This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: ENT
Trismus in parapharyngeal abscess is caused by spasm of which of the following muscle? 
Select and explain. 
A. Medial pterygoid, B. Lateral pterygoid, C. Masseter, D. Temporalis
A: Medial pterygoid
Answer: A: Medial pterygoid 
Explanation: Parapharyngeal space - It is pyramidal in shape . base at base of skull and apex at hyoid bone Its divided into two components anterior & posterior. The trismus is seen in the anterior compament parapharyngeal abscess and it is due to spasm of the medial pterygoid muscle.