In Sialdenitis a salivary stone obstructing the duct of the gland must be excluded as a possible cause.
A so-called Sialolith refers to a concretion in the area of the salivary glands and their salivary ducts respectively. Chemically these stones consist of phosphate- or carbonatesalts of calcium as well as other parts of the saliva, for example glycosaminoglycans. In rare cases foreign material can act as a salivary stone.
When salivary stones obstruct the salivary duct they cause Sialolithiasis.
Relevant fotograph: Salivary Stone of submandibular gland