Effect of the MARA appliance on the position of the lower anteriors in children, adolescents and adults with Class II malocclusion.J Orofac Orthop. 2007 Sep; 68(5):397-412.JO
Aim of this retrospective study was to investigate the effect of the fixed functional appliance MARA (Mandibular Anterior Repositioning Appliance) on the position of the lower anteriors.
PATIENTS AND METHODS
For 1.3 years on average, 90 patients with a skeletal and dental Angle Class II malocclusion were treated simultaneously with the MARA and multi-bracket appliances to attain anterior mandibular repositioning. The patients were divided into the following age groups: 36 patients, mean age 10.6 years (children), 28 patients, mean age 14.9 years (adolescents) and 26 patients, mean age 33.7 years (adults). Lateral headfilms were taken at the onset of MARA treatment (T1), upon MARA removal (T2), and one year after MARA removal (T3). IMP angle (IMPA), incisor position with relation to the pogonion perpendicular, ANB angle, overjet and facial type were analyzed using cephalometric software. The degree of crowding was assessed on the study models. The data were subjected to Welch's paired t-test for statistical analysis.
In children, an average 0.4 mm mesial shift of the lower incisors (change in proclination +1.7 degrees) was observed. This movement averaged 1.0 mm in adolescents (change in proclination +3.6 degrees). The adult age group averaged 1.7 mm (change in proclination +4.5 degrees). In all age groups, a significant linear correlation was detected between position shift of the lower anteriors and the IMPA angle at T1: strongly protruded lower incisors showed less mesial shift than lingually inclined anteriors.
The MARA fixed-functional appliance was an effective device in treating Class II patients in all the age groups studied. The dentoalveolar effect on the lower anteriors was more pronounced in the adult patient group than in the adolescents and children. When the literature on other fixed Class II mechanics is compared, the MARA is revealed as among those with the most Isprinminimal side-effects on the position of the lower anteriors. Ultimately, incisor inclination can be controlled well by therapy with multi-bracket systems.