THE

DENTAL COSMOS VOL. LVIII.

OJ<LGINAL COMMUNICATIONS

Some New Forms of Orthodontic Mechanism. and the Reasons for Their Introduction.

By EDWARD H ANCLE. M.D., D.D.S., Sc. D.

(l( ... ~ before tbe .4.10,,,,.' &Oj~ty of the Anglo Scbool of Orth<>dontiA, New London, C"'ln., July 11 , 1916.)

AT the illSt three meetings of t.hiB !!OCiety 1 h .. v~, by mean. of locture8 and clinics, carefully described iWd

e~pMjlled the use of certain lonna af ortl,od"ntic mochaniom which are nnw known ill; the "pin and tube" appliance. '1'he description and di.scw;sion of the.e appliance. arc recorded in the D ENTAl.

COSMOS for Mar<:h 1910, August 1912, and January 1913. Complete familiar. ity with these artidetl i ! ebsolutely es­sential to a prOpl'r undcrf;tanding of what r shan today otI~r for your con aid ­eration.

THt PI/< ANt> TUDE APPLIANC E, AND WOR'fHLB83 :MODU'ICJoTIO!lS.

The introduction of the pin and tube appliance nru:lonbtedly marl.:OO a great step forward in orthooontic t reaime-nt , for with it W!l.S gainee. not only bettel' control of force for the crown. move-

,~L. u",.~3

men/s of teeth, but aLe.o it was tho first practical mechan ism for \.he proper con· trol and distribution of force for th e mowment of roots of teeth, siuII!Y Ilr collectively, and simultaueously ,,") U, Ilr independently of their crown move­ments. And, what is of still greater im _ port8.nc~, witlt this m~han i8m the foeee for tile mOV'!1nent of ei\l'er crow llJl or roots can be appliee. and controlled in a manner that i~ far more m:srly in accord with the requirements of ilic physiology of the ti'lllues involoee. in t.ootll mOve­ment than with any other previonsly em­ployed. It is well known iliat more n€arly ide&! re.ults in occlusion and in ooue development, as well as in facia l development, have been gained by its use than W/Ill ever possible before.

Its use hl1$ become sbmdard with the bett orthodontists of thia snd other coun­tries, and it is of COUrM very gratifying 1("1 me te know that my pred ictions N-

."

TIU DENTAL C08MOS.

~rding its v81u~ have ~n verifie<! _ Yet It i~ a humi hating fact that many who al"'l attempt ing the practIce of ortho­dontia _'" to ]x, eo la<:king iu judg­ment and in wchll1cal skill as to be unable to ga in anything uearly like the ",eru;ure of &"cce68 that i5 iX"l"ible in the usc of th i" mwhanisrn, of to appr~iate tile fact tllat corr~t fonns and propor_ tions and proper material for the con· st.uction of the various paris, wiUI accuracy and per [~tion of workmaruh ip in manufadure, are esseutial to its proper efficiency. The principal difficulty wilh most of these iCCmi to be inability to properly locate the pin~ and attach them to til e meta! a~h, aud many indeed have ~n the modifications of the m~haniam and the 8u~titntes devised in order to overcome this to them insurmountable difficu lty, and to obviate the necessity for acqui ring wchnical flkill and accnracy. In all insiances delic&Cy and simplicity, sod te> a large eIteut efficiency, ha,·e been .acrificed. Indeed., some of the product ions are 8() crude and clumsy as 10 be mechani~81 ~uriositie8.·

Realizing how apparently hopeleSli to many ill the lUaa\ery of the i<lchnique of thi5 appliance, I hue, stter many months of carefu l thought snd e~peri­mentatiou, sucee6ded in producing an­oth~r type of me<:haniJ;m_that which I am about to do?SCribe, and which, while reta ining much, if not all, of the force control of the pin and tu]x, appliance,

r.sses- other advantag<l$, besides being at easie r to apP? ~nd operate. In fact

it i~ so ~imple think you will ogre<) with me tJld there i8 now no neces.sity whatever for change of principle or moo _ incatiou of iorm, even by the habItual "modifier," that well ·known type of practition", whose greatest h.ppiness seelU~ to cousist in modificatiou of me", detai l, in llle<:haoiSOI- nearly a l wa y~ to ti' e detriment of the mecllaniam_

In p~enting th is uell' mechaoiBDl 1 fully rea lize lhe moral reEpon!.lbility I must assume or that anyone must as­sume when h~ Mkmpb to add Ruything

. s.. II.".. Of I"' ...... '. Jun. I~H. and l>""!Q! ,~ ~"' ... rv. Moy IOl ~

to ilie already vel)" larg<l numbe r and ,·ariety of orthodontic aPflianOO>. If the add<'d dev ice be not tru i" useful and an advance beyond what hn already ~n produced, better by far it should De,·er a.ppear, fQr it will not only CaU~ unne«esary inconvenience and di.ap' poiniment to many patienh and orlhe­donti&ts, aud further add to th~ cou­fnsion of our hwrdure aud to tbe per_ pk'lity of ilie ever-increasing number who revie.' it, but it .. ill l~n confi_ dence in its author. The U8nal crude modificat.ion or mel"'! difference withQut distinction in principle i8 more often a step backward than forwud, but there BI"'! reaSOn. why, at this timt, there ahould be addit.ion8 to our orthodontic merh~ni8m, addit iotl. that Me rell im. pl"O;·emenbl, real inventions, the wonder· fu l adVllnee3 that ha,·e been made in the 'lCience of orthodontia in the pa.t very few yeQ", having made necessary the re­arrang<>ment of our entire plan of treat­ment, and demanding d~ided ]x,tter­ment ill orthodontic mcehani6Dl.

INJUDICIOUS I':XTR.\Cl"ION.

.A1! you know, it was formerly the practice to extract one Or mOI"'l of the teeth thd were moat mi<!placed, hence most difficult to correct, or-\Ollat wa" often worse in elIect-to extrad other~, usualiy two or mote premolars, to "make room" for Ihe malposed teeth. The crowns on ly of those that rem~ine<! were then "pu!led into alignment" wlthout rega.rd to "hat "hould be the true po­~i tiolls of either their roots or thcIT crown. in the typal archii<lctura l line of the arch-tho Jine of occlmion--or of (heir relatioM to the skull. The in· eviiable result of ouch radically wrong pradi~ was to considerably dimioiejl th~ !izes of the denial arch~, thereby corre;;pond ingly impairing the function and leMening the efficiency of the den­tUFt, and renderio" deBcient the growill and fn nction of the as&ICiatcd paJU---­that j~, of the alveolar process, the n(>l!e, throot, tongue, lip5, ek-llIld marring the f&cial hM$ to an nwnt always noticeable and u&uaUy mco;i unpleMing.

J..vor.£.--1lOltv. .'fIlW FOUtS OP 0~OnoH110 )(.cnJ.l<lS)(' 971

l'b.~. plan of lr-ea.tment 10 obviouly il· Iogiet.l alld unsci~lItili\! thould h&oe .... Ions been '0110"'00 without quedion no. &eetltl llIott .urpril;ing, for. IIMlnge u it may appear to ruany, it ia in mOIl! CMe. far ea.ier ro establi. b tho non,,"1 in ocelUlion than to temporiz.e in treat­ment, a. to take the IUppoeed ahort cut by UK mutil.tion route, which ca ll newer be followed by satisfaeto.y ~ulu; be­eouae it ia contrary to D.Ill1te.

".CIIIIIIITT O. BSTARLISfUYO YOIUIJ.L rUIfOT lol< 01 DBNTAL ANa COH U · LAT1:u PARTS.

The duty of the orthodontiat i. not merely to "straighten teeth," but to ..... ltote the ia.t function aT to e!t.bli.h lhe normal 'unetion of the denture and aU ita oor~lat..J parts. Thi. means not only thlt normal relatio ... Ihall be u­tabli.hed bet ..... n the inclined planf. of tllf CI'OWIlJI of an the teeth .hich D.Iture hu decreed lhall be p~nt, but lilat their ~ 1II11st aho be gi.en nO'lIlIi position., with the n\l(;0I$l'Y devtlo~. ment of the a1veol8r p'<)<)eS8 fOT thelf . uppo.!. For be it c.nphuiud that 0" 1M OOTted pooition. of the roots of the u.eth depend. to a very large deS:TM the permaneuce of the nom,.1 relatlOna of tbtlr em.lII. Moreo~., there IUnat be eltlbliabed nonnal funct ionl or li~ toague, 1lOIf, and thro.t, for from th_ intimately related and highly interde­pendent tiRlne. IUId .trudul'fll coma the .n~i!iIrY focool wbieh inUit abo be en· li8ted for the nltimate 81lpport of the koeUI ;n their corrected pC>@i tionl. Th_ fOreel art the penn.nent retaincn whirh "m hold the teeth in normal occlu.ion H normal, and in malocdullon if .hno.· mal. in lhtir ful\ctiolla-

Furthermore, it "folio .... II tIM nigb! the day" that only in proportion u tbe furcea of lTQwth, denlopment, nd func­tion of 1M denture and ill oorrelaw:t ~rll tore nonnalUed "ill there result true h.lan<le, beanty, and harmo"y of Ihe fR~ in accordance with it. type. On U,;I bui. only ca~ orthodontic t .. \.mtn! be pennllDenUy Mneflcial and t ruly IItio/actory, for Incb ollly i. in

aerordaooe with natnre. And thit. i. the true meaning of orthodontia.

INIIICATION S TOR UR1.T TIt&<TNnNT.

Another important point shOUld ~I$O he ..... again M empbuired, namely, thlt childrf n ... ith deweloping malocclulion, which ;. al ... ". progrllli$i"e, lhould not ho- pnt of[ on one preteI! Or another un til they h .. e reached the 'I\" of fifteen y"'!'3, or until malooeh~ion and .nalde­welopment shall hue about reached their mllimum, but !bAt t re.tment ahould be bl>gun promptly u early al! it is mini. festly required, even in the d~idU'OU5 d~ntuT<'. lor .t thi. early period ie un · douhtedly oft'~~ our greatll.t opportu · nity for the ul timate eiUblilhment of normal dev~Jopment aDd function of the pennaneol denture IUd all ito a""""'"ted parts. Yet I would .~ the same time .110 emphuiae that the nHillesa inter. ference ", ith child denwMI, HOW 10

often done, Clnnot M too strongly con· demned. ,

From the foregoing it will be eetll that th~ iICOpo of oTthodont.1l. lin been greatly .. i<!enell, and that the demand for the brOf.der, dfeper nudy of both the theory and practice of the leieuce 3 im· penthe.

TKB rnT810LOO.e J.PPL1{'.'TIOY or I'OIIC8.

A~ we heve ~n, the r«toration of the denture to normal fnndiou demaud. not only the crown movement, but f~· qntntly the bodily movement of teeth. Tooth mooement .I",av, involve. bone· dlAlurhBnce-oone-<iel!tNdiou and bone­growth-and theee d~pmd on tile fune­tioll;"g of bone-co!lll, their .eti.ity re­sulting from m~hlUieal stimnl_in orthodOntic treatment from tloe Ilimulu. of mechanical force front the Ippliancea. We are, Ihere'ore, ... holly dependent on the o&t~lutl and ",teoblestl in OUT ef· fom at i-ooth movt,nent. A. D •. Fred· erick B. Noyeo! hu well said, the~ are the true orthodonlilli!; we but thelt di. N!<:ton.

H tIIit. interp~tltion of tM demandl

of DatUIl! in ttet.tment i8 wrrect, more ",l ion.! mctl: .... d. and lno", appropriate lIlecilauLmt than hue been ~eralLl em­ployed are certainly needed, that we may hue perfect control of the for« D~ sary in the nI'lI:Jumied stimulus we are to.> give n~tu ll! in he r effortl at remodd· ing the ~nture.

Or. ALliin Oppenheim of Vienn., <me of my former student., in hi, muterly, ~poch_marking .paper on his uperimenu. on tooth rnOVllliIcnt in .~, given hefon Ihil aociety in Ihis cit y in 19 li: hall pro1'ed OOIldOllli1'ely Wi gentle force oontiDuGlliIly applied .-ill not only move ~th far more rapidly than grut toroe, but that great foroe CI1l6tll eongl"tiou and often .. holly ntllrds the functional ""Ii"ity of the cella for min, houri to­gether. Thi. being true, how utumely impomn\ doe. it beoome that forw from tJl~ ol"thooonUc IPIIi,nee tOlr Itim­ulating the ad;y; t,. 0 tho! ooll\!...,.,ll. .hall aceoro ..-ilh the phy,iologicN need. of the <;til_that iI, that i~ olian not 00 too grut nor too little in amGuot, th.t it lhall be [me from interrurtiOIll lind diijt~rblnres, and !lull it wa! ~ e~enly dilltributed and colltinuomly .pplied in 1M rig!., dirfGtibn,o oll.l~, Force .-roogly applied, such .. n.pid and he­,<"ent changes in BDlount and direction, alway, inevitable in the liM! of faulty me(hanism, gTeatil. diaturbo the norm~ adivi ty or Ihe cel, and (a~ IIOreneM, paint inll.mmalion, and fK)ffinimN Uen the duth of the pulp, OOaidN, pouibly, per<n.n~nt iPjury to the hone and peri, dental membrane. On the other hand, fol'C1! phy.iologi~lly applied il att£nded by the painle!!8 movement of teeth .nd nonnll reconstruction of lbe t;..uN_

~t:QtlIRJ:)f~"TS or 10-)1 lDlUL API'LUNCH.

It mUlt therefore be apparent that in onler to be trul)' lueft&6fl,l! in meeting the p.-nent dem.nds of t .... tment, ortho­dontic mecitanism mUll peTreclly ""n­trol the Amount, direction, and didri. bulion of force fOT ,It nO!<'!eS'lary looth

• PlIbliohNi iD U .. .1 _"". 0.' ........ 1101, 1'11.

movement, Ind at the wne time that it nnllt be of the (TUle8t po.oible .im. plicit), . nd deliCS<!)'. The ideal appij· .nee would gi.e gentle, COD&tant foro!! in the de6ired direcl.ionl only. With it boll, the root and ~roWll of a single tooth, nr of &11 the teeth in the den tun! thd require mnlement, could be mnTed in the .. me ditee1inn or in oppooite di· re<:t.ion., and, if need be, .lmnll.alle<)lllL!,. 11u)0)0 movements, l nrthotmo"", ...-ould be painleu, !et II rapid II il conoident "lth the phy.iologiCA! functioning of the ctI!. of the aheOhr p-. peridental men,brUJe, aud go'n'_ The ideal .ppli· ance would reduce to the minimum the incon"enience to the ~tient, .. well u the time required for it. lint adjnslment and for making the n_ry "'~u~nt changes. It would .lso mo~e teeth in ,"ch .trict I6OOrda~ with the 1 • .-, governing ho"e·,boorption Iud bone-­growth that thm! .. ould be littl~ if IU,I' neecl for .ubeeq~n t ~ining apph. 11l<:N, for by the time the teeth bad at· tained theiT IIOrmai pooitiollf. the 001>6 would be nOTTnl in an",,,"t and ,true-­lure. Hence it would be .mple for the eupport of the terlh atter the ortho' dontie IpplilooelL had been removed,

r.rolided of cou ..... that lucb correbted 01'Ol!l &I! were lUo pte'l'iouII, abnormll

had muntime hew. wnnalil\!Ol-that iI, for_ from improper habits of lips, tongue, ""pin.tion, ~. - fOT I re~t tblt, withou t the norm,llupporl and co­ol"'ratioD of these there can be no 183\11" anoe of pennanenne in the pooitione of the teeth that han hoon corrected. In ~ word, th~ O..t~OOOllt'" m..,hDo .. "", rhould ~, ... IU'ctml ouil~ and .. ~olly ",b"'rN,,1 10 III pk,Noal and p1syNW~ r«l1'"'" mt .. ta- of 1~G.tm,,,t.

THB W"TII~" I<!W O~Y!OXS.

1'he fonnl of mecN.uism 1 .hall now delCribe, il Dot ,trieUy in aceonI. " ith ,It the ideala ut forth, .nil, [ belie"" upon ~.reful a.nalJ@;' by com~tenl judgee, at 1.,,,,1 be found to be meMUr· .bly neaN!r th_ ideal.r. than any ()f the fonu. hitherto employed. They baft not been hlltil)' e.ol~ed, bu t IN the ",",ult

ANOLB.-SOMB NIIW roR)(Jl 01' OR'l'HOOOIi1'IC lISCIU.SISM. 973

of lon~ Hperi~DC'l, close and careful oil. MrvatlOn, and th~ clO8<'St consideration (>[ eYery detail as to the material of which they are wmp<llle<.l , their ~i:eo;, form&, proportions and rel~tiona of pam, the

FIO. 1

4iIId~-"!!!

M ,

.n<!Chanical principles on which thoy are to operate, and the phymcd and physio­logic~1 laws that are to go.~rn their use_ At ih~ same time the object has be<m to produce an appliance which will ~ e~sy to undc~tllnd aud 0() "impl~ "-'i to

",dUe<! to ihe minimum ihe difficul· t ies and exactions of the t<cl!nique of ooth its adjuatment and operatio,, _ Thi. m<l<;haniBJIl i. of course b_d on that e~e<!Jlent main prweiple of the expansion arch given to n. ](mg ago by thn t great Froncilman, Fauehard, whom e$pe<:ially

811 orthodontid6 are honored in honoring. Some of the de vices life bu t modified forms of my own former, well ·knowu appliancea; othera atO ro.dically new All are harmoniously proportioued, ",fined, and very deli~aie.

BIU.CJ[>;J".

A , F jg, I, aho ws a delicate block of metal, or bra<;ket, actual sioe, and B 8nd c, Fig. 1, show it enJarged to facilitate deecription _ An are shown amelled to band material. The outer edge of the brackd i8 ronnded, "-Ii are alIw ita coruers and its two end., its 8ides being straight and paraJlel. Inwardly, a deep tl1lns­.erse slot extends downward in the bl1lcket one·half the length of the bra<;ket , terminating in ~ conce.ve floor, The walls of this ~lot are parallel, one of them bcing formed by the band material anrl the other by the iIlj!ide of ihe bracket proper. In the center of vIe latter w.ll ia a delicate square perpendicular groove wh ich passea down­"'ard alld , through the l100r of the

bracket. In use will be considered later. 'fhe band material to whi~h the bracket iJ! I!Oldeffil. alId "'hieh forms th6 inne r wall of the slot ~ ih icl<ened at th~ point, whiclt is very import8.nt, in order to give ,t the neoo;sary dreogth . Fig. 2 sho"', ""veral bracketed bands Stted and ceo

9" "fHt; Df,~l''''L COSMOS,

menwd to tloe erowllS of the inc;wra of an upper dental arch lypical of il,OOI!, ~sp<:Cially in ela."" I, in which tI,e W<llh are crowded and Um dental arches pro­portionately dimini,hed in ai'A), It will

(.022") in tbiCknC8S and thirty·six thousandlh$ of an inch (.036') in width . Its ends are also flat, but threaded, Bud are provided with my well.known fric­t ion lock DUU.. which ha.e been greatl~'

Flc. 3.

be specially noted that the seam. of the hands hoe been fonued on the lingual surfaces of the teeth. Bnd that the bra(kets are located d the Ct"tor of their labial su rfaces.

"HIDBO"''' EXPAl<SIQ" Anell.

Fig. 3 shows, in actual size, a ·very dehcde, flat continuous, Or non_sectional, expansion ar~h with rmrallel sidea and round~d edgea. It has, therefo..." the {(lrm (If a ribbon, and in order W du o tinguish it from the other forma of my ~~p8n"ion archei, I ha.e called it the " ribbon" expansion arch. It iB but twenty-two thonsandtru. of an ineh

reduced in diameter in order that they may confonn to the ddiea!e proP'WtiOlU of \h is arch, which ;6 11S00 ;n connection with the \l!llaJ ~nchor clamp bands, the .he~ths of whieh ate all!() reduced m

di.merer and ~ other novel featn ]". which will be described later. They 8re ~hown OIl the teeth in Fig. 2. A trons­vet":le ~tiQn of the ribb<.>n areh, enlarged, is slso shown in Fig. 3.

Al'PLIC~Tl0N 0' IIIBBON ARCH.

In order to place the ribbon arch in position on the teeth, aB shown in .Figs. 2 8nd 4, one of its scre'" enda i. inlleTte<!

A:<OL8.-80XE N EW FOII)'[S OF OR'fHOJ)(lNTIC MECHA.'<ISII. 9r~

in the sheath of the auchor bQnd on one of the fitst molars, and the f riction lock nut is seated The ar~h is then spr~ng with the fiuge,.. into the .lots in the bra~ket.!, ... hi~h it s('Curately tits, begiuniug with the one nearest to the fitst auehor hand alld ~roo::eWing in tegular order until the anchor band on the opposite molar is reached, when the ~e<JOnd nut is adjusted to appro:>:imately iho proper po6jtion on the sreh, bnt neither the end of the arch nor the fric· tion portion of the Dut are at tlt~ time placed within the sheath of the anchor band. The arch is theu disengaged from all the brackets, but not from the .heath of the first anchor b~nd _ Now the screw of the )006« end of the arch is slipped into il.8 ~hoeath on the ~econd anchor band, and the nllt WIlted. Then, begin­ning as before, the arch is roplaced in the bl"l!.cketa in e~aet1y ita former rela­tions, the lut etep being the proper ,;eat· ing and accn rate adjulmenl of tile sec· ond nut ;n it! author "heath. Means for preyenting the accidental displacement of the arch from the br~ket& will be con_ eiderod lAter.

RJ.N(l£ 0" llSE ~llLNE88 OP THE RIDSON ARCH.

By studying the engraving, 1-'ig. 2, it will be """y W un deJ""!tand the manner in .... hid, the force is applied to <llIch of the mslposed teeth in order W effect not on ly their individual. but ali(> their coll('Ctive mo\·emenu, . 1'he eluticity of the lIr<!h, in thill 6pecia) case, operates constautly for tM labial movement of the laterals, the torsional movement of the centrals, Il,e bu('Cal mov<!m~nt of the fird pre­molars, and the lingual mMement of the canines. And, as thero i. no WMW of power throngh Ille "lipping of "tta~h· ments, the movement of the teeth must continue nntil the force from the elastic· ity of the arch u then btn t has become emausted, and the arch pass)'e. Force is renewed by removing the an;h and bending it to more nea rl y ideal fonn, when it is again sprung into place in the brad.els lind sheaths. By this mean. the teeth lire movo>d continuously, until

lillally the ribbon arch h~. boon given the exaet fonn desired for the den­t.l arch, aud the teeth, through their br&Cket at~hment., have boon made to coDform perfectly to it . As the metal of wh ich the an;h 16 made '" very elastic, 8nd u the r ibbon fOTm permits much greater range of elasticity than does a r<Jund arch, the force will be contiuued iN a oorresponrlingly longer p;lriod be­fore it is neces.sary to remove the arch and modify i\.5 fonn _ JJ)deerl, but two Or three modificatioIll dnring the whole CQUI"!Ie of tretotment would probably be enough in most ca&e6. The force is ~ently and almost oontinuouily operative in exactly the right direction, wi thout the i njnriou~ disturba.n~e of cell func­tion which must follow the use of Bny mechBni~m that requires f requent re­rooval ~nd ropl a~ment.

FlO, 5.

17·' -.

-. : \ ....

\ ! '. '" \. ;"

Anothe,- point which .8Cmi of great importe.n~e to me is that the force i~ distributed to the ]fl(><ing teeth auwmat_ ic~lly, ea~h receiving ita proportionate share both in BUlount and in di rection. To e~pla i u this point : The pecuUarity of the b!"acket attachlnent is such that th~ teo:th may slide freely in a lateral direction upon ij-,e ribbon areh. like beads upon /I ... ire, as shown in Fig. 5, f,(> that "a.;h moves along tl,e line of least realslance toward its nonnal position and automatiClllly _i$1.8 di=Uy and ind i­recuy in plncing all thc other teeth. In no other orthodontic !D('Chani.m is sneh wmpJete J1!Ciprocility of movement pos. sible_

Sometimes, however, it is desirable to prevent Qne or mor€ of th" teeth f rom ~hdiu;::: on the arch . 'f bis i. dOM hy soldenng a veri delicote ,pur upon me Oilier .urfaN 0 the ribbon arch close to

'" Tlrll: DENTAL COSIII08.

the bracket in such rw:-itiOIl II tQ pre­vent the sliding of the tootll.

AI the teeth may llide freely on thi~ arch, the c\Ol!lng of 'pace between &uy 1"0 teeth, u for example two cen t""l iudll(l~ (aee }<'ijl;. 6) may 00 effected by mUll' of a metal ligature made to em· bra~ the braeketa upon the t ... o teeth and OC<'UionaUy rene.ed or ti!htened. (The two utreme aid .. of the ipture , Iululd be behind the metal arch, not in front of it, u IhOWIl;n th8 engraving.) If it ia de5!red to move one of the teeth on11, the movement of the other may be pre­Yeated by the means aboye deacribN.

Another point w be emphasi:&ed in the 115<1 of this mechanism is that Ute fo ree ia elerted upon the tooth wholly

PI4 .•.

through the bracket .lId not by '-ring apillilt any other portiou of tooth or NDd. T hIS accurale mechanical .ttach. ment Dot only penuill the fret'r no.nge of eJuliei!y from the metal ,reb and oonacqllenUy m(lte ~dy dialribul>on of the foree, but pre.eut. any pouible un­(. v"uble int\uen(e upon the teeth that aN! being mo~ed . Thi, il because the fiat parallel walll of the metal bllck"et fit the panlltl sidea ot U,e rib­bon .reh $0 accnnleiy that teeth bl-ing moved outw.rd, II the lateral illcison! in . 'ig. 2, Cllllnot be rol1led uof .. orahly by contact with adjoioing teeth. Alllo, whto rotation iA daired, the force is ~xtrted through the bracht and not by prying 00 a 0011l6r of th~ tooth. AI the arch Issume'! i~ perfe-ct fonn, the de­,iled movcmcnu of the teeth take place ill accordance therewith through the QC­

w,o/& "'t~l ~l1ICht rdiltio .... , F'lge. 7 and 8. H eretofore rotatiOIl hu U!ually ~II I"t'gIIrded as U,e mQ&t diffi·

cult of all tooth movemenbl to looom­plilh. TIli, i, becaose romplete force control h .. ~n impossible with the mechAoiem previou5ly at Ollr dilpo&a].. With the mechslIiam here c-oueiderM, the force may be 110 continuou, "nd eyenly diltributed thAt rotAtion beooml!ll no more difl\cult than anJ other tooth lUoyemeol The principle employed i.e that ot the double lever-two elutic leYen! operating with equal foroe in op­polite di~tio .....

PI ... 7.

l'08SIBI~Il'V 0' QRQ W>( .,10 ROOT XOVl\· )1fi>(T.

To uoid confulion iu diJcuuinj!: this mechanism, we have"" far oolUlldered only tll8 erofl'll moyementll of teeth, but the diatribution I.Dd control of force for root mO'l'ement i.e equally feuible with it, either simultaneously "ith ennm movement Ind in the ... me or in oppot.ite direetiolil, or independe!.Uy of eroW1l mOO'ement. The force from the elutic arch i.e di.etribut.ed to the mob throuj(}! the yi.e-like g .... p of the arch by tlie hraehta. (Tbe direction of force upon the root deJl!'ude upon the anfle of in­dinatioll glytU to the .l"'ra.lle ,idei of the metal .reb, ""fore It i.e sprung into

AYGLE .,-SOllE NlIW J"<)B ){S 01' OR1'IIOO(lN1'IO )( I\CIU NIS>I . 977

tho br~keta. ) If the crown and root movements ~re to be equal and in the sam~ direction, ae in A., Fif. 9, where bQth are to be mo\"oo labial y, (It in B,

Fig. 9, where both are to be moved lingually, the ... alls of the ribOOn arch mU8t be perpendicular before the arch is sprung into the bracket, &0 that the force will be dilrtributed equally and in the Mme direction to hoJth root II1Id crown. If the labial movement of a root only is

taining we ribbon arch within ilia slut of the brad:et. Unless the a.reh be f ree from the danger of accidental diepla.ce­ment and firmly maintained in the hrMket slot to its full depth , iliere is a probability of lou of po1DM' and the lack of its pcrfut CQntrol. These two fea­tnl"<'s ate &0 ,·ery essential in ort.hodontk mec.hani~m that their importance i3 at last being keenly recugnized by om best orthodontists, and the many crude app li-

F lO. ~.

•

" . , . , ' ! n N'U\ ! ; "" ... ' \ I : i .

•

requiJW., the ribbon atch is bent in the region of the bracket &0 that it ... ill flare outwardly at the gin!;ival border, and when sprung into pOI!itlOn in the bracht .... ill bind alld exert force in a labial di · rection on the root of the tooth, M in c. l 'ig. 9. By flaring it inwa.«lly, to that it will bind in the oppoolite direction when ~prnng into the bracket, the toot of the tooth will be moved in a ling>lal direction, as in n, ~'ig. 9. So it i. eMily JXlS!ible to mOve either root Or crown to any dfgroo, according to the fonn giwn the ribbon arch and the angle at which it is ind ined ill iIB bracket relations.

" KRF JrCT CONTROL BY >lEANS OF LOCK PIN .

.Before considuing othfr movements frequMtly nece88llty, su~h as elevation or depression of t.eeth in their .....:kets, the tipping of mol,," or othe-r teeth to up­right pc>sitionB, or the bodily movement of Weth meeiaily or distally in th~ line of occlusion, let u.a couOiider another im· portant f""ture of the mechaniJ!m, namely, the meanS of ett(')ciually main-

\® t: \ , ,

ances in which a large p!lrt of Ole JXlwer is .. ·.sted or mischicyously di rected are rapidly losing fa"Of.

After much carefnl thought and €I­

peri mentation in which probably moat, if not all;of the poesjble IUeaM of main_ tain illg proper arch and bracket relationa

rIG 10.

• •

we~ considered, II method was finally de"clo~ which seemed (Iecidedly more effident, simple, lind pradkable thall any uf the others. It consists ill locking ilie arch in th'" bracket. by metw.8 of a lock pin, shown in actual site at A, k'ig. 10, and greatly enla'"l"'d at II, Fig. 10. lt is very delicate- bnt ten thousandth. of an inch (.OION) square- and pointed

'1'11 1 DBNUL COS MOS.

at one ~nd, the other end h1"ing .. he.d .. h ;ch prnjecte to one . ide. In Ih,pe it do .... l,. NlIHnble. the ordinary railroad epLke, a.nd !I proport.ioned to give the gffat«t deheacy COIll15tent .,ith .U De. oeM&ry.strongth. The .rcb being firmly llelted III the bnr.ckH, the point of the locI: pin ;. inaerted in tbe .perture of the sqU&N!.~1"e of the br..:ket, puehed dO .. D until it can be gruped .,ith I p"ir of Ho., pliers, .nd dl"l""ll through until ilA ht"&d ~b ;0 firm contact with the edge of the ,lbooo areh .. F ig. 11. It fib the grooTe Tery .ecu~ rlLtely. The poiu t i, now p1.Llled and bent

• • fO ..... Ard And upwud and clipped oft, thul firm ly clinching it in poIition, U .hown in H, Fig. 11. 1'he roughened end is then smoothed and hurnished 110 lhlt it .,ill not interfere .... ith the lip.

In th;' limple manner the Irch i. securely hcld, yet the lock pin iJ 10 del. icate thAt, when it ill in poolition, it ill h.rdly nouttable Utepl npoD e\oee in. lipootion. By .traightcning it. bent end by rn"""",, of. delia.te ehi .... l or the blade of .. Iman knife, the lock pin ma, be readily removed .. itll the Irch II the I.tter il lifted out of ita IIOCket conDee­tion.

CORRECTION 0' II'PR.<· "11"0 8u n .. • OCC LU6ION.

1'eeth that a~ in infra-«clnlion rnl, be elev.ted lor I prinf!:ing the .rch giagi •• Illl, . nd keyI ng i t mto ill b ... eket nil' tioPJ! by meam of the lock piDs, u in Fig. 12, the Tlpidity _LId extent of the m ovemeut bfing under the (uil eontrol of the orthodontist.

B, r .... ~nling the dirretion of the force teeth in eupra·oociusion may bf dep..-.i

Fl. ... 12.

in thei r .ockeb, all in F ig. 13, . nd this, too, limultanOOU!ly .,ith othe r mon .. mell~ that rna, he n~'1 for ~itheT

rw. 13 .

ULeir crowPJ! Or Ih~ir rOQU, .,. alreldy described.

TIPPINO :UIrl"H 1'0 Ur lHaUT POSITION.

Tloe demands of treatment .180 often necessitate tipping of one Or more Qf the buccal teeth to uptigh t poIitioo, which

;. "sill ItCI."OIDplished after the mann~r shown Ln Fig. H. Camul stud, of the device iU Ultnted in thi. engl"l1"ing will ahow hOlT perlecUy the force i. und .... control for the hin~like fo ...... ni·t ip-ping movement of the premola .... I . the

ANGLE.-SO:llE NBW FORMS OF ORTHOOOl<'flC >!EOIIAN'S)! . 919

nut i~ tightened, the delicate spur at­tached to the Quter surface Qf the arch bearing llga"l~t the dist.tl aurfae<! Qf tile bracket, a, while ti,e anchor tooth Qffers full, even, and ..qUAl t"e$isUu'e<! through · Qut the: tntire .Ioeollr connedion with· Qut the poosibility Qf it.. being tipped Qr the <hrectlQn of [orca upon it being changl!d (stationary anchQrage) ,

It iii Qften deairable to tip the mQlar disWly to an upright positiQn at the same time that the premolar is being tipped mesially (see Fig. U} - in Qrtho­dontic pradice to regain spa~ lQst by mutilatiQn Qr the non-eruption of teeth, !<lld in dental pr.dice lor the beiter re­lation of hridge ~butmcn l8. l'b i~ ma~· be done quite eR.ily hy combining th~ f~= from the elasticity of the rI bbon

f19. 15.

C. '

arch with th~t from tbe IICre ,,- , 'I'he anchor band is adjusted on the molar ~o that the .heath will lin(! below the bAnd upon the prelnolll r, Fig. I:;. After the arch i~ ~eated in the an~hQr 8he..th, it is sprung upward into ita bl"\l~ket J"<l­latiQo, thus e~erting a constant pry up· wl\rd Qn tbe snwrior root and dQwnward on the posterior root of the mQbr, plus the fQrce in a diat~1 direction gained by tighteuing the nuL The lONe is th\l& ideally direcood Rnd ~nd er p<lrfed con· trol, and will he found very ellective.

NQtwithstanding the great I1lnge in the elasticity Qf the ribbon ar~h when w employed, wme of th is elasticity WQuid he lost in springing the areh up over the Quter wall Qf the bracket Qf the band on the pNmQlIl r, espedally when the le<lth U~ cloaer to.l(ether than.is showlI in the engravlUg. Thi. possible lou of spring may be completely Qbviated by reversing the ~itiQn of the slot in the bnlcket

when the balld is formed about the pre­mQlar- that is, by placing the opelling Qf the slQt $inginlly instead of Qeel". · aUy. In tllle ca~e the downward spring Qf the arch would 00 bornc hy the lock pin, which if properly !pphed would amply support it. 'fhe additional mQH· ment of rotation Qf eiiber Qf thcec teeib may be accomplished simultaneo'lsly by bending the ribbon arch 80 that it will bind within the bracket Qr sheath, Bnd e~ert rotatory force in the desired direc­tiQn.

CHATS FO~ mmp A.rrA.C1!)U!NT .

If the bodily movement Qf ally Qr the buccal teeth ie required, tho hm~·like atta~hmcTlt is chenged to a rigid attach-

ment, If, l'ig. 16, which will render tipping of the tooth irnpo&lible. 'l'hi3 rigidity i3 gained by oold~ring two del­icate square ball! of mdal (see (Z, F jg. IS) trans~eraely to the M'th , these barE or cleat.. being parallel and in contact wiih the m(>S;a l and distal surfaC<'ll Qf the brae"e!. The rigid attachment of the cleat. to the nch and their close grasp Qf the sides of tho bracket ellectu­ally pre~ent the tipping of the tooth, alld n~it.ate iu bodily mQnment 3.'j tht nut in ftollt Qf th anchQr sheath i~ oc­cuiQnally a\i.l(htly tightened. Althoull:h simple and ellectiYe, the efficiency Qf the de'"ice depends wholly upon the accuracv with wbid. the clcau fit ti,e brocket. -

PACILITATINO Til l!: SQI.t)~ RINO Qf CI,u'TS.

The ooldering of tl<"Q delicate bk" Qf metal traru;wrsely to the arch 60 tbat tbey will be exactly parallel and at the

'" THE DENT'\L COSMOS.

same time aepa.n>.ted only the exact width of the " racket is a feat in soldering that would tax the most skilful. After much thQllght and e~perimentatioo. a plan Wali hit upon which not only in$ures &C<,lurncy but ]l)ak~a the o~cation & very easy one. 'The deal\! are sLunped from a ahed of metal so tI,at ilia two ue counected at one eno, and they are seps ..... \.e<.I by ex­actly the desiroo distance (see A, Fig. I'l). T his U torm oJ metal ;$ then easiTy SoOlde",d at any point on the fiat areh . aa at B, Fig. 17. The 8urplOQ portion oJ the U is then ~ut off, leaving the deats a~ at C 81ld D, Fig. 17, ill mt"Chan­iCIIUy correct l'<Jlationa. I n order to still further ~;mplify the operation it i! hoped

FlO. 11.

•

that, in manufacturing. the solder may be rolled upou one ~urf,.,.,& of the metal before the U'5 are stamped. This would obviously be of great advantage, 8./1 it would then (>Dly rem~in to apply the proper flUI and heat in ord~, te attach them and would insure the proper qUill" ity Il~d quantity of IIOlder andyreyent ihl acddenu.l di"l'la.ccment durmg IIOlder. ing. Until this i~ done, .ery minute pjecoo n! aolder only JOust be employed, as any surplus solder will prevent the wBting of the arch in the slot in the hracket.

VA&10U8 APPLICATIONS or CLEAT5.

Agllju re ferring to /I., Fig. 16, it will readily be undeTlltood that the root move· ment of the premolar may be ea..ily ac· celerated or retarded b)' bending the ribbon arch alighlly upward or down· wart! just poste rior to thc dee.t IItt..ch· ment , thUB causi n/ol' tJ,e clefl.u, to bind npon the bracket as the arch ] $ spruog

into poi!ition. Or the &ame mault will follow if the deab are originally sol. dered at a shghtl)· different angle on the arch fron' that at Which the brn.::ket i. stu.ched to th ... band.

In order to ruxomplil;h the bodily movement of incisors in a mesial or distal djr~tion, as for e~ample in F ig. 6, the crown movemena of which have already bMn dill¢ussed, it i~ only n<lCe:t­!,lIry to apply the dee.ta to the ucb 110 that they "' ill engage the mesial Iud dislal wall, of both brackeu upon the teeth . The force is then applied. by the gradual formation of a loop or crimp betw""n the two teeth, letting the crimp e~t.end into the embra!ial epace between them-not fonni ng a vertical loop, the bandulne'lll of which I eloall later point

""' Another way of acoomplil;hing the6C results would be to occaaion&\Iy cnt very short "~tions from the areh in tllia region, and then to C&r~ f lllly reunite the end. with 8OId~r_ Th,,* twO methoos combined might of teo be desirable. Or, by meaM of .. ligature, the crown may .5J'\1t be movoo, QS in Fig. 6, and then the root., by the addition of the cleat attachmenb to the arch. For this ih. cluts would 00 00 attached QS to bind On the bl1l.ckets, thus cOllctlntTliling the foree upon the roots in a mesi .. ] direc· tion.

POINTS OF UIPOIlT~Nce I>' SlI"PII<(I TnE IU BBON Alleli .

T he ~ibbon s~h should be 110 shaped that it wi ll exert lull fOml by ib t"", eiuticity through the bracket connro· nons alone, as I have already poiuted out, without touching the teeth, · as in }'ig. . 2, 7, and 8, and with as little in· terference with the lip!! lUI possible. In ca_ where the mal·arrangement of the tooth i~ not great., 0Ji in fi$"' 2, the rih»on arch, will,out any prehml.nary bendlDg,

• It will or <lOU'" be rU'p""sible ~lw.I' to ~"O i" haying th~ ribbon a roh tou.~ \.to" . ening _~, but .hi • • h""l~ be don. ",~.n · eye ' ~ibl ..... ouch <lO.t..et inkrf.,.", .. ;th the It .. • I • • tle;" of the .,."h, .. nd eo_· quenUy with I,,, .. «lnt,ol.

A/fOLK.-80ME NEW FORMS Oil" ORTHOOONT((; MJ!lCH4N"ISM . 981

may ~ elIsily aprung into pooIition in the bmci<et.!; with thefingeMl &lone. But where V,e teeth aro in pronounced mal­ocdusion, the arch must first be most carefully shaped out.!;ide of the mouth, wholly independent of the bracke\.'!, by meana of pliers, in accord alice with the poaiiiona of t.l,e teeth ILJl shown by the plaster model~. To bend it iJl..5ide the mouth, assiated by the brackets on the bands alone, would require snch I".' fo= that the bra~ket would o;<lrtain y be ;trained and ruined, Or the connection between b.nd aud lOOill would be broken. This will apply equally to the finer .hap-. ing of tlJ.e arch in order to CauS<! it to bind within ille bmckets 90 thet power may be applied in p.t:rti<:uler dire<:tion. to ind ividUILI teeth, as for rotation, or for root or bodily movement. Therefol"C, w~ would emphasi,e the fact that we arch mmt be so perfectly formed jnde­pendently of the bracket ill all in~tan,-",. thet it may be .... ily seated with the fingers, or pos~ibly OIith IS piece of wood held lD the fingers, to aV(>1d the danger of straining the bracket. Thll.!! the per­led rot between brocket IIud srcl" so \"Cry necessary for perfect fore~ control and !lO carefully worked out in m~nuf8Cture, mlly be preserve<.!.

Anot1:ter point of mll~h importance in the shaping of the arch is to Qooid bend­ing or marring it !j() a. to change iill fonn in the least at the points where it is to be engllgOO in \.he brackets. Any £hange would render it difficult or im· poesible to scat it " ithollt siraiuing th~ bracket.

flESDISG PLIERS.

So importaut is the proper bending of the arch thet it hM made Ue<:ellllary the special fOml of pIiC!"!l shown in Fig. 18. Round-be>lke<.! pllers must not be used, b"t we nell' plief6 illustrated are ideal for the purpoo;e. The dimeusions of the. trans.erse slot (S<!en nCar the end of on(> of the beaks) co~!pond$ exactly to thoae of the ~Iot in the bracket, Whe'l tlLe erth is placed in thi$ .Iot, and the beab are cla.sed, it is held iu the Mme maUner thllt it wou ld 00 in the bracket on \.be band, but. more rigidly. It may now be

bent a.. deeired wttJLOut marring it in any way and without changing the form of that pat!. of it which eng~ the bracket ylot, go that, when it ia replaced, it will fi t. very ac<:nrately. No other method of shaping the Brch insures such accuracy

Fla. 18.

of fi t between atch and slot, and this is always of the utm~t importance. In shaping the arch _t specific poin\.$ for accelera.ting Or retarding root-mo\"ement, or for rotation, as in Figs. 8 lind 9, theoe pli~rG aTe indispeMable. 'fhis firm grMp of the arch and its .teadv support are abo necewLry while bending

982 THE DMJ<TAL QO$:IIO~.

it edgewise upnrd or dow nw'rd at might he r<!<:!u;roo in cases .imila~ to those shown in ~'igs . 12 a.nd 13, but for mtn, rtalOWl pe1"pl.'ndi~lIl.r bendt in the ardl, "peeiatty aharp bend., m ould al_ ways he avo,aed.

'l'he \I~nal n~ry cunes in tho! rib­bon II'ch between the attachmentl rna, be made w'lh the fin~ra Or with the round portinn of the beak of the&/! plien.

'l'h.e proper ."d uniform I.n.Oealing Qf ~he rI bbon 8~h ;. qlli" .. importut aI I~ that (If the dolicate round areb. of the pin an,1 bl~ de~icetl, Iud in no other ... y \"ell th,~ be .to .u~fulll' Ic.::om­pliehed ... by the ~mploJment of Ihe clecuic .nneale •.

Alto, in order that tile", nay be per_ fect oolltrol 15 to the amonnt and direc. ti'ln of the foT<'<! in the UJf! of the ribbon &«,h, it ;. hight;r imP'>rta.Qt that each In<l ,II modiftcationa in the form oJ tile In;)b ,luring treatment be made in accor. dance ~'ith the archograph, lUI pointo!d ou t by Dr. String in ronn"",tion Tith the .~h of the pin and tub<! appliaDa'. Only >n tillS ,. .• ,. ca.n /l'ueNing be elimi. rlated ~nd ~rlainty and aC<lu racy gained in the «mtrol of the foree th.t il t.:. be Ili ,lrilll'ted to the moving U!etb .

~'.TI':.Ll.L 0 1' TilE A.l'rLlA.1<CI::6.

It is highly delii rable U,.l the bracl:eu ]x. u delicate Ai po8Ilible comialeu t "ith the ~uited strtngth, and much care hu ~ gr.-en to their form and proportiom and to the materilll o( "'hiclt they are con8uucted. I hue ()lind, ... a roault ot mall)' e:rperiIDelllS, that the metal 0( which the round ,...;tional . reh or the pill lIJ1d tube appliQuee and the new rib· bon !In:h are made giVei tmm gre.Wr strength than !lny otller mown prllCti. cable (onn of metal, IlId, more Impor. tant .WI, th~ ~trength of thi. metal i, not impttired "1 the beat neee&Mr)' ill soldering th~ lorS(ket. t.:. the blind. Sinee much &("(:" r80y And akiU are reo q~ired 10 properly attach Ihe brackets t.:. the bands, Ind as it is never ntoe.ary to chan,l(l! their poaitioru On the band., they will only be l upplie(\ by the manu­facture .. already Ittached to sect.ions of the reiutorced ""lid material.

/'lEW OONITIlUCTJOIi or BUIDII.

The balld nraieriRI i~ furni.hed in both precious Ind I>On-pucionl metaia, Ind in t ... o dil'/erent lellgtM, tor large and small t<!Eth. The Itr"in UpOIi tlie band laterally ill rotat ion, Ind perpendic_ ularl), in root-movement, ia!iO great thst it .ro~ld inj~re the ordinary band ot unl lonn thickneu. 'l'hi. haa been over. come by thickening, hence strengthening, the band in the l'I!gioll oJ the IU&cl:tment of the bracket where the It ... in is COIl­~n t.r.ted, and ma king it thinner whert the slrain is dill'nsed, Ia Mt,Wtell the 'ppro:ri",atillg ludlDl!t of the teeth. Thi . i8 an important iml;lrovement in band-mlJr.ing, and In time ,t will donbt. 1_ be employed to advantage ill the con.lntdion o( nl09t orthodon tic bands.

Band-holdin!1 plw-I. The prwent standard method of making plain b4ndl , especially of non·preeiowl metal., ~ to u..., a piece 01 band material long eno~gh '" that ilJi two end. may be firmly gruped by one I'and Ind drawn tightly aboot th tooth, wbile it is pinched lI'ith my blnd-fonn;ng plien held in the other hind. But the erpeuse of pr~ cionl metaia, eapeciall, of a\kl,. which conta in platinum, renden highl), desir­able the use of dripll of baud mueria l of lhe 8hortest practicable length., Tlt i. haa n_itated .orne fonn of in,d.rumen\ to take the pll\Ce of the ti nge.. for holding the eud~ 01 the pie-cea. Dr. Grunberg ho.. IUggetlted BOldering Ihe end, of each piolo;:oo 10sMher Ind U ·

eJ'nng pres~ure on the loop so lormed by meaDS of • right-augle ball-end burni.oher. Th, plan it a good one, but il requireo. e:rtra t in'e Ind t rouble to unite the cnds. To avoid this ne«!tity, Dr. F rederick B. No}" ... luggeeted 10 me the poeeibi lity of lUling lOme form of plie." for g ... oping the ununited t nd. of thu banol malnill, sud woweol III! a pair of obtUAe-aJlgle !low plien lI'hich b ..... IIling-for that purpoee with llOlJIe degree of SUCCell. Ad;ng on Dr. Noyes's luggedion, I hue, afwr wuch upor;­menlillg. produced a pair of plien whieb. I think, fully meet the requiI1'menta, Illd "'hieh are at the same time very limple in design and Ipplicable to either the lingual or labial ,urf~ of the teeth of

A>lO~K.-·S<HfE NEW FORMS 0' ORTHODONTIC MECH .. D · IS).I . 083

either arch. 1'he beaks of the pliers are flat, dQ~e_fiiting, and stanrl at an obtu~ angle to the hM.dlcs (~ee · lIig. 19). F.~eh jaw is provided with a tr~ru;vcrse s!ot for the reo;eption of the two thick­nesses of band material. A piece of band mawrial of the proper length iij bent sharply ~t right angles near both end!,

FIG. 19.

ILS in ~, Fig. 20 These heods ~ re be9t formed in the slot with ,..hkh one of \he hndles i~ pro, ided, thus insuring uni­formitv in V,e;r \eo/(th . The band material is then fonneJ into a loop, B, Fig. 20, \he enda are see.wd in the slot in one of the oo..ks, and the haodles d06ed, 0, Fig. 20, thus giviog the finn · ed grip to the bent ends of the b~nd

material and the firmest 5"pport to the band. The loop is U,en worked over the Crown of the tooth to the desirOO posi­tion, the plie~ sen-ing a.s a most ron­venient handle for this purpose, a5 well ay for fi rmly drawing it about tile tooth ~hi le it is heiDg pinched by my band­formi~g pliers (see F,gs. 21 and 22).

F lO . 20. , A ,

It is thus possible 10 employ piee<>s of band materia! of the minimu m length-00 ohort that they CQuid not he held with the :fingers. Tbe imuument i! very 1atJdactory. Of 00<')1\=, loog pi<lCeS of band material may aloo be used with it,

FIG . 21. Fl •. 2l!.

the surplus Inaterisl p3S-lillg out hetwoon tI)e beab of the pliers.

A fe w words here as to the positions the plain bam\s should occupy 00 in. ~iM,.,. and ~a1UM8 will not be amifjil as to my koowled~, nO defin ite Ioca.'tio~ for these banda has eVfr been indicated by any author, the ~u!t being a ouy ~at lac~ of u:"romuty 'u the placing of bands m IndlVld1l81 mouths, and thi s

'" I'I'IIuh. not .(mly in jlUltabili ~y of .U.ch­ment, but III II. prollQulloedly in .. t irlic .ppeafllnce. In fact, there ill but Qlle

eo rrect po;!!it ioll for ... haud W <x:cupy Oil tach lud,,'idual tooth, because only in 1h;$ positIon can It afrom tho greatest firnmee8 and au.bi1ity of .Uaduuent. 'l'llia poeition ;8 t r.".,.ereely to the crown of the tooth, and the band Ihollid be "" "laCfll as i(I embT&Cto equaUy Ule mesial and dillta] .... 1'.'11. of the C!'OW'II in an tIC­

dUAl and gingi"11 di!'tct.ioll. The IUt.t­u .. l 1,lna] 8wcll of the CroWD of the tooth will prevent the lliding of the hllDd either gingiv.lly or oedUMU)', if it il _\:Cur, lely fitted and properly 00-,nented, And thi. poeitlou should be Itrictly adhered to in the cate of each tooth, regudlOOI of it. poIi ti()1l or G! that of Iny other tooth eJOIIpt .1_ in· complele eruption of the tooth mak\'!ll the correct placing of the b.od temporarily ilUp0e8ible.

Abo, ... hentv"r poaaible the hruket . honld ~ufY Il )lOIIitioll in tI,e COln~r of the labia SUd8ct! 01 the band on a line with We nil. of the tooth. Th~ baud and bracket being Ull" ()()rreo;tly pla06d mecllanically, they '<rill al!l(l be mo.t nearly in a<:<:Ord .. ith the require· menta of art-for, all the teeth are moved iulo harmonious relationa, the band. and brackeu will ..",.,rd in b.l. o.ce and bar­mOlly. Thil. " ill be brite. undenrt.ood by referrin/( to Fig. 4 ... bere it .. ill be ~n that the ",idth of enamel margins above and below the banda harmoni:res in the case of the two lawral •• lnd abo of the two e<mtml~, but tl,at betWl>eJ> tlH! lawrala aud COlntral& th_ marg:in~ "ary proportioll&tely to the variatiou in aize of the t",o kinds or teeth.

The inariiAtic effect of placing the bracket in the wrong poIition ;. Itrik· ingly Mown on the left eeu lno l inci!l(lr, FiA:' 4, "hi~h is an error in the engra~­ing. Had it .been placed in the center of the band. as shown t(I hue been prop-­erl y done in the case of the otl,er COlnt.al Ina Ixlth l.terals, the brackeu and inter­venin¥ "paces on the banda would have been In hannony Ind b. lauCOl and wonld h .. e been far more pleuing in appeot..­anee Ulan;' now the cue. T he inartistic nnougtmen!, as 5ho",0, il the IIIme IS

"'()nld ",olt wure four picturel hung in u n,.uy .~ upon a wan, one ()f the pictuffil being wrongly pi&ced •• to ita space.

Fin.<>lIy, the fonujng of lIe.ml in band~ labially il 80 manifestly out of koop· ing witli correct teehni'lu~ and 10 pro­nouncedl), inartidic io appeanonce that on ly the mOlt ca",l~ ... and doyen!)' aper­atora ('(InUnO! to make banda In th is

wa!;,.protJe(/. u.ea.tk of th gncltor c/4 ... ? N~d. The improvemente in the .tte.th

Fm. U

n •. 24.

• • III the an~hor clamp baud M()Wn in Fig. 23, and A, Fig. 24, are astollow.: Fino!, the uniform diltribution of metal of the .h~ath, the wallo being af the WIle lbiek· ness in ita anterill' pari ... here it inclOleOl the CJlindriCl.! p:lItian of the f riclian I<lcl< nnl, and where it il .ubject to the J"":tat itnw and 1iAbili t::r til inju r}, .. ,n that prort which inc10ge1 the thrtaded I'Ortion of the orch. This giyea the "me dOle adaptation to the arch II to the cylindrical portion of the nnl, and re­duce. the bulk of the ijheath to the min­imum. Second, the main bOOy of the aI,eath h .. been uniformly bent til f()rnl

the arc of a circle. Adrontag4 gf th~ ""noili..ur .hea.tk.

'I'lIi, .hee,th h .. many decided ,dUll'

AIiOLH.--&).lIJ: NJ:W FORKS Qr GBTJ.lQOONTJe IUlC1L .. ,H$1.. 986

ta.tet (I~r the Itr&ight eh8th, "hicb will bo! readily Ipprecillfld by both ortbQ. (loQ tilbi and patienf&.

i'il'lt, the diital end 01 the Iheath lies much dour to the di.to-bue<:al f.llgle of the tooth (oee A, Fig. 2·1), tIlua avoiding III interference ",th U>e cheeh. The llreight oheatho formerly Ileefllary fn)· quently «ueed Ibl'laio", Qf the cOOeka, eepeewly "hen emplQyed on the IeOOnd deciduoul mQlar befQre Ihe t fllplion Qf lhe first permanent molar, or upon the fll'lt petmlIU'nt molar before the eruptiQn Qf the I8COlld. ThiA advantage "in bo! .till more ~videllt Qn oompt.rillg the cuned Iheath with that Qf tht Oettin· gH type of hand .hOWD at ft, Fig. 24: "hich, in order that it may be re. ohed ill clal>lpin.g,. nl<.lui ..... a oery lI.rge Ind neoeaurily Itreight llheath. The fact th.t the .l>H.th iI CUrled migbt .u~est t.o lOme thu it would be dil!\cult Qr lm­~ible to paM the ribbon .reh through It, but the elasticity ot W, arch illueh that the ClIne offen no appreciablt dif!i. culty.

SetQnd, another advaotage which all " ill appreciate i. that if. belore it. in. lenion, that portion of the areh which i. to lie within the "Math be bent to the Ire of • "",aller eirele thin th.t o( the cu ... ilineo.. oheath, the t8ult Qf the elas­ticity 10 gained win be DQt (01)' to pre­~e!lt the nul {rom WQrking out, but to un ... both lIut .... d uch to wQrl< dillaUy aud to hold them in elote appooIitiQIl to the sheath, t.hu. rendering \lie aeo:;iden­tal dilpla<:emenl Qf the nut illlpooleiblc. Keeping thi~ thooght in !nind while carefully . tudying ~'ig. 2, Qne will ",,"l­in how important thil U in ketping the .reh and nuto in proper rel.tiQIlI with the anchQr teeth 80 that the fQrmer will nQt work {Q,.....rd and po.aibly permit Ipao!lI to 'pp"r between the !.eetII durillg t~at­ment. Thil is an .... DQTance which ,11 hIVe uperienood in the 'UN Qf .n Qther orthodontic mechaoi!ml with "h'oh we lore (&mili.r, &lid which hu Qtten made nocetMry ti,. use 01 edr. ligduree or othe. attl.l;hmento to p.event the RTch from l lidin/( forward .

Third , tlLe enrrilineo.r sheath giya !.he beot collt..,1 Qyer the directiQn Qf IQree fQ. mQYing the roob Qf the ."chor teeth either buceally Qr linguall)" in connec­tion with Qr independently Qf tlle; . crown movementa. 'fhe curved IheaU> effectllblly preyenbl the Inrni!l4" of the ribbon 81Ch .ithin it, thuo inaunnl{ oom­plde oontrol olver the force IOOOrthng to the degt"!l Qf perpendicularity Qf the ...u. Qf the ribbon .n:h befQre !.he .reh

~ !·F· <: ' W

ia shd into the !heath. TlliA make. wholly uuueoes&ary any of the numeroUI e<;>mpho.ted Ut6Chmcnbl (see Fig. 2~·) which have been advoca.ted from time to time in oonnectiQn with the expaWJiQn areh IlId Itraight &beau.., to dect U,e buccal Qr lingnl.l mOY\'Dlent Qf the root. QI a~hor teeth.

VQurth, .ith the cunilinelr ohe.th a IQn~. an:h can be used than with • .t. aight "'eath. The ends QI the an:h olay p!ll$ through it an eighth Qf an mw 0. mQre, (or they a re &0 ddicete and lie 10 claM to the adjoining teeth

• T~1o b .. d "U ;n .... l4d bJ D<. \let- • Pull.,., JoII_'. "()pt."'-;'" Dutiot ..,.,~ tI ..... , or loI'-ll, Jolon....... pqe 6$1.

t ....... Lntl._l

,so TilE DENTAL 0(8),10$,

that tl,~y cause IlO interference with the chook~.

Occasionally, also, advantag>! may be taken of this elndic projecting Md of thll "r~h to apply pressure upon the dis­tally adjoiMog looU, for itt lingual movement, or W assi.t in the bnoxal mo.ement nf th~ anehor tooth.

I:ST"BLlS1U [ENT OF NORMAL }1ESIO-DlS­TAt. RE LATIONS OF TERTI[ OF OPPOSING

ARCHES.

After the foregoiug description of the manner of applying and operating the

FIG. 28.

mecj'anwu for ac<:om phtiliing both ~roWIi and root mo,ements either .iugly or col­/ediveJy in either or both dental arches, it should be caey t.o understand how it may also be applied lind opel'lOted, in addition to lOud simultaooouely with these mov~rnellta, in order to el;tablish the normal mesio-di.tal rcbtions of te<Jth ()f opposing denbl arch"" in the >cry distinct types of msloo::iuslon oolonging to ClaSi>'lS II aDd 111, and ilIu!tl1lted in ~'igs_ 26 and 27.

The ,",-,,!ui!"<'nlenb of treatment of in­dividn81 caso:'s of thee" typea of malpcclu_ sinn vary ennslderably, dependmg npon ihe extent of th\l deforn'ity, the 8g<l of the patient, arreflt or modification of bone-development, etc. Yet in nne re-

B~t t.hey are alwal' Ihe eame, namely. that proper fnrm must be gireu to eMh dental ar~h, and that any existent mal· poSltion of individual teeth mnst be cor­rected . Then, when the mesio-dislal re.­lations of the dental sTeh"" have been corrected, the arches will hsrmoni.J:e tIS

to site, f()rm, and other reiatiOD1l, aud the teeth ()( th~ t.wo archea wlll ooclude normally. Of COUrsf-, all these '-ariouo ehRn~ may be bronght about .in",l · tliDeously, but in thew cUes there are two di~tinct classes of movements, and thi s fact Mould be kept dearly in mind througbout the entire COlirse of treat-

mcnt, "ith efforts logically directed I.e­oordingly.

Al'l'WC~TIO~ or TNTM:UAXILW-IiY l:USTTO LlO.4TUIUl8.

'I'he normal mellio-distal relations of the dental arch,," mu~t be established by chAnging either the forms 01 tl'e jaw., eII~ially of the mandibl&, Or tbe rela · tion3 of the crnlVns of the teeth (by t ippillg or by bodily movement), or boUt. The meoio-di~t81 chan~ are effecW largely througb the fotee from inter· IDaxii18ry ellUlue ligatures used in oon· nection with the Ulechn i~Dl we are ber<! considering.

In cases belonging in Cl~B n , the in·

~"'GI.~.--So)fK Nhw HlhMS or OWrIlO OOl!TIO ~IECII ... XISld. '8~

«:rmaxilla ry ligRture!l engtoge the di.tIII enda of the sh"",th. of t he bands 011 the lo .... u first molars and deli~&w hoo\:6 at­tached to the lower margin of the upper ribbon arch, "-'l indicated by the dotted lints in Fig. 26. I II CIMII II I (see Fig. 27), the J.IOO itiona of the ela'!tic ligatures are, of course, re.erwd, and engtoge the distal ends of the oh.eath of ihe upper anchor bauds and hooks att.ached W the upper margin of the low~r ribbon arch . Of oourO(>, the inwrmaxillary force as here used is the same A$ that which we have long employed iu cOlloeciio" with the expansion arch E.

In treating the maloccluaion of ~ typo ical cue belo"ging to division 1, Cill.2s II , a. illu5trated in Fig. 26, the fin;t 8\.1l~ of the operatiou, M ,,'e hav~ 88id, ;, to eorred the form of ~~h deotal areh snd the malpositiollll of the individual Weth ; the secvud. w establish the uom'al mesio·diatal rela tio"s of the two arch .. !.

'I'he geoerbl form of the lower dental arch in th_ cases ia Ul;ua.ily quite nor· ma l, ' but the upper arch is commonly narrowed antnioriy, with characteristic protrusiou of the inei""rs. 'fhi. nooe>J­litat.es its being widen~d in the region of the callines aud pr~molnI"S aud short­ened by tippillg the incisors lingually. T he latter roo~l!Illent .. holild be nnder· ta\:"" first, and by keeping UIO nuts in front of the upper anchor teeth t urned for,,"srd ",bout half th" length of the friction sIMOes, the free mov~men t of the arch dil;tally throogh the sheatru is permitted , and all or tI'e fo= of Ille inronuu illary elastica is concentrated "pon the incisQrs.

Considerable force for the disW mo>e· men t of the ribbon Ircb through th~ anchor WeitthB, in add ition to thut fron, iIle int.:rmuilla ry elaatics, ia w IJ.e de­rived from the elastici ty of the &rch by re&80n of the curves in the sheath., !IS already d=ribed in connection ",iill th is pe<;ulillt fonn of "hcath . Thi~ fore\' shon ld be kept active by c>ccasionally be"dio", w their proper forms tll_ por_ t iOM 01 the r ibbon .. reh which lie "'ithin tha sheaths.

,\ $ the ineiBon ar~ tipp-ed linguall;>·. they will tend w w..oge the can ine!! and

premolurs ootward, Oms widening the anterior pari of the dental arch, and in many instanC<lS it will thus be sufficiently wid~ned . Howe"cr, if ,noTe dired fo= be required, the elastic ribb<>n arch may be used with bl1lcket.ed band$ on theS\' if.'<lth, as in simi la r mo.cmcniil already deMribed, and illu$trated iu },'ig. 2 .

When tl,e work of reshaping the den. tal arches is well under way, attention DISy be $pe<; ially directed toward el!UW­lish ing their normal mesi<>-distal ,...,la ­tion$." This i8 efl'ected by intermaxillary foret!, changing the rel atinIl8 of the np· pOlling teeth either by tipping their CrowlUI or by mOYin g them budi ly. Also, in either caS\' t he forms of the jan, especially of the mandible, are probably . hi·ays favorably modified to a g",ate r or lesser deg'"*, as a result of t he stim­ulua of the rorce direc~d upon tne b<>ues through the roots of the teeth. T he ex­tent of the change in the form of the bon~ d~~nda grellUy on the age 8n~ h~8l th of Ute patieut, the amoont of fo=, the length of time it ~ operative, and the ma nner of il$ didribution to the boM8 through the attachments of the mechanism on the teeth . That is, if the attacbmente are tuch a8 to ravor the tipping of the crowm of th~ upper teeth distally and those of the lower teeth meaially, tile;r norn, al ",csio-dista l rel.iion. IllIly be '" speedily areompl;'hed thbt probab ly but little change will ' e/lult in the forms of the bonel!. If, howe"er, the attachments are mch 11.2 to prevent the t ipping of the CT'OWD8, but necesai tut~ t.~eir bodily Ino.emeut if moved at all, the opern!ion will necessarily reqoire a lon~r p"riod of t.io'~. T he force wm also be more favOr&bll dietribnted to stimulate the growth 0 tne bones, Witll coDS'XJuent greate r ~nd morQ b~orable

• I" f .. ,·o",bl . . . ... of young p .. t i. nto ",h.,. th~ In .. I«< lu.i~" ;. ~f ,_nt oric;n. "n~ l>ef~r~ th~ "'""dib\< h ... l>eeo",e Hu,n· . inly m(>(H~«l in form "" •• W .. ;n hu. mony ..nth tho mal""du ';on , the " ,"pIe trui ug of tbe ueb •• , rondoring _ibl~ and ' . 'Y tho d ooing of tbe ju .. with t b. I«tb in th~ ' 00, · "",t ru<o ;o.J ilItol ~fdion., i. ' h< only tr .. t­ment "<'< _ _ I")", hu t tb, P'>",.ntogo "I ,"on cd ... i • • mall.

"" tH'>: P.o;NU~ CQS .lQS.

modification of t heir forma. Thi. is highly dl'Si rable, as imptovcm~nt in the shapes of the bones in the." deformities should 00 one of the Hry importa.nt ob­jects of treatment., e!peci~lly when the mandible is f)f abnormal form, M it poorly alwaya is in typical, well-devel ­oped Ca_.

rUPIN(l OP U1'PI.R TEETH DISTA.LLY .. I<D W WEl! T&lITIl ME$1ALLY .

When the normal mesio-diml rela_ t ions of the dental .",hell are to be ell­tabhsh~ chiefly through thetippin9 of I". lett" of the upper jaw dl$ially and those of the lower jaw meeially (in ClaM Ill, Ul" ribbon arches must be gi'en such [om, in lJ.oe' r bracket and B"chor slwMh relations ~ will pennit o' faoor this HlO'-ement, 8l\d not bind in thei r .tLwhmenls and prevent it. This nooe.­. itate.! that the !heaths on the "pper aucho. teeth should $Iign, not horirop­tali" as wown in Fig. 26, but olightly obhqnely, ",jth We meoia l end the higher, 6() that, when the upp<lr ribbon arch is place<.! in JIO"ition in the sMaths, and before it engages the bl'1ldebl, itl! an te, r ior part will lie a~ high or higher than the Illarg in of the ginglYB, requinng it to be sprung downward to engage the brn<;kem, Th result will be to pry down, wftrd on the meei.l end. of tile anchor sheaths e.nd upwBrd on the diml end.!, thus contributing mCAAlI ""bly to the for~e from the intenn""illaty elast" ... to t iP the anchor teeth distally, At the ... mc time the force eJ[elUd by the anterior pa rt of the ribbon a reh in an upward di~tion will tend to compress the In­ciwrs in their wckets. Thi~ i~ often desirable, e6pe<:ially when, through lack of proper function, theoo tooth Art !oun~ in supra-ocduaion, a$ thoy nsually are to a f1:reater or less delfTOO in these "",res. 1'h'. prying for<:e of the arch may be n\aintai"e<.! , when requi,.w by the distal t ipping of the t.eeth, by slightly hend~g it upward at POints oome",hat anterlor to the friction lock outs.

Of couroo it is qu iw a ~ n~_ry for the upper buccal teetll anterior to the "ncbor teeth also to be tIpped distany.

This i6 done by plating bracketed bfI.n<h upoo the clUlines, the lmlCkc!.6 engaging tbe ribbon arch, while delkall! ,PUt., at­tached to the ouwr ~urfa~ of ti,e arch, beM agaillllt tbe Il1c~ial 'urfa~ of the brac.ketJo , after the manner already de· ocribed, and shown at <1, Pig. 14 . Tbe res ult of U,i.! opnt and bract~ attach· ment to the canines, with the Duta 00 the arch acting again.t the aochor sheaths, is to dilltribuw the fotce equally aDd di rectly to tip d idally the ~anines aud anchor tooth, and indirectly, through contact, the inte1'\'eoin$ prenloll<N.

Tbe SIlme prin~iple ,. applied fot the m~si al tipping of the lower teeth, bnt the direction of force through the pry of the lower ribbon arch it reverned by $ligni!lg the ohcath. On the lower anchor bao& 110 tha t the anterior put of the arch will li ne higher than the ONlu­... 1 edges of tiw incisors before it ia "pnmg downward and locked within the braok'ete. lIowe,tr, it it now my opin ion th at we lower teeth in tileS<! ~1L3e<I ra rely , i f ever, r«juire tipping. hut, Oil the con­kary, that w is ahonld nearly alway!! be prevented from tile beginning.

»OOTT,Y l!onW':N T OP T8m'J! O~ ONI< OR BOTII ARCHES.

When 11", bodi ly mo.ement 01 the t""th of ooe or both arch.,. i. to be ~ complillhed in order to estab!i.o;h the !lOr­mal mesio-diBtal relatio". of lhe opposiog t""tlt {Clua ll), their attachment to the metal ar<:hes mmt be rigid to pr,-vent tipping. Th i! is made ~y by bl"llcket And band attacbmenta, 8.8 w own 00 tile lowu incisora in Fig. 26, with addit ional bc~~ket, band, and cleQt attachmenta 00 the eanillei, and, usually, Oil th~ fi rat premolal1l, after the manner .hown io ]i"4;. 16. 'fhe ribbon Hch mu.t then be given such form in im relation to these attachmcou 8.8 to bind &nd prevent the tipping of the t<Jeth . A. the de6Cription of thew ~ttachrnenta bas already been giV<!n in conoection wiUt Fig.. ~, 15, and 16, its repetition here ~ unnec .. -w,

Similar mechani~m may be attached to the teeth of th~ upper oteh, \>ut in . uch

AN"(lU.- SQl\E Ntw FOR>!S 0>' O~TI{oOONnC lIBOIIAl<18X. 989

maUner that the direction of for~e from the binding of the arch in ill; attach· menta will be rever&e<l , thus distributing the intermlUillary force distally to the roou of ih" upper and mesi.l1y to ih06lO of the lower teeth.

Another N)l;u lt of ,n~h application of force is, as we hav~ .aid, to modify the fOmlll of tlle j&WS, espeeililly of the angles and rami of the mandible, which baa l:>ecn prove(J to have been done in nnmeroUJI .;age. reported.

The same principle of attachment iUld of force eontrol will IIpply for efl"~ting

the crown or root movements, or bone changes in th~ manJible, in the treat­ment of CaotS belonging to Cla~s III.

aU.BURY 01 ADVANT.,<lIsS 01 T HE NEW D!VICI:t'3.

From tho foregoing it will be apparent tllat the force may be 80 eontroHed as to pennit or to prevent the tipping of any woth or teetll to /lny e:rtent, or to compel the bodily movement of any tooth or teeth in either or both arehel!.

It will ha,-e l:>ecn noted that this mech_ .ni!!m is of the greatellt simplicity, of the maxiroum delicacy of parts, Rnd with all nnMC€I;Sary material elimilliltOO.. Hence it jg of IJle leru;t inconvenience to patients and the eaaieat to keep clean&ed. It wonld .e.lm that the mechanism ill nearly ideal, not only for aecuring the necel!SSry ststic fon:e for snchorage and of dynsmie fOr<:<! for tooth mO"omcut, but for directing ~nd <:ontrolling this force l!O tht ~H cellular clurn~ attend­ant on tooth movement roMt nea,rly ~c­

cordJJ with the law. of physiology. It i. $1&0 gTal!efu\ in its pMportion~ and uot unpleallin$" in appearance . . In a word, the prinCIples of mechamcs, art, and phy~ iology do not confli ct, bot are made II> harmonize beautifully and M w QS

never poosible in orthodontic meehani"", before. Tt i& eo ~imple and eaoy to ap­ply ... greatly to lessen the usual work of tile orthodontiat and the nlna! nmn_ b<cr of vi.its of palicnt!_ It is not ex­pecWd tllat it will wholly superwle the pin lnd tube rooohani,ro, neither will it wholly supplant ihe expan5ion arch in

ill; round form with ligature atw:h­roeuu. In fact, the ligatu re attachment will be found to be of advantage in con­"ootion with ti,e ribbon areh in the move­ment of premolera and of other te<lth that may be so pronouncedly misplaced "" to render impractic~ble the bending of the ribbon ardl to gain bracket at­taehment with them until after they haye first been moved into more fa""r. ahle pooitiollJ! by means of ligatnre •. But in the great majority of cases the mechanism herein shown will be found to )lOW!1!S such obvious adviUltages in force control and in CRee of ~pplicat.ion and Op<lraiion, tha t I believe it "ill find ~ perm~nent place in orthodontia.

In concluding the description of \lJ i9 mechllnism, let me say that I have giyen Sncil c10ae thought snd care to perfecting it in all it. details, and have bee" ro ably supponed by the manufacturers. IJlst I r~J snre it c ... nnot be improved by modification. Or sdditions, 8t lesst not until yon giv~ it years of thought and study, as I h""e. Therefore let me ea rnestly advise tJlat, indead of attempt­ing to modify it, yon devote your ener­gies to llllderstandlllg It and it! poBal­bilities, a'ld to perfect;"g your skill in the technique of il.o. application and op<lraUon. In Ulis way your oppor­tunities for ... If-improvement will be greatest, and you .. ill be able to confer tb. greatest amou nt or good on your patients. Apt in this connection i. the remark of the great IlUrge.;>n, Hamilton: "It i6 not in IJle di'lCOvery and multipli­cation of mechanical e.~pedicnt.l that the ,UJ'goon of this day declares hi •• uper:or_ ity, to much Min lJ,e skil ful and judi­cious employm~nt of those wh ich ar<> al ready inwnted."

R~PORT OP c.oSES TQMTRD WITH TJlR l<RW ){EClU.>lISM.

RecwUy I have treated with thee mechanis,o a typical case belon~ng to CIa&; II, division 1, the charactertatiCli of which were ~ry similar to those illns­trated in Fig. ~6. except that IJle "over­bi te" was greater. nuring this treatment r belie,-. I have made a vsluable dill-

,,, THI> DENTAL ~OS)lOS.

,'O'-cr)', and Oll~ which should henceforth greatly lessen one of Ihe an!loying diffi. culties wh ich we frequently eneOlUlter in the treatmen t of theoe c~namely, in wcuring and ma intaining the proper heigh t or "bite" of the teeth. 1 am au '" it is the common experiente of all of you that in typies l, well-de~elo ped ca&e8 belonging to tl"s d~oa, you frequently find what i8 apparently inf rs-occlusion of the molua and ~upra· oocl usion of the incisors, both upper and lower, !<) th"t the cutting oogeli of the lowe r indsol'!! are often in contact with the mucous memb rane of the li ngual gingiva of the upJ"lr anterior teeth, or even will, that of the hard pala te. And this impmper height of the teeth remaina tQ a greater Or less degree after the cor,...,c! me.io­distal relations of t he teeth have bo;,ell establish€'d, ))~WlitatiDg "bite bands" Or ''bite pla.tl<!·' or oilie r d~v(eee, to 00 worn for long pel'ioda, to effect the sho~wning of the incirors and lengt.hening of the molarll.

I n the trEat.ment of the c~se in <J"­lion I gave plcnty of ipring in a gingi .. ! direction to the anwrior part 01 the CIt.. bon arch ,.. for both npper and lo ... er dental arches, so that when they were engaged in U,e br a>:k:ebl on the inciwrs there WM a conatant teM,on npward on the npper inciaon; and downward on the lower on,... The reIlult has been not only thu ~hOrUn ing of the indson, but a compensating lengthening of the ~(t­lars, in obed ienC<' to the law of ph)'llCl! !hl adion and reaction are equal and opposite. I n other ,,"ora., th~ f.or~ ~' hkh operated to> compre!lS the me"!ors within their sockets acted to an equal e~wnt in the opposite di rection (or :r<!­

ciprocaJly) for the elevation of the mo­lal"1' , and thi~ simultaneously WIth tho mesio -d istal adj,,~tment of the teeth of the two arch.... I even carried U)l! mo~ement a li t tle farther than normal, a prn.ctiC'l I hal'e long followed in t.he movement of all teeth. th". allowing for their possible slight reces~ion aft~r the fi nal remonl of t he appliances, which io this case will of eonroe be worn pa.· ai "ely for retfution . for aome tilne .,·et.

An~thtr featu l'e in connection with

th is case, which will surpri& Inan)" of J o)u who consume an inordinate amount of time in the treat.ment of cases, is that the entire operation of treatment wM acromplished practically withiu eight weeb. I wish, however, to e~pl_in that 1 wag testing the control of the mechan· iam iu thie cue rather tI,n aiming to £amply strictly with the requirement.. of physiology, which woulcl logically nec<.'&­sitate a IIOmewhat longer period for treatment. I have, however, ohilerved no undue SOrCnCM of the tkssuee. In fad, ne>"er before have I treated a case "'ith apparently 110 hille nnfa" orable d inurb· Bnce of the tisEme •.

My patien t il; wi th uS today for yonr inspection of his teeth and of the appli­=<le$ which aN &tili in poeit(on nvon U,em. The modela of the caM at tIle beginning of treatment, and !!eYerai dudy modem during its progrwl, are also hete fot your inijp""tion. One of the studl modds alw reveal~ the verifi · cat ion 0 my pre<liction that the spring from the cibbon arch alone actiug .... ithin Ille cnrviline&r sheath would carry the ribbon arch distally. In tlli~ Calle it car­ried lhe \"'0 upl"'r central i,,~iro", wi th it to a marked degree during the first ten days of ita operation, or hefol"<.' the application of auy intermaxillary elag· tics; e' en b.fore th~ attachment of t he sheath hooh. ThlB Dr. Gongh call verify, as he Raw the ca~ at t he time the sh<lllw hook. fo r ih~ rec<.'pt ioo of the elastic ligat nres ",ere ~ttached to the upper ribbon a",h .·

The firet two c..ses on which th is mechanism w~e used were treated by Dr. G. P . Mend~ll 01 Minneapolis, Minn. The appliancet! were adjusted to the firn case ().(, May 20, 1913, and to the ~econd cru;e BOOn dter this date. The pictures of the latl.er case I "ill here abo .... , giv. ing but a brief d~tiption of them, !ea,'­ing the more detailed l-xount of the

• The piotu,,,,, 1<0 illo,,"'ot<. this ....... ~ too 1M" lor publie.t;Qn, but " ,11 be tho,,"n in Il'~ fo,thQom ing ...,.,,,, tog<tIJ., with too .. 01 ot~., "" ... t, .. I,d ".ith Ibi. ", .. huiom br w.,· .. 1f and by Dro. Goug~. Slrong, Mend.H. ."d Kotch~",

AIIOU.-!(I)(B "",W POIt:N8 or OIl'fIlOOOJ<'fW J.lI!CIIAJ<J51r , 99]

treatment of both this and the fi!'5t calle to Dr, Merode!J, who jt with lUI today

}' m. al).

with Ute ruodfl' of the -. and who rill doubtlO!@ll later "lake a more ex­tended report of them in we litel'i.tu~.

The OCilln~ion of the second cue, ~ fore trtatmenl, i. aha .. " in Fig. 28, and

Fr~ •. 31 A~" n,

the model of the upper a.reh, after trtat­,nent, in ~'ig. 29. Tl'e model of the

Frt, sa.

10,", ,reb after trtllnrent i, not 'llown, " it "'IS rorrreled with tire pin and tnllt I ppliRnce. Although 1l1li toot h

'" Tfn; DIIl<T&L 00&1101.

~.elnenls gained .~ compuati",iy simple, yet the work hi. been beautifully done. By romJll'ring the poII itiOll1 of the toots of ~he t eeth in the t wo rnodeil! lDdlC~ted In Fig. 30, th~ or the lawai., tapecUll!y, aM dearly show" to hue been move;:!.

.The Ilext casc, Fig. 31, wu tn..te.d ,"}i.h thia me<:banilm by Dr. A. H. Ktleham of o..D~er. the thi rd eue to be en !.mated. FiJi!:. 33 Il10 ... the teeth with the apptaDCfl& in por.i tioD upon them, .n~ i.n Fig. 32 JOu will ate the \'try gnu!yu),g ch.~ in the positions of the ~th that we~ &CCOmpliahed. Dr. Ketcham;8 pn>eent will> • full Aeries of model, of thil cue. He wi!! erplaio tilelll to you, and la.ter will probably mike an extended report of the c ..... .

Still other C8ge1 hue been mo ... ~ t(!ntly treated by Dr. F. A. Gough of Bt?Okl)'D, and Dr. R. ll . W. Str.....g of Brldlleport, Conn. 'l'ILeIe gtnt.lemen .... ill aplam the models of their CQeII this afternoon •• t "bieh t ime we will ,110 be· gin Our CliDi~ in .. hic1l yoo .. ill .n.djud the tI"" appliane.ll! to modele, in """",rd. ~nee with the wehnique I have jU!t de­acribe.i, in order Utat there may lawr be no mLlunderstanding in rtgard 10 the technique, nor blunde .. in the Il*e of the n~hanilm in YDur pn.dieee.

CRITlqUJI DP PBltI'Jlli"DICIl~ LODP VS. I'll' AND TUB • • 'PL[A1fQ~

III wmpariwu ... ith the acre ... 88 &.

m~atll of applying foroe from a base of anchorage in orthodontic treatment J now ".i$h to) ooMidc r, in a spirit of f riendly critieism, I very difl'erent me­chlliell principle fDr this p"'rpoMl "'hich has ~Dtly ken ad~ted by n ... Rob· in.on I.Dd Young, eipecially in OOnOOO­tion with my pin aDd tube appliUlet', FiIi:.34.

The plan ia to uert force by rue&DI of the elasticity of a perplllldiculsr loop, or loop', formed in the arch, Ie in Fig. 35, ineteao of by a scre... 1'hil loop is tem· porarily contracied, and is en~, by ita aquare or ellipti""l perpendleule.r at­t.chment, within I do.ely fitting ~eg· meu t of tuhillJl,' &Oldered Yer-tic.lly to the anebor blind. il.8 accidental displ.",,· ",wt be inF pl't"l·enW by • loek-f!lld

projectiOll ill the form of a II\O!ODd loop which eng&jtCS the lower end of the tube. ~~ Corce. (rom the fif'8t loop mUlt con. tmue until th$ ~l53ticity i. exhausted by the movement of tbO'le u...th that are at­tsoched 10 the arch anteriorly, or of the anchor teeth, or both. T hen the uth

l"Ja. 14.

i, dileTlg.~ ~rom . the perpendicular tube, the foop .1& .ligbUy It.r.igbuned, agaIn Wllpon"ly oontraeted, and the I rcl! once more sprong into poIition. l 'hil modification of th~ form 01 the loop ie IHlriodically repeated nnW the loop diaappea11l, more or 1_, through the straighttlling of the bar of /II etal.

My criUcilm i, thai inllead or u.... force being delivered enmly to the anclior tooth Rod m on. dir.ction only, ... (, easily JlO8Sible with the acr<lW ( ~'ig, 14 ), the dlr"eCtion cf l ome ie constantly changed, th"., nuechievously diitu rbing the runction of the cell£ of the pend!n· tal membn.ne and al veolar proc:ul. And this must be repeated with Mell clliogl' in Ille form of the loop. The die'turb-

.. "QL ... """"OlU NEW POl)lS Qf QIITHQIIONTI(I )lilClLlNlS)I'. 993

'Il~ i. lIso further .ggrud~ by the frequent removallIld replaeement ot the meeh.nirm neeeu&ry in ita operation. 'rll ia continUlI pushing IIId pulling of tile iooth b.u;h.ard and forward in its lIOC~et ia in direct violation of the pllysi­ology ot cell function, IIId must inevit­abl, cause irritation, pain, and lbeorp­tion ot Ulllue_ Such lIljuriou. diatllri>­lnce ot the ti!!flUeI, "bich h .. 11 • • )"& been more or less unlY<lid.ble wl100 flnlt, mechanism II .. beeD UHd, b.,. been the chitf cause of toren_ .nd pain in orthodontic trubnent. It ia no w OD­der tllat the andoNlg<l become. 100I!­ened. Neither is it stNln~ \Jut, when a loop ;1 formed farther forward . u in

r ,o. 3&.

the ~gion of the canine teeth (lief! Fig. 36), ei cellli 'e ablOtption occura in the region of the incisor mota. The ,rrect is the u me .. on the enchor teeth_n­fit. nt change in the direction of faT«, with the inevitable disturbance of the cell& of the .tveolar proeeae, from the backward and forward displ'cetnen t of the mota of the ;pci60n. I hve had the priyilege of aamining • number of t.lA8M treated by me&nA of th_ loojllll by oihn orthodontil'ta in ... hieh thia N!fIult ia eyidenl

On the One band, "ith the lie",", wf hue a proctSll in full IICC(Ird "ith pb,..i­ologic.1 priDCipleol, undu complete .... d i~tant control of both ope-utor .nd pa­ti ent by the !imple turnIng of the nut, wiU, vower of \l%aclly the dMired ,mouot applied . teadily in oue direction. MOn!­over, we have a moohllli. m with the minimum amOll.Dt of ma\trial, aud with the leMt interference with oo:e!ulion and inconvenience to the pa.iient.

On \.he other hand, ill the II!e o( the loop there i. unnecessary didun:.IIlO! of <;ell function, often oeriOI1&, noc_Tily lroquel'\t ~haoge in the appliance which ooly the operator can make, and alllO ao eutirely iu.dequ.te knowledge of the amount and direction of VOlfer applied, while the loop itlel! offen more 'nter­ference .,ith oceiUlion, is unAta.ble, un­... nita.ry, bnl ky, IIld inconvenient to the ,,·taNf, beaides being mOllt inartiltic.

Equilly or even more ridicnloUl i. the me of the loop in combination with the ""Ttw, I I ..tfeelted by rome writen, for the urne evil el'rect i! prwmt, with in_ ~rtlllle of ml<terill, and "ithout the leut "eed for ita use. T ho!ol! wllo me a loop

P.o. 11.

• • It

in oonnl'Ctlon with the llerew 8ee\ll to for_ get thit the entire u pans:ion &reb is a loop and mill! cootwue to e~ert foree both liitiu lly .... d dynamically III 1000g lJI there ia lenaiou on any part ot il

Now, it wrongful dilllurbauce of the tissues il tho !'e$ult of power gained from the perpendicular loop, the que.­lion will n.t" .... lly be I.'Iked by some of y"u, Why .,ilI not the .ame resulta fol­low the draii"telling of the Imall hori­'Wntal bend. lP the .reb in order to gi~ iL lrne areh form and carry the teWl labillly, .. in Fig. Sol? The In' ''tr i, very limple: The foree ~vell to the t~th in thi, •• y ia in the nght diMClion for th~i r bodily lab ial movement, for &II the bendl are occuionally slightly atra ightened, both the oental ar.:h Rud the e:rp.nsiou nch are graduaUy .ad uenly tnlargtd. Force;" thus not only nnder proper control, but it is e.urt.ed only in the direction nl'CellUry tor the pro~r enlargement ot the dental areb,

'" TUB DENTAL COSMOS.

and not. in conflicting or disturbing di­tel.tioD.$.

While there could be no objection to this form of locking mechanism fo r the ptIssive support of the end of the arch i ll retention, and independent of all per­pendicular loops. yet 1 am not very

proud or it, 1llIe even bere, and I now tUle in pre.ference any ot the locking mechanisms shown in F~. 37, any of "'hich aTe decidedly more Ilmple, cleanI)', Ind certainly as efficient a8 the An~le­Young lock. I regard this mechlUliIDl ." now obaoJete.