7/28/2019 AJODO - Comparacion de Tejidos

1/9

Comparison of soft-tissue profiles after treatment with headgear or Herbstappliance

Introduction: Herbst and headgear appliances are considered effective forcorrecting Class II malocclusions in growing patients, although their skeletal anddental effects differ. In the literature, there is no comparison between profileesthetic outcomes with the Herbst and headgear. The purpose of this study was toprovide that comparison. Methods: Lateral cephalometric radiographs of 48matched pairs of growing Class II Division 1 patients treated with either the Herbstappliance or headgear (both combined with fixed appliances) were used togenerate pretreatment and posttreatment standardized silhouettes. The silhouetteswere randomly arranged and judged by laypeople and orthodontic residents usinga 7-point Likert scale. Statistical analyses including nonparametric procedures andintraclass correlation were used to compare initial, final, and change profile estheticscores for the 2 groups of subjects and agreement between

evaluators.Results: Both groups of subjects had significant profile improvementswith treatment (P

7/28/2019 AJODO - Comparacion de Tejidos

2/9

Hgg et al9studied patients treated with a high-pull headgear Herbst appliancefollowed by headgear activator for retention compared with those treated with theHerbst followed by retention with the Andresen activator. When the applianceswere combined with high-pull headgear, 70% of the overjet correction was viaskeletal change compared with a skeletal component of correction of less than

30% with the Herbst alone. They concluded that adding headgear to the Herbstresulted in an increased orthopedic effect on the maxilla and greater improvementin skeletal relationships.In summary, Class II correction appears to be effective with either the Herbstappliance or headgear. Headgears are reported to contribute to the correction byboth restricting forward maxillary growth and distalizing the maxillary molars. TheHerbst appliance is reported to have significant headgear effects in terms ofrestricting the maxilla. However, these effects appear to be transient, and Class IIcorrection with these appliances appears to include significant dentoalveolarcomponents.

Because Class II correction appears to be achievable with either appliance, afollow-up question is whether there is a difference in the esthetic outcomes.Dongieux and Sassouni10studied frontal and profile esthetics with variations inmandibular position. They found that the soft-tissue profile view was the mostreliable in assessing esthetics related to anteroposterior and vertical changes inthe position of the mandible.The literature provides ample soft-tissue measures for evaluating various aspectsof facial esthetics. However, because of the complexity of the human face and thesubjectivity of facial beauty, a simple set of measures of lines or angles cannotquantify facial beauty. Some authors have used silhouettes effectively to studyprofile esthetics to neutralize the bias of variables such as coloring andcomplexion; the influence of these features was confirmed by Spyropoulos andHalazonetis.11Previous investigators compared profile silhouettes after treatment with variousmodalities of Class II correction. Barrer and Ghafari12compared profile silhouettesof patients treated without extractions and with either Frnkel, Begg light-wire,straight-wire edgewise, or Tweed edgewise appliances. They found that theposttreatment profiles were strongly preferred, with no difference betweentreatment modalities. ONeill et al

13reported on the profile attractiveness of children

with Class II Division 1 malocclusion after treatment with the Frnkel appliance (n =13) or the Harvold activator (n = 12) compared with a control group (n = 17). Initialand final profile silhouettes were judged by panels of art students, dental students,and parents of orthodontic patients. They found no significant differences in thechanges in profile attractiveness of treated subjects compared with control subjectsbecause profile attractiveness improved in most subjects in each group, includingthe control subjects; however, relatively small sample sizes might have affectedstatistical power. In contrast, Quinto et al

14found soft-tissue differences between

subjects treated with the Twin-block appliance and Class II control subjects.However, their measurements were made immediately after 12 months of Twin-block treatment and did not allow for posttreatment changes.

http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib9http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib9http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib9http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib10http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib10http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib10http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib11http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib11http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib11http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib12http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib12http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib12http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib13http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib13http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib13http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib14http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib14http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib14http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib14http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib13http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib12http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib11http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib10http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib9

7/28/2019 AJODO - Comparacion de Tejidos

3/9

Shelly et al15studied the treatment outcomes of 34 patients who had mandibularadvancement. Laypersons and orthodontic residents evaluated randomizedpretreatment and posttreatment profile silhouettes to quantify changes in profileesthetics. They found that, for patients with an initial ANB angle 6, there wasconsistent improvement in profile esthetics after treatment. However, for patients

with an initial ANB

7/28/2019 AJODO - Comparacion de Tejidos

4/9

ANB range ANB mean

Headgear 4-10 5.47

Herbst 4-10 5.53

Table II. Sex distribution and initial age

Female (n) Initial mean age (y)

Headgear 12 10.93

Herbst 12 10.93

The first group of subjects was treated in the graduate orthodontic clinic at theUniversity of Iowa with headgear (mixed headgear types) and fixed appliances.Extractions were based on treatment need for correction of crowding and not forClass II correction. When extractions were required, 2 maxillary and 2 mandibularpremolars were removed. Extractions were indicated in 27% of the sample. Allsubjects completed treatment with Class I occlusion.

The second group of subjects was treated in a private practice with a bandedHerbst appliance and fixed appliances. The Herbst appliance was placed after thecomplete eruption of all 4 first premolars. Upon placement, the mandible wasadvanced approximately 3 to 4 mm, an additional 2 to 3 mm after 3 months oftreatment, and again after 6 months as needed. In general, Class I occlusion wasachieved after the second advancement. The Herbst appliance remained in place12 to 15 months. The need for extractions was determined after treatment with theHerbst appliance. If extractions were deemed necessary, either 2 maxillarypremolars or 2 maxillary and 2 mandibular premolars were extracted. Extractionswere indicated in less than 10% of the subjects.

Silhouettes were produced from the soft-tissue profile tracings of the pretreatmentand posttreatment lateral cephalometric radiographs of all subjects. The tracingswere scanned into Adobe Photoshop (version 7.0; Adobe Systems, San Jose,Calif) by using ScanMaker (9800XL; Microtek USA, Carson, Calif) set to gray scaleand resolution of 300 dpi and saved as JPEG images. Each line tracing wasarranged with the Frankfort horizontal parallel to the horizontal aspect of thecomputer monitor. The profile tracings were then filled in with solid black against awhite background. The silhouettes were transferred to Windows PowerPoint

7/28/2019 AJODO - Comparacion de Tejidos

5/9

(Microsoft, Redmond, Wash), where they were standardized for size and showedeach profile from soft-tissue glabella to slightly below the throat point.

All silhouettes were randomly sorted for presentation to the evaluators. Eachsilhouette was labeled chronologically in the lower right corner. The silhouettes

were also labeled with identification numbers according to test grouppretreatment or posttreatmentin black text superimposed over the blacksilhouettes, making the labels invisible during projection. These identification labelscould be viewed by clicking and moving the silhouettes.

The presentation and judging of profiles was done according to the method ofMergan et al.

16Five introductory silhouettes (Fig 1) were shown to familiarize the

evaluators with the range of esthetics in the sample and the rating procedure. Theintroductory silhouettes were shown at decreasing intervals of 30, 20, 15, 12, and10 seconds. The actual 192 silhouettes were shown at intervals of 10 seconds.The presentation lasted for 32 minutes. The evaluators consisted of 2 groups, each

comprising 10 people. The first group consisted of 10 laypersons, 6 men and 4women, who had no direct patient contact and whose ages were 19 to 55 years.The second group consisted of 10 orthodontic residents, 6 men and 4 women,whose ages were 26 to 31 years. The evaluators were asked to score each profileusing a Likert scale consisting of 7 points ranging from 1 (very unattractive) to 7(very attractive).19

Introductory silhouettes to familiarize the evaluators with the range of esthetics inthe sample.

Statistical analysis

The nonparametric Wilcoxon rank sum test was used to compare the meandifference for initial rating scores between the Herbst and headgear treatmentgroups. The same test was also used to compare final mean rating scores andchanges of mean rating scores (final minus initial) between the groups. Thenonparametric Wilcoxon signed rank test was used to compare the meandifference in rating scores between resident and lay raters; in addition, theintraclass correlation coefficient was used to determine the level of agreementbetween the 2 groups of evaluators. SAS software (version 9.1; SAS, Cary, NC)was used for the statistical analysis, and all tests had a .05 level of statisticalsignificance.

Means of average initial, final, and change esthetic scores are shown inTable III.The first goal of the study was to determine which treatment resulted in a moreesthetic posttreatment soft-tissue profile. The data provided no evidence ofsignificant differences in average final profile scores between the Herbst andheadgear groups (P= .9357). Treatment with Herbst or headgear produced equallyattractive soft-tissue profiles with mean average scores of 3.60 and 3.55,respectively. The second goal was to determine whether there was a perceived

http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#fig1http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#fig1http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#fig1http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib19http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib19http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib19http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#tbl3http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#tbl3http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#tbl3http://openimgwin%28%27/article/S0889-5406(07)01310-8/journalimage?src=fig&loc=gr1&ishighres=false&allhighres=false&free=no%27,%27journalimage%27);http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#tbl3http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib19http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#fig1http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16

7/28/2019 AJODO - Comparacion de Tejidos

6/9

improvement in the soft-tissue profile from pretreatment to posttreatment for the 2modalities. Data analysis showed that, for both treatment groups, the final scoreswere significantly higher than the initial scores (P

7/28/2019 AJODO - Comparacion de Tejidos

7/9

Group All raters Lay ra

Herbst

Final 3.60 (1.22) 3.61 (1

Initial 3.09 (1.32) 3.19 (1

Change 0.51 (1.40) 0.42 (1

% change 17 13

Significantly different from the initial score for that treatment group, P

7/28/2019 AJODO - Comparacion de Tejidos

8/9

Ninety-six growing subjects with Class II Division 1 malocclusion were included inthis study; 48 subjects treated with the Herbst appliance and 48 treated withheadgear (both combined with fixed appliances) were closely matched for sex,age, and skeletal conformation. Pretreatment and posttreatment silhouette profiles,used to eliminate subjective distractions, were scored by lay and professional

evaluators. Because the mechanism for correction of the dentition differs betweenthe Herbst and headgear appliances, we were surprised to find that the final profileesthetic results were similar for both groups and that both groups had significantimprovements.

It was also unexpected that the initial profile scores for the 2 groups weresignificantly different. This was particularly surprising because the groups werematched carefully for underlying skeletal discrepancies, age, and sex. One mightassume that similar underlying skeletal discrepancies would result in similar soft-tissue profiles; perhaps, however, these initial differences were the result oftreatment selection biases. For example, many headgear subjects were treated

with high-pull headgear, and they might have initially had greater frequencies of lipincompetence and obtuse lip-chin-throat angle, 2 features that impact profilescores negatively.

Another surprising finding was that, on average, all scores were below average onthe 1-to-7 Likert scale. However, after further investigation, we found that our meanscores were similar to those of previous investigators who used the same 7-pointLikert scale.15,16Our mean improvement scores of 0.86 (headgear) and 0.51(Herbst) compared favorably with 0.54 (Mergen et al16) and 0.40 (Shelly et al15) forClass II patients.One limitation of our study was the lack of an untreated Class II control group.ONeill et al13compared profile improvement of subjects treated with either theFrnkel appliance or the Harvold activator with an untreated control group. Thoseauthors found improvement in about two thirds to three fourths of treated subjectscompared with improvement in approximately two thirds of untreated subjects, withno statistical difference between treated and untreated subjects. Their study,however, had small sample sizes (17 untreated controls, 13 subjects treated with aFrnkel, and 12 treated with an activator). Their small sample sizes could havebeen problematic and might have affected their outcome. We plan a futurecomparison with larger samples of treated and control subjects.

A few subjects in each of our groups had extractions. One question that might beof concern is whether this affected their profile esthetics. However, studiesdocument the negligible soft-tissue profile effects of extractions using soundtreatment decisions for Class II treatment.20,21Our final goal was to compare the evaluations of laypeople and orthodonticresidents. For the pretreatment silhouettes, the laypeople were less critical than theorthodontic residents, but overall there was strong agreement between the 2groups of evaluators. These results are similar to those of Mergen et al,

16who

found overall good agreement between evaluators, but the initial profile silhouetteswere judged less critically by laypeople. Kerr and ODonnell22also found lay judges(art students and parents) to be more generous in evaluating profiles than

http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib15http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib15http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib15http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib15http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib15http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib15http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib13http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib13http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib13http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib20http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib20http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib20http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib21http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib21http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib21http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib22http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib22http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib22http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib22http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib21http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib20http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib13http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib15http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib16http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib15

7/28/2019 AJODO - Comparacion de Tejidos

9/9

orthodontists. In general, though, investigators have found agreement about facialattractiveness among lay and professional judges.23,24

Conclusions

Our purpose in this study was to evaluate pretreatment and posttreatment profile

silhouettes of 48 matched pairs of growing Class II Division 1 subjects who weretreated with either the Herbst appliance or headgear (both combined with fixedappliances). Standardized profile silhouettes of the subjects were randomlyarranged and projected for judging by laypeople and orthodontic residents using a7-point Likert scale. Statistical analysis including nonparametric procedures andintraclass correlation coefficients demonstrated the following.

1.Both headgear and Herbst treatment groups had significant profile improvementswith treatment.

2.Both headgear and Herbst treatment groups finished with similarly attractiveprofiles.

3.Despite close matching of the groups, the headgear subjects had lower initialscores and experienced greater percentage changes.

4.There was strong agreement between the evaluations of laypersons andorthodontic residents.

http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib23http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib23http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib23http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib24http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib24http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib24http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib24http://www.ajodo.org/article/S0889-5406(07)01310-8/fulltext#bib23