6. Sphenoid bone
Bone spanning the
width of middle
cranial fossa
Consists of central
body and three
processes; greater
and lesser wings
and pterygoid
process (pos. view)
8. 8
Maxilla
The largest bones of the face, except for the mandible and
form, by their union, the whole of the upper jaw.
Each assists in forming the boundaries of three cavities,
namely, the roof of the mouth, the floor and lateral wall of
the nose, and the floor of the orbit.
Zygomatic, frontal, palatine and alveolar process
Landmarks:
Infra Orbital foramen: hole below the orbit, for blood
vessels and nerves
Alveolar process: arch of the maxilla containing the
upper teeth
Palatine process: horizontal projection of the maxilla
forming the anterior ¾ of the hard palate.
10. Lacrimal canal :
groove posterior to
frontonasal
process, lacrimal
bone and lacrimal
process of inferior
turbinate
Infraorbital
foramen
Greater palatine
canal
11. 11
Ethmoid Bone
An irregularly shaped, spongy bone that provides the floor of the front part
of the skull and the roof of the nasal cavity.
The ethmoid consists of two masses of thin plates enclosing air cells and
looks like a sieve.
Landmarks:
Lateral masses: form most of the wall between the nasal cavity and the
orbits
Perpendicular plate: forms the superior portion of the nasal septum
Cribiform plate: forms the roof of the nasal cavity
Olfactory foramina: small holes within the cribiform plate for passage
of the first cranial nerve (for smell)
Crista galli: upward extension of bone above the cribiform plate, acts as
an anchoring point for one of the coverings of the brain.
Nasal concha (turbinates): two scroll-shaped projections with a mucus
membrane on either side of the nasal septum. Function to cause air
turbulence and trap inhaled particles.
12. Ethmoid bone - landmarks
Cribiform plates
Forms roof of nasal
cavity, fits into the
notch in frontal
bone, foramina :
olfactory nerve
Horizontal and
vertical lamella
lamella
Crista galli
Attachment of the
dura mater which
secures brain in
cavity
13.
14. 14
Nasal Bones
Bridge of nose
Internal surface :
groove for anterior
ethmoidal nerve
Superior border
articulates with
frontal bone
Lateral border :
frontonasal process of
maxilla
15. 15
Lacrimal Bones
Smallest and most
fragile bone of the
face
Contains the lacrimal
sac and the naso-
lacrimal duct.
Orbital surface :
posterior lacrimal
crest
Btwn anterior and
posterior lacrimal
crest : lacrimal sac
Lacrimal bone
16. 16
Palatine bones
Fragile L shaped
bone
It contributes to the
walls of three
cavities: the floor
and lateral wall of
the nasal cavity,
the roof of the
mouth, and the
floor of the orbit
17. Horizontal plate
Posterior section of hard
palate
Perpendicular plate
Part of the posterolateral
walls of nasal cavity
Greater palatine canal
Orbital surface
Part of inferior medial
aspect of orbit
Processes :
Orbital process
Sphenoid process
Between the two :
sphenopalatine notch
Pyramidal process
18. 18
Inferior Nasal Conchae
Extends horizontally
along the lateral wall
of the nasal cavity
and consists of a
lamina of spongy
bone, curled upon
itself like a scroll.
Inferior Nasal Conchae
19. NOSE
Consists of:
External Nose
Nasal cavity
The external nose :
Is a pyramidal projection
of face
tip
Root
dorsum
ala of nose bounding inferiorly a pair of nostrils
19
22. BONY VAULT
Formed by Nasal bones and frontal
process of maxilla
Paired nasal bones, each one is
tapered, thin and bevelled below but
gradually thickens upwards
encroaching upon the nasal cavity
Two nasal bones form a crest in midline
Articulates
Upwards with nasal spine of frontal &
perpendicular plate of ethemoid
Laterally with frontal process of maxilla
(is thick below n thin above) by
nasomaxillary suture
22
24. UPPER CARTILAGENOUS VAULT
Paired, Triangular ULC and part of
septal cartilages enclosed in
common perichondrial sheath
Base at septum, Apex at pyriform
fossa
Cephalic attachment to nasal
bones
Nasal bones overlap over ULC 1cm
Held in place with intimate fusion
b/w perichondrium and periostium
Medial borders are thick and
continuous with dorsal border of
septal cartilage.
Laterally ULC are short of
pyriform edge of maxilla, the gap
is filled by dense fibrofatty tissue
(empty triangle)
24
25. Lowermost part of nasal
fossae, bounded superiorly
by caudal edge of ULC is
vestibule.
Lined by thin skin having
coarse hairs and sebaceous ,
sweat glands.
Internal nasal valve-
triangular area bounded lat
by caudal edge of ULC
,septum medially, nasal
cavity floor inf,is narrowest
part of nasal cavity
25
26. LOWER CARTILAGENOUS VAULT
Paired alar cartilages (few sesamoid
cartilages)
can move freely over ULC and septal
Contribute to formation of lobule,
columella and ala.
Each one made up of single piece of C-
shaped cartilage ,having parts medial,
middle and lateral crura
Lateral crus - 1 mm in thickness
Starts at domal segment and arch
outwardly convex
• Middle crus-
from columella to lateral crus
Divided into domal and lobular
segment
Medial crus-
It starts at footplate and extends
into columella
lies under the thin skin of columella
and two med crura are attached by
fibrous tissue and to lower end of
septum by membranous septum
27. COLUMELLA
Extends between upper lip and
tip of the nose
Divided into three almost equal
parts , upper –lobular, middle
and basal part –wider
Consist of paired medial crura
with covered skin, variable length
of crura may produce projecting
or depressed tip
Anteriorly- diverging crura form
an angle of 30 degrees for tip
formation.
Posteriorly - also diverge to
receive post septal angle,
adjoining septal cartilage and
anterior nasal spine.
Shape of columella depends on
size and shape of medial crura.
27
28. SOFT TISSUE COVERING
Nasal skin : thick over-nasion,
supratip area and thin at rhinion
over lower firmly adherent to
cartilages
over nasal bones and ULC is mobile
Subcutaneous tissue covering
thickens gradually downwards
from rhinion
: has 4 layers
1. Superficial panniculus
2. Fibromuscular layer
3. Deep fatty layer
4. Periosteum/ perichondrium
Incisions in rhinoplasty are
given deep to all these layers
since blood vessels run in deep
fatty layer.
28
29. NASAL MUSCULATURE
Elevators:
Procerus
Levator labii
superioris alaque
nasi
Depressors:
Alar part of nasalis
Depressor septi
Compressor:
Tranverse part of
Nasalis
Compressor narium
minor
Dilators:
dilator naris
29
30. ARTERIAL SUPPLY
Dorsal and external
nasal branch of
ophthalmic artery
Infra orbital br. of
maxillary artery
Lateral nasal and
angular br. of facial
artery
30
33. NERVE SUPPLY TO EXTERNAL
NOSE
Sensory supply:
By branches of ophthalmic
and maxillary div. Of
trigeminal
infra trochlear branch-skin
of root and adjacent sides
of nose
infra orbital, external
nasal nerve- skin of lower
half of nose
terminal branches of
palatine nerves – skin of
base of columella
33
35. NASAL SEPTUM
NASAL SEPTUM HAS 3 PARTS :
COLUMELLAR : Columellar septum. It is formed of
columella
Containing the medial crura of alar cartilages united
together by fibrous tissue and covered on either side by
skin.
Membranous septum. It consists of double layer of skin
with no bony or cartilaginous support. It lies between the
columella and the caudal border of septal Cartilage. Both
columellar and membranous parts are freely movable from
side to side.
36. Septum proper. It consists of osteocartilaginous
framework, covered with nasal mucous membrane.
Cartilagenous portion composed of quadrilateral cartliage,
contributions from lower and upper lateral cartilages.
37.
38. Bony septum : mainly by perpendicular plate of
ethmoid and vomer
Minor contributions : crest of nasal bone
nasal spine of frontal bone
rostrum of sphenoid
crest of palatine bone
crest of maxilla
anterior nasal spine of maxilla
39. Bony septum: perpendicular plate of ethmoid forms
the superior and anterior bony septum, which is
continuous above with the cribriform plate and crista
galli.
Vomer defined as keel shaped bone, extends anteriorly
from spenoid and superiorly from nasal crest of
maxilla and palatine bone.
forms the posterior and inferior nasal septum and
articulates by its two alae with the rostrum of sphenoid
creating vomerinovaginal canals which transmit
pharyngeal branches of maxillary artery.
40. The upper margin expands which is connected to the
upper lateral cartilages.
Bound firmly by collagenous fibres to the nasal bones
And to the perpendicular plate of the ethmoid and
vomer
Inferior border of vomer articulates with nasal crest
formed by maxillae and palatine bones.
Anterior border articulates with perpendicular plate of
ethmoid and septal cartilage inferiorly.
Posterior border forms the free edge
41. LATERAL WALL OF NOSE
The lateral wall of nose:
Maxillary bone
Ethmoid bone
Sphenoid bone
Inferior turbinate
Lacrimal bone
Palatine bone
42. The nasal turbinates are embryologically derived
from a series of outgrowths from the foetal lateral
nasal wall.
The outgrowths form a series of ridges, referred to as
“ethmoturbinals” which are separated by furrows.
Each ridge has an anterior ascending portion and a
posterior descending portion.
The uncinate process develops from the descending
portion of the first ridge, which is also known as the
“nasoturbinal”
43. The agger nasi develop from its ascending
portion.
The second ridge forms the bulla lamella, or
the bulla ethmoidalis when pneumatized.
The middle turbinate develops from the third
ridge, which is the first permanent
ethmoturbinal.
The fourth ridge, the second permanent
ethmoturbinal, forms the superior turbinate.
Based upon this, variations in development
and pneumatization of the ethmoturbinals
may lead to anatomical variations within the
bony structures of the ethmoidal complex.
44. Nasal turbinates:
The turbinates are the most prominent feature of the
lateral nasal wall . They are usually three or sometimes
four in number. These turbinates appear as scrolls of
bone, delicate, covered by ciliated columnar
epithelium. These turbinates sometimes may contain
an air cell, in which case it is termed as a concha.
45.
46. Inferior turbinate, meatus
Largest turbinate and largest meatus
Highest at the jnctn of ant and middle 3 rd (1.6-2.3 cm)
Separate bone covered by thick mucous membrane
Nasolacrimal opening in anterior portion of lateral
wall of inferior meatus
Slit like opening is protected by fold of mucous
membrane, the plica lacrimalis or valve of Hasner
47. Middle turbinate/meatus
Portion of ethmoid bone
It recieves drainage from the frontal, maxillary and
antethmoidal cells
hiatus semilunaris and ethmoid infundibulum.
maxillary hiatus.
ant and post fontanelles
recesses terminalis
48. MIDDLE MEATUS
Infundibulum – Air passage
connecting the maxillary sinus
ostium to middle meatus
Hiatus Semilunaris – Gap
between the uncinate process
and bulla ethmoidalis. Medially
it communicates with middle
meatus. Laterally & inf it
communicates with
infundibulum
49. Middle turbinate
3 parts
Anterior 1/3rd : saggital plane : cribriform plate at the
junction of medial and lateral lamella
Middle 1/3rd : coronal plane; lamina papyracea : ground
lamella / basal lamella
Posterior 1/3rd : horizontal plane : lamina papyracea
and perpendicular plate of palatine bone.
50.
51. OSTEO MEATAL COMPLEX
The osteomeatal complex is the key anatomic area
addressed by endoscopic sinus surgeons. Blockage of the
osteomeatal complex prevents effective mucociliary
clearance, thus leading to a stagnation of secretions and
therefore leading to recurrent or chronic sinusitis.
52. OSTEO MEATAL COMPLEX The OMC is bounded
medially by the middle
turbinate,
posteriorly and superiorly
by the basal lamella, and
laterally by the lamina
papyracea.
Inferiorly and anteriorly
the OMC is open.
54. Uncinate process:
This is the most stable landmark in the lateral nasal
wall.
Horizontal and vertical limb
It is a wing or boomerang shaped piece of bone. It
attaches anteriorly to the posterior edge of the lacrimal
bone, and inferiorly to the superior edge of the inferior
turbinate .
Superior attachment of the uncinate process is highly
variable, may be attached to the lamina palyracea ( 80
% ),or sometimes to the middle turbinate or lie freee
within middle meatus
The configuration of the ethmoidal infundibulum and
its relationship to the frontal recess depends largely on
the behavior of the uncinate process
55. Variations in the superior insertion of the uncinate process are classified
according to criteria developed by Landsber & Friedman
A: Type 1 (insertion into the lamina papyracea).
B: Type 2 (insertion into the posterior wall of agger nasi
cell).
C: Type 3 (insertion into the lamina papyracea and junction
of the middle turbinate with the cribriform plate).
D: Type 4 (insertion in to junction of the middle turbinate
with the cribriform plate).
E: Type 5 (insertion into the skull base).
F: Type 6 (insertion into the middle turbinate)
56.
57. Uncinate attached to lamina : frontal sinus drainage :
medial to uncinate process
Attached to skull base : frontal sinus drains into
infundibulum : disease from frontal sinus spreads to
maxillary
58. The Agger Nasi Air Cell :
Its an ethmoturbinal remnant present in nearly all
patients ( 93 % )
The ANC is the most constant and anterior of the
ethmoidal air cells.
Located anterior to the vertical attachment of the
middle turbinate to the skull base.
59.
60.
61.
62. The degree of ANC pneumatization varies and
has a significant effect on both the size of the
frontal sinus ostium and the shape of the
recess.
If the ANC is small, then the “beak” of the
frontal process of the maxilla, lying anteriorly
and superiorly, will be prominent and extend
posteriorly into the frontal recess, resulting in a
narrow ostium.
If the ANC is large, the beak will be small,
resulting in a wider ostium but potentially
causing obstruction more inferiorly.
63. ETHMOID BULLA
Well pneumatized most constant anterior ethmoid cell
8% rudimentary/ absent
Separated posteriorly from ground lamella by
retrobullar recess
if does not extend upto skull base, suprabullar recess.
64.
65.
66. If both suprabullar and retrobullar recess are absent :
semilunar space above and behind the bulla : sinus
lateralis
Sinus lateralis opens into middle meatus by a cleft :
hiatus semilunaris superioris
Frontal recess may drain into sinus lateralis
67.
68. FRONTAL RECESS
• The frontal recess is an hourglass like narrowing
between the frontal sinus and the anterior middle
meatus through which the frontal sinus drains
• Bounded anteriorly by agger nasi cell
Posteriorly by bulla ethmoidalis
Laterally by lamina papyracea
Medially by middle turbinate, lateral wall of olfactory
fossa.
69.
70. Roof of frontal recess formed by fovea ethmoidalis:
thick bone : resistance to injury
Anterior ethmoid artery runs across fovea ethmoidalis
When ther is a suprabullar recess : ethmoid artery will
be in the frontal recess
Anterior ethmoidal artery may lie in a mesentry in 15-
45% pts, suspended from the skull base.
73. Fronto-ethmoid/kunh cells/bulla frontalis
Are the anterior ethmoid cells which invade the frontal
bone, bulging its floor
They are more easily demonstrated at saggital view,
where they appear as ethmoid air cells located above
the ethmoid bulla and as an extension towards the
frontal sinus.
Depending on their size and pneumatization extent,
such cells may affect the frontal sinus drainage.
These air cells, are categorized into four types
depending on their number and degree of extension
into the frontal sinus.
They are all located superior to the ANC.
74. Type 1 (most common): Single cell superior to
the ANC that does not extend into the frontal
sinus
Type 2: Two or more cells superior to the ANC
that may or may not extend into the frontal
sinus.
Type 3: Single frontal cell superior to the ANC
that extends into the frontal sinus.
Type 4: Completely contained in the frontal
sinus. This configuration is rare.
75.
76. This is formed by lateral and posterior pneumatization of
the most posterior ethmoid cells over the sphenoid sinus.
The presence of Onodi cells increases the chance that the
optic nerve and / or carotid artery would be exposed in the
pneumatized cell.
77.
78. VARIATIONS OF THE CRIBRIFORM PLATE
The cribriform plate may present at variable levels and,
it is classified according to the criteria developed by
Keros.
It is based on the height of the olfactory fossa in
relation to the roof of the ethmoid sinus as compared
with the length of the lateral lamella of cribriform
plate.
The higher the Keros grade, the greater the chance of
injury of the cribriform plate and olfactory fossa.
79. A: Type 1 (lateral cribriform lamella of 1–3 mm, the
cribriform plate and the ethmoid cell roof are
practically parallel to each other).
B: Type 2 (lateral lamella of 4-7 mm, cribriform plate is
much below the nasal cavity as compared with the
ethmoid roof).
C: Type 3 (lateral lamella of cribriform plate of 8–16
mm, ethmoid cell roof is located much above the plate
80.
81. Haller cell
Infraorbital ethmoid cells
or Haller cellsare
ethmoid air cells located
anteriorly to the ethmoid
bulla, along the orbital
floor, adjacent to the
natural ostium of the
maxillary sinus, which may
cause mucociliary drainage
obstruction, predisposing
to the development of
sinusitis.
82. VARIATIONS IN MIDDLE TURBINATE
Concha bullosa is a
variation originated from
pneumatization of the
bone plate by extension of
ethmoid sinus cells.
Such variation may be
either uni- or bilateral.
Varied degrees of
pneumatization of the
concha may be observed,
possibly causing middle
meatus or infundibulum
obstruction.
83. PARADOXICAL TURBINATES
Paradoxical turbinates occur as the convexity of the middle
turbinate is directed towards the medial wall of the
maxillary sinus.
Depending on the degree of curvature of the paradoxical
turbinate compression of the infundibulum and sinusal
obstruction may be observed.
84. A)horizontal uncinate
b)hypertrophy of lt uncinate.
C)pneumatisation of lt uncinate.
D)vertical lt uncinate.
85. ACCESSORY MAXILLARY OSTIA
Accessory maxillary ostia are generally solitary, but
occasionally may be multiple.
Easily seen, circular : tunnel like, ovoid
Such variation may be congenital or secondary to sinusal
diseases.
Possible mechanisms involved in the development of such
variation include:
main ostium obstruction, maxillary sinusitis or
anatomical/pathological factors in the middle meatus,
resulting in rupture of membranous areas.
