Dentist Ellyce Clonan can tell when her patients are stoned.

“I can smell it on them, and then there’s the red eyes and dry mouth,” said Clonan, a clinical assistant professor at the University at Buffalo School of Dental Medicine in New York.

“If I ask, some patients will tell me, ‘I’m so scared of going to the dentist, I had to come stoned,’” she said. “While we love to get folks into our chair for regular checkups, most people don’t understand the oral health dangers of using marijuana, especially on a regular basis.”

A 55% greater risk for cavities. A 41% increased risk for tooth loss. And a threefold higher risk for mouth cancers — this little-known fallout has been documented in a growing number of studies exploring the link between marijuana use and a healthy mouth.

When it comes to lung and oral cancers, most people think of tobacco, a proven culprit. However, a July study that explored California hospital records found people with cannabis use disorder — characterized by daily use that’s hard to stop — were more than three times more likely to develop lip and tongue cancers over the next five years.

“Our analyses suggest that cannabis exposure itself impacts risk of oral cancer,” said study author Raphael Cuomo, a biomedical scientist and professor of medicine at the University of California, San Diego.

A possible reason? Tetrahydrocannabinol, or THC, the part of the marijuana plant that makes you high, may suppress immune responses in mouth and nose tissues exposed to smoke, Cuomo said in an email.

And just as in tobacco smoke, there are volatile compounds in a puff of marijuana that can harm sensitive tissues in the mouth and lungs.

Ammonia, which can cause nose, throat and respiratory tract irritation, is often added to tobacco products to increase the body’s absorption of nicotine and make tobacco more additive, the US Food and Drug Administration states on its website.

“Ammonia was twenty times higher in marijuana smoke” than tobacco, Cuomo said via email.

Marijuana also has much higher levels of hydrogen cyanide — a toxic chemical used for fumigation and the manufacture of plastics and pesticides — as well as organic compounds called aromatic amines that are potentially carcinogenic, according to Cuomo.

While more studies are needed to prove that marijuana smoke can cause mouth cancers, the reality is that breathing in a burning material of any kind is not good for the lungs and mouth, said Clonan, who led a January study that found a high risk for cavities and tooth loss among marijuana users.