Smoking as a risk indicator for periodontal disease in the middle-aged Vietnamese population

BACKGROUND: Studies from developed countries have found smoking a significant risk indicator for periodontitis. However, few such studies have been conducted in developing populations, where the natural history of the disease is rarely confounded by treatment and smoking is highly prevalent. AIM: The present study aimed to confirm the consistency, strength and dose-response of the association of smoking with periodontitis measured by loss of attachment (LOA) in a representative middle-aged adult sample from a developing country. METHODS: A cross-sectional study with a multistage stratified random sample was conducted in two provinces of Vietnam. RESULTS: A total of 575 (response: 84.6%) 35-44-year-old subjects were interviewed and periodontally examined. Data were re-weighted to represent the population of the provinces. 28.9% were current smokers (CS), 8.6% former smokers (FS) and 62.5% never-smokers (NS). Number of cigarette pack-years was calculated to divide CS into light smokers, LS < or = 5 pack-years, and heavy smokers, HS 5+ pack-years. The US NIDR protocol was employed for LOA measurement at two sites per tooth for every tooth. HS presented with the highest prevalence of LOA exceeding various thresholds followed by LS (chi2, P < 0.001). The extent of sites with LOA > or = 4 mm and LOA > or = 6 mm was significantly higher among HS and LS compared to NS (ANOVA; P < 0.001). The severity scores of LOA for NS, FS, LS and HS were 2.42, 2.50, 2.64 and 3.05 mm respectively (ANOVA; P < 0.001). Disease cases were defined as having 2+ sites with LOA > or = 5 mm and 1+ site with PD > or = 4 mm. Compared to NS, the odds ratio for periodontitis among heavy smokers was 7.17 (CI: 2.87-17.92, P < 0.001). CONCLUSION: Smoking is a risk indicator for periodontitis among the middle-aged Vietnamese population. To pursue a population prevention approach for periodontitis, dentistry in Vietnam needs to be part of antismoking and smoking cessation programs.