In addition, the levels of central thyroid hormones sensitivity indices (PTFQI, TFQI, TSHI, TT4RI) and TSH, were significantly higher among participants with periodontitis than non-periodontitis group (P<0.01), and no significant difference was observed in peripheral sensitivity to THs (FT3/FT4) levels between individuals with periodontitis and those without (P=0.170). This evidence concerns the gene TG and periodontitis.