Color change in teeth due to burning: Spectrophotometric analysis

The effect of burning on dental tissue: A macroscopic and microscopic investigation

Teeth are considered unique as fingerprints for identification purposes. Their structure and resilience mean they can remain for thousands and millions of years withstanding extreme conditions, including burning. During burning, bones undergo carbonization at approximately 400°C and calcination at approximately 700°C. This study aimed to investigate the effects of carbonization and calcination on dental tissue. It involved nondestructive analyses of 58 extracted human teeth before and after burning, using x-ray diffraction, micro-CT, and high-resolution confocal microscopy. The results revealed that during carbonization, dentin volume decreased in two thirds of the sample, accompanied by crack formation and significant reduction in hydroxyapatite crystal size (p<0.001). During calcination, dentin volume decreased in all teeth, along with a significant deepening of the cracks (p<0.001), while enamel crystal size increased slightly. Initial changes in teeth occurred at lower temperatures than had once been assumed, as indicated by the cracks during carbonization, and there was up to a 36% decrease in dentin volume during calcination, which should be considered when measuring burnt teeth. The results of this research provide new insight into understanding dental tissue response to burning. Thus, dental remains may contribute to the knowledge needed to reconstruct anthropological and forensic scenarios involving burning.

Possible uses of Hunter-Schreger bands of dental enamel for automated personal identification

BACKGROUND

Hunter-Schreger bands (HSB) are optical phenomena observed on tooth surfaces under polarized light, resulting from the intersection of enamel prisms. Anthropological studies demonstrate the prevalence of HSB in large mammals, contributing to enamel resistance. Historically, John Hunter and Schreger depicted HSB in dental literature. In dentistry, HSB play a role in non-carious cervical lesions (NCCL) and internal dental perikymata, suggesting their potential for personal identification. Personal identification, crucial in both daily and professional life, involves biometric characteristics, such as fingerprints or facial recognition. The need for non-invasive, rapid, and user-friendly methods has prompted the exploration of using HSB dental images for personal identification. The review aimed to consolidate studies employing HSB for personal identification.

METHODS

The scoping review was carried out strictly following the PRISMA-ScR checklist; the search was carried out on tree databases (PubMed, Scopus, Science Direct,) and a register (Cochrane library).

RESULTS

The research produced a number of bibliographic sources totaling 410. With the removal of duplicates, 334 were obtained; potentially eligible articles amounted to 14, of which only 4 fully complied with the criteria of eligibility.

CONCLUSIONS

From the data in the literature, we can assert that HSB could be used in personal identification, as they are characteristics that are difficult to change and easily detectable.

Half a century of systematic research on heat-induced colour changes in bone - A review

Skeletal human remains presenting heat-induced changes have been a focus of study for a long time. However, there is still a long way to go for the anthropologists to be able to fully interpret and understand these changes. Heat-induced colour modifications are one of the least understood phenomena in bone, displaying a variety of exceptions (e.g., tints of yellow, orange, blue, green, pink, and red) to the expected colour variations that bone can produce when exposed to high temperatures (i.e., ivory, brown, black, various shades of grey, and white). In addition to these, there is a lack of uniformization in the literature regarding the methods to determine the exact colourations observed and the nomenclature used, giving way to subjective descriptions. However, commitment to more objective and reliable methods is visible in more recent research. In this review, we compiled data published in the literature throughout the years to portray the state of the art regarding the potential of heat-induced colour changes for inferring the circumstances of death and the applicability of these methods in the legal framework.