The salivary glands make saliva and release it into the mouth.
There are three pairs of relatively large, major salivary glands:
Parotid glands. Located in the upper part of each cheek, close to the ear. The duct of each parotid gland empties onto the inside of the cheek, near the molars of the upper jaw.
Submandibular glands. Under the jaw. They have ducts that empty behind the lower front teeth.
Sublingual glands. Beneath the tongue. They have ducts that empty onto the floor of the mouth.
In addition to these major glands, 600 to 1,000 very tiny, minor salivary glands are scattered throughout the mouth and throat. They are located under the moist skin that lines the:
Back of the throat
Back portion of the tongue
Some of the most common salivary gland disorders include:
Sialolithiasis (salivary gland stones).Tiny, calcium-rich stones sometimes form inside the salivary glands. The exact cause of these stones is unknown. Some stones may be related to:
Dehydration, which thickens the saliva
Decreased food intake, which lowers the demand for saliva
Medications that decrease saliva production, including certain antihistamines, blood pressure drugs and psychiatric medications
Some stones sit inside the gland without causing any symptoms. In other cases, a stone blocks the gland's duct, either partially or completely. When this happens, the gland typically is painful and swollen, and saliva flow is partially or completely blocked. This can be followed by an infection called sialadenitis.
Sialadenitis (infection of a salivary gland). Sialadenitis is a painful infection that usually is caused by bacteria. It is more common among elderly adults with salivary gland stones. Sialadenitis also can occur in infants during the first few weeks of life.
Without proper treatment, sialadenitis can develop into a severe infection, especially in people who are debilitated or elderly.
Viral infections. Systemic (whole-body) viral infections sometimes settle in the salivary glands. This causes facial swelling, pain and difficulty eating. The most common example is mumps.
Cysts (tiny fluid-filled sacs). Babies sometimes are born with cysts in the parotid gland because of problems related to ear development before birth. Later in life, other types of cysts can form in the major or minor salivary glands. They may result from traumatic injuries, infections, or salivary gland stones or tumors.
Benign tumors (noncancerous tumors). Most salivary gland tumors occur in the parotid gland. The majority are benign. The most common type of benign parotid tumor usually appears as a slow-growing, painless lump at the back of the jaw, just below the earlobe. Risk factors include radiation exposure and possibly smoking.
Malignant tumors (cancerous tumors). Salivary gland cancers are rare. They can be more or less aggressive. The only known risk factors for salivary gland cancers are Sjogren's syndrome and exposure to radiation. Smoking also may play some role.
Sjogren's syndrome. Sjogren's syndrome is a chronic autoimmune disorder. The body's immune defenses attack the salivary glands, the lacrimal glands (glands that produce tears), and occasionally the skin's sweat and oil glands.
Most people with this disease are women who first develop symptoms during middle age. In about half of cases, the illness occurs together with rheumatoid arthritis, systemic lupus erythematosus (lupus), scleroderma or polymyositis.
Sialadenosis (nonspecific salivary gland enlargement). Sometimes, the salivary glands become enlarged without evidence of infection, inflammation or tumor. This nonspecific enlargement is called sialadenosis. It most often affects the parotid gland, and its cause remains unknown.