Piriform aperture

{{Infobox anatomy

| Name = Piriform aperture

| Latin = apertura piriformis

| Image = Human skull with piriform aperture circled.png

| Caption = A human skull with the piriform aperture circled in red

| Image2 = Michael Sweerts - self portrait with a skull c.1660.jpg

| Caption2 = A self-portrait by Michiel Sweerts depicting him putting his finger into a skull's piriform aperture

| System =

| Precursor =

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The piriform aperture, pyriform aperture, or anterior nasal aperture is a pear-shaped opening in the human skull.

Its long axis is vertical, and narrow end upward; in the recent state it is much contracted by the lateral nasal cartilage and the greater and lesser alar cartilages of the nose.{{Gray's}}

It is bounded above by the inferior borders of the nasal bones; laterally by the thin, sharp margins which separate the anterior from the nasal surfaces of the maxilla; and below by the same borders, where they curve medialward to join each other at the anterior nasal spine.