Catechol‐O‐methyltransferase (COMT) is an enzyme catalysing the degradation of catecholamines (dopamine, adrenalin, noradrenaline) and several SNPs linked to COMT have been associated with TMD and different pain conditions such as bruxism [49], anxiety [16], pain sensitivity [50, 51] and depressive symptoms‐related pain perception in TMD [50] in previous studies [17, 18]. This evidence concerns the gene COMT and bruxism.