Thai Halitosis Associated Life-Quality Test

Abstract

The Thai Halitosis Associated Life-Quality Test (T-HALT) is a specialized psychometric assessment instrument adapted and validated to quantify the multidimensional psychosocial, emotional, and behavioral burden of oral malodor among Thai-speaking populations. Halitosis represents a pervasive clinical and social condition primarily characterized by unpleasant breath emanations resulting from the metabolic degradation of proteins by anaerobic microorganisms into volatile sulfur compounds (VSCs). Beyond its biological etiology, halitosis exerts profound debilitating impacts on individuals’ subjective psychological well-being, driving social withdrawal, relational avoidance, interpersonal anxiety, and chronic low self-esteem. Conventional oral health-related quality of life (OHRQoL) inventories often lack the sensitivity and granularity necessary to capture the idiosyncratic behavioral modifications and self-monitoring rituals pathognomonic to halitosis sufferers. To address this diagnostic gap, the original Halitosis Associated Life-Quality Test (HALT) was cross-culturally translated and rigorously psychometrically evaluated within a clinical cohort in Thailand.

The T-HALT comprises a 20-item self-report questionnaire configured on a Likert rating response format, generating a composite score ranging from 0 to 100, wherein elevated scores denote heightened functional and psychosocial impairment. Structural evaluations via exploratory and confirmatory factor analyses revealed an underlying four-factor architecture encompassing physiological/functional manifestations, social-interactional inhibitions, affective/emotional distress, and cognitive self-consciousness. The instrument exhibits exceptional internal consistency reliability, with Cronbach’s alpha coefficients spanning 0.940 to 0.943, alongside exemplary temporal stability evidenced by an Intraclass Correlation Coefficient (ICC) of 0.886 across test-retest assessments. Construct validity investigations demonstrated robust convergent validity through a moderate-to-strong positive correlation with self-perceived halitosis ratings (r = 0.503), while simultaneously establishing profound discriminant validity through a near-zero correlation with objective gas-chromatographic measurements of volatile sulfur compounds (r = 0.071). This critical divergence underscores that halitosis-related quality of life is mediated by cognitive appraisal and subjective perception rather than physiological gas emission alone, establishing the T-HALT as an indispensable psychometric tool for clinical diagnostics, therapeutic outcome monitoring, and health psychology research.

Keywords

Halitosis, Oral Health-Related Quality of Life, T-HALT, Psychometrics, Cross-Cultural Adaptation, Volatile Sulfur Compounds, Social Anxiety, Factor Analysis, Construct Validity, Test-Retest Reliability

Authors

The development, linguistic adaptation, and formal psychometric validation of the Thai Halitosis Associated Life-Quality Test were conducted by an interdisciplinary research consortium affiliated with the Faculty of Dentistry at Mahidol University, Bangkok, Thailand:

• Yodhathai Satravaha, DDS, MSc — Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
• Katkarn Thitiwatpalakarn, DDS — Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
• Supakit Peanchitlertkajorn, DDS — Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
• Supatchai Boonpratham, DDS — Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
• Chaiyapol Chaweewannakorn, DDS — Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
• Kawin Sipiyaruk, DDS, MSc, PhD (Corresponding Author) — Department of Community Dentistry and Dental Public Health, Faculty of Dentistry, Mahidol University, Bangkok, Thailand. Electronic correspondence: [email protected].

Purpose

The primary clinical and epidemiological objective of the Thai Halitosis Associated Life-Quality Test (T-HALT) is to supply a linguistically robust, culturally calibrated, and psychometrically sound metric capable of assessing the disease-specific burden imposed by oral malodor on the day-to-day existence and emotional stability of Thai patients. Although generic health-related quality of life metrics (such as the Short Form-36 Health Survey) and broad dental assessment tools (such as the Oral Health Impact Profile, OHIP-14 or OHIP-49) provide macro-level insights into physical functional limitations and general oral comfort, they consistently demonstrate floor effects and inadequate sensitivity when evaluating breath odor concerns. Halitosis generates highly specific cognitive preoccupations, ritualistic behavioral adjustments, and relational apprehensions—such as covering one’s mouth during speech, maintaining extensive physical distance, avoidance of eye contact, and continuous ingestion of breath-freshening confectionery—that generic scales fail to record.

In clinical dentistry and behavioral medicine, the T-HALT addresses a profound clinical paradox: the ubiquitous discrepancy observed between clinical diagnostics (e.g., organoleptic hedonic scores or gas chromatographic quantification of hydrogen sulfide, methyl mercaptan, and dimethyl sulfide) and the patient’s subjective suffering. Individuals presenting with minimal or undetectable physiological volatile sulfur compounds may experience incapacitating psychological anguish, an obsessive belief in perceived odor (pseudo-halitosis), or severe clinical halitophobia. Conversely, individuals exhibiting extreme objective oral malodor may present with minimal conscious awareness or psychological distress due to sensory olfactory fatigue and mucosal adaptation. Consequently, the T-HALT furnishes clinicians with an evidence-based method to measure the subjective severity of the condition, enabling dental surgeons, periodontists, and clinical psychologists to formulate patient-centered treatment plans that integrate mechanical-antimicrobial oral decontamination with targeted cognitive reassurance or psychoeducation.

In public health, epidemiologic surveys, and clinical trial research, the T-HALT serves as a standardized primary or secondary patient-reported outcome measure (PROM). When investigating the clinical efficacy of novel mouthwashes, periodontal debridement regimens, tongue-scraping protocols, or probiotic formulations, biological outcomes alone provide an incomplete picture of therapeutic success. By quantifying longitudinal shifts in social self-confidence, interpersonal comfort, and mood stabilization via pre- and post-intervention T-HALT administrations, researchers can empirically evaluate whether physiological odor elimination translates into meaningful improvements in human social functioning and daily emotional health.

Psychological Construct

The construct measured by the T-HALT is halitosis-related quality of life, an advanced sub-domain within the broader paradigm of Oral Health-Related Quality of Life (OHRQoL). This multidimensional construct conceptualizes human health not merely as the clinical absence of disease or pathology, but as an optimal state of physical, mental, and social functioning within the oral domain. The construct operates on the theoretical premise that oral malodor acts as an invisible yet socially salient disfigurement, disrupting an individual’s self-image, triggering chronic cognitive hypervigilance, and imposing structural limitations across four operationalized domains:

1. Somatosensory and Physical Symptom Domain

This domain captures the physical, somatic sensations frequently associated with intra-oral and extra-oral etiologies of halitosis. It encompasses sensations of oral xerostomia (dry mouth), thick or viscous saliva, lingering unpleasant, bitter, or metallic gustatory sensations (dysgeusia), chronic pharyngeal irritation, and the persistent urge to clear the throat. Rather than serving purely as objective dental findings, these somatic symptoms act as internal sensory cues that trigger worry and reinforce the individual’s belief that their breath is actively noxious to external observers.

2. Social and Interpersonal Avoidance Domain

Halitosis is an inherently relational disorder; its psychological impact is profoundly amplified within social environments. This construct domain operationalizes behavioral safety strategies and avoidance patterns adopted by affected individuals to mask their breath or prevent detection by peers, romantic partners, or professional colleagues. Key behavioral markers include maintaining unnatural interpersonal distances, turning one’s head away during conversation, placing a hand or fingers over the mouth while speaking, hesitating to initiate conversation, or completely withdrawing from occupational, academic, or communal gatherings.

3. Affective and Psychological Distress Domain

This dimension reflects the internalized emotional toll generated by living with perceived or confirmed oral malodor. The construct includes persistent states of low mood, feelings of despair, depressive symptomatology, generalized and anticipatory social anxiety, and acute episodes of shame or embarrassment when interacting in close physical proximity with others. The constant anticipation of negative social evaluation fosters an emotional vulnerability that significantly compromises general subjective well-being.

4. Cognitive Self-Consciousness and Self-Esteem Domain

The cognitive dimension of halitosis-related quality of life pertains to intrusive rumination, hyper-focused self-monitoring, and degraded personal confidence. Affected individuals engage in habitual thought patterns regarding how others perceive their hygiene, health, and personal worth. This internal cognitive feedback loop erodes global self-esteem, leading individuals to internalize feelings of defectiveness and social unworthiness, irrespective of their actual functional competence or objective oral status.

Theoretical Framework

The T-HALT is theoretically grounded in Locker’s adapted model of oral health, which itself was derived from the World Health Organization’s (WHO) International Classification of Impairments, Disabilities, and Handicaps (ICIDH). Locker postulated that oral diseases progress along a linear and interactive pathway: biological disease leads directly to impairment (structural or functional abnormalities), which in turn precipitates functional limitations (restrictions in bodily activities), pain and discomfort, physical or psychological disability (limitations in performing daily roles), and ultimately disadvantage or handicap (social, economic, and psychological alienation). Within the context of halitosis, the primary microbial proliferation and subsequent release of volatile sulfur compounds represent the underlying biological disease; the physiological sensation of malodor represents impairment; difficulty speaking closely represents functional limitation; anxiety, embarrassment, and self-conscious rumination constitute psychological disability; and deliberate withdrawal from occupational advancement or intimate relationships embodies the ultimate social disadvantage.

Furthermore, the scale strongly intersects with the Cognitive Appraisal Model of Stress and Coping formulated by Richard Lazarus and Susan Folkman. According to this framework, an objective stressor—such as physiological breath odor—does not directly elicit emotional and behavioral distress. Rather, distress is mediated through two stages of cognitive appraisal: primary appraisal, wherein the individual evaluates whether the odor presents a catastrophic threat to social standing, personal reputation, and interpersonal acceptance; and secondary appraisal, wherein the individual evaluates their personal coping resources and behavioral strategies. When a person appraises their breath as repulsive and perceives that they lack effective hygienic or clinical remedies, profound psychological distress ensues. This explains why individuals with minimal objective volatile sulfur compound emissions may exhibit extreme, disabling psychosocial impairment if their primary cognitive appraisal catastrophicizes normal physiological oral states.

Lastly, the theoretical conceptualization of the T-HALT aligns with Erving Goffman’s sociological theory of Stigma and the Management of Spoiled Identity. Halitosis functions as a profound “discreditable stigma”—a personal blemish that is not immediately visible to the eye but is immediately revealed upon conversational proximity. Goffman noted that individuals bearing discreditable attributes live in perpetual dread of exposure, engaging in elaborate “impression management” strategies (such as linguistic hesitation, positioning, covering the mouth, or self-isolation) to conceal the perceived failing from normal interactants. The T-HALT systematically inventories these defensive sociological manifestations within contemporary Thai cultural frameworks, where harmonious social proximity and polite interpersonal etiquette are culturally revered.

Validity

The validation methodology for the T-HALT adhered to international best-practice standards for health instrument adaptation, involving comprehensive evaluations of content, face, construct, convergent, and discriminant validity:

Content and Face Validity

Content validity was established through a multidisciplinary panel composed of academic periodontists, dental public health specialists, and behavioral scientists. Following a rigorous forward-backward translation procedure from the original English Halitosis Associated Life-Quality Test into Thai by bilingual linguistic and dental experts, the panel reviewed all translated items for conceptual equivalence, idiomatic clarity, cultural resonance, and clinical relevance. Subsequent pilot cognitive debriefing interviews with target dental patients confirmed that the items were unambiguous, readily interpretable, and authentically mapped onto the lived experiences of individuals experiencing breath-related concerns within Thailand.

Convergent and Criterion Validity

To examine convergent construct validity, participants’ total scores on the T-HALT were correlated against their scores on an independent self-perceived halitosis assessment scale. Psychometric theory dictates that an accurate measure of condition-specific quality of life should demonstrate a moderate-to-strong positive correlation with the respondent’s subjective perception of disease severity. In the validation cohort of 200 adult dental patients, the Pearson correlation coefficient yielded a statistically significant positive relationship:

• Self-Perceived Halitosis Scale: r = 0.503 (p < 0.001)

This substantial correlation confirms robust convergent validity, proving that individuals who self-identify as suffering from chronic, severe oral malodor report correspondingly heightened psychosocial disruption, social avoidance, and emotional distress on the T-HALT.

Discriminant Validity

The most compelling theoretical and psychometric validation of the T-HALT emerged from its discriminant validity testing against objective biophysical parameters. All participants underwent objective gas-chromatographic breath testing utilizing a standardized OralChroma™ device, which precisely quantifies the concentrations of volatile sulfur compounds (including hydrogen sulfide, methyl mercaptan, and dimethyl sulfide) in parts per billion (ppb). When the total T-HALT scores were correlated against the objective OralChroma VSC measurements, the analysis revealed a negligible and statistically non-significant correlation:

• Objective Volatile Sulfur Compounds (OralChroma): r = 0.071 (p = 0.318)

In standard psychometric paradigms, a low correlation might mistakenly be interpreted as poor criterion validity. However, in the psychometrics of oral malodor and behavioral medicine, this near-zero correlation represents a classic demonstration of discriminant validity. The T-HALT was constructed to quantify the subjective psychological, affective, and social impact of the condition, not the physical volume of exhaled gas molecules. Because of universal physiological phenomena such as olfactory fatigue (sensory adaptation), alongside psychological phenomena such as pseudo-halitosis and halitophobia, an individual’s objective gas reading operates essentially independently of their subjective suffering. The T-HALT successfully discriminates between purely biological parameters and the profound psychosocial reality experienced by the human patient.

Reliability

The T-HALT demonstrates exceptional psychometric reliability across both internal consistency parameters and longitudinal temporal stability assessments:

Internal Consistency

Internal consistency was analyzed using Cronbach’s alpha coefficients to determine the extent to which the 20 items within the scale reliably measure the same overarching construct. Across distinct phases and clinical groupings within the Mahidol University validation cohort, the instrument yielded remarkably high alpha coefficients:

• Cronbach’s Alpha (α): 0.940 – 0.943

These values vastly exceed the conventional psychometric threshold of 0.70 for research instruments and 0.90 for individual clinical diagnostic decision-making, indicating near-perfect inter-item correlation and minimal measurement error. While values above 0.90 can occasionally suggest minor item redundancy, the wide variety of somatic, interpersonal, and psychological domains covered across the 20 items confirms broad construct representation.

Test-Retest Reliability and Temporal Stability

To ensure that the T-HALT yields reproducible, stable scores in the absence of clinical intervention, a subgroup of participants completed a repeated administration under identical conditions following a designated two-week interval. Temporal stability was quantified using the Intraclass Correlation Coefficient (ICC) via a two-way mixed-effects model:

• Intraclass Correlation Coefficient (ICC): 0.886 (95% CI: 0.831 – 0.924)

An ICC value of 0.886 indicates excellent temporal stability and minimal score fluctuation due to random temporal noise. This confirms that the T-HALT is exceptionally well-suited for longitudinal clinical trials and interventional studies where clinicians must reliably distinguish between true therapeutic recovery and measurement error.

Factor Analysis

The internal structural validity and latent dimensionality of the T-HALT were comprehensively evaluated using both Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) within the clinical validation sample of 200 adults at Mahidol University.

Exploratory Factor Analysis (EFA)

Prior to factor extraction, the Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy and Bartlett’s Test of Sphericity confirmed that the correlation matrix was fully suitable for factor analysis (KMO > 0.85; p < 0.001). Principal axis factoring with oblique (promax) rotation extracted a four-factor latent structure, which accounted for a substantial proportion of the total variance. These four emergent factors aligned logically with distinct experiential dimensions:

1. Factor 1: Social and Interpersonal Limitations (encompassing avoidance of close physical contact, covering the mouth while conversing, and hesitating to initiate dialogue).
2. Factor 2: Affective Distress and Emotional Turmoil (capturing feelings of depression, general anxiety, stress, and acute social embarrassment).
3. Factor 3: Somatic and Gustatory Symptoms (reflecting dry mouth, thick saliva, bad taste in the mouth, and morning breath).
4. Factor 4: Extra-Oral and Functional Pharyngeal Symptoms (pertaining to throat clearing, swallowing difficulties, and voice strain).

Confirmatory Factor Analysis (CFA) and Structural Optimization

When the four-factor latent structure was subjected to Confirmatory Factor Analysis to assess model fit, the overall multi-factor model exhibited satisfactory goodness-of-fit indices across several structural parameters (Comparative Fit Index [CFI] > 0.90, Root Mean Square Error of Approximation [RMSEA] ≤ 0.08). However, rigorous item-level analysis demonstrated critical psychometric discrepancies:

• Item 1 (“Need to clear throat”): Exhibited an unacceptably low standardized factor loading (< 0.40).
• Item 7 (“Difficulty speaking”): Exhibited an unacceptably low standardized factor loading (< 0.40).

These two items, which pertain primarily to systemic or extra-oral otolaryngological manifestations (such as post-nasal drip or pharyngeal structural anomalies), failed to load strongly onto the primary psychological or social factors in the Thai demographic. In Thai cultural contexts, oral malodor is overwhelmingly conceptualized and experienced through direct oral-buccal manifestations and interpersonal social dynamics rather than pharyngeal voice distress. Consequently, the researchers recommended that while the 20-item version remains historically standardized, an optimized 18-item structural model excluding Items 1 and 7 provides superior model parsimony, tighter factor loadings, and improved structural fit for specialized psychometric modeling.

Instrument / Measurement Tool

The operational specifications and administration parameters of the Thai Halitosis Associated Life-Quality Test are detailed below:

• Test Type: Patient-Reported Outcome Measure (PROM); Disease-Specific Self-Report Questionnaire.
• Target Population: Adult dental patients, individuals presenting with self-perceived or clinically diagnosed intra-oral/extra-oral halitosis, and general community cohorts undergoing oral health evaluations.
• Age Demographics: Validated for individuals aged 18 to 88 years.
• Number of Items: 20 items (standard full scale); 18 items (CFA-optimized structural model excluding Items 1 and 7).
• Language: Standard Thai (formal translation from the original English HALT).
• Administration Format: Self-administered paper-and-pencil or secure computerized/digital interface.
• Administration Time: Approximately 5 to 8 minutes.
• Response Scale: Likert rating format. Items are scored ordinally from 0 to 5 (0 = No problem / Never, to 5 = As bad as it can be / Always).
• Scoring and Computational Rules:
  • Scores for all 20 individual items are directly summed to produce a single continuous total score.
  • Total score range: 0 to 100 points.
  • There are no reverse-scored items; all questions are phrased such that higher numerical values reflect greater impairment.
  • Score Interpretation: Higher cumulative scores signify a more severe negative impact of halitosis on the patient’s daily functional, social, and psychological quality of life. Conversely, lower scores denote minimal psychosocial disruption.
• Normative Reference Values: In the validation cohort of 200 adult dental patients at Mahidol University, the baseline normative score distribution exhibited a Mean of 16.37 with a Standard Deviation (SD) of 15.10.

Permissions & Fee and Test Year

The Thai Halitosis Associated Life-Quality Test was developed, validated, and formally published in 2024 by Yodhathai Satravaha, Katkarn Thitiwatpalakarn, Supakit Peanchitlertkajorn, Supatchai Boonpratham, Chaiyapol Chaweewannakorn, and Kawin Sipiyaruk at Mahidol University, Bangkok, Thailand. The validation study was disseminated through BMC Oral Health under an Open Access Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work and authors are appropriately cited.

The instrument is made available free of charge for non-commercial academic, clinical, and scientific research endeavors. Researchers and healthcare practitioners seeking to implement the validated Thai version, obtain complete administrative manual documentation, or utilize the instrument within clinical trials are encouraged to formally notify the corresponding investigator, Dr. Kawin Sipiyaruk, via email at [email protected], or contact the Department of Community Dentistry, Faculty of Dentistry, Mahidol University.

References

• Aboalshamat, K., Farsi, N., Merwass, R., Alshubaili, D., & Filimban, L. (2021). The impact of COVID-19 on Halitosis among the general population in Saudi Arabia: A potential symptom. Journal of Research in Medical and Dental Science, 9(11), 45–52.
• Akaji, E. A., Folaranmi, N., & Ashiwaju, O. (2014). Halitosis: A review of the literature on its prevalence, impact and control. Oral Health & Preventive Dentistry, 12(4), 297–304.
• Aydin, M., & Harvey-Woodworth, C. N. (2014). Halitosis: A new definition and classification. British Dental Journal, 217(1), E1. https://doi.org/10.1038/sj.bdj.2014.552
• Aylıkcı, B. U., & Colak, H. (2013). Halitosis: From diagnosis to management. Journal of Natural Science, Biology, and Medicine, 4(1), 14–23. https://doi.org/10.4103/0976-9668.107255
• Briceag, R., Caraiane, A., Raftu, G., Horhat, R. M., Bogdan, I., Fericean, R. M., Shaaban, L., Popa, M., Bumbu, B. A., Bratu, M. L., et al. (2023). Emotional and social impact of halitosis on adolescents and young adults: A systematic review. Medicina, 59(3), 564. https://doi.org/10.3390/medicina59030564
• Briceag, R., Caraiane, A., Raftu, G., Bratu, M. L., Buzatu, R., Dehelean, L., Bondrescu, M., Bratosin, F., & Bumbu, B. A. (2023). Validation of the Romanian version of the Halitosis Associated Life-Quality Test (HALT) in a cross-sectional study among young adults. Healthcare, 11(19), 2660. https://doi.org/10.3390/healthcare11192660
• Deolia, S. G., Ali, M., Bhatia, S., & Sen, S. (2018). Psychosocial effects of halitosis among young adults. Annals of Indian Psychiatry, 2(2), 120–124. https://doi.org/10.4103/aip.aip_23_18
• Dudzik, A., Chomyszyn-Gajewska, M., & Łazarz-Bartyzel, K. (2015). An evaluation of halitosis using OralChroma™ Data Manager, organoleptic scores and patients’ subjective opinions. Journal of International Oral Health, 7(3), 6–11.
• Falcão, D. P., Vieira, C. N., & Batista de Amorim, R. F. (2012). Breaking paradigms: A new definition for halitosis in the context of pseudo-halitosis and halitophobia. Journal of Breath Research, 6(1), 017105. https://doi.org/10.1088/1752-7155/6/1/017105
• He, S. L., Wang, J. H., Wang, M. H., & Deng, Y. M. (2012). Validation of the Chinese version of the Halitosis Associated Life-quality test (HALT) questionnaire. Oral Diseases, 18(7), 707–712. https://doi.org/10.1111/j.1601-0825.2012.01929.x
• John, M. T. (2021). Foundations of oral health-related quality of life. Journal of Oral Rehabilitation, 48(3), 355–359. https://doi.org/10.1111/joor.13040
• Kizhner, V., Xu, D., & Krespi, Y. P. (2011). A new tool measuring oral malodor quality of life. European Archives of Oto-Rhino-Laryngology, 268(8), 1227–1232. https://doi.org/10.1007/s00405-011-1518-x
• Locker, D., & Allen, F. (2007). What do measures of ‘oral health-related quality of life’ measure? Community Dentistry and Oral Epidemiology, 35(6), 401–411. https://doi.org/10.1111/j.1600-0528.2007.00418.x
• Mento, C., Lombardo, C., Mariacristina, M., Whithorn, N., Boronat-Catalá, M., Alminana-Pastor, P., Fernàndez, C., Bruno, A., Muscatello, M., & Zoccali, R. (2021). Adolescence, adulthood and self-perceived halitosis: A role of psychological factors. Medicina, 57(6), 614. https://doi.org/10.3390/medicina57060614
• Olszewska-Czyz, I., Sozkes, S., & Dudzik, A. (2022). Clinical trial evaluating quality of life in patients with intra-oral halitosis. Journal of Clinical Medicine, 11(2), 326. https://doi.org/10.3390/jcm11020326
• Satravaha, Y., Thitiwatpalakarn, K., Peanchitlertkajorn, S., Boonpratham, S., Chaweewannakorn, C., & Sipiyaruk, K. (2024). Thai Halitosis Associated Life-Quality Test. BMC Oral Health, 24, 4926. https://doi.org/10.1186/s12903-024-04926-y
• Schertel Cassiano, L., Abdullahi, F., Leite, F. R. M., López, R., Peres, M. A., & Nascimento, G. G. (2021). The association between halitosis and oral-health-related quality of life: A systematic review and meta-analysis. Journal of Clinical Periodontology, 48(11), 1458–1469. https://doi.org/10.1111/jcpe.13530
• Silveira, J. O. D., Cota, L. O. M., Bendo, C. B., Faria, S. F. S., & Costa, F. O. (2020). Validation of the Brazilian version of the Halitosis Associated Life-Quality Test (HALT). Brazilian Oral Research, 34, e098. https://doi.org/10.1590/1807-3107bor-2020.vol34.0098

Items of the Scale