Differential skeletal and dental effects after orthodontic treatment with bite jumping appliance or activator: a retrospective cephalometric study

摘要

Objectives The aim of this retrospective cephalometric study was to compare treatment outcomes with "bite jumping appliance" (BJA) or Andresen-Haupl type activator. It especially focused on skeletal and dental structures in patients with class II malocclusion. The study hypothesis was that differences in treatment-related changes would occur between patients treated with BJA or activator. Material and methods Pre- and posttreatment lateral cephalograms of 73 patients with a class II malocclusion were analyzed. Thirty-seven patients (22 females, 15 males) received treatment with a BJA (pretreatment age 11.1 +/- 1.07 years) and 36 patients (20 females, 16 males) with an activator (pretreatment age 11.3 +/- 1.12 years). Treatment time was 14.0 +/- 1.8 months with BJA and 12.0 +/- 2.0 months with activator. Paired t tests were used for intragroup and t tests for independent samples for intergroup comparisons. Results were considered statistically significant at P < 0.05. Results The comparison of sagittal and vertical skeletal changes after BJA and activator treatment did not reveal significant differences. Significant changes occurred for lower incisor inclination (P = 0.0367) and overjet (P = 0.0125) only. The reduction of overjet and proclination of lower incisors were more pronounced in BJA patients. Conclusions Both "bite jumping appliance" (BJA) and Andresen-Haupl type activator were able to improve the occlusion of patients with a class II malocclusion. Dental effects were more pronounced for the BJA.