Does the 2018 periodontal classification improve patient understanding? A missing piece in periodontal care

The 2018 AAP/EFP Classification of Periodontal Diseases introduced staging and grading to improve the description of periodontitis severity and factors associated with disease progression. Although widely adopted in clinical and research settings, its validation has focused mainly on inter-examiner agreement, diagnostic concordance and prognostic performance, with limited evidence on patient-centred outcomes such as comprehension, recall and behavioural relevance. Available studies suggest that patients retain staging and grading poorly and instead rely on observable and functional indicators of disease, indicating a potential mismatch between clinical constructs and patient-relevant information for decision-making. This article examines the 2018 classification from a communication perspective, distinguishing diagnostic validity from communicative validity and evaluating whether extent, stage and grade can meaningfully support patient understanding. A pragmatic conceptual model reframes these constructs as communication components describing disease distribution, current burden and progression risk. Overall, although the 2018 system provides a structured framework for periodontal classification, its effectiveness as a communication tool remains uncertain. Future research should investigate how periodontal information can be structured to improve comprehension, recall and informed decision-making in practice.