Development and validation of the International Classification for Orofacial Pain Algorithm

Orofacial pain (OFP) encompasses a complex spectrum of conditions that present significant diagnostic challenges. The International Classification of Orofacial Pain (ICOP), introduced in 2020, offers a comprehensive diagnostic framework encompassing nearly 200 distinct OFP conditions. However, its detailed structure can impede practical use in clinical settings. To address this, we developed the International Classification of Orofacial Pain Algorithm (ICOP-AL), a flowchart-based tool designed to simplify the diagnostic process by methodically guiding users through ICOP's hierarchical criteria. International Classification of Orofacial Pain Algorithm integrates well-established diagnostic standards, including those from the International Classification of Headache Disorders, 3rd edition and Diagnostic Criteria for Temporomandibular Disorders, to enhance clinical applicability and diagnostic precision. The algorithm's validity was assessed in a study with 100 anonymized patient cases and further evaluated by clinicians across varied experience levels. The results demonstrated substantial agreement between ICOP-AL-derived diagnoses and expert clinician diagnoses (Cohen's Kappa κ = 0.688, P < 0.001), with ICOP-AL outperforming nonexpert evaluators, thereby underscoring its reliability and potential to standardize diagnostic outcomes across clinical environments. International Classification of Orofacial Pain Algorithm represents a promising step toward improving OFP diagnosis, providing a structured and accessible approach for integrating ICOP into routine clinical practice. Although early results are encouraging, further refinement and real-world validation, particularly for more detailed diagnoses, are necessary to determine its full potential as a diagnostic and educational tool.