AIM: To quantitatively evaluate the impact of smoking on tooth loss.METHODS: We performed a Pub Med search to identify published articles that investigated the risk of tooth loss by smoking, from which RRs and their variance with characteristics of each study were extracted. The random-effects models were used to derive a pooled effect across studies. Potential sources of heterogeneity on the characteristics of the study and their influence on the pooled effect size were investigated using metaregression models. RESULTS: We identified 24 studies containing a total of 95973 participants for analysis. The pooled RR of ever-smokers compared with never- smokers was 1.73(95%CI: 1.60-1.86, P < 0.001). In meta-regression analysis, only the mean age of participants alone was identified as a statistically significant source of heterogeneity. The effect of smoking on tooth loss was stronger when the mean age of study participants was higher, indicating possible enhancement of tooth loss due to aging by smoking. RR was significantly lower in former smokers(1.49, 95%CI: 1.32-1.69, P < 0.001) than in current smokers(2.10, 95%CI: 1.87-2.35, P < 0.001), indicating the substantial benefit of smoking cessation for reducing the risk of tooth loss.CONCLUSION: Smoking is an independent risk factor for tooth loss regardless of many other confounders. Smoking cessation may attenuate this effect. A quantitative analysis of the impact of smoking on tooth loss. METHODS: We performed a Pub Med search to identify published articles that investigated the risk of tooth loss by smoking, from which RRs and their variance with characteristics of each study were extracted. random-effects models were used to derive a pooled effect across studies. Potential sources of heterogeneity on the characteristics of the study and their influence on the pooled effect size were investigated using metaregression models. RESULTS: We identified 24 studies containing a total of 95973 participants The pooled RR of ever-smokers compared with never-smokers was 1.73 (95% CI: 1.60-1.86, P <0.001). In meta-regression analysis, only the mean age of participants was was as a significant significant source of heterogeneity. The effect of smoking on tooth loss was stronger when the mean age of study participants was higher, indicating possible enhancement of tooth loss due to a RR was significantly lower than former smokers (1.49, 95% CI: 1.32-1.69, P <0.001) than in current smokers (2.10, 95% CI: 1.87-2.35, P <0.001) of smoking cessation for reducing the risk of tooth loss. CONCLUSION: Smoking is an independent risk factor for tooth loss regardless of many other confounders. Smoking cessation may attenuate this effect.