Crista Galli Morphology in Fetuses.

Objective: To determine alterations in the crista galli (CG) size in fetuses with advancing weeks.

Methods: Skull bases of 32 fetuses (11 males/21 females) aged 17 to 32 weeks in utero were included in the study. The width (width of CG), height (height of CG), and length (length of CG) of CG were measured, and also olfactory fossa depth (OFD) was measured to determine the relation of CG with OFD.

Results: Width of CG, height of CG, length of CG, and OFD were measured as 1.77 ± 0.59 mm, 5.10 ± 1.70 mm, 12.32 ± 2.25 mm, and 1.56 ± 0.56 mm, respectively. No significant difference was observed between the measurements in terms of sex and side ( P > 0.05). Apart from OFD, the parameters were greater in the third-trimester fetuses than in the second-trimester fetuses ( P < 0.001). Olfactory fossa depth was similar in both trimester fetuses ( P = 0.798). Olfactory fossa depth did not alter with advancing gestational weeks ( P = 0.077), but the others increased ( P < 0.01). Only one configuration regarding Keros types was observed. Type 1 was detected in all fetuses (100%). A linear function was calculated as y=1.442+0.455×age for the length of CG, y=-2.566+0.321×age for the height of CG, y=0.641+0.039×age for OFD, and y=-1.088+0.119×age for the width of CG.

Conclusions: Crista galli size increased with advancing fetal weeks. The authors detected Keros type 1 in all fetuses. The authors' linear functions representing the growth pattern of CG and OFD in fetuses may be useful in estimating their dimensions.