Anatomic Variation of Sphenoid Sinus in Mysore Based Population: CT Scan Study.

ABSTRACT

Introduction: Sphenoid sinus is the most inaccessible paranasal sinus, enclosed within the sphenoid bone and intimately related to numerous vital neural and vascular structures.The internal structure of the sphenoidal sinus varies greatly in different skulls and on opposite sides of the same skull, and the great differences observed may be responsible for the total lack of any previous attempt to determine the arrangement and significance of the ridges and septa which are frequently found therein. Objective: To study the sphenoid air sinus anatomy in detail in relation to its Morphology and Pneumatization. Material and Methods: 80 macerated skulls (Males=48, Females=32) of age group 40-60 yrs are cleaned and subjected to 3D axial multislider CT scan. Axial and coronal images of slice thickness of 4mm were obtained. sphenoid sinus symmetry and pneumatisation was observed and classified. To obtain proper evaluation of the neighboring structures and their relation to the sphenoid sinus, 2-mm contiguous slice thickness will be used from anterior to posterior sphenoid sinus. Results: The present study showed symmetry in 56 skulls( 70%) , asymmetry in 18 skulls(22.5%) and presence of transverse septa in 6 skulls (7.5%). The sellar type of pneumatisation in 68 skulls (85%), presellar type in 8(10%) and post sellar type in 4 skulls (5%). Conclusion: This study will prove invaluable in the trans-sphenoidal approach to the pituitary as this technique needs thorough understanding of the pituitary fossa and surrounding structures.