| Objectives: To determine the skeletal and dentoalveolar effects produced by the MARA functional appliance in the treatment of growing patients with Class II malocclusions. Materials and Methods: A retrospective study was conducted using lateral cephalograms of patients consecutively treated with the MARA appliance (n=40) during their skeletal growth spurt as evaluated by the improved cervical vertebral maturation method recommended by Baccetti et al. 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] pre-treatment; [T2] post-functional appliance treatment; and [T3] fixed orthodontic treatment completion. Treatment changes were evaluated between the time points using 35 variables. Data were analyzed using independent t-tests. Results: At the post-functional appliances' phase (T1-T2), the MARA appliance showed significant increases in the total mandibular length, ramus height and anterior/posterior facial heights. These effects continued during the fixed orthodontic treatment stage (T2-T3). The net changes (T1-T3) revealed significant mandibular growth enhancement with the MARA appliance (+2.7mm) in comparison to untreated controls. The appliance also caused 5.2o of flaring in the mandibular incisors, as well as significant decreases in overjet, overbite and inter-incisal angle. Conclusion: Overall, the MARA appliance showed significant skeletal and dentoalveolar changes resulting in normalization of the Class II malocclusion. |
