Which duct passes across the surface of the masseter muscle and opens into the buccal sulcus opposite the upper second molar?

• A. Wharton's
• B. Sublingual
• C. Stenson
• D. Bartholin's

Answer: (C)

Stensen’s duct, the parotid duct, is the one that matches this description. It begins in the parotid gland, crosses the surface of the masseter muscle, then proceeds medially to pierce the buccinator muscle and drain into the buccal mucosa opposite the upper second molar at the parotid papilla. This pathway is distinctive from the others: Wharton’s duct is the submandibular duct that travels along the floor of the mouth to open near the lingual frenulum at the sublingual caruncle; the sublingual glands have multiple tiny ducts (the ducts of Rivinus) with the main one Bartholin’s duct opening near the floor of the mouth; these do not cross the masseter or open opposite the upper second molar.