Salivary gland diseases (SGD) are multiple and varied in cause.There are three paired major salivary glands in humans – (the parotid glands, the submandibular glands, and the sublingual glands), and about 800-1000 minor salivary glands in the mucosa of the mouth. The parotid gland is located in front of the ear, and it secretes its mostly serous saliva via the parotid duct (Stenson duct) into the mouth, usually opening roughly opposite the maxillary second molar. [Source: Wikipedia 
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