as orthodontic bracket material. 
     The unitary mass of material is preferably formed to have various different external features. A substantially planar base surface  12  defines a side of the bracket  10  configured for attachment to a surface of a tube. In particular, the base surface  12  is typically bonded to the tooth surface using some form of known orthodontic bracket  10  attachment adhesive. The base surface  12  can be entirely planar or slightly curved to more readily match the curvature of the tooth. Lower slots  14  are preferably provided in the base surface  12 . 
     A pair of side channels  16  are preferably provided on upper and lower sides of the bracket  10  spaced a substantially constant distance away from the base surface  12  and at an intermediate location between the base surface  12  and the outer surface. These side channels  16  define one side of each post  20  to facilitate attachment of various different orthodontic structures to the post  20 . These two side channels  16  can have a similar depth or can have varying depths. At least one of the side channels  16  can provide a further function of seating a latch bar  56  portion of the retainer clip  50  when the retainer clip  50  is in a closed position as described in detail below. 
     The embodiment of  FIG. 3  shows the bracket  10  with four separate posts  20  above the side channel  16  and adjacent the outer surface of the bracket  10 . These posts  20  are generally separated from each other by the primary channel  30  and the secondary channel  40 . It is conceivable that there would be merely one post  20  above and below the primary channel  30  or more than two posts  20  could be provided on each side of the primary channel  30 . The posts  20  generally include tips  22  at most distant portions of each post  20 . The posts  20  are also bounded on lateral sides thereof by end walls  24  which define overall lateral sides of the bracket  10 . The ends walls  24  are preferably substantially planar and parallel with each other, defining an overall width of the bracket  10 . The end walls  24  could be non-parallel also. 
     With continuing reference primarily to  FIG. 3 , details of the primary channel  30  formed in the unitary mass of material of which the bracket  10  is comprised, as well as the secondary channel  40 , are described according to a most preferred embodiment. The primary channel  30  provides a primary portion of an arch wire W path adjacent the bracket  10 . This primary channel  30  preferably extends in a planar fashion with a constant width partially down into the outer surface and toward the base surface  12 . This primary channel  30  has a width similar to a width of an arch wire W to be placed within the primary channel  30 . The primary channel  30  can be lined, such as with a metal liner or a glass liner to reduce friction with the arch wire W. 
     Most preferably, the primary channel  30  includes a lower groove  32  in a lowermost portion of the primary channel  30 . A step  34  provides a transition between a width of the primary channel  30  above the lower groove  32  and a width of the lower groove  32  itself. The lower groove  32  preferably has a curved floor  36 . Such a curved floor  36  avoids stress concentrations at the bottom of the primary channel  30  and also maximizes availability of a bonding surface for bonding of the tube  60  to the bracket  10  with the tube  60  located within the lower groove  32 . The floor could be contoured in a manner other than curved as well. The lower groove  32  extends below the primary channel  30  in a most preferred embodiment so the arch wire W can reside within the primary channel  30  above the lower groove  32 . As an alternative, the lower groove  32  could extend up from the base surface  12 , stopping just short of the primary channel  30  to position the tube  60  in a position close to where it is shown in  FIG. 3 . 
     A secondary channel  40  preferably is provided substantially perpendicular to the primary channel  30  and between the separate posts  20 . The secondary channel  40  is provided to separate the posts  20  from each other. If a single post  20  is provided on each side of the primary channel  30 , no secondary channel  40  would be needed. If more than two posts  20  are provided on each side of the primary channel  30 , multiple secondary channels  40  would be provided. The secondary channel  40  can have various different depths, and preferably tapers to have a greater depth adjacent the tips  22  of the posts  20  than adjacent the primary channel  30 . 
     With continuing reference primarily to  FIG. 3 , specific details of the retainer clip  50  are described, according to this most preferred embodiment. The retainer clip  50  is provided to secure (also referred to as “ligating”) the arch wire W adjacent the bracket  10  but allowing arch wire W sliding (along arrow D of  FIG. 1 ). This retainer clip preferably is in the form of a wire of metallic material having an elongate substantially constant circular cross-sectional form. This retainer clip  50  includes an axle  52 , arms  54  and a latch bar  56 . 
     The axle  52  defines at least one linear portion of the retainer clip  50  preferably having a length slightly greater than a width of the bracket  10  between the pair of end walls  24 . This axle  52  is preferably linear and with a diameter slightly less than a diameter of the tube  60  so that the axle  52  can reside within the tube  60 . 
     A pair of arms  54  are preferably provided, with each arm  54  adjacent one of the end walls  24 . As an alternative, conceivably a single arm  54  could be provided at only one end of the axle  52 . Each arm  54  can have a variety of different configurations including continuously curving configurations or a series of linear struts spaced apart by angular bends. In a most preferred form of the invention shown in the figures, the arms  54  are provided with a series of struts of linear form spaced apart by right angle bends. A first short strut extends perpendicular to the axle  52  and joined to the axle  52  by a first bend. A second bend then transitions this first strut into a second strut perpendicular to the first strut. A third bend then transitions the second strut into a third strut. A fourth bend then transitions the third strut into a fourth strut. A fifth bend then transitions the fourth strut into the latch bar  56 . 
     Preferably, each of the struts becomes progressively slightly longer. Preferably, each of the struts are oriented within a common plane perpendicular to the axle  52  and perpendicular to the latch bar  56 , with the axle  52  and latch bar  56  generally parallel with each other. Each of the bends in the arms  54  preferably bend in a common direction so that the arms  54  tend to spiral out away from the axle  52  and towards the latch bar  56 . The first and fifth bends bend the arms  54  out of the plane in which the arms  54  are formed and into the ends of the axle  52  and latch bar  56 . The fourth bend is most preferably bent slightly less than 90°. 
     As an alternative, the arms  54  could continuously spiral between ends thereof from the axle  52  ends to the latch bar  56  ends. Other configurations in the arms  54  could also be provided which generally provide for connection between the axle  52  and the latch bar  56  and provide for clearance to allow the arch wire W to pass along the arch wire path aligned with the primary channel  30  ( FIGS. 1 and 2 ). A single arm  54  could be provided alone, with or without the latch bar  56 . 
     The latch bar  56  and axle  52  preferably each join the two arms  54  together. The latch bar  56  preferably is spaced from the axle  52  by a distance similar to a distance that the tips  22  of the posts  20  extend from the primary channel  30 . By appropriately sizing the retainer clip  50 , the latch bar  56  can just snap over the tips  22  of the posts  20  when rotated (along arrow B of  FIG. 2 ) from the open position ( FIG. 2 ) to the closed position ( FIG. 1 ) where the latch bar  56  resides within the side channel  16 . 
     The retainer clip  50  can be formed of a variety of different materials to function according to this invention. In one form of the invention the retainer clip  50  is formed of stainless steel. In other embodiments, the retainer clip  50  is formed of other metals or other materials and provided with a biocompatible coating. In another embodiment, the retainer clip  50  is formed of titanium or a titanium alloy. 
     Mechanical properties of the retainer clip  50  can be selected to allow the retainer clip  50  to plastically deform and bend over the tips  22  of the posts  20  and then plastically deform into a seated position within the side channels  16  below the posts  20 . As another alternative, the retainer clip  50  can be formed of a material which can stretch elastically slightly to snap over the posts  20  without exceeding an elastic limit of the material forming the retainer clip  50 . 
     As another alternative, the retainer clip  50  can be formed of a nickel titanium alloy having a transition temperature between a temperature dependent higher strength solid phase and a lower strength solid phase and with a shape memory. In such a shape memory configuration, the retainer clip  50  can be cooled into a lower strength phase such as by applying a coolant to the retainer clip to soften the retainer clip. The retainer clip  50  can then be readily snapped off of the posts  20  and out of the side channel  16 , or vice versa. The transition temperature can be designed into the material so that at body temperatures the retainer clip  50  is in a higher strength phase so that the retainer clip  50  most completely resists undesired motion between the open and closed positions. when installed and positioned in use. 
     With continuing reference to  FIG. 3 , details of the tube  60  (defining a preferred form of axle support) is described according to a preferred embodiment of this invention. The tube  60  preferably has a hollow cylindrical shape with a constant circular cross-sectional form extending between ends and with a length similar to a distance between the two end walls  24 . This tube  50  preferably has an outer curvature similar to that of the curved floor  36  of the lower groove  32  within the primary channel  30 . As an alternative, the lower groove  32  could be formed on a lateral side of the primary channel  30  with the tube  60  still residing within such a lower groove  32  in such an alternative position. It is also conceivable that the tube  60  could merely be bonded within a lowermost portion of the primary channel  30  without providing the lower groove  32 . 
     The tube  60  is preferably formed of a metal material, such as stainless steel, or other suitable material. The tube  60  is sized to receive the axle  52  therein to act as an axle support. The tube  60  would typically be formed of a material different than the material forming the unitary mass of the bracket  10 , especially when the bracket  10  is a non-metallic bracket  10 . 
     The tube  60  can be bonded to the bracket  10  within the lower groove  32 , such as by using an adhesive suitable for bonding metal to ceramic. Other techniques for securing the tube  60  within the lower groove  32  or elsewhere include use of a frit (e.g. a glass powder that is fired to bond stainless steel or other metal to the ceramic); metallization (e.g. applying a coating to the ceramic to which the tube  60  can be brazed); or active metal brazing (e.g. where an appropriate flux material facilitates direct brazing of ceramic to metal). 
     Once attached to the bracket  10 , the tube  60  provides an axle support to allow the retainer clip  50  to be pivotably attached to the bracket  10 . This tube  60 , being formed of metal, typically has a more conspicuous appearance, especially relative to an at least partially translucent or naturally colored orthodontic bracket  10 . By positioning this tube  60  within the lower groove  30  in the bottom of the primary channel  30 , the tube  60  hides beneath the arch wire W ( FIGS. 1 and 2 ). Thus, this tube  60  is hidden and the overall impression of the bracket is that it is substantially invisible and only the arch wire and very small diameter retainer clip  50  can be seen. 
     The retainer clip  50  being a continuous loop, requires some special manipulation to install the retainer clip  50  within the tube  60  and adjacent the bracket  10 . In one form of the invention, the axle  52  is split at a midpoint thereof with each axle segment snapped into opposite ends of the tube  60 . As an alternative, the retainer clip  50  can be initially formed as a complete circuit, such as from a single piece of material, and then the tube  60  formed about the retainer clip  50  and then the tube  60  bonded to the bracket  10 . As another alternative, some other portion of the retainer clip  50  can be opened, such as a midpoint of the latch bar  56 , or at one of the bends or struts within one of the arms  54 . The opening can then be welded or use a fastener or adhesive to be closed. 
     The retainer clip  50  can start as a linear section of wire routed through the tube  60  and then be appropriately bent to form the bends and struts until the entire configuration for the retainer clip  50  has been provided. As another alternative, the retainer clip  50  can be provided as two separate arms  54  which do not connect together but are positioned with separate axles  52  residing within ends of a common tube  60  to provide two separate retainer clips one adjacent each of the end walls  24 . In such a configuration, the latch bar  56  could be eliminated. However, the latch bar  56  is preferred as it provides additional stability to the overall retainer clip  50  and secures the two arms  54  of the retainer clip  50  to discourage them from becoming displaced relative to the tube  60 . 
     With particular reference to  FIG. 4 , details of an alternative embodiment bracket  110  are described. This alternative bracket  110  is similar to the bracket  10  of the preferred embodiment ( FIGS. 1-3 ) except that the tube  60  is eliminated or provided with a separate location. In particular, a through-bore  160  ( FIG. 4 ) is provided extending between the two end walls  24  ( FIGS. 1-3 ) near the primary channel  30  but spaced from the primary channel  30 . A tube  60  can be provided as a sleeve within this through-bore  160 , or the tube  60  can be avoided. An axle  152  of the retainer clip  150  of this embodiment passes through the bore  160  rather than passing through the tube  60 . Dimensions of the various struts and bends within the retainer clip  150  are appropriately modified to accommodate this new position for the bore  160  as an alternative axle support with the alternative bracket  110  of this embodiment. Other details of this alternative bracket  110  are similar to those described above with regard to the bracket  10  ( FIGS. 1-3 ). 
     With particular reference to  FIG. 5 , a second alternative bracket  210  is described. This second alternative bracket  210  has two separate bore segments with each bore segment extending as a blind bore  260  into each of the end walls  24 . Each blind bore  260  is preferably substantially collinear with the other. The alternative bracket  210  includes an alternative retainer clip  250 . This alternative retainer clip  250  is preferably similar to the retainer clip  50  of the preferred embodiment ( FIGS. 1-3 ) except that the axle  52  of the preferred embodiment is replaced with a pair of axle segments  252  ( FIG. 5 ) which extend into each of the blind bores  260 . 
     With particular reference to  FIGS. 1 and 2 , details of the use and operation of the bracket  10  of the preferred embodiment of this invention are described, in a method of securing the arch wire W adjacent the bracket  10 . Initially, the bracket  10  is bonded to a surface of a tooth and the retainer clip  50  is positioned in an open configuration as depicted in  FIG. 2 . The arch wire W is then placed within the primary channel  30  by movement of the arch wire along arrow A of  FIG. 2 . 
     Next, the retainer clip  50  is rotated (about arrow B of  FIG. 2 ) from the open position to the closed position. The retainer clip  50  is snapped or otherwise deformed over the posts  20  so that the latch bar  56  snaps into the side channel  16  ( FIG. 1 ). The arch wire W is free to slide (along arrow D of  FIG. 1 ) relative to the bracket  10  but is restrained from displacement away from the bracket  10 . 
     This disclosure is provided to reveal a preferred embodiment of the invention and a best mode for practicing the invention. Having thus described the invention in this way, it should be apparent that various different modifications can be made to the preferred embodiment without departing from the scope and spirit of this invention disclosure. When structures are identified as a means to perform a function, the identification is intended to include all structures which can perform the function specified. When structures of this invention are identified as being coupled together, such language should be interpreted broadly to include the structures being coupled directly together or coupled together through intervening structures. Such coupling could be permanent or temporary and either in a rigid fashion or in a fashion which allows pivoting, sliding or other relative motion while still providing some form of attachment, unless specifically restricted.