Angulation and Dimension of the Sphenoid Ridge in Chiari Malformation Type 2.

OBJECTIVE

To reveal differences in the sphenoid ridge (SR) morphology in patients with Chiari malformation type 2 (CMT2) by comparison with normal subjects.

METHODS

Study universe consisted of pediatric computed tomography images of 50 CMT2 (sex: 23 females and 27 males, and mean age: 7.58 ± 5.64 y) and 50 controls (sex: 24 females and 26 males, and mean age: 7.52 ± 5.47 y). SR's length (L-SR), angle (A-SR), width at the lateral tip (LW-SR), width at the midpoint (MPW-SR), and width at the midline (MLW-SR) were measured.

RESULTS

In comparison with controls, CMT2 patients had smaller L-SR ( P = 0.008), but statistically similar A-SR ( P = 0.353), MPW-SR ( P = 0.232), LW-SR ( P = 0.241), and MLW-SR ( P = 0.062). Three configurations regarding A-SR types were observed in CMT2 (types A: 22%, B: 63%, and C: 15%) and controls (types A: 16%, B: 75%, and C: 9%). The distribution of A-SR types according to study groups displayed that CMT2 did not correlate with A-SR types ( P = 0.175).

CONCLUSION

L-SR and A-SR may represent anterior fossa width and middle fossa depth, respectively; therefore, patients with CMT2 have narrower anterior fossa, but similar middle fossa depth.