Yin Fan, Zhao Junwei, Zhang Hao, Wang Shusi, An Qi, Wei Xiaojiao, Tang Chenxin, Han Shuang
School of Stomatology, Bengbu Medical University, Hefei Stomatological Hospital, Anhui, China.
Department of Stomatology, Anhui Provincial Children's Hospital, Hefei, Anhui Province, China.
Int Dent J. 2025 Aug 7;75(5):100932. doi: 10.1016/j.identj.2025.100932.
This study aimed to measure gingival blood flow under different orthodontic forces using laser speckle contrast imaging (LSCI).
Forty eligible individuals were recruited and randomly assigned into 2 groups: 50 g group and 150 g group. According to the groups, forces of 50 g or 150 g were applied from the maxillary canines to the first molars on the left or right side of each participant. Four regions of interest (ROIs) were selected on the gingiva of the maxillary canine: ROI 1 and ROI 2 were located on the marginal and attached gingiva, respectively, while ROI 3 and ROI 4 were positioned on the mesial and distal interdental papillae. All ROIs was measured using LSCI at different time intervals (baseline, 30 minutes, 1, 3, 7, and 14 days).
In the resting state without force loading, statistically significant differences in blood flow were observed among the marginal gingiva, attached gingiva and interdental papilla. The marginal gingiva exhibited lower blood flow compared to other regions. Evaluation of blood flow between the groups revealed significant differences at ROI 1 at 1 day and 3 days, and at ROI 4 at 1 day and 3 days. Intra-group comparisons showed significant differences in blood flow within each group for each region at each time point (P < .05). After applying orthodontic forces, blood flow reached its nadir within 30 minutes to 1 day. The 150 g group exhibited a more significant decrease compared to the 50 g group. Blood flow peaked at 3 days in the 50 g group and at 7 days in the 150 g group. Both groups finally returned to baseline at day 14.
Laser speckle contrast imaging is a reliable tool for monitoring gingival blood flow in orthodontic treatment. Gingival blood flow decreased after force application, reaching peak values in 3 to 7 days and eventually returning to baseline within 14 days. Although heavier forces induced more severe ischaemia, blood flow returned to baseline within 2 weeks. Given the lack of comparison with other validated methods, emphasis of this study placed on force effects, regional differences and the non-invasive advantages of LSCI.
In orthodontic treatment, LSCI can ensure the safety of orthodontic diagnosis and therapy by monitoring changes in gingival blood flow. Furthermore, compared to previous technologies, LSCI offers numerous advantages, including rapid assessment and low technical sensitivity. The findings of this study provide important guidance for assessing periodontal tissue health and designing optimal, personalised orthodontic force levels during orthodontic treatment.
The trial was registered in Chinese Clinical Trial Registry (ChiCTR2400082438) on 29 March 2024.
本研究旨在使用激光散斑对比成像（LSCI）测量不同正畸力作用下的牙龈血流量。
招募40名符合条件的个体，并随机分为两组：50g组和150g组。根据分组情况，对每位参与者左右上颌尖牙至第一磨牙施加50g或150g的力。在上颌尖牙牙龈上选择四个感兴趣区域（ROI）：ROI 1和ROI 2分别位于边缘龈和附着龈，而ROI 3和ROI 4位于近中及远中龈乳头。在不同时间间隔（基线、30分钟、1、3、7和14天）使用LSCI测量所有ROI。
在无外力加载的静息状态下，边缘龈、附着龈和龈乳头之间的血流量存在统计学显著差异。边缘龈的血流量低于其他区域。两组间血流量评估显示，在第1天和第3天的ROI 1以及第1天和第3天的ROI 4存在显著差异。组内比较显示，每个时间点各区域每组的血流量均存在显著差异（P < 0.05）。施加正畸力后，血流量在30分钟至1天内降至最低点。150g组的下降幅度比50g组更显著。50g组血流量在第3天达到峰值，150g组在第7天达到峰值。两组最终在第14天恢复到基线水平。
激光散斑对比成像在正畸治疗中是监测牙龈血流量的可靠工具。施加力后牙龈血流量下降，在3至7天达到峰值，最终在14天内恢复到基线水平。尽管较大的力会导致更严重的缺血，但血流量在2周内恢复到基线水平。鉴于缺乏与其他验证方法的比较，本研究重点关注力的影响、区域差异以及LSCI的无创优势。
在正畸治疗中，LSCI可通过监测牙龈血流量变化确保正畸诊断和治疗的安全性。此外，与以往技术相比，LSCI具有诸多优势，包括快速评估和低技术敏感性。本研究结果为正畸治疗期间评估牙周组织健康以及设计最佳个性化正畸力水平提供了重要指导。
该试验于2024年3月29日在中国临床试验注册中心（ChiCTR2400082438）注册。
