The submandibular gland is located in the submandibular triangle, and its saliva is secreted and transported to the oral cavity through the submandibular duct, which opens in the sublingual caruncle (the mucosa of the floor of the mouth on the side of the mandibular anterior teeth). Since: 1. the submaxillary gland ducts travel from bottom to top, saliva flows against the direction of gravity, and the ducts are curved, minerals are easily deposited here; 2. the ducts travel longer routes; 3. saliva contains high calcium content and combines with bicarbonate ions to form calcium carbonate; 4. the opening of the ducts is located at the floor of the mouth, foreign bodies and tiny food residues easily enter the mouth of the ducts and form calcified centers of stones in the ducts. Stone obstruction can cause secondary infection of the gland. Smaller submandibular duct stones can be treated conservatively by taking vitamin C and eating more acidic fruits or foods to promote the secretion of saliva to facilitate the discharge of small stones. If the stones are large, the secretion function of the gland exists, and there is no history of recurrent infection, surgery can be considered to remove the stones, and vitamin C can be taken after surgery to promote saliva secretion to keep the ducts open. For those who have inflammatory changes in the gland with repeated infections and no longer have a secretory function, removal of the submandibular gland can be considered.