| Objective: In orthodontic process,if we want to rank the teeth in a new way, we need the alveolar bone be absorbed and remodeled. This is a slowly process. The teeth, periodontium, alveolar bone will be altered with the machine orthodontic power. The orthodontic process can be effect by a lot of factor. To all dentists, if the orthodontic process can be made shorter, and its curative effect can't be impacted, they must very happy. To every patient, they want the process is not very painful. In recent years, there are a lot of studies on such purpose. But there is little study on local use of vitamin D to increase the rate of orthodontic tooth movement, and the same kind of studies did not discuss it in pathological aspect. There is no chiastic comparison in moveable speed and moveable rate. In my experiment, we want to observe effect of local injection on the rate of tooth movement in combination with 1,25-(OH)2D3 and mechanical force in the rat. Through this way we want to find if 1,25-(OH)2D3 can really increase the rate of tooth movement, so we can provide referred experimental data for clinic orthodontion. Methods: Eighty mature (20weeks) female SD rats (Weight from 200g to 220g) were housed. They were distributed in 8 teams in random. Every team has 10 rats. First team is only use activated appliance for 1 day. Second team is 1,25-(OH)2D3 plus activated appliance for 1 day. Third team is use activated appliance for 3days. Forth team is 1,25-(OH)2D3 plus activated appliance for 3 days. Fifth team is used activated appliance for 7 days. Sixth team is 1,25-(OH)2D3 plus activated appliance for 7days. Seventh team is used activated appliance for 14 days. Eighth team is 1,25-(OH)2D3 plus activated appliance for 14 days. Anesthetize the rats by 1% Nembutal. Put the activated appliance between the rat's left maxillary first molar and left upper central incisor. Activated appliance were made up by ligature wire(0.20mm) and nickel titanium spring (0.008"*0.032"). 1, 3, 5, 7team is normal control team. 2, 4, 6, 8, team is experimental group. I did as follow way after 1,3,7,14days: (1) Record every group rats'food-intake exactly. (2) Execute the rats, make the maxillary bone into sample. Make precise upper jaw model before use the activated appliance, and do the same thing after kill rats. Det the distance between first molar mesiolingual groove and third molar mesiolingual groove which are on the model. The job must be done 3 times by one people, take the mean. Caculate the different value. Result: The distances of experiment group and control group were 0.27士0.12mm and 0.27士0.17mm P>0.05, whichwas first day group. The third day groups'distances were 0.49士0.22mm and 0.37 士0.13mm,P>0.05. We find that the experiment group's distance was much longer than the control group's in the seventh day and fourteenth day. On the seventh day experiment group's distance was 0.76士0.30mm, another group's is 0.51士0.27mm,P<0.05.on the fourteenth day, the experiment group's was 1.22士0.39mm, the control group's was 0.97士0.29mm,P<0.05. there is a significant difference between them. To the first day team we found there is not any osteoclast(OLC) in the section of experiment group or control group, but we ken found some osteoprogenitor cells. We could find a lot of OLC in the section of two groups which belonged to the third day. (table 2), P>0.05. There is no significant difference between experiment group and control group. Compared the seventh day team, the data of OLC had a significant difference. About the fourteenth team the result was same as the seventh day's. P<0.05. Through statisticed rats'appetite, we found that no significant difference in two group. The data can be found in table 3. Conclusion: based on the results above, we think that tooth movement distance and speed can be effective promoted in the orthodontic process which use 1,25-(OH)2D3 and activated appliance. This method not only can prevent slow moving phase of tooth movement, but also no unhealthy effect. This... |
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