In terms of morphological parameters, an increase in SSC-A on B cells (OR = 0.93 [0.86,1.00], P = 0.038) was associated with a reduced incidence of chronic periodontitis, while an increase in FSC-A on HLA DR + CD8 + T cells (OR = 1.04 [1.01,1.08], P = 0.024) and SSC-A on plasmacytoid Dendritic Cells (OR = 1.05 [1.00,1.11], P = 0.045) was associated with an increased incidence of chronic periodontitis. This evidence concerns the gene CD8A and chronic periodontitis.