Abstract：
OBJECTIVE: The biomechanics in achieving molar distalization may differ between fixed appliances and clear aligners in the control of tooth movement. The objective of this study was to compare the treatment effects between clear aligners (CA) and fixed appliances (FA) in patients treated with miniscrew-assisted molar distalization.
METHODS: The sample consisted of 46 subjects with mild-to-moderate crowding. A total of 22 patients treated with clear aligners (age, 25.66 ± 6.11 years old) and 24 patients treated with fixed appliances (age, 24.04 ± 4.95 years old) for miniscrew-assisted molar distalization were included in this study. The dental and skeletal changes were evaluated by the pre- and post-treatment lateral cephalograms.
RESULTS: Significant changes were found with the vertical variables SN-OP angle (2.24 ± 3.22°, P < .05) and SN-MP angle (0.73 ± 1.15°, P < .05) for the FA group when compared with the CA group (SN-OP angle 0.41 ± 2.26° and SN-MP angle -0.21 ± 1.38°, P > .05). Both treatment groups achieved a 2-3 mm. molar distalization with significant intrusion of the upper molars. The CA group showed significantly less distal tipping of molars (U6^PP angle -2.29 ± 3.29° and L6^MP angle -2.92 ± 2.49°, P < .05) compared to the FA group (-5.24 ± 4.28° and -5.53 ± 5.03°, P < .05). In addition, significant retraction and lingual inclination of the upper and lower incisors were found in both groups.
CONCLUSIONS: The changes of tooth position were evaluated by 2D lateral cephalograms, not 3D measurements.
CONCLUSIONS: Compared to fixed appliances, clear aligners seemed to have better control of vertical dimension and distal tipping of molars in patients treated with miniscrew-assisted molar distalization.
METHODS: The sample consisted of 46 subjects with mild-to-moderate crowding. A total of 22 patients treated with clear aligners (age, 25.66 ± 6.11 years old) and 24 patients treated with fixed appliances (age, 24.04 ± 4.95 years old) for miniscrew-assisted molar distalization were included in this study. The dental and skeletal changes were evaluated by the pre- and post-treatment lateral cephalograms.
RESULTS: Significant changes were found with the vertical variables SN-OP angle (2.24 ± 3.22°, P < .05) and SN-MP angle (0.73 ± 1.15°, P < .05) for the FA group when compared with the CA group (SN-OP angle 0.41 ± 2.26° and SN-MP angle -0.21 ± 1.38°, P > .05). Both treatment groups achieved a 2-3 mm. molar distalization with significant intrusion of the upper molars. The CA group showed significantly less distal tipping of molars (U6^PP angle -2.29 ± 3.29° and L6^MP angle -2.92 ± 2.49°, P < .05) compared to the FA group (-5.24 ± 4.28° and -5.53 ± 5.03°, P < .05). In addition, significant retraction and lingual inclination of the upper and lower incisors were found in both groups.
CONCLUSIONS: The changes of tooth position were evaluated by 2D lateral cephalograms, not 3D measurements.
CONCLUSIONS: Compared to fixed appliances, clear aligners seemed to have better control of vertical dimension and distal tipping of molars in patients treated with miniscrew-assisted molar distalization.
摘要：
目的：在控制牙齿移动方面，固定矫正器和透明矫正器在实现磨牙扩张方面的生物力学可能有所不同。这项研究的目的是比较使用微型辅助磨牙扩张治疗的患者的清晰矫正器（CA）和固定矫正器（FA）之间的治疗效果。
方法：样本由46名轻度至中度拥挤的受试者组成。共有22例患者接受了清晰的矫正器治疗（年龄，25.66±6.11岁）和24例接受固定矫治器治疗的患者（年龄，24.04±4.95岁），用于微型船员辅助磨牙远距。通过治疗前和治疗后的侧头颅图评估牙齿和骨骼的变化。
结果：发现垂直变量SN-OP角度（2.24±3.22°，P<.05)和SN-MP角度(0.73±1.15°,与CA组相比，FA组的P<.05）（SN-OP角度为0.41±2.26°，SN-MP角度为-0.21±1.38°，P>.05）。两个治疗组达到2-3mm。磨牙远大，上磨牙明显侵入。CA组磨牙远端倾斜明显较少(U6^PP角-2.29±3.29°,L6^MP角-2.92±2.49°,P<.05）与FA组（-5.24±4.28°和-5.53±5.03°，P<0.05)。此外,两组均发现上切牙和下切牙的明显回缩和舌侧倾斜。
结论：通过二维侧位头颅图评估牙齿位置的变化，不是3D测量。
结论：与固定电器相比，在接受微型辅助磨牙扩张治疗的患者中，清晰的矫正器似乎可以更好地控制磨牙的垂直尺寸和远端倾斜。
方法：样本由46名轻度至中度拥挤的受试者组成。共有22例患者接受了清晰的矫正器治疗（年龄，25.66±6.11岁）和24例接受固定矫治器治疗的患者（年龄，24.04±4.95岁），用于微型船员辅助磨牙远距。通过治疗前和治疗后的侧头颅图评估牙齿和骨骼的变化。
结果：发现垂直变量SN-OP角度（2.24±3.22°，P<.05)和SN-MP角度(0.73±1.15°,与CA组相比，FA组的P<.05）（SN-OP角度为0.41±2.26°，SN-MP角度为-0.21±1.38°，P>.05）。两个治疗组达到2-3mm。磨牙远大，上磨牙明显侵入。CA组磨牙远端倾斜明显较少(U6^PP角-2.29±3.29°,L6^MP角-2.92±2.49°,P<.05）与FA组（-5.24±4.28°和-5.53±5.03°，P<0.05)。此外,两组均发现上切牙和下切牙的明显回缩和舌侧倾斜。
结论：通过二维侧位头颅图评估牙齿位置的变化，不是3D测量。
结论：与固定电器相比，在接受微型辅助磨牙扩张治疗的患者中，清晰的矫正器似乎可以更好地控制磨牙的垂直尺寸和远端倾斜。
