B. Gelbrich, G. Gelbrich, R. Lessig
The objective of this analysis was to investigate the dependency of image quality of dental panoramic radiographs on patient’s age and sex, and to demonstrate that forensic science can explain these relationships. The image qualities of 100 dental panoramic radiographs obtained from 50 patients with two devices were assessed by ten independent observers of different specialisations. Image quality decreased with increasing age of the patients (P=0.003). One of the devices turned out to be superior to the other; however, this difference between the devices was present only in older patients but not in young ones (P=0.03). Image quality was higher in women than in men (P=0.01). The observed influences of age and sex are explained by results of forensic investigations concerning age-related changes of the dental pulp and sex differences of the skull geometry. Thus forensic science can elucidate effects relevant for everyday clinical practice. Studies on dental image quality must consider age and sex of the patients
(J Forensic Odontostomatol 2009;27;1:2-11)
F.B. Prado, L.S. de Mello Santos, P.H.F. Caria, J.T. Kawaguchi, A. d’O. G. Preza, E. Daruge Jnr, R.F. da Silva, E. Daruge
In the last years, anthropology has been widely explored mainly when related to bones due to its morphologic characteristics, such as the rhomboid fossa of the clavicle. This study examined the incidence of the rhomboid fossa in paired clavicles of Brazilian subjects obtained from 209 adult bodies of known age and sex (107 males and 102 females) on which postmortem examinations had been performed by the senior author. The data were submitted to qualitative statistical analysis according to Fisher. There was a statistical difference (p= 5.98 x 10-23) between sexes related to the frequency of the rhomboid fossa. The fossa was absent in 97,1% of the female clavicles and the incidence of bilateral fossa was present in 2,9% of females. The incidence of bilateral fossa was 29% for male clavicles. The sexual or side differences in the incidence of the fossa could be found in this study, and qualitative analysis can corroborate sex determination of unidentified bodies in forensic medicine
(J Forensic Odontostomatol 2009;27;1:12-16)
The Discrimination Potential of Amalgam Restorations for Identification: Part 1
V.M. Phillips, M. Stuhlinger
The dental identification of human remains utilizes the matching of dental restorations. The radiographic images of amalgam restorations are paramount in this process. The compound amalgam restoration has a unique radiographic morphology and can be readily identified in both antemortem and postmortem data. To test the radiographic morphology of compound amalgam restorations, 10 out of 40 Typodont teeth, restored by students, were tested for their discriminatory potential by 12 examiners. The results showed that the radiographic morphology of compound amalgam restorations can be accurately matched by dentally trained personnel. This suggests that in cases where accurate radiographic material is used for dental comparison, less than 12 concordant features are necessary for positive dental identification. If the antemortem and postmortem radiographic images of a compound amalgam restoration are exactly the same then this feature is unique and identification can be achieved by a single concordant feature
(J Forensic Odontostomatol 2009;27;1:17-22)
The Discrimination Potential of Amalgam Restorations for Identification: Part 2
V.M. Phillips, M. Stuhlinger
The standard dental bitewing radiograph is used to detect interproximal caries but it also provides a specific view of the dental restorations that can be duplicated for identification purposes. The antemortem and postmortem bitewing radiographs are often not at the same angle and result in distorted images of the restorations. The aim of this study was to investigate the progressive increase in angulations of a bitewing radiograph of the same restoration and to determine at what angle the image is distorted sufficiently as not to be recognized. Bitewing radiographs were taken of the same two restorations at 5 ̊, 10 ̊, 15 ̊ and 20 ̊ superior, inferior, mesial and distal to the original 0 ̊ bitewing radiograph. Twenty examiners were required to determine at what angle the distortion prevented matching of the image with the original bitewing radiograph. The results showed that the image distortion at 15 ̊ became suspect but at 20 ̊none of the images could be matched to the original bitewing radiograph
(J Forensic Odontostomatol 2009;27;1:23-26)
The Discrimination Potential of Radio-Opaque Composite Restorations for Identification: Part 3
H. Zondagh, V.M. Phillips
The methods used for disaster victim identification is comparative postmortem profiling of dental and fingerprint data. Twelve dental concordant features are normally required for dental identification. The radiographic image of dental amalgam restorations has been shown to be highly significant for identification purposes. The aim of this study was to investigate the radiological morphology of standardized radio-opaque composite fillings in premolar teeth with regard to their discriminatory potential for identification purposes. Thirty lower first premolar teeth (“Typodont” acrylic teeth) that were filled with 3- surface fillings (MOD) radio-opaque composite resin (Z100) by 4th year dental students were used for this study. Bitewing radiographs were taken of all thirty fillings and labeled Set 1. A second set (Set 2) consisted of 10 randomly selected duplicate radiographs of Set 1, plus 2 other radiographic images not from Set 1. Instructions were given to 20 dentally trained examiners to match the 12 radiographic images of Set 2 with the 30 images of Set 1. The results showed that 18 of the 20 examiners correctly matched the 12 radiographic images, one scored 11 out of 12 and one scored 10 out of 12. This study shows that if the ante-mortem and post-mortem radiographs of a single composite filling have exactly the same morphology, this image is unique and 12 concordant features are not necessary for dental identification
(J Forensic Odontostomatol 2009;27;1:27-32)
Biomechanical Approach to Human Bitemark Reconstruction
G. Radford, J.A. Kieser, V. Bernal, J.N. Waddell, A. Forrest
This paper investigates the changes in upper and lower dental bite records that occur when the anterior teeth occlude into a three-dimensional rather than a flat object. Methods: anterior bite registrations were obtained from 20 volunteers with full and unrestored dentitions. As a three- dimensional, life-like bite target we cast a silicone replica from the impression of an actual arm, fitted with a rigid bony interior. Each participant was asked to bite into a single layer of softened bite registration wax wrapped around the same location on the fake arm, as well as into a flat wafer of the same material. Upper and lower bite registrations were then scanned in the same location on a flat bed scanner. We analysed the sizes of the different bite marks by means of landmark- and semi-landmark analysis to calculate Procrustes distances between tooth outlines. In order to analyse shape variation between the two types of bite registration we carried out principal components analyses on the partial warp scores. These were derived from partial Procrustes coordinates aligned by means of thin-plate spline decomposition based on a bending energy matrix. Our results show that there are significant differences in the shape of the upper or lower teeth when they occlude into a flat or three- dimensional target. We conclude that the use of a traditional flat bite registration in human bitemark reconstruction and analysis has to be seriously questioned