"Typical" basal skull fracture of both petrous bones: an unreliable indicator of head impact site.

A basilar skull fracture that extends along both petrous bones is generally considered to be a response to impacts to the lateral aspects of the head. This generalization is not warranted as such a fracture often results from impacts to any point around the base of the skull or to the chin. These facts were appreciated as long ago as 1905 but present-day literature does not adequately reflect them. Eight carefully selected autopsy cases of fatal blunt head injury with well-documented single head impact sites and bilateral petrous bone fractures are presented. They illustrate the variety of impact sites that may produce bilateral petrous bone skull fractures.