An anatomical study of pneumatized crista galli.

The literature data on the incidence of pneumatization of the crista galli based on patients' computed tomography (CT) scans ranges from 3 to 37.5%. This study investigated for the first time the incidence of crista galli pneumatization based on CT scans of human skulls. The study examined 102 randomly selected human skulls (≥20 years of age; 76 males, 26 females). Skulls were scanned in a fixed position using cone beam computed tomography (CBCT) with a field of view of 145 × 130 mm and an isotropic voxel size of 0.25 mm. The scans were recorded in Digital Images and Communications in Medicine format. The CBCT images were analyzed using OnDemand3DTM software. A 2-mm contiguous slice thickness was used in the axial and coronal planes. The width, length, and height (cranial-caudal dimension) of the pneumatized space within the crista galli were measured. The crista galli was found to be pneumatized in even 68 (66.6%) of the 102 skulls. Two types of pneumatized crista galli (PCG) were identified: PCG alone (surrounded by bony walls) and PCG + spongiosis (surrounded by spongy bone). Of the 68 pneumatized skulls, 31 were PCG alone (45.58%) and 37 were PCG + spongiosis (54.42%). The pneumatized regions had a width of 0.9-6.6 mm, length of 2.8-12.9 mm, and height of 3.6-17.1 mm. No statistically significant differences have been found regarding the sex and age. Regarding the proportions of pneumatization, the three types of crista galli have been determined resulting in new, practical classification: type S (small), type M (moderate), and type L (large). The crista galli is not always a compact bone; in some cases, it is filled with spongy bone or pneumatized. In respect of proportions of pneumatization, there are three types of pneumatized crista galli: small, moderate, and large. Pneumatized crista galli can play an important role in clinical work, both as an inflamed sinus or other pathologies (sinusitis cristae galli, mucocoelae) or as a morphologic barrier in neurosurgical approaches to some tumors of the anterior skull base.