| Objective:Some congenital or aquired factors such as tumor, trauma and inflammation maylead to defect of jaw bones which results in function impacitation of chewing orspeaking,influencing prosthesis. At the present time, how to form bone tissue andrestore the jaw defect seem to be the difficulty and hotspot we are faced with. Recentyears, it comes to light that subcutaneous injection of recombinant human GrowthHormone (rhGH) can promote growing development and surface of wound healingvia animal experiments and clinical research. And recombinant human GrowthHormone has been widely applied on prevention and treatment of cretinism caused bylacking of human Growth Hormone (hGH), and burn, ect. Some researches reportosteoblast can express the receptor of human Growth Hormone, we can infer hGHmay influent osteogenesis and osteolysis by regulating receptor’s expression on thesurface of the osteoblast. However, there is no report about research and applicationof recombinant human Growth Hormone on promoting the repairment of the jawdefect. This article aims at determining recombinant human Growth Hormonefunction on repairing jaw defect, via Gross sample, histology and serologyexamination, so as to provide theoretical foundation for recombinant human GrowthHormone clinical application on promoting repairing jaw defect in oral cavity.Materials and Methods:This research was mainly carried out by animal experiment. The main three partsare setting up the model of segmental mandibular defect,injecting recombinanthuman Growth Hormone and detecting ossification indexes subsequently. Asexperiment objects60male wistar rat were caused segmental mandibular defect.We chose randomly one side mandibula in which to inject recombinant human GrowthHormone, injecting physiological saline into one side mandibular of Placebo group inthe same volume.0.05mg each time, once a day,continued for7days.24male ratmade up the Placebo group and12male rat made up the control group. The rat werekilled at2,4,6weeks after administration accomplished. Then we examined thecorresponding ossification indexes for the following4aspects: General condition,Gross sample, Histology detection and Alkaline phosphatase (ALP) in serumdetection. The ossification effect of the three groups were compared by observationof the gross sample after obtaining the mandibula sample,then ossification target wasanalyzed by observing the HE-dyeing histology section under light microscope afterdealed with4%paraformal-dehyde, decalcification, embed, sliceand coloration.Theserum thaw at the room temperature,ALP kit detected the activity of ALP in theserum.Results:General condition: The vital signs of all rhe rats were steady after the surgicaloperation,the color of the hair and behavior were main normal. they could have littlefood on the operation day,and the day after operation they have got normal. Thewound healed well, no infection, no inflammation and no pus.The string drop offabout one week after the operation.Gross sample:Two weeks after administration finished:The local inflammationwas not obvious, bone defect was clear, the range of bone defect minished notobviously; There was no clear different between experiments group one and grouptwo, and the control group showed no different either. Four weeks after administrationfinished: The bone defect rang of experiments group one and group two showedminished, the new bone can clearly be seen, white, sub-translucent,firm, can not bestretched intowith probe easily. The bone defect rang of control group minishedunclear. Six weeks after administration finished: Large amount of new bone filled thebone defect area of experiments group one, irregular shape, out-of-flatness surface, hard, can not be stretched into with probe. There was no clear different betweenexperiments group one and group two, and the control group showed bone defect areaminished,some new bone can be seen.HE stining and detect under the light microscope: Two weeks afteradministration finished:Group one bone defect area could be seen clearly, new boneappear at the edge. Large amount of bone trabecula, disorder, osteoblast cell can beseen, but only a few, There was no clear different between experiments group one andgroup two, and the control group showed bone defect area clearly. Four weeks afteradministration finished: In the group one there was large amount of new bone at theedge of the bone defect area. The new bone contained large amount of bone trabecula,the bone trabecula was thickening, conglobation and arraied disorder. whichcontained osteocyte, osteoblast cell row up around the bone trabecula. There was noclear different between experiments group one and group two, and the control groupshowed new bone appeared at the edge of the defect area, the amount of bonetrabecula was little and distributed dispersed. Six weeks after administration finished:Large amount of new bone filled the bone defect area of experiments group one, bonetrabecula went on thickening, conglobation, osseous lacuna and osteocyteappeared,the shape of osteoblast cell became typical. There was no clear differentbetween experiments group one and group two. Control group bone trabecula wasdisordered, reticulation.activity of ALP detect in the serum: The value of the ALP in the serum of theexperiment group was higher than the one of the control group two weeks and fourweeks after administration finished. And the difference came to be statisticalsignificance (P<0.05), but the difference came to be no statistical significance(P>0.05). The value of the ALP in the serum four weeks and six weeks afteradministration finished was lower than the one two weeks after administrationfinished.The value of the ALP in the serum in the same group between the different timewas different,and the difference came to be statistical significance (P=0.00),that is to say the ossification at different time were different, the ossification came to active inthe early stage.Conclusion:1rhGH could active the ossification, advance the appearance of the bonetrabecula,and cut down the time of new bone’ mature by increasing the activity ofthe osteoblast cell,so that it can promote ossification during the bone defectrestoration2The effect of rhGH via local injection seems to be better than subcutaneousinjection at abdomen in the early stage. |
PDF Full Text Request