Objective:

To define a threshold of acceptance of smile esthetics for children and adolescents.

Materials and Methods:

A systematic search in the medical literature (PubMed, PubMed Central, National Library of Medicine's Medline, Embase, Cochrane Central Register of Controlled Clinical Trials, Web of Knowledge, Scopus, Google Scholar, and LILACs) was performed to identify all peer-reviewed papers reporting data regarding the evaluation of children's and adolescents' perceptions of dental esthetic factors. The search was conducted using a research strategy based on keywords such as “children,” “adolescents,” “smile aesthetics perception,” “smile aesthetics evaluation.” Studies analyzing smile esthetics involving at least 10 observers younger than 18 years of age were selected.

Results:

Among the 1667 analyzed articles, five studies were selected for the final review process. No study included in the review analyzed perception of smile anomalies in a quantitative or qualitative way, thus no threshold was identified for smile features. Among the analyzed samples, unaltered smiles were always significantly associated with better evaluation scores when compared with altered smiles.

Conclusions:

Smile esthetics influence social perception during childhood and adolescence. However, thresholds of smile esthetic acceptance in children and adolescents are still not available.

The psychological impact of facial esthetics is of great influence on the overall quality of life. Thus, smile esthetics plays a key role in overall esthetics.1  The importance of correcting malocclusion to improve smile and facial appearance has been confirmed by several authors.24  In 2000, Sarver et al.5  stated the importance of the esthetic paradigm when planning orthodontic treatment. On the other hand, some authors have observed that subjective perception can greatly influence the judgment of facial and smile features. Several clinical studies68  as well as systematic reviews9  have been performed to define the threshold values of acceptance for different smile characteristics from the point of view of laypeople. The majority of studies have been conducted involving adult observers, with few studies considering the perceptions of children and adolescents. However, in pediatric and pubertal ages, the alteration of body self-image may have a great impact on all aspects of life, such as socialization, emotional and functional aspects, and familiar interrelationships.3  Furthermore, several authors confirmed that others' perceptions can influence the way a person acts and even result in long-term developmental changes.1012 

In 2011, Witt and Flores-Mir9  analyzed laypeople's perceptions of tooth-related esthetic factors in a systematic review, which concluded that “Laypeople have varying degrees of sensitivity to certain dental esthetic issues. Consequently, clinicians can expect their patients to be more attentive to some esthetic factors than to others.” However, no systematic review analyzed the perception of smile esthetics from the point of view of children and adolescents, and neither evaluated the impact of smile appearance on social perception features.

Thus, the aim of this systematic review is to answer the following clinical research questions:

  • Could children's and adolescents' thresholds of acceptance of smile esthetics anomalies be defined?

  • How are children's and adolescents' social perceptions influenced by smile esthetics?

This systematic review protocol was registered in the International Prospective Register of Systematic Reviews (http://www.crd.york.ac.uk/PROSPERO/; protocol CRD42015027274).

On October 1, 2015, a systematic search in the medical literature was performed to identify all peer-reviewed papers reporting data regarding the evaluation of laypeople's perceptions of dental esthetic factors. To retrieve lists of potential papers to be included in the review, the search strategy illustrated in Table 1 was used in the following databases (Figure 1):

  • PubMed

  • PubMed Central

  • National Library of Medicine's Medline

  • Embase

  • Cochrane Central Register of Controlled Clinical Trials

  • Web of Knowledge

  • Scopus

  • Google Scholar

  • LILACS

Table 1.

Search Strategy

Search Strategy
Search Strategy
Figure 1.

Flow chart according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

Figure 1.

Flow chart according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

The medical libraries of Turin University as well as the authors' personal libraries were thoroughly analyzed in a search for additional papers. Title and abstract screening was performed to select articles for full-text retrieval. If a paper could not be obtained through the Internet and libraries, the study authors were asked to send a copy for the review process.

The inclusion and exclusion criteria for admittance in the systematic review were based on the review by Witt and Flores-Mir9  and are reported in Table 2. This systematic review analyzed only papers that considered children's perceptions of smile esthetics. The reference lists of these articles were perused, and references related to the articles were used to retrieve papers that met the inclusion criteria. However, no additional study has been selected this way.

Table 2.

Study Selection Criteria

Study Selection Criteria
Study Selection Criteria

Duplicate papers were removed, and the studies were selected for inclusion independently by two of the authors. Disagreements were solved by discussions between all of the authors.

The data extraction was performed following the Population Intervention Comparison Outcome (PICO) template, modified according to the review necessities. The outcomes from each study were extracted and are reported in Table 3. Primary outcomes included children's perceptions of esthetics. The secondary outcome included the thresholds of acceptance for every study.

Table 3.

Summary of Results

Summary of Results
Summary of Results
Table 3.

Extended

Extended
Extended

According to the Centre for Reviews and Dissemination, University of York13  and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements,14  an evaluation of methodological quality was performed to weigh the analyzed studies and the level of evidence coming from each of them. Criteria, according to Witt and Flores-Mir's9  review, were used to conduct the methodological scoring of samples. This scoring method involved the analysis of the following study aspects: number of judges, selection of judges, type of judged images, viewing protocol, intraexaminer reliability, scoring technique.

Among the 1667 analyzed articles, five studies were selected for the final review process.1519 

Regarding data extraction, no standard template (eg, PICO) perfectly fit all of the included studies, so a customized template was created according to the review requirements (Table 2). Nevertheless, this was the best possible approach to a systematic assessment of the included papers. All of the studies were assessed separately by the investigators, and in cases of divergent assessments with regard to the assignment of strengths and weaknesses, consensus was reached by discussion.

The mean age of the evaluated samples ranged from 8 to 16 years, and the sample size among the selected studies ranged from 121 to 840 children and adolescents. The overall mean quality of the studies was 19.5 of 22 possible points. The highest score assigned to an article was 21 points,19  and the lowest score assigned was 18 points.16 

Three studies15,16,19  used a 100-mm visual analog scale to score smile photographs, and the other two studies17,18  adopted the Smile Perception Questionnaire for Children Between the Ages of 8 and 10.

No study included in the review analyzed perception of smile anomalies in a quantitative or qualitative way, thus no threshold was identified for smile features.

This systematic review was conducted to evaluate children's and adolescents' perceptions of smile anomalies and their impact on social perception. A total of five studies1519  were selected for the final review process. The quality assessment of the selected studies revealed a good level of evidence. Minor methodological biases were related to the frequently not mentioned interexaminer reliability analysis and to the heterogeneity of viewing protocols among the samples.

The studies included in the final sample did not answer the first clinical question. Thus a need for well-designed studies analyzing children's and adolescents' thresholds of acceptance of smile esthetic anomalies emerged from the present review.

Regarding social perception, the heterogeneity of analyzed categories made it impossible to perform the meta-analysis required to assess the extent of the influence of smile esthetics. Among the analyzed samples, an unaltered smile was always significantly associated with better evaluation scores.

In 1981, Shaw19  evaluated the smile perceptions of 840 children aged 11 to 13 years with a 100-mm visual analog scale. The author highlighted a significant preference for aligned teeth smile when compared with altered smiles regarding perceived attractiveness (43.1 mm, P < .01), desirability as a friend (52.1 mm, P < .05), and less perceived aggressive tendency (73.5 mm, P < .01). In 2010, Verdecchia et al.17  investigated the influence on social perception in a sample of 121 evaluators. Children with well-aligned teeth resulted in having significantly stronger characteristics of honesty, personal happiness, and intelligence (P < .05) with respect to those with crowding and proclinated upper incisors.

According to Henson et al.,15  on the basis of the Index of Orthodontic Treatment Needs, significant differences were registered for athletic performance (3.42 mm, standard error [SE] 1.39, 95% confidence interval [CI] 0.69–6.15], P < .05), popularity (8.26 mm, SE 1.31, 95% CI 5.69–10.84, P < .01), and leadership ability (5.92 mm, SE 1.31, 95% CI 3.35–8.50, P < .01) between ideal and nonideal smiles. Furthermore, in 2001 DiBiase and Sandler20  observed that young participants reported teasing associated with malocclusion and unfavorable self-perceptions related to their teeth.

In 2011, Lombardo et al.18  analyzed a sample of 180 children aged between 8 and 10 years and revealed that a perception of talkative attitude was significantly associated with ideal incisal occlusion when compared with crowding, diastema, and proclined incisors (P < .05). Furthermore, an ideal smile was characterized with a significant preference when compared with the other three types of smile concerning various aesthetic features (P < .05). In their study from 2014, Pithon et al.16  reported significantly better scores for ideal smiles regarding performance in sport (0.32 mm, standard deviation [SD] 2.00, 95% CI 0.04–06, P < .05), popularity (0.62 mm, SD 1.75, 95% CI 0.3–0.87, P < .01), leadership (0.61 mm, SD 1.93, 95% CI 0.35–0.88, P < .01), intelligence (0.47 mm, SD 2.23, 95% CI 0.16–0.78, P < .05), and health (0.71 mm, SD 2.06, 95% CI 0.42–1, P < .01), when compared with crooked smiles.

As reported by several authors, physical attractiveness also plays a key role for social interaction, influencing the perception of an individual's social skills.2123  Perceptions of more intelligence and talkative attitude in ideal smile participants have been confirmed by several studies.16,17  However, Lombardo et al.18  did not report significant changes for the previously debated features. These contrasting results may be a result of the fact that background facial attractiveness has a significant influence on overall esthetic assessments, thus the whole face is predominant over single dental features.5 

Seehra et al.24  measured the frequency and severity of bullying among a sample of British adolescents. The authors highlighted a significant correlation between bullying and malocclusion as well as a significant negative impact on oral health-related quality of life (OHRQoL) resulting from oral symptoms. The psycho-social impact of malocclusion is not age related, as stated by Marques et al.25  in their study on Brazilian children.

In a recent study, Twigge et al.26  assessed a small association between objective orthodontic treatment needs indexes and OHRQoL. Furthermore, no evidence was found regarding higher index-determined occlusal scores (increased severity) causing worse OHRQoL experiences. The authors stated that the lack of significance could be explained by the absence of a control group. However, in the same study, the discrepancy between subjective and occlusal-related treatment needs was confirmed together with the association of esthetics and psychological-expected improvements after orthodontic treatment from the point of view of adolescent patients.26 

According to our results, the smile appears to be important among overall esthetics for adolescents as well as for children younger than 10 years of age. On the basis of the current evidence, an integrated diagnosis that involves the psychological impact of malocclusion as well as occlusal alterations could represent a significant improvement in patient care. Furthermore, correcting smile alterations, even in young children, may be fundamental in preventing bullying or teasing from others and in improving the quality of social interactions, preserving healthy psychological development.27 

  • The overall quality of evidence is of a moderate or high level despite the small analyzed sample.

  • No threshold was identified regarding the perceptions of smile esthetic defects.

  • Poor smile esthetics influence social interactions negatively during childhood.

1
Gavric
A,
Mirceta
D,
Jakobovic
M,
Pavlic
A,
Zrinski
MT,
Spalj
S.
Craniodentofacial characteristics, dental esthetics-related quality of life, and self-esteem
.
Am J Orthod Dentofacial Orthop
.
2015
;
147
:
711
718
.
2
Abdullah
WA.
Changes in quality of life after orthognathic surgery in Saudi patients
.
Saudi Dent J
.
2015
;
27
:
161
164
.
3
Perillo
L,
Esposito
M,
Caprioglio
A,
Attanasio
S,
Santini
AC,
Carotenuto
M.
Orthodontic treatment need for adolescents in the Campania region: the malocclusion impact on self-concept
.
Patient Prefer Adherence
.
2014
;
19
:
353
359
.
4
Bui
KK,
Rinchuse
DJ,
Zullo
TG,
Cozzani
M.
Perception of facial attractiveness following modification of the nose and teeth
.
Int Orthod
.
2015
;
13
:
195
209
.
5
Sarver
DM,
Ackerman
MB.
Orthodontics about face: the re-emergence of the esthetic paradigm
.
Am J Orthod Dentofacial Orthop
.
2000
;
117
:
575
576
.
6
Zhang
YF,
Xiao
L,
Li
J,
Peng
YR,
Zhao
Z.
Young people's esthetic perception of dental midline deviation
.
Angle Orthod
.
2010
;
80
:
515
520
.
7
Musskopf
ML,
Rocha
JM,
Rösing
CK.
Perception of smile esthetics varies between patients and dental professionals when recession defects are present
.
Braz Dent J
.
2013
;
24
:
385
390
.
8
Pithon
MM,
Santos
AM,
Viana de Andrade
AC,
Santos
EM,
Couto
FS,
da Silva Coqueiro
R.
Perception of the esthetic impact of gingival smile on laypersons, dental professionals, and dental students
.
Oral Surg Oral Med Oral Pathol Oral Radiol
.
2013
;
115
:
448
454
.
9
Witt
M,
Flores-Mir
C.
Laypeople's preferences regarding frontal dentofacial esthetics: tooth-related factors
.
J Am Dent Assoc
.
2011
;
142
:
635
645
.
10
Zebrowitz
LA.
Reading Faces: Window to the Soul?
Boulder, Colo: Westview Press;
1997
:
160
189
.
11
Ma
Q,
Hu
Y.
Beauty matters: social preferences in a three-person ultimatum game
.
PLoS ONE
.
2015
;
10
:
e0125806
.
12
Ma
F,
Xu
F,
Luo
X.
Children's and adults' judgments of facial trustworthiness: the relationship to facial attractiveness
.
Percept Mot Skills
.
2015
;
121
:
179
198
.
13
Centre for Reviews and Dissemination, University of York
.
Systematic Reviews–CRD's Guidance for Undertaking Reviews in Health Care
.
2009
;
33
43
.
14
Moher
D,
Liberati
A,
Tetzlaff
J,
Altman
DG.
The PRISMA group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement
.
PLoS Med
.
2009
;
6
:
e1000097
.
15
Henson
ST,
Lindauer
SJ,
Gardner
WG,
Shroff
B,
Tufekci
E,
Beste
AM.
Influence of dental esthetics on social perceptions of adolescents judged by peers
.
Am J Orthod Dentofacial Orthop
.
2011
;
140
:
389
395
.
16
Pithon
MM,
Andrade
D,
Fernandes
I,
et al.
Influence of malocclusion on social perceptions of adolescents at public and private schools
.
Eur Arch Paediatr Dent
.
2014
;
15
:
37
43
.
17
Verdecchia
F,
Bee
M,
Lombardo
L,
Sgarbanti
C,
Gracco
A.
Influence of anterior tooth alignment on peer perception in 8- to 10-year-old children
.
Eur J Orthod
.
2011
;
33
:
155
160
.
18
Lombardo
L,
Berveglieri
C,
Guarneri
MP,
Siciliani
G.
Anterior dental alignment and smile: perception and sensations in a sample of 8- to 10-year-old children and their parents
.
Orthodontics
.
2011
;
12
:
366
377
.
19
Shaw
WC.
The influence of children's dentofacial appearance on their social attractiveness as judged by peers and lay adults
.
Am J Orthod Dentofacial Orthop
.
1981
;
79
:
399
415
.
20
DiBiase
AT,
Sandler
PJ.
Malocclusion, orthodontics and bullying
.
Dent Update
.
2001
;
28
:
464
466
.
21
Jankowiak-Siuda
K,
Rymarczyk
K,
Żurawski
Ł,
Jednoróg
K,
Marchewka
A.
Physical attractiveness and sex as modulatory factors of empathic brain responses to pain
.
Front Behav Neurosci
.
2015
;
9
:
236
.
22
Ma
Q,
Hu
Y,
Jiang
S,
Meng
L.
The undermining effect of facial attractiveness on brain responses to fairness in the Ultimatum Game: an ERP study
.
Front Neurosci
.
2015
;
9
:
77
.
23
Sofer
C,
Dotsch
R,
Wigboldus
DH,
Todorov
A.
What is typical is good: the influence of face typicality on perceived trustworthiness
.
Psychol Sci
.
2015
;
26
:
39
47
.
24
Seehra
J,
Fleming
PS,
Newton
T,
DiBiase
AT.
Bullying in orthodontic patients and its relationship to malocclusion, self-esteem and oral health-related quality of life
.
J Orthod
.
2011
;
38
:
247
256
;
quiz 294
.
25
Marques
LS,
Ramos-Jorge
ML,
Paiva
SM,
Pordeus
IA.
Malocclusion: esthetic impact and quality of life among Brazilian schoolchildren
.
Am J Orthod Dentofacial Orthop
.
2006
;
129
:
424
427
.
26
Twigge
E,
Roberts
RM,
Jamieson
L,
Dreyer
CW,
Sampson
WJ.
The psycho-social impact of malocclusions and treatment expectations of adolescent orthodontic patients
.
Eur J Orthod
. In press.
27
Al-Bitar
ZB,
Al-Omari
IK,
Sonbol
HN,
Al-Ahmad
HT,
Cunningham
SJ.
Bullying among Jordanian schoolchildren, its effects on school performance, and the contribution of general physical and dentofacial features
.
Am J Orthod Dentofacial Orthop
.
2013
;
144
:
872
878
.