UK researchers initially set out to investigate whether cementum rings—similar to tree rings—could be used in forensic settings to estimate a person’s age when DNA is not available. But what they discovered was something entirely different.
The study, published in the journal PLOS ONE, found that smokers and ex-smokers exhibited signs of disruption in the cementum rings of some teeth—disturbances that were not observed in non-smokers, according to Northumbria University. Cementum, the calcified tissue covering the tooth root, forms annual growth rings that can be analysed to estimate age or detect physiological stressors, including, as this study shows, the long-term impact of smoking.
These disruptions appeared as irregularities in the thickness and pattern of the rings within the teeth.
“Smoking is known to have a systemic impact on the body, and numerous studies have highlighted the correlation between smoking, periodontitis and tooth loss,” said Dr. Valentina Perrone, now a research assistant at the University of Leicester. “This study shows, for the first time, the biological record of smoking-related oral health damage within the dental structure.”
The researchers observed evidence of smoking-related damage in 70 per cent of ex-smokers and 33 per cent of current smokers, compared to just 3 per cent of non-smokers. In total, 88 teeth were examined from both living dental patients and archaeological remains.
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Same signs in teeth from three centuries ago
Researchers also found that cementum analysis of archaeological samples showed the same ring disruptions in the teeth of smokers who died in the 18th and 19th centuries as in those of living donors who were current or former smokers.
“Our research shows that it’s possible to tell if someone was a smoker just by examining their teeth,” said Dr. Ed Schwalbe, associate professor in Northumbria’s Department of Applied Sciences. “We found that the regular annual deposition of rings was disrupted for some individuals and realised that these disruptions were associated with current or ex-smokers, but were very rare in non-smokers.”