The principles and art of retention

THE PRINCIPLES AND ART OF RETENTION* By C. A. HAWLE;Y, D.D.S.,

W.\SH1~GTOX,

D.C.

the practice of orthodontia has developed in the last decade, it 11<1s been A sincreasingly C'vident that the eventual and practical success of thesl' operations greatly depends upon the success of the retention, and that the I'etention of the val'ied malocelmions met with in practiCl' is not by any means as ~imple as it at first seemed to be. The forces operating in thc' retention of t('l'th are mechanieal and lUlll'· By mechanical, we mean yarious fixtures cemented to the teeth or \\'01'11 in the mouth to prevent return to 1heil' original positionf'. By fUlH'I ional. ,VI' mean those forces having to do with the causes of malocclusion and t Iwir l'l'storation to normal condition. Before we can be assur('d of sucecssful !·l'tention, ther(' must be a restoration to normal in the habits of mastication, in thp st1'l'ngth a11(l normal ('xErcisc of tl1(' muscles of the face and internal ~tl'udurps inyolnd. Faulty hahits must ]w corrected, and the bony and soft tis,aH's must ])(' ]'('ston'<1 to a normal condition hdore final retcntion can ]w :ISSUI'PCI. The normal cxen'ise of th('sp funl'tions is a most important fad01' in final rptention. t ional.

During the rc'storation 01 these various conditions to normal it has always heen known that some form of mechanical retention is required. But it must he dearly PYi(lrnt that the length of time necessary for the restoration of these fnnetions is unkno>vn in the various eases and from their nature cannot bc' accurately cstimated. Ewn the nature and manner of working and pathology involYCd. of many of thrm. is unknown and must vary greatly in differrnt cases, '"0 it is rvidt'nt that it is impossible to fix even an accurate approximation 01' t he time necessary fo1' nwchanical retention. Herein lies the cause for many of the failu1'cs in l'l·t('ntion. As this trnth gradually hecame apparent. it was natural that good judgn1l'nt compelled the practice of leaving thr meehanil'al t'etention fixtures in place considerably longer than the extreme time that wn~ possibly necessary. To this practice there are some very deeided objec·tion,.;. First, as experience has shown that the retention period must be a1 l('ast twiee the period of movement ill the average case, and this period of movement averages at least from one to two years, it compels the fixed retention applianer to be worn from two to three yean;. During this time inspection is less frequent than eluring' treatment, and Cl'mrntl'el banels are liable to bee orne loosened and be unobserved eithl'r by the patient or opl'l'ator, and oft('n ell'I'ay or disintegration of the enamel results. Second, the wires may be bent by the force of mastication and the hallelc·d teeth consequently misplaced. *Read before the EUl'o!)f":=ln

01'1

hOflontological

31,)

~o('il'ty.

:316

c.. L.JfUlI'l.f,lj

Third. the brushing ulid el,'uning: 01' th\: it'd]1 j,: iUi"I'f,,],.. l! with. with resulting injury to the enaml'l 1'n','JJt" tlwir sf't,lling iuto J)('J'f,'l't illtP]'lligitntion and locking of the ('usps. Fifth, bands 0111h.. 1eeth arc uusig'htJy aud t lH·\\\.'H I'iug' of them fot· so long' a time ell'(,!'!':!sl':': tlw rlt'siJ'ahility :lIHl th,· pl'ndic'nlJility of thi' whole operatio11 To i11ulo;trat\' thl'st' poiut8 11101"" dearly, 1 will show s.orne -illustrationsbf the most approVl'd fixed retainiug appliances. (~inctcel1 slidc's of the usual t~'PI'S of fixl'\l r\'laiJlilig appliall("(,s \VI'],' hl']'I' :.:hll\vnalld llU·il· objectionable

. ,"

.Fig 1.

Fig. 2.

features discussed.) As these objectionabh' ft'atUl'elo; of fixed retention have always been more 01' h'ss clearly comprcheflded, eertain types of removable fixtures have often been used f6r retaining the expr, none of them were used in cases where teeth were rotated, and this fad Hmited their use to very simple cases. As mentioned in a formerpapCl' on this subj~e1, read before the American Society of Orthodontists at St. LouiH in March. 1919, I am indebted to R. D. McBride of Dresden, Germany, for the vital prinCiple in the removable retainer which I have developed. which obviateR most - of t he ob~ctionablt> features of fixed rt>tention mentiont>el abi)n, In 1!l06. McBride showed me a

317

The P"inciples and Art of Retention

removable retainer which he was then using, involving to me a new principle in the retention of rotated teeth. The original and important feature of this appliance, which I had seen in no other up to this time, consists in the retaining of rotated teeth by means of an accurately fitting lingual plate with the labial

4 1

, l.

it....__ ~.~ -. Fig. 3.

,

....

;:._Fig . .1.

wire, this wire preventing the teeth fmm lifting away from the platc, which they must do in order to return to their original positions. The fact that this can be done has immeasurably extended the possibilities of a removable retainer. While this new and valuable principle was contained in McBride's original retainer, yet it had some very objectionable features. The flat pieces

C. ,1.

}[ull'Il',11

\:'xtending betwl'en 111e first molars awl !'-t'cOJHl premolars e,ompelled a ~ollsid­ crable separation between these teE-th, and food often bE'came pa('ked in the spaces., Also, if i,he !'etainpl' was ldt <>tit for a
~.

;, ~::

t

t i:

l"

'''U'U'~.".,,,,,,.

,.". """"

... "

"I....J'JI'~_·!UlI'·

Fig . ..1,

......, Fig. r"

The retainer, as I have developed and ,am no'\oT using it, ~onsists, of a skeleton plate fitting' accurately the li~gual surfaces of the te~th. Atta.ched te- the plate, or if of vulcanite, imbedded in it, is a nineteen gauge gold wire \"hieh passes out to the labial surface through the space back of the canines: On !he labialsurfuee, loops are formed which. are joined by a,flat wirer',:022- by .036; attached to thdoops and extending distally, are premolar-clasps. (FigI'>. 1 ~na 2:) The ,object th'(' loops is to afford an elastic, pr~ssure ,easily adjustable to any dt'sil'l.'d d('p·cr. T11c clasps 'on the premolars are Ii very im-

of

The Principles and Art of Retention pOl'tant feature, the complete success of the appliance depending largely on their efficiency. This clasp has been greatly improved over the one fihown in 1 ~19. The lower appliance has alRo been much improved and made more sue(·(·ssful. The claHps have a definite elastic aI' spring' adjufitnwnt and ('an 1)(' raised or lowered by bending with pliers just above lhe attadmwnt to tIl(' wain wire. It is the efficiency of thil'; clasp that makeR it posfiible to mil' a "h·ldon plate which iR much m01'e comfortahle than a full roof plate. Tlw low(')' retainl'l' is similar to the upper, exrept that it hal'; hef'll foum1

"

;,t',,:;; •

,<

~','

'.

',:.,.t'

Fig,

L

Fig. 8.

nec('ssary in many cases to make it more stable by the use of bands on the eanines or first premolars. UnleHs the mandibular first premolars arc fully ('rupted, which they seldom are up to the agr of tbil'tern or fourtec·n. 11w clasps are not efficient alone and the plate will be pushed out of place "'ith the tongue. It must snap into place accurately and stay securely. This result I have sec·ured, as Htated before, and shown in the following slide". I Figs. ;1, 4 and 5.) In the form ShO\Hl in Fig, 3, the bands may be remoyecl at a future time. when the prrmolar, are fully f'l'uptrd, and the rl'trntion may be

;-l2U

('. A.. Ii Ilwlf:y

,oontimwd without tht'llJ. As they al'(' only ,1103 jn thidOless, it mu,y not ,"ven require the making of a new l't'tainer, I'XN'pt ill the cases where the canines arE' hllllded, when the addition of the prPlllolar clasps is necessary, I rather prefe.r the two torms ,"vht'l"l' the (Oanincl' are banded fol' the reason "

.,

_

-

1 1 ~

1 1 ~ ~

~,

~~

\ 'uw=.,.,_,.".,._,,

_

,"~ '1-'"r'40''~-SQ-------

.• <- 't~~~:~J~': ,,':i:1tt.,~t

"~_

,.

,

'"

_

","

,.-

T,"_

,

" ' " ' ' •• """ ..

,oj.,.."

~;.

"I, ,-.,

~,..,.

""

\, ••,,.:,,

..;

t

t i

! :l

~;.

,

"

{

1

I ~

~

~. ""'"""!!""'''I'':''I!'IIIII''~'''''''UI''''"."l~.'~'__ ,........ , I,

'.'1..'.

Fig', 11.

.,: ,,',

j

I!''''''~I'''

The Principles Ilnd Art of Rctcntioll

321

t Jwt it is possible to fit a band ~ecUl'ely and accurately to this tooth and it is YlTY seldom that they become loost'ned 01' rause injury to the enam!:'l or soft ti';:-;11\'s. Also, it affords a secure llleans (If rl'taining the ranim>s, which is oftl'll diffit'ult if thry have been eonRillel'ahly rotatcll.

.J1J

iii

~A ,.

.

Fig. 12.

....

.l

;.

Fig.

1:).

":. ,

Fie;

.:. ~..~ ~;:

11.

Since adopting this procedm'e. I have had practieally 110 failures with thl' mandibular treth. It is advisahle to placI' a wire spur on the lower plate opposite the first molars, which bends over into the groove between the lin!!ual cusps and prevents thr platr being' forced downward by the stress of mastiration. (Fig. 6.)

C. .d. 11(/ wle!l

A:; t'xamples o-f the t'fficiency of this appliance, I 'will show four cases invoI-dng' rotated tel,th which have had no other forill of rt'tention. (Pig·s. 7. 8 and 9 show the maxillary only. Figs. 10, 11 aue! 12 show the maxillary and mandibular of fiamc ellSt·, the eOl'J't'ded llwlldHmlar with thl' rt'tainn' in plare. 1 In using this fit·thod of retelltion it is prl'fprablt', though not always UN', .\'Nsary or possible, Jo let the teeth rest in stahle position. aftt'r movement, f.or three or four weeks before applying the l'('tainer; ur ill SOI1l(' cases, to retain with a fixed retainer fO]' a fpw months or II yt'ar, t

"'-:ca:

} 8'i;.~.

,,,,':_,,'~r,,th.-,,,-

,,,,11, r,

......,","10"

...n , •• ,.""" '"

....,-" ... ' ..,",,,

,,,._,,,~••

1,',

,,I,,,,,,, .. ~.".,,,, .... ~ ,,,.,,.,.,"',.,, .. ~ ...... """,,,,,,

...

,'"_,~ ;,,,,.,~,,,.,

.. i" ;

~

~

k~

•~ ..•.

1

,'" ,", <

:;

--_.

..,., ......

,.-''''-~-~-_._-......,

.. ,.

I .~~''e'"_'''

' 'J' ' 'Qi__'''!2

r•

' ' ' .:~,

Fig. 16

The method l'r's Snow White Plaster; though ;,vbite artificial stune is excellent but takes more time. Thl:' wires" are bellt with hand pliers ()D the modei, removed. and then the model is ('{)vered with KQ. 60 tinfoiLh.r the usual method, tJw ",in's placed it ag~in "niHl thp case waxed, yukanized and -finished. iFig.l::U

on

The Principles and .Art of Retention

323

I allow two or three days for this work. In fitting into the mouth, the clasps are first fitted to the proper place just above the gum line over the convex surface of the tooth, and given the proper spring tension to hold them sf'curely in place. This adjustment must be made carefully, as too much pres~nue will extrude the tooth. Then the labial loops are closed until the ,viee has a slight tension against each tooth at the point where the tooth must lift nway to rotate. This adjustment is finally tested by passing a piece of floss silk nlong between the flat bar and the teeth. It is then removed and replaced sl'veral times to make sure that the adjustment is correct. The patient is llsually then dismissed with instructions to wear it all the time for a couple of days before returning. Upon his return he is shown how to remove, eleanse and return it to place, and instmcted to ,veal' it all the time, eXCl'pt to remove it at meals, then to cleanse the teeth and return it. It is worn in this way for from two to six months, when, if the teeth are found to he settled into close occlusion, it need only bl~ worn at night.

, ""

Fig. 1,.

During this period it can be removed for a couple of hours in the evening occasionally, if de::;ired for some special occasion. Young ladies especially appreciate this privilege. After about a year of the night wearing it can be left out for several days or a week with the especial caution that whenever the appliance binds or seems to go into place with any difficulty it is a sign that the teeth are moving and the more constant wearing must be resumed. The retainers should be examined occasionally and the clasps and front bar ndjusted where they have lost any tension from removal and replacement. I have numbers of patients who have kept their retainers for four and five years and more, occasionally during the later period putting them in as a rheck against retrogressive movement. As an example of the possibilities of the method of retention under special condition, I will mention two cases. The first was that of a young lady, t.wenty-seven years of age. The slides show t.he case at the beginning and after a year of retention. This ;young lady was engaged in public work where her appearance was very important.. The movement of the teeth was accomplished in eight months. The retainer ,vas applied about a week after the

324

C. L1. llawley

movement was finished. It 'WM, WOI'11 ~onstantly day aud night except, of course, the removal for rleansing, for three weeks. At the end of this time it was removed from nine in the morning until tWl.'lw. Own replaced for an hour, then removed again from about one 0 'dock to five in the afternoon. It was worn during the evening and night, After two months it was rcmoveJ from nine until five. During all this time it was removed occasionally ij1- the evening for a couple of hours where public app('arance made it very desirable. With this amount of wearing the teeth hav~; j'('mained as yon s('e them. (Figs. 14 and 15.) The second case, a young lady, tWt'nty-one Fars of age, was also engaged in an occupation where her appearance- was important. In this case the matter was complicated by the loss ofth(~ two maxillary first premolars. The movement was completed in tf'n months. .A retainer was applied 'with two teeth attached to fill thc space made by the missing premolars and it was worn in the regular way for abolit threr months. Tlwn a small gold plate waR

.l<'ig. th. -

l"ig. 1ft.

made with teeth attached and wOI'n dUl'ingthe day, thus doing away with the labial wire; at ni-ght this was removed and the regular rdainer substituted. At the end of eighteen months the teeth ha vo -remailwd as you see them. (Figs. 16 and 17. Fig. 18 sho\\'s the gold plate worn during the day.) I have already pointed out the· advantages of this method of retention from the standpoint of cleanliness and safety of the teeth from decay. As time has gone on during the years I have used it, and have observed its action under various eonditions, I more and more impressed with the advantages of this method of retention in furnishing just thecumount of mechanical restriction necessary, arrdallowlngthe greatest freedom for the play and adjustment of thflse natural 101'rf'8 upon which we must r~Iy for finalpermanelice of our work.

am

The Principles ana Art of Retention

325

Among the minor points to be mentioned arc thr cOl'l'ection of small rotatiom; after the retainer is adjmrcrd. If there hm; bren an oprn bitl' thl' labial wire must be placed as high as possibll' and above the convex of thr labial <;urface of the teeth and, ronversely. if the teeth haw heen intrudrd it must he pla('ed low. If the wires hn·ak, they ('an he repaired by first ~wrapping thr nllc'anitr part with a thin laYl'l of wd asbestos wool and then soldrring free hand in the open blowpipe flame. Bite planes (.J1'ig. 19) may be used ~whel'e indieated. either for eorreding' the owrbite or for assistance in holding the mesiodistal relation. They may be made widl' at first and gradually cut down to a narrow ll'dge as the pl'ogrc'ss of the casr may indieate. DISCUSSION

The President said that when he heard that Dr. Hawley was to read a paper to the society he felt sure the members would hear something worth listening to. Certainly the snbject ,vas one of the most practical that orthodontists had to consider. Dr. J. T. Qwintero said he shonLd like to show some slilles on the subject. He hall !>pcn wry pleased to hear what Hawley had said about his retainer, because he had be('n trying to use it fl'om the descriptions Hawlpy publishell two or three years ago in the Cosmos and in the International Journal. He had founll. that that retainer gave him tht' best results when he had had consillerable expansion and little rotation. He supposed hp llid not manipulate his labial wires correctly, but penlonally he lmd found it difficult to retain rotatimul in the anterior teeth witll that appliance. He noticed, however, that the labial wires Hawley now uspd ,,-er(' ,liffert'nt from those whieh he himself hall usell. Thl' slides he had to show illustraterl the allvantage of the appliancps. The case was one which he had 11ea1ted, a Glass II, Division T, according to Angle's classification. The slides showed that he had not obtained perfect interdigitation at the timc he put in the retainer. After the retainer had heen worn f.or a year, there was perfect int€rdigitation anll the teeth were in perfect occlusion all round. He did not think such results coulll 00 obtained ,vith a JiXt'l] retainer, and that was the reason he was so pleased with the retainer shown. He llid not use it in every case, but so' far he had used it only where there had been a snwll amount of rotation and large expansion. He had founll it retained expansion hetter than the :fixed appliances.

D-r. F. L. Stanton said the appliance was very generally used in the United States, and he
326

C. A. llaLdf'!)

in,such position as to !Tl'evellt a leturn to a wrong ,position, whicli, "f f~omse, Ineant mOlt: success with the case. It only showell hoI'\' a little thing, if app-lied logically, eo.ulu hl.' made a success. Dr. E. D. BarrOlL'S asked ""hat Jj,;advalltag'c there ml~ in usin~ the biller arch ani1 tJIf' removabJe outer arch on th~ maxillary teeth. Hr had used the p1atf's fur many Ye'ars an,1 he was using a few of the inner [nehes now, llllCI lie should like to kno>\" what the clf'cisioll was in America as to wlJich was ti,t' betiRe applian<·,e. Dr, .-1. L. lIiplu:/l thauke,l Haw Il')' [OJ' hiH paper lint! sait! It WlIS enClJuragrng to th~~,> who were practising in Europe to hllve n. man like Hawley -('.omini( 0\'(']' and giving ltiH scientific \-jews on retention, It ,eemet! to him that. orthodontists were alllling at obtailling preventative -dentistry alld pren~nta.t.ive ortl]{),lontia, and he was wondering whether 1>]'(" ventatHc retention could ho also obtained. l~ntil the 'chilu or the, patient "'as instrnetr<1 in breathing after the (,peration ha<1 finishe'd, lllill in ceasi_ng the diaholical habit of IiI" biting, there couJil Le nl!' very gollod )-('~ult. If those habits eoulu he ,wel'come,' the <'llil""'0111d feel ver,v much bett!'r, and. tho natural retpntioil '\'i'oulli, be ht'lpetl. He hail l,een toirl that if the child coultl l)e taught 'normal hahits an<1 kept perfectly \\'<·11, that alone, wa~ going' to be better than any nlPchani('a! applial1"",

Dr. Sec'ker (Copen!tagen) Rai,l he p)'efcrrctl thl' natural articul.ation as much as possiblr., Whero it was necessary to Ube a J'ctention ]Jlate Iw wanted to haY<' it S3 arranged that the patient could learn to take it ont (tnt! kP0jJ it cl.'an, and clf>all the teet!I in order that Ill. decay might occur. Dr. C. A. lIo'/L'ley, jn r!'pJy, Haid he ha,! shown two ('a..- tu rptaiH expansion of- the :trch \Titl! removabh~ applianceH, but the question "as \Thctll(-r rotated !!'eth f01rltl he retaiJi(\'l., He w'a~ pleased with what DUTenport had said. He had nwntionetl in the ]JapeI', anll Dlany times beforr, the so)'t ur amusement he had ill thinking there' ,,"as no new th iilg' abuut tlfe retaincr he hau Sllll\\'11. He, had thought he had somethillg nt'\\, ill tho p),~1l101ar clasp, hiit' he found that SOllll'hlllT.,· had' been using that cla~[l hellll'l'. '1'111-' ollly <:1'(-lit lIn could tak,' with rpgal'd to th,- III'\\, thing llC had shown was tlw ue\'l·J"l'llIf'llt and the ~,)mbin'atioll of all the thillgb that hat! gune before. 'l'here \I'as 1t tf'll,ll'lll'," Hllll1l'tilllf'S to .Io"k_with a little awu;'l'rnent at 01,1 thillg-~, but those olu things hall :;;ODll' merit or they would nut have lJeeH us'ed. Many times they were combined with ohjE'l.'tiollaT,le f,'atull'~. We travelled ill cirdPH \ r1'.)' oftell ; it was' "1'." much like goingnp a spjral hill. ,:uming l"itn.d tlJ the same pIare tinw-aft('r timc, out jll,ta. little higher up. With reganl to Kingsley's- applianr0. it had snIDe' bad feature~, but th(> principle was the],0, aD-ll o(lInhine,1 with the plate that was claBpeJ ill place it wa~ {If cOlisiuerable use. Hipwell had mentir)]lpd the fad that natmal, forcf's should he' rp!ieJ. t1P~I1l. That was very true, hnt one sho1l1c1 not get any ~uch ,oChilllerieal idea in onll's !rcad a, that l1fttUJ'al forces would I'etaill teeth at lirst. 'rtlCY helped a good deal. Most of' the ,'anse,' of mouth-breathing and bad haljit~ WI']'<: unkn"",', lmd until they wel'n known it was )H~"eB­ sary t-o have some ml'Chanical l'r.striction, Until that tinw cam-c he felt he had the ,llIost practkal retention, wh'ich did not iliterfere in the least with the natural forcos becoming' established. The r'etention w'as safe, and there was Ill) injury to the, teeth fmm ullobsf>n-en 'decay about the bands, 'I'he pationt was fr<'C<1 aR llUH?h as ppssiblc -from the diSllgr.'eablc appearance of retention. The whole Qppratjon "as ,vory practical, 'and that meant a, guoll dpal. The wearing of a band I'lluld be made flO unpleasant that thf" operation wouM not be undertaken. The appliance he had shown :lidded a g-reat deal to the comfort and plf'a~ll.nt features of the whole opelation, and'he could hardly ex.preS8 the reIid it had been tll hi.m in hiB own practiee. It had really lifte'l from hiE sho,ulders fu1)y, 50 pel' cent of the (] isagreeable feahues, _ On the proposition of the 'plt'~iJent, a Iie,uty '"01.1' of thanks was accortled to IJawJI'Y for his paper, tho prcsidrut huping that Th', Hm,-le)' would' attt'ud tlie meeting ll~X:t ,SPaT and give a further paper on th(' HuhjPI't.