Abstract Background: Psoriasis and periodontitis are chronic inflammatory diseases that may share immune-mediated mechanisms. Recent epidemiological studies suggest a potential bidirectional association, but the strength and mechanisms remain unclear. Objectives: This systematic review and meta-analysis aims to evaluate the bidirectional association and comorbidity between psoriasis and periodontitis, assess periodontal health parameters in psoriasis patients, and discuss potential mechanisms. Methods: This review followed PRISMA guidelines and was registered in PROSPERO (CRD42024569055). MEDLINE, Embase, and Cochrane Library were searched up to April 2025. Case–control, cross-sectional, and cohort studies were included. Two meta-analyses were conducted: One for cohort studies pooling hazard ratios (HRs) and another for case–control studies pooling odds ratios (ORs). Results: We included seven case–control and three cohort studies, totaling 17,271,581 subjects. The meta-analysis revealed a significant association between psoriasis and periodontitis prevalence (pooled OR = 2.21, 95% confidence interval CI: 1.49–3.28, P < 0.0001). Patients with periodontitis also had an increased risk of psoriasis (pooled HR = 1.18, 95% CI: 1.06–1.31, P = 0.003). Subgroup analyses showed worse periodontal parameters in psoriasis patients: Probing depth (standardized mean difference SMD = 0.45, 95% CI: 0.29–0.61), clinical attachment level (SMD = 0.43, 95% CI: 0.13–0.73), bleeding on probing (SMD = 0.26, 95% CI: 0.10–0.41), and plaque index (SMD = 0.19, 95% CI: 0.10–0.28). Conclusion: Our study supports a bidirectional association between psoriasis and periodontitis, as well as poorer periodontal health in psoriasis patients. These results underscore the importance of early periodontal assessment and education in the clinical management of affected individuals.
Tsai et al. (Thu,) studied this question.