<P> Trismus , also called lockjaw , is reduced opening of the jaws ( limited jaw range of motion ) . It may be caused by spasm of the muscles of mastication or a variety of other causes . Temporary trismus occurs much more frequently than permanent trismus . It is known to interfere with eating , speaking , and maintaining proper oral hygiene . This interference , specifically with the patient 's ability to swallow properly , results in an increased risk of aspiration . In some instances , trismus presents with altered facial appearance . The condition may be distressing and painful for the patient . Examination and treatments requiring access to the oral cavity can be limited , or in some cases impossible , due to the nature of the condition itself . </P>
one of the first signs of the onset of tetanus is trismus also referred to as
lockjaw