34 Landmarks Used by 3D-Identification

Initially, up to seventy-five landmarks were collected for each skull depending upon the condition of
the skull and the presence of any obvious pathology. A repeatability and digitizing error study carried
out as part of this project, however, showed that landmarks defined by remote structures or extremal
characteristics, such as euryon, and referred to as Bookstein's Type III landmarks, were difficult to determine reliably as points for coordinate collection (Ross and Williams, 2008). As a result, thirty-four of the original seventy-five selected landmarks were chosen for use by the program. All are Bookstein Type I (clear juxtapositions of tissues) or Type II (maxima of local curvature, e.g., cusps, invaginations, etc.) landmarks. I defined these terms in a way that I would be able to recognize them later for the projects I have been working on.


Abbreviations used in accompanying figures followed by their specific vectors:

• Left asterion - astl: Intersection of left parietal, left temporal, and occipital bones. If sutures are indistinct or include wormian bones, project suture lines until they intersect.

• Right asterion - astr: Intersection of right parietal, right temporal, and occipital bones. If sutures are indistinct or include wormian bones, project suture lines until they intersect.

• Basion - bas: The midline point of the anterior foramen magnum margin where it is intersected by the mid-sagittal plane. Directly opposite of the opisthion. In some cases, thickening of the 1 margin can make position location difficult to determine.

• Bregma - brg: The midline point where the sagittal and coronal sutures intersect. In cases where the intersection is interrupted, such as with fontanelle bones, the suture lines are projected.

• Left Dacryon - dacl:  Left eye orbit: point on the medial border where the frontal, lacrimal, and maxilla bones meet, also noted as the intersection of the lacrimo-maxillary suture and frontal bone. A small foramen is often present.

• Right Dacryon - dacr: Right eye orbit: point on the medial border where the frontal, lacrimal, and maxilla bones meet, also noted as the intersection of the lacrimo-maxillary suture and frontal bone. A small foramen is often present.

• Left Ectomalare - ecml: Left maxilla: positioned at the most lateral point on the lateral surface of the alveolar crest. Found along the second molar on the maxilla.

• Right Ectomalare - ecmr:  Right maxilla: positioned at the most lateral point on the lateral surface of the alveolar crest. Found along the second molar on the maxilla.

• Left Ectoconchion - ectl: Left eye orbit: intersection of the most anterior surface of lateral border and imaginary horizontal line bisecting the orbit.

• Right Ectoconchion - ectr: Right eye orbit: intersection of the most anterior surface of lateral border and imaginary horizontal line bisecting the orbit

• Left Frontomalare Anterior - fmal: Left side of skull: most anterior projecting point on the frontomalare suture (different from the frontomalar orbitale and temporale).

• Right Frontomalare Anterior - fmar: Right side of the skull: most anterior projecting point on the fronto-malare suture (different from the frontomalare orbitale and temporale).

• Left Frontomalare Temporale - fmtl: Left side of the skull: most lateral point on fronto-malare suture

• Right Frontomalare Temporale - fmtr: Right side of the skull: most lateral point on fronto-malare suture

• Glabella - glb:  Most projecting midline point on the frontal bone above frontonasal suture. In juveniles with forward vaulted foreheads the most projecting point may not be the glabella.

• Lambda - lam:  Point where sagittal and lambdoidal sutures meet. If wormian bones are present, project the suture lines to their intersection point.

• Left Mastoidale - mastl: Left mastoid process: point is located on the inferior end.

• Right Mastoidale - mastr: Right mastoid process: point is located on the inferior end.

• Nasion - nas: Midline intersection of the frontonasal suture and mid-sagittal plane.

• Left Lower Orbital Border - obhi: Lower border of the left eye orbit: Measured as the maximum height from the upper to the lower orbital borders perpendicular to the horizontal axis of the orbit and using the middle of the inferior border as a fixed point

• Right Lower Orbital Border - obhir:  Lower border of the right eye orbit: Measured as the maximum
• height from the upper to the lower orbital borders perpendicular to the horizontal axis of the orbit and using the middle of the inferior border as a fixed point.

• Left Upper Orbital Border - obhs: Upper left eye orbit: Upper border of the left eye orbit: Measured as the maximum height from the upper to the lower orbital borders perpendicular to the horizontal axis of the orbit and using the middle of the inferior border as a fixed point

• Right Upper Orbital Border - obhsr: Upper right eye orbit: Upper border of the roght eye orbit: Measured as the maximum height from the upper to the lower orbital borders perpendicular to the horizontal axis of the orbit and using the middle of the inferior border as a fixed point

• Opisthion - ops: Midline point of the posterior foramen magnum margin where the mid-sagittal plan intersects. Opposite of basion.

• Prosthion-Howells estimated pr /proHEST: Most anterior, midline point on the alveolar process of the maxilla between the central incisors.

• Supspinale - ssp: The deepest point of the profile below the anterior nasal spine.

• Left Nasomaxillary Suture Pinch - wnbl (simotic chord): Narrowest portion of the midline of the face to the left naso- maxillary suture. The minimum distance between wnbl-wnbr forms the simotic chord.

• Right Nasomaxillary Suture Pinch - wnbr (simotic chord): Narrowest portion of the midline of the face to the right naso-maxillary suture. The minimum distance between wnbl-wnbr forms the simotic chord.

• Left Zygion - zygl: Left zygomatic: most lateral point on the zygomatic arch. (Point is determined by measuring bizygomatic breadth)

• Left Zygomaxillare - zygoml: Left side of skull: intersection of zygomaxillary suture and most medial masseter muscle attachment.

• Right Zygomaxillare - zygomr: Right side of skull: intersection of zygomaxillary suture and most medial masseter muscle attachment.

• Left Zygoorbitale - zygool: Left eye orbit: point of intersection between zygomaxillary suture and eye orbit.

• Right Zygoorbitale - zygoor: Right eye orbit: point of intersection between zygomaxillary suture and orbit border.

• Right Zygion - zygr: Right zygomatic: most lateral point on the zygomatic arch. (Point is determined by measuring bizygomatic breadth)