The development of a tool to predict temperature-exposure of incinerated teeth using colourimetric and hydroxyapatite crystal size data

Int J Legal Med. 2021 Sep;135(5):2045-2053. doi: 10.1007/s00414-021-02538-7. Epub 2021 Mar 2.

Abstract

This study presents a novel tool to predict temperature-exposure of incinerated pig teeth as a proxy for understanding impacts of fire on human teeth. Previous studies on the estimation of temperature-exposure of skeletal elements have been limited to that of heat-exposed bone. This predictive tool was developed using a multinomial regression model of colourimetric and hydroxyapatite crystal size variables using data obtained from unheated pig teeth and teeth incinerated at 300 °C, 600 °C, 800 °C and 1000 °C. An additional variable based on the observed appearance of the tooth was included in the tool. This enables the tooth to be classified as definitely burnt (600 °C-1000 °C) or uncertain (27 °C/300 °C). As a result, the model predicting the temperature-exposure of the incinerated teeth had an accuracy of 95%. This tool is a holistic, robust and reliable approach to estimate temperature of heat-exposed pig teeth, with high accuracy, and may act as a valuable proxy to estimate heat exposure for human teeth in forensic casework.

Keywords: Colourimetry; Heat-induced change; Multinomial regression model; Teeth; Temperature estimation; X-ray diffraction.

MeSH terms

  • Animals
  • Burns / physiopathology*
  • Colorimetry
  • Crystallization
  • Durapatite / analysis*
  • Fires
  • Hot Temperature*
  • Models, Animal
  • Models, Statistical
  • Sus scrofa
  • Tooth / chemistry*
  • Tooth / physiopathology*
  • Tooth Discoloration / physiopathology*

Substances

  • Durapatite