EARLIEST EVIDENCE OF PROTO-DENTAL TREATMENT IN THE LATE UPPER PALEOLITHIC

Prehistoric dental treatments have been known from the Neolithic - 9,000-7,500 years before present (BP) -, when the adoption of early farming culture caused an increase of carious lesions. They were extremely rare, and the few documented cases were characterized by in vivo perforation of the crown surface made by a drilling tool. Here we document the earliest evidence of proto-dental therapeutic intervention on a Late Upper Paleolithic (ca. 14,000 yr BP) modern human specimen from a burial in Northern Italy (Villabruna shelter). Using Scanning Electron Microscopy (SEM) we show the presence of striations deriving from the manipulation of a large occlusal carious cavity of the lower right third molar. The striations have a “V’’-shaped transverse section and several parallel micro-scratches at their base, as typically displayed by cutmarks on teeth. Based on in vitro experimental replication and a complete functional reconstruction of the Villabruna dental arches, we confirm that the identified striations and the associated extensive enamel chipping on the mesial wall of the cavity were produced ante-mortem by pointed flint tools during scratching and levering activities. The Villabruna specimen is therefore the oldest known evidence of dental caries intervention, suggesting rudimentary knowledge of disease treatment well before the Neolithic. This study also suggests that primitive forms of carious treatment in human evolution entail an adaptation of well-known toothpickings for levering and scratching rather than drilling practices.