Temporomandibular disorders and declarative memory.

Temporomandibular disorder (TMD) is a somatic manifestation of stress. Previous researches suggested hypothalamic-pituitary-adrenal (HPA) axis hyperactivity in TMD, through which TMD patients exhibited abnormalities of the stress response hormone - causing additional cortisol release. Increased cortisol, the principal circulating glucocorticoid in humans, would impair memory retrieval of declarative material. This effect on memory retrieval may in particular be due to glucocorticoid receptors (GR) in the hippocampus. The hypothesis we proposed is that TMD might result in declarative memory impairment by increasing the cortisol.