Self-perception of dental aesthetics among North African students

Introduction

Aesthetics refers to the Greek word “aisthetikos”, which means “to hear or to detect a good sense of beauty” It examines the nature of beauty and the arts [1]. According to Süzen [1], “aesthetics is the philosophy of beauty or the beauty of a subject, such as good, ugly, nice, great, or tragic”. It has two components [2, 3]. The first, being objective, is defined by what you see, and relates to civilizational norms or codes that evolve over time and space. In their daily practice, the practitioner and prosthetist refer to aesthetics adopting a quasi-scientific approach [2]. The second component, which is more subjective, reflects a world of emotions and feelings specific to a person. It requires an investigation to reach patient’s expectations [3].
Smile has a strong impact on how others perceive us as well as on psychosocial well-being. Indeed, during a communication, all attention is directed towards the eyes and smile [4]. A dentist should keep in mind that his/her perception of aesthetics may differ from that of patients [5]. If not acknowledged and addressed, these differences can lead to patient’s dissatisfaction with the results of treatment, and thus to aesthetic failure. Knowledge and awareness of the parameters of dental aesthetics, basic concepts, and evolution of these concepts can help dental students to understand their own smiles and facial aesthetics. This can further improve communication between patients and dentists when planning treatment and implementation of prosthetic rehabilitation [2, 6]. Additionally, dental appearance has been shown to influence facial attractiveness, hence, it impacts human interactions and plays a leading role in social life. Different facial components with varying degree of importance, impact facial attractiveness. Smile is considered to be one of the most significant elements of the appearance [7].

Objectives

The aim of this study was to assess students’ self-perception of their own smiles at the Faculty of Dental Medicine in Monastir (FDMM), and to evaluate the impact of certain facial components on the perception of aesthetics.

Material and methods

This was a descriptive cross-sectional study conducted at the FDMM during the academic year of 2021/2022, with no direct individual benefits for participants. Objectives of the study were explained to volunteering students. The principles of anonymity were respected throughout the data collection and processing. The approval of Ethics Committee of the FDMM for conducting the study was obtained (Supplementary Table 1). Students from the first year to internship registered at the FDMM during the academic year of 2021/2022 were enrolled. According to administration, the number of students enrolled at the FDMM during this academic year was 1,250. Data were collected using a structured questionnaire written in English and according to Goldstein [8], and adapted to Tunisian context. The questionnaire was divided into three sections. First section collected general data of study participants, such as gender, university level, nationality, and marital status. Second one examined degree of students’ satisfaction with their dental aesthetics and their desire to have an ideal smile using 15 dichotomous questions. Third section, inspired by a study of Jornung and Far­dal [9], was related to the importance of each component of the face (i.e., eyes, hair, head shape, teeth, nose, ears, hair line, and lips) in the perception of aesthetics using visual analogue scale (VAS) from 0 to 10. Zero value at the far left indicated no importance of the component, and 10 value at the right end showed a deterministic effect.
The questionnaire was conducted using Google Forms, and was previously tested among 30 students. It was distributed thru social networks in the groups of different promotions. Time required to complete the questionnaire was ten minutes. It was posted between February and June 2022 on Facebook groups of each level. It was also sent by e-mail to those without Facebook accounts in order not withdraw them from participation in the survey, and to collect an optimal number of responses. All incomplete or incorrectly completed forms were excluded. Results were analyzed using statistical package for social sciences (SPSS) version 20.0, with significance threshold of 5% adopted. Distribution of quantitative variables was evaluated using Kolmogorov-Smirnov test. When the distribution was normal and variances were equal, the results were expressed as mean ± standard deviation, otherwise, the results were expressed by their medians (1st-3rd quartile). Student’s t-test was employed for the comparison of means, and  test was utilized for the comparison of percentages.

Results

Out of the 1,250 students enrolled at the FDMM, 817 responded to the questionnaire, with a response rate of 65.4%. The participating students were distri­buted over six university levels. Table 1 shows the general characteristics of the participants of this study. Female predominance was observed (77.0%), and 52 students were foreigners (6.4%). The number of responses from the first year students was the lowest (11.8%), whereas the number of the sixth year (internship) participants was the highest (22.0%). The perception of smile aesthetics is detailed in Table 2. The students were confident of their smiles (73.7%), and 60.3% did not cover their mouth when smiling. When the students compared themselves to their surroundings, 83.2% of them thought that their smiles were not the best. The shape of the teeth and the appearance of the gingiva were respectively the most appreciated parameters of the smile showed by more than 75% of the participants, contrary to the color of the teeth, which was found not satisfactory in 44% of the respondents. Three quarters of the students (75.4%) looked at the stars smiles while reading magazines. In addition, 46.3% of the subjects were influenced by the media; they were impressed by the smiles of models in magazines. The perception of smile’s aesthetics according to sex and study level are detailed in Table 2. Male participants were confident of their smiles (81%), they did not put their hands in front of their mouth when smiling (83%), and were not influenced by the smiles of stars in maga­zines (60%). On the other hand, female respondents preferred to be photographed on one side of their faces (63%). In addition, they were influenced by the smiles of models in magazines (77.6%). Students with clinical training did not wish to have a star smile (61.2%); however, they were attracted to the smiles of models in magazines (77%). They were satisfied with the color of their teeth (60%) and the appearance of their gums (77.8%). The evaluation of various components influencing facial aesthetics was quantified on a scale from 0 to 10, to determine the average of the participants’ responses. Features considered the most relevant and critical for facial aesthetics were teeth, eyes, and hair in descending order of priority (Table 3). A statistically significant difference was found in females for hair, eyes, nose, and teeth (Table 4). In the study population, 41.5% of the female participants assigned a score of 10 to the teeth, and 34% of them gave a score of 10 to the eyes. These two facial components were considered the most attractive. No statistically significant diffe­rences related to university level between the different facial components in the perception of facial aesthetics were observed (Table 5).

Discussion

This study showed that students at the FDMM were satisfied with their smiles. Female participants were more demanding and concerned about their dental aesthetics. The students evaluated the teeth as the determining facial component in the aesthetics of the face. However, in the opinion of the subjects, the color of the teeth was the most troublesome parameter. The emphasis on teeth gradually increased as the students progressed through the university curriculum.
The aesthetics of the face and particularly that of the smile, play a decisive role in psycho-social development, the maintenance of social contacts, and communication links. Moreover, mass media influence the behavior of Tunisians, particularly dental students. To the best of the authors’ knowledge, this is the first study assessing North African students’ self-perception of their smiles, and investigating the impact of certain facial components on the perception of aesthetics.
Tunisian dental students felt comfortable with their smiles. This is in line with the results of previous studies [6, 8, 10]. In fact, similar satisfaction and confidence in dental appearance were observed in the United Kingdom [10], Saudi Arabia [6], and Brazil [8] (76%, 87%, and 92.4%, respectively). However, this satisfaction rate was lower in Turkey [11] and Malaysia [12] (57.3% and 47.2%, respectively).
A gender difference in perception of smile aesthetics was demonstrated. Males were the most satisfied with their smiles. This can be explained by the fact that women are much more critical and demanding of their aesthetics [13]. This finding is contrary to the results of Afroz et al. [14] who concluded that Indian men were more concerned about their smiles than women, whereas the latter were more satisfied with their dental aesthetics. The authors suggested that the impact of marketing has made men as concerned as women about beauty and physical appearance. Satisfaction with the appearance is not related to sex only. It can vary according to personal differences, cultures, and even different timing in the same social environment. It is also influenced by the level of education and university training [15, 16]. A study conducted in Serbia in 2016 observed that participants with a high level of education were more satisfied with their aesthetic appearance than those with a lower level of education [15]. Also Romero et al. [16] found that participants with a university degree had higher scores in terms of confidence about their smiles than participants with only academic training. This could be attributed to maturity and acquisition of aesthetic knowledge.
In the present study, the students were divided into “pre-clinical” and “clinical” groups. Because the first group has not yet had clinical training, their knowledge level can be considered as non-specialists. However, those who received clinical training probably gained much more expertise in aesthetic knowledge, which can influence their perceptions [17]. Therefore, by comparing the degree of confidence across study levels, there was no statistically significant difference between the participants. These results are similar to those of Sakellaropoulos et al. [18], which confirmed that the level of education is not an important factor. On the contrary, Alhammadi et al. [17] reported that clinical training has a significant positive effect on the assessment of smile aesthetics. Indeed, first-year dental students lack the knowledge and clinical training to determine a smile professionally [15]. Their perceptions of smiling may be similar to those of people with no dental medicine training: an exaggerated demand for smile perfection, even if it is not natural [17]. Moreover, dental professionals take a critical look at the aesthetics of smiling by focusing only on the characteristics that make it less pleasant [19]. However, a layperson’s ability to make judgments is subjective. The person notes only “what does not seem beautiful to him/her”. Therefore, the dentist must not influence the patient judgement by imposing the principles of an ideal smile. This is important to ensure satisfaction with the final result after rehabilitation process [3].
Participants felt that “there is always someone else with a better smile”. This is similar for men and women, with no significant difference between university levels. These results are similar and consistent with previous studies [2, 6, 8]. In addition, women keep their gaze fixed at the teeth of models in fashion magazines more than men. They also believe that they photograph themselves better on one side of the face than the other. These attitudes are explained, on the one hand, by women’s greater sensitivity and awareness of beauty compared with men, and on the other hand, by the influence of media and new trends in fashion [19].
In addition, 44.5% of the students were not satisfied with their own teeth color. This finding can be explained by the tendency to want “whiter” teeth, and the fact that tooth whitening takes an important place in aesthetic dentistry. Similar studies conducted in Turkey [11], Jordan [20], and Saudi Arabia [21] showed that 55.1%, 33.7%, and 56.9% of participants, respectively, were not satisfied with their teeth color. In the present study, men appeared to be more comfortable with the color of their teeth than women. Nearly half of those surveyed were dissatisfied, as they paid more attention to their appearance and beauty. A similar study at the Princess Nourah University in Riadh in 2016 demonstrated that 89.4% of participants confirmed that the appearance of their teeth directly affects their attractiveness [22]. Satisfaction with the teeth color is also related to the level of study. This attitude is explained by the interest of clinical training for a better understanding of characteristics of natural color of dental structures. According to Oz et al. [5], the desire to have whiter teeth has been mentioned more by non-professionals than dental professionals, as they have more realistic expectations of the results of dental lightening. Since students in grades 1, 2, and 3 have not yet received clinical training, their knowledge of dentistry can be compared to that of non-professionals. The perception of aesthetics is more obsessive. The “white” color of the teeth is found to be ideal. In fact, students with no dental training preferred whiter teeth than those pursuing dental medicine studies, since they have a better understanding of the natural color of the teeth [23]. According to Tortopidis et al. [24], patients’ expectations regarding dental aesthetics are exaggerated, or even difficult to achieve. Newton et al. [25] reported that about half of the participants were dissatis­fied with the color of their teeth. They justified their choices by the impact of “white” teeth on facial rejuvenation. Unlike “yellowish” teeth, which negatively affect psychological well-being of individuals and justify the use of lightening techniques. Enabulete and Ada­yonfo [26] observed that participants who were dissatisfied with the color of their teeth were not convinced by their general appearance. White teeth positively influence psychology and strengthen relationships between individuals [27]. Color and harmonious arrangement of the teeth are considered to be the two most important parameters for a “beautiful smile” in a young population [28].
Contrary to the color, Tunisian dental students appreciated the shape of their teeth as well as their dimensions. Men appeared more confident than women, which is inconsistent with previous studies [6, 29]. Marunick et al. [30] showed that there is a statistically significant gender difference regarding the shape of teeth. Indeed, women preferred the ovoid shape of teeth, unlike men who preferred the square shape.
Changes in tooth proportions can affect the perception of an aesthetic smile [31]. In addition, several authors confirmed that short or narrow teeth reduce the attractiveness of smiling for both professional dentistry evaluators and non-professionals [32]. Although the shape and alignment of the teeth are considered to be very important aesthetic variables, they are still less important than the color [29].
Gingival exposure is also considered as a critical factor in how dental students and dentists perceive a smile, whereas it is less important to laymen. There is an evident relationship between satisfaction with the appearance of the gums in general and their visibility when smiling. Pinzan-Vercelino et al. [33] agreed that a gingival smile is less attractive, and even unpleasant. Also Omar et al. [34] confirmed that the gingival smile is perceived as a “handicap”, causing discomfort and even speech disorders. Tolerable gum exposure when smiling is 1 to 2 mm. Oz et al. [5] considered beyond 3 mm gum exposure, and the situation was unpleasant with the smile poorly perceived. These results are consistent with those of Wang et al. [35] who found that non-professionals generally preferred a low smile line than a gum smile. The aesthetic and natural appearance of the smile is the result of multiple important factors. There must be a harmonious relationship between facial and dental composition to create a beautiful smile. Facial features are essential for an aesthetic perception and enhancement of physical attractiveness [34]. The eyes followed by the smile are the most important features of a person’s facial appearance [4]. The results of this study proved that the students rated teeth as the most important facial feature. However, these responses may be biased, as all the study participants were dental students. By comparing the results by sex in the survey, female students were most interested in teeth and their importance in facial aesthetics. Clinical training does not have a statistically significant influence on the different scores assigned to various components. Several studies have also confirmed the importance of teeth in judging the attractiveness of the face, even among participants with no dental training [29, 34]. Participants felt that people with less dental disease were more socially competent, had greater intellectual achievement, and had a better psychological balance. Dental problems were correlated with negative social judgments [27].
This study has several limitations, which must be taken into account in interpreting the results. The first limitation was a cross-sectional nature of the study. This type of study uses a unitary approach to evaluate the perception of dental aesthetics in the absence of consensus on an optimal solution, and a standardized and objective evaluation method. Using this approach may have the advantage of being simple and useful for assessing the overall perception of dental appearance, but certainly it is not sufficient. It does not consider various factors, such as emotional state and personality of participants, which may influence the results. Future research should use examinations and objective clinical data to assess participants perception of smiling aesthetics. The second limitation is the distribution of the online questionnaire that may have biased the results, as the students are no longer motivated to fill out this type of survey. The third limitation is related to several objective variables. Indeed, they may interfere with the beauty and attraction of the smile, such as dimensions and proportion of the teeth, the buccal corridor, the curvature of the lips, the shape and contour of gums, black triangles, and embrasures. Therefore, this study needs to be complemented by further research to assess the perception of aesthetics by patients and dentists in order to identify the expectations of each practitioner. This will certainly contribute to the success of aesthetic prosthetic restorations.

Conclusions

According to Tunisian dental students, teeth are judged as the determining component in facial aesthe­tics. The emphasis on teeth gradually increases as the students’ progress through the university curriculum. The further the participant progresses into the university course, the more knowledgeable and therefore better qualified the person is to judge and evaluate the aesthe­tics of a person’s smile.

Disclosures

1. Institutional review board statement: The study was approved by the Ethics Committee of the Faculty of Dental Medicine in Monastir (FDMM), with approval number: 542023.
2. Assistance with the article: None.
3. Financial support and sponsorship: None.
4. Conflicts of interest: The authors declare no potential conflicts of interest concerning the research, authorship, and/or publication of this article.

References