Background: Tooth loss is common among the elderly and often correlates with aging. Existing studies on the link between tooth loss and frailty in older adults yield inconsistent results. This systematic review and meta-analysis aims to clarify the relationship.

Methods: A comprehensive search of PubMed, Web of Science, Embase, and Cochrane Library was conducted to find observational studies on tooth count and frailty in older adults. Study quality was assessed using the Newcastle-Ottawa scale. Heterogeneity was evaluated using Cochran's Q and I² statistics, and subgroup analyses identified factors influencing outcomes. Publication bias and sensitivity analysis confirmed result stability.

Results: From 1,903 articles, 22 comprising 25 studies with 36,406 participants were included. The meta-analysis showed a pooled odds ratio (OR) of 0.98 (95% CI: 0.97 - 0.99) for tooth count and frailty. Individuals with 20 or fewer teeth had a higher risk of frailty (pooled OR = 1.99, 95% CI: 1.57 - 2.53). The highest frailty risk was observed in Japan (pooled OR = 3.02), followed by China (2.27), the UK and USA (1.90), and other regions (1.25). Subgroup analyses revealed no significant differences by country, study design, setting, adjustment model, or frailty assessment tool (P > 0.05).

Conclusions: There is a significant association between tooth count and frailty, particularly in those with 20 or fewer teeth. Policymakers should prioritize oral health within aging populations by promoting early preventive care and education to mitigate frailty risk. Robust, large-scale studies are needed to guide evidence-based interventions and public health policy.