ENT Nose and paranasal sinuses cb8e1892 Sinus least involved in children is: A Ethmoid B Maxillary C Frontal D Sphenoid High-Yield Explanation The reason for sphenoid sinus to be least affected as it opens high up in the sphenoid recess which is not affected by most of the conditions of nose. Ref Dhingra 6/e,p 193