(a)
(b)
(c)
Figure 1: Scheme on the relationship between periodontitis and rheumatoid arthritis. (a) Pathogenesis of periodontitis and the effects promoted by lipopolysaccharides present in periodontopathogens. (b) The involvement of genetic and environmental factors in the development of rheumatoid arthritis. (c) Possible mechanisms that explain the relationship between rheumatoid arthritis and periodontitis.