Your child’s sinuses are not fully developed until age 20. Although small, the maxillary sinuses (behind the cheek) and the ethmoid sinuses (between the eyes) are present at birth. Unlike in adults, pediatric sinusitis is difficult to diagnose because symptoms can be subtle and the causes complex.

http://www.youtube.com/watch?feature=player_embedded&v=m0PeRHPn-lo

What are the symptoms of sinusitis?
How is sinusitis diagnosed?
How is sinusitis treated?
When is surgery necessary for sinusitis?
How can sinusitis be prevented?
When is primary immunodeficiency suspected?