title: [Anatomy in relation to posterior maxillary osteotomy].
abstract: OBJECTIVE
  The most common site of haemorrhage in maxillary osteotomies is the posterior maxilla. Better understanding of the anatomy of this region would minimize possible vascular complications. The aim of this study is to investigate the anatomy of posterior maxilla and establish safety guidelines for Le Fort I osteotomy.
  
  
  METHODS
  Thirty dry human skulls were selected for direct measurement and computerized image analysis.
  
  
  RESULTS
  Synosteosis of the pterygomaxillary junction was noted in 10% of the samples. The height of the pterygomaxillary junction was 13.15 mm. The height from the inferior point of the pterygomaxillary junction to the inferior point of the maxillary tuberosity was 5.25 mm. The height from the superior point of the pterygomaxillary junction to the inferior point of the maxillary tuberrosity was 18.05 mm. The average distance from the piriform rim to the descending palatine canal was 35.25 mm. The width of the pterygoid process was 12.34 mm. The average length from the zygo-alveolar ridge to the pterygomaxillary junction was 25.47 mm. The average length from anterior nasal spine to the posterior nasal spine was 46.27 mm, and the angle between the descending palatine canal and the palate plane was 58 degrees 47'.
  
  
  CONCLUSIONS
  The study is to provide further understanding of the posterior maxillary anatomy in relation to the bone-cut design of Le fort I osteotomy and to create clinical safety guidelines in order to avoid damaging the descending palatine vessels.
authors.affiliation: Shenyang Military General Hospital, Shenyang 110015, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Hua
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: X
authors.initials: X
authors.lastname: Hu
mesh_terms: D000328:Adult; D000886:Anthropometry / Q000379:methods; D001330:Electronic Data Processing; D006801:Humans; D008437:Maxilla / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery*; D019340:Osteotomy, Le Fort; D011859:Radiography