Phenice method

Abstract: Sexual dimorphism of the human pelvis is linked intimately with its adaptive functions. The peculiarly shaped hominid pelvis represents the total response to the diverse forces that have moulded its structure. These diverse forces are requirements for efficient bipedalism and parturition. In some respects, the structural demands of these unrelated functions have been in conflict. The morphological response to the dominant requirement, bipedalism, is clearly discernible, while the changes serving the needs of parturition are seen as compensatory modifications as reflected with greater emphasis for pelvic sexual dimorphism in the female. In addition, sexual selection has made sexual dimorphism even more pronounced. The female buttocks have undergone sexual elaboration through mate choice by males. Thus, total pelvic architecture is a mosaic constituted of the aggregate of differential responses to different functional goals. There are complications during parturition that have been repeatedly prevented or interceded by medical technology, close monitoring, surgical practices such as caesarian sections, and other strategies. With these complications, one could hypothesize that these natural operators, which have exerted their influence since the beginning of mankind, might be becoming increasingly destabilized, attenuated or stochastic. The Male and Female Pelvic Blueprint and Anatomic Variations In general, the structure of the male pelvis is significantly heavier and thicker than that of the female. The male pelvic bones are also adapted to fit a more massive and sturdy body architecture. For example, the male acetabulum has been designed to fit a bigger femur. Though a large amount of the sexual dimorphism of the pelvis is accounted for by size differences, sex-linked shape variation is also very conspicuous and cannot be considered an allometric consequence of differences in body size between the sexes (1). These variations in shape are demonstrated by the more rounded frame of the female pelvis. The sciatic notches are broader, the greater pelvis is shallower, the lesser pelvis is wider and the pelvic inlet and outlet are larger (longer pubic bones and a greater degree of curvature of the pectineal line). The female hipbones are also different in traits associated in the position of the sacroiliac joint in the iliac bone (2). As a result of this ‘flattened’ appearance, the female obturator foramen is more elliptical. The pubic arch is formed by the conjoined rami of the pubis and ischium of the two sides. These rami meet at the pubic symphysis to form the subpubic angle. The subpubic angle is nearly a right angle in females and is considerably less in males; approximately 30° narrower (3). Superficial to the skeleton and musculature of the pelvis, sexual dimorphism in pelvic morphology is most apparent in body fat distribution as measured by waist hip ratio (WHR). The WHR has been shown to be independent of overall body weight and an accurate predictor of risk for various diseases, premature mortality, degree of estrogenicity and fecundity of women (4). Undoubtedly, healthy women have a greater propensity to possess rounder hips and a lower WHR compared to most men (4). Nonetheless, the human pelvis is not always distinctly dimorphic. It has been well established that nature has allowed individual anatomical variation and departures from set norms within each sex. Hence, one could infer that it is possible to find any of the previously defined archetypal features in the ‘wrong’ sex. In addition, there is metric and morphologic variation in the expression of sexual dimorphism between racial phenotypes and populations (5). In other words, the final shape of the female pelvis is affected by multiple etiological factors - cultural, environmental and genetic. The gynecoid pelvis (rounded shape) is said to be the normal female type while the android pelvis (heart-shaped) is often designated a male variant. Women with the android pelvis do not typically present with hyperandrogenism, and signs of hyperandrogenism have been similarly encountered in patients with gynecoid and other types of pelvis. This android pelvis was also found more frequently in women exposed to strenuous physical activity during adolescence and observed more often when the acquisition of erect posture was delayed beyond the usual age of 14 months, while a platypelloid pelvis was more frequent when erect posture was acquired before 14 months (6). In addition to being developmentally discriminating, the distribution of the anthropoid pelvis between both sexes and frequency is ethnically discriminating as well. It was observed that there were significant differences in the accuracy of sex determination from pelvic morphology between both males and females, and whites and blacks. Pubic bone shape was the easiest to assess and was the most consistently reliable morphological indicator of sex in both sexes and population groups. However, in blacks, the greater sciatic notch form allowed the highest separation. This demonstrates that racial differences significantly affect the expression of sexual dimorphism (5).

Abstract: Objective To study the effi ciency of sex determination in a Thai Population by using external morphology of the pelvis. Methods A sample of 300 skeletons from the Forensic Osteology Research Center, Faculty of Medicine, Chiang Mai University were studied. They comprised 150 males and 150 females with an age range from 15 to 96 years. Eleven morphological traits of the pelvis were used for the external morphology as follows: greater sciatic notch, subpubic angle, preauricular sulcus, postauricular sulcus, iliac fossa, acetabulum, ischiopubic ramus ridge, composite arch, ventral arc, pubic bone shape, and dorsal pubic pitting. The score for sex determination by each morphological trait of the pelvis was; 1 = male, 2 = probably male, 3 = sex indeterminate, 4 = probably female, 5 = female. All scores of each morphological trait of the pelvis were analyzed for the accuracy of sex determination. Results The results showed that eleven morphological traits of pelves were present, with a mean accuracy for sex determination of between 72.5% and 98.7%. Subpubic angle, greater sciatic notch, and pubic bone shape were the three most effi cient morphological traits for determining sex, with a mean accuracy of 98.7%, 98.6%, and 98.2%, respectively. Conclusion The most effi cient morphological traits of the pelvis for sex determination were the subpubic angle, greater sciatic notch, and pubic bone shape. These traits should provide an accurate, a rapid and simple determination of sex, which would be benefi cial in the forensic context of Thailand. Chiang Mai Medical Journal 2014;53(4):175-79.

Abstract: The formation of a biological profile (including the estimation of sex and age) is usually the first task undertaken when skeletal remains are analysed by a forensic anthropologist. Recent literature attests to a growing awareness of the value of research focusing on age and sex related morphoscopic features visualized in high resolution multiple detector computerized tomography (MDCT) scans. The present study provides insight into the analysis of MDCT scans, with a specific focus on quantifying the accuracy of the Phenice sex estimation method in a Western Australian population. The sample comprises 448 clinical pelvic MDCT scans representing 226 male and 222 female individuals between 18 and 64 years of age. The scans (all ≤ 1.5 mm slice thickness) are reconstructed using three-dimensional volume rendered models in OsiriX software. A precision test was performed prior to data collection to quantify observer accordance; thereafter the accuracy of the identification of the Phenice pelvic traits (ischiopubic ramus; ventral arc; subpubic concavity) are statistically quantified. Intra-observer accordance is above 0.81 (Kappa value) for each morphological attribute assessed. Congruent with previous research the single most accurate trait overall is the ventral arc (86.61%), albeit an age-related sex-bias in classification accuracy was demonstrated. Based on the combined assessment of the three features, it is demonstrated that the Phenice method facilitates a high degree of expected accuracy in the classification of sex (92.24%), thus indicating that the method can be successfully applied in MDCT scans and is suitable for forensic application in a Western Australian population.

Abstract: One of the main problems in reconstructing the biological profile of unidentified human remains is the reliability of the methods used. These methods are normally developed on modern identificated human skeletal collections, but human variability can introduce problematic biases when applied on osteological collections from different geografical and cronological contexts. This study test the reliability of selected macroscopic methods for sex determination: the index of sexualization of Acsadi and Nemeskeri, the Phenice method and for the age estimation: the synostosis of cranial sutures (Meindl and Lovejoy), the morphological variations at the pubic symphysis (Suchey and Brooks), the morphological variations at ileum surface (Lovejoy, et al.), the modifications of the sternal end of the fourth rib (Iscan et al.) and the variations of the degree of sacral vertebral body fusion (Belcastro et al.) on a large sample (n.489) of know sex and age from Certosa Cemetery of Bologna and “Coleccao Esqueletos Identificados" of Coimbra. Regarding age, for each method was calculated the standard values of bias and inaccuracy. The method of pubic symphysis might be the most reliable for age estimation but we must consider the width of age ranges considered by the method. The values of inaccuracy are over 10 years in individuals older than 50 and 27 years in individuals older than 60. The index of sexualization confirm in more than 99% of cases the known sex and the Phenice method gave good results with the 87% of confirm. The reliability of the tested methods in the two european populations was confirmed, with the pelvis as the most diagnostic district, in particular the pubic symphysis. Nevertheless, the dramatic increase in values of bias and inaccuracy with increasing age confirms the need for new or revised age estimation methods that better suits the study of the remains of older individuals.