Table 2.
General characteristics of included studies.
| Author, Year, Setting | Study Design | Pandemic Period | Participants (F/M); Age [Years] | Comorbidities | Hospitalization and COVID-19 Treatment | Inclusion Criteria | Exclusion Criteria | General Manifestations with Frequency [%] | Smoking Status |
|---|---|---|---|---|---|---|---|---|---|
| Abubakr et al., 2021, Egypt [29] | questionnaire study | 1 May to 1 July 2020 | 573 (408/165); 36.19 ± 9.11 (range: 19–50) | none | non-hospitalized; NR | Egyptian adults, 18–50 years old; laboratory-confirmed COVID-19 infection (PCR test); non-smokers; non-alcoholics; medically free; mild-to-moderate symptoms; good oral hygiene and not suffering from any oral manifestations before the pandemic | failure to complete the whole questionnaire; poor oral hygiene or any of the oral symptoms before the pandemic; chronic illnesses; smokers; alcoholics; serious COVID-19 infection, severe respiratory failure or required hospitalization | muscle pain (76.4), malaise (72.8), headache (70.0), fever (66.0), loss of smell (61.8), cough (55.5), sore throat (52.4), dyspnea (51.8), diarrhea (50.3) | non-smokers |
| Bardellini et al., 2021, Italy [30] | retrospective cross-sectional study | March to April 2020 | 27 (8/19); 4.2 ± 1.7 (range: 3 months–14 years) | NR | hospitalized; NR | pediatric patients (aged 0–14 years old), laboratory evidence of COVID-19 infection, signed informed consent | NR | fever > 38 °C (55.5), mild febrile conditions (37.0), cough (37.0), rhinorrhea (25.9), difficulty in breathing (18.5) | NA |
| Biadsee et al., 2020, Israel [31] | questionnaire study | 25 March to 15 April 2020 | 128 (70/58); 36.25 (range: 18–73) | hypertension (n = 8), hypothyroidism (n = 4), diabetes mellitus (n = 3), asthma (n = 2) | non-hospitalized; NR | diagnosed by RT-PCR and considered to have mild symptoms, according to the latest WHO joint report | questionnaires with missing information | cough (59.4), weakness (47.7), myalgia (46.9), fever (42.2), headache (40.6), impaired sense of smell (38.3), sore throat (26.6), runny nose (26.6), nasal congestion (22.7), gastrointestinal symptoms (18.8) | smokers (n = 26) |
| Bulut et al., 2021, Turkey [32] | questionnaire study | September 2020 to March 2021 | 200 (125/75); ranges: 20–30: 89 (62/27), 31–40: 65 (43/22), 41–50: 27 (14/13), 51–60: 15 (4/11), 61–70: 4 (2/2) | NR | hospitalized (11.5); antiviral drugs (61.7), anticoagulant (16.9), hydroxychloroquine (12.3), antiaggregant (7.1), dexamethasone (5.2), antibiotics (5.2); not use any medication (27.9) | reported COVID-19 in anamnesis | age < 18 years | presence of symptoms (87.5) | NR |
| Eduardo et al., 2022, Brazil [33] | retrospective cohort study | May 2020 to February 2021 | 472 (150/322);majority range: 51–80 | NR | hospitalized (ICU); orotracheal intubation (89.8), tracheostomy (5.1), nasal catheter (3.8) | adults of both genders, adequate information of oral cavity conditions during ICU hospitalization | oral medicine records without adequate information about gender, age, presence and type of mechanical ventilation, and oral conditions or information about | NR | NR |
| El Kady et al., 2021, Egypt [34] | pilot questionnaire study | 15 May to 10 June 2020 | 58 (27/31); range: 18–46 | NR | hospitalized; NR | adults with SARS-CoV-2 infection confirmed by RT-PCR, and isolated in hospitals | NR | NR | NR |
| Elamrousy et al., 2021, Egypt [35] | cross-sectional study | 2 September 2020, to 10 June 2021 | 124 (32/92); 50.32 ± 12.47 | diabetes (n = 52), hypertension (n = 16), cardiac disease (n = 8), renal disease (n = 4), liver disease (n = 4) | hospitalised; zithrocin (100.0), iverzine (100.0), zinc, vitamin C (100.0), anticoagulant (90.3), antibacterial (70.9), prednisolone (61.3), remdesivir (22.6), acetylcysteine (19.3), foradil (12.9), colchicine or hydroxychloroquine (12.9), antihypertensive (12.9), silymarin (3.2) | adults with SARS-CoV-2 infection confirmed by RT-PCR | without a laboratory-confirmed diagnosis of COVID-19 infection, olfactory or gustatory impairment prior to COVID-19 infection, malignant neoplasms or neurodegenerative diseases | asthenia (67.7), breath problems (67.7), cough (67.7), fatigue (19.4), abdominal symptoms (12.9) | NR |
| Fantozzi et al., 2020, Italy [36] | questionnaire study | 6 March to 30 April 2020 | 111 (53/58); median 57 (range: 48–67) | hypertension (n = 29), chronic pulmonary disease (n = 11), diabetes (n = 10), cardiovascular disease (n = 9), cancer (n = 5) | hospitalized; NR | adults with confirmed SARS-CoV-2 infection | NR | fever (90.9), cough (46.8), dyspnea (34.3), diarrhea (4.5), sore throat (3.6), fatigue (3.6), myalgia/arthralgia (2.7), vomiting (2.7) | smokers (n = 7), former smokers (n = 38) |
| Favia et al., 2021, Italy [37] | observational study | October to December 2020 | 123 (53/70); median 72 | NR | hospitalized; NR | adults with SARS-CoV-2 infection confirmed by RT-PCR after nasal and oropharyngeal swabs | certain pre-existing lesions, symptomatic of pre-existing systemic and local conditions previously diagnosed and well-known to the patients, as well as traumatic lesions; the asymptomatic and mild forms | fever, anosmia, cough, sore throat, congestion and runny nose, nausea or vomiting, muscle and body aches, dermatologic manifestation, pneumonia, dyspnea and hypoxia, acute respiratory distress syndrome, multi-organ failure | NR |
| Fidan et al., 2021, Turkey [38] | prospective observational study | April to October 2020 | 74 (25/49); 51.4 ± 6.3 (range: 28–68) | NR | hospitalized; NR | infection confirmed by RT-PCR of nasopharyngeal swab | hormone therapy and/or steroid therapy in the one month prior to the study or taking any drugs that might affect oral lesion; oral lesions prior COVID-19 diagnosis | NR | NR |
| Ganesan et al., 2022, India [39] | observational cross-sectional study | 18 October to 7 November 2020 | 500 (133/367); 53.46 ± 17.50 | NR | hospitalized; NR | hospitalized, age ≥ 16 years, treated in the institute | pediatric population, any other systemic conditions affecting oral mucosa | influenza-like illness (64.6), severe acute respiratory infection (18.4) | smokers (n = 166) |
| Gherlone et al., 202, Italy [40] | retrospective and prospective cohort study | 23 July to 7 September 2020 | 122 (30/92); median 62.5 (IQR 53.9–74.1) | hypertension (n = 50), diabetes mellitus (n = 17), coronary artery disease (n = 12), chronic kidney disease (n = 9), chronic bronchopulmonary disease (n = 8), active neoplasia (n = 7) | hospitalized survivors; antibiotics (83.6), biologics (31.1), steroids (29.5) | adults admitted to the emergency department; positive SARS-CoV-2 nasopharyngeal swab on RT-PCR in the presence of clinical and/or radiological signs of COVID-19; signed the informed consent | NR | NR | smokers (n = 48) |
| Halepas et al., 2021, USA [41] | retrospective cross-sectional study | 15 March to 1 June 2020 | 47 (23/24); 9.0 ± 5.0 (range: 1.3–20.0) | NR | hospitalized; NR | 21 years or younger, fever of prolonged duration, laboratory evidence of inflammation, required hospitalization, multiorgan involvement, confirmed positive COVID RT-PCR or serology test results | NR | multisystem inflammatory syndrome in children; fever > 5 days (100.0), systemic rash (68.1), conjunctivitis (57.5), vomiting (51.1), diarrhea (38.3), myocarditis (36.2), cervical lymphadenopathy (19.2), cough (14.9), irritability (14.9), cranial nerve palsy (12.8), pericardial effusion (12.8), extremity edema (12.8), arthritis (8.5), rhinorrhea (6.4) | NR |
| Katz and Yue, 2021, USA [42] | registry study | NR | 895 (386/509); 0–9: 5.33%, 10–17: 2.47, 18–34: 39.9, 35–44: 11.1, 45–54: 1.2, 55–64: 11.2, 65–74: 12.3, 74–85: 16.5 | respiratory disease, endocrine disease, obesity, diabetes, circulatory disease | hospitalized; NR | diagnosis of COVID-19 ICD-10-U07.1 and/or ICD-10-K12.0 (recurrent aphthous stomatitis) | none | NR | smokers and non-smokers (NR) |
| Naser et al., 2021, Iraq [43] | prospective study | August 2020 to March 2021 | 338 (138/200); mean 42.1 | hypertension (n = 235), diabetes mellitus (n = 218), heart diseases (n = 108), renal diseases (n = 69), blood diseases (n = 37), respiratory disorders (n = 32), gastrointestinal diseases (n = 27), liver diseases (n = 26) | hospitalized; NR | diagnosed with COVID-19 + by PCR; age ≥ 10 years, with acute oral or perioral lesions either during admission or which appeared later during treatment; nonsmoker, no alcohol consumption | age ≤ 10 years; lesions appeared or were well established before SARSCoV-2 infection; not tolerating follow-up or refusing to enroll in study | NR | non-smokers |
| Natto et al., 2021, Saudi Arabia [44] | pilot cross-sectional study | 28 July 28 to 5 October 2020 | 109 (36/73); 39.3 ± 12.4 | diabetes (n = 11), hypertension (n = 8), asthma (n = 3), epilepsy and arthritis (n = 2) | non-hospitalized; NR | symptomatic and non-hospitalized, diagnosed with COVID-19 through a nasopharyngeal swab using RT-PCR | age < 18 years or suspected patients without any definitive diagnosis | muscle pain (77.1), fever (67.9), cough (50.5), headaches (49.5), no smell (44.0), sore throat (35.8), diarrhea (31.2), shortness of breath (22.0), nausea (20.2), runny nose (15.6), vomiting (9.2) | non-smokers (majority) |
| Nuno-Gonzalez et al., 2021, Spain [45] | cross-sectional study | 10 to 25 April 2020 | 666 (386/280); mean 55.7 | NR | hospitalized; NR | positive RT-PCR testing for SARS-CoV-2, or bilateral pneumonia; only adults; mild-to-moderate COVID-19 pneumonia | NR | NR | NR |
| Rafałowicz et al., 2021, Poland [46] | observational study | until mid-2021 | 1256 | present (NR) | survivors—hospitalized (about 30.0); NR | infected with SARS-CoV-2 in the period from 2 to 6 months before the visit | NR | fever, malaise, anosmia, pneumonia, diarrhea, vomiting, fatigue, irritability, trouble sleeping and concentrating, sweating, amnesia, shortness of breath, palpitations | NR |
| Riad et al., 2020, Egypt [47] | case series | April to August 2020 | 13 (8/5); 51.08 ± 8.79 (range: 34–62) | diabetes (n = 3), hypertension (n = 2), asthma (n = 2) | non-hospitalized; dexamethasone (n = 2), chloroquine (n = 2), paracetamol (n = 9) | generalized pain and soreness within the oral cavity related mainly to non-keratinized mucosa without a specific cause; positive RT-PCR testing for SARS-CoV-2 | NR | ageusia (30.8), fever (15.4), anosmia (15.4) | smokers (n = 3) |
| Riad et al., 2021, Egypt [48] | case series | May to August 2020 | 18 (14/4); 35.11 ± 13.3 (range: 18–72) | NR | non-hospitalized; paracetamol (n = 4), ibuprofen (n = 3), prednisolone (n = 1), chloroquine (n = 1) | offensive oral malodor that precipitated notable psychosocial distress; positive RT-PCR testing for SARS-CoV-2 | NR | fever (11.1), anosmia (11.1), dry cough (5.6), ageusia (5.6) | smokers (n = 3) |
| Riad et al., 2022, Egypt [49] | case series | April to June 2020 | 26 (17/9); 36.81 ± 15.65 (range: 16–70) | none | non-hospitalized; paracetamol | pain in the tongue; positive RT-PCR testing for SARS-CoV-2 | NR | fever (15.4), ageusia (11.5), sore throat (7.7), dry cough (3.8) | NR |
| Said Ahmed et al., 2021, Egypt [50] | case series | NR | 14 (4/10); mean 54.2 | diabetes | hospitalized (71.4); NR | 14–30 days post COVID-19 recovery, complaining from pain, loss of one or more maxillary teeth, exposed bone, pus discharge, and bad odor | NR | NR | NR |
| Sinjari et al., 2020, Italy [51] | observational study | May to June 2020 | 20 (9/11); mean 69.2 | hypertension (n = 8), thyroid disorders (n = 5), diabetes (n = 3), obesity (n = 3) | hospitalized; lopinavir/ritonavir and/or hydroxychloroquine | both gender and of any age, hospitalized for COVID-19, able to give consent to participate in the study | in need of intensive care and/or unable to give consent to participate in the study or unable to intend or to want | NR | smokers (n = 2) |
| Soares et al., 2022, Brazil [52] | case series | NR | 14 (4/10); mean 58 (range: 23–88) | hypertension (n = 4), diabetes (n = 3), chronic obstructive pulmonary disease (n = 1) | non-hospitalized; NR | positive RT-PCR testing for SARS-CoV-2; oral lesions | NR | Dysgeusia, anosmia, fever, headache, dyspnea, dry cough | NR |
| Subramaniam et al., 2021, India [53] | short-term observational study | April to June 2020 | 713 (297/416); range: 12–80 | diabetes, hypertension, asthma | hospitalized; multivitamins and vitamin C following prescribed treatment norms for the care of COVID-positive patients | both genders infected with SARS-CoV-2, diagnosed on RT-PCR in the age group of 12–80 years, admitted to the hospital | age < 12 and >80, not willing to give written informed consent, seriously ill requiring intensive care | complaints ranging from mild fever, sore throat, to difficulty in breathing | NR |
| Villarroel-Dorrego et al., 2022, Venezuela [54] | observational study | NR | 55 (25/30); 51 ± 23.24 (range: 1–89) | hypertension (n = 10), asthma (n = 9) | hospitalized (ICU: 34.5); combination of lopinavir and ritonavir, dexamethasone and remdesivir (ICU) | hospitalized with COVID-19 confirmed by PCR and a rapid antigen FIA diagnostic test | NR | NR | NR |
| Zarpellon et al., 2021, Brazil [55] | case series | NR | 26 (15/11); mean 50 (range: 8–76) | hypertension or diabetes | hospitalized (ICU); mechanical ventilation support | SARS-CoV-2 positive deceased who were admitted in ICU | NR | severe acute respiratory syndrome | smokers (n = 2) |
Legend: F, females; M, males; NR, not reported; ICU, intensive care unit; RT-PCR, reverse transcription polymerase chain reaction; FIA, fluorescent immunoassay.