Mehrgarh is a Neolithic (7000-3200 BC) site on the Kachi plain of Baluchistan, Pakistan, and one of the earliest sites with evidence of farming (wheat and barley) and herding (cattle, sheep and goats) in south Asia. The site is located on the principal route between what is now Afghanistan and the Indus Valley.
According to a report in the April 6, 2006 issue of Nature, Italian researchers working at a cemetery site in the Neolithic town of Mehrgarh discovered drill holes on at least eleven molars from people buried in the MR3 cemetery. Light microscopy showed the holes were conical, cylindrical or trapezoidal in shape. A few had concentric rings showing drill bit marks; and a few had some evidence for decay. No filling material was noted; but tooth wear on the drill marks indicate that each of these individuals continued to live on after the drilling was completed.
Dental caries (or cavities) are the result of sugars and starches in the food we eat. Hunter-gatherers, who rely on animal protein, do not generally have cavities; cavities associated with the use of roots and tubers, or starchy grains (Walker and Erlandson 1986).
Drills and Drilling in PrehistoryResearchers point out that only four of the eleven teeth contained clear evidence of decay associated with drilling; however, the drilled teeth are restricted to molars in the back of both lower and upper jaws, and thus are not likely to have been done for decorative purposes. Flint drill bits are known from Mehrgarh, long associated with the bead industry there. The researchers conducted experiments and discovered that using a flint drill bit attached to a bow-drill, it required under a minute to produce similar holes in human enamel.
The dental techniques have only been discovered on about .3% of the population (11 teeth out of a total of 3880 examined from 225 individuals studied to date), so it was a rare occurrence, and, appears to have been a short-lived experiment as well. Although the MR3 cemetery contains younger skeletal material (into the Chalcolithic), no evidence for tooth drilling has been found later than 6500 BP.
For a larger view of the figure, see Early Dentistry: Neolithic Dental Surgery at Mehrgarh.
ReferencesCoppa, A., et al. 2006. Early Neolithic tradition of dentistry. Nature 440(6 April 2006):755-756.
Walker, Philip L. and Jon M. Erlandson 1986 Dental evidence for prehistoric dietary change on the northern channel Islands, California. American Antiquity 51(2):375-383.