Diseases Several general health conditions, including liver disease, calcium deficiency, eating disorders, and metabolic diseases, can cause teeth discoloration
Cases that feature climate as a central issue are catalogued in the Sabin Database
Because the association between CUD and oral cancer remained even after controlling for smoking status, and because CUD was associated with greater oral cancer risk even when the analysis was restricted to smokers, the researchers hypothesize that there may be other factors underlying this risk in addition to smoke inhalation
The underlying assumption is that even if no one in a particular population of people smoked, there would still be a certain small number of lung cancer deaths, and it is possible to know what that small number would be by, for example, looking at the lung cancer mortality rate among nonsmokers from the CPS-II