New International Classification of Orofacial Pain: What Is in It For Endodontists?

Maria Pigg, Donald R. Nixdorf, Alan S. Law, Tara Renton, Yair Sharav, Lene Baad-Hansen, Thomas List

Research output: Contribution to journalReview articlepeer-review

21 Scopus citations


Pain is a common symptom in endodontic conditions, but differential diagnostic procedures are often needed to exclude other pain origins. Thus, general dentists and endodontists need to be aware of alternative painful orofacial conditions and be able to identify them. The new International Classification of Orofacial Pain (ICOP) is the first comprehensive classification that uniquely deals with orofacial pain. The ICOP is a hierarchical classification modeled on the International Classification of Headache Disorders and covers pain in dentoalveolar and anatomically related tissues, muscle pain, temporomandibular joint pain, neuropathic pain affecting cranial nerves, pain resembling primary headaches, and idiopathic pain in the orofacial region. A description of each condition is given, and structured diagnostic criteria for each condition are proposed based on research data when available. This narrative review aims (1) to give an overview and brief explanation of the ICOP system, (2) to describe and give examples of how it can be of use to general dentists and endodontists with special attention to differential diagnosis of tooth pain, and (3) to highlight how endodontic research can contribute to validation and improvement of the classification. A comparison to other classification and diagnostic systems is also included.

Original languageEnglish (US)
Pages (from-to)345-357
Number of pages13
JournalJournal of Endodontics
Issue number3
StatePublished - Mar 2021

Bibliographical note

Funding Information:
The authors wish to acknowledge the co-chairmen of the Orofacial Pain Classification Committee, Drs Rafael Benoliel (United States), Arne May (Germany), and Peter Svensson (Denmark), for their engaged leadership in developing the ICOP and the members of all workgroups for their expertise and extensive work. The collaborating associations providing support were the Orofacial and Head Pain Special Interest Group of the International Association for the Study of Pain, the International Network for Orofacial Pain and Related Disorders Methodology of the International Association of Dental Research, the American Academy of Orofacial Pain, and the International Headache Society. We also wish to thank Dr Mark Jurkovich, for his support in the discussion related to SNODENT. Dr Jurkovich leads the International Health Terminology Standards and Development Organization's Dentistry Clinical Reference Group. The Clinical Reference Group provides expertise in the development of Systematized Nomenclature of Medicine Clinical Terms terminology related to dental care. He is also a member of the Standards Committee on Dental Informatics. The authors deny any conflicts of interest related to this study.

Publisher Copyright:
© 2020 The Authors

Copyright 2021 Elsevier B.V., All rights reserved.


  • Classification
  • diagnostic criteria
  • differential diagnosis
  • pain
  • taxonomy

PubMed: MeSH publication types

  • Journal Article
  • Review


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