Parotid duct

The parotid duct (ductus parotideus; Stensen's duct) is the excretory duct of the parotid gland and is approximately 5 to 7 cm long. It is formed by union of numerous small ducts that join to form a single parotid duct that arises from the anterior border of the gland.

From the anterior border of the parotid gland, the duct passes horizontally forwards across the superficial surface of the masseter muscle. At the anterior border of the masseter, it turns medially almost at a right angle, pierces the buccal fat pad and the buccinator muscle, and then runs obliquely forwards between the buccinator and the oral mucosa. It opens into the oral vestibule through a small papilla on the inner surface of the cheek opposite the upper second molar tooth.

While crossing the masseter, the duct lies between the buccal branches of the facial nerve, with the transverse facial artery and accessory parotid tissue situated superior to it.

Structurally, the parotid duct has a relatively thick wall composed of an outer fibrous coat containing contractile fibres and an inner mucosal lining of columnar epithelium.

Clinical correlates

Clinically, the parotid duct may become obstructed by salivary stones or injured during facial trauma and surgical procedures, resulting in painful gland swelling or salivary fistula formation.