3. ParaNasaL sINuses
The large, air-filled cavities sometimes called the accessory
nasal sinuses because they are lined with mucous
membrane, which is continuous with the nasal cavity.
5. Mucous was not a product of brain but on the
contrary was secreted by the lining mucosa of
paranasal sinuses
Detailed anatomical description of paranasal
sinuses
accurate description of maxillary sinusHighmore
in 1651
C. V.
Schneider
19th
century
Zukerkandl
24. GranGer Projection
Structures seen:
Inner and Middle ear
Anterior ethmoid cells
Petrous pyramid
Frontal sinuses
Sphenoidal sinus
Upper part of antrum
25. • Indications:
b) Investigations of the frontal sinuses
c) Conditions affecting the cranium, particularly,
Paget’s disease
Multiple myeloma
Hyperparathyroidism
d) Evaluate facial growth & development
e) Trauma
f) Developmental abnormalities
26. Film Placement
The cassette is placed perpendicular to the floor in a
cassette holding device
Long axis of cassette is positioned vertically
27. Position of patient
Midsagittal plane should be vertical and perpendicular
to the plane of cassette
Only forehead and nose should touch the cassette
Radiographic baseline is at 90 degree to film
28. Central Ray:
Directed to the midline of skull so that X-ray beam
passes through the canthomeatal plane
perpendicular to the film plane
32. Film Placement:
• Cassette is placed perpendicular to the floor in a
cassette holding device
• Long axis of cassette is positioned vertically
33. Position of patient:
• Mid sagittal plane is vertical and
perpendicular to the cassette
• Only the forehead and nose touch the
cassette
34. Central Ray:Central Ray:
• Directed 23 degree to the canthomeatal
line
• Entering the skull about 3cm above the
external occipital protuberance and exiting
at the glabella
38. standard occiPito meatal
projection
Structures seen:
Facial skeleton
Maxilary antra
Avoids superimposition of dense
bones of the base of the skull
40. • Film placement:
• Cassette placed perpendicular to the floor in a cassette holding
device
• Long axis of the cassete is positioned vertically
41. • Position of patientPosition of patient:
• Midsagittal plane should be vertical and
perpendicular to plane of cassette
• Nose and chin should touch the cassette
• Head is tipped back so that the radiographic
baseline is at 45degree to the film
48. • Film placementFilm placement:
• Cassette placed perpendicular to floor in a cassette holding
device
• Long axis of cassette is positioned vertically
49. • Position of patientPosition of patient:
• Mid sagittal plane is vertical and perpendicular to the cassette
• Head is centered so that the nasion is in the center of the
cassette
• Only the nose and chin touch the cassette, The head is tipped
back so that the radiographic baseline is at 45 degree to the
film
50. • Central RayCentral Ray:
• Directed 30 degree to the horizontal ,centered through the
lower border of orbit
54. • Film PlacementFilm Placement:
• Cassette placed perpendicular to the floor in a cassette holding
device
• Long axis of cassette is positioned vertically
55. Mid sagittal plane should be vertical
and perpendicular to plane of film
Canthomeatal line should be 37 degree
to plane of the film
line from external auditory meatus to
the mental protuberance should be
perpendicular to film
Patient’s head extended so that only
chin touches the cassette
Cassette centered on the Acanthion
(Anterior nasal spine)
56.
57. • Central RayCentral Ray:
• Perpendicular to the midpoint of film
• It enters from vertex and exists from acanthion
58. Step 1
• Interpretation:
• Evaluate the calvarium and sutures starting in the left temporal
area over the supraorbital to the right temporal area. Look for
intracranial calcifications
59. Step 2
Evaluate the orbits and the frontal sinuses. Identify the
supraorbital and infraorbital rim, the inferior orbital foramen, the
floor of the orbit, the zygomaticofrontal sutures and the
innominate line of the infratemporal fossa crossing on the lateral
aspect of each orbit.
60. Step 3
• Evaluate the maxillary sinuses & nasal cavity. Identify the
superior, medial & lateral Walls of the maxillary sinuses; the
nasal septum & the floor & lateral walls of the nasal cavity
61. Step 4
• Evaluate the zygomatic arches. Identify the frontal,
maxillary, and temporal processes of the zygoma and
the zygomaticofrontal suture
62. Step 5
• Evaluate the condylar and coronoid processes of the
mandible
63.
64. • There are three anatomic contours best seen on the Waters
view (occipitomental view )of the face, and they were first
popularized by Dolan et al called Dolan’s line
• The 3 lines of Dolan lead the eye along some facially
important structures. Lee Rogers pointed out that the 2nd and
3rd lines together form the profile of an elephant
65. • McGrigor-Campbell lines
• The ' McGrigor-Campbell lines' are
visible on OM and OM30 views and
can act as anatomical references to
assess the facial bones for injury
• Upper line - (Red) passes through the
zygomatico-frontal sutures (asterisks)
and across the upper edge of the orbits
• Middle line - (Orange) follows the
zygomatic arch (elephant's trunk),
crosses the zygomatic bone and
follows the inferior orbital margins to
the opposite side
• Lower line - (Green) passes through
the condyle (1) and coronoid process
(2) of the mandible and through the
lateral and medial walls of the
maxillary antra on each side
• Midline - used to assess symmetry
67. Careful examination of the three Dolan’s lines on the waters view is key
to the identification of ZMC fracture
68. • Isolated zygomatic arch
fracture
• Disruption of the middle
McGrigor-Campbell line is
due to a comminuted
fracture of the right
zygomatic arch
• Following the upper and
lower lines shows no
fracture
69. • Tripod' fracture
• 1 - The zygoma (asterisk) is
separated from the frontal
bone at the zygomatico-
frontal suture
• 2 - Comminuted fracture of
the zygomatic arch
• 3 - Orbital floor fracture
• 4 - Breach of the lateral wall
of the maxillary antrum
70. • Orbital 'blowout' fracture-
Teardrop sign
• On the left a 'teardrop' of
soft tissue has herniated
from the orbit into the
maxillary antrum
72. • Film Placement:
• Cassette is placed perpendicular to floor in a cassette holding
device
• Long axis of cassette positioned vertically
73. • Position of patient:
• Midsagittal plane should be perpendicular to the plane of film
• Patient’s head extended as far as comfortable to make the
lower border of mandible as parallel to the cassette as possible
• Only chin touches cassette
• Canthomeatal line approximately parallel to plane of film
77. reFerenCeS
1.White SC, Pharoah MJ. Oral radiology: principles and
interpretation,5th edition,
2. Karjodkar FR. Text book of dental and maxillofacial
radiology, 1st edition, Jaypee brothers medical publishers
inciples and interpretation,5th edition,
3.Whites E. Essentials of dental radiography and radiology, 3rd
edition, Churchill