Difference in apical resorption activity during rat molar root formation in response to mechanical force
Difference in apical resorption activity during rat molar root formation in response to mechanical force
复制标题
大鼠磨牙根形成过程中根尖吸收活性对机械力的响应差异
DOI：
10.1093/ejo/cjac071
复制
发表时间：
2023
影响因子：
2.6
通讯作者：
Sachiko Iseki and Takashi Ono
中科院分区：
文献类型：
--
作者：
Yixin Lou;Yoshiro Matsumoto;Sachiko Iseki and Takashi Ono
目的探讨体内牙根发育过程中根尖吸收活性对机械力的响应是否存在差异。方法选取出生后21天和PN35只雄性大鼠上颌第一磨牙(M1)分别作为牙根发育组和牙根完成组的代表。对PN21和PN35上的M1施加3cN的机械力，并在PN28和PN42上收集上颌骨。使用微焦X射线计算机断层扫描研究破牙细胞发生和牙根形态，随后进行免疫组织化学和定量实时聚合酶链反应以阐明牙根吸收活性。结果近颊根（MBR）的发育先于近中根（MR）。在 PN28 施力 (FA) 组中，牙本质弯曲，但包括赫特维希上皮根鞘 (HERS) 在内的组织学完好无损。 MR根尖区未发现破牙细胞和吸收陷窝，仅观察到侧根吸收。在 PN42 (FA) 的 MR 以及 PN28 (FA) 和 PN42 (FA) 的 MBR 中观察到外部根尖吸收 (EARR)。骨桥蛋白的表达也相应发生变化。 PN28（FA）组MR中骨保护素或核因子κB受体激活剂配体表达没有发生显着变化。局限性我们的动物模型没有充分模拟人类牙齿移动的临床过程。结论施加力延迟了正在发育的牙根受压侧的HERS解离，导致对牙骨质形成的抑制作用，从而导致破牙细胞分化减少并预防EARR。
ObjectiveTo investigate whether there is a difference in apical resorption activity during the development of roots in response to mechanical forcein vivo.MethodsMaxillary first molars (M1) from postnatal day (PN) 21 and PN35 male rats were selected as representatives of the root-developing and root-completing groups, respectively. A mechanical force of 3 cN was applied to M1 on PN21 and PN35, and the maxilla was collected on PN28 and PN42. Odontoclastogenesis and root morphology were investigated using micro-focus X-ray computed tomography, followed by immunohistochemistry and quantitative real-time polymerase chain reaction to clarify root resorption activity.ResultsDevelopment of the mesiobuccal root (MBR) preceded the mesial root (MR). In the PN28 force application (FA) group, the dentine was bent, but the histology, including Hertwig’s epithelial root sheath (HERS), was intact. No odontoclasts and resorption lacunae were found in the apical area of the MRs, and only lateral root resorption was observed. External apical root resorption (EARR) was observed in the MR of PN42 (FA) and in the MBR of both PN28 (FA) and PN42 (FA). The expression of osteopontin changed accordingly. No significant change occurred in osteoprotegerin or receptor activator of nuclear factor-κB ligand expression in the MRs of the PN28 (FA) group.LimitationsOur animal model did not adequately simulate the clinical process of tooth movement in humans.ConclusionsForce application delayed HERS dissociation on the compression side of the developing roots, leading to inhibitory effects on cementogenesis, which resulted in decreased odontoclast differentiation and prevention of EARR.