Periodontal disease and COVID-19: a systematic review and meta-analysis of observational studies

Abstract Background: A larger proportion of people with severe cases of Coronavirus Disease 2019 (COVID-19) appears to have comorbidities compared to the general population. However, evidence regarding the roles of periodontal disease(PD), in context of Coronavirus Disease 2019(COVID-19), is limited. Thus, to explore the association between PD and COVID-19, this systematic review and meta analysis was conducted. Methods: 7 online databases were searched by January 31, 2023. Heterogeneity was tested by I 2 index. OR and 95% CI were pooled through either random-effect or fixed-effect models. Subgroup analyses, sensitivity analyses, and publication bias assessments were also conducted. Results: Of the 823 articles identified and reviewed, 11 articles with 16,708 subjects met inclusion criteria and were included. PD was found to be associated with a statistically significant increase in risk of progression to severe diseases for COVID-19 patients(OR=2.20, 95% CI=1.38-3.49). Further analysis suggested that PD was associated with assisted ventilation(OR=5.01, 95% CI:2.61-9.63), ICU admission(OR=1.61, 95% CI:1.24-2.09), pneumonia(OR=5.19, 95% CI:1.17-23.00), and death(OR=2.25, 95% CI:1.55-3.28) for COVID-19 cases. Conclusions: Our results show that individuals with PD have an increased risk for ICU admission, assisted mechanical ventilation therapy, and a significantly increased risk of pneumonia and death. This suggests, to some extent, that the oral cavity is the gateway to COVID-19 infection; in other words, periodontitis is a risk factor for COVID-19 severity.