Evaluation of post-mortem estimated dental age versus real age: A retrospective 21-year survey

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Abstract

The aim of the study was to evaluate the reliability of methods used for forensic dental age estimation. We analysed all cases over the last 21 years (1984–2004) of unidentified bodies that were examined for identification purposes (including age assessment), and of which secure identification was subsequently achieved. In total, the study included 51 cases and 7 different methods had been used for dental age estimation, with the Bang/Ramm and the Gustafson/Johanson methods being the most frequently applied. The age estimates had usually been recorded as 10-year intervals. Factual ages at death were in the range of 6–76 years, with the largest concentration of cases being in the age interval of 25–55 years (34 cases). There was good agreement between estimated age interval and factual age at death in 37/51 (72%) of the cases. In eight cases the factual age at death deviated up to ±5 years from the estimated age, and in six cases by more than 6 years. The average difference between factual age at death and estimated age was 4.5 years. The four subadults in the material were all correctly estimated within an age range of ±3 years.

Our study showed that forensic odontological age estimates are reliable. However, the implementation of the specific methods may need to be adjusted concerning age ranges.

In the future we recommend to register anamnestic information and the different steps in the methods used. Clinical evaluation should contain more details about attrition, colour, number and presumed age of the restorations and periodontal status.

Introduction

Dental development is a complex process that takes place from early foetal life to approximately 20 years of age. The development of dental tissues is less affected by endocrine diseases or nutritional variations than other tissues [1]. Once a tooth is fully mineralised and erupted it forms a very stable entity. Both developmental and regressive changes to the tooth can be related to chronological age. Furthermore, a tooth will resist the influence of many factors and disintegrates only very slowly [2], [3]. This makes teeth very suitable for dental age estimation.

Several methods have been developed to estimate age based on dental tissue and tooth morphology. Some of these methods are especially developed to estimate the age at death, as they require sectioning [4], [5], [6], [7], while others may be used also in clinical situations [8], [9].

Age estimation is a very important branch in the field of forensic odontology. At the Institute of Forensic Medicine in Copenhagen, Denmark, there are between 40 and 80 cases annually in which dental age estimation is carried out. The majority of the cases concern age estimation performed on living people. However, chronological age is also a very important parameter when the identity of a deceased person has to be ascertained. Two to five post-mortem dental age estimations are carried out annually.

In this retrospective study, covering 21 years, all post-mortem cases that involved dental age estimation and that resulted in a final identification were used. The estimated age was compared with the real age of the dead person, and the methods used to estimate the age were noted. Various parameters, associated with the finding and location of the body, were also noted, in order to assess whether they might have an impact of the accuracy of the post-mortem age evaluation. The aim of the present survey was to assess the reliability of the methods used for forensic dental age estimation.

Section snippets

Materials and methods

The study material included 51 cases (11 females and 40 males). Post-mortem age estimation had been performed in 102 cases during the period 1984–2004, half of all these cases were excluded due to lack of information (e.g., date of birth, case never solved, etc.). The age at death was calculated as the interval between the date of birth and the date of finding/discovery of the body. In eight cases there was clear and incontrovertible evidence of exact date of death (e.g., observed suicides and

Results

The estimated ages were in the range between 6 and 90 years with the real ages being between 6 and 74 years. Of the 51 cases, four were subadults. Due to the major differences in evaluating a still-developing dentition versus a fully erupted and developed dentition, the results are presented for the subadults (real age: 6, 7, 16 and 20 years, respectively) and adults (real age range: 22–74 years) per se.

The subadults were all correctly estimated within an age range of ±3 years (Table 1) and the

Discussion

Age estimation is an important and basic parameter when the identity of a deceased person is sought. While final identification may depend on specific odontological matching of pre- and post-mortem dental data, DNA-typing and fingerprinting [2], [3], [15], the estimated age at death is one of the parameters that assists the police in producing a preliminary profile of the deceased person. Several methods for post-mortem dental age estimation have been put forward [4], [5], [6], [7], [16]. Some

Conclusion

It is recommended for adult individuals to give an estimated age range of 10–20 years and use the calculated age and the matching standard deviations instead of approximate values. In cases with a developing dentition the estimated age range can be narrowed to 2–4 years. Depending on the degree of development the dentition of a small child can be estimated within a range of 2 years and for subadults a range of 4 years is more appropriate. Also, the location in which the body was found had no

Acknowledgements

We would like to express our appreciation and gratitude to the Foundations of Julie von Müllen and Christian & Ottilia Brorson. Without their generous financial support this study would not have been completed.

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