Cranial Deformation & Cranial Trauma
Cranial deformation - Two major types of cranial deformation may be observed: artificial and accidental. Artificial deformation is practiced purposely by a number of cultures globally, and can be meant to show social status, ethnic affiliation, or beauty. Pressure may be placed on the frontal, occipital, or circumferentially. Accidental deformation occurs when an infant is strapped to a cradle board for a long period of time, or if an infant is allowed to lay flat on their back. Both accidental forms are known to create flat spots on the back fo the cranium.
Fractures - Depression fractures are most commonly seen in the cranium; bone is pressed inward and may affect any of the three structures of the cranial vault bones.
Gun shot wounds - Circular holes with distinct edges. The entry wound smaller and has a beveled inner table. The exit wound is larger, has beveling of the outer table, and frequently has small fragments associated. Fractures will likely be seen radiating away from the wound, but will end at the cranial sutures. A solid diagnosis would include a use of a radiograph that should show small fragments of metal embedded in the bone (Aufderheide and Rodriguez-Martin 1998).
Trephination - Early form of cranial surgery. Purpose is unknown, but speculation includes decreasing cranial pressure and allowing detrimental spirits to escape. Two forms are common, scraping and cutting. Users of the scraping method employ a sharp surface and scrape across the cranium until a hole is made. A sharp tool is also employed in the cutting method, however instead of scraping hte individual will make linear cuts creating a square fragment of bone that is popped out after perforating the full thickness of the bone. In either method, it is necessary to not penetrate too deeply to protect the dura which aids in holding infection at bay.
Cut marks - Sharp weapons will leave sharply defined margins, and may be observed as elongated v-shaped marks (Aufderheide and Rodriguez-Martin 1998). It is important to note that cut marks occur during excavation and also in the lab during observation. These accidental marks can be differentiated from antemortem/perimortem cut marks on the basis of color. Accidental marks will be lighter in color than the surrounding bone, while the antemortem/perimortem marks will be the same color as the surrounding bone.
Cribra Orbitalia - Appears on the roof s of the orbits as an increase in porosity or expansion of the diploe into the orbital cavity. Cribra Orbitalia is thought to be a general indicator of anemia, although the cause could be a variety of things including malnutritioin, parasittes or other physiological illness.
Porotic Hyperostosis - May appear ectocranially as increased porosity with an associated thickening of the bone. Can only be confirmed through radiography; a "hair-on-end" appearance of the diploe. Porotic Hyperostosis is thought to be a general indicator of anemia, although the cause could be a variety of things including malnutrition, parasites, or other physiological illness.
Craniosynostoses - Early closure of the cranial vault sutures. Depending on the suture that fuses early, the shape of the cranium will become distorted.