LEP and temporomandibular joint disorder: IL-6 levels were significantly higher for TMJOA (13.80 ± 7.69) compared to DDwR (4.05 ± 3.13) and DDwoR (6.47 ± 5.85), but there was no significant correlation with leptin (r2 = 0.056, p > 0.05) in TMD patients [43].