From Big Medical Encyclopedia

LOCKJAW (trismus; Greek trismos peep, gnash, synonym: data of jaws, a stiskivaniye of jaws) — the tonic spasm of chewing muscles leading to restriction of movements in a temporal and mandibular joint. Is a symptom various patol. the processes arising both at direct and at reflex irritation of the third branch of a trifacial, the cortical and nuclear ways participating in an innervation

of masseters.

T. — one of the earliest symptoms of tetanus (see); meets at epilepsy (see), pseudobulbar paralysis (see), with ub and r and hno idalny hemorrhages less often (see the Meninx), tumors of a brain (see the Brain, tumors). Reflex T. develops at nek-ry diseases of a nervous system.

Sometimes T. call the complicated opening of a mouth at inflammatory processes in the muscles lifting a mandible (a periostitis, phlegmon and abscess of alate and maxillary, peripharyngeal areas, a maxillary and lingual fillet, parotid and chewing area, temporal and infratemporal poles) at arthritis and arthrosis of a temporal and mandibular joint (see), and also at osteomyelitis or an injury of jaws (see). Difficulty during the opening of a mouth owing to inflammatory processes can be caused by the pain causing reflex reduction of muscles. At an injury of parotid and chewing area opening of a mouth can be broken as a result of damage of masseters, a mandible and temporal and mandibular joints or sharp pain, and further can be caused by a cicatricial contracture of masseters (see the Contracture) or disturbance of mobility of temporal and mandibular joints of this or that degree. Sometimes data of jaws arise during the carrying out mandibular anesthesia (see Anesthesia local) owing to development of a hematoma in a medial alate muscle.

Distinguish three extents of restriction of movements in a temporal and mandibular joint: at the first extent of restriction of movements opening of a mouth (between top and bottom cutters) to 2 cm is possible, at the second — to 1 cm, at the third disconnection of teeth is impossible.

Usually in T. muscles of both parties are involved. At the same time swelling and consolidation of the reduced masseters is observed. At a contracture hemilesion of masseters is more often observed. At hemilesion of alate muscles the mandible is displaced in an opposite patol. to process the party, at hemilesion actually of a masseter or a temporal and mandibular joint during the opening of a mouth the mandible is displaced towards localization patol. process.

Treatment is directed to elimination patol. the processes causing T.

The forecast depends on an outcome of the basic disease which led To a lockjaw. century I. Zauyeayev.