1960_ricketts_stating objectves and planning with ceph tracings

7/30/2019 1960_Ricketts_Stating Objectves and Planning With Ceph Tracings

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CEPHALOMETRIC SYNTHESIS

AN EXERCWE IN STATING OBJECTIVES AN D PLANNING TREATMENT WITHTRACINGS OF THE HEAD ROENTGENOGRAM

ROBERT MURRAY RICKETTS, D.D.S., M.S., PACIFIC PALISADES, CALIF.

INTRODUCTIONI ORTHODONTIC treatment planning the assumption is usually made thatteeth wi ll move, that the patient wil l grow, and that the clin ician can ac-complish a desired result with his specific therapy. Broadly speaking, theorthodontist is predicting the outcome of the patients treatment. With thefull realization that treatment planning constitutes a prediction, the clin icianshould be more critical in estimating results rather than leaving growth andchange to chance alone. When facial disproportion and ugliness prevail, it isimportant to recognize facial form in addition to occlusion as a problem incontemporary orthodontics. The necessity for an estimation of changes becomesapparent when the possibilit ies of tooth movement and facial change arerecognized. One needs only to observe and understand the changes that occurduring treatment in order to appreciate the importance of dynamic factors.

Cephalometric roentgenology has been the tool used to evaluate morphologyand to study growth and change during treatment.2l 7, 22*24 It naturally followsthat this tool should also be employed for estimating the future behavior ofjaw growth and development of occlusion. The result of such a technique is asort of cephalometric blueprint of the conceived image. We have termedthis method cephalometric synthesis, which indicates a putting-together ofisolated factors.

Natural growth of the skeletal bones comes to mind first when estimationsof the future are being made, but its alteration with treatment must also beconsidered. The possibilit ies of tooth movement, anchorage values of toothunits, and resulting adaptation and growth of soft tissue are likewise essentialfactors. Therefore, growth is only one part of the total change to be estimated

Eased on papers read before the Pacific Coast Society of Orthodontists, Feb. 26, 1968.Santa Barbara, Califo rnia* the Chicago Orthodontic Socket lKarch 23, 1959, Chicago. Illinois:and the Southwestern Society of Orthodontists, Oct. 6, 19& Houston, Texas.*The reader is enjoined to familiarize himself with the publication, A Foundation forCephalom etric Comm unicatio n * in order to appreciate and understand the interpretation ofcephalometric headfilm s prior to engag ing the x-ray for the present theme. Certain basic in-formation must otherwise be assumed. In additio n, the reader should be ac uainted withfacial alteration and the possibilit ies of treatment given in my article entitled she Influenceof Orthodontic Treatment on Facial Growth and Development.=64 7


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648 I11(KEITR i I. I.lrtll ,~ ,~ l e r n t ,c , , 196lJin treatment planning. The estimation procedure Iias I 1111s eefy divided intostatic synthesis for those cases in which g 1~Kwth is not expected alid dynamicsynthesis for cases in which the advantages of @'OWth ilI'(' 10 h. C'lljCJj-ed.

If a clinician does not. particularly care where he moves teeth, or if he hasonly a passing interest in esthetics or permanent results, placing all his con-fidence in late growth and retainers alone, then synthesis probably has littleinterest and little value for him. However, the clin icja il who is interested inthe most expedient and efficient treatment, technique or the operator who ismindful of ultimate functional and ost.hctic balancr aiid harmon\- of the teeth.mouth, jaws, and face should have a lasting interest in i synthesis procedureof this or another type, depending upon his disc ipline.

To apply the synt,hesis procedure, it is ottcn neccssar>- to st.ate rather crit.ica ltreatment objectives in order to be sur(x of where JY~ want lo go. * (Mythen can specific treatment be prescribed. Herein. however, lies a basic danger.The limits of ideal or satisfactory results must bc identified and a,pplird to theindividual case. The dictat,cs of common sense must be obeyed.

At the clinical level this procedure yields a rough estimate of condit,ionsmost like ly to occur. Therefore, it should be considered a guide or an aid inthe sc!ection of the most irnelligcnt aiid practical course to t,akc in t,reatmentplanning. It stil l is subjective on the basis of previous experience with similarcasrs, but it permits a, keener insight into t,he ~oss iOi/ities of an orthodonticcase. It, does not prevent mistakes in judgment, but it reduces the element ofchance. It is intended as an addition to other cephalometric procedures, es-pecially for difficult cases.

THE STATIC SYNTHES lS When no change in basal relationship is expected, the clinician is per-

mitted to use a static method of planning tooth changes to the skeleton.Thus, the growth phases of the synthesis may be omitted. Changes can some-times be anticipated as a result of displacement problems or loss of verticaldimension, but usually these arc minor.

Some clin icians advocate setting up the teeth in plaster for a treatmentplan. However, a cephalometric setup can be made with less effort and inless time. A formula for tooth arrangement can be employed in this instance,since growth and changes in basal relationships are unlikely, except for slightchanges at points A and B.

The teeth can be moved in the minds eye on t,he film, or, they can bemoved in the original tracing. Both procedures confuse the picture and renderit difficult to evaluate later. For this technique, ideally, a copy is made of theoriginal tracing, excluding the teeth and soft tissues. In Fig. 1, a, case ofsevere Class II lip-sucking with retracted lower arch is contrasted to a caseof severe crowding and protrusion in which no growt,h is taking place. Weshall call these patients Robert and Ann, respectively.

Reference Planes for the. Teeth (APog Plane and Occlmal Pla%e).-Thefundamental points employed are point,s A and pogonion (the APog plane).


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Volume 46Number 9 CEPHALOMETRIC SYNTHESIS 649This plane has been termed the denture plane, since it connects the an-teriormost basal bone structures of the upper and lower jaws. In some cases,1 or 2 mm. of change in point A can be expected following vigorous lingualroot movement of the upper incisor. In thr new tracing (Fig. I, C and D), a

Fig. L-Tracings of cephalometric roentgenograms superimposed over photographs. A,Severe Class II in malocclus ion well-dev eloped boy (Robert). Note mandi bular arch retractiognand sublabial tension in the mouth (lower incisor is -7 mm. from the APog plane).Severely crowded and prognathic Class I malocclus ion in Ann (lower incisor inclin ed forwardand located +8 mm. to the AP og plane). C, Roberts tracings after treatment. Note thatthe position of the lower incisor is now almost on the APog plane. Compare with treatmentPlan shown in Fig. 2. D, Anns tracings after treatment. The lower incisor was retractedalmost to the APog plane.

new APog plane is erected for the purpose of tooth profile reference. Theocclusnl plane is drawn near the original line of occlusion of the buccal teeth(although it changes, according to my earlier finding+ IL). The teeth arethen placed in an ideal reciprocal relationship to the basal bones for that


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650 IC ICKETTS \m. J. OrthodonticsSeptember, 1960depending upon the clinic ian s ideas on lip and tongue functim, the best toothposition for ultimate stability, and the heat compromise for esthetic reyuiremcnts.i

Lower Incisor-Location and Position.-When the APog plane is cm-ployed as a reciprocal reference plane, the tip of the lower inc isor is adjusted,if thought possible, to lie within one standard deviation of the natural variationas described by Downs9 and by me.2 The lower inc isor sensib ly should bc1.0 mm. forward to 1.0 mm. backward of the APog plane. One standarddeviation of 1,000 orthodontic cases was 2.5, which ranges from -2.0 mm. to3.0 mm. as satisfactory. I feel obliged to locate t,he lower incisor within thisrange if humanly possible within compatible principles of longevity of thedenture. It is indeed a rare case in which this is impossible. The cases shownin Fig. 2 were anticipated on each side of the mean with respect to originalenvironment of the denture.

l2.G.- 14.4 4-14-53_-.. 16- 2 z-1-55A. 5- 15-l 4- 29-55---- 17-S IO-26.57

b

ROW%1 ANNFig. 2.-Treatment plans and results for Robert and Ann. Note the needed change inthe lower incisors corrected to l ie wi thin one standard deviat ion of the mean , which is+0.6 + 2.5 mm, ; the ant ic ipated forward bodi ly moveme nt of the lower molar in both oaaea :the needed sl ight dr i f t of the upper m olar in Anns case; a nd the backward movemen t inRoberts case the only corrective force was provfded by intermaxfllary elastics. In Annscase, a palatal holding arch and extraction of four f i rst premolars were employed for t reat-ment .

Upper Incisor Angulation.-A normal overbite and overjet are then setup for the upper incisor, depending upon what is desired. Thus, the upperincisor angulation is determined only after that deemed desirable for the lowerincisor. The interincisal angle is up to as high as 145 degrees in the adult case,with the average near 135 to 140 degrees. The relationship deemed possible,sensible, and practical should be established. By comparing the original tracingwith the setup, one can read ily see the needed change in relationship of theupper incisor.

Anchorage Factors.--The extent of tooth movement necessary in the anteriorportion of the denture predetermines the anchorage needed to accomplishthat change. Molar and posterior anchorage can be estimated with experience.


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Volume 46Number 9 CEPHALOMETRIC SYNTHESIS 651The lower arch moves forward 3 to 4 mm. in ordinary Class II treatment withextraction. (See Table III, Group 4.) The possibili ty of extraoral anchoragecan be evaluated for the specific patient. The selection of holding arches andextraction patterns becomes evident. Thus, a treatment plan can be establishedon the objectives as outlined by needed changes in the incisors (Fig. 2).

Fig. 3.-Esthetic and functional changes in superimposed photographs on E plane.a, Note the forward moveme nt of Roberts lower li p. Thickness of the lower lip did notchange appreciably. RI Note retraction of both of Anns lips but slightly more reduction inlower lip. The upper hp is thickened slightly. C, Photographs of both patients superimposed,before treatm ent, on the esthetic plane (nose to chin). Note the differences in the mouthsof these patients as effected by tooth relationship .impose d, after treatment, on the E plane, (Refer to Fig. 1.) D, Photographs super-Note better lip balance and harmony of themouth with the nose and chin. (Refer to Frg. 1.)

Lip Change and Esthetic Objectives.-The upper lip will thicken slightlyfollowing retraction of the upper incisors (1 to 2 mm., depending on strain inthe beginning). The lower lip wil l curl backward or forward, meanwhilemaintaining about its same thickness, depending upon tooth change (Fig. 3, Aand B). The sublabial area below the lower lip usually maintains its thickness


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Volume 46Number 9 CEPHALOMETRIC SYNTHESIS 653(Fig. 3, C and D) . Thus, the lip t issue anterior to point B wil l follow thebehavior of the root of the lower incisor. If a mentalis habit exists, relaxationof the mentalis muscle wil l follow retraction of the denture unless the face isextremely long and the lips are short. Therefore, in nearly all cases the dis-tribution of the soft tissue of the chin over the symphysis wil l change as theteeth are moved (Figs. 3 and 17).

If growth is not contemplated, the nose probably wil l change very little.Therefore, a review of the esthetic changes by viewing the esthetic plane (endof nose to chin) wil l indicate the probable esthetic results.

It should be emphasized that static synthesis, or a formula for treatment,is possible only in conditions in which no growth is anticipated. One standarddeviation of natural variation frcm the mean of the lower incisor is soughtclinically . Similar denture relationships do not take away autonomy (Fig. 3).Each case maintains much of i6s individual characteristics in spite of attemptsto bring the teeth into a rather limited concept of esthetic balance and func-tional harmony.

THE DYN$MIC SYNTHESISWhen growth and change in the relationship of parts are anticipated, the

synthesis must be dynamic. The greater the conceived change, the more im-portant the recognition of an estimation procedure. I have previously describeda long method. *O My technique was established on the basis of findingsmade on fifty treated Class II cases and other growth cbservations made fromlaminagraphy of the joint. It was approached through the vital cranial baseand mandibular joint. It led to a vast understanding and explanation of thechanges in facial relationship, but the knowledge required for its use was toolarge for many clinicians to grasp. In this paper, therefore, I propose asimplif ied technique based on recent findings of current treatment procedures.

In order to obtain information on the morphologic variation to be experi-enced in practice, I studied 1,000 clinical cases. Various indicators wereemployed to analyze the cephalometric tracing. Means, ranges of variation,and standard deviations were established for facial height, depth, and con-vexity. Likewise, the relationship of teeth and soft tissue arrangement weresubjected to analysis, These data were divided into age groups and studiedfor suggestions on growth but, of course, this was not true longitudinal re-search. Accordingly, a serial study was needed and was conducted.

Study of Growth and Treatment.-Serial cephalometric records were ac-cumulated on five groups of patients; there were fifty patients in each group,making a total of 250 cases (Table I). There were two groups of nontreatedcases and three of cases that had been treated. In the nontreated samples,there were fifty Class I cases and fifty Class II cases. The three treatedsamples, all Class II, were corrected by extraoral anchorage, intraoral anchorage,and a combination of these forces, respectively.

Each case was subjected to sixty-three computations. Certain groups weresubdivided as to age, sex, facial type, and malocclusion. The components


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Volume 46Number 9 CEPHALOMETRIC SYNTHESIS 655studied could be classified as cranial base and upper face (Table I), mandibularor lower face (Table II), maxillary or middle face (Table II), change in dentalrelationship (Table III), and soft tissue growth of the face (Table III).

Details of this study are too large to be included here. Certain data, how;ever, are pertinent to the synthesis procedure herein outlined and are there-fore summarized in the accompanying tables. These findings, together withother data of past studies, are offered as documentation for the authenticity qfthe prevailing tendencies described in the procedure.

Sequence of Steps in the Dynamic Synthesis.--Since growth and mandibu-lar change must be related from cranial landmarks or references, the founda-tion for synthesis obviously must be made in certain cranial points and planesof reference.

Past research has suggested that the mandible is the most importantdeterminant of facial morphology.18, IQ,21 Thus, in estimating. facial change,the future growth of the mandible should be of primary concern. Changes in


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656 RICKETTS A m . J, OrtlmdonticsSrprember, 1960the chin merely reflect changes elsewhere in the mandible and in the glenoidfossa. Therefore, a critical consideration of mandibular patterns is: important(Figs. 4 and 5).

A. L.G. P.P. 572

Although natural growth change is less dramatic in variation in the upperjaw than in the lower jaw, changes in the middle face are vital to an estimationprocedure. Recent findings have suggested that the basal bone of the maxil lais amenable to alteration by orthodontic manipulation, and the possibilit iesof these changes must therefore be reeognized.21

Recent studies further indicate that the teeth can be moved safely overgreater distances than previously thought possible.25 Therefore, attentick to


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Volume 46Nmnber 9 CEPHALOMETRIC SYNTHESIS 657anchorage preparation, torquing of teeth, and mechanics of manipulation isalso a general consideration in cephalometric synthesis in addition to estimationof growth.

I

I 14GILBERT

ELiENFig. B.-Above: Before-treatment records on Gilbert, a 12-year-old boy with a ClassII, Division 2 malocclusio n. There is crowding in both arches. Note strong mesognathicand brachycephahc straight pattern, retruded lower denture, and good lip relationship .This patient had excellent growth potenti al on the basis of sex, age, facial pattern andphysical characteristics. Width of man dible is expressed at R-Go-M angle (74 de&ees).Growth estima tion and plan are shown in Figs. 9 to 13.Below : Before-treatment records on Ell en, a 12-year-old girl with a severe Class IIDivision 1 malocclusio n. There are severe lip strain and a mental is habit. Note retro:gnathic and dolicocephal ic pattern with high convexity.protrusion. The lower denture is harmonious with the There is severe maxillary incisoris inclin ed forward. APog plane, but the APog planeCrowding is present in lower arch.plus side, but disposition of the man dible is less favorable. Thickness of ramus is on theman dible (R-Go-M = 90 degrees). Note the narrowness of the

Finally, even less attention has been paid to the changes in the softtissues of the profile and the adaptation of the structure of the tongue. There-fore, estimation of growth of the nose, thickness of the lips, and change in theintegument of the chin must be considerations for the case that requiresesthetic improvement.

*At this writing I do not concur exactly with th e system or philosophy of anchoragepreparation as advocated by Tweed= and his followers.


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658An estimation of growth for a t.wo-year period is usually outlined, althoughsome cases may be projected only one or up to three years. This is done because

it should require about one and one-half t,o two gears of care to get a caseinto retention following the initial records and beca.use t,ime is needed for the

Fig. i.-Before-trea tment records on Gilbert.wi th maybe sl ight strain in oral funct ion. Photographs show a symmetrical faceand contained wi thin the nose-chin l ine. Note early canine furrow. Lips are balancedwith deep bi te and high cuspids. Models show a Class I I , Divis ion 2 malocclusionNote severe rotation of latera l incisors an


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Volume 46Number 9 CEPHALOMETBIC SYNTHESIS 659

cazoldin

The principal features of the estimation procedure wil l be discussed inle presentations (Figs. 6, 7, and 8). A Class II, Division 2 case in a 12-year-i boy (Gilbert), together with a difficult Class II Division 1 extraction casea 12-year-old girl (Ellen), wil l be represented to illustrate the method.

m e 1th eU P YFig. R.-Before-treatment records on El len, Photograph shows severe l ip strain andntal is habi t . as wel l as narrow dol icocephal ic tendency.esthetic plane. Both l ips protrude wel l beyondNote narrowWP arch, Mod els show severe Class II, Division 1 malocc lusion.crowded lower arch, and retained upper second premolars.

The sequence for a short estimation procedure, therefore, is as follows1. Establish cranial reference points (Fig. 9).2. Prognose behavior of the chin (Fig. 9).


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6603. Estimate changes in the maxilla (Fig. 10).4. Set up the teeth cephalometrical ly (Figs. 11 and 121.5. Change the soft tissues of the profile (Fig. 13 1.

Step 1. Cranial reference (sello nasion plane) (Fig. 9): Bji irk has pub-lished probably the finest serial work on the growth of the cranial base. Brodie6has also studied this area, as did II7 Moore,15 however, has stressed the useof the cribriform plate and sphenoid wings as valuable rranial reference points.BjS rk more recently has suggested the midsagittal floor of the anterior cranialfossa as a reference.

S-N

GILBERT ELLENFig. 9.-Growth estimati on of SN, Y axis, and chin. Two-year pro osis for each(See Tables I and II.)?% 2 degrees. Wbert shows a 3 to 4 mm. increaf+e on SN wit f? Y axis cl$&The chin is growing on the Y axis agproxlm.atel~ 6 mm. per year.showa a 2 to 3 mm. increase on SN with Y axis opening 1 to 2 degrees. Chin growing on Yaxis 3 mm. per year or a total of 6 mm . (Budon-nasian plane can also be emtioyed forbetter appreciation of total cranial base registration.) Ba-S increases at three-fourthsrate of SN growth. (See Table I.)Both Brodie5 and Bjiirk* maintain that the SN line constitutes a valuable

reference line for serial comparison. Steinerz4 has also utilized this line.Landel* corrected the Frankfort plane by use of the SN plane in his studies.An important consideration with respect to the SN plane is the tendencyfor forward growth of the maxilla (point A) to paral lel the forward growthof naaion. For practical purposes (Table I), the line SN increases in length atthe rate of nearly 1 mm. per year at the age most li ke ly to be treated. Ingir ls after puberty (14 to 15 years of age) this dimension increases at aboutone-half that rate, if at all. In boys at puberty, changes greater than 1 mm.per year have been noted. Therefore, simply placing a new tracing film overthe initial tracing and advancing nasion about 1.5 to 2 mm. from point S,depending on the case, will yield a practical cranial reference (Fig. 9). Theseobservations are also consistent with those of Nanda.


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Volume 46Number 9 CEPHALOMETRIC SYNTHESIS 661Step 2. Change in the chin position (Y axis or SGn) (Fig. 9): The in-

crease in length of the Y axis from S and its change in direction from the SNplane are estimated.

In a study by Moore, reported by D~wns,~ of nontreated Class II casesin the Mooseheart Series at the University of Illinois, the average case showeda 1 degree increase in the SNGN or opening of the Y axis. The results ofmy subsequent studies on treated Class II cases were consistent with thisfinding.ls KleinW3 study of cases during cervical extraoral treatment re-vealed that the Gn changes also followed this type of behavior. The studiesjust mentioned, however, employed slightly different cranial reference lines.In the serial study referred to in Table I the behavior of the XY axis and theY axis wil l be noted in the samples of facial types.

Although a 1 degree opening is typical, there are rather dramatic changesin some cases, and these are correlated with facial types (Table II). Pre-liminary findings have suggested that mechanical manipulation of appliancesalters the chin behavior. A factor in this connection is opening or closing ofthe bite by rotation of the mandible due to elongation or intrusion of the teeth.Certain cases wil l yield to elongation of molars and the condyle wil l rotatein the fossa as the bite is opened. Thus, the chin will drop downward as themandible grows, str ict ly from the influence of tooth elongation in some cases(that is, opening of the Y axis). My workI constituted an attempt to explainthe factors responsible for changes in the chin. I concluded that growth ofthe condyle was probably most important, although bite opening and rotationof the mandible were significant. Other lesser factors were cranial base changes(glenoid fossa) and positional shifts of the condyle during treatment.Since the mandible is thought to be predominantly responsible for facialform, its growth is of primary importance to change in the face (Figs. 4 and 5).The form of a grown mandible thus is thought to reflect its past behavior andits present tendencies. Therefore, a look at mandibular characteristics is im-portant. The sooner definite identification of these characteristics can be made,the better treatment can be planned. I described mandibular patterns in 1955and 1958. These distinguishing growth characteristics have been compiledfrom observations of the normal and from the study of more than 500 abnormaljoint cases over the, past twelve years. They are as follows:

1. Mandibular plane angles. Low mandibular plane angles are oftenconsistent with chins that grow forward (Fig. 4). High mandibularplane angles are usually associated with vertical growth patterns.(See Table I.)

2. Indinatim of the mandibular gonid angles. Square mandi-bles tend to continue in that shape. Obtuse genial angles tend tomaintain that form, as seen in typical Class III cases (Figs. 4 and 5).The square jaw usually grows forward; the straight mandible tends togrow downward, but not always.

3. Width of the ramus. Width tends to be maintained after theage of 6 years. Thus, the thick ramus is usually consistent with square


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662or brachycephalic growth patterns (Fig. 5). The thin ramus is oftenconsistent .with height of the face and dolichocephalie patterns.

4. Width of the symphysis. A thick, heavy symphysis is oftenconsistent with a thick, strong, well-formed and forward-growing nnmdi-ble. Thin dimensions of the symphysis are often consistent with weakmandibles and dolichocephalic patterns (Fig. 5).

5. Thickness of the condyle head. Heavy condyles are associatedwith heavy mandibles. Thick, heavy condyle heads usually are con-sistent with forward-growing mandibles (Fig. 5).

6. Inclination of the condyle neck. Forward growth patterns of thechin are most frequently associated with condyles that are inclined for-ward (Fig. 4). Conversely, vertical growth patterns are often consistentwith condyle heads tipped backward from the ramus. (See Table I.)

7. Corpus mandib~ular length. Long corpora tend to maintainlength development to the mandible in all patterns (Figs. 4 and 5).8. The coronoid condyle plane (relative condyle coronoid length).If the coronoid lies high above the condyle when measured from themandibular plane, the chin is often growing vertica lly, and vice versa.

9. Occlusal plane to the mandibular plane. Squareness or parallel-ism usually is associated with forward growth. TXvctrging planes tendto increase as the chin grows ve rtically.

10. Excessive notching. A deep antegonial notch is usually sug-gestive of growt,h arrest of the eondyle and lack of post,erior fac ialgrowth.When a ll characteris tics for vertical growth are combined in one patient,the Y axis might open up as much as 5 degrees in two years. When horizontal

tendencies prevail together, the Y axis might close as much as 3 degrees.Reference is further made to the effects OS he muscle pattern on bite opening.Heavy muscles often resist mandibular rotation.

The amount of growth is often difficult to estimate (Table II), but assum-ing the average for the age, sex, phys ical,, and hereditary chara.cteristics of themandible and the facial patt,ern will yield surprisingly consistent results. Ahistory of menstruation or voice change is important. Broadly, I have foundwith laminagraphy18 that up to and during the mixed dentition age childrenof both sexes grow about 2 mm. of condyle per year. Translat,ed to facia lchange with added corpus mandibular growth, the average was 2.5 t,o 3 mm.per year when studied on the Y axis . (See Table I.) At puberty (12.5 to14.5 years), boys will sometimes double th is amount. These findings are con-sistent with earlier studies at the Univers ity of Washington by Baum.l Ex-perience will yie ld a, subjective impression for estimation of these conditions.

The findings for the present cases are gross ly as shown in Table IV.Therefore, the technique for anticipating the change in the chin (Fig. 9)

consists of (1) taking into consideration the form, shape, and size of themandible, (2) evaluating the type of face to which it is associated (that is,facia l pattern), (3) planning the results of possible treatment, procedures that


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Volume 46Number Y CEPHALOMETRIC SYNTHESIS 663might be exercised, (4) changing the direction of the Y axis on the basis ofthe above considerations, and (5) growing the chin by lengthening the Y axis,depending on age, sex, physical constitution, and duration of treatment.Following the drawing of the chin, a new facial plane is erected.

TABLE IV. GROWTH ON THE Y AXIS (SGs IN~~REASE) IN 250 CAS ESBOY S (110) GIRLS (140)

AQE NUMBERIN GROUP 1 MEAN PER YEAR 1 NUMBERIN GROUP) MEAN PER YEARup to 6 6 3.3 19 3.07 4 4.1 12 3.78 15 2.9 19 2.69 13 3.2 17 3.410 16 2.8 20 3.311 17 3.0 15 3.112 15 3.9 19 2.613 16 3.9 12 2.714 6 3.1 3 7

15 2 1.0 4 17Average mean o f all ages: 2.6 for girls; 3.1 for boys.

Step 3. Changes in the maxilla: During normal development, the angleSNA changes but little (Table I). The findings of Brodie5 and Handel* seemto corroborate this contention. BjGrk found that the angle SNA sometimesdecreased in long retrognathic growth patterns. Personal communication withBjSrk did not reveal the frequency of this behavior, but he seems to feel thatit was significant. Studies of patients with normal occlusion suggest that SNAincreases slightly.

The normal behavior of point A has been discussed previously as almostparalleling forward growth of nasion. During orthodontic treatment, point Ahas been demonstrated to change rather dramatically. Holdaway,l King,12and I,2o as well as many others, have demonstrated retraction of point A inthe profile in vigorous Class II treatment (Table I). I have further observedpoint A to move forward in response to treatment of Class III and cleft palatecases and have discussed this in a recent publication.21 Waison28 and Kleinlboth noted a downward tipping of the palatal plane in cases treated withcervical traction which suggests an alteration of the entire maxilla.

Furthermore, the present serial studies on treated cases suggest the pos-sibility of a slight alteration of the entire nose. King has presented data tosuggest that earlier treatment results in greater change in the profile. Thus,the timing of orthodontic treatment is related to its effect, particularly incontour alteration.

The technique for estimating the behavior of point A and the palatalreference is as follows :A. For height estimate (Fig. lo), first divide the increase in

facial height roughly into thirds. Next, lower the palatal plane fromthe SN line about one-third of the total height increase. (Due to biteopening, approximately two-thirds of height increase is usually recorded

* in the denture area.) Finally, tip the palatal plane by high-pull or


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664 neck-pull extraoral anchorage or vigorous interrnaxillaqv elastics,depending upon the case, the degree of force emplo.~~l. and thtr dnra-tion of that force.

B. For alteration of point A (depth), modify point A from alocal and also for complete maxilla changes as desiwd or erpec'ted fol-lowing the listed factors. Simple lingual root torque wit,h retraction ofthe upper inc isor can result in a change in contour of t.ht: suhspinale areaamounting to 2 or 3 mm. of change from the anterior nasal spine.

GILBERT E L L E NFig. lO.-Estimation of Skeletal proflle changes (point A and new APog plane).Register is on facial plane andCl%&98. Palate is tipped alatal plane is dropped one-third tot& facial height in-depend n5 upon growth pattern and anticipated treatment. Itis necessary to move point A rag sterecl from SNA as desired or thou&t possible (seeTable II). Headgear was envisioned in both caees ; therefore, point A w&8 expected to bemoved backward in both. Severe bodily retraction of the upper incisor increased pro$aetedbackward movement of point A in Ellens case.*(See Fig. 10 for follow-through.) New APog plane is thus establietbed.*This is the crux of the use of the APog plane in planning. The plane i tself wil lbe changed by (I.) forward growth of the chin or ( 2) reduction of point A and retractionof the maxi lla. Only after the proper estimati on of these skeletal changes can the propercorrection of the teeth be made.

(See Anns tracings in Fig. 2.) Cervica l traction only has been notedto be consistent with up to 5 mm. posterior change in point A in someretrognathic cases. Heavy intermax illary elastics also contribute to re-duction of point A. Thus, when torque is used and eztrscoral anchorageis employed together with heavy intermaxillary elastics ( 1 x Orthospec) ,up to 7 or 8 mm. reduction of point A in the profile can be demonstratedin cooperative cases.Thus, the changes in point A or the maxilla, together with the change in

pogonion or the chin, now yield a new skeletal profile in the estimation (Fig. 10).Step 4. The setup of the teeth cepha lometrically (Fig. 11): As stated

previously, the APog plane or denture plane serves as a useful recipro&reference line for evaluating the lower incisor. Now that a new reference line


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CEPHALOMETBIC SYNTHESIS

has been established in the cephalometric setup, the procedure for aligningthe incisor is much the same as for the static synthesis described previously.However, certain growth considerations should be observed.

A working occlusal plane is set up by bisecting the palatal and mandibularplanes. I have demonstrated changes in the occlusal plane.1s &OX type andthe duration and force of intermaxillary elastics determine its cha.nge.

GILBERT ELLENFig. Il.--lower incisor to the new APOone standard deviation of the mean f plane. The lower incisor is corrected toconsis ent with local environm ental factors.Gilberts case forward movem ent of the lower in&or w&s indicated; therefore, no extrai?tlon w&8 planned. In Ellen s case backward movem ent with depression of the incisor wasindicated, so extraction of lower flrst premolars w&8 planned .almost on the APog line. Both cases were set upNote the estima tion of occlusal plane changes and molar move-ment as these changes in the incisors are anticipated.

OILBERT

U P P E RTO

LOWER

INC.

INC.

E L L E NFig. 12.-Upper incisor corrected to the lower incisor. The interincisal angle is setUP to 130 to 136 in children to allow for later uprigh ting with growth. In Gilberts trac-ings the final analysis yields a forward movem ent of the upper incisor due to anticipate dmandlbular growth.is indicated. (See Fig. 13 and Table III.) In Ellens case bodily distal movementThe angle SN-upper incisor wil l reveal the behavior of the upper incisor tocranial landmarks (Table III 1.

The lower incisor is first properly located, and then the upper incisor isestablished in relation to it in a normal overbite and overjet. Age is important.


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In mixed-dentition cases an attempt is made to incline the upper incisor atabout 130 degrees to the lower to provide for later uprighting with growth(Fig. 12).In cases in which originally the lower incisor is posterior to the APogplane more than 2 mm. or outside the normal range, the synthetic setup wil lshow whether the lowe,r incisor must be moved forward identiondy with theaccompanying risks or whether man&buLur growth and petruction of pint Awil l account for an improved relationship (Fig. 11 j . Thus, in some cases thelower incisor must be moved forward to satisfy the normal objectives (Figs.1 and II). In patients with very small mouths, tight lips, and a low andsmall tongue, the natural balance is posterior to the normal and should thusbe stated in the objectives and in the ccphalometric srtup. On the other hand,a prominent lower incisor 2 to 3 mm. forward of APog wil l often be in goodbalance when accompanied by long lips that are well forward, a wide mouth,and a large tongue that is located forward. Mouth rharacteristics and tonguesize and function are thus important, to denture stability and should herespected.

After the incisors have been a.ligned, the change in the lower molar canbe also estimated (Fig. II). If no arch length problem prevails and noanchorage problem is anticipated, the lower molar will simply erupt in com-pliance with the pattern usually observed (Table II). It is thus carried down-ward and forward by normal growth. In ordinary extra,ction requiring spaceclosure, the lower molar moves forward about 4 mm. unless held backward bylower headgear or intermaxillary elastics.

The needed change in the upper molar can thus be seen by simply ar-ranging the upper molar in Class I occlusion or as desired (Fig. 13). It isvery difficult to move the upper molar backward more than 2 to 3 mm. Insome cases much vertical increase wi ll permit the upper molar to be moveddownward and backward. In many Class II cases simply holding the uppermolar in its original position wil l produce correction if normal growth is great,enough.

This technique permits a rather critical treatment plan, and unusual ex-traction patterns are not uncommon. Extraction of upper first or second pre-molars or lower first or second premolars, unilateral premolar extraction,or a variety of molar extractions have t~hus been worked out when needed. Anevaluation of extraction cases has revealed that extraction of upper second andlower first premolars has yielded a superb occlusion, ideal esthetics, and quitestable results. Knowledge of the synthesis procedure has made many ofthese extraction patterns evident.

Thus, if desired, the entire denture (including the third molars) can betraced into the estimation. J usually t,ry to estimate at least the incisors,cuspids, and first, molars.Step 5. Changes in the soft tissues of th,e l~ofi/t: The changes in fouraspects are estimated (Fig. 13).First, the end of the nose is a,dvanced away from the anterior nasal spinein the setup about 1 mm. per year in the mixed dentition in both sexes


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CEPHALOMETRIC SYNTHESIS 667

C .

ELLEN

Fig. 13.-Growth and movem ent of the upper molars and possibilitie s of correctionof soft tissues. A and B, Tracings superpositioned on Frankfort plane at posteriorcurvature of pterygomaxillary fissure. Normal behavior is downward and forward 2 mm.per year. (See Table III. 1 Note downward movem ent in Gilbert and horizontal move-ment in Ellen. Second-premolar extraction in Ell en was thus planne d. Growth of thenose is estimated from anterior nasal spine. (See Table III.)setup and soft-tissue outlin e of the chin and lips. C and D, Total denturethe incisors. Chin drops as mental is is reduced. UP er lip thickens and lower lip follows(gee text. 1

0.0.- 12-3 7-0-55 E.B.--- 14 -4 a-27-57 - k-3 I-8-55----14-S s-21-58

GILBERTFig. 14.--Cver-all changes in cases superimposed on BaN at Y axis.growth of man dible and closing of Y axis in Gilbert. Note forward12 mm. in two-year period. Y axis length increase was alin;;;End result is forward movem ent of upper incisors.slight openin g of the Y axis and slightly greater SN growth than expected in Ell en.Note also the large amount of lingual movement of the upper incisor. Y axis increasedonly 6 mm . in this girl at puberty.(See Fig. 17, C. ) Note the bend of the nasal bone as a curve developed.


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668 .AIII J. OrthodonticsSeptember, 19602 mm.nd in girls at puberty. In large-nosed boys at, puberty, it is advanced 1per year (Table III).

Second, the contour of the upper lip wil l not change when no poccurs or when the upper inciscr remains in the original position. Thelip wil l thicken slightly with normal growth, but it. wil l often thicken ;ciably when the upper incisor has been retracted. A good rule oi this 1 mm. thickening for every 3 mm. retraction of the tip of the inrisor3, 13, and 17).

;rowthupperappre-umb(Figs.

Third, the lower lip thickens very little, but. it will curl backward as a resultof upper incisor retraction and come forward with forward movement, as in

Fig. 15.-After-treatment records on Gilbert. Note the decrewe in canine furand excellent lip relationship for 14-year-old boy. Retention of two years was une%Compare to begin ning records in Fig. 8 ahd also see Fig 17.


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Volume 46Number 9 CEPHALOMETRIC SPNTHESI8 669Class II correction. (See Roberts case, Fig. 3.) The greatest noticeablealteration, however, is in the sublabial area. Here the lip tissue follows ratherclosely the change in position of the root of the lower incisor.

Fourth, an increase in the tissue over the chin wil l occur as a result ofloss of lip strain and loss of chin elevation by the mentalis muscle. In some longfaces, due to shortness of the lips, this change wi ll not occur in spite of dentureretraction. In most cases t,he ball of soft tissue wil l lower to proper positionafter treatment (Fig. 17).

Fig. 16.-After-treatme nt records on Elle n.habi t present in the beginn ing (Fig. 9 ). Note the loss of l ip strain and mental isretent ion models.

Teeth are upright and al l spaces are c losed inNo appreciable changes in the denture were noted during retent ion.Note comparison to original in Fig. 17.


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670 \!I\. J. OrthodonticsSeptember, 1960After these changes have been estimated, a superimposing of t,he esthetic

planes of the original and the *setup wi ll demonstrate the probable estheticresults of growth and treatment. Figs. 1-C.15, and 16 show the completed casesplanned by t.he synthesis procedure.

Fig. 17.-Comparison of oriented photographs of Gilbert and Elle n. A, Photographsof Gilbert superimposed on sella. B, Photographs of Gilbert superimposed on E plane.Forward movem ent of the denture and lips was cancelled out by nose a.nd chin growth.C, Photographs of Ell en superimposed on sella. There was more reduction of mouth areathan can be accounted for by growth. D, Photographs of Ell en superimposed on 6plane show dramatic resulting improvement in the profile.

GENERAL DISCUSHIOSThere is a growing effort to attempt to estimate changes in the face and

denture to occur during orthodontic treatment. This has become necessary asclinicians have realized that analys is is one t,hing and that growth and toothchanges constitute indeed another subject. It is realized that this procedure is


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Volume 46Number 9 CEPHALOMETRIC SYNTHESIS 671one of the init ial efforts in this facet of cephalometrics. It is hoped, however,that it is not misrepresented. It is not a crysta l ball. In my opinion, it isstrict ly information that is available utilized with common sense.

A simple method of planning was suggested in order to provide themechanism for anticipating the most important changes. A second tracing isthought necessary when a large amount of growth is anticipated, because ofthe need for superimposing at many different reference points in working outa plan and anticipating change. These tracings thus form a blueprint forthe operator in the orthodontic-orthopedic aspects of the case. The syntheticsetup can be as complete or as partial as desired.Cephalometrics employed in this manner has been indispensable to mypractice. Anything short of full consideration is now considered to be neglectof the patient.In some cases growth may be slower than anticipated. Usually growthwi ll come eventually when it is anticipated to be of benefit and is relied upon.properly. Simple patience with observation will be indicated when growth isslow. In many cases failures blamed on a lack of growth are the results ofmistakes in diagnosis made in the beginning because of a misunderstanding of themanner in which growth helps in treatment.

As more and more information becomes available through research, itwi ll be added to this armamentarium. No doubt new devices and procedureswi ll continue to be developed, and each must be studied carefully.No orthodontist should fear this cephalometric procedure. The resu ltsof viewing, tracing, and planning are gratifying and exciting. In order tointerpret much of the contemporary literature, the orthodontist must keep him-self informed on recent techniques.

This procedure has actually saved time in the office. It saves treatmenttime by aiding in more efficient technique planning and by proper utilizationof natural forces. It permits complete presentation of the case to the parentand helps promote greater confidence and better cooperation on the part ofthe child . Fina lly, there can be no doubt that superior results can be achievedwhen greater attention is given to the kind of details brought out in thisdiscussion. .S U M M A R Y

Any treatment plan is a prediction of change. This article stresses theneed for more understanding of the application of cephalometrics in treatmentplanning. A cephalometric procedure was thus shown to help establish theobjectives for a particular case.

Such terms as prediction, projection, prognosis, estimation, predeter-mination, and cephalometric setup have come to be related to anticipation ofthe future behavior of an orthodontic case. The term cephalometric synthesishas been employed to mean a putting-together of many related growth a&danchorage factors to yield the product or the planned result in a new tracing. Synthesis was divided into static and dynamic types with regardto growth of the jaws. Vhen static conditions exist, or when little or no growth


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672 RICKETTS Am. J. OrthodonticsSeptember, 1960is expected, a formula for tooth arrangement was suggested Sor t,he individualease depending upon local environmental factors. The APog plane or thedenture plane was held to be of great& usefulness for this purpose becauseit represents a reciprocal relationship of the denture bases to which the anteriorteeth must be related functionally. Thus, a mutual role is played by the lowerincisor to both the maxilla and the mandible.

An abstract of a serial study of SO cases was reported to shed light ongrowth and treatment behavior. h sequence of steps was presented as a simpleapproach to estimating growth and desired treatment changes in the dynamicsynthesis. These, simply, were a cranial base reference (sella-nasion) , changein the mandibular profile as viewed from the Y axis, change in the maxillaryprofile, movement of t,eeth, and change in the soft-tissue profile.

Two boys and two girls with different facia1 patterns, malocclusions, andgrowth rates were selected to illustrate the procedure. Differences in the sig-nificance of age, sex, facial pattern, and malocclusion were thus demonstrated.

This technique is a step beyond cephalometric analysis. It is an attemptto put research into action. Its proper use depends upon a background of in-formation on growth and the possibilit ies of change with mechanical therapy.Much of this information has been provided in t,wo of my articles, one pub-lished in 1955l and the more recent and exhaustive work published in 1960.2When this information is properly utilized, a host of different treat,ment plansthat employ natural changes and forces to advantage become obvious. Aknowledge of the possibili ties of treatment is carte bl~lzche for a positive attitudetoward planning rather than the nega,tive attitude imposed by the doctrine oflimitations.

REFERENCES1. Baum, Alfred: A Cephalometric Evaluation of the Normal Skeletal and Denture Pattern

of Children With Excellent Occlusion, Ang le Orthodontist 21: 96-103, 1951.2. BjSrk, A.: The Face in Profile , Lund, 1 947, Berlings lta Boktrycheriet.3. BjGrk, A.:4. Bjark, A.: Cranial Base Developm ent, Au. J. ORTHODONTICS 41: 198-225, 1955.The Signi ficance of Growth Changes in Facial Pattern and Their Rekationshipto Changes in Occlusion, D. Record 71: 197-208, 1951.5. Brodie, A. G.: On the Growth Pattern of the Huma n Head, From the Third Month tothe Eighth Year of Life, Am. J. Anat. 68: 209-262, 1941.6. Brodie, A. G., Jr.: The Behavior of the Cranial Base and Its Componen ts as Revealedby Seria l Cephalom etric Roentgenograms, Ang le Orthodontist 25: 148-160, 1955.7. Downs, W. B.: Variat ion in Facial Relationships , Their Significa nce in Treatment andPrognosis, AM. J. ORTHODONTICS 34: 812-840, 1948.8. Downs, W. B.: The Role of Cephalometrics in Orthodontic Case Analysis and Diagnosis,AX. J. ORTHODONTICS 38: 162-182. 1952.9. Downs, W. B.: Analysis of the Dento*ac ial Profile , Angl e Orthodontist 26: 191-212, 1956.10. Enge l, M. B., and Brodie, A. G.: Condylar Growth and Mandi bular Deformities, Surgery- 22: 976:992, 1947.11. Holdaway, R.: Changes in Relation ship of Points A and B During Orthodontic Treat-ment, AM . J. ORTHODONTICS 42: 176-193, 1956.12. King , Elbert: Cervical Anchorage in Class II Treatment, a Cephalom etric Appraisal,Angle Orthodontist 27: 98-104. 1957.13. Kle in, p.: Behavior of the Uppe; First Molar and Maxi lla During Cervical Traction,Angl e Orthodontist 27: 1, 1957.14. Lande, M ilton: Growth Behavior of the Human Bony Facial Profile as Revealed bySerial Cephalometric Roentgenology, Angle Orthodontist 22: 78-90, 1952.

15. Moore, Alton: Orthodontic Treatment Factors in Class II Malocdus ion, AM . J. ORTHO-DONTICS 45: 323-352, 1959.


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zx 9 CEPHALOMETRIC SYNTHESIS 673r16.17.18.19.20.21.22.23 .

2:

26.

27.28 .

Nanda. R. S.: The Rates of Growth of Several Comoonents Measured From S erialCkphalometric Roentgenograms, AM. J. ORTRODONT& 41: 658-673, 1955.Rickette. R. M.: The Cranial Base and Soft Structures in Cleft Pala te Speech andB&th ine. Plast. & Reconstruct. Sure. 14: 47-61. 1954.Ricketts, R. M..--- -O* A Study of Changes in~Tem porom& dibular Relations A ssociated Withthe Treatment of Class II Malocclusion , Ann. J. ORTHODONTICS 38: 918-933, 1952.Ricketts, R. M.: Facial and Denture Changes During Orthodontic Treatment as AnalyzedFrom the Tempo romandib ular Joint, AM. J. ORTHODONTICS 41: 163-179, 1955.Ricketts, R. M. : Plan ning Treatment on the Basis of the Facial Pattern and an Estima teof Its Growth, Ang le Orthodontist 27: 14-37, 1957.Ricketts, R. M.: The Functional Diagnosis of Malocclus ion, Tr. European OrthodonticSociety, 1958.Ricketts. R. M.: A Foundation for Ceuhalom etric Comm unication . AM. J. ORTHOWNTICS

46; 330-357, 1960. ARicketts, R. M.: The Influence of Orthodontic Treatment on Facial Growth and De-velopme nt, Ang le Orthodontist 30: July, 1960.Steiner, C. : Cephalometrics for You and Me, AM . J. ORTHOWNTICS 39: 729-755, 1953.Stoner, M. M., Lindquist, J. T., Vorhies, J. M., Hanes, R. A., Hapak, F. M., and Haynes,E. T.: A Cephalome tric Evalua tion of Fifty-Seven Consecutive Cases Treated byDr. Charles H. Tweed, A ngle Orthodontist 26: 68-98, 1956.Subtelny, D. : A Longi tudina l Study of Soft Tissue Facial Structures and Their ProfileCharacteristics, Defined in Relati on to Underlying Skelet al Structures, AM . J. ORTHO-DONTICS 45: 481-507, 1959.

Tweed, C. H.: Frankfort Mandi bular Incisor Angles in Diagnosis, Treatment Plan ning,and Prognosis, Ang le Orthodontist 24: 121-169, 1954.Watson, T. J.: Extra Alveolar Cephalom etric Appraisa l During Therapy: a NewApproach, Masters Thesis, Washington University St. Louis, 1954.875 VIA DE LA PAZ.

1960_ricketts_stating objectves and planning with ceph tracings

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