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ORIGINAL ARTICLE Comparison of soft-tissue profiles after treatment with headgear or Herbst appliance Erin A. C. Sloss,a Karin A. Southard,b Fang Qian,c Suzanne E. Stock,d Kyle R. Mann,d David L. Meyer,e and Thomas E. Southardb Denver, Colo, and Iowa City and Dubuque, Iowa Introduction: Herbst and headgear appliances are considered effective for correcting Class II malocclusions in growing patients, although their skeletal and dental effects differ. In the literature, there is no comparison between profile esthetic outcomes with the Herbst and headgear. The purpose of this study was to provide that comparison. Methods: Lateral cephalometric radiographs of 48 matched pairs of growing Class II Division 1 patients treated with either the Herbst appliance or headgear (both combined with fixed appliances) were used to generate pretreatment and posttreatment standardized silhouettes. The silhouettes were randomly arranged and judged by laypeople and orthodontic residents using a 7-point Likert scale. Statistical analyses including nonparametric procedures and intraclass correlation were used to compare initial, final, and change profile esthetic scores for the 2 groups of subjects and agreement between evaluators. Results: Both groups of subjects had significant profile improvements with treatment (P �.05), and there were no statistically significant differences between the groups in average final profile scores. Overall, there was strong agreement between the evaluations of laypersons and orthodontic residents. Conclusions: Class II Division 1 growing patients treated with either Herbst appliance or headgear (both combined with fixed appliances) will benefit from significantly improved profiles that are equally attractive. (Am J Orthod Dentofacial Orthop 2008;133:509-14) Orthodontic treatment with either Herbst appli-ance or headgears can be effective in correct-ing Class II malocclusions, although their skeletal and dental effects differ. A number of authors have described the dentoalveolar and skeletal changes induced by the Herbst appliance. The dentoalveolar effects consist of distalization of the maxillary molars and forward movement of the mandibular dentition.1 The main skeletal change—mandibular stimulation—is acceleration of a patient’s inherent mandibular growth rather than increased growth beyond what would occur without treatment.2-4 Pancherz and Anehus-Pancherz5 described the short-term and long-term effects of the Herbst appli- ance on the maxillary complex of 45 patients followed for 6.4 years after treatment. They noted significant high-pull headgear type changes on the maxillary aPrivate practice, Denver, Colo. bProfessor, Department of Orthodontics, College of Dentistry, University of Iowa, Iowa City, Iowa. cSenior research assistant, College of Dentistry, University of Iowa, Iowa City, Iowa. dDental research assistant, College of Dentistry, University of Iowa, Iowa City, Iowa. ePrivate practice, Dubuque, Iowa. Reprint requests to: Karin A Southard, S-221 Dental Science Bldg, University of Iowa, Iowa City, IA 52242; e-mail, karin-southard@uiowa.edu. Submitted, February 2006; revised and accepted, April 2006. 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2006.04.050 complex, but the effect was temporary without addi- tional retention. The treatment effects of headgears are well doc- umented. High-pull headgears reduce forward and downward maxillary growth. The result of both effects is improvement of the apical base discrepancy in Class II patients. Dentally, high-pull headgears tend to dis- talize and intrude or reduce the eruption of the maxil- lary molars. Cervical-pull headgears, on the other hand, tend to restrict forward maxillary growth, rotate the anterior palatal plane downward, and distalize the maxil- lary molars. Recent evidence indicates that the mandibular plane is maintained with cervical-pull headgear.6-8 Hägg et al9 studied patients treated with a high-pull headgear Herbst appliance followed by headgear acti- vator for retention compared with those treated with the Herbst followed by retention with the Andresen activa- tor. When the appliances were combined with high-pull headgear, 70% of the overjet correction was via skeletal change compared with a skeletal component of correction of less than 30% with the Herbst alone. They concluded that adding headgear to the Herbst resulted in an increased orthopedic effect on the maxilla and greater improvement in skeletal relationships. In summary, Class II correction appears to be effective with either the Herbst appliance or headgear. Headgears are reported to contribute to the correction by both restricting forward maxillary growth and dis- 509 mailto:karin-southard@uiowa.edu American Journal of Orthodontics and Dentofacial Orthopedics April 2008 510 Sloss et al talizing the maxillary molars. The Herbst appliance is reported to have significant headgear effects in terms of restricting the maxilla. However, these effects appear to be transient, and Class II correction with these appli- ances appears to include significant dentoalveolar com- ponents. Because Class II correction appears to be achiev- able with either appliance, a follow-up question is whether there is a difference in the esthetic outcomes. Dongieux and Sassouni10 studied frontal and profile esthetics with variations in mandibular position. They found that the soft-tissue profile view was the most reliable in assessing esthetics related to anteroposterior and vertical changes in the position of the mandible. The literature provides ample soft-tissue measures for evaluating various aspects of facial esthetics. How- ever, because of the complexity of the human face and the subjectivity of facial beauty, a simple set of mea- sures of lines or angles cannot quantify facial beauty. Some authors have used silhouettes effectively to study profile esthetics to neutralize the bias of variables such as coloring and complexion; the influence of these features was confirmed by Spyropoulos and Halazone- tis.11 Previous investigators compared profile silhouettes after treatment with various modalities of Class II correction. Barrer and Ghafari12 compared profile sil- houettes of patients treated without extractions and with either Fränkel, Begg light-wire, straight-wire edgewise, or Tweed edgewise appliances. They found that the posttreatment profiles were strongly preferred, with no difference between treatment modalities. O’Neill et al13 reported on the profile attractiveness of children with Class II Division 1 malocclusion after treatment with the Fränkel appliance (n � 13) or the Harvold activator (n � 12) compared with a control group (n � 17). Initial and final profile silhouettes were judged by panels of art students, dental students, and parents of orthodontic patients. They found no significant differ- ences in the changes in profile attractiveness of treated subjects compared with control subjects because profile attractiveness improved in most subjects in each group, including the control subjects; however, relatively small sample sizes might have affected statistical power. In contrast, Quintão et al14 found 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. Shelly et al15 studied the treatment outcomes of 34 patients who had mandibular advancement. Laypersons and orthodontic residents evaluated randomized pre- treatment and posttreatment profile silhouettes to quan- tify changes in profile esthetics. They found that, for patients with an initial ANB angle �6°, there was consistent improvement in profile esthetics after treat- ment. However, for patients with an initial ANB �6°, profile improvement was seen about half the time, but poorer esthetics were equally likely. Mergen et al16 studiedthe profile silhouettes of 100 patients treated with headgear and fixed appliances. The subjects were divided into 4 groups based on the severity of the skeletal anteroposterior and vertical statuses. Lay and orthodontic resident judges evaluated randomized pretreatment and posttreatment profile sil- houettes. They found that, as initial skeletal discrepan- cies worsened, pretreatment profiles were judged less attractive. With treatment, all groups showed overall profile improvement, and all groups were judged equally attractive. Groups with greater initial skeletal discrepancies had the most profile improvement. The literature suggests that the profile view is the most reliable in assessing esthetics related to antero- posterior and vertical changes in the position of the mandible. Furthermore, profile silhouettes of patients have been successfully used to compare esthetic changes with or without extractions; with the Fränkel, Harvold, Begg, straight-wire, or Tweed edgewise ap- pliances; with mandibular advancement surgery; and with headgears. There is no comparison in the literature between profile esthetic outcomes with the Herbst compared with headgear appliances. The purpose of this study was to evaluate profile outcomes of growing patients treated with Herbst or headgear combined with fixed orthodontic appliances. We had 5 specific goals: to determine (1) which treatment resulted in a more esthetic posttreatment soft-tissue profile, (2) whether there was a perceived improvement in the soft-tissue profile from pretreatment to posttreatment for the 2 treatment modalities, (3) whether the amount of soft- tissue profile improvement from pretreatment to post- treatment was similar between the 2 treatments, (4) whether there were differences in average initial profile scores between the Herbst and the headgear patients, and (5) whether there were differences in the appraisals of laypeople and orthodontic residents. MATERIAL AND METHODS Two groups of 48 growing Class II Division 1 caucasian subjects were individually matched retro- spectively for sex, age, and ANB and SN-MP angles (Tables I and II). The sagittal maxillary skeletal rela- tionship of each subject was deemed normal as defined by the measurement FH:NA to ensure that the skeletal discrepancy was due to mandibular skeletal retru- American Journal of Orthodontics and Dentofacial Orthopedics Volume 133, Number 4 Sloss et al 511 sion.17,18 Inclusion criteria required girls younger than 12 years 0 months and boys younger than 14 years 0 months. The first group of subjects was treated in the graduate orthodontic clinic at the University of Iowa with headgear (mixed headgear types) and fixed appli- ances. Extractions were based on treatment need for correction of crowding and not for Class II correction. When extractions were required, 2 maxillary and 2 mandibular premolars were removed. Extractions were indicated in 27% of the sample. All subjects completed treatment with Class I occlusion. The second group of subjects was treated in a private practice with a banded Herbst appliance and fixed appliances. The Herbst appliance was placed after the complete eruption of all 4 first premolars. Upon placement, the mandible was advanced approximately 3 to 4 mm, an additional 2 to 3 mm after 3 months of treatment, and again after 6 months as needed. In general, Class I occlusion was achieved after the second advancement. The Herbst appliance remained in place 12 to 15 months. The need for extractions was determined after treatment with the Herbst appliance. If extractions were deemed necessary, either 2 maxillary premolars or 2 maxillary and 2 mandibular premolars were extracted. Extractions were indicated in less than 10% of the subjects. Silhouettes were produced from the soft-tissue pro- file tracings of the pretreatment and posttreatment lateral cephalometric radiographs of all subjects. The tracings were scanned into Adobe Photoshop (version 7.0; Adobe Systems, San Jose, Calif) by using Scan- Maker (9800XL; Microtek USA, Carson, Calif) set to gray scale and resolution of 300 dpi and saved as JPEG images. Each line tracing was arranged with the Frank- fort horizontal parallel to the horizontal aspect of the Table I. Initial ANB and SN:MP angles: ranges and means (°) ANB range ANB mean SN:MP range SN:MP mean Headgear 4-10 5.47 20-44 32.77 Herbst 4-10 5.53 21-42 32.24 Table II. Sex distribution and initial age Female (n) Initial mean age (y) Male (n) Initial mean age (y) Headgear 12 10.93 36 12.21 Herbst 12 10.93 36 12.18 computer monitor. The profile tracings were then filled in with solid black against a white background. The silhouettes were transferred to Windows PowerPoint (Microsoft, Redmond, Wash), where they were stan- dardized for size and showed each profile from soft- tissue glabella to slightly below the throat point. All silhouettes were randomly sorted for presenta- tion to the evaluators. Each silhouette was labeled chronologically in the lower right corner. The silhou- ettes were also labeled with identification numbers according to test group—pretreatment or posttreat- ment—in black text superimposed over the black sil- houettes, making the labels invisible during projection. These identification labels could be viewed by clicking and moving the silhouettes. The presentation and judging of profiles was done according to the method of Mergan et al.16 Five introductory silhouettes (Fig 1) were shown to famil- iarize the evaluators with the range of esthetics in the sample and the rating procedure. The introductory silhouettes were shown at decreasing intervals of 30, 20, 15, 12, and 10 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 4 women, 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 profile using a Likert scale consisting of 7 points ranging from 1 (very unattractive) to 7 (very attrac- tive).19 Statistical analysis The nonparametric Wilcoxon rank sum test was used to compare the mean difference for initial rating scores between the Herbst and headgear treatment groups. The same test was also used to compare final mean rating scores and changes of mean rating scores (final minus initial) between the groups. The nonpara- metric Wilcoxon signed rank test was used to compare the mean difference in rating scores between resident and lay raters; in addition, the intraclass correlation coefficient was used to determine the level of agree- ment between the 2 groups of evaluators. SAS software (version 9.1; SAS, Cary, NC) was used for the statis- tical analysis, and all tests had a .05 level of statistical significance. RESULTS Means of average initial, final, and change esthetic scores are shown in Table III. The first goal of the study was to determine which treatment resulted in a more American Journal of Orthodontics and Dentofacial Orthopedics April 2008 512 Sloss et al esthetic posttreatment soft-tissue profile. The data pro- vided no evidence of significant differences in average final profile scores between the Herbst and headgear groups (P � .9357). Treatment with Herbst or headgear produced equally attractive 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 improvement in the soft-tissue profile from pretreatment to posttreatment for the 2 modalities. Data analysis showed that, for both treatment groups, the final scores were significantly higher than the initial scores (P �.05 in each instance). The third goal was to determine whether the amount of soft-tissue profile improvement from pretreatment to posttreatment was similar between the Herbst and theheadgear. Statistical analysis showed no difference in average change profile scores between the 2 groups (P � .0870). The mean change scores were 0.51 in the Herbst group and 0.86 in the headgear group. This represents changes of 17% and 32% for the Herbst and headgear groups, respec- tively. Figures 2 and 3 show 2 subjects whose profiles Fig 1. Introductory silhouettes to familiarize the Table III. Mean average (SD) esthetic scores Group All raters Lay raters Resident raters Headgear Final 3.55 (1.41)* 3.59 (1.33)* 3.50 (1.48)* Initial 2.69 (1.33) 2.85 (1.32) 2.53 (1.33) Change 0.86 (1.57) 0.74 (1.51) 0.97 (1.63) % change 32 26 38 Herbst Final 3.60 (1.22)* 3.61 (1.16)* 3.58 (1.28)* Initial 3.09 (1.32)† 3.19 (1.29)† 2.98 (1.34)† Change 0.51 (1.40) 0.42 (1.41) 0.6 (1.38) % change 17 13 20 *Significantly different from the initial score for that treatment group, P �.05. †Significantly different from corresponding initial headgear scores, P �.05. represent the approximate mean improvement for their group. The fourth goal was to determine whether there were differences in average initial profile scores between the Herbst and the headgear patients. The data analysis showed that the overall average initial scores for the Herbst group (mean, 3.09) were significantly ators with the range of esthetics in the sample. Fig 2. Initial (left) and final (right) silhouettes for a headgear subject demonstrating approximate mean im- provement for the headgear group: initial score, 2.65; final score, 3.6; change score, 0.95 (for all raters com- bined). Fig 3. Initial (left) and final (right) silhouettes for a Herbst subject demonstrating approximate mean improvement for the Herbst group: initial score, 4.1; final score, 4.75; change score, 0.65 (for all raters combined). evalu higher (more esthetic) than those for the headgear American Journal of Orthodontics and Dentofacial Orthopedics Volume 133, Number 4 Sloss et al 513 group (mean, 2.69) (P � .034), despite careful match- ing of subjects for initial skeletal conformation, age, and sex. Finally, we sought to determine whether there were differences between the appraisals of laypeople and trained professionals. There was evidence that the initial scores of the lay raters were greater than those of the orthodontic residents in each treatment group (P � .0035 for the Herbst group; P �.0001 for the headgear group). However, when final profile scores were con- sidered, there was no significant difference in the scores of the evaluator groups (P �.05 in each instance). Furthermore, intraclass correlation coefficients of 0.81 to 0.93 showed strong agreement for initial, final, and change scores for both Herbst and headgear subjects from the 2 groups of evaluators. DISCUSSION Our principal finding was that, despite differences in the mechanism of action of the 2 appliances, growing patients, treated with either Herbst or headgear (com- bined with fixed appliances) have significant profile improvement after treatment; both groups benefited from improved profiles that were equally attractive. Ninety-six growing subjects with Class II Division 1 malocclusion were included in this study; 48 subjects treated with the Herbst appliance and 48 treated with headgear (both combined with fixed appliances) were closely matched for sex, age, and skeletal conforma- tion. Pretreatment and posttreatment silhouette profiles, used to eliminate subjective distractions, were scored by lay and professional evaluators. Because the mech- anism for correction of the dentition differs between the Herbst and headgear appliances, we were surprised to find that the final profile esthetic results were similar for both groups and that both groups had significant im- provements. It was also unexpected that the initial profile scores for the 2 groups were significantly different. This was particularly surprising because the groups were matched carefully for underlying skeletal dis- crepancies, age, and sex. One might assume that similar underlying skeletal discrepancies would result in simi- lar soft-tissue profiles; perhaps, however, these initial differences were the result of treatment selection bi- ases. For example, many headgear subjects were treated with high-pull headgear, and they might have initially had greater frequencies of lip incompetence and obtuse lip-chin-throat angle, 2 features that impact profile scores negatively. Another surprising finding was that, on average, all scores were below average on the 1-to-7 Likert scale. However, after further investigation, we found that our mean scores were similar to those of previous investi- gators who used the same 7-point Likert scale.15,16 Our 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) for Class II patients. One limitation of our study was the lack of an untreated Class II control group. O’Neill et al13 com- pared profile improvement of subjects treated with either the Fränkel appliance or the Harvold activator with an untreated control group. Those authors found improvement in about two thirds to three fourths of treated subjects compared with improvement in approx- imately two thirds of untreated subjects, with no statis- tical difference between treated and untreated subjects. Their study, however, had small sample sizes (17 untreated controls, 13 subjects treated with a Fränkel, and 12 treated with an activator). Their small sample sizes could have been problematic and might have affected their outcome. We plan a future comparison with larger samples of treated and control subjects. A few subjects in each of our groups had extrac- tions. One question that might be of concern is whether this affected their profile esthetics. However, studies document the negligible soft-tissue profile effects of extractions using sound treatment decisions for Class II treatment.20,21 Our final goal was to compare the evaluations of laypeople and orthodontic residents. For the pretreat- ment silhouettes, the laypeople were less critical than the orthodontic residents, but overall there was strong agreement between the 2 groups of evaluators. These results are similar to those of Mergen et al,16 who found overall good agreement between evaluators, but the initial profile silhouettes were judged less critically by laypeople. Kerr and O’Donnell22 also found lay judges (art students and parents) to be more generous in evaluating profiles than orthodontists. In general, though, investigators have found agreement about facial attrac- tiveness among lay and professional judges.23,24 CONCLUSIONS Our purpose in this study was to evaluate pre- treatment and posttreatment profile silhouettes of 48 matched pairs of growing Class II Division 1 subjects who were treated with either the Herbst appliance or headgear (both combined with fixed appliances). Stan- dardized profile silhouettes of the subjects were ran- domly arranged and projected for judging by laypeople and orthodontic residents using a 7-point Likert scale. Statistical analysis including nonparametric procedures and intraclass correlation coefficients demonstrated the following. American Journal of Orthodontics and Dentofacial Orthopedics April 2008 514 Sloss et al 1. Both headgear and Herbst treatment groups had significant profile improvements with treatment. 2. Both headgear and Herbst treatment groups finished with similarly attractive profiles. 3. Despite close matching of the groups, the headgear subjects had lower initial scores and experienced greater percentage changes. 4. There was strong agreement between the evalua- tions of laypersons and orthodontic residents. REFERENCES 1. Peterson JE, McNamara J. Temporomandibular joint adaptations associated with Herbst appliance treatment in juvenile rhesus monkeys (Macaca mulatta). Semin Orthod 2003;9:12-25. 2. Pancherz H, Ruf S, Kohlhas P. Effective condylar growth and chin position changes in Herbst treatment: a cephalometricroentgenographic long-term study. Am J Orthod Dentofacial Orthop 1998;114:437-46. 3. Ruf S, Pancherz H. Temporomandibular joint remodeling in adolescents and young adults during Herbst treatment: a prospec- tive longitudinal magnetic resonance imaging and cephalometric radiographic investigation. Am J Orthod Dentofacial Orthop 1999;115:607-18. 4. Pancherz H. History, background and development of the Herbst appliance. Semin Orthod 2003;9:3-11. 5. Pancherz H, Anehus-Pancherz M. The headgear effect of the Herbst appliance: a cephalometric long-term study. Am J Orthod Dentofacial Orthop 1993;103:510-20. 6. Firouz M, Zernik J, Nanda R. Dental and orthopedic effects of high-pull headgear in treatment of Class II, Division 1 maloc- clusion. Am J Orthod Dentofacial Orthop 1992;102:197-205. 7. Baumrind S, Korn D, Isaacson RJ, West EE, Molthen R. Quantitative analysis of the orthodontic and orthopedic effects of maxillary traction. Am J Orthod 1983;84:384-98. 8. Kirjavainen M, Kirjavainen T, Hurmerinta K, Haavikko K. Orthopedic cervical headgear with an expanded inner bow in Class II correction. Angle Orthod 2000;70:317-25. 9. Hägg U, Du X, Rabie ABM, Bendeus M. What does headgear add to Herbst treatment and to retention? Semin Orthod 2003;9: 57-66. 10. Dongieux J, Sassouni V. The contribution of mandibular posi- tioned variation to facial esthetics. Angle Orthod 1980;50:334-9. 11. Spyropoulos MN, Halazonetis DJ. Significance of the soft tissue profile on facial esthetics. Am J Orthod Dentofacial Orthop 2001;119:464-71. 12. Barrer JG, Ghafari J. Silhouette profiles in the assessment of facial esthetics: a comparison of cases treated with various orthodontic appliances. Am J Orthod 1985;87:385-91. 13. O’Neill K, Harkness M, Knight R. Ratings of profile attractive- ness after functional appliance treatment. Am J Orthod Dento- facial Orthop 2000;118:371-6. 14. Quintão C, Helena I, Brunharo VP, Menezes RC, Almeida MAO. Soft tissue facial profile changes following functional appliance therapy. Eur J Orthod 2006;28:35-41. 15. Shelly AD, Southard TE, Southard KA, Casko JS, Jakobsen JR, Fridrich KL, et al. Evaluation of profile esthetic change with mandibular advancement surgery. Am J Orthod Dentofacial Orthop 2000;117:630-7. 16. Mergen JL, Southard KA, Dawson DV, Fogle LL, Casko JS, Southard TE. 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Am J Orthod Dentofacial Orthop 2005;128:450-7. 22. Kerr WJ, O’Donnell JM. Panel perception of facial attractive- ness. Br J Orthod 1990;17:299-304. 23. DeSmit A, Dermaut L. Soft-tissue profile preference. Am J Orthod 1984;86:67-73. 24. Schlosser JB, Preston CB, Lampasso J. The effects of computer- aided anteroposterior maxillary incisor movement on ratings of facial attractiveness. Am J Orthod Dentofacial Orthop 2005;127: 17-24. Comparison of soft-tissue profiles after treatment with headgear or Herbst appliance MATERIAL AND METHODS Statistical analysis RESULTS DISCUSSION CONCLUSIONS REFERENCES
