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Finding Mr X: What did the teeth reveal?

What clues could the teeth reveal about the identity of Mr X?
© The University of Sheffield

In this article, we’ll discover what clues forensic odontology could provide about the identity of Mr X.

Age

Dental eruption is particularly important in attempting to age the skeleton of a child, but in adulthood, the extent of tooth wear can also provide clues.

One of the best approaches is to measure tooth root translucency. As we age, we lose density in our teeth and by taking thin sections of the roots and measuring the amount of light that passes through them, an estimate of age can be made. Combined with his examination of the pelvis, Professor Evison was able to confirm the man was at least middle-aged and estimate that he could have been over 60 years old.

This is a replica of Mr. X’s demonstrating significant tooth loss of adult teeth This is a replica of Mr. X’s demonstrating significant tooth loss of adult teeth

Habitual behaviour

An unusual habitual activity had worn his molars down and had caused some of his tooth enamel to dissolve. He had clearly chewed something regularly that was causing both physical and chemical abrasion of his teeth. Did he constantly chew tobacco or something similar?

Put together with the partial DNA evidence, it was surmised that the substance he could have chewed was khat. Khat chewing is a habit that is associated with enamel demineralisation. This is used by millions of people especially in Yemen and East African countries.

Khat (Catha edulis) is an ever-green shrub habitually chewed by inhabitants in these regions because of their psycho-stimulant effect. As a result it forms a bolus that is held in one side of the mouth. This habit has clear implications in oral health including oral pigmentation and Keratotic white lesions that can develop into more serious diseases. Moreover, dental discoloration and evidence of periodontal disease was found in some areas of the oral cavity.

In this video clip, DI Cousins explains how khat provided a vital clue for the investigation.

This is an additional video, hosted on YouTube.

Dental charting

Dental charting is a graphic representation of teeth on paper. Dentists and dental assistant will look into the patient’s mouth and perform an examination of the soft tissues, missing and present teeth, and record existing cavities and restorations.

This information will be complemented by dental x-rays and a history of the general health of the patient. These records need to be up to date to be able to facilitate the identification of an individual.

Mr X’s dental chart showed missing teeth, dental wear and evidence of periodontal disease.

Mr X's dental chart which shows a number of teeth are absent (Click to expand this image)

If you’d like to find out more about dental charting, this article from our course Discover Dentistry provides a good summary.

© The University of Sheffield
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