Department of Otolaryngology-Head & Neck Surgery;
Sir Syed College of Medical Sciences;
Karachi;
Pakistan;
Department of Otolaryngology-Head & Neck Surgery;
Aga Khan University & Hospital;
Karachi;
Pakistan;
Department of Otolaryngology-Head & Neck Surgery;
Armed Forces Hospital Southern Region;
Khamis Mushayt;
KSA;
Stanford University;
Palo Alto;
USA;