The sinuses are hollow cavities within the facial bones. Sinuses are not fully developed until after age twelve. When people speak of sinus infections, they are most frequently referring to the maxillary and frontal sinuses.
Reviewed last on: 4/21/2009
Alan Lipkin, MD, Otolaryngologist, Private Practice, Denver, Colorado. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.