|- style="text-align: center; line-height: 1;" class="hiddenStructure"
| colspan="2" |
|- class="hiddenStructure"
|Latin
|colspan="2"|a. piriformis
|- class="hiddenStructure"
|
|colspan="2"|[subject #47 ]
|- class="hiddenStructure"
|System
|colspan="2"|
|- class="hiddenStructure"
|Precursor
|colspan="2"|
|- class="hiddenStructure"
|MeSH
|colspan="2"|[]
|- class="hiddenStructure"
|Dorlands/Elsevier
|colspan="2"|[a_51/12144737]
|}
The Anterior Nasal Aperture (or piriform aperture) is a heart-shaped or pyriform opening, whose long axis is vertical, and narrow end upward; in the recent state it is much contracted by the lateral and alar cartilages of the nose.
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 maxillæ; and below by the same borders, where they curve medialward to join each other at the anterior nasal spine.
