DETERMINATION OF SEX FROM THE STERNUM AND FOURTH RIB MEASUREMENTS (A CROSS-SECTIONAL STUDY( USING THORACIC COMPUTED TOMOGRAPHY (CT) IMAGES

Abstract

Background: Several causes may destroy the skeletal remnants. Environmental causes, blasts, decomposition, and traumatic destruction may impede identification of bones. Furthermore, some forensic science researches showed inconsistency in using skull and pelvis bones in gender identification. In progressive skeletal destruction, the integrity of sternum may be conserved. In the postmortem duration, morphometric investigations of the sternum can be done by using radiological means. Aim of the work: This study was done to assess the sensitivity of sternal and 4th rib measurement analysis for sex determination in Egyptian population. Subjects and methods: CrossSectional study of thoracic Computed Tomography (CT) images of 261 adult Egyptians arrived at Menoufia university hospital. Meso-sternum length (SL), Manubrium length (ML), Sternebra 1 width (MS1), Sternebra 3 width (MS3), 4TH Rib (its width at the level of costochondral junction) were measured. Differences between genders were detected by student t-test. Results: All sternal and forth rib measurements are significantly higher in males. The highest sensitivity and specificity values for sex discrimination were identified in SL as the sensitivity was 90.6% and specificity was 70.6%. Sex equation = -13.134+ (SL*0.06) + (ML*0.111) + (MS1*0.045) + (MS3*0.024) + (4th rib*0.092). Conclusion: The sternum represented a reliable bone for sex determination in Egyptian population, based on a CT scan. The data generated from morphometric sternum studies are population specific data. Researchers can use a rapid and easy CT scanning for sternum and fourth rib as an effective method for sex identification. Recommendation: -we need to increase the number of conducted studies using radiological methods with proper analyses, as we can add other bones for forensic anthropologic evaluation. - As there are ethnic differences within national populations appeared in previous studies outside Egypt, we recommend other studies on the same bone in other Egyptian areas. - Use the equation of the sternal bone and the fourth rib measurement in determining sex.