Abstract

In disaster victims’ identification in forensic science, every piece of evidence is relevant. Biochemical assays, anthropometry, and recently, medical imaging, have all provided some form of evidence. Cephalic index, popular derived by ultrasound in utero, and with sliding calipers ex utero, can also be accurately derived ex utero using the medical imaging tool of computed tomography. To derive cephalic index for an adult Igbo population in Nigeria using computed tomography, with a view to encouraging its adoption by future researchers in the locality. Digital computed tomography (CT) images of one hundred and thirty-seven (137) male and sixty-five (65) female patients aged 18 - 93 years were electronically measured using on-screen measurement cursors (OMC) on CT monitor. For each patient, two scanograms were acquired supine at an azimuth of 90 degrees (lateral) and 180 degrees (postero-anterior). Measurements were for occipito-frontal diameter (OFD) and biparietal diameter (BPD) after which simple mathematical calculations were used to derive cephalic index, in percentage. Cephalic index was eventually computed for the entire population. Enlisted images had the three major categorizations of cephalic index in the following proportion:  brachycephalic (16.3%), mesocephalic (32.2%) and dolicocephalic (51.5%), respectively. However, when the entire population was normalized using mathematical averaging, the observed variations gave way to a clear evidence of mesocephalic head type for Igbo population (male = 77.23 ± 4.8; female = 77.46 ± 5.1; combined = 77.35 ± 5.2). Cephalic index measurement is replicable using an advanced medical imaging modality like computed tomography. This possibly pioneering work in the entire southeast geopolitical zone of Nigeria using Igbo population indicate that they belong to the mesocephalic head type which corroborates several studies done with sliding calipers. This knowledge is useful in first line compartmentalization in disaster victims’ identification.

Keyword: Cephalic Index, Cranial Index, Computed Tomography, Scanogram, Radiographs, Azimuth.