What do black patients expect from orthodontic treatment? The aesthetic perception of facial profile between orthodontists and black laypersons

ABSTRACT Objective: To evaluate the influence of anteroposterior position of the soft tissue on facial attractiveness in black people, and compare the perception of aesthetics and satisfaction between orthodontists and black laypersons. Methods: The sample was composed of 69 orthodontists and 69 laypersons of black ethnicity (n=138). Facial profile photographs of two black volunteers, a man and a woman, were digitally manipulated to change the position of the lips and chin, by making gradual changes of 4mm in relation to the true vertical line, simulating advance or retrusion of the soft tissues by -2, -6, -10, +2, +6, +10mm, totalling six images per sex. The photographs were classified by the research participants using a visual analogue scale (VAS), from 0 (unpleasant) to 100 (pleasant). The results were analyzed by generalized linear model and by the Fisher’s exact test, considering the level of significance of 5%. Results: The orthodontists and black laypersons considered straight profiles the most pleasant. The two groups classified the male profile as being more unpleasant in comparison with the female facial profile, which was concave. When evaluating all the images together, the image most indicated as being the most pleasant, once again, was the one with the straight profile, for both sexes. Conclusion: The influence of orthodontists’ and laypersons’ aesthetic perception on evaluating the facial profile of blacks was similar. The straight profile was classified as the most pleasant and the concave, as the most unpleasant.


INTRODUCTION
Orthodontic patients are of different ethnicities and educational levels, and their perception of beauty also differs. From this perspective, in orthodontic treatment, concepts and norms must be adapted in order to avoid a standard outcome of treatment for all patients. Therefore, orthodontists must perceive the patient as a unique being, whose self-esteem after conclusion of the treatment is as important as the technical results achieved. 1 There is considerable variability in the faces of black people, which differ from those of other races. Thus, it is not suitable to apply the aesthetic standards of soft tissue that have been defined for Caucasian patients. The concept of beauty is subjective, an individual preference, and no racial study can be applicable to all individuals of other races. 2 Black persons have facial features such as acute nasolabial angle, higher and lower lips protrusion, a more pronounced mentolabial groove, and an increased lip-chin ratio, 3 when compared with Caucasians.
Therefore, facial profiles can be considered esthetically unpleasant even in the absence of conditions of dental malocclusion.
A typical example is bimaxillary protrusion, a characteristic prevalent among black persons. This results in a convexity of the facial profile that is frequently unacceptable, in spite of an Angle Class I with normal overjet and overbite, with well-aligned dental arches. [4][5][6] Souza DB, Oliveira AI, Gouvêa GR, Santamaria-Jr M -What do black patients expect from orthodontic treatment? The aesthetic perception of facial profile between orthodontists and black laypersons 5 The soft tissue and bone structure in black individuals are more protruded, in comparison with the pattern for white individuals. A demand for orthodontic treatment to reduce labial protrusion is common among black patients. 7 Changes in dentofacial tissues after orthodontic treatment and retrusion of the maxillary and mandibular incisors result in decreased convexity of soft tissues. 8 Due to the scarcity of aesthetic standards for facial analysis of black persons, in the literature, [9][10][11] this study was conducted to help orthodontists in the quest to achieve more satisfactory treatment results for black patients. Therefore, the aim of this study was to evaluate the influence of soft tissues anteroposterior position on the facial attractiveness in black people, and compare the perception of aesthetics and satisfaction of orthodontists and black laypersons.   Each evaluation was made by measuring the distance, in millimeters, from 0 (UNPLEASANT) to the mark made by the evaluator. [18][19][20] The photographs were projected on a 13.3-in portable LCD screen. The evaluators were initially asked to analyze the side view photographs, one by one, each photo for 15 seconds, without the possibility of going back. 19,21,22 Afterwards, they were asked to analyze all the images simultaneously, and select the most pleasant and the most unpleasant profile, for an estimated time of 30 seconds, for each sex.

STATISTICAL ANALYSIS
Initially, descriptive analysis of the age and sex of the evaluators was performed. Exploratory analysis of the perception and satisfaction score data was made, indicating that the data did not meet the presuppositions of a parametric analysis. Therefore, data were analyzed by generalized linear models, considering that all the observers evaluated all the images. Analysis of the images chosen as being more pleasant or more unpleasant was performed by the Fisher's exact test. The analyses were performed with the R program, considering the level of significance of 5%.
Souza DB, Oliveira AI, Gouvêa GR, Santamaria-Jr M -What do black patients expect from orthodontic treatment? The aesthetic perception of facial profile between orthodontists and black laypersons 10 Table 1 shows that 71.7% of the evaluators were of the female sex, and the mean age of the sample was 36.7 years, with a standard deviation of 11.3 years. Table 2 shows the comparisons between the groups of evaluators, relative to the perception and satisfaction scores attributed to each photographic image. For the images of the man, the orthodontists attributed higher scores to the image with the change of -2mm in relation to the true vertical line, which did not differ significantly only from the image with the change of + 6mm. The black laypersons did not distinguish the changes of +2mm, +6mm, -2mm and -6 mm (p>0.05), these being the images with the highest scores.

RESULTS
Moreover, for the male, the orthodontists and black laypersons attributed lower scores to the profiles with +10 and -10mm, without significant difference between these two images (p>0.05).
For the woman, both orthodontists and blacks attributed higher scores to the change of +2mm, and lower scores to the change of +10mm. The orthodontists attributed significantly lower scores than the black laypersons (p<0.05) to the male patient with change of -10mm, and to the female patient with change of +10mm. The orthodontists also attributed lower scores to the woman than to the man (p<0.05) for the change of +6mm.
The two groups attributed significantly lower scores to the man (p<0.05) for the change of -10mm.

DISCUSSION
Orthodontists must be aware of the aesthetic patterns of their patients, since the parameters of beauty of each of them may be different. 22 This is a great challenge faced by orthodontists who prefer to establish an adequate relation of occlusion and satisfactory facial aesthetics, while their patients frequently prioritize the best aesthetic results and a well-balanced appearance on conclusion of treatment. 23,24 Due to these differences, when professionals evaluate their patients' profile, they can decide about a treatment plan that will satisfy their patients. 17 In a study that compared the differences between laypersons and orthodontists in assessing the correlation between attractiveness and facial components, it was found that the contribution of teeth to facial attractiveness was significantly smaller than and Afro-Brazilians. 6 The profile selected represented a less convex pattern than the type that was considered normal for black individuals, suggesting that the objective of the treat- Black patients, like everyone else, expect to have more beautiful faces at the end of orthodontic treatment. Therefore, the aesthetic perception must be considered in the treatment plan, and will influence the decision about the treatment strategy to be carried out by the orthodontist.