What is Skull superimposition?

               

1. Skull superimposition is the technique applied to determine whether the skull is that of the person in the photograph.
2. It is based on the principle that the shape of the face is related to the bony contours of the facial part of the skin.
3. The negatives of the photographs, the skull are superimposed by aligning the characteristic points in the negative.
4. The resulting superimposed photograph brings out the points of similarity or dissimilarity between the photograph & skull
5. The superimposition is correct if the anatomical landmark accurately correspond to the face in the photograph.
6. Video superimposition
• The skull is fixed on a rotatable universal stand. The photograph is fixed parallel to the skull.
• ONE CAMERA IS DIRECTED TO THE SKULL AND ANOTHER CAMERA TOWARDS THE PHOTOGRAPH.
• Images of the skull & photographs  are  projected on a monitor placed near the skull.
• By performing a series of bending, fading the image of the skull & photograph, the uniformity is analyzed.
• This is an exclusionary method.
7. Computer assisted superimposition:
• The skull & facial photographs are distinguished using a computer.
• Two images are compared morphologically by image processing for confirmity
• All the anatomical landmarks are compared.
8. Physiognomic restoration:
1. Sculptural to give three-dimensional bust
2. Artistic to give drawing in 2 views. Facial & profuse to show cephalic & facial details.
3. Both methods try to achieve an individual likeness which will lead to identification of the suspect skull.
4. When previous X-ray films of the skull is available for comparison  with postmortem films, measurement of the skull & detailed comparison of the frontal sphenoidal & maxillary sinuses, sella turcica & mastoid area are useful for identification in adults