Unit of Orthodontics, University Dental Clinic, Faculty of Medicine, University of Murcia, Murcia, Spain.
Department of Histology and Pathological Anatomy, University of Murcia, Murcia, Spain.
Clin Oral Investig. 2021 Mar;25(3):1383-1394. doi: 10.1007/s00784-020-03446-7. Epub 2020 Jul 9.
To evaluate the influence of diabetes on oxidative stress, periodontal ligament (PDL) orientation, and matrix metalloproteinase (MMP) 8 and 9 expressions during orthodontic tooth movement in a rat model.
An orthodontic appliance was placed in 60 Sprague-Dawley rats divided into three groups: normoglycemics (n = 20) and two streptozotocin-induced diabetic groups, one untreated (n = 20) and one insulin-treated (n = 20). At 24, 48, and 72 h and 1 week, rats were sacrificed. At each time point, myeloperoxidase (MPO) and malondialdehyde (MDA) were quantified by spectrophotometry, tooth movement was evaluated by micro-CT analysis, and hematoxylin and eosin staining was used to evaluate PDL fiber orientation and immunohistochemistry staining with semi-quantitative H-score analysis of MMP-8 and MMP-9 was performed..
At 24 h, MPO activity was significantly higher in untreated-diabetics than normoglycemics. At 24 and 48 h, the MDA level in untreated-diabetic rats was significantly higher than in normoglycemics and insulin-treated animals. At 72 h and 1 week, PDL fibers were oriented significantly more irregularly in untreated-diabetics than in normoglycemics. At all time points, MMP-8 and MMP-9 expressions were significantly higher in both diabetic groups than in the normoglycemic group. After the second day, tooth movement was significantly greater in untreated-diabetics than in the insulin-treated and normoglycemic groups.
Mechanical stress in untreated-diabetic rats produces more inflammatory response, oxidative stress, tooth movement, PDL disorganization, and MMP-8 and MMP-9 expressions than among normoglycemics. Insulin reverses these effects, favoring the reorganization of periodontal ligament.
Our results suggest that the application of orthodontic force in diabetic patients would increase inflammation and delay periodontal restructuring. Insulin would partly reverse this situation although glycemic decompensation episodes may occur. For these reasons, the periods between fixed orthodontic appliance activations should be of sufficient duration to allow adequate tissue recovery.
评估糖尿病对正畸牙齿移动过程中氧化应激、牙周韧带（PDL）方向以及基质金属蛋白酶（MMP）8 和 9 表达的影响。
将正畸器械放置在 60 只 Sprague-Dawley 大鼠中，分为三组：正常血糖组（n=20）和 2 组链脲佐菌素诱导的糖尿病组，一组未治疗（n=20），一组胰岛素治疗（n=20）。在 24、48 和 72 小时和 1 周时处死大鼠。在每个时间点，通过分光光度法定量测定髓过氧化物酶（MPO）和丙二醛（MDA），通过微 CT 分析评估牙齿移动，并用苏木精和伊红染色评估 PDL 纤维方向，并通过半定量 H 评分分析进行 MMP-8 和 MMP-9 的免疫组织化学染色。
在 24 小时时，未治疗的糖尿病大鼠的 MPO 活性明显高于正常血糖组。在 24 和 48 小时时，未治疗的糖尿病大鼠的 MDA 水平明显高于正常血糖组和胰岛素治疗组。在 72 小时和 1 周时，未治疗的糖尿病大鼠的 PDL 纤维定向明显不规则。在所有时间点，两组糖尿病大鼠的 MMP-8 和 MMP-9 表达均明显高于正常血糖组。从第二天开始，未治疗的糖尿病大鼠的牙齿移动明显大于胰岛素治疗组和正常血糖组。
与正常血糖组相比，未治疗的糖尿病大鼠的机械应力导致炎症反应、氧化应激、牙齿移动、PDL 紊乱以及 MMP-8 和 MMP-9 表达增加。胰岛素逆转了这些作用，有利于牙周韧带的重组。
我们的研究结果表明，在糖尿病患者中应用正畸力会增加炎症并延迟牙周组织重建。尽管可能会发生血糖代偿失调发作，但胰岛素会部分逆转这种情况。因此，固定正畸器械激活之间的时间间隔应足够长，以允许组织充分恢复。
