Observations of the marginal incision and lateral crura alar cartilage asymmetry in rhinoplasty: a fixed cadaver study.

OBJECTIVE: This anatomical cadaver study was intended to incrementally determine the precise relationship between the alar rim skin margin and the caudal aspect of the lateral crus of the nose. The second intention was to preliminarily test the hypothesis of sexual dimorphism in the lateral crura size and of right to left asymmetry of the lateral crura in the same individual.

STUDY DESIGN: Demographic information of 39 Caucasian cadavers was collected. Dissection of 28 unilateral and 11 bilateral noses included the removal of all of the soft tissue from the lateral surface of lateral crura cartilages. The distance from the caudal edge of the lateral crus to the alar margin was measured beginning at the junction of the middle and lateral crura moving posteriorly. The lateral crus was then completely dissected out from the remaining surrounding soft tissue for measurement of the length, height, and thickness.

RESULTS: Comparison of the cartilage dimensions between the sexes showed significant differences between the length, height, and thickness of the cartilages. The distance between the caudal aspect of the lateral crus and alar skin margin was less than 6.7 mm on average for the anterior 15 mm of the lateral crus. Comparison for intraindividual right to left asymmetry showed significant differences in 3 infracartilaginous-alar skin margin distance measurements and in cartilage length and height.

CONCLUSION: The marginal incision can be close to the alar skin margin in the first 15 mm. Right to left intraindividual asymmetry in the first 20 mm was significant. Intraindividual right to left asymmetry was significant in the lateral crura length and height. Sexual dimorphism in the lateral crura length, height, and thickness was observed.