咬合力對小鼠磨牙牙根發(fā)育影響的初步研究
發(fā)布時間：2018-08-13 10:01
【摘要】：目的:本研究通過建立咬合力不對稱動物模型,探討咬合力大小在牙根發(fā)育中的作用,并且進一步初步嘗試從分子水平探討影響牙根發(fā)育的機制,為牙根再生提供發(fā)育階段的研究基礎,并在降低口腔治療風險的同時為正畸治療提供更為廣泛的適應癥。方法:選取野生型C57BL/6J近交系小鼠出生后第7.5、14.5、15.5、21.5、28.5、35.5、42.5、49.5、56.5、63.5、70.5、77.5、84.5(PN7.5、14.5、15.5、21.5、28.5、35.5、42.5、49.5、56.5、63.5、70.5、77.5、84.5)日齡第一磨牙作為實驗觀察對象,大體觀察咬合關系及下頜第一磨牙牙根長度變化。再選取PN15.5野生型C57BL/6J近交系小鼠,1%戊巴比妥鈉(3mg/100g)腹腔麻醉,采用拔除上頜牙的方法建立咬合力不對稱的下頜磨牙模型,分別在術后6天、10天、25天、75天(即PN21.5、25.5、40.5、90.5日齡)處死動物;同時取正常生長條件下PN21.5、PN25.5、PN40.5、PN90.5日齡為對照組,取小鼠下頜第一磨牙為研究對象。4%多聚甲醛固定,EDTA脫鈣,參照常規(guī)步驟進行石蠟切片和蘇木精-伊紅(Hematoxylin-Eosin,H.E.)染色、PCNA和Shh抗體進行免疫組織化學染色,以及TRAP染色。結果:1.本研究通過對C57BL/6J野生型小鼠上下頜第一磨牙咬合關系及牙根長度的連續(xù)觀察發(fā)現(xiàn),在PN15.5天時,突破口腔黏膜暴露于口腔中,開始牙合向移動,因此選擇PN15.5天的小鼠為研究對象通過拔除上頜第一磨牙的方法建立了咬合力不對稱的動物模型,用于研究咬合力對于牙根發(fā)育的影響。2.C57BL/6J近交系小鼠磨牙正常發(fā)育過程中,隨生長發(fā)育小鼠下頜第一磨牙的長度逐漸增加,但具有一定的限度;牙根的長度也隨時間逐漸增加,其生長速度先快后慢,在生長發(fā)育的后期牙根長度增加以代償牙尖磨耗維持牙齒的長度;根尖部牙周膜厚度及HERS細胞的數(shù)目會隨著生長發(fā)育逐漸減少,牙齒發(fā)育趨于成熟;根部牙骨質(zhì)逐漸增多,牙根逐漸粗壯,以適應牙齒的功能。3.咬合力作為一個外界因素對牙根的發(fā)育具有一定的影響,無咬合力作用時:牙根狹長、HERS細胞數(shù)目較多、根尖部牙周膜較寬,同時根部牙本質(zhì)形成較多,根尖部細胞增殖活躍,TRAP染色陽性細胞較多;咬合力增強時,牙根短粗、HERS細胞數(shù)目減少、根尖部牙周膜較窄、根部牙本質(zhì)形成較少,TRAP染色陽性細胞較少。4.在牙根發(fā)育過程中,咬合力減弱導致牙根狹長,是HERS及根尖周圍細胞增殖、根尖底部牙槽骨吸收的結果,同時較寬的牙周間隙可為牙根的延長提供空間。咬合力大小可能影響Shh的表達,進而影響牙根的長度,其具體機制需進一步研究。結論:通過對小鼠磨牙的研究發(fā)現(xiàn),咬合力作為一個外界因素在牙根發(fā)育過程中起重要作用。咬合力的改變會影響牙根的長度寬度、牙周膜的寬度及HERS細胞數(shù)目;而造成這一現(xiàn)象的原因可能與HERS及根尖周圍細胞增殖、根尖底部牙槽骨吸收相關。同時,發(fā)現(xiàn)根尖部Shh的表達受咬合力大小的影響,進而影響牙根的長度。
[Abstract]:Objective: to explore the role of bite force in root development by establishing an asymmetric animal model of bite force, and to explore the mechanism of tooth root development at molecular level. To provide the basis for the development of root regeneration, and to reduce the risk of oral treatment and provide a broader indication for orthodontic treatment. Methods: the first molar of the wild-type C57BL/6J inbred strain mice was selected as the experimental object. The first molar of the first molar was selected as the experimental object. The first molar of the wild type C57BL/6J was 7.514.515.515.55.28.514.515.515.515.55.49.56.577.584.5) of the first molar at the age of 28.514.514.515.515.55.52.55.49.56.5. 77.584.5) and the relationship between occlusion and the length of mandibular first molars was observed in a general way. The experimental results showed that the first molar of the wild type of C57BL/6J inbred strain was 77.54.5% and that of the first molar was 77.54.5.The relationship of occlusion and the change of the root length of the first mandibular molars were observed. After intraperitoneal anesthesia with 1% pentobarbital sodium (3mg/100g) in PN15.5 wild-type C57BL/6J inbred strain mice, the mandibular molar model with asymmetric bite force was established by extraction of maxillary teeth. The animals were killed on the 6th day, 10th day, 25 days and 75 days, respectively. At the same time, the normal growth conditions of PN21.5 PN25.5PN40.5 and PN90.5 were taken as the control group. The first mandibular molars of mice were taken as the study object. The EDTA was fixed with 4% paraformaldehyde. The paraffin sections and Hematoxylin-Eosin H.E. were carried out according to the routine procedure. PCNA and Shh antibodies were stained by immunohistochemistry and TRAP staining. The result is 1: 1. In this study, we observed the occlusal relationship and root length of the first molar of C57BL/6J wild type mice. It was found that during the PN15.5 day, the oral mucosa was exposed to the oral cavity and the occlusion began to move. Therefore, an animal model of asymmetric bite force was established by the extraction of maxillary first molar in mice on PN15.5 day, which was used to study the effect of bite force on root development. 2. C57BL / 6J inbred mouse molars developed normally. The length of the mandibular first molar increased gradually with the growth of the mouse, but there was a certain limitation, and the length of the root increased with time, and the growth rate of the first molar increased first and then slowly. At the later stage of growth and development, the root length was increased to replace the attrition of the tip, the thickness of periodontal ligament and the number of HERS cells in the apical region decreased gradually, and the tooth development tended to mature, and the root cementum gradually increased. The root of the tooth grew thicker to fit the function of the tooth. As an external factor, occlusal force has a certain effect on the development of the root. When no bite force is used, the number of HERS cells in the root is more, the periodontal ligament in the apical region is wider, and the root dentin is more formed. The number of HERS cells decreased, the periodontal ligament was narrower, and the formation of root dentin was less, but the positive cells of trap staining were less. 4 when the bite force was enhanced, the number of HERS cells in the root tip was decreased, the periodontal ligament in the apical region was narrower, and the positive cells of trap staining in the root dentin were less than those in the root. In the process of root development, the reduction of bite force leads to the narrow and narrow root, which is the result of the proliferation of HERS and periapical cells, the resorption of alveolar bone at the base of the root tip, and the wide periodontal space can provide space for the extension of the root. The size of occlusal force may affect the expression of Shh and the length of root. Conclusion: as an external factor, bite force plays an important role in the root development of mouse molars. The change of occlusal force may affect the width of root length, the width of periodontal ligament and the number of HERS cells, which may be related to the proliferation of HERS and periapical cells and the resorption of alveolar bone at the root base. At the same time, it was found that the expression of Shh in the apical region was affected by the bite force and the root length.
【學位授予單位】：首都醫(yī)科大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：R783.5
本文編號：2180647
[Abstract]:Objective: to explore the role of bite force in root development by establishing an asymmetric animal model of bite force, and to explore the mechanism of tooth root development at molecular level. To provide the basis for the development of root regeneration, and to reduce the risk of oral treatment and provide a broader indication for orthodontic treatment. Methods: the first molar of the wild-type C57BL/6J inbred strain mice was selected as the experimental object. The first molar of the first molar was selected as the experimental object. The first molar of the wild type C57BL/6J was 7.514.515.515.55.28.514.515.515.515.55.49.56.577.584.5) of the first molar at the age of 28.514.514.515.515.55.52.55.49.56.5. 77.584.5) and the relationship between occlusion and the length of mandibular first molars was observed in a general way. The experimental results showed that the first molar of the wild type of C57BL/6J inbred strain was 77.54.5% and that of the first molar was 77.54.5.The relationship of occlusion and the change of the root length of the first mandibular molars were observed. After intraperitoneal anesthesia with 1% pentobarbital sodium (3mg/100g) in PN15.5 wild-type C57BL/6J inbred strain mice, the mandibular molar model with asymmetric bite force was established by extraction of maxillary teeth. The animals were killed on the 6th day, 10th day, 25 days and 75 days, respectively. At the same time, the normal growth conditions of PN21.5 PN25.5PN40.5 and PN90.5 were taken as the control group. The first mandibular molars of mice were taken as the study object. The EDTA was fixed with 4% paraformaldehyde. The paraffin sections and Hematoxylin-Eosin H.E. were carried out according to the routine procedure. PCNA and Shh antibodies were stained by immunohistochemistry and TRAP staining. The result is 1: 1. In this study, we observed the occlusal relationship and root length of the first molar of C57BL/6J wild type mice. It was found that during the PN15.5 day, the oral mucosa was exposed to the oral cavity and the occlusion began to move. Therefore, an animal model of asymmetric bite force was established by the extraction of maxillary first molar in mice on PN15.5 day, which was used to study the effect of bite force on root development. 2. C57BL / 6J inbred mouse molars developed normally. The length of the mandibular first molar increased gradually with the growth of the mouse, but there was a certain limitation, and the length of the root increased with time, and the growth rate of the first molar increased first and then slowly. At the later stage of growth and development, the root length was increased to replace the attrition of the tip, the thickness of periodontal ligament and the number of HERS cells in the apical region decreased gradually, and the tooth development tended to mature, and the root cementum gradually increased. The root of the tooth grew thicker to fit the function of the tooth. As an external factor, occlusal force has a certain effect on the development of the root. When no bite force is used, the number of HERS cells in the root is more, the periodontal ligament in the apical region is wider, and the root dentin is more formed. The number of HERS cells decreased, the periodontal ligament was narrower, and the formation of root dentin was less, but the positive cells of trap staining were less. 4 when the bite force was enhanced, the number of HERS cells in the root tip was decreased, the periodontal ligament in the apical region was narrower, and the positive cells of trap staining in the root dentin were less than those in the root. In the process of root development, the reduction of bite force leads to the narrow and narrow root, which is the result of the proliferation of HERS and periapical cells, the resorption of alveolar bone at the base of the root tip, and the wide periodontal space can provide space for the extension of the root. The size of occlusal force may affect the expression of Shh and the length of root. Conclusion: as an external factor, bite force plays an important role in the root development of mouse molars. The change of occlusal force may affect the width of root length, the width of periodontal ligament and the number of HERS cells, which may be related to the proliferation of HERS and periapical cells and the resorption of alveolar bone at the root base. At the same time, it was found that the expression of Shh in the apical region was affected by the bite force and the root length.
【學位授予單位】：首都醫(yī)科大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：R783.5
【參考文獻】
相關期刊論文 前2條
1 Xiao-Feng Huang;Yang Chai;;Molecular regulatory mechanism of tooth root development[J];International Journal of Oral Science;2012年04期
2 張瑞;黃曉峰;張方明;;核因子C(Nfic)與牙根發(fā)育[J];北京口腔醫(yī)學;2011年06期
，本文編號：2180647
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