Diameter of the human internal acoustic meatus and sex determination

Abstract

AbstractWe report the results of testing the diameter of the internal opening of the acoustic canal in the petrous part of the temporal bone for sex determination of skeletal remains. The method involves measuring the diameter using a suite of ordinary drills. The method is very simple and has the great advantage of utilising one of the sturdiest bone elements of the human skeleton. The method may be especially useful for the analyses of very fragmented skeletal remains or cremated bones, where the petrous bone may still be readily recognisable. The method was tested using a forensic sample of 113 left petrous bones with known sex. Intra‐ and inter‐observer testing was also performed. We found a statistically significant difference in diameter between males and females (means: males: 3.7 mm; females: 3.4 mm; P < 0.009). However, the low predictive value (70%) for correct sexing using two sectioning points ( < 3.0 mm = female; >3.5 mm = male) was disappointing. No additional accuracy was gained by employing both left and right petrous bones (a bilateral sample of 60 petrous bones was also tested), although left and right side diameter is highly correlated (R = 0.778; P = 0.0001). Copyright © 2005 John Wiley & Sons, Ltd.