title: Incidence, morphology and morphometry of the foramen of Vesalius: complementary study for a safer planning and execution of the trigeminal rhizotomy technique.
abstract: BACKGROUND
  The foramen of Vesalius (FV) is located in the greater wing of the sphenoid bone between the foramen ovale (FO) and the foramen rotundum in an intracranial view. The FO allows the passage of the mandibular branch of trigeminal nerve, which is the target of the trigeminal radiofrequency rhizotomy.
  
  
  OBJECTIVE
  We analyzed its location, morphology, morphometry and interrelation among other foramina.
  
  
  METHODS
  400 macerated adult human skulls were examined. A digital microscope (Dino-Lite plus) was used to capture images from the FV. A digital caliper was used to perform the measurements of the distance between the FV and other foramina (FO, foramen spinosum and the carotid canal) in an extracranial view of the skull base.
  
  
  RESULTS
  In the 400 analyzed skulls, the FV was identified in 135 skulls (33.75%) and absent on both sides in 265 skulls (66.25%). The FV was observed present bilaterally in 15.5% of the skulls. The incidence of unilateral foramen was 18.25% of the skulls of which 7.75% on right side and 10.5% on left side. The diameter of the FV was measured and we found an average value of 0.65 mm, on right side 0.63 mm and on the left side 0.67 mm. We verified that positive correlations were statistically significant among the three analyzed distances.
  
  
  CONCLUSIONS
  This study intends to offer specific anatomical data with morphological patterns (macroscopic and mesoscopic) to increase the understanding of the FV features as frequency, incidence and important distances among adjacent foramina.
authors.affiliation: Department of Biological Sciences, FOB/USP, Av. Octávio Pinheiro Brisolla, 9-75, Aeroporto, Bauru, São Paulo, 17012-901, Brazil.
authors.forename: André Luis
authors.initials: AL
authors.lastname: Shinohara
authors.forename: Carina Guimarães
authors.initials: CG
authors.lastname: de Souza Melo
authors.forename: Elcia Maria Varize
authors.initials: EM
authors.lastname: Silveira
authors.forename: José Roberto Pereira
authors.initials: JR
authors.lastname: Lauris
authors.forename: Jesus Carlos
authors.initials: JC
authors.lastname: Andreo
authors.forename: Antonio
authors.initials: A
authors.lastname: de Castro Rodrigues
mesh_terms: D006801:Humans; D019051:Rhizotomy; D013100:Sphenoid Bone / Q000033:anatomy & histology*; D014276:Trigeminal Nerve / Q000601:surgery