paranasal sinus

PARANASAL SINUSES

Ap.Dr.ALI MOHSIN HASAN
DGS FICS CABS MRCS FRCS

OBJECTIVES:

Anatomical location
Connections
Development
Neurovascular supply
Applied anatomy

PNS:

Air containing cavities

4 pairs :-

Frontal
Maxillary
Ethmoidal
Sphenoidal

FUNCTION:

To make the skull lighter and add resonance to the voice.
The sinuses are rudimentary or even absent at birth.
Enlarge rapidly during the age 6yr and then afterwards.

MAXILLARY SINUS:

Largest of all
Pyramidal in shape
Base pointing to lateral wall of nose.
Apex laterally in the zygomatic process of maxilla.

BOUNDARIES:

Anterior:- facial surface of maxilla
Posterior:-infratemporal and pterygopalatine fossa
Medial:- middle and inferior meatus
Floor:- alveolar and palatine processes of maxilla
Roof:-floor of orbit

BLOOD SUPPLY:

ARTERIAL:
By facial artery branch of ECA.
By infra orbital & greater palatine arteries branch of max. art which is branch of ECA.
VENOUS:
To anterior facial vein& pterygoid plexus.

NERVE SUPPLY:

Infraorbital nerve
Anterior superior alveolar nerve
Middle superior alveolar nerve
Posterior superior alveolar nerve

FRONTAL SINUS:

Resides in frontal bone
2nd largest
Asymmetrical
Right n left are usually unequal

RELATIONS:

Anterior:- skin over the forehead
Inferior:-orbit & its contents
Posterior:- meningeal and frontal lobe of brain

NEUROVASCULAR SUPPLY:

Blood supply - Supra orbital artery
Venous return - Anastomotic veins in supra orbital notch, connecting supra orbital and supra ophthalmic veins.
Lymphatic drainage - Submandibular nodes.
Nerve supply - Supra orbital nerve(ophthalmic nerve)

SPHENOIDAL SINUS:

Resides in body of sphenoid
May be single or paired
Asymmetrical
Unequal in size






RELATIONS:

1.Cavernous sinus lies laterally containing the:

• IIIrd,

• IVth,

• Vth (ophthalmic
and maxillary-
divisions) and

• VIth cranial nerves,

2.Internal carotid artery

SUPERIORLY
Optic chiasma
Hypophysis cerebri

NEUROVASCULAR SUPPLY:

Blood supply:
Posterior ethmoidal artery
Venous drainage:
Pterygoid plexuses
Nerve supply:
Posterior ethmoidal nerve
Lymphatic drainage: Retropharyngeal nodes

ETHMOIDAL SINUS:

Resides in ethmoid bone
3 groups:-
Anterior
Middle
Posterior
Number varies from 3-18
Present from birth

RELATION:

Above:orbital plate of frontal bone
Behind:orbital process of palatine bone
Anteriorly:
lacrimal bone

NEUROVASCULAR SUPPLY:

Arterial supply
Anterior ethmoidal artery(ophthalmic artery)
Post. Ethmoidal artery
Sphenoidal artery(maxillary artery)
Venous drainage
Ant. Ethmoidal vein
Post. Ethmoidal vein

Nerves :

Anterior and posterior ethmoidal nerves.Orbital branches of pterygopalatine ganglion
Lymphatic drainage : Submandibular nodesRetropharyngeal nodes

DEVELOPMENT:

Outpouching from mucus membrane of nose
at birth:-Maxillary and ethmoidal present
At 6-7 yrs:- frontals and sphenoids
At 17-18 :- all fully developed

DRAINAGE:

APPLIED ANATOMY:

SINUSITIS:
Infection of sinus
S/S:
Headache
Thick purulent discharge from nose


DRAINING MAXILLARY SINUS:

SITE OF INCISION:

CLINICAL PICTURE:

APPLIED:

Frontal sinusitis and ethamoidal sinusitis can cause edema of the lids secondary to infection of the sinuses

RADIOGRAPHIC FINDINGS:

BENIGN NEOPLASMS

Osteomas
Fibrous Dysplasia
Ossifying Fibroma
Ameloblastoma
Inverted Papilloma

OSTEOMA

15 to 40 years
Frontal > Ethmoid > Maxillary
Slow-growing bone tumour &
often remains asymptomatic.
It can cause
obstruction of ostium
mucocele formation
pressure symptons
Rx :Local excision

FIBROUS DYSPLASIA

Bone replaced by Fibrous tissue
Maxilla > Ethmoids & Frontal
C/F:
Disfigurement of Face
Nasal Obstruction
Displacement of eyes
Radiology:
Diffuse margins with Ground glass appearance
Rx - Cosmetic restructuring surgery

FIBROUS DYSPLASIA

Axial CT shows radiopaque mass oblitearating maxillary sinus and nasalcavity on the right side

Ameloblastoma(ADAMANTINOMA)

Arises from odontogenic tissue
Locally aggressive
Invades maxillary sinus
Rx :surgical excision

MALIGNANT NEOPLASMS

Ca nose & PNS constitute 0.44% of all malignancies in india
Frequency = Max.s > Ethm.s > Frontal.s > Sphenoid.s
AETIOLOGY
Nickel & Chromium refineries(Sq. Cell Ca & Anaplastic).
Mahogany wood industries (Adeno Ca).
Leather Tanning industries.
Bantus tribes of South Africa –max s Ca due to use of stuff containing Ni & Cr.


Malignant NEOPLASM-lesions
Squamous cell carcinoma-------80%
Adenocarcinoma
Adenoid cystic carcinoma 20%
Melanoma
Sarcomas
etc

CA MAXILLARY SINUS

Arises from the lining of max sinus.
• Middle aged males(40 -60yrs)
Remain silent for a long time or showing only symptons of sinusitis
Late :destroy bony walls & invades in to surrounding structures.

CA MAXILLARY SINUS

Clinical Features
Nasal Stuffiness
Blood stained Nasal discharge
Parasthesia or pain over cheek
Epiphora


These are early C/F.
Often misdiagnosed and treated as sinusitis.

CA MAXILLARY SINUS

Clinical Features based on extention
MEDIAL SPREAD=Nasal obstruction + discharge + epistaxis
Superior spread=Proptosis + diplopia + ocular pain + epiphora
INFERIOR SPREAD=Expansion of alveolus + denatal pain + loosening teeth + poor fitting dentures + ulceration of gingiva + swelling hard palate.
ANTERIOR SPREAD=Swelling of cheek + invasion of facial skin
POSTERIOR spread=Trismus
INTRACRANIAL spread=Via ethmoid , cribriform plate or foramen lacerum
LYMPHATIC SPREAD=Submandibular , Upper jugular nodes and retropharyngeal nodes are enlarged in late stage.
SYSTEMIC SPREAD=in to lungs and occasionally to bones.

CA MAXILLARY SINUS

DIAGNOSIS:
X-ray PNS.
CT Scan of PNS ( Coronal & Axial).
Biopsy - Nasal Mass / Endoscopic.

CA MAXILLARY SINUS

CA MAXILLARY SINUS-classification

OHNGREN’s Classification
Imaginary plane drawn b/w medial canthus of eye & the angle of mandible
Lesion above this : suprastuctural—poor prognosis
Lesion below this : infrastructural

CA MAXILLARY SINUS-classification

AJCC(American Joint Committee on Cancer) Classification
Only for squamous cell Ca
Histopathological
• Well differentiated
• Moderately differentiated
• Poorly differentiated


CA MAXILLARY SINUS-classification
Lederman’s Classification

TNM staging of Ca maxillary sinus

Tumour
T1: Limited to antral mucosa without bony erosion.

T2: Erosion or destruction of the infrastructure, including the hard palate and/or middle meatus

T3: Tumor invades: skin of cheek, posterior wall of sinus, inferior or medial wall of orbit, anterior ethmoid sinus

T4: Tumor invades orbital contents and/or: cribriform plate, post ethmoids or sphenoid, nasopharynx, soft palate, pterygopalatine or infratemporal fossa or base of skull

CA MAXILLARY SINUS

TREATMENT
For SCC, combination of radiotherapy and surgery is the choice.
surgery
Total Maxillectomy
Partial Maxillectomy
PROGNOSIS
5yrs survival rate is 30%

ETHMOID SINUS MALIGNANCY

Primary lesion is not common in ethmoid sinus
Occur as an extension from maxillary sinus growth
C/F :
Nasal obstruction
Blood stained nasal discharge
Retro orbital pain
Lateral displacement of eye & diplopia
Intracranial spread can cause meningitis
Rx :Pre operative radiation + Total ethmoidectomy
Prognosis : 5yrs survival rate is 30%

FRONTAL SINUS MALIGNANCY

Uncommon
40-50 yrs age group ; males more
C/F :
Pain & Swelling in frontal region
Growth can go post to ant cranial fossa
Growth can extent through the ethmoids into orbit
Rx : Pre operative radiation + Frontal sinusectomy


THANKS A LOT FOR KIND ATTENDION !!!!!!!