Early Dentistry: Evidence for Neolithic Dental Techniques

Evidence of dentistry has been identified at a cemetery in the Neolithic site of Mehrgarh, Pakistan, on eleven teeth from different individuals between 7500 and 9000 years ago.

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 prehistoric route between the Indus Valley civilizations and civilizations to the east towards what is now Afghanistan.

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. MR3 is the desigation archaeologists have given to that part of Mehrgarh with the earliest occupations, between 7500 and 9000 years ago. Light microscopy showed the drill holes were conical, cylindrical or trapezoidal in shape. A few had concentric rings, possibly evidence of drill bit wear; 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 are associated with diets including roots and tubers, or starchy grains (Walker and Erlandson 1986). Thus, the presence of cavities in a individual is an indicator of a diet that includes some starch or sugar; this has been used archaeologically as a possible indication that populations relied on agricultural products.

Drills and Drilling in Prehistory

Researchers 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.

The images on this page were produced for the Nature paper by L. Bondioli (Museum L. Pigorini, Rome) & R. Macchiarelli (Univ. of Poitiers). The top picture is a photograph of a molar from an adult male (MR3-90), showing two drill scars. The middle picture is a scanning electron microscope image of the two drill holes. The lower picture is a microtomographic image of the tooth. For a larger view and detailed data on the figures, see Early Dentistry: Neolithic Dental Surgery at Mehrgarh.

References

Coppa, 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.

A story about this has broken on Wired, of all places. Also, a brief comment by afarensis on Anthropology.net, who reports on a story in National Geographic.