This document discusses the radiographic appearance of the maxillary sinus. It describes the maxillary sinus as the largest of the paranasal sinuses. Periapical radiographs may show projections of maxillary tooth roots into the sinus floor. Computed tomography and magnetic resonance imaging provide cross-sectional views of the sinus. Common radiographic views for examining the maxillary sinus include panoramic, Caldwell, Waters, submentovertex and lateral views. Diseases that can affect the sinus include sinusitis, which appears radiographically as thickening of the mucosa and reduced air space, and antroliths, which are radiopaque structures of varying size in the sinus base.
3. The sinus may be considered
as a three sided pyramid its
three sides are:
4. Maxillary sinus are largest
Maxillary sinus are largest
sinuses amongst the other
sinuses amongst the other
paranasal sinuses
paranasal sinuses
5. Intraoral periapical radiograph :
In these radiograph the roots of the maxillary teeth may
appear to project directly into the sinus and may produce
conical elevations on the floor of the sinus ,yet there is
always a layer of bone and mucosa covering these roots
6. In periapical radiograph one must remember that:
*most antral changes caused by
pathosis are radiopaque
*a radiopaque band of tissue following the
contour of the sinus indicate generalized
inflamatory reaction of the sinus mucosa
leading to hyper plasia
*a localized opaque thickening adjacent to the
source of inflammation as in severe
periodontal disease indicated localized
mucosites
7. On the periapical radiograph of canine the
On the periapical radiograph of canine the
floors of the sinus and aa cavity are often
floors of the sinus and nasal cavity are often
nasal
superimposed and maybe seen crossing each
superimposed and maybe seen crossing each
other forming an inverted Y in the area
other forming an inverted Y in the area
8. the anterior maxillary
occlusal projection, the
cross sectional maxillary
anterior projection and
the lateral maxillary
occlusal projection are
excellent techniques to
visualize maxilla from the
palatal aspect
14. Panoramic view
(orthopantomography)
Gives a good display of the lower aspects of antrum
On the panoramic radiograph
maxillary sinus appear as paired
radiolucent areas located above the
apices of maxillary premolars and
molars .the floor of the maxillary
sinus is composed if dense cortical
bone and appear as a radiopaque
line
15. Most of the anterior and posterior walls
of the maxillary sinus are superimposed
upon the medial wall in the
pantomogram.
17. MRI of the paranasal sinuses is a comlimentary
imaging technique to CT
MRI can image intra cranial complications of
inflammatory disease
18. MRI can readily separate tissues oof similar densities better
MRI can readily separate tissues oof similar densities better
than CT which is useful to diffrentiate tumors from
than CT which is useful to diffrentiate tumors from
inflammatory disorders as well as haemorrhage and
inflammatory disorders as well as haemorrhage and
inflammatory secretions
inflammatory secretions
MRI is unable to image bone and air ,so evaluation of bony
MRI is unable to image bone and air ,so evaluation of bony
anatomy and pathology is difficult hence MRI is mainly
anatomy and pathology is difficult hence MRI is mainly
usefull to determine spread of disease ,especially
usefull to determine spread of disease ,especially
intracranially and intraorbitally
intracranially and intraorbitally
19. Antral diseases and their
Antral diseases and their
radiographic appearance
radiographic appearance
Antroliths
These are small bodies of varying
sizes generally found in the base of
sinus
Generally They are homogeneous
density and rarely they may have a
more radiopaque area around
They usually have irregular border
20. Thickining of the
sinus mucosa and
the accumulation of
secretions that
accompany
sinusites reduce air
content of the sinus
and cause it to
become
increasingly
radiopaque
Acute right side maxillary sinusitis and chronic left side
maxillary sinusitis
21. Irregular thickining of
the radiopaque lining on
the inner side of sinus
because of mucosal
hypertrophy
Shrinkage of the
radiolucent cavity of the
sinus
Acute right side maxillary sinusitis and
chronic left side maxillary sinusitis