Anatomical Landmarks
Definition
Fixed cranial reference points (about 25 are used) including glabella, nasion, gonion, gnathion, zygion and prosthion that must align with corresponding soft-tissue features in the photograph.
- Approximate count
- 25 cranial points
- Examples
- Glabella, nasion, gonion, gnathion, zygion, prosthion
- Application
- Skull-photo superimposition
- Requirement
- Alignment with soft-tissue features
Common questions
Why must skeletal landmarks be matched to soft-tissue points rather than to other bone features?+
Superimposition compares a skull directly against a photograph of a living face, so the only visible reference points in the photograph are soft-tissue surface features. Each cranial landmark is chosen because it has a known, tissue-thickness-adjusted correspondence to a visible facial point.
What limits the precision of landmark-based superimposition?+
Soft-tissue thickness and facial expression vary between individuals and even for the same person over time, so landmark correspondence is approximate rather than exact, which is why superimposition is generally used to exclude or support identification rather than to individualise on its own.
Related terms
- AnthropoScope
- Computerised three-dimensional skull and facial reconstruction system using laser scans of the skull and soft-tissue prediction from CT databases.
- FACES
- American computerised composite and reconstruction software (IQ Biometrix) used to generate two-dimensional faces from cranial and witness data.
- Glabella
- The midline prominence on the frontal bone between the superciliary arches. Scored 1 (flat, female) to 5 (highly prominent, male). Correlated with...
- Gonion
- The most posterior and inferior point of the mandibular angle, bilaterally. Used in superimposition to assess the width of the jaw angle...
- Manchester Method
- Three-dimensional facial reconstruction technique developed by Richard Neave at the University of Manchester, building clay muscle by muscle on a skull cast...
- Nasion
- The anatomical landmark at the junction of the nasal bones and the frontal bone (the bridge of the nose). One of the...
- Plastic vs Sculptured Reconstruction
- Plastic (two-dimensional) reconstruction draws the face on a photograph or sketch of the skull; sculptured (three-dimensional) reconstruction builds the face physically in...
- Soft-Tissue Thickness
- Distance from a cranial landmark to the overlying skin surface, measured in millimetres; varies with sex, age, BMI and population, and forms...
- Superimposition
- Overlay technique that matches an unidentified skull with an antemortem photograph of a suspected individual to test anatomical consistency.
- 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...