In a new analysis of thousands of teeth from ancient skeletons buried at a site near Naples (Italy), archaeologists have discovered that people were using their mouths to help with their work - occupations that likely involved processing hemp into string and fabric.
     To archaeologists, the pattern of tooth use that occurs from actions other than chewing is called AIDM -- activity-induced dental modification -- and can reveal cultural information about a person's life, diet, and occupation.
     A group of Italian and American researchers led by Alessandra Sperduti of the Museo delle Civiltà in Rome analysed more than 3,000 teeth from over 200 people who were buried in a cemetery at the Early Bronze Age (2500-1800 BCE) site of Gricignano d'Aversa just north of Naples.
     Sperduti and colleagues found grooves near the chewing surfaces of the teeth of 28 females and 1 male, and further learned that no children under the age of 15 had any evidence of AIDM. The pattern of the grooves is "consistent with the hypothesis of yarn production - or weaving preparation - of small-diameter threads," they note, which were repeatedly pulled across the fronts and sizes of the women's upper incisors and canines. The striking difference in number of women versus men found to have these grooves indicates "a clear gender division in the fiber manipulation."
     The researchers also analyzed the dental calculus - calcified plaque that can trap microscopic pieces of food - from 19 of the skeletons buried in the cemetery."The most interesting find," they write, "is the evidence of three micro-fragments of fibers in two female individuals." The fiber fragments appear to be hemp (Cannabis sp.), and are a perfect match for the width of the tooth grooves.
     It is unclear archaeologically exactly how old hemp production in ancient Italy is, since the fiber does not preserve well, but it was well known in Roman times. At the site of Gricignano d'Aversa, though, hemp was also found attached to a metal blade in the tomb of an adult male - likely the remains of fabric sheath. This discovery of hemp in dental calculus and in a burial at the same site therefore speaks to the importance of the fabric and its manufacture in Bronze Age southern Italy.
     Sperduti and colleagues conclude that "as more work is done analyzing dental calculus in a variety of humans, it is apparent that this biological material holds rich resources documenting non-dietary habits."

Edited from Forbes (30 August 2018)