發(fā)布時(shí)間：2018-05-09 10:49

  本文選題：增齡 + 牙髓�。� 參考：《首都醫(yī)科大學(xué)》2017年碩士論文

【摘要】：目的:觀察不同年齡組大鼠正畸牙齒移動(dòng)過程中牙髓組織HIF-1α、VEGF及細(xì)胞凋亡等的表達(dá)變化,探討增齡性因素對(duì)這些因子及細(xì)胞凋亡的影響,從而進(jìn)一步探究導(dǎo)致青少年及成人正畸差異的原因,為正畸臨床操作提供理論依據(jù)。方法:選取SD雄性大鼠5周齡與8-9月齡各25只,建立正畸牙齒移動(dòng)模型。兩組大鼠均在實(shí)驗(yàn)加力1天、3天、7天、14天及28天時(shí)處死取材,通過HE染色及免疫組化染色、TUNEL染色等方法對(duì)上頜第一磨牙近中移動(dòng)過程中牙髓組織的變化及HIF-1α、VEGF、細(xì)胞凋亡等表達(dá)情況進(jìn)行觀察。結(jié)論如下:1、青少年組與成年組大鼠均發(fā)生牙齒移動(dòng),但成年組牙齒移動(dòng)速度較慢,移動(dòng)距離較少。2、青少年組加力1天時(shí)牙髓組織即可觀察到明顯的血管擴(kuò)張,新生血管形成等反應(yīng),3天時(shí)細(xì)胞增殖及聚集現(xiàn)象明顯,14天時(shí)牙髓組織基本恢復(fù)正常;成年組加力3天時(shí)牙髓組織開始有血管擴(kuò)張、組織水腫等表現(xiàn),7天、14天時(shí)多細(xì)胞區(qū)面積明顯增加,28天時(shí)除牙髓中部血管數(shù)量增多,其余結(jié)構(gòu)基本恢復(fù)正常。由此可見,青少年組較成年組牙髓組織反應(yīng)更迅速,代謝周期更短。3、青少年組實(shí)驗(yàn)側(cè)牙髓組織HIF-1α表達(dá)自加力1天起開始增強(qiáng),3天時(shí)表達(dá)至峰值,隨后逐漸降低;成年組加力3天起牙髓組織HIF-1α表達(dá)逐漸增強(qiáng),7天時(shí)表達(dá)至峰值,隨后逐漸降低。我們推測(cè)增齡性因素可能使牙髓組織對(duì)缺氧調(diào)控的速率減慢,調(diào)控周期延長(zhǎng)。4、青少年組加力1天開始牙髓組織VEGF表達(dá)逐漸增強(qiáng),7天時(shí)表達(dá)量達(dá)峰值,隨后逐漸降低;成年組加力3天開始牙髓組織VEGF表達(dá)逐漸增強(qiáng)、14天時(shí)表達(dá)量達(dá)峰值,隨后表達(dá)逐漸降低。青少年組牙髓組織VEGF表達(dá)在1天、3天、7天、14天時(shí)均高于成年組,且差異具有統(tǒng)計(jì)學(xué)意義。我們推測(cè)增齡性因素使成年組大鼠牙髓組織VEGF表達(dá)增加緩慢,且表達(dá)量降低,從而導(dǎo)致牙髓組織對(duì)正畸力的反應(yīng)較為滯后,反應(yīng)周期延長(zhǎng)。5、青少年組加力3天時(shí)牙髓內(nèi)細(xì)胞凋亡率顯著增高,隨后逐漸降低,14天時(shí)細(xì)胞凋亡率與對(duì)照組無明顯差異;成年組加力3天開始細(xì)胞凋亡率逐漸增加,7天時(shí)達(dá)峰值,隨后逐漸下降;成年組牙髓組織細(xì)胞凋亡率在各個(gè)時(shí)間點(diǎn)均高于青少年組,差異具有統(tǒng)計(jì)學(xué)意義。我們推測(cè)增齡性因素使牙髓組織細(xì)胞凋亡率增高,但細(xì)胞凋亡調(diào)節(jié)周期延長(zhǎng)。正畸牙齒移動(dòng)過程中牙髓組織通過啟動(dòng)細(xì)胞凋亡來保持細(xì)胞繁殖和細(xì)胞死亡之間的平衡,及時(shí)清除無用和有害的細(xì)胞,從而調(diào)節(jié)細(xì)胞數(shù)量,維持牙髓組織內(nèi)環(huán)境穩(wěn)定。
[Abstract]:Objective: to observe the expression of HIF-1 偽 -VEGF and apoptosis in dental pulp tissue during orthodontic tooth movement in rats of different age groups, and to explore the effect of aging factors on these factors and apoptosis. So as to further explore the causes of orthodontic differences between adolescents and adults, and provide theoretical basis for orthodontic clinical operation. Methods: 25 SD male rats aged 5 weeks and 8 to 9 months old were selected to establish orthodontic tooth movement model. The rats of both groups were killed at 1 day, 3 days, 7 days, 14 days and 28 days, respectively. The changes of pulp tissue and the expression of HIF-1 偽 -VEGF and apoptosis during the proximal movement of maxillary first molar were observed by means of HE staining and immunohistochemical staining with Tunel staining. The results showed that tooth movement occurred in both adolescent and adult groups, but tooth movement in adult group was slower and movement distance was less than that in adult group. Significant vasodilation was observed in dental pulp tissue of adolescent group after one day of exertion. The phenomenon of cell proliferation and aggregation was obvious at the 3rd day of neovascularization, and the pulp tissue returned to normal on the 14th day, and the dental pulp tissue began to dilate at the 3rd day after adding stress in the adult group. Tissue edema showed that the area of multicellular area increased significantly at day 14 after 7 days, except the number of blood vessels in the middle of dental pulp increased, and the other structures returned to normal basically at 28 days. It can be seen that the reaction of pulp tissue in juvenile group is faster than that in adult group, and the metabolic cycle is shorter. The expression of HIF-1 偽 in experimental pulp tissue of juvenile group has been increased to its peak value at 3 days since the first day of adding force, and then decreased gradually. In adult group, the expression of HIF-1 偽 increased gradually at 7 days and then decreased gradually. We speculate that aging factors may slow down the rate of hypoxic regulation in dental pulp tissue, and prolong the control cycle by .4. the expression of VEGF in dental pulp tissue of adolescent group increases gradually at day 7 and then decreases gradually at day 7. In adult group, the expression of VEGF increased gradually at day 14 and then decreased gradually at day 14. The expression of VEGF in dental pulp tissue of adolescent group was higher than that of adult group at day 1, day 3, day 7 and day 14, and the difference was statistically significant. We speculate that aging causes the expression of VEGF to increase slowly and decrease in adult group, which leads to the delayed response of dental pulp to orthodontic force. When the reaction cycle was prolonged, the apoptosis rate of dental pulp cells in the juvenile group increased significantly after 3 days of stress, and then decreased gradually at 14 days. There was no significant difference between the juvenile group and the control group at 14 days. The apoptosis rate of adult group increased gradually at 7 days and then decreased gradually. The apoptosis rate of dental pulp tissue in adult group was higher than that in juvenile group at each time point, and the difference was statistically significant. We speculated that aging factors increased the apoptosis rate of dental pulp cells, but prolonged the apoptosis regulation cycle. In the process of orthodontic tooth movement, pulp tissue keeps the balance between cell proliferation and cell death by initiating apoptosis, and removes useless and harmful cells in time, thus regulating the number of cells and maintaining the stability of dental pulp tissue environment.
【學(xué)位授予單位】：首都醫(yī)科大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：R783.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 付洪海;李鵬，

本文編號(hào)：1865731