The teeth marks on the teeth of a hominid OH1 at least 12,000 years old from Olduvai were likely the result of this individual's facial modification (probably a piercing), according to the American Journal of Physical Anthropology. It was previously thought that they appeared due to the abundance of coarse plant foods in that person's diet. If the anthropologists' assumptions are correct, then the remains of OH1 are the second oldest known case of body modification and the oldest found in Africa.
In 1913, the German anthropologist Hans Reck discovered in the Olduvai Gorge in Central Africa an almost complete skeleton of a modern-day man - a man who at the time of his death was 20–35 years old. These were the first human remains found in the area. The dating of the find has long been a subject of controversy, and a comprehensive analysis of the morphometric parameters of the skeleton has not been carried out for a long time.
In 1993, another anthropologist from Germany, Franz Parsche, examined the condition of an individual's teeth (it came to be identified as OH1, Olduvai Hominid 1) and noticed that the front incisors bear on their labial surface (closer to the lips than to the tongue) traces of severe wear and tear, such as were not observed in any other African remains of ancient people. Scab, like his predecessors, attributed the damage to the individual's plant-based diet: in theory, coarse fibers could erase enamel down to dentin.
Now anthropologists from the University of Coimbra, the Catalan Institute of Human Paleoecology and Social Evolution and the University of Bordeaux, led by John C. Willman, have revisited the reasons for the OH1's unusual tooth wear. Wilman previously examined the skulls of Aboriginal Canada and saw similar bevels on the front of the incisors in those who wore body piercings during their lifetime.
Wilman and colleagues determined the lengths and ratios of many measurements of OH1 teeth and compared them with those known for other remains of people from Africa of a similar age (12–20 thousand years). They noticed that not only in the incisors, but also in the molars and premolars (molars and false teeth), the labial surfaces on the right and left sides were worn down to dentin. Similar injuries were not found in other African hominids of that time.

Abrasion marks on incisors (a, b) and canine (c) OH1 (scanning electron microscopy). Scale line 1 cm
Vegetable fibers contain a lot of cellulose and silicon, which can be difficult to chew. Herbivorous mammals have special adaptations for eating such food - in particular, the continuous growth of teeth in rodents and ungulates. In humans, teeth are not renewed in this way and with an abundance of coarse leaves in food they grind off, but not from the front side, but from the one that is closer to the tongue.
It is inconvenient to hold blades of grass, threads, twigs and similar objects between the cheek and teeth in order to somehow process them, so it is doubtful that the grooves on the OH1 tooth enamel appeared for this reason. But facial modifications, in particular piercing with the use of labrettes, were common among the indigenous peoples of Canada, and the marks from its long wearing are also depressions on the labial surface of the teeth.
The authors speculate that the Olduvai man wore one labret in the front in the lower lip and another in the cheeks on each side. However, if these labrettes existed, they have not survived. Nevertheless, if the assumptions of scientists are correct, OH1 becomes the oldest owner of a hominid piercing, whose remains have been found so far in Africa, and the second oldest in the world. The oldest traces of body modifications of this kind are found only in the skeleton from Dolny Vestonice (Czech Republic). They are over 25,000 years old.
Olduvai Gorge is a key site for paleoanthropology. It was there in the 1960s that a skilled man (Homo habilis) and the primitive stone tools that he made were found. Recently it became clear that, despite their simplicity, these "tools" were created for specific tasks that determined the choice of material for the tool.