Evaluation of the Impact of Orthodontic Treatment on Patients' Self-Esteem: A Systematic Review

Malocclusion may affect interpersonal relationships, self-esteem (SE), and psychological well-being, weakening patients' psychological and social activities. Several studies investigated the effect of orthodontic treatment on these social and psychological aspects, such as SE. However, the direct relationship between SE and orthodontic treatment has not yet been confirmed. This systematic review aimed to evaluate the existing evidence in the literature concerning the influences of orthodontic treatment on patients’ SE systematically and critically. An electronic search in the following databases was done in September 2022: PubMed®, Web of Science™, Scopus®, Embase®, GoogleTM Scholar, Cochrane Library databases, Trip, and OpenGrey. Then, the reference list of each candidate study was checked for any potentially linked papers that the electronic search might not have turned up. Inclusion criteria were set according to the population/intervention/comparison/outcome/study design (PICOS) framework. For the data collection and analysis, two reviewers extracted data separately. The risk of bias 2 (RoB-2) and the risk of bias in non-randomized studies (ROBINS-I) tools were used to assess the risk of bias for randomized controlled trials (RCTs) and non-RCTs, respectively. The grading of recommendations assessment, development and evaluation (GRADE) approach was employed to evaluate the quality of the evidence for each finding. Sixteen studies (five RCTs, seven cohorts, and four cross-sectional) were included in this review. Unfortunately, the results could not be pooled into a meta-analysis. Only six studies have reported an increase in SE after orthodontic treatment (P<0.05 in these studies). No agreement between the included studies was observed regarding the influence of fixed orthodontic treatment, gender, or age on SE. The quality of evidence supporting these findings ranged from very low to low. There is low evidence indicating that fixed orthodontic treatment can improve patients' SE. In addition, unclear data are available about the influence of patients' gender and age on SE after orthodontic treatment. Therefore, high-quality RCTs are required to develop stronger evidence about this issue.


Introduction And Background
Malocclusion is a common public health problem, which causes physical and psychological implications for patients and influences their daily life [1].Many studies have shown its negative impact on social perceptions [2].It may affect appearance, interpersonal relationships, self-esteem, and psychological health, weakening patients' psychological and social activities, such as smiling, emotion, and social contact [3,4].
On the other hand, the orthodontic treatment itself and its appliance may affect the psychological and social activities of patients due to the appearance of these devices [5,6], their effect on speech [7][8][9], the accompanying pain and discomfort [10][11][12], and the associated functional impairment [11].
Due to the growing appreciation of the impact of dentofacial problems on social and psychological health [13], orthodontists have argued that the aesthetically pleasing appearance of teeth and associated soft tissue leads to greater self-esteem (SE) and social health [14,15].As a result, several studies investigated the social and psychological aspects of malocclusion and orthodontic treatment, such as oral health-related quality of life (OHRQoL) [1,5] and SE [13,16,17] to understand the impact of malocclusion on patients' lives and to develop effective orthodontic care that improves patient's attitudes toward treatment and their self-concept and SE [18].
Generally, the self-concept embodies the answer to the question, "Who am I?" [19].Piers determined self-concept as a set of attitudes people have about themselves that describe and evaluate their behavior [20].Moreover, self-concept was defined by Beane et al. as the perceptions that a person has of oneself in relation to individual attributes and the various roles performed by the person [21].Self-concept cannot be described as positive or negative since it is irrelevant to value judgments and represents only a description of the perceived self.In contrast, SE refers to the estimation that a person makes about the description of one's self-concept and, more precisely, to what extent one is satisfied or dissatisfied with his/her self-concept, in whole or in part.Thus, King argued that SE and self-concept represent two discrete dimensions [22].
Self-esteem was defined as a multifaceted notion, for which Harter developed a tool to measure both global and specific self-worth [23].Explicit SE refers to beliefs and values in particular domains, such as school competence or close friendship, whereas global SE refers to one's perception and assessment of oneself as a person [24].It has been stated that adolescents with little SE have a higher chance of developing worse mental and physical health, poorer economic well-being, and higher levels of criminal behavior in adulthood [25].
Although this well-known and accepted correlation between SE and malocclusion, the direct relationship between SE and orthodontic treatment has not been confirmed yet; while several studies show that orthodontic treatment may improve SE scores at the end of treatment [13,17,26], others have found no differences in SE after the completion of orthodontic treatment [24,27,28].Thus, there is no clear evidence about the effect of orthodontic treatment on self-esteem.Additionally, no previous systematic review was performed on this topic.Therefore, this systematic review aimed to evaluate the existing evidence in the literature concerning the influences of orthodontic treatment on patients' SE systematically and critically.The focused review question was "How does orthodontic treatment affect patients' self-esteem?"

Scoping Search
A scoping search was conducted in the PubMed database before designing the final systematic review protocol to verify the existence of any systematic reviews with comparable objectives and to investigate potentially relevant papers.No literature reviews regarding how orthodontic treatment affects patients' SE were found as a result of this search.Several articles that were related to the topic of this review were found.

Eligibility Criteria
The participants/interventions/comparisons/outcomes/study design (PICOS) framework was used to define the inclusion criteria.
Participants: Healthy patients of all ages and malocclusions, both males and females, of all racial groups undergoing orthodontic treatment were included.
Interventions: Any orthodontic treatment using fixed or removable orthodontic appliances.
Comparisons: In the case of two-or three-arm comparable studies, the comparison group may be any group of patients who did not undergo any form of orthodontic treatment or a group of patients being treated with another orthodontic technique different from that in the interventional group or a group of subjects with normal occlusion.
Outcomes: Patients' SE after orthodontic treatment is measured by the Rosenberg scale, Harter's selfperception profile, the global negative self-evaluation, or any other validated scale for SE assessment.The effect of the type of orthodontic treatment and patients' age and gender on SE is determined.
Study design: In English, randomized controlled trials (RCTs) or non-RTC (CCTs), prospective cohort studies, and cross-sectional studies were included without time of publication restrictions.

Sources and Search Strategy
PubMed®, Web of Science™, Scopus®, Embase®, Google TM Scholar, Cochrane Library, PsychINFO, Trip, and OpenGrey databases were electronically searched in September 2022 without time limits.The details of the electronic search strategy for each database are presented in Appendix 1.The keywords used in the search strategy are listed in Appendix 2. The reference list of each candidate study was checked for any potentially linked papers that the electronic search might not have turned up.

Study Selection
After electronically removing the duplicated papers retrieved from the databases and manual searches using the Endnote™ reference management software program (Clarivate Analytics, Philadephia, PA, USA), the titles and abstracts of articles were assessed.Two reviewers (RIS and MYH) independently evaluated the suitability of each article in light of the selection criteria.Then, the entire text of all articles that potentially meet the inclusion criteria was assessed by the same two reviewers or could not reach a clear judgment based on the title or summary.Articles were excluded if they failed to satisfy one or more qualifying criteria.In case of disagreement and a conversation did not result in agreement, a third reviewer (ASB) was consulted.

Data Collection Process
The following data were among the information extracted from the included articles in this review and organized into summary tables: author's name, year of publication, country, study design, comparison, sample size (male/female), mean age, malocclusion, type of orthodontic treatment, questionnaire employed, questionnaire administration time, main finding, and p-value.

Risk of Bias Assessment of the Studies
First, the risk of bias of each included study was assessed by the two reviewers (RIS and MYH) separately using Cochrane's risk of bias tool for randomized trials (RoB2) [29] and ROBINS-I tool for non-RCTs [30].Second, the judgments of both reviewers were compared.In case of disagreement, and a conversation did not result in agreement, a third reviewer (MAA) was consulted to help reach a decision.For RCTs, the five domains of the RoB2 tool were judged as having a high, low, or unclear risk of bias.
After that, the overall risk of bias for each study was determined according to the following criteria: a low risk of bias if all fields were assessed as having a low risk of bias; a moderate risk if one or more fields were evaluated as having an unclear risk of bias; and a high risk of bias, if one or more fields were assessed as being at high risk of bias.
For the non-RCTs, the seven domains of the ROBINS-I tool were rated as having a low, moderate, critical, no information, or serious risk of bias.After that, the overall risk of bias for each study was determined according to the following criteria: low risk of bias if all fields were assessed as having a low risk of bias; a moderate risk if all fields were assessed as having a low or moderate risk of bias; serious risk of bias if one or more fields were assessed as having a serious risk of bias, but no critical risk of bias in any field; critical risk of bias if one or more fields were assessed as having a critical risk of bias; and no information when there was a lack of information in one or more key bias categories and no overt indication that the study is at serious or critical risk of bias.

The Quality of the Evidence
Based on the grading of recommendations assessment, development and evaluation (GRADE) approach, the strength of the evidence was rated as high, moderate, low, or very low for each outcome.The quality of the evidence of each outcome was assessed by the two reviewers (RIS and MYH) separately.After that, the judgments of both reviewers were compared.In case of disagreement and a conversation was not resolved, a third reviewer (MAA) was consulted to help reach a decision.

Synthesis of Results
Due to the qualitative nature of the data, meta-analysis was not feasible.Instead, a thematic synthesis approach was employed to synthesize the data.Thematic analysis is a suitable method for qualitative research [26].The findings were summarized based on significant and prominent themes.Consequently, the following thematic headings were identified: (1) effect of orthodontic treatment on SE; (2) the effect of type of orthodontic treatment on SE; and (3) the effect of age and gender on SE.

Literature Search Flow and the Retrieved Studies
The electronic search in the databases and reference lists yielded 2,768 references.After removing duplicate references, 597 citations were carefully checked.A total of 575 documents were removed based on checking the titles and abstracts, and then the eligibility of 22 full-text records was evaluated.As a result, 16 studies were included in the systematic review [13,17,24,[26][27][28][31][32][33][34][35][36][37][38][39][40], and six were excluded.The reasons for exclusion are given in Appendix 3. Figure 1 shows the PRISMA flow chart for the processes of selection and inclusion.
Self-esteem was studied with several types of malocclusions among the included studies; patients with mildto-moderate malocclusion were assessed by Albino et al. [27]; moderate-to-severe malocclusion by Varela et al. [39]; Class III malocclusion in children patients was studied in three studies [37,38,40]; and cases with dental loss or agenesis and missing lateral incisors were evaluated by de Couto Nascimento et al. [33] [28,35].In contrast, the other included studies lacked this information about malocclusion type [13,24,31,32,34,35].
The Index of Orthodontic Treatment Need (IOTN) scale defined the treatment need and assessed malocclusion in five studies [13,24,28,32,35].Meanwhile, the Index of Complexity, Outcome and Need (ICON), and Treatment Priority Index were used in two studies by Show et al. and Albino et al., respectively [27,34].Three independent orthodontists assessed malocclusion severity in Varela et al.'s trial [39].
Among the included studies, fixed orthodontic appliances were used in patients' treatment in nine trials [13,24,[26][27][28]31,33,36,39]; a face mask with a bonded maxillary acrylic expansion device was used in three trials [37,38,40]; and, in the other two trials, a mixture of fixed or removable orthodontic appliances was used in different groups [17,32].In the trial reported by Seehra et al., 59% and 23% of patients were treated with class II functional appliances, followed by fixed appliances and fixed appliances only, respectively [35].

Effects of Interventions: Effect of Orthodontic Treatment on Self-Esteem
Sixteen studies assessed the influence of orthodontic treatment on patient SE in this systematic review.Only six studies have reported a significant increase in patient SE scores after orthodontic treatment (P<0.05) in these studies [13,17,26,[32][33][34].On the other hand, no statistically significant difference in SE scores following orthodontic treatment was observed in the other 10 studies [24,27,28,31,[35][36][37][38][39][40].Low-quality evidence supported this outcome based on the GRADE approach (Table 2).
Facemask and bonded maxillary acrylic expansion device: Treatment with face masks and bonded maxillary acrylic expansion devices was evaluated by Mandall et al. [37] in three trials and over a long period (six years of follow-up).Tiny changes in SE over time as a result of protraction facemask treatment have been reported, and no statistically significant increase in SE score of children patients with class III malocclusion was found after 15 months, three years, and six years of treatment compared to baseline (P=0.22,P=0.56, P=0.48, respectively) [38,40].The strength of the evidence supporting this outcome was moderate, based on the GRADE approach.
The fixed versus removable orthodontic appliances: Jung [17] and Birkeland et al.'s [32] studies investigated the impact of fixed and removable orthodontic treatment on SE in adolescent patients aged 11-16.They found that fixed orthodontic treatment had a more significant effect on SE (P=0.009,P<0.05, respectively) compared to the removable appliances treatment, as no significant increase in SE score was observed after treatment with these appliances (P=0.75,P>0.05, respectively).Notably, no information was reported in these studies about the types of malocclusions, types of removable appliances used, or duration of treatment.The strength of the evidence supporting this outcome was low, based on the GRADE approach.
Second: The effect of age and gender on SE: The relationship between patients' sex and SE after orthodontic treatment was evaluated in five studies [17,24,31,32,36].Two assessed the effect of both patients' ages and gender on SE [24,36].In regards to patients' gender, Jung [17] noted that SE index (SI) increased in girls after fixed appliances treatment (SI=2.71±0.45,2.86±0.43 in the untreated group, and after the fixed orthodontic treatment group, respectively, P<0.05).However, for the boys, orthodontic treatment did not affect SE levels (SI=2.80±0.47,2.89±0.48 in the untreated group, and after fixed orthodontic treatment group, respectively, P>0.05) [17].In contrast, Birkeland et al. [32] found that more girls than boys had developed negative selfevaluation after orthodontic treatment (P<0.001).Avontroodt et al.'s study on adolescents showed a decrease in SE levels for females and an increase for males between baseline and after 12 months of treatment [24].The same results were also reported by O'Regan et al.'s study, as girls had lower SE than boys after orthodontic treatment [31].Despite that, different results were reported by Romero-Maroto et al. in adult patients where no correlation between SE and gender was found [36].Very low-quality evidence supported this outcome based on the GRADE approach.Regarding patients' age, the Avontroodt et al. study showed that younger children had an improvement or stabilization in self-perception, whereas a decreased selfperception was found for older children [24].On the other hand, according to Romero-Maroto et al., age did not have a significant correlation with SE, and it did not appear to be a relevant variable to consider [36].
Based on the GRADE approach, very low-quality evidence supported this outcome.
None of the included trials were judged to be at low risk of bias, and most were at high risk.This has affected the confidence in these findings, and the level or strength of evidence that can be gleaned from the included papers was relatively low.

Effect of Orthodontic Treatment on Self-Esteem
No agreement between the included studies was observed regarding the influence of orthodontic treatment on SE.Only six of the 16 included studies in this review have reported a significant increase in patients' SE scores after orthodontic treatment procedures (P<0.05)[13,17,26,[32][33][34].This may be due to the higher satisfaction with dental appearance after fixed orthodontic treatment in these studies, which may positively affect SE.However, the other 10 trials have not observed any statistically significant difference in SE scores due to treatment [24,27,28,31,[35][36][37][38][39][40].This disagreement may be attributed to the fact that SE is a very complex topic that can change greatly during life's stages.Moreover, it is not just impacted by one factor, such as malocclusion.Thus, there may be a range of interactions with orthodontic therapy.

The Effect of the Type of Orthodontic Treatment on Self-Esteem
The fixed orthodontic appliances: Twelve studies assessed the changes in SE levels due to treatment with fixed orthodontic appliances.There was uncertainty in the evidence as to whether or not there was an improvement in SE at the end of the treatment.A statistically significant increase in SE scores was reported due to treatment in five studies [13,17,26,32,33].In contrast, in the other studies, no differences were reported [24,27,28,31,35,36,39].This inconsistency may be attributed to the differences in the ages, demographic characteristics, types of malocclusions of the samples, and the absence of controlling for other confounder factors that could be responsible for part of the discrepancy between these studies.
Quick correct of teeth alignment can usually be achieved with fixed orthodontic treatment [17]; this may have a positive effect on a patient's SE, as the beautiful and well-aligned smile may boost patients' confidence and improve their appearance, which can, in turn, improve their SE [41].On the other hand, the effect of malocclusion on SE differs between people, depending on the personal perspective of the individual and his satisfaction with dental appearance, as some people consider dental appearance an important factor in their self-evaluation, while others see that dental appearance is not important and does not affect their self-evaluation [42].
Facemask and bonded maxillary acrylic expansion device: No significant increase in SE scores as a result of treatment with a face mask and a bonded maxillary acrylic expansion device in children with class III malocclusion was found by Mandall et al. over six years of follow-up [37,38,40].This may be because of that the effect of orthopedic treatment alone was not strong enough to influence Piers-Harris scores, as it does not have an impact on teeth appearance [37].It is also noteworthy that the questionnaire used in these studies does not include items specifically related to the face or teeth, and it is not designed to assess SE in these specific areas [20].
The fixed versus removable orthodontic appliances: As expected, removable orthodontic appliances had less effect on SE than fixed orthodontic appliances, according to Jung [17] and Birkeland et al. [32].Usually, malocclusion cannot be completely corrected by removable appliance treatment [17].Thus, psychological improvement might not be observed if some malocclusion still existed.

The Effect of Gender and Age on Self-Esteem
A few studies evaluated the effect of patients' gender on SE after orthodontic treatment [17,24,31,32,36].All of these studies were conducted on adolescent patients between 11 and 16 years of age, except for the study of Romero-Maroto et al., which included adult patients with a mean age of 29.80±9.55years [36].The results of this factor were different and somehow opposed between these studies.Therefore, the relationship between SE and patients' gender cannot be emphasized in this review due to this disagreement.Both males and females who feel physically attractive tend to have higher SE [43]; however, many studies have shown that, during adolescence, girls' attitudes about their appearance become more negative [44].This difference between girls and boys may be because females are usually more conscious of their body image as the standards of aesthetics and beauty are more clearly defined for them [45].This decline in girls' perceived physical attractiveness is supposed to affect SE negatively [46].This may also be reflected in orthodontic treatment, as females were reported to have greater concerns at the start and higher expectations at the end of treatment than males [47].This may explain the results of Avontroodt et al., Birkeland et al., and O'Regan et al. studies, as females, had lower SE after orthodontic treatment than males [24,31,32].
There was insufficient evidence about the relationship between patients' age and SE score after orthodontic treatment.Only two cohort trials evaluated this variable after fixed orthodontic treatment [24,36] and reported conflicting results.According to Avontroodt et al.'s study on adolescents, an inverse relationship may exist between patients' age at the start of treatment and SE after treatment in studied subjects.This result disagrees with previous reviews about the development of SE over age in normal persons that have found an increase in SE from adolescence to middle adulthood [48].Therefore, these results may suggest that early initiation of orthodontic treatment positively impacts SE more than in 14-year-old adolescents [24].Romero-Maroto et al.'s study on adult patients reported that age had no significant correlation with SE.This difference with the previous study of Avontroodt et al. could be explained by the difference in the patients' ages (adolescents versus adults, respectively) between these studies.

Limitations of the current review
One main limitation of this review is that only a small number of RCTs were included; all of them, including non-RCTs, were at moderate-to-serious risk of bias.This has affected the degree of confidence in the findings obtained.Another limitation of this systematic review was the variations between the included studies regarding the type of malocclusion, method of SE assessment, and assessment times.Hence, the results could not be pooled into a meta-analysis to provide an accurate estimate of the treatment effect.In addition, the effect of gender and age on patients' SE could not be confirmed across the included studies, and more studies are needed to establish good evidence in this field.

Conclusions
There is low-quality evidence indicating that orthodontic treatment can improve patients' self-esteem at the end of treatment.Results are conflicting about the effect of orthodontic treatment with fixed appliances on self-esteem.However, treatment with these appliances has a greater effect on self-esteem than that with removable appliances.Low-quality evidence supports these results.The influence of patients' gender or age on self-esteem after orthodontic treatment is not clear.Further well-conducted studies using validated measurement scales of self-esteem are required to arrive at more robust conclusions with attention paid to the gender and age effect and the need for long-term follow-up periods.

Figures 2 - 3
Figures 2-3 display an overview of the included RCTs' overall risk of bias.The five included RCTs were classified as having some concern of bias[26,27,37,38,40]. Participants' blinding was the most problematic field for all these trials.Moreover, the random sequence generation was unclear in Albino et al.'s study,

FIGURE 2 :
FIGURE 2: Risk of bias graph: The review authors' judgments about each item's risk of bias for the included RCTs Domains: D1: Bias arising from the randomization process D2: Bias due to deviations from the intended intervention D3: Bias due to missing outcome data D4: Bias in the measurement of the outcome D5: Bias in the selection of the reported result Judgment: Yellow circle: Some concerns Green circle: Low risk of bias

FIGURE 3 :
FIGURE 3: Risk of bias summary: The review authors' judgments about each item's risk of bias, presented as percentages across all the included RCTs

Figures 4 - 5
summarize the overall risk of bias in the non-RCT-included studies.More details about the risk of bias assessment are given in Appendix 5.

FIGURE 4 :
FIGURE 4: Risk of bias graph: The review authors' judgments about each item's risk of bias for the included non-RCTs Domains: D1: Bias due to confounding D2: Bias due to selection of participants D3: Bias in the classification of interventions D4: Bias due to the deviations from intended interventions D5: Bias due to missing data D6: Bias in the measurement of outcomes D7: Bias in the selection of the reported result Judgment: Red circle: Serious risk of bias; Yellow circle: Some concerns; Green circle: Low risk of bias

FIGURE 5 :
FIGURE 5: Risk of bias summary: The review authors' judgments about each item's risk of bias are presented as percentages across all the included non-RCTs.

TABLE 2 : Summary of the findings table according to the GRADE guidelines for the included trials
[24,36]31,32,36]evel for risk of bias (high risk of bias[17,32]), one for inconsistency*, one for indirectness***, and one for imprecision ** e. Decline one level for risk of bias (high risk of bias[17,24,31,32,36]), one for inconsistency*, one for indirectness***, and one for imprecision ** f.Decline one level for risk of bias (high risk of bias[24,36]), one for inconsistency*, one for indirectness***, and one for imprecision ** 2023 Shaadouh et al.Cureus 15(10): e48064.DOI 10.7759/cureus.4806411 of 20 * Wide variance of point estimates across studies ** Limited number of trials *** Interventions delivered differently in different settings OR Class II OR Class III OR overjet OR overbite OR crowding OR spaces OR protrusion OR retrognathism OR malalignment OR orthodontic* OR Orthodontic treatment OR Orthodontic therapy OR fixed appliances OR removable appliances OR myofunctional appliances OR children OR adolescence OR adults #2 Self OR Self-esteem OR SE OR self-perception OR Rosenberg's self-esteem scale OR RSE OR Harter's self-perception profile OR SPPC OR the Global Negative Self-evaluation OR the Self-esteem inventory OR SEI #3 #1 AND #2 EMBASE #1 malocclusion OR Class I OR Class II OR Class III OR overjet OR overbite OR crowding OR spaces OR protrusion OR retrognathism OR malalignment OR orthodontic* OR Orthodontic treatment OR Orthodontic therapy OR fixed appliances OR removable appliances OR myofunctional appliances OR children OR adolescence OR adults #2 Self OR Self-esteem OR SE OR self-perception OR Rosenberg's self-esteem scale OR RSE OR Harter's self-perception profile OR SPPC OR the Global Negative Self-evaluation OR the Self-esteem inventory OR SEI #3 #1 AND #2 PubMed #1 malocclusion OR Class I OR Class II OR Class III OR overjet OR overbite OR crowding OR spaces OR protrusion OR retrognathism OR malalignment OR orthodontic* OR Orthodontic treatment OR Orthodontic therapy OR fixed appliances OR removable appliances OR myofunctional appliances OR children OR adolescence OR adults #2 Self OR Self-esteem OR SE OR self-perception OR Rosenberg's self-esteem scale OR RSE OR Harter's self-perception profile OR SPPC OR the Global Negative Self-evaluation OR the Self-esteem inventory OR SEI #3 #1 AND #2

TABLE 4 : Appendix 2: Keywords used in the search
This study was the same as another article included in the review (A 20-year cohort study of health gain from orthodontic treatment: Psychological outcome), the same research team