Salivary gland diseases 5th Class Oral Medicine Lec 6 Dr. Jamal al dewan BDS , Diploma (oral diagnosis),MSc (oral med.) Saliva is a watery substance formed in the mouths of animals, secreted by the salivary glands. Human saliva comprises 99.5% mostly water, plus electrolytes, mucus, white blood cells, epithelial cells (which can be used to extract DNA), glycoproteins, enzymes (such as amylase and lipase), antimicrobial agents such as secretory IgA and lysozyme. The enzymes found in saliva are essential in beginning the process of digestion of dietary starches and fats. The amount of saliva that is produced in a healthy person per day; estimates range from 0.75 to 1.5 litres per day while it is generally accepted that during sleep the amount drops to nearly zero. In humans, the submandibular gland contributes around 70– 75% of secretion, while the parotid gland secretes about 20– 25% and small amounts are secreted from the other salivary glands. Functions of saliva ???? • Parotid saliva is pure serous and secreted through Stensen’s ducts, the orifices of which are visible on the buccal mucosa in the vicinity of the maxillary first or second molar. • Submandibular gland saliva is mix of mucous and serous types and secreted through the submandibular duct (Wharton’s duct), which exits at side of the lingual frenulum. • sublingual gland saliva is primarily mucous and may enter the floor of the mouth directly via the short, independent ducts of Rivinus. One or more of these ductules may converge to form the major duct also known as Bartholin’s duct, which opens into or near the submandibular duct. Investigations for salivary glands 1-Sialometry: is the collection and measurement of the amount of saliva produced in a certain time. 2-Sialochemistry: examination of the composition of the saliva like electrolytes and enzymes. 3- Imaging • Plain Film Radiography like panoramic or lateral oblique and occlusal projections. • Ultrasonography • CT scan and MRI. • Sialography: using iodine containing contrast media which introduced through the salivary gland duct followed by multiple x-ray views. • Scintigraphy: by using radioactive isotopes(Technetium ) to demonstrate the salivary gland function and to determine abnormalities in gland uptake and excretion. Sialoliths (also termed salivary calculi or salivary stones) • typically calcified masses that form within the secretory system of the major salivary glands. • composed of organic and inorganic substances including calcium and phosphates, cellular debris, glycoproteins, and mucopolysaccharides. • Although the exact mechanism of sialolith formation has not been proven but there are etiologic factors favoring salivary stone formation • irregularities in the duct system, • local inflammation, • dehydration, • medications such as anticholinergics and diuretics • calcium saturation The higher rate of sialolith formation in the submandibular gland is due to • (1) the torturous course of Wharton’s duct, • (2) the higher calcium and phosphate levels of the secretion • (3) the increased mucoid nature of the secretion Clinical Presentation • Patients with sialoliths most commonly present with a history of acute, periprandial pain and intermittent swelling of the affected major salivary gland. • If there is concurrent infection, there may be expressible suppurative or nonsuppurative drainage and erythema or warmth in the overlying skin. The patient may complain from systemic manifestations such as fever Treatment • During the acute phase of sialolithiasis, therapy is primarily supportive. • Stones at or near the orifice of the duct can often be removed by milking the gland, but deeper stones require intervention with conventional surgery. Mucocele • Mucocele is a clinical term that describes swelling caused by the accumulation of saliva at the site of a traumatized or obstructed minor salivary gland duct. • Mucoceles can be classified histologically as extravasation types or retention types. Clinical Presentation • Mucoceles often present as discrete, painless, smooth-surfaced swellings that can range from a few millimeters to a few centimeters in diameter. Superficial lesions frequently have a characteristic blue hue. • Deeper lesions can be more diffuse, covered by normal-appearing mucosa. • The lesions vary in size over time; and frequently traumatized, causing them to drain and deflate. • Extravasation mucoceles most frequently occur on the lower lip, followed by buccal mucosa, tongue, floor of the mouth, and retromolar region while mucous retention cysts are more commonly found on the upper lip, palate, buccal mucosa, floor of the mouth Treatment • Conventional definitive surgical treatment of mucoceles involves removal of the entire lesion along with the feeder salivary glands and duct. • Alternative treatments that have been explored with varying degrees of success include cryosurgery and laser surgery. Ranula • A form of mucocele located in the floor of the mouth is known as a Ranulas are believed to arise from the sublingual gland usually following mechanical trauma to its ducts of Rivinus, resulting in extravasation of saliva. • Other possible causes include an obstructed salivary duct or a ductal aneurysm. Clinical Presentation • It is presented as painless, slow-growing, fluctuant, movable mass located in the floor of the mouth. • Usually, the lesion forms to one side of the lingual frenulum; however, if the lesion extends deep into the soft tissue, it can cross the midline. • The superficial ranulas can have a typical bluish hue, but when the lesion is deeply seated, the overlying mucosa may have a normal appearance. The size of • the lesions can vary, and larger lesions can cause deviation of the tongue. In a “plunging” ranula, the swelling may observed extraorally. treatment • The most predictable method of eradicating both oral and plunging ranulas is to remove the associated sublingual gland because this will almost certainly eliminate recurrences Necrotizing Sialometaplasia • Necrotizing sialometaplasia is a benign, selflimiting, reactive inflammatory disorder of salivary tissue. • Clinically and histopathologically, NS can resemble a malignancy and its misdiagnosis has resulted in unnecessary radical surgery. • The etiology is unknown, although it likely represents a local ischemic event, infectious process, or perhaps an immune response to an unknown allergen. • Development of NS has been associated with: • smoking • trauma • denture wear • surgical procedures. Clinical Presentation • The incidence of NS appears to be higher in male patients and especially in those older than 40 years • Most commonly it presents as a painful, rapidly progressing swelling usually unilateral of the hard palate with central ulceration and peripheral erythema. • Numbness or\ anesthesia in the associated area may be an early finding. • The lesions are typically of rapid onset and range in size from 1 to 3 cm. Diagnosis • Histopathologic diagnosis is warranted to rule out a malignant process, biopsy specimens should be submitted to a pathologist with extensive training in oral and maxillofacial pathology. Treatment • NS is considered a self-limiting condition typically resolving within 3–12 weeks. • During this time, supportive and symptomatic treatment is usually adequate.