Skip to main content
NCBI home page
Clinical and Experimental Dental Research logoLink to Clinical and Experimental Dental Research
. 2021 May 1;7(5):852–860. doi: 10.1002/cre2.429

Oral manifestations of COVID‐19 patients: An online survey of the Egyptian population

Dina M El Kady 1,✉, Esraa Ahmad Gomaa 2, Walid Shaban Abdella 3, Reham Ashraf Hussien 4, Rawda H Abd ElAziz 1, Ahmad G A Khater 5
PMCID: PMC8239795  PMID: 33931952

Abstract

Objectives

This pilot survey aims to study the oral manifestations associated with COVID‐19 infection and report the prevalence of oral signs and symptoms in COVID‐19 patients.

Materials and Methods

From May 15 to June 10, 2020, we used an online questionnaire containing the oral manifestations that are expected to be associated with the COVID‐19 infection. Adults in our survey who have been diagnosed with COVID‐19 positive were confirmed with reverse transcriptase PCR (RT‐PCR), and isolated in various hospitals in Cairo, Egypt.

Results

This pilot study included 58 (53.4% males and 46.6% females) COVID‐19 patients ages 18–46 years, and 13 (22.4%) were healthcare workers. Our results showed that 67.2% of the patients had at least one manifestation related to the oral cavity and salivary glands, and 32.8% (n = 19) did not have any symptoms associated with the oral cavity. The highest prevalence symptoms were dry mouth 39.7% (n = 23), gustatory dysfunction as 34.5% (n = 20) loss of salt sensation, 29.3% (n = 17) loss of sweet sensation, and 25.9% (n = 15) altered food taste, while the least prevalent symptoms were tongue redness 8.8% (n = 5), and gingival bleeding 7% (n = 4). The most frequently associated symptoms were loss of salt and sweetness, as reported by 27.6% of the participants. However, there was no significant association between the incidence of oral symptoms and demographic data (age, gender, or job) of the patients (p > 0.05).

Conclusions

Based on limited data, COVID‐19 significantly impacts the oral cavity and salivary glands, as salivary gland‐related symptoms and taste disorders are highly prevalent in COVID‐19 patients.

Keywords: coronavirus disease 2019, COVID‐19, oral health, oral lesions, SARS‐CoV‐2

1. INTRODUCTION

The novel coronavirus disease 2019 (COVID‐19) is a human‐to‐human transmitted disease caused by one of the coronaviruses, which are a large family of viruses that can cause serious disorders such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS; Dar Odeh et al., 2020; Fini, 2020; Speth et al., 2020). The World Health Organization (WHO) recognized COVID‐19 as a pandemic disease, with most countries reporting significant numbers of infected people and deaths as of December 2019 (Organization, 2020).

The typical clinical symptoms of COVID‐19 patients were fever, cough, shortness of breath, and myalgia or weakness with abnormal chest CT, while the less prevalent symptoms were sputum formation, headache, hemoptysis, and diarrhea. Often, alteration or loss of taste and smell sensation has been observed (Guan et al., 2020; Huang et al., 2020; Lechien et al., 2020; Vinayachandran & Balasubramanian, 2020).

Coronavirus attacks human cells by angiotensin‐converting enzyme 2 (ACE2) receptors since the current evidence indicated that ACE2 acts as the primary host cell receptor for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2; Zou et al., 2020). As such, the virus will bind to ACE2 using the spike‐like protein on its surface, and ACE2 will serve as a cellular portal for viral entry into the cell to cause COVID‐19 infection (Ciaglia et al., 2020). Hence, organs with high ACE2 expression (e.g., lung) can become target cells during SARS‐CoV‐2 infection that cause inflammatory reactions in related organs and tissues, such as salivary glands and tongue, which could explain the occurrence of both loss of taste and oral ulceration due to destruction of keratinocytes and oral fibroblasts (Zhou et al., 2020). Otherwise, high viral load in the saliva and nasal secretion can be a pathogenic factor involved in developing the oral changes associated with COVID‐19 infection, which indicates the direct effect of the virus on the oral tissues (Cruz Tapia et al., 2020).

On the other side, these effects may be attributed to the virus's indirect influence on the immune system, contributing to other opportunistic infections, such as recurrent herpes simplex virus (HSV‐1) infection and oral ulcerations (Brandão et al., 2020; Dziedzic & Wojtyczka, 2020).

COVID‐19 has two routes of transmission, either directly or indirectly. It can be transmitted indirectly through saliva, while it may be spread directly by coughing, sneezing, and droplet inhalation or via direct contact with oral, nasal, and ocular mucous membranes (Peng et al., 2020; Speth et al., 2020).

The oral cavity is known to be an indicative mirror reflecting the underlying health condition. Therefore, careful examination of the mouth will assist in early diagnosis and treatment since some oral symptoms (e.g., oral ulcerations, gingival bleeding, dry mouth, and oral discomfort, halitosis, burning sensation, or difficulty swallowing) that can be associated with certain systemic disorders (Chi et al., 2010). Several studies have considered oral transmission to be one of the main routes of COVID‐19 infection (Gu et al., 2020; Hindson, 2020; Yeo et al., 2020). Even though many studies addressed the validity of saliva in the COVID‐19 diagnosis (Fernandes et al., 2020; Pedrosa et al., 2020; Sabino‐Silva et al., 2020; To et al., 2020), as well as the precautions and implications for dental practice during the COVID‐19 pandemic era (Coulthard, 2020; Ge et al., 2020; Sabino‐Silva et al., 2020; Spagnuolo et al., 2020), there is still a gap of knowledge regarding the oral manifestations related to COVID‐19 and its impact on the oral cavity. Therefore, this pilot survey aims to study the oral manifestations associated with COVID‐19 infection and report the superiority of oral signs and symptoms in COVID‐19 patients.

2. METHODS

We reported this pilot study based on the Checklist for Reporting Results of Internet E‐Surveys (CHERRIES) (24). The protocol was registered in ClinicalTrials.gov (NCT04391881) and approved by the Research Ethics Committee, Faculty of Dentistry, Cairo University, Egypt. After reviewing the literature about the pathogenesis of COVID‐19 and its related manifestations, we developed an online Arabic survey using Google form to target adults (over 18 years old) who live in Cairo, Egypt, via Facebook advertisement (Table S1).

Since it was not feasible to examine the patients clinically, and to avoid selection biases due to convenience sampling, all participants were volunteers to minimize the risk of bias. We included only adults diagnosed with COVID‐19 positive, confirmed with reverse transcriptase PCR (RT‐PCR), and are isolated in various hospitals in Cairo, Egypt, from May 15 to June 10, 2020.

We used a Google Form to create an online questionnaire containing multiple manifestations that were to be associated with COVID‐19 based on the available evidence. All symptoms included in this questionnaire were in four primary categories; the first category was the gustatory disorders described as a loss of salt sensation, loss of sweetness, and altered food taste. The second category was the symptoms associated with salivary glands infection described as dry mouth (i.e., hyposalivation), difficulty swallowing, pain or swelling in the submandibular gland area, and pain or swelling in the parotid gland area. The third category was the oral mucosal changes (i.e., oral lesions) described as oral ulcers, spots of mouth or lips, tongue redness, gingival bleeding, and burning sensation. The last category was the patients with no symptoms related to the oral cavity and salivary glands.

2.1. Statistical methods

We presented the categorical data as frequencies and percentages and analyzed using Fisher's exact test. The significance level was set at p ≤ 0.05 within all tests, and p‐values were corrected for multiple comparisons using Bonferroni correction. Statistical analysis were conducted with Windows version 4.0.3 of the R software (Team, 2020).

3. RESULTS

A total of 58 (53.4% males and 46.6% females) COVID‐19 patients ages 18–46 years were included in this pilot study, while 13 (22.4%) were healthcare workers, and there were no significant differences in age or gender between participants (p = 0.094 and 0.580 respectively; Table 1).

TABLE 1.

Demographic data

Parameter Frequency (n) Percentage (%) p‐Value
Gender Male 31 53.4% 0.580
Female 27 46.6%
Age ≤30 years 34 58.6% 0.094
>30 years 24 41.4%
Job Health worker 13 22.4% <0.001*
Non‐health worker 31 * 53.4%
Not working 14 24.1%
Open in a new tab
*

Statistically significant (p ≤ 0.05).

Our results found that 67.2% of the patients had at least one of the oral manifestations, while about 32.8% (n = 19) did not have any symptoms related to the oral cavity. The high prevalence symptom was dry mouth 39.7% (n = 23), followed by gustatory dysfunction as 34.5% (n = 20) loss of salt sensation, 29.3% (n = 17) loss of sweet sensation, and 25.9% (n = 15) altered food taste. The prevalence of symptoms associated with salivary glands infection was 22.4% (n = 13) difficult swelling, 13.8% (n = 8) pain or swellings in the salivary gland or cheek, and 10.3% (n = 6) pain or swelling below mandible. While the oral mucosal changes were less prevalent as 22.4% (n = 13) of burning mouth sensation, 17.2% (n = 10) of ulceration, 13.8% (n = 8) of mouth and lip spots, 8.8% (n = 5) of tongue redness, and 7% (n = 4) of gingival bleeding (Figure 1).

FIGURE 1.

FIGURE 1

Open in a new tab

Prevalence of oral manifestations associated with COVID‐19 patients

The most associated symptoms were loss of salt and sweetness, as observed in 16 (27.6%) participants, while the dry mouth and gustatory impairment symptoms were often associated in 14 (27.6%) participants for each manifestation. However, the association between the tongue's redness either with lips or mouth spots, discomfort or swelling below the mandible, or gingival bleeding, was the least frequent, which occurred in one case (Figure 2).

FIGURE 2.

FIGURE 2

Open in a new tab

Heat‐map showing the oral symptoms correlated with each other

However, there was no significant association between the incidence of oral symptoms and demographic data (age, gender, or job) of the patients (p > 0.05; Table 2).

TABLE 2.

Association between the occurrence of oral symptoms and status of different demographic aspects

Symptoms Parameter No Yes p‐Value
n % n %
Oral symptoms Gender Male 21 67.7% 10 32.3% 0.431
Female 18 66.7% 9 33.3%
Age ≤30 years 19 55.9% 15 44.1% 0.474
>30 years 20 83.3% 4 16.7%
Job Health worker 7 53.8% 6 46.2% 0.175
Non‐health worker 22 71.0% 9 29.0%
Not working 10 71.4% 4 28.6%
Dry mouth Gender Male 18 58.1% 13 41.9% 0.870
Female 17 63.0% 10 37.0%
Age ≤30 years 23 67.6% 11 32.4% 0.492
>30 years 12 50.0% 12 50.0%
Job Health worker 8 61.5% 5 38.5% 0.785
Non‐health worker 17 54.8% 14 45.2%
Not working 10 71.4% 4 28.6%
Loss of salt sensation Gender Male 21 67.7% 10 32.3% 0.798
Female 17 63.0% 10 37.0%
Age ≤30 years 24 70.6% 10 29.4% 0.988
>30 years 14 58.3% 10 41.7%
Job Health worker 8 61.5% 5 38.5% 0.358
Non‐health worker 20 64.5% 11 35.5%
Not working 10 71.4% 4 28.6%
Loss of sweet sensation Gender Male 21 67.7% 10 32.3% 1
Female 20 74.1% 7 25.9%
Age ≤30 years 25 73.5% 9 26.5% 0.739
>30 years 16 66.7% 8 33.3%
Job Health worker 8 61.5% 5 38.5% 0.171
Non‐health worker 23 74.2% 8 25.8%
Not working 10 71.4% 4 28.6%
Altered food taste Gender Male 24 77.4% 7 22.6% 0.715
Female 19 70.4% 8 29.6%
Age ≤30 years 27 79.4% 7 20.6% 0.181
>30 years 16 66.7% 8 33.3%
Job Health worker 10 76.9% 3 23.1% 0.295
Non‐health worker 21 67.7% 10 32.3%
Not working 12 85.7% 2 14.3%
Burning sensation in mouth or tongue Gender Male 21 67.7% 10 32.3% 0.431
Female 24 88.9% 3 11.1%
Age ≤30 years 28 82.4% 6 17.6% 0.497
>30 years 17 70.8% 7 29.2%
Job Health worker 12 92.3% 1 7.7% 0.669
Non‐health worker 22 71.0% 9 29.0%
Not working 11 78.6% 3 21.4%
Difficult swallowing Gender Male 26 83.9% 5 16.1% 0.918
Female 19 70.4% 8 29.6%
Age ≤30 years 29 85.3% 5 14.7% 0.547
>30 years 16 66.7% 8 33.3%
Job Health worker 11 84.6% 2 15.4% 0.756
Non‐health worker 22 71.0% 9 29.0%
Not working 12 85.7% 2 14.3%
Oral ulcers Gender Male 25 80.6% 6 19.4% 0.361
Female 23 85.2% 4 14.8%
Age ≤30 years 29 85.3% 5 14.7% 0.911
>30 years 19 79.2% 5 20.8%
Job Health worker 12 92.3% 1 7.7% 0.508
Non‐health worker 24 77.4% 7 22.6%
Not working 12 85.7% 2 14.3%
Spots of mouth or lips Gender Male 26 83.9% 5 16.1% 0.811
Female 24 88.9% 3 11.1%
Age ≤30 years 30 88.2% 4 11.8% 1
>30 years 20 83.3% 4 16.7%
Job Health worker 11 84.6% 2 15.4% 0.914
Non‐health worker 27 87.1% 4 12.9%
Not working 12 85.7% 2 14.3%
Pain or swelling in the salivary gland or cheek Gender Male 27 87.1% 4 12.9% 1
Female 23 85.2% 4 14.8%
Age ≤30 years 31 91.2% 3 8.8% 0.864
>30 years 19 79.2% 5 20.8%
Job Health worker 12 92.3% 1 7.7% 0.902
Non‐health worker 27 87.1% 4 12.9%
Not working 11 78.6% 3 21.4%
Pain or swelling below the mandible Gender Male 28 90.3% 3 9.7% 0.300
Female 24 88.9% 3 11.1%
Age ≤30 years 31 91.2% 3 8.8% 0.431
>30 years 21 87.5% 3 12.5%
Job Health worker 12 92.3% 1 7.7% 0.571
Non‐health worker 28 90.3% 3 9.7%
Not working 12 85.7% 2 14.3%
Tongue redness Gender Male 30 96.8% 1 3.2% 0.852
Female 25 92.6% 2 7.4%
Age ≤30 years 32 94.1% 2 5.9% 0.700
>30 years 23 95.8% 1 4.2%
Job Health worker 12 92.3% 1 7.7% 0.505
Non‐health worker 30 96.8% 1 3.2%
Not working 13 92.9% 1 7.1%
Gingival bleeding Gender Male 30 96.8% 1 3.2% 0.840
Female 24 88.9% 3 11.1%
Age ≤30 years 31 91.2% 3 8.8% 0.573
>30 years 23 95.8% 1 4.2%
Job Health worker 12 92.3% 1 7.7% 0.975
Non‐health worker 30 96.8% 1 3.2%
Not working 12 85.7% 2 14.3%
Open in a new tab

4. DISCUSSION

COVID‐19 patients have a wide variety of signs and symptoms, so the study of these manifestations will contribute to the early diagnosis and isolation of infected patients (Vaira et al., 2020). Also, COVID‐19 as an acute infection with multiple therapeutic measures could adversely affect oral health leading to opportunistic infections (e.g., recurrent herpes simplex virus (HSV‐1) infection and oral ulcerations) due to the compromised immune system and xerostomia associated with the reduced salivary flow (Dziedzic & Wojtyczka, 2020).

This pilot study revealed a high prevalence of salivary gland‐related symptoms supporting the beneficial effect of saliva on virus detection and the negative impact of saliva on viral transmission hypotheses (Han & Ivanovski, 2020; Xu et al., 2020). The effect of COVID‐19 on salivary glands was reflected in different ways: first patients complained of pain or swelling in either parotid or submandibular areas (13.8% and 10.3%, respectively), and second 39.7% suffered from a dry mouth. These findings indicates the protective role of saliva which continuously cleans the oral cavity and antiviral response against COVID‐19 (Farshidfar & Hamedani, 2020; Malamud et al., 2011).

Hyposalivation might be a potential complication of chronic sialadenitis caused by COVID‐19. As a repair mechanism following the inflammatory destruction of the salivary glands, this destruction could be repaired by fibrosis affecting both the acini and the duct leading to hypo‐secretion. Hyposalivation raises the risk of inorganic salts deposition on the ductal wall that induces sialolithiasis contributing to stenosis and dilatation of the ducts (Wang et al., 2020). Respiratory infection incidence will then increase by enhancing virus adhesion and colonization and destroying the oral mucosa surfaces and airways, thus, decreasing antimicrobial peptides and proteins (Han & Ivanovski, 2020; Iwabuchi et al., 2012).

However, T‐cell receptors for human pathogenic saliva can be the initial portal of the virus to the body; thus, the proliferation of the COVID‐19 in the salivary gland may be responsible for the spread of infection from asymptomatic patients (Liu et al., 2011; Zhang et al., 2020). As well, salivary glands can act as a harbor for a latent infection that can be reactivated later with a risk of chronic sialadenitis (Wang et al., 2020); therefore, physicians should pay more attention to any variation in salivary glands or salivary secretions (Vinayachandran & Saravanakarthikeyan, 2020).

Taste loss (ageusia) occurs due to the viral infection to the olfactory cranial nerve or from rhinitis and nasal obstruction. The loss of smell (anosmia) is related to retro‐nasal olfaction which is a sensory process, combining ortho‐nasal smell and taste patterns and enabling people to perceive flavor. This mechanism is temporarily disrupted during upper respiratory infections due to mucosal inflammation and obstruction of the nasal passages, thereby physically blocking flavor and odor molecules from entering the olfactory cleft (Melley et al., 2020). In this study, consistent with the current evidence, olfactory dysfunction was the primary factor identified either with or without gustatory dysfunction (Amorim dos Santos et al., 2020; Passarelli et al., 2020).

Burning sensation of the mouth (22.4%) could be due to several reasons (e.g., candidal infection, dry mouth, oral ulceration, or drug‐induced). Evidence show that viral infection could weaken the immune system thus, creating secondary infections such as oral candidiasis. Candidiasis is the most prevalent opportunistic infection in HIV (Nokta, 2008) and is also reported in COVID‐19 (dos Santos et al., 2020; Vinayachandran & Saravanakarthikeyan, 2020).

Concerning the oral ulceration (17.2%), mouth and lip spots (13.8%), their prevalence was higher than other oral changes which supports the case report of ulceration and skin rash in COVID‐19 patients (Soares et al., 2020). As such, many patients might have the same symptoms undetected due to the lack of oral examination by healthcare professionals (Martín Carreras‐Presas et al., 2020). Another case report of oral ulceration revealed that the history of the lesion was a 24‐hr painful inflammation of the tongue papilla, followed by 24‐hr erythematous macula, which evolved into irregular and asymptomatic ulcers; hence, many patients might not be aware of having oral ulceration due to lack of pain (Chaux‐Bodard et al., 2020). Moreover, a careful oral examination is recommended to obtain accurate data about oral manifestations associated with COVID‐19. Ulcers and vesiculobullous lesions may be discussed from a different perspective, as case reports that found significant hemorrhage, vascular congestion, lymphocytic infiltration in the connective tissue, and different‐sized thrombi after the incisional biopsy (Cruz Tapia et al., 2020; Magro et al., 2020). Thus, the immune response to COVID‐19 stimulates the Langerhans' cells and lymphocytes, inducing vasculitis (lymphocytic thrombophilic arteritis; Guerini‐Rocco et al., 2020).

Although gingivitis and gingival bleeding are a common feature in HSV‐1 and In EVD (Ebola virus disease; Scully & Samaranayake, 2016), our results showed that they were less prevalent (6.9%) in symptoms associated with COVID‐19. However, the prevalence of tongue redness was 5.2%, indicating that viral infections may change in the coating and color of the tongue. The case report identified that a geographic tongue was associated with candidiasis and ulceration in COVID‐19 patients, which suggests that the geographic tongue in this pilot study was not specific to COVID‐19 (dos Santos et al., 2020).

On the other hand, this pilot study revealed that 32.8% of the patients had no symptoms related to the oral cavity or salivary glands, consistent with the suggested estimation of asymptomatic patients with COVID‐19 (Mizumoto et al., 2020; Nishiura et al., 2020).

Our study has further limitations. First, the main methodological limitation is the limited sample size since this is a pilot study. Second, this is an online questionnaire; thus, we have not been able to document the patient's full history and a clinical oral examination (e.g., length of infection, the severity of the case, oral hygiene, habits, and the taken medications), which might have a misleading impact on the results. Despite the limitations, this pilot study's findings could help understand the oral manifestations associated with COVID‐19.

5. CONCLUSION

Our study indicates a significant impact of COVID‐19 on the oral cavity based on limited sample size. Salivary gland‐related symptoms and taste disorders are high prevalence in COVID‐19 patients, while the detailed oral manifestations associated with COVID‐19 and their pathophysiology required further investigation. Further clinical studies with larger sample sizes and detailed patient's history, are required to confirm our results and clarify the full impact of COVID‐19 on the oral cavity and salivary glands.

CONFLICT OF INTEREST

All authors declare no conflicts of interest.

AUTHOR CONTRIBUTIONS

Conceptualization: D.M.E.; Methodology: D.M.E., E.A.G., and A.G.A.K.; Data collection: W.S.A., R.H.A., and R.A.H.; Data analysis: A.G.A.K., W.S.A.; Writing original draft preparation: A.G.A.K., E.A.G., D.M.E., R.H.A., and R.A.H.; Writing–review and editing: A.G.A.K., D.M.E., and E.A.G.; All authors have read and agreed to the published version of the manuscript.

Supporting information

Supplementary Table S1 An example of the online survey that we used

Click here for additional data file. (18.3KB, docx)

Appendix S1: Supporting Information

Click here for additional data file. (18.1KB, pdf)

ACKNOWLEDGMENT

Authors acknowledge the funding of article publication fees from the Egyptian Knowledge Bank (EKB).

El Kady DM, Gomaa EA, Abdella WS, Ashraf Hussien R, Abd ElAziz RH, Khater AGA. Oral manifestations of COVID‐19 patients: An online survey of the Egyptian population. Clin Exp Dent Res. 2021;7:852–860. 10.1002/cre2.429

Funding information Egyptian Knowledge Bank (EKB)

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

REFERENCES

  1. Amorim dos Santos J., Normando A. G. C., Carvalho da Silva R. L., Acevedo A. C., De Luca Canto G., Sugaya N., … Guerra E. N. S. (2021). Oral Manifestations in Patients with COVID‐19: A Living Systematic Review. Journal of Dental Research, 100(2), 141–154. 10.1177/0022034520957289. [DOI] [PubMed] [Google Scholar]
  2. Brandão T. B., Gueiros L. A., Melo T. S., Prado‐Ribeiro A.C., Nesrallah A. C. F. A., Prado G. V. B., … Migliorati C. A. (2021). Oral lesions in patients with SARS‐CoV‐2 infection: could the oral cavity be a target organ?. Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 131(2), e45–e51. 10.1016/j.oooo.2020.07.014. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Chaux‐Bodard, A.‐G. , Deneuve, S. , & Desoutter, A. (2020). Oral manifestation of Covid‐19 as an inaugural symptom? Journal of Oral Medicine and Oral Surgery, 26(2), 18. [Google Scholar]
  4. Chi, A. C. , Neville, B. W. , Krayer, J. W. , & Gonsalves, W. C. (2010). Oral manifestations of systemic disease. American Family Physician, 82(11), 1381–1388. [PubMed] [Google Scholar]
  5. Ciaglia, E. , Vecchione, C. , & Puca, A. A. (2020). COVID‐19 infection and circulating ACE2 levels: Protective role in women and children. Frontiers in Pediatrics, 8, 206. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Coulthard, P. (2020). Dentistry and coronavirus (COVID‐19)‐moral decision‐making. British Dental Journal, 228(7), 503–505. [DOI] [PubMed] [Google Scholar]
  7. Cruz Tapia, R. O. , Peraza Labrador, A. J. , Guimaraes, D. M. , & Matos Valdez, L. H. (2020). Oral mucosal lesions in patients with SARS‐CoV‐2 infection. Report of four cases. Are they a true sign of COVID‐19 disease? Special Care in Dentistry, 40, 555–560. [DOI] [PubMed] [Google Scholar]
  8. Dar Odeh, N. , Babkair, H. , Abu‐Hammad, S. , Borzangy, S. , Abu‐Hammad, A. , & Abu‐Hammad, O. (2020). COVID‐19: Present and future challenges for dental practice. International Journal of Environmental Research and Public Health, 17(9), 3151. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Amorim dos Santos, J. , Normando, A.G. C. , Carvalho da Silva, R.L. , De Paula, R.M. , Cembranel, A.C. , Santos‐Silva, A. R. , & Guerra, E. N. S. (2020). Oral mucosal lesions in a COVID‐19 patient: New signs or secondary manifestations?. International Journal of Infectious Diseases, 97, 326–328. 10.1016/j.ijid.2020.06.012. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Dziedzic A., Wojtyczka R. (2021). The impact of coronavirus infectious disease 19 (COVID‐19) on oral health. Oral Diseases, 27(S3), 703–706. 10.1111/odi.13359. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Farshidfar N., Hamedani S. (2021). Hyposalivation as a potential risk for SARS‐CoV‐2 infection: Inhibitory role of saliva. Oral Diseases, 27(S3), 750–751. 10.1111/odi.13375. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Fernandes, L. , Pacheco, V. , Borges, L. , Athwal, H. , de Paula Eduardo, F. , Bezinelli, L. , … Lombaert, I. (2020). Saliva in the diagnosis of COVID‐19: A review and new research directions. Journal of Dental Research, 99, 1435–1443. [DOI] [PubMed] [Google Scholar]
  13. Fini, M. B. (2020). What dentists need to know about COVID‐19. Oral Oncology, 105, 104741. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Ge Z‐Y, Yang L‐M, Xia J‐J, Fu X‐H, & Zhang Y‐Z (2020). Possible aerosol transmission of COVID‐19 and special precautions in dentistry. Journal of Zhejiang University‐SCIENCE B, 21(5), 361–368. 10.1631/jzus.b2010010. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Gu, J. , Han, B. , & Wang, J. (2020). COVID‐19: Gastrointestinal manifestations and potential fecal–oral transmission. Gastroenterology, 158(6), 1518–1519. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Guan W‐J, Ni Z‐Y, Hu Y., Liang W‐H, Ou C‐Q, He J‐X, … Zhong N‐S. (2020). Clinical Characteristics of Coronavirus Disease 2019 in China. New England Journal of Medicine, 382(18), 1708–1720. 10.1056/nejmoa2002032. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Guerini‐Rocco, E. , Taormina, S. V. , Vacirca, D. , Ranghiero, A. , Rappa, A. , Fumagalli, C. , … Tagliabue, M. (2020). SARS‐CoV‐2 detection in formalin‐fixed paraffin‐embedded tissue specimens from surgical resection of tongue squamous cell carcinoma. Journal of Clinical Pathology., 73, 754–757. [DOI] [PubMed] [Google Scholar]
  18. Han, P. , & Ivanovski, S. (2020). Saliva—Friend and foe in the COVID‐19 outbreak. Diagnostics, 10(5), 290. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Hindson, J. (2020). COVID‐19: Faecal–oral transmission? Nature Reviews Gastroenterology & Hepatology, 17(5), 259–259. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Huang, C. , Wang, Y. , Li, X. , Ren, L. , Zhao, J. , Hu, Y. , … Gu, X. (2020). Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. The Lancet, 395(10223), 497–506. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Iwabuchi, H. , Fujibayashi, T. , Yamane, G.‐Y. , Imai, H. , & Nakao, H. (2012). Relationship between hyposalivation and acute respiratory infection in dental outpatients. Gerontology, 58(3), 205–211. [DOI] [PubMed] [Google Scholar]
  22. Lechien J. R., Chiesa‐Estomba C. M., De Siati D. R., Horoi M., Le Bon S. D., Rodriguez A., … Saussez S. (2020). Olfactory and gustatory dysfunctions as a clinical presentation of mild‐to‐moderate forms of the coronavirus disease (COVID‐19): a multicenter European study. European Archives of Oto‐Rhino‐Laryngology, 277(8), 2251–2261. 10.1007/s00405-020-05965-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Liu, L. , Wei, Q. , Alvarez, X. , Wang, H. , Du, Y. , Zhu, H. , … Zhang, L. (2011). Epithelial cells lining salivary gland ducts are early target cells of severe acute respiratory syndrome coronavirus infection in the upper respiratory tracts of rhesus macaques. Journal of Virology, 85(8), 4025–4030. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Magro, C. , Mulvey, J. J. , Berlin, D. , Nuovo, G. , Salvatore, S. , Harp, J. , Baxter‐Stoltzfus, A. , … Laurence, J. (2020). Complement associated microvascular injury and thrombosis in the pathogenesis of severe COVID‐19 infection: A report of five cases. Translational Research, 220, 1–13. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Malamud, D. , Abrams, W. , Barber, C. , Weissman, D. , Rehtanz, M. , & Golub, E. (2011). Antiviral activities in human saliva. Advances in Dental Research, 23(1), 34–37. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Martín Carreras‐Presas C., Amaro Sánchez J., López‐Sánchez A. F., Jané‐Salas E., & Somacarrera Pérez M. L. (2021). Oral vesiculobullous lesions associated with SARS‐CoV‐2 infection. Oral Diseases, 27(S3), 710–712. 10.1111/odi.13382. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Melley, L. E. , Bress, E. , & Polan, E. (2020). Hypogeusia as the initial presenting symptom of COVID‐19. BMJ Case Reports CP, 13(5), e236080. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Mizumoto, K. , Kagaya, K. , Zarebski, A. , & Chowell, G. (2020). Estimating the asymptomatic proportion of coronavirus disease 2019 (COVID‐19) cases on board the Diamond Princess cruise ship, Yokohama, Japan, 2020. Eurosurveillance, 25(10), 2000180. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Nishiura, H. , Kobayashi, T. , Miyama, T. , Suzuki, A. , Jung, S.‐M. , Hayashi, K. , … Akhmetzhanov, A. R. (2020). Estimation of the asymptomatic ratio of novel coronavirus infections (COVID‐19). International Journal of Infectious Diseases, 94, 154–155. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Nokta, M. (2008). Oral manifestations associated with HIV infection. Current HIV/AIDS Reports, 5(1), 5–12. [DOI] [PubMed] [Google Scholar]
  31. World Health Organization . (2020). WHO health emergency dashboard—WHO (COVID‐19) homepage. Vol. 2020. Webpage. World Health Organization.
  32. Passarelli, P. C. , Lopez, M. A. , Bonaviri, G. N. M. , Garcia‐Godoy, F. , & D'Addona, A. (2020). Taste and smell as chemosensory dysfunction in COVID‐19 infection. American Journal of Dentistry, 33, 135–137. [PubMed] [Google Scholar]
  33. Pedrosa, M. , Sipert, C. R. , & Nogueira, F. N. (2020). Salivary Glands, Saliva and Oral Findings in COVID‐19 Infection. Pesquisa Brasileira em Odontopediatria e Clínica Integrada, 20(suppl 1). 10.1590/pboci.2020.112. [DOI] [Google Scholar]
  34. Peng, X. , Xu, X. , Li, Y. , Cheng, L. , Zhou, X. , & Ren, B. (2020). Transmission routes of 2019‐nCoV and controls in dental practice. International Journal of Oral Science, 12(1), 1–6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Sabino‐Silva, R. , Jardim, A. C. G. , & Siqueira, W. L. (2020). Coronavirus COVID‐19 impacts to dentistry and potential salivary diagnosis. Clinical Oral Investigations, 24(4), 1619–1621. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Scully, C. , & Samaranayake, L. (2016). Emerging and changing viral diseases in the new millennium. Oral Diseases, 22(3), 171–179. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Soares, C. D. , Carvalho, R. , Carvalho, K. , Carvalho, M. , & Almeida, O. (2020). Letter to editor: Oral lesions in a patient with Covid‐19. Medicina oral, patologia oral y cirugia bucal, 25(4), e563–e564. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Spagnuolo, G. , De Vito, D. , Rengo, S. , & Tatullo, M. (2020). COVID‐19 Outbreak: An Overview on Dentistry. International Journal of Environmental Research and Public Health, 17(6), 2094. 10.3390/ijerph17062094. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Speth, M. M. , Singer‐Cornelius, T. , Obere, M. , Gengler, I. , Brockmeier, S. J. , & Sedaghat, A. R. (2020). Olfactory dysfunction and Sinonasal symptomatology in COVID‐19: Prevalence, severity, timing, and associated characteristics. Otolaryngology—Head and Neck Surgery, 163, 114–120. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. R Core Team . (2020). R: A language and environment for statistical computing. In: Vienna, Austria.
  41. To, K. K‐W. , Tsang, O. T‐Y. , Yip, C. C.‐Y. , Chan, K.‐H. , Wu, T.‐C. , Chan, J. M.‐C. , … Yuen, K.‐Y. (2020). Consistent Detection of 2019 Novel Coronavirus in Saliva. Clinical Infectious Diseases, 71(15), 841–843. 10.1093/cid/ciaa149. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Vaira, L. A. , Salzano, G. , Petrocelli, M. , Deiana, G. , Salzano, F. A. , & De Riu, G. (2020). Validation of a self‐administered olfactory and gustatory test for the remotely evaluation of COVID‐19 patients in home quarantine. Head & Neck., 42, 1570–1576. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Vinayachandran D., Balasubramanian S.K. (2021). Is gustatory impairment the first report of an oral manifestation in COVID‐19?. Oral Diseases, 27(S3), 748–749. 10.1111/odi.13371. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Vinayachandran, D. , & Saravanakarthikeyan, B. (2020). Salivary diagnostics in COVID‐19: Future research implications. Journal of Dental Sciences., 15, 364–366. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Wang, C. , Wu, H. , Ding, X. , Ji, H. , Jiao, P. , Song, H. , … Du, H. (2020). Does infection of 2019 novel coronavirus cause acute and/or chronic sialadenitis?. Medical Hypotheses, 140, 109789. 10.1016/j.mehy.2020.109789. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Xu, R. , Cui, B. , Duan, X. , Zhang, P. , Zhou, X. , & Yuan, Q. (2020). Saliva: Potential diagnostic value and transmission of 2019‐nCoV. International Journal of Oral Science, 12(1), 1–6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Yeo, C. , Kaushal, S. , & Yeo, D. (2020). Enteric involvement of coronaviruses: Is faecal–oral transmission of SARS‐CoV‐2 possible? The Lancet Gastroenterology & Hepatology, 5(4), 335–337. [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. Zhang, Z. , Zhang, L. , & Wang, Y. (2020). COVID‐19 indirect contact transmission through the oral mucosa must not be ignored. Journal of Oral Pathology & Medicine, 49(5), 450–451. [DOI] [PMC free article] [PubMed] [Google Scholar]
  49. Zhou, P. , Yang, X.‐L. , Wang, X.‐G. , Hu, B. , Zhang, L. , Zhang, W. , … Huang, C.‐L. (2020). A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature, 579(7798), 270–273. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Zou, X. , Chen, K. , Zou, J. , Han, P. , Hao, J. , & Han, Z. (2020). Single‐cell RNA‐seq data analysis on the receptor ACE2 expression reveals the potential risk of different human organs vulnerable to 2019‐nCoV infection. Frontiers of Medicine, 14(2), 185–192. 10.1007/s11684-020-0754-0. [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Supplementary Table S1 An example of the online survey that we used

Click here for additional data file. (18.3KB, docx)

Appendix S1: Supporting Information

Click here for additional data file. (18.1KB, pdf)

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

Articles from Clinical and Experimental Dental Research are provided here courtesy of Wiley

RESOURCES