<prompt> Risus-sardonicus term used in:RabiesTetanusSyphilisFrost-bite  <response>: Tetanus: Ref: 840 - H 899-Hn,hClinical manifestations of Tetanus Most common form of the disease is characterized by increased muscle tone and generalized spasms. Median time of onset after injury is 7 days Trismus or lockjaw - First noticed increased tone in the masseter muscle Dysphagia or stiffness or pain in the neck, shoulder and back muscles, Rigid abdomen and stiff proximal limb muscles, The hand and feet are relatively spared. Risus sardonicus - Sustained contraction of the facial muscles results in a grimace or sneer Opisthotonos - Contraction of the back muscles produces on arched back Cyanosis and threaten ventilation, Deep tendon reflexes may be increased Other complications include aspiration pneumonia, fractures, muscle rupture, deep vein thrombophlepbitis, pulmonary emboli, decubitus ulcer and rhabdomyolysis 