ICOP secondary myofascial orofacial pain myofascial orofacial pain attributed to muscle spasm 2025-07-01T17:49:34Z Pain caused by sudden, involuntary, reversible tonic contraction of a muscle. Such spasm may affect any of the masticatory muscles. Acute malocclusion may be present. PMID:32103673 ICOP number: 2.2.3 Ava E. Cunningham