title: Analysis of experimental cranial skin wounding from screwdriver trauma.
abstract: As part of a more extensive investigation of skin wounding mechanisms, we studied wounds created by five common screwdrivers (straight, star, square or Robertson, Posidriv and Phillips) on the shaven foreheads of 12 freshly slaughtered pigs. We fixed the different screwdriver heads to a 5-kg metal cylinder which was directed vertically onto each pig head by a droptube of 700 mm length. We examined skin lesions by photography and also by scanning electron microscopy (SEM). Our evaluation of differences in wound shape and size was based on geometric morphometric methods. Our results show that there are obvious morphological differences between the straight head and the other types. The straight-headed screwdriver penetrates the skin by a mode II crack which results in a compressed skin plug with bundles of collagen fibres forming skin tabs within the actual wound. The sharper-tipped screwdrivers wedge open the skin (mode I), with a clearly defined edge with no skin plugs. Geometric morphometric analysis indicates that shapes of skin wounds created by the five screwdriver types could be classified into three different groups. The straight head results in the most differentiated wound profile, with the Robertson or square and some specimens of star, and also the Posidriv and Phillips giving similar wound outlines. SEM evaluation of wounds created by a new and worn straight-head screwdrivers shows that the outline of the worn screwdriver head is reflected in the shape of the wound it created.
authors: Department of Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New Zealand. jules.kieser@stonebow.otago.ac.nz
authors: Jules
authors: J
authors: Kieser
authors: Valeria
authors: V
authors: Bernal
authors: Paula
authors: P
authors: Gonzalez
authors: Wendy
authors: W
authors: Birch
authors: Mark
authors: M
authors: Turmaine
authors: Ionut
authors: I
authors: Ichim
mesh_terms: D000818:Animals; D005260:Female; D049429:Forensic Pathology; D020197:Head Injuries, Penetrating / Q000473:pathology*; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D010781:Photography; D012867:Skin / Q000293:injuries* / Q000473:pathology*; D034421:Sus scrofa
references: Arch Kriminol. 1978 Jan-Feb;161(1-2):31-40
references: 655761
references: J Forensic Sci. 2001 Nov;46(6):1288-93
references: 11714137
references: Int J Legal Med. 2006 Nov;120(6):369-71
references: 16237559
references: J Orthop Trauma. 2003 Oct;17(9):642-3
references: 14574192
references: J Accid Emerg Med. 2000 May;17 (3):225-6
references: 10819394
references: J Forensic Sci. 2005 Jul;50(4):796-801
references: 16078480
references: Neuroimage. 2002 Jan;15(1):233-51
references: 11771992
references: Forensic Sci Int. 2007 Apr 11;167(2-3):255-60
references: 16876351
references: Med Image Anal. 1997 Apr;1(3):225-43
references: 9873908
references: Forensic Sci Int. 1995 Dec 29;76(3):211-6
references: 8566924
references: Forensic Sci Int. 2001 Aug 15;120(1-2):48-52
references: 11457609
references: Forensic Sci Int. 2002 Jul 17;127(3):225-230
references: 12175953
references: Surg Neurol. 1991 Apr;35(4):294-9
references: 2008646
references: Syst Biol. 2003 Feb;52(1):66-9
references: 12554441
references: J Forensic Sci. 2000 Sep;45(5):1023-7
references: 11005176
references: Arch Kriminol. 1993 Jul-Aug;192(1-2):27-36
references: 8215759
references: Am J Forensic Med Pathol. 1996 Mar;17(1):70-2
references: 8838475
references: J Forensic Sci. 1983 Jul;28(3):794-9
references: 6619784
references: J Anat. 2006 Jun;208(6):769-84
references: 16761977
references: J Trauma. 2002 Jun;52(6):1189-91
references: 12045652