A Test of Dental Ablation Scoring Criteria

Intentionally modified teeth provide a durable record of past identities, but their identification in archaeologi-cal samples has been inconsistent. This study assesses common diagnostic criteria for identifying intentional dental ablation by testing for false-positive cases of ablation in a control group of non-human primates where no true cases of dental ablation are expected. The primary author observed the dentition of 849 non-human pri-mates from the National Museum of Natural History's Division of Mammals, including great apes, lesser apes, and relatively large- bodied, Old-World monkeys. A smaller sample was selected for further study based on an-temortem tooth absence and collection history. Seven different methodologies using combinations of six diag-nostic criteria for the identification of dental ablation were chosen from a sample of published studies. To determine which criteria combinations may have falsely identified dental ablation in these specimens were they human, the non-human primate control group was analyzed based on anterior tooth loss, lack of disease, sym-metry of loss, full healing of the alveolus, lack of evidence for trauma, and normal tooth spacing. All scoring methodologies produced false-positive results, many diverging significantly from expected results. Dental abla-tion was falsely identified in 2-17% of the non-human primate control group, with the highest false-positive rates when symmetry or normal spacing were not included as discriminating criteria. This work demonstrates the necessity for thorough and descriptive methodologies for replicability to be possible. It also highlights the importance of symmetry and tooth spacing as diagnostic criteria to avoid false positives.