SLC6A4 and Myalgia: Spearman's correlations coefficients (rs) between characteristic pain intensity on one hand, and psychological distress (PSS-10, GAD-7, PHQ-9, PHQ-15) and parafunctions (OBC) on the other hand, in 117 TMD myalgia patients grouped according to the common homozygous and rare homozygous combined with the heterozygous genotypes for the HTR2A (rs9316233), HTR3A (rs1062613), HTR3B (rs1176744), SERT (5-HTTLPR), and COMT (rs4680) polymorphisms.