Copyright 2006 Martin S. Spiller, D.M.D. courtesy of Dr. Ed Cataldo
This is an image of the flap of tissue overlying Stenson’s duct. It is swollen due to an aphthous ulcer (canker sore) which happened to form directly on top of it. The swelling and redness make it easier to see. Otherwise, they are very difficult to photograph. Normally this small flap of mucosa is bluish pink in color, the same as the surrounding buccal (cheek) mucosa. In this image, the flap is bright red due to the inflammation caused by the aphthous.
Stenson’s duct is actually an internal duct, or “pipe” which carries saliva from the parotid gland (located in front of the ear) to the mouth. The duct’s opening is high in the cheek just behind the second molar. In the mouth is is more easily felt with the tongue than actually seen. It feels like a little flap of skin high in the back part of the cheek. It is, of course, normal anatomy, but sometimes people will notice it for the first time with their tongues and become alarmed, thinking it is some sort of growth.
Upon occasion, this area can become inflamed and sore due to bacteria entering the duct. An infection of this nature is called a retrograde infection since it is caused by a reversal of the direction of flow of fluid in the duct. Most of the time, the infection will resolve on its own, but occasionally, especially if the patient experiences dry mouth syndrome, the duct may become blocked. When this happens, the parotid gland can become sore and inflamed and the patient can experience swelling of the side of the face in front of the ear, sometimes extending to under the eye. When this happens, antibiotics are necessary to get the infection under control. In rare instance, an oral surgeon must place a small stent (plastic pipe) inside of the swollen duct to allow the escape of saliva until the swelling goes down. (Click here to see a diagram showing the parotid gland and its associated duct.)
The image above shows another aphthous ulcer, but this one does not involve Stenson’s duct. The duct itself is protected by a small flap of mucosa and has a slightly bluish tinge in this image.