Supernumerary Nostril, Proboscis Lateralis and Polyrhinia

Supernumerary nostrils can be divided into three categories: extranostrils added to normal pair of nostrils as simple supernumerary, Proboscis lateralis when only one nostril present and a new nostril develop later, Polyrhinia is described as double set of noses in a single face. GnRH required for growth and manifestation of sexual organs originated at nasal placodes and settles at hypothalamus later. Formation of a new nostril requires a new nasal placode to form and grow.