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Preferences of AP position of the straight Caucasian facial profile
Several investigators have compared the perception of profile attractiveness between professional and non-professional people, different groups of cli…
Introduction
Schwartz suggested that there are subdivisions of a Class I profile which are generated by horizontally shifting the lower anterior face. Specifically, the lower facial half can slide forward in the antero-posterior direction, which creates a "straight ante profile", whereas a "straight retro profile" holds a lower facial height more to the rear (Fig. 1).
These two profile lines should be regarded as “straight” variations of the average. Schwartz also stressed that the head position is essential for evaluating a face in profile. Orientation of the head should occur according to the Frankfurt horizontal (FH). The line perpendicular to the FH ideally contains three outline landmarks (sellion, subnasal point, and the upper lip), and serves as a reference for the straight average profile.
Materials and methods
Portrait images were taken of one male and one female professional model with a Class I occlusal relationship. The models were seated and looking at a perpetual point and were oriented according to the Frankfurt plane.
Frankfurt plane:
The Frankfurt horizontal plane is defined clinically as a line connecting the tragion (the notch in the superior margin of each tragus) and orbitale (the lowest palpable point on the inferior orbital rim)
Based on the subdivisions of Schwartz there were nine variations constructed for each profile (Fig. 2)
The three acceptable profile types according to Schwartz area straight average profile (also called the biometric face), a straight “retro”-profile (where the lower anterior face is in a more dorsal position), and a straight “ante”-profile (where the lower anterior face is in a more ventral position).
The maxilla and mandible are as one entity with a Class I occlusion with positive lip step. There were also six extra profiles constructed using the warping tool of Adobe Photoshop CS3. These extra profiles were generated as one third of the distance between the most ventral or most dorsal position of the lower anterior face according to Schwartz, and the average.
A digital template was used as a base for warping the standard profile to a 2/3 retro profile, a 1/3 retro profile, a 1/3 ante profile, a 2/3 ante profile, a 4/3 ante profile, and a 5/3 ante profile. As a result, a full straight retro profile (Full-), a 2/3 straight retro profile (2/3-), a 1/3 straight retro profile (1/3-), a straight average profile (Av), a 1/3 straight ante profile (1/3þ), a 2/3 straight ante profile (2/3þ), a full straight ante profile (Fullþ), a 4/3 straight ante profile (4/3þ), and a 5/3 straight ante profile (5/3þ) made up the nine profile lines for the female (Fig. 3) and the male model (Fig. 4).
An internet site was established to reach as many people as possible, and a request was sent by email to participate in a scientific experiment.
The profiles were shown at random as a slideshow, which was manageable with a mouse click. Ratings of attractiveness were ranked with a visual analogue scale (VAS) that ranged from 0 (very unattractive) to 100 (very attractive). Participants were only allowed to score once in order to have a consistent group of observers. There was no time limit to complete the assessment in order not to cause mental pressure.
Results
A group of 1707 white observers (from 3145 website visitors) was obtained through the internet by means of an exponential mailing list. The mean age of the participants was 27.7 ± 11.1 years. The ages of the participants ranged from 18 to 78 years. From the sample of observers there were two age groups generated: under 30 years and older than 30.
Regarding the female model, the profiles assigned the highest scores by the entire study sample were the straight average profile and the 2/3 straight ante profile. The profile types straight full retro, 5/3 straight ante, and 4/3 straight ante seemed to be least favoured by the study sample (Table 1).
For the male model, the profiles assigned the highest scores by the entire study sample were the straight full ante and the 2/3 straight ante. A distinct consensus was found for the least favourable profile types for the male model, which were, in descending order, 1/3 straight retro, 2/3 straight retro, and straight full retro.
Differences between sexes
Male and female raters both assigned the highest scores to the straight average profile and the 2/3 straight ante profile for the female model.
Female participants gave higher scores for every type of female profile in comparison to men, but these scores were only significant for the average (p = 0.008), 2/3 retro (p < 0.001), full retro (p < 0.001), and 5/3 ante profiles (p = 0.017). The least attractive female profiles seemed to be all of the retro profiles, especially the straight full retro, the straight 5/3, and the straight 4/3 ante profiles.
For the male model, the profiles of preference were the full ante, 2/3 ante, 4/3 ante, and 5/3 ante profiles. These results were all highly significantly different for male and female participants, with women assigning higher scores (all p < 0.001). The male profiles considered to be the least attractive were 1/3 retro, 2/3 retro, and full retro (all of which are retro profiles); however, these rates were significantly lower for the female group (p = 0.022, p = 0.002, and p = 0.017, respectively) (Table 1).
Differences between age groups
There were significant differences between those equal to or younger than 30 years of age and the group of people over 30 years.
Relative to the younger group, older participants assigned higher scores to all of the profile types for the female model. In particular, these scores were significantly higher for the full ante (p = 0.002), the full retro (p = 0.002), the 5/3 ante (p < 0.001) and the 4/3 ante profiles (p < 0.001).
Considering the male model, it appeared that people aged 30 years or younger tended to give higher values to the profiles with a more protruded lower anterior face than did those older than 30 years, with those specifically being the 2/3 ante (p = 0.004), the full ante (p < 0.001), the 4/3 ante (p = 0.031) and the 5/3 ante profiles. The scores given by people of 30 years or younger for the less protruded and retruded profile types and full retro profile were lower than those given by the older group (p < 0.001) (Table 1).
Conclusion
In a Caucasian population, there is a strong tendency towards a more protruded lower anterior and midface, especially in men. A straight full ante profile is preferred in men, while a straight full retro profile is strongly disliked. The straight average profile and straight 2/3 ante profile are preferred in females, while straight 5/3 and 4/3 ante profiles are disfavoured. Differences were found in ratings by men and women.
The age of the assessor had no influence on the classification of the profile types, however some significant differences in assigning scores were found. These results show a trend towards more protrusion in facial profiles.
