<prompt> Most common site of sinusitis in childrenMaxillary sinusEthmoidal sinusFrontal sinusSpenoid sinus  <response>: Acute ethmoid sinusitis Aetiology Acute ethmoiditis is often associated with infection of other sinuses. Ethmoid sinuses are more often involved in infants and young children. Ref: Diseases of ENT, PL Dhingra, 7th edition, of no. 216 