Anatomy and Function
There are four major salivary glands - the parotid on each side in front of and just under the ear and the submandibular glands on either side of the neck just under the jawline. There are also two rows of glands under the tongue called the sublingual glands, and many thousands of individual glands scattered throughout the mouth and throat known as minor salivary glands. These glands produce saliva, commonly called “spit." The major glands each have a tube, or “duct” that extends from the gland to the inside of the mouth and serves as a pipe for the saliva to go from the gland into the mouth. Saliva helps to soften and moisten our food as we chew it and also has enzymes that begin to break down some parts of the food. Saliva has antibacterial qualities that help prevent tooth decay. Anything that blocks up the flow of saliva in the duct can cause swelling and pain in the duct that that connects with the gland. One common cause of this is a salivary gland stone.
What are salivary stones?
Salivary gland stones are a common condition, but you may have never heard about them before. Most people have heard of kidney stones, and while they are similar to salivary stones, they are not related and have different causes, but both can cause pain and infections. Salivary stones are thought to occur due to a particle of debris in the salivary duct that then becomes encrusted in protein and calcium, similar to how an oyster forms a pearl from a grain of sand.
Diagnosis of salivary stones
Salivary stones are often suspected in a patient with recurrent swelling of the neck or cheek associated with eating. There is typically a visible lump in the neck or below the ear depending on which gland is involved. Confirmation of the diagnosis is by either CT scan or Ultrasound which will detect a stone in most cases, although small stones may not show up well. Once a stone is diagnosed, treatment is typically surgical, although some stones will pass spontaneously with time. If the symptoms are mild, a course of hydration by drinking extra water and a so-called “sialogogue” or sour candy may be attempted. Antibiotics are only helpful if infection is suspected.Prior to the development of a prodedure known as a sialendoscopy, the treatment of salivary gland stones was to excise the gland. This required an incision on the neck or face with risk to several important nerves and loss of the gland as a source of saliva. This may still be necessary in some patients who have very large or multiple stones that may not be able to be removed with sialendoscopy. For most stones, sialendoscopy is currently the preferred treatment.