DEFINITION of trismus

Medically, trismus describes any reduction in the jaw’s range of motion, typically from tonic contraction of masticatory muscles like the masseter or temporalis, mediated by the trigeminal nerve. It impairs eating, speaking, swallowing, and oral hygiene, raising risks like aspiration or infection; temporary cases often resolve in under two weeks, while permanent forms stem from trauma, tumors, or radiation.

Related Terms

  • Lockjaw: Historical synonym, especially for tetanus-induced trismus.​
  • **Masticatory muscles]]: Masseter] temporalis, pterygoids—primary sites of spasm.​
  • Temporomandibular disorder (TMD): Often overlaps, causing similar jaw restriction.[​
  • Bruxism: Teeth grinding, sometimes confused with trismus but allows mouth opening.

ETYMOLOGY of trismus

greek The term derives from Greek trismos (τρισμός), meaning “a scream, grinding, or gnashing of teeth,” akin to trizein “to squeak or gnash,” entered English via New latin around 1693 to denote tetanus-related lockjaw



Med roots dictionary Appendix A Prefixes Appendix B Combining Forms Appendix C Suffixes Appendix D Suffix forms