There are some double whammies in the mouth-body connections. One of them is smoking.
By Richard H. Nagelberg, DDS
There are some double whammies in the mouth-body connections. One of them is smoking. Smoking is deadly and everyone knows it, but not everyone knows it is deadly by more than one mechanism. The effects of tobacco smoke on the heart, lungs, and vascular system are so well documented that these associations are now facts. For example, individuals who smoke for 50 or more years and live into their nineties demonstrate the central impact of genetics. Of course, at this point in time we cannot predict who will get away with smoking in advance, and any health-care provider who condones smoking would certainly be practicing outside the standard of care.
In the oral cavity, the effects of smoking are also well documented. Numerous studies have demonstrated that smokers have less gingival inflammation than nonsmokers, which is counterintuitive. These observations do not mean that smoking reduces inflammation, but rather that smokers have a decreased expression of clinical inflammation due to the effects of tobacco on the microvasculature. According to Carranza's Clinical Periodontology, "An overwhelming body of data points to smoking as a major risk factor for increasing the prevalence and severity of periodontal destruction."
The second part of the double whammy of smoking, then, is the impact of burning tobacco on periodontal disease, increasing its prevalence and severity. Smoking, however, also increases the colonization of shallow periodontal pockets by periodontal pathogens, and increases the levels of periodontal pathogens in deep pockets. So smoking negatively impacts two pathways by which the mouth affects the body: the contribution of the inflammatory component of periodontal disease to the total inflammatory burden in the body and the direct effects of periodontal pathogens on the vasculature. The impact of smoking may be a triple whammy. It kills on its own, and even if it does not kill the smoker, it kills his or her health. Smoking increases periodontal disease and does so in an insidious manner by masking the clinical signs of periodontal disease and increases the load of periodontal pathogens.
Many risk elements for periodontal disease operate by more than one mechanism. Diabetes may have the greatest number of pathways by which it negatively affects the oral cavity and the body as well. Neutrophil function is knocked down, reducing the body's ability to defend itself against bacterial invasion. Healing is significantly reduced as is the response to periodontal therapy, just to name a few. Stress impairs the immune system and can cause xerostomia. Medication primarily causes xerostomia, but some antibiotics can upset the normal flora and lead to an overgrowth of opportunistic microbes such as candida. The risk element of poor oral hygiene is a rather obvious example of a multifactorial influence. The elevated levels of periodontal pathogens can directly affect arteries and lead to periodontal disease. Hormonal variations such as those that occur during pregnancy are primarily the result of the elevated levels of progesterone, which is a proinflammatory hormone. The elevated levels of progesterone persist if the mother is nursing the newborn baby. This becomes an important consideration for our patients who are pregnant, since the elevated tendency for periodontal inflammation may extend beyond the delivery. Other risk elements such as poor nutrition, faulty dentistry, and immunocompromise, among others, affect the mouth and the body by one or more mechanisms.
Among the most important things for clinicians to keep in mind are the things going on beyond the oral cavity for our patients who smoke, are pregnant, and present with periodontal disease. The mouth is just another part of the body, and it is not possible that disease processes and microbes that originate in the oral cavity are not having an impact on the rest of the body. We operate between the nose and the chin, but the impact of our intervention occurs beyond the mouth.
Taking a more active role in smoking cessation is something we should contemplate. Sometimes a patient's awareness of the impact of smoking is the result of the effects on the oral cavity. We have a responsibility to tell our patients about the impact of smoking on the oral cavity especially since the clinical evidence may not be obvious.
Richard Nagelberg, DDS, has practiced general dentistry in suburban Philadelphia for more than 30 years. He is a speaker, advisory board member, consultant, and key opinion leader for several dental companies and organizations, and he lectures on a variety of topics centered on understanding the impact dental professionals have beyond the oral cavity. Contact him at firstname.lastname@example.org