Preauricular sulcus: Radiological incidence in the female gender in a multicultural population

Introduction: The preauricular sulcus is a bony groove seen on the inferior aspect of the iliac bone. It is thought and accepted to be an indicator of female gender. To our knowledge, this study would be the first to examine the sulcal incidence in a multicultural population. To date, there are limited studies to also test the existing hypothesis that the sulcus is only seen in the female gender. The results of this study would be applicable to the field of forensic medicine and gender identification in the post-mortem setting.

Methods: Retrospective review of 500 adult pelvic X-ray radiographs (250 female and 250 male) obtained as part of routine medical care in a metropolitan public health service (encompassing three hospitals) was performed. The radiographs were examined by two post-FRANZCR examination senior registrars who recorded their results independently.

Results: The mean age of the female population was 70.1 years, and the mean age of the male population was 75.5 years. This study found that the preauricular sulcus is only present in the female pelvis. The incidence was 41.2% (103 of 250) in the examined female patient population. The sulcal incidence in this study was also found to be significantly higher than previously reported in prior studies.

Conclusion: This study supports the previous notion that the presence of preauricular sulcus in a pelvic specimen would indicate the female gender. The absence of the sulcus does not necessarily confer the male gender.