The normal inferior turbinate: Histomorphometric analysis and clinical implications

Objective: To study the histological and morphometric features of the normal inferior turbinate. Study Design: A prospective, nonrandomized study. Methods: Sixteen specimens were removed at autopsy and during septoplasty operations, stained with H&E, and investigated microscopically. The soft tissue and bony elements were measured. Morphometric analysis included measurements of the relative proportions of the soft tissue constituents. Results: The medial mucosal layer is thicker than the bone and the lateral mucosa; the difference between the mucosal layers is statistically significant. The inferior turbinate is almost exclusively covered with a pseudostratified ciliated columnar epithelium that houses more goblet cells on its lateral side. It has a well-defined basement membrane zone that is significantly thicker on the medial side. The main bulk of the inferior turbinate is the lamina propria that is built of loose connective tissue and superficially harbors an inflammatory cell infiltrate. The area fraction of glands in the lateral mucosa significantly exceeds that of the medial and inferior mucosal layers, whereas that of venous sinusoids varies significantly, with the greatest difference inferiorly. Decreased proportion of glands and an increase in venous sinusoids are associated with advanced age. The cancellous central bony layer is made of interwoven trabeculae and houses the major arterial supply of the turbinate. After the major arteries exit the bone, they lie in the deepest portions of the medial and lateral mucosal layers but are missing from the inferior layer. Conclusion: In-depth histomorphometric analysis can assist in developing new function-preserving approaches to turbinate surgery.