Pneumatization patterns of human sphenoid sinus associated with the internal carotid artery and optic nerve by CT scan

Introduction. The sphenoid sinus is an unique space arises within the nasal capsule of the embryonic nose and remains undeveloped until age three years. It appears before birth in small size; but a recognized definitive cavity revealed at birth. Secondary pneumatization does not begin until ten years old and finally by age 18 it reaching the full size. Aim. To demonstrate the extent of sphenoid sinus pneumatization and identify the extent of pneumatization for two related anatomical structures, the internal carotid artery and optic nerve by CT scanning. Materials and methods. A cross-sectional study with randomized sample of 250 individuals attending the Radiology Section of both Baghdad Medical City and Salah Aldeen Teaching Hospitals from February 2019 to January 2020. All the participated adult individuals were undergo examination for the extent of sphenoid sinus pneumatization with two anatomically neighbor structures, the internal carotid artery and optic nerve, by CT scanning. Outcomes. Three patterns of sphenoid sinus pneumatization were recognized, the pre-sellar, sellar and post-sellar with prevalence 11.2%, 14% and 74.8% respectively. The internal carotid artery was pneumatized within sphenoid sinus in four differentiated types with prevalence 10%, 30.8%, 56% and 3.2% respectively; while the optic nerve was pneumatized within the same sinus in five distinguishable types with prevalence 4%, 52%, 34%, 3.6% and 6.4% respectively had been reported. Conclusions. A higher prevalence of optic nerve extension into the lateral wall of sphenoid sinus causing bulged optic canal in same sinus, also superio-posterior aspect of it tends to be more pneumatized than other aspects; all these findings can be with magnificent importance to determine the gender, age or even race and ethnic group of alive or dead individuals