hrvatski

Infrared spectrum absorption analysis in determining dental age: a pilot study

Introduction: Determining age on posthumous dental remains is one of the forensically demanding procedures. By analyzing teeth, we can determine the age of unknown human remains, living people or archaeological dental remains. No method for determining age in adults is completely accurate and can give an approximate result ranging from 5 to 10 years. The introduction of infrared spectrometry with Fourier transformation in the analysis in this pilot study opens the possibility to add another method to the current forensic methods that could relatively quickly determine the dental age of an unknown human body. Materials and methods: A total of twenty tooth samples were used, which are part of the archive of the Department of Dental Anthropology, Faculty of Dentistry, University of Zagreb. The teeth were extracted, cleaned of blood and soft tissue residues, and disinfected in 2% H2O2 solution. After drying at room temperature, the teeth were embedded in quick-setting acrylate and cut into 0.5-1.1 mm thick cuts with a precision cutter. The samples were divided into five age groups: 10-19, 30-39, 40-49, 50-59, 60-69 years. Each group had 4 samples, each from a different person, different sex and different teeth. The samples were then placed in a spectrometer, and sampling was performed using attenuated total reflectance. A spectrum analysis of 400-4000 cm-1 in the area of tooth dentin was performed. As a control, the analysis of the acrylate spectrum was performed in order to eliminate possible contamination of the images. Results: After reducing the dimensionality of the spectrum by analyzing the main components of the spectrum and analyzing linear discriminants, no statistically significant difference between the absorption coefficients between groups (p> 0.05) was proven, but wherein the maximum values of absorption between groups the difference is observed. Wave numbers () 823, 1000, 1400, 1540 and 1650 cm-1 were isolated, with the largest increase in the absorption coefficient (present in all age groups). Differences in absorbance coefficients between groups for each of these wave numbers were tested by analysis of variance with post-hoc Holm-Šidak correction. The results showed a difference between groups 50- 59 and 60-69 at 873 cm-1. Conclusion: In this pilot study, there is a statistically significant difference between two of the 5 groups: 50–59 and 60–69 years. We conclude that it is necessary to increase the number of samples in order to obtain a statistically significant difference between other groups

spectrophotometry ; infrared ; dental age ; forensic odontology

Acknowledgments: The research was funded by the Croatian Science Foundation through the project: Tooth Analysis in Forensic and Archaeological Research, IP-2020-02-9423

engleski

Infrared spectrum absorption analysis in determining dental age: a pilot study

Introduction: Determining age on posthumous dental remains is one of the forensically demanding procedures. By analyzing teeth, we can determine the age of unknown human remains, living people or archaeological dental remains. No method for determining age in adults is completely accurate and can give an approximate result ranging from 5 to 10 years. The introduction of infrared spectrometry with Fourier transformation in the analysis in this pilot study opens the possibility to add another method to the current forensic methods that could relatively quickly determine the dental age of an unknown human body. Materials and methods: A total of twenty tooth samples were used, which are part of the archive of the Department of Dental Anthropology, Faculty of Dentistry, University of Zagreb. The teeth were extracted, cleaned of blood and soft tissue residues, and disinfected in 2% H2O2 solution. After drying at room temperature, the teeth were embedded in quick-setting acrylate and cut into 0.5-1.1 mm thick cuts with a precision cutter. The samples were divided into five age groups: 10-19, 30-39, 40-49, 50-59, 60-69 years. Each group had 4 samples, each from a different person, different sex and different teeth. The samples were then placed in a spectrometer, and sampling was performed using attenuated total reflectance. A spectrum analysis of 400-4000 cm-1 in the area of tooth dentin was performed. As a control, the analysis of the acrylate spectrum was performed in order to eliminate possible contamination of the images. Results: After reducing the dimensionality of the spectrum by analyzing the main components of the spectrum and analyzing linear discriminants, no statistically significant difference between the absorption coefficients between groups (p> 0.05) was proven, but wherein the maximum values of absorption between groups the difference is observed. Wave numbers () 823, 1000, 1400, 1540 and 1650 cm-1 were isolated, with the largest increase in the absorption coefficient (present in all age groups). Differences in absorbance coefficients between groups for each of these wave numbers were tested by analysis of variance with post-hoc Holm-Šidak correction. The results showed a difference between groups 50- 59 and 60-69 at 873 cm-1. Conclusion: In this pilot study, there is a statistically significant difference between two of the 5 groups: 50–59 and 60–69 years. We conclude that it is necessary to increase the number of samples in order to obtain a statistically significant difference between other groups

spectrophotometry ; infrared ; dental age ; forensic odontology

Acknowledgments: The research was funded by the Croatian Science Foundation through the project: Tooth Analysis in Forensic and Archaeological Research, IP-2020-02-9423