New glossary standardises root canal anatomy terms

Iveta Ramonaite, Dental Tribune International

Fri. 16. October 2026

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KUALA LUMPUR, Malaysia/DUBLIN, Ireland: Some terms used to describe root and canal anatomy are defined inconsistently in the literature, and the same anatomical features are often described using different terms. This can create confusion in clinical communication, dental education and research reporting, making it difficult to compare findings across studies. To address these inconsistencies, an international panel of experts has developed a consensus-based glossary covering 15 terms that were identified as requiring clarification or standardisation. The resource aims to establish shared terminology for endodontic practice, education and research.

Dr Hany Mohamed Aly Ahmed highlighted the roles of researchers, educators, journal editors and professional societies in promoting its use in scientific reporting, teaching and clinical practice. (Image: Dr Hany Mohamed Aly Ahmed)

“The initiative arose from a broader recognition that several terms used across endodontics lack universally accepted definitions, despite terminology being fundamental to accurate scientific and clinical communication,” lead author Dr Hany Mohamed Aly Ahmed, an associate professor of endodontics in the Faculty of Dentistry at Universiti Malaya in Malaysia, told Dental Tribune International.

He explained that a 2024 narrative review he co-authored had identified considerable inconsistency in how anatomical structures and variations are described in the growing body of literature on root and canal anatomy. Terms relating to accessory canals, canal isthmuses and pulp chamber anatomy, for example, have been used or defined differently by different authors. Such inconsistency can hinder comparisons between anatomical studies. It can also make it more difficult for educators and students to develop a shared understanding of root canal morphology.

“Clinically, ambiguous terminology may hinder communication between practitioners and other stakeholders. The glossary was therefore intended to provide internationally agreed, precise definitions that could serve as a common language across research, education and clinical practice,” Dr Ahmed explained.

Drawing on the terminology identified in the narrative review, a seven-member working group compiled an initial list of 15 terms and proposed definitions. An international panel of 32 experts then independently assessed their clarity and suitability for inclusion in the glossary through an iterative consensus process.

The glossary addresses different types of terminological inconsistency. For example, “canal isthmus” and “transverse canal anastomosis” have sometimes been used interchangeably, although they describe distinct anatomical features. It also recommends “pulp chamber ceiling” instead of “pulp chamber roof” for more appropriate terminology, as well as “minor apical foramen” and “major apical foramen” instead of “minor apical diameter” and “major apical diameter”, respectively, to distinguish anatomical structures from measurements. The glossary also replaces “root dilaceration” with “severe root curvature” because the former derives from a Latin term meaning “to tear apart”, which is not relevant to most teeth.

“When investigators apply the same terminology and definitions, anatomical findings obtained using different populations and different methodologies can be interpreted and compared accurately,” co-author Dr Henry F. Duncan, an associate professor at Trinity College Dublin and consultant in endodontics at the Dublin Dental University Hospital, told Dental Tribune International.

“Clinically, ambiguous terminology may hinder communication between practitioners and other stakeholders.”—Dr Hany Mohamed Aly Ahmed, Universiti Malaya in Malaysia

He noted that when studies use different imaging technologies, inconsistent terminology can make it difficult to determine whether differences in their findings reflect actual anatomical variation or differences in how structures are defined and described. Adopting the glossary’s definitions could therefore facilitate more accurate comparisons between laboratory and clinical studies and improve the reliability of future systematic reviews and meta-analyses.

“Consistent terminology can additionally strengthen reproducibility by ensuring that investigators are measuring and reporting equivalent anatomical entities. Ultimately, widespread adoption should improve the methodological and reporting quality of root and canal anatomy research,” he commented.

According to Dr Henry F. Duncan, standardised definitions could strengthen research reproducibility and support more reliable systematic reviews and meta-analyses. (Image: Paul Sharp/SHARPPIX)

According to Dr Ahmed, the next step is to encourage widespread adoption of the glossary. Researchers can incorporate the agreed terminology into study protocols, data presentations and manuscript reporting. Journal editors and reviewers may also encourage authors to use standardised definitions when reporting root and canal anatomy. In education, the terminology could progressively be incorporated into undergraduate and postgraduate curricula and teaching materials, helping students learn a consistent language from the outset. Clinical adoption can similarly be supported through continuing professional education and professional societies.

The root and canal anatomy glossary is part of a broader initiative proposed in 2023 by Dr Ahmed, Dr Duncan and three colleagues to develop a series of consensus-based glossaries addressing controversial terminology in different areas of endodontics. The researchers hope that this work will provide a model for further international consensus initiatives aimed at improving clarity and consistency across the specialty.

The research is being highlighted ahead of World Endodontic Day on 16 October, an annual observance dedicated to raising awareness of endodontics and its vital role in preserving natural teeth. The initiative highlights the importance of continued advances in endodontic research, education and clinical practice.

The article, titled “A consensus-based glossary for controversial terminology in root and canal anatomy”, was published online on 26 August 2026 in the International Endodontic Journal, ahead of final publication.