Intra- and interobserver error of the Greulich-Pyle method as used on a Danish forensic sample.

The Section of Forensic Medicine at the University of Copenhagen performs age evaluations of the living at the request of the police. The established procedure in these cases involves: (1) a physical examination; (2) an odontological examination based on evaluation of an orthopantomogram and intraoral dental radiographs. Different methods are used depending on the maturity of the individual examined; and (3) a carpal X-ray examination, using the Greulich and Pyle Atlas (GPA) method. We present the results of intra- and interobserver tests of carpal X-rays in blind trials, and a comparison of the age estimations by carpal X-rays and odontological age estimation. We retrieved 159 cases from the years 2000-2002 (inclusive). The intra- and interobserver errors are overall small. We found full agreement in 126/159 cases, and this was between experienced users and novices. Overall, the mean difference was 0.053 years, with a standard deviation of +/-0.567 years. Our results show that the direct and naïve use of the GPA is simple and reproducible, even when applied by non-experienced users. This is probably also why the method is still widely applied, even though other authors have stated that atlas-based techniques are obsolete and ought to be replaced by other methods. Specifically, the GPA test sample consisted of American "white" children "above average in economic and educational status", leading to the question as to how comparable subjects being scored by the GPA method today are to this original sample. Indeed, we found a minor difference in the age estimations for older juveniles between odontologists and radiologists, which may indicate that more studies on comparative dental and skeletal aging for geographically different populations would be beneficial. Finally, if using the GPA method in legal cases, we would advise that one should closely adhere to the standard deviations given, and intermediary scores should be noted and not just a resultant age. The final age statement should also address the problems of reference populations.

An historical skull collection and its use in forensic odontology and anthropology.

The Institute of Forensic Medicine, Copenhagen, houses a collection of historical skulls of unclear origin, marked with a general geographic or "racial descriptor". Would these historical skulls be of any value for the forensic odontologist and anthropologist concerned with teaching and casework? We tried to clarify this question by recording non-metric dental traits and by performing craniometric analyses. A morphological and morphometric investigation of anatomical/dental traits in 80 adult skulls was performed. For each skull four non-metric dental traits using the ASU-System and three non-metric cranial traits were recorded. Nineteen cranial measures were also taken following the FORDISC programme manual. The non-metrical data were tabulated as frequencies, and the metric data were entered in the FORDISC programme. Observed non-metric trait frequencies were compared with published data. The FORDISC programme computed a discriminatory analysis for each skull and thereby assigned the skull to the most probable ethnic category. The results for the non-metric traits showed that the traits generally followed the expected frequencies in 80% of the cases. The FORDISC programme correctly assigned ethnicity based on skull measurements in overall 70% of the cases. It was found that this historical collection does show expected dental non-metric and craniometric traits and the collection may be of value in forensic casework in terms of comparison and for teaching purposes.

Unidentified bodies/skulls found in Danish waters in the period 1992-1996.

In the period 1992-1996 a total of 89 unidentified bodies/skulls found in Danish waters were investigated at the three University Institutes of Forensic Medicine in Denmark. Males constituted 79% of the total material. Open water was the finding place in half the cases, about one-fourth was found on shore and another fourth in a harbor basin. Totally 73 bodies and one skull were identified. Danes constituted 57% of the material. Almost all non-Danes originated from countries with borders to the waters surrounding Denmark. The cause of death was in 71% stated as presumably/possibly drowning, in 5% as severe lesions (precipitation) and in 25% it could not be solved. The manner of death was in non-Danes most often stated as an accident (56%), and according to this the finding place in non-Danes most frequently was the open water (66%). In Danes suicide predominated (71%) and the finding place in Danes was almost equally distributed among open water, shores and harbors, respectively. Among the totally 74 identified cases, 83% of the total material, an initial suggestion of the identity based on effects found on the body was possible in 43 cases (58%). The final identification was performed by means of forensic dental examination in total 58 cases (78%), in Danes in 93% and in non-Danes in 59%. In the remaining 16 cases one or more of the following contributed to the final identification: information about dental condition, clothing, personal papers, X-ray photos, jewelry, tattoos/scars and fingerprints. The importance of a close collaboration between the police, the forensic pathologist and the forensic dental expert in order to reach a fair number of positive identifications is emphasized.

Growth in the external cranial base evaluated on human dry skulls, using nerve canal openings as references.

The purpose of this investigation was to measure on human dry skulls the postnatal widening and lengthening of the external cranial base, including the hard palate, using nerve canal openings as references. Forty-five Indian dry skulls were examined, 36 from children and 9 from adults. The age evaluation was made on the basis of dental development. The dimensions of the external cranial base were determined by direct measurements on the skulls and by measurements from photographs of the skulls. The study showed that growth in width of the external cranial base followed two distinct patterns. The two regions represent different embryologic developmental fields. The study points out that different growth patterns in these fields ought to be taken into account in future investigations of normal and pathologic craniofacial growth.

Human palatal growth evaluated on medieval crania using nerve canal openings as references.

The purpose of this investigation was to measure postnatal lengthening and widening of the hard palate by use of nerve canal openings as references. The relationship of the dentition to the greater palatine foramina was also investigated. Thirty-nine medieval dry skulls were examined, 22 from children and 17 from adults. All crania were photographed at a 1.1 scale. The dimensions of the maxilla and the location of the dentition were determined from the photographs. The study showed that palatal growth in length in the sagittal plane takes place anterior to the greater palatine foramen. The growth increment in the area between the incisive foramen and the transverse palatine suture is more pronounced than the growth increment in the area between the transverse palatine suture and the greater palatine foramen. The distance from the greater palatine foramina to the posterior margin of the palate did not increase significantly with age. The growth in width seems to continue into adult life. The first permanent molars and the surrounding bone are moved forwards in relation to the greater palatine foramina during growth. The space for the developing maxillary premolars and molars therefore has to be obtained by growth in the transverse palatine suture.

Scanning electron microscopy, a useful tool in forensic dental work.

In selected cases there is a need for microscopic information found on the surface of tooth specimens. Scanning electron microscopy is the method of choice. Based on the knowledge of the structural organization of the mineralized dental tissues differential diagnoses of physical and chemical changes can be made. It is suggested that the forensic dental profession cooperates in establishing a collection of reference material illustrating different traumas to enamel and dentin, deposits on teeth and the structure of restorative dental materials as they will appear after some years in position on a tooth. Four different cases are presented.

Agenesis of permanent incisors in a mediaeval maxilla and mandible: aetiological aspects.

A paleopathological maxilla and mandible with tooth agenesis were analyzed, focussing on the aetiology of the condition. The jaw material, derived from an adult mediaeval male, was examined by standard anthropological analyses, including radiography. In the maxilla there was agenesis of three permanent incisors and one premolar, and in the mandible of one permanent incisor and two permanent molars. Absence or marked reduction of the incisive foramen and the nasopalatine canal was found. The premaxillary area was reduced without general alveolar bone resorption. The pattern of tooth agenesis was similar to the pattern observed in contemporary individuals, except for the agenesis of one permanent maxillary central incisor. It is suggested that the pronounced lack of teeth in the maxillary anterior region is connected with deficient development of the premaxillary area of the nasopalatine canals and the incisive foramen. As the condition can be ascribed to deviations in the prenatal development, this investigation shows that embryological developmental patterns, which form the basis for the pattern of tooth agenesis, should be taken into account when evaluating dry bone pathology.

The human incisal suture and premaxillary area studied on archaeologic material.

The purpose of this study was to investigate the extent of the incisal suture, the size of the premaxillary area, and the developmental status of the dentition. Sixty-three medieval crania were examined: 30 from children and 33 from adults, including 5 cases with tooth deviations. All crania were photographed at a 1:1 scale. From the photographs the size of the premaxilla and the length of the incisal suture were measured. In addition, the spatial conditions in the anterior region were recorded. The study showed that the main closure of the suture takes place shortly after the crowns of the permanent incisors have attained their final width size. The mean size of the premaxillary area was larger in individuals with interincisal spacing and smaller in individuals with crowding when comparing with normal spatial conditions. In the cases of tooth agenesis the premaxillary areas were markedly reduced.