1

Paranasal Sinuses: Anatomy and Function

Glen T. Porter, MD

Francis B. Quinn, MD

UTMB Department of Otolaryngology

Galveston, TX

January 2002

2

Case Report—1000B.C.

3

7 bones4 paired sinuses4 turbinates3 meatiDrainage systemNervous supplyVascular supplyRelated structures

Sinus Anatomy Overview

4

MaxilloturbinalEthmoturbinal Middle turbinate Superior turbinate Supreme turbinate

Agger nasiUncinate processEthmoid infundibulumSinuses Maxillary Ethmoid

Embryology

5

SinusDevelopment

6Pediatric Sinuses

7

EthmoidMaxillaPalatineLacrimalPterygoid plate of

SphenoidNasal Inferior Turbinate

Bony Structure

8

Arterial Supply

External Carotid Maxillary A. SphenopalatineInternal Carotid Ophthalmic A. Ant. Ethmoid Post. Ethmoid Supraorbital Supratrochlear

9

Innervation

10

Neurovascular Supply

11

Sinus Drainage Schema

12

Ethmoid Sinus

DevelopmentPresent at birthAnterior/PosteriorVariability

StructureVolume/shapeRoofLateral wall

13

Ethmoid Roof

•Anterior 2/3•Posterior 1/3

Keros IKeros IIKeros III

14

Ethmoid Cells

Supraorbital, Frontal Bulla, Concha Bullosa, Haller’s, Onodi Cells

15

Ethmoid Sinus—Related Structures

Basal Lamella of the Middle Turbinate Three planes

Agger nasi cell Childhood sinus

Ethmoid Bulla Hiatus Semiluninaris/Superior Hiatus Semilunaris Suprabullar/retrobullar recesses (Sinus Lateralis)

Ethmoid Infundibulum/Uncinate ProcessAnterior/Posterior Ethmoid ArteriesOsteomeatal complex

16

Basal/GroundLamella

Basal/Ground LamellaOf the Middle Turbinate

17

The Agger Nasi Cell

18

Ethmoid BullaUncinate Process

Hiatus Semilunaris

19

Ethmoid Infundibulum

20

Suprabullar/Retrobullar Recess

21

Ethmoid Arteries

22

Osteomeatal Complex Middle meatus Maxillary Sinus Ostium Anterior Ethmoid Drainage

23

Maxillary Sinus

DevelopmentPresent at birthBiphasic growthLevel of the floor

StructureVolume & shapeWalls, floor, roof

24

Maxillary Sinus

25

Maxillary Sinus

26

Maxillary Sinus

Related StructuresFontanellesNatural ostium

Haller’s Cells &SinusitisOsteomeatal complex

Accessory OstiumNasolacrimal duct

27

Fontanelles

28

Natural Ostium -Haller’s cellsAccessory Ostium

29

Nasolacrimal Duct

30

Frontal Sinus

Development Frontal bone at birth Age 5

Structure Volume and shape Ostium Walls

Anterior vs. posterior

Related Structures Frontal recess

31

Frontal SinusOstiumFrontal recess Boundaries

Dumbbell shape

Sinus LateralisFrontal Bulla

32

Sphenoidal Sinus

DevelopmentArise within the nasal capsule (no pouch)

Age 3 begins to pneumatize

Structure Volume/variable pneumatization Wall thickness Position within the sphenoid

Relation to sella turcica Sellar and postsellar relationships

33

Sphenoid Sinus Pneumatization

34

Sphenoid Sinus

Sphenoid Sinus

35

Sphenoid Sinus

36

Sphenoid Sinus

Ostium Size (.5-4mm) Location (sinus floor, anterior nasal floor, anterior

sinus wall, superior turbinate, cribiform plate) Bony dehiscence

Related Structures Sphenoethmoidal recess Sphenoid rostrum Onodi cell

37

Sphenoid OstiumSphenoethmoid RecessSphenoid Rostrum

38

The Onodi Cell

39

Microscopic Anatomy

MucosaCilliated columnar epithelial cells

AnatomyBeat frequency Inhibitory effects of contact

Noncilliated columnar cellsDistributionFunction

Basal cells

40

Microscopic Anatomy—Cont’d

Goblet CellsGlycoproteins—viscosity and elasticity Innervation (para=thick, symp=thin)

Basement membraneSubmucosal glands

Distribution

41

Microscopic Anatomy

42

Mucous Blanket

Two layersSuperficial layerSol layer

FunctionSuperficial layer traps bacteria and

particulate matter.Enzymes, antibodies, immune cells

43

Mucociliary Transport

Directional Flow of MucousToward the choanae

Ostium drainage—a stubborn beastHilding, MD

Contact inhibitionHaller’s cellsSurgery

44

Mucociliary Transport

45

Function of Paranasal Sinuses

Humidifying and warming inspired air

Regulation of intranasal pressure

Increasing surface area for olfaction

Lightening the skull

Resonance

Absorbing shock

Contribute to facial growth

46

New Frontiers

Sleep apnea and the sinuses Humidification contributes up to 6.9mm Hg serum

pO2 Mouth breathers noted to have decreased end-tital

CO2—increased serum CO2—apneas (high baseline)

Nitric Oxide (NO) NO produced primarily in sinuses Toxic to bacteria, fungi, viruses Increases cilliary motility

47

Case Report

39 yom with h/o sinus disease c/o headache, rhinorrhea.

PMHx of “sinus surgery” years ago

ROS reveals h/o two episodes of meningitis in past few years

PE: right superior nasal mass. S/p FESS. Clear rhinorrhea.

48

49

References

Anon, Jack B., et al, Anatomy of the Paranasal Sinuses, Theime, New York, c1996. Bhatt, Nikhil J., Endoscopic Sinus Surgery: New Horizons, Singular Publishing Group, Inc., San Diego, c1997. Bailey, Byron J., et al, Head & Neck Surgery -- Otolaryngology, Lippincott Williams & Wilkins, Philadelphia, c2001. Lundberg, J., Weitzberg, E. Nasal Nitric Oxide in Man. Thorax 1999; 54(10):947-952. McCaffrey, Thomas V., Rhinologic Diagnosis and Treatment, Thieme, New York, c1997. Marks, Steven C. Nasal and Sinus Surgery, W.B. Saunders Co., Philadelphia, c2000. Navarro, Joao A.C., The Nasal Cavity and Paranasal Sinuses, Springer, Berlin, c2001. Watelet, J.B., Cauwenberge P. Van, Applied Anatomy and Physiology of the Nose and Paranasal Sinuses. Allergy 1999; 54, Supp 57:14-25.