Evaluation of structural skeletal asymmetry of the glenoid fossa in adult patients with unilateral posterior crossbite using surface-to-surface matching on CBCT images

Objectives: To compare, using surface-to-surface (StS) matching, any shape differences between the crossbite and noncrossbite side of the glenoid fossa and articular eminence in adult patients affected by posterior unilateral crossbite (PUXB) and compare them with unaffected controls. Materials and Methods: 32 cone beam computed tomography (CBCT) scans of patients (mean age: 23.72 6 3.74 years) undergoing surgical maxillary expansion were analyzed to obtain three-dimensional models of the left and right glenoid fossae that were superimposed using stable anatomical reference points and then compared using StS matching to evaluate the presence of any shape differences. These findings were compared with those obtained from 16 CBCT scans of unaffected controls (mean age: 23.72 6 3.73 years). Results: A mean difference of .11% was found between the study group and controls when comparing the matching percentages of the two sides of the glenoid fossa and articular eminence at all three levels of tolerance selected for this study. These differences were found to be highly statistically significant (P ≤ .0001). Conclusions: According to the shape analysis findings, adult PUXB patients exhibit a higher degree of glenoid fossa and articular eminence shape differences compared to unaffected controls.