Abstract:
Background: Olfactory fossa is a depression in the anterior cranial cavity which harbours
the olfactory nerve and bulb. The depth of olfactory fossa is directly proportional to Body
Mass Index. Hence, higher Body Mass Index individuals have deeper olfactory fossa and
are most vulnerable to Cerebrospinal fluid leaks during Skull base surgeries and
Functional endoscopic sinus surgeries.
Aim: The aim was to study the relationship between depth of the olfactory fossa and Body
Mass Index by using Multidetector Computed Tomography in North Karnataka region.
Methods: Paranasal multidetector computed tomographic scans of 820 patients were
collected in North Karnataka region, Karnataka, India by using bone window. The depth of
olfactory fossa, width, angle of olfactory fossa, thickness of lateral lamella of cribriform
plate and length of cribriform plate were estimated on both the sides in both genders. Side
symmetry and relation of morphology of olfactory fossa in both genders were calculated
by using Student ‘t’ (unpaired) test. Correlation between the depth of olfactory fossa and
BMI was calculated by using Pearson’s correlation. The data was considered statistically
significant if p was less than 0.05.
Results: Type II keros was most common when compared to other types of Keros of
olfactory fossa. Statistically significant differences were observed in the depth of olfactory
fossa, angulation of olfactory fossa and length of Cribriform plate when compared between
male and female patients. Significant differences were not observed in the width of
olfactory fossa and thickness of Lateral Lamella of Cribriform Plate when compared
between males and female patients. There was a linear correlation between Body Mass
Index and Olfactory Fossa depth; as Body Mass Index increases, depth of olfactory fossa
shifts from type II to type III.
Conclusion: This would help Radiologists, Neurosurgeons and Endoscopic surgeons toevaluate the complex ethmoidal skull base which are difficult to approach without
distortion and without damaging other structure
