Preauricular Sulcus Research Articles

Sexual dimorphism of pelvic scarring: A new method of adult biological sex estimation.

Estimating biological sex is a crucial aspect of forensic anthropology, and is pivotal in forensic investigations. Presently, the most frequently adopted osteological sex estimation methods focus on the anterior pelvis, which is easily susceptible to postmortem damage, revealing a need for additional accurate methods. This study introduces a novel method for estimating adult sex through metric pelvic scar analysis, using a known skeletal sample (169 females; 51 males). Relationships between sex and scar dimensions were subjected to Kendall's tau-B testing, and the strongest associated measurements were further analyzed using binary logistic regression to determine their predictive capacity. The final estimation method was tested on an additional known-sex sample of 43 males and 43 females from the Spitalfields skeletal collection. All associations between biological sex and scar measurements were significant, with the preauricular sulcus and newly defined inferior interosseous cavity presenting the strongest relationships (τb 0.223-0.504). Individual regression models using the approximate volume of each feature predicted sex with over 80% accuracy, but when combined in a single regression model, the accuracy increased to an impressive 97.1%. When then applied to the validation sample, the final estimation model achieved an accuracy of 90.7%. These results highlight the high estimation accuracy achieved by simultaneously utilizing the approximate volume of the sulcus and the inferior cavity. This is not only highly accurate but also utilizes the sturdier posterior pelvis, making it a promising tool for forensic investigations and the wider field of osteology.

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

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. 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. 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. 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.

Usability of preauricular sulcus for sex and pregnancy⁄ parturition estimation in human skeletons: A test on the Cyprus population

Coxa kemiklerinde, iliac auricular yüzeyin inferiorüne paralel ve bitişik bir oluk görünümündeki preauricular sulcusun (PS), kadın iskeletleriyle ve hamilelik/doğumla ilişkilendirilmesi tartışmalı bir konu olup, her ikisini birlikte antemortem bilgileri mevcut modern iskeletler üzerinde test etmiş çalışmalar oldukça azdır. Bu çalışmanın amacı, PS’nin insan iskeletlerinde cinsiyet belirlemede ve kadın iskeletlerinde hamilelik/doğum tayininde kullanılabilirliğini Kıbrıs popülasyonu üzerinde test ederek bu alanda yapılmış benzer çalışmalara katkı koymaktır. Çalışmamızda, 14-80 yaş arası 35 erkek ve 14-79 yaş arası 31 kadın (doğum yapmadığı/yaptığı ve çocuk sayısı bilinen) bireyden oluşmak üzere 66 modern iskelete ait toplam 132 adet sağ ve sol coxa kemikleri makroskobik olarak incelenmiş, PS morfolojik olarak üç kategoriye ayrılmış ve skorlanmıştır. Ön test niteliğindeki bu çalışmamızın sonuçları, PS’nin mevcut olmaması veya mevcut ve sığ olmasının cinsiyet ayırımında kullanışlı olmadığını, kadınlarda PS’nin mevcut olmaması veya mevcut ve sığ olmasının hamilelik/doğum geçmişinin olmama olasılığını gösterdiğini, geniş ve derin PS’nin kadın bireylere işaret ettiğini ve hamilelik/doğumla yakından ilişkili olduğunu göstermiştir. Bu testin ileri aşamasında materyal sayısı artırılarak, geniş ve derin PS’nin cinsiyet ayırımında kullanılabilirliği ve kadınlarda hamilelik/doğumla doğrudan ilişkili olup olmadığı test edilecektir. Bu testin sonuçları, insan kemiklerinden cinsiyet tayini ve PS’nin hamilelik/doğumla ilişkisini araştıran popülasyona özgü çalışmalara katkısından ve bu konuda Kıbrıs popülasyonu üzerine yapılmış ilk bilimsel çalışma özelliğine sahip olmasından dolayı önemlidir.

Anatomic basics and technical approaches: sacral preauricular extensions, preauricular sulci and dorsal pubic pits in modern anatomical specimens.

The aim of this study is the evaluation of three selected osseous pelvic features in modern anatomical specimen - the sacral preauricular extension, the preauricular sulcus and pits on the dorsal side of the pubic bone laterally to the symphysis. The specificity and significance of these features are under debate and their genesis is largely unclear. Descriptive data of specific soft tissue structures surrounding the anterior sacroiliac joint gap and the pubic symphysis were generated by assessing 20 fresh pelves and 12 embalmed hemipelves from human body donors. Computed tomography (CT) was performed on all specimens and three-dimensional (3D) surface models were generated and analysed. Afterwards, all the specimens underwent anatomical dissection and finally maceration. During dissection, it became apparent that the anterior sacroiliac ligament, due to its position, shape and potential impact on the sacroiliac joint and adjacent osseous structures, requires a detailed analysis of its dimension. The most promising result, in terms of the sacral preauricular extension, was that the measurements of the triangular part of the anterior sacroiliac ligament were significantly longer in females than in males. Pelvic floor muscle fibres and fascial parts were directly connected to this ligament in some specimens, which is an important starting point for a larger in-depth study. The evaluation of the anatomic structures in connection to dorsal pitting refutes the assumption that the pelvic floor muscles or fasciae could exert influence on its formation. A histological evaluation of the ligaments of the pubic symphysis, especially the dorsal pubic ligament, would be expedient to clarify the etiology of this feature.

Sacral preauricular extensions and notches as parts of a 'Pelvic Pattern' may provide information on past pregnancies and parturitions.

During the analyses of several hundred prehistoric individuals from Austria, we observed that some women display a "Pelvic Pattern" at the innominate bones and the sacrum, i.e. specific combinations of pronounced expressions of pelvic features. We recorded classic pelvic features (dorsal pubic pitting, preauricular sulcus, extended pubic tubercle) as well as new ones (SPE: sacral preauricular extension, a ventrally pointing flat bone formation at the ventrosuperior margin of the ala ossis sacri; SPN: sacral preauricular notch, a loss of convexity at the same location; CF: corresponding facets at the ilium), and some less well-known features, i.e. the margo auricularis groove, ventral pubic exostoses and lesions. To quantify the assessed features, we developed a specific formula to calculate the 'Pelvic Pattern Index' (PPI). As pregnancies and/or parturitions are suspected to contribute to or be at least partly causative of the occurrence of pelvic features, we analyzed 48 well-preserved female individuals and 15 males from identified skeletal collections with obstetric information in Geneva and London. In these collections, we found a pelvic pattern of at least four out of ten distinctly expressed pelvic features only in multiparous females, but not in nulli- or primiparous females or in males. This pattern was found in 40.6% of the multiparous females and 29.2% of all females from the identified collections, compared to 56.1% of well-preserved prehistoric females with unknown parity status from Austria (n = 41). The mean PPI of the multiparae from the identified collections is 0.25, compared to a mean PPI of 0.19 for all women from the identified collections, and 0.28 for the prehistoric female individuals. We conclude from this that a high PPI (≥ 0.30), especially in cases where SPE or SPN are present, can give insights into past motherhood.

Are parturition scars truly signs of birth? The estimation of parity in a well‐documented modern sample

AbstractParturition scars have been frequently studied in the last decades, but their association with pregnancy and birth is still controversial. Other biomechanical, biometric, and lifestyle factors are also likely to influence the development of pelvic features. Most previous studies of pelvic features were based on skeletal collections with no reliable information on parity or even sex and thus were unable to disentangle these factors. Here, we study the association of pelvic features with birth and other body variables (age, stature, weight, osteoarthritis, and centrum–collum–diaphyseal angle) using multiple regression and path modeling in a modern sample of female individuals from New Mexico (USA) with detailed background information (n = 150). We also explored the utility of pelvic features to predict the number of births. To this end, we scored the expression of the preauricular sulcus, sacral preauricular extension, extended pubic tubercle, exostosis at the pectineal line, dorsal, and ventral pubic pitting using CT scans from the New Mexico Decedent Image Database. Quantitative measurements of pelvic features were then used as predictors of parity. Overall, the regression models accounted only for relatively small fractions of variance in pelvic feature expression. The only feature significantly associated with the number of births was dorsal pubic pitting (R2 = 0.2372), whereas the expression of most pelvic features increased with age, independent of parity. Presumably, the development of dorsal pubic pitting is affected both by biomechanical stress and the increased hormonal secretion during pregnancy and birth. The individual prediction of parity based on pelvic features is too imprecise for forensic or archeological applications. However, using a size score of dorsal pubic pitting allowed us to estimate the mean parity in groups of individuals relatively well. Hence, pelvic features may still be used to compare average parity across recent or historic populations.

The association of parturition scars and pelvic shape: A geometric morphometric study.

ObjectivesPelvic features, mostly known as parturition scars, have been extensively studied in the last decades and are frequently investigated in archaeological and forensic contexts. It is still unclear, however, whether they really relate to pregnancy and birth, or whether these features are caused by other biomechanical factors. Because the length and difficulty of labor correlates with the form of the birth canal, we studied the association between the expression of pelvic features and pelvic shape using geometric morphometrics.Materials and MethodsWe scored the expression of the preauricular sulcus, margo auricularis groove, sacral preauricular extension, dorsal and ventral pubic pitting for 54 individuals from a 19th century collection and 19 individuals from the Bronze Age cemetery of Hainburg‐Teichtal, Austria. Based on photogrammetric surface models, pelvic shape was captured by 331 landmarks and semilandmarks. The multivariate association between pelvic features and pelvic shape was explored by partial least squares analysis.ResultsWithin the female subsample, we detected a significant association of a constrained birth canal with a strong expression of the preauricular sulcus, the margo auricularis groove, and a retroverted position of the acetabulum. No significant association was found among males.DiscussionThis suggests that difficult or prolonged labor may indeed cause more strongly expressed pelvic features, presumably because of increased strain of the pelvic ligaments during birth. Furthermore, the retroversion of the acetabulum, which is known to cause sacroiliac joint dysfunction, changes the strain on pelvic ligaments and can thus also result in the development of pronounced pelvic features.

Sex estimation of skeletons in middle and late adulthood: reliability of pelvic morphological traits and long bone metrics on an Italian skeletal collection.

There are several metric and morphological methods available for sex estimation of skeletal remains, but their reliability and applicability depend on the sexual dimorphism of the remains as well as on the availability of preserved bones. Some studies showed that age-related changes on bones can cause misclassification of sex. The purpose of this study was to establish the reliability of pelvic morphological traits and metric methods of sex estimation on relatively old individuals from a modern Italian skeletal collection. The data for this study were obtained from 164 individuals of the Milano CAL skeletal collection and average age of the samples was 75years. In the pelvic morphological method, the recalibrated regression formula of Klales and colleagues (2012), pre-auricular sulcus, and greater sciatic notch morphology were used for sex estimation. With regard to the metric method, 15 standard measurements from upper and lower limbs were analyzed for sexual dimorphism. The results showed that in pelvic morphological approach, the application of regression formula of the revised Klales and colleague formula (2017) resulted in 100% accuracy. Classification rates of metric methods vary from 75.19 to 90.73% with the maximum epiphyseal breadth of proximal tibia representing the most discriminant parameter. This study confirms that the effect of age on sex estimation methods is not substantial, and both metric and morphological methods of sex estimation can be reliably applied to individuals of Italian descent in middle and late adulthood.

Comparing the Accuracy of Morphometric and Morphological Criteria of Hip Bone in Gender Determination

Background: A primary aim of forensic medicine is gender determination. Although hip is the optimal bone for this purpose, different determining criteria of this bone do not have the same accuracy. This is important in conditions that only parts of hip remain to determine gender. This study aimed to evaluate the accuracy of different hip criteria in gender determination. Methods: This cross-sectional study evaluated a total of 160 paired hips (80 males and 80 females) removed from the bodies for bone transplantation. Morphometric criteria were vertical and horizontal acetabular diameters and superior and inferior pubic ramus widths. Morphological criteria were a greater sciatic notch, obturator foramen, pubic body, preauricular sulcus, acetabular fossa position, and ischial tuberosity. The obtained data were analyzed using Cross Tab, t-test, and logistic regression analysis by SPSS. The significance level was set at P 0.05). In gender determination, acetabular diameter and greater sciatic notch had the highest accuracy (85%), and obturator foramen (67.5%) and superior and inferior pubic ramus widths (65%) had the lowest accuracy. Conclusion: Hip bone is not always completely available and preserved to determine gender. Moreover, sometimes not all anthropometric criteria of the bone are in favor of one gender. Therefore, investigating the accuracy of different criteria can be very important in interpreting the results. Thus, it has always been emphasized on the use of all available information in gender determination.

Evaluating macroscopic sex estimation methods using genetically sexed archaeological material: The medieval skeletal collection from St John's Divinity School, Cambridge.

ObjectivesIn tests on known individuals macroscopic sex estimation has between 70% and 98% accuracy. However, materials used to create and test these methods are overwhelming modern. As sexual dimorphism is dependent on multiple factors, it is unclear whether macroscopic methods have similar success on earlier materials, which differ in lifestyle and nutrition. This research aims to assess the accuracy of commonly used traits by comparing macroscopic sex estimates to genetic sex in medieval English material.Materials and MethodsSixty‐six individuals from the 13th to 16th century Hospital of St John the Evangelist, Cambridge, were assessed. Genetic sex was determined using a shotgun approach. Eighteen skeletal traits were examined, and macroscopic sex estimates were derived from the os coxae, skull, and os coxae and skull combined. Each trait was tested for accuracy to explore sex estimates errors.ResultsThe combined estimate (97.7%) outperformed the os coxae only estimate (95.7%), which outperformed the skull only estimate (90.4%). Accuracy rates for individual traits varied: Phenice traits were most accurate, whereas supraorbital margins, frontal bossing, and gonial flaring were least accurate. The preauricular sulcus and arc compose showed a bias in accuracy between sexes.DiscussionMacroscopic sex estimates are accurate when applied to medieval material from Cambridge. However, low trait accuracy rates may relate to differences in dimorphism between the method derivative sample and the St John's collection. Given the sex bias, the preauricular sulcus, frontal bossing, and arc compose should be reconsidered as appropriate traits for sex estimation for this group.

A test of the preauricular sulcus as an indicator of sex.

Although the presence of a preauricular sulcus is often cited as an indicator of female sex, very little research has been conducted to substantiate this claim. This article examines both the relationship between the incidence and morphology of the preauricular sulcus and sex. A total of 500 left ossa coxae from the Hamann-Todd Human Osteological Collection belonging to 261 males and 239 females were examined to investigate the relationship between the preauricular sulcus and sex. The sample includes both American Blacks and Whites. Each individual was scored based on groove presence and morphology. Differences between the sexes in terms of overall prevalence and morphology were investigated using chi-squared tests. Additionally, possible relationships between ancestry and the manifestation of the preauricular sulcus were investigated using multiple regression analysis. Overall, the presence or absence of the preauricular sulcus resulted in correct sex assessment in 75.8% of ossa coxae. However, the accuracy differed between the sexes, with 62.84% of males and 89.96% of females being assessed correctly. Males were significantly more likely to display a short, narrow sulcus (score 4) than females, whereas females were observed to be significantly more likely to have a wide, long sulcus. Ancestry was not related to sulcus manifestation. The results presented here suggest that the presence of a preauricular sulcus should not be considered positive proof of female sex. However, the complete lack of a sulcus could be considered suggestive of male sex.

Virtual reconstruction of the Australopithecus africanus pelvis Sts 65 with implications for obstetrics and locomotion

Characterizing australopith pelvic morphology has been difficult in part because of limited fossilized pelvic material. Here, we reassess the morphology of an under-studied adult right ilium and pubis (Sts 65) from Member 4 of Sterkfontein, South Africa, and provide a hypothetical digital reconstruction of its overall pelvic morphology. The small size of the pelvis, presence of a preauricular sulcus, and shape of the sciatic notch allow us to agree with past interpretations that Sts 65 likely belonged to a female. The morphology of the iliac pillar, while not as substantial as in Homo, is more robust than in A.L. 288-1 and Sts 14. We created a reconstruction of the pelvis by digitally articulating the Sts 65 right ilium and a mirrored copy of the left ilium with the Sts 14 sacrum in Autodesk Maya. Points along the arcuate line were used to orient the ilia to the sacrum. This reconstruction of the Sts 65 pelvis looks much like a “classic” australopith pelvis, with laterally flared ilia and an inferiorly deflected pubis. An analysis of the obstetric dimensions from our reconstruction shows similarity to other australopiths, a likely transverse or oblique entrance of the neonatal cranium into the pelvic inlet, and a cephalopelvic ratio similar to that found in humans today.

Parturition pit: the bony imprint of vaginal birth.

To retrospectively evaluate for pits along the dorsum of the pubic body in females and compare the presence/absence of these pits to vaginal birth data. We retrospectively reviewed females with vaginal birth data who underwent pelvic CT. The presence of pits along the dorsum of the pubic body, pit grade (0 = not present; 1 = faintly imperceptible; 2 = present; 3 = prominent), and the presence of osteitis condensans ilii, preauricular sulcus, and sacroiliac joint vacuum phenomenon were assessed on imaging. Musculoskeletal radiologists who were blinded to the birth data evaluated the CTs. 48 males were also evaluated for the presence of pits. 482 female patients underwent CT pelvis and 171 were excluded due to lack of vaginal birth data. Of the 311 study patients, 262 had prior vaginal birth(s) and 194 had pits on CT. Only 7 of the 49 patients without prior vaginal birth had pits. There was a statistically significant association between vaginal birth and presence of pits (p < 0.0001). Patients with more prominent pits (grades 2/3) had a greater number of vaginal births. As vaginal deliveries increased, the odds of having parturition pits greatly increased, adjusting for age and race at CT (p < 0.0001). No males had pits. Our study indicates that parturition pits are associated with prior vaginal birth and should be considered a characteristic of the female pelvis. The lytic appearance of prominent pits on imaging can simulate disease and create a diagnostic dilemma for interpreting radiologists.

Scars of Parturition? Influences Beyond Parity

AbstractIn the 40 years since the phrase ‘scars of parturition’ was coined, studies have attempted to show the relationship between scars on the bony pelvis and parity history. Despite numerous studies, the relationship of parity and scarring remains unclear. The challenge facing these studies is the rarity of skeletal collections of known parity. The alternative study approach is examining relationships between scars and factors other than pregnancy‐related strains that may affect their manifestation.Skeletal remains of 312 individuals were examined for scarring at the dorsal pubic surface, pubic tubercle, preauricular sulcus, interosseous groove and iliac tuberosity. Pelvic and femoral measurements were also taken. Features were compared according to sex and age. Principal components analysis was performed to assess the influence of body and pelvic size on scar manifestation.Scars occurred in both sexes, although they were more common and more severe in females. Scar severity remained unchanged or increased with age in both sexes. Females had smaller bodies but larger pelves than males. The interspinous and transverse inlet diameters and the femur measurements increased with age. Principal components analysis showed that body and pelvic sizes represented the majority of the observed variation, with scars occurring more commonly in small‐bodied individuals with large pelves, most of which were females. Both sexes also show a difference in the magnitude of scarring at the pubis and ilium.These results suggest that weight‐bearing and pelvic stability may be a better explanation for scarring than parturition‐related strain. Female pelves are more flexible and require more ligamentous stabilization, causing increased scar formation. The weight‐bearing strain on male pelves may sometimes also be sufficiently large to cause similar scars.Future studies may be able to test this theory on samples of known parity history. Copyright © 2014 John Wiley &amp; Sons, Ltd.

A study of morphological features of ilium for sex determination in Gujarat state

Background: Hip bone is most commonly used by forensic personnel as well as anatomist and anthropometric expert for sex determination. Many workers have calculated different types of indices to determine the sex of hip bone. Aim: In present study, determination of sex of hip bone was done by using morphological features. Materials & Method: Present study was conducted at Dept of Anatomy, PDU medical college, Rajkot on 108 (27 male & female of each side) adult human hip bones. Four morphological features of ilium, 1) Preauricular sulcus 2) Post auricular sulcus 3) Post auricular space and 4) iliac tuberosity were observed. Results: Iliac tuberosity was most efficient parameter to identify male hip bones (90.74%), while post-auricular sulcus was most efficient parameter to identify female hip bones (72.22%). Conclusion: Combination of morphological feature is more effective in sex determination than a single feature alone. Keywords: Morphological features, Sex determination, Ilium

Determining Sex of the Posterior Ilium from the Robert J. Terry and William M. Bass Collections

Morphological traits of the posterior ilium are commonly used for sex determination in bioarcheological and forensic skeletal analysis. This study was designed to compare the classification correctness of standard scoring systems and measurements of the posterior ilium, including using logistic regression, to develop new formulae to predict sex. Metric measurements and morphological scores for the preauricular sulcus (PS), the elevation of the auricular surface, and the greater sciatic notch width were recorded for 97 males and 101 females of both European and African ancestry from the William M. Bass and Terry Collections. Correct classification of sex was high using individual traits such as the greater sciatic notch score (88.4%), the presence or absence of a PS (78.8%), and the scoring of a present PS as 1, 2, or 3 (100%). Furthermore, an equation combining multiple traits of the posterior ilium had a high classification of 94.9%.

A description of the Omo I postcranial skeleton, including newly discovered fossils

Recent fieldwork in the Kibish Formation has expanded our knowledge of the geological, archaeological, and faunal context of the Omo I skeleton, the earliest known anatomically modern human. In the course of this fieldwork, several additional fragments of the skeleton were recovered: a middle manual phalanx, a distal manual phalanx, a right talus, a large and a small fragment of the left os coxae, a portion of the distal diaphysis of the right femur that conjoins with the distal epiphysis recovered in 1967, and a costal fragment. Some researchers have described the original postcranial fragments of Omo I as anatomically modern but have noted that a variety of aspects of the specimen's morphology depart from the usual anatomy of many recent populations. Reanalysis confirms this conclusion. Some of the unusual features in Omo I—a medially facing radial tuberosity, a laterally flaring facet on the talus for the lateral malleolus, and reduced dorsovolar curvature of the base of metacarpal I—are shared with Neandertals, some early modern humans from Skhul and Qafzeh, and some individuals from the European Gravettian, raising the possibility that Eurasian early modern humans inherited these features from an African predecessor rather than Neandertals. The fragment of the os coxae does not unambiguously diagnose Omo I's sex: the greater sciatic notch is intermediate in form, the acetabulum is large (male?), and a preauricular sulcus is present (female?). The preserved portion of the left humerus suggests that Omo I was quite tall, perhaps 178–182 cm, but the first metatarsal suggests a shorter stature of 162–173 cm. The morphology of the auricular surface of the os coxae suggests a young adult age.

Multivariate analysis of the sexual dimorphism of the hip bone in a modern human population and in early hominids

A large sample of hip bones of known sex coming from one modern population is studied morphologically and by multivariate analysis to investigate sexual dimorphism patterns. A principal component analysis of raw data shows that a large amount of the hip bone sexual dimorphism is accounted for by size differences, but that sex-linked shape variation is also very conspicuous and cannot be considered an allometric consequence of differences in body size between the sexes. The PCA of transformed ("shape") variables indicates that the female hip bones are different in those traits associated with a relatively larger pelvic inlet (longer pubic bones, a greater degree of curvature of the iliopectineal line, and more posterior position of the auricular surface), as well as a broader sciatic notch. The analysis of nonmetric traits also shows marked sexual dimorphism in the position of the sacroiliac joint in the iliac bone, in the shape of the sciatic notch, in pubic morphology, and in the presence of the pre-auricular sulcus in females. When the australopithecine AL 288-1 and Sts 14 hip bones are included in the multivariate analysis, they appear as "ultra-females." In particular these early hominids exhibit extraordinarily long pubic bones and iliopectineal lines, which cannot be explained by allometry.

Evaluation of the obstetric significance of some pelvic characters in an 18th century British sample of known parity status.

The excavations at Christ Church, Spitalfields (1984-86) produced a sample of 968 human skeletons which were interred between 1729 and 1859. Of these, 387 were recovered in association with coffin plates stating name, age at death, and date of death. There are 138 adult females in the named sample and the obstetric histories of 94 have been reconstructed from historical documentation. Such variables as birth spacing, number of children, and age at first and last births are known for the majority of this sample. Any individual about whose history there is any doubt has been excluded from the analysis. A middle-class group, they were largely of high nutritional status and, by the standards of the day, lived in sanitary and comfortable conditions. Both males and females have a mean age at death of 56 years. The presence or absence, the typology, the severity, the width and the length of the preauricular sulcus, the presence or absence and the number of pits on the dorsal aspect of the pubic body, sulci along the anterior sacrum adjacent to the auricular facet, and the extension of the pubic tubercle were evaluated in relation to the obstetric histories of these females. Statistical analysis has demonstrated a relationship between the presence of pubic tubercle extension and parity status and between the degree of extension and the number of children borne (P < .02). Statistically there is no significant relationship (P > .05) between either the preauricular sulcus or pubic pitting and parity status. Sacral scarring is significantly associated (P < .05) with parity status, but as it was evident in only eight females it has little practical application. Sample sizes are small, and it must be considered that statistical evaluation of larger samples might detect associations between variables not demonstrated here. There is no significant relationship between any of the cortical variants under consideration and age at death.

Morphology of the pubis and preauricular area in relation to parity and age at death in Macaca mulatta

Some adult human females show bone resorption (pitting) at the dorsal aspect of the pubis and preauricular area of the ilium. The etiology of pelvic bone resorption is attributed alternatively to reproduction and to pelvic anatomy. While most researchers infer that pelvic pitting is related to reproduction, only a few studies are based on women of known parity. Degree of pubic resorption is directly associated with both parity (Suchey et al.: Am. J. Phys. Anthropol. 51:517-539, 1979; Bergfelder and Hermann: J. Hum. Evol. 9:611-613, 1980) and age (Suchey et al.: Am. J. Phys. Anthropol. 51:517-539, 1979). The relationship between parity and degree of resorption of the preauricular area is equivocal, found to be significant by Dunlap (A Study of the Preauricular Sulcus in a Cadaver Population, Ph.D. dissertation, East Lansing, Michigan State University, 1981) but not by Spring et al. (Am. J. Phys. Anthropol. 79:247-252, 1989); both studies report that age is not associated with resorption of the preauricular area. Other mammals evidence public resorption, but the morphology of the preauricular area is less well known. This study addresses the issue on the etiology of pelvic bone resorption using a sample of Macaca mulatta (the free-ranging population from Cayo Santiago) for which parity and age at death are known for all specimens. The following results are reported. Resorption of the pubis is common among females but infrequent among males. Contrary to Rawlins (Am. J. Phys. Anthropol. 42:477-488, 1975), the degree of pubic resorption in female macaques is significantly related to both parity and age at death.(ABSTRACT TRUNCATED AT 250 WORDS)