Radiological observations on the olfactory fossa and ethmoid roof.

OBJECTIVE: To establish normative dimensions for the depth of the olfactory fossa, the length and angulation of the lateral lamella of the cribriform plate, and the height of the ethmoid roof, in adult males and females. DESIGN: The study assessed 300 high resolution, multislice computed tomography scans of the paranasal sinuses, which were evaluated using Merge Efilm software (version 2.0.0, build 37). RESULTS: According to the original Keros classification, the type II olfactory fossa was the commonest type in men (66.7 per cent), while the type I fossa was commonest in women (53 per cent). A difference of 3 mm or more between the depths of the right and left olfactory fossae was present in 11 per cent of men and 2 per cent of women. The lateral lamella of the cribriform plate was significantly shorter and less oblique in men than in women. The length of the lateral lamella was greater anteriorly than posteriorly in both sexes. There was a statistically significant difference between the angle of the lateral lamellae, comparing right and left sides. The ethmoid roof was lower in women than men. CONCLUSION: The observed differences between men and women and between the right and left sides are of surgical importance, and should alert surgeons to the need for thorough, systematic pre-operative evaluation of computed tomography scans.

The septal body revisited.

INTRODUCTION: The term septal body refers to a thickened area of the nasal septum which is located superior to the inferior turbinate and anterior to the middle turbinate. Despite its important role in changing nasal airflow resistance, it has received little attention. Clinically, a well developed septal body may be misdiagnosed as high septal deviation. AIM: The aim of the present study was to reassess the histological characteristics of the septal body mucosa and the morphometric differences between it and the adjacent septal mucosa. This information was then used to determine the exact location and surface area of the septal body. MATERIALS AND METHODS: The study was performed on 30 cadaveric specimens (60 sides). Serial numbered sections of the whole septal mucosa were stained with haematoxylin and eosin as well as periodic acid Schiff - Alcian blue. Morphometric analysis was performed to determine the histological differences between the septal body mucosa, the anterior septal mucosa and the inferior septal mucosa. The precise boundaries of the septal body area were then defined in a manner similar to the Mohs micrographic surgical technique. RESULTS: The histological characteristics of the septal body mucosa included thick (more than 60 microm), pseudostratified, ciliated respiratory epithelium with goblet cells, abundant seromucinous glands and many blood sinusoids. Morphometric analysis showed that the septal body mucosa had thicker epithelium and more glandular acini and blood sinusoids than the rest of the septal mucosa. Mapping of the septal body area showed that its anterior end was 2.2 +/- 0.3 cm (mean +/- standard deviation) behind the caudal edge of the septal cartilage, and its inferior border was 1.1 +/- 0.2 cm above the floor of the nose. The mean horizontal diameter of the septal body was 2.0 +/- 0.15 cm, and the mean vertical diameter was 1.5 +/- 0.11 cm. CONCLUSIONS: The present study determined the morphometric characteristics of the septal body as well as its location and surface area. The intimate relationship of the septal body to the internal nasal valve and the histological characteristics of its mucosa should stimulate research into its potential role in modifying nasal airflow pattern and resistance, and its role in changing the humidity and temperature of the inspiratory air stream.