1. ENT and Head and Neck Surgery Department, University Hospital Center “Gabriel Touré”, Bamako, Mali
2. ENT and Head and Neck Surgery Department, University Hospital Center “Kamenge”, Bujumbura, Burundi
3. ENT and Head and Neck Surgery Department, Reference Health Center, Kalaban Coro, Mali
4. ENT and Head and Neck Surgery Department, Commune VI Reference Health Center, Bamako, Mali