IL17A and periodontal disorder: Due to chronic bacterial colonization, periodontal disease induces local inflammation that can be extended systemically by the production of pro-inflammatory mediators such as interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-17 (IL-17), leukotrienes, prostaglandins, tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), fibrinogen, matrix metalloproteinases (MMPs), Type 1 T helper cells (Th1), or T helper 17 cells (Th17—its cellular response may be a critical factor in inflammatory diseases of the oral mucosa) [11,12].