Department of Orthodontics and Dentofacial Orthopedics, Faculty of Dentistry, Cairo University, Cairo, Egypt.
Eur J Orthod. 2024 Aug 1;46(4). doi: 10.1093/ejo/cjae034.
Extraction space closure is a challenging phase during orthodontic treatment that affects not only the total treatment duration but also the whole treatment outcome.
To compare the efficiency of friction and frictionless mechanics during en-masse retraction of maxillary anterior teeth in adult patients with bimaxillary dentoalveolar protrusion.
Two-arm parallel group, single-center randomized clinical trial.
Thirty-two adult patients with bimaxillary protrusion were recruited and randomly allocated to two different retraction mechanics. A friction group, using NiTi coil springs and a frictionless group using closing T-loops for en-masse retraction. Randomization in a 1:1 ratio was generated by Microsoft Excel. The randomization numbers were secured in opaque sealed envelopes for allocation concealment. Retraction started in all patients following first premolars extraction using miniscrews as a source of indirect anchorage. Activation was done on a monthly basis until complete retraction of anterior segment. The rate of retraction, amount of anchorage loss, the dental, and soft tissue changes were analyzed on digital models and lateral cephalograms taken before retraction and after space closure.
The outcome assessor was blinded through data concealment during assessment.
Two patients were lost to follow up, so 30 patients completed the trial. The rate of anterior segment retraction was 0.88 ± 0.66 mm/month in the frictionless group compared to 0.72 ± 0.36 mm/month in the friction group which was statistically significant. Anchorage loss of 1.18 ± 0.72 mm in the friction group compared to 1.29 ± 0.55 mm in the frictionless group with no significant difference. Comparable dental and soft tissue changes following en-masse retraction were reported in both groups, with no statistically significant difference.
one patient complained of soft tissue swelling following miniscrew insertion, but the swelling disappeared after one week of using mouth wash.
The study focused only on the maxillary arch.
Both mechanics have successfully achieved the required treatment objectives in patients with bimaxillary dentoalveolar protrusion. Frictionless group showed a faster rate of retraction than the friction group, which was statistically but not clinically significant.
Clinicaltrials.gov with the identifier NCT03261024.
在正畸治疗中，关闭拔牙间隙是一个具有挑战性的阶段，它不仅影响总治疗时间，还影响整个治疗效果。
比较在成人双颌前突患者中使用镍钛螺旋扩弓器和关闭曲簧进行上颌前牙整体内收时的效率。
双臂平行组、单中心随机临床试验。
招募了 32 名成人双颌前突患者，并随机分配到两种不同的内收机制中。摩擦组使用镍钛螺旋扩弓器，无摩擦组使用关闭曲簧进行整体内收。通过 Microsoft Excel 生成 1:1 的随机分组。将随机数字密封在不透明的信封中以进行分组隐藏。所有患者在前磨牙拔除后，使用微型种植体作为间接支抗的来源，开始进行内收。每个月进行一次激活，直到前牙段完全内收。在牵引前和空间关闭后，使用数字模型和侧位头颅侧位片分析牵引速度、支抗丧失量、牙齿和软组织变化。
通过在评估过程中数据隐藏，对结果评估者进行盲法。
有 2 名患者失访，因此 30 名患者完成了试验。无摩擦组的前牙段内收速度为 0.88±0.66mm/月，而摩擦组为 0.72±0.36mm/月，差异有统计学意义。摩擦组支抗丧失 1.18±0.72mm，无摩擦组为 1.29±0.55mm，差异无统计学意义。两组患者在整体内收后均报告了类似的牙齿和软组织变化，差异无统计学意义。
一名患者在微型种植体植入后出现软组织肿胀，但在使用漱口水一周后肿胀消失。
该研究仅关注上颌弓。
两种力学机制都成功地达到了双颌前突患者的治疗目标。无摩擦组的内收速度快于摩擦组，但差异无统计学意义，但有临床意义。
Clinicaltrials.gov，标识符为 NCT03261024。
