Combined modified Nance arch and maxillary protraction in correction of skeletal class Ⅲ malocclusion
ZHU Jing1 and RAN Yidong2
1. Department of Stomatology, Ningxia Autonomous Regional Hospital, Chinese People’s Armed Police Forces, Yinchuan 750001, China; 2. Department of Stomatology,the No. 2 Hospital of Baoding, Baoding 071000, China
Abstract:Objective To evaluate the dental, skeletal and profile changes in the patients with skeletal class III malocclusion after using maxillary protraction appliance combined with modified Nance arch. Methods 21 patients with skeletal class Ⅲ malocclusion in mixed dentition were treated by maxillary protraction combined with modified Nance arch. Cephalometric radiographs and plaster model were analyzed to evaluate skeletodental and profile changes and Peer Assessment Rating (PAR) index before and after treatment. Results SNA and ANB angle, NA-PA, Ptm-A, ANS-Ptm, Wits values were increased and subspinale was protracted by 2.15 mm. All of the changes were statistically significant (P<0.05).PAR index indicated that the weighted PAR reduction percentage was 86.67%. The anterior overjet and overbite, posterior occlusion were effectively improved. All the patients’ anterior crossbites were corrected after treatment, but there was no significant change in teeth alignment and midline correction. Conclusions The maxillary protraction combined with modified Nance arch are obviously effective for skeletal class III malocclusion in mixed dentition, but posterior occlusion, teeth alignment and midline need to be adjusted with fixed appliance in the further treatment.
祝静,冉屹东. 改良Nance弓配合上颌前方牵引矫治骨性Ⅲ类错牙合的效果[J]. , 2014, 25(6): 576-578.
ZHU Jing and RAN Yidong. Combined modified Nance arch and maxillary protraction in correction of skeletal class Ⅲ malocclusion. , 2014, 25(6): 576-578.