title: Helpful and unhelpful parts of the superior petrosal triangle.
abstract: BACKGROUND
  The root of zygoma-head of malleus line may guide to the internal auditory canal, but few anatomic studies address its accuracy.
  
  
  OBJECTIVE
  The precision of measurements is excellent, the "superior petrosal triangle" components (foramen spinosum, root of zygoma, and head of malleus) have a consistent relationship and accurately guide to Bill's bar, and distances correlate with pneumatization.
  
  
  METHODS
  Forty-one bequeathed adult human cranial base specimens (82 temporal bones) were dissected in a surgical manner.
  
  
  RESULTS
  Measurements had excellent repeatability. The root of zygoma-head of malleus reference line always projected onto or posterior to Bill's bar, but distances measured had wide ranges. No measurement correlated with pneumatization.
  
  
  CONCLUSIONS
  The root of zygoma-head of malleus line extends onto or posterior to Bill's bar. Measurement guides to the head of the malleus are not predictable.
authors.affiliation: Temporal Bone Laboratory, Emory University, Atlanta, Georgia 30342, USA. ntodd@emory.edu
authors.forename: N Wendell
authors.initials: NW
authors.lastname: Todd
mesh_terms: D000328:Adult; D035301:Cranial Fossa, Middle / Q000033:anatomy & histology*; D007758:Ear, Inner / Q000033:anatomy & histology*; D006801:Humans; D008307:Malleus / Q000033:anatomy & histology*; D015203:Reproducibility of Results; D013701:Temporal Bone / Q000033:anatomy & histology; D015050:Zygoma / Q000033:anatomy & histology*