Trismus
Pronunciation: TRIZ-mus
Restricted or painful opening of the mouth due to spasm or fibrosis of the masticatory muscles, often documented post-procedurally in dental hygiene records.
Full Definition
Trismus is characterised by reduced maximum interincisal opening, typically defined as less than 35–40 mm in adults. In dental contexts, it may arise following inferior alveolar nerve block injection, third molar surgery, infection, radiation therapy to the head and neck, or temporomandibular joint disorders. Dental hygienists must document trismus when it affects patient positioning, instrument access, and the ability to complete treatment. Editors should not confuse trismus with general temporomandibular dysfunction (TMD) or with lockjaw (tetanus-associated trismus), which has a distinct aetiology. The term appears in post-operative instructions, clinical notes, and oncology-related oral care guidelines.
Usage
Usage note: Avoid using 'lockjaw' as a synonym in formal clinical documents, as the term is strongly associated with tetanus in general medicine. Use 'trismus' with an aetiological qualifier if needed.
In Context
- "Post-radiation trismus was noted in the patient's record, requiring modified instrumentation and shorter appointment times." — Head and neck oncology dental hygiene note
- "The author used 'lockjaw' to describe post-injection trismus; the editor replaced it with the clinical term to avoid confusion with tetanus." — Clinical article editing