Assessing Mandibular Condylar and Coronoid Pathologies: A Computed Tomography-Based Normalization Approach

This study aimed to establish a CT-based normalization protocol for the mandibular condylar (CoP) and coronoid (CrP) processes and to determine whether pathology-specific patterns can be distinguished from physiologic variation. Retrospective CT data of 251 patients without mandibular pathology (502 hemi-mandibles) were analyzed. Posterior mandibular height (PMH) was defined as the distance between the mandibular angle tangent and the deepest point of the mandibular notch. CoP and CrP lengths were measured perpendicular to this baseline and expressed as CoP/PMH and CrP/PMH ratios. Additional CT scans of patients with coronoid hyperplasia (n=7; 12 sides), condylar hyperplasia (n=8; 9 sides), and condylar resorption (n=7; 10 sides) were evaluated, and associations between pathology and normalized ratios were examined using linear mixed-effects models. In the control group, both ratios showed narrow prediction intervals and defined reference values. Coronoid hyperplasia was associated with a significantly increased CrP/PMH ratio, condylar hyperplasia with an increased CoP/PMH ratio, and condylar resorption with a decreased CoP/PMH ratio, demonstrating distinct, pathology-specific measurement patterns. Normalizing posterior mandibular process lengths to PMH effectively reduces interindividual variability and differentiates physiologic from pathologic changes on routine CT. The protocol is applicable to both CT and CBCT and may support earlier recognition and monitoring of mandibular alterations. Larger prospective studies and correlation with clinical severity and functional imaging are needed to refine diagnostic thresholds and further standardize quantitative craniofacial assessment.