The association between the number of teeth and frailty among older adults: a systematic review and meta-analysis

Background As people age, tooth loss often accompanies the process of aging in the elderly. There were several studies to explore the association between the number of teeth and frailty among older people, with inconsistent results. We aimed to summarize the evidence for the association between tooth loss and frailty among older adults by using systematic review. Methods We systematically searched PubMed, Embase, and Ovid databases. Observational studies were included to examine the relationship between tooth loss and frailty in older adults. The Newcastle‒Ottawa scale was used to evaluate the studies’ quality. Results A total of 1454 articles were identified from the retrieved databases. We extracted 17 studies involving 24,897 participants for the final analysis. The pooled association between the number of teeth and frailty among older adults was 0.98 (Odd ratio, OR) (95% confidence interval [CI]: 0.97 − 0.99). In addition, older people with fewer than 20 teeth had a higher risk of frailty than those with more than 20 teeth, the pooled OR was 1.91 (95% CI: 1.48 − 2.47). Tooth loss increases the risk of frailty, regardless of age group, study design, setting, and frailty assessment tools ( P <0.05). Conclusions Our study revealed a negative association between the number of teeth and frailty among older individuals. Furthermore, older people with fewer than 20 teeth faced a higher risk of frailty compared to those with more than 20 teeth.