ORBIT & OCULAR ADNEXAE - Paranasal Sinuses

Question 1

Which sinuses drain into…
1. the superior meatus
2. middle meatus
3. inferior meatus

Answer 1

1. superior - sphenoid and posterior ethmoid
2. middle and hiatus semilunaris - maxillary, anterior ethmoid, frontal
3. inferior - opening of nasolacrimal duct

Question 2

Which is the largest paranasal sinus?

Answer 2

Maxillary sinus

Question 3

What is the nerve supply of
1. Maxillary sinus (4)
2. Frontal sinus (1)
3. Sphenoid sinus (1)
4. Ethmoid sinus (3)

Answer 3

Maxillary: infraorbital, anterior/middle/ posterior superior alveolar nerves

Frontal: supraorbital nerve (ophthalmic)

Sphenoid: posterior ethmoidal nerve

Ethmoid: anterior and posterior ethmoidal nerves and pterygopalatine ganglion

Question 4

Which paranasal sinuses are present at birth (3)

Answer 4

1. ethmoid
2. maxillary
3. frontal (sometimes, usually at 2 years)

Question 5

Which paranasal sinuses develop 2-3 years after birth (2)

Answer 5

1. sphenoid
2. frontal (usually at 2 years, sometimes at birth)

Question 6

What is the osseous canal of the nasolacrimal duct formed by? (3)

Answer 6

1. Maxilla
2. Lacrimal bone
3. Inferior nasal concha

Question 7

Which structures travel through the roof of the maxillary sinus?

Answer 7

Infraorbital nerve and artery

Question 8

Which sinus cannot be seen radiologically until 6th year of life?

Answer 8

Frontal sinus

Question 9

Which sinus is the most common cause of orbital cellulitis?

Answer 9

Sinisitus in the ETHMOIDS