Keywords
esthetics - nose - image processing - computer-assisted - photography
Introduction
An esthetic nose plays an important role in the definition of a face's beauty. This
is not only due to its central location on the face, but also because it is among
the first facial features that draw an observer's attention.[1]
[2]
[3] From ancient times, humans have sought to define the ideal nasal parameters, resulting
in the neoclassical cannons that defined the ideal nose from average European-American
facial features under the influence of ancient Greek and Renaissance findings.[4]
[5]
Although plastic surgeons use neoclassical cannons as a goal in their procedures,
they are not desirable for all ethnicities.[2]
[3]
[6]
[7]
[8] These inconsistencies highlight an insufficiency in the concept of universally ideal
nasal characteristics and point to the importance of regional research so that plastic
surgeons may reach satisfactory results in different societies.
Despite many studies trying to find ideal nasal characteristics using two-dimensional
(2D) pictures in different ethnicities,[1]
[3]
[6]
[7]
[9] this format is not as practical as three-dimensional (3D) imaging to represent body
part characteristics such as nasal features alongside other facial subunits.[8]
To our knowledge, this is one of the first studies evaluating ideal nose shapes using
3D technology in the Middle East. The purpose of our study is to evaluate viewer opinions
on the esthetic nose using 3D imaging with specific focus on five parameters, including
nasofrontal angle (NFA), nasolabial angle (NLA), dorsal height (DH), alar width (AW),
and tip projection (TP).
Methods
This cross-sectional study was authorized by the Institutional Review Board, and its
execution adhered to the ethical principles set forth in the Declaration of Helsinki
regarding human subject research. Written consent was obtained from the two selected
models (one male and one female) in the facial plastic clinic of a tertiary university
hospital from 2020 to 2021, allowing their images to be used for research and publication
purposes. The inclusion criteria for male and female models in the study were Iranian
ethnicity, aged between 20 and 29, body mass index between 18 and 24.9, absence of
craniofacial deformity (such as cleft nose), and no previous history of esthetic surgery
(such as rhinoplasty) or significant facial trauma. The subjects were photographed
using a Vectra H1 (Canfield Scientific, Parsippany, NJ). The Mirror software (Canfield
Scientific, Inc., NJ) and the Vectra Analysis Module (Canfield Scientific, Inc., Fairfield,
NJ) were used respectively to measure and modify to desired scales the NFA, NLA, TP,
AW, and DH of the 3D photographs of the models.
The NFA is defined as the angle formed by the intersection of the line drawn from
the nasion tangential to the superior surface of the nose and the line from the soft
tissue glabella to the nasion ([Fig. 1A]). The NLA is defined as the angle formed by the intersection of the lines tangent
to the labial surface of the upper lip on the lateral view and the inferior border
of the nose ([Fig. 1B]). We also described the level of the nasal dorsum in relation to a line connecting
the nasal tip-defining points to the radix ([Fig. 1C]). The distance between the left and right ala was defined as AW ([Fig. 1D]). The nasal TP was described as the ratio of the length of the line from the alar
crease to the nasal tip that is perpendicular to the line tangent to the alar crease
divided by the length of the line from the nasion to the nasal tip ([Fig. 1E]).
Fig. 1 Five different parameters were modified in the selected female subject including
(A) nasofrontal angle (NFA), (B) nasolabial angle (NLA), (C) dorsal height (DH), (D) alar width (AW), and (E) tip projection (TP).
NFAs of 125, 130, 135, 140, and 145 degrees were chosen for both male and female noses.
NLAs of 95, 100, 105, 110, 115, and 120 degrees were selected for the female model,
and NLAs of 85, 90, 95, 100, and 105 degrees were chosen for the male model. The DHs
selected for the female nose included a straight dorsum, 1- and 2-mm concave dorsums,
and a 1-mm convex dorsum in comparison to the straight nasal dorsum in the female
model. The DHs selected for the male nose included a straight dorsum, 1- and 2-mm
concave dorsums, and 1- and 2-mm convex dorsums compared with the straight nasal dorsum
in the male model. The AWs selected for the male and female noses consist of a width
equal to the intercanthal distance, widths 2 and 4 mm narrower than the intercanthal
distance, and widths 2 and 4 mm wider than the intercanthal distance. For TP, the
ratios of 0.55, 0.57, and 0.59 were selected for both male and female noses. By changing
only one of the nasal parameters in each picture, a total of 46 3D faces were generated.
The 3D faces were merged to make a single 21-second length video clip for each nasal
parameter.
The required sample size for the study was determined using G*Power (version 3.1.9.2
for Windows, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany) with analysis
of variance, which resulted in 200 participants with a margin of error of 5% and power
of 80%. A two-part questionnaire was developed based on the videos and subsequently
filled out by patients willing to participate in the study ([Supplementary Data S1]). The volunteers were asked to sit at a desirable distance from a 20-inch monitor
and select the most esthetically pleasing option from the displayed alternatives ([Supplementary Video S2]). No time limitation was placed on the questions, and the videos were replayed until
participants chose an answer. The volunteers were also asked about their age, sex,
education, residency, and prior history of esthetic surgery. Based on the Medical
Subject Headings keywords, age groups were divided into adolescent, young adult, adult,
middle-aged, and aged. Any incomplete questionnaires were excluded, and the related
answers were not considered in the study results. Non-Iranian participants living
in Iran and Iranians who had lived abroad were excluded to reduce confounding cultural
effects on responses.
Supplementary Video S2
All data were collected and analyzed anonymously using IBM SPSS Statistics for Mac,
version 16 (IBM Corp., Armonk, NY). The chi-square and Fisher's exact tests were used
to compare categorical values, while the t-test was used to compare numeric values. Two-sided p-values of less than 0.05 were considered statistically significant.
Results
A total of 203 volunteers partook in the study. The majority were female (79.8%),
25 to 44 years old (65.5%) with a mean age of 31.2 ± 9.9, had a bachelor's degree
(38.4%), and a history of esthetic surgery (59.6%). Participants were from 35 different
cities in Iran, but most of them lived in Tehran (63.5%; [Table 1]).
Table 1
Demographic characteristics of the population
|
Demographic characteristics
|
N (%)
|
|
Age
|
|
|
Adolescent (< 18 y)
|
13 (6.4)
|
|
Young adult (19–24 y)
|
39 (19.2)
|
|
Adult (25–44 y)
|
133 (65.5)
|
|
Middle aged (45–64 y)
|
17 (8.4)
|
|
Aged (> 65 y)
|
1 (0.5)
|
|
Gender
|
|
|
Male
|
41 (20.2)
|
|
Female
|
162 (79.8)
|
|
Residency
|
|
|
Tehran
|
129 (63.5)
|
|
Non-Tehran
|
74 (36.5)
|
|
Education
|
|
|
High school
|
9 (4.4)
|
|
Diploma
|
61 (30.1)
|
|
Bachelor's degree
|
78 (38.4)
|
|
Master of science
|
33 (16.3)
|
|
PhD (Doctor of Philosophy)
|
22 (10.8)
|
|
Previous esthetic surgery
|
|
|
Yes
|
121 (59.6)
|
|
No
|
82 (40.4)
|
Nasofrontal Angle
For all volunteers in this study, 133.55 ± 4.53 degrees was the most esthetic female
NFA with a median and mode of 135 degrees. The most preferred female NFA was 135 degrees
(43.8%), while only a small portion of participants considered 145 degrees esthetic
for the female NFA (3.4%). The most esthetic male NFA was 137.64 ± 4.20 degrees among
all participants with a median and mode of 140 degrees ([Fig. 2]). Of the participants, 43.8% chose 140 degrees as the most esthetic male NFA. The
least esthetic male NFA was 125 degrees with only 2% of volunteers selecting it. Age
was found to have a significant impact on participant perception of the most esthetic
female NFA. Volunteers aged between 25 and 44 years preferred more acute NFAs for
females than comparators (39.1% vs. 20% for 130 degrees, p-value = 0.051). On the other hand, young adult participants preferred acute female
NFAs less than older age groups (15.4% vs. 36.6% for 130 degrees, p-value = 0.050). There was no statistically significant difference among the age subgroups
about male NFAs or the residency subgroups about female and male NFAs (p-value = 0.057 and 0.307, respectively; [Fig. 3] and [Table 2]).
Fig. 2 The nasofrontal angle (NFA) was modified to 125, 130, 135, 140, and 145 degrees in
the selected male subject.
Fig. 3 Distribution of participant opinions regarding nasofrontal angle (NFA), nasolabial
angle (NLA), dorsal height (DH), alar width (AW), and tip projection (TP) based on
age group.
Table 2
Distribution and p-values of participant opinions regarding nasofrontal angle, nasolabial
angle, dorsal height, alar width, and tip projection based on gender, residency, and
history of previous esthetic facial surgery
|
|
Female nose
|
Male nose
|
|
Nasofrontal angle
|
Angle (degree)
|
125
|
130
|
135
|
140
|
145
|
p-Value
|
125
|
130
|
135
|
140
|
145
|
p-Value
|
|
Gender
|
Female
|
12 (7.4)
|
52 (32.1)
|
73 (45.1)
|
21 (13.0)
|
4 (2.5)
|
0.565
|
2 (1.2)
|
12 (7.4)
|
61 (37.7)
|
70 (43.2)
|
17 (10.5)
|
0.583
|
|
Male
|
4 (9.8)
|
14 (34.1)
|
16 (39.0)
|
4 (9.8)
|
3 (7.3)
|
2 (4.9)
|
2 (4.9)
|
15 (36.6)
|
19 (46.3)
|
3 (7.3)
|
|
Previous esthetic surgery
|
Yes
|
8 (6.6)
|
41 (33.9)
|
51 (42.1)
|
15 (12.4)
|
6 (5.0)
|
0.576
|
1 (0.8)
|
8 (6.6)
|
45 (37.2)
|
53 (43.8)
|
14 (11.6)
|
0.595
|
|
No
|
8 (9.8)
|
25 (30.5)
|
38 (46.3)
|
10 (12.2)
|
1 (1.2)
|
3 (3.7)
|
6 (7.3)
|
31 (37.8)
|
36 (43.9)
|
6 (7.3)
|
|
Nasolabial angle
|
Angle (degree)
|
95
|
100
|
105
|
110
|
115
|
120
|
p-Value
|
85
|
90
|
95
|
100
|
105
|
p-Value
|
|
Gender
|
Female
|
3 (1.9)
|
15 (9.3)
|
56 (34.6)
|
62 (38.3)
|
20 (12.3)
|
6 (3.7)
|
0.021
|
4 (2.5)
|
10 (6.2)
|
33 (20.4)
|
75 (46.3)
|
40 (24.7)
|
0.205
|
|
Male
|
1 (2.4)
|
13 (31.7)
|
12 (29.3)
|
11 (26.8)
|
3 (7.3)
|
1 (2.4)
|
1 (2.4)
|
6 (14.6)
|
12 (29.3)
|
14 (34.1)
|
8 (19.5)
|
|
Previous esthetic surgery
|
Yes
|
3 (2.5)
|
15 (12.4)
|
39 (32.3)
|
42 (34.7)
|
18 (14.9)
|
4 (3.3)
|
0.477
|
4 (3.3)
|
6 (5.0)
|
27 (22.3)
|
55 (45.5)
|
29 (24.0)
|
0.366
|
|
No
|
1 (1.2)
|
13 (15.9)
|
29 (35.4)
|
31 (37.8)
|
5 (6.1)
|
3 (3.7)
|
1 (1.2)
|
10 (12.2)
|
18 (22.0)
|
34 (41.5)
|
19 (23.2)
|
|
Dorsal height
|
Height (mm)
|
–2
|
–1
|
0
|
1
|
p-Value
|
–2
|
–1
|
0
|
1
|
2
|
p-Value
|
|
Gender
|
Female
|
9 (5.6)
|
18 (11.1)
|
94 (58.0)
|
41 (25.3)
|
0.528
|
1 (0.6)
|
20 (12.3)
|
90 (55.6)
|
41 (25.3)
|
10 (6.2)
|
0.883
|
|
Male
|
2 (4.9)
|
7 (17.1)
|
19 (46.3)
|
13 (31.7)
|
0 (0.0)
|
3 (7.3)
|
24 (58.5)
|
12 (29.3)
|
2 (4.9)
|
|
Previous esthetic surgery
|
Yes
|
6 (5.0)
|
17 (14.0)
|
63 (52.1)
|
35 (28.9)
|
0.541
|
1 (0.8)
|
5 (7.3)
|
52 (63.4)
|
23 (28.0)
|
1 (1.2)
|
0.037
|
|
No
|
5 (6.1)
|
8 (9.8)
|
50 (61.0)
|
19 (23.2)
|
0 (0.0)
|
17 (14.0)
|
62 (51.2)
|
30 (24.8)
|
11 (9.1)
|
|
Alar width
|
Width (mm)
|
–4
|
–2
|
0
|
2
|
4
|
p-Value
|
–4
|
–2
|
0
|
2
|
4
|
p-Value
|
|
Gender
|
Female
|
33 (20.4)
|
62 (38.3)
|
36 (22.2)
|
25 (15.4)
|
6 (3.7)
|
0.638
|
24 (14.8)
|
49 (30.2)
|
54 (33.3)
|
26 (16.0)
|
9 (5.6)
|
0.101
|
|
Male
|
6 (14.6)
|
18 (43.9)
|
10 (24.4)
|
4 (9.8)
|
3 (7.3)
|
6 (14.6)
|
7 (17.1)
|
15 (36.6)
|
6 (14.6)
|
7 (17.1)
|
|
Previous esthetic surgery
|
Yes
|
33 (27.3)
|
42 (34.7)
|
22 (18.2)
|
18 (14.9)
|
6 (5.0)
|
0.005
|
23 (19.0)
|
26 (21.5)
|
45 (37.2)
|
18 (14.9)
|
9 (7.4)
|
0.067
|
|
No
|
6 (7.3)
|
38 (46.3)
|
24 (29.3)
|
11 (13.4)
|
2 (3.7)
|
7 (8.5)
|
30 (36.6)
|
24 (29.3)
|
14 (17.1)
|
7 (8.5)
|
|
Tip projection
|
Ratio
|
0.55
|
0.57
|
0.59
|
p-Value
|
0.55
|
0.57
|
0.59
|
p-Value
|
|
Gender
|
Female
|
23 (14.2)
|
86 (53.1)
|
53 (32.7)
|
0.913
|
41 (25.3)
|
92 (56.8)
|
29 (17.9)
|
0.607
|
|
Male
|
6 (14.6)
|
20 (48.8)
|
15 (36.6)
|
13 (32.5)
|
20 (48.8)
|
8 (19.5)
|
|
Previous esthetic surgery
|
Yes
|
17 (14.0)
|
59 (48.8)
|
45 (37.2)
|
0.384
|
30 (24.8)
|
65 (53.7)
|
26 (21.5)
|
0.328
|
|
No
|
12 (14.6)
|
47 (57.3)
|
23 (28.0)
|
24 (29.3)
|
47 (57.3)
|
11 (13.4)
|
Nasolabial Angle
For the study population, 107.56 ± 5.20 degrees was the most preferred female NLA
with a median and mode of 110 degrees. The most esthetic choice for female NLA was
110 degrees (36.0%), while 95 degrees was represented as the least esthetic female
NLA with only 2.0% of the population selecting it. In this study, 98.92 ± 4.88 degrees
was the most esthetic male NLA with a median and mode of 100 degrees. Of the participants,
43.8% chose 100 degrees as the most esthetic male NLA. On the other hand, 85 degrees
was the least esthetic male NLA with only 2.5% choosing it. Gender statistically affected
participant opinions about the most esthetic female NLA. Male volunteers preferred
more acute female NLAs than female comparators (31.7% vs. 9.3% for 100 degrees, p-value = 0.021). We did not find a statistically significant difference between male
and female opinions about the most esthetic male NLA. Age also played an important
role in presumptions about male NLAs. The young adult group preferred more acute male
NLAs compared with other participants (33.3% vs. 19.5% for 95 degrees, p-value = 0.024). There was no statistically significant difference between the age
subgroups for female NLAs or the residency subgroups about female and male NLAs (p-value = 0.485 and 0.383, respectively; [Fig. 3] and [Table 2]).
Dorsal Height
The study findings indicate that the most desirable female DH was 0.03 ± 0.78 mm,
with a median and mode of 0 mm. Over half of the participants (55.7%) favored a straight
dorsum (0 mm) over other options, while the least acceptable choices were concave
DHs, with only 5.4% of volunteers choosing –2 mm. The most preferred male DH in this
study was 0.26 ± 0.75 mm, with a median and mode of 0 mm. The majority of the population
(56.2%) chose a straight dorsum over the other options. A male DH within –2 mm from
the base was the least desirable choice, with only 0.5% of the population choosing
it. Patients with a prior history of esthetic surgery preferred a straight dorsum
for the male nose more frequently than comparators (63.4% vs. 51.4%, p-value = 0.037). There was no statistically significant difference between residency
subgroups regarding female and male DHs (p-value = 0.335 and 0.644, respectively; [Fig. 3] and [Table 2]).
Alar Width
In this study, the ideal female AW was –1.09 ± 2.18 mm, with a median and mode of
–2 mm. Of the population, 39.4% selected the female nose that was 2 mm narrower than
the intercanthal distance. AWs wider than the intercanthal distance were least desirable.
Only 14.3% of the population chose the AW 2 mm wider than the intercanthal distance,
while 4.4% chose the AW 4 mm wider than the intercanthal distance. The ideal male
AW was –0.51 ± 2.26 mm with a median and mode of 0 mm. Among the volunteers, 34% chose
the male nose with an AW equal to the intercanthal distance. Like the female nose,
AWs wider than the intercanthal distance were the least desirable male features. Age
differences played an important role in participant opinion on the ideal female AW,
with a higher percentage of middle-aged volunteers preferring the AW equal to the
intercanthal distance compared with the other age groups (47.1 vs. 20.4, p-value = 0.015). There was no statistically significant difference between residency
subgroups regarding the preferences for female and male AWs (p-value = 0.474 and 0.802, respectively; [Fig. 3] and [Table 2]).
Tip Projection
The results showed that the ideal female TP is 0.57 ± 0.01, with a median and mode
of 0.57. More than half of the participants (52.2%) chose this ratio as the most esthetic
among the various options, while only a small percentage (14.3%) favored a ratio of
0.55. The most esthetic male TP was 0.56 ± 0.01, with a median and mode of 0.57. The
majority of the population (55.2%) chose 0.57 as the most esthetic feature for the
male TP, while only 18.2% of the population chose 0.59 as the most esthetic. There
was no statistically significant difference in the opinions of the residency subgroups
about female and male TPs (p-value = 0.077 and 0.664, respectively; [Fig. 3] and [Table 2]).
Discussion
The present study investigated the preferred nasal characteristics among Iranian patients.
Our findings demonstrated that the perception of nasal beauty is influenced by various
factors, including ethnicity, gender, age, and prior history of esthetic surgery.
A successful rhinoplasty procedure relies on not only a functional and esthetic nose
but also the satisfaction of the patient.
Although the neoclassical canons have been widely used as the standard for esthetic
parameters in rhinoplasty, the literature shows that the textbook ideal proportions
may not be acceptable for all ethnicities,[4]
[10] making research into the desirable facial characteristics of people in different
regions important.[11]
[12] The emergence of 3D imaging as a novel technology has provided a great opportunity
to assess the ideal nasal parameters of different ethnicities by overcoming the shortcomings
of 2D imaging.[13]
[14] Despite rhinoplasty being one of the most common plastic surgery procedures in Middle
Eastern countries,[15] there is a paucity of data on the ideal nasal characteristics for people from this
region. To our knowledge, this study is among the first to utilize 3D imaging technology
to identify the ideal nasal profile of the general population in the Middle East.
Based on the study conducted by Powell and Humphreys, the ideal NFA varies between
115 and 130 degrees.[16] However, our findings do not conform to neoclassical cannons by showing that Iranian
patients may prefer more obtuse NFAs. In line with our findings, Mafi et al have also
demonstrated wider NFAs to be more acceptable in Iran.[12] The influence of ethnicity on the ideal NFA is further supported by Yu et al research
conducted on Korean patients, which found that they preferred wider NFAs for both
males and females than the neoclassical facial standards.[17] These differences in preference can be attributed to morphological variations among
different ethnic groups. For example, Iranian patients have a straighter frontonasal
area, which can affect the position of the glabella, one of the key positions in NFA
measurement.[12]
The established articles define the ideal NLAs of 103 to 108 degrees for females and
95 to 100 degrees for males,[18]
[19]
[20] and our study indicates that the ideal NLAs for Iranian patients are consistent
with these neoclassical cannons. The results of Biller and Kim agree with ours in
that the ethnicities of the model and voters do not affect the preferred NLA, and
that younger participants tend to prefer more acute NLAs than older volunteers.[21] The outcomes of research by Sinno et al validate our own discoveries, showing that
a female NLA range of 104.9 ± 4.0 degrees is ideal, while for males, the ideal is
97.0 ± 6.3 degrees. No statistically significant differences were observed among gender
and age cohorts.[6] On the other hand, the results of Alharethy and Armijo et al are inconsistent with
ours by showing more acute ideal male and female NLAs than what is reported in the
literature.[10]
[22] Variations in methods used for NLA measurement may be the main reason for differences
in nasolabial values and thus divergences in outcomes. Leach recommended measuring
the NLA as the angle between the long axis of the nostril and the line perpendicular
to the Frankfurt horizontal plane.[23] Although this method is a better way of measuring NLA in faces with procumbent incisors
or protruding maxillae, the Frankfort horizontal line is less accurate on soft tissues.[21] Due to this shortcoming, determining the NLA as the angle between the labial surface
of the upper lip and the inferior border of the nose on the lateral view is not only
the most common method in studies with esthetic purposes but also a suitable method
in 3D imaging technologies such as Vectra.[24]
Our study shows that a straight nasal dorsum is the most preferred form for both male
and female noses. This conclusion is supported by Alharethy, who revealed that a straight
nasal dorsum is the most desirable nasal profile in the Middle Eastern region, and
that a posterior nasal dorsum within 2 mm is the most approved male nasal dorsum.[25] The findings of a study conducted by Yu et al also corroborate ours by showing that
a straight dorsum is the most acceptable nasal form among both males and females.[17] The neoclassical cannons suggest that the most esthetically pleasing AW is equal
to the intercanthal distance,[26] but we found that this ideal does not hold true for the female nose in the Middle
Eastern region. Participant age differences can affect perceptions about the most
desirable AW, as older participants tend to prefer AWs equal to the intercanthal distance,
unlike younger ones. Many published articles have proposed various ratios for the
most esthetic nasal TPs.[27]
[28] However, Devcic et al showed that the most esthetic faces have TPs that are close
to the Goode ratio.[9] Mohebbi et al also demonstrated that the Goode ratio is the most preferred among
the general Iranian populace.[29] Our results show that a TP ratio of 0.57 is the most preferred for both male and
female noses within the range proposed by the Goode ratio and that deviation from
0.57 decrease the perceived esthetics of the TP.
To our knowledge, this is one of the first reports leveraging 3D imaging technology
to evaluate the ideal nasal profile of the general population in the Middle East.
Even though the data were collected in a single city in Iran (Tehran), the study population
comprised participants from different cities in Iran with various genders, age subgroups,
and educational levels. While the sample size cannot show the Iranian society's perspective
about the ideal nose, it can help the researcher understand the differences in the
conception of beauty among various societies and ethnicities.
When interpreting the results of our current analysis, several limitations should
be taken into account. First, although the pictures were manipulated to have typical
characteristics of the Iranian profile, the impact of each nasal characteristic on
other features was not considered. Second, some patients had difficulty discerning
the differences between AWs, which makes AW calculations susceptible to biases. Third,
some patients were unwilling to participate in the study, which may have introduced
biases.
Our study shows that the general Middle Eastern population prefers thinner female
noses with wider NFAs for both genders. The ideal NLA, DH, and TP did not depart from
the ideal characteristics of neoclassical cannons. Furthermore, the perception of
nasal esthetics is affected by factors such as gender, age, and prior history of esthetic
surgery.
