SCN9A and inflammatory response: As shown in Figures 2(c) and 2(d), Nav1.7 mRNA and protein expression were significantly upregulated in the sham + CFA group compared with the control group (P < 0.05), and TMJ inflammation-induced Nav1.7 expression in the ovariectomized groups was partially inhibited by P4 in a dose-dependent manner (P < 0.05).