Marijuana Had an Even Larger Negative Effect on Teen Dental Health Than Tobacco | Research

The takeaway

An 8-year study of nearly 67,000 Nevada adolescents found marijuana use had a larger negative effect on dental health than tobacco, with both substances significantly increasing cavity prevalence and severity.

Read this if you use cannabis and want to understand its effects on dental health.

Marijuana had the largest negative effect on dental caries, exceeding tobacco

What the researchers found

Researchers screened 66,941 adolescents (ages 13-18) across Nevada middle and high schools from 2002 to 2010. Marijuana use rates were significantly higher than the national average (12.0% vs. 3.3%). Both tobacco and marijuana use were associated with significantly higher prevalence and severity of dental caries across all demographic variables and across all 8 years.

Marijuana had the largest negative effect on dental health, exceeding even tobacco's impact. These associations held after controlling for gender, race/ethnicity, location, and secondhand smoke exposure.

Why it matters

Dental health is often overlooked in discussions of cannabis harm. This large study demonstrates that marijuana use has a substantial negative impact on adolescent dental health that exceeds tobacco, a substance with well-established oral health consequences. This finding adds to the harm profile for adolescent cannabis use.

The numbers in context

66,941 adolescent dental screenings. 8 years of data (2002-2010). Nevada marijuana use: 12.0% vs. 3.3% national average. Marijuana had the largest negative effect on dental caries. Both substances associated with higher prevalence and severity across all subgroups.

How the study worked

Retrospective cohort study using an ongoing statewide school-based dental health screening initiative across 8 years (2002-2010). 66,941 dental screenings. Self-reported tobacco and marijuana use. Caries prevalence and severity measured by dental professionals. Effect sizes reported.

What this study cannot tell us

Self-reported substance use may be underreported in a school setting. The study cannot establish that marijuana directly caused worse dental health versus confounders like diet, oral hygiene habits, or access to dental care. Cross-sectional within each year, though trend data spans 8 years.

How to read the evidence

Large retrospective cohort with consistent findings across 8 years; moderate evidence with appropriate controls.

When this study was published

Published in 2013. Oral health effects of cannabis continue to be studied as usage increases.

The bigger picture

This study adds dental health to the list of adolescent health outcomes negatively affected by cannabis use. The mechanism may involve xerostomia (dry mouth) from cannabis use, which reduces saliva's protective effect on teeth, combined with potential dietary changes (increased sugar intake when using cannabis).

Questions still open

What biological mechanism explains marijuana's dental impact? Does the method of cannabis consumption (smoking vs. edibles) affect dental outcomes differently? Would dental screenings be an opportunity to screen for adolescent substance use?

Common questions

Why does marijuana affect dental health?

Several mechanisms are likely involved: cannabis smoke irritates oral tissues, THC reduces saliva production (dry mouth allows bacteria to thrive), cannabis users may consume more sugary foods and drinks, and cannabis use may reduce attention to oral hygiene habits. The combined effect was larger than tobacco in this study.

Is smoking cannabis worse for teeth than eating edibles?

This study did not differentiate between consumption methods. However, smoking exposes teeth and gums directly to hot smoke and byproducts, while edibles avoid this exposure. Both methods could cause dry mouth (a major dental risk factor), and edibles often contain sugar. The specific dental impact by consumption method remains an open question.

Read the original research

The effect of tobacco and marijuana use on dental health status in Nevada adolescents: a trend analysis.

The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 52(5), 641-8

View on PubMed ↗Publisher’s paper ↗

Citation

Ditmyer, Marcia; Demopoulos, Christina; McClain, Mildred; Dounis, Georgia; Mobley, Connie. (2013). The effect of tobacco and marijuana use on dental health status in Nevada adolescents: a trend analysis.. The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 52(5), 641-8. https://doi.org/10.1016/j.jadohealth.2012.11.002