This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Buccinator is pierced by all of the following except: 
Select and explain. 
A. Labial branch of facial nerve, B. Buccal branch of mandibular nerve, C. Parotid duct, D. Molar mucous glands
B: Buccal branch of mandibular nerve
Answer: B: Buccal branch of mandibular nerve 
Explanation: Ans: B. Buccal branch of mandibular nerve(Ref Grays 41/e 4(Y 10/e p487; Snells 9/e p582)Buccal branch of facial run crosses the buccinator muscle and innervates it, without piercing it.Buccinator - Structures passing:Anteriorly (Superficial buccinator surface):Muscles - zygomaticus major, risorius, levator & depressor anguli oris muscles.Duct - Parotid duct.Pierces buccinator opposite third upper molar tooth & lies on deep muscle surface before opening into mouth opposite maxillary second molar tooth.Blood vessel - Crossed by facial aery, facial vein & branches of facial & buccal nerves.