Cephalometrics In Clinical Practice

Cephalometrics In Clinical PracticeCECIL C. STEINER, D.D.S.Beverly Hills, Cali/.To those of you who are not fullyemploying cephalometric principles inyour orthodontic practices, I ask thesequestions : "DO you really want to knowwhat you are doing to your patients,or are you afraid to find out? DO yoususpect that, if you did know, you mightsometimes be unhappy? If you did notlike what you found, would you dosomething about it?" If the answerto these questions is no, then you don'tneed a cephalometer. If the answer isyes, then careful and intelligent use ofcephalometric principles can be themeans of greatly enhancing your use-fulness to those you serve. Even thoughsome of these principles are being usedby a large percentage of the ortho-dontists today, this usage is generallysuperficial and falls far short of thepotential benefits that are available.The greatest value of cephalometricsis in the field of comparative studies;wch comparisons divulge and demon-strate changes that have occurred andstrongly indicate the responses to thetreatment therapy that has been em-ployed. Cephalograms demonstrate notonly the effectiveness of treatment, butalso what is equally, or even more im-pcrtant, its shortcomings. Properlyviewed, they give strong evidence of theanchorage principles employed and thedegree of its effectiveness. I refer notonly to the bodily movement of teeth,but also to their inclinations, whichindicate whether movement has oc-curred bodily, root first or crown first.A discerning and experienced eye canalso see the story of tissue responses,Read at the Charles H. Tweed Foundationfor Orthodontic Research, Tucson, Arizona,October, 1956.bony changes and, sometimes, changesof muscle function.This knowledge is not gleaned froma few simple measurements on anoriginal cephalometric tracing, It be-comes apparent only from carefullysuperposed serial tracings and fromcomparison of important serial meas-urements. Those of you who are notfaithfully and routinely making andstudying progress or "follow-up"cephalograms, taken during and afterboth treatment and retention, are, inmy opinion, missing the principalbenefits made available by the ceph-alometer. A knowledge of what wehave done and, particularly, what wehave not done, moulds and crystallizesour treatment philosophy and condi-tions it for better service for those whocome to 11s for treatment.Much credit should be given toRroadbent and to those other men whoparticipated with him in doing thegroundwork which led to the creationof the cephalometer. Acknowledgmentmust be given also to those who de-veloped methods to make ceph-alometrics useful to clinical ortho-dontists. High on the list of these isDowns who first gave us a practicalmethod of using cephalometrics inclinical practice. Basic ideas developedby him are still the foundation formost of the later developments thathave evolved.Four years aao we suggested a seriesof measurements, which, at that time,we felt were a vital minimum for treat-ment diagnosis and for a determinationof the results achieved during treat-ment.lR Some of these measurementswere ideas of, and had been originallypresented by, Downs, Riedel, Thomp-8 Vol. 29, No. 1 Cephalornetricsson, Wylie and others. To these wemade additions. Time and the clinicalexperience of many practitioners havenow tested them. These testings in-dicate the need for some additions andmodifications of the original measure-ments. Further time and usage will un-doubtedly point out others. Themodifications and additions now pro-posed have evolved principally as theresult of studying comparative tracingsmade during and after treatment.To try to justify all of the measure-ments that we have proposed in thepast is clearly contra-indicated in thispaper. I believe, however, we shouldtry to encourage the use of those thatrelate to the mandible, for they havenot all been widely used and do involvewhat are probably the most vital andimportant questions before the pro-fession today. These questions are: CanUJR stimulate or retard the groreith of:he mandible by orthodontic meansand. if so, how can it best be accom-plished?There has always been a marked dif-ference of opinion among orthodontistsas to what constitutes correct and ef-fective therapy for the mandible. Theseopinions vary from simply "jumpingthe bite" to various appliance pro-cedures aimed at changing its size,shape and location. To those of youwho have a desire to know what effectyour treatment is having upon themandible, I sincerely suggest that, ifvou follow the technic we have out-lined, you will obtain much valuableinformation.This procedure necessitates adequatepictures, not only of the body of themandible, but of the ramus, neck andcondyle as well. The following thoughtsmay be helpful to those of you whotake cephalocrams in your offices.Recause the condyle lies partiallyhidden behind the zygomatic processand is sometimes partially covered bythe ear-posts of the head holder, it is9Fig. 1 Above, method of filtering the raysto more fully expose the condylar area.Below, one half of the film is used to recordthe condyle with the mouth wide open. Theother half is used to recwifl tlir lest pnsitloltand the soft tissue.helpful to give this area additionalradiation by filtering out all other areaswhile the exposure is being made. Thiswill "burn in" or more fully expose thecondylar area (Fig. 1). If necessary,the soft tissue profile can be filteredin by the reverse process.A more accurate and satisfactorymethod of recording the condyle is totake an additional picture of the man-dible with the mouth wide open so thatthe condyle is moved forward anddownward and free of the zygoma (Fig.1 ) . A template of it can then be madeand used for other tracings of the case.The other half of the same film may beused to demonstrate the rest position,to show the soft tissue outline, or forsuch other purposes as may be desired(Fig. 1).With pictures of the complete man-dible (Fig. 2), its size and shape canbe observed and measured. It can belocated anteroposteriorly by projectingit onto the line SN and locating this 10Steiner January, I959Fig. 3 A l)lcs:i is ~ii:itle to iecorrl :dl oftlir iii:iii(lit)lc iiicludiiip tlic coii~lylar ;ir~i.I iiiport:int prowtli c.li:ii~gcs occur in this :I r~:itluring the ort.liodoiitic age span. The direr-tion :ind tlist:uirc~ of closure from the rest tothe c!o,ce(l position ciin he recortlrd :trillslioiiltl lie of iritrrcst to ort,hoilontists.projection with reference to the pointS. The distance SE is of special in-terest (Wylie) because it infers condyleto hinge-axis relationship anteroposte-riorly. The mandible's inclination canGoGn-SN, a principle used by Downs.If you are sufficiently interested infunction and in the thoughts of Thomp-son and others regarding it, and I thinkyou should be, you can use a ceph-alogram of the rest position to recordthe direction and the distance of themovement of the condyle and of thechin, from rest position to closure (Fig.I must confcs that although we nowhave hundreds of records of the direc-tion of the mandible from rest to theclosed position, and have a largesample of the results of treatment onthese positions and motions, we do notknow as yet how to make specific useof this information advantageously inour orthodontic problems. We do knowthat it tells part of the story of func-tion and that function is fundamentalto orthodontic knowledge. We havefound, as others have, that in cases ofmalocclusion the rest position is general-L- .I -* -...-- :.-- J L.. ,-..-1:-- rL. 1IJC UCLC1llllll~U Uy 1CLUl Ulllg Lllt: illl~l?2).ly different from the rest position ofnormal occlusions. We have ampleevidence that, when malocclusions aresuccessfully treated, the rest positionsgenerally change to one more nearlyor actually resembling that of a normalocclusion. (Fig. 3) .For those of you who are busy inclinical practice and are looking to theuniversities and to others for the de-velopment of new ideas and guidance,I do not feel justified in pleading forthe use of these recordings of move-ment. I do sincerely hope that your in-terest in advancing orthodontic knowl-edge will stimulate you to gatherfurther information in this field. Thesemeasurements and comparisons do giveus a peep through a small windowinto that complex and nearly dark, buthighly important, c,avern of mystery,function.To those who are interested in know-ing whether or not mandibular growthis bein: produced by orthodontic means,I --Irn 111L(1\\ 2 rt..r\** ,7,,,,.15 n r!. on u for :rc=rding theI,@pcc 5Fig. 3 A. The closed and rest position lw-fore trea#tment. Fig. 3 B. Closed and restposition after treatment. A comparisonsliows tlie changed direction mid distanre oftlie closure of a treated case. Note the morenornial closure after trmtment,. Vol. 29, No. 1 Cephalornetricsentire mandible, including its principlegrowth centers, the ramus, the neckand the condyle. I also suggest thatboth before and after treatment trac-ings of it be carefully related to a checkpoint so that changes in its locationmay be measured and evaluated andthus be distinguished from growth. Weha\.e used point S in this manner.Let us now consider some of thesenew measurements and assessmentprinciples. The first and most importantof these was described to us by Hold-away. I believe it to be extremely im-portant and I wish to give him fullcredit for bringing it to my attention.Wc have used it for some time andhave adopted it as a part of our routineanalysis.I am sure it has been obvious to allof you that the chin contributes gener-ously to the facial outline, especially inprofile. It practically establishes thecharacter of the lower face. We havecarefully considered the anteroposteriorrelationships of the teeth and the partthey play in determining facial con-tour. We have talked about point Aand point B but have said little aboutan evaluation of the chin point. Theanteroposterior location of the chin canbe expressed as point pogonion (Po).Certainly the degree of prominenceof the chin should contribute tre-mendously to a determination of theplacement of the teeth. Therefore, letus measure from pogonion (Po) atright angles to the line NB and recordthis measurement as is shown in Figure4. This distance will vary so widelyamong individuals that a mean meas-urement for it would have little diag-nostic value. The relationship of themeasurement, pogonion to the line NB,to the measurement, labial surface ofthe lower incisor to NB, is the importantfactor to be considered. The differencebetween these two measurements willvary widely among normal individualsbecause the chin point varies consider-h'ig. 4 The ~~~eiisureiiiei~ts pogotiioii to tlicline SB :ind lower inrisor to the line N3.These iiieasiireiiieiits are related aiid slioulilbe considered in treatment and di:ignosis(mi(ittn :IF).ably, according to type, in all individ-uals. It is now too early to make definitepredictions as to what the relationshipof these measurements should be. At thepresent time Holdaway would like tosee the distances, pogonion to the lineNB and lower incisor to the line NB,equal. He believes that, if the over-lying soft tissues are of average thick-ness and arrangement, acceptable re-sults can be achieved when these meas-urements vary within a range of twomillimeters. He regards a threemillimeter variance as being less de-sirable but tolerable. He states that,when the difference between them isfour millimeters or more, extraction ofteeth or other remedial measures aregenerally necessary to bring the dif-ferences within acceptable limits. I have'seen ample proof that the ratio be-tween these two measurements can begreatly influenced by orthodontic ther-apy and, in most instances, can bebrought within acceptable limits.We have now had enough experiencewith the use of this measurement, 12 Steiner January, 1959pogonion to NB, to know that the loca-tion of pogonion as related to the otherstructures of the face has a direct bear-ing on the manner in which, and Iquote Holdaway: "the neck and facialmuscles drape over the chin and neckand thus affect both esthetics andfunction." The location of pogonionis certainly one of the important factorsin establishing facial contour and itmust be carefully considered along withother factors when estimating theproper placement of the teeth.Both tracings shown in Figure 5have an ANB angle of four degrees. Therelationship of the upper teeth and thelower teeth to their respective linesNA and NR are identical. The twocases differ in the measurementpogonion to the line NB. It is obviousthat this difference indicated an in-dividual placement of the teeth foreach case and that the same treatmentfor both cases is contraindicated. It isequally clear that the measurement Poference.From our early experience withcephalometric tracing we have knownthat the alveolar process about theteeth moves markedly as the teeth aremoved and that it continues to moveand to adjust itself during and afterthe retention period. These changesinvolve point A (Fig. 6A). For thatreason we have suggested that theangle SNA and the line NA be copiedfrom the first tracing to all serial trac-ings (Fig. 6B j to accomplish correctpositioning of serial tracings for com-parison and to provide identical linesfrom which to measure and assess thelocation of the upper central incisor andthe first molar. These measurementsare comparable only if they are madeto identical lines.We now suggest that in addition tocarrying forward the old angle SNAand the line NA from the first tracingto all other serial tracings, we alsoto NE has a direct hearkg cn this dif=Fig. 5 Two cases that hme identicalmeasurements, except, that in case (A) thepogonion to the line NB measurement is4.5 mm. In ease (B) it is 0 mm. Obviouslythese two cases require different tooth re-placement and the measurements Po to NBand 1 to NB are vital to the determinationof this difference.draw the line NA on the new tracingin the usual way, using the new pointA, which in many instances will havemoved as the teeth have moved (Fig.SC) . If movement has occurred to pointA, it will create a different SNA angle0 @ 0Fig. 6 (A) Showing the change in pointA during treatment. (B) After treatmentwith the angle SNA and the line NA copiedfrom the first, tracing onto the second one.This is for the purpose of superimposingthese tracings on the maxillae and to deter-mine the movement of the maxillary teethin the maxillae. (C) After treatment trac-ing, with both the original line NA (solid)copied from the first tracing and the newline NB (dashed), which evaluates thechanged location of the maxillary apicalbase. Vol. 29, No. 1 Cephalornetrics 13and thus relocate the apical base ofthe maxilla.Consider now the mandible and themandibular teeth. Point B moves withinthe mandible as the lower incisors aremoved, but generally not to the sameextent as does point A when the upperteeth are moved. As point B moves,the line NB moves correspondingly andthe measurement, lower incisor to theline NB, is thereby influenced eventhough the incisor has not moved, Theangle SNB has also changed as a resultof the changed position of point B,within the mandible, even though theposition of the mandible may have re-mained constant.For a long time we have searchedfor a more stable and revealing pointon the mandible from which to measureand express movement of teeth and thechanged positions of the mandible.The location of this point should be asdevoid of growth changes and be asfree of the influences af the movementof teeth and other environmental in-fluences a8 is possible. Pogonion is notgod, far it is the site of secondarygrowth changes, particularly in themale, We had hoped that the junc-tion of the lower border of the man-dible with a cross section of the sym-physis might be useful, but tracingexperience soon ruled it out becausethe junction of the lower border of themandible with the symphysis is agradual transition and is often vague.Ws have alss teated muscle attach-ment areas and typical depressions with-out finding one that offered muchpromise, For eeme time we have useda new point which we believe is logicaland useful as a diagnostic landmark.The majority of the profession ac-cepts point S as being an acceptableestimate of the center of sella turcicaand believe it to be a reliable and use-ful landmark for measurement, If thepmeibility of determining the exactGentar of this irregular figure ie qua-tioned, we can logically answer that itcan be estimated within a fraction ofa millimeter and that this degree ofaccuracy is sufficient for our purpose,providing this estimate is carried overto subsequent tracings by copying thepoint from the first tracing when theyare correctly superposed.By a method that is similar to thatused to establish point S, we can estab-lish a point on the mandible to servean equivalent purpose. We will con-sider only the cross section of the bodyof the symphysis. We will ignore thealveolar process for it is influenced bythe positions of the teeth and is change-able. Either visually, or with instru-ments, establish a point at the center ofthe mass of this cross-section. We willcall this point D, Fig. 7. Like point Sin the cranium, it is well surroundedby sturdy bone; it is protected fromoutside influences and is well isolatedfrom the areas where movement ofthe teeth and normal growth changesoccur. Deviation from the exact centerof the symphysis is not serious. Thepoint is to be used principally as areference point and is to be transferredto subsequent tracings by copying itdirectly from the first. It can be copiedonto subsequent tracings as accuratelyas you can superpose the tracings ofone mandible over another. This is noteasy, for over a period of time prac-tically all parts of the mandible changein both size and shape,We believe that the most accuracycan be achieved by the followingmethod. First, let us freely admit thatpoints Go and Gn are difficult to locateand therefore the line GoGn is not al-ways ideally placed. We can minimizethe undesirability of this error by copy-ing the line GoGn from the first to sub-sequent tracings and, for use as areference line, this nullifies the possibleerror. To copy it accurately we mustsuperimpose the tracings by using allof the evidence that can be found any- 14SteinerJanuary, 1959h'ig. 7 Poilit 11 is 1oc:itetl at the cellt.rr ofthe cross section of the body of the syi1lp11y-sis. We suggest it, to represent the antero-posterior location of the body of the man-tlible and to evaluate chaiiged positmioils ofit. Illustrated also is :I method of superim-Iwsing tracings of inandibles.where on the mandibles.Especially to be considered is thecross section of the symphysis, partic-ularly its lower and posterior borders,with special emphasis on those portionsjust above and below the attachmentof the geniohyoideus and genio-gloxus muscles (Fig. 7). These areasshow a minimum amount of change.Having established this superposition-ing and seeing that the lower bordersof the mandibles as well as the ascend-ing rami are parallel and the directionof the growth of the condylar areas isin the right direction, copy the lineGoGn and the point D from the firstto the subsequent tracing. The lineGoGn and point D will serve thesame purposes for the moving mandible,as does the line SN and the point Nfor the rest of the skull. When themandible moves, line GoGn and pointL) move with it.We now measure the angle SND(Fig. 8-above) as an assessment of theposition of the mandible in its antero-posterior relationship to the rest of theskull. Let point A and point B continueto express the apical bases of the den-ture and let the angles SNA and SNBdemonstrate the location of these apicalbases to the skull and to each other.Angle SND more accurately expressesthe location of the mandible, as awhole, to the skull.It has been our experience, and I/\ CC.Fig. 8 Above. Angle SND is suggested toexpress and ewluate the :iiiteroposteriorlocation of the anterior portio11 of the i11:111-dible ill relation to the head as n whole. ,Below. Line D is erected throng11 poiiit D:Ins perpeiidicuhr to the liiw GoGn. It isused to locate the positioii of the louerceiitr:Ll incisor.think you will find it true, that anassessment of the changing positions ofthe mandible arrived at by using theangle SND will record changes more Vol. 29, No. I Cephalornetrics 15accurately than when using the anglesSNB or SNPo.Point D can also be used to deter-mine changes in the position of themandibular teeth within the mandible.To do so, erect a line through D per-pendicular to the line GoGn to a posi-tion even with the incisal edge of thelobver incisor. (Fig. 8-below). We willcall it the D line. It will generally passthrough the lower central incisor butthe varied relationship of this tooth tothis D line will surprise you. It will con-vince you not only of how teeth inmalocclusion vary in their relationshipsto the mandible, but also how teethin normal occlusion in different in-dividuals vary in this regard.To locate the incisor to this line,measure at right angles from the lineto the most anterior point on the crown.Also measure the angle formed by thelong axis of the tooth to the D line.Because the upper end of the line wasdrawn even with the upper extremityof the incisor in the original tracing,the line, when copied to subsequenttracings. can also be used to determinedepression or elongation of the incisorteeth.The D line is transferred to serialtracings directly from the first one bysuperpositioning, as is also the lineGoGn and the point D. Because theline travels with the mandible in ex-actly the same manner as do the in-cisors, it is useful in locating these teethin the mandible and in determiningchanges of their positions in serial trac-ings. For treatment planning, we stillprefer to evaluate the positions of thelower incisors to a facial plane.A more graphic method of deter-mining changed positions of teeth thatis both accurate and revealing will nowbe described. Its accuracy is directlydependent upon our ability to super-pose serial tracings.When we compare serial tracings,we are accustomed to superimposingthem one on the other for the purpose.Cases are usually reported at meetingsand in the literature by using super-positioned tracings which are dis-tinguished one from the other by theuse of solid and broken lines. Thesedrawings are often complicated andconfusing. We offer the followingmethod as being simple, clear andeasily understood.Because it is important to the methodof superpositioning, let me first saythat in our office we use colors forserial tracings. They help to selectspecific serial tracings and to distinguishone from the other when comparingthem. After considerable experimenta-tion and thought, the following colorshave been selected and their use isrecommended. For the original tracing,black is used for all lines and measure-ment figures. After treatment tracingsare done in red, intermediate tracingsin blue, retention tracings in green andsubsequent tracing in terracotta. Thesecolors have been chosen for contrast,zensitivity to color film for ease in slidemaking, availability of quality pencils,etc. To identify their origin, all linesand figures are copied from one trac-ing to subsequent ones in the color inwhich they originare. Due to the un-availability of colors we will use solidand broken lines in this printed articleto represent different colors and, inthat way, identify different tracings.When comparing an after treatmenttracing with a before treatment tracingto determine changes that have oc-curred to the upper incisor, superimposethe serial tracings under discussion asfollows; place the second or after treat-ment tracing, on the first, with theline. SN superimposed and registeredat N. With a black pencil copy theline NA of the first tracing onto thesecond tracing. Now slide the secondtracing up or down along these blacklines until, by the greatest amount ofevidence in the region of the maxillae, Steiner January, 195916the drawings of the maxillae are super-imposed (Fig. 9-abwe).Now, represent the position of theincisor of the first tracing onto thesecond tracing by drawing a dashedline from the tip of the incisal edge tothe tip of the root of the upper incisortooth of the first tracing (Fig. 9-above) .Place a small but definite dot at eachend of this line to clearly determine itsends. We call this line the upper in-cisor line.View the second tracing alone (Fig.9-below). The dashed line just describ-ed is a graph of the upper incisor as itoccurred on the before treatment trac-ing. It demonstrates its original positionanteroposteriorly and vertically andshows its original inclination. By com-paring the line with the drawing of theincisor in its new position after treat-ment, you can determine how far theroot has moved; how far the crown hasmoved and in what directions and com-binations of them. Changes in the in-ciinarion or angulaiiwri becciiie ~p-parent.We apply this method of evaluationto the upper molars and find its useequally important for them. Changesthat take place in the positions of theseimportant "anchor teeth" dictate chap-ters in the story of anchorage. To ap-ply the method to the upper molar teethwe proceed as follows: superpose theafter treatment tracing on the beforetreatment tracing by superimposing themaxillae as formerly described (Fig.9-above). Draw a dashed line repre-senting the first molar of the first trac-ing onto the after treatment record inthe following manner: from the tipof the mesial cusp to the tip of themesial root, draw a dashed line andplace a small dot at each end. We willcall this line the upper molar line.Viewing the after treatment tracing byitself (Fig. 9-below) , you can quicklysee the movement that has occurredto this tooth in this plane of space.Changes in its inclination and its verticalheight will be particularly interesting,especially in the treatment of Class I1malocclusions.Fig. 9 Above. Before and after treatmenttracings superimposed on the maxillae toestabhh the upper incisor and molar lines.Below, the upper incisor and the uppermolar line, recording the original positionsof these teeth. Vol. 29, No. 1 Cephalornetrics 17The same procedures can be used were established on the second tiacingwith the lower incisors and lower first from the first one by superpositioningmolars. The line GoGn and the point as previously described. It only remains,D have been determined and drawn on therefore, to superimpose these linesboth tracings. This line and this point and points to re-establish this carefulsuperpositioning (Fig. 10-above) . Hav-ing done so, draw onto the after treat-ment tracing the graph of the lowerincisor from the before treatment trac-ing by drawing a dashed line as describ-ed for the upper incisor. Draw in thegraph of the lower first molar by usinga dashed black line extending from thetip of the mesial cusp to the tip of themesial root. Place a dot at each end.View these lines and their relationshipsto the teeth in their new positions asshown in Figure 10-below.These methods can be used on aseries of tracings of the same case and,if these lines are recorded on the lasttracing, the history of the experienceof these teeth will be charted as shownin Figure 11. Evidence such as this is-an index to such questions as: the in-dications for and against and the ul-timate effect of tipping molars exces-sively, and whether or not these tippedmolars tend to right themselves at theexpense of the roots or of the crowns.In this day of special interest in de-pression or elongation of the uppermolars during treatment, particularlythose cases of Class 11, Division I mal-occlusions, this method of assessmentgives interesting and important in-3"1 formation.Since anchorage preparation is ofconcern to many orthodontists and thecreation or loss of anchorage is vitalto all, it seems desirable that a graphicpicture of the conditions made easilydiscernible by the use of these incisorand molar lines will be stimulating andhelpful. These lines do not show any-Fig. 10 Above. Before and after treatment thing that is not shown by supe~mpos-tracings superimposed on the mandibles toestablish the lower incisor line and the ing tracings, but they do show it morelower molar line. Below, the lower incisor graphically and more quickly andand lower molar lines which record theori@nal position of these teeth. easily. 18SteinerJanuary, 1959\ CcslFig. 11 Tracing at approximately the endof retention. Dashed lines - original posi-tioiis of teeth, dotted lines - positions ofteeth at end of anchorage preparation, solidlines - teet,h at end of treatment.Figure i2-above shows a case efdouble protrusion presenting a seriousanchorage problem. Figure 12-belowillustrates the case immediately afterhaving what I believe to be a commontype of active treatment. It consistedof vigorous and repeated tipping of theanchor teeth and generous use of Classtwo elastics. Probably no extraoralanchorage was used. It is evident that"the good fight" (if this type is good)had been fought to resist the forwardmovement of the anchor teeth. A highprice of excessive tipping the anchorteeth was paid and a long period ofretention is anticipated, for thesemolars, particularly the upper ones, willerect themselves at the expense of thecrowns coming forward. Elongation ofthe teeth of the upper posterior segmentsdig not occur. Such movement is nowsometimes thought to be desirable,particularly *in the treatment of ClassI1 cases. Look at the iupper molar inFigure 12-below. The dashed line was' 2137-A\ ccsFig. 12 Above. A typical case showing theincisor and the molar lines (dotted) on thebefore treatment tracing. Below, the sameciise after treatment. The lines under dis.cussion show the original position of theniolar tooth. Note the bodily movement ofthe incisor and the tipping of the molar, theprice paid for intraoral anchorage only.copied from the before treatment trac-ing. Its upper end represents the tipof the mesio-buccal root before treat-ment. Its lower end shows the original Vol. 29, No. I Cephalornetrics 1919504Fig 13 Above, before treatment, and, be-low, after treatment. Note how these linestell a different story from the last case.Here extraoral anchorage and anchoragepreparations have kept the molars back andnearly erect. The upper one is elongated asis desired by some orthodontists, particularlyin Class I1 t,reatment.position of the tip of the mesio-buccalcusp. We see that this cusp has comeforward and upward 4 millimeters. Thetip of the root has come forward 5millimeters and the tooth has tippedfrom its original position 5 degrees.In like manner the lower molar linedemonstrates that the tip of the mesio-buccal cusp has come forward 3 milli-meters and elongated 3 millimeters; thetip of the mesial root has tipped for-ward and upward 8 millimeters andthe inclination of the molar has chanF-ed 9 degrees. The movement of theupper an4 lower incisors is obvious.A rimilar, but more difficult case isshown in Figure 13-above. "Anchoragepreparation" as advocated by Tweedwas used. Extensive use was made ofhead-gear applied by means of theKloehn-type fixed double-bow. ClassI11 elastics followed by Class I1 elasticswere worn. See the difference in the re-sults achieved (Fig. 13-below). Notethe small amount of tipping of theupper m6lar and the fact that it re-mained almost in its original positionmesio-distally. Notice also its elonga-tion. The lower molar is well positionedto resist the pull of the Class I1 rubberligatures and it has not been extrudedby them. In both of these cases note theeffectiveness of the incisor and molarlines to draw distinction between theresults achieved by these two differentmethods of treatment.Examine Fi gure 14 using the in-cisor and molar lines augmented bysome of the incisal and apical basemeasurements. This case presents alees serious problem but, because theanchorage has been squandered andwasted: the case is a dismal failure. Thecrown of the upper incisor has beenretracted little, the root none. Theupper molar has come forward almostbodily. Both the lower incisor and lowermolar have come forward and, un-forgivably, crown first. Even thoughfour bicuspids were extracted the linesunder discussion and the soft tissuestell a story of the wanton waste of 20SteinerJanuary, 1959. -- ._ ...F5g. 14 Above, ease before treatment and,below, after treatment. Anchorage waswasted. The case is probably worm aftertreatment.-3Fig. 15 Above, before treatment. Middle,after eighteen monkhs of treatment withtwo upper molar bands, Kloehn-type doublebow and neck strap only. Note tremendoustipping of the upper molars due to faultyapplication of pull. Below, four years later.Mother Nature has been kind. This caseahows the effectiveness of the incisor andmolar lines. Vol. 29. No. 1Cephalometricsanchorage and of the poor result thatwas achieved.The case shown in Figure 15-abovehas been treated to the stage shownin Figure 15-middle solely with twoupper first molar bands and a Kloehntype double-bow used with a cervicalanchorage. From the obvious drasticovertipping of the upper molar it isevident that the cervical pull was ap-plied to an outer bow that was tooshort and doubtless too low. This spec-tacular movement of the upper molaris, in the writer's opinion, useless andcontraindicated. The Kloehn bow andthe cervical strap can be equally ef-fective in keeping a molar upright oreven tipped in the other direction.The distal movement of the lowermolar as well as the upper one can beseen. We have often observed this effecton the mandibular teeth when usingextraoral anchorage against the upperteeth and we believe that this phenom-enon is significant, interesting and use-ful. Note also the distal displacementof the mandible and the angle SND.We believe that this is temporary andwill recover when the distal influenceis discontinued. Figure 15-below showsthe case about four years later. Naturehas been kind. This case graphicallyshows the effectiveness of the incisorand molar lines.If we are to attempt to evaluate thepositions of teeth to one half of amillimeter or to one half of a degree,we must have accurate tracings thatrepresent the teeth. It is my opinionthat sufficient accuracy for the purposeof these fine determinations is usuallynot accomplished by tracing directlyfrom the radiograms.To solve this problem a plastictemplate from which all tracings of theteeth are made is very helpful (Fig. 16).In addition to saving time in tracing,it will assist considerably in establishingthe outlines of the teeth; it producesa much better looking tracing and as-21Fig. 16 A plastic template to drawsymbols of the teefh which can be dupli-cated in serial tracing8 and be compared.sures that serial tracings of the sameteeth will be similar and therefore canhe compared. Cephalometric measure-ments are made only on certain areasof teeth usually the labial, mesial andocclusal surfaces, the incisal edges andthe long axis. These parts can be ac-curately traced by the use of a template.It seems to the writer that methodsof evaluating the hard tissues shown incephalograms have been sufficientlywell developed to permit using the in-formation that is available in them togood advantage. Methods for survey-ing the soft tissues have not been asthoroughly explored. Information re-garding these soft tissues is importantto orthodontic problems and should befully used. It is the writer's opinionthat, when methods of measuring andintegrating the data of the soft tissuesare decided upop, they will be similarto those for the hard tissues and theywill be predicated upon similar or per-haps identical landmarks. We are nowparticularly interested in the "E Line"of Ricketts, which is drawn from thetip of the chin to the tip of the noseand also in the "Soft Tissue Line'' ofHoldaway. This soft tissue line is drawnfrom the tip of the chin through the 22 Steiner January, 1959tip of the upper lip and intersects theline SN. Many other attempts to evalu-ate the soft tissues have been made re-cently, one of them, published by Ston-er and co-workers.l"It is apparent that many membersof the profession are prejudiced againstusing cephalometric procedures in theirpractices because of their lack of under-standing of how standard measure-ments should be used, Downs presenteda mean for each measurement he pro-posed and he also wisely provided plusand minus limits within which measure-ments of individuals can vary and stillbe within the normal range. Wylie hasmade it clear that variations withinthese limits must occur in the right com-binations, if the individual is to benormal. Human judgment is stillnecessary to decide the desirable com-binations of these variations.Other writers attempting to simplifythe presentation of their ideas and thusstimulate their adoption have presentedone set of figures as a mean, tu `ut:varied by judgment as is indicated forthe individual. No one, `I hope. hasclaimed that every individual shouldconform to one set of measurements.We chose a revised set of fiquresgraphically shown in Figure 17 whichexpresses our concept of a normalaverage American child of averageage. These figures can and should bevaried for the use of those who have adifferent concept of what constitutes a"good face." They muct be varied whenmalocclusions have occurred Thesevariations will be not only in the sizeof the measurements, but also in theratios between them. Figure 18 showsa chart used by the author to deter-mine these sizes and variations.As is almost universally true through-out the realm of nature, as soon as avariation from the typical appears inone part of an individual, compensat-ing variations often appear in otherparts. Cephalometric standards are\Fig. 17 Average nie:isureiiieiits of normalssuggestrd to be used for comparisons. Thegraph of the upper and lower incisors showsthe ineasureinents of the upper incisor to theline NA and the lower incisor to the lineSB. Tlie top figure is the :ingle ANB.merely gauges by which to determinemore favorable compromises as a treat-ment goal. For a consideration of whatthese variations in and between meas-urements should be under different cir-cumstances, we offer the following sug-gestions.Graphicaily expressed is the normalpattern shown in Figure 19-A. Insucha case the angle ANR is 2 degrees, theapical base of thc mandible being 2degrees posterior to the apical base ofthe maxilla. The upper central incisorto the line NA is 4 millimeters at 22degrees. The lower incisor to the lineNR is 4 millimeters at 25 degrees.The upper and lower incisors then oc-clude normally.If, as in Figure 19-R, the measure- Vol. 29, No. 1SNA (angle)Cephalornetrics82.23SNB (angle) 80'NSlmG?: No: Age: Sex:CEPHALOMETRIC ANALYSISSTEINIIIRef. Norm.1 ANBI Om1 to SN (angle) I 14. I I I I I I ICormArch Form -LOWER ARCH + -TotalJANI1 m6. IDEAL ha+ b-T5.5..Fig. 18 A cepl~alwietric~ appraisal chart showing :.verage nieawrements of normal cases,presented for comparisons and to deterniine possible nccept:ible arrangements of the tee!h\vhen the :ipical bas? re1nt:onship v: ries from normal. The graph forms :it the bottom nredrs:gnetl for diagiinstic prwedurcs. 24 SteinerJanuary, 19592" IO' 6'Fig. 19~YHRC~ 011 the demand8 of the Rngle ANR.A - average normal. R - hypothetical mitlocclusion. C - predicted treatmentments of the upper incisor and thelower incisor to their respective linesremain the same, but the angle ANBis 10 degrees instead of 2 degrees (themandible is then displaced posteriorlyin relation to the maxilla), the upperand lower teeth will not meet; instead,the mandibular teeth will occupy aposition posterior to the upper ones.A desirable way to treat the case' isto reduce the apical difference from 10degrees to 2 degrees. This calls for re-tracting the maxilla and/or developingthe mandible forward, each memberbeing restored to its normal size andlocation. This is generally not possibleto accomplish, so a compromise isnecessary. From past experience weknow that in this particular case wecan reduce the apical base difference(angle ANB) from 10 to 6 degrees.Many things influence this estimate; Vol. 29. No. 1 Cephalomeir ics 25age, growth potential, type of maloc-clusion, type of treatment and theability of the orthodontist are the prin-cipal ones. The remaining discrepancybetween the upper and the lower in-cisors must of necessity be treated by adifferent procedure. The case underdiscussion has been reduced to an ANBangle of 6 degrees. Figure 19-C willshow our suggestions for the placementof the teeth as dictated by this 6 degreeangle. The justification for these sug-gestions will be discussed later. Thisformula must be altered by other fac-tors and conditions, particularly therelationship of the measurement pogo-nion to NB and its relationship to themeasurement, lower incisor to NB.As a matter of fact, the measure-ment, pogonion to the line NB, i:sprobably just as important for a con-sideration of where to place the teeth/\/3--\6Fig. 20 A - measurement pogonion to the line NB is 2 mm. B - measurement pogonionto the line NB was estimated to change to 3 mm. Lower incisor is placed at 3 mm. to theline NB to be in a 1:l ration to the measurement pogonion t~ the line NB (Holdaway).C - predicted treatment based on the demands of the nieasurement pogonion to the line NB. 26SteinerJanuary, 1959as is the angle ANR. Let us thereforereevaluate the case, this time on thebasis of pogonion to the line NB whichin this case was originally 2 millimeters(Fig. 20-A). From experience withsimilar cases we will estimate that be-cause of normal growth, developmentand treatment therapy, the distance Poto NB will increase in this particularpatient from 2 millimeters to 3 milli-meters during treatment. Using Hold-away's desired ratio of one to one, be-tween the measurements pogonion tothe line NR and lower incisor to NB,our formula for the lower incisors willbe a? shown in Figure -20-B.We have previously estimated thatthe angle ANB would change duringtreatment to 6 degrees. The 6 degreeangle in conjunction with the lowerincisor in its new position will dictatethe location of the upper incisor, be-cause, under the circumstances, the up-per incisor can occlude properly withthe lower in only one location, thisposition being minus 2 miiiimeters andat 16 degrees to the line NA (Fig.These figures are arrived at as fol-lows: let us accept the positions of theupper and lower incisors dictated bythe ANB angle of 6 degrees (Figs. 19-Cand 20-C) as being satisfactorily re-lated to each other. If the measure-ment pogonion to NB indicates thatthe lower incisor be retracted from thisotherwise satisfactory position of 5millimeters to a position of 3 milli-meters, Fig. 20-B, then the upper in-cisor, to remain in occlusion, must beretracted a similar distance. This will befrom 0 millimeters to minus 2 milli-meters. (Fig. 20-C) .We have now evaluated the case ona basis of the relationship of the apicalbases expressed by the angle ANB (Fig.19-C) and also on the basis of the de-gree of protrusion of the chin. (Fig.20-C\. Let 11% now reconcile the twomethods.20-C) .Figure 2 1 -A graphically expresses ourhypothetical problem. Figure 21-Bshows the proposed arrangement of theteeth as dictated by the angle ANB.Figure 21-C depicts the arrangementof the teeth as indicated by the meas-urement pogonion to the line NR.Figure 21-D shows a reconciliation be-tween the two made by establishing theaverage between them. We must alsotake into account many other factorsthat must be considered such as age,rex, race, individual growth pattern,health, growth potential and the in-dividual variations within these andother variations. Let us therefore ad-iust these figures as these conditionsdictate. On another graph of the teeth(Fig. 21-E) modify the formula to thedemands of the individual conditionsas your judgment dictates. Let us callit the "adjusted" or the "individualiz-ed" treatment goal. See the place onthe diagnostic chart marked, TreatmentGoal Individualized, provided for thispurpose. These adjustments must for-ever be dictated by human judgment.For the sake of simdicity I will takefor granted that in this particular in-stance all conditions are typical of thestandards from which they came. Tomodify them and justify the changeswould necessitate a lengthy paper initself. In this hypothetical case, formula21-E is identical to formula 21-D. Inpractice this would be unusual.In effect we now have a prescrip-tion for treatment of this case and astandard by which results achieved maybe assessed. It is a goal toward whichto work, a base from which to cal-culate progress and a record with whichto evaluate what has been done as abasis for future treatment.From evidence gleaned while study-ing the relationship of the upper andlower anterior teeth to each other aftergood results were achieved by orthodon-tic treatment in cases where the apicalbases were in various mal-relationships, Vol. 29, No. 14+\4.9 25'Cephalometries6'A- -06'276' !ccsFig. 51 A - our 1iypthetic~:il prol~lein. B - the proposed :in.:ingeiiieiit. of the teeth astlirj:itetl by the :ingle ASB (See Fig. 19). C - the arrmigeineiit of the t.eeth as indicatetlby the uie:isurenieiit 1)ogniiir.n to the line SI3 (See Pig. 20) D - n reconciliation betweellFigures B :iiitl C, ni:ctle by establishing the arerages betweell ,t.hem. E - the "adjusted" orintliric1u::lizetl fnmiula. If it is intlicated, it h:is been adjusted for age, sex, mce, iiidividu:ilgrowth pattem, groivth potcnti;il, health :iiiil a11 other conditions tlin8t. influence this partic-u1 1r l"ob1elll.and also from evidence seen on thedrawing board and from large scalemodels of teeth, we now offer ourpresent estimates for the placement ofthe upper and lower central incisors asdictated by the angle ANB, in caseswhere their apical bases are progressive-ly more mal-posed. Figure 22 illustratesthese estimates.PLEASE bear in mind that these arerough estimates, to be used as a start-ing point from which to vary and mustbe modified by other factors, not onlypogonion to the line NB, but also age,sex, race, growth potential and theindividual variations within these andother groupings. These figures can betailored by those who use them to fittheir own standards of treatment ideals.I agree with the many who claimthat fixed numerical standards shouldnot be used to dictate treatment therapyfor living human beings. They can,8'2'4, (. 22` :G: 4 ::{4-.Fig. 22 Our present estimates for theplacement of the upper and lower centralincisors, dictated by the angle ANB, as themandible is more distally placed in relation-ship to the niaxilln. These are rough esti-mates to be used as a starting point fromwhich to `vary mid must be modified byother factors. 28 Steiner January, 1959however, contribute as guides to thejudgment of those with limited ex-perience and they can assist all inreaching individual decisions. Observa-tion has convinced me that treatmenttherapy based solely upon experienceand artistic sense is not infallible norwithout its shortcomings. As the Ger-mans say, "Eine hand wascht dieandere." (One hand washes the other).It sounds complicated? Well, it isat first. So is a harmonica until youlearn to play it. Then it practicallyplays itself.Cephalometric procedures do giveimportant and vital information toguide orthodontic therapy but the an-swers are not written out withmathematical precision and clarity.A remarkable amount of information isavailable, however, for those who arewilling to put forth the effort to findit. Cephalometric studies can be so re-warding, that I now question the rightof orthodontists to offer their servicesto the pubiic without giving their pa-tients the protection and the benefitsmade possible by the intelligent use ofthese principles. I can honestly say thatcephalometric findings have practicallyrevolutionized treatment procedures inour office.The use of cephalometric principlesin orthodontics is growing fast. Largelyby trial and error, its usage is evolvingtowards simpler and clearer standard-ized methods that all can understand. Itis my hope that by presenting some ofthese problems for public scrutiny andappraisal, this paper will contribute tothat end.SUM MARY1. Point D is a useful landmark andwe suggest the use of the angle SNDas a basis for evaluating the anteropos-terior position of the mandible.2. We recommend the D line tolocate the lower central incisor in themandible and to assess changes of itsposition.3. Approval is given the measure-ment pogonion to the line NB to helpprognosticate the position of the lowerincisor teeth.4. We propose the upper and lowerincisor lines and the upper and lowermolar lines to evaluate changes in thepositions of these teeth.5. The recording of the entire pictureof the mandible and the use of themeasurements that we have proposedto evaluate changes in its size, shapeand location is recommended.6. A plea is made for quality andaccuracy in x-ray technic and for careand precision in tracings.7. We implore, that if you have notalready done so, you familiarize your-self with the tremendous opportunitiesthat cephalometrics offers in the fieldof orthodontics, to analyze problems,to determine solutions for themj toevaluate the results of treatment, toimprove orthodontic knowledge andthus to enhance our usefulness tohumanity.253 South Lasky Drive-4C K N 0 WLEDGEME N TSThe writer sincerely desires to give creditfor the evolution of these measurementswhere credit is due. This is not easy for inmany instances they are founded upon prin-ciples which overlap and these principles areapplied in different ways. After seriouslytrying to separate them and to allocatespecific credit for each, he ,takes refuge inmerely stating: 66Special credit should begiven to Doctors William B. Downs, AllanG. Brodie, Wendell L. Wylie, Richard A.Riedel, John R. Thompson, Reed A. Holda-way and to others for suggesting many ofthese measurements and for popularizingtheir usage. " Vol. 29. No. 1 Cephalometrics 29BIBLIOGRAPHY1. B:iuni, Alfred: A Cephalometric Evalu-ation of Normal Skeletal and Dental Pat-tern of Children with Excellent Occlu-sions. Angle Ortho., 21: 96-103, 1951.2. Boman, V. R.: Research Studies on theTemporomandibular Joint ; Their Inter-pretation and Application to ClinicalPractice. Angle Ortho., 22: 154-164,1952.3. Broadbent, B. Holly: A New X-rayTechnique and Its Application to Ortho-dontia. Angle Ortho., 1: 45-66, 1931.4. Brodie, A. G. et, al.: CephalometricADDraisal of Orthodontic Results : AP; minary Report. Angle Ortho.,' 8:261-351, 1938.J. - On the Growth Pattern of theHuman Head From the Third Monthto the Eighth Year of Life. Am. J.Anat., 68: 209-262, 1941.6. Downs, Wm. B.: Variations in FacialRelationships ; Their Significance inTreatment and Prognosis. Am. J. Ortho.,7. Donovan, R. W.: Recent Research forDiagnosis. Am. J. Ortho., 39: 340-357,1953.8. Elsasaer, Wm. : Studies of Dento-FacialMorphology. Angle Ortho., 21: 163-171,1951.9. Fischer, Bercu: Recording the Mandib-ular Plane Angle, Using OrientedModels. Angle Ortho., 15: Jan. April,1945.10. Graber, T. M.: A Oritical Review ofClinical Cephalometric Radiography. Am.813-840, 1948.J. Ortho., 40: 1-26, 1954.11. Griffith, Frank: Unpublished,12, Higley, L. B.: A New and ScientificMethod of Producing Temporo-mandib-ular Articulation Radiograms. Int. ,7.Ortho 0. Surg., 22: 983-991, 1936.13. Holdtiway, R. A.: Changes in Relation-ship of Points A B During Ortho-dontic Treatment, Am. J. Ortho., 42:176-193, March, 1956.14. Margoh, H. L,: A Plastic and GraphicTechnique for Recording Deutal Changes and Facial Growth, Amer. J. OralBurg., 25: 1027-1039, 1939. A BasicFacial Pattern and Its Applicatioii inClinical Orthodontics. I. The Maxillo-r'acial Triangle Am. J. Ortho Oral13. Riedel, R. R.: The Relation of Maxillary Structures to Cranium in Mal-occlusionand in Normal Occlusion. Angle Ortho.,22: 142-145, 1952.16. Ricketts, R. M.: Variations of theTemporo-Mandibular Joint as Revealedby Laminagraphy. Am. J. Ortho., 36:17. Salznian, J. A.: The Maxillator; A NewInstrument, for Measuring the Frankfort-Mandibular Base Angle, the Incisor-Mandibular Base Angle and Other Com-ponent Parts of the Face and Jaws.18. Steiner, C. C.: Cephalometries for You and Me. Amer. J. Ortho., 39: 729-755, 1953.19. Stoner, et. al.: A Cephalometric Eval-uation of Fifty-Seven Consecutive CasesTreated by Dr. Chas. A. Tweed. Angle00. Thompson, J. R.: The Rest Position ofthe Mandible and Its Significance toDental Science. J. A. D. A., 33: 151- 180, 1946.21. Thurow, R. C. : Cephalonietric Methodsin Research and Private Practice. Angle22. Vorhies, J. M. and Adams, J. W.: Poly-genic Interpretation of CephalometricFindings. Angle Ortho., 21 : 194-197, 1951.23. Wylie, W. L.: A Quantitative Methodfor the Comparison of Cranio-facial Pat-terns in Different Individuals; Its Ap-plication to a Study of Parents andOffspring. Amier. J. Anat., 74: 39-60, 1944.24. -- Anteroposterior Dysplasia.Angle Ortho., 17: 97-109.2:. ~ Heredity and the Ortho-dontist; A Study in Confusion. Amer.J. Ortho Oral Surg., 33: 154-161, 1947.26. Wylie, W. L. and Johnson, E. L.: RapidEvaluation of Facial Dysplasia in theVertical Plane. Angle Ortho., 22: 165- 182, 1952.Surg., 33: 631-641.877-898, 1950.Ant. J. Ortho., 31:608-617, 1945.Ortho., 26: 68-98, 1956.Ortho., 21: 105-115, 1951.