Facial aesthetics and the assignment of personality traits before and after orthognathic surgery

Abstract

Processing and interpreting the face is generally very important because one is often required to make rapid decisions in life on the basis of meagre information. Ninety-two volunteers used a computer-assisted test battery to assess 40 profiles of patients (8 skeletal Class II and 8 skeletal Class III patients, each pre- and postoperatively, with 8 skeletal Class I photographs serving as controls). On a 7-point Likert scale the raters were asked to evaluate aesthetics and a few relevant personality traits (e.g. unintelligent, inhibited, aggressive, brutal). The photographs of the two patient groups were rated significantly less attractive and intelligent prior to surgery than the photographs of the control group. In respect of personality traits, the photographs of the skeletal Class III group differed more strongly from normal ones. In respect of aesthetics and intelligence, both patient groups benefited markedly from surgery. For some personality traits, significant interactions were found between the two groups on pre–post comparison. The method underlying the study is useful for evaluating the outcome of orthognathic surgery, but also indicates the strongly generalized and unconscious processes involved in the estimation of people’s personality traits, especially when these concern deviations from the socially normal condition.

The attractive or beautiful face has been a major focus in art and literature since time immemorial. Humans have been trying for centuries to manipulate their outward appearance in favour of the ideal concept of beauty. According to D ion et al. , a person’s attractiveness is correlated with a number of positive traits. Even when selecting a partner, beauty plays a major role: more attractive individuals have more sexual contacts, more social relationships, and their interpersonal interactions are more satisfactory . Interculturally, there are universal preferences regarding the selection of a sexual partner: smooth, regular and soft skin, shining hair, and clear eyes. These are indicators of a person’s state of health, and the intensity of these characteristics is deemed attractive in all cultures . A number of general preferences apply to one’s perception of beauty: a youthful appearance, symmetry, averageness, and the intensity of gender-specific signs of maturity .

The term ‘averageness’ in this context is used to denote specific physical characteristics of a face that constitute a ‘mean’ of several individual faces. The anthropologist Francis Galton discovered, a long time ago, that an image composed of several superimposed photographs was deemed more attractive than the individual photographs.

In recent studies, advanced computer techniques have permitted individual photographs to be ‘mixed’ digitally to generate an average face. The latter has been rated more attractive than the original photographs .

Orthognathic surgery is routinely used today to correct skeletal dysgnathias for functional, and especially for aesthetic reasons . The majority of patients are satisfied with the outcome of orthognathic surgery .

Any improvement in appearance brought about by orthognathic surgery is associated with better psychosocial adjustment . Personal relationships were also reported to be improved . Initial impressions of a person are directly connected to their face. Processing and interpreting faces is generally very important in daily life because one is frequently required to make rapid decisions on the basis of rather meagre information .

In this context, the phenomenon of interpretation and the assignment of traits are interesting, especially when one has to assess people who do not correspond to social ideals or standards. In addition to aesthetic interpretation, assignments by way of ‘implicit personality theories’ are also worthy of mention (i.e. opinions as to personality traits that occur simultaneously and those that mutually exclude each other). Although these processes usually do not take place at the conscious level, they constitute an important foundation for inference in one’s perception of individuals . These processes are at work especially when a person meets a previously unknown person and lacks any additional information from previous meetings. Empirical evidence of this fact was obtained by means of the paradigm of ‘zero order acquaintance’ a sub-discipline of social psychology that was popular in the 1980s. According to this paradigm, a high degree of consensus was achieved in the raters’ assessment of persons who had been previously unknown to them. According to this theory, judgments were primarily made on the basis of existing information concerning physical appearance characteristics and its interpretation .

Such effects may specifically result from facial characteristics. A face that is marked by a dominant chin is usually assigned characteristics associated with leadership, whereas a so-called baby face is more easily associated with social submissiveness and compliance. In a recent report, L ivingston and P earce presented the relative nature of research results concerning factors such as ethnic groups, summing up this phenomenon under a term they refer to as the teddy-bear effect. The authors were able to show that the so-called baby face is interpreted differently in the context of financial success when the faces of Afro-Americans versus Caucasians are evaluated in terms of their leadership qualities.

The aim of the present investigation is to analyse how aesthetics and certain personality traits concerning patients with dysgnathia are assessed by those unaffected by this condition and who are not related or acquainted with the patients. Special attention was given to whether one’s assessment of a patient is significantly altered after orthognathic surgery, and whether significant differences exist in comparison with the normal population. A distinction is made between the dimensions of appearance and personality.

Materials and methods

Between 1999 and 2005, 208 patients (aged 14–59 years; mean 25.46 years) underwent orthognathic surgery at the authors’ clinic. Of these, 70 patients who fulfilled the following criteria were selected: they had been referred for orthognathic surgery by an orthodontist; were female; and were between 17 and 29 years of age at the start of therapy. This age spectrum is a time slot during which patients are no longer in puberty, yet demonstrate no obvious signs of ageing. A further inclusion criterion was the availability of profile photographs prior to the start of the orthodontic therapy, and after completion of orthodontic therapy, but at least 6 months postoperatively. Photographs of patients who had undergone other operations in addition to orthognathic surgery (such as correction of the nose) were excluded from analysis. Of these 70 patients, 16 (8 with Class II and 8 with Class III) who had had obvious dysgnathia (visible even to a lay-person) on their preoperative profile photographs, and had achieved an attractive aesthetic outcome postoperatively, were selected by three experts (K.S., R.J., G.M.). All of the selected Class III patients and four Class II patients underwent a bimaxillary procedure whilst the remaining four Class II patients underwent isolated mandibular advancement.

In order to obtain standardized conditions and keep the patients’ background variables (such as hairstyle, colour of hair, clothing, jewellery) constant, only the surgically altered portion of the face between the eyes and the lower margin of the mandible were cut out of the postoperative photograph by means of computer technology. The altered portion of the face was then pasted on the preoperative photograph. Hard contour transitions were evened out if necessary. Colours and tones were adjusted using Photoshop. The result was a postoperative photograph that differed from the preoperative one only in terms of the change effected by the operation (nose, cheeks, maxilla and upper lip, and mandible and lower lip). All other parts of the face such as the eyes, ears, and hair as well as clothes remained identical. Thus, it was ensured that aesthetics and personality would not be assessed on the basis of varying environmental variables, but exclusively on the basis of the different profile characteristics of the photographs ( Figs 1 and 2 ).

Fig. 1
Photograph of a patient with skeletal Class II (a) before and (b) after orthognathic surgery.

Fig. 2
Photograph of a patient with skeletal Class III (a) before and (b) after orthognathic surgery.

The eight photographs of Class I patients were selected from the patients in the authors’ clinic by K.S. on the basis of a ‘clinical orthodontic and lateral X-ray analysis’ ( Fig. 3 ). The following prerequisites were applied: female, aged 17–29 years, dental and skeletal Class I, overjet and overbite between 1 and 3 mm with crowding of maximum 2 mm/jaw.

Fig. 3
Photograph of a patient with skeletal Class I (control group).

Raters sample

The inclusion criteria used to select raters for the study were a minimum age of 17 years and voluntary participation in the study. A quota plan was created on the basis of gender and age. Equal distribution in terms of gender (male/female) and age (younger than 30 years/older than or equal to 30 years) was ensured. The median age of the raters was selected in this manner because the patients on the photographs were young. The raters had to be ‘naïve’ regarding the level of research, so they had no personal experience of orthognathic surgery and no contact with such surgery in their immediate social environment. Special expertise in aesthetics or art was regarded as an exclusion criterion. All tests were performed by one of the co-authors (B.B.).

Ninety-two raters were asked to evaluate 40 portrait photographs of female patients in profile: 8 of Class I, 16 of Class II (8 pre and 8 post), and 16 of Class III patients (8 pre and 8 post).

Using a randomisation technique, 10 types of presentations were created; each consisted of the same photographs, but presented in a different sequence. An expert (R.J.) checked the different types for potentially biasing effects. Such effects included, for instance, two photographs of a single patient in immediate sequence or frequent presentation of photographs of a specific type of dysgnathia. Five equivalent parallel forms of the test battery were selected and presented alternately for the purpose of testing. The eight pairs of traits were asked about in a fixed sequence for each photograph. Every photograph had to be assessed individually by the raters on a 7-point Likert scale. After a brief explanation of the test procedure, the raters were left alone in a quiet room, but could speak to the coordinator of the experiment (B.B.) at any time.

After the rating had been submitted, the next photograph was presented automatically. An opinion given once could not be modified ( Table 1 ).

Table 1
The 7-point Likert scale and what the ratings signify for the eight dimensions included in the investigation.
1 2 3 4 5 6 7
Absolutely Very much Quite Neither/nor Quite Very much Absolutely
Ugly Beautiful
Unpleasant Pleasant
Unattractive Attractive
Unintelligent Intelligent
Aggressive Good-natured
Inhibited Confident
Brutal Gentle
Dominant Flexible

Statistics

SPSS 16.0 for Windows was used for statistical analysis of the data. Photographs of Class I persons were treated as control photographs and were presented only once to the raters, because control subjects had not undergone surgical treatment. Evaluations were doubled for the purposes of statistical between-group comparisons pre- and postoperatively.

These data were used as an ‘anchor’ for the respective dimension being evaluated. Owing to lack of homogeneity of variances, all between-group outcome comparisons were carried out by parameter-free procedures, namely the Kruskal–Wallis rank variance analysis. In case of a significant Kruskal–Wallis test, multiple comparisons by means of Mann–Whitney U -tests were performed, taking into account the alpha error correction due to the anticipated cumulative effect. Temporal comparisons in the individual groups were performed using t -tests for paired samples. For the purpose of analysis, the level of significance was set at P < 0.01.

Results

Of 92 raters, 44 (48%) were men and 48 (52.2%) women. Their mean age was 32.02 years (SD = 11.08, range 17–63 years). No significant differences were found in respect of the five parallel forms ( P = 0.095). The grand means of all submitted ratings of the five different pre-given forms were between 3.60 (minimum, parallel form 1) and 3.87 (maximum, parallel form 3). The results for all the dimensions are given in Table 2 .

Table 2
Descriptive statistics for all dimensions pre- and postoperatively.
Class II Class III Class I
Pre Post Pre Post Control group
Dimensions Mean (SD) Mean (SD) Mean (SD) Mean (SD) Mean (SD)
Ugly/beautiful 2.24 (0.86) 3.45 (1.29) 2.21 (0.92) 3.33 (1.18) 3.76 (1.24)
Unpleasant/pleasant 2.84 (1.10) 3.51 (1.35) 2.87 (1.36) 3.68 (1.46) 3.94 (1.38)
Unattractive/attractive 2.35 (0.95) 3.43 (1.35) 2.38 (1.06) 3.29 (1.25) 3.77 (1.27)
Unintelligent/intelligent 3.52 (0.90) 4,15 (0.97) 3.68 (0.98) 4.15 (0.99) 4.41 (0.91)
Aggressive/good-natured 4.43 (1.15) 4.42 (1.07) 4.01 (1.29) 4.48 (1.20) 4.55 (1.04)
Inhibited/confident 3.75 (1.37) 4.38 (1.30) 4.28 (1.34) 4.46 (1.31) 4.67 (1.14)
Brutal/gentle 4.38 (1.01) 4.32 (0.98) 3.90 (1.10) 4.30 (1.04) 4.38 (0.88)
Dominant/flexible 4.10 (1.44) 3.76 (1.30) 3.39 (1.33) 3.76 (1.36) 3.68 (1.23)
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Jan 26, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Facial aesthetics and the assignment of personality traits before and after orthognathic surgery
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