Rodriguez-Lozano B, et al. - In this case-control study, 187 subjects were assessed to investigate the relationship of periodontitis with rheumatoid arthritis (RA) and also to estimate the link of progression of periodontitis severity to RA disease activity. RA disease activity and severity were measured by the Disease Activity Score 28, the Simplified Disease Activity Index, the Clinical Disease Activity Index, rheumatoid factor, anti-citrullinated protein antibody titers, the erythrocyte sedimentation rate, C-reactive protein, the presence of extra-articular manifestations and type of RA treatment. Investigators observed parameters associated with periodontal status like plaque index, bleeding on probing, probing pocket depth and clinical attachment levels, significantly worse in RA subjects. With an adjusted OR of 2.66, they noticed a marked association between periodontitis severity and RA disease activity.