Predicting mouth width from inter-canine width--a 75% rule

It has been suggested that inter-canine width plus 57% of the cumulative distance between the lateral aspect of the canines and the pupil centers can be used to estimate mouth width. Evidence also suggests that the distance between the medial irises approximates actual mouth width fairly well. However, these soft tissue prediction guidelines are limited because they rely on accurate medio-lateral positioning of the pupils within the orbits, for which no systematic empirical evidence appears to exist at this stage. It would, therefore, be more appropriate to use only known hard tissue landmarks in mouth width prediction. This study reports the results of using inter-canine width as a percentage of mouth width for its prediction. This method seems favorable in comparison to the other guidelines because it is as accurate, uses known hard tissue landmarks, and does not rely on assumptions concerning pupil location. Estimating mouth width by using the canines alone, therefore, seems the best guideline to use in facial approximation techniques, at least given knowledge existing at this stage.     

Building faces from dry skulls: are they recognized above chance rates?

Methods of facial approximation have successfully aided the identification of deceased individuals. Successes may be due to either accurate facial approximation techniques or chance. This study aims to determine if any of 16 facial approximations, built using standard techniques, are sufficiently accurate to produce correct identifications of target individuals above chance. Four skulls were approximated using four commonly used methods of facial approximation. The resulting 16 facial approximations were judged by 37 assessors of varying ages. Assessors attempted to identify the target individual of each facial approximation from a face pool of ten photographed faces. Only one facial approximation resulted in true positive identification rates above chance at statistically significant levels. It is concluded that it is rare for facial approximations to be sufficiently accurate to allow identification of a target individual above chance. Since 403 incorrect identifications were made out of 592 identification scenarios, facial approximation should be considered to be a highly inaccurate and unreliable forensic technique. These results suggest that facial approximations are not very useful in excluding individuals to whom skeletal remains may not belong. Evidence from this experiment supports suggestions by others that facial approximation should be used in forensic science when all other methods of identification have failed and only to provide tentative identification.     

Further Evidence on the Anatomical Placement of the Human Eyeball for Facial Approximation and Craniofacial Superimposition*

Abstract: Recently a small sampled cadaver study (n = 4) suggested that the human eyeballs are placed closer to the orbital roof and lateral orbital wall as first reported in the anatomical literature many years previously. This contrasts with central positioning of the eyeball within the orbit as advocated by the facial approximation literature. Given the limits of such small samples, this study re-examined globe position in nine new cadavers to help clarify which relationship is accurate. The results essentially confirm prior empirical findings except that the mean lateral divergences from the orbit center were found to be larger—the eyeball was found to be “displaced” 1.4 mm superiorly and 2.4 mm laterally. Medians calculated across all 13 cadavers from this study and the above-mentioned recent report refine these measurements to 1.4 and 2.3 mm respectively. Globe projection values were identical to those observed for living individuals (c. 16 mm).     

Reduction of postmortem angiography-induced tissue edema by using polyethylene glycol as a contrast agent dissolver

Postmortem investigation is increasingly supported by computed tomography (CT) and magnetic resonance imaging, in which postmortem minimal invasive angiography has become important. The newly introduced approach using an aqueous contrast agent solution provided excellent vessel visualization but was suspected to possibly cause tissue edema artifacts in histological investigations. The aim of this study was to investigate on a porcine heart model whether it is possible to influence the contrast agent distribution within the soft tissue by changing its viscosity by dissolving the contrast agent in polyethylene glycol (PEG) as a matrix medium. High-resolution CT scans after injection showed that viscosities above c. 15 mPa s (65% PEG) prevented a contrast agent distribution within the capillary bed of the left ventricular myocardium. Thereby, the precondition of edema artifacts could be reduced. Its minimal invasive application on human corpses needs to be further adapted as the flow resistance is expected to differ between different tissues.     

Are Some Citizens More Equal than Others? Evidence from a Field Experiment

The equal treatment of all citizens is one of the fundamental principles of good administrative practice. Nevertheless, there are growing numbers of media and scientific reports on unequal treatment by public administrations. This article examines the unequal treatment of citizens by gender and ethnic origin by means of a survey‐based field experiment in German local government. With the help of two vignettes and randomized assignment of names, responses to fake citizen requests by local governments are analyzed for speed, quality, and service orientation. The results show very limited discrimination effects. While there is no evidence for general ethnic discrimination, a more differentiated analysis indicates patterns of ethnic discrimination conditioned by gender.