Sialolithiasis is a common disease of salivary glands, mainly afflicting the major salivary glands. Characterized by the obstruction of the salivary secretion by a calculus, its main symptoms are recurrent swelling and pain, and may be aggravated during eating. Owing to the rapid developments in endoscopic techniques, it is now possible to perform diagnostic and interventional procedures directly within the salivary ductal system with less invasiveness. The etiology of these calculi and the exact mechanism of formation, however, are unclear. Sialoliths are composed of a central mineralized core and laminar layers of organic and inorganic substances. Irritant factors trigger a response and cause spasmodic contraction of the canal and stasis of saliva and then lead to the development of calculus. During the development of sialoliths, multi-factorial events can be involved, including secretory disturbances（microlith formation, ductal obstruction and anatomical abnormity） and influence of saliva（high calcium affinity, decreased concentration of crystallisation inhibitors, influence of pH, diversification of bacteria and components of protease）.
