Rs4880 ( SOD2 47 C/T) is a commonly studied SNP that has been associated with diminished levels of SOD219 ; which has been previously studied in the context of periodontal disease, being associated with susceptibility to treatment response.20 On the other hand, polymorphisms in the promoter region of the catalase gene ( CAT ) are rarely investigated in the context of oral diseases. This evidence concerns the gene CAT and periodontal disorder.