A comparison of the MARA and the AdvanSync functional appliances in the treatment of Class II malocclusion

To determine the skeletal and dentoalveolar effects produced by the MARA and the AdvanSync functional appliances in the treatment of growing patients with Class II malocclusion.

A retrospective study was conducted using lateral cephalograms of patients consecutively treated with MARA (n  =  40) and AdvanSync (n  =  30) during their skeletal growth spurt as evaluated by the improved cervical vertebral maturation method. A comparison was made with 24 untreated Class II control subjects obtained from the University of Michigan growth study and matched with the experimental groups for skeletal age, sex, and craniofacial morphology. Cephalograms were taken at three time points: (T1) pretreatment, (T2) postfunctional appliance treatment, and (T3) fixed orthodontic treatment completion. Treatment changes were evaluated between the time points using 35 variables. Data were analyzed using one-way analysis of variance and Scheffe's post hoc test.

At the postfunctional appliances' phase (T2-T1), both appliances showed significant increases in total mandibular length, ramus height, and anterior/posterior facial height. The AdvanSync resulted in significant restriction of maxillary growth, 1° more than MARA. This effect continued during the fixed orthodontic treatment stage (T3-T2). The net changes (T3-T1) revealed significant mandibular growth enhancement with MARA (+2.7mm) and significant headgear effect with AdvanSync. Both appliances caused 5° flaring in mandibular incisors as well as significant decreases in overjet and overbite. The treatment time for AdvanSync was 1 year less than MARA.

The MARA and the AdvanSync resulted in normalization of the Class II malocclusion. The AdvanSync showed more headgear effect but less mandibular length enhancement than MARA did. Both appliances showed similar dentoalveolar changes.