Considering oral diseases as an exposure of a particular NCD, the following associations were found: dental caries with iron deficiency (n = 2) (Fig. 2); tooth loss with cognitive impairment (n = 2), with dementia (n = 3) and with lung cancer (n = 1) (Fig. 2); edentulism with pancreatic cancer (n = 1) (Fig. 2); endodontic infection with serum C-reactive protein (CRP) (Fig. 3). Here, CRP is linked to lung cancer.