[1] St Vincents Hosp, Skull Base Surg, Dept Otolaryngol Head & Neck, Sydney, NSW 2010, Australia
[2] Changi Gen Hosp, Dept Otolaryngol Head & Neck Surg, Singapore, Singapore
[3] Macquarie Univ, Australian Sch Adv Med, Sydney, NSW 2109, Australia
[4] Univ New S Wales, Fac Med, Sydney, NSW, Australia