Chapter 22 - Sinonasal anatomy/embryology/radiology

Question 1

Preferred method of evaluating sinonasal anatomy

Answer 1

CT triplanar recon

Question 2

Epithelium lining sinuses

Answer 2

pseudostratified ciliated columnar (respiratory)

Question 3

Direction cilia beat

Answer 3

Beat mucous toward natural ostium, and from there, to nasopharynx

Question 4

Theories of function of sinuses

Answer 4

lighten skull
vocal resonance
absorb mechanical force during trauma to protect eyes/brain
produce/resevoir NO may regulate pulmonary fxn

Question 5

Medial boundary and drainage of posterior ethmoid cells

Answer 5

superior turbinate

superior meatus

Question 6

Onidi Cell

Answer 6

Sphenoethmoidal air cell

Question 7

Gestational age when sinuses begin to develop

Answer 7

3rd fetal month

Question 8

When sinuses grow

Answer 8

Maxillary: as face grows, significantly after permanent dentition
Ethmoid: also present at birth, grow until age 12
Frontal: rapidly pneumatizes in second decade, final size by end of this decade
Sphenoid: not much development until 7 yo, final size during adolescence

Question 9

Main function of MRI in sinus eval

Answer 9

Diff secretions from neoplasm

Question 10

Structures making up OMU

Answer 10

Ethmoid bulla (largest anterior ethmoid cell)
Uncinate (ant to bulla)
Ethmoid Infundibulum (trough between uncinate, lateral wall)
Hiatus Semiluminaris (gap between bulla, uncinate, leads to infundibulum)

Question 11

Agger Nasi

Answer 11

Area in lateral wall projects medially, superior to middle turbinate’s ant/sup attachment, commonly pneumatized

Question 12

Typical size of ostium

Answer 12

1-3mm

Question 13

Sinus drainage into nasal cavity

Answer 13

Max: to ethmoid infundibulum, then mid meatus
Frontal: ethmoid infundibulum
If uncinate attaches to lamina, then drains directly into middle meatus
Sphenoid: into sphenoethmoidal recess (between ST, septum)
Ethmoid: Mid Meat (ant), sup meat (post)

Question 14

Haller cells

Answer 14

Infraorbital ethmoid

may narrow infundibulum

Question 15

Frontal Recess Boundaries

Answer 15

Ant: Agger Nasi
Post/Sup: Anterior fossa cranial base
Medial: Mid Turb
Lateral: Lamina
Posterio/Inf: Ethmoid Bulla

Question 16

Kuhn Classification for ethmoid cells within frontal drainage

Answer 16

1- single sup to agger nasi
2- >1 sup to agger nasi
3- extend into frontal sinus
4- isolated within frontal sinus

Question 17

Describe blood supply to nose/sinus

Answer 17

A/P ethmoid: ethmoid, sup septum. br of ophthalmic
SPA: br max, one br passes inf to sphenoid ostium (post septum supply), another enters into middle turbinate, has small br for nasal floor, inf turb

Question 18

Venous drainage sinuses

Answer 18

PPF, to cavernous sinus (lat to sphenoid sin)

Frontal sinus drains intracranially through vv perforate posterior table

Question 19

5 lamellas in sinus surgery

Answer 19

1- Agger Nasi (ascending), Uncinate (descending)
2- bulla ethmmoidalis
3- basal lamella MT (border a/p ethmoids)
4- sup turb
5- fusion of 5th/6th ethmoturbinals, supreme turbinate

Question 20

What to evaluate on CT prior to FESS

Answer 20

inflammation, sinuses/OMU
Lamina integrity
Cribiform depth/symmetry
Ethmoid SB integrity
Anterior ethmoid a location (SB or inferior)
Onidi cell
Optic nerve/ICA