Which among the following sinuses is most commonly affected in a child?

Ethmoiditis is often associated with infections of other sinuses. Ethmoid sinuses are more often involved in infants and young children. C/F: pain over the bridge of nose medial deep to the eye. Aggravated by movements of the eyeball. Oedema of eyelids, increased lacrimation, Nasal discharge and Swelling of the middle turbinate. Complications: orbital cellulitis and abscess, Visual deterioration and blindness due to the involvement of optic nerve, Cavernous sinus thrombosis, Extradural abscess and meningitis or brain abscess. (Ref: PL Dhingra, Diseases of ENT, Edition 7th, pg no.216)