A radiological anatomic study of the cribriform plate compared with constant structures

Understanding of the anterior skull base anatomy is crucial to avoid intracranial violations during endoscopic surgery. The aims of this study were to define the normative data about cribriform plate depth and the relationship between this dimension and the measurements of the adjacent anatomical structures such as middle turbinate length, maximal vertical orbital height and distance between the ethmoid roof and the nasal floor.

Paranasal computerized tomographic scans of 136 healthy adults were included into the study. The cribriform plate depth compared to the ethmoid roof and the adjacent anatomical structures mentioned above were measured bilaterally.

The maximal vertical orbital height was detected as the most constant anatomic measurement. We found the mean level difference between the ethmoid roof and the cribriform plate as 6.1 +/- 2.3 (range 1-12 mm) on the left side and 6.1 +/- 2.2 (1-15 mm) on the right side. The middle turbinate was significantly longer in the Keros Type I group than in the other groups (p<0.05). Furthermore, the distance between the ethmoid roof and the nasal floor was lowest in the Keros Type I group (p<0.01). The distance between the ethmoid roof and the nasal floor was statistically higher in Keros group 3 among all groups (p<0.01). The deeper the cribriform plate, the higher the nasal cavity.

To the best of our knowledge, our study has a unique feature by including the data of the constant anatomical structures comparing with the cribriform plate depth. Since in the group with excessive cribriform plate depth, the middle turbinate was short, care should be taken especially during middle turbinate resections.