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Discussion Starter #1
A 46 year farmer presented with abnormal facial expression and he appears as if grinning with inability to move the jaw. History taking elicited a previously ignored wound without appropriate sterilization and medical attention.
What two nerves supply the muscles that caused the abnormal facial expression in this patient?

  • a- Vagus and Glossopharyngeal
  • b- Facial and Trigeminal
  • c- Trigeminal and Vagus
  • d- Facial and Vagus
  • e- Maxillary and Mandibular
 

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The Correct Answer

This patient definitely had developed tetanus after his wound has been contaminated with C. tetani spores from his farm's soil.
Grinning refers to Risus sardonicus which is abnormal spastic grimacing of the muscles surrounding the mouth (orbicularis oris ) supplied by the facial nerve.
Inability to open the mouth refers to Trismus (locked jaw) which is due to spastic contraction of the messater which is supplied by the mandibular branch of the Trigeminal nerve. (see Muscles of Mastication)
So the correct answer is B :D
 
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