Anthropology, Department of
Quantification of the Mincer et al. 1993 Method of Age Estimation for the Purpose of Increasing the Reliability and Accuracy of Scores Within the System
Dr. Bill Belcher
Dr. Brittany Walter
Dr. Emily Hammerl
Date of this Version
Oettel, B. A. (2021). Quantification of the Mincer et al. 1993 Method of Age Estimation for the Purpose of Increasing the Reliability and Accuracy of Scores Within the System. (Unpublished Master's thesis). University of Nebraska.
There is currently a need to test new methods of increasing the accuracy and reliability of the stages scored by users of subjective methodologies within the forensic sciences. One way this can be done is through the quantification of these subjective stages through metric measurements and the application of sectioning points. This research assesses the quantification of the subjective stages within the Mincer et al. (1993) method of age estimation through odontometric measurements and the application of sectioning points. In this study, five odontometric measurements taken from radiographs of fifty-five third mandibular molars from thirty-nine individuals were used to establish measurement ratios. Using a Spearman correlation coefficient, the measurement ratios were tested to determine which were significantly correlated to their respective Mincer stages. Sectioning points were then derived through descriptive statistics for the significantly correlated measurement ratios. These sectioning points were then tested in a separate validation sample of ten individuals comprising twelve third molars. Results found the reliability of the scores obtained from the measurement ratio sectioning point systems to be excellent (ICC values 0.972–1.000). However, when the scores obtained through the sectioning points were compared to the scores obtained through the subjective Mincer et al. (1993) method by trained forensic anthropologists, there was poor agreement, with correct classification percentages ranging from 25% to 75% for the various sectioning point systems. This indicates that the accuracy of the measurement ratio sectioning point systems is low. Additionally, the Mincer et al. (1993) method was validated for the entire sample with results showing a difference between observed (known) age and expected age using the Mincer method. Furthermore, the probability of having obtained the age of eighteen was tested for each of the Mincer stages with results showing a 100% probability of being at least eighteen years old for all of the stages within the sample. However, this may have been affected by the absence of individuals under eighteen years of age within the sample. This study represents an important steppingstone, with more research needed in the future.
Advisor: William R. Belcher
A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Arts, Major: Anthropology, Under the Supervision of Professor William Belcher. Lincoln, Nebraska: April 22, 2021
Copyright 2020 Bailey A. Oettel