title: The forgotten foramina: a study of the anterior cribriform plate.
abstract: OBJECTIVE
  The olfactory cleft has garnered interest since the advent of endoscopic skull base surgery. Its precise anatomy, however, is still partially unknown. According to Rouvière, an "ethmoidal foramen" is located in its antero-medial part and contains a process of the dura mater. In a more lateral and anterior location, a second foramen, the "cribroethmoidal foramen", contains the anterior ethmoidal nerve. The aim of this study was to verify the existence of these elements and to establish landmarks for surgery.
  
  
  METHODS
  We performed an anatomical and histological study of eight olfactory clefts in four cadavers using both endonasal endoscopic and endocranial dissection.
  
  
  RESULTS
  An ethmoidal and a cribroethmoidal foramen were found in, respectively, 100 and 75% of cases. Their mean length was, respectively, 4.1 and 1.8 mm. They were located, respectively, in mean at 5.3 and 5.8 mm from the anterior ethmoidal artery.
  
  
  CONCLUSIONS
  Our anatomical study demonstrates the existence of both foramina. The ethmoidal foramen clearly represents an area of least resistance in the anterior part of the olfactory cleft, which could predispose to anterior skull base cerebrospinal fluid leaks and meningoceles.
authors.affiliation: Department of Head and Neck Surgery, CHU de Caen, Avenue de la Côte de Nacre, Caen Cedex 9, 14033, France, vtromps@yahoo.fr.
authors.forename: Vincent
authors.initials: V
authors.lastname: Patron
authors.forename: Julie
authors.initials: J
authors.lastname: Berkaoui
authors.forename: Roger
authors.initials: R
authors.lastname: Jankowski
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Lechapt-Zalcman
authors.forename: Sylvain
authors.initials: S
authors.lastname: Moreau
authors.forename: Martin
authors.initials: M
authors.lastname: Hitier
mesh_terms: D002102:Cadaver; D004210:Dissection / Q000379:methods; D004388:Dura Mater / Q000033:anatomy & histology; D004724:Endoscopy / Q000379:methods; D005004:Ethmoid Bone / Q000033:anatomy & histology* / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D019635:Neurosurgical Procedures / Q000379:methods; D009830:Olfactory Bulb / Q000033:anatomy & histology; D019291:Skull Base / Q000033:anatomy & histology*
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