Wendling Lisa K, McNamara James A, Franchi Lorenzo, Baccetti Tiziano
Graduate Orthodontic Program, The University of Michigan, Ann Arbor, Michigan 48109-1078, USA.
Angle Orthod. 2005 Jan;75(1):7-14. doi: 10.1043/0003-3219(2005)075<0007:APSOTS>2.0.CO;2.
This prospective clinical study evaluated the short-term treatment effects of acrylic-splint rapid maxillary expander in conjunction with lower Schwarz appliance (RME-Sz) therapy to the acrylic-splint rapid maxillary expansion alone (RME-only group). Pretreatment and posttreatment lateral cephalograms were analyzed for 25 RME patients and 19 RME-Sz patients. The average time between films ranged between nine and 12 months. Statistical comparisons of the treatment changes in the RME-only and RME-Sz groups were performed by means of independent sample t-tests (P < .05). The largest difference between the two groups was in lower anterior facial height (LAFH). The normally occurring increase in LAFH was not observed in the RME-only group during the treatment period, indicating that the acrylic-splint expander had a posterior "bite block effect" on the developing craniofacial complex. LAFH increased by 1.7 mm in the RME-Sz group, a value similar to that observed in untreated individuals. Slight forward displacement of the maxilla was observed when RME was used alone, and the sagittal position of the maxilla remained unchanged in the RME-Sz group. A significant amount of intrusion of the maxillary molars (-0.8 mm) was noted in the RME-only group, whereas the maxillary molars were prevented from erupting in the RME-Sz group. The lower dentition showed a significantly greater amount of extrusion in the RME-Sz group than in the RME-only group. Finally, the Sz appliance prevented the mesial movement of the lower molars during the treatment period.
这项前瞻性临床研究评估了丙烯酸夹板快速上颌扩弓器联合下颌施瓦茨矫治器（RME-Sz）治疗与单纯丙烯酸夹板快速上颌扩弓治疗（仅RME组）的短期治疗效果。对25例RME患者和19例RME-Sz患者的治疗前和治疗后侧位头影测量片进行了分析。两次拍片之间的平均时间为9至12个月。通过独立样本t检验对仅RME组和RME-Sz组的治疗变化进行统计学比较（P <.05）。两组之间最大的差异在于下前牙面部高度（LAFH）。在治疗期间，仅RME组未观察到LAFH正常出现的增加，这表明丙烯酸夹板扩弓器对发育中的颅面复合体具有后部“咬合阻挡效应”。RME-Sz组的LAFH增加了1.7毫米，这一数值与未治疗个体中观察到的相似。单独使用RME时观察到上颌有轻微向前移位，而RME-Sz组上颌的矢状位置保持不变。仅RME组中上颌磨牙有明显的压低（-0.8毫米），而在RME-Sz组中上颌磨牙的萌出受到抑制。与仅RME组相比，RME-Sz组下牙列的伸长量明显更大。最后，施瓦茨矫治器在治疗期间防止了下颌磨牙的近中移动。
