Rhinoplasty: the lateral crura-alar ring

Area of Science:

• Plastic Surgery
• Anatomy
• Rhinology

Background:

• Rhinoplasty often involves excising or incising lateral crura, potentially causing nostril rim retraction, bossa, and collapse.
• There's a growing emphasis on preserving lateral crura in rhinoplasty.
• A detailed anatomical review of the lateral crura is necessary.

Purpose of the Study:

• To quantify specific anatomical aspects of the lateral crura.
• To provide data for preserving lateral crura during rhinoplasty.
• To understand anatomical factors contributing to alar malposition.

Main Methods:

• A two-part study involving 40 rhinoplasty patients and 20 cadaver dissections.
• Clinical measurements included alar position, axis, and width.
• Cadaver dissections focused on inaccessible parts of the lateral crura and alar ring.

Main Results:

• Clinical measurements showed lateral crura distance from mid-nostril point averaged 5.9 mm and cephalic orientation averaged 43.6 degrees.
• The lateral crura axis was typically smooth-straight horizontally, with the cephalic border higher than the caudal border vertically.
• Cadaver dissections revealed average dimensions: 23.4 mm length, 6.4 mm width at domal notch, 11.1 mm at the turning point (TP), and 0.5 mm thickness.

Conclusions:

• The lateral crura-alar ring forms a circular structure not abutting the pyriform.
• The lateral crura extends from the domal notch to accessory cartilages, featuring a distinct turning point and specific horizontal/vertical vectors.
• Proper caudal border positioning (higher than cephalic) is essential; malposition may relate to position, orientation, or configuration.