1. Department of Otolaryngology, Loyola University Medical Center, Maywood, Illiniois
2. Cincinnati Sinus Institute, a division of Group Health Associates of Cincinnati, Cincinnati, Ohio
3. St. Cloud Ear, Nose, and Throat-Head and Neck Clinic, St. Cloud, Minnesota
4. Texas Sinus Center, San Antonio, Texas
5. Austin Ear, Nose, and Throat Clinic, Austin, Texas