The sinuses are hollow cavities within the facial bones. Sinuses are not fully developed until after age 12. When people speak of sinus infections, they are most frequently referring to the maxillary and ethmoid sinuses.
Review Date: 5/25/2016
Reviewed By: Sumana Jothi, MD, specialist in laryngology, Assistant Clinical Professor, UCSF Otolaryngology, NCHCS VA, SFVA, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.