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].