Evaluation of the effect of different mandibular fractures on the temporomandibular joint using magnetic resonance imaging: five years of follow-up.

A prospective cohort study was performed to investigate concurrent and delayed temporomandibular joint (TMJ) injuries following different types of mandibular fracture using magnetic resonance imaging (MRI). One hundred adult male patients with a recent history of mandibular fracture were included. The patients were divided into five groups according to the site of fracture. The patients underwent MRI within 10 days of the primary injury. The same clinical, radiographic, and MRI examinations were performed 5 years later. The aetiological factor of the mandibular fractures was a road traffic accident in all cases. The results of the study suggest that there is no direct correlation between TMJ pain and the presence of MRI changes. Patients who had a condylar fracture associated with a fracture of the angle or body could develop more TMJ damage on both sides. TMJs on the same side as the fractures could develop internal derangement as a result of the acute stage of the trauma and its delayed consequences. Trauma caused more delayed TMJ derangement on the non-fractured side than on the fractured side of the mandible. Disturbances of the TMJ on the side of the fracture develop during both the acute stage and follow-up.