Trismism (reduction of the jaws) is a tonic spasm of the chewing muscles, caused by irritation of the trigeminal nerve , with the result that movements of the lower jaw are limited or completely absent.
Trismism is an early sign of tetanus and rabies, often seen in cerebrospinal meningitis, sometimes in trigeminal neuralgia, as well as in various neurotic conditions (for example, hysteria). The most common cause of trisism is inflammatory diseases of the jaws and the circulatory tissues, especially pericoronitis (see Teeth), the temporomandibular joint, fractures of the mandible, and sometimes a complication after anesthesia or surgical interventions.
Chewing and temporal muscles are sharply tense, hard to touch.
Prolonged trisism leads the patient to exhaustion due to the impossibility of a normal diet.
Treatment . In the case of trism, which is a symptom of various diseases, it is necessary to treat the underlying disease; in case of a neurotic origin, a sedative is used (bromides, valerian, etc.). In the case of trismus caused by an inflammatory focus, sulfa drugs , antibiotics, physiotherapy , etc. are used, as well as eliminate the focus of infection (for example, the causative tooth) or the effects of trauma (splinting of the jaw), etc.
The prognosis is favorable, with the exception of those cases when trism is a consequence of tetanus or rabies. In case of prolonged trism and also in case of suspected infectious diseases or injuries mentioned above, the patient should be sent to the appropriate hospital.