Angle Orthod. 2022 Mar 1;92(2):197-203. doi: 10.2319/050921-363.1.
To compare the clinical effectiveness of Hawley retainers (HRs) and modified vacuum-formed retainers (mVFRs) with palatal coverage in maintaining transverse expansion during a 12-month retention period.
Data were collected from postorthodontic treatment patients who met the inclusion criteria. A total of 35 patients were randomly allocated using a centralized randomization technique into either mVFR (n = 18) or HR group (n = 17). The outcome assessor and data analyst were blinded to the retention method. Dental casts of patients were evaluated at debond, 3 months, 6 months, and 12 months of retention. Intercanine width (ICW), interpremolar width (IPMW), interfirst molar mesiobuccal cusp width 1 (IFMW1), and interfirst molar distobuccal cusp width 2 (IFMW2) were compared between groups over time using mixed analysis of variance.
No statistically significant differences were found between the two groups for ICW (P = .76), IPMW (P = .63), IFMW1 (P = .16), and IFMW2 (P = .40) during the 12-month retention period.
The null hypothesis could not be rejected. HR and mVFR had similar clinical effectiveness in the retention of transverse expansion cases during a 12-month retention period.
比较带腭侧覆盖的 Hawley 保持器（HR）和改良型真空成型保持器（mVFR）在 12 个月保持期内维持横向扩张的临床效果。
从符合纳入标准的正畸治疗后患者中收集数据。共 35 名患者采用中心化随机分组技术随机分为 mVFR 组（n = 18）或 HR 组（n = 17）。结果评估者和数据分析者对保持方法均不知情。患者的牙模在去粘结、3 个月、6 个月和 12 个月保持期时进行评估。采用混合方差分析比较两组在不同时间点的尖牙间宽度（ICW）、磨牙间宽度（IPMW）、第一磨牙近中颊尖宽度 1（IFMW1）和第一磨牙远中颊尖宽度 2（IFMW2）。
在 12 个月的保持期间，两组之间在 ICW（P =.76）、IPMW（P =.63）、IFMW1（P =.16）和 IFMW2（P =.40）方面均无统计学差异。
不能拒绝零假设。在 12 个月的保持期间，HR 和 mVFR 在横向扩张病例的保持方面具有相似的临床效果。
