RESUMO
This study aimed to evaluate how different study designs influences the presence and characteristics of diagnosis of oral manifestations in patients with COVID-19. Methods: This study is a meta-search conducted with studies evaluating the relationship between patients with oral manifestations and COVID-19. A search was conducted in three databases (PubMed, Web of Science, and Scopus), using terms specific to COVID-19 and oral lesions, including only primary studies. Study selection was undertaken by two reviewers independently. A descriptive analysis was performed. Results: The results included 55 studies in the data synthesis analysis. Most of the studies were case reports and case series. Some of the studies did not relate a biological test to confirm COVID-19. The ulcer lesion and that clinical examination by specialists were the most reported lesion in case reports and case series studies, while taste alterations and patient self-report were more reported in observational studies. Conclusions: This review concluded that the oral lesions in patients with COVID-19 differ according to the study design. The lack of high-quality scientific evidence in the dental literature on COVID-19 makes the findings inconsistent by the lack of sample selection criteria, diagnostic criteria and classification of oral lesions