Heavy use of marijuana has been reported to cause respiratory problems, bronchial complaints, diarrhea, abdominal cramps, tachycardia, acute panic and paranoia and impairment with short-term memory and motor skills.
The most beneficial use of marijuana is its antiemetic properties, especially for patients receiving chemotherapy and its ability to reduce intraocular pressure in the treatment of glaucoma. It is used widely for cancer patients, AIDS patients and other chronic diseases.
Marijuana use can lead to several oral problems. Of most concern to dental providers are the development of xerostomia (dry mouth) and an often dramatic increased rate of caries (cavities). Additionally, irritation, edema and erythema of the oral tissues have been seen. A limited numbers of studies have linked a correlation between marijuana use and the risk of periodontal disease. As far as a link to the development of oral cancer, the high intraoral temperature from marijuana smoking can cause changes in oral tissues and cellular disruption. Although these changes likely could lead to oral cancer, the link has not been established.
ADA News February 20, 2017