CSD changed inflammatory cytokine levels in TMJ. A. Representative immunoblots of MMP-1, MMP-3, MMP-9 and MMP-13 subjected to CSD in the TMJ tissue at the different groups. B. Mean relative protein levels of MMP-1, MMP-3, MMP-9 and MMP-13 at different groups (n = 10). *P<0.05 vs the control group, **P<0.01 vs the control group. CON: control group, CSD: chronic sleep deprivation group.