Rhinoplasty: The Lateral Crura-Alar Ring

Background: Rhinoplasty surgeons routinely excise or incise the lateral crura despite nostril rim retraction, bossa, and collapse. Given recent emphasis on preserving the lateral crura, a review of the lateral crura's anatomy is warranted. Objectives: The authors quantify specific anatomical aspects of the lateral crura in cadavers and clinical patients. Methods: This was a 2-part investigation, consisting of a prospective clinical measurement study of 40 consecutive rhinoplasty patients (all women) and 20 fresh cadaver dissections (13 males, 1 female). In the clinical phase, the alar cartilages were photographed intraoperatively and alar position (ie, orientation), axis, and width were measured. Cadaver dissections concentrated on parts of the lateral crura (alar cartilages and alar ring) that were inaccessible clinically. Results: Average clinical patient age was 28 years (range, 14-51 years). Average cadaver age was 74 (range, 57-88 years). Clinically, the distance of the lateral crura from the mid-nostril point averaged 5.9 mm, and the cephalic orientation averaged 43.6 degrees. The most frequent configuration of the axis was smooth-straight in the horizontal axis and a cephalic border higher than the caudal border in the vertical axis. Maximal lateral crura width averaged 10.1 mm. In the cadavers, average lateral crural dimensions were 23.4 mm long, 6.4 mm wide at the domal notch, 11.1 mm wide at the so-designated turning point (TP), and 0.5 mm thickness. The accessory cartilage chain was present in all dissections. Conclusions: The lateral crura-alar ring was present in all dissections as a circular ring continuing around toward the anterior nasal spine but not abutting the pyriform. The lateral crura (1) begins at the domal notch and ends at the accessory cartilages, (2) exhibits a distinct TP from the caudal border, (3) has distinct horizontal and vertical vectors, and (4) should have a caudal border higher than the cephalic border. Alar malposition may be associated with position, orientation, or configuration.