Human nasal cartilage ultrastructure: characteristics and comparison using scanning electron microscopy

Abstract

Objectives/hypothesis: Human nasal cartilage is hyaline cartilage, although the function and loads placed on it are different depending on the location. We hypothesized that important differences exist between the nasal septal cartilage and lower lateral cartilage (LLC) ultrastructures. Such differences would be important in the field of cartilage engineering.

Methods: Ten specimens (6 septum and 4 LLC) of cartilage from patients undergoing nasal surgery (rhinoplasty or septoplasty) were obtained and examined using scanning electron microscopy. Micrographs were then analyzed and measured using photograph analysis software.

Results: The collagen fibers of septal cartilage were found to be arranged in a mesh framework, with larger lacunae and thicker fibers measuring 3.18 microm (standard deviation = 0.75 microm), with a 99.9% confidence interval of 2.74 to 3.54 microm. LLC fibers, on the other hand, were arranged in less-organized sheets, with fibrous extensions, and had fewer, narrower lacunae. The fibers from the LLC averaged 2.29 microm, with a 99.9% confidence interval of 1.17 to 3.42 microm.

Conclusions: Significant ultrastructural differences exist between the cartilage of the nasal septum and LLC. These are almost certainly the result of their embryologic origins and different forces placed on the structures they support. A less-organized pattern with smaller collagen fibers is present in the LLC versus the more-organized, layered, thicker collagen fibers of the septum. These differences may prove to be critical in the future of cartilage engineering.

Fig. 1

Scanning electron micrographs of human lower lateral cartilage. Each successive image from A to C is of increasing magnification of ×1,000, ×2,000, and ×3,000. (A) General arrangement of superficial structures. (B and C) Higher magnifications show thin collagen fibers clearly arranged in loosely woven pattern around narrower lacunae.

Fig. 2

Scanning electron micrographs of different human lower lateral cartilage specimen than those in Figure 1. Each successive image from A to C is of increasing magnification of ×1,000, ×2,000, and ×3,000. (A) General arrangement of superficial structures. This specimen demonstrates increased number of fine, fibrous projections compared with Figure 1. (B and C) Higher magnifications show thin collagen fibers under fibrous projections and at least one chondrocyte.

Fig. 3

Scanning electron micrographs of human nasal septal cartilage. Each successive image from A to C is of increasing magnification of ×1,000, ×2,000, and ×3,000. (A) General arrangement of tightly associated sheets of collagen fibers. (B and C) Higher magnifications show thick collagen fibers clearly arranged in tight linear array around broader, more round lacunae.

Fig. 4

Scanning electron micrographs of different human nasal septal cartilage than that in Figure 3. Each successive image from A to C is of increasing magnification of ×1,000, ×2,000, and ×3,000. (A) Arrangement of tightly associated sheets of collagen fibers. (B and C) Higher magnifications show more of same thick collagen fibers and round lacunae as noted in Figure 3.