referring to fig1 - 8 , various embodiments of a bracket 20 are shown , wherein the bracket includes : ( a ) a generally square bracket base 24 having an upper side 29 , a tooth affixing side 26 , opposing mesial - distal sidewalls 27 , and opposing gingival - occlusal sidewalls 30 as shown in fig1 , 2 a and 2 b . additionally , the bracket base 24 has a pair of retaining ridges 25 extending from each of the opposing gingival - occlusal sidewalls 30 toward the interior of the upper side 29 . fig1 and 2a show one of retaining ridges 25 ; fig3 a shows both retaining ridges . each of the retaining ridges 25 is provided by a corresponding thickened portion 23 ( fig1 , 2 a and 2 b ) of the bracket base 24 that extends in the gingival - occlusal direction of the bracket 20 approximately along a gingival - occlusal center line of the bracket base 24 ( e . g ., along the line l of fig4 ). the thickened portion 23 gradually thins in the mesial - distal direction of the bracket 20 , ending with the same thickness as the sidewalls 27 . ( b ) a pair of inverted archwire retaining regions 40 a and 40 b on the gingival side of the bracket 20 ( fig1 and 2a ), and another pair of inverted archwire retaining regions 44 a and 44 b ( fig1 ) on the occlusal side of the bracket . each of the pairs ( 40 a , b and 44 a , b ) is for retaining a respective archwire ( e . g ., archwire 68 , fig2 b ) therein . in particular , each of the inverted archwire retaining regions 40 a and 40 b provide a recess 37 ( fig1 and 2a ) for grasping or holding an archwire provided therein . also , each of the inverted archwire retaining regions is attached to ( and generally integral with ) a corresponding support 39 ( fig2 a ) that connects the retaining region with the bracket base 24 . each support 39 extends outwardly from the upper side 29 by a distance somewhat larger than the cross section of largest archwire to be retained in the recesses 37 . moreover , each of the recesses 37 has an edge 43 ( fig2 a , b and 3 b ) that is spaced apart from the support 39 for the recess , wherein the distance between the edge and the support is also somewhat larger than the cross section of largest archwire to be retained in the recesses 37 . note that for each of the pairs of the inverted archwire retaining regions 40 a , b and 44 a , b , a corresponding one of the retaining ridges 25 ( fig1 , 2 a , 2 b and 3 a ) assists in securing an archwire ( e . g ., archwire 68 ) in the two recesses 37 of the pair . accordingly , for each of the pairs 40 a , b and 44 a , b , the recesses 37 for the pair operatively cooperate with a corresponding one of the retaining ridges 25 to provide a corresponding archwire retention channel , i . e ., for an archwire retention channel 28 , the pair 40 a , b , defines one side of the channel 28 ( i . e ., an “ outer ” side ) and the corresponding retaining ridge 25 provides the opposing side of the channel 28 ( i . e ., an “ inner ” side ), and for an archwire retention channel 36 , the pair 44 a , b , defines one side of the channel 36 ( i . e ., an “ outer ” side ) and the corresponding retaining ridge 25 provides the opposing side of the channel 36 ( i . e ., an “ inner ” side ). thus , when an archwire is received ( and held ) in the inverted archwire retaining regions 40 a , b or 44 a , b ( i . e ., archwire retention channel 28 or 36 ), this archwire is operatively coupled together with the bracket attached to a patient &# 39 ; s tooth . ( c ) two archwire retention bridges 56 and 60 ( fig1 , 2 a , 2 b , 4 , 5 a , 6 and 7 ), wherein each end of each bridge attaches to one of the inverted archwire retaining regions and / or the support 39 therefor . for example , i . e ., the ends of the bridge 56 may be attached to the inverted archwire retaining regions 40 a and 44 a ( or attached to the support 39 therefor ), and the ends of the bridge 60 may be attached to the inverted archwire retaining regions 40 b and 44 b ( or attached to the support 39 therefor ). ( d ) an archwire retention channel 32 ( fig1 , 3 a , and 5 a ) extending in the mesial and distal direction along a central portion of the bracket 20 . the two archwire retention bridges 56 and 60 ( together with their corresponding inverted archwire retaining regions ) enclose , and substantially define , spaced apart portions of the archwire retention channel 32 for securing an archwire therein ( fig8 b ). the bracket base 24 may be made of a variety of materials , but in one embodiment may be stainless steel for strength . however , other materials may be used including ceramics and plastics . the remainder of the bracket 20 may be composed of various materials in addition to those recited above ( e . g ., polycrystalline alumina material , alumina ( aluminum oxide ), zirconia ). in one embodiment , the bracket 20 may be formed via an injection molding technique . the bracket base 24 may be a universal bracket design in that it can be attached to the surface of various tooth types ( e . g ., incisor , bicuspid , molar , etc ). moreover , such a universal bracket design does not require bracket identification to aid in identifying placement of the bracket and / or identifying a particular embodiment of the bracket 20 . such a universal bracket design also leads to simplified inventory management since only one embodiment of the bracket 20 may be needed for placement on all teeth types instead of different embodiments of the bracket for different teeth types . however , such universal bracket design may be primarily for the lingual side of patients &# 39 ; teeth . for embodiments of the bracket 20 to be provided on the labial / buccal side of patients &# 39 ; teeth , the curvature of the tooth affixing side 26 may be specific to particular tooth types as one skilled in the art will understand . accordingly , it is also within the scope of the present disclosure that markings or identifications may be provided on embodiments of the bracket 20 for identifying the bracket ( e . g ., as a universal bracket , or specific to a particular tooth type ( s )), for identifying the manufacturer or distributor of the bracket , and / or for identifying a particular placement or orientation of the bracket on a tooth or tooth type . note that descriptions of providing such markings and / or identifications are disclosed in u . s . patent application publication 2008 / 0020338 filed jul . 24 , 2007 and published jan . 24 , 2008 , this application being fully incorporated herein by reference . the bracket base 24 design allows for the bracket 20 to be used in both direct and indirect bonding . note that the term direct bonding refers to applying adhesive directly to a patient &# 39 ; s tooth and subsequently attaching a bracket 20 thereto . indirect bonding refers to positioning one or more brackets 20 on a dental cast of a patient &# 39 ; s teeth . the dental cast , having the brackets 20 attached thereto , is then surrounded with a material , wherein the material , once solidified , secures the brackets therein and can act as a transportation device for the brackets once the dental cast is dissolved away . adhesive is then applied to the back of each of the brackets 20 prior to placing the transportation device containing the brackets onto the patient &# 39 ; s teeth . accordingly , in the indirect bonding technique , all of the brackets 20 are bonded to the patient &# 39 ; s teeth simultaneously . once the brackets 20 are bonded , the transportation device is removed from the teeth , leaving behind the brackets attached to the teeth . regarding the retaining ridges 25 described above , each such ridge corresponds to a maximal offset from the tooth affixing side 26 along a corresponding one of the archwire retention channels 28 and 36 . moreover , in at least some embodiments , such a ridge 25 has its maximal offset centered on line l of fig4 . in the embodiment of the bracket 20 shown in fig2 a and 2b , the contour of each of the retaining ridges 25 is a smooth arc without undulations in the mesial - distal direction , and may also be a smooth arc in the gingival - occlusal direction without undulations . however , it is within the scope of the present disclosure that in the gingival - occlusal direction , such a ridge 25 may reach its maximal offset at any point where the ridge transverses its corresponding archwire retention channel ( 28 or 36 ) as long as the ridge effectively assists in wedging or holding an archwire in the channel ( i . e ., the recesses 37 of the channel ). thus , the thickened portion 23 ( fig1 ) for each retaining ridge 25 may induce a force upon an archwire 68 or 64 ( e . g ., fig5 a ) to retain it in the archwire retaining regions of the corresponding archwire retention channel 28 or 36 . note that each of the two retaining ridges 25 may have symmetrical profiles ( i . e ., minor images of one another about the center line l of fig4 , and about mesial - distal center line through the bracket ). moreover , note that the maximal offset for a retaining ridge 25 may occur just outside its corresponding archwire retention channel , e . g ., on the mesial - distal perimeter of the channel furthest from the central retention channel 32 . such placements of the maximal offsets may not only provide forces for securing an archwire within the corresponding recesses 37 , but also apply a force on the archwire for inhibiting the archwire from moving in a direction generally lateral to the upper side 29 . in another embodiment of the bracket 20 , the retaining ridges 25 may have a larger or smaller maximal offset from the tooth affixing side 26 to the upper side 29 of the bracket base 24 when compared to the embodiments of the figures . moreover , one of the retaining ridges 25 may have a larger maximal offset from the tooth affixing side 26 than the other retaining ridge 25 . this variance in the maximal offset of the retaining ridges 25 may allow for and aid in the retention of different diameter archwires in the retaining regions 40 a , b and 44 a , b . in another embodiment of the bracket 20 , one or more of the retaining ridges 25 may have a corresponding secondary retaining ridge located at the gingival or occlusal edges of the bracket base 24 . these secondary retaining ridges may be located on the upper side 29 at the gingival and / or occlusal edges of the bracket base 24 . such secondary retaining ridges may extend in the mesial - distal direction on the upper side 29 of the bracket base 24 . the secondary retaining ridges may have varying shapes ( e . g ., hemispherical or elliptical ). accordingly , the retaining regions 40 a , b and 44 a , b , in conjunction with the secondary retaining ridges , keep the corresponding archwire secured in one of the corresponding archwire retention channels 28 and 36 ( more specifically their recesses 27 ). for further description of the archwire retention channels 28 , 32 and 36 , reference is made to fig3 a which provides a lateral ( side ) view of the bracket 20 along a gingival - occlusal side . the center archwire retention channel 32 of the bracket 20 is enclosed by the two spaced apart portions of the archwire retention bridges 56 and 60 ( fig1 , 2 a , 2 b , 4 , 5 a , 6 and 7 ), and the upper side 29 of the bracket base 24 . as described above , each of the gingival archwire retention channel 28 and the occlusal archwire retention channel 36 is provided by : ( i ) partially enclosed spaced apart recesses 27 of a pair of inverted archwire retaining regions , respectively , 40 a , b or 44 a , b , and ( ii ) the upper side 29 of the bracket base 24 . both the gingival archwire retention channel 28 and the occlusal archwire retention channel 36 may be mirror images of one another . each of the inverted archwire retaining regions 40 a , b for the gingival archwire retention channel 28 , and each of the retaining regions 44 a , b for the occlusal archwire retention channel 36 may be generally circular in profile ( as shown in , e . g ., fig3 a ). each such profile may generally match the curvature of , e . g ., the cross section of a corresponding archwire to be provided therein . in fig3 a , a dashed circular cross section 38 of such an archwire is shown in the archwire retaining regions 44 a , b of the occlusal archwire retention channel 36 . the diameter 39 of the archwire retention channel 36 may be sufficiently surrounded by the inverted archwire retaining regions 44 a , b to grip and retain the archwire therein . in at least one embodiment , the opening 42 for receiving the archwire into the channel 36 is preferably approximately the same size as the diameter of the archwire cross section 38 along the axis 37 , e . g ., smaller or larger by approximately 0 . 01 to 0 . 02 inches . as also illustrated in fig3 a , each of the inverted archwire retaining regions 44 a , b may surround somewhat more than 180 degrees of the circular cross section of an archwire positioned in the occlusal archwire retention channel 36 . note that a similar description can also be provided for the gingival archwire retention channel 28 in that the channel 28 may be a mirror image of occlusal archwire retention channel 36 . however , it is within the scope of the present disclosure that the gingival archwire retention channel 28 may be configured differently from the occlusal archwire retention channel 36 , e . g ., the gingival archwire retention channel 28 may secure different sizes of archwires therein from the archwires for the occlusal archwire retention channel 36 . also , either or both of the archwire retention channels 28 and 36 may have an elliptical profile or other profile instead of the circular profile shown in fig3 a . further , an embodiment of the bracket 20 may have only one of the archwire retention channels 28 or 36 . referring to fig3 b , an embodiment of the bracket 20 a is shown that includes a retaining region ( e . g ., 44 a ) that is shaped or configured to retain archwires having substantially different cross sectional diameters . an archwire having a diameter 39 ( fig3 a ) may be snapped into the retaining region 44 a as indicated in fig3 a . however , an archwire having a much smaller cross section 41 , as shown in fig3 b , may also be provided in the channel 36 . in particular , the smaller diameter archwire may snap into ( or is otherwise retained ) in an upper section 57 of the retaining region . note that in one embodiment , a bead ( not shown ) may be strung on this smaller diameter archwire such that the bead is positioned between the retaining regions 44 a and 44 b so that the bead contacts the corresponding retaining ridge 25 for the occlusal archwire retention channel 36 in a manner that assists in locking the archwire into the upper section 57 . whether the bracket embodiment of fig3 a or 3 b is provided , multiple sizes of archwires may be utilized in each of the archwire retention channels 28 , 32 and 36 . the range in the maximal cross sectional extent of the archwires that may be utilized can be from 0 . 008 inches to 0 . 024 inches , and such cross sections may be generally circular in cross sectional shape but different cross sectional shapes may be used , e . g ., at least rectangular or square cross sectional shapes for the central archwire retention channel 32 . the multiple sizes of archwires may provide varying forces and friction levels ranging from an alignment force having a low friction , to a leveling force having a moderate friction , to a finishing force having a maximum friction as one skilled in the art will understand . in particular , the inverted archwire retaining regions 40 a , b and 44 a , b allow for the archwires 68 or 64 ( fig5 a , 6 and 7 ) to be attached to the bracket 20 without the use of ligatures . in another embodiment , the archwire retaining regions 40 a and 44 a ( or 40 b and 44 b ) may be joined together , above the upper side 29 . such joining of the retaining regions for one of the archwire retention channels 28 or 26 may form a single integral retaining region , or the joining may be in form of a bridge therebetween similar to the bridges 56 and 60 ( except extending in the mesial - distal direction rather than the gingival - occlusal direction ). regardless , there may be a cutout ( not shown ) over the corresponding retaining ridge 25 so that when the archwire contacts the retaining ridge 25 , the archwire is wedged into this cutout . in another embodiment , there may be only one of the outer archwire retention channels 28 and 36 utilized to retain an archwire . referring to fig4 , a top view of the bracket 20 is shown wherein the center archwire retention channel 32 on the bracket is defined by the spaced apart portions of the archwire retention bridges 56 and 60 and the upper side 29 of the bracket base 24 . the archwire retention bridges 56 and 60 connect and reinforce the inverted archwire retaining regions 40 a to 44 a and 40 b to 44 b . the smooth rounded contours and edges 65 of the inverted archwire retaining regions 40 a , b and 44 a , b provide for patient comfort , particularly when such brackets are placed on the lingual side of a patient &# 39 ; s teeth . in the center archwire retention channel 32 , the archwire is enclosed on all sides ( fig3 a and 3b ) at two points along the channel , i . e ., using the archwire retention bridges 56 and 60 ( fig4 ). a lateral view of the bracket 20 , as shown in fig5 , shows an archwire 64 in the occlusal archwire retention channel 36 and an archwire 68 in the gingival archwire retention channel 28 . the occlusal 64 and gingival 68 archwires are held place via the friction system created by the inverted archwire retaining regions 40 a , b and 44 a , b in combination with the ridges 25 ( not shown in fig5 ). fig5 also shows where the bracket 20 may reside on a tooth when it is bonded thereto . the arrows 77 and 78 ( fig5 ) indicate the forces for a torque that the bonded bracket 20 may apply to the tooth . fig6 provides a top view of the bracket 20 bonded to a tooth 80 wherein there is an archwire 64 in the occlusal archwire retention channel 36 , and an archwire 68 in the gingival archwire retention channel 28 . the arrows 90 and 91 indicate the motion of tip ( angulation ) that the bracket 20 may apply to the tooth once it is bonded and the archwires are configured appropriately . an end perspective view of the bracket 20 is shown in fig7 with an archwire 64 in the occlusal archwire retention channel 36 and an archwire 68 in the gingival archwire retention channel 28 . this figure also shows the bracket bonded to a tooth 84 thereby showing where the bracket 20 may reside on the tooth when it is bonded thereto . the arrows 93 and 94 indicate the motion of rotation that the bracket 20 and the archwires 64 and 68 may apply to the tooth . a plurality of the brackets 20 is shown connected together by archwires in fig8 a and 8b . fig8 a shows the plurality of brackets 20 connected together by an archwire 88 extending through the corresponding occlusal archwire retention channels 36 of the brackets . fig8 a also shows a second archwire 92 secured in the center archwire retention channel 32 of the brackets 20 , providing dynamic sectional control in the movement of the teeth , as one skilled in the art will understand . fig8 b displays how another configuration , wherein there is an archwire 96 in the occlusal archwire retention channel 36 of the brackets 20 . the archwire 96 is also configured so that its end is secured in the center archwire retention channel 32 of the rightmost one of the brackets 20 , thereby creating a loop like shape . it is worth noting that due to the diminutive size of the brackets 20 relative to the teeth to which they are attached ( as shown in fig8 a and 8b ), the size of these brackets 20 may allow for the bonding of two such brackets 20 on a single tooth . for example , fig8 b shows two such brackets 20 affixed to a molar . alternative embodiments of the bracket 20 include providing the inverted archwire retaining portions so that instead of their recesses 37 opening toward the base 24 , such recesses open in another direction ( e . g ., away from the base , or generally parallel with the upper side 29 of the base ). in such embodiments , the retaining ridge 25 is also repositioned to face in the direction toward such recesses for retaining an archwire in the same manner as , e . g ., shown in fig2 b except that the base 24 in this figure would no longer be the base of the bracket . instead , the base would attach , e . g ., to the top of the retaining portions 40 a , b and 44 a , b , or alternatively attach the bracket components shown fig2 b to a ( new ) bracket base that is oriented substantially perpendicular to the base shown in fig2 b . in each of the embodiments of the bracket 20 disclosed hereinabove , at least one of the archwire retention channels 28 and 36 is provided , wherein for an archwire provided therein , the elasticity of the archwire to retain an initial non - curved shape causes the archwire to resist the channel induced bow in the archwire ( such curving shown in fig2 b ). thus , as an orthodontist positions the archwire in the at least one channel of the bracket 20 , the corresponding retaining regions ( 40 and 44 ) for the channel together with the corresponding retaining ridge 25 bind or wedge the archwire within the at least one channel . accordingly , the opposing forces between the channel and archwire are believed to secure the archwire within the channel . thus , it is a feature of the bracket 20 that for each such archwire channel ( e . g ., 28 and / or 36 ), there are channel archwire bowing portions that retain the archwire within the channel , wherein a spaced apart plurality of these bowing portions ( e . g ., 40 a and 40 b for channel 28 ) contact the archwire at spaced apart locations on one side of the archwire &# 39 ; s length , and wherein between such locations , there is at least one additional channel archwire bowing portion on an opposite side of archwire for inducing the archwire to press against the spaced apart plurality of contacting portions . thus , the spaced apart plurality of bowing portions , and the at least one additional bowing portion induce oppositely directed forces on the archwire ( such forces being traverse to the length of the archwire ), and causing the archwire to bow or bend somewhat and to press against these bowing portions for holding the archwire within the channel . in use , after an orthodontist has secured the bracket 20 to one of a patient &# 39 ; s teeth , the orthodontist may exert a force ( e . g ., substantially parallel to the upper side 29 ) on a corresponding archwire to force the archwire enter one or both of the archwire retention channels ( 28 or 36 ), wherein such force induces the corresponding archwire to bow in the channel alternatively , the orthodontist may thread the archwire into such a channel , wherein the orthodontist pushes the archwire into the channel by purposely bowing or binding the archwire to follow the bow of the channel , and then once the archwire is threaded through the channel , the orthodontist can then bend the archwire into the correct orientation to attach the archwire to , e . g ., a next orthodontic appliance attached to , e . g ., a next tooth . note , that such subsequent bending of the archwire by the orthodontist is believed to also provide similar forces on the archwire ( and traverse to the length thereof ) as described above for securing the archwire within the channel . the disclosure herein describes the best mode known to carry out the invention as claimed in the claims hereinbelow . moreover , the foregoing disclosure has been provided for purposes of illustration and description . this disclosure is not intended to limit the invention claimed hereinbelow , and various embodiments thereof . variations , embodiments and modifications will be apparent to those skilled in the art and are intended to be within the scope of the following claims .
an orthodontic bracket is disclosed having three archwire retention channels in the mesial - distal directions , a central channel and two side channels . the two side channels each include a pair of spaced apart inverted archwire retaining regions having a recess that opens generally towards the bracket base . each such recess is for grasping or holding an archwire therein . each of the side channels has an archwire retaining ridge extending gingivally - occlusally along the adjacent side of the bracket base between the two retaining regions of the channel . for each channel , its retaining ridge exerts a force on a portion of an archwire facing away from the archwire portion residing in the recesses of the retaining regions of the channel the force on the archwire is directed toward the interiors of the recesses of the retaining regions for assisting in seating the archwire in the recesses .