Relationship between condylar position, dentofacial deformity and temporomandibular joint dysfunction: an MRI and CT prospective study.

The possible relationship between the morphometric characteristics (condylar and temporomandibular joint (TMJ) disc position) of the TMJ and the TMJ clinical findings (normal versus TMJ disorders) in different types of dentofacial deformities was studied. Forty-eight patients with dentofacial deformities (96 TMJs) were investigated preoperatively and 10 patients (20 TMJs) without deformities were studied as a control group, clinically and radiographically, using computer tomography (CT) and magnetic resonance imaging (MRI), to assess the position of the mandibular condyle and the TMJ disc in the sagittal, coronal and horizontal planes. Fifteen of the 28 joints (53.6%) of patients diagnosed as class II dentofacial deformity had internal derangements and anteriorly displaced discs. The incidence of internal derangement in the class I and class III groups was lower (10%). An increased horizontal angle of the mandibular condyle and a posteriorly seated condyle were found in patients diagnosed as class II dentofacial deformity when compared with the control group. The rest of the patients studied showed no significant differences. The same results were encountered when the patients with moderate to severe TMJ pathology were studied, both clinically (using the Helkimo index modified by Athanasiou) and by MRI.