Effects of Fixed Functional Appliance Therapy on Temporomanibular Joint Assessed by MRI: A Literature Review

Class II malocclusion is one of the most common skeletal or dental deformities, affecting approximately one-third of the patients seeking orthodontic treatment. Mandibular retrognathism is considered most prevalent among all the etiological factors. Removable& fixed Functional appliances (FFA) have been used for the correction of mandibular retrognathism preferably during active skeletal growth. FFA leads to adaptive changes in the glenoid fossa, condylar remodelling and changes in articular disc position that causes growth modulation of the condylar cartilage. The objective of this review is to examine the main effects on the TMJ of using fixed functional appliances, both in healthy patients and in patients with a pre-existing disorder. Many methods have been used to evaluate the TMJ tissues. The multiplanar imaging of both the soft and hard tissues of the TMJ has been made possible by the introduction of MRI. This technique is non-invasive, radiation-free and gives a more superior contrast resolution than any other imaging modality. Following this review, it may be concluded that observations after treatment with fixed functional appliances for mandibular advancement have found, the condyle in a more advanced position. Condylar remodeling and adaptation of the morphology of the glenoid fossa. No significant adverse events concerning the TMJ have been found in healthy patients. This treatment can improve joints that initially present forward disc dislocation.