ABSTRACT
This group of disorders includes those which limit mouth opening and those which result in excess mandibular excursion. Haematoma, local sepsis and mandibular trauma all limit the range and extent of mouth opening that is possible. Trismus is reflex muscle spasm and usually occurs as a response to local injury or infection. Periarticular disease with sepsis, haematoma formation, mandibular neck fracture or injection of local anaesthetic solution into muscle may all provoke and trismus.
