Twin Block appliance combined with straight wire appliance used in correcting Angle II malocclusion

Objective To investigate the efficacy of Twin Block appliance combined with straight wire appliance in the correction of AngleⅡ malocclusion. Methods Sixteen patients with Angel Ⅱ malocclusion were selected. Twin Block appliance combined with straight wire appliance was used for correction without tooth extraction. The lateral films of head were shot before and after treatment in order to conduct X-ray cephalometric analysis. Results All patients completed active corrective treatment within(18±2.0) months. After treatment, the lower jaw moved forward and the classⅠ molar-canine relationship was established. Normal overbite and cover was obtained. The patients with lower mandible retrusion achieved obvious corrective effects and their appearance improved. After treatment, X-ray cephalometric analysis showed that SNB increased by 3.25° on average, SNA remained the same, ANB reduced by 6.50° on average, IMPA reduced by 6.95° on average, FMIA increased by 3.61° on average, FMA increased by 2.53° on average,Po-Co increased by 5.12 mm on average, and Vits reduced by 1.29 mm on average(P0.05). Conclusion In the correction of early Angle Ⅱ malocclusion, Twin Block functional appliance combined with straight wire appliance shows evident effects and patient satisfaction, thereby worthy of clinical promotion.