PDF(Pubmed)
Abstract：
BACKGROUND: to evaluate the predictability of expansion achieved in patients in early mixed dentition treated with Clear Aligners (CA), analyzing the efficiency of the expansion at the end of the first set of aligners and at the end of the therapy in the upper and lower arch.
METHODS: 36 patients (20 F, 16 M; mean age 8.3 ± 1.5 years) were selected retrospectively from the Department of Orthodontics of the Hospital of Rome \"Tor Vergata\". All subjects were treated with CA with no other auxiliaries than attachments. For each patient a standardized sequential expansion protocol was planned for both arches. Digital dental casts were created at three observation periods from an intraoral scanner: prior to treatment (T0), at the end of the first set of aligners (T1), at the end of treatment (T2). The 3D models in planned position determined by the first Clincheck (CC) were obtained for comparison with T1 and T2. Six linear transversal measurements were used to evaluate the dimensional changes and the predictability of expansion movements, comparing T1-CC and T2-CC.
RESULTS: a statistically significant increase within the pre-treatment and the final outcomes for all the variables examined was found. In the upper arch, the greatest level of predictability was detected at the level of the first (46.44%) and second deciduous molar width (44.95%) at T1. The analysis of T2-CC changes showed a significant increase in the percentage of predictability of expansion at the level of the first permanent molars, at mesial (54.86%) and distal (58.92%) width. In the lower arch, a higher percentage of predictability than the upper arch was reported at T1-CC and T2-CC, with the greatest values at the level of second (T1-CC: 48.70%; T2-CC: 75.32%) and first deciduous molar width (T1-CC: 45.71%; T2-CC: 72.75%).
CONCLUSIONS: CA can induce significant transversal increments. The predictability of expansion is variable, but it did not exceed the 50% during the first set of aligners. It was necessary to apply refinement set to achieve a good predictability for expansion of about 70%. The expansion in the lower arch was observed to be more predictable than in the upper arch.
METHODS: 36 patients (20 F, 16 M; mean age 8.3 ± 1.5 years) were selected retrospectively from the Department of Orthodontics of the Hospital of Rome \"Tor Vergata\". All subjects were treated with CA with no other auxiliaries than attachments. For each patient a standardized sequential expansion protocol was planned for both arches. Digital dental casts were created at three observation periods from an intraoral scanner: prior to treatment (T0), at the end of the first set of aligners (T1), at the end of treatment (T2). The 3D models in planned position determined by the first Clincheck (CC) were obtained for comparison with T1 and T2. Six linear transversal measurements were used to evaluate the dimensional changes and the predictability of expansion movements, comparing T1-CC and T2-CC.
RESULTS: a statistically significant increase within the pre-treatment and the final outcomes for all the variables examined was found. In the upper arch, the greatest level of predictability was detected at the level of the first (46.44%) and second deciduous molar width (44.95%) at T1. The analysis of T2-CC changes showed a significant increase in the percentage of predictability of expansion at the level of the first permanent molars, at mesial (54.86%) and distal (58.92%) width. In the lower arch, a higher percentage of predictability than the upper arch was reported at T1-CC and T2-CC, with the greatest values at the level of second (T1-CC: 48.70%; T2-CC: 75.32%) and first deciduous molar width (T1-CC: 45.71%; T2-CC: 72.75%).
CONCLUSIONS: CA can induce significant transversal increments. The predictability of expansion is variable, but it did not exceed the 50% during the first set of aligners. It was necessary to apply refinement set to achieve a good predictability for expansion of about 70%. The expansion in the lower arch was observed to be more predictable than in the upper arch.
摘要：
背景：为了评估用ClearAligners（CA）治疗的早期混合性牙列患者实现的扩张的可预测性，分析在第一组对准器结束时以及在上弓和下弓中的治疗结束时的扩张效率。
方法：36例患者（20F，16M；平均年龄8.3±1.5岁）是从罗马“TorVergata”医院正畸科回顾性选择的。所有受试者均接受CA治疗，除附件外没有其他辅助手段。对于每位患者，都计划了两个拱门的标准化顺序扩展方案。从口内扫描仪在三个观察期创建数字牙模：治疗前（T0），在第一组对准器(T1)的末尾，在治疗结束时(T2)。获得由第一个Clincheck（CC）确定的计划位置的3D模型，以与T1和T2进行比较。使用六个线性横向测量来评估膨胀运动的尺寸变化和可预测性，比较T1-CC和T2-CC。
结果：发现所有变量在治疗前和最终结果中的统计学显着增加。在上拱门，在T1时，在第一（46.44％）和第二落叶磨牙宽度（44.95％）的水平上检测到最大的可预测性。对T2-CC变化的分析表明，在第一恒磨牙的水平上，扩张的可预测性百分比显着增加，在内侧（54.86%）和远端（58.92%）宽度。在下拱门，在T1-CC和T2-CC报告的可预测性百分比高于上弓，在第二（T1-CC：48.70％；T2-CC：75.32％）和第一落叶磨牙宽度（T1-CC：45.71％；T2-CC：72.75％）的水平上具有最大值。
结论：CA可诱导显著的横向增量。扩张的可预测性是可变的，但在第一组对准器时，它没有超过50％。有必要应用细化集以实现约70％的扩展的良好可预测性。观察到下弓的扩张比上弓的扩张更可预测。
方法：36例患者（20F，16M；平均年龄8.3±1.5岁）是从罗马“TorVergata”医院正畸科回顾性选择的。所有受试者均接受CA治疗，除附件外没有其他辅助手段。对于每位患者，都计划了两个拱门的标准化顺序扩展方案。从口内扫描仪在三个观察期创建数字牙模：治疗前（T0），在第一组对准器(T1)的末尾，在治疗结束时(T2)。获得由第一个Clincheck（CC）确定的计划位置的3D模型，以与T1和T2进行比较。使用六个线性横向测量来评估膨胀运动的尺寸变化和可预测性，比较T1-CC和T2-CC。
结果：发现所有变量在治疗前和最终结果中的统计学显着增加。在上拱门，在T1时，在第一（46.44％）和第二落叶磨牙宽度（44.95％）的水平上检测到最大的可预测性。对T2-CC变化的分析表明，在第一恒磨牙的水平上，扩张的可预测性百分比显着增加，在内侧（54.86%）和远端（58.92%）宽度。在下拱门，在T1-CC和T2-CC报告的可预测性百分比高于上弓，在第二（T1-CC：48.70％；T2-CC：75.32％）和第一落叶磨牙宽度（T1-CC：45.71％；T2-CC：72.75％）的水平上具有最大值。
结论：CA可诱导显著的横向增量。扩张的可预测性是可变的，但在第一组对准器时，它没有超过50％。有必要应用细化集以实现约70％的扩展的良好可预测性。观察到下弓的扩张比上弓的扩张更可预测。
