Sinus not present at bih is/are: September 2010
Ans. C: Frontal The paranasal sinuses are hollow, air-filled cavities that are lined by a mucous membrane. The ethmoid and maxillary sinuses are present at bih. The frontal sinus develops about the second year of life and the sphenoid about the third year. Sometimes, the frontal sinuses do not develop.
Maxillary
Ethmoidal
Frontal
All of the above