A salivary gland stone -- also called salivary duct stone -- is a calcified structure that may form inside a salivary gland or duct. It can block the flow of saliva into the mouth.
The majority of stones affect the submandibular glands located at the floor of the mouth. Less commonly, the stones affect the parotid glands, located on the inside of the cheeks, or the sublingual glands, which are under the tongue. Many people with the condition have multiple stones.