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ORIGINAL ARTICLE

Long-term profile changes in extraction andnonextraction patientsCorbett K. Stephens,a Jimmy C. Boley,b Rolf G. Behrents,c Richard G. Alexander,d and Peter H. Buschange

Tyler and Dallas, Tex, and Saint Louis, Mo

Introduction: The purpose of this investigation was to determine the long-term differences in soft tissue

profile changes between extraction and nonextraction patients who had been treated to the same incisor

position and lip line. Methods: Twenty extraction and 20 matched nonextraction patients, with posttreatment

and long-term follow-up (average 15 years) records, were selected from a single private orthodontic practice.

Posttreatment and long-term follow-up profile photos of the patients nose, lip, and chin areas were

evaluated by 105 orthodontists and 225 laypeople, who indicated their preferences and the amount of

change they perceived among the 40 profiles. The patients had similar dental protrusion, soft tissue profile

measurements, and ages at the posttreatment observation. Results: No significant cephalometric differ-

ences between the extraction and nonextraction groups were found at long-term follow-up; both groups

showed similar long-term changes. Significant (P .05) differences were found between males and femalesat long-term follow-up; male lips became relatively more retrusive, and their profiles became flatter.

Significant (P .05) changes in the profiles were also perceived over time, but there was no relationship

between the amount of change perceived and profile changes measured cephalometrically. There were also

no significant (P .05) differences in preferences between orthodontists and laypeople, between extraction

and nonextraction patients, or between males and females. Conclusions: If extraction and nonextraction

patients are treated to the same incisor position and lip line, the treatment modality does not affect long-term

soft tissue profile changes. Furthermore, the amounts of change perceived by either orthodontists or

laypeople were not related to the amount of change measured cephalometrically. (Am J Orthod Dentofacial

Orthop 2005;128:450-7)

T

he extraction-nonextraction debate, ongoing for

almost 100 years, has often been based more onsupposition than fact.1,2 Those who favor non-

extraction have often presumed that extraction treat-ment tends to dish in the face; those who favorextraction, on the other hand, often presume the lipstend to be blown out by excessive incisor flaring. Wenow have good data showing only small posttreatmentdifferences between extraction and nonextraction pa-tients.3-7 Extraction patients tend to be 2 to 4 mmflatter, on average, than nonextraction patients at theend of treatment.

Perhaps even more important than the cephalomet-

ric comparisons, we now have a better understanding of

profile preferences after extraction and nonextraction

treatments. Regardless of whether cephalometric stud-ies show differences between extraction and nonextrac-tion patients, an important issue is whether the differ-ences can be perceived. It has been shown thatextraction faces are flatter directly after treatment andare preferred over nonextraction faces by dentists andlaypeople, with the dentists preferring flatter faces morethan laypersons.6 Bishara and Jakobsen,8 who ran-domly presented extraction and nonextraction profilesilhouettes of pretreatment and posttreatment patientsto laypeople, demonstrated that the general public doesnot prefer the profiles of 1 group over the other.

Information about preferences is important because amajor goal of orthodontic treatment is to attain andmaintain a good esthetic result, which ultimately mustbe based on the general publics opinions.

The extraction-nonextraction debate has also beenbased on suppositions about what occurs after treat-ment. Lectures and discussion sections often noteanecdotallythat extractions cause long-term dishingin of the face, and nonextraction therapy causes exces-sive lip strain and lip incompetence. There have beenfew long-term cephalometric comparisons, suggestingthat posttreatment differences between extraction and

aPrivate practice, Tyler, Tex.bClinical assistant professor, Baylor College of Dentistry, Dallas, Tex.cProfessor, Saint Louis University Center for Advanced Dental Education,Saint Louis, Mo.dClinical professor, Baylor College of Dentistry, Dallas, Tex.eProfessor, Baylor College of Dentistry, Dallas, Tex.Reprint requests to: Dr Peter H. Buschang, Department of Orthodontics, BaylorCollege of Dentistry, Texas A & M University System, 3302 Gaston Ave,Dallas, TX 75246; e-mail, [email protected], March 2004; revised and accepted, April 2004.0889-5406/$30.00Copyright 2005 by the American Association of Orthodontists.doi:10.1016/j.ajodo.2004.04.034

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nonextraction patients are small and relatively insignif-icant.3-5,7 Paquette et al3 found that most of the signif-icant differences observed between their borderlineextraction and nonextraction patients at the end oftreatment were also present 10 to 15 years later.Cephalometric evaluations generally show significantsoft tissue profile changes from posttreatment to long

term, but the changes are not significantly differentbetween extraction and nonextraction groups.3,6,7

We currently have little or no information aboutpreferences of long-term follow-up profiles of extrac-tion and nonextraction patients. Over the short term, ithas been shown that there is little or no difference inhow orthodontists and laypeople rate the profiles ofextraction and nonextraction patients.8 However, thesepatients were followed for only 2 years, and soft tissuechanges take longer to develop in subjects with reducedgrowth potential.9 Moreover, Drobocky and Smith10

discussed how subjective evaluations of desirable andundesirable profiles often do not coincide with differ-

ences measured cephalometrically. Because changesthat are not perceivedeven though they can bemeasuredmust be considered highly questionable,the purpose of this study was to determine whetherlong-term differences in soft tissue profile changesoccur between extraction and nonextraction patients,and, if so, how they are perceived by orthodontists andlaypeople.

MATERIAL AND METHODS

Forty white, Class I and Class II patients, all treatedby the same orthodontist, were selected for the study.

Twenty patients were treated with 4-premolar extrac-tions, and 20 were treated with a nonextraction proto-col. The groups had similar ages at posttreatment andlong-term follow-up; the average long-term intervalwas 15 years (Table I). In addition to age and sex, theextraction and nonextraction patients were matchedaccording to 3 measurements taken from the immediateposttreatment cephalograms. Two measurements ofdental protrusion, U1-SN and L1-NB, were chosenbased on a discriminant analysis11 that showed them tobe among the major determining factors in the extrac-tion-nonextraction decision. Holdaways H-line was

Fig 1. Reference lines and landmarks: S, sella; N,

nasion;UIA, upper incisor root apex;UIE, upper incisor

incisal edge; LIE, lower incisor incisal edge; LIA, lower

incisor root apex;B, B-point;N, soft tissue nasion;Pn,pronasale; Col, columella; Sn, subnasale; Sls, superior

labial sulcus; Ls, labrale superior; Li, labrale inferior; Pg,

soft tissue pogonion.

Table I. Average ages of subjects and intervals in yearsat posttreatment and long-term follow-up

Subjects

Extraction Nonextraction

Mean SD Mean SD

Male (n 6) (n 6)Posttreatment 15.6 1.5 15.1 1.5Long-term follow-up 30.3 3.4 30.1 5.3Posttreatment to long-

term follow-up14.7 2.5 15.0 4.9

Female (n 14) (n 14)Posttreatment 14.8 1.1 15.1 2.2Long-term follow-up 28.9 5.0 30.0 4.4Posttreatment to long-

term follow-up14.1 4.6 14.9 2.9

Table II. Cephalometric measurements, definitions, andmethod error

Measurements Definition

Method

error

N-Pn-Pg () Total facial convexity 1.40N-Sn-Pg () Facial convexity 1.07Ls-E-Line (mm) Upper lip to Ricketts E-line 0.34Li-E-Line (mm) Lower lip to Ricketts E-line 0.29Ls-S-Line (mm) Upper lip to Steiners S-line 0.44Li-S-Line (mm) Lower lip to Steiners S-line 0.29H-Line (mm) Perpendicular distance from Holdaways

H-line to superior labial sulcus0.28

U1-SN () Maxillary incisor to sella-nasion line 1.45L1-NB (mm) Mandibular incisor to nasion-B-point

line0.44

American Journal of Orthodontics and Dentofacial Orthopedics

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chosen because it allows evaluation of lip protrusionindependent of nose length. The extraction group wasselected first, with the 3 measurements in the normalrange. Nonextraction patients were then matched to theextraction patients.

All posttreatment and long-term follow-up cepha-lograms were traced and digitized with DentofacialPlanner software (Dentofacial Software, Toronto, On-tario, Canada). Fifteen landmarks (Fig 1), based ondefinitions from Riolo et al12 and Daskalogiannakis,13

were digitized. The horizontal and vertical positions of

the landmarks were described by a rectangular (x and y)coordinate system. Distances were measured relative toposttreatment sella and oriented along a reference lineconstructed from S-N 7 (Fig 1). For example, thehorizontal change in position of pronasale was mea-sured parallel to the reference line (Pn-h) and thevertical change perpendicular to the reference line(Pn-v). Nine additional measurements, as defined byHsu14 and Subtelny,15 were computed to evaluateprofiles and profile changes (Table II). Replicate anal-yses of 15 patients showed no significant systematicerrors; method errors ranged from 0.3 to 1.4 mm.

A survey was developed to quantify the amount ofchange perceived and to judge the preferences of thepatients profiles. A pilot study was conducted todetermine the number of patients to include in thesurvey instrument and to develop a set of instructionsthat could be clearly understood. Two versions of thesurvey were prepared, each pertaining to approximatelyequal numbers of extraction, nonextraction, male, fe-male, Class I, and Class II subjects. Each surveypresented posttreatment and long-term follow-up pro-file photos (Fig 2) of the 20 patients. The 2 profileswere randomly displayed between right and left for

each patient. There were 4 profile comparisons perpage, and each survey consisted of a full set ofinstructions. The instruction page consisted of a fullinstructions, with examples, and an area to indicate thesex and age of the evaluator and whether he or she wasan orthodontist.

Three groups of evaluators received 1 of the 2versions of the survey with instructions to compare theprofiles. The evaluators were 115 laywomen, 110laymen, and 105 orthodontists. They were asked to

indicate their preferences and the amount of differencethey perceived between the 2 profiles. The sample oflaypeople was collected in doctors waiting areas, at thedental school, and through family and friends. Thesample of orthodontists was collected at orthodonticmeetings, by mailings based on random lists obtainedfrom the American Dental Association, and by mailingsto Baylors orthodontic alumni. A 60% reply rate wasobtained from the mailings.

The cephalometric and survey data were analyzedwith SPSS software (Chicago, Ill). The amount ofchange perceived between the 2 profiles was measured

on a 106-mm visual analog scale with same as the leftanchor and very different as the right anchor. Thedistance from the left anchor was measured and dividedby 106 to compute the percentage of change perceived.T tests were used to compare the extraction andnonextraction groups. Changes between the posttreat-ment and long-term follow-up observations were eval-uated with paired t tests. Perceived changes wereevaluated by using a single-samplettest and related tothe cephalometric changes by using Pearson product-moment correlations. A chi-square test was used tocompare proportions of preferences expressed.

Fig 2. Profile photograph comparison.


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RESULTS

No significant differences were found between theextraction and nonextraction groups at the posttreat-ment time interval (Table III). Significant (P .05)changes occurred between posttreatment and long-termfollow-up for 5 of the 9 measurements. These differ-

ences were related mainly to the position of the lips,which became relatively more retruded in both groups.There was also a significant (P .05) increase in facialconvexity for both groups. Lip protrusion and totalfacial convexity showed no significant changes. Theextraction and nonextraction groups showed similarchanges over time; there were no significant groupdifferences for the changes or for the long-term fol-low-up measurements. No significant differences werefound between the extraction and nonextraction groupsfor the horizontal and vertical changes of the individuallandmarks.

Males and females were not significantly differentat posttreatment (Table IV). Both groups showed sig-nificant (P .05) changes over time. Generally, malesshowed a greater number of changes and more pro-nounced changes over time than females. Male lipsbecame significantly more retrusive in relation to the

esthetic lines and showed greater increases in facialconvexity. Most soft and hard tissue landmarks movedforward and down more in males than in females (TableV;Fig 3).

Orthodontists and laypeople perceived 33.9% to39.2% of the changes between photographs, indicatinga small-to-moderate change (Table VI). The perceivedchanges were all statistically significant (P .01).Variation in amounts of change perceived was high,ranging from 7.3% to 14.9%. Slightly less change wasperceived for nonextraction than extraction patients,males were perceived to change more than females, and

Table III. Posttreatment and long-term follow-up ceph-alometric measurements, changes, and group differ-ences for extraction and nonextraction groups

Variable

Extraction Nonextraction

ProbabilitydifferenceMean SD Mean SD

PosttreatmentN-Pr-Pg () 131.2 3.3 132.2 3.4 .33N-Sn-Pg () 163.6 4.9 163.5 4.8 .95LS-E-line (mm) 5.9 1.4 5.4 2.1 .37LI-E-Line (mm) 3.6 2.2 4.2 2.2 .42LS-S-line (mm) 2.2 1.1 2.4 1.9 .73LI-S-line (mm) 1.2 2.1 2.2 2.1 .15H-line (mm) 3.7 1.1 3.6 1.3 .88U1-SN () 105.6 6.2 103.8 6.6 .38L1-NB (mm) 3.9 1.8 3.4 1.8 .42Long-term follow-upN-Pr-Pg () 132.1 3.4 132.1 4.2 .99

N-Sn-Pg () 167.6 4.9 166.4 5.6 .47LS-E-Line (mm) 7.3 2.0 7.0 2.7 .63LI-E-Line (mm) 4.9 3.0 5.7 2.7 .36LS-S-Line (mm) 3.2 1.4 3.5 2.1 .49LI-S-Line (mm) 2.1 2.4 3.4 2.2 .10H-Line (mm) 3.7 1.2 3.2 1.1 .19U1-SN () 105.1 6.6 104.9 7.6 .93L1-NB (mm) 3.9 2.3 3.1 2.0 .24Long-term changesN-Pr-Pg () 0.9 2.8 0.2 3.4 .29N-Sn-Pg () 4.0* 3.5 2.9* 3.7 .33LS-E-Line (mm) 1.5* 1.5 1.6* 2.5 .82LI-E-Line (mm) 1.3* 1.5 1.6* 2.2 .66LS-S-Line (mm) 1.0* 1.4 1.2* 2.0 .70LI-S-Line (mm) 0.9* 1.4 1.2* 1.8 .56

H-Line (mm) 0.1 1.1 0.4 1.0 .21U1-SN () 0.6 4.3 1.1 4.0 .23L1-NB (mm) 0.1 1.0 0.3 1.2 .32

*Significant (P .05) changes.

Table IV. Posttreatment and long-term follow-up ceph-alometric measurements, changes, and group differ-ences for males and females

Variable

Males Females


PosttreatmentN-Pr-Pg () 132.8 3.5 131.3 3.2 .18N-Sn-Pg () 164.4 4.9 163.2 4.7 .48LS-E-Line (mm) 5.8 1.6 5.5 1.9 .69LI-E-Line (mm) 4.7 2.1 3.5 2.2 .13LS-S-Line (mm) 2.4 1.3 2.3 1.7 .85LI-S-Line (mm) 2.4 1.9 1.4 2.2 .19H-Line (mm) 4.0 1.3 3.5 1.2 .23U1-SN () 107.0 5.9 103.8 6.5 .15L1-NB (mm) 3.0 1.4 3.9 1.9 .17Long-term follow-upN-Pr-Pg () 133.4 4.4 131.5 3.4 .14

N-Sn-Pg () 169.8 4.1 165.8 5.3 .02LS-E-line (mm) 9.0 2.0 6.4 2.1 .01LI-E-line (mm) 7.6 2.5 4.3 2.4 .01LS-S-line (mm) 4.3 1.7 2.9 1.6 .02LI-S-line (mm) 4.4 2.2 2.1 2.2 .01H-line (mm) 3.8 1.3 3.3 1.1 .16U1-SN () 109.6 5.3 103.0 6.8 .01L1-NB (mm) 2.3 1.6 4.0 2.2 .02Long-term changesN-Pr-Pg () 0.6 4.3 0.3 2.5 .79N-Sn-Pg () 5.5* 3.6 2.6* 3.3 .02LS-E-line (mm) 3.2* 2.1 0.9* 1.5 .01LI-E-line (mm) 3.0* 1.7 0.8* 1.5 .01LS-S-line (mm) 1.9* 1.7 0.7* 1.6 .03LI-S-line (mm) 2.0* 1.4 0.7* 1.5 .01

H-line (mm) 0.1 1.0 0.2 1.1 .87U1-SN () 2.6* 3.3 .80 4.2 .02L1-NB (mm) 0.7 1.4 0.1 0.9 .08

*Significant (P .05) changes.




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laypeople perceived more changes than orthodontists,but none of these differences was statistically signifi-cant.

A moderately high positive correlation (r 0.89;P .001) was found between the amounts of changeperceived by orthodontists and laypersons. However,only 1 of the 18 possible correlations between theactual cephalometric changes and the perceivedchanges was statistically significant. The greater theincrease in total angle of facial convexity (N-Pn-Pg),the greater the change perceived by orthodontists (r 0.34;P .03).

Orthodontists and laypeople showed no clear pat-tern of preferences between the posttreatment andlong-term follow-up photographs (Table VII). Approx-imately 30% preferred the posttreatment photograph;30%, the long-term follow-up photograph; and 30%chose neither photograph over the other. On average,orthodontists tended to prefer the posttreatment photo-graphs over the long-term follow-up photographs for allgroups, and the laypeople tended to prefer the long-term photograph for all groups except the males.Variation in profile preferences was high, and thedifferences between orthodontists and laypeople were

not statistically significant. Orthodontists and laypeoplehad clear preferences for individual profiles. For 87.5%of the patients, chi-square analyses showed significant(P .05) differences in the proportions of orthodon-

tists and laypeople who preferred either posttreatmentlong-term follow-up or neither profile over the other.But there was no consistency of preferences expressedacross cases. For example, approximately 90% of theorthodontists preferred the long-term photograph for 1case, whereas 80% preferred the posttreatment photo-graph for another. Preferences for individual patientswere similar for orthodontists and laypeople.

DISCUSSION

The results clearly showed that the extraction andnonextraction patients were comparable at the end oftreatment. Both groups had similar amounts of lipprotrusion in relation to the esthetic lines, similaramounts of dental protrusion, and similar soft tissuefacial convexities. Zierhut et al7 also reported nosignificant differences in hard and soft tissue profilesbetween their extraction and nonextraction patientsimmediately posttreatment, even though there werepretreatment differences. Perhaps this dictated differenttreatment modalities, leading to similar profiles post-treatment. Paquette et al,3 on the other hand, startedwith morphologically similar patients at pretreatmentand showed significant differences between their ex-traction and nonextraction groups at posttreatment. On

average, the extraction group profiles became flatterand the lips more retrusive (about 2 mm). Others havealso shown group differences at posttreatment, indicat-ing more lip retrusion and decreased facial convexitywith extractions.3,4,16Our goal was to select a sampleof extraction and nonextraction subjects who weresimilar at posttreatment. By meeting this goal, we couldassume that any profile differences between the 2groups during the posttreatment period must have beendue to the type of treatment (extraction or nonextrac-tion).

Our extraction and nonextraction groups also

turned out to be no different at the long-term follow-up15 years later, indicating that the changes were similarfor both groups. No significant differences in posttreat-ment changes between extraction and nonextractiongroups have also been previously reported.3,7 Bishara etal4 showed that differences between extraction andnonextraction groups in lip position relative to theE-line increased during their posttreatment follow-up,but this was only 2 to 3 years later.

Although they were not different, both groupsdemonstrated significant changes over time. Theirlips became significantly more retruded in relation to

Table V. Sex differences in horizontal (h) and vertical(v) changes (mm) in the soft-tissue cephalometriclandmarks

Variable

Males Females


Pn-h 6.7* 4.8 3.1* 3.3 .01Pn-v 2.7* 2.9 0.4 2.5 .01Col-h 4.9* 3.6 2.6* 3.3 .05Col-v 3.0* 3.9 0.8 2.3 .03Sn-h 3.5* 3.0 1.5* 3.3 NSSn-v 2.3 4.1 0.7 2.3 NSSls-h 3.4* 2.9 1.6* 3.0 NSSls-v 3.5* 3.5 1.9* 2.1 NSLs-h 4.1* 3.7 1.8* 3.1 .05Ls-v 3.5* 2.8 1.5* 2.9 .04Li-h 5.0* 3.2 2.5* 3.2 NSLi-v 2.6* 3.5 1.6* 3.2 .03

Pg-h 7.9* 4.2 4.0* 3.9 .01Pg-v 5.6* 4.8 1.8* 3.8 .01UIE-h 4.7* 2.6 3.3* 2.9 NSUIE-v 3.1* 3.2 1.9* 3.1 NSUIA-h 4.2* 2.9 3.3* 2.6 .01UIA-v 4.6* 3.3 1.9* 2.5 NSLIE-h 3.9* 2.7 2.5* 2.8 NSLIE-v 1.6 3.2 0.2 3.1 NSLIA-h 4.6* 2.8 2.0* 3.3 .02LIA-v 3.8* 4.0 1.3* 3.5 .06B-h 5.1* 3.1 2.7* 3.2 .04B-v 2.2 3.8 0.2 3.5 NS


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the E- and S-lines, and their facial convexity de-creased considerably over the long term. Similarposttreatment changes have been reported for bothextraction and nonextraction patients.3,7,16 Those

changes, as well as ours, follow patterns expected foruntreated subjects15,17and are due to greater relativegrowth in the nose and chin areas.18 This suggeststhat the extraction and nonextraction patients in this

Fig 3. Male and female 1:1 scaled illustrations for growth at individual landmarks.

Table VI. Treatment and sex differences in changes perceived by orthodontists and laypeople

Extraction NonextractionProbability

difference

Male Female

Mean SD Mean SD Mean SD Mean SD

Orthodontists 35.8 12.8 33.9 13.5 .63 36.6 10.7 34.2 14.1 .59Laypeople 38.2 8.2 37.5 10.1 .80 39.2 6.9 37.3 10.0 .57Combined 36.5 9.7 36.3 10.9 .95 38.3 7.9 35.6 11.0 .45

*Significant (P .05) differences.

Table VII. Percentage of orthodontists and laypeople who preferred posttreatment photo, long-term follow-up photo,or neither photo

Orthodontist preference Laypeople preference

Posttreatment Long-term Neither Posttreatment Long-term Neither

Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD

Extraction 37.5 19.0 36.0 21.2 26.5 17.4 32.0 13.0 38.6 19.1 29.5 14.7Nonextraction 38.3 26.5 28.9 25.5 32.8 21.0 32.5 16.9 32.9 19.2 34.6 16.8Male 42.3 21.9 29.0 21.3 28.7 15.3 36.9 12.4 29.6 13.3 33.5 13.9Female 36.0 23.3 34.0 24.5 30.0 21.0 30.3 15.6 38.3 20.8 31.4 16.7

*Significant (P .05) differences.




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study, who were chosen for posttreatment similarity,grew similarly during the posttreatment follow-upperiod.

Males and females showed no significant differ-

ences in any of the soft tissue profile measurements atthe end of treatment. Lack of significant sex differenceshas been previously reported for treated and untreatedsubjects.9,20 Bishara et al5 also reported similaritiesbetween males and females at posttreatment for facialconvexity and the relative position of the upper andlower lips. Untreated males and females have beenshown to differ: in 1 study, females had more protrudedupper lips,19 but, in another study, they had moreretruded upper lips9 than males. Again, the groups inour study were selected to be similar.

Males and females demonstrated significant differ-ences in their posttreatment changes. Males showedsignificantly more retrusion of the lips in relation to theE- and S-lines than females. Males also had signifi-cantly more growth in the soft tissue nose and chin aftertreatment (Fig 3). This agrees with growth differencesbetween males and females originally reported15,21 andlater substantiated by others.18,22 Because the averageposttreatment age of our sample was approximately 15years, males might be expected to be only 1 year pastpeak adolescent velocity and have greater future growthpotential than females. The greater growth potential ofthe male nose and chin after puberty causes their lips tobecome significantly more retruded in relation to the

E-line than those of females.Orthodontists and laypeople perceived that simi-

lar amounts of change took place between the post-treatment and long-term follow-up photos. The liter-ature pertaining to perception of profiles by dentalprofessionals and laypeople is equally divided inregard to perceptions.6,8,23-26 Our results show thatlaypeople and orthodontists perceived slight to mod-erate changes between the posttreatment and long-term follow-up profiles (ie, both groups saw signif-icant changes). Although many significantdifferences between males and females were found

cephalometrically, on the basis of amount of changeperceived, neither orthodontists nor laypeopleseemed to consistently pick up on sex differences inthe profile changes on the photos. Could it be thatwhat we measure on cephalograms for diagnosticpurposes is not what we, and laypeople, actually payattention to when evaluating everyday profiles ofrandom patients? Moreover, there does not appear tobe any relationship between changes perceived in theprofile photos and those measured cephalometrically.A weak correlation was identified between totalfacial convexity (N-Pn-Pg) and the change per-

ceived by orthodontists; this simply indicates that theorthodontists noticed a difference as the profilestraightened. The results clearly showed that every-one saw changes in the profiles, but the patients

perceived to change the most were not the same oneswho had the greatest cephalometric changes. Thisagain supports the notion that people look beyondtraditional cephalometric profile measures whenmaking judgments about facial appearance.

The proportions of those who preferred the post-treatment and long-term follow-up profiles were verysimilar for all groups. On average, none of the profilechoices (posttreatment, long-term follow-up, or nei-ther) were preferred over the others. Orthodontistsand laypeople showed similar preferences with sim-ilar patterns of variation, as previously reported.6,23

There were clear preferences for certain profiles overothers, and, for certain patients, there was agreementamong orthodontists and laypeople concerning pref-erences. These preferences were not related to thechanges that were actually perceived. The laypeopletended to prefer the long-term photos, and theorthodontists leaned toward the posttreatment pho-tos, but neither was statistically significant. Lines etal26 reported that laypeople and orthodontists pre-ferred straighter profiles for males and more convexprofiles for females. Because the male profiles in oursample were significantly straighter at long-termfollow-up than the female profiles, this might explain

why no significant differences in the preferencesbetween males and females were noted.

Because there was no clear relation betweentreatment modality and the profile preferences oforthodontists and laypeople, it cannot be concludedthat 1 type of treatment produces better, or worse,long-term profiles than the other. Variability ofprofile preference is sufficient to support any bias.For example, there was a nonextraction patient forwhom most evaluators preferred the posttreatmentprofile. On the other hand, there was an extractionpatient whose appearance clearly improved over time

according to both orthodontists and laypeople. Thissimply demonstrates that some profiles changed forthe better, and some changed for the worse. Whetherteeth were extracted had no bearing on whether theprofiles got better or worse. Boley et al27 alsoshowed that dental professionals could determineonly 50% of the time whether a patient was treatedwith extractions. We, as orthodontists, cannot deter-mine whether a patient will age for the better or forthe worse. The results also showed that just becauseones appearance changes over time does not neces-sarily mean that it will get worse or better.


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CONCLUSIONS

1. Extraction and nonextraction patients treated to thesame incisor position and lip line were also similarin these respects at long-term follow-up, demon-

strating that the long-term posttreatment changeswere not due to the type of treatment.2. Significant long-term changes were seen in profiles

between 15 and 30 years of age, resulting in relativeretrusion of the lips in relation to the E- and S-lines.Because there was no significant long-term changein lip fullness measured by the H-line, which isindependent of the nose, the changes must havebeen mainly due to increased growth in the noseand chin.

3. Although there were no significant posttreatment dif-ferences, males showed greater long-term changesthan females because of normal sexual dimorphismin aging of the soft tissue profile, especially in thenose and chin.

4. Small-to-moderate changes in profile were per-ceived during the long-term follow-up period. Theamounts of change perceived by orthodontists andlaypeople were not different, and there was nosignificant correlation between changes perceivedand those measured cephalometrically.

5. There was no pattern of profile preferences amongorthodontists or laypeople. Although clear prefer-ences were expressed for 87% of the profiles, therewere no significant findings to indicate what was

actually guiding those choices.

REFERENCES

1. Case CS. The question of extraction in orthodontia. Dent Cosmos1912;54:137-57, 276-84.

2. Dewel BF. The Case-Dewey-Cryer extraction debate: a commen-tary. Am J Orthod 1964;50:862-5.

3. Paquette DE, Beattie JR, Johnston LE. A long-term comparisonof nonextraction and premolar extraction edgewise therapy inborderline Class II patients. Am J Orthod Dentofacial Orthop1992;102:1-14.

4. Bishara SE, Cummins DM, Jakobsen JR, Zaher AR. Dentofacialand soft tissue changes in Class II, Division 1 cases treated withand without extractions. Am J Orthod Dentofacial Orthop 1995;

107:28-37.5. Bishara SE, Cummins DM, Zaher AR. Treatment and posttreat-

ment changes in patients with Class II, Division 1 malocclusionafter extraction and nonextraction treatment. Am J OrthodDentofacial Orthop 1997;111:18-27.

6. Bowman SJ, Johnston LE. The esthetic impact of extraction andnonextraction treatment on Caucasian patients. Angle Orthod2000;70:3-10.

7. Zierhut EC, Joondeph DR, rtun J, Little RM. Long-term profilechanges associated with successfully treated extraction and

nonextraction Class II Division 1 malocclusions. Angle Orthod2000;70:208-19.

8. Bishara SE, Jakobsen JR. Profile changes in patients treated withand without extractions: assessments by lay people. Am J OrthodDentofacial Orthop 1997;112:639-44.

9. Nanda RS, Meng H, Kapila S, Goorhuis J. Growth changes in thesoft tissue facial profile. Angle Orthod 1990;60:177-90.10. Drobocky OB, Smith RJ. Changes in facial profile during

orthodontic treatment with extraction of four first premolars.Am J Orthod Dentofacial Orthop 1989;95:220-30.

11. Luppanapornlarp S, Johnston LE Jr. The effects of premolar-extraction: a long-term comparison of outcomes in clear-cutextraction and nonextraction Class II patients. Angle Orthod1993;63:257-72.

12. Riolo ML, Moyers RE, McNamara JA, Hunter WS. An atlas ofcraniofacial growth, monograph 2. Craniofacial Growth Series.Ann Arbor: Center for Human Growth and Development; Uni-versity of Michigan; 1974.

13. Daskalogiannakis J. Glossary of orthodontic terms. Chicago:Quintessence Books; 2000.

14. Hsu BS. Comparisons of the five analytic reference lines of thehorizontal lip position: their consistency and sensitivity. Am JOrthod Dentofacial Orthop 1993;104:355-60.

15. Subtelny JD. The soft-tissue profile, growth and the treatmentchanges. Angle Orthod 1961;31:105-22.

16. Finnoy JP, Wisth PJ, Boe OE. Changes in soft tissue profile duringand after orthodontic treatment. Eur J Orthod 1987;9:68-78.

17. Skinazi GL, Lindauer SJ, Isaacson RJ. Chin, nose, and lips:normal ratios in young men and women. Am J Orthod Dentofa-cial Orthop 1994;106:518-23.

18. Behrents RG. Growth in the aging craniofacial skeleton, mono-graph 17. Craniofacial Growth Series. Ann Arbor: Center forHuman Growth and Development; University of Michigan;1985.

19. Bishara SE, Hession TJ, Peterson LC. Longitudinal soft-tissueprofile changes: a study of three analyses. Am J Orthod 1985;88:209-23.

20. Bishara SE, Jakobsen JR, Angelakis D. Posttreatment changes inmale and female patients: a comparative study. Am J OrthodDentofacial Orthop 1996;110:624-9.

21. Anderson JP, Joondeph DR, Turpin DL. A cephalometric studyof profile changes in orthodontically treated cases ten years outof retention. Angle Orthod 1973;43:324-36.

22. Formby WA, Nanda RS, Currier GF. Longitudinal changes in theadult facial profile. Am J Orthod Dentofacial Orthop 1994;105:464-76.

23. De Smit A, Dermaut L. Soft-tissue profile preference. Am JOrthod 1984;86:67-73.

24. Rushing SE, Silberman SL, Meydrech EF, Tuncay OC. How

dentists perceive the effects of orthodontic extraction on facialappearance. J Am Dent Assoc 1995;126:769-72.

25. Cochrane SM, Cunningham SJ, Hunt NP. A comparison of theperception of the facial profile by the general public and 3 groupsof clinicians. Int J Adult Orthod Orthognath Surg 1999;14:291-5.

26. Lines PA, Lines RR, Lines CA. Profilemetrics and facial esthet-ics. Am J Orthod 1978;73:648-57.

27. Boley JC, Pontier JP, Smith S, Fulbright M. Facial changes inextraction and nonextraction patients. Angle Orthod 1998;68:539-46.



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