An interesting article titled “Parturitions, menopause and other physiological stressors are recorded in dental cementum microstructure” appears in Scientific Reports written by Paola Cerrito and et al. (vol. 10, pp. 5381, 2020). The article discusess how the life events that people have experienced can be told by their teeth.
In the article the researchers conducted a study of cementum microstructure of 47 human teeth, from 15 individuals with a known life history. The teeth were processed at the Hard Tissue Research Unit of the NYU College of Dentistry. The life history events of the patiens like age, illnesses, and relocations were known and had been reported from the patients relatives. The researchers used a series of imaging techniques that illuminated cementum rings, and then linked the rings to different life stages. Doing so allowed them to reveal connections between tooth formation and other occurrences. The authors found that mineralized tissues, like enamel, dentine, and cementum, form incremental layers that are related to repeated physiological cycles from the time the tooth surfaces in the mouth. These annual layers are similar to the more well known tree’s growth rings. It was found that abnormal growth lines in the tissues of teeth affect normal matrix formation, leaving distinctive permanent marks that correlate to life events, like birth, disease, weaning, malnutrition, climate, and lifestyle changes.
The authors were also able to detect reproductive events and menopause in all females. They could also detect stressful events, such as systemic illnesses and incarceration. The researchers thus were able to show that teeth continuously change and responds to physiological events. The authors state:
“…our results demonstrate that dental cementum constitutes a chronologically faithful biological archive of an individual, from which life history milestones, thus far not inferable from other mineralized tissues, can be detected and accurately timed.”
The authors thus feel that major life events can be seen in teeth, particularly in dental cementum. This has implications that teeth have a role in organismal physiology, endocrinology, and mineral homeostasis. The authors note a few limitations of the study such as that without medical and lifestyle records, it is not possible to tell what the cause of the change in cementum microstructure was such as illness, childbirth, relocation, or some other life event. The authors do note that it is possible to determine the sex of person from the analysis of amelogenin peptides present in
tooth enamel and the age at death/extraction of the tooth can be determined from a count of yearly incremental cementum bands. The researchers say in the future they plan to include full elemental analysis of cementum, via laser ablation and mass spectrometry, to attempt to identify event-specific changes in elemental composition.