Revisiting the Sphenoid Sinus Anatomy in Trisomy 21: A CT Study

The aim of the study was to compare morphologic features of the sphenoid sinus (SS) in patients with trisomy 21 (T21) with a control group.

This retrospective study contained computed tomography images of 50 T21s and 60 controls. Of 50 T21 patients aged 11.38±4.21 years, 22 were females and 28 were males. Of 60 controls aged 11.25±4.61 years, 30 were females and 30 were males. The volume (SSV), surface area (SSA), width (SSW), thickness (SST), and height (SSH) of SS were measured. The shape of SS was noted.

In T21s, median values for SSV, SSA, SSW, SST, and SSH were determined as 1.99 mm 3 , 1.52 mm 2 , 20.10 mm, 9.85 mm, and 13.60 mm, respectively. In controls, median values for SSV, SSA, SSW, SST, and SSH were determined as 9.55 mm 3 , 5.50 mm 2 , 30.44 mm, 19.67 mm, and 19.88 mm, respectively. T21s had statistically smaller SSV, SSA, SSW, SST, and SSH compared with controls ( P <0.001). Four types related to SS shape were observed in T21s (conchal: 42%, presellar: 30%, sellar: 24%, and postsellar: 4%) and controls (presellar: 33.3%, sellar: 31.7%, postsellar: 30%, and conchal: 5%). Thus, SS shape was affected by T21s ( P <0.001).

Patients with T21 had statistically smaller SSV (about 79%), SSA (about 72%), SSW (about 34%), SST (about 50%), and SSH (about 32%) compared with controls. The most common pneumatization pattern in T21s was the conchal type.