ICOP causally related to acute pain primary myofascial orofacial pain acute primary myofascial orofacial pain 2025-06-30T18:38:53Z ICOP number: 2.1.1 PMID:32103673 Mild to moderate levels of deep aching or pressing pain in the masticatory muscles, occurring episodically or unremittingly, often associated with functional impairment such as perceived difficulties in moving the lower jaw, chewing and/or yawning, etc., and with onset within the last 3 months. Ava E. Cunningham