trismus
Pronunciation: TRIZ-mus
Restricted mouth opening due to muscle fibrosis or spasm, often following head and neck cancer treatment.
Full Definition
Trismus is a condition characterized by restricted mouth opening, typically defined as an interincisal distance of less than 35mm in adults. In head and neck oncology, trismus commonly develops as a late effect of radiation therapy due to fibrosis of the muscles of mastication, particularly the pterygoid muscles and masseter muscles. The condition can also result from surgical trauma, tumor invasion, or infection. Trismus significantly impacts quality of life by affecting oral intake, speech articulation, and oral hygiene. Prevention involves early mouth opening exercises during treatment, while established trismus may require intensive physical therapy or mechanical devices.
Usage
Usage note: Measure and document interincisal distance; distinguish from other causes of limited opening.
In Context
- "The patient developed progressive trismus with mouth opening limited to 20mm at six months post-radiation." — Follow-up assessment
- "Prophylactic mouth opening exercises were prescribed to prevent radiation-induced trismus." — Rehabilitation plan