Download Esthetic perception of black spaces between maxillary central

ORIGINAL ARTICLE
Esthetic perception of black spaces between
maxillary central incisors by different age groups
Matheus Melo Pithon,a Georgia Wanderley Bastos,b Nathallye Silva Miranda,b Tamires Sampaio,b
Tarcisio Pereira Ribeiro,b Leonard Euler Andrade Gomes do Nascimento,c and Raildo da Silva Coqueirod
Jequie, Bahia, and Teresina, Brazil
Introduction: The aim of this research was to evaluate esthetic perceptions of the smile, especially regarding
black spaces between the maxillary central incisors, by laypersons in 3 age groups. Methods: Photographs
were digitally manipulated to simulate black spaces in the region of the maxillary central incisor crenations.
The images were printed on photographic paper and attached to a questionnaire that was given to 150 laypersons in 3 age groups: 15 to 19, 35 to 44, and 65 to74 years. They were asked to use a visual analog scale method
to rate the smiles from a score of 0, corresponding to “not very attractive,” to 10, “very attractive.” Differences
between the examiners were verified by the Mann-Whitney test. All statistics were performed with a degree of
confidence of 95%. Results: The results showed that older persons had more difficulty perceiving black spaces.
In the younger groups, the subjects were better able to perceive the black spaces, and the larger the black space,
the less attractive they rated the photograph (P \ 0.01). Conclusions: Younger people are more likely than
older people to perceive black spaces in maxillary incisor crenations. The larger the black spaces, the less attractive they rate the smile. (Am J Orthod Dentofacial Orthop 2013;143:371-5)
T
he appearance of a smile has direct implications
for esthetics and facial attractiveness.1 Among
the parts of the face, the eyes play the most important role in esthetics, followed by the mouth—especially
when smiling.2
Orthodontic literature has given greater emphasis to
studies about the dentoskeletal relationship, in spite of
the appearance of the smile's having gained much clinical importance, because frequently it is from this point
of view of self-perception that patients also seek to evaluate their treatment.3-6 Therefore, the orthodontist's
perception of beauty might differ from the concepts of
laypersons about what is attractive and satisfactory.7-9
a
Professor of orthodontics, Department of Health, Southwest Bahia State University-UESB, Jequie, Bahia, Brazil.
b
Dentistry student, Southwest Bahia State University-UESB, Jequie, Bahia,
Brazil.
c
Invited professor of the orthodontics specialization course, Universidade Federal
do Piaui, Teresina, Brazil.
d
Professor of epidemiology, Center for Studies in Aging, Southwest Bahia State
University-UESB, Jequie, Bahia, Brazil.
The authors report no commercial, proprietary, or financial interest in the products or companies described in this article.
Reprint requests to: Matheus Melo Pithon, Av. Otavio Santos, 395, sala 705,
Centro Odontomedico Dr. Altamirando da Costa Lima, Bairro Recreio, CEP
45020-750, Vit
oria da Conquista, Bahia, Brazil; e-mail, matheuspithon@
gmail.com.
Submitted, July 2012; revised and accepted, October 2012.
0889-5406/$36.00
Copyright Ó 2013 by the American Association of Orthodontists.
http://dx.doi.org/10.1016/j.ajodo.2012.10.020
Quite often, the consequence of orthodontic treatment is the creation of black spaces in the region of
the crenations of the maxillary central incisors. These
can be the result of an accentuated inclination of the incisors in the mesial direction, bone loss during treatment, or the triangular shape of the maxillary central
incisors. These black spaces might cause esthetic alterations, depending on the patient's self-evaluation.
Pertinent questions arise when black spaces occur at
the end of orthodontic treatment. Will these spaces affect the esthetics of the smile? Does age affect the perception of these black spaces? Because the prevalence of
black spaces increases with aging as a result of periodontal disease and aging of the periodontium, one could deduce that the older the person, the more tolerant he or
she would be of these black spaces.
Based on this premise, we proposed in this study to
evaluate the degrees of perception of laypersons in various age groups about the influence of black spaces between the maxillary central incisors on the esthetics of
the smile. Subjects with age ranges of 15 to 19, 35 to
44, and 65 to 74 years were used, as recommended by
the World Health Organization and International Dental
Federation.
MATERIAL AND METHODS
An extraoral photograph of a 30-year-old patient, in
normal occlusion, was obtained with a digital camera
371
Pithon et al
372
(Rebel XTI; Canon, Tokyo, Japan). The photograph was
cropped to show the lips, teeth, and gingiva to focus attention on the smile. The photograph was manipulated
with the Photoshop (CS3; Adobe Systems, San Jose, Calif) computer program to make black spaces of different
sizes in the region of the crenations between the maxillary central incisors; the mandibular arch was left intact.
This resulted in 8 photographs: 1 had no black spaces,
and the others had increasing sizes of black spaces
(0.5, 1, 1.5, 2, 2.5, 3, and 3.5 mm). No image showed
a deviation of the midline (Fig).
The photographs were evaluated by 150 laypersons in
3 age groups: 15 to 19, 35 to 44, and 65 to 74 years. None
had received orthodontic treatment. They were asked to
complete questionnaires about the images. First, they analyzed a series of miniatures (10 3 6 cm) and chose the
most and the least pleasing images. Then a sequence of
the images was made, starting with the most pleasing,
going to the least. The process was repeated to evaluate
the reliability of the evaluation. After this, the evaluators
analyzed larger (20 3 12 cm) versions of each image and
rated them according to a visual analog scale: 0, not very
attractive; 5, attractive; and 10, very attractive. The evaluators were not allowed to make comparisons among the
images. All images were placed at a distance of 30 cm
from the evaluators' eyes. One factor for exclusion of an
evaluator was lack of visual acuity.
The frequencies of replies by the participants in each
age group (15-19, 35-44, and 65-74 years) were compared with the chi-square test. When the expected frequency was less than 5, the Fisher exact test was used.
The scores awarded to each photograph were compared
with the Kruskal-Wallis test, and comparisons between
pairs were performed with the Mann-Whitney test. The
means of scores awarded to each photograph were calculated in each group to determine the Spearman correlation coefficients, to evaluate the similarity between
perceptions according to the age groups. The level of
significance adopted was 5% (P \0.05). The data were
tabulated and analyzed in the statistical program BioEstat (version 5.0; Bioestat, Belem, Para, Brazil).
RESULTS
Table I shows the demographic data of the study participants. Of the 150 subjects, 60.7% were women.
Table II presents the perceptions of participants with
respect to the differences and preferences regarding image 1. There were significant differences in the perceptions of the differences in the photographs, with
younger participants more likely to note a lack of similarity between the images than older participants.
Among the participants who saw differences between
March 2013 Vol 143 Issue 3
Fig. Images showing black spaces between the incisors.
Image 1 (left): A, without space; B, space of 0.5 mm; C,
space of 1.0 mm; D, space of 1.5 mm; E, space of 2.0
mm; F, space of 2.5 mm; G, space of 3.0 mm; H, space
of 3.5 mm. Image 2 (right): A, space of 3.5 mm; B, space
of 3.0 mm; C, space of 2.5 mm; D, space of 2.0 mm; E,
space of 1.5 mm; F, space of 1.0 mm; G, space of 0.5
mm; H, without space.
the photographs, there were statistical differences in
the proportions among the groups for both the most
preferred and the least preferred pictures. The
American Journal of Orthodontics and Dentofacial Orthopedics
Pithon et al
373
Table I. Demographic data of study participants
Table III. Participants' perceptions with respect to dif-
ferences and their preferences for image 2
Age group (y)
Characteristics
Sex
Male
Female
15-19
(n 5 49)
35-44
(n 5 51)
65-74
(n 5 50)
21 (42.9%)
28 (57.1%)
16 (31.4%)
35 (68.6%)
22 (44.0%)
28 (56.0%)
Table II. Participants' perceptions with respect to dif-
ferences and their preferences for image 1
Age group (y)
Answer
Perceive differences
Yes
No
Image I like most*
A
B
C
D
E
F
G
H
Image I like least*
A
B
C
D
E
F
G
H
15-19
35-44
65-74
37 (75.5% 38 (74.5%) 16 (32.0%)
12 (25.5%) 13 (25.5%) 34 (68.0%)
33 (89.2%) 19 (50.0%)
0 (0.0%)
4 (10.5%)
3 (8.1%)
3 (7.9%)
1 (2.7%)
8 (21.1%)
0 (0.0%)
1 (2.6%)
0 (0.0%)
0 (0.0%)
0 (0.0%)
1 (2.6%)
0 (0.0%)
2 (5.3%)
7 (43.8%)
3 (18.8%)
3 (18.8%)
0 (0.0%)
1 (6.3%)
2 (12.5%)
0 (0.0%)
0 (0.0%)
0 (0.0%)
1 (2.6%)
0 (0.0%)
1 (2.6%)
0 (0.0%)
2 (5.3%)
0 (0.0%)
1 (2.6%)
0 (0.0%)
1 (2.6%)
0 (0.0%)
2 (5.3%)
4 (10.8%) 5 (13.2%)
33 (89.2%) 25 (65.8%)
0 (0.0%)
1 (6.3%)
1 (6.3%)
2 (12.5%)
0 (0.0%)
2 (12.5%)
3 (18.8%)
7 (43.8%)
P
value
\0.001y
\0.001z
z
0.024
*Answered only by those who perceived differences between the
images; yChi-square test; zFisher exact test.
proportion of subjects who liked photograph A most was
highest in the age group from 15 to 19 years, followed by
the group from 35 to 44 years. The same was observed
for the least attractive photograph (photograph H).
Table III presents the perceptions of the participants
with respect to the differences and preferences regarding image 2. The data showed significant differences in
the perceptions of the differences in the photographs,
with more subjects noting a lack of similarity between
the images in the 2 younger age groups. Among the
participants who saw differences between the photographs, there were statistical differences in the proportions among the groups for both the most preferred
and the least preferred pictures. The proportion of subjects who defined photograph H as the “most attractive” was higher in the age group of 15 to 19 years,
followed by the group of 35 to 44 years. The same
Age group (y)
Answer
Perceive differences
Yes
No
Image I like most*
A
B
C
D
E
F
G
H
Image I like least*
A
B
C
D
E
F
G
H
15-19
35-44
65-74
39 (79.6%) 34 (66.7%) 17 (34.0%)
10 (20.4%) 17 (33.3%) 33 (66.0%)
1 (2.6%)
3 (8.8%)
0 (0.0%)
2 (5.9%)
0 (0.0%)
3 (8.8%)
0 (0.0%)
0 (0.0%)
0 (0.0%)
0 (0.0%)
4 (10.3%) 1 (2.9%)
2 (5.1%)
3 (8.8%)
32 (82.1%) 22 (64.7%)
0 (0.0%)
1 (5.9%)
0 (0.0%)
1 (5.9%)
3 (17.6%)
5 (29.4%)
4 (23.5%)
3 (17.6%)
33 (84.6%) 25 (73.5%)
1 (2.6%)
1 (2.9%)
5 (12.8%) 2 (5.9%)
0 (0.0%)
0 (0.0%)
0 (0.0%)
2 (5.9%)
0 (0.0%)
1 (2.9%)
0 (0.0%)
1 (2.9%)
0 (0.0%)
2 (5.9%)
2 (11.8%)
2 (11.8%)
4 (23.5%)
3 (17.6%)
0 (0.0%)
0 (0.0%)
2 (11.8%)
4 (23.5%)
P
value
\0.001y
\0.001z
\0.001z
*Answered only by those who perceived differences between the
images; yChi-square test; zFisher exact test.
was observed with regard to photograph A, considered
the “least attractive.”
The means of the grades awarded to each image are
shown in Table IV. Photographs A and H were scored as
the most and least attractive, respectively, by the 2 age
groups. For the more advanced age group (65-74 years),
it was not possible to perceive remarkable differences in
relation to the scores attributed to the photographs. The
grades awarded to all photographs had significant difference among the groups. Comparisons between pairs
showed that the subjects in the oldest group awarded
better scores to all photographs, compared with participants in the younger groups.
Correlations between the mean scores awarded to the
photographs are shown in Table V. A significant, perfect,
and positive relationship was verified between the mean
scores of the 2 younger age groups, showing agreement
in their evaluations. No significant correlation of the
scores of the 2 younger groups with the scores of the
older group was observed.
DISCUSSION
Esthetic appearance has been prioritized with greater
frequency in orthodontic treatment; however, a professional's perception is not the same as that of a patient.
The concept of beauty is subjective; each person will
American Journal of Orthodontics and Dentofacial Orthopedics
March 2013 Vol 143 Issue 3
Pithon et al
374
Table IV. Mean scores (SD) of photographs awarded
by the study participants by age group
Age group (y)
Photograph
Image A
Image B
Image C
Image D
Image E
Image F
Image G
Image H
15-19
65.6 (25.3)a
61.1 (24.4)a
55.7 (22.8)a
50.3 (22.8)a
45.8 (23.8)a
39.3 (24.1)a
35.5 (25.4)a
31.7 (26.8)a
35-44
61.0 (21.6)a
55.5 (21.8)a
54.0 (19.1)a
49.8 (22.0)a
45.9 (23.2)a
43.9 (22.7)a
42.0 (24.2)a
38.3 (26.2)a
65-74
81.2 (26.8)b
81.5 (27.1)b
80.4 (28.1)b
81.9 (26.8)b
80.8 (27.3)b
81.1 (27.2)b
80.5 (27.4)b
79.7 (28.8)b
P
value
\0.001
\0.001
\0.001
\0.001
\0.001
\0.001
\0.001
\0.001
The scores were compared with the Kruskal-Wallis test. Values with
different superscript letters are significantly different (Mann-Whitney test).
Table V. Spearman correlation coefficients of the
mean scores for the photographs
Age group (y)
15-19
35-44
r
r
35-44 y
1.00*
1.00
65-74 y
0.59
0.59
*P \0.01 (2-tailed).
have a different self-perception. Researchers are paying
more heed to patients' evaluations about the esthetics
of the smile. Black spaces between the maxillary central
incisors at the end of orthodontic treatment might influence the perception of the smile.9,10 It is necessary to ask:
will this black space compromise the esthetics of the
smile? Based on this premise, the proposal of our study
was to evaluate perceptions about the esthetics of the
smile in patients with black spaces of different sizes.
To evaluate the degree of perception, the visual analog scale method was used because it is fast, simple, and
economical for obtaining value judgments; therefore, it
has good practical application for evaluating esthetic
preferences. This method consists of absolute scores
on a scale from 0 to 100, with the marks of 0 being
“not very attractive”; 50, “attractive”; and 100, “very attractive.”1,3,8,11-15
As was previously mentioned, in some patients, orthodontic treatment can lead to the appearance of black
spaces between the maxillary central incisors. This might
be due to periodontal retraction with concomitant bone
loss, accentuated inclination of the incisors in the mesial
direction from an error in bracket bonding, or extremely
triangular maxillary incisors.6,11,16,17
By manipulation with a computer program, black
spaces were created in the region of the maxillary central
March 2013 Vol 143 Issue 3
incisor crenations, simulating this possible consequence
of orthodontic treatment in photographs of the front
view of a smile in a patient with complete dentition
and normal occlusion.1,6,8,11,13-15,18-20 Thus, a file was
made with 8 images and an attached questionnaire
that was used by the evaluators of the 3 age groups
(15-19, 35-44, and 65-74 years).9-16 No study in the
literature has evaluated this proposal; therefore, these
results are unprecedented.
Some factors, such as sex and age, are considered to
have an influence on the esthetic perception of the smile.
This study showed no influence of sex on the evaluations; however, there were statistically significant differences with regard to age.13,18,21
In the small images, the evaluators answered whether
they were able to note differences between the images arranged in increasing order of black spaces for image 1 and
in decreasing order for image 2. The age group from 65 to
74 saw the black triangles; however, they could not appreciate the subtle changes made in the consecutive pictures. In addition, in these same images, the evaluators
were asked to choose the image that most pleased them
and the one that least pleased them. Once again, the older
group differed from the others; in relation to the younger
persons, the difference doubled. A and F were considered
the most and least preferred, respectively, for image 1. For
image 2, the order of preference was reversed.
The lack of perception of asymmetries by the older
age group might suggest that advancing age leads to
a reduced perception of the esthetic details of the smile.
In the other 2 groups, in addition to the perceptible
asymmetry, there was less tolerance, as shown by the
low scores regarding each image.9
The results of the individual analyses of the larger
photographs showed that the 2 younger groups awarded
higher scores to image A (65.6 and 61.0), indicating preference for the absence of black spaces, and that image H
(31.7 and 38.3) obtained the lowest scores because it had
the largest black space. The subjects in the oldest group
awarded high scores to all images, and there was no statistical difference. They were unable to define which
were the best and the worst photographs. These results
represented a perfect correlation between the groups
of 15 to 19 and 35 to 44 years, showing agreement in
the scores and preferences of the images. For the older
age group, there was no agreement, suggesting no statistical pattern for the scores awarded.
Based on this study, we can affirm that black spaces
in the region of the maxillary central incisor crenations
could not be noted by all age groups. It remains at the
discretion of the professional to evaluate which procedure is necessary when orthodontic intervention creates
a black space in this region.
American Journal of Orthodontics and Dentofacial Orthopedics
Pithon et al
The orthodontist must always use orthodontic resources, such as interproximal wear and subsequent
space closure, for excessively triangular teeth or artistic
folds, with a view to correcting the black spaces, because
the patient with the defect when smiling will be seen not
only by older persons, but also by those with a wide
range of ages.
CONCLUSIONS
It can be inferred that esthetic perception of the smile
decreases with advancing age, and the esthetic critical
sense is most evident in younger people.
SUPPLEMENTARY DATA
Supplementary data related to this article can be
found in the online version at http://dx.doi.org/10.
1016/j.ajodo.2012.10.020.
REFERENCES
1. Berto PM, Lima CS, Lenza MA, Faber J. Esthetic effect of orthodontic appliances on a smiling face with and without a missing
maxillary first premolar. Am J Orthod Dentofacial Orthop 2009;
135(Supp):S55-60.
2. Sodagar A, Rafatjoo R, Gholami Borujeni D, Noroozi H, Sarkhosh A.
Software design for smile analysis. J Dent (Tehran) 2010;7:170-8.
3. Bernabe E, Kresevic VD, Cabrejos SC, Flores-Mir F, Flores-Mir C.
Dental esthetic self-perception in young adults with and without
previous orthodontic treatment. Angle Orthod 2006;76:412-6.
4. Johnson DK, Smith RJ. Smile esthetics after orthodontic treatment
with and without extraction of four first premolars. Am J Orthod
Dentofacial Orthop 1995;108:162-7.
5. Maple JR, Vig KW, Beck FM, Larsen PE, Shanker S. A comparison of
providers' and consumers' perceptions of facial-profile attractiveness. Am J Orthod Dentofacial Orthop 2005;128:690-6.
6. Pinho S, Ciriaco C, Faber J, Lenza MA. Impact of dental asymmetries on the perception of smile esthetics. Am J Orthod Dentofacial
Orthop 2007;132:748-53.
7. Desai S, Upadhyay M, Nanda R. Dynamic smile analysis: changes
with age. Am J Orthod Dentofacial Orthop 2009;136:
310.e1-310.e10:discussion, 310-1.
375
8. Thomas M, Reddy R, Reddy BJ. Perception differences of altered
dental esthetics by dental professionals and laypersons. Indian J
Dent Res 2011;22:242-7.
9. Van der Geld P, Oosterveld P, Van Heck G, Kuijpers-Jagtman AM.
Smile attractiveness. Self-perception and influence on personality.
Angle Orthod 2007;77:759-65.
10. McLeod C, Fields HW, Hechter F, Wiltshire W, Rody W Jr,
Christensen J. Esthetics and smile characteristics evaluated by laypersons. Angle Orthod 2011;81:198-205.
11. Schlosser JB, Preston CB, Lampasso J. The effects of computeraided anteroposterior maxillary incisor movement on ratings of facial attractiveness. Am J Orthod Dentofacial Orthop 2005;127:
17-24.
12. Thomas JL, Hayes C, Zawaideh S. The effect of axial midline angulation on dental esthetics. Angle Orthod 2003;73:359-64.
13. Roden-Johnson D, Gallerano R, English J. The effects of buccal
corridor spaces and arch form on smile esthetics. Am J Orthod Dentofacial Orthop 2005;127:343-50.
14. Schabel BJ, McNamara JA Jr, Franchi L, Baccetti T. Q-sort assessment vs visual analog scale in the evaluation of smile esthetics. Am
J Orthod Dentofacial Orthop 2009;135(Supp):S61-71.
15. Zange SE, Ramos AL, Cuoghi OA, de Mendonca MR, Suguino R.
Perceptions of laypersons and orthodontists regarding the buccal
corridor in long- and short-face individuals. Angle Orthod 2011;
81:86-90.
16. Geron S, Atalia W. Influence of sex on the perception of oral and
smile esthetics with different gingival display and incisal plane inclination. Angle Orthod 2005;75:778-84.
17. Janson G, Branco NC, Fernandes TM, Sathler R, Garib D, Lauris JR.
Influence of orthodontic treatment, midline position, buccal corridor and smile arc on smile attractiveness. Angle Orthod 2011;81:
153-61.
18. Rodrigues Cde D, Magnani R, Machado MS, Oliveira OB. The perception of smile attractiveness. Angle Orthod 2009;79:634-9.
19. Ritter DE, Gandini LG, Pinto Ados S, Locks A. Esthetic influence of
negative space in the buccal corridor during smiling. Angle Orthod
2006;76:198-203.
20. Pithon MM, Santos AM, Couto FS, da Silva Coqueiro R, de
Freitas LM, de Souza RA, et al. Perception of the esthetic impact of mandibular incisor extraction treatment on laypersons,
dental professionals, and dental students. Angle Orthod 2012;
82:732-8.
21. Soh J, Chew MT, Wong HB. A comparative assessment of the perception of Chinese facial profile esthetics. Am J Orthod Dentofacial
Orthop 2005;127:692-9.
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