DISEASES OF THE ORAL MUCOSA IN PATIENTS IN THE POST-COVID PERIOD.

The impact of SARS-CoV-2 (severe acute respiratory syndrome-related coronavirus-2) on the entire human body causes irreversible changes in all organs and systems. Complications in the form of chronic diseases require the treatment of clinicians in various fields of medicine. Dentists are faced with diseases of the oral mucosa in apparently healthy patients who are not predisposed to them but have undergone COVID-19. Purpose of the study - to assess the impact of the coronavirus infection (COVID-19) on the course of diseases of the oral mucosa. We examined 51 patients aged 20 to 75 who had undergone COVID-19 with various diseases of the oral mucosa. The study used clinical and laboratory methods. The features of the clinical course of certain diseases of the oral mucosa were revealed, the dynamics of the local immune defense of the oral cavity in the post-covid period was determined.

Maternal and infant NR3C1 and SLC6A4 epigenetic signatures of the COVID-19 pandemic lockdown: when timing matters.

Stress exposure during pregnancy is critically linked with maternal mental health and child development. The effects might involve altered patterns of DNA methylation in specific stress-related genes (i.e., glucocorticoid receptor gene, NR3C1, and serotonin transporter gene, SLC6A4) and might be moderated by the gestational timing of stress exposure. In this study, we report on NR3C1 and SLC6A4 methylation status in Italian mothers and infants who were exposed to the COVID-19 pandemic lockdown during different trimesters of pregnancy. From May 2020 to February 2021, 283 mother-infant dyads were enrolled at delivery. Within 24 h from delivery, buccal cells were collected to assess NR3C1 (44 CpG sites) and SLC6A4 (13 CpG sites) methylation status. Principal component (PC) analyses were used to reduce methylation data dimension to one PC per maternal and infant gene methylation. Mother-infant dyads were split into three groups based on the pregnancy trimester (first, second, third), during which they were exposed to the COVID-19 lockdown. Mothers and infants who were exposed to the lockdown during the first trimester of pregnancy had lower NR3C1 and SLC6A4 methylation when compared to counterparts exposed during the second or third trimesters. The effect remained significant after controlling for confounders. Women who were pregnant during the pandemic and their infants might present altered epigenetic biomarkers of stress-related genes. As these epigenetic marks have been previously linked with a heightened risk of maternal psychiatric problems and less-than-optimal child development, mothers and infants should be adequately monitored for psychological health during and after the pandemic.

Vascularized free fibula flap oral rehabilitation using tissue engineered mucosa: Report of 3 cases.

The aim of this report is to introduce the use of the dermal substitute Integra® in the context of free fibula flap prelamination for mandibular reconstruction. Three cases of mandibular reconstruction with prefabricated and Integra-prelaminated vascularized fibula flaps are reported in this article. The patients reported in this case series presented with the following tumours: an extensive cemento-ossyfying fibroma, a multicystic ameloblastoma and an extensive calcifying epithelial odontogenic tumour. Virtual three-dimensional (3D) planning and 3D-printed cutting guides were used for the mandibulectomies, the flap harvest and the positioning of the implants. The dermal substitute Integra was used for prelamination instead of skin grafts. Treatment of all 3 patients was performed in two stages; the first consisted of the fibula prefabrication (dental implant insertion) and prelamination, and the second consisted of tumor resection and reconstruction with the vascularized implant-bearing fibula flap. Integra was shown to be able to generate complete mucosa-like tissue over the fibula flaps and in the peri-implant areas. The patients have been followed up for 1, 3 and 7 years, respectively, with satisfactory prosthetic, functional and aesthetic results. None of the patients developed peri-implant disease. It was observed that prelamination with the dermal substitute Integra leads to development of mucosal lining with clinical features similar to oral mucosa. In this report of three cases, use of Integra as part of the prelamination and prefabrication process, instead of skin grafts, appears able to clinically generate mucosal lining with avoidance of skin grafts.

Oral mucosa lesions in confirmed and non-vaccinated cases for COVID-19: A systematic review.

This systematic review purposed to investigate reports of oral lesions in confirmed COVID-19 patients summarizing clinical characteristics, histological findings, treatment and correlation of oral lesions and COVID-19 severity. Electronic search was conducted on November 2021 using seven databases to identify case reports/series describing lesions in oral mucosa in COVID-19 confirmed cases. A total of 5,179 studies were found, being 39 eligible from 19 countries, totalling 116 cases. It was observed only COVID-19 non-vaccinated cases and no sex or age predilection. The oral lesions presentation was mostly single location (69.8%), commonly in the tongue, lips, and palate, being ulcer the main clinical presentation. According to severity index for COVID-19, the reports were more frequent in patients with mild and moderate symptoms, being 75.8% in acute phase. The oral lesion appearance in post-acute COVID-19 were described after 14 to two months after patient recovery. Histologically, keratinocytes with perinuclear vacuolization, thrombosis and mononuclear inflammatory infiltrate were also described with the presence of the virus in keratinocytes, endothelial cells, and minor salivary glands. In conclusion, health care professionals should consider COVID-19 association when patient present ulcerated oral lesions and mild to moderate symptoms for COVID-19 or had acute-COVID-19.

Oral manifestations in SARS-CoV-2 infection.

BACKGROUND: We aimed to evaluate the prevalence of predisposing factors and oral manifestations in SARS-CoV-2 infection. MATERIAL AND METHODS: 204 SARS-CoV-2 positive patients were included in the study. Questions regarding the systemic, periodontal health, oral hygiene habits, common symptoms and, oral manifestations of COVID-19 such as oral lesions, and dry mouth were included in the survey. The Visual Analogue Scale (VAS) was used. RESULTS: 47.5% of individuals had various systemic diseases. Dry mouth (44.2%) and oral lesions (22.4%) were the most common oral manifestations in COVID-19 patients. Also, dry mouth had the highest VAS score. The most common oral lesion locations were buccal mucosa (15.2%) and tongue (10.8%). The majority of participants (142 patients) were affected by taste disorders. Patients who received periodontal treatment before SARS-CoV-2 infection reported fewer oral complaint and manifestations than those who did not receive periodontal therapy (p=0.032). There was no statistically significant difference between males and females on the presence of any oral manifestations, and taste disorders. CONCLUSIONS: Our results showed that SARS-CoV-2 could cause oral manifestations. However various predisposing factors may be part of the etiology and promote oral findings.

Detection of persistent SARS-CoV-2 IgG antibodies in oral mucosal fluid and upper respiratory tract specimens following COVID-19 mRNA vaccination.

COVID-19 mRNA vaccines are highly effective at preventing COVID-19. Prior studies have found detectable SARS-CoV-2 IgG antibodies in oral mucosal specimens of participants with history of COVID-19. To assess the development of oral SARS-CoV-2 IgG antibodies among people who received either the Moderna or Pfizer/BioNTech COVID-19 vaccination series, we developed a novel SARS-CoV-2 IgG enzyme-linked immunosorbent assay (ELISA) to quantify the concentrations of oral and nasal mucosal SARS-CoV-2 IgG levels. We enrolled 52 participants who received the Moderna vaccine and 80 participants who received the Pfizer/BioNTech vaccine. Oral mucosal specimens were self-collected by participants prior to or on the day of vaccination, and on days 5, 10, 15, and 20 following each vaccination dose and 30, 60, and 90 days following the second vaccination dose. A subset of the cohort provided additional nasal mucosal specimens at every time point. All participants developed detectable oral mucosal SARS-CoV-2 IgG antibodies by 15 days after the first vaccination dose. There were no significant differences in oral mucosal antibody concentrations once participants were fully vaccinated in the Moderna and Pfizer/BioNTech vaccines. Oral or nasal mucosal antibody testing could be an inexpensive and less invasive alternative to serum antibody testing. Further research is needed to understand the duration of detectable oral or nasal mucosal antibodies and how antibody concentrations change with time.

A cross-sectional and histological analysis to understand the cytological effects of cell phone radiation on buccal mucosa of children.

Context: The ongoing pandemic has affected all the spheres of life and one of the severely affected avenues is the education of a child. The online education has seen an upward curve since the start of COVID-19 pandemic. Schools globally have adopted online class tutorials as the main method to impart education and directly increasing the screen time for a child. Aim: The aim of the present study was to evaluate the cytological effects of prolonged mobile phone usage on the buccal mucosa of children. Settings and Design: Stratified sampling was used for the selection of subjects for the study. After a questionnaire regarding the usage of a mobile phone was distributed among the parents of children. Among them, 90 children were selected on the basis of pattern and frequency of mobile phone usage in the child. Materials and Methodology: The children were divided into three groups based on the per day hours of viewing of mobile phone, i.e., Group 1: Usage of 1-2 h a day, Group 2: Usage of 3-6 h a day, and Group 3: Usage of >6 h a day. The time frame taken into consideration was 1 year after the pandemic started. This was specifically to understand the impact of the online education. Swab was obtained by using the conventional ice-cream stick method from the buccal mucosa. Statistical Analysis: The samples were subjected to histological and microscopical analysis to observe for cytological changes. One-way ANOVA was used to determine the statistical significance if any. Results: The results obtained clearly showed that Group 3 (>6 h usage per day) showed the highest number of cellular and chromosomal aberrations which was significant. Conclusion: The results indicated that impact due to the prolonged screen time on the buccal mucosa is significant. A direct proportionality was seen between the apoptotic changes and chromosomal aberrations and the number of daily hour usage.

Oral Pathology in COVID-19 and SARS-CoV-2 Infection-Molecular Aspects.

This review article was designed to evaluate the existing evidence related to the molecular processes of SARS-CoV-2 infection in the oral cavity. The World Health Organization stated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and transmission is produced by respiratory droplets and aerosols from the oral cavity of infected patients. The oral cavity structures, keratinized and non-keratinized mucosa, and salivary glands' epithelia express SARS-CoV-2 entry and transmission factors, especially angiotensin converting enzyme Type 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). Replication of the virus in cells leads to local and systemic infection spread, and cellular damage is associated with clinical signs and symptoms of the disease in the oral cavity. Saliva, both the cellular and acellular fractions, holds the virus particles and contributes to COVID-19 transmission. The review also presents information about the factors modifying SARS-CoV-2 infection potential and possible local pharmacotherapeutic interventions, which may confine SARS-CoV-2 virus entry and transmission in the oral cavity. The PubMed and Scopus databases were used to search for suitable keywords such as: SARS-CoV-2, COVID-19, oral virus infection, saliva, crevicular fluid, salivary gland, tongue, oral mucosa, periodontium, gingiva, dental pulp, ACE2, TMPRSS2, Furin, diagnosis, topical treatment, vaccine and related words in relevant publications up to 28 December 2021. Data extraction and quality evaluation of the articles were performed by two reviewers, and 63 articles were included in the final review.

The Priming Potential of Interferon Lambda-1 for Antiviral Defense in the Oral Mucosa.

The oral mucosa is one of the first lines of the innate host defense system against microbial invasion. Interferon (IFN) lambda-1 (IFN-λ1), a type III IFN, exhibits type I IFN-like antiviral activity. In contrast to ubiquitously expressed type I IFN receptors, IFN-λ receptor 1 (IFN-λR1), which has higher affinity for type III IFNs than low-affinity interleukin (IL)-10 receptor 2, is mainly expressed on epithelial cells. Although IFN-λ1 has been shown to exert antiviral effects in the respiratory tract, gastrointestinal tract, and skin, the regulation of type III IFN receptor expression and its functions in the oral mucosa remain unclear. We herein showed the expression of IFN-λR1 in human gingival keratinocytes. The expression of IL-6, angiotensin-converting enzyme 2 (a critical molecule for severe acute respiratory syndrome coronavirus 2 infection), and IL-8 in human primary gingival keratinocytes (HGK) were significantly higher following treatments with either type I IFN (IFN-ß) or type II IFN (IFN-γ) than with IFN-λ1. However, the IFN-λ1 treatment strongly induced toll-like receptor (TLR) 3 and retinoic acid-inducible gene I (RIG-I), which mainly recognize viral nucleic acids, via the STAT1-mediated pathway. Furthermore, a stimulation with a RIG-I or TLR3 agonist promoted the production of IL-6, IL-8, and IFN-λ in HGK, which was significantly enhanced by a pretreatment with IFN-λ1. These results suggest that IFN-λ1 may contribute to the activation of innate immune responses to oral viral infections by up-regulating the expression of RIG-I and TLR3 and priming their functions in keratinocytes.

SARS-CoV-2 Specific IgG Antibodies Persist Over a 12-Month Period in Oral Mucosal Fluid Collected From Previously Infected Individuals.

Background: Developing an understanding of the antibody response, seroprevalence, and seroconversion from natural infection and vaccination against SARS-CoV-2 will give way to a critical epidemiological tool to predict reinfection rates, identify vulnerable communities, and manage future viral outbreaks. To monitor the antibody response on a larger scale, we need an inexpensive, less invasive, and high throughput method. Methods: Here we investigate the use of oral mucosal fluids from individuals recovered from SARS-CoV-2 infection to monitor antibody response and persistence over a 12-month period. For this cohort study, enzyme-linked immunosorbent assays (ELISAs) were used to quantify anti-Spike(S) protein IgG antibodies in participants who had prior SARS-CoV-2 infection and regularly (every 2-4 weeks) provided both serum and oral fluid mucosal fluid samples for longitudinal antibody titer analysis. Results: In our study cohort (n=42) with 17 males and 25 females with an average age of 45.6 +/- 19.3 years, we observed no significant change in oral mucosal fluid IgG levels across the time course of antibody monitoring. In oral mucosal fluids, all the participants who initially had detectable antibodies continued to have detectable antibodies throughout the study. Conclusions: Based on the results presented here, we have shown that oral mucosal fluid-based assays are an effective, less invasive tool for monitoring seroprevalence and seroconversion, which offers an alternative to serum-based assays for understanding the protective ability conferred by the adaptive immune response from viral infection and vaccination against future reinfections.

Expression profile of SARS-CoV-2 cellular entry proteins in normal oral mucosa and oral squamous cell carcinoma.

OBJECTIVE: Besides angiotensin converting enzyme 2 (ACE2), an active involvement of proteases (FURIN and/or TMPRSS2) is important for cellular entry of SARS-CoV-2. Therefore, a simultaneous expression profiling of entry proteins in a tissue might provide a better risk assessment of SARS-CoV-2 infection as compared to individual proteins. In an attempt to understand the relative susceptibility of oral squamous cell carcinoma (OSCC) lesions as compared to the normal oral mucosa (NOM) for SARS-CoV-2 attachment/entry, this study examined the mRNA and protein expression profiles of ACE2, FURIN, and TMPRSS2 in the corresponding tissues using public transcriptomic and proteomics datasets. METHODS AND METHODS: Public transcriptomic and proteomics datasets (the Cancer Genome Atlas (TCGA)/the Genotype-Tissue Expression (GTEx), the Human Protein Atlas (HPA), and two independent microarray datasets) were used to examine the expression profiles of ACE2, TMPRSS2 and FURIN in NOM and OSCC. RESULTS: ACE2, TMPRSS2, and FURIN mRNAs were detected in NOM, however, at lower levels as compared to other body tissues. Except for moderate up-regulation of FURIN, expression levels of ACE2 and TMPRSS2 mRNA were unchanged/down-regulated in OSCC as compared to the NOM. CONCLUSIONS: These results indicate that NOM may serve as a possible site for SARS-CoV-2 attachment, however, to a lesser extent as compared to organs with higher expression levels of the SARS-CoV-2 entry proteins. However, the evidence is lacking to suggest that expression status of entry proteins predisposes OSCC lesions to additional risk for SARS-CoV-2 attachment/entry as compared to NOM.

Cytogenetic Biomonitoring in Buccal Mucosa Cells of COVID-19 Patients: Preliminary Findings.

BACKGROUND/AIM: COVID-19 may lead to progressive respiratory failure as a consequence of alveolar damage, resulting in death. The aim of this study was to evaluate cytogenetic damage in oral cells of COVID-19 patients by micronucleus assay. PATIENTS AND METHODS: A total of 11 COVID-19 patients aged 40.7±9.3 years (5 men and 6 women) were included in this study. For the control group, a total of 15 participants not infected with SARS-CoV-2 virus were included. The mean age was 41.6±6.2 years (5 men and 10 women). RESULTS: The results showed statistically significant differences (p<0.05) in micronucleated buccal mucosa cells of COVID-19 patients. In addittion, a statistically significant increase in karyolysis and karrhyorexis (p<0.05) was observed in COVID-19 patients compared to control. CONCLUSION: SARS-CoV-2 virus can induce mutagenesis and cytotoxicity in oral cells.

Bifunctional molecules targeting SARS-CoV-2 spike and the polymeric Ig receptor display neutralization activity and mucosal enrichment.

The global health crisis and economic tolls of COVID-19 necessitate a panoply of strategies to treat SARS-CoV-2 infection. To date, few treatment options exist, although neutralizing antibodies against the spike glycoprotein have proven to be effective. Because infection is initiated at the mucosa and propagates mainly at this site throughout the course of the disease, blocking the virus at the mucosal milieu should be effective. However, administration of biologics to the mucosa presents a substantial challenge. Here, we describe bifunctional molecules combining single-domain variable regions that bind to the polymeric Ig receptor (pIgR) and to the SARS-CoV-2 spike protein via addition of the ACE2 extracellular domain (ECD). The hypothesis behind this design is that pIgR will transport the molecule from the circulation to the mucosal surface where the ACE ECD would act as a decoy receptor for the nCoV2. The bifunctional molecules bind SARS-Cov-2 spike glycoprotein in vitro and efficiently transcytose across the lung epithelium in human tissue-based analyses. Designs featuring ACE2 tethered to the C-terminus of the Fc do not induce antibody-dependent cytotoxicity against pIgR-expressing cells. These molecules thus represent a potential therapeutic modality for systemic administration of neutralizing anti-SARS-CoV-2 molecules to the mucosa.

ACE2 and TMPRSS2 in human saliva can adsorb to the oral mucosal epithelium.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is primarily transmitted through droplets. All human tissues with the angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serines 2 (TRMPRSS2) are potential targets of SARS-CoV-2. The role of saliva in SARS-CoV-2 transmission remains obscure. In this study, we attempted to reveal ACE2 and TRMPRSS2 protein expression in human parotid, submandibular, and sublingual glands (three major salivary glands). Then, the binding function of spike protein to ACE2 in three major salivary glands was detected. The expression of ACE2 and TMPRSS2 in human saliva from parotid glands were both examined. Exogenous recombined ACE2 and TMPRSS2 anchoring and fusing to oral mucosal epithelial cells in vitro were also unraveled. ACE2 and TMPRSS2 were found mainly to be expressed in the cytomembrane and cytoplasm of epithelial cells in the serous acinus cells in parotid and submandibular glands. Our research also discovered that the spike protein of SARS-CoV-2 binds to ACE2 in salivary glands in vitro. Furthermore, exogenous ACE2 and TMPRSS2 can anchor and fuse to oral mucosa in vitro. Thus, the expression of ACE2 and TMPRSS2 in human saliva might have implications for SARS-CoV-2 infection.

COVID-19-related oral mucosa lesions among confirmed SARS-CoV-2 patients: a systematic review.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for coronavirus disease 2019 (COVID-19), which manifests as a flu-like respiratory infection affecting multiple organ systems, including the gastrointestinal system, central nervous system, cardiovascular system, skin, and mucosa. In this review, we investigated the literature on specific manifestations of COVID-19 in the oral mucosa. An online literature search in PubMed, Scopus, Google Scholar, and Medline was conducted to retrieve relevant studies on confirmed COVID-19 patients with oral mucosa findings published between December 31, 2019, and April 07, 2021. After an independent review by two authors, 39 articles considering 59 laboratory-confirmed cases of SARS-CoV-2 infection were included in the final analysis. The most common finding, reported in 29 patients (43.9%), was Kawasaki-like syndrome. In addition, oral ulcers including aphthous, hemorrhagic, and necrotic ulcers were reported in 24 patients (36.3%). Other lesions reported included pustules, macules, bullae, maculopapular enanthema, and erythema multiforme-like lesions. Concomitant skin lesions were present in 60.6% of patients. Fever was reported in 86.2% of patients. Forty-eight patients (76.1%) were hospitalized. Loss of taste and smell was present in 30.8% of the patients. A comprehensive understanding of the dermatologic manifestations of COVID-19 can improve and facilitate patient management and referrals.