1. Orange County Sinus Institute, Southern California Permanente Medical Group, Irvine, California
2. Department of Head and Neck Surgery, David Geffen School of Medicine at University of California–Los Angeles, Los Angeles, California
3. Department of Neurosurgery, Anaheim Medical Center, Southern California Permanente Medical Group, Anaheim, California
4. Department of Pathology, Woodland Hills Medical Center, Southern California Permanente Medical Group, Woodland Hills, California