Uncinate process is one of the important landmarks during the endoscopic sinus surgery. so it is important to know about the variation of unicinate process.

1. ALL ABOUT
UNCINATE PROCESS
OF NASAL CAVITY
Prof. Dr. Bikash Lal Shrestha
Department of ENT-HNS
Dhulikhel Hospital
Kathmandu University Hospital
Prof Dr Bikash Lal Shrestha 1 7/19/2020

2. Uncinate process
O Thin, sickle shaped structure, a part
of the ethmoid bone, runs almost in
the sagittal plane from anterosuperior
to posteroinferior direction.
Left uncinate process
shaded area Right uncinate process
attached to skull base
Left uncinate
process attached
to middle turbinate
Prof Dr Bikash Lal Shrestha
2
7/19/2020

3. Attachment of Uncinate
Process
O Anterior: Attached to the lacrimal bone and in the
sagittal plane, may have a “common” attachment to the
medial surface of the agger nasi cell and the middle
turbinate.
7/19/2020Prof Dr Bikash Lal
Shrestha
3
ANTERIOR – Attached with lacrimal bone
Lacrimal
bone
Uncinat
e
Process
Medial
surfac
e of
middle
turbina
te
Agger
nasi
Anterior attachment – lacrimal bone
Common attachment

4. OPosterior:
Concave free margin that usually lies parallel to the anterior
surface of the ethmoidal bulla.
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Uncinate process
Bulla ethmoidalis
Posterior free margin lies parallel
Uncinat
e
process
Bulla
ethmoi
dalis
Posterior free margin
of uncinate lies
parallel to anterior
surface of bulla

5. OPosteroinferior:
It attaches to the perpendicular process of the
palatine bone and the ethmoidal process of the
inferior turbinate.
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Posteroinferior attachment of
Uncinate process to ethmoidal
process of inferior turbinate

6. OSuperior:
O Superior attachment is very variable, with 6 variations
identified.
O The most common superior attachments are to the lamina
papyracea (up to 52%) and/or to skull base or to middle
turbinate.
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Attachment of
uncinate process to
lamina papyracea

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Attachment of
uncinate process to
skull base
Attachment of
uncinate process to
middle turbinate
Schematic diagram of
superior attachment of
uncinate process
A. Skull base. B. Middle
turbinate. C. Lamina
papyracea.

8. Everted (Bent/Paradoxical)
Uncinate Process
O Curves medially towards the middle
turbinate.
7/19/2020Prof.Dr. Bikash Lal Shrestha
Everted Uncinate
process right side
Middle
turbinate
Nasal septum

9. 7/19/2020Prof.Dr. Bikash Lal Shrestha
Left Everted Uncinate process
Surgical
importance:
May be
mistaken for a
‘double’ middle
turbinate.

10. Aerated (Pneumatized)
Uncinate Process
O Uncinate process contains an air-space (rare
variant)
O Also known as
uncinate bulla.
7/19/2020Prof.Dr. Bikash Lal Shrestha
Aerated Uncinate process bilateral
Nasolacrimal duct

11. Concave uncinate process
O Rarely a lateralized, concave uncinate may narrow the
infundibulum leading to an atelectatic infundibulum.
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Concave uncinate
narrowing the
infundibulum

12. Uncinate process
OSurgical importance:
O It is important to check the CT scan
for the distance from the uncinate
process to the medial wall of the
orbit to evaluate the width of the
ethmoidal infundibulum.
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13. References
O Stammberger HR, Kennedy DW. Paranasal sinuses:anatomic terminology and nomenclature. Ann Otol Rhinol
Laryngol Suppl. 1995;167:7-16.
O Bolger WE, Butzin CA, Parsons DS. Paranasal sinus bony anatomic variations and mucosal abnormalities: CT
analysis for endoscopic sinus surgery. Laryngoscope. 1991;101(1 Pt 1):56-64.
O Han D, Zhang L, Ge W, Tao J, Xian J, Zhou B. Multiplanar computed tomographic analysis of the frontal recess
region in Chinese subjects without frontal sinus disease symptoms. ORL; journal for oto-rhino- laryngology and
its related specialties. 2008;70(2):104-12.
O Isobe M, Murakami G, Kataura A. Variations of the uncinate process of the lateral nasal wall with clinical
implications. Clin Anat.1998;11(5):295-303.
O El-Shazly AE, Poirrier AL, Cabay J, Lefebvre PP. Anatomical variations of the lateral nasal wall: The secondary
and accessory middle turbinates. Clinical anatomy (New York, NY). 2012;25(3):340-6.
O Landsberg R, Friedman M. A computerassisted anatomical study of the nasofrontal region. Laryngoscope.
2001;111(12):2125-30.
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14. Thank you for watching.
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