CA1252651A - Lingual orthodontic appliance system for edgewise therapy - Google Patents

Abstract

Abstract:
The present invention is directed to an orthodontic bracket system for edgewise orthodontic therapy which is adapted for attachment to the lingual surface portions of a patient's teeth. The lingual orthodontic bracket system of this invention is designed to permit occlusal and mesial insertion of an edgewise archwire into precision archwire slots that are defined by the respective brackets of incisors, cuspids, bicuspids and molars. The lingual bracket system of this invention incorporates a molar tube that is designed for mesio-occlusal insertion of the end portion of the edgewise archwire and also permits pivoting or rotation of the archwire about the molar tube structure so as to bring the archform portion thereof occlusally into properly seated relation with respect to the archwire slots of other brackets.

Description

LINGUAL ORT~IODONTIC APPLIANCE SYSTEM FOR EDGEWISE THERAPY
The present application has been divided out of Canadian Patent Application Serial No. 476,773 filed on March 18, 1985.
Field of the Invention This invention relates generally to orthodontic brackets which are utilized by orthodontists ~o accomplish accurate movement and positioning of the teeth of a patient More specifically, the present invention concerns the provision of a lingual orthodontic bracket system which may be utilized to permit the labial and buccal surfaces of the teeth to be free of orthodontic appliances to thus retain a pleasing appearance during the period of orthodontic therapy. Even further, this invention concerns the provlsion of a lingual orthodontic bracket system which permits orthodontists to impart forces directly to the lingual surfaces of a patient's teeth in order to accomplish desirable tooth movement.
Background of the Invention Although a number of differing orthodontic techniques exist, the majority of orthodontists in practice in the United States, at the present time, utilize one of two basic tech-niques of orthodontic therapy in their treatment of patients.
These basic techniques are the "light-wire" technique and the "edgewise" technique. Light-wire appliances were first designed and pcesented to the pcofession by an Austealian orthodontist, R.
P. Begg, who intcodueed the idea of difecential ~occe eontrol.
Since some types of tooth movements evoke moce tissue cesistanee than othecs, and some movements oecur ~aster than othecs, Begg reasoned that by seleetively ehoosing the movements requiced and relating the ceeiproeal reaetions properly, tooth movement might be aeeomplishe~ in orderly manner. The Begg light-wire teehnique is ehacaeterized by a number of signifieant features. Brackets are fixed to all of the teeth of the patient anterioc to and ineluding the first molars. A~ehwires are round in cross-seetion and provide arehform and leveling o~ the teeth. ArehwiCes are loosely pinned to the braeket and are not ligated. The ~egg braekets provide a single point eontact with the arehwire to minimize ~rietion and permit the teeth to slide, rotate, tip and tocque freely. Tip, torque and rotation are aeeomplished by auxiliaries and not by the aetive fit between the arehwire and braeket as in the edgewise technique. Extra oral anchorage is not used. Reeiproeal anehorage is provided ~or by selectively utilizing teeth posterior to extraction sites to retcaet teeth anterioc to the extraction sites with intra and inter maxillary elasties. The ligh~-wire applianees are now several and varied ~rom the original design, although all e~ploy sophisticated eonee,ots in theories o~ tooth movement and anchorage control.
Standard light-wire therapy does not utilize extca-oral traction, ;51 frequently involves ex~raction of teeth and typically employs moce auxiliaries than conventional e~gewise therapy.
The most widely utilized octhodontic thecapy techni~ue in this country, and the technique to which this invention is dicected, is the ~edgewise" technique, which was brought to the industry by Dr. Edward H. Angle. It should be understood, however, that this invention is also applicable to other orthodontic techniques such as the multi-phase and twin wire techniques, for example. In the beginning stages of edgewise therapy, archwires of circular cross-sectional configuration are employed The greater flexibility of the round wire used in initial edqewise thecapy permits gceater range of movement o~
malposed teeth with less force to the teeth. For secondary and finishing therapy, the edgewise technique typically incorporates 15 a multibanded precision appliance consisting of a labial acchwice of cectangular ccoss-section configuration that is ordinarily of greater dimension at the sides ~han at the edges thereof. The acchwire is fitted and ligated with metal ligatuce wire, or ligature elastics, or any othec suitable form of mechanical 20 cetention, into pcecision mating horizontal archwire slots that are focmed in bcackets on all of the permanent teeth including ~irst molacs an~ ~ce~uently second molars. The acchwice tecminateS in buccal tubes e~ch having a rectangul~c ?~ssage through which the end poctions of the rectangul~r acchwire 25 extend. The acchwice, which may be comPosed o~ stainless steel oc pcecious alloy, is tyoically positioned with its na~row dimension or edge lying against the labial and buccal suc~aees of the teeth. This eeature gives the technique its name ~edgewise.~
The edgewise technique makes contcol possible in all dicections S and any individual tooth may be moved simultaneously in three directions; for example, an incisor may be moved lingually, distally and cotated acound its long axis with one adjustment of the archwire. The rectangulac cross-sectional configuration of the edgewise archwire pecmit~ it to be twisted to a desired extent and, being of spring-like nature, the twisting focces will be applied through the acchwire to the teeth, thereby inducing a tor~uing movemen~ of the teeth as the acehwire becomes untwisted an~ returns to its nocmal configuration. The brackets are pcecision milled to define archwir~ slots of cectangular shape so lS tha~ the orthodontist can select precision mllled archwires to fit as precisely as desiced. Tip, torque and rotation are accomplished by the fit between the archwire and the bracket.
Extra oral anchorage may oc ~ay not be used as desiced.
Reciorocal anchoc~ge can be pcovided by extraction of teeth and selectively uti~izing t'eeth posterior to extraction sites to retract teeth anterioc to the extraction sites with intr~ and intec maxillacy elastics and/or closing loop archwires. This invention is generally ~irected to the edgewise technique ~nd concecns an octhodontic ap21iance system th~t integr~tes specific ;5~

advantages that are afforded by edgewise aQplianees with both single and twin ligating tie wings~
As mentioned above, eonventional edgewise therapy is typieally aeeomplished by means of a labial acehwire that is reeeived by pceeision arehwire slots formed by orthodontie braekets that are positioned at the labial surfaees of a patient's teeth. In many eases, undesirable psyehologieal phenomena occues since the otherwise pleasant appeacance of a patient's teeth might be consi~ered unpleasant, especially by the patient, beeause of the presenee of orthodontie applianees on the labial and bueeal surfaees of the patient's teeth. Suppliers of orthodontie braekets and systems, to provide more esthetically pleasing applianees, have in some eases eliminated metal bands that eneirele the teeth and have developed braekets that are adapted for diceet bonding to the enamel surfaee of the teeth.
Still, with the arehwire present at the iabial and buecal surfaees of the patient's teeth, it is not possible to provide the patient with an octhodontie appliance system that pcesents the teeth in their nocmal appearanee. Further, by positioning orthodontic brackets on~the labial and buccal surfaces of the patient's teeth, the orthodontic brackets frequently cause tissue irritation with the lip and mouth tissues of the patient.
~oreover, the mere presence of orthodontic brackets between the teeth and lips or cheeks can intefere to some extent with muscle tone an~ develop undesicable speech charactecistics. In some cases, a patient's teeth ~ay tend to decalcify oc become permanently discolored in the area covered by or adjacent to metal bands. Also, in many cases, the orthodontic appliances interfere with eEEicient oral hygiene and cacies can develop on tooth surfaces that cannot be pcoperly cleaned. Consequently, when the appliances are removed from the patient's teeth, the otherwise pleasant appearance of prop~cly occlu~ing teeth can be marred by irregular sucfaces, band lines of discoloration and fissures that can be developed in the enamel. By locating the appliances on the lingual surfaces of ~he patient's teeth, the labial surfacé will remain clear of obstructions that otherwise would interfere with ef~icient oral hygiene. It is desirable, thereEore, to provide ~or lingual e~gewise orthodontic therapy because of the effective nature ;hereof and to allow the labial surfaces of the teeth of the pati nt to remain unobstructed to 15 permit efficient cleaning thereof and to provide the patient with a pleasant facial appearance during the period of octhodontic thecapy. It is also desirable to provide lingual edge~ise orthodontic therapy without subjecting the patient to the presence of brackets and,archwires between the teeth and lip and 20 cheek surfaces.

In some cases, it is desirable that the octhodontist be capable of applying tooth movement forces to the lingual surEaces of a patient's teeth. ~ith conventional edgewise therapy, Eorces are tyoic~lly ap?lied through hrackets that ~re positioned only ~;2S'Z~S~

at the labial and buccal surfaces. It is ~esirable, therefore, to provide otthodontic brackets that ~ermit edgowise therapy through location of octhodontic bcackets at the lingual sur~aces of the patient's teeth.
Single bcackets for edgewise therapy typically inCorpocate a base structure which is formed to define a precision active archwire slot ~hich ceceives the rectangular edgewise archwire there,in. Single brackets also incorporate a pair of tie wings that extend from the base and are positioned on opposite sides of the precision archwire slot. These tie,wings are typically centered with respect to the bcacket structuce and are therefore intended to be positioned in substantially centered mesio-distal relation with the ~acial surface of the tooth ~o which the bracket is secured. ~ ligature wire or elastic is 15 looped over each of the tie wings and is passed over the archwire, thus securing the archwire ficmly in its precision slot.
Single brackets pcovide maximum efficiency in the application of tipping and torquing movements to teeth but are 20 minimally ef~icient in cdtational control. Initially, rotational control was accomplished by soldecing oc welding eyelets at the extceme mesial oc ~istal of the band attache3 to the tooth. The octhodontist coul~ ligate the eyelot to the archwiro, pulling that surface closer to the archwire and c~using the tooth to t;~jl cotate about the centrally loeated br~eket. This is a cumbersome and ineffieient method of rotational eontrol.
Subsequently, fixed or flexible rotation levecs, pcojecting mesially and distally, were added to the eentrally 5 loeated single bracket. Thust a rotated tooth would have the rotation wing projecting more faeially than the braeket. The arehwire would touch the rotation wing and, as the wire is ligated into the bracket, eause the tooth to rotate about the braeket. The rotation lever is adjustable to projeet more or 10 less to the ~aeial as desiced. This permits the orthodontist to seleet the amount of rotation desired by a~justing the rotation lever rather than adjusting the archwire.
The disadvantage of the rotation lever is evident in the initial stages of treatment. The archwire will not toleh the 15 rotation lever if a tooth is tipped and eotated severely and will prevent either aetion from oceurring unless ~the arehwire is adjusted to strike the cotation lever when ligated. Thus, initial arehwire insertion can be ineffieient and require more expertise to ligate.
Twin brackets~ were introduced to alleviate the ineffieient rotation effe^tiveness of the single bcacket.
Instea~ of one centrally located bracket, two brackets wece placed at the mesial and distal poctions of the tooth. Thua, when each bracket is li~ated to the archwice, the f~cial surface 25will ali~n itself with the acchwire, cot~tillg the tooth.

t;s~

One of the pcineiples of rotation in ~rthodontics is over-eorreetion of the original problem to eompensate for the rebound or relapse tendency. This is espeeially indieated for rotated teeth. Twin braekets do not have the eapacity to over-rotate within themselves. Foc over-rotation with twin brae~ets, the arehwice has to be bent or some auxilliary must be added to foree the mesial or distal portion of the braeket away from the arehwire. Further, single edgewise brackets, without rotation levers, are also lacking in over-rotation control capability 10 whieh will be diseusse~ in more detail hereinbelow.
One of the more important advantages of single braekets is the advantage that is affor~ed by the a^tive length of arehwire existing betwoen the points of eonneetion to adjaeent braekets. This active arehwire length is known in the industry 15 as ~interbraeket widthn. Sinee the eonneeting Doint between a~jaeent single braekets is established at substantially the eentec of the a~jacent teeth, the archwire length, and thus the interbracket width, extends to points near the eenters of adjacent teeth. The lengthy archwire span that exists between 20 single brackets allows lowec magnitude focces to be applied to the teeth over longer periods o~ time as comp~red to eircumstances where the interbraeket width is limited and the active archwice span is short. The long span of acchwice may be twisted mueh further without causing pec~anent yielding or 25 defor,nation of the m~tal of the archwice. ~here the archwice between beackets is of limited length, which is typical whece twin bcackets are employed with the edgewise technique, application of lacge magnitude forces to the teeth can occur with only minimal twisting oc other deformation o the acchwire.
Thus, aftec limited movement of the teeth occucs, the forces induced by the archwice dissipate quickly, thereby requicing frequent adjustment in order to maintain optimum force application. Of eoucse, it is evident that f~equent adjustment of orthodontlc appliances necessitates fcequent visits by the patient for adjustment of the octhodontic applianee and is therefore disadvantageous to the patient in this regacd. Such frequent adjustment also requi~es a significant amount of chair time in the office of the orthodontist, thereby either increasing the cost of treatment to the patient, or minimizing the 15 commercial a~vantage of orthodontic treatment on the pact of the octhodontist It is desirable, therefore, to provi~e a system for orthodontic tceatment wherein patient visits ace minimized and chair time is also minimized, to the mutual benefit of both the p~tient and orthodontist.
Twin brackets for the edgewise technique have been employed for a considerable period of time. Twin brackets ty?ically incocporate a pair ~f spaced ?rojections that extend from or are formed by the bracket base, each ?rojection being ocmed to define a precision active archwire slot segment. The 25 spaced active archwire slot segments coope~ate to ~efine a ~;~S~t~5:1 pceeision arehwice slot having the effeet of ext~nding the entire length of the base. Eaeh of the pcojeetions is provided with gingival and oeelusal tie wings, the tie wings tecminating at the opposed side portions of the base stcueture. With the base strueture eenteced in respeet to the tooth being moved, the tie wings will be positioned in p~irs at opposite sides of the tooth, thereby defining braeket stcueture with rotational eontrol. The o~thodontist may utilize ligature wires or elastie membecs between selected tie wings an~ the archwire to develop the force moments that are neeessacy for effieient rotational eontrol.
One of the typieal disadvantages in utilization of twin bcaekets is the eonsequent minimization of interbraeket width that exists as the result of positioning the tie wings at opposed side portions of the braeket strueture. Ordinarily, as explained above, minimization of intecbraeket width in eonjunetion with the edgewise theraDy, suffers the disadvantage of cequiring fcequent patient visits and ineceasing ehaic time beeause of the neeessity foc fcequent adjustment of the applianee in ocder to maintiin the focee levels within the optimum rango for effieient tooth movement. It is d,esirable, theeefoce, to provide lingual edgewise thecapy with twin braekets having the interbraeket width of single braekets.
Anothec signi~ieant disadvant~ge in the utiliz~tion of twin bcackets is th~t the spaees that aro typieally available 25 between the tie win~s oE adjacent brackets leave insu~iciont tj3l coom between the teeth foc elosing loops an~ ti~-baek looos. It is desicable, thecefoce, to pcovide a lingual octhodontie applianee system that affocds the advantages offeced by t~in bcaekets and yet pcovides ample spaee between eectain tie wings S of ~djaeent bcaekets to faeilitate effieient use of elosing loops and tie-baek loops in eonjunetion with edgewise octhodontie thecapy.

Summary of the Invention It is a principal featuce of the pcesent invention to 10 provide a novel lingual octhodontie bcaek_t system whieh permits utilization of edgewise orthodontie thecapy at the lingual portions of the teeth.
It is also a featuce of this invention to pcovide a novel lingual octhodontie applianee system whieh ineludes 15 struetuce permitting applieation of effieient rotational eontrol focees to the teeth of the patient.
It is an even fucthec featuce of this invention to pcovide a novel linyual octhodontie a?plianee syst~m whieh allows the labial and bueeal sucfaees of the patient's teeth to cemain 20 free of orthodontie app~ianees, theceby permitting the normal rel~tionship of the faeial tissues and teoth to remain undistucbed and to provide the pa~ient with a ple~.sant oral appearanee during orthodontie thera?y.

l2 ;Sl Among the sevecal features of the pcesent invontion is eontemplated the pcovision of a novel lingual octhodontie applianee system which enables mesial-oeelusal insertion of an edgewise acehwire into in~erfitting relation with the vacious octhodontie braekets of the antecior teeth, the euspids, bieuspids and molars.
It is an even ucther featuce of the present invention to provide a lingual octhodontic ap~liance system incorpocating a specifically designed lingual tube that per~its mesial-occlusal insertion of the end poctions of an arehwire therein and further per~its rotation of the arehwire relation to the lingual tube to per~it oeelusal insection of the acehwire into the pceeision arehwire slots of other bcaekets of the orthodontie applianee system.
It is anothec feature of this invention to provide a novel lingual ort~iodontie applianee system employing twin tie wings for effeetive rotational and tipping eontrol and whieh also provides for maintenanee of effieient intecbcaeket spaeing to pecmit effieient torquing movements in response to the edgewise 20 teehnique.
It is ~lso a fQature of the present invention to pcovide a novel lingual orthodontie applianee system enabling an octhodontist to selectively utilize various eo~bin~tions of cotation an~ over-rotation control, torque an~ tipping control 25 simply through selection oE various lingu~l edgewise brack?ts of single or twin form, at least some of which embody a centralized fulcrum and at least one precision active arch wire slot in accordance with the principals of this invention.
Briefly, the lingual orthodontic appliance system of the present invention incorporates a base structure which is adapted to be secured in irnmovable relation with a tooth.
The base may be at~ached to bands that are positioned about the teeth and cemented in place or the base may be adapted for direct bondin~ to the tooth structure. The lingual base and bracket structure may take any one of several different forms within the spirit and scope of this invention, depend-ing upon the teeth to which the brackets are to be secured.
Regardless of the design of the particular brackets involved in lingual edgewise therapy, the archwire slots are oriented for occlusal insertion of the archwire therein. The terminal lingual attachments are designed to retain the tubular function thereof but are also of a configuration allowing mesio-occlusal insertion of the archwire end portions therein to thus permit occlusal insertion of the arch portion of the archwire into the respective archwire slots of each of the other brackets.
As described in the parent application, to provide for efficient rotation, the lingual brackets may be in the form of twin bracket structures having archwire relief between each of the pairs of tie wings and an intermediate fulcrum portion that defines the precision archwire slot ~S~;51 of the bracket. Thus, twin type lingual orthodontic brackets are provided which have ma~imum interbracket width such as is ordinarily afforded by single brackets for maintenance of maximum active archwire length between adjacent brackets.
By providing an intermediate fulcrum section with pairs of tie wings at each extremity thereof and by providing arch-wire relief between each of the pairs of tie wings, a twin lingual bracket is provided having efficient rotational -control. Further, since the in-termediate fulcrum section of L0 the bracket is machined to form an active archwire slot, the twin lingual brackets also incorporate the efficient tipping and torquing activity ordinarily achieved by single brackets.
Lingual brackets may also be provided of the single tie wing type as desired for particular teeth of the patient.
The single tie wing lingual bracket will have an archwire slot that opens toward the occlusal and will be extended to provide tie wings for ligating and pinning. The appliance system will include lingual tube brackets which are adapted for mesio-occlusal insertion of the archwire ends into proper position therein. Each lingual tube is designed so that the archwire may be inserted in angular or in mesio-occlusal relation therewith. After having been inserted mesio-occlusally into the lingual tubes, the archwire is pivoted about pivot portions defined by the tubes to thus allow occlusal insertion of the arch portions of the arch wire into properly seated relation within the archwire slots defined by the other brackets of the lingual appliance.

~;~S~t~5~l Spec.ifically, in one aspect the present invention is directed to a lingual tube orthodontic bracket Eor use in edgewise orthodontic th~apy, comprising: (a) base means for attachment in fixed relation with a molar; (b) precision archwire slot means being defined by said means; and (c) archwire insertion passage means being defined by said bas~ means and permitting mesio-occlusal insertion of said archwire into said lingual tube to posi-ti.on said archwire in partially oriented relation with sa.id archwire slot means and further permitting pivotal movement of said archwire relative thereto for changing the orientation of said archwire from said partially oriented position to a fully seated position within said archwire slot means.
In another aspect the present invention is directed to an orthodontic bracket for use in edgewise therapy, said bracket comprising: (a) base means adapted for attachment to the enamel surface of a tooth, said base means defining active edgewise archwire slot means; (b) retainer receptacle means being defined by said base means; and (c) retainer pin means being received by said retainer receptacle means and defining transverse retainer head means for retention of an edgewise arc'hwir.e in active relation within said archwire slot means.
Brief Description of the Drawing In order that the manner in which the above recited advantages and features of the present invention and the invention of the parent application are attained and can be l~S~

understood in detail, more particular description of the inventions briefly summarized above may be had by reference to the specific embodiments thereof that are illustrated in the appended drawings, which drawings form a part of this specification. It is to be understood, however, that the appended drawings illustrate only typical embodiments of the inventions and are, therefore, not to be considered limiting of their scope, for the inventions may admit to other equally effective embodiments.
In the Drawings Fig. 1 is a pictorial representation of lingual orthodontic appliances which are attached to the teeth of an orthodontic patient;
Fig. 2 is an isometric view of a twin lingual orthodontic bracket;
Fig. 3 is a fragmentary isometric view of a twin lingual bracket such as shown in Fig. 2 and which represents an alternative embcdiment illustrating archwire relief by means of angulated surfaces extending from the active archwire slot;
Fig. 4 is an isometric view illustrating a single tie wing type orth'odontic bracket being configured for occlusal insertion of an archwire into the precision active archwire slot thereof;
Fig. 5 is an end view of a single tie wing type lingual orthodontic bracket such as that shown in Fig. 4, which bracket is adapted for attachment to the anterior teeth of a patient;

Fig. 6 is a fragmentary plan view of a bracket structure such as shown in Figs. ~ and 5 and representing a further modified embodiment wherein the active arch~ire slot of the bracket structure is shown to be of arcuate configuration so as to receive the arcuate portion of an edgewise archwire.
Fig. 7 is an isometric view of a lingual bicuspid bracket that is adapted for occlusal insertion of an arch-wire into the active archwire slot thereof;
Fig. 8 is.an end view of the lingual bicuspid bracket of Fig. 7;
Fig. 9 is an isometric view illustrating a lingual tube such as constructed in accordance with the teachings of this invention and showing a portion of an archwire received therein in full line and further showing the angulated relation of an archwire in relation thereto during mesio-occlusal insertion of the archwire therein;
Fig. 10 is a sectional view taken along line 10-10 of Fig. 9 and illustrating in full line an edgewire archwire being received in opera-tive relation therewith and further showing in broken line the angulated position of the archwire during mesio-occlusal insertion of the archwire therein, Fig. 11 is a plan view of the lingual tube bracket structure of Fig. 9;
Fig. 12 is an elevational view of a lingual bicuspid brac~et representing a modified embodiment of this ;5~

invention wherein the edgewise archwire is secured within the archwire slot of the bracket by means of a retainer pin;
Fig. 13 is a sectional view taken along line 13-13 of Fig. 12;
Fig. 14 is a sectional view of an anterior lingual bracket illustrating pinned retention of the edgewise archwire;
Fig. 15 is a view of a lingual tube bracket for mesio-occlusal archwire insertion and illustrating pinned retention of an edgewise archwire;
Fig. 16 is a view toward the gingival of a lingual tube bracket representing a modified embodiment of the invention and illustrating an insertion slot for mesio-occlusal archwire insertion; and Fig. 17 is a sectional view of the bracket taken along line 17-17 of Fig. 16.

Detailed Description of _referred Embodi~ents Referring now to the drawings and first to Fig. 1, the fragmentary sectional pictoral illustration shows lingual portions of the maxillary and mandibular arches of a patient undergoing orthodontic therapy in accordance with the edgewise technique and incorporating a lingual orthodontic appliance system. As shown in Fig. 1, the various brackets of the lingual orthodontic system will be of differing construction, depending upon the characteristics of the teeth to which the brackets are to be applied. For example, at the left hand portion of Fig. 1, the brackets lZS2~5~

10 and 12 of incisors 14 and 16 respectively will have the general configuration shown by the respective side views that are shown. For bicuspids such as shown at 18 and 20, lingual brackets will typically take another suitable form as shown at 22 and 24. At the respective ends of each of the maxillary and mandibular arches lingual tube orthodontic appliances such as shown at 26 and 28 are applied to respective molars 30 and 32 and will receive the respective end portions of the archwire 33 and 35. As will be explained in detail hereinbelow, the lingual tube brackets 26 and 28 are each adapted to receive the archwire extremities by mesio-occlusal insertion and provide the usual tube function as well as permitting occlusal insertion of the archwir~
into the archwire slots of other brackets of the orthodon-tic appliance system. The various orthodontic brackets of the lingual appliance system of Fig. 1 are explained in detail in Figs. 2~11 hereinbelow.
Referring now to Fig. 2, a twin orthodontic bracket is shown generally at 34 which incorporates a bracket body structure 36 which may be of integral construction such as being formed of cast metal. The bracket body structure 36 incorporates a bonding pad 38 which is typically composed of metal and which is adapted to be bonded to the enamel lingual surface of a patient's teeth. The bonding pad 38 may be of any suitable configuration as is suitable to the bonding process and may be formed integrally with the bracket body structure 36 or attached to the bracket body by means Or welding or by any other sultable form of attachment.
The bracket body is also formed to define pairs of tie wings such as shown at 40-42 and 44-46 which allow the arch-wire to be ligated to the bracket structure by means of ligature wire, ligature elastics or any other suitable means for securing the archwire to the bracket or applying force between the archwire and bracket.
It is desirable to provide a lingual orthodontic bracket for the edgewise technique that is basically in the form of a twin bracket structure which also incorporates over-rotational capability. In accordance with the invention disclosed in the parent application, the orthodontic bracket body 36 is formed to deEine an intermediate fulcrum section 50 which forms an intermediate projection 52. The intermediate fulcrum section 50 defines an intermediate fulcrum edge 54 which is positioned in spaced relation with an opposed curved fulcrum surface 56 that is defined by the projection 52. The fulcrum edge 54 and the curved fulcrum surface 56 cooperate to define a precision active archwire slot which is adapted to receive the respective edgewise archwire 33-35 in close fitting relation therewith. Although edgewise archwires for finishing activities are of rectangular cross-sectional configuration, it should be borne in mind that edgewise arch-wires for accomplishing tooth movement in the initial stages of orthodontic therapy are defined by wires having a round cross-sectional configuration. The archwire slot is completed by a bottom wall or surface 58 which is contiguous with flat surfaces 60 and 62 and which faces toward the occlusal. In tact, the flat surfaces 60 and 62, together with the bottom ~tall surface 5~ of the active archwire slot can be said to be defined by a single flat surface. It is not necessary, however, that surfaces 60 and 62 be of flat configuration except that these - 21a -sur~aces should have no interferenee with the relationship of the acchwire to the bottom w~ll surface 58 of the acchwire slot.
The intermediate fulcrum section 50 provides for rotation of the bracket an~ tooth in relation to the acchwi~e.
To pcovide the bracket with this rotational eapability, it is necessary th~t the bracket strueture provide archwire relief on either side of the fulerum section. To aeco~plish these purposes, the bracket body 36 is formed to define concave, curved relie~ surfaces 64 and 66 which are positioned in recessed relation with respeet to the fuleru~ edge 54 of the arehwire slot. It is desirable ~hat the surfaces 54 and 66 be suffieiently relieved in relation to the archwice that these suFfaces do not eo~e into eontaet with the archwire even under eiccumstanees where the arehwire is in angulated relation with the acchwire slot at the tie wing portions of the braeket structure. ~lthough it is preferable that the~acchwice not co~e into contact with the relieved surfaces 64 and 66, it should be bocne in ~in~ that ducing the early stages of orthodontie treat~ent, especially in c3ses of gLOSS nalocclusiOn, the archwire may cequiro suf~icient ben,3ing that it co~es into contact with an outer edge 65 or 57 defined by one of the archwire relief suc~aces at the respective si3e portion of the bracket. Logic311y, interbracket wi3th is then li~ited. ~s soon as the ~aloccluded teeth begin to ~ove in cesoonse to thec~oy, howeveL, the outer e3ge S5 oc 67 oE the bL~cket will nove out of iLZSZ~S~

eontact with the arehwi~e. ~s soon as this occurs, ~axi~uln interbracket width will be established and, ~co.~ that point oc further tooth novenent will oeeur in response to the total interbeaeket width between adjaeent fulerum seetions. The arehwire may, therefore, be ligated with either one of the Dairs of ~tie wings o~ the braeket in sueh .nanner that the arehwire provides braeket and tooth rotational eapability as the arehwire tends to return to its n~ormal configuration and thus imparts a rotational focee through the braeket to the tooth. ~urther, the inter~ediate fulerum seetion of the braeket and the relieved portions of the bracket strueture in the tie wing areas eooperate to define a bracket strueture having greatec intecbraeket width than is ordinarily afforde~ by twin orthodontie braekets~ In faet, assu~ing the aetive arehwire slot o~ the braeket stcueture 15 of Fig. 2 to be the sa!ne or less width as eo~pared to the length of the arehwire slot of a eonventional single orthodontie braeket, the twin lin~u~l braeket of Fig. 2, therefore, defines an intecbcackèt width that is at least as great as the interbcacket wi~th defined by eonventional single orthodontic 20 bcackets. ~s ~nentioned 'above, the length oE the archwire span that exists between adjaeent single orthodontic braekets allows lower ~nagnitu~e forees to be applie~ to the teeth ovec longer periods of ti,ne as co~npared to circu~nstances where the intecbracket width is linited and the archwire span is short, ~5~;51 such as is typical in the case of adjacent twin bcackets o~
conventional nature. ~y pcoviding the twin bcacket of Fig. 2 with an inter~ediate fulceum section an~ with relieved areas between the pairs o tie wings, the ree archwire between the adjacent ~ulerum sections of adjacent brackets will be as long as ordinarily possible in edgewise orthodontic therapy. The lon~
span of archwire may, there~ore, be twisted much further without causing permanent yielding or deformation of the metal from which the arehwire is formed In returning or springing back to its normal configuration, the edge~ise archwire ~ill, thereore, apply a tooth moving force to the tooth over a longer period of ti~e, as compaced to conventional t~in brackets, without adjust~ent of the orthodontic appLiance. This feature, of course, minimizes the frequency of adjustment of the orthodontic appliance and thus significantly minimizes the amount o chair tine and the fcequency of visits that are re~uired during the period of orthodontic thecapy.
The intecmediate ulcru;n section of the bracket stcucture, together with the celieved tie wing portions o the bracket, provi~e eEicient ovec-rotational contcol, thus allowin~
the octhodontist to move the teeth eapidly to the ~inal positions thereo ~nd niniinizing the tceatnent tine necessacy oc e~fecting novement of the teeth to proDer occlusion within the ~lveol~r acch.

~4 S~

Fig. 3 is a ragmentary isometric view ill~strating a braeket strueture si~ilar to that of Fig. 2, wherein the archwice relief is defined by angulated surfaces ~0 and 32 diverging from a eentral fulcrum edge 84. ~s shown in Fig. 3, the alternative embodiment illustrated generally at 70 ineorporates a bracket body stcueture 72 forming twin tie wing areas similar to that of Fig. 2 and forming an intermediate fulcrum section having an active archwire slot that is defined by a vertical fulccum edge 74 and a curved fulcrum surface 75, toge~hec with a bottom surface 7S. Desired acehwire relief for over-rotational eontrol and maxi~i~ing interbraeket width is defined by a pair of angulated relief surfaees 6~ and 82 that extend from the fulcrum edge 84. The fulerum edge 84 eooperates with the eurved fulerum surfaee 76 to de-~ine line eontaet on eaeh side of the arehwire.
15 This parallel line eontraet establishes opposed lines of aetive arehwire reaetion and defines intecbraeket width o~ maximum span.
~ny bending or twisting of the arehwice between adjaeent braekets extends from the line eontact with fulerum edge ~4 and line eontaet with eurved fulerum surfaee 76. The funetion of the 20 orthodontie braeket of ~ig. 3 is essentially the sane as that deseribe~ above in connection with Fig. 2.
It may be desirable to pcovide a lingual type sing1e octhodontie bracket under circumstances where size makes twin tie wings impraetica1. In such case, the bracket structure nay 25 conveniently take the form i11ustr~ted in Fig. 4 where a sing1e ~2S;~

lingual orthodontic bracket is shown generally at ~38. The octhodon~ic bracket 8~3 incorpor~tes a bcacket bo~y structure 9~
to which is intecconnected oc integrally ~ocmed a bonding base 92 ~oc bonding of the bracket to the lingual sucfaces of the teeth of a patient under~oin~ octhodontic thecapy.
The bcacket body is formed to define a single pair o~
opposed tie wings 94 and 96 which enable the a~chwire t-o be ligated to the bracket structure with liga~ure wire, ligature el3stics or other suitable ~eans of ligation. The body structuce 90 is also for~e~ to define a pair of curved relie~ suefaces 95 and 97 which are positioned on opposed sides o~ ~ centc~lly oriented fulcru~ edge ~ extending to ou~er edges 99 and 10~.
planar surface 101 is also formed by the bracket body which also est3blishes the bottom wall of the active archwire slot.
projection 102 extends from the body structurç 90 opposite the ulcru~ edge 9~ and orms a curve~ fulcrum surface 10~.
Projection 102 is positioned between the opposed tie wings 94 and 96 so that 3 lig-3ture wire or elastic looped 3roun~ the tie wings will also be looped aroun~ the intermediate projection ln2 to thus secuce the archwire to the bracket structure in close proximity to the projection 102. The projection lO2 is ~or~ed integr311y with the bracket body structure 90 and presents the curved fulcrum surf~ce l03 in p~rallel oriented celation with the opposite fulcru~ e~ge 9~. The ooposed fulcrum edge 99 an1 curved l~S~ S~

fulcrum surface 103 cooperate to define a precision archwire slot 104 within with an edyewise archwire is received in active relation therewith. That portion of planar surface 101 that extends between the opposed fulcrum edge 98 and curved fulcrum surface 103 also functions to define the bottom wall of the precision archwire slot. The flat sided edgewise archwire will have line contact with the fulcrum edge 98 and curved fulcrum projection surface 103.
The projection 102 functions as an integral part fulcrum portion of the bracket structure thus providing a pivot area intermediate the extremities of the bracket. Further, the projection 102, being relieved at each extremity ther~of, allows the archwire to have a maximum interbracket width with respect to the intermediate projection or fulcrum of the adjacent orthodontic bracket.
Since the archwire of the lingual orthodontic appliance system will have an arched or curved portion having less radius of curvature as compared to conventional labial ortho-dontic appliances, it may be necessary to provide the various active archwire slots of the brackets with the capability of receiving the curved archwire in active engagement therewith.
As shown in Fig. 6" the brackets may be provided having a precision archwire slot such as shown at 106 which is at leas~ partially defined by a generally planar surface 108 and an opposed convex surface 110 that are cooperately formed by the body ;51 portion of the bracket stcucture. ~s shown, planar s~c~ace 10~
is foc~ed by the body of the bcacket while the convex sucface 110 is for~ed by an intermediate pco jection 112 exten~ing from the body. Otheewise, the bracket structure shown in Fiq. 5 ~ay be quite si~ilar to the bracket structure o Fig. 5 or ~ay conor~
to the bracket structuees of ~igs. 2 and 3. Obviously, only those orthodontic brackets that are located on anteriOC teeth would be provided with active acchwire slots of cueved configuration because the brackets of bicuspids and molars ordinacily receive relatively stcaight portions of the edgewise archwire.
In accordance with the lingual edgewise technique of this invention, orthodontic brackets for bicuspids and molars must have a configuration substantially differing fcom the configuration of brackets foc anterior teeth. -~s shown in ~igs.
8 and 9, a lingual bracket for the edgewise technique ~ay conveniently take the for~ illustr~ted geneca11y at 114. The lingual bicuspid bracket ~ay incorpocate a bracket body structure 116 of gener~lly cecta~gular ~orm having a bonding pad 11~
20 extending therefrom. The bonding pad will ordinarily be co~posed of ~etal and ~ay be for~ed integcally ~ith the bracket body 116 or, in the a1ternativo, ~ay be connected to the bracket body in ~ny s~litable ~anner such as by welding, bon~ling, etc. 1~
desired, the ~on~ing pad 11~ ~ay be composed o~ any suit~ble ~5~;51 ,~aterial other than ~etal or attachrnent o~ the bracket to the lingual surEace of a bicuspid or ~olac. The bon~ing pad de~ines a curved bonding surface 119 that corresponds to the curvature o~
the lingual surface of the bicuspid.
The body structure 11~ o~ the bracket is ~ormed to de~ine an inter~ediate shelf 120 which extends laterally fcom the intermediate portion of the bracket body and is oriented in generally parallel celation with t~e occlusal~ ~lthough the inter~ediate shel~ ~ay be of generally rectan~ular configuration, it ~ay also be of the configuration shown in Fig. 8 where the shelf ~efines spaced projecting tie wing retainer portions 122 and 124. These tie wing retainer portions ace provided to facilitate retention of the acchwire in pcopec relation with the shelf and with the acchwire slot. The tie wing retainec pcojections of the bcacket structure each ~efine uppec and lo~er tie wing projections 12~ and 130 that extend respectively beyond the horizontal surfaces of the shel~ 120. The upper portion 12 o~ each of the tie wings 122 an~ 12~ each de~ines an inner planar sur~ace 132 as shown in Fig. ~ that is oositioned in parallel, spaced relation with a pianar surface 134 ~o~ined by the bcacket boly 11~ thus fornin~ an active ar_hwiLe slot to receive the ed~ewise archwice. ~he planac sur~ace 136 o~ the shel~ 120 coo?er~tes with parallel suc~aces 132 and l34 to de~ine the bottom wall or suc~ace o~ the active ~cchwire slot. The bracket stcucture 114 is also ~orned to ~e~ine an anqulated, generally t;Sl planac surface 1~ which functions as a guide surface to per~it ef~icient entry of the edgewise archwire into its active relationship with the archwire slot defined by surfaces l32-134-136. The an~ulated planar sur~ace 138 also provides relief to thus enable efficient ligating of the archwire in respect to the tie wing portion of the bracket st{ucture. It should be borne in ~ind that the acchwire slot of the bracket 114 is readily adapte~ to allo~ occlusal inser~ion of the archwice thecein~
This feature effectively facilitates efficient handling of the archwire ducing installation thereo~. Further, for maloccluded teeth, simple force application to the archwire will enable it to be guided by surface 138 into the active archwire slot, thus appropriately bending or twis~ing the archwire to allow archwire developed force application to the bracket and tooth.
In accordance with edgewise orthodontic therapy, the opposed end portions of each archwire are typically received by ~olar tubes. In order to allow occlusal insertion of the archwire into the active acchwire slots of the cespective brackets of the lingual orthodontic appliance syste~n, it is 20 desirable to provide a lingual type tube bracket having the capability of receiving the extce~nities of the archwire in accordance with typical tube function and yet havin~ the ca~oability of pernitting ~esio-occlusal insertion o~ the archwice therein to pernit occlusal insertion of the acchwire into the ~1~

~S;~51 i~rchwire slots o~ the reinaining braekets. In aeeor~ance with the present invention, a lingual tube braeket may eonveniently take the for~ illustrated in Figs. 9-11. '~s shown in the isornetric vie~ o~ Fi~. 9, thu~ lingual tube braeket is illustrated generally at 140 and incorporates a body struetuce 142 de~ining an archwire slot portion 144 at one extre~ity of the braeket whieh opens ~oward the gingiv 11 while at ~he opposite extre~nity of the bracket, an acchwire slot portion 146 is defined which opens toward the occlusal. The archwire slot portion 144 is defined by parallel intermediate braeket surfaees 148 and 150 shown in broken line in Fig. ll and a tra,nsvecse planar surface 152 that intecseets surfaces 148 and 150 in normal relation. Thus, sucfaees 148, 150 and 152 cooperate to define rectangular acehwire slot portion 144.
The acchwire slot portion 146 is ~efined by parallel surfaces 154 and 156 which are dispose~ in parallel relation and a transverse surface 158 which intersects sur~aces 154 and 155 in nornal relation. The pairs of parallel suraces 14~-150 an~3 154-156 are each ~ocmed by precision machining or molding such that the acchwire 150 is ceceived in active relation within the respective archwire slot poctions 144 and 145.
As ~entioned aibove, it is desirable that the archwire 160 have the capability o~ bein~ inserted into assembly with tne lingual tube bracket structure 140 by ~eans o~ mesio-occlusal 25 insertion. This ~eature is shown in ~ull lines anrl broken lines ~;~S;~

in Figs. 9 and 10. To permit ~esio-oeelusal insection o the arehwire, the lingual tube bcaeket is formed to deEine an opening 162 whieh extends eo~pletely ~hrough the braeket strueture. This opening is defined in part by sucfaees 164 and 166 whieh are identiEied ~ore elearly in the seetional view o~ Fig. 1~ and the plan view oE Fig. Il. The edge 1-68 deEined by interseeting surfaces 158 and 166 funetions as a pivot, about which the archwire 150 is enabled to rotate as it is moved Ero~ the inelined, bcoken line position shown in Fig. 10 to the nor~al, opecative position shown in futl line in Figs. 9 and 10. The extre~ities of the arehwire 160 are thus inserted mesio-Oeelusally ~hrough the openings 162 oE th lingual tubes and, after being so positioned, the arehwire is then rotated about the edge 168 to the ~ull line position shown in Rigs. 9 and 10. Upon reaehing the ~ull line position, the remaining portions o~ the arehwire are inserted occlusally into the respeetive aetive arehwice slots o~ the othec brackets o~ the lingual orthodontic aopliance. -~hen the archwire 16~ is in eontact with the tube deEining surE~ces 152 and 158 o~ the lingual tube, it ~unetions in the s~e ~annec as iE the lingual tube were orovided with a single elongated cectangular opening~ The archwire is then ligated with respect to the lingual tube by ~eans oE ligature wires or el~stics which extend about opposed tie wing portions 170 and 172 oE the bracket structure. The body structure oE the bracket is cut away at 171 and 173 forming corners or notches that adapt the bracket to receive ligating devices such as wires, elastic members, etc., as shown in broken line. As shown in broken line, the tie wings 170 and 172 may be in registry with the outer wall surface 174 of the bracket structure or, as shown in full line, may extend outwardly beyond the wall surface to facilitate ease of ligation.
Ligating devices such as wires, elastic bands, etc., may also be looped around the tie wings 170 and 172 as shown in broken line at 175, A lingual orthodontic bracket system has been shown in Figs. 1-11 wherein an edgewise archwire may be inserted mesio-occlusally into the archwire slots of the interrelated bracket system and may then be ligated to the brackets by means of ligature wire, elastic bands, etc. It may be desirable to secure the edgewise archwire in assembly within the active archwire slots of the brackets by means other than a ligating system. Such a bracket structure may conveniently take the form set forth in Figs. 12-14. Figs.
12 and 13 relate to lingual orthodontic bracket structures which are received by the bicuspids of the patient while Fig. 14 shows a lingual orthodontic bracket for anterior teeth. In each case, the archwire is secured to the bracket structure by means of a retainer pin similar to that utilized in conjunction with the Begg light-wire technique.

1;~5~t;ri~l Re~ecring now to Figs. 12 and 13, a linqual orthodontic bracket is shown generally at 1~0 which incorporates a bonding base 182 having a bonding surface which is contoured for close fitting celation with the lingual surface of the bicuspid.
bracket body stcucture 184 extends com the bonding base and defines a projecting support shel~ 186 which extends the width o~
the body. Tie wing projections 188 and 190 extend from cespective extremities of the suppoct shelf 186 and define upoer and lower tie wings that receive ligating devices to secure an edgewise archwire in assembly with the bracket structuce. ~s shown, the tie wing pcojection l88 defines tie wing portions 190 and 192 whil-e tie wing pcojection 190 defines tie wing extensions 194 and 196. In this manner, the lingual bracket 180 is similar to the bcacket construction illustrated in ~ig. 7.
In order to provide for pinned retention of the edgewise archwire in asse~bly with the bcacket, an intermediate projection 198 extends ~ro~ the central portion of the support shelf 186. The interme~iate projection 198 defines a bore or passage 200 through which is extended the shaft portion 202 of a 20 retainer pin 204. The retainer pin includes a tcansverse retainer head portion 206 which overlies the edgewise archwire 208 which is received within the active archwice slot portions defined at each extcemity of the bracket stcuctuce in the mannec discussed above in connection with Fig. 7. The elongated shaft 25 poction 202 of the cetainec pin extends well beyond one extcemity ~4 1~5;~;51 of the intermediate projection 198 and may be bent over as shown in Fig. 12, thus locking the retainer pin in connection with the intermediate pcojection. In this ~anner, the archwire ~ay be secured in assembly with the bracket structure without necessitating the use of ligating devices. ~Lso, if desired, ligating devices may be employed on one or the other of the tie wing projections 188 or 190 as desired for accomplishing tooth move~ent in accordance with the edgewise technique. The pin 204 is removed by straightening the lower extre~ity and then extcacting it from the bore 200.
A pin retention type orthodontic bracket for the antecior teeth is shown generally at 210 in ~ig. l4. The bracket 210 incorporates a bonding base 212 for bonding of the bracket structure to the lingual surface of a patient's tooth. The 15 bracket also incorporates a body structure 214 which defines an archwice slot 216 in the same manner as discussed above in co-nnection with Figs. 4 and S, ~or exa~ple. The intermediate fulcru~ portion of the bracket structure is formed to define a pin receptacle or projection portion 21~ which defines a bore or 20 passage 220 within which is received the elongated shaft oc shank portion 224 of a retainec pin 226. The retainer pin also defines a transverse retainer head poction 22~ which overlies the archwire slot 216 and functions to secure an ed~ewise archwire in ac~ive relation therein. The elongated shaft or shank 224 o~ the ;51 pin extends well beyond one eXtremitY o~ the pcojection 218 and may be bent over in the same manner as shown in ~i~. 12 in order to secure the pin in locked relation within the bore or passage 222.
The retainer pins 204 and 225 of Figs. 13 and 14 respectively ~ay be co~posed o any suitable malleable metal oc other material which may be bent ovec to secure the pin in olace and may be stcaightened without breaking although the bracket structure shown in Figs. 12-14 incorporate a Begg-type retainer pin, nevertheless, these brackets incorporate the edgewise technique and are not to be confused with ~he light-wire technique of Begg.
It may also be desirable to secure an acchwire in assembly with a lingual tube bracket by pinning rathec th~n by ligation as is the case with the lingual tube bracket of Fig. 9.
In order to acco~plish this feat~e, a ~odi-~ied lingual tube ~racket may be provide~ in the manner illustrate~ generally at 23~ in Fig. l5. The lingual tube bracket 230 incorporates a body structure Z32 w~ich Eorms an elongated active archwire gcoove 234 in the sa~e mannec as ~iscussed above in connection with ~ig. 9.
The archwice groove or slot 234 is of gener~lly rect~ngular Eorn and has an active relations!lip with thP flat surfaces oE the rectangular edgewise archwire ~36. The body structure 232 is Eormed to define a cetainer orojection 23~ h~ving ~n elon~ate.
P~SSa~e 240 exten~ing there~hrougtl. ~ retainer oin 24Z Eor~in~

tj Jl an elongated shank 243 is adapted to be extended th~ough the passage 240 in such ~anner that a tecminal portion of the shank extends beyond the retainer portion 238 o~ the bracket. The retainer pin 242 is formed at one extce~ity to define an enlarged eetainer head 244 which is ofEset relative to the shank poction o~ the retainer pin. ~ portion of the enlar~ed head is adapted to overlie and engage the upper portion of the archwire 236 theceby positively sec~ring it in active rel~tion within the archwire slot 234.
For ~esio-occlusal insertion of an edgewise acchwire into the active arch~ire slot of a lingual tube bcacket, the bracket structure ~ay take the for~ shown generally at 250 in Figs. 16 and 17. Fig. 16 is a view toward the gingival while ~ ig. 17 is a sectional view taken along line 17-17 of Fig. l5 and viewing toward the lingual~ ~s shown in ~ig. 16, the lingual tube bracket structure 250 co,nprises 3 bracket body stcucture 252 having a bonding base 251 extending thereEro~. The bonding base ~efines an accuate bonding surface confor~ing to the curvature of the ~olar to which the bracket is to be bonded. The bo~y structure 252 oE the brac~ket deEines an elongated active archwire slot 254 Eor~ed in part by upper and lowec surfaces 256 and 258 an~ by pl~nar surfaces 252 ~nd 264. ~n edgewise archwire 268 is received in active rel~tion within the archwire slot 2S4.

;i5~

To ~acilitate insertion of the free extcemities of the edgewise archwire 26~, the body structure 252 of the bracket is ormed to define an entry groove 266 which is forned in pact by an angulated guide surface 260 and by extended poctions o~ the pl3nar surfaces ~62 and 264. ~s shown in broken line in Fig. l7, the archwire 26~ is positioned in angulated relation with the archwire slot 254 and is inserted mesio-occlusally into the archwire slot. The angulated guide sucface 260 guides the free extremities of the archwire from the entry slot 256 into active relation within the acchwire slot. ~lthough the archwire 26~ ~ay be quite stif~, such as during finishing therapy, it nevectheless is flexible to some de~ree. ~fter the free extre~nities of the archwire have been inserted into ~he entry slot 266 an~ are fed into the beginning portion of the archwire slot 254, the archwire 15 m~y be fl2xed to so~e extent towar~ the gingiv~l. Flexing of the free extre!nities causes the end portions of the archwire to becolne oriented in substantially oarallel relation with respect to the active archwire slot 254. 8y sinply applyin~ ~ ~or~e to the archwire, the free extre~nities of the archwire will be guided 20 into and along the archwice slot. ~he angular relationship of the archwice during such ~nesio-occlusal insection ~nove~ent is quite snall since the curve~ portion o~ the archwire need only clear the antecior teeth ~e~oce the ar~hwire is pivote~ to ~nove the curved portion into the active archwire slots of the anterior 25 bicuspid and nolar teeth.

,;S~

In co~nparing the lingual tube bracket stcuctures oE
~igs. 16 and 17 with that oE ~igs. 9-ll, it is clear that the archwiee need not be extended completely thcough the bracket structure of Figs. 16 and 17 to acco~21ish Inesio-occlusa1 S insection of the archwice into the active slots of the respective bcackets.
In view of the foregoin~, it is app~cent that I have povided ~ lingu~1 orth`odontic appliance syste~ which ~ay be eff~ctively utilized in accor~ance with the edgewise technique for effieient orthodontic therapy. Orthodontic therapy may be ceadily conducted while at the sa~e tine, the labial and buccal surfaces of the teeth of the patient cemain cleac of obstructions so that efEicient cleaning m3y be ceadily conducte~ and oral hygiene more easily maintained. Moceover, the outward appearance 15 of the teeth of the patient will be quite pleasant and the patient will not, therefor, be subjected to the de~cee of psychological tcau,na oc~inarily associated with application of octhodontic appliances ~o the labial surfaces of the teeth.
The lin~ual orthodontic appliances oE the present 20 invention are designed such that the edgewise archwire is ada?ted to be inserted into the r2spective active archwice slots by ~neans of occlus31 insection. This feature e~fectively Easilitates ease o~ installation oE the archwire and ease oE adjust~ents that ~re ty?ically na1e 1uring orthodontic therapy.

.1~5~

The lingual orthodontic appliance system of this invention incorporates molar tubes which allow mesio-occlusal insertiun of the archwire therein and which provides a typical tube bracket function when the archwire is in operative relation therewith. The bracket structures may be designed for ligature or pin retention of the edgewise archwire as desired. It is, therefore, apparent that the present invention is one adapted to attain all of the objects and features hereinabove set forth, together with other features whi,ch are inherent in the description of the apparatus itself.
While the foregoing is directed to the preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basi,c concept thereof, and the scope of this invention is determined by the claims which follow.

'10

Claims (4)

Claims:

1. A lingual tube orthodontic bracket for use in edgewise orthodontic therapy, comprising:
(a) base means for attachment in fixed relation with a molar;
(b) precision archwire slot means being defined by said base means; and (c) archwire insertion passage means being defined by said base means and permitting mesio-occlusal insertion of said archwire into said lingual tube to position said archwire in partially oriented relation with said archwire slot means and further permitting pivotal movement of said archwire relative thereto for changing the orientation of said archwire from said partially oriented position to a fully seated position within said archwire slot means.

2. A lingual tube orthodontic bracket as recited in Claim 1, wherein:
said archwire, in the partially oriented position thereof, is disposed in angularly oriented relation with said archwire groove means, said archwire being pivoted about a part of said base means to said fully seated position thereof.

3. A lingual tube orthodontic bracket as recited in Claim 1, wherein:
said base means defines internal shoulder means forming a part of said archwire insertion passage means, said archwire being pivoted occlusally about said shoulder means from said partially oriented position to said fully seated position.

4. A lingual tube orthodontic bracket as recited in Claim 1, wherein:
(a) said base means defines a first archwire slot segment opening gingivally and defines a second archwire slot segment opening occlusally, said first and second archwire slot segments cooperating to define said archwire slot means;
(b) said archwire insertions passage means inter-secting each of said first and second archwire slot segments; and (c) said base means permitting pivoting of said archwire within said archwire insertion passage and being movable into each of said first and second archwire slot segments.