title: A multipurpose landmark for skull-base surgery: Henle's spine.
abstract: OBJECTIVE
  To determine whether Henle's spine could be used as a reliable and multipurpose landmark for the other important structures of the skull base.
  
  
  METHODS
  Ninety-two specimens from 46 cadaveric adult dry skulls were studied. Two imaginary lines and a triangle were defined: a spinopterygoidal line extending from Henle's spine to the root of the medial pterygoid plate, a bispinal line extending from one Henle's spine to the contralateral one, and a parapetrosal triangle lying between the spinopterygoidal line, the bispinal line and the sagittal midline. The parapetrosal triangle encompasses nearly all the main structures of the skull base, including the petrosal internal carotid artery.
  
  
  RESULTS
  Along the spinopterygoidal line the distance from Henle's spine to the spine of the sphenoid was found to be about 3 cm, to the foramen spinosum 3.5 cm, to the posterior and anterior margins of the foramen ovale 4 and 4.5 cm, to the root of the lateral pterygoid plate 5 cm, to the root of the medial pterygoid plate 5.5 cm, and to the vomer 6.5-7 cm. Along the bispinal line, the distance from Henle's spine to the stylomastoid foramen was found to be about 1.5 cm, to the lateral and medial margins of the jugular foramen 2.5 and 3.5 cm, to the external orifice of the hypoglossal canal 4 cm, and to the foramen magnum 5 cm.
  
  
  CONCLUSIONS
  Henle's spine with its superficial and central position can be used to localize important anatomical structures during skull-base surgery.
authors.affiliation: Department of Otorhinolaryngology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey. tuncayu@veezy.com
authors.forename: Tuncay
authors.initials: T
authors.lastname: Ulug
authors.forename: Adnan
authors.initials: A
authors.lastname: Ozturk
authors.forename: Kayihan
authors.initials: K
authors.lastname: Sahinoglu
mesh_terms: D000328:Adult; D002508:Cephalometry / Q000379:methods; D003399:Craniotomy; D006346:Heart Septum / Q000033:anatomy & histology; D006801:Humans; D008297:Male; D013506:Otologic Surgical Procedures / Q000379:methods; D019291:Skull Base / Q000033:anatomy & histology* / Q000601:surgery*; D013100:Sphenoid Bone / Q000033:anatomy & histology; D013701:Temporal Bone / Q000033:anatomy & histology*