Abstract: [Abstract]Objective:In view of the Ann Ⅱ classes for children with mandibular retraction correct implementation of the muscle power training and analyzes its application effect. Methods: Selected from January 2018 to March 2019 in our hospital for treatment of 65 cases of Ann Ⅱ class children with mandibular retraction as the research object, all wearing muscle training, on the basis of the cooperate with muscle function training in orthodontic treatment. Clinical observation indexes such as SNA, SNB, ANB and anterior tooth coverage level before and after treatment were analyzed, as well as the compliance of children and the satisfaction of parents on correction.Results:Before correction, the coverage levels of SNA, SNB, ANB and anterior teeth were (85.12±6.39) °, (86.13±6.87) °, (5.37±1.24) ° and (6.38±1.25) mm, respectively. After correction, the levels of SNA, SNB, ANB and anterior tooth coverage were (81.31±4.20) °, (79.10±3.34) °, (3.45±0.71) ° and (3.27±0.64) mm, respectively, which were significantly improved after correction compared with those before correction, with no statistical significance (P > 0.05). The compliance at 1 week of correction was 87.68%(57/65), and 96.92%(63/65) at 12weeks of correction. The compliance at 12 weeks of correction was higher than that at 1 week, and the difference was statistically significant (P<0.05). At 1 week of correction, parents' total satisfaction on the correction effect was 84.62%(55/65), and at 12 weeks of correction, parents' total satisfaction on the correction effect was95.38%(62/65). The compliance at 12 weeks of correction was higher than that at 1 week, and the difference was statistically significant (P<0.05).Conclusion: Muscle function training application in Ann Ⅱ class mandibular retraction in orthodontic treatment, can effectively improve phase for teeth second deep deep coverage and mandibular retraction, adherence to rectify the ascending children, the parents of fully endorsed, has high clinical value, is worth popularizing widely. [Key words] Muscle trainer; Muscle work training; Ann Ⅱ classes; Ankylosis of the jaw; Clinical curative effect

Key words: [Key words] Muscle trainer, Muscle work training, Ann Ⅱ classes, Ankylosis of the jaw, Clinical curative effect