The supraorbital keyhole approach effectively exposes the frontal lobe base, anterior clinoid process, canalis opticus, olfactory sulcus, olfactory tract, optic nerve, optic chiasm, oculomotor nerve, anterior communicating artery, anterior cerebral artery A1 segment, pituitary stalk, diaphragma sellae, dorsum sellae, posterior clinoid process
, basilar artery apex, posterior cerebral artery P1 segment, superior cerebellar artery proximal, front upper pontine and interpeduncular cistern, anteromedial temporal lobe, internal carotid, middle cerebral artery (M1, M2 segment, and part of M3 segment), anterior choroidal artery, posterior communicating artery; and contralateral carotid artery medial surface, anterior cerebral artery A1 and A2 proximal, middle cerebral artery M1 and M2 proximal.
Gruber described the ligament extending from the apex of the petrous temporal and sphenoid posterior clinoid process
and gave the name petrosphenoidal ligament (Marom; Ambekar et al., 2012).
Posterior clinoid process
was normal in all the cases.
In relation to the basilar tip aneurysms, sometimes, trough the posterior part of the superior wall is necessary drilling out the posterior clinoid process
to approach the basilar aneurysm neck when it is hidden behind the dorsum sellae (31,32,33).
Its posterior border is marked by the petroclinoidal (petrosphenoidal or Gruber's) ligament extending between the petrous apex and posterior clinoid process
of the sphenoid.
The anterior edge of the pituitary fossa is completed laterally by the middle clinoid process and the posterior boundary is formed by the dorsum sellae, the superolateral angles of which are expanded to form the posterior clinoid process
A spinner dolphin, Stenella longirostris, from the Gulf of Mexico has both an anterior and a posterior clinoid process
bordering its sella turcica.
The frequency of frail quadrilateral plate dorsum sellae, with small posterior clinoid process
found here (38.4 %) is higher than that previously reported, whereas the incidence of the other categories is in substantial agreement with previous reports (Halim).
MI = Internal acoustic meatus, PC = Posterior clinoid process
, FJ = Jugular foramen, HC = Hypoglossal canal, A = Asterion, n = needle.
The sella turcica bridge (STB) is the true bony union of the anterior and posterior clinoid processes
while the clinoid enlargement (CLEN), is the overlapping of the anterior and posterior clinoid processes4 and not necessarily real bony fusion.5 Bridging of the sella turcica is considered as an anatomical abnormality and has been reported to occur in skeletal and dental malformations and in several syndromes.6
The particular emphasis of the cranial work was on the following locations: where those cranial nerves cross the borders of tentorium cerebelli, as they pass through cavernous sinus, where the particularly vulnerable spot was, the fibro-osseous canal beneath the posterior clinoid processes
, at sutura petrobasilaris, and where those nerves enter the orbit through fissure orbital is superior.
Anteriorly, it is bounded by a bony ridge, the tuberculum sella, and posteriorly by the dorsum sella and the posterior clinoid processes
. The anterior clinoid processes of the lesser wing of the sphenoid are lateral to the tuberculum sella and project posteriorly.