Dental or oral cysts are a fairly common occurrence in the mouth. In addition to cysts that grow along the gum line, they may also grow on the inside of the cheek, the tongue, as well as the floor of the mouth. A cyst is medically defined as a fluid filled sac or pouch, but can also appear as a growth of any kind, including an irregularly shaped patch of skin. Regardless, this should be removed and tested by your oral surgeon to ensure that growth is benign.