Post-treatment occlusal changes in Class II division 2 subjects treated with the Herbst appliance.

摘要

The aim of this retrospective study was to analyse and compare the post-treatment occlusal changes of Class II division 2 treatment with the Herbst appliance in early adolescent, late adolescent, and adult subjects. The subjects were 37 Class II division 2 patients (19 females and 18 males) treated at the Orthodontic Department, University of Giessen, Germany. All were in the late mixed or permanent dentition and exhibited a Class II molar relationship > or =0.5 cusp width (CW) bilaterally or > or =1.0 CW unilaterally, an overbite (OB) >3.0 mm, and two upper central incisors retroclined. The subjects were divided into three skeletal maturity groups based on evaluation of hand wrist radiographs: early adolescent (n = 10, stages MP3-E to MP3-FG at start of treatment, age range: 11.3-13.2 years), late adolescent (n = 14, stages MP3-G to MP3-I at start of treatment, age range: 14.1-16.4 years), and adult (n = 13, stages R-I to R-J at the start of treatment, age range: 16.3-25.6 years). Study casts from before treatment (T1), after Herbst-Tip-Edge-Multibracket appliance treatment (T2), and after an average retention time of 27 months (T3) were analysed. Statistical analysis was undertaken using t-tests for paired and unpaired samples. For the whole sample, the molar relationship at T3 was stable in 82.4 per cent, the canine relationship in 82.9 per cent, and OB in 75.7 per cent of the cases. In the different skeletal maturity groups, the stability of the molars, canines, and overbite was as follows: early adolescents: 95.0, 100.0, and 70.0 per cent, respectively; late adolescents: 92.9, 74.1, and 85.7 per cent, respectively; and adults 61.5, 80.8, 69.2 per cent, respectively. Occlusal correction of Class II division 2 malocclusions with Herbst treatment was relatively stable 2 years post-treatment. The outcome of treatment of adolescents was more stable than that of adults.