Cao Yanli, Zhou Yanheng, Song Yang, Vanarsdall Robert L
Department of Orthodontics, School & Hospital of Stomatology, [corrected] Peking University, Beijing, China.
Am J Orthod Dentofacial Orthop. 2009 Sep;136(3):348-54. doi: 10.1016/j.ajodo.2008.03.017.
The purpose of this retrospective study was to evaluate the dentoskeletal changes after slow maxillary expansion in adults.
Three kinds of maxillary expanders (Haas [Dyna Flex, Laboratory, St Louis, Mo], MAX-2000 [Dyna Flex], and DMAX-2000 [Dyna Flex]) were used randomly in 3 study groups of 65 adults treated with nonsurgical slow maxillary expansion, followed by full straight-wire appliance therapy. A control group of 22 adults, meeting the same inclusion criteria, were treated only with full straight-wire appliance therapy without expansion. Posteroanterior and lateral cephalometric records were taken before the start of treatment (T1) and after fixed orthodontic treatment (T2). The data were analyzed statistically by using paired t tests and Kruskal-Wallis H tests.
From T1 to T2, there was no significant change in nasal width, maxillary width, and mandibular width in the 3 groups. The sella-nasion-mandibular plane angle increased 0.97 degrees (P <0.05) in the DMAX-2000 group. The mandibular incisor-mandibular place angle in the Haas, MAX-2000, DMAX-2000, and control groups had mean increases of 4.90 degrees, 4.42 degrees, 4.55 degrees, and 5.20 degrees (P <0.05 for each), respectively. The maxillary incisor-nasion-A-point angle increased 3.04 degrees (P = 0.05), and the distal root of the maxillary first molar-nasion perpendicular decreased 1.48 mm (P <0.05) in the control group. The distal facet of the maxillary first molar-nasion perpendicular decreased 3.57 mm (P <0.05), and the distal root of the maxillary first molar-nasion perpendicular decreased 2.50 mm (P <0.05) in the MAX-2000 group.
After expansion treatment, there were no evident transverse or significant sagittal and vertical skeletal maxillary changes in the 3 groups.
本回顾性研究的目的是评估成人上颌慢速扩弓后的牙颌面变化。
三种上颌扩弓器（Haas[Dyna Flex，实验室，密苏里州圣路易斯]、MAX - 2000[Dyna Flex]和DMAX - 2000[Dyna Flex]）被随机应用于3个研究组，每组65名接受非手术上颌慢速扩弓治疗的成人，随后进行全直丝矫治器治疗。一个由22名符合相同纳入标准的成人组成的对照组仅接受全直丝矫治器治疗而不进行扩弓。在治疗开始前（T1）和固定正畸治疗后（T2）拍摄正位和侧位头影测量片。数据采用配对t检验和Kruskal - Wallis H检验进行统计学分析。
从T1到T2，3组的鼻宽、上颌宽度和下颌宽度均无显著变化。DMAX - 2000组的蝶鞍 - 鼻根点 - 下颌平面角增加了0.97度（P<0.05）。Haas组、MAX - 2000组、DMAX - 2000组和对照组的下颌切牙 - 下颌平面角平均分别增加了4.90度、4.42度、4.55度和5.20度（每组P<0.05）。对照组的上颌切牙 - 鼻根点 - A点角增加了3.04度（P = 0.05），上颌第一磨牙远中根 - 鼻根点垂线减少了1.48毫米（P<0.05）。MAX - 2000组的上颌第一磨牙远中面 - 鼻根点垂线减少了3.57毫米（P<0.05），上颌第一磨牙远中根 - 鼻根点垂线减少了2.50毫米（P<0.05）。
扩弓治疗后，3组均未出现明显的横向或显著的矢状和垂直向颌骨变化。
