Dental esthetics affects how people are perceived by society and how they perceive themselves, and this may also affect their oral health–related quality of life (OHRQoL). The aim of this study was to compare the impacts of self-perceived and normatively assessed dental esthetics on the OHRQoL of a young adult population.
This was a cross-sectional descriptive study involving 375 undergraduate university students, aged 18 to 30 years old. Data collection was carried out through oral examinations and self-administered questionnaires. Dental esthetics of the students was assessed using the esthetic component of the Index of Orthodontic Treatment Need. Two OHRQoL instruments were used: the shortened version of the Oral Health Impact Profile and the Psychosocial Impact of Dental Aesthetics Questionnaire.
Statistically significant relationships ( P <0.05) were recorded between both self-perceived and normatively assessed dental esthetics of the students, respectively, and 3 of the 4 Psychosocial Impact of Dental Aesthetics Questionnaire subscales: dental self-confidence (Kruskall-Wallis, P = 0.000; P = 0.000), psychological impact ( P = 0.003, P = 0.047), and esthetic concern ( P = 0.006, P = 0.003). The only exception was the social impact subscale, in which a significant relationship was recorded only with self-perceived dental esthetics ( P = 0.040). For the shortened version of the Oral Health Impact Profile scale, marked differences were also observed between the impacts recorded for both self-assessments and normative assessments, respectively, particularly for the psychological disability domain (Fisher exact test, P = 0.021, P = 0.000; P = 0.064, P = 0.096).
Differences exist between the impacts of self-perceived and normatively assessed dental esthetics on the OHRQoL of young adults, particularly in the psychosocial domains. These differences should be considered in orthodontic treatment planning for young adult populations.
Self-perceived and normatively assessed impacts of dental esthetics on oral health–related quality of life differ.
Marked differences were seen in psychological disability.
Associations for physical pain and physical disability were directly contrasted.
Differences should be considered when planning orthodontic treatment for young adults.
Facial and dental attractiveness represents important elements of quality of life for patients seeking orthodontic treatment. Most of these patients are often more concerned with improving their appearance and social acceptance than they are with improving their oral function or health. This is reinforced by the fact that research has shown that people may be judged by others based on their dental esthetics; with poor dental esthetics in children and adults associated with lower intelligence, whereas adults with ideal smiles are considered more intelligent and have a greater chance of finding a job, than do those with nonideal smiles.
However, there are considerable differences between a clinician’s and a patient’s perceptions of dental appearance and needs for orthodontic treatment. The clinician often uses traditional methods of measuring dental health and appearance, such as the Index of Orthodontic Treatment Need (IOTN) and the Dental Aesthetic Index; these cannot create a living picture of how people’s daily lives are affected by oral health issues. A major limitation of this approach is that it fails to take into account the way people really feel and therefore does not correspond to broader concepts of health and needs. To overcome this shortcoming, research has focused on developing broader sociodental concepts of oral health and as a result numerous sociodental or oral health–related quality of life (OHRQoL) measures have been developed.
OHRQoL is defined as “a standard of health of the oral and related tissues which enables an individual to eat, speak and socialize without active disease, discomfort or embarrassment,” or “the absence of negative impacts of oral conditions on social life and a sense of dentofacial self-confidence.” Assessment of OHRQoL allows a shift from the traditional medical and dental criteria to assessment and care that focus on a person’s social and emotional experiences and physical functioning in defining appropriate goals and outcomes. These measures have mainly been used to assess the impact of oral health on daily life and the relationship between subjective and clinical measures, and at the same time exploring their use as a screening tool for clinical measures. The use of OHRQoL measures as a part of the diagnostic procedures can provide information on priorities for treatment to maximize patient satisfaction.
Liu et al, in a systematic review to assess the impact of malocclusion and orthodontic treatment need on quality of life, reported a modest association between malocclusion and the need for orthodontic treatment with quality of life. This review highlighted the fact that most studies in this area had been restricted to children and adolescents. Thus, the authors recommended the need for future studies in adults, using standardized OHRQoL assessment instruments. Two good examples of these standardized instruments are the shortened version of the Oral Health Impact Profile (OHIP-14) and the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ).
The few studies that focused on adults have suggested that dental esthetics can have direct effects on all OHRQoL values. However, bearing in mind the differences between clinicians’ and patients’ perceptions of dental appearance and needs for orthodontic treatment, an important consideration not addressed in these studies is whether there is any difference between the impacts of self-perceived and normatively assessed dental esthetics on OHRQoL in young adults. The need for this study is further reinforced by the increasing percentage of adults seeking orthodontic treatment. Thus, the aim of this study was to compare the impacts between self-perceived and normatively assessed dental esthetics on the OHRQoL of a young adult population.
Material and methods
This was a cross-sectional study carried out with 420 undergraduate university students aged 18 to 30 years, chosen from 4 randomly selected residence halls (2 male and 2 female halls) at the University of Lagos, Akoka, Lagos, Nigeria, with a total student population of slightly over 50,000. Ethical approval for the study was obtained from the institutional review board, and permission to carry out the study was also obtained from the university’s Students’ Affairs Office. In addition, informed written consent was obtained from all students selected to participate in the study after it had been fully explained to them.
The study was restricted to students of native Nigerian origin: ie, students with Nigerian parents. In addition, students with a current or previous history of orthodontic treatment were not excluded from the study. Data were collected through self-administered questionnaires, interviews, and dental examinations performed by 2 orthodontists (G.I.I. and another). Dental esthetics was assessed using the aesthetic component of the IOTN (AC-IOTN). This was used to assess the self-perceived and normatively assessed dental esthetics of the students. The AC-IOTN records any esthetic impairment through a 10-point photographic scale with progressive degrees of esthetic problems, ranging from 1 (most attractive) to 10 (least attractive). It consists of 10 photographs of anterior teeth displaying varying degrees of malocclusion. Each student was asked to select the photograph that best represented the attractiveness of his or her dental appearance. This was used as a measure of their self-perceived dental esthetics. There was no time limit given to the subjects to study the photographs. The clinical examination (normative assessment) by the orthodontist (G.I.I.) was also carried out using this scale. The dental examinations and diagnostic criteria followed the World Health Organization’s recommendations for oral health surveys.
Two instruments were used to assess the OHRQoL of the students: the OHIP-14 and the PIDAQ. Data on the OHIP-14 were collected through structured interviews. These were used to measure the impacts of oral problems, capturing an overall measure of functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability, and handicap. Questions were scored on a 5-point scale (4, very often; 3, fairly often; 2, occasionally; 1, hardly ever; and 0, never). The individual item responses were added together to generate an overall OHIP-14 score, with possible values ranging from 0 to 56.
Data on the PIDAQ scales were obtained from the self-administered questionnaires. The PIDAQ is a 23-item psychometric instrument for assessment of orthodontic-specific aspects of quality of life, expressed in 4 domains: dental self-confidence (6 items), social impact (8 items), psychological impact (6 items), and esthetic concerns (3 items). A 5-point Likert scale was used to rate how much dental esthetics exerted a positive or negative impact, ranging from 0 to 4 (0, not at all; 1, a little; 2, somewhat; 3, strongly; and 4, very strongly). An overall PIDAQ score for each domain was obtained by summing all item scores in the domain.
Participants were categorized into groups based on their AC-IOTN scores. The AC-IOTN was collapsed from a 10-point scale to a 3-point scale. Photographs 1 to 4 represented no need for treatment; 5 to 7, borderline need for treatment; and 8 to 10 definite need for treatment on esthetic grounds. The OHIP-14 was scored using the simple-count method and the sum OHIP-14. The simple-count method of the OHIP was done by counting the number of items to which a student responded “occasionally,” “fairly often,” and “often,” which were regarded as impacts, and “hardly ever” and “never” were regarded as no impact. On the other hand, the sum OHIP involved summing the numeric response codes (0, never; 1, hardly ever; 2, occasionally; 3, fairly often; and 4, very often) for all 14 items to produce a single summary score for a subject. A sum OHIP score of 14 or less indicated no impact, and 15 or more indicated an impact.
Two orthodontists (G.I.I. and another) were involved in determining the normatively assessed dental esthetics of the students. Thus, to assess for interexaminer reliability, both orthodontists independently examined 10 students using the AC-IOTN, before the study. A weighted kappa score of 0.7 was recorded, showing good agreement between the 2 examiners. Intraexaminer reliability values for both examiners were also recorded to give weighted kappa scores greater than 0.7. Furthermore, to assess intraexaminer reliability, 20 students were reinterviewed and reexamined 7 days after their first assessments.
Descriptive statistics were used for the students’ age, perceptions of their dental esthetics compared with normative assessments, and the scores obtained for the different domains in the PIDAQ assessment. The Spearman rank correlation coefficient was used to compare the self-perceived with the normatively assessed dental esthetics. The Kruskal-Wallis test was used to test for the relationship between the PIDAQ subscale scores and the dental esthetics of the students. Chi-square and Fisher exact tests were also used to test for the associations between the OHIP-14 scores and the AC-IOTN of the students. The level of significance was set at P <0.05.
The final study sample included 375 subjects. Although 420 students were surveyed initially, data for 45 were incomplete, and thus those students were excluded from the final data analysis. Males made up 53.3% (200) of the sample, and females made up 46.7% (175). Their mean age was 21.16 + 2.65 years. Only 2 students surveyed were currently receiving orthodontic treatment, and 3 other students had previously received orthodontic treatment. Thus, only 5 students (0.01%) had a current or previous history of orthodontic treatment.
In the self-rating of their dental esthetics and orthodontic treatment need, 359 (95.7%) of the students rated their dentition as esthetically acceptable (AC-IOTN grades 1-4) and thus requiring no need for orthodontic treatment; 8 (2.1%) students rated themselves as having moderately acceptable esthetics and thus in moderate need of orthodontic treatment; another 8 (2.1%) rated themselves as having poor dental esthetics and thus in definite need of treatment. There was no statistically significant sex difference ( P = 0.064) in the self-perceived dental esthetics ( Table I ).
|No need for treatment||187 (93.5)||172 (98.3)||359 (95.7)|
|Moderate need for treatment||6 (3.0)||2 (1.1)||8 (2.1)|
|Definite need for treatment||7 (3.5)||1 (0.6)||8 (2.1)|
|Total||200 (100)||175 (100)||375 (100)|
The normatively assessed dental esthetics showed that 324 students (86.4%) had esthetically acceptable teeth and no need for orthodontic treatment (AC-IOTN grades 1-4), 46 students (12.3%) had a moderate need for orthodontic treatment (AC-IOTN grades 5-7), and 5 students (1.3%) had poor dental esthetics (AC-IOTN grades 8-10) and a definite need for orthodontic treatment. The normative assessment showed a statistically significant difference ( P <0.05) between the dental esthetics for the male and female subjects ( Table II ).
|No need for treatment||183 (91.5)||141 (80.6)||324 (86.4)|
|Moderate need for treatment||16 (8.0)||30 (17.1)||46 (12.3)|
|Definite need for treatment||1 (0.5)||4 (2.3)||5 (1.3)|
|Total||200 (100)||175 (100)||375 (100)|
A statistically significant association ( P = 0.000) was observed between the self-perceived and normatively assessed dental esthetics of the students. The Spearman rank correlation coefficient showed a weak but significant correlation (r = 0.325; P = 0.000) between the 2 assessments. Three hundred twenty-four students were rated by the orthodontists as having acceptable dental esthetics and no need for orthodontic treatment; of them, 315 students rated themselves likewise, whereas 46 students were rated by the orthodontists as having moderately acceptable dental esthetics and thus in moderate need of orthodontic treatment, but only 4 agreed. Of the 5 students who were normatively assessed to have poor dental esthetics and thus in definite need of orthodontic treatment, only 2 rated themselves likewise ( Table III ).
|Self-perceived dental esthetics||Professionally assessed dental esthetics||Fisher exact test||Spearman rank correlation coefficient|
|No need||Moderate need||Definite need||Total|
|No need||315 (84.0)||41 (10.9)||3 (0.8)||359 (95.1)|
|Moderate need||4 (1.1)||4 (1.1)||0 (0.0)||8 (2.1)|
|Definite need||5 (1.3)||1 (0.3)||2 (0.5)||8 (2.1)|
|Total||324 (86.4)||46 (12.3)||5 (1.3)||375 (100.0)||0.0000||r = 0.325, P = 0.000|
There was a statistically significant difference in the mean PIDAQ subscale scores of the students when analyzed according to their self-perceived dental esthetics using the AC-IOTN. This statistically significant difference ( P <0.05) was noticed for all 4 PIDAQ subscales of dental self-confidence, social impact, psychological impact, and aesthetic concern, with the greatest difference observed in the dental self-confidence subscale ( P <0.000). This finding implies that there was a statistically significant difference in the OHRQoL of the students using the PIDAQ scale, based on their self-perceived dental esthetics and orthodontic treatment need. The mean value for dental self-confidence gradually decreased with poorer dental esthetics and increased orthodontic treatment need ( Table IV ).
|PIDAQ subscale||AC-IOTN (self-perceived)||P value|
|No need for treatment||Borderline need for treatment||Definite need for treatment|
|Dental self-confidence||14.4 (6.1)||8.5 (5.4)||7.5 (4.8)||0.000 ∗|
|Social impact||5.3 (6.2)||14.3 (13.3)||9.8 (8.1)||0.040 ∗|
|Psychological impact||8.0 (5.5)||15.9 (5.0)||11.5 (5.0)||0.003 ∗|
|Esthetic concern||1.51 (2.6)||5.1 (5.1)||3.5 (3.4)||0.006 ∗|
Furthermore, there was a statistically significant difference ( P <0.05) in the OHRQoL of the students across the 3 treatment need categories in the PIDAQ subscales of dental self-confidence, psychological impact, and aesthetic concern when analyzed based on their normatively assessed dental esthetics and orthodontic treatment need. However, this statistically significant difference was observed in only 3 of the 4 PIDAQ subscales, with the social impact subscale showing no statistically significant difference ( P >0.05) across the treatment need categories ( Table V ).
|PIDAQ subscale||AC-IOTN (normatively assessed)||P value|
|No need for treatment||Borderline need for treatment||Definite need for treatment|
|Dental self-confidence||14.7 (6.0)||10.7 (6.0)||8.8 (5.0)||0.000 ∗|
|Social impact||5.4 (6.5)||6.8 (7.2)||6.8 (8.8)||0.305|
|Psychological impact||7.9 (5.6)||9.8 (6.2)||1.2 (3.4)||0.047 ∗|
|Esthetic concern||1.5 (2.6)||2.8 (3.5)||2.6 (3.2)||0.003 ∗|
A statistically significant association was observed between the self-perceived dental esthetics of the students and all 14 daily activities listed in the OHIP-14, except for 2: “had a painful aching in the mouth” (physical pain) and “had an unsatisfactory diet” (physical disability). Thus, the OHIP-14 domains of functional limitation, psychological discomfort, physical disability, psychological disability, social disability, and handicap were significantly associated with the self-perceived dental esthetics of the students, whereas parts of the domains of physical pain and physical disability showed no significant relationship. Strong significant associations were observed in the psychological discomfort, psychological disability, social disability, and handicap domains, but relatively weaker associations were observed in the functional limitation, physical pain, and handicap domains ( Table VI ).
|OHIP-14 daily activity||No need||Moderate need||Definite need||Fisher exact value|
|1. Had problems pronouncing words|
|-No impact||285 (79.4)||5 (62.5)||6 (75.0)||0.048 ∗|
|-Impact||74 (20.6)||3 (37.5)||2 (25.0)|
|2. Had worsened sense of taste|
|-No impact||301 (83.8)||7 (87.5)||5 (62.5)||0.039 ∗|
|-Impact||58 (16.2)||1 (12.5)||3 (37.5)|
|3. Had a painful aching in the mouth|
|-No impact||168 (46.8)||3 (37.5)||4 (50.0)||0.067|
|-Impact||191 (53.2)||5 (62.5)||4 (50.0)|
|4. Found it uncomfortable to eat any food|
|-No impact||215 (59.9)||4 (50.0)||6 (75.0)||0.050|
|-Impact||144 (40.1)||4 (50.0)||2 (25.0)|
|5. Have you been self-conscious?|
|-No impact||207 (57.7)||3 (37.5)||0 (0.0)||0.000 ∗|
|-Impact||152 (42.3)||5 (62.5)||8 (100.0)|
|6. Felt tense|
|-No Impact||281 (78.3)||2 (25.0)||4 (50.0)||0.000 ∗|
|-Impact||78 (21.7)||6 (75.0)||4 (50.0)|
|7. Had an unsatisfactory diet|
|-No impact||270 (75.2)||6 (75.0)||7 (87.5)||0.086|
|-Impact||89 (24.8)||2 (25.0)||1 (12.5)|
|8. Had to interrupt meals|
|-No impact||291 (81.1)||5 (62.5)||6 (75.0)||0.041 ∗|
|-Impact||68 (18.9)||3 (37.5)||2 (25.0)|
|9. Found it difficult to relax|
|-No impact||306 (85.2)||5 (62.5)||6 (75.0)||0.021 ∗|
|-Impact||53 (14.1)||3 (37.5)||2 (25.0)|
|10. Had been a bit embarrassed|
|-No impact||286 (79.7)||4 (50)||2 (25.0)||0.000 ∗|
|-Impact||73 (20.3)||4 (50)||6 (75.0)|
|11. Had been irritable with other people|
|-No impact||271 (75.5)||4 (50.0)||5 (62.5)||0.018 ∗|
|-Impact||88 (24.5)||4 (50.0)||3 (37.5)|
|12. Had difficulty doing usual jobs|
|-No impact||323 (92.5)||5 (62.5)||7 (87.5)||0.008 ∗|
|-Impact||27 (7.5)||3 (37.5)||1 (12.5)|
|13. Felt life in general is less satisfactory|
|-No impact||269 (74.9)||5 (62.5)||5 (62.5)||0.046 ∗|
|-Impact||90 (25.1)||3 (37.5)||3 (37.5)|
|14. Had been totally unable to function|
|-No impact||347 (96.7)||6 (75.0)||6 (75.0)||0.000 ∗|
|-Impact||12 (3.3)||2 (25.0)||2 (25.0)|
There was a statistically significant association between the normatively assessed dental esthetics of the students and 8 of the 14 daily activities listed in the OHIP-14 scale. These were “had problems pronouncing words” and “felt sense of taste had worsened” (functional limitation), “painful aching in the mouth” (physical pain), “being self-conscious” and “feeling tense” (psychological discomfort), “had an unsatisfactory diet” (physical disability), “had been irritable with other people” (social disability), and “felt life in general was less satisfying” (handicap). Thus, the OHIP-14 domains of functional limitation, physical pain, psychological discomfort, physical disability, social disability, and handicap were significantly associated with the normatively assessed dental esthetics of the students. Conversely, the only unaffected domain was the psychological disability domain ( Table VII ).