A smoking habit is visible on the roots of one’s teeth after quitting and even after death, giving clues for forensics and archaeology.
By Aarjav Mishra
Scientists from Northumbria University have found that teeth can keep a permanent record of smoking habits, even many years after a person quits.
Teeth that remember smoking habit
A study by Dr. Ed Schwalbe and Dr. Valentina Perrone from Northumbria University, with Dr. Sarah Inskip from the University of Leicester, shows that a smoking habit leaves marks deep inside one’s teeth. These marks stay for life and can be seen in the cementum rings, which are thin growth layers on the roots of teeth that form every year like rings on a tree.
Teeth are made of three hard parts that are enamel, dentin, and cementum, and one soft part that is the pulp. Enamel is the strong white outer layer on the top part of the tooth. Dentin lies below enamel, and cementum covers the root and holds the tooth in the jawbone. The pulp, in the center, has nerves and blood vessels. In this research, scientists studied cementum because it can store a record of certain life events, including smoking.
How the study was done
The research team studied 88 teeth. This included 70 from living patients and 18 from archaeological remains from the years 1776 to 1890. People who gave their teeth for the study also shared their medical and smoking habit history. The archaeological teeth had information about the person’s age, sex, and date of death.
The researchers used microscopes to look at the acellular extrinsic fiber cementum (AEFC) and measured the thickness of its yearly rings. They found that 70 percent of ex-smokers and 33 percent of current smokers had disturbed or uneven cementum rings, compared to just 3 percent of non-smokers. Ex-smokers often had thicker cementum because normal growth started again after they quit, which created extra layers over the damaged part.
Forensic and historical clues
This method can help forensic experts find out if someone was a smoker, which is useful when DNA is not available. It can also help archaeologists learn about smoking habits and health problems of people in the past. One example is a living donor whose tooth showed damage between the ages of 22 and 41. Records showed the person smoked between ages 28 and 38 years old. Some archaeological teeth had pipe marks and tobacco stains, and their cementum rings showed the same smoking-related damage seen in modern smokers.
RELATED: Using archaeological tooth records to trace leprosy
Why this matters
This is the first time that the study of cementum rings, called cementochronology, has been used to detect tobacco use. It can help identify unknown people such as disaster victims, and it can give more information about how smoking affected health over centuries.
Even after quitting, the signs of a smoking habit remain in the teeth. By studying these microscopic marks, scientists can connect lifestyle habits with a person’s health and history.
This study appeared in the peer-reviewed journal PLOS One.
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Reference
Perrone, V., Davies-Barrett, A. M., Migliario, M., Randolph-Quinney, P., Inskip, S. A., & Schwalbe, E. C. (2025). Reconstructing smoking history through dental cementum analysis – A preliminary investigation on modern and archaeological teeth. PLOS One, 20(5), e0323812. https://doi.org/10.1371/journal.pone.0323812
About the Author
Aarjav Mishra is a postgraduate in Forensic Science with a specialization in Forensic Chemistry and Toxicology. He is UGC-NET qualified and has a strong interest in research, writing, and science communication. His work focuses on making complex scientific concepts understandable for everyone, with a special emphasis on forensic science and public awareness.
