title: Topographic anatomy of the great auricular point: landmarks for its localization and classification.
abstract: OBJECTIVE
  The great auricular point (GAP) marks the exit of the great auricular nerve at the posterior border of the sternocleidomastoid muscle (SCM). It is a key landmark for the identification of the spinal accessory nerve, and its intraoperative localization is vital to avoid neurological sequelae. This study delineates the topography and surface anatomy landmarks that used to localize the GAP.
  
  
  METHODS
  Thirty cadaveric heminecks were dissected on a layer-by-layer approach. The topography of the GAP was examined relative to the insertion point of the SCM at the clavicle, tip of the mastoid process, and angle of the mandible. The GAP and its relation to the SCM were determined as a ratio of the total length of the SCM.
  
  
  RESULTS
  The GAP was demonstrated to be in a predictable location. The mean length of the SCM was 131.4 ± 22 mm, and the mean distance between the GAP and the mastoid process was found to be 60.4 ± 13.76 mm. The ratio of the GAP location to the total SCM length ranged between 0.33-0.57. The mean distance between the angle of the mandible and the GAP was determined to be 57 ± 22.2 mm. Based on the midpoint of the SCM, the GAP was above it in 66.7 % of subjects and classified to Type A, and below it in 33.3 % of subjects appointed to Type B.
  
  
  CONCLUSIONS
  The anatomical landmarks utilized in this study are helpful in predicting the location of the GAP relative to the midpoint of the SCM and can reduce neural injuries within the posterior triangle of the neck.
authors.affiliation: Anatomical Sciences, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, QLD, 4229, Australia. a.raikos@yahoo.com.
authors.forename: Athanasios
authors.identifier: http://orcid.org/0000-0003-0362-4196
authors.initials: A
authors.lastname: Raikos
authors.affiliation: Anatomical Sciences, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, QLD, 4229, Australia.
authors.forename: Thomas
authors.initials: T
authors.lastname: English
authors.affiliation: Anatomical Sciences, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, QLD, 4229, Australia.
authors.forename: Omar Khalid
authors.initials: OK
authors.lastname: Yousif
authors.affiliation: Anatomical Sciences, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, QLD, 4229, Australia.
authors.forename: Mandeep
authors.initials: M
authors.lastname: Sandhu
authors.affiliation: Anatomical Sciences, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, QLD, 4229, Australia.
authors.forename: Allan
authors.initials: A
authors.lastname: Stirling
mesh_terms: D000055:Accessory Nerve / Q000033:anatomy & histology*; D059925:Anatomic Landmarks; D000718:Anatomy, Regional; D002102:Cadaver; D002968:Clavicle / Q000294:innervation; D006801:Humans; D008334:Mandible / Q000294:innervation; D008416:Mastoid / Q000294:innervation; D009333:Neck / Q000294:innervation*; D037981:Neck Dissection; D009334:Neck Muscles / Q000294:innervation*
keywords: Erb’s point; Great auricular nerve; Greater auricular nerve; Greater auricular point; McKinney’s point; Spinal accessory nerve