Association of Lateral Crural Overlay Technique With Strength of the Lower Lateral Cartilages

Abstract

IMPORTANCEThe lateral crural overlay technique is a powerful technique for altering nasal tip projection and rotation. By overlapping and thus shortening the lateral crura, the nasal tip is shortened and rotated upward, thus decreasing projection and increasing rotation. There is no data to show the association of this technique with the strength of the lower lateral cartilage. Strengthening of the lower lateral cartilages would presumably lead to resistance to external nasal valve collapse and improved airway.OBJECTIVE In this cadaver study, we set out to determine the differences in the strength and resilience of the lateral crura after performing lateral crural overlay using 2 different techniques.DESIGN, SETTING, AND PARTICIPANTS Seven individual lower lateral cartilages were harvested from 6 cadavers for analysis. Each of the 7 cartilages was included sequentially in 3 test groups in the following order: a preprocedure group (preP), a postprocedure group (postP) in which the lateral crural overlay technique was performed, and a postprocedure with glue group (postPG) in which cyanoacrylate glue was added to the postP cartilages to simulate cartilage healing. A force gauge was used to measure the force required to deflect the lower lateral cartilages distances from 1 to 6 mm. MAIN OUTCOMES AND MEASURESDifferences measured in newtons (N) for strength and resilience of lateral crura between the preP, postP, and postPG groups.RESULTS A statistically significant increase in lower lateral cartilage resilience was noted between the preP and postPG groups at all distances of tip deflection (1 mm, 0.20 vs 0.70 N;

Effect of Lateral Crural Procedures on Nasal Wall Stability and Tip Aesthetics in Rhinoplasty

“…Consistent with prior studies, we do show that the LCO positively impacts nasal tip cosmesis with subjective improvement between 82% to 92% from baseline 48,49 . In cadaveric studies, the LCO has shown to objectively add strength and resilience to the LC, which subsequently decreases the likelihood of external valve collapse postoperatively 50 . Objectively, in this study, the LCO with or without support did not compromise zone 2, however, we did not find that the LCO alone improved lateral wall stability at zone 2.…”

“…48,49 In cadaveric studies, the LCO has shown to objectively add strength and resilience to the LC, which subsequently decreases the likelihood of external valve collapse postoperatively. 50 Objectively, in this study, the LCO with or without support did not compromise zone 2, however, we did not find that the LCO alone improved lateral wall stability at zone 2. As such, despite the overlap and shorter LC length, the increased tension or support of the side wall may not be sufficient to overcome inspiratory pressures.…”

Comparative Functional Effect of Alternative Surgical Techniques Used in Rhinoplasty

“…The findings of these studies are coherent, as both strut grafts and turn-in flaps create double-layered cartilages throughout the extent of the lateral crura, though strut grafts, usually made from thicker septal cartilage, will probably increase resilience to a further extent. Also studying on cadaver cartilages, Insalaco et al 51 found lateral crural overlay to increase strength and resilience of lateral crura, which should account for a better ENV function. Lateral crural overlay doubles cartilage thickness, but only on a limited extent of the crura.…”

Rhinoplasty as an Adjunct to Facial Rejuvenation

“…Overlapping the lateral crura has the added advantage that it increases the strength of the lateral crus. 32 Another option to increase rotation is a lateral crural steal. This has the added benefit that the projection is also increased.…”