Parotitis is inflammation of the parotid gland caused by infection (viral or bacterial), Parotitis presents in many forms and the symptoms vary from modest to prostrating.  Parotitis can be unilateral or bilateral, acute or chronic. Parotitis is now more common in elderly patients because many take medications with an atropine effect that retards salivary flow and predisposes to ascending infection.

 Dry mouth, drooling, swelling, and pain are essentially the only symptoms caused by dysfunction of the salivary glands. The major salivary glands and their ducts are strategically situated on either side of the dental occlusal planes to irrigate and saturate a food bolus with saliva during chewing. Inflammatory swelling of the glands may present a serious diagnostic challenge.  

Mumps, one of the classic childhood infections.  Mumps is an extremely contagious viral infection of the salivary glands that most commonly affects children.  The virus travels from the respiratory tract to the salivary glands and reproduces, causing swelling of one or both of the salivary glands on the sides of the face .