Oral Manifestations in Patients with COVID-19: A 6-Month Update

Severe acute respiratory syndrome coronavirus 2 pathology and cell tropism in tongue tissues of COVID-19 autopsies

Since 2019, Coronavirus Disease 2019(COVID-19) has affected millions of people worldwide. Except for acute respiratory distress syndrome, dysgeusis is also a common symptom of COVID-19 that burdens patients for weeks or permanently. However, the mechanisms underlying taste dysfunctions remain unclear. Here, we performed complete autopsies of five patients who died of COVID-19. Integrated tongue samples, including numerous taste buds, salivary glands, vessels, and nerves were collected to map the pathology, distribution, cell tropism, and receptor distribution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the tongue. Our results revealed that all patients had moderate lymphocyte infiltration around the salivary glands and in the lamina propria adjacent to the mucosa, and pyknosis in the epithelia of taste buds and salivary glands. This may be because the serous acini, salivary gland ducts, and taste buds are the primary sites of SARS-CoV-2 infection. Multicolor immunofluorescence showed that SARS-CoV-2 readily infects Keratin (KRT)7+ taste receptor cells in taste buds, secretory cells in serous acini, and inner epithelial cells in the ducts. The major receptors, angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine subtype 2 (TMPRSS2), were both abundantly expressed in these cells. Viral antigens and receptor were both rarely detected in vessels and nerves. This indicates that SARS-CoV-2 infection triggers pathological injury in the tongue, and that dysgeusis may be directly related to viral infection and cellular damage.

Frequency of Oral Lesions, Olfactory, and Gustatory Disorders and Xerostomia in Patients with COVID-19

COVID-19, a respiratory illness with a global impact on millions, has recently been linked to manifestations affecting various bodily systems, including the oral cavity. Studies highlight oral issues, like ulcers, blisters, and white patches, alongside olfactory and gustatory dysfunction, influencing an individual's quality of life. In this context, our study aimed to assess the frequency of oral lesions, olfactory and gustatory disorders, and xerostomia resulting from COVID-19. An observational study was conducted with 414 patients to evaluate the frequency of oral symptoms resulting from COVID-19. Patients were diagnosed with mild symptoms and evaluated through clinical examination of the oral cavity and a questionnaire to assess functional alterations. The findings showed that 139 out of 414 patients presented clinical manifestations, with oral lesions being the most prevalent (19.1%), followed by gustatory disorders (18.1%), xerostomia (14.2%), and olfactory dysfunction (14%). The most prevalent oral lesions were ulcerations (n = 51), candidiasis (n = 8), and erythema or red plaques (n = 7). Unfortunately, 50 (12.1%) patients died during this study. Therefore, oral lesions, olfactory and gustatory dysfunctions, and xerostomia are common symptoms associated with COVID-19.

Identification of receptors and factors associated with human coronaviruses in the oral cavity using single-cell RNA sequencing

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) ravaged the world, and Coronavirus Disease 2019 (COVID-19) exhibited highly prevalent oral symptoms that had significantly impacted the lives of affected patients. However, the involvement of four human coronavirus (HCoVs), namely SARS-CoV-2, SARS-CoV, MERS-CoV, and HCoV-229E, in oral cavity infections remained poorly understood. We integrated single-cell RNA sequencing (scRNA-seq) data of seven human oral tissues through consistent normalization procedure, including minor salivary gland (MSG), parotid gland (PG), tongue, gingiva, buccal, periodontium and pulp. The Seurat, scDblFinder, Harmony, SingleR, Ucell and scCancer packages were comprehensively used for analysis. We identified specific cell clusters and generated expression profiles of SARS-CoV-2 and coronavirus-associated receptors and factors (SCARFs) in seven oral regions, providing direction for predicting the tropism of four HCoVs for oral tissues, as well as for dental clinical treatment. Based on our analysis, it appears that various SCARFs, including ACE2, ASGR1, KREMEN1, DPP4, ANPEP, CD209, CLEC4G/M, TMPRSS family proteins (including TMPRSS2, TMPRSS4, and TMPRSS11A), and FURIN, are expressed at low levels in the oral cavity. Conversely, BSG, CTSB, and CTSL exhibit enrichment in oral tissues. Our study also demonstrates widespread expression of restriction factors, particularly IFITM1-3 and LY6E, in oral cells. Additionally, some replication, assembly, and trafficking factors appear to exhibit broad oral tissues expression patterns. Overall, the oral cavity could potentially serve as a high-risk site for SARS-CoV-2 infection, while displaying a comparatively lower degree of susceptibility towards other HCoVs (including SARS-CoV, MERS-CoV and HCoV-229E). Specifically, MSG, tongue, and gingiva represent potential sites of vulnerability for four HCoVs infection, with the MSG exhibiting a particularly high susceptibility. However, the expression patterns of SCARFs in other oral sites demonstrate relatively intricate and may only be specifically associated with SARS-CoV-2 infection. Our study sheds light on the mechanisms of HCoVs infection in the oral cavity as well as gains insight into the characteristics and distribution of possible HCoVs target cells in oral tissues, providing potential therapeutic targets for HCoVs infection in the oral cavity.

Association between dysbiotic perio-pathogens and inflammatory initiators and mediators in COVID-19 patients with diabetes

It has been suggested that a corona virus infection is linked to chronic periodontitis (COVID-19). Our objectives were to look at the expression of angiotensin-converting enzyme-2 (ACE2) in periodontal compartments containing periodontal infections to determine if ACE2 is directly or indirectly responsible for the inflammation in periodontal tissues getting worse. In this study, six non-COVID-19 periodontitis patients without diabetes served as controls, and 23 hospitalized periodontitis patients were admitted with PCR-confirmed COVID-19 with diabetes mellitus (Group 1/G1, n = 10), and without diabetes (Group 2/G2, n = 13). We evaluated the mRNA expression of ACE2, IL-6, IL-8, complement C3, and LL-37, as well as the relative proportion of Porphyromonas gingivalis, Fusobacterium nucleatum, and Veillonella parvula to represent the dysbiosis condition in periodontal microenvironment using subgingival plaque and gingival crevicular fluids (GCF) samples and quantitative real time PCR (qPCR). Every analysis was done to ascertain how they related to one another. The area under the curve (AUC) and receiver operating characteristic (ROC) curve were used to determine the sensitivity and specificity of inflammatory indicators. All the grouped patients had ACE2 detected, according to our findings, but only the G1 patients had a positive correlation (p < 0.05) between ACE2 expression and the inflammatory markers. The combination of IL-6 and C3 mRNAs was found to be 0.78 and 0.55 for the G1 group and the G2 group, respectively, based on the ROC and AUC values. According to our research, the relationship between complement C3 and IL-6 may be able to predict the degree of periodontal inflammation in COVID-19 patients who also have diabetes.

Comparison of Salivary Secretion, pH, and Buffer Capacity Between COVID-19 Vaccinated and Unvaccinated Child Patients Visiting Dental Clinics of University Hospitals in Riyadh City, Saudi Arabia

Objective

This study aimed to assess and compare the salivary secretion, pH, and buffer capacity between COVID-19 vaccinated and unvaccinated child patients visiting the clinics of private university dental hospitals in Riyadh, Saudi Arabia.

Methods

This is the first comparative assessment of salivary parameters between unvaccinated and COVID-19-vaccinated child patients. The study sample comprised COVID-19 unvaccinated (n = 66) and vaccinated (n = 66) pediatric dental patients aged 4-12 years seeking dental care in clinics of private university hospitals. Paraffin-stimulated saliva was collected from unvaccinated and vaccinated study participants, and the amount of saliva secreted per minute was noted. Salivary pH and buffering capacity (by 5 mmol Hydrochloric acid titration) were measured using a benchtop digital pH meter. The data obtained were compared between unvaccinated and vaccinated participants using an independent t-test.

Results

The results showed a significantly higher salivary secretion rate in unvaccinated than vaccinated study participants (0.83 ± 0.24 mL/min vs 0.67 ± 0.24 mL/min, p = 0.001). Similarly, unvaccinated subjects compared to vaccinated subjects exhibited a significantly higher pH (7.33 ± 0.39 vs 7.04 ± 0.46, p < 0.001) and buffering capacity (6.31 ± 1.55 vs 5.40 ± 1.22, p < 0.001). Moreover, unvaccinated females demonstrated a significantly higher salivary secretion (0.87 ± 0.23 vs 0.71 ± 0.25, t = 2.627, p = 0.011) and buffering capacity 6.19 ± 1.52 vs 5.34 ± 1.25, t = 2.404, p = 0.019) than vaccinated females. Similarly, unvaccinated male exhibited significantly higher salivary secretion (0.80 ± 0.25 vs 0.64 ± 0.23, t = 2.670, p = 0.009), salivary pH (7.39 ± 0.45 vs 6.94 ± 0.41, t=4.309, p<0.001) and buffering capacity (6.42 ± 1.60 vs 5.45 ± 1.21, t = 2.875, p = 0.005) than the vaccinated male subjects.

Conclusion

The vaccinated subjects showed a significantly lower mean salivary secretion, pH, and buffering capacity than unvaccinated participants. Hence, COVID-19 vaccination is likely to affect salivary parameters among pediatric patients.

Evidence of a Sjögren's disease-like phenotype following COVID-19 in mice and humans

Sjögren's Disease (SjD) is a systemic autoimmune disease characterized by lymphocytic inflammation of the lacrimal and salivary glands (SG), dry eyes and mouth, and systemic symptoms. SARS-CoV-2 may trigger the development or progression of autoimmune diseases. To test this, we used a mouse model of SARS-CoV-2 infection and convalescent patients' blood and SG in order to understand the development of SjD-like autoimmunity after infection. First, SARS-CoV-2-infected human angiotensin-converting enzyme 2 (ACE2) transgenic mice exhibited decreased salivation, elevated antinuclear antibodies (ANA), and lymphocytic infiltration in the lacrimal and SG. The sera from patients with COVID-19 sera showed increased ANA (i.e., anti-SSA [Sjögren's-syndrome-related antigen A]/anti-Ro52 and anti-SSB [SS-antigen B]/anti-La). Male patients showed elevated anti-SSA compared with female patients, and female patients exhibited diverse ANA patterns. SG biopsies from convalescent COVID-19 patients were microscopically similar to SjD SG with focal lymphocytic infiltrates in 4 of 6 patients and 2 of 6 patients exhibiting focus scores of at least 2. Lastly, monoclonal antibodies produced in recovered patients blocked ACE2/spike interaction and cross-reacted with nuclear antigens. Our study shows a direct association between SARS-CoV-2 and SjD. Hallmark features of SjD-affected SGs were histologically indistinguishable from convalescent COVID-19 patients. The results implicate that SARS-CoV-2 could be an environmental trigger for SjD.

A reflection on COVID-19 and oral mucosal lesion: a systematic review

Introduction

The aim of this systematic review is to provide a clinical update of the current knowledge on COVID-19 and oral mucosal lesions, to analyze the types and prevalence of oral mucosal lesions in patients with COVID-19, and to clarify the potential association between COVID-19 and oral mucosal lesions.

Methods

The literature search was conducted using PubMed, Web of Science, Scopus and the Cochrane Library, as well as literatures via manual searches of the reference lists of included studies. Studies published in English that mentioned oral mucosal lesions in patients with COVID-19 were included, resulting in a total of 31 studies.

Results

Most of the included studies were considered to have a moderate to high risk of bias according to the Joanna Briggs Institute bias assessment tools. Based on COVID-19 severity, the characteristics and patterns of oral mucosal lesions in COVID-19 patients were described, analyzed and synthesized. Overall, ulcers without specific diagnosis had the highest prevalence in COVID-19 patients, followed by traumatic ulcers, candidiasis, petechiae and aphthous-like lesions. Homogeneity of data cannot be achieved in statical analysis, indicating randomness of outcome (ulcers without specific diagnosis, 95% CI: 28%-96%, I2 = 98.7%).

Discussion

Given the limited evidence from currently available studies, the association between COVID-19 and oral mucosal lesions remains difficult to clarify. Healthcare professionals should be aware of the possible association between COVID-19 and oral mucosal lesions, and we hereby discuss our findings.

Awareness of undergraduate dental students, interns, and freshly graduated dentists about oral manifestation associated with COVID-19

OBJECTIVE

There is growing evidence supporting the presence of oral manifestations associated with COVID-19. The study investigates the knowledge of dental undergraduates and recently graduated dentists concerning oral presentations related to COVID-19.

METHODS

A cross-sectional descriptive study in Saudi Arabia comprised 305 individuals, including undergraduate dental students, interns, and freshly graduated dentists. Data were collected using a questionnaire disseminated to approximately 500 subjects via WhatsApp groups and other applications. The questionnaire was tested in a pilot study for validity, edited, and validated by 2 supervisors at the College of Dentistry, Qassim University, Buraydah, Saudi Arabia. The questionnaire consisted of questions regarding sociodemographic attributes, the level of expertise of dental practitioners, and their knowledge and perspectives regarding COVID-19 and the implementation of oral lesions interrelated to it. The data was subjected to analysis through the utilization of descriptive statistics and chi-square tests, employing the statistical software SPSS (version 24).

RESULTS

About 43.9% of subjects stated that COVID-19 causes oral symptoms. Respondents most frequently reported COVID-19-related dry mouth. Oral ulcers, Candida infection, Hyperpigmentation, tongue coating, atrophy, Petechiae, Herpes, white lesions, Gingivitis, and Periodontitis are further symptoms. COVID-19's oral manifestation was unknown to 41.0% of subjects, and 37.7% of respondents lacked knowledge regarding the most impacted locations of oral manifestations. Oral signs and COVID-19 symptoms are debated and significantly associated with higher educational levels.

CONCLUSION

The dental students and freshly graduated dentists in this study have proper knowledge of COVID-19 and its symptoms. Also, most dental students and newly graduated dentists recognize the potential correlation between COVID-19 and oral manifestations with an average to excellent knowledge of the types and sites commonly affected. The level of awareness was associated with higher educational levels.

Estimating the prevalence of oral manifestations in COVID-19 patients: a systematic review

BACKGROUND

Patients with coronavirus disease 2019 (COVID-19) present with a variety of oral manifestations. Therefore, we conducted a systematic review to estimate the prevalence of oral lesions among COVID-19 patients.

METHODS

An extensive literature search of several electronic bibliographic databases (PubMed, Scopus, Science Direct, Litcovid) was conducted to retrieve all articles published in the English language from January 1, 2020 to March 31, 2023 that reported the prevalence of oral manifestations among COVID-19 patients. A meta-analysis of pooled prevalence was performed using Jamovi ver. 2.3 (2022). The I2 and Q statistics were used to assess heterogeneity between studies, and p-values <0.01 were considered statistically significant.

RESULTS

In total, 79 studies with data from 13,252 patients were included. The articles were predominantly published in 2020 (n=33), and Italy was the most common country (n=14). Most of the affected patients more than 50 years old and women (56.6%). The most common sites of involvement were the tongue (n=65), followed by the oral mucosa (n=37) and lips (n=19). High heterogeneity was found between studies. The most common oral manifestation was taste alteration, followed by xerostomia and ulceration, showing pooled prevalence rates of 48%, 35%, and 21%, respectively.

CONCLUSION

COVID-19 patients show various oral manifestations that may help clinicians identify the disease promptly. Recognition of the signs and symptoms of COVID-19 is critical for an early diagnosis and better prognosis.

Oral manifestations in hospital-admitted COVID-19 patients: a case control study

The oral cavity can present early manifestations of several systemic diseases. Since the emergence of the COVID-19 pandemic, there have been many published studies reporting the direct effect of the virus on orofacial structures. In the present study, oral signs and symptoms of 22 hospital-admitted COVID-19 patients were examined and compared to a matching control group. Loss of taste and smell was the most prevalent symptom (65%), followed by oral dryness (45%) and halitosis (30%). The most common oral lesions were candidal infections (68%). Other less common manifestations were oral ulcerations (36%) followed by the appearance of white patches (27.3%). There was a statistically significant association between candidal infection and age in the study group, where the p-value was 0.008. In the present study, 80% of those who had candida infections were aged 60 years or above. There was no significant association with comorbidities such as diabetes mellitus and hypertension.

Methodological quality and reporting quality of COVID-19 living systematic review: a cross-sectional study

OBJECTIVES

The main objective of this study is to evaluate the methodological quality and reporting quality of living systematic reviews (LSRs) on Coronavirus disease 2019 (COVID-19), while the secondary objective is to investigate potential factors that may influence the overall quality of COVID-19 LSRs.

METHODS

Six representative databases, including Medline, Excerpta Medica Database (Embase), Cochrane Library, China national knowledge infrastructure (CNKI), Wanfang Database, and China Science, Technology Journal Database (VIP) were systematically searched for COVID-19 LSRs. Two authors independently screened articles, extracted data, and then assessed the methodological and reporting quality of COVID-19 LSRs using the "A Measurement Tool to Assess systematic Reviews-2" (AMSTAR-2) tool and "Preferred Reporting Items for Systematic reviews and Meta-Analyses" (PRISMA) 2020 statement, respectively. Univariate linear regression and multivariate linear regression were used to explore eight potential factors that might affect the methodological quality and reporting quality of COVID-19 LSRs.

RESULTS

A total of 64 COVID-19 LSRs were included. The AMSTAR-2 evaluation results revealed that the number of "yes" responses for each COVID-19 LSR was 13 ± 2.68 (mean ± standard deviation). Among them, 21.9% COVID-19 LSRs were rated as "high", 4.7% as "moderate", 23.4% as "low", and 50% as "critically low". The evaluation results of the PRISMA 2020 statement showed that the sections with poor adherence were methods, results and other information. The number of "yes" responses for each COVID-19 LSR was 21 ± 4.18 (mean ± standard deviation). The number of included studies and registration are associated with better methodological quality; the number of included studies and funding are associated with better reporting quality.

CONCLUSIONS

Improvement is needed in the methodological and reporting quality of COVID-19 LSRs. Researchers conducting COVID-19 LSRs should take note of the quality-related factors identified in this study to generate evidence-based evidence of higher quality.

Oral side effects of COVID-19 vaccines in 32 European countries: Analysis of EudraVigilance reports

The recent reports of oral side effects (SEs) following COVID-19 vaccination warrant further investigation into their prevalence, severity, and aetiology. This study was conducted to synthesize the first-ever population-level evidence about oral SEs of COVID-19 vaccines in Europe. The European Union Drug Regulating Authorities Pharmacovigilance (EudraVigilance) database was accessed in August 2022 to extract summary data of all potential oral SEs reported after COVID-19 vaccination. The data were reported descriptively and cross-tabulated to facilitate sub-group analysis per vaccine type, sex, and age group. Dysgeusia was the most commonly reported oral SE (0.381 case per each 100 received reports), followed by oral paraesthesia (0.315%), ageusia (0.296%), lip swelling (0.243%), dry mouth (0.215%), oral hypoaesthesia (0.210%), swollen tongue (0.207%), and taste disorder (0.173%). Females had significantly (Sig. < 0.001) a higher prevalence of all most common (top 20) oral SEs, except for salivary hypersecretion, which was equally prevalent among females and males. The present study revealed a low prevalence of oral SEs, with taste-related, other sensory and anaphylactic SEs being the most common SEs in Europe, similar to what was found earlier among the US population. Future studies should explore the potential risk factors of oral sensory and anaphylactic SEs to verify whether they are causally linked to COVID-19 vaccines.

Oral lesions in patients with severe COVID-19 in the National Institute of Respiratory Diseases in Mexico: Case series

Oral manifestations in patients with COVID-19 have already been reported in the literature. Determining whether the oral manifestations in these cases are directly related to SARS-CoV-2 infection or not has been challenging for both clinicians and researchers, although at present it has not been possible to prove. There are several possible causes for the development of the oral lesions in patients with COVID-19, among them are, opportunistic infections, drug reactions, iatrogenic and those directly related to viral infection. The present work describes the main characteristics of 10 severe COVID-19 hospitalized patients with oral manifestations. By analyzing the characteristics of the reported patients, and what is published in the literature, we conclude that for this series of cases the manifestations are not directly related to SARS-CoV-2, however, it is a possibility that should be considered for all patients.

Detection of SARS-CoV-2 IgG antibodies and inflammatory cytokines in saliva-a pilot study

Objective

The pandemic caused by SARS-CoV-2 virus continues to have a profound effect worldwide. However, COVID-19 induced oral facial manifestations have not been fully described. We conducted a prospective study to demonstrate feasibility of anti-SARS-CoV-2 IgG and inflammatory cytokine detection in saliva. Our primary objective was to determine whether COVID-19 PCR positive patients with xerostomia or loss of taste had altered serum or saliva cytokine levels compared to COVID-19 PCR positive patients without those oral symptoms. Our secondary objective was to determine the correlation between serum and saliva COVID-19 antibody levels.

Materials and methods

For cytokine analysis, saliva and serum were obtained from 17 participants with PCR-confirmed COVID-19 infection at three sequential time points, yielding 48 saliva samples and 19 paired saliva-serum samples from 14 of the 17 patients. For COVID-19 antibody analyses, an additional 27 paired saliva-serum samples from 22 patients were purchased.

Results

The saliva antibody assay had 88.64% sensitivity [95% Confidence Interval (CI) 75.44%, 96.21%] to detect SARS-CoV-2 IgG antibodies compared to serum antibody. Among the inflammatory cytokines assessed - IL-6, TNF-α, IFN-γ, IL-10, IL-12p70, IL-1β, IL-8, IL-13, IL-2, IL-5, IL-7 and IL-17A, xerostomia correlated with lower levels of saliva IL-2 and TNF-α, and elevated levels of serum IL-12p70 and IL-10 (p < 0.05). Loss of taste was observed in patients with elevated serum IL-8 (p < 0.05).

Conclusions

Further studies are needed to construct a robust saliva-based COVID-19 assay to assess antibody and inflammatory cytokine response, which has potential utility as a non-invasive monitoring modality during COVID-19 convalescence.

Knowledge mapping of COVID-19 and dentistry: A bibliometric analysis

Background

COVID-19 has a significant impact on dental medicine. The present study aims to overview dental-related research on COVID-19 by visual mapping method.

Methods

We analyzed the publications in the "Dentistry Oral Surgery Medicine" category in the Web of Science core collection. On June 10, 2022, we conducted an advanced search using the items TS = ("Novel coronavirus 2019" or "COVID 19" or "Coronavirus disease 2019" or "2019-nCOV" or "SARS-CoV-2" or "coronavirus-2") and WC = ("Dentistry Oral Surgery medicine") to screen publications in the dental field that focus on COVID-19 or SARS-CoV-2. The contributions of authors, journals, institutions, and countries were described using Microsoft Excel 2010 and VOSviewer. The keywords co-occurring analysis and references analysis were visualized using VOSviewer and CiteSpace.

Results

A total of 1,732 papers were identified between 2020 and 2022. The United States, the United Kingdom, and Brazil were three major contributors to this field. Univ São Paulo (Brazil) ranked first with 55 publications in this field. Martelli Junior, Hercilio from Universidade Jose do Rosario Vellano (Brazil) was the most prolific author with 19 publications. Oral Diseases and British Dental Journal were the two most productive journals. The central topics were dental practice and infection control, oral manifestation related to COVID-19, dental education and online learning, teledentistry, and mental health problems.

Conclusion

The growth rate of publications regarding dental research on COVID-19 has risen sharply. Research topics shifted from "Dental practice and infection control, oral manifestation related to COVID-19" in 2020 to "Dental education and online learning, teledentistry, mental health problems," which are three important research topics for the future.

The oral manifestations and related mechanisms of COVID-19 caused by SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19) was reported to be associated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, and patients present mostly with respiratory symptoms. There have been an increasing number of reports on oral manifestations, and some of these signs are informative in terms of identifying SARS-CoV-2 infection. The goal of present study was to review and synthesize the clinical characteristics and underlying mechanisms of COVID-19 oral manifestations, as well as to evaluate the factors influencing SARS-CoV-2 infectivity, in order to conduct further in-depth investigations and help clinicians diagnose COVID-19 patients exhibiting oral symptoms.

Comparison of proteins with anti-influenza virus effects in parotid and submandibular-sublingual saliva in humans

BACKGROUND

Saliva possesses antiviral activity, with submandibular-sublingual (SMSL) saliva having higher antiviral activity than parotid saliva. Various salivary proteins have inactivating effects on influenza A virus (IAV), but the detailed relationship between antiviral proteins and salivary anti-IAV activities in the parotid and SMSL glands is unknown. Here, to identify salivary proteins with anti-IAV activity, salivary proteins from parotid and SMSL glands were identified, quantified, and compared using liquid chromatography-mass spectrometry.

METHODS

Twelve healthy male volunteers participated in the study. Parotid and SMSL saliva was collected by suction and collection devices. We assessed anti-IAV activities, protein concentrations, and protein-bound sialic acid concentrations in parotid and SMSL saliva.

RESULTS

SMSL had significantly higher anti-IAV activity than parotid saliva. SMSL also had higher concentrations of glycoproteins, such as mucin 5B and mucin 7, protein-bound sialic acid, cystatins, and lysozyme C, compared with parotid saliva. Salivary mucin 5B and mucin 7 concentrations significantly positively correlated with the salivary protein-bound sialic acid concentration. Salivary anti-IAV activity significantly positively correlated with protein-bound sialic acid, mucin 5B, mucin 7, cystatin-C, -S, and -SN concentrations.

CONCLUSION

Salivary mucins, cystatins, and lysozyme C contribute to the high anti-IAV activity of SMSL saliva.

Evidence of a Sjögren's disease-like phenotype following COVID-19

Objectives

Sjögren's Disease (SjD) is a chronic and systemic autoimmune disease characterized by lymphocytic infiltration and the development of dry eyes and dry mouth resulting from the secretory dysfunction of the exocrine glands. SARS-CoV-2 may trigger the development or progression of autoimmune diseases, as evidenced by increased autoantibodies in patients and the presentation of cardinal symptoms of SjD. The objective of the study was to determine whether SARS-CoV-2 induces the signature clinical symptoms of SjD.

Methods

The ACE2-transgenic mice were infected with SARS-CoV-2. SJD profiling was conducted. COVID-19 patients' sera were examined for autoantibodies. Clinical evaluations of convalescent COVID-19 subjects, including minor salivary gland (MSG) biopsies, were collected. Lastly, monoclonal antibodies generated from single B cells of patients were interrogated for ACE2/spike inhibition and nuclear antigens.

Results

Mice infected with the virus showed a decreased saliva flow rate, elevated antinuclear antibodies (ANAs) with anti-SSB/La, and lymphocyte infiltration in the lacrimal and salivary glands. Sera of COVID-19 patients showed an increase in ANA, anti-SSA/Ro52, and anti-SSB/La. The male patients showed elevated levels of anti-SSA/Ro52 compared to female patients, and female patients had more diverse ANA patterns. Minor salivary gland biopsies of convalescent COVID-19 subjects showed focal lymphocytic infiltrates in four of six subjects, and 2 of 6 subjects had focus scores >2. Lastly, we found monoclonal antibodies produced in recovered patients can both block ACE2/spike interaction and recognize nuclear antigens.

Conclusion

Overall, our study shows a direct association between SARS-CoV-2 and SjD. Hallmark features of SjD salivary glands were histologically indistinguishable from convalescent COVID-19 subjects. The results potentially implicate that SARS-CoV-2 could be an environmental trigger for SjD.

Key Messages

What is already known about this subject?SAR-CoV-2 has a tropism for the salivary glands. However, whether the virus can induce clinical phenotypes of Sjögren's disease is unknown.What does this study add?Mice infected with SAR-CoV-2 showed loss of secretory function, elevated autoantibodies, and lymphocyte infiltration in glands.COVID-19 patients showed an increase in autoantibodies. Monoclonal antibodies produced in recovered patients can block ACE2/spike interaction and recognize nuclear antigens.Minor salivary gland biopsies of some convalescent subjects showed focal lymphocytic infiltrates with focus scores.How might this impact on clinical practice or future developments?Our data provide strong evidence for the role of SARS-CoV-2 in inducing Sjögren's disease-like phenotypes.Our work has implications for how patients will be diagnosed and treated effectively.

Oral Lesions Associated with COVID-19 and the Participation of the Buccal Cavity as a Key Player for Establishment of Immunity against SARS-CoV-2

BACKGROUND

Some oral lesions have been described in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); the possibility has been raised that the buccal lesions observed in patients with the coronavirus disease 2019 (COVID-19) are due to this virus and the patient's systemic condition. The aim of this review was to integrate the knowledge related to the oral lesions associated with COVID-19 and the participation of the buccal cavity in the establishment of immunity against SARS-CoV-2.

METHODS

A literature search on the manifestations of buccal lesions from the beginning of the pandemic until October 2021 was carried out by using the PubMed database. A total of 157 scientific articles were selected from the library, which included case reports and reports of lesions appearing in patients with COVID-19.

RESULTS

Oral lesions included erosions, ulcers, vesicles, pustules, plaques, depapillated tongue, and pigmentations, among others. The oral cavity is a conducive environment for the interaction of SARS-CoV-2 with the mucosal immune system and target cells; direct effects of the virus in this cavity worsen the antiviral inflammatory response of underlying oral disorders, immunodeficiencies, and autoimmunity primarily.

CONCLUSIONS

The oral cavity is an accessible and privileged environment for the interaction of SARS-CoV-2 with the mucosal immune system and target cells; the direct effects of the virus in this cavity worsen the antiviral inflammatory response of underlying oral disorders, in particular those related to immunodeficiencies and autoimmunity.

Characteristics of Living Systematic Review for COVID-19

Purpose

The systematic review aims to analyze and summarize the characteristics of living systematic review (LSR) for coronavirus disease 2019 (COVID-19).

Methods

Six databases including Medline, Excerpta Medica (Embase), Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Database and China Science, and Technology Journal Database (VIP), were searched as the source of basic information and methodology of LSR. Descriptive analytical methods were used to analyze the included COVID-19 LSRs, and the study characteristics of COVID-19 LSRs were further assessed.

Results

Sixty-four COVID-19 LSRs were included. Eighty-nine point one percent of LSRs were published on Science Citation Index (SCI) journals, and 64.1% publication with an impact factor (IF) >5 and 17.2% with an IF >15 among SCI journals. The first unit of the published LSRs for COVID-19 came from 19 countries, with the largest contribution from the UK (17.2%, 11/64). Forty point six percent of LSRs for COVID-19 were related to therapeutics topic which was considered the most concerned perspective for LSRs for COVID-19. Seventy-six point six percent of LSRs focused on the general population, with less attention to children, pregnant women and the elderly. However, the LSR for COVID-19 was reported incomplete on “living” process, including 40.6% of studies without search frequency, 79.7% of studies without screening frequency, 20.3% of studies without update frequency, and 65.6% of studies without the timing or criteria of transitioning LSR out of living mode.

Conclusion

Although researchers in many countries have applied LSRs to COVID-19, most of the LSRs for COVID-19 were incomplete in reporting on the “living” process and less focused on special populations. This could reduce the confidence of health-care providers and policy makers in the results of COVID-19 LSR, thereby hindering the translation of evidence on COVID-19 LSR into clinical practice. It was necessary to explicitly enact preferred reporting items for systematic reviews and meta-analyses (PRISMA) to improve the reporting quality of LSR and support ongoing efforts of therapeutics research for special patients with COVID-19.

Oral Manifestations of COVID-19: A Cross-Sectional Study of Their Prevalence and Association with Disease Severity

Background: COVID-19, caused by SARS-CoV-2, has impacted the world in an unprecedented way since December 2019. SARS-CoV-2 was found in the saliva of patients, and entry points for the virus may have been through the numerous angiotensin-converting enzyme 2 receptors in the oral cavity. Oral manifestations of COVID-19 could contribute to the burden of oral disease. Objective: To determine the prevalence of oral manifestations of COVID-19 in patients and their association with disease severity. Methods: Interviews were conducted with adult participants diagnosed with COVID-19 between October 2021 and March 2022 to document their demographic and health status data, symptoms, and the presence of oral manifestations of COVID-19. Chi-square and the Fisher’s exact test were used to compare data on the presence or absence of oral manifestations of COVID-19. Results: Of 195 participants interviewed, 33% were 18 to 24 years old, 33% were 25 to 34 years old, and 75% were female. A total of 57 (29%) had oral manifestations; the most common were taste disorders (60%), xerostomia (42%), and oral ulcers (11%). There was no relationship between the severity of COVID-19 and the presence of the oral manifestations. Conclusion: Oral manifestations of COVID-19 were common among female patients and linked to certain general COVID-19 symptoms regarding frequency and extent.

Immunohistochemical expression of angiotensin-converting enzyme 2 in superficial and deep maxillofacial tissues: A cross-sectional study

Background and Aims

The involvement of maxillofacial tissues in SARS-CoV-2 infections ranges from mild dysgeusia to life-threatening tissue necrosis, as seen in SARS-CoV-2-associated mucormycosis. Angiotensin-converting enzyme 2 (ACE2) which functions as a receptor for SARS-CoV-2 was reported in the epithelial surfaces of the oral and nasal cavities; however, a complete understanding of the expression patterns in deep oral and maxillofacial tissues is still lacking.

Methods

The immunohistochemical expression of ACE2 was analyzed in 95 specimens from maxillofacial tissues and 10 specimens of pulmonary alveolar tissue using a semiquantitative immunohistochemical scoring procedure, taking into account all superficial and deep maxillofacial tissue cells. We also explored the associations of age, gender, and anatomical site with expression scores.

Results

ACE2 was detected in keratinized epithelia (57.34%), non-keratinized epithelia (46.51%), nasal respiratory epithelial cells (73.35%), pulmonary alveolar cells (82.54%), fibroblasts (63.69%), vascular endothelial cells (58.43%), mucous acinar cells (59.88%), serous acinar cells (79.49%), salivary duct cells (86.26%) skeletal muscle fibers (71.01%), neuron support cells (94.25%), and bone marrow cells (72.65%). Age and gender did not affect the expression levels significantly in epithelial cells (p = 0.76, and p = 0.7 respectively); however, identical cells expressed different protein levels depending on the site from which the specimens were obtained. For example, dorsal tongue epithelia expressed significantly lower ACE2 scores than alveolar epithelia (p < 0.001). A positive correlation was found between ACE2 expression in fibroblasts and epithelial cells (r = 0.378, p = 0.001), and between vascular endothelial and epithelial cells (r = 0.395, p = 0.001).

Conclusion

ACE2 is expressed by epithelial cells and subepithelial tissues including fibroblasts, vascular endothelia, skeletal muscles, peripheral nerves, and bone marrow. No correlation was detected between ACE2 expression and patient age or sex while the epithelial expression scores were correlated with stromal scores.

Oral Adverse Events Following COVID-19 Vaccination: Analysis of VAERS Reports

Background

Oral adverse events (AEs) following COVID-19 vaccination have been sporadically reported during the previous months, warranting further investigation for their prevalence and suspected relationship with vaccine-elicited immune response.

Methods

A retrospective analysis using the Vaccine Adverse Event Reporting System (VAERS) data was conducted to evaluate AEs within the oral cavity (mucosa, tongue, lips, palate, dentition, salivary glands) and AEs involving taste and other sensations. Oral AEs reported after receiving COVID-19 vaccination (test group) and seasonal influenza vaccination (control group) were extracted and cross-tabulated to assess their relative prevalence.

Results

Among the 128 solicited (suspected) oral AEs, oral paresthesia (0.872%) was most reported after receiving COVID-19 vaccines, followed by the swelling of lips (0.844%), ageusia (0.722%), oral hypoesthesia (0.648%), swollen tongue (0.628%), and dysgeusia (0.617%). The reported prevalence of oral AEs was higher in the COVID-19 vaccine group than in the seasonal influenza group. The distribution pattern of the most reported oral AEs was similar for both COVID-19 and seasonal influenza vaccines. Female sex, older age (>39 years old), primer doses, and mRNA-based COVID-19 vaccines exhibited a higher reported prevalence of oral AEs.

Conclusion

Within the limitations of this study, COVID-19 vaccines were found to be associated with rare oral AEs that are predominantly similar to those emerging following seasonal influenza vaccines. The most commonly reported oral AEs were oral paraesthesia (mouth-tingling), lip swelling, and ageusia, representing various pathophysiologic pathways that remain unclear. Taste-related AEs should be acknowledged in the context of the COVID-19 pandemic and the public should be adequately informed about a potential taste dysfunction after receiving the COVID-19 vaccination. Dentists and dental teams need to be aware of the prevalence, severity, and prognosis of oral AEs to inform their patients and increase public confidence in vaccines.

Pathogenic Mechanism and Multi-omics Analysis of Oral Manifestations in COVID-19

Coronavirus disease 2019 (COVID-19) is a respiratory infectious disease that seriously threatens human life. The clinical manifestations of severe COVID-19 include acute respiratory distress syndrome and multiple organ failure. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-19, spreads through contaminated droplets. SARS-CoV-2 particles have been detected in the saliva of COVID-19 patients, implying that the virus can infect and damage the oral cavity. The oral manifestations of COVID-19 include xerostomia and gustatory dysfunction. Numerous studies showed that the four structural proteins of SARS-CoV-2 are its potential pathogenic factors, especially the S protein, which binds to human ACE2 receptors facilitating the entry of the virus into the host cells. Usually, upon entry into the host cell, a pathogen triggers the host’s immune response. However, a mount of multi-omics and immunological analyses revealed that COVID-19 is caused by immune dysregulation. A decrease in the number and phenotypes of immune cells, IFN-1 production and excessive release of certain cytokines have also been reported. In conclusion, this review summarizes the oral manifestations of COVID-19 and multi-omics analysis of SARS-CoV-2 infection.

Dental Care and Education Facing Highly Transmissible SARS-CoV-2 Variants: Prospective Biosafety Setting: Prospective, Single-Arm, Single-Center Study

With the arrival of the highly transmissible Omicron variants (BA.4 and BA.5), dentistry faces another seasonal challenge to preserve the biosafety of dental care and education. With the aim of protecting patients, students, teachers and healthcare professionals, this paper introduces a prospective sustainable biosafety setting for everyday dental care and education. The setting developed by dental clinicians, epidemiologists, and teachers of dentistry consists of a combination of modern technologies focused on the air-borne part of the viral pathway. The introduced biosafety setting has been clinically evaluated after 18 months of application in the real clinical environment. The protocol has three fundamental pillars: (1) UVC air disinfection; (2) air saturation with certified virucidal essences with nebulizing diffusers; (3) complementary solutions including telehealth and 3D printing. A pseudonymous online smart form was used as the evaluation method. The protocol operates on the premise that everybody is a hypothetical asymptomatic carrier. The results of a clinical evaluation of 115 patient feedbacks imply that no virus transmission from patient to patient or from doctor to nurse was observed or reported using this protocol, and vice versa, although nine patients retrospectively admitted that the clinic visit is likely to be infectious. Despite these promising results, a larger clinical sample and exposition to the current mutated strains are needed for reliable conclusions about protocol virucidal efficiency in current dental environments.

Prevalence, Features and Degree of Association of Oral Lesions in COVID-19: A Systematic Review of Systematic Reviews

Regardless of rapidly emerging findings on oral lesions described in adult SARS-CoV-2-positive subjects, the evidence level remains quite low and rather contrasting; therefore, the present systematic review of systematic reviews primarily aims to point out the overall prevalence of diagnosed cases. Secondary aims are to estimate the degree of association between oral lesions and SARS-CoV-2 infection and to grade, based on the reported frequency, the primary oral lesions, with related clinical presentations and microscopic features, in relation to COVID-19 forms. A study protocol compliant with the PRISMA statement was developed. Twelve studies were included, reporting highly heterogeneous and incomplete findings, thus precluding a meta-analysis. Further studies should be conducted to assess the overall prevalence of cases diagnosed with oral lesions among adult SARS-CoV-2-positive subjects, especially considering novel viral variants, and to determine their degree of association with SARS-CoV-2 infection and COVID-19 forms. Moreover, the reported findings noticed the need to evaluate the putative role both of SARS-CoV-2 in oral lesions genesis and of periodontitis and periodontal microbiome in COVID-19 worsening and re-activations. Deeper insights into oral lesions in adult SARS-CoV-2-positive subjects could enhance the comprehension of illness pathogenesis, natural history and clinical presentation, thus improving the preparedness of health professionals in the inter-disciplinary management of COVID-19.

Post-Operative Bleeding Complications in a Periodontitis Patient Testing Positive for COVID-19

Recent scientific evidence states that a subset of COVID-19 patients may have a risk of increased bleeding tendency. This case report presents a healthy 38-year-old woman with generalized stage III, grade C periodontitis with an abnormal post-operative blood clot formation who tested positive for COVID-19 after a standard periodontal surgery. Previously, two periodontal surgeries proceeded without any complications and were considered standard. On day one after the third periodontal surgery the patient had no complaints. On day two the patient reported excess bleeding in the oral cavity from the operated area simultaneously with fever and loss of taste. On day three the patient was seen in our clinic; general malaise symptoms and bleeding tendency had started to decline and the patient received a COVID-19 PCR test. At day four the test resulted positive, and she reported no further complaints of intraoral bleeding. Six months later the taste of the patient was still distorted. For this patient with free medical anamnesis, we suggest that the patient had increased plasma levels of tissue plasminogen activator during the crucial postoperative period due to an acute COVID-19 infection. This led to increased plasmin levels with a hyper-fibrinolytic state as a consequence.

Translating Science into Improved Health for All

Our world is at a turning point with biological and social pathogens wreaking havoc at the same time that science and technology are exploding with new discoveries. It is a pivotal time for the new report Oral Health in America: Advances and Challenges to be released and a pivotal time for our profession to take action and lead. The art, science, and practice of dentistry is very different from 20 y ago when the original Surgeon General's report was released. We are on the precipice of individualized health care where providers will collaborate to deliver diagnostics and therapeutics that are data driven and inclusive of the social determinants of health. To move forward with alacrity requires a strong scientific foundation, effective educational approaches, an understanding of the upstream determinants of health, and partnerships across the health professions and beyond. Oral health has never been more important, and now is the time for our profession to further develop, elevate, and translate the science into practice and policy to improve the nation's health.

Morphological and tissue-based molecular characterization of oral lesions in patients with COVID-19: A living systematic review

OBJECTIVE

This living systematic review aims to integrate the morphological and tissue-based molecular characterization of oral lesions occurring in individuals infected by COVID-19 (OLICs).

MATERIALS AND DESIGN

This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Web of Science, Scopus, Ovid, Embase, and LILACS were searched to identify reports on OLICs with morphological and/or tissue-based molecular data.

RESULTS

Four studies reporting five cases were included. Three patients were male, and the mean age of the individuals was 47.6 years. The most reported anatomical location was the palate (n = 4), whereas ulcers were the most frequent clinical presentation (n = 3). Histopathologically, all cases revealed cell vacuolization and exocytosis in the epithelial layer. In the mesenchymal layer, inflammatory cell infiltrate and thrombi/microvascular thrombosis were observed in three cases. Immunohistochemical reactions were performed in two cases. Both cases were negative for HHV-1, HHV-2, and CMV. One case revealed positivity for SARS-CoV-2 spike protein. No other molecular tests were found for the characterization of OLIC.

CONCLUSIONS

The pathological characteristics of OLICs are still unspecific. However, with the ongoing COVID-19 pandemic and well-documented new cases, whether OLICs are due to coinfections or has a primary origin can be determined.

Prevalence of oral manifestations in COVID-19: A systematic review

Coronavirus disease 2019 (COVID-19) is a novel disease caused by a newly identified virus Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causing diverse systemic manifestations. The oral cavity too is not spared and the symptoms appear either independently, concurrently, or sequentially. In view of the rising documented cases of oral lesions of COVID-19, this systematic review aims to assess the prevalence of oral manifestations in COVID-19 confirmed individuals. An extensive literature search was conducted in databases like Scopus, Pubmed/Medline, Livivo, Lilacs and Google Scholar and varied oral signs and symptoms were reported as per the PRISMA guidelines. Studies published in English language literature only were included and were subjected to the risk of bias using the Joana Briggs Institute Appraisal tools for prevalence studies, case series and case reports. In a two-phase selection, 34 studies were included: 21 observational, 3 case-series and 10 case reports. These observational studies included approximately 14,003 patients from 10 countries. In this review, we explored the most commonly encountered oral and dental manifestations in COVID-19 and identified that loss of taste acuity, xerostomia and anosmia were frequently reported. Elevated incidence of opportunistic infections like mucormycosis and aspergillosis were reported during the treatment due to prolonged intake of steroids. Immunosuppression and poor oral hygiene led to secondary manifestations like enanthematous lesions. However, it is not clear that oral signs and symptoms are due to COVID-19 infection itself or are the result of extensive treatment regimen followed [PROSPERO CRD42021258264].

Gustatory and Saliva Secretory Dysfunctions in COVID-19 Patients with Zinc Deficiency

Given the ever-progressing studies on coronavirus disease 2019 (COVID-19), it is critical to update our knowledge about COVID-19 symptomatology and pathophysiology. In the present narrative review, oral symptoms were overviewed using the latest data and their pathogenesis was hypothetically speculated. PubMed, LitCovid, ProQuest, and Google Scholar were searched for relevant studies from 1 April 2021 with a cutoff date of 31 January 2022. The literature search indicated that gustatory dysfunction and saliva secretory dysfunction are prevalent in COVID-19 patients and both dysfunctions persist after recovery from the disease, suggesting the pathogenic mechanism common to these cooccurring symptoms. COVID-19 patients are characterized by hypozincemia, in which zinc is possibly redistributed from blood to the liver at the expense of zinc in other tissues. If COVID-19 induces intracellular zinc deficiency, the activity of zinc-metalloenzyme carbonic anhydrase localized in taste buds and salivary glands may be influenced to adversely affect gustatory and saliva secretory functions. Zinc-binding metallothioneins and zinc transporters, which cooperatively control cellular zinc homeostasis, are expressed in oral tissues participating in taste and saliva secretion. Their expression dysregulation associated with COVID-19-induced zinc deficiency may have some effect on oral functions. Zinc supplementation is expected to improve oral symptoms in COVID-19 patients.

TASTE DISORDERS AND XEROSTOMIA ARE HIGHLY PREVALENT IN PATIENTS WITH COVID-19

Article Title and Bibliographic Information

J. Amorim dos Santos, A.G.C. Normando, R.L.Carvalho da Silva, A.C. Acevedo G. De Luca Canto, N. Sugaya, A.R. Santos-Silva , E.N.S. Guerra (2021). ``Oral Manifestations in Patients with COVID-19: A Living Systematic Review.'' J Dent Res 100(2): 141-154.

Source of Funding

Non-profit, Foundations, etc.? National Council for Scientific and Technological Development, Ministry of Education, Brazil and the Department of Research and Innovation, University of Brasilia, Brazil.

Type of Study/Design

Systematic review with meta-analysis of data.

The Impact of Information Sources on COVID-19-Related Knowledge, Attitudes, and Practices (KAP) among University Students: A Nationwide Cross-Sectional Study

COVID-19 is an emerging respiratory disease caused by a novel coronavirus accompanied by a tsunami of misinformation and fake news. This can weaken the public health responses by affecting the COVID-19-related knowledge, attitudes, and practices (KAP) of the public. Therefore, this cross-sectional study was designed during the early stage of the pandemic to evaluate the KAP of Palestinian university students and their commonly used information sources. We found that the most trusted information source among students was the World Health Organization (WHO), followed by the Palestinian Ministry of Health (MoH) briefings and healthcare workers, whereas social media was the most frequently used source of information. The participants exhibited a high level of COVID-19-related knowledge, having an average score of 8.65 (range: 0–10). In total, 76% avoided going to crowded places, and only 33% wore a mask while being outdoors. The vast majority (93%) checked the accuracy of COVID-19-related information before publishing it, 56% used the WHO and MoH briefings for fact-checking, and only 8% relied on healthcare workers. This was particularly the case for those who lived in refugee camps. This study provides an insight into the information sources used by Palestinian university students, the sources they trust, and the information formats they prefer. These results may help public health authorities to locate the information sources through which university students should be targeted. Efforts should be made to recommend healthcare workers as credible information sources. In this way, they will be able to prevent the spread of misleading information and provide high-quality information, especially within unconventional settings such as refugee camps.

Knowledge, Attitude, and Practices of Dentists in Caribbean Countries during the COVID-19 Pandemic: A Multicenter Cross-Sectional Study

Background: The COVID-19 pandemic has affected dentists globally, both financially and mentally. This study aimed to determine the knowledge, attitude, and practices of dentists in Caribbean countries during the COVID-19 pandemic. Methods: A non-probability sample was obtained from dentists in more than ten different Caribbean countries. They were invited to complete a self-reported questionnaire, which was conducted from December 2020 to March 2021. Ethics approval was sought and an exemption was received from the UWI ethics committee. Results: One hundred and fifty-two dentists responded. More than one-third (38.8%) were in the >35–45 age group, and 58.6% were females. Most (84.9%) were general dentists and 75% were stressed by the COVID-19 situation with 80.9% being affected financially. The majority, 94.7%, believed that the highest risk of transmission of COVID-19 was via aerosol-generating procedures and 87.5% were worried about contracting it clinically. The majority (69.1%) were willing to receive the vaccine, the main reason reported for vaccine hesitancy was due to the possible side effects (35.3%). Most (75%) consumed alcohol. When the locus of control was determined, 54.6% felt they were in control of protecting themselves while 52% felt that external factors controlled their lives. Conclusions: The findings suggest that most dentists in the Caribbean were knowledgeable about COVID-19 and followed current guidelines in their practice and were willing to receive the vaccine.

Characterization and Pathogenic Speculation of Xerostomia Associated with COVID-19: A Narrative Review

Patients with coronavirus disease 2019 (COVID-19) have become known to present with different oral symptoms. However, xerostomia remains poorly recognized compared with taste dysfunction. For better understanding of COVID-19 symptomatology, xerostomia associated withCOVID-19 was characterized and its possible pathogenesis was speculated by a narrative literature review. Scientific articles were retrieved by searching PubMed, LitCovid, ProQuest, Google Scholar, medRxiv and bioRxiv from 1 April 2020 with a cutoff date of 30 September 2021. Results of the literature search indicated that xerostomia is one of prevalent and persistent oral symptoms associated with COVID-19. In contrast to taste dysfunction, the prevalence and persistence of xerostomia do not necessarily depend on ethnicity, age, gender and disease severity of patients. COVID-19 xerostomia is pathogenically related to viral cellular entry-relevant protein expression, renin-angiotensin system disturbance, salivary gland inflammation, zinc deficiency, cranial neuropathy, intercurrent taste dysfunction, comorbidities and medications. Despite a close association with COVID-19, xerostomia, dry mouth and hyposalivation tend to be overlooked unlike ageusia, dysgeusia and hypogeusia. Although mouth dryness per se is not life-threating, it has an impact on the oral health-related quality of life. More attention should be paid to xerostomia in COVID-19 patients and survivors.

Universal Predictors of Dental Students' Attitudes towards COVID-19 Vaccination: Machine Learning-Based Approach

BACKGROUND

young adults represent a critical target for mass-vaccination strategies of COVID-19 that aim to achieve herd immunity. Healthcare students, including dental students, are perceived as the upper echelon of health literacy; therefore, their health-related beliefs, attitudes and behaviors influence their peers and communities. The main aim of this study was to synthesize a data-driven model for the predictors of COVID-19 vaccine willingness among dental students.

METHODS

a secondary analysis of data extracted from a recently conducted multi-center and multi-national cross-sectional study of dental students' attitudes towards COVID-19 vaccination in 22 countries was carried out utilizing decision tree and regression analyses. Based on previous literature, a proposed conceptual model was developed and tested through a machine learning approach to elicit factors related to dental students' willingness to get the COVID-19 vaccine.

RESULTS

machine learning analysis suggested five important predictors of COVID-19 vaccination willingness among dental students globally, i.e., the economic level of the country where the student lives and studies, the individual's trust of the pharmaceutical industry, the individual's misconception of natural immunity, the individual's belief of vaccines risk-benefit-ratio, and the individual's attitudes toward novel vaccines.

CONCLUSIONS

according to the socio-ecological theory, the country's economic level was the only contextual predictor, while the rest were individual predictors. Future research is recommended to be designed in a longitudinal fashion to facilitate evaluating the proposed model. The interventions of controlling vaccine hesitancy among the youth population may benefit from improving their views of the risk-benefit ratio of COVID-19 vaccines. Moreover, healthcare students, including dental students, will likely benefit from increasing their awareness of immunization and infectious diseases through curricular amendments.

Side Effects of mRNA-Based COVID-19 Vaccine: Nationwide Phase IV Study among Healthcare Workers in Slovakia

mRNA-based COVID-19 vaccines such as BNT162b2 have recently been a target of anti-vaccination campaigns due to their novelty in the healthcare industry; nevertheless, these vaccines have exhibited excellent results in terms of efficacy and safety. As a consequence, they acquired the first approvals from drug regulators and were deployed at a large scale among priority groups, including healthcare workers. This phase IV study was designed as a nationwide cross-sectional survey to evaluate the post-vaccination side effects among healthcare workers in Slovakia. The study used a validated self-administered questionnaire that inquired about participants' demographic information, medical anamneses, COVID-19-related anamnesis, and local, systemic, oral, and skin-related side effects following receiving the BNT162b2 vaccine. A total of 522 participants were included in this study, of whom 77% were females, 55.7% were aged between 31 and 54 years, and 41.6% were from Banska Bystrica. Most of the participants (91.6%) reported at least one side effect. Injection site pain (85.2%) was the most common local side effect, while fatigue (54.2%), headache (34.3%), muscle pain (28.4%), and chills (26.4%) were the most common systemic side effects. The reported side effects were of a mild nature (99.6%) that did not require medical attention and a short duration, as most of them (90.4%) were resolved within three days. Females and young adults were more likely to report post-vaccination side effects; such a finding is also consistent with what was previously reported by other phase IV studies worldwide. The role of chronic illnesses and medical treatments in post-vaccination side effect incidence and intensity requires further robust investigation among large population groups.

Predictors of Willingness to Receive COVID-19 Vaccine: Cross-Sectional Study of Palestinian Dental Students

The overarching aim of this study was to assess the predictors related to the willingness of Palestinian dental students to receive the COVID-19 vaccine when it becomes available. A cross-sectional study was conducted among a universal sample of dental students in the Palestinian territories. Willingness to get the COVID-19 vaccine was related to the following factors: Demographic characteristics, COVID-19-related experiences, beliefs and knowledge about the vaccine, attitudes toward vaccinations in general, and other factors outlined by the WHO SAGE Vaccination Hesitancy Questionnaire. Four hundred and seventeen students completed the questionnaire (response rate = 41.7%). In general, 57.8% (n = 241) were willing to take the COVID-19 vaccine when it became available to them, 27% (n = 114) were hesitant, and 14.9% (n = 62) were not willing to get vaccinated. The final regression model explained 46% of the variation in the willingness to receive the COVID-19 vaccine as follows: Attitudes towards new vaccines (β = 6.23, p < 0.001), believing in a favorable risk-benefit ratio (β = 5.64, p < 0.001), trust in the pharmaceutical industry (β = 5.92, p = 0.001), believing that natural immunity is better than being vaccinated (β = -4.24, p < 0.001), and having enough information about the vaccine (β = 4.12, p < 0.001). Adequate information about vaccines, their risk-benefit ratios, and natural and acquired immunity are important to build trust and favorable attitudes towards vaccines among future dentists.