It is considered an anatomic variation of the canal if it has a diameter larger than 1 mm, an ending that differs from the anterior nasal spine
, or divisions of the canal along its pathway (Shelly et al., 1999; Valcu et al., 2011; Neves et al., 2012; de Oliveira-Santos et al.; von Arx et al.; Torres et al., 2015).
On the other hand, if this is done overzealously in front of the anterior nasal spine
, in the postoperative period when scarring is taking place, columellar retraction may occur, leaving the columella in a relatively 'hanging' position.
Cross-sectional area was measured in eleven coronal levels, and nasal cavity volume was evaluated from anterior nasal spine
to posterior nasal spine.
Certain other researchers such as Winstead et al, 200016 were unable to find the openings but did observe septal fossae consistently located 7 10 mm above the palatal mucosa and 10 20 mm posterior to the anterior nasal spine
. Zbar et al, 200017 have proposed a classification system dividing into four classes ranging from absent VNO through to lumen size of less than 2 mm to more than 2 mm and multiple lumina.
Infiltration of nasal structures may lead to sensation of nasal stuffiness, epistaxis, saddle deformity due to septal perforation and destruction of the anterior nasal spine