Unilateral condylar bone change, inclination of the posterior slope of the articular eminence and craniofacial morphology

The purpose of this study was to investigate the association of frontal and lateral craniofacial morphology with the inclination of the articular eminence and TMJ pathology, in orthodontic patients with TMJ disorders and unilateral condylar bone change, using helical CT scans.Fifty-nine female patients were divided into a unilateral condylar bone change (UBC) group (39 subjects) and a no condylar bone change (NBC) group (20 subjects). Lateral and frontal cephalograms and panoramic radiographs were taken to evaluate their craniofacial morphology, and condylar and ramal heights. All subjects had CT scans taken to evaluate their TMJs. The inclination angle of the posterior slope of the articular eminence was then measured using National Institute of Health software.CT and cephalometric measurements showed that articular eminence inclination was significantly smaller on the affected side than on the non-affected side (p < 0.0001), and that the mandible deviated to the ipsilateral side in UBC, with decreased condylar height and more inclined frontal maxillary, interocclusal and gonial planes (p < 0.0001). The difference in articular eminence inclination was correlated significantly with UBC (p < 0.05).These results suggested that asymmetrical frontal craniofacial morphology could be clinical indicators of unilateral condylar bone change and remodeling of the articular eminence.