Temporomandibular joint and skeletal changes in response to Twin block and Advansync appliance therapy – A three dimensional study

This study aimed to analyze and compare the temporomandibular joint (TMJ) and skeletal changes three dimensionally in growing patients with Class II malocclusion treated with the Twin block (TB) and Advansync appliance. This prospective study included 20 patients with Class II Division 1 malocclusion of which ten patients comprised the TB group and ten patients the Advansync group. Cone-beam computed tomographs were taken before treatment, and at the end of the functional phase (6–8 months). The condyle, glenoid fossa, and skeletal changes were assessed in all the three planes and the measurements were made using CARESTREAM software. The TB group demonstrated a significant increase in the condylar dimensions, superior joint space, mandibular length (P = 0.005), and decrease in anterior joint space (P = 0.001) in response to treatment and the Advansync group showed a significant increase in the condylar dimensions, mandibular length, and a significant restriction in the maxillary length. Comparison between the two groups showed a significant increase in the fossa depth in the TB group and restriction in the maxillary growth in the Advansync group. TB and Advansync group showed TMJ and skeletal changes. However, the Advansync showed more headgear effect but less glenoid fossa changes compared to the TB group.