Occlusal bite force change after orthodontic treatment with Andresen functional appliance.

OBJECTIVES The aim of this study was to determine the occlusal bite force (OBF) changes, at the incisal and molar regions, after orthodontic treatment with functional appliance therapy in preadolescent subjects. MATERIALS AND METHODS OBF was measured for patients (17 females and 16 males) before and after the treatment with Andresen functional appliance for an average period of 9 months (mean age was 11.8±1.1 years). Three variables were registered; maximum OBF at molar region and the average of three readings at the molar (AOBF) and incisal regions (IOBF). The same variables were measured in two occasions for a matching non-treated control group with a period of 9 months between the two measurements. RESULTS No significant changes were seen in the OBF measured parameters in the control group. There was a reduction in all measured parameters. The mean reduction in maximum OBF was 76.1±12.4 N (P < 0.001), 58.5±13.0 N in AOBF (P < 0.001), and 69.3±11.6 N IOBF (P < 0.001). CONCLUSIONS Treatment with functional appliance caused a significant reduction in OBF immediately after treatment.