Following a penetrated injury in the submandibular triangle, the tongue of 45 year old patient detes to the left on protrusion. Which of the following nerves is injured?: (A) Right lingual nerve, (B) Left lingual nerve, (C) Right hypoglossal nerve, (D) Left hypoglossal nerve
Answer is D. A lesion of the hypoglossal nerve causes detion of the tongue toward the injured side on protrusion. The lingual and glossopharyngeal nerves do not supply the tongue muscles. Hence option 4 i.e. left hypoglossal nerve (same as the side of detion) is correct.