Metopic skull with occipitalisation of the atlas.

In this study we report a combination of anatomic variations in the neurocranium of an adult male skull. The skull is scanned using an industrial μCT system Nikon XT H 225. The cranial vault shows a persistent metopic suture, a remnant from the mendosal suture and supernumerary bones. Cranial base inspection reveals atlas occipitalisation (AO), basilar kyphosis, unusually shaped dorsum sellae and bilateral interclinoid bridging. AO is extensive without signs of atlantooccipital articulation. The anterior and posterior arches of the atlas and the right transverse process are fussed to the occipital bone above. The complete fusion of the posterior arch causes a formation of bone canals for the vertebral arteries passage into the cranium. AO in this case is not related to a reduction of the foramen magnum dimensions and clivus length.