PATENT ABSTRACT
A module for attaching an orthodontic bite corrector to an orthodontic buccal tube appliance includes two segments, and each segment includes a rotation stop for limiting undesired rotational movement of bite corrector during movement of the patient&#39;s jaws. The segments are movable relative to each other during installation of the attachment module for facilitating placement of the rotation stops in regions next to the buccal tube appliance that might otherwise be difficult to access.

PATENT DESCRIPTION
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 12/144,728, filed Jun. 24, 2008, which is a continuation-in-part application of U.S. application Ser. No. 11/831,445, filed Jul. 31, 2007. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an attachment module used in the course of orthodontic treatment. More particularly, the present invention is directed to an attachment module for connecting bite correctors, force modules or other devices to other orthodontic components in the oral cavity. 
     2. Description of the Related Art 
     Orthodontic treatment is a specialized form of treatment within the field of dentistry, and involves movement of malpositioned teeth to orthodontically correct locations. Orthodontic treatment often greatly improves the aesthetic appearance of the patient&#39;s teeth. Orthodontic treatment can also improve the patient&#39;s occlusion, so that when the jaws are closed the upper teeth are in proper positions relative to the lower teeth. 
     Orthodontic treatment is often carried out by use of a system of tiny appliances, wires and other components that are commonly known collectively as “braces”. Typically, a small appliance known as a bracket is connected to each of the patient&#39;s anterior, cuspid and bicuspid teeth and an archwire placed in a slot of each bracket. The archwire forms a track to guide movement of the brackets and the associated teeth to desired positions. 
     End sections of orthodontic archwires are often held by appliances known as buccal tubes that are secured to the patient&#39;s molar teeth. Each buccal tube has a passage that slidably receives the end section of the archwire. Buccal tubes may be placed on the patient&#39;s first molar teeth or the patient&#39;s second molar teeth. 
     In orthodontic treatment, the molar teeth often serve as convenient points of anchorage for applying force to other teeth because the molar teeth are relatively large and have a plurality of roots. As a consequence, many buccal tube appliances have one or two additional passages located next to the archwire slot. The additional passages (sometimes called auxiliary tubes) can be used for connection to other orthodontic devices as desired. 
     For example, the orthodontic treatment of some patients includes correction of the alignment of the upper dental arch to the lower dental arch. Certain patients have a condition referred to as a Class II malocclusion wherein the lower dental arch is located an excessive distance rearward of the upper dental arch when the jaws are closed. Other patients may have an opposite condition referred to as a Class III malocclusion wherein the lower dental arch is located forward of the upper dental arch when the jaws are closed. 
     A number of intra-oral devices for correcting Class II and Class III malocclusions are known in the art. For example, U.S. Pat. Nos. 4,708,646, 5,352,116, 5,435,721 and 5,651,672 describe intra-oral bite correctors with flexible spring members that are connected to upper and lower arches of a patient. The length of the bite corrector is selected such that the member is curved in an arc when the patient&#39;s jaws are closed. The inherent spring bias tends to urge the members toward a normally straight orientation and provide a force that pushes one dental arch forward or rearward relative to the other dental arch when the jaws are closed. 
     U.S. Pat. No. 6,913,460 describes an orthodontic coupling for releasably connecting intra-oral bite correctors to buccal tubes. The coupling described in this patent includes a body with a shank that is received in a passage of the buccal tube with a flexible, snap-in retention movement. In certain embodiments described in this patent, the coupling includes rotation stops that are moved into operative positions as the shank is received in the passage. The rotation stops function to limit pivoting movement of the associated bite corrector so that the bite corrector does not contact adjacent oral tissue and cause irritation. 
     Relatively large intra-oral forces are often applied to orthodontic components during movement of the jaws. For example, the forces generated when chewing can be significant, especially when the patient bites into a hard food object such as hard candy, nuts or ice. The chewing forces can be especially large in molar regions of the patient&#39;s jaws, and hard food objects can transmit the forces to the attached orthodontic components. In some instances, the forces can break the components or cause the components to spontaneously detach from the teeth such that the progress of treatment is interrupted. 
     SUMMARY OF THE INVENTION 
     The present invention is directed toward an improved attachment module for an orthodontic bite corrector, along with related orthodontic assemblies and methods. The attachment module comprises two segments, and each segment includes a rotation stop. The segments are movable relative to each other in order to facilitate placing both rotation stops in beneficial operative positions that help limit undue rotational movements of associated orthodontic components. 
     In more detail, the present invention in one aspect is directed toward an orthodontic attachment module for an orthodontic bite corrector. The attachment module comprises a first segment including an elongated shank for reception into a passage of an orthodontic buccal tube appliance. The first segment also includes a first rotation stop that is spaced from the shank in a direction along a first reference axis. The first rotation stop extends in a direction generally parallel to the shank. The attachment module also comprises a second segment that includes a coupling for connection to an orthodontic bite corrector. The second segment also includes a second rotation stop. The second segment is movable relative to the first segment between an open orientation and a closed orientation. The second rotation stop is spaced from the shank in a direction along a second reference axis that is generally perpendicular to the first reference axis. 
     Another aspect of the present invention is directed toward an orthodontic assembly that comprises a buccal tube appliance including a base and a body extending outwardly from the base. The body includes first wall portions defining an archwire slot extending in a generally mesial-distal direction and second wall portions defining a passage extending in a generally mesial-distal direction. The assembly also comprises an attachment module that is releasably connected to the buccal tube appliance. The attachment module includes a shank extending into the passage and a first rotation stop extending over the body. The first rotation stop is located in a facial direction relative to at least a portion of the body. The attachment module also includes a second rotation stop extending along the second wall portions and located in a lingual direction relative to the passage. The second rotation stop is movable relative to the first rotation stop. 
     Another aspect of the present invention is directed toward a method of coupling an orthodontic attachment module to an orthodontic buccal tube appliance. The method comprises: 
     providing a buccal tube appliance having first wall portions defining an elongated archwire slot and second wall portions defining an elongated passage extending alongside the archwire slot; 
     placing a shank of an attachment module in the passage; and 
     moving a rotation stop of the attachment module into a region that is located in a lingual direction relative to the second wall portions, and wherein the act of moving the rotation stop into the region is carried out at a time other than during the act of placing the shank in the passage. 
     The attachment module of the present invention provides a secure and robust connection between the buccal tube appliance and a bite corrector, force module or other intra-oral component. The movable relationship of the first rotation stop to the second rotation stop helps enable the rotation stops to be securely coupled to the buccal tube appliance in a manner that might otherwise be difficult or impossible to attain. As a result, the orthodontic components such as a bite corrector associated with the attachment module can better resist undue forces from jaw movement that may be encountered during the course of treatment. 
     These and other aspects of the invention are described in more detail in the paragraphs that follow and are illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a fragmentary side elevational view showing an example of a patient undergoing orthodontic treatment, wherein an attachment module of the present invention is used to connect a bite corrector to a buccal tube appliance that is mounted on the patient&#39;s upper right first molar tooth; 
         FIG. 2  is an enlarged front elevational view of the attachment module and buccal tube appliance alone that are depicted in  FIG. 1 , looking at the attachment module and the buccal tube appliance in a lingual direction; 
         FIG. 3  is a side elevational view of the attachment module and buccal tube appliance shown in  FIG. 2 , looking in a mesial direction; 
         FIG. 4  is a view somewhat similar to  FIG. 3  except looking at the attachment module and buccal tube appliance in a distal direction; 
         FIG. 5  is a view somewhat similar to  FIG. 2  except showing the attachment module in an open orientation; 
         FIG. 6  is a perspective view of the attachment module alone that is illustrated in  FIGS. 1-5 , showing the attachment module in an open orientation; 
         FIG. 7  is a perspective view somewhat similar to  FIG. 6  except looking at the attachment module from a different viewpoint; 
         FIG. 8  is a front elevational view of an attachment module according to another embodiment of the present invention along with an orthodontic buccal tube appliance, illustrating the attachment module in an open orientation; 
         FIG. 9  is a view somewhat similar to  FIG. 8  except depicting the attachment module in a closed orientation; 
         FIG. 10  is a side elevational view of the attachment module and buccal tube appliance illustrated in  FIGS. 8 and 9 , looking in a mesial direction; 
         FIG. 11  is a front elevational view of an attachment module according to still another embodiment of the present invention along with a portion of a bite corrector; and 
         FIG. 12  is side elevational view of the attachment module and bite corrector shown in  FIG. 11 , looking at the attachment module and bite corrector in a mesial direction. 
     
    
    
     DEFINITIONS 
     As used herein:
     “Mesial” means in a direction toward the center of the patient&#39;s curved dental arch.   “Distal” means in a direction away from the center of the patient&#39;s curved dental arch.   “Occlusal” means in a direction toward the outer tips of the patient&#39;s teeth.   “Gingival” means in a direction toward the patient&#39;s gums or gingiva.   “Facial” means in a direction toward the patient&#39;s lips or cheeks.   “Lingual” means in a direction toward the patient&#39;s tongue.   

     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An orthodontic assembly according to one embodiment of the present invention is illustrated in  FIG. 1  and is broadly designated by the numeral  20 . The assembly  20  includes an attachment module  22 , a buccal tube appliance  24  and a bite corrector  26 . The assembly  20  is connected to other components of an orthodontic brace that is worn by a patient undergoing orthodontic treatment. 
     In  FIG. 1 , a number of slotted orthodontic brackets  28  are fixed to the teeth of the patient&#39;s upper jaw  30  and an archwire  32  is received in the archwire slot of each bracket  28 . An elastomeric O-ring ligature  34  extends around tiewings of each bracket  28  in order to retain the archwire  32  in the archwire slots of the brackets  28 . 
     Similarly, a number of slotted orthodontic brackets  36  are fixed to the teeth of the patient&#39;s lower jaw  38 . An archwire  40  is received in the slot of each bracket  36 . An elastomeric O-ring ligature extends around the tiewings of each bracket  36  in order to retain the archwire  40  in the archwire slots of the brackets  36 . 
     The right distal end of the upper archwire  32  is received in an archwire slot  60  ( FIGS. 2-3 and 5 ) of the buccal tube appliance  24 . Optionally, an end section of the archwire  32  is bent as shown in  FIG. 1  in a location adjacent the distal side of the buccal tube appliance  24 . 
     The bite corrector  26  is preferably similar to the bite corrector described in U.S. Pat. No. 5,964,588. In brief, the bite corrector  26  includes a first elongated tubular member, a second elongated tubular member that is received in the first member in sliding, telescoping relation, and a third member  44  that is received in the second member. A helical compression spring  46  extends around the first tubular member and has an outer end that bears against a connector  48  of the bite corrector  26  that is fixed to the first member. The opposite end of the spring  46  bears against an annular fitting  50  that is secured to an outer end section of the second member. 
     Preferably, the outer end of the third member  44  is formed into a loop-type configuration as shown in  FIG. 1  that extends around a section of the lower archwire  40 . Additional examples of suitable loop-type configurations are set out in U.S. Pat. No. 6,669,474 (Vogt). The outer end of the third member  44  also preferably includes a line of weakness such as a recess or other area of reduced thickness for ease of bending the outer end section around the lower archwire  40 . Examples of suitable commercially-available bite correctors  26  include “Forsus” brand fatigue resistant Class II correctors from 3M Unitek Corporation. 
     Preferably, the overall effective length of the bite corrector  26  is selected so that the first and second members are not fully compressed and the second member is not fully inserted into the first member when the patient&#39;s jaws  30 ,  38  are closed. As a consequence, the inherent bias of the spring  46  provides the desired corrective forces by urging the first and second member away from each other in order to move one dental arch relative to the other. 
     The buccal tube appliance  24  is shown in enlarged view in  FIGS. 2-5  and includes a base  50 . In the illustrated example, the base  50  is affixed to a band  52  that is depicted in  FIG. 1 . The band  52  encircles the patient&#39;s upper right first molar tooth  54  and is connected to the buccal tube appliance  24  by a weld or a braze joint. Optionally, the buccal tube appliance  24  may be connected to the molar tooth  54  by other means such as an adhesive bond between the base  50  and the enamel surface of the molar tooth  54 , although use of the band  52  as illustrated is often preferred. 
     The buccal tube appliance  24  has a body  56  that extends outwardly from the base  50  in a generally facial direction. The body  56  includes first wall portions  58  adjacent the archwire slot  60 . In the illustrated embodiment, the first wall portions  58  include parallel, spaced-apart occlusal and gingival inner flat wall surfaces and an inner flat lingual wall surface that is perpendicular to the occlusal and gingival wall surfaces. The inner surfaces of the first wall portions  58  present a generally “U”-shaped configuration in transverse view and define the archwire slot  60 . 
     The buccal tube appliance  24  also includes a cap  62  that extends across the archwire slot  60  and is detachably connected to the first wall portions  58 . The cap  62  can be removed if desired to open the archwire slot  60  during a later stage of orthodontic treatment, such as a point in time after the second molar tooth of an adolescent patient has sufficiently erupted. Once the cap  62  is removed, the archwire slot  60  functions in a manner similar to the archwire slots of the orthodontic brackets  28 ,  36 . 
     The body  56  of the buccal tube appliance  24  also includes second wall portions  64  that extend next to a passage  66 . Both the archwire slot  60  and the passage  66  extend in generally mesial-distal directions, although the passage  66  may not extend in a direction that is precisely parallel to the direction of extension of the archwire slot  60 . For example, the archwire slot  60  may be inclined relative to the base  50  of the buccal tube appliance  24  in order to apply forces to the adjacent teeth in certain inclined directions or along rotational paths. 
     In the embodiment shown in the drawings, the inner surfaces of the second wall portions  64  have a generally cylindrical configuration and define the passage  66 . Examples of suitable buccal tube appliances  24  include “double tube” molar appliances with a passage similar to passage  66  for optional reception of an orthodontic facebow or headgear component. Other examples of suitable buccal tube appliances include “triple tube” appliances that have, in addition to the passage and archwire slot of the “double tube” appliance, a third passage for another auxiliary component such as a wire arch segment. This auxiliary passage is optional and in  FIGS. 2-4  is designated by the numeral  68 . Examples of suitable commercially available buccal tube appliances include “Victory Series” brand triple convertible appliances from 3M Unitek Corporation. 
     The attachment module  22  illustrated in  FIGS. 1-7  is releasably coupled to the buccal tube appliance  24 . The attachment module  22  includes a first segment  70  and a second segment  72  that is movably coupled to the first segment  70  by a hinge section  74 . The hinge section  74  enables relative movement of the segments  70 ,  72  between an open orientation that is shown in  FIGS. 5-7  and a closed orientation that is shown in  FIGS. 1-4 . The movement between the open and closed orientations in this embodiment represents a pivotal motion about a facial-lingual reference axis that is also perpendicular to the plane of the drawings of  FIGS. 1, 2 and 5 . 
     The first segment  70  includes an elongated shank  76  that preferably has a generally circular cross-sectional configuration that is complemental to the circular cross-sectional configuration of the passage  66 . When the attachment module  22  is installed on the buccal tube appliance  24 , the shank  76  extends through the passage  66  and preferably extends past the distal end of the passage  66  in a distal direction. Preferably, and as shown in the drawings, the outer or distal free end of the shank  76  is tapered to a rounded shape to facilitate reception of the shank  76  in the mesial opening of the mating passage  66  during installation of the attachment module  22 . 
     The first segment  70  also includes a first rotation stop  78  that extends in generally parallel but spaced apart relation to the direction of extension of the shank  76 . When the attachment module  22  is connected to the buccal tube appliance  24 , the first rotation stop  78  is received in a location extending over the cap  62 . In this embodiment, the rotation stop  78  is elongated but shorter in length than the overall length of the shank  76 , although other constructions are also possible. 
     The second segment  72  includes two parallel, spaced apart pegs  80  that are remote from the hinge section  74 . When the attachment module  22  is in its closed orientation, the pegs  80  straddle a distal section of the shank  76  and are located in a distal direction from the distal side of the buccal tube appliance  24 . The pegs  80  help resist deformation of the attachment module  22  when unexpected forces are encountered, such as twisting movement of the second segment  72  relative to the first segment  70  in an arc about an occlusal-gingival reference axis. 
     The second segment  72  also includes a second rotation stop  82  that has a generally flat shape. The second rotation stop  82  is located in a lingual direction relative to the pegs  80 , and is also located in a lingual direction relative to the shank  76  when the attachment module  22  is in its closed orientation. The second rotation stop  82  extends along the lingual side of the second wall portions  64  that define the passage  66  when the attachment module  22  is secured to the buccal tube appliance  24 . 
     The second segment  72  also includes an outermost, distal end with a coupling that comprises a cylindrical opening  84  in this exemplary embodiment. The bite corrector  26  ( FIG. 1 ) is pivotally connected to the attachment module  22  by a pin  86  that extends through the opening  84  as well as through a matching opening of the connector  48  of the bite corrector  26 . The pin  86  has an enlarged, outer head to prevent detachment of the bite corrector  26  from the attachment module  22 , and may be secured to the second segment  72  by any suitable means such as a laser weld, a resistance weld, an interference fit or the like. 
     Preferably, the attachment module  22  is supplied to the practitioner by the manufacturer in the open orientation that is shown in  FIGS. 5-7 , and preferably has been previously connected to the bite corrector  26  by the manufacturer. The practitioner installs the attachment module  22  by placing the distal, free end of the shank  76  in the mesial opening of the passage  66 . The attachment module  22  is then moved in sliding fashion in a distal direction relative to the buccal tube appliance  24  until such time as the mesial side of the buccal tube appliance  24  engages the flange of the attachment module  22  that surrounds the mesial end of the shank  76 . In this position of the attachment module  22 , the outer, distal end section of the shank  76  extends past the distal side of the buccal tube appliance  24  in a distal direction. 
     Next, the attachment module  22  is pinched or squeezed to a closed orientation as shown in  FIGS. 1-4 . For example, the practitioner may use a hand instrument such as Weingart pliers or How pliers to pivot the second segment  72  relative to the first segment  70  and move the second segment  72  in an upward direction and along a curved path. When the attachment module  22  is in its closed orientation, the upper or gingival side of the second segment  72  is in contact with or closely adjacent the bottom or occlusal side of the buccal tube appliance  24  and the pegs  80  straddle the distal end section of the shank  76  on its lingual and facial sides. 
     As the attachment module  22  is moved from its open orientation to its closed orientation, the second rotation stop  82  moves upwardly in an arc and into a region between the lingual side of the second wall portions  64  and the adjacent surface of the molar tooth  54  (or adjacent the band  52  as the case may be, depending on the size and location of the adjacent portions of the band  52 ). Once the attachment module  22  is closed, the second rotation stop  82  limits bending or twisting movements of the second segment  72  in generally facial directions away from the molar tooth  54 . In addition, the first rotation stop  78  serves to limit movement of the attachment module  22  and the bite corrector  26  in a counterclockwise arc viewing  FIG. 3  about the longitudinal axis of the shank  76 . 
     Advantageously, movement of the second segment  72  relative to the first segment  70  during installation of the attachment module  22  enables the rotation stop  82  to be placed into the relatively small region on the lingual side of the second wall portions  64  without undue difficulty. This advantage is especially beneficial since components such as the attachment module  22  and the buccal tube appliance  24  are relatively small and access to areas of the oral cavity adjacent the first molar teeth is limited. Moreover, the mesial portions of certain commercially available buccal tube appliances may have structure that precludes placement of the rotation stop  82  in the position shown in  FIGS. 2-4  by approaching this position from the mesial side of the appliance. 
     The hinge section  74 , and optionally the entire attachment module  22 , is comprised of a highly malleable metallic material, such as 17-4 PH stainless steel. Optionally, the hinge section  74  has a lower temper than remaining portions of the attachment module  22 . Preferably, the attachment module  22  is integral and fabricated as a single component. Optionally, the attachment module  22  is manufactured using a metal injection molding process. 
     Although not shown in the drawings, an assembly somewhat similar to assembly  20  may be affixed to orthodontic components on the left side of the patient&#39;s jaws. In addition, other types of bite correctors or force modules and buccal tube appliances may be used in place of the bite corrector  26  and buccal tube appliance  24  illustrated in the drawings. 
     An orthodontic assembly  20   a  according to another embodiment of the invention is illustrated in  FIGS. 8-10 . The assembly  20   a  includes a buccal tube appliance  24   a  and a bite corrector (not shown in  FIGS. 8-10 ). The buccal tube appliance  24   a  and the bite corrector of the assembly  20   a  are similar to the buccal tube appliance  24  and the bite corrector  26  described above, and as such a detailed description of such components need not be repeated. 
     The orthodontic assembly  20   a  also includes an attachment module  22   a  releasably coupled to the buccal tube appliance  24   a . The attachment module  22   a  includes a first segment  70   a  that comprises an elongated shank  76   a  and a first rotation stop  78   a . The shank  76   a  and the rotation stop  78   a  extend in generally parallel directions along a mesial-distal reference axis when the attachment module  22   a  is connected to the buccal tube appliance  24   a.    
     The first segment  70   a  also includes a curved arm  90   a  that first extends in an occlusal direction away from the mesial end of the shank  76   a  and then extends in a distal direction. An outer end of the arm  90   a  includes a shoulder  92   a . The distal end of the shank  76   a  also includes a shoulder  100   a.    
     The attachment module  22   a  also includes a generally “U”-shaped second segment  72   a  having a mesial aperture  96   a  and a distal aperture  98   a  on opposite ends. The mesial aperture  96   a  includes a restriction such as a flange or shoulder (not shown) that contacts the shoulder  100   a  as the first segment  70   a  is moved in a mesial direction relative to the second segment  72   a . As a consequence, the first segment  70   a  cannot detach from the second segment  72   a  in ordinary use. The center, occlusal portion of the second segment  72   a  includes a shoulder  94   a  (see, e.g.,  FIG. 8 ). 
     The attachment module  22   a  includes a second rotation stop  82   a  that extends along the distal and lingual portions of the second segment  72   a . The second rotation stop  82   a  is releasably received in a region located in a lingual direction from wall portions of the buccal tube appliance  24   a  adjacent the passage, similar to the position of the second rotation stop  82  relative to the second wall portions  64  described in connection with the embodiment shown in  FIGS. 1-7 . The second segment  72   a  also includes an opening  84   a  for connection to the bite corrector. 
     To install the attachment module  22   a  and secure the attachment module  22   a  to the buccal tube appliance  24   a , the attachment module  22   a  is initially in its open orientation as depicted in  FIG. 8 . If not previously provided, this open orientation is attained by movement of the first segment  70   a  in directions away from the second segment  72   a , preferably until the limit of such movement is reached due to contact of the shoulder  100   a  with the restriction provided in the mesial aperture  96   a . Next, the second segment  72   a  is placed along the occlusal side of the buccal tube attachment  24   a  and moved in a gingival direction. Continued movement of the attachment module  22   a  in a gingival direction brings the second rotation stop  82   a  to a position next to the lingual side of the wall portions defining the passage of the buccal tube appliance  24   a  and also moves the center portion of the second segment  72   a  proximal to the occlusal side of the buccal tube appliance  24   a . In this position of the second segment  72   a , the apertures  96   a ,  98   a  are in alignment with the central axis of the passage  66   a.    
     Next, the first segment  70   a  is moved relative to the second segment  72   a  and in a distal direction in order to move the shank  76   a  through the mesial aperture  96   a  and into the passage  66   a . Movement of the first segment  70   a  in a distal direction is continued until the shoulder  92   a  latches with shoulder  94   a . The attachment module  22   a  is then its closed orientation as shown in  FIG. 9 . 
     When the attachment module  22   a  is in its closed orientation, the first rotation stop  78   a  extends over the cap of the buccal tube appliance  24   a . In addition, the latching provided by the engagement of the shoulders  92   a ,  94   a  prevents inadvertent movement of the first segment  70   a  in a mesial direction relative to the second segment  72   a . As a consequence, the attachment module  22   a  is securely connected to the buccal tube appliance  24   a  until such time as the practitioner decides to move the attachment module  22   a  to its open orientation. To open the attachment module  22   a , the arm  90   a  is moved in an occlusal direction with a hand instrument until such time as the shoulders  92   a ,  94   a  disengage each other. The first segment  70   a  is then shifted in a mesial direction. 
     An orthodontic assembly  20   b  according to a further embodiment of the invention is illustrated in  FIGS. 11 and 12 . The assembly  20   b  includes an attachment module  22   b  and a bite corrector  26   b . The assembly  20   b  also includes a buccal tube appliance that is not shown in  FIGS. 11 and 12 , but is optionally similar or identical to the buccal tube appliances  24 ,  24   a  depicted in  FIGS. 1-5 and 8-10 . 
     The attachment module  22   b  includes a first segment  70   b  that comprises an elongated shank  76   b  and a first rotation stop  78   b  that is spaced from the shank  76   b . The shank  76   b  and the rotation stop  78   b  extend in generally parallel directions along a mesial-distal reference axis when the attachment module  22   b  is connected to a buccal tube appliance. 
     The attachment module  22   b  also includes a second segment  72   b  with a second rotation stop  82   b . The distal end of the second segment  72   b  terminates in a body  83   b  that presents a shoulder  85   b . A post  86   b  extends outwardly from the body  83   b  in a facial direction. A second post  89   b  extends in generally parallel relation to the post  86   b  and is connected to the second segment  72   b  at a location adjacent the shoulder  85   b . Preferably, the posts  86   b ,  89   b  are integrally molded as part of the second segment  72   b.    
     A third segment  74   b  of the attachment module  22   b  has a generally “C”-shaped configuration and integrally connects the first segment  70   b  to the second segment  72   b . The third segment  74   b  is sufficiently resilient to enable movement of the second segment  72   b  relative to the first segment  70   b  in directions toward and away from each other. Preferably, the first segment  70   b  and the second segment  72   b  are oriented as shown in  FIGS. 11 and 12  when the third portion  74   b  is in its normal, relaxed condition. 
     The attachment module  22   b  is connected to a buccal tube appliance such as the appliance  24  shown in  FIGS. 1-5  by placing the distal free end of the shank  76   b  in the mesial opening of a passage in the buccal tube appliance, such as the passage that is otherwise often used to receive an orthodontic facebow or headgear component. The outer or distal free end of the shank  76   b  is tapered as shown in the drawings to facilitate reception of the shank  76   b  in the passage of the buccal tube appliance. 
     As the orthodontic practitioner urges the attachment module  22   b  against the buccal tube appliance in a distal direction, the first and second segments  70   b ,  72   b  self-move away from each other a distance sufficient to enlarge the space between the outer end of the shank  76   b  and the shoulder  85   b  of the body  83   b . Such movement is enabled by the inherent resilience of the third segment  74   b  and preferably can be carried out by finger pressure against the module  22   b  without the use of hand instruments or the like. 
     As the attachment module  22   b  continues to move in a distal direction relative to the buccal tube appliance, the outer end of the shank  85   b  emerges from the distal side of the passage of the buccal tube appliance. Continued movement of the attachment module  22   b  in a distal direction enables the shoulder  85   b  to be located on the distal side of the buccal tube appliance. Once the shoulder  85   b  has cleared the buccal tube appliance in this manner, the inherent resilience of the third segment  74   b  causes the first and second segments  70   b ,  72   b  to relatively move toward each other and toward their closed, relaxed orientations as shown in  FIGS. 11 and 12 . 
     The resilience of the third segment  74   b , in combination with the shape of the second segment  72   b  including the shoulder  85   b , enables the buccal tube appliance to “snap-fit” into its position located on the mesial side of the shoulder  85   b  such that the attachment module  22   b  is held captive in place. This “snap-fit” relationship is similar to the “snap-fit” relationship described in connection with the orthodontic coupling described in the aforementioned U.S. Pat. No. 6,913,460. During treatment, the inherent resilience of the third segment  74   b  helps to ensure that the attachment module  22   b  remains connected to the buccal tube appliance until such time as the practitioner desires to release the attachment module  22   b  from the buccal tube appliance. In practice, the attachment module  22   b  may be released when desired by pressing on the attachment module  22   b  or the bite corrector  26   b  in an occlusal direction (i.e., in a downwardly direction viewing the arrangement shown in  FIG. 11 ) in order to widen the space between the shank  76   b  and the shoulder  85   b  so that the attachment module  22   b  can then be moved in a mesial direction for disengagement from the buccal tube appliance. 
     When the attachment module  22   b  is connected to the buccal tube appliance, the first rotation stop  78   b  extends over a facial portion of the buccal tube appliance, such as a facial side of a removable cap similar to the archwire slot cap  62  described above. The first rotation stop  78   b  serves to limit movement of the attachment module  22   b  and the bite corrector  26   b  in a counterclockwise arc viewing  FIG. 12  about the longitudinal axis of the shank  76   b.    
     Additionally, when the attachment module  22   b  is connected to the buccal tube appliance, the second rotation stop  82   b  extends along a lingual portion of the buccal tube appliance, similar to the orientation of the second rotation stop  82  relative to the buccal tube appliance  24  as shown in  FIGS. 2-4 . The second rotation stop  82   b  limits bending or twisting movements of the second segment  72   b  in generally facial directions away from the adjacent tooth. As can be appreciated by reference to  FIGS. 11 and 12 , the first rotation stop  78   b  is spaced from the shank  76   b  in a direction along a first reference axis and extends in a direction generally parallel to the shank  76   b , while the second rotation stop  82   b  is spaced from the shank  76   b  in a direction along a second reference axis that is generally perpendicular to the first reference axis. 
     The bite corrector  26   b  is optionally similar to the bite corrector  26  described above and includes a first elongated tubular member  47   b  that is shown in  FIG. 11 . A helical compression spring  46   b  extends around the first tubular member  47   b  and has an outer end that bears against a connector  48   b  of the bite corrector  26   b  that is fixed to the first member  47   b.    
     The connector  48   b  of the bite corrector  26   b  includes a tab with a circular opening that is received on the post  86   b  of the second segment  72   b . A flat, oval-shaped cap  87   b  is welded to the outer ends of the posts  86   b ,  89   b  and serves to secure the bite corrector  26   b  in a pivotally connected relationship to the attachment module  22   b . Advantageously, the flat facial side of the plate  87   b  is relatively broad and reduces the risk of patient discomfort if contact is made with adjacent oral tissue of the patient. Moreover, the two integrally molded posts  86   b ,  89   b  serve to securely connect the bite corrector  26   b  to the attachment module  22   b  through a stronger structure than may be provided by a ball pin or the like. 
     Other aspects of the assembly  20   b  including the attachment module  22   b  are similar to the various aspects of the assemblies  20 ,  20   a  including the attachment modules  22 ,  22   a  described above. 
     All of the patents and patent applications mentioned above are hereby expressly incorporated by reference. The embodiments described above are illustrative of the present invention and other constructions are also possible. Accordingly, the present invention should not be deemed limited to the embodiments described in detail above and shown in the accompanying drawings, but instead only by a fair scope of the claims that follow along with their equivalents.