“…If the oronasal membrane is not ruptured and remains intact, the posterior choana is obstructed by membrane, bone, or a combined structure, and this is called congenital choanal atresia. One out of 5,000 to 10,000 people have choanal atresia 12 . O'Rahilly 9 reported that in the 18th developmental stage, both the nasal septal cartilage and cartilaginous nasal capsule are formed.…”