Sex Determination of Iliac Bone in a Thai Population

Abstract

Sex determination is one of the four most important steps in human identification. The most reliable bone for sex determination is the pelvis. This study was carried out on the ilium, a part of the pelvis, for sexing. A sample of 325 Thai pelvises, 214 males, 111 females with an age range between 15-96 years from the department of Anatomy, Faculty of medicine, Chiang Mai University was used to observe the preauricular and postauricular areas of both iliums for the existence of a streak or sulcus. A measurement of the widest dimension of each streak or sulcus, if present, was made in millimeter. The results showed that in the preauricular area, the streak was present in 5.4% of female pelvises with a width of 3.44-7.5 mm; sulcus in 86.5-87.4% with a width of 5.06-18.68 mm. Female pelvises without streak or sulcus were 7.2-8.1%. While in the male, the streak was present in 4.7-6.1% and the width was 2.58-5.98 mm. The sulcus was present in 0.5-0.9% with a width of 4.22-8.34 mm. Male pelvises without streak or sulcus were 93.4-94.4%. There were no significant differences statistically between the right and left sides (p>0.01), but there were significant statistical differences between male and female regarding the presence or absence of preauricular streak or sulcus (p<0.01). In the postauricular areas, the presence of sulcus was 60-66% in female and none in male. There was no significant statistical differences between the right and left sides (p>0.01) while there were in the presence of postauricular sulcus in male and female (p<0.01). In summary, the presence of preauricular and postauricular sulcus as a main feature of female pelvis may be used as a basic data for an accurate quick sex determination for Thai population.