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.
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