Salivary Gland Disorders
Saliva is the watery fluid in your mouth that helps you chew and digest food, protects your teeth, and keeps the lining of your mouth healthy. This fluid is produced by the major and minor salivary glands. There are three pairs of major salivary glands located in and adjacent to the mouth:
- Parotid Glands,
- Submandibular Glands,
- Sublingual Glands.
The Parotid glands are the largest salivary glands in the body and are found on the side of the face. The Submandibular glands are located under the mandible (jawbone). The Sublingual glands, the smallest of the major salivary glands, are located in the floor of the mouth, under the tongue.
A number of disorders may affect the major salivary glands, including infection/inflammation (sialadenitis), tumours, and generalised painless enlargement (sialadenosis).
Sialadenitis (Infection & Inflammation)
The most common salivary gland disorder is a painful enlargement of a gland caused by infection and inflammation. This is called sialadenitis. This inflammation is usually caused by blockage of the duct that drains saliva from the affected gland. This blockage may be caused by a narrowing of the duct (a stricture), or by a stone (also called a calculus) that may form in the duct. If the duct is blocked the gland cannot discharge the saliva it is making into the mouth, and the gland swells up. A secondary bacterial infection may then occur.
These episodes of infection and inflammation are usually treated with antibiotics and pain relief. It is also important to maintain good hydration (drink plenty of water), to massage the gland (to encourage salivary flow into the mouth), and to use sialogogues, which are substances that increase salivary flow to flush the duct clear. Useful sialogogues include citrus flavoured sweets - preferable sugar free.
If infections become a recurrent problem further investigations may be required, such as an ultrasound scan, a CT scan, a sialogram (an x-ray of the ductal system of a gland obtained by injecting a special dye into the duct opening) or an MR sialogram (a non-invasive scan of the ductal system of a gland).
Occasionally a surgical procedure may be required to prevent recurrent infections. The types of surgery used include:
- Removal of a stone
- Ductal dilation
- Removal of the affected gland (Parotidectomy, Submandibualr Gland Excision, Sublingual Gland Excision)
Any salivary gland (major or minor) may develop a tumour, that is usually noticed as a localised lump within the gland. Salivary gland tumours occur most commonly in the parotid gland. The majority of tumours within the parotid gland are benign, and most of these are of one particular type: a pleomorphic adenoma. Salivary glands may also develop malignant tumours (cancers), and so it is important to have all salivary glands lumps evaluated thoroughly. The investigations used most often for salivary gland tumours are a fine needle aspirate (FNA) of the lump, and imaging, such as an ultrasound scan or a CT scan.
The treatment for a salivary gland tumour is removal of part or all of the affected gland: either a Parotidectomy, Excision of the Submandibular Gland, or Excision of the Sublingual Gland. Sometimes additional surgery, such as a Neck Dissection, is performed at the same time if the tumour is a cancer.
Sialadenosis is the generalised enlargement of a major salivary gland, without any infection, inflammation or tumour present. The parotid glands are the salivary glands most commonly affected by this disorder. This enlargement is not usually painful, which differentiates it from swelling cause by infection or inflammation.
There are many causes of sialadenosis including:
- Diabetes mellitus
- High alcohol intake
- Nutritional disorders
- Vitamin deficiencies
The investigations for sialdenosis include blood tests, imaging (an ultrasound scan or CT scan), and occasionally a biopsy is required. It is important to determine whether or not there is an underlying nutritional or metabolic disorder that needs to be treated. For mild sialadenosis no specific treatment of the gland is required, however if the enlargement is severe and is causing cosmetic concerns, part or all of the affected gland(s) may be removed.