The maxillary sinus is the largest of the paranasal sinuses. It is located within the body of the maxilla and communicates with the nasal cavity via an opening called the ostium. Radiographic examination of the maxillary sinus can be performed using various techniques including periapical, panoramic, Waters view and CT imaging. These techniques allow visualization of the sinus walls and floor as well as detection of any abnormalities.

1. Maxillary
Sinus
Imaging

2. CONTENTS
Introduction
Normal anatomy of the Maxillary Sinus
Examination of the Maxillary Sinus
Radiological Investigations of the Maxillary Sinus
Normal Radiological appearance of the Maxillary Sinus
Radiological Features of the various diseases of the Maxillary Sinus

3. INTRODUCTION
1

4. Introduction
An air sinus is an air-
containing space within a bone
Paranasal sinuses- paired, mucosa
lined, air filled cavities of the
craniofacial complex
Present within bones around the
nasal cavity and communicate
with the nasal cavity through its
lateral wall. - ‘Paranasal’ sinuses
• Frontal
• Maxillary
• Sphenoidal
• Ethmoidal
There are four paranasal air
sinuses:-

5. Maxillary sinus
Largest paranasal sinus
Synonyms:
• Sinus Maxillaris
• Maxillary Antrum
• Antrum of Highmore

6. “
￮ “Maxillary sinus is the pneumatic
space that is lodged inside the body
of maxilla and that communicates
with the environment by way of the
middle meatus and nasal vestibule.”
6
Drake, Richard; Vogl, A. Wayne; Mitchell, Adam W. M. Gray's Anatomy for Students E-Book London: Churchill Livingstone, 2009

7. 7

8. 8
Possible relation between dental
pathology and spread of
infection to the maxillary antrum
was described by Scottish
surgeon- Sir John Hunter

9. Development of Maxillary Sinus
• First paranasal sinus to develop
￮ 4th month of fetal life: shallow groove between the oral cavity
and the floor of the orbit.
￮ At birth: slit like out-pouching of the nasal cavity
￮ Develop as an evagination of the mucous membrane of the
lateral wall of the nasal cavity at the level of the middle nasal
meatus forming a minute space that expands primarily in an
inferior direction into the primordium of the maxilla.
￮ Grows rapidly by a process known as ‘Pneumatization’ during
the eruption of deciduous teeth
￮ Reaches half its adult size by 3yrs of age
￮ Reaches full size after eruption of permanent dentition

10. Development of Maxillary Sinus
Courtesy: White SC, Pharaoh MJ. Oral Radiology: principles and Interpretation. 5th ed.St.Louis (US): Mosby/Elsevier; 2004.p.177-180.

11. Development of Maxillary Sinus9-12years
•Antral floor same level
with nasal floor
•Assumes pyramidal
shape
12-18years
•Floor of sinus 5–12.5 mm
below nasal floor
•Dimensions 32-34 mm x
28-33 mm x 23-25 mm
•Volume 15-20 ml
•Floor i.r.t 1st and 2nd
molars and 2nd
premolar
Oldage
•Resorption of ridge –
thinning of sinus wall
•Extension of sinus till
crest
•Anterior & infratemporal
surface reverts to
infantile condition

12. Pneumatization
Courtesy: White SC, Pharaoh MJ. Oral Radiology: principles and Interpretation. 5th ed.St.Louis (US): Mosby/Elsevier; 2004.p.177-180.
Growth of the maxillary
sinus is determined by a
process of bone
remodeling referred to as
pneumatization
Carried out by resorption
of the internal walls
(except the medial wall) at
a rate that lightly exceeds
growth of the maxilla.
• At young age, sinus growth by pneumatization α growth of the maxilla
• With the advance of age, pneumatization exceeds maxillary growth.
• Thus the antrum will expand at the expense of the maxillary process.

13. 13
In old age pneumatization becomes more pronounced, the floor of the sinus moves at more
downward position particularly when the maxillary teeth are lost.

14. Functions Of The Maxillary Sinus
14
Humidification and warming of inspired air
Assisting in regulating intranasal pressure
Lightening the skull to maintain proper head balance
Imparting resonance to the voice
Absorption of shocks to the head
Filtration of the inspired air
(Bailey 1998).

15. Maxillary
Sinus
Normal
Anatomy
Various
Imaging
Techniques
Normal
radiological
Appearance
Radiological
features of
various
diseases of
maxillary
sinus
15

16. Out of all the Paranasal sinuses, Maxillary sinus is the most important for an Oral
Physician due to its close proximity to the roots of maxillary teeth
Nerves that supply maxillary teeth are those that supply the maxillary sinus
accounting for dental pain from healthy teeth arising from maxillary sinusitis
Bone forming the floor of the sinus can also be the bone surrounding the apex of a
tooth. Consequently periapical infection of teeth can spread to maxillary sinus
Pain from carious lesion or other insults to the dental pulp may be referred to the
maxillary sinus.
Accidental communication between the sinus and oral cavity may occur during
tooth extraction or surgical procedures leading to oroantral fistula.

17. Normal Anatomy
￮ Located within the body of the maxillary
bone
￮ Pyramidal in shape
￮ Apex: directed laterally, is formed by
the zygomatic process
￮ Base: directed medially, is formed by
the lateral wall of nose
￮ Floor: formed by the alveolar
process of the maxilla

18. Anatomical Relations
Mediolaterally
￮ Central air-filled cavity
￮ Roof: bounded by the orbit
￮ Medial wall: bounded by the nasal cavity
￮ Lateral wall: related to the zygoma and
cheek
Anteroposteriorly
￮ Anterior wall: related to the facial surface
of maxilla
￮ Posterior wall: related to the
pterygopalatine fossa
￮ Floor: related to the apices of the maxillary
posterior teeth
18

19. 19

20. Anatomical Relations
￮ It communicates with the middle
meatus of the nasal cavity in the lower
part of the hiatus semilunaris through
opening called ostium maxillare
￮ It is about 3-6mm in diameter
￮ A second opening is usually seen at the
posterior end of the hiatus
20

21. Anatomical Relations
￮ The internal surface of the maxillary
sinus may have bony septa that
partially divide it into
intercommunicating compartments
￮ Separate ostia may be found in relation
to these compartments
21

22. Maxillary Sinus
• Height (opposite first molar tooth)-3.5cm
• Width-2.5cm
• Antero-posterior depth- 3.25cm
• Average volume -15ml
22

23. Blood Supply
23
The major blood supply of the maxillary sinus is via branches of the
maxillary-artery although the facial artery may make a small
contribution.
The branches of the maxillary artery supplying the maxillary sinus are:
• § Infraorbital artery.
• § Greater palatine artery.
• § Posterosuperior and anterosuperior alveolar arteries.
• § Lateral nasal branches of the sphenopalatine artery.
Venous drainage occurs anteriorly via the anterior facial vein into the
jugular vein orposteriorly via tributaries of the maxillary vein into the
retromandibular vein, which empty into the jugular system.
The region of the infratemporal fossa, the maxillary vein communicates
with the pterygoid venous plexus, which in turn has anastomoses with
the dural

24. Lymphatic Drainage
￮ Lymphatic drainage from the maxillary
sinus is relatively poor.
￮ Lymphatics from the skin over the
anterolateral wall drains to the
submandibular nodes.
￮ From the antrum it drains into
retropharyngeal lymph nodes and then
to the upper deep cervical lymph
nodes
24

25. Histology of Maxillary Sinus
￮ Contains air
￮ Lined by mucoperiosteum with a
pseudostratified ciliated
columnar epithelium
25

26. Histology of Maxillary Sinus
￮ Maxillary sinus is lined by three
layers: epithelial layer, basal
lamina and sub epithelial layer
with periostium.
￮ Epithelium is pseudo stratified,
columnar and ciliated.
￮ As cilia beats, the mucous on
epithelial surface moves from
sinus interior towards nasal
cavity.
26

27. Clinical Examination
27
Asymmetry
Deformity
Swelling
Erythema
Ecchymosis
Hematoma
Middle third of face should be
inspected for presence of:

28. Palpation
28
Place index finger and
middle fingers on either
side of nose below the rim
of the orbit
If gentle pressure does not
produce pain, percussion
can be carried out
Palpating fingers are
placed in the same position
and the sinus is percussed
using the tip of the middle
finger of the other hand

29. Transilllumination
29
Requirements: Dark room, bright light source
Place the light source in the mouth and press it firmly
against the anterior and lateral aspects of the hard
palate with the patient’s lips closed
Amount of light passing through each sinus is compared

30. Intraoral Examination
￮ Intraoral examination should be
performed looking for the following
in upper molar and premolar
region:-
￮ Alveolar ulceration
￮ Expansion
￮ Tenderness
￮ Paresthesia
30

31. Radiological
Investigations
31

32. Radiological Investigations
￮ Conventional
￮ Intraoral
￮ Periapical
￮ Occlusal
￮ Lateral Occlusal
￮ Extraoral
￮ Water’s view
￮ Standard
occipitomental- 00
OM
￮ True lateral skull
￮ Caldwell view
￮ Submentovertex
￮ Advanced imaging
￮ CT
￮ MRI
￮ CBCT

33. Periapical Radiograph
￮ Radiolucent area above apices of
maxillary molars.
￮ Floor appears as a thin radiopaque line
￮ Septa appear as radiopaque lines
within the sinus
33
Area of Antrum shown
Base of antral cavity
Relationship with maxillary posterior teeth

34. Periapical Radiograph
Borders of the maxillary sinus appear as a thin, delicate radiopaque line .
(White & Pharoah 2000)
In the absence of disease it appears continuous, but on close examination it has
small interruptions in its smoothness or density.
The roots of maxillary molars usually lie in close apposition to the maxillary sinus
and may project into the floor of the sinus, causing small elevations or
prominences.
34

35. Relation between maxillary posterior
teeth roots and inferior wall of sinus
Acc to Sharan et al
￮ 0- the root is not in contact with the cortical
border of sinus
￮ 1- an inferiorly curving sinus floor with the
root in contact with the cortical border of
sinus
￮ 2- an inferiorly curving sinus floor with the
root projecting laterally on the sinus cavity
but with the root apex outside the sinus
boundary
￮ 3- an inferiorly curving sinus floor with the
root apex projecting into the sinus cavity
￮ 4- a superiorly curving sinus floor
enveloping part or all of the tooth root
35
Sharan A, Majdar D. Correlation between maxillary sinus floor topography and related root position of posterior teeth using panoramic and cross-sectional computed tomography imaging 2016 3:102 375-381

36. Maxillary Lateral Occlusal
36
Area of Antrum shown
Floor
Lower half of antral cavity
Relationship with upper
posterior teeth

37. Panoramic Radiograph
37
1. Floor of Maxillary Sinus
1
2
2. Posterior wall maxillary sinus
Area of Antrum shown
Floor
Posterior wall
Base of antral cavity
Relationship with upper posterior teeth
Medial wall
Comparison of both sides

38. Extraoral Landmarks used in
Patient Positioning
￮ Median plane of the head (Mid
Sagittal plane): Vertical plane
passing through the mid sagital
suture dividing the skull into two half's.
￮ Frankfort horizontal line: This line
passes from the lower most border of
the bony orbit to the upper border of
the external acoustic meatus
38

39. Extraoral Landmarks used in
Patient Positioning
￮ Orbitomental line(Canthomeatal
line): Imaginary line from the outer
canthus of the eye to the tragus of
ear.
This is also known as radiographic
base line
39

40. Water’s View
40
Area of Antrum shown
Antral cavity
Roof of the antrum
Lateral and medial wall
Comparison of internal
radiopacities

41. 00 Occipitomental
41
Area of Antrum shown
Main antral cavity
Lateral Wall
Roof or upper border
Medial wall
Allows comparison of both sides

42. True Lateral Skull
42
Area of Antrum shown
Main antral cavity
Posterior wall
Anterior wall
Relation to hard palate and
maxillary posterior teeth
(Note: Superimposition of one antral
shadow on the other)

43. Caldwell View
43
Area of Antrum shown
Medial wall
Mid portion of the antral roof
1- Frontal sinus 2- Ethmoid sinus 3-Petrous
apex
4-Inferior orbital fissure
5-Maxillary sinus obscured by petrous apex
*- Site of anterior ethmoidal artery

44. Submentovertex View
44
Area of Antrum shown
Lateral and posterior walls
Comparison of both sides

45. Systematic approach to
examine the Antra
• Compare antral shadows on both
sides- they should be radiolucent
• Compare the radiodensity of the
antrum on each side with the density of
the soft tissue shadow lateral to it
• The antra should be more radiolucent
• Check the integrity and shape of the
roof and lateral walls
• Also check the medial wall even though
it is the least well defined and difficult
to interpret
45

46. COMPUTED TOMOGRAPHY
46
A-Frontal sinus
B- Ethmoid sinus
C- Maxillary sinus
D- Nasal septum
E- Eye socket
Black- Air
Gray- soft tissue
White- Bone
Area of Antrum shown
Main antral cavity
Floor
All walls
Roof or upper border
Surrounding structures
Allows comparison of both sides
Hard and soft tissue images

47. COMPUTED TOMOGRAPHY
47
Coronal CT
81- maxillary sinus
Axial CT
81- maxillary sinus

48. CBCT
48

49. MRI
49
Coronal T1 weighted
MRI
Axial T1 and T2 weighted MRI
Area of Antrum shown
Main antral cavity
Floor
All walls
Roof or upper border
Surrounding structures
Allows comparison of both sides
Hard and soft tissue images

50. Ultrasonography
￮ Ultrasound is becoming the
diagnostic tool of choice for more
and more physicians in detecting
sinusitis.
￮ Offers fast, reliable and radiation free
method or diagnosing sinusitis and
has been used successfully in Finland
for around 15 years
￮ (Landman 1986)
￮ Ultrasound beam sent out by the
sinus ultra is reflected from the
posterior wall of the sinus when the
sinus contains fluid and from the
anterior wall when sinus contains air.
50

51. 51
Periapical (paralleling or
bisected angle technique)
Floor
Base of antral cavity
Relationship with upper
posterior teeth
Panoramic Radiograph Floor
Posterior wall
Base of antral cavity
Relationship with upper
posterior teeth
Medial wall
Allows comparison of both
sides
0° occipitomental
(0° OM)
Main antral cavity
Lateral wall
Roof or upper border
Medial wall
Allows comparison of both
sides

52. 52
Upper Oblique Occlusal Floor
Lower half of antral cavity
Relationship with upper
posterior teeth
True lateral skull Main antral cavity
Posterior wall
Anterior wall

53. 53
Linear or spiral tomography
in coronal or sagittal plane
Main antral cavity
Floor
Anterior wall
Lateral wall
Posterior wall
Medial wall
Roof or upper border
Allows comparison of both sides (coronal only)
Computed tomography
(CT) or MRI
Main antral cavity
Floor
All walls
Roof or upper border
Surrounding structures
Allows comparison of both sides
Images hard and soft tissue

54. Thank You
54

55. Maxillary
Sinus
Imaging –
Session 2

56. Radiology and
Radiography
Radiology : The science or study of radiation as used in medicine, a
branch of medical science that deals with the use of x-rays,
radioactive substances, and other forms of radiant energy in the
diagnosis and treatment of disease
Radiography : The art and science of making radiographs by the
exposure of film to x-rays
Dental Radiography : The production of radiographs of the teeth
and adjacent structures by exposure of film to xrays
Haring JI, Howerton LJ. Dental Radiography : Principles and Techniques. 3rd Ed. Elsevier.

57. Radiology and
Radiography
Radiology : The branch of medicine concerned with the use of
radiation including x-rays and radioactive substances in the
diagnosis and treatment of disease.
Radiography : The technique of examining the body by directing
the x-rays through it to produce images on photographic plates or
fluorescent screens.
L.M Harrison. The Pocket medical Dictionary. 1st ed 1986

58. Radiology and
Radiography
Radiology : The branch of health sciences dealing with radioactive
substances and radiant energy and with diagnosis and treatment
of disease by means of both ionizing and non ionizing radiation
Radiography : The making of film records of internal structures of
the body by passing x-rays or gamma rays through the body to act
on specially sensitized films.
Dorlands. The Pocket medical Dictionary. 1st ed 1995

59. Radiology
Radiology : It is the study and use of radiant energy including
roentgen rays, radium and radioactive isotopes as applied to
medicine and dentistry.
Sikri VK. Fundamentals of Dental Radiology. 1st ed 1992.

60. Maxillary Sinus Lining
60
The lining membrane of paranasal sinuses is a respiratory
mucosa – 1mm thick
When inflamed – increase in thickness 10-15 times
Mucosal membrane thickening greater than 3 mm is most
likely pathologic
Radiographically – radiopaque band more radiopaque than
air filled sinus, paralleling bony wall of sinus

61. Occlusal Radiograph
61
MAXILLARY CROSS SECTIONAL
VIEW
Area of Antrum shown
Antero-inferior aspects of
each antrum
Relationship with upper
posterior teeth

62. Radiography Of
Paranasal Sinuses
￮ Radiography of paranasal sinuses
￮ Posteroanterior projection (occipito frontal projection of nasal
sinuses)
￮ 2 methods for obtaining this
￮ Posterior Anterior (Granger projection)
￮ Modified Method, inclined posterior anterior (Caldwell
Projection)
￮ Radiography of maxillary sinuses
￮ Standard occipitomental projection (0° OM)
￮ Modified method (30° OM projection)
￮ Bregma Menton
￮ PA Waters
62

63. Postero-anterior of the skull (PA skull)/
occipitofrontal (OF)
￮ The main clinical indications include:
￮ • Fractures of the skull vault
￮ • Investigation of the frontal sinuses
￮ • Conditions affecting the cranium,
particularly:
￮ — Paget's disease
￮ — multiple myeloma
￮ — hyperparathyroidism
￮ • Intracranial calcification.
63

64. Posteroanterior
(Granger) Projection
￮ Excellent for
evaluating the
inner and middle
ear because the
petrous pyramid
can be viewed
through the orbits.
64

65. Caldwell View
65
Area of Antrum shown
Medial wall
Mid portion of the antral roof
1- Frontal sinus 2- Ethmoid sinus 3-Petrous
apex
4-Inferior orbital fissure
5-Maxillary sinus obscured by petrous apex
*- Site of anterior ethmoidal artery

66. 00 Occipitomental
66
Area of Antrum shown
Main antral cavity
Lateral Wall
Roof or upper border
Medial wall
Allows comparison of both sides
Projection taken
with patients
mouth open for
investigation of
sphenoidal
sinus

67. ￮ Examine the 0° OM using an
approach based broadly on
that suggested originally by
McGregor & Campbell (1950),
often referred to as Campbell's
lines.
67

68. 68

69. 30° Occipitomental (30°
OM)
￮ This projection also shows the facial
skeleton, but from a different angle
from the 0° OM, enabling certain bony
displacements to be detected.
￮ The main clinical indications include:
￮ Detecting the following middle third
facial fractures:
￮ — LeFortI
￮ — Le Fort II
￮ — Le Fort III
￮ • Coronoid process fractures
69

70. Bregma Menton View
￮ This projection used
primarily – walls of
maxillary sinus-
especially in posterior
areas, the orbits, the
zygomatic arches and
the nasal septum
￮ Demonstrated medial
or lateral deviations of
the mandible
70

71. Water’s View
71
Area of Antrum shown
Antral cavity
Roof of the antrum
Lateral and medial wall
Comparison of internal
radiopacities

72. Maxillary Sinus Septa
￮ First mentioned – Underwood in 1910
￮ Formation
Bony septa originating in sinus floor – Underwood Septa.
Divide the sinus into multiple compartments known as posterior recesses.
￮ Location
Present in maxillary sinus, act as walls to divide the sinus floor
￮ Septa Origin : Classification
Underwood – maxillary sinus floor divided into three basins
Small anterior one over the premolar region
A large median one descending between roots of first and second molars
Small posterior one corresponding to third molar region 72

73. Maxillary Sinus Septa
￮ Krenmair et al divided septa into primary and secondary.
￮ Primary septa corresponding to those first described by
Underwood, arising from development of maxilla
￮ Secondary septa arising from irregular pneumatisation of the sinus
floor following tooth loss
￮ Variations with age
￮ Other authors classified septa related to the presence/absence of
maxillary teeth.
￮ Primary septa located superior to maxillary teeth and secondary
septa located on edentulous maxillae.
73

74. Diseases
of the
Maxillary
Sinus
74

75. Diseases of the Maxillary
Sinus
Intrinsic
Diseases
Extrinsic
Diseases

76. Intrinsic Diseases
76
• Mucositis
• Sinusitis
• Retension Pseudocyst
• Polyps
• Antrolith
• Mucocele
Inflammatory
Diseases
• Papilloma
• OsteomaBenign Neoplasms
• Squamous Cell Carcinoma
• Pseudotumor
Malignant
Neoplasms

77. Extrinsic Diseases
77
• PeriostitisInflammatory
Diseases
• Odontogenic cysts
• Odontogenic tumors
• Fibrous dysplasia
Benign Odontogenic
cysts and Tumours

78. 78
• Mucositis
• Sinusitis
• Mucosal Retention Pseudocyst
• Polyps
• Mucocele
Inflammatory
Diseases
• Radicular Cyst
• Dentigerous Cyst
• Odontogenic Keratocyst
Dental Cysts
• Epithelial Papilloma
• Osteoma
• Ameloblastoma
• Squamous cell carcinoma
Tumors

79. Inflammatory
Diseases
79

80. Mucositis
• Thickened mucosa
• Non corticated band more radiopaque
than the air filled sinus, parallelling the
bony wall of sinus
80

81. Sinusitis
81
Generalized
inflammatio
n in sinus
mucosa
Allergen
Bacteria
Virus
Acute
Subacute
Chronic
•Radiographically there is thickening of sinus mucosa
•The appearance of thickened mucosa helps to
differentiate between an allergic reaction and an
infection
•In case of allergic reaction, the mucosa tends to be more
lobulated
•In case of infection, the mucosal outline is more
smoother with the contour following the sinus wall

82. 82
According to Veterans Affairs general medicine clinic study, the accuracy of
diagnosing sinusitis increases to more than 80% if the following criteria are
considered in the water’s view:
1. Presence of air fluid level
2. Sinus opacity
3. Mucosal thickening greater than 6 mm

83. 83
￮ The resolution of acute sinusitis
becomes apparent on
radiograph as a gradual
increase in the radiolucency of
the sinus
￮ The thickened mucosa
gradually shrinks
￮ In time it again becomes
radiographically invisible
￮ In chronic sinusitis the
inflammation may stimulate the
sinus periosteum to produce
bone resulting in thick sclerotic
borders of the maxillary antrum

84. Staging of Sinusitis
￮ Kennedy’s Staging
￮ 1992, based on history, CT finding
and endoscopic appearance
￮ Four stages; Stage I, Stage II, Stage
III and Stage IV
84
￮ Harvard Staging
￮ 1994, similar to Kennedy's
￮ Thickening of inflammatory
disease
￮ 2mm is normal thickness, anything
more than 2mm is disease
￮ Levine and May Staging
￮ 1993, considers involvement of
osteomeatal complex
￮ Lund-Mackay Staging
￮ 1993, most accepted
￮ Stage 0: No abnormality
￮ Stage 1: Partial Opacification
￮ Stage 2 : Total Opacification

85. Retention Pseudocyst
85
Well defined, non corticated, smooth, dome
shaped, homogeneous radiopaque mass

86. Retention Pseudocyst
￮ Radiographic features
Cysts usually found projecting from the floor of the sinus, though
some form on the lateral walls
Base may be narrow or broad
Dodd and Jing – Mucous cysts are more likely to have a broad base,
serous more pedunculated
Mucous cyst smaller than serous cyst
Mucous cyst associated with thickened mucosa
86

87. Polyp
￮ Thickened mucous membrane
￮ Maxillary sinus shows radiopacity; which is present despite of
the position in which the radiograph is taken.
￮ Usually, the radiopacity has convexity pointing upward
87

88. 88
Pseudocyst Odontogenic cysts
Dome shaped More rounded or tear drop shaped
Lacks corticated border as that of a cyst Floor of antrum is displaced
Corticated border of cyst becomes coincident with
the bony sinus floor
In case of radicular cyst, the lamina dura of involved
tooth is not intact
Pseudocyst Antral polyps
Solitary Often multiple
Adjacent mucous membrane lining is not
apparent
More commonly associated with a thickened
mucous membrane
Benign neoplasms are usually separated from the sinus cavity by a radiopaque border
Malignant neoplasms may destroy the osseous border of the sinus and are less likely to be
dome shaped

89. Anthrolith
• Radiopaque masses having a well
defined periphery which may be
smooth or irregular in shape
• Internal density- Homogenous or
heteogenous
89
Deposition of
mineral salts
Calcium phosphate,
calcium carbonate,
magnesium
Nidus Antrolith

90. Mucocele
• Radiographically : Uniform radiopacity with
a more circular or hydraulic shape
• Bony expansion with thinning of bony walls
• Displacement or resorption of teeth
• Erosion of septa and of bony walls may be
seen 90
Intra antral, intra nasal
inflammation/ polyp/
Neoplasm
Blockage of sinus
ostium
Mucocele

91. Dental
Cysts
91

92. Odontogenic Cysts
￮ Radicular cyst,
dentigerous cyst,
odontogenic keratocyst
92

93. Radicular Cysts
￮ Cause elevation of floor of
sinus - Appears as a halo
93

94. 94

95. Odontogenic Keratocyst
95
Keratocystic odontogenic tumor, maxilla; 16-year-old
male with painless expansion of maxilla,complicated
by sinusitis.
Axial CT image (after biopsy with a drain in place)
shows expansive process in left maxillary sinus
(arrow), multilocular in posterior part (arrowheads).
Axial CT image shows expansion of posterior
thinned sinus wall with cortical defects (arrow), and
fluid.

96. Odontogenic Keratocyst
96
Keratocystic odontogenic tumor, maxilla;
27-year-old female with painless swelling of alveolar process.
Panoramic view shows radiopacity in maxillary sinus (arrow) and radiolucency in right alveolar bone and absent alveolar sinus wall
(arrow).

97. 97
Axial CT image shows scalloped radiolucency in hard palate and alveolar bone
with defect cortical outline (arrow).
Coronal CT image shows mass occupying right maxillary sinus and nasal cavity
(arrow), expanding orbital floor.

98. Large Cysts
98
Odontogenic cysts Sinusitis
Cyst wall is often thicker and more
regular
A cyst that occupies the entire sinus
causes expansion of medial wall of
sinus
Loculation- round shape with a
cortex, appears more radiolucent
than the fluid within the cysts

99. Tumors
99

100. Papilloma
100
Epithelial papilloma is a rare
neoplasm of respiratory
epithelium
Male predilection
Homogeneous radiopaque
mass of soft tissue density
May cause pressure erosion
if bone destruction is
apparent

101. Osteoma
101
This type of mesenchymal
neoplasm of the maxillary
sinuses is ocassionally seen
Incidence vary between 3.9% to
28.5%
Usually appear lobulated or
rounded with a sharply defined
margin
Internal structure is
homogeneous and extremely
radiopaque
Borumandi F, Lukas H, Yousefi B, Gaggl A. Maxillary sinus osteoma: From incidental finding to surgical management. J Oral Maxillofac Pathol 2013;17:318

102. Ameloblastoma
￮ Ameloblastoma, solid/multicystic,
maxilla; 80-year-old female with
painless swelling in vestibule and
palate
￮ Axial CT image shows scalloped
expansive process with destruction of
palate and cortical bone defects
(arrow)
￮ Coronal CT image, soft-tissue window,
shows well-defined soft-tissue mass
without cortical outline palatally or
buccally (arrow)
102

103. Squamous Cell Carcinoma
103
Radiopaque
Destruction of walls of sinus- diagnostic of malignancy
On CT, characteristic sign of malignancy- invasion into the soft
tissue facial planes beyond the sinus walls
CT is helpful in revealing the extent of the neoplasm
Distance between antero-lateral wall of maxilla and coronoid process
of the mandible is measured. If it is increased on one side, it indicates
involvement of infratemporal fossa by the malignancy. This is
called Handousa's sign.

104. 104

105. Fibrous Dysplasia
￮ Posterior maxilla
￮ The normally radiolucent maxilla may
be partially or totally replaced by
radiopacity of this lesion
￮ ‘ground glass’ appearance on extra
oral radiographs
￮ ‘orange peel’ appearance on intra oral
views
105

106. Fibrous Dysplasia
￮ Fibrous dysplasia; 23-year-old female with painless swelling of cheek.
￮ 3D CT image, of face shows expanded right maxilla and zygoma (arrow)
with elevated orbital floor.
￮ Axial CT image shows ground-glass appearance (arrow). 106

107. Pseudotumour
107
Term used for a group of apparently
related diseases of fungal origin that
occur in the paranasal sinuses and in
other parts of head and neck
Radiographic findings include
masses simulating malignant
neoplasms that cause erosion of
bony walls of the involved sinus
CT is done to detect bony destruction,
extent of disease and intracranial
involvement

108. Traumatic
Injuries
108

109. Traumatic Injuries to
Maxillary Sinus
Oro Antral Fistula
￮ Oroantral fistula is an abnormal
communication between the oral cavity
and the maxillary sinus.
￮ It can result due to several causes such as
extraction of teeth, massive trauma,
surgery to maxillary sinus, osteomyelitis of
maxilla, malignant tumor, infected upper
implant denture, Malignant granuloma
￮ Radiograph may show break in continuity of floor
of maxillary sinus
109

110. Traumatic Injuries to
Maxillary Sinus
Root Or Foreign Body In The Antrum
The inadvertent displacement of a root, even a whole
tooth into the maxillary sinus may cause an oro antral
fistula
Following incomplete extraction of a tooth the apical
segment remaining in the socket may be dislodged by
injudicious use of elevators into the sinus
A root tip in the sinus does not have lamina dura around
it. may change its position in the sinus which changes
with patient’s head position. It will not change its
position when it is trapped between the mucosa and
floor of the sinus.
110

111. Traumatic Injuries to
Maxillary Sinus
Blow Out Fracture
Blow to the eye – pressure exerted against orbital
walls
Pressure of blow forces the inferior periorbital
contents (fat and muscle) through the fracture –
become entrapped
Radiographically – opacification of maxillary sinus
with or without fluid level, soft tissue mas sin upper
portion of sinus, image of depressed bone
fragments
In Water’s projection – fractures of the thin walls
are imaged as “bright lines” (white) superimposed
over sinus
111

112. Traumatic Injuries to
Maxillary Sinus
Isolated Fractures
Isolated fractures of paranasal sinuses involve only
a single wall
Radiographs –identified by fracture line “bright line”
Clouding of involved sinus
112

113. 113
Mucositis
:
IOPAR
Sinusitis :
Water’s
view ,
CBCT , CT
Retension
Pseudocy
st : OPG, ,
CBCT , CT
Polyps:
Water’s
view,
Cardwell
view
Antrolith:
Water’s
view, OPG,
Coronal
CT
Mucocele
: Water’s
view, OPG,
, CBCT ,
CT

114. 114
Periostitis :
IOPAR
Odontogen
ic cysts:
IOPAR.,
Occlusal,
water’s
view, CT ,
CBCT
Odontogen
ic tumors:
IOPAR.,
Occlusal,
water’s
view, CT ,
MRI, CBCT
Fibrous
dysplasia :
Water’s , CT,
CBCT
Tooth roots:
IOPAR.,
Occlusal,
water’s
view, CT ,
CBCT

115. Role In Forensics
￮ It has been reported that maxillary sinuses remain intact,
although the skull and other bones may be badly disfigured
in victims who are incinerated.
￮ Hence maxillary sinuses can be used for identification.
￮ Maxillary sinus imaging plays an important role in analysis of
maxillary sinus based on its volume, shape and dimensions to
determine ethnicity and gender
￮ It can assist in giving accurate dimensions for which certain
formulae can be applied to determine the gender.
115

116. CONCLUSION 116

117. 117
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118. 118
REFERENCES
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119. 119
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122. THANK YOU
122