CASE REPORT Intersecting fractures of the skull and gunshot wounds. Case report and literature review Guido Viel Æ Axel Gehl Æ Jan P. Sperhake Accepted: 12 September 2008 / Published online: 15 October 2008 Ó Humana Press 2008 Abstract When two fracture lines of a solid surface (ice, glass, eggshell, etc.) intersect, it is always possible to tell which one has been made first. Indeed pre-existing damage of the surface arrests all the fracture lines produced by subsequent impacts. This well-known principle (estab- lished by Puppe in 1903) has been largely used in glass fracture analysis, but can be applied also to the examina- tion of skull fractures. It can help sequencing blunt force or gunshot injuries determining the direction of fire and dif- ferentiating entrance from exit wounds in the absence of specific distinguishing features (i.e., internal/external bev- eling of the skull or overlying skin indicators). In this context, we report the case of a 76-year-old man who shot himself in the mouth with a Walther PPK 7.65 handgun and highlight the utility of the application of both Puppe’s Rule and Multislice Computed Tomography (MSCT) in the examination of gunshot wounds to the skull. Keywords Gunshot wounds Á Forensic Á Skull fractures Á Intersecting fractures of the skull Á Sequence of fire Á Puppe’s rule Á Entrance and exit wounds Á Multislice Computed Tomography (MSCT) Introduction Puppe’s Rule, established by the German forensic pathol- ogist Puppe in 1903 [1], states that when two or more fracture lines of the skull produced by different blunt forces intersect, it is possible to reconstruct the sequence of injuries [1–3]. The intact skull allows fracture lines to develop nor- mally while the presence of bone damage causes the subsequent injuries to stop in the point of intersection with the previous wounds. In other words, the fracture lines produced by subsequent impacts are arrested at pre-exist- ing fractures of the skull (Fig. 1)[2, 3]. No exception to this rule has been found in systematic investigation on skulls, glass, and eggs stricken with sub- sequent blows [4]. Although multiple gunshots cause an extensive and sometimes very complex pattern of fractures (hydrody- namic effect produced by the bullet transversing the temporal cavity of the brain) [5–8], in the majority of cases Puppe’s rule can be successfully applied [3, 4, 9–13]. Indeed, by impacting the skull the bullet creates a bone deformation very similar to that produced by a blunt force instrument when medium or large caliber handguns are used [4, 7, 11–13]. Depending on the mass, velocity, direction, and site of impact of the bullet [3, 7, 9], gunshot wounds to the skull vault usually show two pattern of fractures: radial fractures originating from the point of impact and concentric frac- tures centered around the entrance or exit hole [3, 5, 8]. Generally specific features help distinguishing entrance from exit wounds: the former show a round or ovoid shape with internal beveling of the inner table, while the latter are larger, and more irregular and present an external beveling of the outer table [8, 14, 15]. G. Viel (&) Department of Environmental Medicine and Public Health, Legal Medicine, Via Falloppio, 50, 35121, Padova, Italy e-mail: guido.viel@unipd.it A. Gehl Á J. P. Sperhake Department of Forensic Pathology, Institute of Legal Medicine, University of Hamburg, Butenfeld 34, 22529, Hamburg, Germany Forensic Sci Med Pathol (2009) 5:22–27 DOI 10.1007/s12024-008-9062-8