Interobserver Error Research Articles

Specific-age group sex estimation of infants through geometric morphometrics analysis of pubis and ischium

Sex determination of unknown individuals is one of the primary goals of Physical and Forensic Anthropology. The adult skeleton can be sexed using both morphological and metric traits on a large number of bones. The human pelvis is often used as an important element of adult sex determination. However, studies carried out about the pelvic bone in subadult individuals present several limitations due the absence of sexually dimorphic characteristics. In this study, we analyse the sexual dimorphism of the immature pubis and ischium bones, attending to their shape (Procrustes residuals) and size (centroid size), using an identified sample of subadult individuals composed of 58 individuals for the pubis and 83 for the ischium, aged between birth and 1year of life, from the Granada osteological collection of identified infants (Granada, Spain). Geometric morphometric methods and discriminant analysis were applied to this study. The results of intra- and inter-observer error showed good and excellent agreement in the location of coordinates of landmarks and semilandmarks, respectively. Principal component analysis performed on shape and size variables showed superposition of the two sexes, suggesting a low degree of sexual dimorphism. Canonical variable analysis did not show significant changes between the male and female shapes. As a consequence, discriminant analysis with leave-one-out cross validation provided low classification accuracy. The results suggested a low degree of sexual dimorphism supported by significant sexual dimorphism in the subadult sample and poor cross-validated classification accuracy. The inclusion of centroid size as a discriminant variable does not imply a significant improvement in the results of the analysis. The similarities found between the sexes prevent consideration of pubic and ischial morphology as a sex estimator in early stages of development. The authors suggest extending this study by analysing the different trajectories of shape and size in later ontogeny between males and females.

Ancestry estimation of three Mediterranean populations based on cranial metrics

The estimation of ancestry is an essential benchmark for positive identification of heavily decomposed bodies that are recovered in a variety of death and crime scenes. This is especially true when reconstructing the biological profile of the deceased as most methods for sex, age and stature estimation are population-specific. Ancestry estimation methods vary from traditional morphological assessment of cranial features and biometric quantification to computer-aided shape analysis and classification with specialised software. The current paper aims to explore population differences between three neighbouring countries (Greece, Cyprus and Turkey) that have been in constant interaction through conflicts and population movements from the ancient past to the present day, through cranial measurements.The sample consists of 160 dry crania of Greek origin, 137 dry crania of Greek-Cypriot of origin Cyprus and 380 CT scans from Turks individuals. Twelve measurements were taken in both dry and virtual skulls. Data were submitted to principal component analysis and discriminant function analysis. Intra- and inter-observer error as well as the measurement error between virtual and physical measurements were quantified using TEM, rTEM and R.Measurement error was very low in all cases. Classification accuracy for cross-validated data ranged from 74.1 to 97.9%. The highest accuracy was obtained for the Turks sample both in males and females. The results are in accordance with genetic data on the three populations.These results create great confidence in the application of the produced functions in forensic cases requiring ancestry estimation in Cyprus, specifically to unidentified individuals from the 1974 conflict. In addition, these standards can be applied in other forensic situations where ethnicity is an issue but the geographic area of origin is limited to the area encompassing Turkey, Cyprus and Greece.

Reliability of length measurements collected by community nurses and health volunteers in rural growth monitoring and promotion services

BackgroundLength measurements are important in growth, monitoring and promotion (GMP) for the surveillance of a child’s weight-for-length and length-for-age. These two indices provide an indication of a child’s risk of becoming wasted or stunted, and are more informative about a child’s growth than the widely used weight-for-age index (underweight). Although the introduction of length measurements in GMP is recommended by the World Health Organization, concerns about the reliability of length measurements collected in rural outreach settings have been expressed by stakeholders. Our aim was to describe the reliability and challenges associated with community health personnel measuring length for rural outreach GMP activities.MethodsTwo reliability studies (A and B), using 10 children less than 24 months each, were conducted in the GMP services of a rural district in Ghana. Fifteen nurses and 15 health volunteers (HV) with no prior experience in length measurements were trained. Intra- and inter-observer technical error of measurement (TEM), average bias from expert anthropometrist, and coefficient of reliability (R) of length measurements were assessed and compared across sessions. Observations and interviews were used to understand the ability and experiences of health personnel with measuring length at outreach GMP.ResultsInter-observer TEM was larger than intra-observer TEM for both nurses and HV at both sessions and was unacceptably (compared to error standards) high in both groups at both time points. Average biases from expert’s measurements were within acceptable limits, however, both groups tended to underestimate length measurements. The R for lengths collected by nurses (92.3%) was higher at session B compared to that of HV (87.5%). Length measurements taken by nurses and HV, and those taken by an experienced anthropometrist at GMP sessions were of moderate agreement (kappa = 0.53, p < 0.0001).ConclusionsThe reliability of length measurements improved after two refresher trainings for nurses but not for HV. In addition, length measurements taken during GMP sessions may be susceptible to errors due to overburdened health personnel and crowded GMP clinics. There is need for both pre- and in-service training of nurses and HV on length measurements and procedures to improve reliability of length measurements.

Abstract P4-13-13: The correlation between mastectomy specimen weight and volume- a guide to the choice of implant size in breast reconstruction

Abstract Introduction: The concept of “conservative” mastectomy with breast reconstruction has led to a huge positive impact on the quality of life of breast cancer survivors. In 2015, 106,338 breast reconstructions were performed with implant-based reconstruction (IBR) constituting 86,013 (80.9%) of those procedures. Technically speaking, there is still no consensus on the most accurate method of assessing the size of implant used to achieve the desirable aesthetic results and symmetry. Some surgeons use the volume of the mastectomy specimen, believing that the volume of the implant replacing the volume of breast tissue removed is a logical way of thinking. Others prefer to depend on the weight of the specimen owing to the presumption that a mixture of fat and fibroglandular tissue will give an approximate overall density of 1.0g/cm3. To the authors' knowledge, the correlation between the mastectomy specimen volume and weight has been scarcely reported in the literature. Materials and Methods: Patients undergoing nipple or skin-sparing mastectomy with immediate IBR at the London Breast Institute between January 2014 and December 2016 were included in this study. They were under the care of two senior Oncoplastic breast surgeons. Data on breast weight and volume as well as the size of implants used were prospectively collected. The volume of the breast tissue was assessed by volume displacement method while the weight was measured on a scale in grams. The exclusion criteria included patients with mastectomy specimen weighing more than 2000 grams. Further subgroups were divided into patients younger and those older than 50 years old. The presence or absence of cancer was also reviewed to assess whether the tumor tissue would have heavier weight when compared with volume. Results: Between January 2014 and December 2016, a total of 236 mastectomies were performed, of which 144 were accompanied with IBR. The mean age of the patients was 45 years (range= 25-74). There were 79 right and 65 left breast specimens. Among these cases, 36 were bilateral. Tissue volume and weight had a strong direct correlation (N=144, R=0.99, P&amp;lt;0.00). Mastectomy volume had a marginally stronger correlation with implant volume/size (N=144, R=0.82, P=&amp;lt;0.00) than weight (N=144, R=0.79, P=&amp;lt;0.00). Further subgroup analysis showed that neither the presence of cancer nor the variation in breast density with age or menopausal status seemed to affect the correlation between the weight and volume of the breast tissue. 75% of reconstructions had implant size within 100 mls or grams of the mastectomy specimen. Conclusions: Our study has shown that mastectomy specimen weight and volume have close enough correlation. The volume measurement was best estimated to the nearest 25 to 50 mls. On the other hand, the weight assessment was more accurate, objective, easier, and more reproducible with minimal inter-observer error. Hence, we believe that the breast weight can be reliably used to estimate the size of the implant. However, there are many other factors that should be taken into consideration when choosing an implant. For instance, the woman's wish for smaller or larger size, the width and height of the breast base, and the availability of a wide range of implants. Citation Format: Wazir U, El Hage Chehade H, Choy C, Kasem A, Mokbel K. The correlation between mastectomy specimen weight and volume- a guide to the choice of implant size in breast reconstruction [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-13-13.

Transforaminal Lumbar Interbody Fusion With Viable Allograft: 75 Consecutive Cases at 12-Month Follow-up

When conservative treatments fail to alleviate the discomfort of abnormal motion, spinal fusion has been shown to provide symptomatic treatment for spinal instability, stenosis, spondylolisthesis, and symptomatic degenerative disc disease. The trend and rates of fusion over the past few years have been dramatic in the United States. Accompanying that higher incidence has been the shifting from traditional open surgery to minimally invasive techniques to reduce scar tissue formation, extent of muscle stripping, and muscle retraction which all have been shown to adversely affect outcomes. Other reasons supporting the widespread transition to minimally invasive surgical (MIS) techniques include decreased postoperative pain, decreased intraoperative blood loss, shorter postoperative hospital stay, faster return to normal activity, and reduced reoperation rates. Spinal fusion procedures rely on a bony fusion substrate in addition to fixation hardware. While available grafting options include autogenous, allogeneic, and synthetic materials, recent interest in viable allograft material with living cells has drawn attention and attraction for incorporating a biologic basis for regenerative consideration. A recent viable allograft, complete with cellular and designated bone carrier (VIA Graft, Vivex Biomedical, Marietta, Georgia) has been developed. This study represents a retrospective review of a single-practice, single-surgeon evaluation of the product in 75 consecutive patients for fusion by computed tomography (CT) and radiographic evaluation at 12 months in conjunction with a MIS approach. Viable allograft was used to fill the peri-implant space, and central implant lumen was filled with a cancellous bone sponge soaked in perivertebral bone marrow. Posterolateral supplementation was attained with beta-tricalcium phosphate as a bulking agent. A retrospective review identified patients treated for both primary and revision surgery who received VIA Graft cellular bone matrix material in minimally invasive interbody fusion (MIS-TLIF) with a minimum of 12-month follow up. The patient diagnoses included radiculopathy in all instances and varied collateral indications such as foraminal collapse, recurrent disc herniation, and spondylolisthesis to which pain and morbidity had been unresolved by conservative treatment. Adverse events including infection, revisions, and evidence of immune response were evaluated and patient comorbidities defined for the entire population of patients. Patient fusion status was assessed using thin slice CT by 2 independent radiologists separate from the surgeon. There were 75 consecutive adult patients with degenerative conditions of the lumbar spine who underwent MIS-TLIF surgery of which 40 (53%) were male and 35 (47%) were female. Mean age, height, and weight were 58 years, 170.18 cm (67 in), and 88.45 kg (195 lbs), respectively. The mean body mass index was 30. There were 16 patients (21%) who smoked and 12 (16%) with a history of diabetes. Independent blinded review of fusion was obtained by a board certified musculoskeletal radiologist and an experienced board certified orthopaedic surgeon to assess patient fusion status. Spinal segments were deemed fused if 12-month CT scans demonstrated evidence of bridging bone at the fusion site without observed motion on flexion-extension radiographs. Findings such as osteolysis around the implant or pedicle screws, extensive endplate cystic changes, or linear defects parallel to the endplates through intradiscal new bone formation were interpreted as signs of pseudarthrosis. Interobserver and intraobserver error and κ assessments were analyzed to assure agreement in the CT outcomes assessment where interpretation of κ were as follows: <0.00 = poor agreement, 0.00-0.20 = slight agreement, 0.21-0.40 = fair agreement, 0.41-0.60 = moderate agreement, 0.61-0.80 = substantial agreement, and 0.81-1.00 = almost perfect agreement. Differences were resolved by consensus amongst the observers. In total, 96% of the 75 patients with a total of 85 levels (96.5% of levels treated) achieved a fusion at 12 months. There were no perioperative or latent complications and no transfusions in all 75 patients. In this population, 96% of the patients treated achieved the surgical objective in 96.5% of the levels treated. IV. The high rate of fusion, the lack of secondary morbidity with autologous bone harvest, and the clinical success account for the benefits of viable allograft matrix for MIS-TLIF use.

The distribution of ocular biometrics among patients undergoing cataract surgery

Background: Ocular biometry is essential in many clinical and research applications; for example, axial length is essential in intraocular lens power calculation prior to cataract and refractive surgeries, making diagnosis of staphyloma, etc. Various factors affect their values. We intend to study the distribution of ocular biometrics among cataract patients in our environment. Materials and Methods: This is a cross-sectional observational study. One hundred fifty-one patients with bilateral cataract scheduled for cataract surgery during the 1-year study period (July 2016–June 2017) were consecutively recruited for the study. Medical records including age and gender were collected. Ocular biometric data including axial length (AL), anterior chamber depth (ACD), cataractous lens thickness (LT), and vitreous chamber depth (VCD) values were measured for both eyes before cataract operation for either eye, using an optical biometer (ophthalmic A/B ultrasound system: CAS-2000BER, England). All the metric data were observed by the same experienced ophthalmic technician to avoid interobserver error. Result: The mean AL was 23.51 [95% confidence interval (CI), 23.33–23.64], mean ACD was 3.22 mm (95% CI, 3.12–3.30), mean LT was 4.23 mm (95% CI, 4.17–4.29), and the mean VCD was 16.06 mm (95% CI, 15.89–16.20). AL was longer among those ages less than 30 years, ACD was decreasing with increasing age, and the mean LT was higher for ages 30 years and above. The median ACD was decreasing with increasing age up to ≥50 years, whereas the median LT increased with increasing age. The male–female variation in mean AL and mean VCD were statistically significant (P

Validation of the Total Body Score/Accumulated Degree-Day Model at Three Human Decomposition Facilities

A few studies have examined the accuracy of the Megyesi et al. (2005) total body score/accumulated degree-day (TBS/ADD) method; however, no study has investigated the validity of the method using human remains at known ADD intervals. The current study validates the TBS method for human cadavers placed in three different human decomposition facilities in the United States. Twenty-eight donated cadavers, with known ADD and dates of death, in the first (fresh) stage of decomposition, were placed in sun and shade environments four times per year. The validity of the method was examined by conducting an interobserver error test of the TBS and analyzing the accuracy of the equation at predicting ADD. Nine individuals, experienced with the TBS method, participated in the interobserver error test. The results of the interclass correlation coefficient show that there was no statistically significant difference between observers for any of the body sections (trunk = 0.975, head = 0.959, limbs = 0.940, p < 0.001). Using the TBS regression equation, mean ADD with error ranges was calculated for all subjects and compared to actual ADDs of 100, 300, 500, and 1,000. Results show that mean ADD estimates do not correlate well with actual ADD for any of the actual ADDs (100, 300, 500, and 1,000). The accuracy of the TBS equation is insufficient in estimating mean ADD and error is largely unpredictable, other than it increases with postmortem time. KEYWORDS: forensic anthropology, taphonomy, total body score, accumulated degree-days

Dutch population specific sex estimation formulae using the proximal femur

Sex estimation techniques are frequently applied in forensic anthropological analyses of unidentified human skeletal remains. While morphological sex estimation methods are able to endure population differences, the classification accuracy of metric sex estimation methods are population-specific. No metric sex estimation method currently exists for the Dutch population. The purpose of this study is to create Dutch population specific sex estimation formulae by means of osteometric analyses of the proximal femur. Since the Netherlands lacks a representative contemporary skeletal reference population, 2D plane reconstructions, derived from clinical computed tomography (CT) data, were used as an alternative source for a representative reference sample.The first part of this study assesses the intra- and inter-observer error, or reliability, of twelve measurements of the proximal femur. The technical error of measurement (TEM) and relative TEM (%TEM) were calculated using 26 dry adult femora. In addition, the agreement, or accuracy, between the dry bone and CT-based measurements was determined by percent agreement. Only reliable and accurate measurements were retained for the logistic regression sex estimation formulae; a training set (n=86) was used to create the models while an independent testing set (n=28) was used to validate the models. Due to high levels of multicollinearity, only single variable models were created. Cross-validated classification accuracies ranged from 86% to 92%.The high cross-validated classification accuracies indicate that the developed formulae can contribute to the biological profile and specifically in sex estimation of unidentified human skeletal remains in the Netherlands. Furthermore, the results indicate that clinical CT data can be a valuable alternative source of data when representative skeletal collections are unavailable.

Improving the quality of child anthropometry: Manual anthropometry in the Body Imaging for Nutritional Assessment Study (BINA).

Anthropometric data collected in clinics and surveys are often inaccurate and unreliable due to measurement error. The Body Imaging for Nutritional Assessment Study (BINA) evaluated the ability of 3D imaging to correctly measure stature, head circumference (HC) and arm circumference (MUAC) for children under five years of age. This paper describes the protocol for and the quality of manual anthropometric measurements in BINA, a study conducted in 2016–17 in Atlanta, USA. Quality was evaluated by examining digit preference, biological plausibility of z-scores, z-score standard deviations, and reliability. We calculated z-scores and analyzed plausibility based on the 2006 WHO Child Growth Standards (CGS). For reliability, we calculated intra- and inter-observer Technical Error of Measurement (TEM) and Intraclass Correlation Coefficient (ICC). We found low digit preference; 99.6% of z-scores were biologically plausible, with z-score standard deviations ranging from 0.92 to 1.07. Total TEM was 0.40 for stature, 0.28 for HC, and 0.25 for MUAC in centimeters. ICC ranged from 0.99 to 1.00. The quality of manual measurements in BINA was high and similar to that of the anthropometric data used to develop the WHO CGS. We attributed high quality to vigorous training, motivated and competent field staff, reduction of non-measurement error through the use of technology, and reduction of measurement error through adequate monitoring and supervision. Our anthropometry measurement protocol, which builds on and improves upon the protocol used for the WHO CGS, can be used to improve anthropometric data quality. The discussion illustrates the need to standardize anthropometric data quality assessment, and we conclude that BINA can provide a valuable evaluation of 3D imaging for child anthropometry because there is comparison to gold-standard, manual measurements.

Evaluating causes of error in landmark-based data collection using scanners.

In this study, we assess the precision, accuracy, and repeatability of craniodental landmarks (Types I, II, and III, plus curves of semilandmarks) on a single macaque cranium digitally reconstructed with three different surface scanners and a microCT scanner. Nine researchers with varying degrees of osteological and geometric morphometric knowledge landmarked ten iterations of each scan (40 total) to test the effects of scan quality, researcher experience, and landmark type on levels of intra- and interobserver error. Two researchers additionally landmarked ten specimens from seven different macaque species using the same landmark protocol to test the effects of the previously listed variables relative to species-level morphological differences (i.e., observer variance versus real biological variance). Error rates within and among researchers by scan type were calculated to determine whether or not data collected by different individuals or on different digitally rendered crania are consistent enough to be used in a single dataset. Results indicate that scan type does not impact rate of intra- or interobserver error. Interobserver error is far greater than intraobserver error among all individuals, and is similar in variance to that found among different macaque species. Additionally, experience with osteology and morphometrics both positively contribute to precision in multiple landmarking sessions, even where less experienced researchers have been trained in point acquisition. Individual training increases precision (although not necessarily accuracy), and is highly recommended in any situation where multiple researchers will be collecting data for a single project.

Automatic Localization of Cochlear Implant Electrode Contacts in CT.

Determining the exact location of cochlear implant (CI) electrode contacts after implantation is important, as it helps quantifying the relation between CI positioning and hearing outcome. Unfortunately, localization of individual contacts can be difficult, because the spacing between the electrode contacts is near the spatial resolution limit of high-resolution clinical computed tomography (CT) scanners. This study introduces and examines a simple, automatic method for the localization of intracochlear electrode contacts. CI geometric specifications may provide the prior knowledge that is essential to accurately estimate contact positions, even though individual contacts may not be visibly resolved. The prior knowledge in CI geometry is used to accurately estimate intracochlear electrode contact positions in high-resolution CT scans of seven adult patients implanted with a CI (Cochlear Ltd.). The automatically detected electrode contact locations were verified against locations marked by two experienced observers. The interobserver errors and the errors between the averaged locations and the automatically detected locations were calculated. The estimated contact positions were transformed to a cylindrical cochlear coordinate system, according to an international consensus, in which the insertion angles and the radius and elevation were measured. The linear correlation of the automatically detected electrode contact positions with the manually detected locations was high (R = 0.98 for the radius, and R = 1.00 for the insertion angle). The errors in radius and in insertion angle between the automatically detected locations and the manually detected locations were 0.12 mm and 1.7°. These errors were comparable to the interobserver errors. Geometrical measurements were in line with what is usually found in human cochleae. The mean insertion angle of the most apical electrode was 410° (range: 316° to 503°). The mean radius of the electrode contacts in the first turn of the cochlear spiral was 3.0 mm, and the mean radius of the remainder in the second turn was 1.7 mm. With implant geometry as prior knowledge, automatic analysis of high-resolution CT scans enables accurate localization of CI electrode contacts. The output of this method can be used to study the effect of CI positioning on hearing outcomes in more detail.

Consistency of selected craniometric landmark locations and the resulting variation in measurements

Recently, forensic anthropology has undergone a major shift to quantitative methodologies, including the standardization of osteometric measurements. This study is an analysis of inter-observer error rates for eight “standardized” cranial measurements. Thirty participants, of varied experience, were asked to note the location of landmarks used in each measurement, and to record the resulting measurement. None of the tested measurements met the previously established 80% consensus rate necessary to be considered “standardized-in-practice” [1]. The highest consensus rate was that of nasal breadth (67.9%), followed by that of the mastoid height (57.1%). This low precision yielded percent mean differences of 2–48% of the total measurement, with range differences of up to 42mm. These results indicate that the field should take steps to improve osteometric standardization, including re-examining all measurements currently listed in osteometric canon and re-issuing a comprehensive guide.

Estimating the error of CT-based measurements of aortic lumen volume used in endovascular planning

IntroductionPlanning of endovascular sealing of abdominal aortic aneurysms requires measurement of the aortic lumen volume. The aim of this study was to investigate mathematically the effect of intra- and inter-observer variability error, as well as cardiac cycle-related variability, on these measurements. MethodsMean (±2SD) intra- and inter-observer error in lumen measurements and mean (+2SD) cardiac cycle-related variability were obtained from published literature and added to the measurement of the flow lumen volume of a 57 mm abdominal aortic aneurysm to calculate average and extreme error possibilities. ResultsThe aneurysm volume was measured at 165 ml. The calculated possible mean measurement error due to cardiac cycle variation, intra- and inter-observer variability was +11.0%, resulting in a potential measurement of 183.1 ml. The calculated extreme errors were +24.3% (if 2SD of all errors were added to the mean) and +3.5% (if 2SD of all errors, except cardiac cycle, were subtracted from the mean), resulting in potential measurements of 170.8 ml and 205.1 ml, respectively. When considering the errors combined, the proportion of patients who may have volume measurement errors of up to ±2.5 ml, ±2.6 to ±5.0 ml and ±5.1 to ±7.5 ml were 18%, 17% and 15%, respectively. ConclusionMeasurement of CT-based aortic lumen volumes in abdominal aortic aneurysms is imprecise. This has practical implications for the planning and the performance of complex endovascular therapies.

4D modelling for rapid assessment of biventricular function in congenital heart disease.

Although more patients with congenital heart disease (CHD) are now living longer due to better surgical interventions, they require regular imaging to monitor cardiac performance. There is a need for robust clinical tools which can accurately assess cardiac function of both the left and right ventricles in these patients. We have developed methods to rapidly quantify 4D (3D + time) biventricular function from standard cardiac MRI examinations. A finite element model was interactively customized to patient images using guide-point modelling. Computational efficiency and ability to model large deformations was improved by predicting cardiac motion for the left ventricle and epicardium with a polar model. In addition, large deformations through the cycle were more accurately modeled using a Cartesian deformation penalty term. The model was fitted to user-defined guide points and image feature tracking displacements throughout the cardiac cycle. We tested the methods in 60 cases comprising a variety of congenital heart diseases and showed good correlation with the gold standard manual analysis, with acceptable inter-observer error. The algorithm was considerably faster than standard analysis and shows promise as a clinical tool for patients with CHD.

The auricular surface as age indicator in a modern Greek sample: A test of two qualitative methods

The auricular surface is often found very well preserved, thus age-related changes in this anatomical area can be important for any set of human remains that require identification under different taphonomic conditions. This study tests the Buckberry and Chamberlain (2002) and Schmitt et al. (2005) methods in predicting the age of individuals in a documented sample from Crete, Greece. Both methods were used to record changes on the auricular surface in a mixed-sex sample of 74 individuals, directly as well as through photographs, by two independent observers. Cohen’s kappa and intra class correlation coefficients (ICC) were used in order to assess inter-observer and intra-observer agreement. Results showed than none of the methods predicted age with sufficient accuracy, as high error rates were recorded. The Schmitt et al. (2005) method performed better, mainly because the age ranges it uses are broader. Scoring through photographs does not seem to introduce bias in predicting age, as demonstrated by the high intra-observer agreement rates. Inter-observer agreement was also high. The low intra- and inter-observer error rates suggest that the poor performance of both methods in the Cretan sample is not due to a lack of clarity in the description of the morphological changes recorded on the auricular surface; rather it should be attributed to a poor correlation between these changes and age at death in our material.

Standardized anthropological measurement of postcranial bones using three-dimensional models in CAD software

This study introduces a standardized protocol for conducting linear measurements of postcranial skeletal elements using three-dimensional (3D) models constructed from post-mortem computed tomography (PMCT) scans. Using femoral DICOM datasets, reference planes were generated and plane-to-plane measurements were conducted on 3D surface rendered models. Bicondylar length, epicondylar breadth, anterior-posterior (AP) diameter, medial-lateral (ML) diameter and cortical area at the midshaft were measured by four observers to test the measurement error variance and observer agreement of the protocol (n=6). Intra-observer error resulted in a mean relative technical error of measurement (%TEM) of 0.11 and an intraclass correlation coefficient (ICC) of 0.999 (CI=0.998–1.000); inter-observer error resulted in a mean %TEM of 0.54 and ICC of 0.996 (CI=0.979–1.000) for bicondylar length. Epicondylar breadth, AP diameter, ML diameter and cortical area also yielded minimal error. Precision testing demonstrated that the approach is highly repeatable and is recommended for implementation in anthropological investigation and research. This study exploits the benefits of virtual anthropology, introducing an innovative, standardized alternative to dry bone osteometric measurements.

Error in geometric morphometric data collection: Combining data from multiple sources.

This study compares two- and three-dimensional morphometric data to determine the extent to which intra- and interobserver and intermethod error influence the outcomes of statistical analyses. Data were collected five times for each method and observer on 14 anthropoid crania using calipers, a MicroScribe, and 3D models created from NextEngine and microCT scans. ANOVA models were used to examine variance in the linear data at the level of genus, species, specimen, observer, method, and trial. Three-dimensional data were analyzed using geometric morphometric methods; principal components analysis was employed to examine how trials of all specimens were distributed in morphospace and Procrustes distances among trials were calculated and used to generate UPGMA trees to explore whether all trials of the same individual grouped together regardless of observer or method. Most variance in the linear data was at the genus level, with greater variance at the observer than method levels. In the 3D data, interobserver and intermethod error were similar to intraspecific distances among Callicebus cupreus individuals, with interobserver error being higher than intermethod error. Generally, taxa separate well in morphospace, with different trials of the same specimen typically grouping together. However, trials of individuals in the same species overlapped substantially with one another. Researchers should be cautious when compiling data from multiple methods and/or observers, especially if analyses are focused on intraspecific variation or closely related species, as in these cases, patterns among individuals may be obscured by interobserver and intermethod error. Conducting interobserver and intermethod reliability assessments prior to the collection of data is recommended.

New methodology to reconstruct in 2-D the cuspal enamel of modern human lower molars.

In the last years different methodologies have been developed to reconstruct worn teeth. In this article, we propose a new 2-D methodology to reconstruct the worn enamel of lower molars. Our main goals are to reconstruct molars with a high level of accuracy when measuring relevant histological variables and to validate the methodology calculating the errors associated with the measurements. This methodology is based on polynomial regression equations, and has been validated using two different dental variables: cuspal enamel thickness and crown height of the protoconid. In order to perform the validation process, simulated worn modern human molars were employed. The associated errors of the measurements were also estimated applying methodologies previously proposed by other authors. The mean percentage error estimated in reconstructed molars for these two variables in comparison with their own real values is -2.17% for the cuspal enamel thickness of the protoconid and -3.18% for the crown height of the protoconid. This error significantly improves the results of other methodologies, both in the interobserver error and in the accuracy of the measurements. The new methodology based on polynomial regressions can be confidently applied to the reconstruction of cuspal enamel of lower molars, as it improves the accuracy of the measurements and reduces the interobserver error. The present study shows that it is important to validate all methodologies in order to know the associated errors. This new methodology can be easily exportable to other modern human populations, the human fossil record and forensic sciences.

Anatomical study of the maxillary tuberosity using cone beam computed tomography.

To examine the dimensions (width, length, and height) of the maxillary tuberosity (MT) and their correlations with age and sex, and to identify different anatomical types for adequate positioning of miniscrews in this area. The study enrolled 39 patients attending the University of Valencia. The patients comprised 21 males and 18 females with a mean age of 39.7±8.4years. The dimensions of all 78 MTs were measured on cone beam computed tomography (CBCT) images using Invivo Dental 5 software. The intraobserver and interobserver errors were good for all measurements. A total of 858 MT measurements were taken. The widths were greater in men than in women, with significant differences. The MT dimensions showed correlations with patient age, whereby older patients presented with greater widths and lengths, but reduced heights. Three different anatomical types were detected according to patient age. The dimensions (width, length, and height) of the MT vary according to patient age and sex. The MT dimensions conform to particular anatomical types, which should be taken into account when placing miniscrews in this region.

Accuracy and Reliability of the Klales et al. (2012) Morphoscopic Pelvic Sexing Method

Klales etal. (2012) devised an ordinal scoring system for the morphoscopic pelvic traits described by Phenice (1969) and used for sex estimation of skeletal remains. The aim of this study was to test the accuracy and reliability of the Klales method using a large sample from the Hamann-Todd collection (n=279). Two observers were blinded to sex, ancestry, and age and used the Klales etal. method to estimate the sex of each individual. Sex was correctly estimated for females with over 95% accuracy; however, the male allocation accuracy was approximately 50%. Weighted Cohen's kappa and intraclass correlation coefficient analysis for evaluating intra- and interobserver error showed moderate to substantial agreement for all traits. Although each trait can be reliably scored using the Klales method, low accuracy rates and high sex bias indicate better trait descriptions and visual guides are necessary to more accurately reflect the range of morphological variation.