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: 1/25/2022
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.