Halitosis: prevalence, risk factors, sources, measurement and treatment - a review of the literature

Comparative study of photodynamic therapy with LED and probiotics in the treatment of halitosis: protocol for a randomised controlled clinical trial

INTRODUCTION

Halitosis is a term that defines any unpleasant odour smell originating from the oral cavity and may have a local or systemic origin. This project aims to determine the effectiveness of treatment involving antimicrobial photodynamic therapy (aPDT) combined with treatment using probiotics at reducing halitosis.

METHODS AND ANALYSIS

92 individuals from 18 to 60 years of age with a diagnosis of halitosis (sulfide≥112 ppb, gas chromatography) will be selected. The participants will be randomly allocated to four groups (n=23). Group 1 (control): brushing, dental floss and tongue scraper; group 2: brushing, dental floss, tongue scraper and aPDT with blue Light Emitting Diode (LED) +annatto; group 3: brushing, dental floss, tongue scraper and aPDT with blue Light Emitting Diode (LED) +annatto and probiotic lozenges containing Streptococcus salivarius K12 (BLIS K12); and group 4: brushing, dental floss, tongue scraper and probiotic lozenges containing S. salivarius K12 (BLIS K12). Comparisons will be made of the respiratory analysis results before and immediately after the first treatment session, at the end of the 30-day treatment period and again 60 days after the treatment initiation. Microbiological analysis (counts of colony-forming units of viable bacteria from coated tongue) will be performed at the same time. The microbiome analysis will be conducted before treatment, 30 days after treatment completion and 60 days after treatment initiation, following DNA extraction. All groups will receive oral hygiene instructions as well as brushes, toothpaste and dental floss. Data normality will be checked using Shapiro-Wilk test. In the case of normality, analysis of variance is used for the comparisons. In the case of non-parametric data, Kruskal-Wallis test will be used. Wilcoxon test will be used to analyse the results of each treatment between two assessment times.

ETHICS AND DISSEMINATION

This protocol has been approved by the Human Research Ethics Committee of Nove de Julho University (certificate number: 82830524.6.0000.5511; approval date: 2 October 2024). Participants will agree to take part in the study by signing an informed consent form. The findings will be published in a peer-reviewed journal. The collected data will be available in the OSF data repository.

TRIAL REGISTRATION NUMBER

NCT06583720.

The Home Use of Probiotics and Paraprobiotics for the Maintenance of Tongue Eubiosis: A Case Report

Aim: Halitosis is the unpleasant odor emitted from the oral cavity during exhalation and phonation. Using oral care products containing specific probiotics and paraprobiotics, combined with lifestyle changes, this study is aimed at resolving the patient's altered breath odor. Case Report: A 49-year-old male patient suffered from retronasal discharge, bacterial plaque on the back of his tongue, and bad breath. He underwent a professional oral hygiene session, received instructions in proper home oral hygiene techniques, and was advised on appropriate lifestyle changes. The use of oral care products based on probiotics and paraprobiotics was recommended. Sixty days later, the patient was reevaluated and was satisfied with the results, as his tongue had improved significantly, and he no longer experienced any bad sensations in his mouth. Conclusion: Systematic removal of bacterial biofilm and the use of probiotics and paraprobiotics can be useful in the prevention and treatment of halitosis.

Clinical and measurement variables affecting halitosis intensity following cysteine challenge test

The cysteine challenge test is a reliable and efficient method for halitosis diagnosis and assessing treatment effectiveness by measuring the capacity to produce hydrogen sulfide. However, several aspects related to the test including evaluation timing and total duration following cysteine loading has not been investigated in-depth and a standardized protocol is yet to be established. This observational study compared concentrations of volatile sulfur compounds (VSCs) following cysteine challenge at various time points based on different measurement tools to investigate clinical factors influencing the results. Cysteine challenge (rinsing for 30 s with 5 mL of 6 mM L-cysteine solution) was applied in 100 healthy subjects. VSC concentration of oral cavity gas was analyzed with standard and portable gas chromatography (GC) at 5 time points (before, immediately, 10, 20, and 30 min after cysteine challenge). The Community Periodontal Index of Treatment Needs (CPITN), Winkel's Tongue Coating Index, and salivary flow rate were assessed. VSC levels significantly increased immediately after cysteine challenge (p < 0.001 for hydrogen sulfide, p < 0.001 with standard GC and p < 0.05 with portable GC for methyl mercaptan). Levels significantly decreased at 10 min after cysteine challenge except for methyl mercaptan measured with standard GC (p < 0.001). Subjects still showing VSCs 20 min after cysteine challenge was less than 15% of those initially positive. The amount of tongue coating showed significant association with methyl mercaptan levels immediately after (β = 0.202, p = 0.049) and 10 min following (β = 0.207, p = 0.045) cysteine challenge and CPITN showed acceptable discriminative power for persistent detection of methyl mercaptan (cut-off = 1.5, AUC = 0.668). Cysteine challenge may enhance the possibility of detecting VSCs during halitosis diagnosis. Standardized test protocols should address measurement timing, tools used, and tongue coating levels as clinical factors influencing VSC detection.

Bibliometrics and altmetrics on halitosis: exploring the top 100 most-cited papers

Halitosis has a multifactorial etiology being of interest by different health areas. The aim of this study was to perform a bibliometric and altmetric analyzes of the top 100 most-cited papers on halitosis to provide a comprehensive view of their scientific and alternative metrics. This would give perspectives on citation dynamics and online attention of the research outputs. A search strategy was designed, tested and applied in the Web of Science database on August 1st, 2023. The 100 most-cited papers were selected by two reviewers. Data on title, year of publication, number of citations, authorship, journal title, study design, halitosis etiology and subject/field of the study or pathogenesis of halitosis were extracted from each paper. Altmetric attention score (AAS) for each paper was registered. Papers were published between 1972 and 2019. Most cited papers were non-systematic reviews (28%). USA was the country with the greatest number of publications (20%). Journals with the greater number of citations were related to dentistry. The altmetric analysis did not show correlation with the citation count but showed a few papers with elevated AAS and a good diffusion in social media. The level of evidence of the study design did not influence the citation number. This can indicate the need for citing studies with more robust designs in order to provide better scientific evidence of citations in epidemiology, etiology, diagnosis and treatment. Databases showed positive correlation among citation counts, but no correlation with the online attention.

Effectiveness of a combination of laccase and green coffee extract on oral malodor: a comparative, randomized, controlled, evaluator-blind, parallel-group trial

Oral malodor negatively impacts a person's quality of life and may affect up to 50% of the population. The aim of this randomized, placebo and no-product controlled, evaluator-blind, proof-of-concept study was to evaluate the effectiveness and safety of the single use of two experimental lozenges containing the laccase enzyme and green coffee extract (with and without flavor) in reducing intrinsic oral malodor. Following 12-16 h of avoidance of oral hygiene,156 generally healthy subjects presented at screening and baseline visits with a mean organoleptic odor intensity (OI) score of ⩾2 and an OralChromaTMreading of ⩾125 parts per billion (ppb) hydrogen sulfide (H2S) gas and were randomly assigned to receive either one of the two experimental lozenges, a placebo lozenge, or no-product. Following the supervised use of the assigned products, subjects' oral malodor was evaluated using OI assessments and OralChromaTMmeasurement for volatile sulfur compounds (VSCs) immediately following product use (approximately 5 min), and at 30 min, 1 h, 2 h, 3 h and 4 h. The two experimental lozenges, with and without flavor, showed significant reductions in OI scores compared with the placebo and no-product groups at all time points (p< 0.001). At 5 min post-product use, the experimental lozenges, with and without flavor, were significantly better than the no-product group in reducing the VSCs (p< 0.04). The results of individual VSC components (hydrogen sulfide, methyl mercaptan and dimethyl sulfide) were variable; both experimental lozenges notably reduced hydrogen sulfide and methyl mercaptan levels in most post-use assessments. Four minor adverse events were reported, none of which were directly linked to the product. In conclusion, the experimental lozenges, whether flavored or not, were safe and effective in reducing oral malodor over a span of 4 h, based on organoleptic OI scores.Clinical Trial No: NCT05950529.

Halitosis in oral lichen planus patients

To investigate the halitosis level in oral lichen planus (OLP) patients and OLP-free participants. This cross-sectional study recruited 70 participants at the New Zealand's National Centre for Dentistry. Halitosis was determined using the objective measurements (parts per billion (ppb) volatile sulphur compounds (VSCs) in the exhaled air) and subjective measurement (self-reported halitosis questionnaire). The VSCs values of OLP participants (mean ± SD: 144.64 ± 23.85 ppb) were significantly greater than that in the OLP-free participants (105.52 ± 22.31ppb) (mean difference: 39.12 ppb;p< 0.05; 95% CI: 27.95, 50.29). The VSCs value of hyperplastic (mean difference: 34.11; 95% CI: 20.07, 48.15;p< 0.05) and erosive/ulcerative (mean difference: 57.47; 95% CI: 34.19, 80.76;p< 0.05) OLP participants were statistically greater than that of OLP-free participants. No statistical significance was found between hyperplastic and erosive/ulcerative OLP (p> 0.05). 'Type (OLP-free/OLP)' has a significant effect on the dependent variable VSCs. 78.6% of OLP and 90.5% of OLP-free brushed their teeth at least twice daily, with a statistically significant observation (Mean square: 1.61; F: 13.13;p< 0.05). The levels of VSCs were greater in participants with hyperplastic and erosive/ulcerative OLP than that in the OLP-free participants.

Therapeutic efficacy of a probiotic preparation on idiopathic halitosis: a retrospective observational study

Idiopathic halitosis is an unusual condition of unclear causes, which has never been thoroughly investigated. We aimed to explore the role of small intestinal bacterial overgrowth (SIBO) in the pathogenesis of idiopathic halitosis, and to evaluate the therapeutic efficacy of a probiotic preparation on this condition. This retrospective observational study included 162 idiopathic halitosis patients and 198 healthy controls (HCs). Halitosis was diagnosed using the organoleptic test, and idiopathic halitosis was diagnosed by excluding known causes. SIBO was identified through the hydrogen/methane lactulose breath test, and accordingly, patients were identified as SIBO-positive or SIBO-negative. Idiopathic halitosis patients were treated with the probiotic preparationBifidobacteriumtriple viable capsule for two months, followed by re-evaluation of halitosis and SIBO. This study found that all cases of idiopathic halitosis were extra-oral. The SIBO positivity rate in idiopathic halitosis patients was significantly higher than that in HCs (74.69% [121/162] vs 3.03% [6/198],P< 0.001), with an odds ratio of 94.44% (95% CI: 39.99%-211.35%). After treatment, 80.17% (97/121) of the SIBO-positive patients became SIBO-negative. Moreover, 87.60% (106/121) of the SIBO-positive patients experienced improved halitosis, a rate significantly higher than that observed in SIBO-negative patients (2.75%, 3/41) (P< 0.001). In addition, 98.97% (96/97) of the post-treatment SIBO-negative patients experienced improved halitosis, a rate significantly higher than that of post-treatment sustained SIBO-positive patients (41.67%, 10/24) (P< 0.001). Our findings suggest that idiopathic halitosis is an extra-oral condition which mostly originates from the small intestine. SIBO is one of its underlying causes. The probiotic preparation can effectively improve idiopathic halitosis, probably through its impact on SIBO.

Volatile sulfur compounds in asthmatic children and adolescents: A cross-sectional study in breath and saliva

BACKGROUND

Halitosis in children implies psychosocial repercussions. Risk factors associated with this condition are unclear, and detection methods are inaccurate.

AIM

To quantify the levels of sulfur-like compounds in children with asthma and healthy children from a novel validated assay, and to establish the risk factors related to halitosis.

DESIGN

One hundred and twenty-eight individuals (63 healthy and 65 asthmatic) from 3 to 17 years of age were tested using a passive colorimetric sensor to measure the levels of sulfur-like compounds in breath and saliva. Information was collected on oral hygiene habits, gingival and dental health, breathing type, and dental malocclusion.

RESULTS

The mean values of hydrogen sulfide were 4.0 ± 6.8 and 19.7 ± 12.2 ppbv (parts per billion in volume) in the control and asthmatic groups, respectively (p < .001). The presence of higher concentrations of sulfur compounds was significantly associated (p < .05) with the presence of gingival inflammation, tongue coating, dental plaque, mouth breathing, hypomineralization, age, tongue brushing, and the use of dental floss.

CONCLUSION

The level of sulfur in breath and saliva was significantly higher in patients with asthma. These results can serve as a precedent to raise awareness among paediatricians and parents about oral hygiene care in children and adolescents.

Polyamines in Dysbiotic Oral Conditions of Older Adults: A Scoping Review

Polyamines modulate cellular proliferation and function. Their dysregulation results in inflammatory and oncological repercussions. This study aims to map the current literature and provide an overview of polyamines in dysbiotic oral conditions among older adults. English publications indexed in MEDLINE, Scopus, and Web of Science from January 2000 to May 2024 were screened. Eligibility criteria included clinical and laboratory studies using samples from adults aged 65 or above. This scoping review identified 2725 publications and included 19 publications. Ten studies detected that older adults with oral carcinoma had increased levels of polyamines such as spermidine in saliva and tumour-affected tissues. Eight studies reported older adults suffering from periodontal infection had increased levels of polyamines such as putrescine in saliva, gingival crevicular fluid, and biofilm from the gingival crevice. Two studies showed polyamine levels could reflect the success of periodontal therapy. Three studies found older adults with halitosis had increased levels of polyamines such as cadaverine in saliva and tongue biofilm. Polyamines were suggested as biomarkers for these oral conditions. In conclusion, certain polyamine levels are elevated in older adults with oral cancer, periodontal infections, and halitosis. Polyamines may be used as a simple and non-invasive tool to detect dysbiotic oral conditions and monitor treatment progress in older adults (Open Science Framework registration).

Clinical parameters in patients with halitosis: a cross-sectional study

Background

Halitosis, a socially and psychologically impactful condition often resulting from oral or systemic issues, is exacerbated by factors like aging, poor oral hygiene, and dietary choices. This study aimed to investigate the association between halitosis and stress by measuring salivary cortisol levels and the Cohen's Perceived Stress Scale (CPSS).

Methods

A cross-sectional study of 40 participants was conducted using questionnaires and clinical measurements to assess halitosis and stress levels. Saliva samples were collected and analyzed for cortisol using ELISA. Participants' stress was assessed with the Cohen's Perceived Stress Scale Questionnaire (CPSS-10) questionnaire, and halitosis was measured with a Halimeter and self-assessment questionnaire. Clinical measurements included Plaque Index (PI) and the Decayed, Missing, and Filled Teeth (DMFT) score.

Results

Forty subjects were split into a halitosis group (mean age 30.75 ± 10.15) and group with no halitosis (mean age 26 ± 5.3). Objective measures confirmed higher halitosis scores (3.70 ± 0.73) in the halitosis group vs. the second group (2.60 ± 1.67). Compared with the group with no halitosis, the halitosis group exhibited significantly (p < 0.05) more plaque (27.92% ± 17.16% vs. 47.50 ± 33.57%; p < 0.05) and higher DMFT scores (10.10 ± 2.51 vs. 26 ± 5.30), respectively. Salivary cortisol levels were similar across groups (1.721 ng/ml halitosis, 1.781 ng/ml without halitosis). Correlations showed a moderate positive relationship between DMFT and halimeter scores (r = 0.377, p = 0.018) and a moderate negative correlation between stress and plaque index (r = -0.403, p = 0.011), with no correlation between halimeter score and cortisol or CPSS score.

Conclusions

Our findings showed that while halitosis severity correlated with higher DMFT scores and plaque accumulation, there was no significant association with salivary cortisol levels, suggesting that stress, as measured by salivary cortisol, may not be a direct contributor to halitosis. Furthermore, the data suggest that poor oral hygiene is a more significant factor in the development of halitosis than stress levels, as assessed by the CPSS-10.

Self-perceived halitosis and associated factors among university students in Dhaka, Bangladesh

BACKGROUND

Bad breath (halitosis) is a common problem affecting psycho-social wellbeing of young people. We aimed to explore the extent of self-perceived halitosis and associated factors among university students in Dhaka, Bangladesh.

METHODS

A cross-sectional study was conducted among university students from November 2021 to April 2022. Six private and two public universities were approached. A total of 318 participants were conveniently selected for the study. A self-administered questionnaire was used for data collection. Students unwilling to participate were excluded. Multivariable logistic regression analysis was used to examine factors associated with halitosis. Statistical analysis was conducted using Stata Version 17.

RESULTS

A total of 55.97% of students had self-perceived halitosis, with females (74.53%) having a significantly higher proportion than males (36.94%) (p < 0.001). A significantly higher proportion of halitosis was found among participants who were overweight ( 61%), had obesity (60.77%), smoked cigarette (46.79%), consumed alcohol (71.43%), lacked exercise (66.29%), were on unhealthy diet (57.35%), consumed coffee/tea (61.35%), breathed through mouth (64.60%), brushed tooth infrequently (85.71%), changed toothbrush after 6 months (77.42%), did not use toothpaste (94.74%), did not use/ sometimes used fluoride toothpaste (75.76%), lacked dental floss use (60.85%), did not use toothpick (62.87%), did chew or sometimes chewed sugar-free chewing gum (75.82%), did not clear / cleaned tongue sometimes (76.14%), did use mouth freshener regularly or occasionally (64.97%), did not use or used mouthwash sometimes (58.87%) were also associated with higher self-perceived halitosis (p < 0.05 for all). Students with gum bleeding, swollen gums, dry mouth, dental caries, food accumulation, and tooth sensitivity had a significantly (p < 0.05 for all) higher proportion of self-perceived halitosis (76.85%, 81.82%, 72.50%, 67.78%, 64.13% and 67.40%, respectively) compared to those without this problem. Being female (OR = 5.04; 95% CI: 2.01-12.62; p < 0.001), alcohol consumers (OR 7.35; 95% CI: 1.77-30.50; p = 0.006); not using sugar free chewing gum (OR = 0.25; 95% CI: 0.10-0.58; p = 0.001), lack of tongue cleaning (OR 4.62; 95% CI: 2.16-9.84; p < 0.001), and gum bleeding (OR = 7.43; 95% CI: 3.00-18.35; p < 0.001) were independently associated with halitosis on multivariable regression.

CONCLUSION

This study reveals a high proportion of self-perceived halitosis and relevant factors. There should be more public education on the causes of halitosis and potential management approaches.

Management of functional constipation-associated halitosis: a retrospective study

The features of functional constipation (FC)-associated halitosis were identified in the author's previous report. In this report, the author aimed to further investigate its treatment and efficacy. This retrospective study reviewed 100 FC patients, including 82 (82%) halitosis patients and 18 (18%) non-halitosis patients. They underwent the organoleptic test (OLT) to diagnose halitosis, and the organoleptic score (OLS) (0-5) was used to evaluated halitosis severity. The Cleveland Clinical Constipation Score (CCCS) (0-30) was used to evaluate FC severity. Patients were treated with the laxative polyethylene glycol electrolyte powder (PGEP) for four weeks. These tests were performed before and after treatment. The author found that, before treatment, the CCCS was 20.00 (18.00-23.00) for all patients, 21.00 (19.00-24.00) for halitosis patients, and 18.00 (17.00-18.25) for non-halitosis patients. A significant difference was observed between halitosis patients and non-halitosis patients (P< 0.001). The OLS for halitosis patients was 3.00 (3.00-4.00). A positive correlation (r= 0.814, 95% CI: 0.732-0.872,P< 0.001) was found between OLS and CCCS. A CCCS ⩾18 predicted over 50% probability of halitosis. After treatment, the CCCS significantly decreased to 11.50 (6.00-14.75) (P< 0.001), and OLS significantly decreased to 1.00 (0.00-2.00) (P< 0.001). A positive correlation (r= 0.770, 95% CI: 0.673-0.841,P< 0.001) persisted between OLS and CCCS. A pre-treatment CCCS ⩾21 predicted over 50% probability of post-treatment halitosis, while a post-treatment CCCS ⩾12 predicted over 50% probability of post-treatment halitosis. The author concludes that the severity of FC parallels the severity of FC-associated halitosis, and can predict the probability of halitosis. Laxative treatment with PGEP is effective in improving FC-associated halitosis.

Laser Therapy: An Alternative Approach for the Management of Halitosis

Halitosis is the result of combining the Greek word "osis" (pathological alteration) with the Latin phrase "halitus" (breath). No matter what the cause, halitosis can be described as the presence of a foul odour. Effective treatment of halitosis may be facilitated by knowledge of the illnesses and factors that contribute to the condition as well as its symptoms. To properly diagnose and treat patients, healthcare professionals, general practitioners, and dentists must comprehend the cause of the ailment and the best course of treatment. A prevalent issue affecting a large proportion of the global population is halitosis. In 90% of cases, the onset of this illness is oral; however, in 10% of cases, it is systemic. The primary source of the unpleasant smell is the volatile sulphur compounds that Gram-negative bacteria create. The majority of halitosis sufferers find their disease humiliating which makes it difficult for them to go about their daily lives and social lives. A thorough examination was carried out. An evaluation of the tongue was done. The halitosis was treated in afflicted areas using the "Epic Biolase Laser". It is the most robust dental laser and has a low power output which uses a solid-state diode to produce invisible infrared radiation. This device operates aseptically and offers more convenience due to its wireless design, which is powered by a Bluetooth foot pedal. This is used to lower the number of bacteria, and then periodic maintenance is performed to keep them under control. Benefits and outcomes were accomplished. Laser therapy destroys the bacteria that produce volatile compounds and efficiently treats foul breath for a longer period of time. But with a combination of conventional techniques, the results we obtain are even better.

Effect of sleeve gastrectomy on the levels of oral volatile sulfur compounds and halitosis-related bacteria

Background

The association between sleeve gastrectomy and halitosis remains relatively unknown. Therefore, this study aimed to evaluate the effect of sleeve gastrectomy on halitosis and the oral bacterial species associated with halitosis in patients with obesity.

Methods

This was a prospective longitudinal cohort study that examined patients before and after sleeve gastrectomy and followed the patients at three time intervals (1, 3, and 6 months) after sleeve gastrectomy. Clinical periodontal measurements (plaque index [PI], gingival index [GI], and probing depth [PD]) were obtained. In addition, plaque samples were collected for quantification of the periodontopathogenic bacteria: Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Fusobacterium nucleatum using real-time quantitative polymerase chain reaction (qPCR). In addition, breath samples were collected to analyze the concentration of volatile sulfur compounds (VSCs), namely hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and dimethyl sulfide (CH3SCH3), via portable gas chromatography (Oral Chroma™).

Results

Of the 43 patients initially included, 39 completed the study, with a mean age of 32.2 ± 10.4 years. For PI and GI repeated measurements one way analysis of variance showed a significant increase (p-value < 0.001 for both) one month after surgery, with mean values of 1.3 and 1.59, respectively, compared to the baseline. During the same period, the number of P. gingivalis increased, with a p-value = 0.04. Similarly, the levels of hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) increased significantly in the first month after surgery (p-value = 0.02 and 0.01, respectively).

Conclusion

This study demonstrated that sleeve gastrectomy may lead to increased halitosis one month post-surgery, attributed to elevated and P. gingivalis counts, contributing to the development of gingivitis in obese patients who underwent sleeve gastrectomy. This emphasizes the importance of including oral health professionals in the multidisciplinary team for the management of patients undergoing bariatric surgery.

The association between halitosis and periodontitis: a systematic review and meta-analysis

OBJECTIVES

The purpose of this systemic review and meta-analysis was to explore the association between halitosis and periodontitis in observational studies.

MATERIALS AND METHODS

A systematic search covered PubMed, Web of Science, Embase, Scopus, and Cochrane Library until August 18, 2023. Nine observational studies (585 cases, 1591 controls) were analyzed using Stata 17, with odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses considered halitosis assessment methods.

RESULTS

The review found a positive association between halitosis and periodontitis. Significant differences were observed with organoleptic test (OR = 4.05, 95% CI: 1.76, 9.30, p < 0.01) and volatile sulfur compound readings (OR = 4.52, 95% CI: 1.89, 10.83, p < 0.01).

CONCLUSIONS

A positive association was observed between halitosis and periodontitis, supported by significant differences in both organoleptic and volatile sulfur compound readings. However, conclusive findings are limited by statistical heterogeneity, emphasizing the need for additional research.

CLINICAL RELEVANCE

Understanding the halitosis and periodontitis association is clinically significant, informing potential interventions for improved oral health. Further research is vital to refine understanding and guide effective clinical strategies, acknowledging the limitations in current findings.

Tongue-Coating Microbial and Metabolic Characteristics in Halitosis

Halitosis is a common oral condition, which leads to social embarrassment and affects quality of life. Cumulative evidence has suggested the association of tongue-coating microbiome with the development of intraoral halitosis. The dynamic variations of tongue-coating microbiota and metabolites in halitosis have not been fully elucidated. Therefore, the present study aimed to determine the tongue-coating microbial and metabolic characteristics in halitosis subjects without other oral diseases using metagenomics and metabolomics analysis. The participants underwent oral examination, halitosis assessment, and tongue-coating sample collection for the microbiome and metabolome analysis. It was found that the microbiota richness and diversity were significantly elevated in the halitosis group. Furthermore, species from Actinomyces, Prevotella, Veillonella, and Solobacterium were significantly more abundant in the halitosis group. However, the Rothia and Streptococcus species exhibited opposite tendencies. Eleven Kyoto Encyclopedia of Genes and Genomes pathways were significantly enriched in the halitosis tongue coatings, including cysteine and methionine metabolism. Functional genes related to sulfur, indole, skatole, and cadaverine metabolic processes (such as serA, metH, metK and dsrAB) were identified to be more abundant in the halitosis samples. The metabolome analysis revealed that indole-3-acetic, ornithine, and L-tryptophan were significantly elevated in the halitosis samples. Furthermore, it was observed that the values of volatile sulfur compounds and indole-3-acetic abundances were positively correlated. The multiomics analysis identified the metagenomic and metabolomic characteristics to differentiate halitosis from healthy individuals using the least absolute shrinkage and selection operator logistic regression and random forest classifier. A total of 19 species and 39 metabolites were identified as features in halitosis patients, which included indole-3-acetic acid, Bacillus altitudinis, Candidatus Saccharibacteria, and Actinomyces species. In conclusion, an evident shift in microbiome and metabolome characteristics was observed in the halitosis tongue coating, which may have a potential etiological significance and provide novel insights into the mechanism for halitosis.

Self-reported periodontitis association with impaired smell and taste: A multicenter survey

OBJECTIVES

To investigate the association between self-reported periodontitis and the senses of taste and smell among employees of one Danish and two American universities.

MATERIALS AND METHODS

Data were collected through a digital survey. A total of 1239 individuals from Aarhus University - Denmark, the University of Iowa, and the University of Florida - USA were included. Self-reported periodontitis was the exposure. The perceived senses of taste and smell were the outcomes and were measured through a visual analog scale (VAS). Self-perceived halitosis was the mediator. Confounders were age, sex, income, education, xerostomia, COVID-19, smoking, body mass index, and diabetes. The total effect was decomposed into direct and indirect using a counterfactual approach.

RESULTS

The total effect of periodontitis on an impaired sense of taste was OR 1.56 (95% CI [1.02, 2.09]), of which 23% was mediated by halitosis (OR 1.13; 95% CI [1.03, 1.22]). Additionally, individuals with self-reported periodontitis had a 53% higher chance of having impaired smell (OR 1.53; 95% CI [1.00, 2.04]), with halitosis mediating 21% of the total effect (OR 1.11; 95% CI [1.02, 1.20]).

CONCLUSION

Our findings suggest that periodontitis is associated with distorted senses of taste and smell. Additionally, this association appears to be mediated by halitosis.

Narrative review on artificially intelligent olfaction in halitosis

Halitosis, commonly known as oral malodor, is a multifactorial health concern that significantly impacts the psychological and social well-being of individuals. It is the third most frequent reason for individuals to seek dental treatment, after dental caries and periodontal diseases. For an in-depth exploration of the topic of halitosis, an extensive literature review was conducted. The review focused on articles published in peer-reviewed journals and only those written in the English language were considered. The search for relevant literature began by employing subject headings such as 'halitosis, oral malodor, volatile sulfur compounds, artificial intelligence, and olfaction' in databases such as PubMed/Medline, Scopus, Google Scholar, Web of Science, and EMBASE. Additionally, a thorough hand search of references was conducted to ensure the comprehensiveness of the review. After amalgamating the search outcomes, a comprehensive analysis revealed the existence of precisely 134 full-text articles that bore relevance to the study. Abstracts and editorial letters were excluded from this study, and almost 50% of the full-text articles were deemed immaterial to dental practice. Out of the remaining articles, precisely 54 full-text articles were employed in this review. As primary healthcare providers, dentists are responsible for diagnosing and treating oral issues that may contribute to the development of halitosis. To effectively manage this condition, dentists must educate their patients about the underlying causes of halitosis, as well as proper oral hygiene practices such as tongue cleaning, flossing, and selecting appropriate mouthwash and toothpaste. This narrative review summarises all possible AI olfaction in halitosis.

Preliminary investigation of a combined herbal extract of Aruncus dioicus, Cirsium nipponicum, and Ocimum basilicum for halitosis

BACKGROUND

Halitosis, the unpleasant odor in the oral cavity, has garnered increased attention and concern due to the growing significance of social interaction. SGE-107, a blend of 3 botanical drugs-Korean goat's beard, Cirsium tanakae, and Basil-with caffeic acid as its indicator component. This study aims to investigate the efficacy of SGE-107 in treating halitosis in patients with mild gastrointestinal symptoms.

METHODS

We enrolled 25 participants with oral malodor and dyspeptic symptoms. We assessed the severity of halitosis using the visual analog scale. Throughout a 4-week period of administering SGE-107, we evaluated both objective and subjective parameters, including the halitosis-associated life-quality test, the Korean gastrointestinal symptom rating scale, levels of volatile sulfur compounds, salivary flow rate, oral moisture, tongue index, Winkel tongue coating index, and tongue temperature.

RESULTS

After the intervention period, both the visual analog scale (5.88 ± 1.03 vs 2.38 ± 0.93, P < .001) and the scores of the halitosis-associated life-quality test (31.21 ± 11.78 vs 13.83 ± 6.38, P < .001) showed significant reductions. The proportion of participants with abnormal levels of methyl mercaptan (a volatile sulfur compound) also significantly decreased (17, 70.8% vs 9, 37.5%, P = .039). Furthermore, there were significant improvements in reflux, constipation, diarrhea, and the total scores on the Korean gastrointestinal symptom rating scale. Throughout the study period, only 2 participants experienced mild adverse events.

CONCLUSION

SGE-107 appears to be a safe and effective treatment for halitosis-associated with gastrointestinal symptoms; nevertheless, the limited sample size necessitates further large-scale randomized, controlled studies to confirm our findings.

Effects of preoperative oral care on bacterial colonisation and halitosis in patients undergoing elective surgery: A randomised controlled study

OBJECTIVES

To evaluate the effects of single-dose chlorhexidine oral care on bacterial colonisation and halitosis in patients undergoing elective surgery.

RESEARCH METHODOLOGY

We conducted a two-arm parallel, single-blinded, randomised controlled trial. The intervention group (n = 102) received preoperative oral care with 0.12% chlorhexidine gluconate, and the control group (n = 105) received standard care. The data of the microbiological cultures between the groups were compared at the time of tracheal intubation, at extubation and 30 min after surgery. The presence of halitosis was measured using a survey questionnaire administered to the anaesthesia nurses assigned to the patients.

RESULTS

At baseline, no significant differences were found between the intervention and control groups for bacterial colonisation or halitosis. After the intervention, there was no significant difference in microbiological culture, including gram-positive, gram-negative bacilli and cocci results, between the two groups (p > 0.05). The presence of halitosis in the intervention group was significantly lower than in the control group during intubation (p < 0.0001) and at 30 min after surgery (p < 0.02). Regression analysis indicated that receiving oral was protective towards halitosis, while poor oral health was a risk factor.

CONCLUSIONS

Preoperative oral care using a single dose of chlorhexidine significantly improved the patients' halitosis in the perioperative period, but no significant effect was found on bacterial colonisation. Further studies are needed regarding the safe use of chlorhexidine for oral care.

IMPLICATION FOR CLINICAL PRACTICE

Oral hygiene using chlorhexidine could be beneficial in improving halitosis for anaesthesia personnel who take care of intubated adult patients undergoing elective surgery with general anaesthesia.

Characteristics of extra-oral halitosis induced by functional constipation: a prospective cohort study

Characteristics of extra-oral halitosis induced by functional constipation (FC) have never been revealed. To address this, this prospective cohort was conducted with 100 FC patients, who were divided into a halitosis group and a negative group. Organoleptic score (OLS) ⩾ 2 in nose breath was diagnosed as extra-oral halitosis. Concentration of overall volatile sulfur compounds (VSCs) measured by Halimeter, concentration of hydrogen sulfide (HS), methanethiol (MT), dimethyl sulfide (DMS) and their total amount measured by OralChroma in nose breath was recorded asC-VSC,C-HS,C-MT,C-DMS andC-sum respectively. We found that 82% (82/100) of the FC patients had extra-oral halitosis. However, only 12.5% (3/82) and 1.22% (1/82) of halitosis group were correctly diagnosed with the current diagnostic threshold ofC-VSC ⩾ 110 parts per billion (ppb) and ⩾150 ppb.C-VSC,C-DMS andC-sum were significantly higher in the halitosis group compared to the negative group (allP< 0.001), with ratios of about 2.2 times, 3.1 times and 2.1 times respectively.C-HS andC-MT were low and not significantly different between the groups. Positive correlations were observed among OLS,C-VSC,C-DMS andC-sum. The area under curve of receiver operating characteristics ofC-VSC, C-DMS andC-sum for predicting FC-induced halitosis was 0.909, 0.9073 and 0.962 respectively, with the threshold values of ⩾36 ppb, ⩾52 ppb and ⩾75 ppb respectively. Therefore, we conclude that: (1) DMS is the primary contributor to FC-induced extra-oral halitosis. (2) OLS, Halimeter and OralChroma are consistent in detecting FC-induced extra-oral halitosis. (3) The diagnostic threshold for Halimeter should be adjusted toC-VSC ⩾ 36 ppb and the diagnostic threshold for OralChroma should be set asC-DMS ⩾ 52 ppb for diagnosing FC-induced extra-oral halitosis.

Enterogenous extra-oral halitosis has a more severe impact on quality of life in females compared to males

Some studies have examined the impact of intra-oral halitosis on quality of life (QOL), but the impact of enterogenous extra-oral halitosis (EOH) on QOL has not been previously studied. We conducted a retrospective analysis of data from 88 patients with enterogenous EOH who visited our online halitosis clinic. A specialized halitosis associated life-quality test (HALT) questionnaire was used to assess QOL of these patients. Spearman correlation analysis was performed to investigate the relationship between HALT score and age. We found that 21 (23.86%) patients were male and 67 (76.14%) patients were female. HALT scores in females were significantly higher than in males (57.6 ± 13.6vs.45.5 ± 11.9,P< 0.001). Additionally, 13 of the 20 items of the HALT questionnaire showed significant differences between the sexes. No correlation was identified between HALT score and age. Therefore, we conclude that: (1) enterogenous EOH has a more severe impact on QOL in females compared to males. (2) More females with EOH visit the offline halitosis clinic compared to males. (3) The QOL of patients with enterogenous EOH does not decline with age.

Gastric Helicobacter pylori infection does not contribute to extraoral halitosis and its eradication cannot achieve substantial reduction of halitosis

Background

Some researchers have suggested that Helicobacter pylori (H. pylori) infection is attributed to extraoral halitosis. However, this viewpoint is increasingly challenged by clinical practice. This study was conducted with the aim of investigating changes of extraoral halitosis before and after H. pylori eradication.

Materials and Methods

Data of patients who had H. pylori infection and extraoral halitosis were retrospectively collected. H. pylori infection was diagnosed by positive 13C urea breath test (UBT). Extraoral halitosis was diagnosed by organoleptic score (OLS) ≥2 in nose breath. A 14‐day bismuth‐based quadruple therapy was administered for H. pylori eradication. Extraoral halitosis was examined before eradication (T1), on the first day after eradication (T2), 1 month after eradication (T3), and 3 months after eradication (T4). Eradication effect was checked by UBT at T3.

Results

A total of 100 patients were included. Eradication was successful in 74 out of 100 (74%) patients (success group) and failed in 26 out of 100 (26%) patients (failure group). 32 out of 74 (43.24%) patients in success group and 10 out of 26 (38.46%) patients in failure group had reduced halitosis at T2, 9 out of 74 (12.16%) patients in success group and 2 out 26 (7.69%) patients in failure group had relapsed halitosis at T3, and 23 out of 74 (31.08%) patients in success group and 8 out of 26 (30.77%) patients in failure group had relapsed halitosis at T4, without significant difference between groups at any time (p = 0.918, p = 0.808, and p = 0.808 respectively).

Conclusions

Helicobacter pylori infection does not contribute to extraoral halitosis. H. pylori eradication can achieve sustained but slight reduction of extraoral halitosis, probably due to its antibiotic effects on the gut microbiota rather than H. pylori.

Halitosis: etiology, prevention, and the role of microbiota

OBJECTIVES

This study aims to review halitosis research, discuss its various causes, and propose effective interventions based on the underlying etiologies and mechanisms. The main research question is to identify the primary factors contributing to halitosis and appropriate strategies to address them.

MATERIALS AND METHODS

A comprehensive literature review was conducted on halitosis and its associated causes, including oral pathological factors, oral microbial influences, microbial metabolic pathways, gastrointestinal diseases, and gut microbiota dysbiosis.

RESULTS

Unhealthy eating habits and an imbalance of microorganisms in the oral cavity and gastrointestinal tract were identified as primary causes of halitosis. Dental caries, periodontal disease, xerostomia, and digestive disorders like gastritis and irritable bowel syndrome were also found to be related to the development of halitosis. Due to poor oral hygiene or antibiotic use, disruption of microbial communities can result in dysbiosis, inflammation, and halitosis.

CONCLUSIONS

Halitosis is a multifactorial condition with various underlying causes, including oral and systemic diseases. Effective interventions should be tailored based on the specific etiologies and mechanisms involved.

CLINICAL RELEVANCE

Understanding the factors contributing to halitosis is crucial for developing appropriate treatment strategies. Enhancing oral hygiene habits, using antimicrobial drugs, or administering probiotics may help regulate oral or intestinal flora, thereby improving halitosis and overall oral health.

Antimicrobial photodynamic therapy for the treatment of oral infections: A systematic review

Oral infection is a common clinical symptom. While antibiotics are widely employed as the primary treatment for oral diseases, the emergence of drug-resistant bacteria has necessitated the exploration of alternative therapeutic approaches. One such modality is antimicrobial photodynamic therapy (aPDT), which utilizes light and photosensitizers. Indeed, aPDT has been used alone or in combination with other treatment options dealing with periodontal disease for the elimination of biofilms from bacterial community to achieve bone formation and/or tissue regeneration. In this review article, in addition to factors affecting the efficacy of aPDT, various photosensitizers, the latest technology and perspectives on aPDT are discussed in detail. More importantly, the article emphasizes the novel design and clinical applications of photosensitizers, as well as the synergistic effects of chemical and biomolecules with aPDT to achieve the complete eradication of biofilms and even enhance the biological performance of tissues surrounding the treated oral area.

Investigation of volatile sulfur compound level and halitosis in patients with gingivitis and periodontitis

This study aimed to measure the levels of volatile sulfur compounds and investigate the occurrence of halitosis in patients with gingivitis and periodontitis. Additionally, the incidence rates of gingivitis and periodontitis in patients with halitosis were investigated. Through various statistical analyses, we attempted to determine the relationship between periodontal disease and halitosis. One-hundred-and-four participants (52 females and 52 males, mean age: 46.49 ± 16.03 years) were enrolled in this cross-sectional study, comprising 33 healthy controls, 43 patients with gingivitis, and 28 patients with periodontitis. Gas chromatography was used to measure hydrogen sulfide (H2S) and methyl mercaptan (CH3SH), which are representative VSCs. The VSC cut-off values for diagnosing halitosis were 65.79 ppb for women and 79.94 ppb for men. Total VSC level was significantly higher in the gingivitis than the healthy control group (186.72 ± 374.83 ppb vs. 19.80 ± 40.19 ppb, p = 0.035). There was no significant difference between the gingivitis and periodontitis (153.79 ± 278.51 ppb) groups. H2S level was significantly higher in the gingivitis (100.51 ± 183.69 ppb) and periodontitis (91.57 ± 132.06 ppb) groups than in healthy controls (14.97 ± 31.22 ppb), and CH3SH level was significantly higher in gingivitis group (29.31 ± 59.16 ppb) than in the healthy control (5.73 ± 14.10 ppb) (all p < 0.05). Halitosis was found in 3% of healthy controls and 39.5% and 42.9% of patients with gingivitis and periodontitis patients, respectively, making it significantly higher in the gingivitis and periodontitis groups than the healthy controls (p = 0.005). Conversely, among participants with halitosis, 53.1% had gingivitis, 37.5% had periodontitis, and 90.6 incidence had periodontal disease. Multivariate logistic regression analysis to predict the presence of halitosis, found periodontal disease was a significant predictor of halitosis (OR = 3.607, 95% CI 1.023-12.718, p = 0.046). Considering area under curve value for halitosis, the cut-off value of healthy control (H2S:61.5 ppb, CH3SH:3.5 ppb), gingivitis (H2S:50.0 ppb, CH3SH:6 ppb), and periodontitis (H2S:62.0 ppb, CH3SH:3.5 ppb) were (all p < 0.05). Our results emphasize the close and strong relationship between periodontal disease and halitosis through human clinical evidence based on the high co-occurrence rate of mutual diseases. Additionally, the presence of periodontal disease increased the probability of halitosis by 3.607 times. These results suggest that H2S can be used as a biomarker of halitosis in patients with periodontal disease.

Evaluation of the antibacterial activity of Elsholtzia ciliate essential oil against halitosis-related Fusobacterium nucleatum and Porphyromonas gingivalis

The broad-spectrum antimicrobial activity of Elsholtzia ciliate essential oil (ECO) has been previously reported, but its effectiveness against halitosis-causing bacteria such as Fusobacterium nucleatum and Porphyromonas gingivalis is not well understood. In this study, we investigated the bacteriostatic activity of ECO against planktonic cells and biofilms of F. nucleatum and P. gingivalis, as well as its ability to inhibit bacterial metabolism and production of volatile sulfur compounds (VSCs) at sub-lethal concentrations. Our findings revealed that ECO exhibited comparable activities to chlorhexidine against these oral bacteria. Treatment with ECO significantly reduced the production of VSCs, including hydrogen sulfide, dimethyl disulfide, and methanethiol, which are major contributors to bad breath. As the major chemical components of ECO, carvacrol, p-cymene, and phellandrene, were demonstrated in vitro inhibitory effects on F. nucleatum and P. gingivalis, and their combined use showed synergistic and additive effects, suggesting that the overall activity of ECO is derived from the cumulative or synergistic effect of multiple active components. ECO was found to have a destructive effect on the bacterial cell membrane by examining the cell morphology and permeability. Furthermore, the application of ECO induced significant changes in the bacterial composition of saliva-derived biofilm, resulting in the elimination of bacterial species that contribute to halitosis, including Fusobacterium, Porphyromonas, and Prevotella. These results provide experimental evidence for the potential clinical applications of ECOs in the prevention and treatment of halitosis.

Causes and Management of Halitosis: A Narrative Review

Halitosis is defined as the presence of an unpleasant odor in exhaled air, regardless of its cause. In most patients with halitosis, the condition causes embarrassment and interferes with social interactions and daily life. Furthermore, bad breath can be a sign of an underlying disease. Understanding the factors and causes that lead to halitosis and its manifestations could facilitate proper management of this condition. To properly diagnose and treat patients, healthcare professionals, including primary care physicians and dental professionals, must be familiar with the etiology and appropriate management of the disease. Consequently, this review aims to provide practitioners with up-to-date information on the etiological factors of halitosis to facilitate the establishment of preventive measures and provide accurate diagnosis and management.

Prevalence and associated factors of self-reported halitosis among institutionalized adolescents: Cross-sectional study

OBJECTIVE

To assess the prevalence and associated factors of self-reported halitosis in institutionalized adolescents in a city in southern Brazil.

METHODS

This cross-sectional study involved male institutionalized adolescents, aged 15-19 years old, at the Socio-Educational Assistance Center in the city of Passo Fundo, Brazil. Data collection was performed by a research team composed of two interviewers, two clinical examiners of oral health and two examiners of salivary flow. A structured questionnaire was applied, which included demographical, socioeconomical, general health behaviour, presence of health problems and oral health self-perception variables. Decayed, Missing, Filled Index was used for the clinical examination. The salivary flow collection was performed using the mechanically stimulated total saliva method, in which only the liquid component was measured.

RESULTS

The prevalence of self-reported halitosis in this sample was 51.5% (n = 35). In the final multivariate analysis, halitosis was significantly associated with the non-white racial group (prevalence ratio [RP]:1.703; 95% confidence interval [95%CI]:1.101-2.634), use of crack (RP:1.857; 95%CI:1.270-2.714) and number of decayed teeth (PR: 1.123; 95%CI:1.008-1.252). The use of alcohol and access to dental care in the last 12 months were not significantly associated with self-reported halitosis.

CONCLUSION

It was concluded that non-white and crack-user youngsters had a high occurrence of self-reported halitosis. Higher rates of dental caries are also associated with halitosis.

The Role of the Oral Microbiome in the Development of Diseases

Periodontal disease (PD) is a complex and infectious illness that begins with a disruption of bacterial homeostasis. This disease induces a host inflammatory response, leading to damage of the soft and connective tooth-supporting tissues. Moreover, in advanced cases, it can contribute to tooth loss. The aetiological factors of PDs have been widely researched, but the pathogenesis of PD has still not been totally clarified. There are a number of factors that have an effect on the aetiology and pathogenesis of PD. It is purported that microbiological, genetic susceptibility and lifestyle can determine the development and severity of the disease. The human body’s defence response to the accumulation of plaque and its enzymes is known to be a major factor for PD. The oral cavity is colonised by a characteristic and complex microbiota that grows as diverse biofilms on all mucosal and dental surfaces. The aim of this review was to provide the latest updates in the literature regarding still-existing problems with PD and to highlight the role of the oral microbiome in periodontal health and disease. Better awareness and knowledge of the causes of dysbiosis, environmental risk factors and periodontal therapy can reduce the growing worldwide prevalence of PDs. The promotion of good oral hygiene, limiting smoking, alcohol consumption and exposure to stress and comprehensive treatment to decrease the pathogenicity of oral biofilm can help reduce PD as well as other diseases. Evidence linking disorders of the oral microbiome to various systemic diseases has increased the understanding of the importance of the oral microbiome in regulating many processes in the human body and, thus, its impact on the development of many diseases.

Revisiting Standard and Novel Therapeutic Approaches in Halitosis: A Review

Halitosis, or bad breath, is an oral health problem characterized by an unpleasant malodor emanating from the oral cavity. This condition can have different origins and causes a negative burden in social interactions, communication and quality of life, and can in uncommon cases be indicative of underlying non-oral non-communicable diseases. Most cases of halitosis are due to inadequate oral hygiene, periodontitis and tongue coating, yet the remaining proportion of cases are due to ear-nose-throat-associated (10%) or gastrointestinal/endocrine (5%) disorders. For this reason, the diagnosis, treatment and clinical management of halitosis often require a multidisciplinary team approach. This comprehensive review revisits the etiology of halitosis as well as standard and novel treatment that may contribute to higher clinical success.

Prevalence of halitosis among young adults in Dunedin, New Zealand

OBJECTIVES

To investigate the prevalence of halitosis in young adults.

METHODS

Young adults (n = 372; mean age = 21.0 ± 2.6 years old, range = 18-30 years) in Dunedin, New Zealand were recruited into the cross sectional study after providing informed consent. The prevalence of halitosis was determined using both objective measurements (parts per billion [ppb] volatile sulphur compounds [VSCs] in the exhaled air) and subjective measurements (self-reported halitosis questionnaire, tongue coating index, and organoleptic assessment).

RESULTS

VSC measurements indicated that the prevalence of halitosis (values ≥ 140 ppb) was 31.2%; 25.6% of participants self-reported halitosis. The organoleptic assessment revealed that 14.3% of the participants had a score of ≥2. A positive correlation was found between the VSC measurements and organoleptic assessment (p < 0.05). No significant relationship was found between self-reported halitosis and either organoleptic assessment or VSC measurements. Self-reported dry mouth, smoking, oral hygiene index, DMFT index, and tongue coating score were significantly associated with the organoleptic assessment (p < 0.05). The self-reported dry mouth, mouth breathing and tongue coating score were significantly associated with the VSC scores (p < 0.05).

CONCLUSION

Halitosis, as represented by VSC, was found in 31.2% of the participants. VSC scores and organoleptic assessment were positively correlated. There was no significant relationship between self-reported halitosis and either organoleptic assessment or VSC measurements.

Hematological biomarkers of systemic inflammation in genuine (physiologic and pathologic) halitosis

Halitosis is an unpleasant odor discharged through the oral cavity with a prevalence as high as 30%-50% of the general population. Conventional diagnostic methods have been focused on mouth air analysis measuring the amount of sulfur compounds which does not directly reflect the cause of halitosis. Also, the possible role of halitosis as an indicator of general health status has been steadily suggested and inflammation has been constantly associated with aversive body odor. Therefore, this study aimed to search for inter-relationships between hematologic indicators, clinical characteristics, and halitosis measurement that can predict the presence of pathologic halitosis and its intensity. Furthermore, the tentative relationship between halitosis and the presence of systemic inflammation was investigated. A total of 125 patients were divided into 103 patients in the genuine halitosis group (value ⩾80 ppb) and 22 patients in the pseudo halitosis group (value <80 ppb) based on portable sulfide monitor measurements. Clinical examination and hematological indices including inflammatory prognostic factors and halitosis measurements including organoleptic testing, portable sulfide monitor, and gas chromatography were evaluated. The genuine halitosis group showed a significantly higher white blood cell (WBC) count (p< 0.01) compared to the pseudo halitosis group. Erythrocyte sedimentation rate (ESR,β= 0.341,p< 0.05) values and duration of halitosis (β= 0.353,p< 0.05) showed a significant association with halitosis intensity and neutrophil to lymphocyte ratio (NLR) values (β= 3.859,p< 0.05) were significantly related to genuine halitosis diagnosis. A new WBC cut-off value of 5575μl^-1showed near to fair discriminative power in predicting genuine halitosis (area under the curve 0.661,p< 0.05). The results of this study showing an increased WBC count in genuine halitosis and its strong association with hematologic indices of subclinical inflammation including ESR and NLR suggest inflammatory hematologic markers as potential diagnostic tools in the diagnosis of genuine halitosis.

Profiling volatile compounds from culture supernatants of periodontal bacteria using gas chromatography/mass spectrometry/olfactometry analysis with a monolithic silica gel adsorption device

Halitosis is formed mainly by the volatile compounds produced by periodontal bacteria. Three volatile sulfur compounds (VSCs), hydrogen sulfide, methanethiol, and dimethyl sulfide, have attracted attention as major components of halitosis. However, these compounds cannot account for all odors. In this study, we profiled volatile compounds from the culture supernatants of periodontal bacteria using gas chromatography/mass spectrometry/olfactometry analysis with a monolithic silica gel adsorption device to investigate the potential odorous compounds. Periodontal bacteria have been found to produce volatile compounds belonging to various classes, such as alcohols, ketones, fatty acids, and aromatic compounds, in addition to VSCs. In addition, VSCs different from hydrogen sulfide and methanethiol, which are considered important causative compounds, may also influence to halitosis.

[Oral manifestations of COVID-19 and the role of the ACE2 receptor: what is known so far?]

COVID-19 is a currently pandemic disease that worries professionals in all areas of the Health Sciences. Current literature indicates that certain components of the stomatognathic system (such as lips, oral mucosa, tongue, and tonsils) express ACE2 receptors, responsible for the binding of SARS-CoV-2 to the human cell. This expression has a big impact on organular compromise, turning the oral cavity not only into an important route of viral entry but also into a region with the possibility of various manifestations such as xerostomia, halitosis, chemosensory alteration, opportunistic coinfection, and mucosal lesions. The fact that mouth manifestations are reported in the early stages of this disease suggests a possible predictive nature, which would make them very useful for diagnostic referral. In this sense, it is important that the dental professional knows how to recognize this early presentation symptomatology, being able to presumptively detect patients with COVID-19 in whom a significant systemic commitment has not yet been consolidated. This would allow the referral to medical consultation for definitive diagnostic purposes and, if correct, prevent both transmission and the advancement of the disease in the patient. Based on this important work, this review article synthesizes the scientific evidence published in the last 3 years (2019-2021 period) about the oral manifestations of COVID-19.

Self-perceived halitosis among young adults undergoing orthodontic treatment

INTRODUCTION

Halitosis is a common oral health problem that significantly impacts the quality of life of the affected individuals. In most cases, poor oral hygiene is responsible for the problem. Orthodontic therapy aims to correct malocclusion using different devices. It has been suggested that orthodontic treatment can promote gingival health by facilitating daily oral hygiene measures. However, the treatment may harm gingival health as these appliances may lead to a more significant accumulation of plaque, increasing the microbial load in the subgingival environment leading to halitosis.

OBJECTIVE

The primary goal of this survey is to assess the prevalence of self-perceived halitosis in patients undergoing orthodontic treatment.

MATERIALS AND METHODS

An online questionnaire was randomly distributed to patients undergoing orthodontic treatment. A total of 289 subjects completed the questionnaire. It included questions about: demographic data, medical history, social habits, past dental treatment and oral hygiene habits. Descriptive statistics as frequency distributions and percentages were calculated for the study variables.

RESULTS

The prevalence of self-perceived halitosis was 41.5%. The majority of the participants started to notice this problem during and after orthodontic treatment (62.5%). A statistically significant correlation was found between the regular dental visits and halitosis in patients with fixed orthodontic appliances (p-value = 0.010). Also, those patients had a substantial increase in tongue coating formation (p- value = 0.010).

CONCLUSION

Self-perceived halitosis is a common problem in patients receiving orthodontic treatment.

A Literature Review and Framework Proposal for Halitosis Assessment in Cigarette Smokers and Alternative Nicotine-Delivery Products Users

Halitosis is a health condition which counts cigarette smoking (CS) among its major risk factors. Cigarette smoke can cause an imbalance in the oral bacterial community, leading to several oral diseases and conditions, including intraoral halitosis. Although the best approach to decrease smoking-related health risks is quitting smoking, this is not feasible for many smokers. Switching to potentially reduced-risk products, like electronic vapor products (EVP) or heated tobacco products (HTP), may help improve the conditions associated with CS. To date, there have been few systematic studies on the effects of CS on halitosis and none have assessed the effects of EVP and HTP use. Self-assessment studies have shown large limitations owing to the lack of reliability in the participants' judgment. This has compelled the scientific community to develop a strategy for meaningful assessment of these new products in comparison with cigarettes. Here, we compiled a review of the existing literature on CS and halitosis and propose a 3-layer approach that combines the use of the most advanced breath analysis techniques and multi-omics analysis to define the interactions between oral bacterial species and their role in halitosis both in vitro and in vivo. Such an approach will allow us to compare the effects of different nicotine-delivery products on oral bacteria and quantify their impact on halitosis. Defining the impact of alternative nicotine-delivery products on intraoral halitosis and its associated bacteria will help the scientific community advance a step further toward understanding the safety of these products and their potentiall risks for consumers.

Efficacy of a Zinc Lactate Mouthwash and Tongue Scraping in the Reduction of Intra-Oral Halitosis: A Single-blind, Controlled, Crossover Clinical Trial-A Pilot Study

Intra-oral halitosis is defined as an unpleasant odor that comes out of the mouth. The aim of this study was to investigate the effect of zinc lactate mouthwash and tongue scraping on intra-oral halitosis. The study was conducted on 60 volunteers that were divided into two groups and fol-lowed two types of 14-day oral hygiene protocols on a cross-over basis after a 7-day wash-out period. One protocol was based on tooth brushing only, while the other was based on additional mouth rinsing with a zinc lactate product and tongue scraping. Morning mouth breath was as-sessed organoleptic and by volatile sulfur compound concentrations. The highest mean organo-leptic and volatile sulfur compound measurement values were found in the tooth brushing without mouth washing and tongue scraping oral hygiene protocol (p < 0.05). The zinc lactate mouthwash combined with tongue scraping appears to be an important hygienic procedure to reduce breath odor.

Quality and Reliability of Halitosis Videos on YouTube as a Source of Information

Halitosis is a common condition that adversely affects quality of life. Through YouTube, people access oral health information. This study aimed to analyze the quality and comprehensiveness of the content, and reliability of halitosis videos hosted on YouTube. In total, 300 videos were collected based on three search keywords, and the number of likes, dislikes, views, duration, interaction index, viewing rate, and source category. Subsequently, the video score, which represents the content quality and comprehensiveness was used to categorize videos as poor, good, and excellent. DISCERN score was used to assess video reliability. Of the 105 videos analyzed, 68 (64.8%) were uploaded by personal users. In general, videos were categorized as poor and have low reliability. Videos sourced from healthcare professionals showed the highest quality, comprehensiveness of the content, and reliability (p < 0.05). There was no difference in the number of viewers for video duration less than or more than 4 min (p > 0.05). YouTube users prefer low-quality videos over high-quality ones, indicating that viewers cannot differentiate between reliable and potentially biased content. It is critical to enable viewers to critically assimilate information hosted on YouTube to make effective oral healthcare decisions.

Halitosis, what experiences and methods apply Dutch dental hygienists

OBJECTIVES

The aim of this research is to gain more insight in the methods and experiences of dental hygienists in the Netherlands regarding the treatment of patients with halitosis.

MATERIAL AND METHODS

A total of 92 dental hygienists completed the questionnaire (consisting of 19 questions on personal and professional characteristics, clinical observation and treatment of halitosis, the referral of patients with halitosis, the presence and usefulness of a protocol). The questionnaire was distributed using a social media platform for dental professionals in oral health care from all over the Netherlands.

RESULTS

83.4% of 90 dental hygienists had paid attention to the patient's breath but only 37.8% of dental hygienists always informed the patient. Reasons for not informing patients were the fear of the patient's possible reaction or because other oral health problems were more important. Of the included dental hygienists 67.8% had never referred a patient for treatment of halitosis. 86.7% of the dental hygienists stated there was no protocol for diagnosis and treatment of patients with halitosis. However, 90.0% of the dental hygienists acknowledged a protocol would be useful.

CONCLUSIONS

The majority of the dental hygienists in the Netherlands had paid attention to the patient's breath, but only a small group of dental hygienists informed their patients about halitosis. In dental practices halitosis is an underestimated problem. During the coronavirus pandemic people are more aware with the smell of their breath. Dental hygienists indicated scaling and root planning and/or providing information and instruction by patients with a bad breath.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2020 professional literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to this work to cover this broad topic. Specific subject areas addressed include prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders (TMDs); sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence day-to-day dental treatment decisions with a keen eye on future trends in the profession. With the tremendous volume of dentistry and related literature being published today, this review cannot possibly be comprehensive. The purpose is to update interested readers and provide important resource material for those interested in pursuing greater detail. It remains our intent to assist colleagues in navigating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the dental patients they encounter.

Self-perceived and self-reported breath odour and the wearing of face masks during the COVID-19 pandemic

Objectives

To assess the self‐perception of breath odour (SPBO) and oral hygiene habits (OHHs) while the wearing of face masks during the COVID‐19 pandemic.

Subjects and Methods

This cross‐sectional study included 4647 individuals who answered a structured questionnaire containing demographic, medical and dental variables and self‐perceived breath odour. Variables associated with changes in self‐perceived breath odour, self‐perceived halitosis and changes in OHHs were assessed through multivariate logistic regression.

Results

Changes in self‐perceived breath odour were reported by 1572 individuals and were associated with smoking, systemic conditions, dry mouth, tongue coating, the period of face mask use and its interaction with prior thinking of having bad breath. Likewise, 645 individuals started to consider having bad breath. This was associated with the interaction between prior family/friends saying they have bad breath and period of face mask use. Changes in OHHs were strongly associated with changes in SPBO and starting to consider having bad breath.

Conclusion

Changes in one's SPBO was associated with the wearing of face masks and was significant for changes in OHHs. Findings may be important to guide comprehensive preventive and therapeutic strategies in relation to oral health care.

Identification of Salivary Microorganisms and Metabolites Associated with Halitosis

Halitosis is mainly caused by the action of oral microbes. The purpose of this study was to investigate the differences in salivary microbes and metabolites between subjects with and without halitosis. Of the 52 participants, 22 were classified into the halitosis group by the volatile sulfur compound analysis on breath samples. The 16S rRNA gene amplicon sequencing and metabolomics approaches were used to investigate the difference in microbes and metabolites in saliva of the control and halitosis groups. The profiles of microbiota and metabolites were relatively different between the halitosis and control groups. The relative abundances of Prevotella, Alloprevotella, and Megasphaera were significantly higher in the halitosis group. In contrast, the relative abundances of Streptococcus, Rothia, and Haemophilus were considerably higher in the control group. The levels of 5-aminovaleric acid and n-acetylornithine were significantly higher in the halitosis group. The correlation between identified metabolites and microbiota reveals that Alloprevotella and Prevotella might be related to the cadaverine and putrescine pathways that cause halitosis. This study could provide insight into the mechanisms of halitosis.

Effect of antimicrobial photodynamic therapy with red led and methylene blue on the reduction of halitosis: controlled microbiological clinical trial

To determine the effect of antimicrobial photodynamic therapy (aPDT) using a red light-emitting diode (LED) on the reduction of halitosis and microbiological levels in the tongue coating immediately after irradiation, 7, 14, and 30 days after treatment. Forty-five young adults diagnosed with halitosis were allocated to three groups: G1, aPDT with 0.005% methylene blue and red LED (660 nm, four irradiation points, 90 s per point, power of 400 mW, 36 J per point, radiant exposure of 95 J/cm², continuous wave); G2, tongue scraping; and G3, tongue scraping and aPDT. Gas chromatography was performed before and immediately after treatment, as well as at the different follow-up times. Microbiological samples were collected at the same times from the dorsum of the tongue, and bacteria were quantified in the samples using real-time PCRq. The Wilcoxon test was used for the intragroup analyses, and the Kruskal-Wallis test was used for the intergroup analyses. In the intragroup analyses, differences were found before and immediately after treatment in all groups (p < 0.05). The effect was maintained after 7 days only in the tongue scraping group (p < 0.05). In the intergroup analysis, no statistically significant differences were found among the groups (p > 0.05). For the microbiological analyses, no statistically significant differences were found in the groups/bacteria that were analyzed (p > 0.05). aPDT using a red LED and 0.005% methylene blue caused an immediate reduction in halitosis, but the effect was not maintained after 7, 14, or 30 days. No reduction occurred in the number of bacteria investigated or the quantification of universal 16S rRNA. ClinicalTrials.gov Identifier: NCT03656419.

Investigation of oral malodor prevention by dentifrices as measured by VSC reduction

The oral malodor reduction efficacy of dentifrices containing stannous fluoride (SnF₂) or zinc plus arginine (Zn/Arg) was evaluated using a halimeter to measure volatile sulfur compounds (VSCs) in two randomized, controlled, single-blind, cross-over pilot clinical trials. Study 1 (N= 16) had five 1100 ppm F dentifrices and five treatment periods: negative control (NC): 0.243% sodium fluoride (NaF); SnF₂A: 0.454% SnF₂+ pyrophosphate; SnF₂B: 0.454% SnF₂+ sodium hexametaphosphate; SnF₂C: 0.454% SnF₂+ citrate; and SnF₂D: experimental 0.454% SnF₂with increased bioavailable Sn. Study 2 (N= 16) had four 1450 ppm F dentifrices and four treatment periods: NC: 0.1% NaF + 0.76% sodium monofluorophosphate; Zn/Arg: NaF + zinc + arginine; SnF₂E: 0.454% SnF₂+ 0.078% NaF + sodium hexametaphosphate; SnF₂F: 0.454% SnF₂+ 0.078% NaF + citrate. Each period took 96 h; baseline (day 0) morning to day 4 morning. Subjects brushed 2x/day with the treatment dentifrice. VSC levels were measured in the morning, prior to morning brushing, on days 0 and 4. Changes in VSC scores from day 0 to day 4 were assessed using a mixed-model analysis of covariance for cross-over studies. In study 1, SnF₂dentifrices B, C and D showed statistically significant reductions (31.3%, 24.8%, 34%, respectively) in VSC scores versus baseline (p< 0.001); the benefits of these treatments versus NC and SnF₂dentifrice A were statistically significant (p⩽ 0.001). In study 2, SnF₂dentifrices E and F showed statistically significant reductions (31.2%, 22.1%, respectively) in VSC scores versus baseline (p⩽ 0.010); the benefits of these treatments versus NC and the Zn/Arg dentifrice were statistically significant (p⩽ 0.035). The Zn/Arg dentifrice showed a significant increase of 35.2% (p< 0.001) in VSC scores versus baseline. These studies demonstrated that SnF₂dentifrices can provide significant oral malodor reductions, but the benefit is formulation dependent. The presence of SnF₂is not sufficient to ensure efficacy. The Zn/Arg dentifrice increased VSC levels, indicating greater malodor.Clinical Trial Numbers: 20190429 and 20191028.

Relationship between Fixed Dental Crowns and Volatile Sulphur Compounds

Objectives: The aim of this study was to investigate and compare the level of halitosis in patients with/without fixed crowns and in addition the influence of various crown parameters on halitosis was also explored. Methods: In total, 96 subjects (fixed crowns = 52; no crowns = 44) participated in the study. The levels volatile sulphur compounds (VSCs) of hydrogen sulphide (H2S), methyl mercaptan (CH3SH), and dimethyl sulphide (CH3SCH3) were evaluated with breath samples using gas chromatography and used for classification as presence or absence of halitosis. The periodontal clinical parameters for all the participants as well as the crown parameters for participants with fixed crowns were also evaluated. Cross tabulation, Chi-square test, and one-way analysis of variance tests were used for the statistical analysis and comparisons. Results: Breath samples revealed, 50 (52.1%) participants were suffering from halitosis. Out of VSCs, the level of CH3SCH3 (62.5%) was found to be the most prevalent. Significant correlations were observed between the presence of fixed crowns and oral halitosis (p < 0.001). Statistically significant difference in the concentration of H2S and CH3SH (p < 0.001) and no significance for CH3SCH3 (p = 0.075) between patients with/without fixed crowns was found. The presence of halitosis was more prevalent in the subjects with crown parameters (subgingival margin, over-contoured margin, open-crown margin, over-contoured and under-contoured crowns) considered clinically defective/unacceptable (p < 0.05). Conclusions: Presence of fixed dental crowns significantly contributes to the oral halitosis. Dental crowns with defects significantly impair the hygienic conditions and oral microflora resulting in high prevalence of halitosis.

Knowledge and Management of Halitosis in France and Lebanon: A Questionnaire-Based Study

Halitosis is a growing issue and its management is highly challenging. The aim of this study was to evaluate the knowledge and treatment strategies used by French (FD) and Lebanese (LD) dentists. A self-administered structured questionnaire was sent to FD and LD comprising questions about professional characteristics, management, and treatment of halitosis, patients’ referral, and halitosis-related knowledge. A multivariate analysis was conducted to determine differences between FD and LD and to identify parameters that could influence dentists’ management of halitosis. The questionnaire was filled out by 156 FD and 257 LD. Among them, 78.8% of FD and 68.9% of LD were confronted with halitosis management, while only a few routinely asked their patients about halitosis (16% FD, 13.2% LD). Regarding anamnesis, oral hygiene habits were more investigated by FD than LD (p < 0.05). The overall treatment satisfaction was low with 39.7% of FD and 28.4% of LD considering their treatment effective. Regarding halitosis-related knowledge, extra-oral causes were overestimated in both populations. FD (83.4%) and LD (65.8%) considered their education regarding halitosis as insufficient. This study highlights the need of professional education in both countries, targeting proper diagnosis and treatment strategies of halitosis.

The Role of Oral Microbiota in Intra-Oral Halitosis

Halitosis is a common ailment concerning 15% to 60% of the human population. Halitosis can be divided into extra-oral halitosis (EOH) and intra-oral halitosis (IOH). The IOH is formed by volatile compounds, which are produced mainly by anaerobic bacteria. To these odorous substances belong volatile sulfur compounds (VSCs), aromatic compounds, amines, short-chain fatty or organic acids, alcohols, aliphatic compounds, aldehydes, and ketones. The most important VSCs are hydrogen sulfide, dimethyl sulfide, dimethyl disulfide, and methyl mercaptan. VSCs can be toxic for human cells even at low concentrations. The oral bacteria most related to halitosis are Actinomyces spp., Bacteroides spp., Dialister spp., Eubacterium spp., Fusobacterium spp., Leptotrichia spp., Peptostreptococcus spp., Porphyromonas spp., Prevotella spp., Selenomonas spp., Solobacterium spp., Tannerella forsythia, and Veillonella spp. Most bacteria that cause halitosis are responsible for periodontitis, but they can also affect the development of oral and digestive tract cancers. Malodorous agents responsible for carcinogenesis are hydrogen sulfide and acetaldehyde.