Tobacco and Public Health - TCSC Indonesia

Caries and tooth loss
Because periodontitis is a cause of tooth loss, a few studies, have assessed the effect of
smoking on tooth loss, primarily in the elderly, those who are edentulous. Although
the evidence is not as strong as with periodontitis there is a suggestion of an effect
(Table 34.14). Amongst the elderly, smokers are about twice as likely to have no teeth left
than non-smokers.
Table 34.15 shows the results from one study that looked at differences between smokers
and non-smokers with regards to indicators of caries. There are clear associations that
smokers tend to have more missing teeth and more decayed, missing, or filled surfaces.
Conclusion
ALLAN HACKSHAW 611
The literature on smoking and the disorders briefly described in this section is extensive.
Many disorders have long been regarded as partly caused by smoking. Whilst most studies
have provided evidence for an association, establishing causality has required careful
consideration, and in some cases still does. Many studies showed dose–response relationships
(risk of the disorder increased with increasing cigarette consumption) and that
ex-smokers had a lower risk than current smokers. Allowing for factors that may artificially
produce a relationship with smoking and risk has also been addressed, particularly
in the more recent and large studies. This has been important when there are established
confounding factors, such as alcohol, which is associated with both smoking and several
disorders (for example, psoriasis and gallstones). Study design has also been of importance.
Cohort studies of disease incidence can overcome many of the limitations of
cross-sectional or case–control studies. A good example is Alzheimer’s disease, which
had been thought by some to be less common in smokers. After careful analysis of
the published studies it is clear now that at best there is no association; in fact it may
increase the risk. Biological plausibility can, in many instances, only be postulated due
to the multi- factorial nature of the disorders. This is unsurprising given the number of
toxins and chemicals in tobacco smoke and the many biological pathways associated
with disease.
Table 34.16 provides approximate estimates of the effect of smoking on the population
assuming that all the disorders listed are caused in part by smoking (as mentioned
before, this is yet to be established for some such as Alzheimer’s disease, but the
estimates are presented for interest). For disorders, such as Crohn’s disease in women
and periodontitis, as much as half of all diagnosed cases may be due to smoking. For
others, though this proportion is relatively low, smoking can account for several
hundred or several thousand extra cases amongst smokers (for example, hip fracture
and miscarriage).
In summary, smoking is a risk factor for many disorders other than cancer, respiratory,
and cardiovascular disease. It is associated with significant morbidity in society
much of which can be avoided.