Background: The objective of this study was to evaluate the treatment effects of Forsusââ??¢ Fatigue Resistant Device\n(FRD; 3M Unitek, Monrovia, CA, USA) in growing patients with Class II non-extraction malocclusions.\nMethods: A retrospective sample of 24 class II patients treated consecutively with the FRD followed by comprehensive\northodontic treatment was compared to a sample of untreated control subjects from the Bolton Brush Study who was\nmatched in age, sex, and craniofacial morphology. Lateral cephalometric radiographs were taken before treatment (T1)\nand after removal of fixed appliances (T2). Growth changes were subtracted from the treatment changes to obtain the\ntreatment effects of the appliance. Data were analyzed using ANOVA and a match paired t test.\nResults: Significant differences were found between the treated and control groups for 12 of the 29 measured variables\n(Co-Gn minus Co-Apt, Wits, Is-OLp, Ii-OLp, overjet, Mi-OLp, molar relationship, overbite, Mic-ML, SNA, ANB, and Ii-ML).\nWith 27.8 months of treatment, all patients were corrected to a class I dental arch relationship. Overjet and molar\nrelationships were improved by an average of 4.7 and 3.1 mm, respectively. This was contributed by a 1.2 mm of\nrestraint in forward maxillary growth, 0.7 mm of forward movement of the mandible, 1.5 mm of backward movement\nof the maxillary incisors, 1.3 mm forward movement of the mandibular incisors, 0.5 mm backward movement of the\nmaxillary molars, and 1.3 mm of forward movement of the mandibular molars. The overbite was decreased by 2 mm\nwith no significant change in the occlusal, palatal, or mandibular plane. Individual variations in response to the FRD\ntreatment were large for most of the parameters tested. Significant differences in treatment changes between male\nand female subjects were found only in a few parameters measured.\nConclusions: These results demonstrate that significant overjet and overbite corrections can be obtained with the\nForsus FRD in conjunction with comprehensive orthodontic treatment.
Loading....