Evaluation of congruency of condyle convexity and fossa concavity and interrelationship bony components in temporomandibular joint anterior dislocation.

Abstract

This study aimed to compare the congruency of surface geometry of the articulating bones and morphologic differences in temporomandibular joint (TMJ) structure, between patients with TMJ anterior dislocation and healthy controls. The study included 15 patients with TMJ anterior dislocation and 15 controls who underwent cone-beam computed tomography. The surface angle of the articular fossa (fossa-concavity) and condyle (condyle-convexity) and joint spaces were measured from both sagittal and coronal views. The articular eminence morphology and horizontal condyle position were also evaluated. Coronal fossa angles were significantly lower in controls than in patients (p < 0.05). There was a positive correlation between coronal condyle and fossa angle values in controls and in patients' joints (p < 0.05), however, the fossa-condylar congruence was higher in controls than in patients. Superior joint space was significantly higher in controls than in patients (p < 0.05). There were no significant differences in articular eminence measurements, mean condyle angle variables and condyle position between the patients and controls (p > 0.05). The findings of this study which include lower joint congruency, higher fossa concavity and superior joint space distance in patients with anterior dislocation may be related to the inferior positioning of the condyle away from the fossa and potentially the elongation of the capsular ligament.