Objective:This study aimed to evaluate and compare the extent of orthodontically induced inflammatory root resorption (OIIRR) in patients treated with clear aligners (Invisalign) versus self-ligating fixed appliances (Damon Ultima), using three-dimensional volumetric analysis via cone-beam computed tomography (CBCT) and artificial intelligence-assisted diagnostic software. Methods: A retrospective cohort design was used to assess root resorption in 70 orthodontically treated patients (50 with Damon Ultima and 20 with Invisalign) and 10 untreated control subjects. Pre- and post-treatment CBCT scans were analyzed using Diagnocat, an artificial intelligence (AI) platform, to quantify root volume changes. A total of 1,078 teeth from the experimental group and 251 teeth from the control group were included. Root volume loss was expressed as a percentage of pre-treatment volume. Cephalometric and occlusal parameters, including overjet, overbite, upper and lower incisor proclination, and Wits appraisal, were analyzed for correlation with resorption. Statistical analyses included Wilcoxon rank-sum, Kruskal-Wallis, and Spearman correlation tests. Results: Root resorption was observed in all groups, including controls, though to varying degrees. The Invisalign group exhibited the highest median root volume loss (–0.03%), followed by the Damon group (–0.008%) and the control group (–0.002%) (p = 0.02). Despite statistical significance, all values remained clinically minimal. No significant correlation was found between resorption and patient age, gender, or treatment duration. Certain teeth demonstrated increased susceptibility to resorption depending on the treatment modality: mandibular first molars in Invisalign, and mandibular premolars and canines in Damon Ultima. Vertical overbite changes, particularly in tooth #20, were significantly associated with increased OIIRR in the Invisalign group (p = 0.036), suggesting system-specific biomechanical influences. Conclusions: While Invisalign was associated with a slightly greater degree of root resorption compared to Damon Ultima and control groups, the differences were not clinically significant. Root resorption was not influenced by treatment time or demographic variables, highlighting the importance of biological and tooth-specific factors. This study supports the integration of CBCT and AI diagnostics in orthodontic research and clinical care to enhance the accuracy of OIIRR assessment. Further research should focus on aligning tooth movement data with root changes and expanding AI capabilities for routine orthodontic evaluation.