Private practice, Raymond, Maine.
Department of Orthodontics, Saint Louis University, St Louis, Mo.
Am J Orthod Dentofacial Orthop. 2021 Jan;159(1):e41-e48. doi: 10.1016/j.ajodo.2020.08.016. Epub 2020 Nov 19.
This research aimed to determine whether Class II malocclusion can be treated with clear aligners after completing treatment with the initial set of aligners.
A sample of 80 adult patients were divided into Group 1 with Class I molar malocclusions (n = 40 [11 men and 29 women]; 38.70 ± 15.90 years) and Group 2 with Class II molar malocclusions (n = 40 [11 men and 29 women]; 35.25 ± 15.21 years). All patients had finished treatment with the initial set of Invisalign aligners (Align Technology, Santa Jose, Calif) without known centric occlusion-centric relation discrepancies, issues of compliance, or overcorrection. The 7 measurements using the American Board of Orthodontics (ABO) Model Grading System and millimetric measurements for anteroposterior (AP) and vertical dimensions were assessed and compared between the 2 groups at pretreatment, posttreatment ClinCheck (Align Technology) prediction, and posttreatment.
No improvements were observed in the AP correction. The amount of AP correction in patients with Class II malocclusion was 6.8% of the predicted amount. The amount of overbite correction achieved was 28.8% and 38.9% of the predicted amounts in patients with Class I and Class II malocclusion, respectively. Significant improvements in alignment and interproximal contact scores were observed, with only slight improvements in total ABO scores. An increase in mean occlusal contacts score was observed after treatment. No patient with Class II malocclusions would meet the ABO standards after Invisalign treatment.
The Invisalign system successfully achieves certain tooth movements but fails to achieve other movements predictably. No significant Class II correction or overjet reduction was observed with elastics for an average of 7-month duration in the adult population. Additional refinements may be necessary to address problems created during treatment, as evidenced by a posterior open bite incidence.
本研究旨在探讨在完成初始隐形矫正器治疗后，使用透明牙套治疗 II 类错颌畸形是否可行。
选择 80 名成年患者作为研究对象，分为 I 类磨牙错颌组（n=40[男 11 例，女 29 例]；平均年龄 38.70±15.90 岁）和 II 类磨牙错颌组（n=40[男 11 例，女 29 例]；平均年龄 35.25±15.21 岁）。所有患者均完成初始 Invisalign 矫正器（Align Technology，圣何塞，加利福尼亚州）治疗，且不存在正中关系-正中关系不调、顺应性问题或矫枉过正等情况。使用美国正畸医师协会（ABO）模型分级系统 7 项测量指标和前后向（AP）及垂直向毫米测量指标，比较两组患者治疗前、治疗后 ClinCheck（Align Technology）预测值及治疗后的各项指标。
AP 向的改善不明显。II 类错颌患者的 AP 矫正量为预测矫正量的 6.8%。II 类错颌患者的覆盖矫正量分别为预测矫正量的 28.8%和 38.9%。I 类和 II 类错颌患者的排齐和邻接评分均显著改善，仅 ABO 总评分略有改善。治疗后，平均牙合接触评分增加。II 类错颌患者经 Invisalign 治疗后无一例符合 ABO 标准。
Invisalign 系统可成功实现某些牙齿移动，但无法可预测地实现其他移动。在成年人群中，使用橡皮圈平均持续 7 个月，未观察到 II 类错颌的显著矫正或覆牙合减小。需要进一步改进，以解决治疗中出现的问题，如后牙开牙合的发生率。
