Tooth loss is a major public health problem globally with around 30% of those aged 65-74 being edentulous. Smoking is a risk factor for periodontal disease and has also been linked with a higher prevalence of tooth loss. The aim of this study was to evaluate the association between cigarette smoking and smoking cessation and the prevalence and incidence of tooth loss in a large cohort study in Germany.

Methods

Data from participants in the European Prospective Investigation into Cancer and Nutrition (EPIC)–Potsdam Study was analysed. Participants were recruited between 1994 and 1998 from the general population with the preferred ages of 35 to 65 y in women and 40 to 65 y in men. Following a baseline examination, self-administered questionnaires, and personal computer-guided interviews. Information on incident diseases and changes in lifestyle or diet is assessed by mailed follow-up questionnaires. Response rates to date have been around 90%.

Smoking was assessed using a questionnaire from which pack years of smoking were calculated. Educational attainment, body mass index, hypertension, diabetes, alcohol consumption and vitamin or mineral supplements were assessed from measurements and questionnaires. Tooth loss was also assessed by questionnaire returned between 2004-6. With the exception of the tooth loss data analysis was based on data collected at baseline.

Analysis was restricted to participants completing the forth follow up questionnaire. Negative binomial regression and tooth-specific logistic regression models were fit to evaluate the association between smoking and the baseline prevalence and incidence of tooth loss during follow-up, respectively

Results

• 23,376 participants (9,032 men and 14,344 women;) were included in the sample.
• 1,566 (6.7%) were edentulous at baseline.
• 4,394 (19%) participants were current cigarette smokers, and 7,268 (31%) were former cigarette smokers.
• Compared with never smokers, current smokers were more likely to be male, less educated, more likely to be hypertensive, and less likely to take vitamins/mineral supplements, and they had higher alcohol consumption.
• Cigarette smoking was associated with higher prevalence of tooth loss at baseline as well as higher incidence of tooth loss during follow-up.
• The association between cigarette smoking and incident tooth loss during follow up for the fully adjusted model (adjusted for age, sex, education, diabetes, body mass index, waist-to-hip ratio, hormone replacement therapy, contraception, intake of vitamin and mineral supplements, physical activity, alcohol intake, hypertension, and cardiovascular disease) is shown in the table.

	Male Odds ratio (95% CI)	Female Odds ratio (95% CI)
Current smoker < 15 cig/d	1.69 (1.30 to 2.21)	1.74 (1.51 to 2.01)
Current smoker >15 cig/d	3.64 (3.00 to 4.42)	2.47 (2.11 to 2.89)

Conclusions

The authors concluded:

There is a strong dose-dependent association between cigarette smoking and the risk of tooth loss. The risk declines after cessation of cigarette smoking; however, the risk may remain elevated for up to 20 y compared with never smokers. Efforts to improve the oral health of the population should include the prevention of smoking as well the promotion of smoking cessation.

Comments

This large cohort study shows a string dose dependent association between cigarette smoking and risk of tooth loss. It also showed that the risk falls once smoking is stopped, although it remains elevated for around 20 years. The authors highlight a difference between males and females noting that females had more missing teeth at baseline and a higher incidence of tooth loss during follow up relating this to possible differences in dental care, treatment preferences and ability/willingness to pay for dental treatment.

An important limitation noted by the authors is the lack of detailed data on oral health, dental service utilisation and habits. In addition, while a number of confounders have been considered there is the possibility of confounding for other measures that could impact on the estimates of the association between smoking and tooth loss. A 2011 systematic review by Hanioka et al  ( (Dental Elf -10th Aug 2011) included 2 cohort studies and 6 cross-sectional studies suggesting that a causal link was likely.

Links

Dietrich T, Walter C, Oluwagbemigun K, Bergmann M, Pischon T, Pischon N, Boeing H. Smoking, Smoking Cessation, and Risk of Tooth Loss: The EPIC-Potsdam Study. J Dent Res. 2015 Oct;94(10):1369-75. doi: 10.1177/0022034515598961. Epub 2015 Aug 4. PubMed PMID: 26243734.