Parotid duct

The parotid duct,also known as Stensen duct, drains saliva from the parotid gland into the oral cavity. It primarily secretes serous saliva.

Gross anatomy

After emerging from the anterior borderFollowing confluence of two main tributaries within the parotid gland, the parotid duct coursesemerges anteriorly from its substance through the adjacent buccal fat, superficial to the masseter muscle over which it passes horizontally ⁹.

At the anterior border of the masseter muscle, the duct makesturns medially, making a right-angled turn, and piercing the buccopharyngeal fascia (middle layer of the deep cervical fascia) and buccinator muscle to lie. Here it lies in the submucosa of the oral cavity⁹. In

Within the submucosa, the duct travels a short distance obliquely forwards to open at the papilla, adjacent to the second maxillary molar tooth in the oral vestibule. The oblique submucosal course of the parotid duct acts as a valve, preventing reflux of contents when intraoral pressure increases ⁸.

ItTradiationally the parotid duct is described as being approximately 5 cm long, At four and 3mm wide ⁹. Studies have suggested varying diameters at different points along its length, it has mean diameters ranging between 1.4 mm and 0.5 mm, with a maximum of 2.3 mm and a minimum of 0.1 mm, depending on the site ⁷.

Relations

Several other structures run alongside the parotid duct:

• superiorly: transverse facial artery

• inferiorly: buccal nerve

History and etymology

It is named after the Danish anatomist Niels Stensen (1638-1686) ² (also known as Nicolaus Steno)who was the first to describe it, initially in a sheep, in 1660. His colleague Sylvius (1614-1672) confirmed its presence in the human body and van Horne in Leyden named it after Stensen ⁶. 

Related pathology

Blockage of the parotid duct can occur secondary to salivary duct stones or external compression. Either cause of obstruction can cause pain and parotitis. Stones are more common in the submandibular gland and duct.