Effects of ethnicity on skeletal maturation: consequences for forensic age estimations

Enhanced possibilities to make statements on the ossification status of the medial clavicular epiphysis using an amplified staging scheme in evaluating thin-slice CT scans

Thin-slice computed tomography provides the imaging modality of choice in analysing the ossification process of the medial clavicular epiphysis for the purpose of forensic age diagnostics in the living in the course of criminal proceedings. The classification of the ossification stages by Schmeling et al. compass the emergence of an epiphyseal ossification centre (stage 2), the partial fusion of the epiphysis with the metaphysis (stage 3), the complete fusion of these osseous elements including a visible epiphyseal scar (stage 4), and the complete fusion without a visible epiphyseal scar (stage 5). In the present study, each of the ossification stages 2 and 3 was divided into an early, intermediate and late phase. The authors evaluated the thin-slice CT scans of 185 patients aged between 13 and 26 years. In all these cases, a stage 2 or 3 had been determined in a previous study. The late stage 3, which is characterized by a fusion between metaphysis and epiphysis completing more than two thirds of the former epiphyseal gap, first appeared at age 19 in both sexes. If a late stage 3 is found, it is therefore possible to substantiate that an individual has already reached the legally important age threshold of 18 years.

Dental age assessment for Kuwaiti children using Demirjian's method

BACKGROUND

Dental age can be estimated based on the level of tooth mineralization during the developmental process. Various methods of determining chronological and radiographical stages have been used for dental age estimation.

AIM

To test the validity of the standards of dental maturation of Demirjian and Goldstein (Ann Hum Biol 3:411-421, 1976) when applied to Kuwaiti children.

SUBJECTS AND METHODS

The sample was selected from healthy Kuwaiti children attending the routine and emergency dental clinics of the Faculty of Dentistry, Kuwait University. Good quality rotational pantomographs were obtained for 509 children (263 girls and 246 boys) between 3 and 14 years. Maturation of the seven permanent teeth on the left side of the mandible was determined according to the crown and root development stages described by Demirjian et al. (Hum Biol 45:211-227, 1973).

RESULTS

There were statistically significant differences in the mean of dental maturation between Kuwaiti and French-Canadian children (p<0.0001). Kuwaiti children were dentally delayed compared to the Canadian standards (mean dental maturation difference of 0.69 year, SD=1.25 years, CI=0.58-0.80). The mean delay in girls was 0.67 year (SD=1.30 years, CI=0.51-0.83) and in boys it was 0.71 year (SD=1.18 years, CI=0.56-0.86). Using a non-linear regression model, function formulae were developed for Kuwaiti girls and boys.

CONCLUSION

The standards of dental maturation described by Demirjian and Goldstein (1976) may not be suitable for Kuwaiti children.

Forensic age estimation in living subjects based on the ossification status of the medial clavicular epiphysis as revealed by thin-slice multidetector computed tomography

Determination of the stage of ossification of the medial clavicular epiphysis is a crucial part of age estimation in criminal proceedings when evaluating individuals with completed hand ossification. In order to ensure a maximum of accuracy in forensic age estimation practise, it is recommended to perform thin-slice CT scans; but to date there exist no reference data on the bone development of the region in question based on thin-slice computed tomography. In this retrospective study, the authors evaluated thin-slice multidetector CT images of 592 individuals aged between 10 and 35 years produced in the University Hospital of Münster. The ossification status of the medial epiphysis of the clavicle could be reliably determined in 502 cases using the classification of stages by Schmeling et al. In male individuals, stage 2 was first noted at age 14, in female individuals at age 13. Stage 3 was first achieved by male individuals at age 17, by female individuals at age 16. The occurrence of stage 4 was first found in both sexes at the age of 21. In either sex, the earliest observation of stage 5 was at age 26. The findings are basically in line with those from the only CT-based study on the subject in question using the same classification of five stages, except from the fact that in the present study, stage 5 first occurs at age 26, which is 4 or 5 years later than what was found in the CT study using 7 mm slices in the majority of cases. This vast difference may be explained through the partial volume effect occurring with thick-slice CT images by a visual deception of the epiphyseal scar occurring with stage 4.

Age estimation from stages of union of the vertebral epiphyses of the ribs

This study attempts to fill a persistent gap in the literature by documenting the timing of epiphyseal union at the vertebral end of the ribs in a sample of modern Portuguese skeletons. The skeletal remains of 53 females and 45 males, between the ages of 11 and 30, were taken from the Lisbon documented skeletal collection. Individuals in the sample have been previously described as being representative of a middle-to-low socioeconomic segment of the early 20th century Lisbon population. Three anatomical locations were examined for epiphyseal union: the head, the articular tubercle and the nonarticular tubercle. The first epiphysis to show partial union is that of the nonarticular tubercle (females, 11-19 years; males, 11-19 years), followed by the epiphysis of the articular tubercle (females, 11-20 years; males, 16-20 years), and finally by the head epiphysis (females, 15-24 years; males, 16-22 years), which can still show incomplete epiphyseal closure at 25 and 24 years for females and males, respectively. A trend for earlier female maturation was observed, but the statistical tests only confirmed this result for some ribs and age groups. No directional asymmetry was found, but a significant fluctuating asymmetry was observed in all three epiphyses. A preliminary analysis showed that the asymmetric group of individuals in the study sample includes all the rural-to-urban migrants, relative to the symmetric group.

Comparison of the three age estimation methods: which is more reliable for Turkish children?

BACKGROUND

Three atlases-the GOK, the Greulich-Pyle (GP), and the Tanner-Whitehouse (TW3)-are used frequently for age determination in Turkey. The purpose of this study was to evaluate the applicability of these three methods related to the skeletal age assessment for Turkish adolescents.

MATERIALS AND METHODS

The conventional roentgenograms of the left hands and wrists, elbows, shoulders, and pelvises of 333 healthy Caucasian children (164 females, 169 males) who fit the study and the criteria of each atlas were obtained. The mean differences (+/- standard deviation [S.D.] in years) between the chronologic age (CA) and the skeletal age (BA), which were obtained by using each age estimation method, were calculated and tested using t-test.

RESULTS

For girls, the most accurate method was the TW3 (mean differences (d): -0.21 (p<0.05)), following by the GP (d: 0.66 (p<0.001), and the GOK (d: 2.99 (p<0.001)). For boys, the most accurate method was the GP (d: -0.02 (p>0.05)), followed by the TW3 (d: -0.18 (p<0.05)) and GOK (d: 1.05 (p<0.001)).

DISCUSSION AND CONCLUSIONS

Results show that the TW3 (for girls) and the GP (for boys) methods are more appropriate than the GOK atlas for estimating the BA. GOK could be used for boys aged 11-14 years but it should not be used for girls.

Variables affecting the probability of complete fusion of the medial clavicular epiphysis

In this study, we have combined data on clavicle fusion from different studies and applied a binomial logistic regression analysis. As such, we aimed to assess whether or not variables such as sex, socioeconomic status, and ethnicity influence the probability of having mature, i.e., completely fused clavicles at a given age. We further explored whether the method of clavicle examination, i.e., diagnosis from either a dry bone specimen, an examination of X-rays, or an examination of computed tomography scans, affects the probability of being diagnosed with mature clavicles. It appeared that only ethnicity did not significantly affect this probability. Finally, we illustrated how the logit model may be used to predict the probability of being diagnosed with mature clavicles.

Studies in use of the Greulich-Pyle skeletal age method to assess criminal liability

In recent years, skeletal age determination has become increasingly important for determining the age of live subjects as part of criminal investigation. The most widely used method worldwide to determine skeletal age is the Greulich-Pyle atlas method. The present study examines the suitability of the Greulich-Pyle method given the particular requirements of forensic age estimates. It is a retrospective analysis of 649 hand radiographs originally taken from persons aged between 1 and 18 years, separately for each sex. If the Greulich-Pyle method is used exclusively, it can be claimed with a probability of 95% that a young man has reached the age of 14 years and thus the age of criminal liability if his skeletal age is at least 15.5 years. In the case of female subjects, even if they are estimated as being 16.0 years old, it cannot be asserted with a probability of 95% that they have reached the age of 14. To reduce the margin of error of age estimates, determining the skeletal age should always go hand in hand with a physical examination to determine indications of sexual maturity and a dental examination to record dental status. The reference values given in the present study can be applied to members of all ethnic groups for age estimate purposes. If the person under examination has a different socio-economic status, the expert performing the age estimate should address this issue in his expert opinion and discuss the possible effects that might have on the age diagnosis.

Epiphyseal union at the innominate and lower limb in a modern Portuguese skeletal sample, and age estimation in adolescent and young adult male and female skeletons

This study documents the timing of epiphyseal union at the innominate, femur, tibia, and fibula in a sample of modern Portuguese skeletons. The sample was taken from the Lisbon documented skeletal collection and it is comprised of 57 females and 49 males between the ages of 9 and 25. Individuals are mostly representative of the middle-to-low socioeconomic segment of the early 20th century Lisbon population. A total of 18 anatomical locations were examined for epiphyseal union using a three-stage scheme: 1) no union; 2) partial union; and 3) completed union, all traces of fusion having disappeared. Results show that females are ahead of males by 1-2 years and provide similar age ranges for the stages of union than previous studies. Some variations between studies can be explained by methodological differences between dry bone and radiographic observations. However, a review of the literature indicates that socioeconomic status of a given population seems to be of decisive importance to the rate of ossification and most of the differences in skeletal maturation across studies and populations can probably be ascribed to different levels of social and economic development of the societies in which the individuals lived. Although the effects of socioeconomic status in skeletal maturation are greater during childhood than in adolescence, as to make the timing of epiphyseal union a reliable estimate of age at death, they are not negligible and age estimates should take into account the likely socioeconomic status of the individual, whose remains are under examination.

Giant cell tumor of bone in children and adolescents

BACKGROUND

There are very few series that document giant cell tumor of bone (GCT) in the immature skeleton, and the reported incidence in literature varies from 1.8% to 10.6%. The purpose of this study was to document the incidence of GCT in patients with open physis in the Indian population and study the course of the disease with respect to its adult counterpart to see if it behaved any differently.

METHODS

Between January 2000 and December 2005, 17 (6%) of 285 surgically treated patients with histologically proven GCT had open physis on imaging. Treatment was directed toward local control without sacrificing joint function, with most lesions treated with intralesional curettage.

RESULTS

Fourteen (82%) patients were girls. The most common site was around the knee (53%). Of 15 lesions in tubular bones, 13 were epiphysiometaphyseal in location. An open physis did not prevent GCT from penetrating the epiphyseal cartilage. Histologically, the tumors were typical of GCT. Of 15 patients available for follow-up, 3 (20%) developed local recurrence.

CONCLUSIONS

Although the overall incidence of GCT may be higher in the Asian population, the percentage of skeletally immature patients or those nearing skeletal maturity is similar to that described in literature. The biological behavior of the disease is similar to that seen in adults, except a marked female preponderance, principles of treatment, recurrence patterns, and course of the disease mirror the behavior of its adult counterpart.

The chronology of third molar mineralization in the Austrian population—a contribution to forensic age estimation

The aim of the present study was to determine the chronology of third molar mineralization and to establish Austrian reference data. Therefore, a cross-sectional study was undertaken by evaluating 610 panoramic radiographs in order to assess the mineralization status of the mandibular third molars of Austrian male and female individuals (275 males and 335 females) between the ages of 12 and 24. The evaluation was carried out using the eight grade scheme of Demirjian et al. (1973). Mean ages, standard deviations, standard errors and percentile distributions are presented for each stage of development. Significant differences between the left and right mandibular third molars were not found. Males reach the developmental stages earlier than females, statistically significant differences were noted in stages E and F. Both mandibular third molars were observed in the majority of the individuals of the Austrian sample (477 individuals, 78.2%). For medicolegal purposes the likelihood of whether an Austrian individual is older than 18 years or not was determined.

Comparative analysis of the applicability of the skeletal age determination methods of Greulich–Pyle and Thiemann–Nitz for forensic age estimation in living subjects

Evaluation of hand ossification is a main pillar of radiological age diagnosis in living subjects. In the present study, we comparatively assessed the Greulich-Pyle and Thiemann-Nitz methods for accuracy of age estimation and degree of acceleration in the respective reference populations. For this, the skeletal age of 649 hand X-rays from German subjects aged 1-18 years was determined by both methods. Accuracy of the age estimates was determined based on regression and measures of certainty. In terms of accuracy, both methods seem to be equally well suited for forensic age diagnostics. The degree of acceleration in the reference populations for the two methods was calculated as the mean difference between the estimated skeletal age and the actual age of a test subject. Compared to the Greulich-Pyle population, the Thiemann-Nitz population was accelerated by 0.44 years in both male and female subjects. When an expert opinion is required and one cannot exclude the possibility that the investigated subject may come from a population with a high acceleration status, the Thiemann-Nitz method should preferably be used to prevent overestimation of age.

Is the assessment of bone age by the Greulich-Pyle method reliable at forensic age estimation for Turkish children?

BACKGROUND

Estimation of age is an important task for forensic experts especially in developing countries where birth records are often not well maintained. In this study, we investigated whether or not the Greulich-Pyle (G-P) method is sufficient at forensic age estimation for Turkish children.

METHODS

Plain radiographies of left hands and wrists of 492 (241 (49.0%) female, 251 (51.0%) male) healthy children between 11 and 18 years of age for girls and 11 and 19 years of age for boys were taken. Mean chronological ages (CA) were compared with mean skeletal ages according to G-P atlas for each gender and in the second step the differences those for each age group were determined. The children were Caucasian and had a low-middle socioeconomic status in this study population. The paired sample t test was used to indicate the difference between G-P (mean skeletal age according to G-P atlas) and CA (mean chronological age). In order to indicate the relation Pearson correlation coefficient was used. Modeling the relationship between G-P and CA linear regression was used. The analyses were done under SPSS 11.5.

RESULTS

The G-P compared to their CA. The CA was 14.52+/-2.18 S.D. years, S.E.: 0.14 (median: 14.47, range: 11.07-18.92 years) whereas G-P was 15.06+/-2.31 S.D. years, S.E.: 0.15 (median: 15.00, range: 10-18 years) for girls. The difference between the two parameters was statistically significant (p<0.001). The CA was 15.28+/-2.41 S.D. years, S.E.: 0.15 (median: 15.09, S.E. range 11.13-19.94 years) and G-P was 15.41+/-2.92 S.D. years, S.E.: 0.18 (median: 15.60, range 9-19 years) for boys. The difference was not statistically significant (p>0.05). There was a high correlation (Pearson r=0.882, p<0.001) for girls and (Pearson r=0.900, p<0.001) for boys. The determination coefficient (R2) is equal to 0.778 for girls and 0.81 for boys. The regression model also tested by ANOVA and it is found significant (p<0.01) for both genders. According to age groups G-P was advanced (0.17-1.1 year) almost for all ages and differences were significant at 11, 12, 14, 16 ages for girls. G-P was delayed at 11-14 ages (0.01-0.58 year) but not significant except for 13 years and G-P were significantly advanced in 15-17 ages (0.88-0.98 years) but then delayed in 18-19 years of age (0.02-0.48) for boys. The difference's standard deviation at 12, 13, 15, 16 years of ages for girls and between 12 and 16 and 18 years of ages for boys were more than 1 year.

CONCLUSION

When the results of the previous study and this study are compared, the test method could be used technically by pediatricians and other clinicians, but it is even more important for ethically unacceptable errors to disappear, especially in cases involving the possible criminal liability of the supposed minor. So standard deviation at 12, 15 years of ages for girls and 12, 15, 18 years of ages for boys were more than 1 year. But it is not known that the other methods whether more useful or not than this method. For the time being unless any other methods will be proved more useful, we have to use this method cautiously for possible criminal liability cases in forensic age diagnosis.

Age estimation

While age estimation of unidentified corpses and skeletons for identification purposes has a long tradition in forensic sciences, age estimation of living persons has formed a relatively recent area of forensic research which is becoming increasingly important. The international interdisciplinary Study Group on Forensic Age Diagnostics (AGFAD) issued recommendations for age estimation of living persons for the purpose of criminal, civil, asylum and old-age pension procedures as well as for determining the sex and age of skeletons. In the present work, the authors set out state-of-the art age estimation methods for specific case groups, define minimum requirements for reference studies and specify the need for further research. In addition, ethical and medico-legal aspects as well as issues relating to quality assurance are discussed.

Studies on the progress of third-molar mineralisation in a Black African population

The forensic determination of the age of living people has become increasingly important in recent years. With regard to the relevant age group, the radiographic assessment of third-molar mineralisation is of particular importance. So far, the influence of geographic origin on the mineralisation rate has been insufficiently analysed. The paper is based on a total of 595 conventional orthopantomograms of 474 male and 121 female Black Africans aged between 10 and 26 years for whom dates of birth were known. The mineralisation status of third molars was evaluated based on Demirjian's classification of stages [Demirjian et al., 1973. A new system of dental age assessment. Hum. Biol. 45, 221-227]. This study presents the means and standard deviations, median values and the lower and upper quartiles separately for both sexes for the mineralisation stages D-H. Statistically significant differences between the upper and lower jaws were observed in males examined with regard to their attaining the stage F. Mandibular teeth developed 0.8 years earlier than maxillary teeth. Significant sex-specific differences were found with regard to the age at which tooth 38 reached the stage G. In females, tooth 38 reached stage G 1.5 years earlier than in males. In comparison to White probands, the Black African sample showed a tendency to achieve the mineralisation stages earlier. We would recommend using population-specific standards for age determination purposes.

Age estimation of unaccompanied minors

In recent years many countries have experienced a sharp increase in the demand for forensic age estimates of unaccompanied minors. In many countries the age thresholds of relevance to criminal prosecution lie between 16 and 22 years. In line with recommendations issued by the Study Group on Forensic Age Diagnostics, for determining the age of live subjects a forensic age estimate should combine the results of a physical examination, an X-ray of the hand and a dental examination which records dentition status and evaluates an orthopantomogram. To assess the age of persons who are assumed to be at least 18 years old, an additional radiographic or CT examination of the collar bones is recommended. Forensic age estimates should take account of the ethnic origin and socio-economic status of the person under examination.

Reliability of the methods applied to assess age minority in living subjects around 18 years old

We present a review of a population of 114 immigrant Moroccan males for which an age estimation was requested. The subjects' real chronological age was confirmed by the Moroccan Embassy in Spain. The confirmed age range was between 13 and 25, with an average age of 18.1 years and a standard deviation of 2.03. The following tests were performed to arrive at the forensic estimation of age: general physical examination, carpus X-ray (Greulich and Pyle method) and dental orthopantomography to determine the degree of maturity of the third inferior molars (Demirjian's method). Carpus X-ray (skeletal age) was the most useful method, followed by Demirjian's method (dental age), as prediction factors of a chronological age of over or under 18. The combination of skeletal and dental age variables represented a significant improvement in the prediction of the chronological age of the subjects in this population, reducing the number of ethically unacceptable test errors to a minimum.

Reference data for the Thiemann-Nitz method of assessing skeletal age for the purpose of forensic age estimation

The aim of this study was to determine the statistical parameters of deviation in the Thiemann-Nitz method for use in forensic age diagnostics. To this effect, 402 hand radiograms, originally taken in two large German cities between 1983 and 2002 for the purpose of diagnosing trauma, were analyzed. At the time of examination, the patients were aged between 10 and 18 years. The study presents the mean, standard deviation, and median, with lower and upper quartiles, for the skeletal ages of 11.0 through 18.0 years. The simple standard deviations range between 0.2 and 1.2 years. To increase the accuracy of age estimates and improve the identification of age-relevant developmental disorders in forensic age estimation practice, the methods for determining skeletal age should always be combined with a physical and dental examination. In addition, the expert opinion should pay attention to the issue of different modernization levels in relevant populations.

The impact of economic progress and modernization in medicine on the ossification of hand and wrist

One of the main criteria used for age estimations of young living subjects is the developmental status of the ossification of hand bones. The impact of economic progress and modernization in medicine on ossification rates in a given population still requires further clarification. We selected 36 samples from literature for which the ossification status had been determined with the Greulich-Pyle method and analyzed specific economic data (per capita income) and demographic data (life expectancy at birth) as parameters of modernization. To describe the influence of these parameters on the rate of ossification, we performed a regression analysis and found that a relatively high level of economic progress and modernization in medicine coincides with high ossification rates, while relatively low modernization seems to delay ossification. When performing age estimations, the expert opinion should therefore pay attention to the issue of different modernization levels.

Studies on the time frame for ossification of the medial epiphysis of the clavicle as revealed by CT scans

The authors retrospectively analyzed 629 CT images of patients aged between 15 and 30 years produced during multiple trauma diagnostics at the Unfallkrankenhaus Berlin. For the purposes of this study, the authors reliably determined the ossification status of the medial epiphysis of the clavicle in 556 cases, using the classification of stages by Schmeling et al. In both sexes, stage 2 was first noted at age 15. In male patients, the earliest occurrence of stage 3 was noted at age 17, in female patients at age 16. Stage 4 was first achieved by both sexes at age 21. Stage 5 was first noted in female patients at age 21 and in male patients at age 22, which is 4 or 5 years earlier than was observed by a comparable study using conventional radiographs. The partial-volume effect in computed tomography using the thick slice scanning mode was discussed as a possible explanation for this early visualization. The question of how slice thickness affects the age intervals between ossification stages identified by CT examinations should be examined in additional studies.

Forensic age diagnostics of living people undergoing criminal proceedings

In the German-speaking area, recent years have seen a rapid growth of the need for forensic age estimations. Such need arises, for example, if no verified information on the age of a person suspected of a criminal offence is available; the issue at question in terms of criminal law is whether the person concerned has reached the age of criminal responsibility and whether general criminal law in force for adults is to be applied. The relevant age tresholds in criminal proceedings are 14, 18 and 21 years of age. According to recommendations of the Study Group on Forensic Age Diagnostics, a forensic age estimate should consist of a physical examination, an X-ray of the hand, and a dental examination which records dentition status and evaluates an orthopantomogram. In addition, a radiological or CT examination of the clavicles is recommended to establish whether a person has attained 21 years of age. The present article addresses the influence of ethnic origin on the examined developmental systems.

Forensic age diagnostics of living individuals in criminal proceedings

Age estimations of living individuals are increasingly important in criminal matters. If doubts arise regarding the age of a person suspected of a criminal offense, forensic age estimation is prompted by the need to ascertain whether the person concerned has reached the age of criminal responsibility and whether general criminal law in force for older juveniles or adults is to be applied. According to the recommendations of the Arbeitsgemeinschaft für Forensische Altersdiagnostik (study group for forensic age diagnostics), age estimates in criminal proceedings should be based on the general physical examination, the X-ray examination of the hand and the odontological examination by a dentist, including dental status and orthopantomogram. In order to improve diagnostic reliability, these methods should always be used in combination, ensuring that each part is performed by forensically trained and experienced experts of the relevant disciplines. In order to demonstrate that the proband has reached the age of 21, an additional X-ray examination or CT scan of the clavicles is recommended. Future research projects should assess the variation for a combination of the above methods, quantify the impact of socio-economic status and ethnicity on the examined development systems and review the suitability of non-ionizing imaging methods of age estimation.

Forensic age estimation in living subjects: the ethnic factor in wisdom tooth mineralization

Radiological assessment of the mineralization stage of third molars is a major criterion for age estimation of living people involved in criminal proceedings. To date insufficient knowledge has been obtained about how the ethnic origin can influence tooth mineralization. A comparative study of wisdom tooth mineralization was carried out on three population samples: one German, one Japanese and one South African. To this end, 3,652 conventional orthopantomograms were evaluated on the basis of Demirjian's stages. The Japanese subjects were on average 1-2 years older than their German counterparts upon reaching stages D-F, whereas the South African subjects were on average 1-2 years younger than the Germans when displaying stages D-G. To enhance the accuracy of forensic age estimates based on wisdom tooth mineralization we recommend the use of population-specific standards.

Third molar root development in relation to chronological age: a large sample sized retrospective study

The aim of the present investigation, which is a continuation and extension of a previous published pilot study [Forensic Sci. Int. 129 (2002) 110], was to calculate the chronological age of an individual based on the dental developmental stages of third molars (so-called wisdom teeth). The evaluated material consisted of 2513 orthopantomograms (OPG's) of patients all of Belgian Caucasian origin between 15.7 and 23.3 years. The sample of OPG's was scored by two observers who were calibrated for intra- and interobserver reliability by means of kappa statistics. The kappa statistics revealed a strong agreement between the intra- and interobserver measurements. Further statistical analysis was performed in order to obtain multiple regression formulae for dental age calculation with the chronological age as the independent variable and the third molar developmental stages as dependent variables. Both for males and females a significant Pearson correlation coefficient was noticed for contralateral third molars, a smaller less significant one for the antimeres. For the application of the regression formulae one has to take into consideration the gender, the location and number of wisdom teeth. Probabilities for an individual to be older than 18 years were also calculated in case of fully developed wisdom teeth.

Statistical analysis and verification of forensic age estimation of living persons in the Institute of Legal Medicine of the Berlin University Hospital Charité

In recent years, the increase in international migration movements has led to a greater demand for forensic age estimation of foreigners without valid identification documents in numerous countries. The growing importance of forensic age determination is underlined by a rapid rise in the number of expert reports by the Institute of Legal Medicine of the Berlin University Hospital Charité. A total of 247 expert opinions on estimated age were given between 1992 and 31 December 2000. Subject to formal court ruling, age is estimated based on the physical inspection, in combination with an X-ray of the left hand and the clavicles as well as dental assessment. However, the statistical proof of the range of scatter for the summarized age diagnosis still remains to be clarified in the context of this assessment procedure. The age estimations made by the Institute of Legal Medicine of the Berlin University Hospital Charité were statistically analyzed with respect to the validity of the different methods. For verification of the age diagnoses, the age estimates were compared with the court records and the age determined in the course of legal proceedings. In 45 cases, the age diagnoses could be verified. In all cases where the age could be verified beyond doubt, deviations from the actual age did not exceed +/-12 months. From this, it can be concluded that the combined application of the above-mentioned methods allows forensic age estimations with a sufficiently high degree of reliability.

Dental age estimation and third molars: a preliminary study

The aim of the present investigation was to reconstruct the chronological age based on the dental developmental stages of third molars evaluated on orthopantomograms. A total of 1175 orthopantomograms were assembled from patients of Caucasian origin between 16 and 22 years of age. Each third molar present was scored by two observers according to a 10-stage developmental scale. The kappa statistics measured the intra- and inter-observer reliability. The general statistical analysis was based on multiple regression analysis in order to obtain multiple regression formulas for dental age estimation based on the number of third molars present on the evaluated orthopantomogram. No regression models were statistically significant when there was only one-third molar present because of the relatively small number of orthopantomograms that fitted this criterion. A strong agreement was found between the intra- and inter-observer measurements. The statistical analysis revealed both for males and females high Pearson correlation coefficients between contralateral third molars and smaller coefficients between antimeres. The obtained multiple regression formulas are only applicable in certain specified conditions, for instance when four third molars are present the following formulas should be used in a Caucasian male "age=10.2000+0.5122UL+0.5273LL" (developmental stage of upper and lower left third molars) or in case of a female "age=13.6206+0.1933UR+0.5080LR" (developmental stage of upper and lower right third molars). This investigation revealed that the chronological age of a Caucasian individual may be estimated based on regression formulas with a S.D. of 1.52 or 1.56 years for males and females, respectively, when all four third molars are present.