Three-dimensional volumetric/linear analysis and axial classification of root resorptions using cone beam computed tomography: A retrospective study

Abstract

Objectives: The purpose of this study was to investigate the volumetric-linear analysis and to present a new axial classification of root resorptions using cone beam computed tomography (CBCT). Materials and Methods: A total of 43 teeth with root resorption (external cervical resorption (ECR) (n=27), external replacement resorption (ERR) (n=4) and internal root resorption (IRR) (n=12)) from 34 patients were included in this study. On CBCT images of teeth, the volume of total tooth and resorption for the volumetric analysis, the widest lengths of resorptions and the amount of thinnest dentin thickness around them for the linear analysis were measured, and volumetric/linear measurements were compared according to age and gender. In addition, the eight regional axial classification was performed, and these regions were compared. Data were evaluated using Shapiro-Wilk, Pearson’s r., Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner post-hoc tests. Significance was set at p=0.05 for statistical analysis. Results: No significant difference was found between the volumetric and linear measurements of ECRs, ERRs, and IRRs. No difference between genders in volumetric and linear measurements of ECRs and IRRs, except total tooth volume, was higher in males than in females in ECRs (p<0.05). With increasing age in ECRs, the buccal dentin thickness increased, and bucco-lingual length and total tooth volume decreased (p<0.05). In axial classification, ECRs were mostly found in lingual, while IRRs and ERRs did not show regional differences. Conclusions: Although root resorptions had different localizations and classifications, they did not differ in terms of volumetric and linear measurements due to having similar nature. Using CBCT imaging, the volumetric/linear analysis and axial classification of resorptions, and demographic differences according to these parameters can help clinicians in understanding the nature of resorption and in determining appropriate management.