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Paranasal Sinuses: Anatomy and FunctionGlen T. Porter, MD

Francis B. Quinn, MDUTMB Department of Otolaryngology

Galveston, TX

January 2002

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Case Report—1000B.C.

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7 bones4 paired sinuses4 turbinates3 meatiDrainage systemNervous supplyVascular supplyRelated structures

Sinus Anatomy Overview

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MaxilloturbinalEthmoturbinal

Middle turbinateSuperior turbinateSupreme turbinate

Agger nasiUncinate processEthmoid infundibulumSinuses

MaxillaryEthmoid

Embryology

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SinusDevelopment

6 Pediatric Sinuses

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EthmoidMaxillaPalatineLacrimalPterygoid plate of

SphenoidNasal Inferior Turbinate

Bony Structure

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Arterial Supply

External CarotidMaxillary A.

SphenopalatineInternal CarotidOphthalmic A.

Ant. EthmoidPost. Ethmoid

SupraorbitalSupratrochlear

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Innervation

10Neurovascular Supply

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Sinus Drainage Schema

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Ethmoid Sinus

Development! Present at birth! Anterior/Posterior! Variability

Structure! Volume/shape! Roof! Lateral wall

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Ethmoid Roof

•Anterior 2/3•Posterior 1/3

Keros IKeros IIKeros III

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Ethmoid Cells

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

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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

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Basal/GroundLamella Basal/Ground Lamella

Of the Middle Turbinate

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The Agger Nasi Cell

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Ethmoid BullaUncinate Process

Hiatus Semilunaris

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Ethmoid Infundibulum

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Suprabullar/Retrobullar Recess

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Ethmoid Arteries

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Osteomeatal ComplexMiddle meatusMaxillary Sinus OstiumAnterior EthmoidDrainage

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Maxillary Sinus

Development! Present at birth! Biphasic growth! Level of the floor

Structure! Volume & shape! Walls, floor, roof

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Maxillary Sinus

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Maxillary Sinus

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Maxillary Sinus

Related Structures! Fontanelles! Natural ostium

! Haller’s Cells &Sinusitis! Osteomeatal complex

! Accessory Ostium! Nasolacrimal duct

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Fontanelles

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Natural Ostium-Haller’s cells

Accessory Ostium

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Nasolacrimal Duct

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Frontal Sinus

Development! Frontal bone at birth! Age 5

Structure! Volume and shape! Ostium! Walls

! Anterior vs. posterior

Related Structures! Frontal recess

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Frontal SinusOstiumFrontal recess

BoundariesDumbbell shape

Sinus LateralisFrontal Bulla

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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

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Sphenoid Sinus Pneumatization

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Sphenoid Sinus

Sphenoid Sinus

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Sphenoid Sinus

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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

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Sphenoid OstiumSphenoethmoid RecessSphenoid Rostrum

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The Onodi Cell

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Microscopic Anatomy

Mucosa! Cilliated columnar epithelial cells

! Anatomy! Beat frequency! Inhibitory effects of contact

! Noncilliated columnar cells! Distribution! Function

! Basal cells

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Microscopic Anatomy—Cont’d

Goblet Cells! Glycoproteins—viscosity and elasticity! Innervation (para=thick, symp=thin)

Basement membrane! Submucosal glands

! Distribution

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Microscopic Anatomy

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Mucous Blanket

Two layers! Superficial layer! Sol layer

Function! Superficial layer traps bacteria and

particulate matter.! Enzymes, antibodies, immune cells

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Mucociliary Transport

Directional Flow of Mucous! Toward the choanae

Ostium drainage—a stubborn beast! Hilding, MD

Contact inhibition! Haller’s cells! Surgery

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Mucociliary Transport

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Function of Paranasal Sinuses

Humidifying and warming inspired airRegulation of intranasal pressureIncreasing surface area for olfactionLightening the skullResonanceAbsorbing shockContribute to facial growth

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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

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Case Report

39 yom with h/o sinus disease c/o headache, rhinorrhea.PMHx of “sinus surgery” years agoROS reveals h/o two episodes of meningitis in past few yearsPE: right superior nasal mass. S/p FESS. Clear rhinorrhea.

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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.