Faces of Pain during Dental Procedures: Reliability of Scoring Facial Expressions in Print Art

Background: Observational tools have been developed to assess pain in cognitively impaired individuals. It is not known, however, whether these tools are universal enough so that even pain depicted in print art can be assessed reliably. Therefore, the aim of this study was to assess the reliability in scoring facial expressions of pain in dental print art from the 17th, 18th, and 19th century, using a Short Form of the 15-item Pain Assessment in Impaired Cognition (PAIC15-SF) tool. Methods: Seventeen prints of patients undergoing dental procedures were scored twice by two inexperienced observers and an expert and once by a Gold Standard observer. Results: All observers achieved high intra-observer reliability for all four items of the category “facial expressions” and for three items of the category “body movements” (ICC: 0.748–0.991). The remaining two items of the category “body movements”, viz., “rubbing” and “restlessness”, were excluded from further research because it was not possible to calculate a reliable ICC. Overall, the intra-observer reliability of the expert was higher than that of the inexperienced observers. The inter-observer reliability scores varied from poor to excellent (ICC: 0.000–0.970). In comparison to the Gold Standard, the inter-observer reliability of the expert was higher than that of the inexperienced observers. Conclusion: The PAIC15-SF tool is universal enough even to allow reliable assessment of facial expressions of pain depicted in dental print art.