1. Rhinology and Endoscopic Sinus Surgery; Division of Otolaryngology-Head and Neck Surgery; Department of Surgery; University of Calgary; Calgary Alberta Canada
2. Division of Neurosurgery; Department of Clinical Neurological Sciences; University of Calgary; Calgary Alberta Canada
3. Department of Neurosurgery; Medical University of South Carolina; Charleston South Carolina U.S.A
4. Division of Rhinology and Sinus Surgery; Department of Otolaryngology-Head and Neck Surgery; Medical University of South Carolina; Charleston South Carolina U.S.A