Orthodontics
A cone-beam computed tomography evaluation of maxillary protraction with repetitive rapid palatal expansions and constrictions
Weitao Liu, Yang Song, Xuedong Wang, Danqing He, Yanheng Zhou
Published 2015-02-09
Cite as Chin J Stomatol, 2015, 50(2): 78-83. DOI: 10.3760/cma.j.issn.1002-0098.2015.02.004
Abstract
ObjectiveTo investigate the effects of maxillary protraction combined with repetitive rapid palatal expansions and constrictions(RPE/C) vs. rapid palatal expansion(RPE) alone using cone-beam computed tomography(CBCT).
MethodsTwenty four subjects with maxillary retrusion were recruited and block randomized into either the control group(n=12) or the RPE/C(n=12) group. Control group: facemask protraction after RPE. RPE/C group: facemask protraction after RPE/C. 3D reconstruction, landmarks identifying, superimposition and cephalometric analysis were performed to compare the pre-treatment and post-treatment CBCT images.
ResultsOne subject in the RPE/C group was lost to follow up during the treatment. Maxilla moved forward[(2.5±1.0) mm] after maxillary protraction with RPE/C, which was significantly greater than that in the control group[(1.6±0.8) mm](P<0.05). The distance of basion to subspinale(Ba-A) increased[(3.1± 1.0) mm] in the RPE/C group, which was significantly greater than that in the control group[(2.2±0.9) mm] (P<0.05). The amount of forward movement of upper first molars was significantly greater in the RPE/C group(P<0.05).
ConclusionsMaxillary protraction with RPE/C might positively affect the forward movement of maxilla compared with the RPE alone protocol with the early treatment of maxillary retrusion patients.
Key words:
Palatal expansion technique; Extraoral traction appliances; Cone-beam computed tomography
Contributor Information
Weitao Liu
Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China
Yang Song
Xuedong Wang
Danqing He
Yanheng Zhou
畸形患者存在不同程度上颌后缩[1,2]。正畸临床实践显示，上颌快速扩弓后前方牵引是一种有效的早期治疗上颌后缩的方法[3,4]。2005年，有学者使用双轴扩弓器，反复快速扩缩上颌，结合口内前方牵引，取得了较好的效果[5,6]。随后，国内外临床研究初步证实上颌反复快速扩缩后前方牵引的临床效果[7,8,9,10,11]。传统头颅侧位X线片因拍摄质量、放大率、解剖结构重叠及双侧解剖结构不对称等因素而有诸多局限性[12]。近年，锥形束CT成为一种新的诊断和研究手段[13]。本项研究通过锥形束CT三维重建和测量分析，比较传统上颌单次快速扩弓后前方牵引和上颌反复快速扩缩后前方牵引的矫治效果，以期为临床提供参考。
