Psychosocial Impact of Dental Aesthetics Questionnaire – Portuguese Version

Abstract

The Psychosocial Impact of Dental Aesthetics Questionnaire – Portuguese Version (PIDAQ-PT) is a standardized, multidimensional psychometric instrument developed to evaluate the profound influence of dental aesthetics on psychological well-being and social functioning among adult populations. Originating from the foundational work of Klages and colleagues (2006), the instrument captures how individuals perceive, internalize, and emotionally react to their dentofacial appearance. Validated in Portugal by Fidalgo, Botelho, Proença, Mendes, Machado, and Delgado (2022), the PIDAQ-PT provides clinicians and researchers with an empirically verified patient-reported outcome measure (PROM) adapted to the linguistic and cultural realities of European Portuguese speakers.

The questionnaire consists of 23 items structured across four distinct theoretical domains: Dental Self-Confidence (6 items), Social Impact (8 items), Psychological Impact (6 items), and Esthetic Concern (3 items). Participants rate each item using a 5-point Likert scale ranging from 0 (“not at all”) to 4 (“very strongly”). Items belonging to the Dental Self-Confidence subscale are reverse-scored, such that higher overall scores consistently reflect a greater negative psychosocial burden associated with dental aesthetics.

Psychometric evaluation of the PIDAQ-PT in a sample of 501 adult clinical patients (mean age = 48.7 years; range = 18–88; 52.3% female) demonstrated outstanding measurement properties. Confirmatory factor analysis (CFA) affirmed the robust fit of the original four-factor multidimensional model, yielding Comparative Fit Indices (CFI) between 0.905 and 0.921 and Root Mean Square Error of Approximation (RMSEA) values from 0.088 to 0.090. Internal consistency reliability was exceptional, evidenced by an overall Cronbach's alpha coefficient of 0.91 and subscale alphas ranging from 0.93 to 0.98. Temporal stability assessed via test-retest analysis over a one-week interval demonstrated excellent reproducibility, with total Intraclass Correlation Coefficients (ICC) of 0.84 and subscale ICCs ranging from 0.87 to 0.96. The PIDAQ-PT bridges the longstanding divide between normative clinical indices and subjective patient experiences in orthodontics, periodontology, and cosmetic dentistry.

Keywords

Psychosocial Impact, Dental Aesthetics, Oral Health-Related Quality of Life, PIDAQ, Psychometrics, Cross-Cultural Validation, Orthodontics, Patient-Reported Outcome Measures, Self-Concept, Social Anxiety

Authors

The cross-cultural adaptation, psychometric validation, and clinical translation of the Portuguese Version of the Psychosocial Impact of Dental Aesthetics Questionnaire were conducted by an interdisciplinary research team affiliated with the Clinical Research Unit and Dental Clinic of the Egas Moniz School of Health & Science:

• João Fidalgo, DDS, MSc — Clinical Research Unit (CRU), Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Egas Moniz Dental Clinic, Instituto Universitário Egas Moniz, Caparica, Almada, Portugal.
• João Botelho, DDS, PhD (Corresponding Author) — Clinical Research Unit (CRU), Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Egas Moniz Dental Clinic, Instituto Universitário Egas Moniz, Caparica, Almada, Portugal. Contact: [email protected].
• Luís Proença, PhD — Quantitative Methods for Health Research Unit (MQIS), Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz, Caparica, Almada, Portugal.
• José João Mendes, DDS, PhD — Clinical Research Unit (CRU), Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Egas Moniz Dental Clinic, Instituto Universitário Egas Moniz, Caparica, Almada, Portugal.
• Vanessa Machado, DDS, PhD — Clinical Research Unit (CRU), Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Egas Moniz Dental Clinic, Instituto Universitário Egas Moniz, Caparica, Almada, Portugal.
• Ana Sintra Delgado, DDS, PhD — Clinical Research Unit (CRU), Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Egas Moniz Dental Clinic, Instituto Universitário Egas Moniz, Caparica, Almada, Portugal.

Purpose

The primary clinical and scientific objective of the Psychosocial Impact of Dental Aesthetics Questionnaire – Portuguese Version (PIDAQ-PT) is to provide an empirically grounded, patient-centered instrument that quantifies the psychological distress, behavioral inhibition, and aesthetic self-perceptions associated with malaligned teeth, tooth discoloration, or dentofacial disharmony. For over half a century, clinical dental decision-making was dominated by normative, physical measures of oral pathology. Indices such as the Index of Orthodontic Treatment Need (IOTN), the Dental Aesthetic Index (DAI), and the Peer Assessment Rating (PAR) assess anatomical malocclusions strictly through millimeters of overjet, crowding, crossbites, and cephalometric angles.

However, extensive clinical research indicates that clinician-rated normative severity frequently correlates poorly with the actual subjective distress reported by patients. Individuals with clinically severe malocclusions may experience negligible psychological impairment, whereas patients with clinically minor anterior crowding or mild diastemas can manifest acute interpersonal anxiety, severe self-consciousness, and depressive symptoms. The PIDAQ-PT addresses this fundamental clinical divergence by capturing the nuanced intrapsychic and interpersonal impacts of dental appearance, effectively serving as an essential subjective adjunct to objective clinical diagnoses.

In clinical practice, the PIDAQ-PT serves three pivotal functions:

• Baseline Diagnostic Assessment and Triage: It allows orthodontists, prosthodontists, periodontists, and restorative dentists to systematically screen for psychological distress, identify patient motivations for treatment, and distinguish between realistic aesthetic dissatisfaction and broader body image psychopathologies such as body dysmorphic disorder.
• Personalized Treatment Planning: By dissecting a patient's aesthetic profile across four distinct latent dimensions (e.g., distinguishing whether a patient suffers predominantly from social anxiety versus internalized feelings of inferiority), clinicians can tailor communication, prioritize aesthetic corrections, and establish shared therapeutic objectives.
• Longitudinal Outcome Monitoring: Administered pre- and post-intervention, the PIDAQ-PT enables practitioners to measure the true psychosocial efficacy of orthodontic movement, orthognathic surgery, dental bleaching, or veneer placement, demonstrating whether physical alterations genuinely translate into improved psychological well-being.

In epidemiological and clinical research, the PIDAQ-PT equips dental and behavioral researchers with a validated psychometric metric to examine the systemic relationships among oral health-related quality of life, socioeconomic disparities, mental health outcomes, and health-seeking behaviors across diverse adult populations in Portugal.

Psychological Construct

The psychological construct operationalized by the PIDAQ-PT is the multidimensional psychosocial impact of dental aesthetics. Dental aesthetics do not merely represent isolated visual characteristics; rather, they serve as prominent facial signifiers that actively mediate social interactions, interpersonal perceptions, and internalized identity formation. The instrument deconstructs this broad construct into four distinct, theoretically coherent latent dimensions:

1. Dental Self-Confidence (Items 1–6)

The Dental Self-Confidence subscale captures the positive psychological states, emotional pleasure, and personal pride an individual derives from the aesthetic appearance of their teeth. Rather than evaluating pathology or deficits, this domain measures positive hedonic and eudaimonic components of body image. It assesses the individual’s comfort and spontaneous joy when smiling in public, exhibiting feelings such as being proud of one’s teeth (Item 1), enjoying showing teeth during laughter (Item 2), and perceiving one’s smile as attractive to others (Item 3). In the scoring architecture of the PIDAQ-PT, these positive items are reverse-scored to ensure that lower confidence scores contribute to higher overall psychosocial impact metrics, reflecting an absence of protective positive self-worth.

2. Social Impact (Items 7–14)

The Social Impact subscale measures the disruptive behavioral modifications and interpersonal anxiety provoked by perceived dental aesthetic deficiencies. This dimension captures social inhibition, anticipatory dread of negative peer evaluations, and physical avoidance behaviors. Patients who score high on this subscale report holding back smiles to prevent exposure of their dentition (Item 7), anxiety regarding peer judgment in unfamiliar company (Item 8), intense fear of being mocked or ridiculed (Item 9), and active physical concealment, such as covering the mouth with a hand while speaking or laughing (Item 14). This factor closely mirrors clinical manifestations of social anxiety and interpersonal sensitivity.

3. Psychological Impact (Items 15–20)

The Psychological Impact subscale evaluates the deeply internalized, negative emotional sequelae of dental aesthetic dissatisfaction. Unlike the interpersonal focus of the Social Impact subscale, this domain reflects intrapsychic distress, unfavorable social comparisons, and affective demoralization. High scores indicate that the individual harbors profound envy toward peers possessing harmonious smiles (Item 15), recurrent feelings of unhappiness or shame regarding dental appearance (Item 16), persistent beliefs that their teeth are inferior to those of most acquaintances (Item 17), and generalized dysphoria or demoralization centered on dentofacial aesthetics (Item 18). It captures cognitive rumination and the negative self-appraisal components of the self-concept.

4. Esthetic Concern (Items 21–23)

The Esthetic Concern subscale is a focused, three-item dimension that quantifies visual dissatisfaction and direct aversion to viewing one's own dentition across reflective or recorded media. This factor assesses visceral discomfort and distress when observing one's teeth in mirrors, photographs, or digital video recordings (Items 21, 22, and 23). In an era saturated with digital imagery, social media exposure, and virtual video conferencing, this subscale captures an increasingly prevalent manifestation of facial aesthetic dissatisfaction, reflecting heightened self-focused visual attention and dysmorphic preoccupation.

Theoretical Framework

The PIDAQ-PT is firmly anchored within the contemporary theoretical frameworks of Oral Health-Related Quality of Life (OHRQoL), cognitive-behavioral models of body image, and classic social psychological theories of self-presentation.

Locker's Conceptual Framework and the Wilson & Cleary Model

Historically, oral health was conceptualized through biomedical frameworks, such as David Locker’s (1988) adaptation of the World Health Organization’s International Classification of Impairments, Disabilities, and Handicaps. Locker postulated a linear sequence progressing from physical disease to physiological impairment, functional limitation, psychological discomfort, and social disability. The Wilson and Cleary (1995) health-related quality of life model expanded this perspective by integrating biological parameters, symptom status, functional status, general health perceptions, and overall quality of life. The PIDAQ-PT operates precisely within the psychosocial tiers of these frameworks, recognizing that aesthetic variations (structural impairment) do not directly dictate functional disability, but rather trigger subjective cognitive appraisals that profoundly shape quality of life.

Festinger's Social Comparison Theory

The psychological underpinnings of the PIDAQ are deeply rooted in Leon Festinger’s (1954) Social Comparison Theory. Festinger asserted that humans possess an innate drive to evaluate their own opinions, abilities, and physical traits by comparing themselves to others. In modern societies, societal standards of dental aesthetics—characterized by bilateral symmetry, high incisal display, straight alignment, and tooth whiteness—are pervasive across media. When individuals make “upward social comparisons” against these idealized cultural archetypes, perceived discrepancies between their actual dentition and the cultural ideal precipitate feelings of envy, inferiority, and psychological distress (operationalized directly in PIDAQ Items 15 and 17).

Goffman's Theory of Stigma and Social Presentation

Erving Goffman’s (1963) sociological treatise on stigma provides another vital conceptual anchor. Goffman identified physical deformities and visual abnormalities as “abominations of the body” that can instantly spoil an individual’s social identity, reducing them from a whole person to a discounted, tainted figure. The mouth and teeth represent the focal nexus of facial communication, verbal articulation, and emotional expression. When an individual perceives their teeth as defective, they anticipate social stigmatization, stereotyping (e.g., the unconscious attribution of low intelligence, poor hygiene, or low social status to individuals with irregular dentition), and ridicule. In response, the individual adopts Goffmanian impression-management tactics, such as masking the mouth, smiling with closed lips, or withdrawing from interpersonal encounters—behavioral strategies directly mapped onto the PIDAQ Social Impact dimension.

Validity

The construct, convergent, and discriminant validity of the PIDAQ-PT were rigorously evaluated by Fidalgo and colleagues (2022) in accordance with internationally recognized psychometric guidelines and the COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) criteria.

Construct Validity

Construct validity was primarily assessed through Confirmatory Factor Analysis (CFA) to determine whether the empirical covariance structure observed in the Portuguese clinical population replicated the theoretical four-factor multidimensional model established by Klages et al. (2006). Testing the four latent variables (Dental Self-Confidence, Social Impact, Psychological Impact, and Esthetic Concern) across 501 adult participants confirmed adequate to strong goodness-of-fit:

• Comparative Fit Index (CFI): Ranged from 0.905 to 0.921 across model iterations. In structural equation modeling conventions (Hu & Bentler, 1999; Marsh et al., 2004), CFI values exceeding 0.90 establish an acceptable and theoretically congruent representation of sample data.
• Root Mean Square Error of Approximation (RMSEA): Yielded values between 0.088 and 0.090 (90% Confidence Interval: 0.082–0.096). While strict cutoffs in cross-sectional research occasionally target RMSEA < 0.06, values between 0.08 and 0.10 are widely recognized as demonstrating acceptable fit in complex, multidimensional, highly correlated psychological inventories.

Convergent and Discriminant Validity

Convergent validity was substantiated by examining the associations between PIDAQ-PT dimensions and independent measures of oral health status and subjective aesthetic self-appraisal. Statistically significant positive correlations were established between the negative PIDAQ subscales (Social Impact, Psychological Impact, and Esthetic Concern) and self-reported aesthetic dissatisfaction, self-perceived orthodontic treatment need, and poor self-rated oral health ($p < 0.001$). Conversely, the Dental Self-Confidence subscale exhibited strong, statistically significant inverse correlations with self-rated aesthetic concern and subjective malocclusion severity, demonstrating convergent coherence.

Discriminant validity was established by confirming that the latent factors, while intercorrelated as expected within an overarching psychosocial construct, demonstrated distinct factor loadings. Multitrait-multimethod correlation matrices and average variance extracted (AVE) parameters confirmed that each latent construct accounted for greater variance in its designated indicator items than shared variance with other latent constructs, confirming that the subscales capture distinct aspects of psychological functioning rather than redundant expressions of general distress.

Reliability

The PIDAQ-PT displays exceptional psychometric reliability, evaluated through both internal consistency metrics and temporal stability (test-retest reproducibility) assessments.

Internal Consistency

The overall internal consistency of the 23-item Portuguese questionnaire was outstanding, yielding a total Cronbach's alpha coefficient ($lpha$) of 0.91. Analysis of individual subscale performance revealed exceptionally high internal consistency coefficients that equaled or surpassed original validation studies across the globe:

• Dental Self-Confidence Subscale: Cronbach's $lpha = 0.93$
• Social Impact Subscale: Cronbach's $lpha = 0.98$
• Psychological Impact Subscale: Cronbach's $lpha = 0.96$
• Esthetic Concern Subscale: Cronbach's $lpha = 0.94$

These values demonstrate that the individual items within each domain reliably measure identical underlying psychological constructs with minimal measurement noise. Inter-item correlations within subscales remained within the optimal range ($r = 0.50$ to $0.85$), confirming high coherence without excessive semantic redundancy.

Temporal Stability (Test-Retest Reliability)

To establish that the PIDAQ-PT yields stable, reproducible measurements unaffected by temporal fluctuations in mood, the authors conducted a test-retest reliability study with an independent pilot subgroup ($n = 50$) reassessed over a one-week interval under identical clinical conditions. The analysis utilized the Intraclass Correlation Coefficient (ICC) based on a two-way mixed-effects, absolute-agreement model:

• Total Scale ICC: 0.84 (95% CI: 0.76–0.90), demonstrating strong overall stability.
• Dental Self-Confidence Subscale ICC: 0.87 (95% CI: 0.80–0.92).
• Social Impact Subscale ICC: 0.96 (95% CI: 0.93–0.98).
• Psychological Impact Subscale ICC: 0.91 (95% CI: 0.85–0.95).
• Esthetic Concern Subscale ICC: 0.89 (95% CI: 0.82–0.94).

Following established psychometric conventions (Weir, 2005; Koo & Li, 2016), ICC values between 0.75 and 0.90 indicate good reliability, while values exceeding 0.90 indicate excellent temporal reproducibility. The high stability coefficients confirm that changes observed across longitudinal evaluations reflect genuine treatment effects rather than random measurement error.

Factor Analysis

The internal structural architecture of the PIDAQ-PT was rigorously interrogated using Confirmatory Factor Analysis (CFA) conducted via structural equation modeling (SEM) packages in AMOS and R. Because the original four-factor dimensional structure proposed by Klages et al. (2006) has been consistently corroborated across numerous global adaptations (including Brazilian Portuguese, Spanish, Italian, Chinese, and Swedish cohorts), the Portuguese investigators implemented a confirmatory rather than exploratory framework.

Sample Characteristics and Statistical Power

The CFA was powered by a clinical sample of 501 adult patients recruited consecutively from the triage department of the Egas Moniz Dental Clinic in Almada, Portugal. Methodological guidelines for structural equation modeling generally mandate a minimum ratio of 10 to 20 participants per observed variable. With 23 items, the minimum requisite sample size was 230 to 460 subjects; thus, a sample of 501 individuals provided ample statistical power to avoid parameter distortion, ensure convergence, and yield stable asymptotic covariance matrices.

Factor Loadings and Structural Fit

The specified measurement model posited four first-order correlated latent factors mapped onto their respective manifest indicator variables:

• Factor 1: Dental Self-Confidence ← Items 1, 2, 3, 4, 5, 6 (Standardized factor loadings $lambda$ ranged from 0.78 to 0.92).
• Factor 2: Social Impact ← Items 7, 8, 9, 10, 11, 12, 13, 14 (Standardized factor loadings $lambda$ ranged from 0.82 to 0.95).
• Factor 3: Psychological Impact ← Items 15, 16, 17, 18, 19, 20 (Standardized factor loadings $lambda$ ranged from 0.80 to 0.94).
• Factor 4: Esthetic Concern ← Items 21, 22, 23 (Standardized factor loadings $lambda$ ranged from 0.85 to 0.96).

All standardized factor loadings were statistically significant at $p < 0.001$, exceeding the conventional psychometric retention threshold of 0.50 and the stringent standard of 0.70. The global goodness-of-fit indices demonstrated model adequacy ($\chi^2/df < 4.0$, $ ext{CFI} = 0.905–0.921$,$ ext{RMSEA} = 0.088–0.090$), empirically confirming that the 23 items retain their designated conceptual allocation without significant cross-loadings in the Portuguese cultural context.

Instrument / Measurement Tool

The structured attributes, administration conditions, and scoring architecture of the PIDAQ-PT are outlined below:

• Instrument Name: Psychosocial Impact of Dental Aesthetics Questionnaire – Portuguese Version (PIDAQ-PT)
• Original Developers: Udo Klages, Angelika Bruckner, and Andreas Zentner (2006)
• Portuguese Validation Authors: João Fidalgo, João Botelho, Luís Proença, José João Mendes, Vanessa Machado, and Ana Sintra Delgado (2022)
• Construct Measured: Multidimensional psychosocial impact of dentofacial and dental aesthetics
• Assessment Format: 23 items; self-administered or face-to-face clinical interview questionnaire
• Response Scale: 5-point Likert scale (0 = “not at all”, 1 = “a little”, 2 = “somewhat”, 3 = “strongly”, 4 = “very strongly”)
• Subscale Allocation:
  • Dental Self-Confidence: Items 1, 2, 3, 4, 5, 6 (6 items)
  • Social Impact: Items 7, 8, 9, 10, 11, 12, 13, 14 (8 items)
  • Psychological Impact: Items 15, 16, 17, 18, 19, 20 (6 items)
  • Esthetic Concern: Items 21, 22, 23 (3 items)
• Scoring Formula and Directionality:
  • Reverse Scoring: Items 1, 2, 3, 4, 5, and 6 (Dental Self-Confidence) must be reversed prior to computing subscale or composite scores ($0
    ightarrow 4$, $1
    ightarrow 3$, $2
    ightarrow 2$, $3
    ightarrow 1$, $4
    ightarrow 0$).
  • Direct Scoring: Items 7 through 23 are scored directly from 0 to 4.
  • Subscale Scores: Computed by summing the respective item scores within each factor (or calculating the subscale mean).
  • Total Composite Score: Computed by summing all 23 items (with Items 1–6 reversed). Total raw scores range from 0 to 92. Higher scores indicate a greater negative psychosocial impact, heightened social inhibition, and severe aesthetic dissatisfaction.
• Target Population: Adults and adolescents aged 18 to 88 years presenting for routine, orthodontic, or cosmetic dental care
• Administration Time: Approximately 5 to 8 minutes
• Language: European Portuguese (Portuguese)

Permissions & Fee and Test Year

The Portuguese adaptation and validation study for the PIDAQ was officially published in 2022. The article is licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are appropriately credited.

The PIDAQ-PT is an open-access psychometric instrument available free of charge for non-commercial clinical practice, academic research, and institutional educational purposes. Clinicians and researchers wishing to utilize the instrument in formal clinical trials or health services research should cite the primary Portuguese validation paper (Fidalgo et al., 2022) as well as the original seminal developmental paper (Klages et al., 2006). Commercial entities or corporate third parties seeking to integrate the instrument into commercial software suites or proprietary cosmetic treatment evaluation platforms should contact the corresponding author, Dr. João Botelho ([email protected]), and the original copyright holders.

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Items of the Scale