Morphometric and morphological changes in the temporomandibular joint after orthognathic surgery: a magnetic resonance imaging and computed tomography prospective study.

The possible morphological and morphometric changes in the different components of the temporomandibular joint (TMJ) after orthognathic surgery were analysed using computed tomography (CT) transverse scans and sagittal and coronal magnetic resonance imaging (MRI) images. Twenty-four patients with class III dentofacial deformity were studied. Nine had isolated maxillary osteotomies and 15 had combined maxillary and mandibular subcondylar osteotomies (MSO). Ten patients were studied as a control group. The patients were studied clinically, radiographically and with CT and MRI in four different phases in order to locate the position of the mandibular condyle in relation to the glenoid fossa. No statistically significant differences were found in the group of patients who had had isolated maxillary osteotomies throughout the four phases of the study. Patients treated by bimaxillary surgery showed different condylar movements after surgery. Intra-articular effusion was evident during the early postoperative period in patients treated by bimaxillary surgery. Although different changes in the position of the bony components of the TMJ occurred after MSO, these seemed to be transient, with no major alterations in the final outcome in the patients.