There are three major pairs of salivary glands in the mouth. The largest pair of salivary glands, called the parotid glands, lies just behind the angle of the jaw, below and in front of the ears. Two smaller pairs, the sublingual glands and the submandibular glands, lie deep in the floor of the mouth and under the jaw. In addition to these major glands, many tiny salivary glands are distributed throughout the mouth. All of the glands produce saliva, which aids in breaking down food as part of the digestive process.
There are four basic things that can cause your glands to swell:
- OBSTRUCTION: A blockage of saliva most commonly occurs in the parotid and submandibular glands, often due to stone formation. Symptoms typically occur when eating. Saliva production is started, but the saliva cannot flow into the mouth, leading to swelling of the involved gland and significant pain, sometimes with an infection.
- INFLAMMATION: In some individuals, the duct system of the major salivary glands may be abnormal (possibly from repeatedly passing stones) . These ducts can develop small constrictions that reduce salivary flow, leading to infection and obstructive symptoms.
- INFECTION: The most common salivary gland infection is mumps, which involves the parotid glands. While this is most common in children, it can occur in adults. However if an adult has swelling or infection in a salivary gland on one side, it is more likely due to an obstruction or a tumor.
Infections also occur because of ductal obstruction or sluggish flow of saliva because the mouth has abundant bacteria.
You may have a secondary infection of salivary glands from nearby lymph nodes. These lymph nodes are the “glands” in the upper neck that often become tender during a common sore throat. In fact, many of these lymph nodes are actually located on, within, and deep in the substance of the parotid gland or near the submandibular glands. When these lymph nodes enlarge through infection, you may have a red, painful swelling in the area of the parotid or submandibular glands. Lymph nodes also enlarge due to tumors and inflammation.
- TUMORS: Primary benign and malignant salivary gland tumors usually show up as painless enlargements of these glands. Tumors rarely involve more than one gland and are detected as a growth in the parotid, submandibular area, on the palate, floor of mouth, cheeks, or lips. These enlargements should be checked by an otolaryngologist-head and neck surgeon.
Malignant tumors of the major salivary glands can grow quickly, can be painful, and can cause loss of movement of part or all of the affected side of the face. These symptoms should be immediately investigated.
- OTHER: Salivary gland enlargement is also seen in autoimmune diseases, which cause significant inflammation. Patients often have a dry mouth or dry eyes. This may occur with other systemic diseases such as rheumatoid arthritis. Diabetes may also cause enlargement of the salivary glands, especially the parotid glands. Salivary gland swelling (usually on both sides) is also seen in alcoholism. Cysts in the salivary glands are often caused by viral infections.
Evaluation for swelling of the salivary glands:
The diagnosis of salivary gland disease depends upon a careful history, a physical examination, and if necessary, laboratory tests and imaging studies. If a mass is found in the salivary gland, it is helpful to obtain a CT scan or MRI. The study will show whether the mass is an actual part of a salivary gland, or an associated lymph node. A needle biopsy (FNA) can also assist in determining the origin of the mass.
Treatment for swelling of the salivary glands:
Treatment of salivary diseases is broadly classified into two categories: medical and surgical. Selection of treatment depends upon the nature of the problem. If it is due to a systemic disease (diseases that involve the whole body, not one isolated area), then the underlying problem or process must be treated. This may require consultation with other specialists. If the disease process relates to salivary gland obstruction and subsequent infection, antibiotics are used. Sometimes dilation of the ducts will be needed and occasionally surgery must be done for cases where stones have caused an obstruction.
If a mass has developed within the salivary gland, removal of the mass may be required. Most masses in the parotid gland area are benign. When surgery is necessary, great care must be taken to avoid damage to the facial nerve which lies within this gland. When a malignant mass are present in the parotid gland, it may be possible to surgically remove this and preserve most of the facial nerve.
In summary, salivary gland diseases are due to many different causes. These diseases are treated both medically and surgically. Such treatment is readily managed by an otolaryngologist-head and neck surgeon with experience in this area.