Griswold Olivia, Li Chenshuang, Orr Justin C, Boucher Normand S, Shah Shalin R, Chung Chun-Hsi
Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Private Practice, Princeton Junction, West Windsor, NJ 08550, USA.
J Clin Med. 2022 Oct 13;11(20):6032. doi: 10.3390/jcm11206032.
Lip bumper (LB) therapy is used as a treatment approach for mild to moderate crowding without extraction of teeth. Previous studies demonstrated that LB increases arch length through molar uprighting and lateral expansion. However, the effects of LB on mandibular incisors are inconclusive. The controversial results from different studies may be due to limitations including absence of a control group and/or use of 2D radiography. To address this issue, the current retrospective longitudinal CBCT study compared a rapid maxillary expansion (RME) group with no lower treatment [16 patients (9 females, 7 males); median age 8.86 years at T1 and 11.82 years at T2] and an RME + LB group [18 patients (13 females, 5 males); median age 9.46 years at T1 and 12.10 years at T2]. The CBCTs taken before and after phase 1 treatment were 3D superimposed based on the mandibular structure and were measured to determine the angular and linear changes of the mandibular incisors over the course of LB treatment. For comparisons between different timepoints within a group, a Wilcoxon matched-pairs signed rank test was used. For intergroup comparisons, a Mann-Whitney test was used. Both groups showed eruption and protrusion of the mandibular incisors during the observation period, while there was no significant change in proclination of the lower incisors. When comparing the discrepancy of change between groups, there was no statistically significant difference detected. In summary, by utilizing a longitudinal 3D database, the current study demonstrated that the effect of LB on the position of the mandibular incisors is limited.
唇挡（LB）疗法被用作一种治疗轻至中度牙列拥挤且不拔牙的方法。先前的研究表明，唇挡通过磨牙直立和横向扩展增加牙弓长度。然而，唇挡对下颌切牙的影响尚无定论。不同研究结果存在争议可能是由于包括缺乏对照组和/或使用二维放射摄影等局限性。为解决这一问题，当前这项回顾性纵向CBCT研究将快速上颌扩弓（RME）组（未进行下颌治疗，16例患者（9名女性，7名男性）；T1时中位年龄8.86岁，T2时中位年龄11.82岁）与RME + LB组（18例患者（13名女性，5名男性）；T1时中位年龄9.46岁，T2时中位年龄12.10岁）进行了比较。在第一阶段治疗前后拍摄的CBCT基于下颌结构进行三维叠加，并进行测量以确定在唇挡治疗过程中下颌切牙的角度和线性变化。对于组内不同时间点的比较，使用Wilcoxon配对符号秩检验。对于组间比较，使用Mann-Whitney检验。两组在观察期内均出现下颌切牙萌出和前突，而下切牙的前倾度无显著变化。在比较两组之间的变化差异时，未检测到统计学上的显著差异。总之，通过利用纵向三维数据库，当前研究表明唇挡对下颌切牙位置的影响有限。
