The sphenoid sinuses are extensions of the ethmoid sinuses into the sphenoid bones. The sphenoid sinus is supplied by the posterior ethmoidal nerves. Tumours of the sphenoid and frontal sinuses are extremely rare. The spine of sphenoid falls medial and posterior to the foramen. On axial planes, it sits just posterior to the sphenoid sinuses. Additionally, portions of the sphenoid and left mandibular fossa are missing. Sinus films are helpful in the diagnosis of sphenoid sinusitis. It is formed by the sphenoid bone and maxilla. The foramen ovale is an opening in the greater wing of the sphenoid bone. The pterion is the region where the frontal, parietal, temporal, and sphenoid bones join together. By the twenty-fifth year the sphenoid and occipital are completely fused. It is one of two foramina in the greater wing of the sphenoid bone. Their palate differs from other ratites in that the sphenoid and palatal bones are unconnected. The superior aspect is the base of skull, namely the sphenoid and temporal bones. The sphenoid bone is an unpaired bone of the neurocranium.