A variety of diseases ranging from obstructions, infections, to benign and malignant tumors occur in salivary glands. The most common problem is painful blockage of ducts by stones that prevents drainage of saliva. Sialadenitis can be due to either infectious or noninfectious factors. Bacterial or viral infections are the most common causes of acute sialadenitis. Staphylococcus is the usual bacterial cause, whereas paramyxovirus (mumps) is the common viral cause. Eighty percent of salivary tumors are benign, whereas about 20% are malignant. Most tumors occur in the parotid gland and on the hard palate. Classifications, imaging, and suggested treatment are described.
Key points
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Sialolithiasis is the most common problem in the salivary gland.
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Dry mouth is associated with xerogenic medications, dehydration, exposure to radiation, and smoking.
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Infections are either bacterial or viral.
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Most salivary tumors are benign.
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Several systemic diseases can cause enlargement of salivary glands.
There are 3 pairs of major salivary glands: parotid, submandibular, and sublingual glands and thousands of minor salivary glands dispersed throughout the oral cavity. The parotid is the largest of the major salivary gland and is situated lateral to the ramus of the mandible and anterior to the sternocleidomastoid muscle. This gland is encapsulated and secretes serous saliva. The submandibular glands are the second largest and are located below the angle of the mandible in the submandibular triangle of the neck and makes up part of the floor of the mouth. This gland secretes a mixed serous and mucous saliva. The sublingual glands are the smallest of the major salivary glands and lies below the mucosa of the floor of the mouth above the mylohyoid muscle. Unlike the parotid and the submandibular glands, the sublingual gland is not encapsulated and it is dispersed throughout the sublingual space. The sublingual gland secretes mucous saliva. The minor salivary glands are composed of 800 to 1000 small salivary glands concentrated along the buccal mucosa, labial mucosa, lingual mucosa, soft/hard palate, and floor of mouth. These clusters of glands secrete primarily mucous saliva ( Box 1 ).
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Aids in digestion and taste perception
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Moistens food bolus to assist swallowing
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Lubricate the oral soft tissues to assist the movement against each other and against the teeth.
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Neutralizes bacterial acids by its buffering action.
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Promotes enamel remineralization
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Protects the teeth and the oral mucosa by the presence of immunoglobulin’s tissue repair factors and antibacterial system
Salivary gland diseases
A variety of disease processes, ranging from painful obstructions, infections, to benign and malignant tumors, can occur within the salivary glands. Despite the rarity in which salivary gland diseases are encountered in the practice of general dentistry, it is essential that general dentists be knowledgeable about salivary gland function, abnormalities, and the diseases that can affect these glands. They should be able to recognize and diagnose problems involving the major and minor salivary glands as well as in the management of certain problems such as oral dryness associated with salivary problems and stones and other problems related to the ducts of the glands. This article reviews several important diseases affecting the glands, their clinical presentations, trends in diagnosis, and their general management ( Table 1 ).
| Inflammatory Disorders | |
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| Noninflammatory Enlargement | |
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| Obstructive Disorders | |
| Traumatic |
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| Stones | Mostly submandibular |
| Impaction of foreign body into a duct | |
| Secretory Disorders | |
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| Systemic Diseases | |
| Autoimmune | Sjörgen Mikulicz Sarcoidosis |
| Benign lymphoepithelial lesions Fibrocystic disease (mucoviscidosis) |
Amyloidosis HIV-associated benign lymphoepithelial cysts of the parotid glands Rare |
| Drug and Hypersensitivity Reactions | |
| Clonidine (Catapres) Methyldopa (Aldomet) Tranquilizers Antihistamines Anticholinergics |
Causes a reduction of saliva production or secretion |
| Neoplasms | |
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Clinical examination, laboratory studies, and imaging
A careful history is the first step in the diagnosis of salivary gland conditions ( Table 2 ). Nearly all diseases that affect the salivary glands present as painful or painless swelling of the gland. In addition, there may be dryness of the mouth (xerostomia), as well as local and systemic symptoms of an infection.
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In a lot of cases the clinical examination by itself can provide a diagnosis. A ranula or mucocele is easily identified on clinical examination. Salivary stones and tumors can also usually be visualized and/or palpated and a good educated conditional diagnosis established ( Box 2 ).
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Diseases of the salivary glands can be diagnosed by lumps in the submandibular area, lumps on the side of the face in front of the ear. OR: lumps, ulcers, or fluid-filled sacks inside the mouth.
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With the submandibular gland the most common reason for lumps is stone formation. Tumors are less common.
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Benign salivary gland tumors grow slowly over months or even years.
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Salivary gland tumors occur with a higher incidence in the upper lip than in the lower lip.
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Lower lip masses are most frequently cystic masses.
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Upper lip: tumor
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Lower lip: cyst
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Palate—most common site of intraoral tumor. Pleomorphic adenoma—most common tumor.
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Malignancy should be suspected if the growth has been short or if there is any pain.
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Ulcerations should be considered malignancy until proved otherwise.
Laboratory Studies
For most of the salivary gland diseases, laboratory testing is not indicated. If Sjögren syndrome or sarcoidosis is suspected, however, then antinuclear antibodies, SS-A or SS-B (Sjögren syndrome antibodies to duct epithelium), and angiotensin-converting enzyme levels would be the indicated laboratory tests. The workup of a suspected infection would consist of complete blood count with differential blood count and C-reactive protein. Salivary secretion rate is indicated in the assessment of xerostomia. Fine-needle aspiration biopsy is used to obtain tissue for the histologic diagnosis of neoplasms.
Imaging
Conventional radiography has a very limited role in the diagnosis of salivary gland pathology and is useful only for identifying salivary stones. Intraoral occlusal radiograph is useful in diagnosis and localization of stones in the submandibular duct.
Sialography is used to evaluate the ductal system of salivary glands using a contrast medium injected into the duct. It is useful in the assessment of salivary gland dysfunction secondary to obstructive disorders. Because of the risks in the use of contrast medium, this technique is no longer favored and is contraindicated in acute conditions of salivary glands. Instead of sialography, sialoendoscopy and magnetic resonance Sialography can be used for evaluation of the ductal system of the salivary glands ( Table 3 ).
