Fig 1.
Right lateral view of the Cioclovina calvaria exhibiting a large depressed fracture.
Table 1.
Forensic criteria for estimating the timing of the injuries.
Fig 2.
A-C: Cioclovina, D-F: modern cranium with perimortem trauma (data obtained from the archives of the Department of Radiology, Heraklion University Hospital, Crete, Greece with permission), G-I: archaeological cranium with post-mortem damage (medieval specimen from the Ballumbie Collection, Department of Archaeology, University of Edinburgh, Scotland). Note the plastic deformation of the perimortem fractures in the 2-dimensional figures (B, C, E and F) compared to the sharp edges at right angles to the bone surface indicating post-mortem damage (H and I).
Fig 3.
a) Coronal section of a) Cioclovina showing obtuse fracture angles (red lines) consistent with perimortem trauma and b) the Ballumbie skull showing right angle fractures (blue markers) consistent with postmortem damage.
Fig 4.
Perimortem fractures LF (in blue) and DF (in red yellow and black) are illustrated in Frontal (A), Occipital (C) Lateral (B,D) views. The right parietal bone of Cioclovina calvaria exhibits a central depressive fracture radiating to the right temporal, occipital and left parietal bones (Fig 2A). The centre of the depression fracture is located on the right parietal bone, approximately 2 cm superiorly to the inferior temporal line. There is an inward displacement of a bow-like bony fragment (r = 35.2 mm). Six linear fractures (R1-R6), radiating from the centre of impact are observed, as well as two main concentric fractures (C1-C2) perpendicular to the radiating fractures (Fig 2B). The first radial fracture (R1) extends superiorly to the centre of impact up to the sagittal suture. There it changes course following the suture towards lambda for about 31 mm. At a distance of approximately 29.5 mm from lambda it turns 90 degrees to the direction of the left parietal bone, crosses the right superior and inferior temporal line and moves slightly posteriorly and downwards to the left parietal squama. It crosses the left squamosal suture in a distance of 40mm from the superior border of the left external acoustic meatus. At that point gives rise to 2 smaller fracture lines (R1a, R1b) which extend to the temporal squama. R1a stops once it meets the temporal suture and R1b reaches the cranial base. R2 starts at the middle of the arc produced by the inward displacement of the central fragment and moves posterior to the right parietal bone stopping at the right lambdoid suture. R3 starts in the middle of the parietal bone, moves to the anterior part of the bone and stops at the edge of a linear fracture (LF). LF starts at the middle left of the inferior nuchal line, moves diagonally accross the tuberculum linearum, crosses the right lamdoid suture, moves slightly inferiorly and anteriorly, crossing the right squamosal suture and the right temporal bone and ends at the inferior part of the right lateral wing of the sphenoid bone (B and C). R4 begins at the impact point slightly posteriorly and then turns inferiorly and parallel to R3, crosses the right inferior temporal line, runs the right parietal bone, and ends at the right squamosal suture about 35.1 mm above the superior border of the right external acoustic meatus. R5 starts from the impact point directly posteriorly to the parietal bone. It turns slightly inferiorly when crossing the inferior temporal line and ends at the right coronal suture. R6 starts at the impact point, moves slightly posteriorly and inferiorly and crosses almost perpendicularly the sagittal suture at a distance of approximately 30.6 mm from bregma. After running approximately 29.5 mm on the posterior part of the left parietal bone, R6 turns 144 degrees anteriorly and inferiorly for approx. 43.9 mm. At the level of the left superior temporal line it turns 131 degrees anteriorly and stops at the R2 fracture line.
Fig 5.
Mechanism of blunt force trauma on the vault A) Low velocity impact on the skull causing fracture formation at the impact point due to initial inbending of the cranial vault with peripheral outbending; inward displacement of the bony fragment due to plastic deformation; small fragments remaining in place suggest that the impact took place while soft tissue was present. B) Radiating fractures in the area of outbending which start at one or more points distant to the impact site, progressing both towards to the impact point and in the opposite direction (away from it); C) The radiating fractures stop when they meet the sutures (e.g. R1). D) Formation of concentric fractures forming perpendicular to the radiating fractures. Image credit: Iakovos Ouranos.
Fig 6.
a) Strike with a wooden baseball bat on the vault b) Strike with a wooden baseball bat near the foramen magnum c) strike with a volcanic rock d) Fall from 10 m.
Table 2.
Summary of the BFT simulations.
Fig 7.
Two strikes with a wooden Baseball bat on a head against a solid surface result in a linear fracture after the first blow (white arrow) and a depressed fracture after the second blow (black arrow).