CA1264573A - Lingual orthodontic appliance system for edgewise therapy - Google Patents

Abstract

LINGUAL ORTHODONTIC APPLIANCE SYSTEM FOR EDGEWISE THERAPY
Abstract of the Disclosure 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. At least some of the lingual orthodontic brackets incorporate fulcrum controlled twin tie wing systems to permit efficient controlled rotation of the teeth as well as archwire tipping and torque activities. The lingual bracket system of this invention also 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

5~3 P'~#8/5324SPE'`~l)R~5/102 ~ttorney Docket No. 5324 LINGUAL ORTHODO~TIC 3~PPLI)'.NCE SYSl`E~I F~R EDGEWISE THERD-PY

Field of the Invention . . _ _ This invention relates generally to orthodontic brackets which are utilized by orthodontists to acco~plish accurate move~ent and positioning of the teeth of ~ patient.
Moce specifically, the present invention concerns the provision of a lingual orthodontic bracket system which may be utilized to per~it the labial and buccal sur~aces of the teeth to be ~ree o~
orthodontic applicances to thus retain a pleasing appearance during the period of orthodontic therapy. Even further, this invention concerns the provision of ~ lingual orthodontic bracket system which per~its orthodontists to impart forces directly to the lingual surfaces of a patient's teeth in order to accomplish desir'able tooth move~ent.

~ackqround of the Invention __ Although a number of differing orthodontic techniques exist, the ~ajority of orthodontists in practice in the Unite~
States, at the present ti~e, utilize one of two basic techniques of orthodontic therapy in their treatment of patients. These basic techniques ~re the ~light-wire~ technique and the "edgewise" techniqu~. ~ight-wire applianres were first designed ~6~5~

and presented to the profession by an ~ustralian orthodontist, R.
P. ~egg, w~o introduced the idea of di~erential force control.
Since some types of tooth movements evoke more tissue resistance than othecs, and some movements occur faster than others, Begg reasoned that by selectively choosing the movements required and celating the reciprocal reactions properly, tooth movement might be accomplished in orderly manner. The 8egg light-wire technique is characterized by a number of significant features. Brackets are fixed to all of the teeth of the patient anterior to and including the first molaes. Archwires are round in cross-section and provide archform and leveling of the teeth. Archwires are loosely pinned to the bracket and are not ligated. The Begg brackets provide a single point contact with the archwire to minimize friction and permit the teeth to slide, rotate, tip and torque freely. Tip, torque and rotation are accomplished by auxiliaries and not by the active fit between the archwire and bracket as in the edgewise technique. Extra oral anchorage is not used. Reciprocal anchoeage is provided eOr by selectively utilizing teeth posterior to extraction sites to retract teeth anterior to the extraction sites with intra and inter maxillary elastics. The light-wire appliances are now several and varied from the oeiginal design, although all employ sophisticated concepts in theories of tooth movement and anchorage control.
Standard light-wire therapy does not utilize extra-oral traction, iit73 ~requently involves extcaction of teeth and typically employs more auxiliaries than conventional e~gewise therapy~
The most wi~ely utilized orthodontic therapy technique in this country, and the technique to which this invention is dicected, is the ledgewise~ technique, which was brought to the industry by Dr. Edward H. Angle. It should be understood, however, that this invention is ~lso applicable to other orthodontic techniques such as the multi-pXase 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 edgewise therapy permits greater range of movement of malposed teeth with less force to the teeth. For secondary and finishing therapy, the edgewise technique typically incorporates a multibanded pcecision appliance consisting of a labial archwire of rectangular cross-section configuration that is ordinarily of greater dimension at the sides than at the edges thereof. The archwire is fitted and ligated with metal ligature wire, or ligature elastics, or any other suitable form of mechanical retention, into precision mating horizontal archwire slots that are formed in brackets on all of the permanent teeth including first molaes and frequently second molars. ~he archwire terminates in buccal tubes each having a rectangular ?~ssage through which the end portions of the rectangular archwire extend. ~he archwire, which may be compose~ of stainless steel or precious alloy, is tyoically positioned with its narrow dimension or edge lying against the labial and buccal sur~aces o~
the teeth. This feature gives the technique its name "edgewise."
The edgewise technique makes control possible in all directions and any individual tooth may be moved simultaneously in three directions; for example, an incisor may be moved lingually, distally and rotated around its long axis with one adjustment of the archwire. The rec~angular cross-sectional configuration of the edgewise archwire permits it to be twisted to a desired extent and, being of spring-like nature, the twisting forces will be applied through the archwire to the teeth, thereby inducing a torquing movement of the teeth as the archwire becomes untwisted and returns to its normal configuration. The brackets are precision milled to define archwice slots of rectangular shape so that the orthodontist can select precision milled archwires to fit as precisely as desired. Tip, torque and rotation are accomplished by the fit between the archwire and the bracket.
Extra oral anchorage may or ~ay not be used as desired.
Reciprocal anchorage can be provided by extraction of teeth and selectively utilizing teeth posterior to extraction sites to retract teeth anterior to the extraction sites with intra and inter maxillary elastics and/or closing loop archwires. This invention is ~enerally directed to the e~gewise technique and concerns an orthodontic ap?liance system that integrates speci~ic ~6~

advantages that are afforded by edgewise appliances with both single and twin ligating tie wings.
As mentioned above, conventional edgewise therapy is typically accomplished by means of a labial archwire that is received by precision archwire slots formed by orthodontic brackets that are positioned at ~he labial surfaces of a patient's teeth. In many cases, undesirable psychological phenomena occurs since the otherwise pleasant appearance of a patient's teeth might be considered unpleasant, especially by the patient, because of the presence of orthodontic appliances on the labial and buccal surfaces of the patient's teeth. Suppliers of orthodontic brackets and systems, to provide more esthetically pleasing appliances, have in some cases eliminated metal bands that encircle the teeth and have developed brackets that are adaptea for direct bonding to the enamel surface of the teeth.
5till, with the archwire present at the labial and buccal surfaces of the patient's teeth, it is not possible to provide the patient with an orthodontic appliance system that presents the teeth in their normal appearance. Further, by r,ositioning orthodontic brack~ts on the labial and buccal surfaces of the patient's teeth, the orthodontic brackets frequently cause tissue irritation with the lip and mouth tissues o~ the patient.
~oreover, the mere presence of orthodontic brackets between the teeth and lips or cheeks can intefere to some extent w;th muscle tone and develop undesirable speech characteristics. In some cases, a patient~s teeth may tend to decalcify or become permanently discolored in the area covered by or adjacent to metal bands. Also, in many cases, the orthodontic appliances interfere with eEficient oral hygiene and caries can develop on tooth surfaces that cannot be properly cleaned. Consequently~
when the appliances are removed from the patient's teet~, the otherwise pleasant appearance of properly occlu~ing teeth can be marred by irregular surfaces, band lines of discoloration and fissures that can be developed in the enamel. By locating the appliances on the lingual surfaces of the patient's ~eeth, the labial surface will re~.ain clear of obstructions that otherwise would interfere with efficient oral hygiene. It is desirable, therefore, to provide for lingual edgewise orthodontic therapy because of the effective nature ~hereof and to allow the labial surfaces of the teeth of the patient to remain unobstructed to permit efficient cleaning thereof and ~o provide the patient with a pleasant facial appearance during the period of orthodontic therapy. It is also desicable to provide lingual edge~ise orthodontic therapy without subjecting the patient to the presence of brackets and archwires between the teeth and lip and cheek surEaces.
In some cases, it is desirable that the orthodontist be capable of applying tooth movement forces to the lingual surfaces of a patient's teeth. ~ith conventional edgewise therapy, ~orces are typically ap?lied through brackets that are positioned only i73 at the labial and buccal surfaces~ It is ~esirable, therefore, to provide orthodontic brackets that permit edgewise therapy thcough location of orthodontic brackets at the lingual surfaces of the patient's teeth.
Single brackets for edgewise therapy typically incorporate a base structure which is formed to define a precision active archwire slot which receives the rectangular edgewise archwire therein~ 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 ~ypically centered with respect to the bracket structure and are therefore intended to be positioned in substantially centered mesio-dis~al relation with the facial surface of the tooth to which the bracket is secured. ~ ligature wire or elastic is looped over each of the tie wings and is passed over the archwire, thus securing the archwire firmly in its precision slot.
Single brackets provide maximum efficiency in the application of tipping and torquing movements to teeth but are minimally efficient in rotational contcol. Initially, rotational control was accomplished by soldering or welding eyelets at the extreme mesial or ~istal of the band attached to the tooth. The orthodontist coul~ ligate the eyelet to the archwirer pulling that surface closer to the archwire and causing the tooth to ~2~ 73 rotate about the centrally located br~cket. This is a cumbersome and inefficient method of rotational control.
Subsequently, fixed or flexible rotation levers, proiecting mesially and distally, were added to the centrally located single bcacket. Thus, a rotated tooth would have the cotation wing projecting more facially than the bracket. The archwire would touch the rotation wing and, as the wire is ligated into the bracket, cause the tooth to rotate about the bracket. The rotation lever is adjustable to project more or less to the facial as desired. This permits the orthodontist to select the amount of rotation desired by adjusting the rotation levec rather than adjusting the archwire.
The disadvantage of the rotation lever is evident in the initial stages of treatment. The archwire will not tolch the rotation lever if a tooth is tipped and rotated severely and will prevent either action from occurring unless the archwire is adjusted to strike the rotation lever when ligated. Thus, initial acchwire insertion can be inefficient and require more expertise to ligate.
Twin brackets were introduced to alleviate the inefficient rotation effe~tiveness of the single bracket.
Instead of one centrally located bracket, two brackets were placed at the ~esial and distal portions of the tooth. Thus, when each bracket is ligated to the archwire, the f~cial surface will ali~n itself with the archwire, rotating the tooth.

One of the principles of rotation in orthodonties is ovec-corcection of the original pcoblem to eompensate foc the rebound or relapse tendency. This is espeeially indicated foc rotated teeth. Twin brackets do not have the capaeity to over-rotate within themselves. Foc over-rotation with twin braekets, the archwire has to be bent or some auxilliary must be added to force the mesial or distal poction of the braeket away fcom the arehwire. Further, single edgewise brackets, without rotation levers, ~re also laeking in over-rotation eontrol eapability whieh will be discusse~ in more detail hereinbelow.
One of the more important advantages of single braekets is the advantage that is afforded by the aetive length of archwire existing between the points of connection to adjaeent braekets. This aetive arehwire length is known in the industry as ~interbraeket widthn. Sinee the eonneeting point between adjaeent single braekets is established at substantially the eenter of the a~jaeent teeth, the arehwire length, and thus the intecbraeket width, extends to points near the eenters of a~jaeent teeth. The lengthy arehwire span that exists between single braekets allows lower magnitude forees to be applied to the teeth ovec longer periods of time as eom~red to circumstances where the interbraeket width is limited and the active ar^hwire span is short. The long span of arehwire may be twisted much ~urther without causing permanent yietding or defor,nation of the metal of the archwire. ~here the archwire i73 between brackets is of limited length, which is typical where twin brackets are e~ployed with the edgewise technique, application of large magnitude forces to the teeth can occur with only minimal twisting or other deformation of the archwire.
Thus, a~ter limited movement of the teeth occurs, the forces induced by the arehwire dissipate quickly, thereby requiring frequent adjustment in order to maintain optimum force application. Of course, it is evident that frequent adjustment of orthodontie applianees neeessitates frequent visits by the patient for adjustment of the octhodontic applianee and is therefore disadvantagèous to the patient in this cegacd. Sueh frequent adjustment also requires a signifieant amount of chair time in the offiee of the orthodontist, thereby either increasing the eost of treatment to the patient, or minimizing the commercial advantage of orthodontic treatment on the paet of the orthodontist. It is desicable, therefore, to provide a system for octhodontie tceatment wherein patient visits are minimized and ehair time is also minimized, to th mutual benefit of both the patient and orthodontist.
Twin braekets for the ed~ewise technique have been employed for a considerable period of time. Twin brackets typically incorpocate a pair ~f spaced projections that extend from oc ace formed by the bracket base, each projection being formed to define a pcecision active acchwice slot segment. ~he spaced active archwice slot segments cooperate to define a 7~

precision archwire slot having the effec~ of ext~nding the entire len~th of the base. Each of the projeetions is provided with gingival and occlusal tie wings, the tie wings tecminating at the opposed side poctions of the base strueture. With the base strueture eentere~ in respeet to the tooth being moved, the tie wings will be positioned in pairs at opposite sides of the tooth, theceby defining bracket strueture with rotational control. The orthodontist may utilize ligature wires or elastic members between seleeted tie wings and the archwire to develop the foree moments that are neeessacy for efieient rotational eontco~.
One of the typieal disadvant~ges in utilization of twin bcaekets is the eonsequent minimization of interbraeket width that exists as the cesult of ~ositioning the tie wings at opposed side portions of the braeket structure. Ordinarily, as explained abovel minimization of interbraeket width in eonjunetion with the edgewise therapy, suffers the disadvantage of requiring frequent patient visits and inereasing ehaic time beeause of the neeessity for fcequent adjustment of the applianee in order to maint~in the focee levels within the optimum range foc effieient tooth movement. It is desirable, thecefoce, to provide lingual edgewise therapy with twin braekets having the interbraeket width of single brackets.
Anothec si~nificant disadvantage in the utiliz~tion of twin bcackets is th~t the spaces that ace typically av~ilable between the tie win~s of a~jacent bcaekets leave insuffi~ient ll 5i73 room between the teeth for closing loops and tie-back looos. It is desirable, ~herefoco, to pcovide a lingual octhodontic appli~nce syst~ that affocds the advantages o~fered by twin brackets and yet provides ample space betweon cectain tie wings of adjacent brackets to facilitate e~ficient use of closing loops and tie-back loops in conjunction with edgewise orthodontic theeapy.

Summary of the Invention It is a principal feature of the present invention to provide a novel lingual orthodontic bracket system which permits utilization of edgewise orthodontic therapy at the lingual portions of the teeth.
It is also a feature of this invention to provide a novel lingual orthodontic appliance system which includes structure permitting application of efficient rotational control forces to the teeth of the patient.
It is an ev~n further feature of this invention to provide a novel lingual or~hodontic aopliance system which allows the labial and buccal surfaces of the patient's teoth to remain ~ree of orthodontic appliances, thereby pecmitting the normal relationship of the facial tissues and teoth to remain undisturbed and to provide the pa~ient with a ple~sant oral appeacance during orthodontic thera?y.

l2 Among the several features of the present invention is contemplated the provision of a novel lingual orthodontic appliance system which enables mesial-occlusal insertion of an edgewise archwire into interfit~ing relation with the various octhodontic brackets of the anterior teeth, the cuspids, bicuspids and molars.
It is an even further feature of the present invention to provide a lingual orthodontie applianee system ineorporating a speeifieally designed lingual tube that permits mesial-oeelusal insection of the end portions of an arehwire therein and further permits rotation of the arehwire relation to the lingual tube to permit ocelusal insertion of the archwire into the preeision archwire slots of other braekets of the orthodontie applianee system.
It is another feature of this invention to provide a novel lingual orthodontie applianee system employing twin tie wings for effeetive rotational and tipping eontrol and whieh also provides for maintenanee of efficient interbracket spacing to permit effieient torquing movements in response to the edgewise technique.
It is ~lso a f ature of the present invention to provide a novel lingual orthodontic appliance system enabling an orthodontist to selectiv?ly utilize various combinations of cot~tion and over-cotation control, torque and tipping control simply throu~h selection of various lingu~1 edgewis? brack?ts of 5~

single or twin Eorm, at least some of which embody a centralized fulcrum and at least one precision active archwire slot in accor~ance with the princip31s of this invention.
It is an even further feature of this invention to provide a novel lingual orthodontic appliance system embodying fulcrum control and which system is of simple nature, is comparable with other orthodontic brackets fcom the standpoint of ease of installation and use and suffers no competitive disadvantage in comparison with other similar orthodontic bracket systems.
Briefly, the lingual orthodontic appliance s~stem of the present invention incorporates a base structure which is adapted to be secured in immovable relation with a tooth. The base may be attached to bands that are positioned about the teeth and cemented in place or the base may be adapted for direct bonding 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, depending upon the teeth to which the brackets are to be secured~ Regardless of the design of the particular brackets involved in lingual edgewise thecaoy, the acchwice slots are oriented for occlusal insertion of the archwire thecein. ~he terminal lingual attachments are designed to retain the tubular function thereof but are also of a conEirguation allowing mesio-occlusal insertion of the archwire end portions therein to thus permit occlusal insertion of the 7~3 arch poction o~ the archwire into the respective archwire slots of each of the other brackets.
To provide for eÇficient rotation, the lingual brackets may be in the ~orm of twin bracket structures having archwire relie~ between each of the pairs of tie wings and an intermediate fulcrum portion that defines the precision archwire slot of the bracke~. Thus, twin type lingual orthodontic brackets are provided which have maximum interbracket width such as is ordinarily afforded by single brackets for maintenance of maximum active archwire length between adjacent brackets. ~y providing an inter~e~iate fulcrum section with pairs of tie wings at each extremity thereof and by providing archwire relief between each of the pairs of tie wings, a twin lingual bracket is provided having eficient rotational contcol. ~urther, since the intermediate fulcrum section of the bracket is machined to form an active archwire slot, the twin lingual brackets also incorporate the e~ficient tipping and torquing activity ordinarily achieved by single brackets.
Lingual brackets may also be provi~ed oÇ the single tie wing type as dlsired for particular teeth of the patient. The single tie ~ing lingual bracket will have an archwire slot that opens toward the occlusal an~ wil be extended to provide ti~
wings for ligating and pinning. The appliance syste~
include lingual tube brackets which ace adapted ~or mesio-occlusal insertion oÇ the archwire ends into proper position therein. Each lin~ual tube is designed so that the archwire may be inserted in angular or in mesio-occlusal relation there-with. 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.
Specifically, in one aspect the present invention is directed to a fulcrum controlled lingual orthodontic bracket for edgewise orthodontic therapy, comprising: (a) base means adapted for attachment to the lingual surface of a tooth;
(b) ligating tie wing means extending from said base means;
(c) fulcrum means being formed by said base means and defining precision archwire contacting means oriented for occlusal and mesial insertion of an edgewise archwire; and (d) said base means defining archwire relief at each side of said archwire slot.
In another aspect the present invention is directed to a lingual orthodontic appliance for edgewise orthodontic therapy, comprising: (a~ a plurality of ligual orthodontic brackets for attachment to the lingual surfaces of a patient's anterior teeth, bicuspids and molars, each of said lingual orthodontic brackets defining active archwire slots opening toward the occlusal for insertion of an archwire toward the gingival therein; (b) intermediate fulcrum means forming said active archwire slot; (c) pairs of tie wing means extending beyond respective side portions of said fulcrum means to facilitate ~;2 6~S~3 ligation of said ed~ewise archwire to said brackets; and (d) archwire relief being defined intermediate each pair of tie wing means, said archwire relief providing for archwire induced rotation and over-rotation of said brackets and the teeth to which said brckets are secured.
In yet a further aspect the present invention is directed to a lingually oriented orthodontic bracket for edgewise ortho-dontic therapy, said orthodontic bracket comprising: (a) means for securing said bracket in substantially immovable relation with a tooth; and (b) base means extending from said securing means and being formed to define a precision active archwire slot having an occlusially directed archwire opening.
Brief Descri~tion of the Drawings _________ __________ __ In order that the manner in which the above recited advan-tages and features of this invention are attained and can be understood in detail, more particular description of the inven-tion 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 specif-ication. It is to be understood, however, that the appended drawings illustrate only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, Eor the invention may admit to other equally effective embodiments.
In the Drawin~s __________ _ Fig. 1 is a pictorial representation of lingual orthodon-tic appliances which are attached to the teeth of an orthodontic patient.

16a ~Z~S73 Fig. 2 is an isometric view of a twin lingual orthodontic bracket eonstructed in aeeordance with the present invention.
Fig. 3 is a fragmentary isometric view of a twin lingual bracket such as shown in Fig. 2 and which represents an ~lternative embodiment illustrating arehwire relief by means of angulated surfaces extending from the active arehwire slot.
Fig. 4 is an isometric view illustrating a single tie wing type orthodontic bracket being eonfigured for oeelusal insertion of an arehwire into the preeision aetive archwire slot thereof.
Fig. 5 is an end view Oe a single tie wing type lingual orthodontie braeket sueh as that shown in Fig. fl, whieh braeket is adapted for attaehment to the anterior teeth of a patient.
Fiq. 6 is a fragmentary plan view of a braeket stcueture sueh as shown in Figs. 4 ~nd 5 and representing a further modi~ied embodiment wherein the active archwire slot of the braeket strueture is shown to be of areuate eoneiguration so as to reeeive the areuate portion Oe an edgewise arehwire.
Fig. 7 is an isometrie view Oe ~ lingual bieuspid braeket that is eonstructe~ in accordance with the present invention and is adapted foc oeclusal insertiOn of an archwire into the active archwire slot theceo~.
Fig. 8 is an end view of the lingual bicuspid bracket of Fig. 7.

7~

Fig. 9 is an isometric view illustrating a lingual tube such as constructe~ in accordance with the teachings of this invention and showing a poction 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 illus~rating in full line an edgewire archwire being received in operative 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 bracket representing a modified embodiment of this 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. 1~.
Fig. 14 is a se_tional view of an antecior lingual bracket illustrating pinned retention o~ the edgewise archwire.
Fig. l5 is a view of a lingual tube bracket for ~esio-occulsal archwire insertion and illustrating pinned retention of an edgewise archwire.

l~

ii7~3 Fiy. 16 is a view towacd the gingival o~ a lin~ual tube bracket representing a modified e~bodiment of the invention and illustrating an insertion slot for ~esio-occlusal archwire insertion.
Fig. l7 is a sectional view of the bracket taken along line 17-17 of Fi~. 16.

Detailed Description~of Preferred E~bodiments Refecring now to the drawings and first to Fig. 1, the fr~g~entary sectional pictor~l illustration shows lingual portions o~ the ma~illary and mandibular arches of a patient under~oing orthodontic therapy in accordance with the edgewise technique and incOrQOrating a lingual orthodontic applicance system. ~s shown in Fig. 1, the various brackets of the lingual orthodontic system will be of differing construction, dependin~
upon the characteristics of the teeth to which the brackets are to be applied. For ex~ le, at the left hand portion o~ Fig. 1, the brackets 10 and 12 o incisors 14 and 16 respectively will have the genecal coni~uration sho~n 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. ~t the respective ends -o each of the ~axillary and ~andibular arches lingual tube orthodontic appliances such as shown at 26 and 28 are applied to respective ~olars 30 and 32 and will receive the respe_tive end portions o 57~

the archwire 33 and 35. ~s will be explained in detail hereinbelow, the lingual tube bcackets 26 and 28 are each adapte~
to receive the archwire extremities by mesio-occlusal insertion and provlde the usual tube function as well as permitting occlusal insertion of the archwire into the archwire slots of other brackets of the orthodontic appliance syste~. The various orthodontic brackets of the lingual appliance syste~ of Fig- I
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. ~he bracket body structure 36 incorporates a bonding pad 38 which is typically composed of metal and which is adapted to be bonded to the ena~el lingual surace 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 ~eans of welding or by any other suitable ~or~ of attachment.
The bracket body is also formed to define pairs of tie win~s such as shown at 40-42 and 44-45 which allow the archwire 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 ~esirable to pcovide a lingual orthodontic bracket foc th~ edgewise technique that is basically in the ~orn o a twin bracket structure which also incorporates over-rotational capability. In accordance with the present invention, the orthodontic bracket body 36 is ~or~ed to define an inter~edia~e fulcrum section 5~ which forns an inter~ediate projection 52. The intermediate fulcrum section 50 defines an in~ermediate ful~r~m edge 54 which is positioned in spaced relation with an opposed curved fulcrum surface 56 that is defined by the projection 52. The ulcru~ 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. ~lthough edgewise archwires for finishing activities are of rectangular cross-sectional configuration, it should be borne in ~ind that edgewise archwires for acco~nplishing tooth novelnent in the initial stages of orthodontic therapy are defined by wires havin~
a round cross-sectional configuration. The archwire slot is conpleted by a botto~ wall or surface 5~ which is contiguous with ~lat surfaces 50 an~ 6~ and which ~aces towar~ the occlusal. In fact, the flat sur~aces 5~ and 52, together with the botto~ wall surface 58 of the active archwire slot can be said to be defined by a singlP ~lat surface. It is not necessary, however, that sur~aces 60 and 52 be o~ flat con~iguration except that these -3L;~i6~L~73 surfaces should have no interference with the relationship o~ the archwire to the bottom wall surface 58 o~ the archwire slot.
The inter~ediate fulcrum section 50 provides ~or cot~tion of the bracket and tooth in relation to the archwire.
To provide the bracket with this rotational capability, it is necessacy that the bracket structure provide archwire relief on either side of the fulcrum section. To accom~lish these purposes, the bracket body 36 is formed to de~ine concave, curved relief surfaces 64 and 66 which are positioned in recessed relation with respect to the fulcrum edge S4 of the archwire slot. It is ~esirable that the surfaces 54 and 66 be sufficiently relieved in relation to the archwire that these surfaces do not co~e into contact with the archwire even under circumstances where the archwir~ is in angulated relation with the archwire slot at the tie wing portions of the bracket structure. ~l~hough it is pre~erable that the archwire not co~e into con~act with the relieved surfaces 64 and 66, it should be borne in mind that ducing the early stages of orthodontic treat~ent, especially in cases of gross ~alocclusion, the acchwire may require su~icient bending that it co~es into contact with an outer edge 65 or 57 de~ined by one of the archwire relie~ surfaces at the respective side portion of the bracket. ~ogically, interbracket width is then ii~ited. ~s soon as the ~aloccluded teeth begin to ~ove in resoonse to thecapy, however, the outer e~ge S5 or 57 of the bracket will ~ove out of ~2~i73 contact with the archwire. ~s soon as this occurs, ~axi~num interbracket width will be established and, ~co;n that point Ot urther tooth novenent will occur in response to the total interbracket width between adjacent f~lcrum sections. The archwire may, ~here~ore, be ligated with either one o~ the pairs of tie wings of the bracket in such ~anner that the archwire provides bracket and tooth rotational capability as the archwire tends to return to its normal configuration and thus i~parts a rotational ~orce through the bracket to the tooth. Further, the inter~nediate fulcrum section of the bracket and the relieved portions of the bracket structure in the tie wing areas cooperate to define a bracket structure having greater interbracket width than is ordinarily afforded by twin orthodontic brackets. In fact, assu~ing the active archwire slot of the bracket structure of Fig. 2 to be the same or less width as co~npared to the length of the archwire slot of a conventional single orthodontic brac'~et, the twin lin~u~l bracket o~ Fig. ~, therefore, defines an interbracket width that is at least as great as the interbracket wi~th defined by conventional single orthodontic brackets. ~s \nentioned above, the length o~ the archwire span that exists between adjacent single orthodontic brackets allows lower ~nagnitude forces to be applied to the teeth over longer periods of ti,ne as co~npared to circu~nstances where the interbracket width is li,nited and the archwire span is short, ~IL2~i73 such as is typical in the case of a~jacent twin brackets of conventional nature. ~y pcovidin~ the twin bracket of Fig. 2 with an inter~ediate fulcrum section and with relieved areas between the pairs of tie wings, the free archwire between the adjacent fulcrum sections of adjacent brackets will be as long as ordinarily possible in edgewise orthodontic therapy. The lon~
span of acchwire may, therefore, be twisted much further without causing permanent yielding or deformation of the metal from which the archwire is for~ed. In returning or springing back to its normal con~iguration, the edge~ise archwire will, therefore, apply a tooth moving force to the tooth over a longer period of ti~e, as compared to conventional twin brackets, without adjustment of the orthodontic appliance. This feature, of course, minimizes the frequency of adjustment of the orthodontic appliance and thus significantly minimizes the amount of chair ti~ne and the fcequency of visits that are required during the period of orthodontic therapy.
The inter~ediate fulcru~ section of the bracket structure, together with the relieved tie wing portions of the bracket, provi~e e~ficient over-rotational control, thus allowin~
the orthodontist to move the teeth ca~idly to the final ~ositions thereof and nini~izing the treat~ent tine necessary for e~fecting move,nent of the teeth to proper occlusion within the ~lveol~r arch.

~4 7~

Fig. 3 is a ~ragmentary iso~etric view illustrating a bracket structure similar to that of Fig. 2, wherein the acchwire relie~ is defined by angulated surfaces ~0 and ~2 diverging from a central fulcrum edge 84. ~s shown in Fig. 3, the alternative embodiment illustr~ted generally at 70 incorporates a bracket body structure 72 forming twin tie wing areas similar to that of Fig. 2 and forming an intermediate fulerum section having an aetive arehwire slot that is defined by a vertieal fulcrum edge 74 and a eurved f~lerum surfaee 75, togethec with a bottom surfaee 78. Desired arehwire relief for over-rotational control and maxi~nizing interbraeket width is defined by a pair of angulated relief surfaees 8~ and 82 that extend from the fulcrum edge 84. The fulerum edge 8g eooperates with the eurved ulerum surfaee 76 to de.ine line eontaet on eaeh side of the archwire.
This parallel line contraet establishes opposed lines of active acchwire reaction and defines interbraeket width of maximum span.
~ny bending or twisting of the archwire between adjaeent brackets extends ~rom the line contact with fulerum edge ~4 and line eontaet with eurved fulcrum sur~aee 76. The funetion of the orthodontie bracket o~ ~ig. 3 is essentially the sane as that deseribed above in connection with Fig. 2.
It nay be desirable to ~rovide a lingual type single orthodontic bracket under circumstances where size nakes twin tie wings impractical. In such case, the bracket structure may conveniently take the form illustrated in ~ig. 4 where a single lingual orthodontic bracket is shown generally at 38. The orthodontic bracket 8~ incorpor~tes a bracket body stLucture sn to which is interconnecte~ or integrally formed a bondin~ base 92 for bonding of the bracket to the lingual surfaces of the teeth of a patient undergoing orthodontic therapy.
The bracket body is formed to define a single pair o'c opposed tie wings 94 and 96 which enable the archwire to be ligated to the bracket structure with ligature wire, ligature elastics or other suitable means of ligation. The body structure 90 is also ormed to define a pair of curved relief surfaces 95 and 97 which are positioned on opposed sides o'c 3 centrally oriented fulcrum edge ~8 extending to outer edges 99 and 10~.
planar surface 101 is also for~ed by the bracket body which also establishes the botto.~ wall of the active archwire slot.
projection 102 extends fro~ the body structure 90 oppOSitQ the fulcru~ edge 9~ and for~s a curved fulcrum sur~ace 103.
Projection 102 i5 positioned between the opposed tie wings 94 and 96 so that a lig~ture wire or elastic looped aroun~ the tie wings will also be looped aroun~ the inter~ediate projection ln2 to thus secure the archwire to the bracket structure in close proxi~ity to the projection 132~ The projection 102 is formed integrally with the bracket body structure 90 and presents the curved fulcrum surf~ce 103 in parallel oriented relation with the opposite fulcrum edge 9~. The ODpOse~ fulcrum edge 9~ and curved fulccum surface 103 cooperate to define a pcecision archwire slot 104 within with an edgewise acchwice is ceceived in active relation therewith. That portion of planar surface 101 that extends between the opposed fulcrum edge 9~ and curved fulcrum surface 103 also funetions to deine the bottom wall of the preeision arehwire slot. The flat sided edgewise arehwire will have line eontaet with the fulerum edge ~8 and eurved fulerum pcojeetion surfaee 103.
The projection 102 functions as an integral part fuleru~ portion of the braeket strue~ure thus providing a pivot area inter~ediate the extremities of the braeket. ~urther, the projeetion 102, being relieved at eaeh extre~ity thereof, allows the arehwire to have a maximum interbraeket width with respeet to the intermediate projeetion or fulerum of the ad~aeent octhodontie braeket.
Sinee the arehwire of ~he lingual orthodontie applianee system will have an arehed or eurved portion having less radius of eurvature as eompared to eonventional 13bial orthodontie applianees, it m~y be neeessary to provile the vacious a~tive arehwire slots of the braekets with the capability of reeeiving the eurved arehwire in aetive engage~ent therewith. ~s shown in Fig. ~, braekets aeeording to this invention ~ay be provided having a precision archwire slot such ~s shown at 10~ which is at least partially ~efine~ by a genecally ~lanar surface 108 and an opposed convex surface ll~ that are cooperatel for~ed by the body S~3 portion of the bracket structure. ~s shown, planar surface 108 is ~or~ed by the body of the bracket while the convex surface 110 is for~ed by an intermediate projection 11~ extending from the body. Otherwise, the bracket structure shown in Fi~. 6 ~ay be quite si~ilar to the bracket structure of Fig. 5 or ~ay confor~
to the bracket structures of ~igs. 2 and 3. Obviously, only those orthodontic brackets that are located on anterior teeth would be provide~ with active archwire slots of curved configuration because the brackets of bicuspids and molars ordinacily receive rel~tively straight 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 from the configuration of brackets for anterior teeth. ~s shown in Figs.
8 and 9, a lingual bracket for the edgewise technique ~ay conveniently take the eor~ illustr~ted generally at 114. The lingual bicuspi~ bracket ~ay incorporate a bracket body structure 116 of gener~lly rectan~ular ~orm h~ving a bonding pad ll~
extending therefrom. The bonding pad will ordinarily be co~posed of ~etal and may be for~ed integr~lly with the bracket body 115 or, in the alternative, ~ay be connected to the bracket body in any suitable ~anner such as by welding, bondin~, etc. If desired, the bonding pad 1~ ~ay be co~posed of any suitable ~t~ 3 ,~aterial other than metal for attach~ent of the bracket to the lingual sur~ace of a bicuspid or ~olar. The bon~ing pad de~ines a curved bonding surface 119 that corresponds to the curvature of the lingual suc~ace of the bicuspid.
The body structure 11~ of the bracket is formed to define an inter~ediate shelf 120 which extends laterally from the inter~ediate portion of the bracket body and is oriented in generally parallel relation with the occlusal. ~lthough the intermediate shelf ~ay be of generally rectangular 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 are provided to facilitate retention of the archwire in proper relation with the shelf and with the archwire slot. The tie wing retainer projections of the br~cket structure each ~efine upper and lower tie wing projections 128 and 130 that extend respectively beyond the horizontal surfaces of the shelf l20. The upper portion 128 of each of the tie wings 122 an~ 121 each de~ines an inner planar sucface 132 as shown in ~ig. 8 that is positioned in parallel, spaced relation with a planar surface 134 de~ined by the bracket body 116 thus for~nin~ an active archwire slot -to receive the edgewise archwire. ~he planar surface l36 of the shelf 120 cooperates with parallel surfaces 132 and l34 to define the bottom wall oc surface of the active archwire slot. The bracket structure 114 is also foc~ed to ~efine an angulated, generally planar sur~ace 1~8 which functions as a guide surface to per~it eEficient entry of ~he edgewise archwire into its active relationship with the archwire slot defined by sur~aces l32-134-136. The angulated planar suc~ace 138 also provides relie~ to thus enable effieient ligating o~ the archwire in respect to the tie wing portion of the bracket structure. It should be borne in ~ind that the archwire slot of the bracket 114 is readily adapte~ to allow oeelusal insertion of the archwire therein.
This feature effeetively faeilitates effieient han~ling of the arehwire during inst311ation thereof. Further, for maloeeluded teeth, si~ple ~oree application to the arehwire will enable it to be guided by surface 138 into the active arehwire slot, thus appropriately bending or twisting the archwire to allow arehwire developed foree applieation to the braeket and tooth.
In aecordance with edgewise orthodontie therapy, the opposed end portions of eaeh acehwice ace typieally ceceived by molar tubes. In or~er to allow oeclusal insertion o~ the arehwire into t~le aetive arehwire slots of the respeetive braekets of the lingull orthodontie appliance system, it is desirable to peovide ~ lingual type tube bracket having the capability of reeeiving the extremities of the archwire in aceordanee with typical tube function and yet having the capability of per~itting mesio-occlusal insertion of the archwire therein to permit occlusal insertion of the archwire into the 3~

~V~ 7~

archwice slots o~ the remaining brackets. In accocdance with the present invention, a lingual tube bracket may conveniently take the form illustrated in Figs. 9~ s shown in the iso-netric view of Fig. 9, the lingual tube bracket is illustrated generally at 140 and incorporates a body structure 142 ~efining an archwire slot portion 144 at one extre!nity of the bracket which opens toward the gingiv~l while at the opposite extrelnity of the bracket, an archwire slot portion 146 is defined which opens toward the occlusal. The archwire slot portion 144 is defined by parallel interme~iate bracket surfaces 148 and 150 shown in broken line in Fig. l~ and a transverse planar surface 152 that intersects surfaces 148 ~nd 150 in normal relation. Thus, surfaces 148, 150 and 152 cooperate to define rectangular archwire slot portion 144.
The archwire slot portion 146 is defined by parallel surfaces 154 and 15h which are disposed in parallel relation and a transverse surface 158 which intersects surfaces 154 and 15~ in nor~al relation. The pairs of parallel surfaces 14~-150 and 154-156 are each ~or~e~ by precision machining or ~olding such that the archwire l50 is received in active relation within the respective archwire slot portions 144 and 145.
As ~entioned above, it is desirable that the archwire 150 have the capability of heing inserted into asseinbly with tne lingual tube bracket structure 140 by ~eans of nesio-occlusal insertion. This ~eature is shown in ~ull lines an~ broken lines ~1 in Figs. 9 and 10. To permit ~esio-occlusal insertion of the archwice, the lingual tube bracket is ~ormed to de~ine an opening 162 which extends co~pletely through the bracket structure. This opening is defined in part by surfaces 164 and 166 which are identified ~oce clearly in the sectional view of Fig. 1~ and the plan view o~ Fig. Il. The edge 168 define~ by intersecting surfaces 158 and 166 functions as a pivot, about which the archwire 1~0 is enabled to rotate as it is moved ~ro~ the inclined, broken line position shown in Fig. 10 to the normal, operative posi~ion shown in full line in Figs. 9 and 10. The extre~ities of the archwire 160 are thus inserted mesio-occlusally through the openings 152 of the lingual tubes and, afte~ being so positioned, the archwire is then rotated about the edge 168 to the full line position shown in Figs. 9 and 10. Upon reaching the full line position, the remaining poctions of the archwire are inserted occlusally into the respective active archwire slots o~ the other brackets of the lingual orthodontic appliance. ~hen the archwire 160 is in contact with the tube defining surf~ces 152 and 158 o~ the lingual tube, it functions in the sa~e manner as if the lingual tube were provi~ed with a single elongated rectangular opening. The ar~hwire is then ligated with respect to the lingual tube by ~eans o~ ligature wires or el3stics which extend about oppose~ tie wing portions 170 and 172 o~ the bracket structure. The body structure of the ~2~7~

bracket is cut away at l71 and 173 for~in~ corners or notches that adapt the bracket to ceceive ligating ~evices such as wires, elastic ~embers., etc., as shown in broken line. ~s shown in broken line, the tie wings 170 and 172 ~ay be in registry with the outer wall surfaee 174 of the bracket structure or, as shown in full line, ~ay extend outwardly beyond the w~ll sucface to faeilitate ease o~ ation. Ligating deviees sueh as wires, elastie bands, etc., may also be looped around the tie wings 170 and 172 as shown in broken line at 175.
lingual orthodontic braeket syste~ has been shown in ~igs. 1-11 wherein an edgewise arehwire may be inserted ~esio-occusally into the arehwire slots of the interrela~ed bracket system and may then be li~ated to the braekets by ~eans of ligatuce wire, elastie bands, ete. It may be desirable to seeure the edgewise arehwire in asse~bly within the aetive arehwire slots of the braekets by ~eans other than a ligating syste~. In aceordanee with the features of this invention, sueh braeket structure ~ay conveniently take the for~ set forth in Figs. l2-14. Fi~s. 12 and l3 relate to lingu~l orthodontic braeket struetures whieh are ceeeived by the bieusoids of the patient while Fig. 14 shows ~ lingual orthodontie braeket Eor anteriOr teeth. In eaeh ease, the arehwire is seeured to the braeket strueture by ~eans of a retainer oin si~ilar to that utilized in eonjunetion with the ~egg light-wire technique.

Refecring now to Figs. 12 and 13, a lingual orthodontic bracket is shown generally at 180 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 st~ucture 184 extends from the bonding base and de~ines a projec~ing support shel~ 186 which extends the width o the body. Tie wing projections 188 and 190 extend from respective extremities of the support shelf 186 and define upper and lower tie wings that receive ligating devices to secure an edgewise archwire in assembly with the bracket structure. ~s shown, the tie wing projection 188 defines tie wing portions 190 and 192 while tie wing projection 190 deflnes tie wing extensions 194 and 196. In this manner, the lingual bracket 180 is si~ilar to the bracket construction illustrated in Fig. 7.
In order to provide for pinned retention of the edgewise aechwire in asse~bly with the bracket, an intermediate projection 198 extends fco~ the central portin of the support shelf 186. The intermediate projection 198 defines a bore or passage 200 through which is extended the shaft portion 202 of a retainer pin 204. The retainer pin includes a transverse retainer head portion 206 which overlies the edgewise archwire 208 which is received within the active archwire slot portions defined at each extremity of the bracket structure in the manner discussed above in connection with Fig. 7. The elongated sha~t portion 202 of the retainer pin extends well beyond one extremity ~73 of the intermediate projection 198 and may be bent over as shown in Fig. I2, thus locking the retainer pin in connection with the intermediate projection. In this manner, the acchwire may be secured in asse~bly with the bracket structure without necessi~ating the use of ligating devices. ~Iso, if desired, ligating devices may be employed on one or the other of the tie wing projections 1~8 or l90 as desired for accomplishing tooth move~ent in accordance with the edgewise technique. The pin 204 is removed by stcaightening the lower extremity an~ then extracting it from the bore 200.
A pin retention type orthodontic bracket for the anterior teeth is shown generally at 210 in ~ig. 14. The bracket 210 incorporates a bonding base 212 for bonding of the bracket steuctuee ~o the lingual surface of a patient's tooth. The bracket also incorporates a body structure 214 which defines an archwire slot 216 in the same mannec as discussed above in connection with Figs. 4 and 5, eor exa~ple. The intermediate fulcrum portion of the bracket structure is formed to define a pin receptacle or projection portion 218 which defines a bore or passage Z20 within which is received the elongated shaft or shank portion 224 of a retainer pin 226. The retainer pin also defines a transverse retainer head portion 228 which overlies the archwire slot 216 and functions to secure an edgewise archwire in active relation therein. The elongated shaft or shank 224 Oe the pin extends well beyond one extremi~ of the projection 218 and may be bent over in the same manner as shown in Fig. l2 in ocder 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 of any suitable malleable metal or other material which may be bent over to secure the pin in place and ~ay be straightened 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 the light-wire technique of Begg.
It may also be desirable to secure an archwire in asseinbly with a lingual tube bracket by pinning rather t~an by ligation as is the case with the lingu~l tube bracket of Fig. 9.
In order to accomplish this featuer, a ~nodified lingual tube bracket rnay be provided in the manner illustrated generally at 230 in Fig. l5. The lingual tube bracket 230 incorporateS a body structure 232 which eocms an elongated active archwire groove 23q in the same manner as discussed above in connection with Fig. 9.
The archwire groove or slot 234 is of generally rectangulac for~
and has an active relationship with the flat surfaces of the rectangular edgewise archwire 236. The body structure 232 is forned to define a retainer orojection 2~8 having an elongated passage 240 extending therethrough. ~ retainQr pin 24~ ~orming an elongated shank 243 is adapted to be extended through the passage 240 in such ~anner that a ter~inal poction o~ the shank extends beyond the retainee portion 238 of the bracket. The retainer pin 242 is formed at one extre~ity to define an enlarged reta~ner head 244 which is offset rel~tive to the shank portion of the retainer pin. ~ portion of the enlarged head is adapte~
to overlie and engage the upper portion oc the archwire 236 thereby positively securi~g it in active relation within the archwire slot 234.
For ~esio-occlusal insertion of an edgewise archwire into the active archwire slot of a lingual tube bracket, the bracket structure may take the ~or~ shown generally at 250 in Figs. 16 and 17. Fig. 16 is a view toward the gingival while Fig. 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 comprises a bracket body structure 252 having a bonding base 251 extending therefro~. The bonding base defines an arcuate bonding surface concor~ing to the curvature of the ~olar to which the bracket is to be bonded. The body structure 252 of the bracket defines an elongated active archwire slot 254 for~ed in part by upper an~ lower surfa-ces 256 and 258 an~ by planar surfaces 252 and 264. ~n edgewise archwire 268 is received in active relation within the acchwice slot 254.

To eacilitate insertion of the free extremities o the edgewise archwire 26~, the body stcucture 252 o~ the bracket is for~ed to define an entry groove 266 which is for~ed in part by an angulated guide surface 260 and by extended portions Oe the planar 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 surface 260 guides the free extremities of the archwire from the entry slot 256 into active relation within the archwire slot. ~lthough the archwire 26~ nay be quite sti~f, such as during finishing therapy, it nevertheless is 1exible to some de-~ree. ~ter the free extrernities o~ the archwire have been inserted into the entry slot 266 an~ are fed into the beginning portion of the archwire slot 254, the acchwire may be flexed to so~ne e~tent toward the gingival. Flexing o the free extremities causes the end portions oE the archwire to becorne oriented in substantially parallel relation with respect to the active acchwire slot 254. ~y sinply applying 3 orce to the archwire, th~ eree extrernities of the archwire will be gui-]ed into and along the archwice slot. ~he angular relationship o~
the archwire during such ~esio-occlusal insertion ~nove-nent is quite s~all since the curve~ portion Oe the archwire need only clear the anterior teeth beore the ar^hwire is pivoted to ~nove the curved portion into the active archwire slots of the ant-rior bicuspid and ~ol~r teeth.

In comparing the lingu31 tube bracket structures of aigs. 16 and 17 with that o~ ~igs. 9-ll, it is cleat that the archwire need not be extended completely thcough the bracket structure of Figs. 16 and 17 to acco~plish mesio-occlusal insertion of the archwire into the active slots of the respeetive brackets.
In view of the foregoin~, it is apparent that I have provided a lingual orthodontie applianee syste~ which may be effeetively utilized in aeeordance with the edgewise teehnique for eEEieient orthodontic thera~y. Orthodontic therapy may ~e readily eondueted while at the sa~e ti~e, the labial and buecal sur~aces of the teeth of the patient re~ain clear of obstructions so that ef~ieient cleaning ~y be readily conducte~ and oral hygiene more easily maintained. Moreover, the outward appe3rance of the tee~h oE the patient will be quite pleasant and the patient will not, therefor, be subjeeted to the degree of psyehologieal trauma or~inarily assoei3ted with applieation of orthodontic appliances to the labial surfaees of the teeth.
The lingual orthodontic appliances oE the present invention are designed sueh that the edgewise archwire is adaoted to be inserted into the c~spective active acchwire~slots by ~e3ns of occlus31 insertion. This feature effectively facilitates ease oE installation oE the acchwire and ease of adjust~ents that ~re typic311y ~a1e during orthodontic therapy.

The vari~us orthodontic appliances of this lingual system shall employ a ulcrum controlled twin tie wing technique where appropriate for acco~plishmen~ of efficient rotation which is ordinarily beyond the capability of twin orthodontic appliances in conjunction with the edgewise technique. The lingual orthodontic appliance system of this invention also incorporates molar tubes which allow ~esio-occlusal insertion of the archwire ~herein and which provides a typical tube bracket function when the archwire is in operative relation therewith.
The bracket structures ~ay be desi~ned for ligature or pin retention of the edgewise archwire as desired. It is, there~ore~
apparent that the present invention is one adapted to attain all of the objects and features hereinabove set forth, together with other features which are inherent in the description of the apparatus itself.
While the foregoing is directed to the preferred embo~iments of the present invention, other and further e~bodiments of the invention may be devised without departing fron the basic concept thereo~, and the scope of this invention is deter~ined by the claims which follow.
I CLAI.~:

~0 ..

Claims (21)

Claims:

1. A fulcrum controlled lingual orthodontic bracket for edgewise orthodontic therapy, comprising:
(a) base means adapted for attachment to the lingual surface of a tooth;
(b) ligating tie wing means extending from said base means;
(c) fulcrum means being formed by said base means and defining precision archwire contacting means oriented for occlusal and mesial insertion of an edgewise archwire; and (d) said base means defining archwire relief at each side of said archwire slot.

2. A fulcrum controlled lingual orthodontic bracket as recited in Claim 1, wherein said edgewise archwire is of rectangular cross-section configuration defining parallel labial and lingual surfaces and parallel occlusal and gingival surfaces, and:
said archwire contacting means is defined by parallel opposed archwire engaging means oriented to control torque by interaction with said labial and lingual surfaces of the edgewise archwire.

3. A fulcrum controlled lingual orthodontic bracket as recited in Claim 1, wherein said ligating tie wing means comprises:
(a) pairs of twin tie wings located at respective mesial and distal extremities of said base means said pairs of twin tie wings being oriented in spaced relation; and (b) said fulcrum means being a fulcrum edge and a curved fulcrum surface being located at least partially between said spaced pairs of tie wings, said curved surface being parallel with said fulcrum edge.

4. A fulcrum controlled lingual orthodontic bracket as recited in Claim 1, wherein said ligating tie wing means comprises:
(a) a first tie wing extending from said base means on one side of said archwire slot;
(b) a second tie wing extending from said base means on the opposite side of said archwire slot; and (c) said fulcrum means being located between said first and second tie wings.

5. A fulcrum controlled lingual orthodontic bracket as recited in Claim 1, wherein:
said archwire relief extends from said archwire contacting means to respective extremities of said base means, said archwire relief being both labial and lingual relief to permit controlled rotational movement of the tooth to which the bracket is secured.

6. A fulcrum controlled lingual orthodontic bracket as recited in Claim 5, wherein:
said archwire relief is defined by lingually diverging inclined surfaces extending from said archwire contacting means to respective extremities of said base means.

7. A fulcrum controlled lingual orthodontic bracket as recited in Claim 5, wherein:

said archwire relief is defined by recesses formed by said base means and extending from said archwire contacting means to respective extremities of said base means.

8. A fulcrum controlled lingual orthodontic bracket as recited in Claim 1, including:
a fulcrum projection extending from said base means, said fulcrum projection being formed to define said archwire contacting means, said fulcrum projection being positioned intermediate the extremities of said base means and cooperat-ing with said base means to form at least a portion of said archwire relief means.

9. A fulcrum controlled lingual orthodontic bracket as recited in Claim 8, wherein said archwire contacting means comprises:
(a) a fulcrum edge defined by said body and adapted for active engagement by said archwire; and (b) a curved fulcrum surface being defined by said ful-crum projection, said fulcrum surface being parallel with said fulcrum edge and spaced sufficiently therefrom to permit active engagement with said archwire in accordance with the edgewise technique.

10. A lingual orthodontic appliance for edgewise orthodontic therapy, comprising:
(a) a plurality of ligual orthodontic brackets for attachment to the lingual surfaces of a patient's anterior teeth, bicuspids and molars, each of said lingual orthodontic brackets defining active archwire slots opening toward the occlusal for insertion of an archwire toward the gingival therein;

(b) intermediate fulcrum means forming said active arch-wire slot;
(c) pairs of tie wing means extending beyond respective side portions of said fulcrum means to facilitate ligation of said edgewise archwire to said brackets; and (d) archwire relief being defined intermediate each pair of tie wing means, said archwire relief providing for archwire induced rotation and over-rotation of said brackets and the teeth to which said brackets are secured.

11. A lingual orthodontic appliance as recited in Claim 10, wherein at least some of said lingual orthodontic brackets comprise:
(a) base means adapted for attachment to the lingual surface of a tooth;
(b) ligating tie wing means extending from said base means;
(c) fulcrum means being formed by said base means and defining a precision archwire slot oriented for occlusal insertion of an edgewise archwire therein; and (d) said base means defining archwire relief at each extremeity of said archwire slot.

12. A lingual orthodontic appliance as recited in Claim 11, wherein:
(a) said edgewise archwire is of rectangular cross-sectional configuration defining parallel labial and lingual surfaces and parallel occlusal and gingival surfaces; and (b) said archwire slot is defined by parallel archwire reaction fulcrum means oriented to control torque by inter-action with said labial and lingual surfaces of the edgewise archwire.

13. A lingual orthodontic appliance as recited in Claim 12, wherein at least some of said lingual orthodontic brackets comprise:
(a) pairs of twin tie wings located at respective mesial and distal extremities of said base means said pairs of twin tie wings being oriented in spaced relation; and (b) said fulcrum means being located at least partially between said spaced pairs of tie wings.

14. A lingual orthodontic appliance as recited in Claim 12, wherein at least some of said lingual orthodontic brackets comprise:
(a) a first tie wing extending from said base means on one side of said archwire slot;
(b) a second tie wing extending from said base means on the opposite side of said archwire slot; and (c) said fulcrum means being located between said first and second tie wings.

15. A lingual orthodontic appliance as recited in Claim 12, wherein:
said archwire relief extends from the extremities of said archwire slot to respective extremities of said base means, said archwire relief being both labial and lingual relief to permit controlled rotational movement of the tooth to which the bracket is secured.

16. A lingual orthodontic appliance as recited in Claim 15, wherein:

said archwire relief is defined by lingually diverging inclined surfaces extending from respective extremities of said archwire slot to respective extremities of said base means.

17. A lingual orthodontic appliance as recited Claim 15, wherein:
said archwire relief is defined by recesses formed by said base means and extending from respective extremities of said archwire slot to respective extremities of said base means.

18. A lingual orthodontic appliance as recited in Claim 11, wherein:
a fulcrum projection extends from said base means, said fulcrum projection being formed to define said archwire slot, said fulcrum projection being positioned intermediate the extremities of said base means and cooperating with said base means to form at least a portion of said archwire relief means.

19. a lingually oriented orthodontic bracket for edgewise orthodontic therapy, said orthodontic bracket comprising:
(a) means for securing said bracket in substantially immovable relation with a tooth; and (b) base means extending from said securing means and being formed to define a precision active archwire slot having an occlusially directed archwire opening.

20. A lingually oriented orthodontic bracket as recited in Claim 19, wherein:

said base means defines a fulcrum portion intermediate the extremities thereof, said fulcrum portion defining said precision active archwire slot,

21. A lingually oriented orthodontic bracket as recited in Claim 19, wherein said bracket includes:
(a) a pair of spaced ligating tie wings extending from said base means and being disposed on one side of said precision archwire slot; and (b) at least one ligating tie wing extending from said base means and being disposed on the opposite side of said precision archwire slot.