title: Endoscopic transnasal anatomy of the infratemporal fossa and upper parapharyngeal regions: correlations with traditional perspectives and surgical implications.
abstract: BACKGROUND
  The aim of this study was to illustrate the endoscopic surgical anatomy of the infratemporal fossa (ITF) and upper parapharyngeal space and to provide useful landmarks by comparing transnasal perspectives with external ones.
  
  
  METHODS
  6 fresh double injected heads were dissected. External lateral dissection was performed through a pre-auricular skin incision while external anterior dissection started with a modified Weber-Ferguson incision. External medial to lateral dissection was performed starting from the rhinopharyngeal and pterygoid regions, after cutting the specimen in 2 halves passing through the nose. Endoscopic dissection was performed through an endonasal approach (0° and 45° scopes).
  
  
  RESULTS
  Among all the structures identified during the dissection, the most useful landmark when dissecting the ITF in a lateral to medial direction is the lateral pterygoid muscle. In anterior approaches (mostly endoscopic) the role of the lateral pterygoid muscle is less important and the Eustachian tube (ET) represents the most important landmark to point out the upper portion of the parapharyngeal internal carotid artery (ICA). The role of the ET, in lateral dissection is, on the contrary, by far less important given the fact that it is very deep in the surgical field and that the ICA is encountered earlier during surgical approaches. Another crucial landmark during anterior endoscopic surgery is the vidian nerve because it points to the anterior genu of the internal carotid artery.
  
  
  CONCLUSIONS
  The complex 3-dimensionality of the ITF and the upper parapharyngeal space needs a sound knowledge of the surgical anatomy. The role of the same landmarks changed in different approaches. The ability to orientate oneself in this complex area is related to an accurate knowledge of its anatomy through comparison of endoscopic and external perspectives.
authors.affiliation: Unit of Otorhinolaryngology, Department of Neuroscience, University of Pisa, Pisa, Italy. iacopodallan@tiscali.it
authors.forename: I
authors.initials: I
authors.lastname: Dallan
authors.forename: R
authors.initials: R
authors.lastname: Lenzi
authors.forename: M
authors.initials: M
authors.lastname: Bignami
authors.forename: P
authors.initials: P
authors.lastname: Battaglia
authors.forename: S
authors.initials: S
authors.lastname: Sellari-Franceschini
authors.forename: L
authors.initials: L
authors.lastname: Muscatello
authors.forename: V
authors.initials: V
authors.lastname: Seccia
authors.forename: P
authors.initials: P
authors.lastname: Castelnuovo
authors.forename: M
authors.initials: M
authors.lastname: Tschabitscher
mesh_terms: D002343:Carotid Artery, Internal / Q000033:anatomy & histology* / Q000601:surgery; D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology* / Q000601:surgery; D004724:Endoscopy / Q000379:methods*; D006801:Humans; D010614:Pharynx / Q000033:anatomy & histology* / Q000601:surgery