Twin-block矫治器早期矫治安氏Ⅱ类1分类错的临床效果

目的　研究Twin-block矫治器治疗快速生长期安氏Ⅱ类1分类错患者的临床效果。方法　选择30名快 速生长期安氏Ⅱ类1分类错患者作为研究对象,治疗组18例采用Twin-block矫治器治疗,对照组12例未作矫治。 治疗组治疗前后、对照组观察开始和结束时分别拍摄头颅侧位片,采用Pancherz分析法进行分析。结果　与对照组 相比,治疗组ANB角、前牙覆盖、磨牙关系、下颌基骨位置、髁突位置和下颌长度的变化均有统计学意义(P<0·05), 而上颌基骨位置的变化无统计学意义(P>0·05)。前牙覆盖减小和磨牙关系改善主要来源于骨骼效应。结论　 Twin-block矫治器治疗生长快速期安氏Ⅱ类1分类错患者,可有效改善前牙覆盖和磨牙关系。这种改善包括骨骼 效应和牙齿效应,其中下颌骨矢状方向的生长较为显著。

Effect of Early Treatment with the Twin-block Appliance

OBJECTIVE: To evaluate the effectiveness of early treatment with the Twin-block appliance for the developing Class II division 1 malocclusion. METHODS: A Total of 30 children with Class II division 1 malocclusion, 18 (8 male, 10 female) out of which received treatment with the Twin-block appliance, the other 12 cases (6 male, 6 female) without treatment served as control group. Cephalometric data were collected at the start and the end of the study and statistical analysis were applied. RESULTS: Except the factor of growth, treatment with the Twin-block appliance resulted in reduction of ANB (1.55 degrees), overjet (5.46 mm) and correction of molar relationship (4.07 mm). These changes were due to the change of Pg/OLp, Co/OLp and mandibular length. The change of A/OLp was not significant. The skeletal effect contributing to the change on overjet and molar relation were 58% and 78% respectively. CONCLUSION: Early treatment with the Twin-block appliance was effective in reducing ANB angle, overjet and correction of molar relationship. The changes were mainly profit from the favorable skeletal change of mandible, especially from its length, while the effect on maxillary was not significant.