Prognostication of External Cervical Resorption Based on Heithersay's and Patel et al. Classifications: A Narrative...

External cervical resorption (ECR) is a relatively rare form of tooth resorption. It is commonly classified either using two-dimensional imaging according to the Heithersay or cone-beam computed tomography using the Patel et al.

Effective disease classification systems should provide categories that guide clinical decision-making and support the prediction of management outcomes. This principle should apply to the classification systems for ECR.

To assess the association between Heithersay's and Patel's classification systems and the recently proposed core outcome set measures for endodontic treatment.

A narrative review study type was adopted due to the anticipated heterogeneity regarding clinical management. An electronic citation search of the studies by Heithersay 1999 and Patel et al. 2018 was made on 17 September, 2025 in three electronic databases (PubMed, Web of Science, and Scopus) for cohort studies that included various categories of the classifications. No language or publication date restrictions were applied. Articles were excluded when inclusion criteria were not met. Four clinical registers were searched for emerging evidence using the same criteria. The main features of the study were extracted, tabulated, and a narrative summary was made. Two authors contributed to the process independently.

Searches of the databases and clinical trials registers yielded six and nil studies, respectively. The identified studies originated from seven countries, were mostly set in postgraduate teaching clinics and were published within the past five years. The recall periods extended up to 10 years with all six studies using Heithersay's classification, with three also using Patel's classification. In total, 657 teeth were assessed against Heithersay's classification and 128 also assessed with Patel's. The three studies that included both classifications had relatively limited sample sizes and relatively short final recall periods. An association between Heithersay's classification with outcomes was evident; Classes I and II were associated with high rates of survival and 'success', and Class IV the opposite. No association was found between Patel's classification with outcomes.

The available literature supports an association between Heithersay's classification with management outcomes for ECR. There is insufficient evidence to assess Patel's classification regarding prognostication.