The Dental Dangers of Marijuana

This experience led me to believe that dentists need to be better informed about the role of marijuana in contributing to dental disease. Let’s face it. Whether or not you personally approve of marijuana, this drug is fast becoming a part of life for millions of Americans. While marijuana smokers lag far behind the estimated 36 million Americans who smoke tobacco, their numbers are rapidly rising. Medical marijuana is now legal in 28 states, and recreational marijuana use is ballooning in every segment of the population. A recent Gallop poll found that one in eight adults acknowledged puffing on pot, and some of these may well be your gray-haired patients. In 2015 CBS News reported that the number of people 55 and older indulging in marijuana increased from 2.8 million in 2013 to 4.3 million a year later. 

Seniors, in particular, are increasingly turning to medical marijuana as an effective alternative drug to relieve the ills that typically beset their generation, such as insomnia, arthritis, chronic pain, and depression. For example, among the dozens of recreational and social groups the residents of Rossmoor, an upscale retirement community in Walnut Creek, California, organize is the cannabis club. One of the community’s most popular groups, the club provides programs and information about medical marijuana.

As cannabis becomes more routinely accepted as a successful treatment for a variety of medical conditions, it is important for dentists to become knowledgeable about the oral problems that can develop from frequent pot smoking. The dental danger common to both tobacco smoking and pot smoking comes from their shared link to inflammation. Undoubtedly, some of the hundreds of compounds in cannabis stimulate the inflammatory response, which is the culprit underlying so many health issues. Primary among them in dentistry is periodontal disease—deemed by the American Dental Association as the most common chronic disease in America and the major cause of tooth loss among adults. Marijuana is now considered a significant potential risk factor in the severity of periodontal disease along with factors such as genetics, aging, diabetes, cigarette smoking, and oral hygiene. 

In a 2005 New Zealand study of adults born between 1972 and 1973, those who self-identified as cannabis users were three times more likely to have significant periodontal attachment loss than non-users. The most frequently cited study on the relationship between cannabis and periodontitis is the National Health and Nutrition Examination Survey from 2011 to 2012. Of the 1938 participants, 26.8% were cannabis users. Data showed they exhibited deeper pocket depth, higher attachment loss, and greater odds of having severe periodontitis. 

But the severity of the issue goes even further. Because periodontal disease is known to be associated with conditions such as diabetes, cardiovascular disease, and rheumatoid arthritis, it is clear that marijuana can affect not only oral but also general health in a certain subset of patients. 

Periodontal disease is not the only oral by-product of cannabis smoking. A group of dentists has coined the term grass mouth to describe these oral manifestations related to cannabis use. The most common are severe xerostomia and throat dryness, likely due to chemical 9-tetrahydroannabinol, the component in cannabis responsible for the “pot high.” Almost certainly, this has also led to a dramatic rise in the rate of caries detected as well as more cases of erythema of the oral cavity, leukoplakia, and hyperkeratotic lesions. Dentists will in all likelihood be seeing more of the complications from marijuana use that they were once accustomed to seeing from tobacco addiction.

Some marijuana smokers, like their compatriot cigarette smokers, are trying to cut down on the effects of smoke by vaping, which delivers either cannabis or nicotine through an electronic device that heats the product and turns it into vapor. For tobacco smokers this is popularly known as the e-cigarette. So far evidence is mixed over whether vaping is as dangerous as outright smoking. Some vapers report sore throats, dry mouth, dry cough, and mouth ulcers, but they tend to be in the minority. On the positive side, a small number of studies find that e-cigarettes are an effective aid to smoking cessation. However, these studies conclude that the aerosol of e-cigarettes is primarily absorbed in the buccal and pharyngeal mucosa rather than in the lungs, which suggests potential oral problems. While the ultimate safety of vaping versus smoking is still being debated, vaping seems to have oral hazards that cannot be ignored.

The conundrum facing the dental community boils down to a hard reality. For your patients who are getting emotional relief or pharmacologic benefits from cannabis, you cannot simply tell them what you tell tobacco users: “Just quit!” Unlike cigarettes, there are demonstrative reasons for using cannabis to relieve pain, deal with sleeping problems, and reduce anxiety. However, these benefits may be offset by the oral problems cannabis causes. Dentists can suggest that cannabis users switch from smoking to edibles as one possible solution. But what’s critical is that you do not ignore the issue. Be forthright with patients, openly discuss the pros and cons, and work together to find a mutually agreeable treatment plan. Marijuana use is here to stay and we, as dentists, have to deal with it.

Louis F. Rose, DDS, MD
Editor-In-Chief
Compendium
Private Practice
Philadelphia, Pennsylvania