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Gonion

Definition

The most posterior and inferior point of the mandibular angle, bilaterally. Used in superimposition to assess the width of the jaw angle as seen in the portrait against the skull's actual gonial angle width.

Anatomical location
Most lateral point on the angle of the mandible; posterior and inferior aspect
Bilateral
Found on both sides of the mandible
Primary use in forensics
Assessment of jaw angle width in skull superimposition and facial reconstruction

Common questions

What is the gonion and where is it on the skull?+

The gonion is the most lateral and posterior-inferior point of the mandibular angle. It sits where the back of the lower jaw meets the angle, bilaterally on both sides.

Why does gonion matter in skull superimposition?+

The gonion is a key landmark for assessing jawline width. Forensic experts compare the skull's actual gonial angle width against the width shown in photographs or video to verify alignment and exclude or support identity.

How is gonion used in forensic overlay work?+

When superimposing a skull onto a photo or video, the gonion controls the width of the jaw angle in the overlay. Matching the gonion positions helps confirm the skull's fit with the facial features visible in the image.

Related terms

Nasion
The anatomical landmark at the junction of the nasal bones and the frontal bone (the bridge of the nose). One of the...
Video Superimposition
The updated superimposition workflow using a motorised skull turntable, a calibrated video camera, and real-time electronic mixing of the skull video image...
Anatomical Landmarks
Fixed cranial reference points (about 25 are used) including glabella, nasion, gonion, gnathion, zygion and prosthion that must align with corresponding soft-tissue...
AnthropoScope
Computerised three-dimensional skull and facial reconstruction system using laser scans of the skull and soft-tissue prediction from CT databases.
Consistent with
The categorical superimposition conclusion that examined morphological features do not exclude the skull as deriving from the same individual as the portrait....
Exclusion
The categorical conclusion that one or more examined features are clearly inconsistent in a way that cannot be explained by projection angle,...
FACES
American computerised composite and reconstruction software (IQ Biometrix) used to generate two-dimensional faces from cranial and witness data.
Frankfurt Horizontal Plane
The anatomical reference plane defined by the upper border of the external acoustic meatus and the lowest point of the orbital margin...
Glabella
The midline prominence on the frontal bone between the superciliary arches. Scored 1 (flat, female) to 5 (highly prominent, male). Correlated with...
Glaister-Brash Method
The original photographic-transparency superimposition protocol developed by John Glaister Jr and James Couper Brash for the 1935 Buck Ruxton case in Lancaster...
Gnathion
The most inferior point of the mandibular symphysis in the midline, corresponding to the tip of the chin in the portrait photograph....
Iscan-Helmer 1993
The edited volume 'Forensic Analysis of the Skull' (Iscan and Helmer, Wiley-Liss, 1993) that brought together the first systematic reliability assessment of...

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