title: Medial orbital wall landmarks in three different North American populations.
abstract: OBJECTIVE
  We sought to measure the medial orbital wall foramina distances in two previously unstudied populations, to describe a new bony medial wall feature, and to validate the accuracy of a new coordinate measurement device within the orbit.
  
  
  METHODS
  Dried, well-preserved, complete human skulls without orbital defects were studied. Age, gender, birthplace, ethnicity, and laterality of the orbit were recorded for each skull. Supranumerary ethmoidal foramina were recorded, and the fronto-ethmoidal groove depth was measured. The distances between the anterior lacrimal crest (ALC) - anterior ethmoidal foramen (AEF), AEF - posterior ethmoidal foramen (PEF), and PEF - optic canal (OC) were measured first by surgical ruler and wire and then by the Microscribe coordinate measurement device.
  
  
  RESULTS
  One hundred and forty-six orbits were studied. Fifty-seven orbits were of European or Caucasian descent, 68 orbits of African American descent, 2 orbits of West African descent, 11 orbits of Eskimo descent, and 8 orbits of unknown origin. No significant differences existed between the manual and Microscribe measurements for the ALC-AEF, AEF-PEF, and PEF-OF distances (p < 0.0001). A significant frontoethmoidal groove was observed in 27/146 (19%) orbits, in 6/57 (11%) Caucasian orbits, in 17/70 (24%) African American orbits, and in 4/11 (36%) Eskimo orbits. Supranumerary ethmoidal foramina were found in 50/146 orbits (34.2%) and in 17/27 (63%) orbits with a significant frontoethmoidal grooves.
  
  
  CONCLUSIONS
  No significant differences in medial wall foramina distances exist between African American and Caucasian orbits; however, a frontoethmoidal groove occurs more commonly in African American orbits. This groove often occurs in the presence of supernumerary ethmoidal foramina. The Microscribe coordinate measurement system represents a valid tool to measure distances within the orbit.
authors: The Cole Eye Institute, Cleveland Clinic Foundation , Cleveland, Ohio , USA.
authors: Milap P
authors: MP
authors: Mehta
authors: Julian D
authors: JD
authors: Perry
mesh_terms: D000293:Adolescent; D000328:Adult; D000354:Africa, Western; D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D059925:Anatomic Landmarks / Q000033:anatomy & histology*; D000886:Anthropometry; D005004:Ethmoid Bone / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D004930:Inuit; D008297:Male; D008875:Middle Aged; D009915:Orbit / Q000033:anatomy & histology*; D012886:Skull / Q000033:anatomy & histology; D044465:White People
keywords: Ethmoid bone; ethmoidal foramina; orbit anatomy