Association of lateral crural overlay technique with strength of the lower lateral cartilages

IMPORTANCE: The 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 MEASURES Differences 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; P < .001; 2 mm, 0.26 vs 1.13 N; P < .001; 3 mm, 0.31 vs 1.53 N; P < .001; 4 mm, 0.41 vs 2.05 N; P < .001; 5 mm, 0.68 vs 2.60 N; P < .001; 6 mm, 1.49 vs 3.26 N; P = .03). There was a statistically significant difference between the postP and postPG groups in the amount of force required to deflect the cartilages 1 to 5 mm (1 mm, 0.24 vs 0.70 N; P < .001; 2 mm, 0.34 vs 1.13 N; P < .001; 3 mm, 0.51 vs 1.53 N; P < .001; 4 mm, 0.77 vs 2.05 N; P < .001; 5 mm, 1.32 vs 2.60 N; P = .01), but not 6 mm (2.33 vs 3.26 N; P = .31). CONCLUSIONS AND RELEVANCE: The lateral crural overlay technique affords increased strength and resilience to the lateral crura of the lower lateral cartilages, which should in turn decrease the likelihood of external nasal valve collapse postoperatively. LEVEL OF EVIDENCE: NA.