title: Microsurgical anatomy and variations of the anterior clinoid process.
abstract: OBJECTIVE
  The aim of this study was to better define the microsurgical anatomy of the supra/parasellar region and describe variations of the anterior clinoid process (ACP).
  
  
  METHODS
  Fifteen formalin-fixed cadaver heads and 25 dry skulls were used to define the microsurgical anatomy of the ACP and related structures. The presence of the caroticoclinoid foramen (CaCF) as well as other relevant measurements were all noted. Radiological examination of the CaCF was also demonstrated on dry skulls.
  
  
  RESULTS
  Interosseous bridges, which form between the anterior and middle clinoid processes or connect all three (anterior, middle and posterior) clinoid processes, were found in 30% of the specimens. The average basal width, length and thickness of the ACP were 7.3 mm, 9.7 mm and 5.4 mm, respectively. Length of the optic nerve (ON) up to the falciform ligament (FL) was 10.9 mm; length of the ON under the FL was 2.7 mm; length of ON after removal of the ACP and unroofing the optic canal was 21.1 mm.
  
  
  CONCLUSIONS
  This study contributes to the relationship of important vascular, neural, bone and dural layers of this region and also demonstrates the variations of ACP by means of microsurgical dissections and radiological examinations.
authors: Mersin University, School of Medicine, Department of Neurosurgery, Mersin, Turkey.
authors: Ahmet
authors: A
authors: Dagtekin
authors: Emel
authors: E
authors: Avci
authors: Denız
authors: D
authors: Uzmansel
authors: Zeliha
authors: Z
authors: Kurtoglu
authors: Engin
authors: E
authors: Kara
authors: Kutluay
authors: K
authors: Uluc
authors: Erinc
authors: E
authors: Akture
authors: Mustafa K
authors: MK
authors: Baskaya
mesh_terms: D002102:Cadaver; D002426:Cavernous Sinus / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D004388:Dura Mater / Q000033:anatomy & histology; D006801:Humans; D008866:Microsurgery / Q000379:methods*; D019635:Neurosurgical Procedures / Q000379:methods*; D009900:Optic Nerve / Q000033:anatomy & histology; D011859:Radiography; D012886:Skull / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D019291:Skull Base / Q000033:anatomy & histology* / Q000000981:diagnostic imaging