Salivary Gland Disorders

Geriatric Essentials

• Saliva production does not decrease because of aging itself and should be evaluated for treatable causes.

Saliva helps digest food; helps form and move food boluses; aids chewing, swallowing, and speech; and protects against infection and dental caries. It also contains antimicrobial proteins that control bacterial, fungal, and viral growth; buffers acids produced by bacteria; cleans the mouth after eating; and helps in taste and denture retention. The number of acinar cells in salivary glands decreases with aging, but saliva production does not decline.

Most salivary gland disorders cause a range of oral and pharyngeal conditions; these conditions manifest as dry mouth (xerostomia). Major causes in the elderly are systemic physical disorders, drugs, radiotherapy, and local (eg, oral, head, and neck) tumors or obstructions. Specific disorders include dehydration, Sjögren's syndrome, and diabetes mellitus. Alzheimer's disease, sarcoidosis, and AIDS also may impair salivary gland function; in Alzheimer's disease, cortical destruction may affect both global cognition and efferent stimuli for salivary secretion. Drugs are the most common cause of dry mouth in the elderly, especially drugs with anticholinergic or diuretic properties (see Table 104-1). Other medical treatments, such as external beam radiation therapy (see Photo 104-21) or chemotherapy for head and neck cancer, cause salivary hypofunction. Oral, head, and neck causes of salivary hypofunction include duct obstructions (eg, sialoliths, mucoceles), infections (eg, acute or chronic viral or bacterial sialadenitis), and tumors (eg, pleomorphic adenomas, adenoid cystic carcinomas, adenocarcinomas, acinic cell carcinomas).

Patients who experience xerostomia when salivary gland function is normal may have defective oral sensory receptors or impaired cognition.

Symptoms and Signs

Although many elderly patients report mild xerostomia, patients with true salivary gland disorders have difficulty swallowing dry foods and require fluids for swallowing; their lips and mouth are dry during eating and speaking. Signs include an unexpected recent increase in dental caries; the presence of oral fungal infections; and desiccated, ulcerated, erythematous, or furrowed lips and intraoral mucosa. However, the mucosa may appear normal even when the glands are dysfunctional.

Diagnosis

Salivary gland examination involves palpating the face under the mandible (submandibular glands) and anterior to the ear (parotid gland) for detection of enlarged, painful, or tender glands, which may be signs of obstruction, tumor, infection, or Sjögren's syndrome. Inside the mouth, palpation of the submandibular gland orifices (anterior to the base of the tongue in the floor of the mouth) and parotid gland orifices (buccal mucosa adjacent to the maxillary first molar) is required to determine patency. If no saliva appears, salivary hypofunction is likely. Suppuration from the gland orifice indicates acute or chronic inflammation of the salivary gland (sialadenitis), and a specimen should be sent for culture and sensitivity testing (Staphylococcus aureus is the most common bacterial cause). Fever and swelling, pain, or erythema over the affected gland suggests sialadenitis.

Retrograde sialography is particularly useful when an inflammatory disorder or obstruction is suspected. Technetium-99m pertechnetate scintigraphy can determine whether acinar parenchymal tissues are functional and whether saliva production is impaired. CT and MRI of the major salivary glands can detect inflammatory disorders, obstructions, and tumors.

If Sjögren's syndrome is suspected, the minor labial salivary glands are biopsied (usually by an oral and maxillofacial surgeon or oral medicine/pathology specialist), and lacrimal gland function is evaluated. Many patients have one or more abnormal autoimmune markers (particularly anti-SS-A, anti-SS-B, and antinuclear antibodies and rheumatoid factor).

Treatment

Primary treatment is tailored to the underlying condition when the condition is reversible. Treatment of sialadenitis is rehydration and antibiotics (typically amoxicillin [with or without clavulanic acid] 500 mg po tid for 10 days, depending on culture and sensitivity test results). Abscesses require surgical drainage. Sialoliths and benign and malignant tumors must be surgically removed.

Secondary treatment is stimulation or replacement of salivary gland function. If there is evidence that some secretory function remains (ie, saliva is expressed when salivary gland orifices are palpated), the glands can be stimulated with sialogogues (eg, sugarfree hard candies, mints, gum). Alternatives include pilocarpine (5 mg po tid or qid, last dose at bedtime) and cevimeline (30 mg po tid), but these drugs should be avoided in patients with heart failure, asthma, COPD, cholelithiasis, biliary tract disease, or angle-closure glaucoma. Adverse effects of these drugs can include diaphoresis, nausea, and polyuria. Patients with minimal or no residual secretory function require saliva substitutes, which can control hard-tissue (eg, dental caries) but not soft-tissue (eg, ulcers, fissured tongue, oral yeast infections) complications, which are treated symptomatically with analgesic and antimicrobial elixirs or mouth rinses.

All patients with significant chronic salivary gland dysfunction require frequent, comprehensive, preventive dental care.

Salivary Gland Cancer

(See also the National Cancer Institute's summaries of evidence for screening, prevention, and general summary on treatment of lip and oral cavity cancer.)

Most salivary gland tumors are benign and involve the parotid gland; 80% of these are pleomorphic adenomas. Pleomorphic adenomas tend to be unilateral and most commonly manifest as an asymptomatic mass in the tail of the parotid gland. They are slow growing, well delineated, and encapsulated.

Malignant salivary gland tumor incidence increases with aging. The tumors are most common in the submandibular and sublingual glands; they may also occur on the palate and the upper lip. Mucoepidermoid carcinoma is the most common malignant salivary gland tumor, followed by adenoid cystic carcinoma, acinic cell carcinoma, and adenocarcinoma. Adenoid cystic carcinomas are aggressive tumors that undergo perineural invasion. Patients with these tumors have good 10-yr survival rates. Symptoms and signs of a malignant salivary gland tumor include swelling (see Photo 104-22) with facial nerve paralysis, pain, or facial paresis. Diagnosis is by biopsy, with head and neck images (eg, CT, MRI) to determine the extent of the tumor and any evidence of lymphatic spread. Treatment is surgery with postoperative external beam radiation therapy. Close follow-up with oncologic surgeons, radiation oncologists, and dentists is required to monitor tumor recurrence and to prevent and initiate early therapy for the oral consequences of surgery and radiation.

This topic was last updated September 2005.