Cerruto Carmen, Ugolini Alessandro, Di Vece Luca, Doldo Tiziana, Caprioglio Alberto, Silvestrini-Biavati Armando
Private Practice in Siena, Siena, Italy.
Division of Orthodontics, Department of Surgical and Diagnostic Sciences, University of Genoa, Genoa, Italy.
J Orofac Orthop. 2017 Sep;78(5):385-393. doi: 10.1007/s00056-017-0092-2. Epub 2017 Apr 10.
To assess radiographic changes and dental arch changes with Haas-type rapid maxillary expansion (H-RME) anchored to deciduous versus permanent molars in children with unilateral posterior crossbite.
In all, 70 patients with unilateral posterior crossbite were randomly allocated to group GrE (H-RME on second deciduous molars) or Gr6 (H-RME on first permanent molars) and compared between T0 (before treatment) and T1 (at the RME removal; i.e., 10 months after the end of the activation of the screw). At T0 and T1, cephalometric head films were digitally traced, dental casts were scanned, and rotations of the upper first molars, of the upper central, and of the upper lateral incisors on the models were measured.
Between T0 and T1, the cephalometric analysis showed a significant decrease of the angulation of the upper central incisors to the SN line and to the palatal plane in GrE together with a significant increase of the lower incisors to the mandibular plane (IMPA). The digital dental cast analysis showed that the central and lateral incisors mesiorotated significantly more in GrE than in Gr6. Patients in GrE also showed a statistically significant distorotation of the upper first permanent molars after RME.
GrE showed a significant and spontaneous retraction and alignment of the upper central and lateral incisors compared to Gr6. This is probably due to a more pronounced expansion in the anterior area and more accentuated pressure of the upper lip in GrE. IMPA increased significantly in GrE vs Gr6. GrE also showed a more significant distorotation of the upper first permanent molars compared to Gr6. This is probably due to the design of the H-RME in GrE, where the screw is more anteriorly positioned and the bands are absent on the upper first permanent molars which are, therefore, free to adapt to the best occlusal situation.
ClinicalTrials.gov Identifier NCT02798822.
评估在单侧后牙反合儿童中，使用哈斯式快速上颌扩弓器（H-RME）分别固定于乳牙和恒牙磨牙时的影像学变化及牙弓变化。
总共70例单侧后牙反合患者被随机分配至GrE组（在第二乳磨牙上进行H-RME）或Gr6组（在第一恒磨牙上进行H-RME），并在T0（治疗前）和T1（拆除RME时，即螺旋器激活结束后10个月）进行比较。在T0和T1时，对头影测量头颅侧位片进行数字化描记，扫描石膏模型，并测量模型上上颌第一磨牙、上颌中切牙和上颌侧切牙的旋转度。
在T0和T1之间，头影测量分析显示，GrE组中上颌中切牙与SN线及腭平面的夹角显著减小，同时下颌切牙与下颌平面（IMPA）的夹角显著增大。数字化石膏模型分析显示，GrE组中切牙和侧切牙的近中旋转明显多于Gr6组。GrE组患者在RME后上颌第一恒磨牙也出现了统计学上显著的远中旋转。
与Gr6组相比，GrE组上颌中切牙和侧切牙出现了显著且自发的后缩和排列整齐。这可能是由于GrE组在前部区域扩张更明显，上唇压力更大。与Gr6组相比，GrE组的IMPA显著增加。与Gr6组相比，GrE组上颌第一恒磨牙的远中旋转也更显著。这可能是由于GrE组中H-RME的设计，螺旋器位置更靠前，且上颌第一恒磨牙上没有带环，因此它们可以自由适应最佳咬合情况。
ClinicalTrials.gov标识符NCT02798822。
