Masticatory muscle spasm is one of the early symptoms of the onset of Clostridium tetani infection. Clostridium tetani (clostridiumtetani) is the pathogenic bacterium that leads to tetanus, which exists in large numbers in the intestinal tract of humans and animals, and is contaminated with soil by feces and causes disease by wound infection. Etiology: When tetanus spasm toxin is produced locally, it causes generalized transverse muscle spasm. After local production, the toxin is absorbed through the motor end plate, along the nerve fiber gap to the nerve cells in the anterior horn of the spinal cord and up to the brainstem, or it can be absorbed lymphatically and reach the central nervous system through the bloodstream. The toxin binds to gangliosides in the nerve tissue, closing the inhibitory synaptic terminals of the spinal cord and preventing the release of glycine and γ-aminobutyric acid, the transmission mediators of inhibitory impulses, thus disrupting the transmission of normal inhibitory impulses between the upper and lower neurons, resulting in hyperreflexia (abnormally high excitability) and transverse muscle spasm. Tetanus is mostly seen in battle wounds. In addition to traumatic infections, unclean umbilical cord during delivery and poorly sterilized surgical instruments can cause morbidity. Neonatal tetanus (commonly known as umbilical wind) is particularly common.