Salivary Gland Diseases and Surgery

Saliva is the secretion that carries out the part of digestion that takes place in the mouth. Saliva is secreted by the glands under the jaw (submandibular), in front of the ear (parotid) and under the tongue (sublingual). There are also thousands of tiny microscopic glands inside the mouth and throat. Saliva keeps the mouth moist, has a disinfecting effect against germs and contains proteins called enzymes that aid digestion. The glands produce between 0.5 and 1.5 liters of saliva per day and release it into the mouth.

Diseases of the salivary glands can be classified as follows:

• Viral infections of the salivary glands
• Bacterial infections of the salivary glands
• Salivary gland stones (sialolithiasis)
• Dry mouth and Sjögren’s syndrome
• Benign tumors
• Malignant tumors
• Salivary gland enlargement

Viral infections

Mumps is the most common. This disease, which affects the parotid gland located in front of and below the ear, is usually seen in children aged 4–6. The virus, spread through the air, causes pain, swelling, tenderness below the ears on both sides and fever 14–21 days after entering the body. It is highly contagious. Difficulty opening the mouth may develop due to spasm of the muscles around the parotid gland. The diagnosis is made based on the history and detection of antibodies against the mumps virus in the blood. No specific treatment is required; rest, fluid intake and fever-reducing, pain-relieving medications are usually sufficient.

Rarely, complications may develop if the virus affects the brain, kidneys, inner ear or testicles. In this case, specific treatment for the affected organ may be needed. Since the introduction of the mumps vaccine, the incidence has decreased considerably.

Bacterial infections

This condition, which most often affects the parotid gland, presents with sudden pain, swelling, skin redness and tenderness in front of and below the ear. It is usually seen in people who do not drink enough fluids, older adults, people with weakened immune systems and often in the postoperative period when inpatient treatment is needed. On examination, pus is seen draining from the openings of the salivary gland ducts inside the mouth. If treatment is delayed, abscess formation or the spread of infection can lead to a life-threatening infection, especially in older patients. Treatment is with antibiotics selected according to a culture taken from the salivary duct and, if necessary, abscess drainage.

Salivary Gland Stones (Sialolithiasis)

This is a progressive inflammatory condition that usually results from reduced saliva production and the buildup of thick secretions in the salivary ducts. Slowed secretion allows bacteria normally found in the mouth to spread through the duct toward the salivary gland. Chronic inflammation changes the structure of the salivary duct and the nature of the secretion, causing the problem to become permanent over time. Stones that remain in the duct for a long time can also cause this problem. Recurrent acute infections, weakened immune defenses, radiation therapy, smoking and poor oral hygiene can predispose to this disease.

The most notable complaint is painful swelling that increases especially during meals; there are usually no signs of acute inflammation such as fever or redness. Treatment includes increasing fluid intake, massage to help the secretions drain, antibiotics during acute flare-ups and surgical removal of the salivary gland.

Dry Mouth (Xerostomia)

Dry mouth can also cause problems such as a weakened sense of taste, difficulty swallowing, pain and tooth decay. This problem, which can be seen in parotid gland diseases, can also be caused by factors such as stress, diabetes, chronic inflammation and radiation therapy. Dryness of the mouth and mucous membranes is also seen in Sjögren’s syndrome, which results in reduced secretion from all the glands in the body. Treatment includes treating the underlying disease, increasing fluid intake, medications that stimulate saliva production and artificial saliva.

Benign Tumors of the Salivary Glands

70–80% of salivary gland tumors arise from the parotid gland, and 90% of parotid tumors are benign. In contrast, tumors are seen in the submandibular gland at a rate of 15%, with a benign rate of 50–60%; tumors occur in the sublingual and minor salivary glands at a rate of about 10%, and 35% of these tumors are benign.

Salivary gland tumors usually appear as slow-growing masses between the ages of 50 and 70. In addition to examination and imaging, fine-needle biopsy plays an important role in diagnosis. Needle biopsy distinguishes whether the tumor is benign or malignant, and the treatment plan is shaped accordingly. Ultrasound, CT and MRI are also used for diagnosis.

Most benign salivary gland tumors are a type called mixed tumor or pleomorphic adenoma, which is more common between the ages of 30 and 60 and in women. In general, surgical treatment is used for all benign tumors.

Malignant Tumors of the Salivary Glands

Malignant salivary gland tumors make up 3–4% of malignant tumors in the head and neck region. Malignant salivary gland tumors occur most often in the parotid gland (75–80%), in the submandibular gland in 15–20% of cases and rarely in the sublingual or minor glands.

Surgery is the first option in the treatment of malignant salivary gland tumors. During surgery, the tumor must be removed widely, along with a margin of surrounding normal tissue into which the tumor has not spread. As long as they are not involved by the tumor, important nerves passing through the surgical area, such as the facial nerve and the nerve that provides sensation to the tongue, should be preserved. In tumors with confirmed spread to the lymph nodes in the neck, and in tumors with a high risk of spreading to the neck lymph nodes even without obvious involvement, the nearby lymph nodes are also removed during surgery (neck dissection). Radiation therapy may rarely be chosen as the primary treatment for small tumors. In large tumors with a high risk of spread, radiation therapy is given to the surgical area after surgery to prevent the tumor from recurring in the same area.

In patients who are not suitable for surgery due to other health problems and in patients whose tumor has spread extensively in the region and/or metastasized to distant sites, drug therapy (chemotherapy) may be preferred.

Submandibular salivary gland surgery

The surgery is performed under general anesthesia. It takes about one hour. It is performed for chronic inflammation, stones in the duct, and benign and malignant tumors. It is done through a 4–5 cm incision under the jaw, parallel to the bone. In about 5% of patients, temporary or permanent impairment of lower lip movement may occur.

Parotid gland surgery

It is performed under general anesthesia. It is used for benign and malignant tumors. During this surgery, the salivary gland containing the tumor is removed as a whole. An important feature of the parotid gland is that the facial nerve, which moves the muscles of the face, passes through it. The part of the gland lying above the nerve and its branches is called the superficial lobe, and the part below it is called the deep lobe. In benign parotid tumors, if the deep lobe is not involved by the tumor, only the superficial lobe is removed. In benign tumors, permanent movement impairment may occur in 1–4% of patients. To prevent this, the surgeon must be experienced, the location and pathology of the tumor must be known, and a microscope and nerve stimulation devices (facial nerve stimulator) must be used.