London: Scientists have found the earliest evidence for widespread tooth decay in humans - in a group of Stone-Age hunter-gatherers living in Morocco more than 13,700 years ago.
The skeletal remains of the Moroccan Stone Age hunters suggest that the individuals were eating a lot of high-carbohydrate nutty foods.
The poor condition of their teeth suggests that besides pain, the individuals on occasion probably had extremely bad breath.
"At a certain point, the tooth nerve dies but up until that moment, the pain is very bad and if you get an abscess the pain is excruciating because of the pressure on the jaw," said Dr Louise Humphrey, from London`s Natural History Museum.
"Then, of course, the bone eventually perforates and the abscess drains away, and we see this in a lot of the jaw remains that we studied," Humphrey said.
Scientists reviewed the dental condition of 52 skeletons dug up at the Grotte des Pigeons complex at Taforalt in eastern Morocco over the past 10 years.
These skeletons covered a period from 13,700 years ago to about 15,000 years ago.
Except for three individuals all displayed tooth decay, with cavities or other lesions affecting more than half of the surviving teeth. In some individuals, the oral health was so bad that destructive abscesses had developed.
Wild plant remains at Taforalt indicate these Stone Age people were snacking frequently on sweet acorns, pine nuts and pistachios. Snails were also popular.
With little if any oral hygiene, the Taforalt diet would have fuelled the mouth bacteria that produce the acid that rots tooth enamel.
The new study is interesting as it identifies high rates of tooth decay several thousand years before the wide-scale adoption of agricultural practices, `BBC News` reported.
It is clear the Taforalt individuals practiced cultural modification of the teeth. In more than 90 per cent of cases, one or both upper-central incisors (the top front teeth) had been removed. Whether rotten teeth were also removed is uncertain, however.
"You don`t normally get bad decay on the upper-central incisors, so this must have been a ritual removal. Why they did it, we don`t know; and so although they obviously knew how to remove teeth, we don`t have the evidence to say they were also removing unhealthy teeth," Humphrey said.
The study was published in the PNAS journal.