Trismus
Pronunciation: TRIZ-mus
Restricted opening of the mouth due to spasm or fibrosis of the muscles of mastication, frequently documented as a post-operative or pathological finding in dental records.
Full Definition
Trismus refers to a sustained reduction in the maximum mouth-opening distance, typically defined clinically as an inter-incisal opening of less than 35 mm in adults. It may result from infection, trauma, post-injection muscle haematoma, radiation fibrosis, or temporomandibular joint pathology. In dental documentation, trismus is recorded as a presenting complaint, a post-operative complication, or a contraindication to certain procedures. Editors should note that trismus is distinct from ankylosis, which implies bony or fibrous fusion of the joint itself. The term appears in oral surgery reports, post-extraction notes, and oncology-related dental assessments.
Usage
Usage note: 'Lockjaw' is colloquial and associated specifically with tetanus; prefer 'trismus' in clinical documentation. Quantify with inter-incisal measurement where possible.
In Context
- "Post-operative trismus was noted three days after surgical removal of the lower-right third molar, with a recorded inter-incisal opening of 22 mm." — Post-operative surgical notes
- "Radiation-induced trismus was listed as a complication in the patient's oncology dental referral." — Oncology dental referral letter