title: Effectiveness of Computed Tomography for Blow-out Fracture.
abstract: OBJECTIVE
  This study assessed the association between eye symptoms (enophthalmos or diplopia) and site of damage, volume, deviated inferior rectus muscle (IRM) and type of fracture with computed tomography (CT). The intent is to anticipate the prognosis of orbital trauma at initial diagnosis.
  
  
  METHODS
  Forty-five patients were diagnosed with fractures of the inferior wall of one orbit. Fracture area, volume of displaced tissue, deviated IRM, and type of fracture were evaluated from coronal CT by one investigator. The association of those variables with the occurrence of eye symptoms (diplopia and enophthalmos) was assessed.
  
  
  RESULTS
  Of 45 patients, 27 were symptom-free (Group A) and 18 had symptoms (Group B) of enophthalmos and/or diplopia. In Group B, 12 had diplopia, one was enophthalmos, and five had both. By CT measurement, group A mean area was 192.6 mm(2) and the mean volume was 673.2 mm(3). Group B area was 316.2 mm(2) and volume was 1,710.6 mm(3). The volume was more influential on symptom occurrence. Each patient was categorized into four grades depending on the location of IRM. Symptom occurrence and higher grade were associated. Twenty-six patients had trap-door fracture (one side, attached to the fracture), and 19 had punched-out fracture (both sides detached). The punched-out fracture was more strongly associated with symptoms and had statistically significantly higher area and volume.
  
  
  CONCLUSIONS
  In orbital trauma, measurement of fracture area and volume, evaluation of the deviated IRM and classification of the fracture type by coronal CT can effectively predict prognosis and surgical indication.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University.
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Rhee
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University.
authors.forename: Tae-Seup
authors.initials: TS
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University.
authors.forename: Jae-Min
authors.initials: JM
authors.lastname: Song
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University.
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Shin
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University.
authors.forename: Jae-Yeol
authors.initials: JY
authors.lastname: Lee
keywords: Blow-out fractures; Computed tomography; Orbital injury; Volume measurement