3. 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 .
4. inflammatory disorders
Inflmmatory 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.
5. 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.
9. 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 .
10. 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 pathoses
in the areas of the salivary glands that may be
mistakenly identified as salivary gland disease,
such as resorptive or osteoblastic changes in
adjacent bone .
11. PLAIN FILM
RADIOGRAPHY Panoramic and conventional posteroanterior (PA) skull radiographs
may demonstrate bony lesions, thus eliminating salivary pathosis
from 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).
12. Sialoliths in the anterior two thirds of the submandibular duct are
typically imaged with a cross-sectional mandibular occlusal
projection
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 Stensen
duct around the anterior border of the masseter and through the
buccinator muscle. As a rule, only sialoliths anterior to the masseter
muscle
can be imaged on an intraoral film.
14. Periapical radiographs of the same case. The
radiopaque calculus can be localized lingual to the
teeth by applying appropriate object localization
rules
15. An axial bone algorithm CT image
showing a sialolith in the
submandibular duct (arrow).
16. A panoramic projection frequently demonstrates
sialoliths in the posterior duct or reveals
intraglandular sialoliths in the submandibular
gland.
The image of most parotid sialoliths is
superimposed over the ramus and body of the
mandible .
To demonstrate sialoliths in the submandibular
gland, the lateral projection is modified by
opening the mouth, extending the chin, and
depressing the tongue with the index finger.
17. Sialoliths in the distal portion of Stensen duct
or in the parotid gland are difficult to
demonstrate by intraoral or lateral extraoral
views. However, a PA skull projection with the
cheeks puffed out may move the image of the
sialolith free of the bone .
18.
19.
20. Anteroposterior skull view with cheek blown
out to provide air contrast to reveal a parotid
sialolith (arrow).
21. 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 infused
until the patient feels discomfort (usually between 0.2 and 1.5 ml).
22. 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 extravasation
of lipid-soluble agents .
Sialography is indicated for the evaluation of chronic inflammatory
diseases and ductal pathoses. Contraindications include acute
infection, known sensitivity to iodine-containing compounds, and
immediately anticipated thyroid function tests.
23. 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 opacifi
cation.
24.
25. Sialogram of Normal Submandibular Gland. This lateral
view demonstrates parenchymal blushing. Normal fine branching
is
visible. Lack of parenchymal blushing at the anteroinferior
margin is
caused by radiographic burnout.
26. 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.
27. •CT Images with Soft Tissue Algorithm. A, Axial view
demonstrating bilateral enlargement of the parotid
glands (arrowheads).
B, Coronal view of the same patient. The
clinical/histopathologic
diagnosis was
•autoimmune parotitis.
28. MRI for soft tissue mass details and localization
Differanciates :
St vs. Ht
Normal vs. abnormal tissue
Identifies facial nerve ( parotid )
Containdications:
-pacemaker
-cochlear implant
29. 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
30. reveals that the lesion has a high
internal signal because of the fluid
content
32. Scintigraphy. A, 99m Tc-pertechnetate
scan of the salivary glands (right and left anterior
oblique views) demonstrates increased uptake of
radioisotope in the right parotid gland (black
arrowhead). B, Scintigram taken after
administration
of a sialogog (lemon juice) demonstrates
retention of isotope in right parotid gland (white
arrowheads). This is a typical presentation of
salivary
stasis, Warthin tumor, or oncocytoma.
35. ULTRASONOGRAPHY
Ultrasonography (US) Image of Right Parotid
Gland. A
well-delineated solid mass is suggested by
echo returns within the
lesion (arrows). US appearance is typical of a
benign salivary tumor
