Dental diagnosticians have responsibility for detecting disorders of the salivary glands

A familiarity with salivary gland disorders and

applicable current imaging techniques is an essential element of the clinician ’ s armamentarium .

inflammatory disordersInflmmatory disorders are acute or chronic and may be secondary to

ductal obstruction by sialoliths, trauma, infection, or space-occupying lesions such as neoplasia.

Non – inflammatory disorders are metabolic and secretory abnormalities associated with diseases of

nearly all the endocrine glands, malnutrition, and neurologic disorders.

space-occupying masses.

are cystic or neoplastic; the neoplasms are benign or malignant.

Clinical Signs and Symptoms

Disease of major salivary glands may have single or multiple feature :-

A. Swelling in the area of parotid and submandibular gland

B. Pain and altered salivary flow

C. The periodicity and longevity of these symptoms

D. a review of the medical history and physical

condition of the patient may provide important information.

BILATERALUNILATERAL

Bacterial sialadenitis Viral sialadenitis (mumps) Sjögren syndromeAlcoholic hypertrophyMedication-induced hypertrophy (iodine, heavy metals) Human immunodefi ciencyvirus – associated multicentriccystsMasseter muscle hypertrophy Accessory salivary glands Temporomandibular joint –

Bacterial sialadenitis Sialodochitis Cyst Benign neoplasmMalignant neoplasm Intraglandular lymph nodeMasseter muscle hypertrophy Lesions of adjacent osseous structures

BILATERALUILATERAL

Bacterial sialadenitis Sjögren syndrome Lymphadenitis Branchial cleft cyst Submandibularspace infection

Bacterial sialadenitis Sialodochitis Fibrosis Cyst Benign neoplasmMalignant neoplasm

Diagnostic imaging of salivary gland disease may be undertaken to differentiate inflammatory processes from neoplastic disease .

diffuse disease from focal suppurative disease, identify and localize sialoliths, and demonstrate ductal morphology anddetermine the anatomic location of a tumor, in addition , differentiate benign from malignant tumor .

Plain film radiography is a fundamental part of the examination of the salivary glands and may provide sufficient information to preclude

the use of more sophisticated and expensive imaging techniques .

It has the potential to identify unrelated pathosesin the areas of the salivary glands that may be mistakenly identified as salivary gland disease, such as resorptive or osteoblastic changes in adjacent bone .

PLAIN FILM RADIOGRAPHY

Panoramic and conventional posteroanterior (PA) skull radiographs may demonstrate bony lesions, thus eliminating salivary pathosisfrom the differential diagnosis.

Unilateral or bilateral functional or congenital hypertrophy of the masseter muscle may clinically mimic a salivary tumor. A plain film extraoral radiograph may demonstrate a deep antegonial notch, overdeveloped mandibular angle, and exostosis on the outer surface of the angle in cases of masseter hypertrophy.

Plain film radiographs are useful when the clinical impression, supported by a compatible history, suggests the presence of

sialoliths (stones or calculi).

Sialoliths in the anterior two thirds of the submandibular duct are typically imaged with a cross-sectional mandibular occlusalprojection

The posterior part of the duct is demonstrated with an over-the-shoulder occlusal projection view, where the directing cone is placed on the shoulder and central

ray directed in an anterior direction through the angle of the mandible, with the patient ’ s head tilted to the unaffected side and rotated back .

Parotid sialoliths are more difficult to demonstrate than the submandibular variety as a result of the tortuous course of Stensenduct around the anterior border of the masseter and through the buccinator muscle. As a rule, only sialoliths anterior to the massetermuscle

can be imaged on an intraoral film.

Underexposed mandibular occlusalradiograph demonstrating radiopaque

sialolith inWharton duct. Note the classic

laminated appearance.

.

Periapical radiographs of the same case. Theradiopaque calculus can be localized lingual to the teeth by applying appropriate object localization

rules

An axial bone algorithm CT image showing a sialolith in the

submandibular duct (arrow).

A panoramic projection frequently demonstrates sialoliths in the posterior duct or reveals intraglandular sialoliths in the submandibulargland.

The image of most parotid sialoliths is superimposed over the ramus and body of the mandible .

To demonstrate sialoliths in the submandibulargland, the lateral projection is modified by opening the mouth, extending the chin, and depressing the tongue with the index finger.

Sialoliths in the distal portion of Stensen duct or in the parotid gland are difficult to demonstrate by intraoral or lateral extraoralviews. However, a PA skull projection with the cheeks puffed out may move the image of the sialolith free of the bone .

Anteroposterior skull view with cheek blownout to provide air contrast to reveal a parotid

sialolith (arrow).

First performed in 1902, sialography is a radiographic technique where a radiopaque contrast agent is infused into the ductal system of a salivary gland before imaging with plain films, fluoroscopy, panoramic radiography, conventional tomography, or CT. Sialography remains the most detailed way to image the ductal system .

The parotid and submandibular glands are more readily studied with this technique. A survey or “ scout” film is usually made before the infusion of the

contrast solution into the ductal system.With this technique, Lipid-soluble (e.g., Ethiodol) or non –Lipid-soluble (e.g.,

Sinografi n) contrast solution is then slowly infuseduntil the patient feels discomfort (usually between 0.2 and 1.5 ml).

These iodine-containing agents render the ductal system radiopaque, The image of the ductal system appears as “ tree limbs, ” with no area of the gland devoid of ducts. With acinar filling, the “ tree ” comes into “ bloom, ” which is the typical appearance of the parenchymal opacification phase .

Non – lipid-soluble contrast agents are preferred because of reports of inflammatory reactions subsequent to inadvertent extravasationof lipid-soluble agents .

Sialography is indicated for the evaluation of chronic inflammatorydiseases and ductal pathoses. Contraindications include acuteinfection, known sensitivity to iodine-containing compounds, and immediately anticipated thyroid function tests.

A, Lateral projection of the parotid demonstrating opacification all the way to the terminal ducts and acini. B, Anteroposterior projection of the same gland demonstrating“ parenchymal blushing ” from acinar opacification.

Sialogram of Normal Submandibular Gland. This lateralview demonstrates parenchymal blushing. Normal fine branching

isvisible. Lack of parenchymal blushing at the anteroinferior

margin iscaused by radiographic burnout.

CT is useful in evaluating structures in and adjacent to salivary glands; it displays both soft and hard tissues and minute differences in soft tissue densities .

CT is useful in assessing acute inflammatory processes and abscesses as well as cysts, mucoceles, and neoplasia. Calcifications such as sialoliths are also well depicted with CT.

•CT Images with Soft Tissue Algorithm. A, Axial viewdemonstrating bilateral enlargement of the parotid glands (arrowheads).

B, Coronal view of the same patient. The clinical/histopathologic

diagnosis was

•autoimmune parotitis.

MRI for soft tissue mass details and localization

Differanciates :

St vs. Ht

Normal vs. abnormal tissue

Identifies facial nerve ( parotid )

Containdications:

-pacemaker

-cochlear implant

These magnetic resonance images reveal a lymphoepithelial cyst involving the right

parotid gland. This axial T1-weighted image reveals a well-defined circular lesion involving the right

parotid gland with an internal signal isointense to muscle, and the matching T2-weighted image

reveals that the lesion has a high internal signal because of the fluid

content

SCINTIGRAPHY (NUCLEAR MEDICINE, POSITRON

EMISSION COMPUTED TOMOGRAPHY)

Selective up take of techntium

Assesees silvary gland function (not anatomy)

Expel technetium after stimulations

Scintigraphy. A, 99m Tc-pertechnetatescan of the salivary glands (right and left anterioroblique views) demonstrates increased uptake ofradioisotope in the right parotid gland (blackarrowhead). B, Scintigram taken after administrationof a sialogog (lemon juice) demonstratesretention of isotope in right parotid gland (whitearrowheads). This is a typical presentation of salivarystasis, Warthin tumor, or oncocytoma.

ULTRASONOGRAPHY

For superficial , soft tissue swilling

Differentioates cystic vs. solid

Us-guide FNA

ULTRASONOGRAPHY

Ultrasonography (US) Image of Right Parotid Gland. Awell-delineated solid mass is suggested by echo returns within thelesion (arrows). US appearance is typical of a benign salivary tumor

ULTRASONOGRAPHY