Consultant Orthodontist, The University of Western Australia
Program Director, Orthodontics, Dental School, The University of Western Australia
This study investigated the influence of changing the antero-posterior (AP) position of the lower face on the rankings of facial attractiveness.
Three hundred and eighty two people of various ages and professions rated the attractiveness of antero-posteriorly altered male and female profile images on a computer based survey. Attractiveness ranking scores were obtained from the visual assessment of 3 digitally altered male and 3 female profile photographs that represented a range of 5 different AP positions from a more retrusive historical profile, to a more protrusive contemporary profile. There were two parts to the survey, the first part involved selecting the preferred image for each subject, and the second part rated each image individually for attractivness using a 5 point Likert scale. Statistical analyses were employed for comparison between the different age groups, genders, and professions.
The results showed a trend that raters’ occupation has an influence on how attractiveness was rated. Plastic surgeons, oral surgeons, and orthodontists preferred a mid to more protrusive profile, however only statistically significant in one subject. Dentists, dental students and laypeople appeared to have no preference in profile, with similar ratings between all the profiles. Gender had a limited influence on the perception of attractiveness. Occupations had a significant influence on difficultly rating the images, and difficultly telling the images apart. All groups found it moderate to very difficult. Dentists, dental students, and laypeople finding it significantly more difficult than the orthodontists, oral surgeons and plastic surgeons. Overall, minor facial profile variations of lip and chin position do not have a significant influence on the perception of facial profile attractiveness among the general population.
Attractiveness refers to a person’s physical traits which are perceived to be aesthetically pleasing or beautiful. The term often implies sexual attractiveness or desirability, but can also be distinct from the two1. It only takes a fraction of a second to decide whether we find someone attractive. The face remains a key feature in the determination of human physical attractiveness.1 One reason why patients seek orthodontic treatment is to improve facial aesthetics. Orthodontic treatment can influence facial aesthetics in a number of ways, including well-aligned teeth,2,3 an attractive smile,3,4 and a pleasing facial profile.3,5 Evidence would suggest that people with attractive faces are likely to be regarded as more competent, likeable and in a broad sense ‘better’ than those who are not considered facially attractive.6 To have an attractive facial appearance confers a greater variety of positive social responses.
There are many aspects of a face which are reported to make it attractive, including its symmetry, proportions, harmony, balance, and features. Historically, the Egyptians showed their aesthetic attitudes within their art. Monuments, statues and tombs reflecting the Egyptian ideal of beauty, harmony and proportion have been discovered. Idealised form included a round, broad face with a sloped forehead, weak brow ridge, prominent eyes, evenly contoured nose, thick lips and a mild yet positive chin. Kings were portrayed with “ideal” proportions, lesser nobles were more realistically carved. The Greeks had a different view on aesthetics with sculptures showing a mildly convex profile, but with prominent noses, fleshy chin, and a deep mentolabial sulcus. It appears that the ideal sagittal positions of the lips and chin are constantly evolving. Peck and Peck studied beauty contest winners and noted that there was a general trend towards a fuller and more protrusive lower face. Turley and coworkers ,studied profile photographs of adult Caucasian males and females from periodical magazines spanning 100 years. They concluded that both in males and females the soft tissue profile as depicted in fashion magazines has become fuller in the lips through the 20th century, with a trend toward more protrusive lips and an increase in vermilion display.
Over the past 60 years with the common use of cephalometic headfilms there have been many attempts to determine the ideal facial profile. This has been subjective and researchers used fashion models, or people with ideal dental relationships to determine what would be the ideal facial profile. From the cephalometric headfilms, various analyses were developed in an attempt to qualitate and quantitate aesthetic facial profiles. Downs attempted to use hard tissue measurements to analyse profile imbalance to differentiate between good and poor dentofacial profiles. In addition to Down’s, prominent among these analyses were those suggested by Margolis, Tweed, and Steiner that were helpful in planning orthodontic treatment. Other attempts have been made to include an element of soft tissue profile assessment to evaluate soft tissue facial aesthetics which included the development of several lines and angles. The H-angle is formed by a line tangent to the chin and upper lip with the NB line.16 Holdaway said the ideal face has an H-angle of 7 degrees to 15 degrees, which is dictated be the patient’s skeletal convexity.16 The aesthetic plane (E-line) as described by Ricketts, describes the ideal position of the lower lip as two millimeters behind the E-line.17 Merrifield 18 said the Z-angle measurement and the profile line provides an accurate critical description of the lower face relationship. The Steiner aesthetic plane 15 and the Riedel plane 19 have also been used to describe the facial profile. Another measurement used to study the soft tissue is the angle of convexity described by Legan and Burstone. 20 This angle formed by the soft tissue glabella, subnasale, and soft tissue pogonion.
The second way to analyse a lateral cephalogram is to display the normal data in the form of a template, which is an average tracing for the reference group or perhaps a synthetic ideal23. It is more or less appropriate for any given patient, depending on how well that person is a representative of the reference group. Moorrees developed a mesh template this was established about 50 years ago, and updated in 1976 which was developed from males and females with a broad range of normal occlusion21 24. However, questions have been raised with regard to its relevance to today’s version of the ideal profile given the trend toward a more protrusive lower face.11,25
Arnett and coworkers22 in 1999 studied 46 Caucasian models to establish a set of more contemporary norms with the soft tissue cephalometric anaylsis. These are a series of ideal angles and measurements found in models with good facial balance and harmony. Arnett emphasizes the use of his anaylsis for implications of orthognathic surgery and orthodontics 22. Arnett’s norms show a fuller lower face and more projection than seen on Moorrees’s mesh template.
Assessors of the aesthetic facial profile have also differed, some using mixed panels of dental staff members, students and laymen 5, staff members from plastic surgery departments 26, artists 27, the general public 9,19,28-30 or a panel of judges 31. Some of these investigations compared cephalometric measurements of individuals selected for beauty with standards obtained from cases with excellent occlusions 9,19.
Several studies have looked at profile aesthetics. Cox and Van der Linden32 compared the aesthetic standards of I0 orthodontists and 10 lay persons. After grading full-head silhouettes for good facial balance in grades from best to worst, it was concluded that the cephalometric radiographic analysis did not show statistically different evaluations between the two groups. The persons with poor facial aesthetics had convex faces. In a study by Czarnecki and coworkers33 had 545 professionals evaluate androgynous facial silhouettes. These silhouettes had varied nose, lips and chin relationships and changes in convexity. They reported that a straighter profile was preferred in males, and slightly convex in females. The unfavourable profiles where those with an extremely retrusive chin or an excessively convex profile.
More recently, Naini and coworkers34 (2011) assessed patients perceptions of mandibular retrusion and protrusion. Fifty patients before surgery (T1) and then again after surgery (T2) rated profile silhouettes. They reported little difference between T1 and T2 and reported that the more severe the retrusion or protrusion the lower the rating of the images. Abu Arqoub35 (2011) looked at perception of profile attractiveness with different antero-posterior and vertical proportions. One male and one female had their profile photographs digitally altered and 454 native Jordanians of various ages and professions rated their attractiveness. The Class I male profile with a normal lower face height and Class I female profile with reduced lower facial height were ranked as the most attractive. As the vertical and AP dimensions diverged from normal the attractiveness decreased. The evidence appears to show that raters, whether laypeople, surgeons, dentists or orthodontist find the Class I profile the most attractive. However, there are still variations within a Class I profile, tending more protrusive or more retrusive.
Do we base our facial profile goals on historical norms which appears to be a Class I profile tending more retrusive, or do we base them on models in the late 90s whose profiles are tending more protrusive? Since the subject of facial aesthetics is of significant importance to not just to orthodontists but all people, everywhere. The ultimate source of our aesthetic values should be the people, not just orthodontists. The aim of this study is to assess people’s perception of facial profile attractiveness comparing historical and contemporary norms.
The last page of the survey asked about the difficultly of rating the images, and the difficulty of seeing differences between the images.
Six groups of raters was chosen for the study, including laypersons, dentists, dental students, orthodontists, plastic surgeons, and oral surgeons.
A convenience sample of 6 groups of raters were chosen for this study. There was a total of 382 raters. This included 66 dentists, 61 dental students, 133 laypersons, 88 orthodontists, 10 oral surgeons, and 24 plastic surgeons. The laypersons comprised of a selection of blue and white collar workers and undergraduate students from a local university. All groups had both male and female raters, however the specialist groups had predominantly men. The raters were given a small amount of information about the project and instructions about the method of rating. The raters did the survey independently to prevent dilution of their ratings because of other opinions.
The survey was divided into 2 parts. The first part of the survey consisted of viewing all 5 images of each subject and selecting the most preferred image (see figures 1 and 2) The second part of the survey randomly showed each of the images, giving 30 images in total. These were rated on a 5 point likert scale from “more attractive” to “less attractive” (see figure 3).
The effects o f the factors of occupation, age, gender, previous cosmetic surgery, previous orthodontic treatment, and ethnicity were tested against the preferred profile image for each individual using multivariate analyses to determine if there was statistical significance. For the second part of the survey mean attractiveness values were calculated for each image to look for trends and significance between the factors.
All analysis were carried out with SAS/STAT software, version 9.3 (SAS, Cary, NC) with all graphics produced using SPSS version 20.0 (SPSS, Chicago, Ill).
There was a total of 382 raters comprising of 173 females and 209 males. Ethnicity included 198 (52%) Caucasian, 85 (22%) Mongoloid, 48 (13%) Indian and 51 (13%) in the Other category consisting of a wide range of ethnicities. Less than 2% had had cosmetic or orthognathic surgical treatment, and 38.7% had had orthodontic treatment (see table 1).
There appears to be a trend showing that raters’ occupation has an influence on how attractiveness was rated. A trend can be seen that the plastic surgeons, oral surgeons, and orthodontists tend to prefer a mid to more protrusive profile (figure 4). Whereas the dentists, dental students and laypeople appeared to have no preference in profile, with similar ratings between all the profiles. However, statistically, only 1 female subject (Subject G3) showed a statistically significant difference with plastic surgeons and dentists preferring a more protrusive profile, followed by oral surgeons, orthodontists, dental students then laypeople.
For male subject number 1 (Subject B1) a statistically significant difference was seen between the genders rating the images, with the male group preferring a more protrusive profile (figure 5). However, this gender difference is not seen for any other subjects.
The raters’ occupations also had a significant influence on how difficult they found rating the images, and how difficult they found telling the images apart. All groups found it moderate to very difficult. With the dentists, dental students, and laypeople finding it significantly more difficult. The orthodontists, oral surgeons and plastic surgeons did no find it easy, but overall rated less difficult than the previous group (see figures 6 and 7).
For the second part of the survey where the raters had to rate each image individually there was no significant difference see between any of the occupations or groups. All images appeared to get overall an average attractiveness to high attractiveness rating regardless of how protrusive or retrusive the images were.
Facial profile images were used as a means of presentation. It has been shown that photographs provide valid, reproducible, and representative ratings of dental and facial appearance 8. On the other hand, silhouettes have the advantages of subjectivity and simplification of facial aesthetics, discarding many extrinsic (hair style, make up) and intrinsic (skin complexion, emotional expression) factors that may influence the individual’s concept of beauty.
The success of orthodontic treatment is measured by many factors including smile aesthetics, facial aesthetics, and facial profile aesthetics. The facial profile is constantly used in treatment planning, surgical planning, and assessing treatment results and success. It is the basis for cephalometric analysis. However, the present study suggests that small variations in profile fullness are not noticed by a large proportion of the population. Those professionals (orthodontists, oral surgeons, and plastic surgeons) who evaluate profiles on a daily basis appear to have a stronger opinion in what they call “attractive”, whereas a small variation from historical to contemporary norms and are not considered significantly more attractive or less attractive to the general population.
It must be recognized that there are significant limitations with static profile images as they are 2-D images and it has become increasingly recognised that in the pursuit of optimal facial aesthetics the analyses must go beyond merely assessing a static profile silhouette.50,51
There are significant limitations to this study, however it does look at one small aspect of the facial aesthetics which is important when treatment planning.
Minor facial profile variations of lip and chin position do not have a significant influence on the perception of facial profile attractiveness among the general population.
Plastic surgeons, oral surgeons and orthodontists might have a tendency to find an objective need for treatment that is biased by their occupational focus and does not represent the patient’s subjective treatment needs.
There is a need for concordance among providers of specialist treatment, general dentists and the patients who receive treatment to ensure satisfaction with the results.
There are signficiant limitations given the two dimensional nature of this study, further research with a three dimensional dynamic representation of the face needs to be undertaken as technology progresses.
72. Drobocky OB, Smith RJ. Changes in facial profile during orthodontic treatment with extraction of four first premolars. American journal of orthodontics and dentofacial orthopedics. 1989;95:220-230.