18 - Development and Growth of ParaNasal sinuses

SINUS	STATUS AT BIRTH And First radiological evidence	GROWTH
Frontal sinus	Not present; First radiological evidence at 6 years of age	Invades frontal bone at the age of 4 years. Size increases until teens.
Sphenoid sinus	Not present; First radiological evidence at 4 years of age	Reaches sella turcica by the age of 7 years, dorsum sellae by late teens and basisphenoid by adult age. Reaches full size between 15 years to adult age.
Maxillary sinus	Present at birth; First radiological evidence at 4-5 months of age	Rapid growth from birth to 3 years and from 7-12 years. Adult size – 15 years .
Ethmoidal sinus	Present at birth -Anterior group = 5x2x2mm -Posterior group = 5x4x2 mm; First radiological evidence at 1 year of age	Reach adult size by 12 years

17 - PGI Chandigarh December 2007 ENT Mcqs with answers

1q: Nasopharyngeal carcinoma causes deafness by ?

a. Blocking the eustachian tube
b. serous otitis media
c. Temporal bone metastasis
d. Radiation

answer a and b

2q: About otosclerosis, following are true except ?

a. more common in males
b. commonly unilateral
c. sensory neural hearing loss
d. stapedectomy done

answer b and c are wrong statements. The hearing loss in otosclerosis is bilateral conductive type. Normally females are twice as often affected with this disease than males, but in india it is predominant in males.

3q: Bone which is pneumatic ?

a. maxillary
b. parietal
c. temporal
d. frontal
e. ethmoidal

answer a, d, e.

4q: True about tympanic membrane ?

a. tympanosclerosis increases compliance
b. ossicular disruption with intact tympanic membrane decreases compliance
c. fluid in middle ear cavity increases compliance
d. otosclerosis decreases compliance

answer d is the only true statement. Otosclerosis and tympanosclerosis decreases compliance. option b increases compliance.Middle ear effusions result in no change in compliance.

5q: True in temporal bone surgery ?

a. mastoid makes landmark
b. trautmenn's triangle used as a guide for incision
c. antrum acts as landmark

answer b is the only true statement. Trautmenn's triangle is defined as the area limited by the anterior border of the sigmoid sinus posteriorly, the petrous ridge superiorly and a line connecting the jugular bulb to the petrous apex anteriorly .